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Schedule III (Details) (USD $)
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]      
Real Estate, Gross $ 5,253,064,000 $ 4,879,278,000 $ 4,810,239,000
Real Estate Additions 511,834,000 423,498,000 108,695,000
Real Estate, Cost of Real Estate Sold (4,038,000) (49,712,000) (39,656,000)
Real Estate, Gross 5,760,860,000 5,253,064,000 4,879,278,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]      
Real Estate Accumulated Depreciation 1,047,336,000 923,790,000 822,648,000
Real Estate Accumulated Depreciation, Depreciation Expense 140,571,000 144,284,000 147,299,000
Real Estate Accumulated Depreciation, Real Estate Sold (17,877,000) (20,738,000) (46,157,000)
Real Estate Accumulated Depreciation 1,170,030,000 1,047,336,000 923,790,000
Total Real Estate [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Amount of Encumbrances 297,600,011    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,064,320,817    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,877,919,655    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,818,619,339    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,158,824,969    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,602,034,842    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,760,859,811    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,170,030,224    
Allianz, John Hancock and LaSalle Bank [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Net Book Value of Collateralized Real Estate Properties 236,500,000    
Operating Properties [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 465,539    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,258,868    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 466,413    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,257,994    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,724,407    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,278,799    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 6680 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6680 Southpoint Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 998,432    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,055,727    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,153,152    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,002,704    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,204,607    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,207,311    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,329,583    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 8212 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8212 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 820,882    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,322,720    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 37,907    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 820,882    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,360,627    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,181,509    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 921,291    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 2955 Xenium Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2955 Xenium Lane    
Real Estate and Accumulated Depreciation, Location of Property Plymouth, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 151,238    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,370,140    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 526,357    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 151,238    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,896,497    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,047,735    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 837,942    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 701 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 701 Distribution Drive    
Real Estate and Accumulated Depreciation, Location of Property Morrisville, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,300,889    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,147,960    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 372,450    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,301,211    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,520,088    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,821,299    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 841,066    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 300 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 300 Technology Drive    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 368,626    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,350,184    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 374,497    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,344,313    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,718,810    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 853,114    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 120 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 120 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 533,142    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,830,515    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,855,638    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 558,142    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,661,153    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,219,295    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,430,944    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1980    
Operating Properties [Member] | 116 Pleasant Ridge Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 116 Pleasant Ridge Road    
Real Estate and Accumulated Depreciation, Location of Property Greenville, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,547,811    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 14,085,575    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,712,683    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,920,703    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,633,386    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,345,706    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 1501 Perryman Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1501 Perryman Road    
Real Estate and Accumulated Depreciation, Location of Property Aberdeen, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,813,324    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 18,874,059    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,694,290    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,816,839    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 23,564,834    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 29,381,673    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,784,213    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 400 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 400 Nestle Way    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances       
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,065,500    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 27,420,765    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 8,184,096    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 27,302,169    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 35,486,265    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 12,132,001    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 7248 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7248 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,670,849    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 13,307,408    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,423,128    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,670,673    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 17,730,712    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 20,401,385    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,688,975    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 7339 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7339 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,187,776    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,867,470    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,197,447    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,857,799    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,055,246    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,083,115    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 7437 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7437 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 717,488    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,022,413    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,099,066    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 726,651    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,112,316    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,838,967    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,189,178    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1976    
Operating Properties [Member] | 700 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 700 Nestle Way    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,473,120    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 20,110,683    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,174,970    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 19,408,833    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 23,583,803    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 8,225,644    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 794 Roble Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 794 Roble Road    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,147,541    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,088,041    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,183,791    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,147,541    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,271,832    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,419,373    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,257,885    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 8014 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8014 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,019,258    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 9,880,091    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,645,117    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,254,232    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,899,349    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,127,812    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 705 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 705 Boulder Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 10,594,027    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 28,618,782    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 10,596,767    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 28,616,042    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 39,212,809    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 7,614,993    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 651 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 651 Boulder Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,308,646    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 17,435,618    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,308,646    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 17,435,618    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 21,744,264    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,823,659    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 8150 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8150 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,564,167    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,388,830    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,571,466    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,381,531    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,952,997    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,336,861    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 8250 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8250 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,025,667    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,339,263    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,035,854    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,329,076    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,364,930    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,600,657    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 650 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 650 Boulder Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,208,248    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 31,718,180    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 9,961,788    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 26,964,640    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 36,926,428    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,754,934    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 7165 Ambassador Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7165 Ambassador Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 792,999    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,533,868    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 804,848    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,522,019    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,326,867    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,447,189    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 200 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 200 Boulder Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,722,683    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 18,922,645    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 440,557    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,722,683    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 19,363,202    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 24,085,885    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,118,610    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 250 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 250 Boulder Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,599,936    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 12,099,145    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,149,322    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,717,733    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,130,670    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 17,848,403    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,311,315    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 8400 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8400 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,725,948    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 27,079,140    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 7,521,211    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 26,283,877    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 33,805,088    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,604,798    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 6560 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6560 Stonegate Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 458,281    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,805,111    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 458,945    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,804,447    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,263,392    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,773,524    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 6370 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6370 Hedgewood Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 540,795    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,869,825    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 541,459    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,869,161    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,410,620    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,825,426    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 6390 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6390 Hedgewood Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 707,203    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,943,701    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 707,867    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,943,037    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,650,904    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,549,064    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 6350 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6350 Hedgewood Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 360,027    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,028,297    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 560,691    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,827,633    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,388,324    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,008,649    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 6330 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6330 Hedgewood Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 531,268    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,331,744    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 532,047    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,330,965    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,863,012    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,071,554    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 6580 Snowdrift Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6580 Snowdrift Road    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 388,328    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,120,963    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 389,081    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,120,210    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,509,291    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,217,779    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 6540 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6540 Stonegate Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 422,042    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,967,718    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 422,730    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,967,030    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,389,760    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,433,957    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 6520 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6520 Stonegate Drive    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 453,315    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,693,787    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 484,361    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,662,741    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,147,102    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 846,135    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 7620 Cetronia Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7620 Cetronia Road    
Real Estate and Accumulated Depreciation, Location of Property Allentown, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,091,806    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,851,456    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 258,140    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,093,724    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,107,678    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,201,402    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,798,175    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 180,190 Cochrane Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 180,190 Cochrane Drive    
Real Estate and Accumulated Depreciation, Location of Property Annapolis, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,670,256    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 23,130,884    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,752,293    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 23,048,847    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 26,801,140    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 12,525,279    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 4606 Richlynn Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4606 Richlynn Drive    
Real Estate and Accumulated Depreciation, Location of Property Belcamp, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 299,600    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,818,861    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 712,788    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 299,600    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,531,649    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,831,249    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 851,020    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 74 West Broad Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 74 West Broad Street    
Real Estate and Accumulated Depreciation, Location of Property Bethlehem, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,096,127    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 14,202,628    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,099,079    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,199,676    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,298,755    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,396,771    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 6601-6625 W. 78th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6601-6625 W. 78th Street    
Real Estate and Accumulated Depreciation, Location of Property Bloomington, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,263,060    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 41,238,311    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,310,246    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 41,191,125    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 43,501,371    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 14,157,488    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 6161 Green Valley Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6161 Green Valley Drive    
Real Estate and Accumulated Depreciation, Location of Property Bloomington, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 740,378    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,311,602    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,114,197    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 709,961    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,456,216    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,166,177    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,659,663    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1992    
Operating Properties [Member] | 10801 Nesbitt Avenue South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10801 Nesbitt Avenue South    
Real Estate and Accumulated Depreciation, Location of Property Bloomington, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 784,577    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,010,219    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 786,382    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,008,414    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,794,796    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,159,283    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 5775 West Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5775 West Old Shakopee Road    
Real Estate and Accumulated Depreciation, Location of Property Bloomington, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,052,018    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,849,649    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,618,350    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,060,644    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,459,373    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,520,017    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,812,297    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 5715 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5715 Old Shakopee Road West    
Real Estate and Accumulated Depreciation, Location of Property Bloomington, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,263,226    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,360,782    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,012,357    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,264,758    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,371,607    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,636,365    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,304,350    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 5735 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5735 Old Shakopee Road West    
Real Estate and Accumulated Depreciation, Location of Property Bloomington, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,263,226    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,360,782    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,024,178    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,264,758    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,383,428    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,648,186    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,000,156    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 5705 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5705 Old Shakopee Road    
Real Estate and Accumulated Depreciation, Location of Property Bloomington, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,113,223    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,520,731    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,148,571    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,485,383    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,633,954    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,361,360    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 951 Broken Sound Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 951 Broken Sound Parkway    
Real Estate and Accumulated Depreciation, Location of Property Boca Raton, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,426,251    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,098,952    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,868,100    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,426,251    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,967,052    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,393,303    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,335,731    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 1455 Remington Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1455 Remington Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Bolingbrook, IL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,501,294    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 10,577,814    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 126,904    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,501,293    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,704,719    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,206,012    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 10,316    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 777 Yamato Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 777 Yamato Road    
Real Estate and Accumulated Depreciation, Location of Property Boca Raton, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,101,247    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 16,077,347    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,255,151    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,501,247    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 21,932,498    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 26,433,745    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 8,139,489    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 750 Park of Commerce Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 750 Park of Commerce Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Boca Raton, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,430,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 22,129,358    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,473,406    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 22,085,952    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 24,559,358    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,072,669    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 400 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 400 Boulder Drive    
Real Estate and Accumulated Depreciation, Location of Property Breinigsville, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,358,721    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,865,575    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,493,146    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,358,721    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,202,785    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 8201 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8201 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Breinigsville, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,089,719    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,328,910    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,222,168    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,196,461    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,418,629    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,418,477    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 8500 Industrial Bouldvard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8500 Industrial Bouldvard    
Real Estate and Accumulated Depreciation, Location of Property Breinigsville, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,752,708    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 39,603,301    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 11,511,499    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 36,844,510    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 48,356,009    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,259,513    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 860 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 860 Nestle Way    
Real Estate and Accumulated Depreciation, Location of Property Breinigsville, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,118,881    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 18,885,486    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,400,855    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 8,118,881    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 26,286,341    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 34,405,222    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,766,054    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 602 Heron Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 602 Heron Drive    
Real Estate and Accumulated Depreciation, Location of Property Bridgeport, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 524,728    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,240,478    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,650    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 524,728    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,248,128    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,772,856    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 828,330    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 1485 W Commerce Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1485 W. Commerce Avenue    
Real Estate and Accumulated Depreciation, Location of Property Carlisle, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,249,868    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 13,886,039    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,241,826    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,095,262    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 16,282,471    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,078,698    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 95 Kriner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 95 Kriner Road    
Real Estate and Accumulated Depreciation, Location of Property Chambersburg, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,695,501    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 34,926,589    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 9,407,871    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 34,214,219    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 43,622,090    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,467,744    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 9000 109th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9000 109th Street    
Real Estate and Accumulated Depreciation, Location of Property Champlin, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,251,043    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 11,322,978    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 340,017    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,251,043    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,662,995    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,914,038    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 500,838    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 12810 Virkler Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 12810 Virkler Drive    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 475,368    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,367,586    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 701,532    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 476,262    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,068,224    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,544,486    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 123,692    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2010    
Operating Properties [Member] | 2700 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2700 Hutchinson McDonald Road    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 912,500    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,669,101    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 84,818    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 912,500    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,753,919    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,666,419    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 171,098    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 2701 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2701 Hutchinson McDonald Road    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,275,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,575,283    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 304,544    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,275,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,879,827    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,154,827    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 187,273    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 2730 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2730 Hutchinson McDonald Road    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,878,750    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,967,061    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 165,495    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,878,750    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,132,556    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,011,306    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 335,000    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 2801 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2801 Hutchinson McDonald Road    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,065,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,917,382    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 122,851    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,065,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,040,233    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,105,233    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 237,994    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 3000 Crosspoint Center Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3000 Crosspoint Center Lane    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,831,250    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 10,639,164    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 334,261    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,831,250    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,973,425    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,804,675    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 386,970    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 3005 Crosspoint Center Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3005 Crosspoint Center Lane    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,990,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,461,888    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 531,728    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,990,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,993,616    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,983,616    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 227,418    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 4045 Perimeter West Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4045 Perimeter West Drive    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,418,928    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,873,797    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 632,732    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,418,928    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,506,529    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,925,457    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 336,446    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 4525 Statesville Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4525 Statesville Road    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 841,250    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,215,795    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 74,264    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 837,144    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,294,165    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,131,309    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 180,087    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 4835 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4835 Sirona Drive    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 3,823,410    
Real Estate and Accumulated Depreciation, Initial Cost of Land 690,750    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,027,217    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 59,170    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 690,749    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,086,388    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,777,137    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 30,442    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 4925 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4925 Sirona Drive    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 3,816,899    
Real Estate and Accumulated Depreciation, Initial Cost of Land 603,003    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,807,150    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 161,860    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 603,002    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,969,011    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,572,013    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 30,229    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 5033 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5033 Sirona Drive    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 3,232,357    
Real Estate and Accumulated Depreciation, Initial Cost of Land 509,247    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,536,597    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 173,620    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 613,961    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,605,503    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,219,464    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 31,011    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 8910 Pioneer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8910 Pioneer Avenue    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 527,873    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,884,419    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 121,513    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 527,873    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,005,932    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,533,805    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 150,394    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 8916 Pioneer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8916 Pioneer Avenue    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 557,730    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,756,677    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 372,999    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 557,730    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,129,676    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,687,406    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 173,841    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 1309 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1309 Executive Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Cheaspeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 926,125    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,098,066    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 955,374    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,068,817    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,024,191    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,501,750    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 1305 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1305 Executive Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 861,020    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,721,660    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,129,850    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,452,830    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,582,680    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,192,540    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 1313 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1313 Executive Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,180,036    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,129,180    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,708,050    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,601,166    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,309,216    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,275,522    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 500 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 500 Independence Parkway    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 864,150    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,427,285    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 660,242    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 866,609    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,085,068    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,951,677    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,188,988    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 700 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 700 Independence Parkway    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,950,375    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,236,994    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 695,893    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,951,135    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,932,127    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,883,262    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,144,725    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 501 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 501 Independence Parkway    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,202,556    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,975,538    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,563,800    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,292,273    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,449,621    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,741,894    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,593,125    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 505 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 505 Independence Parkway    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,292,062    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,456,515    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,167,659    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,292,254    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,623,982    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,916,236    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,559,011    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 510 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 510 Independence Parkway    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,012,149    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,546,882    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 945,228    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,014,689    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,489,570    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,504,259    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,863,681    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 1301 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1301 Executive Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,160,743    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 970,151    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,190,592    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,160,743    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,014,774    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 676 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 676 Independence Parkway    
Real Estate and Accumulated Depreciation, Location of Property Chesapeake, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,527,303    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 11,321,991    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,562,903    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,286,391    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,849,294    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,010,996    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 6230 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6230 Old Dobbin Lane    
Real Estate and Accumulated Depreciation, Location of Property Colombia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,004,075    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,868,622    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,746,455    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,126,242    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,872,697    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,013,211    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 9755 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9755 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,917,094    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 13,678,435    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,186,432    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,922,382    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 16,859,579    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 20,781,961    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,669,096    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 9770 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9770 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 341,663    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,033,309    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,876,157    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 341,663    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,909,466    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,251,129    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,180,837    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 9780 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9780 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 218,542    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,940,636    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 694,384    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 218,542    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,635,020    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,853,562    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,085,437    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 9790 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9790 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 243,791    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,164,094    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 675,071    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 243,791    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,839,165    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,082,956    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,133,196    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 9810 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9810 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 266,684    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,366,901    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 836,994    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 266,684    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,203,895    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,470,579    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,169,811    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 9800 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9800 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 299,099    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,654,069    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 835,685    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 299,099    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,489,754    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,788,853    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,348,718    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 9820 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9820 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 237,779    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,110,835    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,136,339    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 237,779    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,247,174    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,484,953    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,317,725    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 9830 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9830 Patuxent Woods Drive    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 296,262    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,628,933    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 582,878    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 296,262    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,211,811    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,508,073    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,303,411    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 6250 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6250 Old Dobbin Lane    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 958,105    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,626,552    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,295,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,289,657    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,584,657    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,060,463    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 6200 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6200 Old Dobbin Lane    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 958,105    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,828,691    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,295,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,491,796    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,786,796    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 987,855    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 6210 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6210 Old Dobbin Lane    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 958,105    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,140,646    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,307,300    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,791,451    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,098,751    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,253,108    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 6240 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6240 Old Dobbin Lane    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 958,105    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,035,885    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,599,259    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,394,731    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,993,990    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 894,485    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 6220 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6220 Old Dobbin Lane    
