GOODWILL AND OTHER INTANGIBLE ASSETS - Change in the Carrying Amount of Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($)
Goodwill [Roll Forward]
Balance, beginning of period	$ 1,232,796
Translation	10,122
Balance, end of period	1,242,918
NAST
Goodwill [Roll Forward]
Balance, beginning of period	907,230
Translation	7,449
Balance, end of period	914,679
Global Forwarding
Goodwill [Roll Forward]
Balance, beginning of period	159,050
Translation	1,306
Balance, end of period	160,356
Robinson Fresh
Goodwill [Roll Forward]
Balance, beginning of period	139,558
Translation	1,146
Balance, end of period	140,704
All Other and Corporate
Goodwill [Roll Forward]
Balance, beginning of period	26,958
Translation	221
Balance, end of period	$ 27,179