Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Deferred rent receivable	$ 40,614	$ 43,162
Initial direct costs	25,639	24,651
Internal-use software	17,179	17,708
Prepaid expense	6,778	7,090
Corporate furniture, fixtures and equipment	4,607	5,006
Deferred financing costs - revolving credit facility	2,472	2,880
Other	885	1,793
Total	$ 98,174	$ 102,290