XML 92 R77.htm IDEA: XBRL DOCUMENT v3.21.1
Pension and Postretirement Health and Life Benefits (Schedule of Estimated Future Benefit Payments) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Pension Plan, Defined Benefit [Member]    
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months $ 53.8  
Defined Benefit Plan, Expected Future Benefit Payment, Year Two 52.1  
Defined Benefit Plan, Expected Future Benefit Payment, Year Three 50.9  
Defined Benefit Plan, Expected Future Benefit Payment, Year Four 49.3  
Defined Benefit Plan, Expected Future Benefit Payment, Year Five 47.9  
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter $ 223.3  
Other Postretirement Benefits Plan [Member]    
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months   $ 11.6
Defined Benefit Plan, Expected Future Benefit Payment, Year Two   11.1
Defined Benefit Plan, Expected Future Benefit Payment, Year Three   10.6
Defined Benefit Plan, Expected Future Benefit Payment, Year Four   10.0
Defined Benefit Plan, Expected Future Benefit Payment, Year Five   9.4
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter   $ 38.8