Investments in and Advances to Unconsolidated Real Estate Ventures - Condensed Combined Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2019	Dec. 31, 2018
Equity Method Investment, Summarized Financial Information, Assets, Operating Leases, Right of Use Assets					$ 52,400
Operating Lease, Liability					$ 44,100
Combined balance sheet information:
Real estate, net	$ 2,086,486		$ 2,086,486			$ 2,050,985
Other assets, net	196,752		196,752			169,264
Total assets	2,283,238		2,283,238			2,220,249
Borrowings, net	1,155,596		1,155,596			1,125,368
Other liabilities, net	147,263		147,263			94,845
Total liabilities	1,302,859		1,302,859			1,220,213
Total equity	980,379		980,379			1,000,036
Total liabilities and equity	2,283,238		2,283,238			$ 2,220,249
Combined income statement information:
Total revenue	74,796	$ 87,518	134,787	$ 160,691
Operating income	10,542	12,484	10,109	16,858
Net loss	$ (1,460)	$ (514)	$ (16,687)	$ (5,189)