Investments in Unconsolidated Real Estate Ventures - Condensed Financial Information of Unconsolidated Real Estate Ventures (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Net real estate assets		$ 906,637	$ 1,389,974
Other		34,116	33,703
Total		940,753	1,423,677
Liabilities and members' equity:
Notes payable		296,607	299,730
Other liabilities		19,878	25,715
Members' equity		624,268	1,098,232
Total		940,753	1,423,677
Statements of Income:
Rents and other income		269,858	286,857	$ 273,231
Expenses		(143,805)	(155,851)	(153,973)
Gain on sale of real estate	$ 60,495	0	60,495	0
Net income		$ 126,053	$ 191,501	$ 119,258