Investments in and Advances to Unconsolidated Affiliates - Unconsolidated Affiliates (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Combined and Condensed Balance Sheets
Real estate under development	$ 237,434		$ 237,434		$ 543,486
Investments in and advances to unconsolidated affiliates	270,245		270,245		272,028
Other assets	213,018		213,018		192,786
Total assets	4,092,957		4,092,957		3,995,960
Total liabilities and equity	4,092,957		4,092,957		3,995,960
Investments in and advances to unconsolidated affiliates, net of Company's share of distributions in excess of income from and investments in unconsolidated affiliates	254,983		254,983		258,337
Combined and Condensed Statements of Income
Total revenues	62,678	$ 43,855	184,181	$ 135,818
Operating and other expenses	(56,934)	(42,601)	(161,798)	(115,277)
Depreciation and amortization	(26,652)	(15,217)	(77,245)	(46,744)
Income from continuing operations before gain on disposition of properties	313	326	26,392	18,391
Company’s equity in earnings (losses) of unconsolidated affiliates	4,001	(102)	21,044	3,592
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Related party revenue	400	300	1,000	900
Expenses, related party	500	600	1,400	1,800
Unconsolidated Affiliates
Combined and Condensed Balance Sheets
Rental property, net	540,609		540,609		576,505
Real estate under development	22,359		22,359		18,884
Investments in and advances to unconsolidated affiliates	6,854		6,854		6,853
Other assets	103,335		103,335		75,254
Total assets	673,157		673,157		677,496
Mortgage notes payable	401,768		401,768		407,344
Other liabilities	57,125		57,125		30,117
Partners’ equity	214,264		214,264		240,035
Total liabilities and equity	673,157		673,157		677,496
Company's share of accumulated equity	177,251		177,251		191,049
Basis differential	69,728		69,728		61,827
Deferred fees, net of portion related to the Company's interest	5,662		5,662		3,268
Amounts receivable by the Company	2,342		2,342		$ 2,193
Combined and Condensed Statements of Income
Total revenues	20,883	26,590	63,460	58,984
Operating and other expenses	(6,847)	(7,066)	(18,985)	(18,082)
Interest expense	(4,788)	(5,242)	(13,967)	(11,355)
Depreciation and amortization	(6,208)	(15,398)	(18,720)	(24,262)
Loss on debt extinguishment	0	0	(154)	0
(Loss) gain on disposition of properties	0	(1,452)	17,778	(1,452)
Income from continuing operations before gain on disposition of properties	3,040	(2,568)	29,412	3,833
Operating Partnership, as General Partner or Managing Member
Combined and Condensed Statements of Income
Company’s share of equity in net income of unconsolidated affiliates	4,544	377	23,156	4,267
Basis differential amortization	(543)	(479)	(2,112)	(675)
Company’s equity in earnings (losses) of unconsolidated affiliates	$ 4,001	$ (102)	$ 21,044	$ 3,592