Investment in Unconsolidated Joint Ventures - Income Statement of Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Schedule of Equity Method Investments [Line Items]
Operating expenses	$ (93,356)	$ (115,439)	$ (185,902)	$ (222,846)
Depreciation and amortization			(80,571)	(96,192)
Operating income	14,153	11,466	32,671	23,743
Interest expense	(15,798)	(17,676)	(32,713)	(36,874)
Loan cost amortization			(1,551)	(1,624)
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Revenues	5,059	3,167	8,682	6,134
Operating expenses	(1,782)	(949)	(3,170)	(1,983)
Depreciation and amortization	(2,145)	(1,664)	(3,686)	(3,815)
Operating income	1,132	554	1,826	336
Interest expense	(1,323)	(251)	(2,171)	(500)
Loan cost amortization	(36)	(41)	(61)	(84)
Net income (loss)	$ (227)	$ 262	$ (406)	$ (248)