Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 644,231	$ 546,010
Equipment, capital lease obligation				$ 26,400
Equipment, capital lease obligation, net	12,300	14,700
Depreciation and amortization expense related to property and equipment	43,400	35,900	$ 28,300
Amortization expense under capital lease obligation	2,300	2,600	$ 2,600
Transportation Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	472,634	405,322
Computer Software and Hardware [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 91,302	$ 77,887