Real Estate and Accumulated Depreciation, Location of Property Columbia, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,865,848    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,741,067    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,166,951    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,439,964    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,606,915    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,469,750    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 1250 Hall Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1250 Hall Court    
Real Estate and Accumulated Depreciation, Location of Property Deer Park, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 2,780,889    
Real Estate and Accumulated Depreciation, Initial Cost of Land 829,570    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,680,603    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 145,123    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 831,611    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,823,685    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,655,296    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 803,089    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 170 Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 170 Parkway West    
Real Estate and Accumulated Depreciation, Location of Property Duncan, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 598,348    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,584,023    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 232,890    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 598,918    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,816,343    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,415,261    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 756,385    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 190 Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 190 Parkway West    
Real Estate and Accumulated Depreciation, Location of Property Duncan, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 551,663    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,151,517    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 212,352    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 552,211    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,363,321    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,915,532    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 594,261    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 265 Parkway East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 265 Parkway East    
Real Estate and Accumulated Depreciation, Location of Property Duncan, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 901,444    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,399,523    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 542,505    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 902,374    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,941,098    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,843,472    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,268,669    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 285 Parkway East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 285 Parkway East    
Real Estate and Accumulated Depreciation, Location of Property Duncan, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 975,433    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,545,234    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 665,213    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 976,393    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,209,487    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,185,880    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,050,421    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 3169 Dodd Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3169 Dodd Road    
Real Estate and Accumulated Depreciation, Location of Property Eagan, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 988,594    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,418,735    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 182,665    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 988,594    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,601,400    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,589,994    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 148,286    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 3255 Neil Armstrong Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3255 Neil Armstrong Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Eagan, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,131,017    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,368,614    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,103,860    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,395,771    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,499,631    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,190,350    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 3711 Kennebec Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3711 Kennebec Drive    
Real Estate and Accumulated Depreciation, Location of Property Eagan, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 999,702    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,656,866    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 388,608    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 999,702    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,045,474    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,045,176    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 217,136    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 10301-10305 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10301-10305 West 70th Street    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 120,622    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,085,226    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 412,373    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 118,300    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,499,921    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,618,221    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 642,974    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 10321 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10321 West 70th Street    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 145,198    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,305,700    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 483,786    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 142,399    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,792,285    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,934,684    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 593,660    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 10333 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10333 West 70th Street    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 110,746    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 995,868    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 297,812    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 108,610    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,295,816    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,404,426    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 568,175    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 10349-10357 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10349-10357 West 70th Street    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 275,903    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,481,666    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 523,647    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 270,584    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,010,632    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,281,216    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,260,673    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 10365-10375 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10365-10375 West 70th Street    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 291,077    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,618,194    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 564,092    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 285,464    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,187,899    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,473,363    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,285,920    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 10393-10394 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10393-10394 West 70th Street    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 269,618    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,423,318    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,003,242    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 264,419    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,431,759    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,696,178    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,348,124    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 10400 Viking Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10400 Viking Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,912,391    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 22,492,416    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,938,372    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 22,466,435    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 25,404,807    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 8,819,451    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 6321-6325 Bury Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6321-6325 Bury Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 462,876    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,151,790    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,490,605    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 462,876    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,642,395    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,105,271    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,967,575    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 7075 Flying Cloud Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7075 Flying Cloud Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 10,232,831    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 10,855,851    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 53,337    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 10,243,977    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,898,042    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 21,142,019    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,590,745    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 7078 Shady Oak Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7078 Shady Oak Road    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 343,093    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,085,795    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,500,861    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 336,481    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,593,268    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,929,749    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,641,183    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 7400 Flying Cloud Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7400 Flying Cloud Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 195,982    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,762,027    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,656,743    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 773,243    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,841,509    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,614,752    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 933,527    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 7615 Smetana Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7615 Smetana Lane    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,011,517    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,433,375    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,000,555    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,444,337    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,444,892    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,145,416    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 7625 Smetana Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7625 Smetana Lane    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,500,641    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,987,321    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,916,609    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,571,353    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,487,962    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,051,903    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7660-7716 Golden Triangle Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7660-7716 Golden Triangle Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 568,706    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,115,177    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,543,610    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,289,215    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,938,278    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,227,493    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,851,981    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 7695-7699 Anagram Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7695-7699 Anagram Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 760,525    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,254,758    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 637,651    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 760,525    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,892,409    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,652,934    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,797,299    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 7777 Golden Triangle Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7777 Golden Triangle Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 993,101    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,136,862    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,152,171    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 993,101    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,289,033    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,282,134    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,191,667    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 7800 Equitable Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7800 Equitable Drive    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,188,525    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,788,762    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 146,688    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,188,525    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,935,450    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,123,975    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,369,691    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1993    
Operating Properties [Member] | 7905 Fuller Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7905 Fuller Road    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,229,862    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,075,167    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,980,136    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,230,965    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,054,200    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,285,165    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,605,528    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1994    
Operating Properties [Member] | 8855 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8855 Columbine Road    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,400,925    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,226,017    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,599,757    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,027,185    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,626,942    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,093,297    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 8911 Columbine Road (B2) [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8911 Columbine Road (B2)    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 916,687    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,766,331    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,718,407    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,964,611    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,683,018    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 961,772    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 8937 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8937 Columbine Road    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,325,829    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,196,524    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,739,966    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,782,387    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,522,353    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,170,668    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 8967 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8967 Columbine Road    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,450,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,580,357    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,450,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,580,357    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,030,357    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,324,269    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 8995 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8995 Columbine Road    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,087,594    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,669,304    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,055,296    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,701,602    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,756,898    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 927,105    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 9023 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9023 Columbine Road    
Real Estate and Accumulated Depreciation, Location of Property Eden Prairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,956,273    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,878,828    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,956,273    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,878,828    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,835,101    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,935,384    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 7351 Coca Cola Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7351 Coca Cola Drive    
Real Estate and Accumulated Depreciation, Location of Property Elkridge, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,897,044    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,161,615    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,023,417    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,035,242    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,058,659    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,095,316    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 21705-21707 Mississippi Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 21705-21707 Mississippi Street    
Real Estate and Accumulated Depreciation, Location of Property Elwood, IL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 10,594,259    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 30,240,876    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 468,426    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 10,594,259    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 30,709,302    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 41,303,561    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,200,753    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 27143 S Baseline Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 27143 S. Baseline Road    
Real Estate and Accumulated Depreciation, Location of Property Elwood, IL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,022,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,566,330    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 238,590    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,022,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,804,920    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,826,920    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 261,712    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 180 Sheree Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 180 Sheree Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Exton, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 4,633,690    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,647,861    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 10,181,016    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,809,421    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,649,426    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 13,988,872    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 16,638,298    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,696,545    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 1100 Virginia Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1100 Virginia Drive    
Real Estate and Accumulated Depreciation, Location of Property Fort Washington, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 35,619,946    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 50,384,186    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 16,927,524    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 36,374,955    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 66,556,701    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 102,931,656    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 11,664,074    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 1250 Virginia Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1250 Virginia Drive    
Real Estate and Accumulated Depreciation, Location of Property Fort Washington, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,639,166    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,928,574    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 309,971    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,650,703    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,227,008    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,877,711    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 371,886    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 275 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 275 Commerce Drive    
Real Estate and Accumulated Depreciation, Location of Property Fort Washington, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,775,894    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,160,855    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,601,617    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,790,041    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,748,325    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,538,366    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,552,263    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 414 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 414 Commerce Drive    
Real Estate and Accumulated Depreciation, Location of Property Fort Washington, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,267,194    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,217,460    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 617,386    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,267,937    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,834,103    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,102,040    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 619,550    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 420 Delaware Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 420 Delaware Drive    
Real Estate and Accumulated Depreciation, Location of Property Fort Washington, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,766,931    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,802,494    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,826,994    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,742,431    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,569,425    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,461,872    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 9601 Cosner Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9601 Cosner Drive    
Real Estate and Accumulated Depreciation, Location of Property Fredericksburg, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 475,262    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,917,234    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 242,595    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 475,262    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,159,829    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,635,091    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,818,049    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Operating Properties [Member] | 200 W Cypress Creek Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 200 W Cypress Creek Road    
Real Estate and Accumulated Depreciation, Location of Property Ft Lauderdale, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,414,989    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,399,738    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 9,124,335    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,414,989    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,524,073    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,939,062    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,415,744    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 5410 - 5430 Northwest 33rd Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5410 - 5430 Northwest 33rd Avenue    
Real Estate and Accumulated Depreciation, Location of Property Ft. Lauderdale, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 603,776    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,176,238    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,422,957    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 625,111    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,577,860    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,202,971    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,080,988    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 45 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 45 Brookfield Oaks Drive    
Real Estate and Accumulated Depreciation, Location of Property Greenville, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 818,114    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,310,278    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 825,529    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,302,863    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,128,392    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 541,950    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 1487 South Highway 101 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1487 South Highway 101    
Real Estate and Accumulated Depreciation, Location of Property Greer, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 464,237    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,729,472    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,301,738    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,891,971    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,193,709    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 482,594    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 11841 Newgate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 11841 Newgate Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Hagerstown, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,356,207    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 30,555,105    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 9,741,685    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 24,169,627    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 33,911,312    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,854,489    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2008    
Operating Properties [Member] | 1 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1 Enterprise Parkway    
Real Estate and Accumulated Depreciation, Location of Property Hampton, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 974,675    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,579,869    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,739,690    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 974,675    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,319,559    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,294,234    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,848,620    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 1317 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1317 Executive Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Hampton, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,650,423    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,942,718    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,128,829    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,464,312    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,593,141    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,435,173    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 21 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 21 Enterprise Parkway    
Real Estate and Accumulated Depreciation, Location of Property Hampton, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 263,668    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 8,167,118    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,046,754    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 265,719    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,211,821    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,477,540    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,894,704    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 22 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 22 Enterprise Parkway    
Real Estate and Accumulated Depreciation, Location of Property Hampton, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,097,368    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,760,778    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,378,098    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,097,368    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,138,876    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,236,244    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,033,736    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 5 Manhattan Square [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5 Manhattan Square    
Real Estate and Accumulated Depreciation, Location of Property Hampton, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 207,368    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,535,912    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 212,694    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,530,586    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,743,280    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 559,985    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 521 Butler Farm Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 521 Butler Farm Road    
Real Estate and Accumulated Depreciation, Location of Property Hampton, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 750,769    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,911,149    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 365,780    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 710,486    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,317,212    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,027,698    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 875,353    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 7361 Coca Cola Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7361 Coca Cola Drive    
Real Estate and Accumulated Depreciation, Location of Property Hanover, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,245,187    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 9,384,583    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,822,710    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,807,060    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,629,770    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 771,266    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 500 McCarthy Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 500 McCarthy Drive    
Real Estate and Accumulated Depreciation, Location of Property Harrisburg, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,194,872    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 19,991,436    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,534,843    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,687,013    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 24,034,138    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 29,721,151    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,870,088    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 600 Industrial Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 600 Industrial Drive    
Real Estate and Accumulated Depreciation, Location of Property Harrisburg, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 7,743,800    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 29,097,362    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 9,368,557    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 27,472,605    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 36,841,162    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,356,024    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 1498 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1498 Eagle Hill Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 94,274    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,197,538    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 791,880    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,499,932    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,291,812    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 833,771    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 4183 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4183 Eagle Hill Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 122,203    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,250,598    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 526,266    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,846,535    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,372,801    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 854,677    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 4189 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4189 Eagle Hill Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 100,106    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,501,345    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 431,106    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,170,345    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,601,451    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,106,642    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 4195 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4195 Eagle Hill Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 107,586    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,543,825    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 505,700    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,145,711    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,651,411    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 696,113    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 4300 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4300 Federal Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 264,038    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,128,781    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 276,038    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,116,781    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,392,819    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 677,247    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 4328, 4336 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4328, 4336 Federal Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 2,471,065    
Real Estate and Accumulated Depreciation, Initial Cost of Land 521,122    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,306,605    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 825,092    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,002,635    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,827,727    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,204,766    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Operating Properties [Member] | 4344 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4344 Federal Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 484,001    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,848,373    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 173,623    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,158,751    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,332,374    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,404,706    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 4380 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4380 Federal Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 282,996    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,148,892    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 283,368    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,148,520    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,431,888    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 844,852    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 4388 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4388 Federal Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 143,661    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,213,832    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 132,655    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,224,838    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,357,493    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 453,915    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 4475 Premier Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4475 Premier Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 748,693    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,801,791    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,525,421    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,025,063    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,550,484    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 675,961    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 4500 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4500 Green Point Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 230,622    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,273,803    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 231,692    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,272,733    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,504,425    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,186,696    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 4501 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4501 Green Point Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 319,289    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,092,344    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 320,450    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,091,183    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,411,633    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,324,034    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 4523 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4523 Green Point Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 234,564    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,304,700    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 235,698    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,303,566    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,539,264    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,655,030    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 4524 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4524 Green Point Drive    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 182,810    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,738,364    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 183,888    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,737,286    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,921,174    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,383,159    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 100 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 100 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 38,729    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 349,811    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 59,073    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 38,729    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 408,884    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 447,613    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 140,166    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 100 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 100 Witmer Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,102,784    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 20,472,373    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,764,784    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 19,810,373    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 23,575,157    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,969,535    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 100-107 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 100-107 Lakeside Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 239,528    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,163,498    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 462,398    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 255,528    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,609,896    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,865,424    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 971,382    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 101 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 101 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 651,990    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,888,989    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,923,603    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 732,552    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,732,030    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,464,582    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,995,795    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1977    
Operating Properties [Member] | 101-111 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 101-111 Rock Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 350,561    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,166,389    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,163,717    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 452,251    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,228,416    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,680,667    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,724,474    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 102 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 102 Rock Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,110,209    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,301,302    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,203,706    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,185,500    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,429,717    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,615,217    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,038,610    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 103-109 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 103-109 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 270,906    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,448,500    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 362,164    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 270,906    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,810,664    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,081,570    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,118,468    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1978    
Operating Properties [Member] | 104 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 104 Witmer Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,248,148    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 593,622    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 189,793    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,651,977    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,841,770    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 599,777    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 110 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 110 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 673,041    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,776,369    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,503,096    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 673,041    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,279,465    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,952,506    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,433,460    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1979    
Operating Properties [Member] | 111-159 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 111-159 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 489,032    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,126,151    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,184,555    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 489,032    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,310,706    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,799,738    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,190,060    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1981    
Operating Properties [Member] | 113-123 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 113-123 Rock Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 351,072    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,171,001    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 709,029    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 451,731    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,779,371    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,231,102    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,458,646    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 123-135 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 123-135 Rock Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 292,360    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,411,677    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,125,649    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 393,019    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,436,667    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,829,686    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,568,357    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 132 Welsh Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 132 Welsh Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,333,642    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,110,782    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,408,041    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,036,383    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,444,424    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,736,821    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 161-175 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 161-175 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 294,673    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,663,722    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 957,148    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 294,673    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,620,870    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,915,543    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,456,312    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1976    
Operating Properties [Member] | 181-187 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 181-187 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 360,549    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,259,984    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 787,154    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 360,549    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,047,138    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,407,687    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,747,214    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 2 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2 Walnut Grove Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,281,870    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,767,374    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,368,807    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,265,363    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,152,688    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,418,051    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,734,061    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 200 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 200 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 638,513    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,811,323    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,898,474    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 638,513    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,709,797    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,348,310    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,932,775    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 200-264 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 200-264 Lakeside Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 502,705    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,540,597    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,318,765    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 502,705    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,859,362    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,362,067    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,435,447    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 201 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 201 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 380,127    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,433,433    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,326,813    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 380,802    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,759,571    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,140,373    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,134,443    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 210-223 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 210-223 Witmer Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 270,282    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,441,276    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,954,380    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 270,282    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,395,656    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,665,938    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,646,500    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1972    
Operating Properties [Member] | 220 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 220 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 629,944    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,733,228    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,198,484    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 629,944    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,931,712    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,561,656    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,081,835    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 231-237 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 231-237 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 436,952    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,948,963    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,008,706    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 436,952    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,957,669    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,394,621    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,041,929    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1981    
