XML 96 R81.htm IDEA: XBRL DOCUMENT v3.20.4
Employee Benefit Plans - Terminated vested lump sum payment offer (Details)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Employees
Dec. 31, 2018
USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment $ (0.5) $ (9.8) $ 0.0
Terminated vested lump sum payment offer [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Defined benefit plan, number of plan participants eligible for settlement | Employees   2,000  
Defined benefit plan, number of plan participants included in settlement | Employees   616  
Defined Benefit Plan, Benefit Obligation, Payment for Settlement   $ 28.4  
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement   32.5  
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment   $ (9.8)