Unconsolidated Joint Venture (Investment Property Contributions To Joint Venture) (Details) (Unconsolidated Joint Venture [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013 sqft
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	1,060,473
Gross Value	$ 366,420
4700 Old Ironsides Drive [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	90,139
Gross Value	29,064
4650 Old Ironsides Drive [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	124,383
Gross Value	56,258
7505 Mason King Court [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	109,650
Gross Value	25,475
43790 Devin Shafron Drive [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	152,138
Gross Value	45,505
444 Toyama Drive [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	42,083
Gross Value	28,310
21551 Beaumeade Circle [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	152,504
Gross Value	30,700
2950 Zanker Road [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	69,700
Gross Value	45,669
900 Dorothy Drive [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	56,176
Gross Value	25,383
14901 FAA Boulevard [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property	263,700
Gross Value	$ 80,056