Investments in Partially Owned Entities (Summary of Condensed Combined Financial Information) (Details) - Partially Owned Properties - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets	$ 13,258	$ 24,812
Liabilities	10,456	22,739
Noncontrolling interests	139	140
Equity	2,663	1,933
Total revenue	1,798	12,991	$ 13,600
Net loss	$ 52	$ (542)	$ (65)