Operating Properties [Member] | 240 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 240 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 629,944    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,733,234    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,667,071    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 629,944    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,400,305    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,030,249    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,432,271    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 255 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 255 Business Center Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,154,289    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,007,214    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 730,765    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,140,597    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,751,671    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,892,268    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 782,693    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 261-283 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 261-283 Gibraltar Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 464,871    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,951,972    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,781,425    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 464,871    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,733,397    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,198,268    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,160,531    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1978    
Operating Properties [Member] | 300 Welsh Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 300 Welsh Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 696,061    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,339,991    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 570,429    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 696,061    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,910,420    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,606,481    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,610,518    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 300 Welsh Road - Building 3 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 300 Welsh Road - Building 3    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 180,459    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,441,473    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 602,418    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 180,459    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,043,891    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,224,350    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 766,680    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 300 Welsh Road - Building 4 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 300 Welsh Road - Building 4    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 282,493    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,256,508    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,740,348    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 282,493    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,996,856    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,279,349    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,615,523    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 300-309 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 300-309 Lakeside Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 369,475    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,338,761    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,822,004    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 376,475    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,153,765    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,530,240    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,377,024    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 335 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 335 Commerce Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,898,941    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 182,400    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,716,541    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,898,941    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,320,824    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 355 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 355 Business Center Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 483,045    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 898,798    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 520,506    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 471,171    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,431,178    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,902,349    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 451,623    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 4 Walnut Grove [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4 Walnut Grove    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,515,115    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,809,109    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,515,115    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,809,109    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,324,224    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,987,158    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 400-445 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 400-445 Lakeside Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 543,628    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,910,226    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,440,949    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 583,628    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,311,175    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,894,803    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,984,953    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1981    
Operating Properties [Member] | 455 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 455 Business Center Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,351,011    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,503,449    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,827,089    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,322,317    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,359,232    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,681,549    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,128,658    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 5 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5 Walnut Grove Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,065,951    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,537,565    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,939,712    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,663,804    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,603,516    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,234,764    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 506 Prudential Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 506 Prudential Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 208,140    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 895,470    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 894,621    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 208,140    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,790,091    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,998,231    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 725,863    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1973    
Operating Properties [Member] | 555 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 555 Business Center Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 727,420    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,353,650    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 590,775    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 709,967    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,961,878    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,671,845    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 394,807    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 680 Blair Mill Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 680 Blair Mill Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,527,151    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 17,475,489    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,138,577    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 16,864,063    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 21,002,640    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,624,063    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 7 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7 Walnut Grove Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,631,696    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 18,432,489    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,631,956    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 18,432,229    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 21,064,185    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,495,383    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 700 Dresher Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 700 Dresher Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,551,777    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,020,638    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,421,163    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,565,140    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,428,438    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,993,578    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,000,659    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 507 Prudential Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 507 Prudential Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances       
Real Estate and Accumulated Depreciation, Initial Cost of Land 644,900    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,804,100    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,408,030    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,131,380    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 13,725,650    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,857,030    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,932,749    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 747 Dresher Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 747 Dresher Road    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,607,238    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,032,004    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,607,977    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,031,265    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,639,242    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,848,287    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 767 Electronic Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 767 Electronic Drive    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,229,685    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,436,397    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,241,970    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,424,112    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,666,082    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,203,195    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 10301 Round Up Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10301 Round Up Lane    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 545,501    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,927,700    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 647,820    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 545,501    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,575,520    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,121,021    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 151,851    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2010    
Operating Properties [Member] | 10305 Round Up Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10305 Round Up Lane    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,340,609    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,489,720    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,132,595    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,340,609    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,622,315    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,962,924    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 415,125    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2010    
Operating Properties [Member] | 10735 West Little York Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10735 West Little York Road    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,110,988    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,351,946    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,244,493    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,135,483    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,571,944    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,707,427    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,974,061    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 10739 West Little York Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10739 West Little York Road    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 797,931    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,950,894    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 275,922    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 799,560    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,225,187    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,024,747    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,590,735    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 11201 Greens Crossing Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 11201 Greens Crossing Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,006,194    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,412,584    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,777,537    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,008,542    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,187,773    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,196,315    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,335,539    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 14200 Hollister Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 14200 Hollister Road    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,396,794    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,854,459    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,699,632    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,551,621    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,251,253    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 76,214    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 16405 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16405 Air Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 438,853    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,030,396    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 467,475    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 438,853    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,497,871    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,936,724    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,391,979    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 16445 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16445 Air Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 363,339    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,509,186    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 253,123    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 363,339    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,762,309    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,125,648    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,033,854    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 1646 Rankin Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1646 Rankin Road    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 329,961    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,983,836    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 592,234    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,721,563    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,313,797    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,108,215    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 16580 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16580 Air Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 289,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,559,857    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 290,890    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 289,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,850,747    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,139,747    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,320,572    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 16602 Central Green Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16602 Central Green Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 284,403    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,495,522    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 503,779    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,276,146    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,779,925    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 797,099    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 16605 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16605 Air Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 298,999    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,333,536    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 496,186    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,136,349    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,632,535    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 842,762    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 16680 Central Green Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16680 Central Green Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 311,952    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,165,907    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 492,869    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,984,990    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,477,859    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 698,360    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 16685 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16685 Air Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,905,166    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 414,691    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,490,475    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,905,166    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 547,622    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 1755 Trans Central Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1755 Trans Central Drive    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 293,534    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,036,269    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 469,765    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 306,147    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,493,421    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,799,568    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,006,097    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 5200 N. Sam Houston Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5200 N. Sam Houston Parkway    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,519,458    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,135,548    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,484,365    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,520,074    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,619,297    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,139,371    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,792,374    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 5250 N. Sam Houston Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5250 N. Sam Houston Parkway    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,173,287    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 8,868,256    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,581,783    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,173,942    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,449,384    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,623,326    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,663,552    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 8103 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8103 Fallbrook Drive    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,515,862    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 23,946,674    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,877,884    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 22,584,652    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 28,462,536    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,923,877    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 850 Greens Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 850 Greens Parkway    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,893,405    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 11,593,197    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,803,196    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,899,861    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,389,937    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 17,289,798    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,937,750    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 860 Greens Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 860 Greens Parkway    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,399,365    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,344,650    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,579,558    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,374,012    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,949,561    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,323,573    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,081,655    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 8801-19 & 8821-49 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8801-19 & 8821-49 Fallbrook Drive    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,290,001    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 15,297,141    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,942,017    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,290,002    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 17,239,157    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 19,529,159    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,278,401    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 8802-8824 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8802-8824 Fallbrook Drive    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,774,995    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,364,767    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,323,270    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,775,021    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,688,011    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,463,032    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,862,584    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 8825-8839 N Sam Houston Pkwy [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8825-8839 N Sam Houston Pkwy    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 638,453    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,258,815    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 709,721    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 638,477    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,968,512    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,606,989    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 972,040    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 8850-8872 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8850-8872 Fallbrook Drive    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 504,317    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,878,351    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,054,230    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 504,341    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,932,557    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,436,898    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,119,479    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 10 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10 North Park Drive    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,211,969    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,816,042    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,066,771    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,211,969    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,882,813    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,094,782    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,323,045    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 20 Wright Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 20 Wright Avenue    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,205,946    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,035,875    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,861,025    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,380,796    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,241,821    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,369,085    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 307 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 307 International Circle    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,538,319    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 14,190,832    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 14,271,044    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,542,881    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 28,457,314    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 32,000,195    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,745,578    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 309 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 309 International Circle    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 613,667    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,458,204    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,101,241    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 615,096    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,558,016    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,173,112    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 722,028    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 311 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 311 International Circle    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 313,365    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,281,093    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 121,986    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 314,572    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,401,872    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,716,444    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 265,528    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 4 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4 North Park Drive    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,269,948    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 13,551,370    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,291,523    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,269,948    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 18,842,893    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 22,112,841    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,490,794    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 6 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6 North Park Drive    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,077,949    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 8,770,566    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,997,827    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,077,949    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,768,393    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,846,342    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,968,013    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 10245 Centurion Parkway North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10245 Centurion Parkway North    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 852,644    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,510,889    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 925,812    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 853,704    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,435,641    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,289,345    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,532,813    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 4190 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4190 Belfort Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 821,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,866,000    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,447,734    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 827,420    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,307,314    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,134,734    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,668,892    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 4345 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4345 Southpoint Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,599,894    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 418,093    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,181,801    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,599,894    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,988,317    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 4801 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4801 Executive Park Court - 100    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 554,993    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,993,277    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 280,903    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 554,542    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,274,631    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,829,173    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,233,797    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 4801 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4801 Executive Park Court - 200    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 370,017    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,995,518    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 191,034    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 370,039    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,186,530    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,556,569    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 855,635    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 4810 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4810 Executive Park Court    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 369,694    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,045,639    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 782,108    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 370,039    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,827,402    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,197,441    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,530,723    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 4815 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4815 Executive Park Court - 100    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 366,317    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,975,393    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 78,401    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 366,339    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,053,772    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,420,111    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 746,594    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Operating Properties [Member] | 4815 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4815 Executive Park Court - 200    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 462,522    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,494,397    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 345,175    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 462,549    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,839,545    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,302,094    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,042,435    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Operating Properties [Member] | 4820 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4820 Executive Park Court    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 555,173    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,693,130    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 605,408    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 555,213    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,298,498    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,853,711    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,284,863    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 4825 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4825 Executive Park Court    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 601,278    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,242,491    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 50,343    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 601,401    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,292,711    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,894,112    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,259,298    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 4875 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4875 Belfort Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,089,347    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,024,417    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,287,152    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,826,612    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,113,764    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,793,058    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 4887 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4887 Belfort Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,299,202    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,921,089    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,665,915    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,554,376    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,220,291    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,670,342    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 4899 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4899 Belfort Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,299,201    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,852,142    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,168,062    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,983,281    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,151,343    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,730,928    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 4901 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4901 Belfort Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 877,964    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,360,742    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,749,279    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 877,964    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,110,021    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,987,985    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,730,837    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 4905 Belfort Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4905 Belfort Street    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 638,154    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,257,564    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 641,272    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,254,446    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,895,718    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,163,576    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 5201 Gate Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5201 Gate Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,836,532    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 21,433,694    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,269,346    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 21,000,880    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 25,270,226    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,204,196    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 6601 Executive Park Circle North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6601 Executive Park Circle North    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 551,250    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,128,361    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 267,953    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 551,250    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,396,314    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,947,564    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,245,018    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1992    
Operating Properties [Member] | 6602 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6602 Executive Park Court - 100    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 388,519    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,095,293    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 217,788    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 388,541    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,313,059    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,701,600    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 878,603    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1993    
Operating Properties [Member] | 6602 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6602 Executive Park Court - 200    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 296,014    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,596,347    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 413,216    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 296,032    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,009,545    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,305,577    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 752,432    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1993    
Operating Properties [Member] | 6631 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6631 Executive Park Court - 100    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 251,613    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,356,849    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 477,995    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 251,627    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,834,830    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,086,457    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 840,339    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1994    
Operating Properties [Member] | 6631 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6631 Executive Park Court - 200    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 406,561    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,195,070    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 435,692    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 407,043    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,630,280    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,037,323    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,077,944    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1994    
Operating Properties [Member] | 6700 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6700 Southpoint Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 620,719    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,989,746    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 188,569    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 624,215    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,174,819    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,799,034    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,299,964    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 7014 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7014 AC Skinner Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 574,198    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,444,377    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 780,486    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,238,089    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,018,575    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,142,614    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 7016 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7016 AC Skinner Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 597,181    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,373,251    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 602,633    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,367,799    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,970,432    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,328,508    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 7018 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7018 AC Skinner Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 840,996    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,584,514    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 846,461    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,579,049    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,425,510    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,508,744    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 7020 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7020 AC Skinner Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 398,257    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,327,622    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 749,811    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,976,068    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,725,879    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 890,932    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 7022 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7022 AC Skinner Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 706,934    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,984,235    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 853,981    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,837,188    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,691,169    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,301,315    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 7077 Bonneval Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7077 Bonneval Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 768,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,789,000    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,642,514    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 774,020    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,425,494    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,199,514    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,201,054    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 7251 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7251 Salisbury Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,382,617    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 662,559    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,720,058    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,382,617    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 817,888    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 7255 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7255 Salisbury Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 392,060    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,653,838    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 680,766    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,365,132    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,045,898    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 580,895    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 7259 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7259 Salisbury Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,228,709    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,724,437    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,179,063    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,774,083    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,953,146    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,957    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 8665,8667,8669 Baypine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8665,8667,8669 Baypine Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 966,552    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,398,317    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 974,959    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,389,910    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,364,869    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,869,575    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 8775 Baypine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8775 Baypine Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 906,804    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 9,842,206    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 913,013    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,835,997    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,749,010    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,316,770    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 151 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 151 South Warner Road    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,218,086    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,937,866    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,191,697    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,187,900    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,159,749    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,347,649    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,820,036    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1980    
Operating Properties [Member] | 180 South Warner Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 180 South Warner Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 9,749,428    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,749,428    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,749,428    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 612,993    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2009    
Operating Properties [Member] | 2100 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2100 Renaissance Boulevard    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,110,111    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 12,003,349    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,132,519    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,980,941    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,113,460    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,125,447    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 2201 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2201 Renaissance Boulevard    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 17,648,408    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,413,514    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 15,234,894    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 17,648,408    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,901,071    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 2300 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2300 Renaissance Boulevard    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 509,580    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,042,297    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 574,152    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,977,725    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,551,877    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,347,321    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 2301 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2301 Renaissance Boulevard    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,645,246    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 30,080,438    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,581,649    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 27,144,035    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 31,725,684    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 9,366,432    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 2500 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2500 Renaissance Boulevard    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 509,580    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,653,720    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 592,886    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,570,414    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,163,300    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,124,607    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 2520 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2520 Renaissance Boulevard    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,020,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,621,206    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 978,402    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,662,804    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,641,206    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,971,168    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 2560 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2560 Renaissance Boulevard    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,729,254    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 649,792    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,079,462    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,729,254    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,283,702    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 2700 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2700 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 764,370    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,643,566    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 867,815    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,540,121    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,407,936    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,381,478    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 2900 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2900 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 679,440    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,503,074    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 774,096    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,408,418    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,182,514    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,440,492    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 3200 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3200 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 928,637    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,271,084    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,210,137    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,989,584    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,199,721    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,980,170    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 3400 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3400 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 776,496    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,139,068    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,511,259    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 776,496    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,650,327    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,426,823    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,587,308    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Operating Properties [Member] | 3600 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3600 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 236,432    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,856,252    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 784,645    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 236,432    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,640,897    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,877,329    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,288,193    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 3602 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3602 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 217,734    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,759,489    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 194,524    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 217,809    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,953,938    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,171,747    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 795,621    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 3604 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3604 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 397,178    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,830,845    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 350,874    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,877,149    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,228,023    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 649,040    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 440 East Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 440 East Swedesford Road    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 717,001    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,816,121    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,823,888    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 717,001    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,640,009    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,357,010    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,345,862    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 460 East Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 460 East Swedesford Road    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 705,317    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,737,487    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,101,975    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 705,317    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,839,462    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,544,779    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,393,390    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 650 Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 650 Swedesford Road    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 952,911    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,722,830    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,998,201    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 952,911    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,721,031    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,673,942    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,275,267    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1971    
