Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Other Assets.
Deferred leasing costs	$ 32,118	$ 33,121
Deferred rent receivable	37,743	36,393
Internal-use software	15,254	14,440
Prepaid expense	8,746	4,390
Corporate furniture, fixtures and equipment	6,196	5,356
Deferred financing costs - revolving credit facility	1,442	1,604
Other	1,458	1,068
Total	$ 102,957	$ 96,372