Investments in Real Estate Entities (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Assets:
Real estate, net	$ 1,005,924		$ 1,005,924		$ 1,392,833
Other assets	52,992		52,992		57,044
Total assets	1,058,916		1,058,916		1,449,877
Liabilities and partners' capital:
Mortgage notes payable and credit facility	720,703		720,703		947,205
Other liabilities	20,771		20,771		20,471
Partners' capital	317,442		317,442		482,201
Total liabilities and partners' capital	1,058,916		1,058,916		$ 1,449,877
Combined summary of the operating results of the accounted for using the equity method
Rental and other income	30,771	$ 43,868	101,534	$ 132,518
Operating and other expenses	(12,069)	(17,910)	(39,206)	(52,622)
Gain on sale of communities	0	66,410	180,256	98,899
Interest expense, net	(7,919)	(14,883)	(37,857)	(35,694)
Depreciation expense	(8,081)	(11,213)	(26,027)	(35,058)
Net income	$ 2,702	$ 66,272	$ 178,700	$ 108,043