GOODWILL AND OTHER INTANGIBLE ASSETS - Change in the Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Balance, beginning of year	$ 1,108,337	$ 825,038
Acquisitions	132,797	287,220
Translation	(8,338)	(3,921)
Balance, end of year	1,232,796	1,108,337
NAST
Goodwill [Roll Forward]
Balance, beginning of year	815,639	607,156
Acquisitions	97,727	211,369
Translation	(6,136)	(2,886)
Balance, end of year	907,230	815,639
Global Forwarding
Goodwill [Roll Forward]
Balance, beginning of year	142,993	106,443
Acquisitions	17,133	37,056
Translation	(1,076)	(506)
Balance, end of year	159,050	142,993
Robinson Fresh
Goodwill [Roll Forward]
Balance, beginning of year	125,469	93,398
Acquisitions	15,033	32,515
Translation	(944)	(444)
Balance, end of year	139,558	125,469
All Other and Corporate
Goodwill [Roll Forward]
Balance, beginning of year	24,236	18,041
Acquisitions	2,904	6,280
Translation	(182)	(85)
Balance, end of year	$ 26,958	$ 24,236