Operating Properties [Member] | 680 Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 680 Swedesford Road    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 952,361    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,722,830    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,217,277    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 952,361    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 13,940,107    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,892,468    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,778,719    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1971    
Operating Properties [Member] | 170 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 170 South Warner Road    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 547,800    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,137,400    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,855,285    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 458,232    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,082,253    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,540,485    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,448,347    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1980    
Operating Properties [Member] | 190 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 190 South Warner Road    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 552,200    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,162,600    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,063,496    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 461,909    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,316,387    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,778,296    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,996,095    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1980    
Operating Properties [Member] | 3000 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3000 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,191,449    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,476,299    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 946,703    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,721,045    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,667,748    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 964,964    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 3100 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3100 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 601,956    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,224,116    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 611,436    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,214,636    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,826,072    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 745,466    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Operating Properties [Member] | 3500 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3500 Horizon Drive    
Real Estate and Accumulated Depreciation, Location of Property King of Prussia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,204,839    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,830,072    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,223,875    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,811,036    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,034,911    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,123,827    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 1700 Interstate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1700 Interstate Drive    
Real Estate and Accumulated Depreciation, Location of Property Lakeland, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 650,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,359,845    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 84,375    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 650,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,444,220    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,094,220    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 8,569    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 11425 State Highway 225 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 11425 State Highway 225    
Real Estate and Accumulated Depreciation, Location of Property LaPorte, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 975,974    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,291,952    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 126,040    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 977,542    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,416,424    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,393,966    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 630,381    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 11503 State Highway 225 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 11503 State Highway 225    
Real Estate and Accumulated Depreciation, Location of Property LaPorte, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,561,931    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,593,118    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 339,649    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,566,047    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,928,651    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,494,698    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,685,895    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7528 Walker Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7528 Walker Way    
Real Estate and Accumulated Depreciation, Location of Property Lehigh Valley, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 893,441    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,510,456    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 779,330    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,624,567    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,403,897    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,419,546    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 8301 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8301 Industrial Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Lehigh, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 11,249,550    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 44,324,333    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 11,254,716    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 44,319,167    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 55,573,883    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 8,008,883    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 8500 Willard Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8500 Willard Drive    
Real Estate and Accumulated Depreciation, Location of Property Lehigh, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 3,054,750    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,398,815    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 21,851,472    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 7,734,826    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 20,515,461    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 28,250,287    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,482,104    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 7533 Insurtial Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7533 Insurtial Parkway    
Real Estate and Accumulated Depreciation, Location of Property Lower Macungie, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,603,460    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 18,807,987    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,434,039    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,603,460    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 21,242,026    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 26,845,486    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,197,518    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 1901 Summit Tower Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1901 Summit Tower Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Maitland, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,078,791    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 12,348,567    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,047,679    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,083,206    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,391,831    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 20,475,037    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,771,297    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 1 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1 Country View Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 400,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,600,000    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 437,856    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 406,421    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,031,435    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,437,856    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,223,299    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 1 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 419,460    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,792,570    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 813,913    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 419,460    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,606,483    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,025,943    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,690,775    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 10 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 823,540    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,341,376    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 459,973    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 832,244    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,792,645    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,624,889    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 519,885    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 100 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 100 Chesterfield Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,320,625    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,709,379    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,451,139    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,578,865    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,030,004    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,232,114    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 1001 Cedar Hollow Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1001 Cedar Hollow Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,436,814    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 16,128,428    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,676,470    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 15,888,772    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 17,565,242    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 7,374,286    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 11 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 11 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 496,297    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,960,712    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 708,331    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,748,678    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,457,009    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 818,775    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 11,15 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 11,15 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,837,050    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 14,958,472    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,837,878    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,957,644    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 16,795,522    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 11,336,838    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 18 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 18 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 394,036    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,976,221    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 68,969    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 397,293    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,041,933    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,439,226    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,402,305    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1980    
Operating Properties [Member] | 2 West Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2 West Liberty Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,405,041    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 11,846,282    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,405,042    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,846,281    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 17,251,323    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,771,172    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 200 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 200 Chesterfield Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 495,893    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,739,093    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 578,648    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 588,384    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,225,250    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,813,634    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,478,285    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 27-43 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 27-43 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 448,775    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,347,289    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 449,447    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,346,617    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,796,064    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,753,983    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1977    
Operating Properties [Member] | 3 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3 Country View Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 814,278    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,142,433    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,128,881    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,827,830    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,956,711    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,726,641    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 375 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 375 Technology Drive    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 191,114    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,616,195    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 234,922    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,572,387    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,807,309    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 601,655    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 40 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 40 Liberty Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,241,137    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 17,737,090    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,649,251    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,241,167    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 20,386,311    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 24,627,478    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 7,924,812    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 425 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 425 Technology Drive    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 191,114    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,700,603    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 321,473    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,570,244    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,891,717    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 588,227    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 45 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 45 Liberty Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,380,221    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 15,322,821    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,749,748    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,953,294    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 19,703,042    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,941,978    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 45-67 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 45-67 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 795,143    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,195,540    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 795,831    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,194,852    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,990,683    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,784,680    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1974    
Operating Properties [Member] | 5 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 684,200    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,181,661    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,605,728    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 684,200    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,787,389    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,471,589    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,145,477    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 50 Morehall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 50 Morehall Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 849,576    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,079,506    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,337,076    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,592,006    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,929,082    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,307,490    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 600 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 600 Chesterfield Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,013,750    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,255,849    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,171,080    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,098,519    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,269,599    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,786,054    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 700 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 700 Chesterfield Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,013,750    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,216,674    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,158,337    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,072,087    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,230,424    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,760,197    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 10 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10 Valley Stream Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 509,075    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,699,241    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 509,899    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,698,417    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,208,316    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,720,891    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 10, 20 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10, 20 Liberty Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 724,058    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,828,095    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 724,846    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,827,307    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,552,153    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,313,973    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 12,14,16 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 12,14,16 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 130,689    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,326,294    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 128,767    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,328,216    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,456,983    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 877,803    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 14 Lee Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 14 Lee Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 664,282    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,569,322    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 643,892    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,589,712    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,233,604    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,522,564    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 155 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 155 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 625,147    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,640,082    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 626,068    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,639,161    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,265,229    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,887,661    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1981    
Operating Properties [Member] | 20 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 20 Valley Stream Parkway    
Operating Properties [Member] | 257-275 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 257-275 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA [1]    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 504,611    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,076,691    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 505,458    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,075,844    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,581,302    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,279,873    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 277-293 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 277-293 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 530,729    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,390,465    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 531,534    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,389,660    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,921,194    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,652,769    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 30 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 30 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 128,126    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 554,378    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 128,783    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 553,721    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 682,504    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 340,151    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 300-400 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 300-400 Chesterfield Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 937,212    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,162,646    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,012,843    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,087,015    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,099,858    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,755,579    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 311 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 311 Technology Drive    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 397,131    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,983,506    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 397,948    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,982,689    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,380,637    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,897,101    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 333 Phoenixville Pike [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 333 Phoenixville Pike    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 523,530    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,708,843    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 524,230    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,708,143    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,232,373    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,170,389    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 40 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 40 Valley Stream Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 322,918    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,233,318    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 325,775    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,230,461    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,556,236    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,294,803    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 420 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 420 Lapp Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,054,418    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,617,860    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,055,243    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,617,035    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,672,278    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,903,764    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 5 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5 Country View Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 785,168    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,678,632    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 885,185    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 786,235    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,562,750    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,348,985    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,750,581    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 50 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 50 Valley Stream Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 323,971    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,112,785    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 323,792    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,112,964    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,436,756    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,054,064    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 500 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 500 Chesterfield Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 472,364    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,922,205    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 519,742    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,874,827    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,394,569    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,601,361    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 508 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 508 Lapp Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 331,392    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,712,794    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 332,216    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,711,970    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,044,186    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,198,302    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 510 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 510 Lapp Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 356,950    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 926,587    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 357,751    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 925,786    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,283,537    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 702,362    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 55 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 55 Valley Stream Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 215,005    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,048,827    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 215,818    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,048,014    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,263,832    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,739,220    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 60 Morehall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 60 Morehall Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 865,424    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,285,000    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,182,805    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 884,974    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,448,255    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,333,229    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 8,775,233    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 65 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 65 Valley Stream Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 381,544    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,715,903    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 382,361    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,715,086    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,097,447    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,817,405    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 7 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 176,435    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,068,019    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 177,317    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,067,137    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,244,454    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,890,865    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 75 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 75 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 143,074    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 618,372    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 143,811    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 617,635    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 761,446    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 492,163    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1977    
Operating Properties [Member] | 77-123 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 77-123 Great Valley Parkway    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 887,664    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,128,170    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 888,359    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,127,475    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,015,834    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,607,633    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1978    
Operating Properties [Member] | 7550 Meridian Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7550 Meridian Circle    
Real Estate and Accumulated Depreciation, Location of Property Maple Grove, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 513,250    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,901,906    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,093,039    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 513,250    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,994,945    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,508,195    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,432,707    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 301 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 301 Lippincott Drive    
Real Estate and Accumulated Depreciation, Location of Property Marlton, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,069,837    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,780,163    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,399,019    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,069,838    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,179,181    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,249,019    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,617,454    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 303 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 303 Lippincott Drive    
Real Estate and Accumulated Depreciation, Location of Property Marlton, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,069,837    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,780,163    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,942,344    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,069,838    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,722,506    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,792,344    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,026,134    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 400 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 400 Lippincott Drive    
Real Estate and Accumulated Depreciation, Location of Property Marlton, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 69,402    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,668,348    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 317,799    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,419,951    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,737,750    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,508,543    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 406 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 406 Lippincott Drive    
Real Estate and Accumulated Depreciation, Location of Property Marlton, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 321,455    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,539,871    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,119,185    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 327,554    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,652,957    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,980,511    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,064,731    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 65 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 65 Brookfield Oaks Drive    
Real Estate and Accumulated Depreciation, Location of Property Mauldin, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 557,174    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,842,439    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 506,318    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,893,295    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,399,613    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 497,224    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 75 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 75 Brookfield Oaks Drive    
Real Estate and Accumulated Depreciation, Location of Property Mauldin, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 419,731    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,338,822    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 430,909    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,327,644    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,758,553    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 495,571    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 4600 Nathan Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4600 Nathan Lane    
Real Estate and Accumulated Depreciation, Location of Property Minneapolis, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,063,558    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,308,857    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,038,197    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,334,218    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,372,415    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,391,013    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 4700 Nathan Lane North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4700 Nathan Lane North    
Real Estate and Accumulated Depreciation, Location of Property Minneapolis, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,501,308    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 8,446,083    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,598,534    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,501,308    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 22,044,617    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 23,545,925    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,167,217    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 12501 & 12701 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 12501 & 12701 Whitewater Drive    
Real Estate and Accumulated Depreciation, Location of Property Minnegonka, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,175,209    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,948,085    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,512,893    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,177,953    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,458,234    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,636,187    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,190,381    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 12800 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 12800 Whitewater Drive    
Real Estate and Accumulated Depreciation, Location of Property Minnetonka, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,273,600    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,158,737    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,080,274    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,273,730    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,238,881    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,512,611    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 101,121    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 12900 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 12900 Whitewater Drive    
Real Estate and Accumulated Depreciation, Location of Property Minnetonka, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,236,560    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,762,325    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,016,780    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,236,686    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,778,979    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,015,665    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 88,467    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 5400-5500 Feltl Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5400-5500 Feltl Road    
Real Estate and Accumulated Depreciation, Location of Property Minnetonka, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 883,895    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,983,345    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,453,848    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 883,895    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,437,193    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,321,088    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,156,664    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 5600 & 5610 Rowland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5600 & 5610 Rowland Road    
Real Estate and Accumulated Depreciation, Location of Property Minnetonka, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 828,650    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,399,409    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,611,297    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 829,263    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,010,093    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,839,356    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,363,765    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 6000 Clearwater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6000 Clearwater Drive    
Real Estate and Accumulated Depreciation, Location of Property Minnetonka, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 985,016    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,091,371    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,503,147    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 985,117    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,594,417    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,579,534    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 66,861    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 456 International Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 456 International Parkway    
Real Estate and Accumulated Depreciation, Location of Property Minooka, IL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,862,683    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 13,673,262    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 684,719    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,862,683    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,357,981    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 18,220,664    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 247,114    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 3100 SW 145th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3100 SW 145th Avenue    
Real Estate and Accumulated Depreciation, Location of Property Miramar, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,204,407    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 17,043,437    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,265,000    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 16,982,844    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 23,247,844    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,663,898    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 3350 SW 148th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3350 SW 148th Avenue    
Real Estate and Accumulated Depreciation, Location of Property Miramar, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,960,511    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 18,244,896    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,980,689    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 18,224,718    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 21,205,407    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,789,968    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 3400 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3400 Lakeside Drive    
Real Estate and Accumulated Depreciation, Location of Property Miramar, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,022,153    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 11,345,881    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,703,556    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,022,153    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 13,049,437    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,071,590    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,956,270    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 3450 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3450 Lakeside Drive    
Real Estate and Accumulated Depreciation, Location of Property Miramar, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,022,152    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 11,357,143    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,702,765    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,022,152    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,059,908    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 16,082,060    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,681,575    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 323 Park Knoll Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 323 Park Knoll Drive    
Real Estate and Accumulated Depreciation, Location of Property Morrisville, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 2,690,326    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,071,600    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,294,089    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 938,228    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,071,600    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,232,317    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,303,917    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 464,061    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2010    
Operating Properties [Member] | 324 Park Knoll Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 324 Park Knoll Drive    
Real Estate and Accumulated Depreciation, Location of Property Morrisville, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,449,092    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,252,934    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 502,293    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,449,450    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,754,869    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,204,319    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 751,123    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 619 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 619 Distribution Drive    
Real Estate and Accumulated Depreciation, Location of Property Morrisville, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,031,430    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,466,955    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 529,813    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,031,685    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,996,513    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,028,198    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 911,987    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 627 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 627 Distribution Drive    
Real Estate and Accumulated Depreciation, Location of Property Morrisville, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,061,370    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,971,939    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 772,687    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,061,632    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,744,364    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,805,996    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 801,595    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 330 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 330 Fellowship Road    
Real Estate and Accumulated Depreciation, Location of Property Mount Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,730,570    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 17,127,277    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,758,270    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 17,099,577    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 20,857,847    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,114,000    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 300 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 300 Fellowship Road    
Real Estate and Accumulated Depreciation, Location of Property Mt Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,354,051    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,098,904    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,255,147    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,354,051    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,676,701    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 3001 Leadenhall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3001 Leadenhall Road    
Real Estate and Accumulated Depreciation, Location of Property Mt Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,925,719    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 191,390    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,965,396    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,936,489    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,146,016    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,082,505    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,363,501    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 302 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 302 Fellowship Road    
Real Estate and Accumulated Depreciation, Location of Property Mt Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,512,120    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,876,559    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 539,060    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,849,619    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,388,679    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 747,465    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 350 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 350 Fellowship Road    
