Annual report pursuant to Section 13 and 15(d)

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

v3.3.1.900
PENSIONS AND OTHER POSTRETIREMENT BENEFITS PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Unobservable Inputs, Level 3) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets $ 193.4 $ 188.1 $ 169.8
Defined Benefit Plan, Actual Return on Plan Assets Still Held 5.5 15.5  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 2.5 3.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 5.7 6.8  
Defined Benefit Plan, Divestitures, Plan Assets (8.4) (7.0)  
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 250.6 269.3 251.8
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 33.1 31.2 29.1
Defined Benefit Plan, Actual Return on Plan Assets Still Held 1.5 3.2  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 2.5 3.0  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 5.7 1.4  
Defined Benefit Plan, Divestitures, Plan Assets (7.8) (5.5)  
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 5.5 6.2  
Structured Finance [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 62.1 65.4 61.0
Defined Benefit Plan, Actual Return on Plan Assets Still Held (3.3) 4.4  
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  
Real Estate [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 57.5 50.0 40.9
Defined Benefit Plan, Actual Return on Plan Assets Still Held 8.1 5.2  
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 5.4  
Defined Benefit Plan, Divestitures, Plan Assets (0.6) (1.5)  
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 10.0 8.7  
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 5.8 6.1  
Hedge Funds [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Fair Value of Plan Assets 40.7 41.5 38.8
Defined Benefit Plan, Actual Return on Plan Assets Still Held (0.8) 2.7  
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 11.5  
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 32.5 32.5 57.3
Defined Benefit Plan, Actual Return on Plan Assets Still Held 1.0 2.8  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.4 1.9  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.1 0.1  
Defined Benefit Plan, Divestitures, Plan Assets (1.5) (29.6)  
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 5.5 6.2 6.0
Defined Benefit Plan, Actual Return on Plan Assets Still Held 0.3 1.0  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.4 0.4  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.1 0.1  
Defined Benefit Plan, Divestitures, Plan Assets (1.5) (1.3)  
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 10.0 8.7 13.2
Defined Benefit Plan, Actual Return on Plan Assets Still Held 1.3 0.9  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.0 0.5  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets 0.0 (5.9)  
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 5.8 6.1 13.5
Defined Benefit Plan, Actual Return on Plan Assets Still Held (0.3) 0.4  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.0 0.4  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets 0.0 (8.2)  
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 11.5 $ 24.6
Defined Benefit Plan, Actual Return on Plan Assets Still Held (0.3) 0.5  
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period 0.0 0.6  
Defined Benefit Plan, Business Combinations and Acquisitions, Plan Assets 0.0 0.0  
Defined Benefit Plan, Divestitures, Plan Assets $ 0.0 $ (14.2)