Summary of Revenue by Segment and Business Line (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 1,179,093	$ 923,596	$ 2,275,064	$ 1,816,352
Intermodal [Member]
Segment Reporting Information [Line Items]
Revenue	660,690	550,643	1,261,688	1,082,009
Truck brokerage [Member]
Segment Reporting Information [Line Items]
Revenue	218,020	186,848	438,402	370,809
Logistics [Member]
Segment Reporting Information [Line Items]
Revenue	226,530	186,105	440,741	363,534
Dedicated [Member]
Segment Reporting Information [Line Items]
Revenue	73,853		134,233
Operating Segments [Member] | Hub [Member]
Segment Reporting Information [Line Items]
Revenue	888,238	704,344	1,719,823	1,380,824
Operating Segments [Member] | Mode LLC [Member]
Segment Reporting Information [Line Items]
Revenue	314,078	242,998	601,977	484,832
Operating Segments [Member] | Intermodal [Member] | Hub [Member]
Segment Reporting Information [Line Items]
Revenue	526,028	451,420	1,008,522	875,843
Operating Segments [Member] | Intermodal [Member] | Mode LLC [Member]
Segment Reporting Information [Line Items]
Revenue	141,221	112,089	270,995	234,269
Operating Segments [Member] | Truck brokerage [Member] | Hub [Member]
Segment Reporting Information [Line Items]
Revenue	114,936	104,289	234,955	210,473
Operating Segments [Member] | Truck brokerage [Member] | Mode LLC [Member]
Segment Reporting Information [Line Items]
Revenue	103,168	82,869	203,889	161,031
Operating Segments [Member] | Logistics [Member] | Hub [Member]
Segment Reporting Information [Line Items]
Revenue	173,421	148,635	342,098	294,508
Operating Segments [Member] | Logistics [Member] | Mode LLC [Member]
Segment Reporting Information [Line Items]
Revenue	69,689	48,040	127,093	89,532
Operating Segments [Member] | Dedicated [Member] | Hub [Member]
Segment Reporting Information [Line Items]
Revenue	73,853		134,248
Intersegment Elims [Member]
Segment Reporting Information [Line Items]
Revenue	(23,223)	(23,746)	(46,736)	(49,304)
Intersegment Elims [Member] | Intermodal [Member]
Segment Reporting Information [Line Items]
Revenue	(6,559)	(12,866)	(17,829)	(28,103)
Intersegment Elims [Member] | Truck brokerage [Member]
Segment Reporting Information [Line Items]
Revenue	(84)	(310)	(442)	(695)
Intersegment Elims [Member] | Logistics [Member]
Segment Reporting Information [Line Items]
Revenue	$ (16,580)	$ (10,570)	(28,450)	$ (20,506)
Intersegment Elims [Member] | Dedicated [Member]
Segment Reporting Information [Line Items]
Revenue			$ (15)