Summary of Significant Accounting Policies - Variable Interest Entities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Real estate, net	$ 3,028,326	$ 3,397,922
Total assets	3,441,467	3,808,403
Mortgages and notes payable, net	738,047	872,643
Total liabilities	2,028,976	2,345,872
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Real estate, net	778,265	1,072,463
Total assets	899,801	1,192,944
Mortgages and notes payable, net	364,099	431,599
Total liabilities	$ 395,332	$ 448,057