SIGNIFICANT ACCOUNTING POLICIES - INVESTMENT IN TERMINAL JOINT VENTURE (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Investments in affiliates
Investment in Terminal Joint Venture	$ 79.1		$ 79.1		$ 93.2
Financial information for equity method investment
Company Share of Net Income	9.2	$ 7.5	28.8	$ 19.3
SSAT
Financial information for equity method investment
Operating revenue	289.4	227.4	806.5	638.2
Operating costs and expenses	(259.5)	(203.9)	(719.7)	(581.9)
Operating Income	29.9	23.5	86.8	56.3
Net Income	$ 27.7	$ 23.7	$ 82.7	$ 57.5

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The amount of the cost of sales reported by an equity method investment of the entity.

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