Investments in and Advances to Unconsolidated Affiliates - Unconsolidated Affiliates (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Combined and Condensed Balance Sheets
Real estate under development	$ 208,966		$ 208,966		$ 543,486
Investments in and advances to unconsolidated affiliates	272,736		272,736		272,028
Other assets	207,203		207,203		192,786
Total assets	4,048,845		4,048,845		3,995,960
Total liabilities and equity	4,048,845		4,048,845		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	257,378		257,378		258,337
Combined and Condensed Statements of Income
Total revenues	59,504	$ 43,918	121,503	$ 91,963
Operating and other expenses	(52,762)	(34,482)	(104,864)	(72,676)
Depreciation and amortization	(26,057)	(14,678)	(50,593)	(31,527)
Income from continuing operations before gain on disposition of properties	6,108	9,583	26,079	18,065
Company’s equity in earnings of unconsolidated affiliates	4,340	1,740	17,043	3,694
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Related party revenue	300	400	600	600
Expenses, related party	400	600	900	1,200
Unconsolidated Affiliates
Combined and Condensed Balance Sheets
Rental property, net	544,210		544,210		576,505
Real estate under development	19,381		19,381		18,884
Investments in and advances to unconsolidated affiliates	6,854		6,854		6,853
Other assets	106,407		106,407		75,254
Total assets	676,852		676,852		677,496
Mortgage notes payable	399,574		399,574		407,344
Other liabilities	58,308		58,308		30,117
Partners’ equity	218,970		218,970		240,035
Total liabilities and equity	676,852		676,852		677,496
Company's share of accumulated equity	179,729		179,729		191,049
Basis differential	70,199		70,199		61,827
Deferred fees, net of portion related to the Company's interest	5,170		5,170		3,268
Amounts receivable by the Company	2,280		2,280		$ 2,193
Combined and Condensed Statements of Income
Total revenues	20,974	19,022	42,577	32,394
Operating and other expenses	(6,272)	(7,286)	(12,138)	(11,016)
Interest expense	(4,641)	(3,377)	(9,179)	(6,113)
Depreciation and amortization	(6,063)	(4,984)	(12,512)	(8,864)
Loss on debt extinguishment	(3)	0	(154)	0
Gain on disposition of properties	3,332	0	17,778	0
Income from continuing operations before gain on disposition of properties	7,327	3,375	26,372	6,401
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	5,044	1,838	18,612	3,890
Basis differential amortization	(704)	(98)	(1,569)	(196)
Company’s equity in earnings of unconsolidated affiliates	$ 4,340	$ 1,740	$ 17,043	$ 3,694