Annual report pursuant to Section 13 and 15(d)

BENEFIT PLANS (Reconciliation of Beginning and Ending Balances for Plan Assets Valued using Significant Unobservable Inputs) (Details)

v3.6.0.2
BENEFIT PLANS (Reconciliation of Beginning and Ending Balances for Plan Assets Valued using Significant Unobservable Inputs) (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2016
USD ($)
Private Equity  
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Roll Forward]  
Balance at December 31, 2015 $ 41.9
Return on plan assets:  
Unrealized 0.2
Realized 1.0
Purchases 1.7
Sales (11.3)
Balance at December 31, 2016 33.5
Hedge Funds  
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Roll Forward]  
Balance at December 31, 2015 54.0
Return on plan assets:  
Unrealized 0.5
Realized 0.0
Purchases 0.0
Sales (20.8)
Balance at December 31, 2016 33.7
Real Assets  
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Roll Forward]  
Balance at December 31, 2015 17.4
Return on plan assets:  
Unrealized 0.7
Realized 0.1
Purchases 2.0
Sales (0.9)
Balance at December 31, 2016 $ 19.3