Real Estate (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Pro forma financial information
Total revenue	$ 57,809	$ 51,100	$ 114,847	$ 97,983
Total operating expenses	40,559	37,574	80,264	69,084
Operating income	17,250	13,526	34,583	28,899
Net income (loss)	2,624	455	5,495	14,051
As Reported [Member]
Pro forma financial information
Total revenue			114,847	97,983
Total operating expenses			80,264	69,084
Operating income			34,583	28,899
Net income (loss)			5,495	14,051
Pro Forma [Member]
Pro forma financial information
Total revenue			115,093	111,571
Total operating expenses			80,438	80,938
Operating income			34,655	30,633
Net income (loss)			$ 5,582	$ (31,980)