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Employee Postretirement Benefits - Narrative (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
USD ($)
year
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Defined Benefit Plan Disclosure [Line Items]      
Payment for pension benefits $ 0 $ 20,000 $ 10,000
Defined contribution plan, cost $ 7,800 6,700 $ 6,500
Pension Benefits (Pension Plan)      
Defined Benefit Plan Disclosure [Line Items]      
Age for compensation | year 65    
Age below which compensation is reduced | year 62    
Vesting period 5 years    
Investment redemption, notice period 95 days    
Subscriptions, lock-up period 3 years    
Accumulated benefit obligation $ 288,800 $ 283,200  
Discount rate (as a percent) 5.57% 5.51%  
Decrease in benefit obligation for change in discount rate $ 2,200 $ 117,100  
Increase in benefit obligation for change in expected future compensation 7,900    
Increase from plan participant census data 3,100    
Actual returns 34,200    
Expected returns 25,900    
Obligation impact $ 8,300    
Other Postretirement Benefits Plan      
Defined Benefit Plan Disclosure [Line Items]      
Health insurance benefits, requisite age 55 years    
Health insurance benefits, requisite service period 10 years    
Reduction from plan amendment $ 20,100    
Reduction attributable to increase in discount rate to measurement plan liability $ 2,600    
Discount rate during time of amendment (as a percent) 6.06%    
Discount rate (as a percent) 5.53% 5.52%  
Savings attributable to the plan change $ 17,500    
Expected remaining service period (in years) 4 years 9 months 18 days    
Decrease in benefit obligation for change in discount rate $ 1,300 $ 17,900  
Increase in benefit obligation for change in expected healthcare cost trends 1,100    
Executive Survivor and Supplemental Retirement Plan      
Defined Benefit Plan Disclosure [Line Items]      
Accumulated benefit obligation $ 35,800 $ 35,600  
Discount rate (as a percent) 5.53% 5.51%  
Decrease in benefit obligation for change in discount rate $ 100 $ 10,200