Real Estate and Accumulated Depreciation, Location of Property Mt Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,960,159    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,449,611    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,622,153    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,970,687    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,061,236    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,031,923    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,242,368    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 1000 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1000 Briggs Road    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 288,577    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,546,537    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,757,724    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 288,577    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,304,261    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,592,838    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,535,702    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 1001 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1001 Briggs Road    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 701,705    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,505,652    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,115,907    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 701,705    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,621,559    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,323,264    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,715,719    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 1015 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1015 Briggs Road    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 356,987    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,602,599    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 470,659    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,488,927    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,959,586    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,312,844    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 1020 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1020 Briggs Road    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 494,334    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,818,894    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 569,184    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,744,044    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,313,228    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,441,594    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 1025 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1025 Briggs Road    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 430,990    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,714,828    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,308,915    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 430,990    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,023,743    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,454,733    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,198,737    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 11000, 15000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 11000, 15000 Commerce Parkway    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 310,585    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,394,900    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 279,828    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 311,950    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,673,363    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,985,313    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,307,105    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 12000, 14000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 12000, 14000 Commerce Parkway    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 361,800    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,285,817    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 881,054    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 362,855    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,165,816    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,528,671    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,048,995    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 16000, 18000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16000, 18000 Commerce Parkway    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 289,700    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,512,683    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,021,740    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 290,545    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,533,578    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,824,123    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,742,754    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 17000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 17000 Commerce Parkway    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 144,515    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,948,572    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 144,515    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,948,572    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,093,087    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,006,545    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 5000 Dearborn Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5000 Dearborn Court    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,057,763    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,191,827    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,251,735    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,058,832    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,442,493    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,501,325    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,871,182    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 6000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6000 Commerce Parkway    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 234,151    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,022,683    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 515,996    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 234,151    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,538,679    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,772,830    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 984,530    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 8000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8000 Commerce Parkway    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 234,814    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,995,098    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 587,719    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 234,814    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,582,817    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,817,631    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,121,048    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 9000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9000 Commerce Parkway    
Real Estate and Accumulated Depreciation, Location of Property Mt. Laurel, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 286,587    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,474,820    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,352,500    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 286,587    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,827,320    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,113,907    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,516,718    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 550-590 Hale Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 550-590 Hale Avenue    
Real Estate and Accumulated Depreciation, Location of Property Oakdale, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 765,535    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,488,754    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 303,570    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 766,390    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,791,469    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,557,859    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,327,239    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 1879 Lamont Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1879 Lamont Avenue    
Real Estate and Accumulated Depreciation, Location of Property Odenton, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,976,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 8,099,579    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,469,160    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,011,030    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,533,709    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,544,739    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,488,629    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 350 Winmeyer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 350 Winmeyer Avenue    
Real Estate and Accumulated Depreciation, Location of Property Odenton, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,778,400    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,289,165    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,069,298    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,809,927    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,326,936    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,136,863    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,004,576    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 1000 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1000 Gills Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 415,906    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,712,377    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 435,400    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,692,883    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,128,283    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 338,797    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 10003 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10003 Satellite Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 680,312    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,120,754    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,258,779    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 680,312    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,379,533    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,059,845    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 894,648    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 10511 & 10611 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10511 & 10611 Satellite Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 517,554    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,568,186    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 424,226    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 522,991    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,986,975    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,509,966    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,196,850    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 10771 Palm Bay Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 10771 Palm Bay Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 664,605    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,363,613    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 685,383    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,342,835    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,028,218    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 651,050    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 1090 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1090 Gills Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 878,320    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,558,833    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,400,491    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 878,320    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,959,324    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,837,644    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 937,703    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 1400-1440 Central Florida Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1400-1440 Central Florida Parkway    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 518,043    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,561,938    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 959,445    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 518,043    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,521,383    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,039,426    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,289,418    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1962    
Operating Properties [Member] | 1902 Cypress Lake Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1902 Cypress Lake Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 523,512    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,191,790    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,489,884    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 538,512    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,666,674    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,205,186    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,672,265    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 1950 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1950 Summit Park Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,573,700    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 17,478,646    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,245,115    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,583,667    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 20,713,794    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 23,297,461    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,697,553    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 1958 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1958 Summit Park Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,573,961    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 11,206,937    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,133,864    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,583,216    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 21,331,546    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 23,914,762    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,105,388    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 201 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 201 Summit Park Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,435,921    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 38,416,263    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,510,990    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 38,341,194    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 42,852,184    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,959,369    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2008    
Operating Properties [Member] | 2202 Taft-Vineland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2202 Taft-Vineland Road    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,631,110    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,283,713    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,347,397    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,631,110    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,087,234    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 2256 Taft-Vineland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2256 Taft-Vineland Road    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 467,296    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,494,667    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 825,673    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,136,290    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,961,963    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 509,428    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 2351 Investors Row [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2351 Investors Row    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,261,924    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,496,249    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,855,906    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,263,211    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,350,868    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,614,079    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,920,977    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 2400 South Lake Orange Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2400 South Lake Orange Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 385,964    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,193,150    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 642,427    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,936,687    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,579,114    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 794,601    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 2412 Sand Lake Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2412 Sand Lake Road    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,236,819    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,243,314    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 15,060    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,240,976    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,254,217    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,495,193    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,442    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 2416 Lake Orange Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2416 Lake Orange Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 535,964    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,926,205    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 704,800    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,757,369    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,462,169    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 963,211    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 6200 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6200 Lee Vista Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,435,301    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,907,266    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 606,440    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,435,301    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,513,706    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,949,007    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,092,952    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 6501 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6501 Lee Vista Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 903,701    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,660,760    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 925,671    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,638,790    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,564,461    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,597,662    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 6918 Presidents Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6918 Presidents Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 872,550    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,476,443    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 49,600    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 872,550    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,526,043    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,398,593    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,665    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 6923 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6923 Lee Vista Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 903,701    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,790,427    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 830,953    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,863,175    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,694,128    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 740,664    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7022 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7022 TPC Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,443,510    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,501,571    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 800,668    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,457,286    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,288,463    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,745,749    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,236,451    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7100 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7100 TPC Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,431,489    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,583,998    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,158,702    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,445,807    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,728,382    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,174,189    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,619,911    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7101 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7101 TPC Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,553,537    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,574,187    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 441,400    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,570,863    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,998,261    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,569,124    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 987,036    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7315 Kingspointe Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7315 Kingspointe Parkway    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,931,697    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,388,203    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,030,841    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,932,004    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,418,737    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,350,741    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,480,531    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 8201 Chancellor Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8201 Chancellor Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,295,972    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 12,598,544    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,944,499    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,295,972    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 18,543,043    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 22,839,015    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,215,817    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2010    
Operating Properties [Member] | 851 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 851 Gills Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 332,992    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,861,135    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 373,500    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,820,627    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,194,127    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 355,819    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 950 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 950 Gills Drive    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 443,989    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,907,134    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 464,800    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,886,323    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,351,123    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 319,378    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 9550 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9550 Satellite Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 574,831    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,497,841    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 587,319    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,485,353    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,072,672    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 901,950    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 9600 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9600 Satellite Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 252,850    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,297,923    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 71,943    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 252,850    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,369,866    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,622,716    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 514,444    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 9700 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9700 Satellite Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 405,362    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,146,546    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 272,501    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 405,362    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,419,047    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,824,409    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 536,000    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | South Center Land-Phase II [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property South Center Land-Phase II    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 838,853    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,084,540    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 767,953    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,155,440    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,923,393    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 823,157    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 1 Crescent Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1 Crescent Drive    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 567,280    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 15,221,634    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 347,892    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 15,441,022    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,788,914    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,599,727    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 150 Rouse Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 150 Rouse Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 567,531    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 14,226,850    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 569,349    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,225,032    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,794,381    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 59,980    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 3 Crescent Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3 Crescent Drive    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 214,726    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 22,198,745    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 417,823    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 21,995,648    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 22,413,471    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,658,371    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2008    
Operating Properties [Member] | 3 Franklin Plaza [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3 Franklin Plaza    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,483,144    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 32,164,217    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,514,519    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 32,132,842    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 34,647,361    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 11,255,502    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 4300 South 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4300 South 26th Street    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 402,673    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 34,862,598    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 413,030    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 34,852,241    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 35,265,271    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,969,038    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2008    
Operating Properties [Member] | 4751 League Island Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4751 League Island Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 992,965    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 331,924    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,854,092    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,022,081    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,156,900    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,178,981    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,827,391    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 4775 League Island Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4775 League Island Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 891,892    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,684,847    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 366,982    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,209,757    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,576,739    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 845,611    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 8801 Tinicum Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8801 Tinicum Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,474,031    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 43,774,779    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 125,087    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 46,123,723    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 46,248,810    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 20,744,336    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 2626 South 7th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2626 South 7th Street    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,519,510    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,791,779    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 28,321    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,519,510    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,820,100    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,339,610    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 31,793    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 4207 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4207 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,409,908    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,590,603    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,190,407    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,410,248    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,780,670    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,190,918    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,215,170    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4217 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4217 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,920,980    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,082,544    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,720,122    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,690,321    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,033,325    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 20,723,646    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,499,438    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4303 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4303 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,619,964    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,246,292    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 473,070    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,619,964    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,719,362    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,339,326    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,632,865    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4313 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4313 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,895,539    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 15,853,754    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,270,877    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,895,539    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 18,124,631    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 22,020,170    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,250,143    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4405 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4405 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,646,318    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,456,358    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 424,694    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,646,318    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,881,052    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,527,370    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,585,023    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4410 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4410 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,758,484    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 10,559,563    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,587,576    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,765,172    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 16,140,451    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 20,905,623    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,667,277    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4415 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4415 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,749,957    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,393,860    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 739,732    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,749,957    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,133,592    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,883,549    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 597,260    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4425 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4425 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 7,318,457    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 22,368,188    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,707,787    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 7,318,457    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 24,075,975    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 31,394,432    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,275,114    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4435 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4435 E. Cotton Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,910,584    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,954,020    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,166,649    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,911,045    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,120,208    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,031,253    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 858,220    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4610 South 44th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4610 South 44th Street    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,539,310    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,331,533    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,827,288    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,043,555    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 16,870,843    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,250,228    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 4750 S. 44th Place [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4750 S. 44th Place    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,756,307    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 8,336,400    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,190,610    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,761,587    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,521,730    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 16,283,317    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,736,013    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 9801 80th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9801 80th Avenue    
Real Estate and Accumulated Depreciation, Location of Property Pleasant Prairie, WI    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,692,077    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,934,794    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 275,264    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,689,726    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,212,409    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,902,135    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,929,794    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1994    
Operating Properties [Member] | 2250 Hickory Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2250 Hickory Road    
Real Estate and Accumulated Depreciation, Location of Property Plymouth Meeting, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,015,851    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,175,555    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,994,455    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,024,040    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,161,821    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,185,861    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,046,410    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 14630-14650 28th Avenue North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 14630-14650 28th Avenue North    
Real Estate and Accumulated Depreciation, Location of Property Plymouth, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 198,205    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,793,422    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 733,274    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 198,205    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,526,696    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,724,901    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,083,968    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1978    
Operating Properties [Member] | 2800 Campus Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2800 Campus Drive    
Real Estate and Accumulated Depreciation, Location of Property Plymouth, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 395,366    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,554,512    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 997,888    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 395,366    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,552,400    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,947,766    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,855,788    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 2905 Northwest Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2905 Northwest Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Plymouth, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 516,920    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,646,342    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,388,724    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 516,920    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,035,066    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,551,986    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,621,411    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1983    
Operating Properties [Member] | 2920 Northwest Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2920 Northwest Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Plymouth, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 392,026    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,433,678    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 459,193    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 384,235    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,900,662    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,284,897    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,499,037    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 9600 54th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9600 54th Avenue    
Real Estate and Accumulated Depreciation, Location of Property Plymouth, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 332,317    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,077,820    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,220,841    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 534,993    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,095,985    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,630,978    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,412,302    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 1400 SW 6th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1400 SW 6th Court    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,157,049    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,620,956    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 649,754    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,157,049    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,270,710    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,427,759    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,899,927    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 1405 SW 6th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1405 SW 6th Court    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 392,138    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,565,787    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 441,833    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 392,138    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,007,620    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,399,758    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 789,882    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 1500 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1500 SW 5th Court    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 972,232    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,892,085    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 398,894    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 972,232    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,290,979    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,263,211    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,603,200    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1957    
Operating Properties [Member] | 1501 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1501 SW 5th Court    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 203,247    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 811,093    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 211,077    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 203,247    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,022,170    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,225,417    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 364,687    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 1601 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1601 SW 5th Court    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 203,247    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 811,093    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 248,183    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 203,247    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,059,276    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,262,523    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 472,764    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 1651 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1651 SW 5th Court    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 203,247    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 811,093    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 179,738    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 203,247    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 990,831    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,194,078    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 323,652    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 595 SW 13th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 595 SW 13th Terrace    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 359,933    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,437,116    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 624,145    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 359,933    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,061,261    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,421,194    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 752,838    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 601 SW 13th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 601 SW 13th Terrace    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 164,413    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 655,933    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 274,236    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 164,413    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 930,169    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,094,582    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 406,175    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1984    
Operating Properties [Member] | 605 SW 16th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 605 SW 16th Terrace    
Real Estate and Accumulated Depreciation, Location of Property Pompano Beach, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 310,778    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,238,324    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 204,004    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 310,178    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,442,928    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,753,106    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 639,794    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1965    
Operating Properties [Member] | 301 Hill Carter Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 301 Hill Carter Parkway    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 659,456    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,836,010    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 159,898    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 659,456    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,995,908    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,655,364    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,236,563    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 4101-4127 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4101-4127 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 310,854    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,279,597    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,081,581    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 310,854    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,361,178    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,672,032    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,395,699    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1973    
Operating Properties [Member] | 4201-4261 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4201-4261 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 693,203    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,083,493    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,850,735    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 693,203    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,934,228    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,627,431    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,024,978    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 4263-4299 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4263-4299 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 256,203    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,549,649    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,156,012    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 256,203    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,705,661    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,961,864    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,891,282    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1976    
Operating Properties [Member] | 4263F-N. Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4263F-N. Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 91,476    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,759,512    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 91,599    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,759,389    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,850,988    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 724,101    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1975    
Operating Properties [Member] | 4301-4335 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4301-4335 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 223,696    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,640,435    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,450,318    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 223,696    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,090,753    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,314,449    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,400,436    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1978    
Operating Properties [Member] | 4337-4379 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4337-4379 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 325,303    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,385,557    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,215,253    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 325,303    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,600,810    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,926,113    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,613,794    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1979    
Operating Properties [Member] | 4401-4445 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4401-4445 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 615,038    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,510,272    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 481,677    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 615,038    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,991,949    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,606,987    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,196,072    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 4447-4491 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4447-4491 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 454,056    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,729,742    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 364,252    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 454,056    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,093,994    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,548,050    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,490,443    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 4501-4549 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4501-4549 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 486,166    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,565,211    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 551,647    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 486,166    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,116,858    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,603,024    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,750,528    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1981    
Operating Properties [Member] | 4551-4593 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4551-4593 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 474,360    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,478,646    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 937,626    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 474,360    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,416,272    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,890,632    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,888,175    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1982    
Operating Properties [Member] | 4601-4643 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4601-4643 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 652,455    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,784,675    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 743,370    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 652,455    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,528,045    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,180,500    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,615,497    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 4645-4683 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4645-4683 Carolina Avenue    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 404,616    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,967,187    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 539,865    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 404,616    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,507,052    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,911,668    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,508,021    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 4717-4729 Eubank Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4717-4729 Eubank Road    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 449,447    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,294,697    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,209,667    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 452,263    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,501,548    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,953,811    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,049,810    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1978    
