XML 107 R92.htm IDEA: XBRL DOCUMENT v3.20.4
Benefit Plans - Salary Continuation Plan (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]    
Percentage of salary paid upon retirement 25.00%  
Period before ratable vesting begins 5 years  
Age ratable vesting ends 65 years  
Liability under the Salary Continuation Plan $ 3.2 $ 3.0
Minimum    
Defined Benefit Plan Disclosure [Line Items]    
Payment period determined by service period 7 years  
Maximum    
Defined Benefit Plan Disclosure [Line Items]    
Payment period determined by service period 15 years