GENERAL AND SIGNIFICANT ACCOUNTING POLICIES - GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	3 Months Ended
Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015
Changes in the Company's goodwill
Balance at the beginning of the period	$ 241.6	$ 241.6	$ 27.4	$ 27.4
Additions	3.5		214.2
Balance at the end of the period	245.1	241.6	241.6	27.4
Intangible Assets, Net
Accumulated amortization of intangible assets	16.0				$ 12.3
Ocean Transportation
Changes in the Company's goodwill
Balance at the beginning of the period	215.0	215.0	0.8	0.8
Additions	3.5		214.2
Balance at the end of the period	218.5	215.0	215.0	0.8
Logistics
Changes in the Company's goodwill
Balance at the beginning of the period	26.6	26.6	26.6	26.6
Additions
Balance at the end of the period	$ 26.6	$ 26.6	$ 26.6	$ 26.6

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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