Table 1 - Schedule of Mortgages ... (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 04, 2012	Dec. 31, 2011
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Sep. 30, 2013	[1]
Interest Rate	4.75%	[1]
Total mortgage notes	$ 479,206			$ 584,245
Other Long-term Debt	12,000			0
Long-term Debt	491,206			584,245
Net debt premium (discount) on assumed debt	1,779			(1,750)
Mortgage notes payable, net	492,985			582,495
Metropolitan Park North [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Mar. 23, 2012
Interest Rate	5.73%
Total mortgage notes	0			56,513
105 Kendall Park Lane [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Jul. 02, 2012
Interest Rate	4.92%
Total mortgage notes	0			12,371
Marketplace at Northglenn [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Jul. 11, 2012
Interest Rate	10.50%
Total mortgage notes	0			61,269
4001 North Norfleet Road [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Dec. 27, 2012
Interest Rate	5.60%
Total mortgage notes	0			24,230
36 Research Park Drive [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Jul. 01, 2013
Interest Rate	5.60%
Total mortgage notes	10,682			10,841
Monument IV at Worldgate [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Sep. 01, 2013
Interest Rate	5.29%
Total mortgage notes	35,195			35,195
Dignity Health Office Portfolio [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Nov. 01, 2013
Interest Rate	5.75%
Total mortgage notes	15,926			16,285
Dignity Health Office Portfolio 2 [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Nov. 01, 2013
Interest Rate	5.75%
Total mortgage notes	13,860			14,174
Dignity Health Care Office Portfolio 3 [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Nov. 01, 2013
Interest Rate	5.75%
Total mortgage notes	14,354			14,678
Dignity Health Office Portfolio 4 [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Mar. 01, 2014
Interest Rate	5.79%
Total mortgage notes	31,427			32,112
Stirling Slidell Shopping Centre [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Apr. 01, 2014
Interest Rate	5.15%
Total mortgage notes	12,483			12,777
Cabana Beach Gainesville [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Dec. 01, 2014
Interest Rate	5.57%
Total mortgage notes	47,163			47,843
Cabana Beach San Marcos [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Dec. 01, 2014
Interest Rate	5.57%
Total mortgage notes	18,872			19,144
Campus Lodge Columbia [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Dec. 01, 2014
Interest Rate	5.57%
Total mortgage notes	15,694			15,920
Campus Lodge Athens [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Dec. 01, 2014
Interest Rate	5.57%
Total mortgage notes	13,180			13,369
The Edge at Lafayette [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Feb. 01, 2015
Interest Rate	5.57%
Total mortgage notes	16,812			17,052
4 Research Park Drive [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Mar. 01, 2015
Interest Rate	6.05%
Total mortgage notes	6,419			6,611
111 Sutter Street [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Jun. 01, 2015	[1]
Interest Rate	5.58%	[1]
Total mortgage notes	54,061	[1]		0	[1]
Other Long-term Debt	12,000
Mortgage notes payable, net			54,130
Campus Lodge Tampa [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Oct. 01, 2016
Interest Rate	5.95%
Total mortgage notes	33,053			33,438
Station Nine Apartments [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	May 01, 2017
Interest Rate	5.50%
Total mortgage notes	36,885			36,885
Canyon Plaza [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Jun. 01, 2017
Interest Rate	5.90%
Total mortgage notes	29,001			29,453
The District at Howell Mill [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Jun. 01, 2017	[2]
Interest Rate	6.14%	[2]
Total mortgage notes	9,931	[2]		10,000	[2]
Railway Street Corporate Centre [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Sep. 01, 2017
Interest Rate	5.16%
Total mortgage notes	29,614			29,085
The District at Howell Mill 2 [Member]
Summary of mortgage notes payable
Debt Instrument, Maturity Date	Mar. 01, 2027
Interest Rate	5.30%
Total mortgage notes	$ 34,594			$ 35,000

[1] The seller of 111 Sutter Street provided a short-term financing at closing at the prime rate (3.25% at December 31, 2012) plus 150 basis points.

[2] This loan is denominated in Canadian dollars, but is reported in U.S. dollars at the exchange rate in effect on the balance sheet date.