Annual report pursuant to Section 13 and 15(d)

PENSIONS AND OTHER POSTRETIREMENT BENEFITS PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Unobservable Inputs, Level 3) (Details)

v3.6.0.2
PENSIONS AND OTHER POSTRETIREMENT BENEFITS PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Unobservable Inputs, Level 3) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets $ 202.4 $ 193.4 $ 188.1
Defined Benefit Plan, Actual Return on Plan Assets Still Held 12.3 5.5  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 3.3 2.5  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 8.0 5.7  
Defined Benefit Plan, Divestitures, Plan Assets (14.6) (8.4)  
Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 253.0 250.6 269.3
Private Equity Funds [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 36.1 33.1 31.2
Defined Benefit Plan, Actual Return on Plan Assets Still Held (2.7) 1.5  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 3.7 2.5  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 8.0 5.7  
Defined Benefit Plan, Divestitures, Plan Assets (6.0) (7.8)  
Private Equity Funds [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 4.3 5.5  
Structured Finance [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 63.8 62.1 65.4
Defined Benefit Plan, Actual Return on Plan Assets Still Held 10.0 (3.3)  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period (0.3) 0.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets (8.0) 0.0  
Real Estate [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 61.9 57.5 50.0
Defined Benefit Plan, Actual Return on Plan Assets Still Held 5.1 8.1  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period (0.1) 0.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets (0.6) (0.6)  
Real Estate [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 11.1 10.0  
Structured Credit [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 6.9 5.8  
Hedge Funds [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 40.6 40.7 41.5
Defined Benefit Plan, Actual Return on Plan Assets Still Held (0.1) (0.8)  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.0 0.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets 0.0 0.0  
Hedge Funds [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 11.2 11.2  
Fair Value, Inputs, Level 3 [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 33.5 32.5 32.5
Defined Benefit Plan, Actual Return on Plan Assets Still Held 1.9 1.0  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.1 0.4  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.1  
Defined Benefit Plan, Divestitures, Plan Assets (1.0) (1.5)  
Fair Value, Inputs, Level 3 [Member] | Private Equity Funds [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 4.3 5.5 6.2
Defined Benefit Plan, Actual Return on Plan Assets Still Held (0.3) 0.3  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.1 0.4  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.1  
Defined Benefit Plan, Divestitures, Plan Assets (1.0) (1.5)  
Fair Value, Inputs, Level 3 [Member] | Real Estate [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 11.1 10.0 8.7
Defined Benefit Plan, Actual Return on Plan Assets Still Held 1.1 1.3  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.0 0.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets 0.0 0.0  
Fair Value, Inputs, Level 3 [Member] | Structured Credit [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 6.9 5.8 6.1
Defined Benefit Plan, Actual Return on Plan Assets Still Held 1.1 (0.3)  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.0 0.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets 0.0 0.0  
Fair Value, Inputs, Level 3 [Member] | Hedge Funds [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 11.2 11.2 $ 11.5
Defined Benefit Plan, Actual Return on Plan Assets Still Held 0.0 (0.3)  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.0 0.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets $ 0.0 $ 0.0