XML 66 R57.htm IDEA: XBRL DOCUMENT v3.24.0.1
Employee Benefit Plans - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Defined Contribution Feature      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Compensation expense $ 4.0 $ 3.7 $ 3.1
Other postretirement benefits      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Discount rate 5.16% 2.82% 2.45%
Voluntary 401(k) Savings Plan      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Pretax income allowed to be deferred (as a percent) 50.00%    
Company match (as a percent) 25.00%    
Maximum match of employee's salary (as a percent) 7.00%    
Compensation expense $ 1.2 $ 1.1 $ 0.9
Officers and Key Employees | Supplemental Non-Qualified Plans | Other postretirement benefits      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Discount rate 5.09% 2.61% 2.08%
Amount accrued $ 0.8 $ 0.7