Operating Properties [Member] | 510 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 510 Eastpark Court    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 261,961    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,110,874    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 350,849    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 262,210    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,461,474    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,723,684    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,106,311    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 520 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 520 Eastpark Court    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 486,118    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,083,582    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 263,481    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 486,598    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,346,583    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,833,181    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,816,264    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 530 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 530 Eastpark Court    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 266,883    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,522,231    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 334,772    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,454,342    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,789,114    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 915,202    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 540 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 540 Eastpark Court    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 742,300    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,415,233    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,066,839    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,090,694    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,157,533    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 581,418    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 5600-5626 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5600-5626 Eastport Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 489,941    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,592,900    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 256,136    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 489,941    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,849,036    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,338,977    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,696,359    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 5601-5659 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5601-5659 Eastport Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0 [1]    
Real Estate and Accumulated Depreciation, Initial Cost of Land 705,660    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,800,706    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 720,100    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,786,266    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,506,366    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,986,153    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 5650-5674 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5650-5674 Eastport Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 644,384    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,025,480    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 87,419    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 644,384    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,112,899    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,757,283    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,876,972    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 5700 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5700 Eastport Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 408,729    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,697,348    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 677,432    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 408,729    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,374,780    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,783,509    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,661,092    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 5701-5799 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5701-5799 Eastport Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 694,644    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,449,444    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 700,503    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,443,585    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,144,088    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,128,543    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 5900 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5900 Eastport Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 676,661    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,967,683    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 687,898    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,956,446    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,644,344    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,083,269    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 6000 Eastport Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6000 Eastport Blvd    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 872,901    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,486,258    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 901,666    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,457,493    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,359,159    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 893,312    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 2020 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2020 US Highway 301 South    
Real Estate and Accumulated Depreciation, Location of Property Riverview, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,233,639    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 13,355,975    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 362,409    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,233,800    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 13,718,223    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,952,023    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,424,182    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 6530 Judge Adams Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6530 Judge Adams Road    
Real Estate and Accumulated Depreciation, Location of Property Rock Creek, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 305,821    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,809,770    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 335,061    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,780,530    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,115,591    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,658,290    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 6532 Judge Adams Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6532 Judge Adams Road    
Real Estate and Accumulated Depreciation, Location of Property Rock Creek, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 354,903    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,981,740    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 399,988    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,936,655    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,336,643    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,500,814    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 13098 George Weber Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 13098 George Weber Drive    
Real Estate and Accumulated Depreciation, Location of Property Rogers, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 895,811    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,823,028    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 790,536    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 895,811    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,613,564    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,509,375    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 288,695    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 1070 Windham Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1070 Windham Parkway    
Real Estate and Accumulated Depreciation, Location of Property Romeoville, IL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,672,143    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 23,946,964    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 197,900    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 8,672,143    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 24,144,864    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 32,817,007    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 74,903    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 8501 East Raintree Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8501 East Raintree Drive    
Real Estate and Accumulated Depreciation, Location of Property Scottsdale, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,076,412    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 27,621,159    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,115,137    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 27,582,434    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 31,697,571    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,102,042    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 1150 Gateway Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1150 Gateway Drive    
Real Estate and Accumulated Depreciation, Location of Property Shakopee, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,126,865    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,619,373    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 64,805    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,126,865    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,684,178    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,811,043    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 8,971    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 5555 12th Avenue East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5555 12th Avenue East    
Real Estate and Accumulated Depreciation, Location of Property Shakopee, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 887,285    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,243,070    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 78,130    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 887,285    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,321,200    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,208,485    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 9,271    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 6900 Harbor View Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6900 Harbor View Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Suffolk, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 904,052    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,565,297    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 807,006    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,662,343    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,469,349    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,435,251    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 6920 Harborview Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6920 Harborview Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Suffolk, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 603,391    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,705,020    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,628,635    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,679,776    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,308,411    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 54,678    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 6950 Harbor View Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6950 Harbor View Blvd    
Real Estate and Accumulated Depreciation, Location of Property Suffolk, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 929,844    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,216,485    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 794,848    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,351,481    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,146,329    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,181,131    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 1301 International Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1301 International Parkway    
Real Estate and Accumulated Depreciation, Location of Property Sunrise, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,100,162    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 24,219,956    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,405,671    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,100,791    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 31,624,998    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 36,725,789    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,772,051    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 13621 NW 12th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 13621 NW 12th Street    
Real Estate and Accumulated Depreciation, Location of Property Sunrise, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,570,820    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 8,450,463    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,713,729    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,570,822    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,164,190    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 17,735,012    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,586,426    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2008    
Operating Properties [Member] | 13630 NW 8th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 13630 NW 8th Street    
Real Estate and Accumulated Depreciation, Location of Property Sunrise, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 659,797    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,596,275    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 472,408    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 659,825    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,068,655    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,728,480    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,022,112    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1991    
Operating Properties [Member] | 13650 NW 8th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 13650 NW 8th Street    
Real Estate and Accumulated Depreciation, Location of Property Sunrise, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 558,223    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,171,930    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 237,268    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 558,251    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,409,170    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,967,421    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 837,623    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1991    
Operating Properties [Member] | 111 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 111 Kelsey Lane    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 359,540    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,461,850    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,139,535    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 359,540    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,601,385    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,960,925    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 763,034    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 131 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 131 Kelsey Lane    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 511,463    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,437,886    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 559,527    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,389,822    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,949,349    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,373,295    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1985    
Operating Properties [Member] | 150-182 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 150-182 Kelsey Lane    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 403,541    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,154,342    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,181,609    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,376,274    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,557,883    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 465,586    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 200-34 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 200-34 Kelsey Lane    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 330,097    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,314,788    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 933,362    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,711,523    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,644,885    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 490,548    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 3102,3104,3110 Cherry Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3102,3104,3110 Cherry Palm Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 503,767    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,787,585    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,277,486    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 503,767    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,065,071    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,568,838    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,641,198    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 3401-3409 Cragmont Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3401-3409 Cragmont Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 556,952    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,833,132    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 16,104    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 556,952    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,849,236    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,406,188    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,403    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 3502 Roga Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3502 Roga Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 201,600    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,260,543    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,588    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 201,600    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,263,131    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,464,731    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,818    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 3505 Cragmont Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3505 Cragmont Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 936,336    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,008,738    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 146,782    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 936,336    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,155,520    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,091,856    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 11,013    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 3608 Queen Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 3608 Queen Palm Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 650,384    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,746,890    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 17,411    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 650,384    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,764,301    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,414,685    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 10,851    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 4502 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4502 Woodland Corporate Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,875,253    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,071,535    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,803,718    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,875,253    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,354,985    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 4503 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4503 Woodland Corporate Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,496,413    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 619,913    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,876,500    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,496,413    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 891,619    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 4505 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4505 Woodland Corporate Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,960,031    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 716,594    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,243,437    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,960,031    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 705,941    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 4508 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4508 Woodland Corporate Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 498,598    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,057,752    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 556,887    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,999,463    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,556,350    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,051,020    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 4511 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4511 Woodland Corporate Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,828,102    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 686,594    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,141,508    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,828,102    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 566,436    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 4520 Seedling Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4520 Seedling Circle    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 854,797    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 42,131    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,721,233    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 854,797    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,763,364    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,618,161    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 600,481    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 4630 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4630 Woodland Corporate Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 943,169    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,253,411    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,560,099    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,636,481    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,196,580    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,397,439    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 4631 Woodland Corporate Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4631 Woodland Corporate Blvd    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,453,367    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,361,348    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,908,792    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,905,923    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,814,715    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,374,385    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 501 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 501 US Highway 301 South    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 898,884    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,412,262    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 900,508    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,410,638    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,311,146    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 922,397    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 5250 Eagle Trail Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5250 Eagle Trail Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 952,860    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,464,999    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 952,860    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,464,999    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,417,859    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,234,391    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 5501-5519 Pioneer Park Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5501-5519 Pioneer Park Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 162,000    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,613,000    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,057,041    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 262,416    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,569,625    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,832,041    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,087,669    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1981    
Operating Properties [Member] | 5690-5694 Crenshaw Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5690-5694 Crenshaw Street    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 181,923    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,812,496    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 688,772    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 181,923    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,501,268    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,683,191    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 909,219    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1979    
Operating Properties [Member] | 701-725 South US Hwy 301 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 701-725 South US Hwy 301    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 419,683    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,414,251    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 661,680    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,172,254    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,833,934    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,242,889    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 7621 Bald Cypress Place (Bldg N) [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7621 Bald Cypress Place (Bldg N)    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,482,613    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 447,498    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,035,115    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,482,613    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 309,357    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 7724 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7724 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 235,893    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,150,387    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 235,894    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,150,386    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,386,280    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 872,578    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 7725 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7725 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 553,335    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,396,664    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 771,501    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,178,498    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,949,999    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,085,726    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 7802-50 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7802-50 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 357,364    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,578,427    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 506,949    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,428,842    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,935,791    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 900,943    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 7851-7861 Woodland Center Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7851-7861 Woodland Center Blvd    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 548,905    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,206,559    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 239,266    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 548,905    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,445,825    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,994,730    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 433,136    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7852-98 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7852-98 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 357,364    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,671,312    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 506,949    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,521,727    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,028,676    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 914,241    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 7920 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7920 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,082,648    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,445,444    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 77,964    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,082,648    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,523,408    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,606,056    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 971,608    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Operating Properties [Member] | 7930, 8010-20 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7930, 8010-20 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,408,478    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,247,246    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,048,782    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,408,478    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,296,028    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,704,506    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,556,714    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1990    
Operating Properties [Member] | 8001 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8001 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 350,406    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,261,233    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 438,061    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,173,578    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,611,639    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 740,548    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Operating Properties [Member] | 8110 Anderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8110 Anderson Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 912,663    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,382,724    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 42,419    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 912,663    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,425,143    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,337,806    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 9,142    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 8112-42 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8112-42 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 513,263    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,230,239    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 649,274    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 513,263    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,879,513    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,392,776    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,653,552    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Operating Properties [Member] | 8130 Anderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8130 Anderson Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 655,668    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,034,546    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 97,530    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 655,668    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,132,076    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,787,744    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,934    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 8154-8198 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8154-8198 Woodland Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 399,088    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,868,834    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 965,687    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 399,088    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,834,521    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,233,609    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,409,258    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 8401-8408 Benjamin Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8401-8408 Benjamin Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 789,651    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,454,648    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 265,544    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 611,626    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,898,217    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,509,843    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,290,150    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1986    
Operating Properties [Member] | 8705 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8705 Henderson Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,303,870    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 19,118,151    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,088,949    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,304,102    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 23,206,868    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 27,510,970    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,767,516    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 8715 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8715 Henderson Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,343,910    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 15,880,004    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,768,818    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,344,090    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 18,648,642    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 21,992,732    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,115,645    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 8725 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8725 Henderson Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,167,787    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 17,145,139    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,333,058    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,167,958    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 19,478,026    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 22,645,984    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,382,433    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 8735 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8735 Henderson Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,166,130    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 17,023,069    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,889,384    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,166,300    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 19,912,283    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 23,078,583    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,482,583    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 8745 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8745 Henderson Road    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,050,439    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 10,028,436    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,821,312    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,050,548    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,849,639    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,900,187    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,464,084    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 8900-34 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8900-34 Brittany Was    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 537,194    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,622,389    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 978,019    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,181,564    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,159,583    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 791,143    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | 8921 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8921 Brittany Way    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 224,369    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,063,882    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 990,985    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 254,493    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,024,743    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,279,236    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 803,061    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Operating Properties [Member] | 9001-9015 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9001-9015 Brittany Way    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 209,841    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,806,688    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 364,514    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,652,015    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,016,529    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 596,915    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Operating Properties [Member] | 9002-9036 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9002-9036 Brittany Way    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 492,320    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,785,603    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 899,284    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,378,639    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,277,923    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,109,154    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2004    
Operating Properties [Member] | 901-933 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 901-933 US Highway 301 South    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 500,391    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,041,964    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 840,314    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,702,041    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,542,355    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,389,301    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 9020 King Palm [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9020 King Palm Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,718,496    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 11,242,248    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 455,133    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,718,496    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,697,381    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,415,877    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 18,037    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 910-926 Chad Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 910-926 Chad Lane    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 201,771    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,214,583    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 628,237    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,788,117    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,416,354    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 834,327    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 9110 King Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9110 King Palm Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,203,200    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,796,486    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 117,090    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,203,200    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,913,576    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,116,776    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 12,703    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 9203 King Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9203 King Palm Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 754,832    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,751,621    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 215,243    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 754,832    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,966,864    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,721,696    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 10,960    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 9306-24 East Broadway Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9306-24 East Broadway Avenue    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 450,440    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,303,369    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 486,004    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,267,805    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,753,809    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 393,850    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 9319 Peach Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9319 Peach Palm Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 612,536    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 4,140,224    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 28,249    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 612,536    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,168,473    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,781,009    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 5,972    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 9704 Solar Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9704 Solar Drive    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 374,548    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,352,582    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,218    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 374,548    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 1,354,800    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,729,348    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,170    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 921 South Park Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 921 South Park Lane    
Real Estate and Accumulated Depreciation, Location of Property Tempe, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,192,820    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,580,155    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 436,229    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,192,820    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,016,384    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,209,204    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 44,908    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 8313 West Pierce Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8313 West Pierce Street    
Real Estate and Accumulated Depreciation, Location of Property Tolleson, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,295,090    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,079,811    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,224,097    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,295,090    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 12,303,908    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,598,998    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,217,424    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 8591 West Washington [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8591 West Washington Street    
Real Estate and Accumulated Depreciation, Location of Property Tolleson, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,574,912    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 7,286,002    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 169,238    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,574,912    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,455,240    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,030,152    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 140,930    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 8601 West Washington [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8601 West Washington Street    
Real Estate and Accumulated Depreciation, Location of Property Tolleson, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,524,603    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,256,412    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 223,080    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,524,603    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,479,492    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,004,095    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 157,237    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Operating Properties [Member] | 1457 Miller Store Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1457 Miller Store Road    
Real Estate and Accumulated Depreciation, Location of Property Virginia Beach, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 473,689    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,663,045    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 547,565    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 474,746    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 3,209,553    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,684,299    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 940,145    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2003    
Operating Properties [Member] | 200 Golden Oak Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 200 Golden Oak Court    
Real Estate and Accumulated Depreciation, Location of Property Virginia Beach, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,116,693    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,770,480    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,923,767    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,116,693    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,694,247    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,810,940    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,256,992    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 208 Golden Oak Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 208 Golden Oak Court    
Real Estate and Accumulated Depreciation, Location of Property Virginia Beach, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 965,177    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,728,717    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,634,302    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 965,177    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,363,019    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,328,196    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,293,054    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 2809 South Lynnhaven Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2809 South Lynnhaven Road    
Real Estate and Accumulated Depreciation, Location of Property Virginia Beach, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 953,590    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,142,742    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,697,528    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 953,590    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,840,270    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,793,860    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,985,403    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 484 Viking Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 484 Viking Drive    
Real Estate and Accumulated Depreciation, Location of Property Virginia Beach, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 891,753    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 3,607,890    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 492,286    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 891,753    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,100,176    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,991,929    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,519,469    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1987    
Operating Properties [Member] | 5700 Cleveland Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5700 Cleveland Street    
Real Estate and Accumulated Depreciation, Location of Property Virginia Beach, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 700,112    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 9,592,721    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,654,071    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 700,564    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 11,246,340    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,946,904    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,210,792    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1989    
Operating Properties [Member] | 629 Phoenix Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 629 Phoenix Drive    
Real Estate and Accumulated Depreciation, Location of Property Virginia Beach, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 371,694    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,108,097    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 308,935    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 371,694    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,417,032    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,788,726    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 947,504    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Operating Properties [Member] | 1100 17th Street NW [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1100 17th Street NW    
Real Estate and Accumulated Depreciation, Location of Property Washington, DC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 16,558,660    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 29,178,028    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,295,997    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 16,558,660    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 32,474,025    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 49,032,685    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,586,616    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 1200 Liberty Ridge Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1200 Liberty Ridge Drive    
Real Estate and Accumulated Depreciation, Location of Property Wayne, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,215,667    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,990,562    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,223,660    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 9,982,569    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 15,206,229    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 3,501,928    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Operating Properties [Member] | 1500 Liberty Ridge [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1500 Liberty Ridge    
