SIGNIFICANT ACCOUNTING POLICIES - GOODWILL (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Goodwill [Line Items]
Balance at the beginning of the period	$ 323.7	$ 241.6
Additions
Balance at the end of the period	323.7	241.6
Ocean Transportation
Goodwill [Line Items]
Balance at the beginning of the period	218.5	215.0
Additions
Balance at the end of the period	218.5	215.0
Logistics
Goodwill [Line Items]
Balance at the beginning of the period	105.2	26.6
Additions
Balance at the end of the period	$ 105.2	$ 26.6