Schedule III - Changes in Accumulated Depreciation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Balance at beginning of period	$ 232,675	$ 181,441	$ 144,235
Depreciation	81,010	60,796	46,935
Depreciation on disposed property	(19,086)	(8,887)	(9,213)
Other	(1,813)	(675)	(516)
Balance at end of period	$ 292,786	$ 232,675	$ 181,441