Real Estate and Accumulated Depreciation, Location of Property Wayne, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,287,555    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 32,790,711    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 11,636,499    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 29,441,767    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 41,078,266    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 9,230,604    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | 825 Duportail Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 825 Duportail Road    
Real Estate and Accumulated Depreciation, Location of Property Wayne, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,536,619    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 16,179,213    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,166,290    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,539,281    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 21,342,841    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 26,882,122    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 6,775,075    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1979    
Operating Properties [Member] | 400-500 Brandywine Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 400-500 Brandywine Parkway    
Real Estate and Accumulated Depreciation, Location of Property West Chester, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 845,846    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 6,809,025    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 656,823    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 845,846    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,465,848    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,311,694    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,813,438    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 600 Brandywine Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 600 Brandywine Parkway    
Real Estate and Accumulated Depreciation, Location of Property West Chester, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 664,899    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,352,410    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 868,895    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 664,899    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,221,305    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,886,204    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,407,599    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1988    
Operating Properties [Member] | 1 Kings Hill Aveune [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1 Kings Hill Aveune    
Real Estate and Accumulated Depreciation, Location of Property West Malling, UK    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 14,593,735    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,065,426    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,528,309    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,593,735    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,723,344    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 42 Kings Hill Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 42 Kings Hill Avenue    
Real Estate and Accumulated Depreciation, Location of Property West Malling, UK    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 18,577,867    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,413,541    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 14,164,326    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 18,577,867    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 2,062,915    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Operating Properties [Member] | Liberty Square Retail Blocks [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Liberty Square Retail Blocks    
Real Estate and Accumulated Depreciation, Location of Property West Malling, UK    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 559,590    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 5,113,902    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,880,498    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,169,118    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,384,872    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,553,990    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,621,527    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Operating Properties [Member] | 7805 Hudson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7805 Hudson Road    
Real Estate and Accumulated Depreciation, Location of Property Woodbury, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,279,834    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,795,909    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,385,739    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,690,004    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,075,743    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 4,410,781    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2002    
Operating Properties [Member] | Total Operating Properties [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Amount of Encumbrances 263,001,459    
Real Estate and Accumulated Depreciation, Initial Cost of Land 820,066,151    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 1,877,919,655    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,555,948,151    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 900,500,763    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 4,353,433,194    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,253,933,957    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,170,030,224    
Operating Properties [Member] | 4047 Perimeter West Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4047 Perimeter West Drive    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,279,004    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,294,688    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,279,003    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,294,689    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,573,692    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 97,252    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 5500 N. Sam Houston Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5500 N. Sam Houston Parkway West    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,243,541    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,406,104    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,513,151    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,136,494    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,649,645    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 22,634    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 4000 S 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4000 S 26th Street    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 51,784    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,275,708    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 616,466    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,711,026    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,327,492    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 32,562    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 4050 S 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4050 S 26th Street    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 46,301    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,196,379    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 616,669    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 5,626,011    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,242,680    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 52,712    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Operating Properties [Member] | 4450 South 44th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 4550 South 44th Street    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,380,972    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 9,257,593    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,391,283    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 8,247,282    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,638,565    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 1,378,654    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Operating Properties [Member] | 9801 South 51st Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 9801 South 51st Street    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,225,839    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 2,059,235    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 898,897    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,225,839    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,958,132    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,183,971    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 87,218    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Development in Progress [Member] | 2785 Commerce Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2785 Commerce Center Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Bethlehem, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 11,961,623    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 38,368,918    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 50,330,541    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 50,330,541    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Development in Progress [Member] | 40 Logistics Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 40 Logistics Drive    
Real Estate and Accumulated Depreciation, Location of Property Carlisle, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 7,981,850    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 27,075,579    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 35,057,429    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 35,057,429    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Development in Progress [Member] | 14300 Hollister Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 14300 Hollister Road    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,377,193    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,044,729    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 6,421,922    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,421,922    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Development in Progress [Member] | 14400 Hollister Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 14400 Hollister Road    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,830,419    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,132,582    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,963,001    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,963,001    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Development in Progress [Member] | 16330 Central Green Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 16330 Central Green Boulevard    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,540,109    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 6,241,864    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 7,781,973    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,781,973    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Development in Progress [Member] | Liberty 11 at Central Green [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Liberty 11 at Central Green    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,748,348    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,184,763    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 2,933,111    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,933,111    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Development in Progress [Member] | 5 Crescent Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 5 Crescent Drive    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,765,341    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 70,489,646    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 72,254,987    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 72,254,987    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Development in Progress [Member] | 8th & Walnut Streets [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 8th & Walnut Streets    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 34,598,552    
Real Estate and Accumulated Depreciation, Initial Cost of Land 734,275    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 37,951,177    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 38,685,452    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 38,685,452    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Development in Progress [Member] | Cotton Center Building 18 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Cotton Center Building 18    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 11,222,938    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,947,287    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 17,170,225    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 17,170,225    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Development in Progress [Member] | 13320 Wilfred Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 13320 Wilfred Lane    
Real Estate and Accumulated Depreciation, Location of Property Rogers, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 508,532    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 9,494,475    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 10,003,007    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 10,003,007    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Development in Progress [Member] | Total Development in Progress [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Amount of Encumbrances 34,598,552    
Real Estate and Accumulated Depreciation, Initial Cost of Land 40,670,628    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 207,931,020    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 248,601,648    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 248,601,648    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Land Held for Development [Member] | Old Scotland Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Old Scotland Road Land    
Real Estate and Accumulated Depreciation, Location of Property Shippensburg, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,322,686    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,842,562    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 13,165,248    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,165,248    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Suffolk Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Suffolk Land    
Real Estate and Accumulated Depreciation, Location of Property Suffolk, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,715,714    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 757,581    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,473,295    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,473,295    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | Perryman Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Perryman Road Land    
Real Estate and Accumulated Depreciation, Location of Property Aberdeen, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 12,052,635    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 281,269    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 12,333,904    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 12,333,904    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Land Held for Development [Member] | 2 Womack Drive Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 2 Womack Drive Land    
Real Estate and Accumulated Depreciation, Location of Property Annapolis, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,796,667    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,677    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,810,344    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,810,344    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | LVIP Area VII-Lots 3, 4, 5 Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property LVIP Area VII-Lots 3, 4, 5 Land    
Real Estate and Accumulated Depreciation, Location of Property Bethlehem, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,058,664    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 216,958    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,275,622    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,275,622    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Land Held for Development [Member] | Mill Creek Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Mill Creek Road Land    
Real Estate and Accumulated Depreciation, Location of Property Bethlehem, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 18,548,585    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 874,034    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 19,422,619    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 19,422,619    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Land Held for Development [Member] | Boca Colannade Yamato Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Boca Colannade Yamato Road    
Real Estate and Accumulated Depreciation, Location of Property Boca Raton, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,039,735    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 566,124    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,605,859    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,605,859    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Land Held for Development [Member] | 12912 Virkler Drive Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 12912 Virkler Drive Land    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 208,646    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 10,291    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 218,937    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 218,937    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2010    
Land Held for Development [Member] | Charlotte Distribution Center Land-Lot 1 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Charlotte Distribution Center Land-Lot 1    
Real Estate and Accumulated Depreciation, Location of Property Charlotte, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 654,713    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 654,713    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 654,713    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Land Held for Development [Member] | Amberpoint Business Park Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Amberpoint Business Park Land    
Real Estate and Accumulated Depreciation, Location of Property Dallas, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,040,233    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,040,233    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,040,233    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Land Held for Development [Member] | Flying Cloud Drive Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Flying Cloud Drive Land    
Real Estate and Accumulated Depreciation, Location of Property Eden Pairie, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,051,631    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 24,559    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,076,190    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,076,190    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Camelback 303 Business Center Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Camelback 303 Business Center Land    
Real Estate and Accumulated Depreciation, Location of Property Goodyear, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 16,857,556    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,228,531    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 20,086,087    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 20,086,087    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Pleasant Ridge Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Pleasant Ridge Road Land    
Real Estate and Accumulated Depreciation, Location of Property Greensboro, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 564,535    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,893,669    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,458,204    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,458,204    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | Caliber Ridge Ind. Park Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Caliber Ridge Ind. Park Land    
Real Estate and Accumulated Depreciation, Location of Property Greer, SC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,297,492    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,631,680    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,929,172    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,929,172    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Hunters Green Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Hunters Green Land    
Real Estate and Accumulated Depreciation, Location of Property Hagerstown, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,489,586    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 8,364,015    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 13,853,601    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 13,853,601    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | Lakefront Plaza II Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Lakefront Plaza II Land    
Real Estate and Accumulated Depreciation, Location of Property Hampton, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 138,101    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 101,157    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 239,258    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 239,258    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Land Held for Development [Member] | Hanover Crossing [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Hanover Crossing    
Real Estate and Accumulated Depreciation, Location of Property Hanover, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 7,835,761    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 14,638    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 7,850,399    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,850,399    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Land Held for Development [Member] | Ridge Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Ridge Road Land    
Real Estate and Accumulated Depreciation, Location of Property Hanover, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,371,183    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 452,208    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,823,391    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,823,391    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2008    
Land Held for Development [Member] | Piedmond Centre Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Piedmond Centre Land    
Real Estate and Accumulated Depreciation, Location of Property High Point, NC    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 913,276    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 914,318    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,827,594    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,827,594    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | Commonwealth Corporate Center Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Commonwealth Corporate Center Land    
Real Estate and Accumulated Depreciation, Location of Property Horsham, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,043,938    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 25,160    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,069,098    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,069,098    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Land Held for Development [Member] | Greens Crossing Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Greens Crossing Land    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,476,892    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 49,846    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,526,738    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,526,738    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Interwood Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Interwood Land    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,160,668    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 5,211    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,165,879    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,165,879    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Land Held for Development [Member] | Rankin Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Rankin Road Land    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 5,756,865    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 229,574    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 5,986,439    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 5,986,439    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Taub Beltway 8 Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Taub Beltway 8 Land    
Real Estate and Accumulated Depreciation, Location of Property Houston, TX    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 14,165,813    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 14,165,813    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 14,165,813    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Land Held for Development [Member] | Noxell Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Noxell Land    
Real Estate and Accumulated Depreciation, Location of Property Hunt Valley, MD    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 3,278,574    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 13,806    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,292,380    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,292,380    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Land Held for Development [Member] | 7024 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 7024 AC Skinner Parkway    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 751,448    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 73,504    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 824,952    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 824,952    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Land Held for Development [Member] | Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Belfort Road    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 492,908    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 87,649    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 580,557    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 580,557    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1998    
Land Held for Development [Member] | Imeson Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Imeson Road Land    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,153,948    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,110,854    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,264,802    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,264,802    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2008    
Land Held for Development [Member] | Liberty Business Park Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Liberty Business Park Land    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 456,269    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 83,801    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 540,070    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 540,070    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Land Held for Development [Member] | Salisbury Road Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Salisbury Road Land    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 173,628    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 270,118    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 443,746    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 443,746    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Land Held for Development [Member] | Skinner Land Parcel B [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Skinner Land Parcel B    
Real Estate and Accumulated Depreciation, Location of Property Jacksonville, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,295,790    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,231,852    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 3,527,642    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 3,527,642    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Land Held for Development [Member] | Kent County, UK [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Kent County, UK    
Real Estate and Accumulated Depreciation, Location of Property Kent County, UK    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 0    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 7,568,786    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 7,568,786    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 7,568,786    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1999    
Land Held for Development [Member] | Commodore Business Park [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Commodore Business Park    
Real Estate and Accumulated Depreciation, Location of Property Logan, NJ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 792,118    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,194,790    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,986,908    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,986,908    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1995    
Land Held for Development [Member] | 380 Old Morehall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 380 Old Morehall Road    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,340,075    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,340,075    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,340,075    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2012    
Land Held for Development [Member] | Quarry Ridge Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Quarry Ridge Land    
Real Estate and Accumulated Depreciation, Location of Property Malvern, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 4,774,994    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 4,963,394    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 9,738,388    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 9,738,388    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2001    
Land Held for Development [Member] | Miami International Tradeport Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Miami International Tradeport Land    
Real Estate and Accumulated Depreciation, Location of Property Medley, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 19,351,823    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,690,053    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 21,041,876    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 21,041,876    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Land Held for Development [Member] | Monarch Towne Center Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Monarch Towne Center Land    
Real Estate and Accumulated Depreciation, Location of Property Mirarar, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,085,337    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 413,927    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 6,499,264    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 6,499,264    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | South 27th Street Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property South 27th Street Land    
Real Estate and Accumulated Depreciation, Location of Property Oak Creek, WI    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 2,169,232    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,421,050    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 4,590,282    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 4,590,282    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | Beachline Industrial Park Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Beachline Industrial Park Land    
Real Estate and Accumulated Depreciation, Location of Property Orlando, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 365,230    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 365,230    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 365,230    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | 26th Street North Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 26th Street North Land    
Real Estate and Accumulated Depreciation, Location of Property Philadelphia, PA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 90,774    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,051,585    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,142,359    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,142,359    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2009    
Land Held for Development [Member] | Cotton Center Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Cotton Center Land    
Real Estate and Accumulated Depreciation, Location of Property Phoenix, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 8,238,461    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 8,238,461    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,238,461    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Eastport IX [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Eastport IX    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 211,627    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,325    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 214,952    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 214,952    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Land Held for Development [Member] | 6119 W. Linebaugh Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 6119 W. Linebaugh Avenue    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 180,136    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 30,499    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 210,635    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 210,635    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2000    
Land Held for Development [Member] | Legacy Park Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Legacy Park Land    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 10,358,826    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 1,324,447    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 11,683,273    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 11,683,273    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2006    
Land Held for Development [Member] | Renaissance Park Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Renaissance Park Land    
Real Estate and Accumulated Depreciation, Location of Property Tampa, FL    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 1,995,375    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 219,098    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 2,214,473    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 2,214,473    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2007    
Land Held for Development [Member] | Total Land Held for Development [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 203,584,038    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 54,740,168    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 258,324,206    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 258,324,206    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Land Held for Development [Member] | Eastport VIII [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Eastport VIII    
Real Estate and Accumulated Depreciation, Location of Property Richmond, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 382,698    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 3,325    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 386,023    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 386,023    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1997    
Land Held for Development [Member] | 1315 Brockton Lane North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property 1315 Brockton Lane North    
Real Estate and Accumulated Depreciation, Location of Property Rogers, MN    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 758,414    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 260,929    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 1,019,343    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 1,019,343    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2011    
Land Held for Development [Member] | Woodlands Center Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Woodlands Center Land    
Real Estate and Accumulated Depreciation, Location of Property Sandston, VA    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 148,314    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 21,717    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 170,031    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 170,031    
Real Estate and Accumulated Depreciation, Accumulated Depreciation 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 1996    
Land Held for Development [Member] | Northsight Land [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Description of Property Northsight Land (LPLP)    
Real Estate and Accumulated Depreciation, Location of Property Scottsdale, AZ    
Real Estate and Accumulated Depreciation, Amount of Encumbrances 0    
Real Estate and Accumulated Depreciation, Initial Cost of Land 6,176,464    
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements 2,204,597    
Real Estate and Accumulated Depreciation, Carrying Amount of Land 8,381,061    
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements 0    
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements 8,381,061    
Real Estate and Accumulated Depreciation, Accumulated Depreciation $ 0    
Real Estate and Accumulated Depreciation, Date Acquired or Developed 2005    
Maximum [Member] | Operating Properties [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6680 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8212 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2955 Xenium Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 701 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 300 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 120 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 116 Pleasant Ridge Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1501 Perryman Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 400 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7248 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7339 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7437 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 700 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 794 Roble Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8014 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 705 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 651 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8150 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8250 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 650 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7165 Ambassador Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 200 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 250 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8400 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6560 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6370 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6390 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6350 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6330 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6580 Snowdrift Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6540 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6520 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7620 Cetronia Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 180,190 Cochrane Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4606 Richlynn Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 74 West Broad Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6601-6625 W. 78th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6161 Green Valley Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10801 Nesbitt Avenue South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5775 West Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5715 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5735 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5705 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 951 Broken Sound Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1455 Remington Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 777 Yamato Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 750 Park of Commerce Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 400 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8201 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8500 Industrial Bouldvard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 860 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 602 Heron Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1485 W Commerce Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 95 Kriner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9000 109th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 12810 Virkler Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2700 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2701 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2730 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2801 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3000 Crosspoint Center Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3005 Crosspoint Center Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4045 Perimeter West Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4525 Statesville Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4835 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4925 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5033 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8910 Pioneer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8916 Pioneer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1309 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1305 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1313 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 500 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 700 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 501 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 505 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 510 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1301 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 676 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6230 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9755 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9770 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9780 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9790 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9810 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9800 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9820 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9830 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6250 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6200 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6210 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6240 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6220 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1250 Hall Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 170 Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 190 Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 265 Parkway East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 285 Parkway East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3169 Dodd Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3255 Neil Armstrong Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3711 Kennebec Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10301-10305 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10321 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10333 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10349-10357 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10365-10375 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10393-10394 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10400 Viking Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6321-6325 Bury Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7075 Flying Cloud Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7078 Shady Oak Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7400 Flying Cloud Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7615 Smetana Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7625 Smetana Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7660-7716 Golden Triangle Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7695-7699 Anagram Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7777 Golden Triangle Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7800 Equitable Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7905 Fuller Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8855 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8911 Columbine Road (B2) [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8937 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8967 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8995 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9023 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7351 Coca Cola Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 21705-21707 Mississippi Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 27143 S Baseline Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 180 Sheree Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1100 Virginia Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1250 Virginia Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 275 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 414 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 420 Delaware Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9601 Cosner Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 200 W Cypress Creek Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5410 - 5430 Northwest 33rd Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 45 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1487 South Highway 101 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 11841 Newgate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1317 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 21 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 22 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5 Manhattan Square [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 521 Butler Farm Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7361 Coca Cola Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 500 McCarthy Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 600 Industrial Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1498 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4183 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4189 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4195 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4300 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4328, 4336 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4344 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4380 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4388 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4475 Premier Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4500 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4501 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4523 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4524 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 100 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 100 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 100-107 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 101 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 101-111 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 102 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 103-109 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 104 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 110 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 111-159 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 113-123 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 123-135 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 132 Welsh Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 161-175 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 181-187 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 200 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 200-264 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 201 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 210-223 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 220 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 231-237 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 240 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 255 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 261-283 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 300 Welsh Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 300 Welsh Road - Building 3 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 300 Welsh Road - Building 4 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 300-309 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 335 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 355 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4 Walnut Grove [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 400-445 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 455 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 506 Prudential Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 555 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 680 Blair Mill Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 700 Dresher Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 507 Prudential Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 747 Dresher Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 767 Electronic Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10301 Round Up Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10305 Round Up Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10735 West Little York Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10739 West Little York Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 11201 Greens Crossing Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 14200 Hollister Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16405 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16445 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1646 Rankin Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16580 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16602 Central Green Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16605 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16680 Central Green Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16685 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1755 Trans Central Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5200 N. Sam Houston Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5250 N. Sam Houston Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8103 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 850 Greens Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 860 Greens Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8801-19 & 8821-49 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8802-8824 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8825-8839 N Sam Houston Pkwy [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8850-8872 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 20 Wright Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 307 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 309 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 311 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10245 Centurion Parkway North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4190 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4345 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4801 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4801 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4810 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4815 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4815 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4820 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4825 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4875 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4887 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4899 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4901 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4905 Belfort Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5201 Gate Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6601 Executive Park Circle North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6602 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6602 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6631 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6631 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6700 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7014 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7016 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7018 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7020 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7022 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7077 Bonneval Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7251 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7255 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7259 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8665,8667,8669 Baypine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8775 Baypine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 151 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 180 South Warner Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2100 