Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENTS (Fair Value of Assets and Liabilities) (Details)

v3.10.0.1
FAIR VALUE MEASUREMENTS (Fair Value of Assets and Liabilities) (Details) - USD ($)
$ in Millions
Jun. 30, 2018
Jan. 01, 2018
Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Cash equivalents $ 557.0   $ 616.9
Derivative assets 174.7 $ 49.5 37.9
Total Asset 731.7   654.8
Derivative Liability 3.1   2.0
Total Liability 3.1   2.0
Fair Value, Inputs, Level 1 [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Cash equivalents 10.5   66.3
Derivative assets 0.0   0.0
Total Asset 10.5   66.3
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 546.5   550.6
Derivative assets 0.1   0.0
Total Asset 546.6   550.6
Derivative Liability 0.1   0.3
Total Liability 0.1   0.3
Fair Value, Inputs, Level 3 [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Cash equivalents 0.0   0.0
Derivative assets 174.6   37.9
Total Asset 174.6   37.9
Derivative Liability 3.0   1.7
Total Liability $ 3.0   $ 1.7