REPORTABLE SEGMENTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014 segment	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment results
Number of segments	2
Revenue	$ 441.8	$ 415.0	$ 1,270.7	$ 1,226.3
Operating income	45.0	27.2	90.6	82.4
Interest expense, net	(4.4)	(3.6)	(13.0)	(10.9)
Income before income taxes	40.6	23.6	77.6	71.5
Income taxes	(19.1)	(6.4)	(34.6)	(25.1)
Net Income	21.5	17.2	43.0	46.4
Ocean Transportation Segment [Member]
Segment results
Revenue	329.5	310.1	945.2	920.0
Operating income	42.6	25.5	84.8	78.3
Logistics Services Segment [Member]
Segment results
Revenue	112.3	104.9	325.5	306.3
Operating income	$ 2.4	$ 1.7	$ 5.8	$ 4.1