Description of Business and Summary of Accounting Policies - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 995,514	$ 891,145
Land [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	57,506	53,632
Structures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	181,769	140,206
Tractors [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	314,326	290,718
Trailers [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	256,494	237,262
Other Revenue Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	36,828	37,220
Technology Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	72,707	63,773
Other [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 75,884	$ 68,334