Schedule III - Real Estate and Accumulated Depreciation (Details) - Reconciliation of Accumulated Depreciation - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance	$ 134,311	$ 88,173	$ 57,500
Depreciation expenses	63,872	49,619	38,890
Properties sold during the year	0	0	(2,081)
Property assets fully depreciated and written off	(5,162)	(3,481)	(6,136)
Balance	$ 193,021	$ 134,311	$ 88,173