Acquisition - Additional Information (Detail) $ in Thousands		12 Months Ended
	Jul. 01, 2017 USD ($) Tractor Trailer	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Business Acquisition [Line Items]
Amortization expense of intangible assets		$ 3,900	$ 1,300
Hub Group Dedicated [Member]
Business Acquisition [Line Items]
Number of tractors in operating fleet | Tractor	1,100
Number of trailers in operating fleet | Trailer	4,700
Estenson Logistics, LLC [Member]
Business Acquisition [Line Items]
Business acquisition date		Jul. 01, 2017
Business acquisition, purchase price	$ 284,691
Contingent consideration related to an earn-out provision	6,000
Business acquisition, final consideration	172,014
Business acquisition, debt assumed	112,677
Business acquisition, cash paid	165,945
Amount of cash borrowed under new credit agreement	55,000
Business acquisition costs		$ 1,600
Tax deductible goodwill		$ 80,600
Intangible assets estimated useful life		15 years
Assumed liabilities	$ 137,938	$ 5,900
Amortization expense of intangible assets		$ 2,600
Intangible assets, weighted average useful life		15 years