XML 102 R86.htm IDEA: XBRL DOCUMENT v3.20.4
Employee Benefit Plans and Other Postretirement Benefits - Change in Benefit Obligations and Change in Fair Value of Plan Assets Related to Pension and Postretirement Plans (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Amounts Recognized on Consolidated Balance Sheets:      
Noncurrent liabilities $ (298.3) $ (375.5)  
Pension Plans      
Change in Benefit Obligations [Roll Forward]      
Benefit obligation at beginning of period 1,420.1 1,204.9  
Service cost 23.0 24.5 $ 25.0
Interest cost 39.8 47.0 42.4
Plan amendments 1.3 2.3  
Actuarial (gain) loss [1] 132.0 188.6  
Participant contributions    
Benefits paid (50.6) (47.2)  
Benefit obligation at plan year end 1,565.6 1,420.1 1,204.9
Accumulated benefit obligation portion of above 1,520.4 1,374.4  
Change in Fair Value of Plan Assets [Roll Forward]      
Plan assets at fair value at beginning of period 1,073.8 873.2  
Actual return on plan assets 193.8 188.9  
Company contributions 83.7 58.9  
Benefits paid (50.6) (47.2)  
Fair value of plan assets at plan year end 1,300.7 1,073.8 873.2
Underfunded status (264.9) (346.3)  
Amounts Recognized on Consolidated Balance Sheets:      
Current liabilities (1.2) (1.4)  
Noncurrent liabilities (263.7) (344.9)  
Accrued obligation recognized at December 31 (264.9) (346.3)  
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) (Pre-Tax):      
Prior service cost (credit) 21.7 24.7  
Actuarial loss (gain) 223.5 239.2  
Total 245.2 263.9  
Postretirement Plans      
Change in Benefit Obligations [Roll Forward]      
Benefit obligation at beginning of period 14.5 14.6  
Service cost 0.3 0.3 0.3
Interest cost 0.4 0.5 0.5
Plan amendments   (0.3)  
Actuarial (gain) loss [1] (1.5) 0.2  
Participant contributions 0.9 1.1  
Benefits paid (1.5) (1.9)  
Benefit obligation at plan year end 13.1 14.5 $ 14.6
Change in Fair Value of Plan Assets [Roll Forward]      
Company contributions 0.6 0.8  
Participant contributions 0.9 1.1  
Benefits paid (1.5) (1.9)  
Underfunded status (13.1) (14.5)  
Amounts Recognized on Consolidated Balance Sheets:      
Current liabilities (0.6) (0.7)  
Noncurrent liabilities (12.5) (13.8)  
Accrued obligation recognized at December 31 (13.1) (14.5)  
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) (Pre-Tax):      
Prior service cost (credit) (4.9) (5.3)  
Actuarial loss (gain) (5.5) (4.4)  
Total $ (10.4) $ (9.7)  
[1] For the year ended December 31, 2020, the most significant driver of the increase in benefit obligations for the plans was the actuarial losses due to the decrease in the discount rate assumption. The OPEB plans experienced a net actuarial gain primarily due to changes in demographic assumptions that were partially offset by the effect of the change in the discount rate assumption. For the year ended December 31, 2019, the benefit obligation loss for the pension plans was due largely to a decrease in the discount rate assumption and a change in the mortality assumption to adopt the Society of Actuaries’ newly released longevity study. For the OPEB plans, the net loss on the benefit obligation was driven by the decrease in the discount rate assumption partially offset by the effect of favorable demographic experience and the repeal of the excise tax originally implemented with the Affordable Care Act.