Property and Equipment, Net - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation and amortization of property and equipment	$ 89,124	$ 66,591	$ 55,355
Accumulated amortization for capitalized leased assets	8,300	6,600
Capitalized interest	$ 2,900	$ 2,700	$ 1,400