Segment Information - Reconciliation of Consolidated NOI to Consolidated Net Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 14, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting [Abstract]
Consolidated net operating income		$ 76,960	$ 89,299	$ 158,687	$ 179,007
Less:
Interest expense		(19,829)	(27,895)	(43,520)	(56,071)
Interest expense - amortization of deferred financing costs		(644)	(1,288)	(1,418)	(2,367)
Interest expense - financing obligation		(242)	(324)	(523)	(610)
Depreciation and amortization		(46,907)	(50,930)	(95,780)	(102,041)
General and administrative expenses		(6,076)	(6,791)	(15,196)	(15,427)
Equity in loss of Real Estate Ventures		(1,666)	(873)	(2,069)	(742)
Provision for impairment		(5,679)	(782)	(13,069)	(2,508)
Loss on early extinguishment of debt	$ (66,600)	0	0	(66,590)	0
Plus:
Interest income		359	313	679	1,063
Net gain (loss) on disposition of real estate		(727)	1,571	114,729	10,590
Net gain from remeasurement of investments in Real Estate Ventures		0	758	0	758
Net gain on Real Estate Venture transactions		3,128	0	9,057	0
Net income (loss)		$ (1,323)	$ 3,058	$ 44,987	$ 11,652