XML 108 R91.htm IDEA: XBRL DOCUMENT v3.22.0.1
Employee Benefit Plans (Net Periodic Pension Costs Included in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
After-Tax Amount      
Prior service credit (cost) arising during the year $ 10.0 $ 0.3 $ (4.7)
Net loss recognized due to settlement 0.1 0.3 0.6
Net loss recognized due to curtailment 6.3 0.0 0.0
Net actuarial loss arising during the year 53.6 (32.7) (23.3)
Amortization of prior service cost 0.6 2.1 1.6
Amortization of net actuarial losses 12.3 13.1 11.8
Defined Benefit Pension Plans      
After-Tax Amount      
Prior service credit (cost) arising during the year 10.0 0.3 (4.7)
Net loss recognized due to settlement 0.1 0.3 0.6
Net loss recognized due to curtailment 6.3    
Net actuarial loss arising during the year 53.6 (32.7) (23.3)
Amortization of prior service cost 0.6 2.1 1.6
Amortization of net actuarial losses 12.3 13.1 11.8
Postretirement benefits      
Before-Tax Amount      
Accumulated other comprehensive loss, beginning of period (5.5)    
Accumulated other comprehensive loss, end of period (2.1) (5.5)  
Postretirement benefits | Defined Benefit Pension Plans      
Before-Tax Amount      
Accumulated other comprehensive loss, beginning of period (412.5) (393.2)  
Prior service credit arising during the year 13.1 0.3  
Net loss recognized due to settlement 0.1 0.3  
Net loss recognized due to curtailment 8.5    
Net actuarial loss arising during the year 71.0 (37.8)  
Amortization of prior service cost 0.8 2.2  
Amortization of net actuarial losses 16.6 15.7  
Accumulated other comprehensive loss, end of period (302.4) (412.5) (393.2)
Income Tax      
Accumulated other comprehensive loss, beginning of period (99.2) (96.8)  
Prior service credit arising during the year 3.1 0.0  
Net loss recognized due to settlement 0.0 0.0  
Net loss recognized due to curtailment 2.2    
Net actuarial loss arising during the year 17.4 (5.1)  
Amortization of prior service cost 0.2 0.1  
Amortization of net actuarial losses 4.3 2.6  
Accumulated other comprehensive loss, end of period (72.0) (99.2) (96.8)
After-Tax Amount      
Accumulated other comprehensive loss, , beginning of period (313.3) (296.4)  
Prior service credit (cost) arising during the year 10.0 0.3  
Net loss recognized due to settlement 0.1 0.3  
Net loss recognized due to curtailment 6.3    
Net actuarial loss arising during the year 53.6 (32.7)  
Amortization of prior service cost 0.6 2.1  
Amortization of net actuarial losses 12.3 13.1  
Accumulated other comprehensive loss, end of period $ (230.4) $ (313.3) $ (296.4)