Other Assets (Schedule of Other Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Equity Method Investments And Other Assets [Abstract]
Accounts receivable and other assets	$ 2,962	$ 6,381
Regulatory escrows	8,208	8,208
Unamortized lease incentive payments	9,673	7,456
Restricted cash	10,903	5,253	$ 5,404
Other Assets	$ 31,746	$ 27,298