Summary of Significant Accounting Policies - Schedule Operating Partnership's VIEs (Details) - Operating Partnership's VIEs - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, net
Variable Interest Entity [Line Items]
Assets	$ 288,881	$ 307,582
Other assets
Variable Interest Entity [Line Items]
Assets	60,586	68,863
Total assets
Variable Interest Entity [Line Items]
Assets	349,467	376,445
Mortgage notes payable
Variable Interest Entity [Line Items]
Liabilities	129,436	133,245
Other liabilities
Variable Interest Entity [Line Items]
Liabilities	72,705	75,913
Total liabilities
Variable Interest Entity [Line Items]
Liabilities	$ 202,141	$ 209,158