Fees, expenses and revenue paid to and/or received from advisor (dollars in thousands) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Advisory fee	$ 8,915	$ 9,957	$ 11,919
Construction advisory fee	181	2,429	1,761
Mortgage brokerage and equity refinancing	1,873	812	1,569
Net income fee	180	54	99
Property acquisition	20		31
Total fee paid	11,169	13,252	15,379
Cost reimbursements	2,247	2,908	3,250
Interest paid	1,194	1,048	2,350
Total Other Expense paid	3,441	3,956	5,600
Rental revenue	587	434	2,248
Property acquisition related parties	71	0	106
Property management, construction management and leasing commissions related parties	2,087	1,759	1,905
Real estate brokerage related parties	2,263	0	1,497
Total fee paid to related parties	$ 4,421	$ 1,759	$ 3,508