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2201 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2300 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2301 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2500 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2520 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2560 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2700 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2900 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3200 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3400 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3600 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3602 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3604 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 440 East Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 460 East Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 650 Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 680 Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 170 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 190 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3000 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3100 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3500 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1700 Interstate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 11425 State Highway 225 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 11503 State Highway 225 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7528 Walker Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8301 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8500 Willard Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7533 Insurtial Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1901 Summit Tower Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 100 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1001 Cedar Hollow Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 11 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 11,15 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 18 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2 West Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 200 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 27-43 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 375 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 40 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 425 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 45 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 45-67 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 50 Morehall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 600 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 700 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10, 20 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 12,14,16 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 14 Lee Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 155 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 257-275 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 277-293 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 30 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 300-400 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 311 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 333 Phoenixville Pike [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 40 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 420 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 50 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 500 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 508 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 510 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 55 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 60 Morehall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 65 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 75 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 77-123 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7550 Meridian Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 301 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 303 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 400 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 406 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 65 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 75 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4600 Nathan Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4700 Nathan Lane North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 12501 & 12701 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 12800 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 12900 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5400-5500 Feltl Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5600 & 5610 Rowland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6000 Clearwater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 456 International Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3100 SW 145th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3350 SW 148th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3400 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3450 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 323 Park Knoll Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 324 Park Knoll Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 619 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 627 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 330 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 300 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3001 Leadenhall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 302 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 350 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1000 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1001 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1015 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1020 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1025 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 11000, 15000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 12000, 14000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 16000, 18000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 17000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5000 Dearborn Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 550-590 Hale Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1879 Lamont Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 350 Winmeyer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1000 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10003 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10511 & 10611 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 10771 Palm Bay Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1090 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1400-1440 Central Florida Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1902 Cypress Lake Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1950 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1958 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 201 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2202 Taft-Vineland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2256 Taft-Vineland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2351 Investors Row [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2400 South Lake Orange Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2412 Sand Lake Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2416 Lake Orange Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6200 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6501 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6918 Presidents Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6923 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7022 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7100 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7101 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7315 Kingspointe Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8201 Chancellor Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 851 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 950 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9550 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9600 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9700 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | South Center Land-Phase II [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1 Crescent Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 150 Rouse Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3 Crescent Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3 Franklin Plaza [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4300 South 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4751 League Island Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4775 League Island Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8801 Tinicum Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2626 South 7th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4207 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4217 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4303 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4313 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4405 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4410 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4415 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4425 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4435 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4610 South 44th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4750 S. 44th Place [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9801 80th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2250 Hickory Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 14630-14650 28th Avenue North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2800 Campus Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2905 Northwest Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2920 Northwest Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9600 54th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1400 SW 6th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1405 SW 6th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1500 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1501 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1601 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1651 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 595 SW 13th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 601 SW 13th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 605 SW 16th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 301 Hill Carter Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4101-4127 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4201-4261 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4263-4299 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4263F-N. Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4301-4335 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4337-4379 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4401-4445 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4447-4491 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4501-4549 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4551-4593 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4601-4643 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4645-4683 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4717-4729 Eubank Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 510 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 520 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 530 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 540 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5600-5626 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5601-5659 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5650-5674 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5700 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5701-5799 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5900 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6000 Eastport Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2020 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6530 Judge Adams Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6532 Judge Adams Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 13098 George Weber Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1070 Windham Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8501 East Raintree Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1150 Gateway Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5555 12th Avenue East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6900 Harbor View Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6920 Harborview Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 6950 Harbor View Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1301 International Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 13621 NW 12th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 13630 NW 8th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 13650 NW 8th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 111 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 131 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 150-182 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 200-34 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3102,3104,3110 Cherry Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3401-3409 Cragmont Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3502 Roga Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3505 Cragmont Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 3608 Queen Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4502 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4503 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4505 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4508 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4511 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4520 Seedling Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4630 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4631 Woodland Corporate Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 501 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5250 Eagle Trail Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5501-5519 Pioneer Park Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5690-5694 Crenshaw Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 701-725 South US Hwy 301 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7621 Bald Cypress Place (Bldg N) [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7724 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7725 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7802-50 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7851-7861 Woodland Center Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7852-98 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7920 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7930, 8010-20 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8001 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8110 Anderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8112-42 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8130 Anderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8154-8198 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8401-8408 Benjamin Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8705 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8715 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8725 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8735 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8745 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8900-34 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8921 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9001-9015 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9002-9036 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 901-933 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9020 King Palm [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 910-926 Chad Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9110 King Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9203 King Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9306-24 East Broadway Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9319 Peach Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9704 Solar Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 921 South Park Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8313 West Pierce Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8591 West Washington [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 8601 West Washington [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1457 Miller Store Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 200 Golden Oak Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 208 Golden Oak Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 2809 South Lynnhaven Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 484 Viking Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5700 Cleveland Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 629 Phoenix Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1100 17th Street NW [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1200 Liberty Ridge Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1500 Liberty Ridge [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 825 Duportail Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 400-500 Brandywine Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 600 Brandywine Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 1 Kings Hill Aveune [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 42 Kings Hill Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | Liberty Square Retail Blocks [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 7805 Hudson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4047 Perimeter West Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 5500 N. Sam Houston Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4000 S 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4050 S 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 4450 South 44th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Maximum [Member] | Operating Properties [Member] | 9801 South 51st Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 40 years    
Minimum [Member] | Operating Properties [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6680 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8212 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2955 Xenium Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 701 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 300 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 120 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 116 Pleasant Ridge Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1501 Perryman Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 400 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7248 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7339 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7437 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 700 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 794 Roble Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8014 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 705 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 651 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8150 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8250 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 650 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7165 Ambassador Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 200 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 250 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8400 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6560 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6370 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6390 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6350 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6330 Hedgewood Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6580 Snowdrift Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6540 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6520 Stonegate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7620 Cetronia Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 180,190 Cochrane Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4606 Richlynn Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 74 West Broad Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6601-6625 W. 78th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6161 Green Valley Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10801 Nesbitt Avenue South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5775 West Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5715 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5735 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5705 Old Shakopee Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 951 Broken Sound Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1455 Remington Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 777 Yamato Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 750 Park of Commerce Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 400 Boulder Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8201 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8500 Industrial Bouldvard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 860 Nestle Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 602 Heron Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1485 W Commerce Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 95 Kriner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9000 109th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 12810 Virkler Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2700 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2701 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2730 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2801 Hutchinson McDonald Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3000 Crosspoint Center Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3005 Crosspoint Center Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4045 Perimeter West Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4525 Statesville Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4835 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4925 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5033 Sirona Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8910 Pioneer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8916 Pioneer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1309 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1305 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1313 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 500 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 700 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 501 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 505 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 510 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1301 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 676 Independence Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6230 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9755 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9770 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9780 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9790 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9810 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9800 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9820 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9830 Patuxent Woods Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6250 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6200 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6210 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6240 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6220 Old Dobbin Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1250 Hall Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 170 Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 190 Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 265 Parkway East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 285 Parkway East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3169 Dodd Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3255 Neil Armstrong Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3711 Kennebec Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10301-10305 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10321 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10333 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10349-10357 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10365-10375 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10393-10394 West 70th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10400 Viking Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6321-6325 Bury Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7075 Flying Cloud Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7078 Shady Oak Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7400 Flying Cloud Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7615 Smetana Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7625 Smetana Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7660-7716 Golden Triangle Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7695-7699 Anagram Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7777 Golden Triangle Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7800 Equitable Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7905 Fuller Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8855 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8911 Columbine Road (B2) [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8937 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8967 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8995 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9023 Columbine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7351 Coca Cola Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 21705-21707 Mississippi Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 27143 S Baseline Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 180 Sheree Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1100 Virginia Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1250 Virginia Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 275 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 414 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 420 Delaware Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9601 Cosner Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 200 W Cypress Creek Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5410 - 5430 Northwest 33rd Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 45 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1487 South Highway 101 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 11841 Newgate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1317 Executive Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 21 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 22 Enterprise Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5 Manhattan Square [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 521 Butler Farm Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7361 Coca Cola Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 500 McCarthy Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 600 Industrial Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1498 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4183 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4189 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4195 Eagle Hill Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4300 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4328, 4336 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4344 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4380 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4388 Federal Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4475 Premier Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4500 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4501 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4523 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4524 Green Point Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 100 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 100 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 100-107 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 101 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 101-111 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 102 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 103-109 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 104 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 110 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 111-159 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 113-123 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 123-135 Rock Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 132 Welsh Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 161-175 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 181-187 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 200 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 200-264 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 201 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 210-223 Witmer Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 220 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 231-237 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 240 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 255 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 261-283 Gibraltar Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 300 Welsh Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 300 Welsh Road - Building 3 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 300 Welsh Road - Building 4 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 300-309 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 335 Commerce Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 355 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4 Walnut Grove [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 400-445 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 455 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 506 Prudential Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 555 Business Center Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 680 Blair Mill Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7 Walnut Grove Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 700 Dresher Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 507 Prudential Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 747 Dresher Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 767 Electronic Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10301 Round Up Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10305 Round Up Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10735 West Little York Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10739 West Little York Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 11201 Greens Crossing Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 14200 Hollister Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16405 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16445 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1646 Rankin Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16580 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16602 Central Green Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16605 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16680 Central Green Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16685 Air Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1755 Trans Central Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5200 N. Sam Houston Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5250 N. Sam Houston Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8103 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 850 Greens Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 860 Greens Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8801-19 & 8821-49 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8802-8824 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8825-8839 N Sam Houston Pkwy [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8850-8872 Fallbrook Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 20 Wright Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 307 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 309 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 311 International Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6 North Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10245 Centurion Parkway North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4190 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4345 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4801 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4801 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4810 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4815 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4815 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4820 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4825 Executive Park Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4875 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4887 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4899 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4901 Belfort Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4905 Belfort Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5201 Gate Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6601 Executive Park Circle North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6602 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6602 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6631 Executive Park Court - 100 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6631 Executive Park Court - 200 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6700 Southpoint Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7014 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7016 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7018 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7020 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7022 AC Skinner Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7077 Bonneval Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7251 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7255 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7259 Salisbury Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8665,8667,8669 Baypine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8775 Baypine Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 151 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 180 South Warner Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2100 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2201 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2300 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2301 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2500 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2520 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2560 Renaissance Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2700 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2900 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3200 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3400 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3600 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3602 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3604 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 440 East Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 460 East Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 650 Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 680 Swedesford Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 170 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 190 South Warner Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3000 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3100 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3500 Horizon Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1700 Interstate Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 11425 State Highway 225 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 11503 State Highway 225 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7528 Walker Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8301 Industrial Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8500 Willard Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7533 Insurtial Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1901 Summit Tower Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 100 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1001 Cedar Hollow Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 11 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 11,15 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 18 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2 West Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 200 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 27-43 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 375 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 40 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 425 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 45 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 45-67 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 50 Morehall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 600 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 700 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10, 20 Liberty Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 12,14,16 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 14 Lee Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 155 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 257-275 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 277-293 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 30 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 300-400 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 311 Technology Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 333 Phoenixville Pike [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 40 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 420 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5 Country View Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 50 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 500 Chesterfield Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 508 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 510 Lapp Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 55 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 60 Morehall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 65 Valley Stream Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 75 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 77-123 Great Valley Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7550 Meridian Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 301 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 303 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 400 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 406 Lippincott Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 65 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 75 Brookfield Oaks Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4600 Nathan Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4700 Nathan Lane North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 12501 & 12701 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 12800 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 12900 Whitewater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5400-5500 Feltl Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5600 & 5610 Rowland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6000 Clearwater Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 456 International Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3100 SW 145th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3350 SW 148th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3400 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3450 Lakeside Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 323 Park Knoll Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 324 Park Knoll Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 619 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 627 Distribution Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 330 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 300 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3001 Leadenhall Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 302 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 350 Fellowship Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1000 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1001 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1015 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1020 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1025 Briggs Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 11000, 15000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 12000, 14000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 16000, 18000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 17000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5000 Dearborn Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9000 Commerce Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 550-590 Hale Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1879 Lamont Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 350 Winmeyer Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1000 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10003 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10511 & 10611 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 10771 Palm Bay Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1090 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1400-1440 Central Florida Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1902 Cypress Lake Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1950 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1958 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 201 Summit Park Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2202 Taft-Vineland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2256 Taft-Vineland Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2351 Investors Row [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2400 South Lake Orange Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2412 Sand Lake Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2416 Lake Orange Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6200 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6501 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6918 Presidents Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6923 Lee Vista Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7022 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7100 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7101 TPC Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7315 Kingspointe Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8201 Chancellor Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 851 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 950 Gills Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9550 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9600 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9700 Satellite Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | South Center Land-Phase II [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1 Crescent Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 150 Rouse Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3 Crescent Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3 Franklin Plaza [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4300 South 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4751 League Island Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4775 League Island Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8801 Tinicum Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2626 South 7th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4207 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4217 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4303 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4313 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4405 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4410 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4415 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4425 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4435 E. Cotton Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4610 South 44th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4750 S. 44th Place [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9801 80th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2250 Hickory Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 14630-14650 28th Avenue North [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2800 Campus Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2905 Northwest Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2920 Northwest Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9600 54th Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1400 SW 6th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1405 SW 6th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1500 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1501 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1601 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1651 SW 5th Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 595 SW 13th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 601 SW 13th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 605 SW 16th Terrace [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 301 Hill Carter Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4101-4127 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4201-4261 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4263-4299 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4263F-N. Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4301-4335 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4337-4379 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4401-4445 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4447-4491 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4501-4549 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4551-4593 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4601-4643 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4645-4683 Carolina Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4717-4729 Eubank Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 510 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 520 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 530 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 540 Eastpark Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5600-5626 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5601-5659 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5650-5674 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5700 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5701-5799 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5900 Eastport Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6000 Eastport Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2020 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6530 Judge Adams Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6532 Judge Adams Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 13098 George Weber Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1070 Windham Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8501 East Raintree Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1150 Gateway Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5555 12th Avenue East [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6900 Harbor View Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6920 Harborview Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 6950 Harbor View Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1301 International Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 13621 NW 12th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 13630 NW 8th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 13650 NW 8th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 111 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 131 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 150-182 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 200-34 Kelsey Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3102,3104,3110 Cherry Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3401-3409 Cragmont Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3502 Roga Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3505 Cragmont Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 3608 Queen Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4502 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4503 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4505 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4508 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4511 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4520 Seedling Circle [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4630 Woodland Corporate Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4631 Woodland Corporate Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 501 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5250 Eagle Trail Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5501-5519 Pioneer Park Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5690-5694 Crenshaw Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 701-725 South US Hwy 301 [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7621 Bald Cypress Place (Bldg N) [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7724 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7725 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7802-50 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7851-7861 Woodland Center Blvd [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7852-98 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7920 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7930, 8010-20 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8001 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8110 Anderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8112-42 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8130 Anderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8154-8198 Woodland Center Boulevard [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8401-8408 Benjamin Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8705 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8715 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8725 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8735 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8745 Henderson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8900-34 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8921 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9001-9015 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9002-9036 Brittany Way [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 901-933 US Highway 301 South [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9020 King Palm [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 910-926 Chad Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9110 King Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9203 King Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9306-24 East Broadway Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9319 Peach Palm Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9704 Solar Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 921 South Park Lane [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8313 West Pierce Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8591 West Washington [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 8601 West Washington [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1457 Miller Store Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 200 Golden Oak Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 208 Golden Oak Court [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 2809 South Lynnhaven Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 484 Viking Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5700 Cleveland Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 629 Phoenix Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1100 17th Street NW [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1200 Liberty Ridge Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1500 Liberty Ridge [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 825 Duportail Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 400-500 Brandywine Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 600 Brandywine Parkway [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 1 Kings Hill Aveune [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 42 Kings Hill Avenue [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | Liberty Square Retail Blocks [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 7805 Hudson Road [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4047 Perimeter West Drive [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 5500 N. Sam Houston Parkway West [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4000 S 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4050 S 26th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 4450 South 44th Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
Minimum [Member] | Operating Properties [Member] | 9801 South 51st Street [Member]
      
Real Estate and Accumulated Depreciation [Line Items]      
Real Estate and Accumulated Depreciation, Life Used for Depreciation 5 years    
[1] Denotes property is collateralized under mortgages with Allianz, John Hancock and LaSalle Bank totaling $236.5 million.