Quarterly report pursuant to Section 13 or 15(d)

REVENUE (Narrative) (Details)

v3.10.0.1
REVENUE (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Jan. 01, 2018
Dec. 31, 2017
Deferred revenue, current $ 16.1   $ 16.1     $ 23.8
Deferred revenue, noncurrent 42.8   42.8     51.4
Other current liabilities 61.3   61.3   $ 68.8 67.4
Customer Supplemental Payments [Member]            
Deferred revenue 55.6   55.6     64.2
Deferred revenue, current 12.8   12.8     12.8
Take or Pay Contracts [Member]            
Deferred revenue 3.3   3.3     $ 9.6
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]            
Other current liabilities 0.2   0.2   $ 1.4  
Not Designated as Hedging Instrument [Member]            
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net $ 135.9 $ 38.6 $ 334.4 $ 101.6