v2.4.0.8
EMPLOYEE RETIREMENT PLANS (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Weighted-average healthcare cost trend rate        
Weighted-average healthcare cost trend rate (as a percent)     7.49%  
Weighted-average healthcare cost trend rate in the year 2024 (as a percent)     4.50%  
Pension Benefits
       
Components of net periodic benefit income (expense):        
Interest cost $ (7.9) $ (7.5) $ (23.7) $ (20.5)
Service cost (0.9) (1.7) (2.7) (4.5)
Expected return on plan assets 11.8 9.8 35.4 27.0
Amortization of actuarial gain (loss) 0.1 (0.5) 0.3 (1.6)
Total net periodic benefit income (expense) 3.1 0.1 9.3 0.4
Assumptions used to determine net periodic benefit (income) cost        
Discount rate (as a percent)     4.83% 4.09%
Expected return on assets (as a percent)     7.42% 6.81%
Rate of compensation increase (as a percent)     3.00% 3.15%
Contributions        
Contributions to the pension plan trusts 0 0 0 0
Estimated payments for the current fiscal year 1.9   1.9  
OPEB Benefits
       
Components of net periodic benefit income (expense):        
Interest cost (1.1) (2.0) (3.3) (5.3)
Service cost (0.2) (0.6) (0.6) (1.7)
Amortization of prior service credit 2.2   6.8  
Total net periodic benefit income (expense) 0.9 (2.6) 2.9 (7.0)
Assumptions used to determine net periodic benefit (income) cost        
Discount rate (as a percent)     4.65% 4.35%
Rate of compensation increase (as a percent)     3.00% 3.11%
Contributions        
Estimated payments for the current fiscal year $ 7.8   $ 7.8