FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS (Fair Value of Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 160.0	$ 177.0
Derivative Asset	72.5	33.1
Total Asset	232.5	210.1
Derivative Liability	20.8	0.5
Total Liability	20.8	0.5
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	40.0	177.0
Derivative Asset	0.0	0.0
Total Asset	40.0	177.0
Derivative Liability	0.0	0.0
Total Liability	0.0	0.0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	120.0	0.0
Derivative Asset	0.0	1.5
Total Asset	120.0	1.5
Derivative Liability	0.0	0.0
Total Liability	0.0	0.0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0.0	0.0
Derivative Asset	72.5	31.6
Total Asset	72.5	31.6
Derivative Liability	20.8	0.5
Total Liability	$ 20.8	$ 0.5