SCHEDULE III Accumulated depreciation reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate and Accumulated Depreciation [Line Items]
Beginning balance	$ 852,407	$ 795,753	$ 734,067
Depreciation for the period	201,157	159,706	121,103
Asset impairment	0	0	(1,033)
Dispositions and other	(26,706)	(103,052)	(58,384)
Ending balance	$ 1,026,858	$ 852,407	$ 795,753