v3.26.1
Employee Benefit Plans (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Pension and SERPA Benefits:    
Defined Benefit Plan Disclosure    
Service cost $ 878 $ 963
Interest cost 19,948 20,501
Expected return on plan assets (30,444) (32,799)
Amortization of unrecognized: Prior service cost 252 380
Amortization of unrecognized: Net gain (loss) 1,054 (174)
Net periodic benefit income (8,312) (11,129)
Postretirement Healthcare Benefits:    
Defined Benefit Plan Disclosure    
Service cost 532 643
Interest cost 2,243 2,618
Expected return on plan assets (4,736) (4,675)
Amortization of unrecognized: Prior service cost 149 149
Amortization of unrecognized: Net gain (loss) (1,562) (1,369)
Net periodic benefit income $ (3,374) $ (2,634)