v3.26.1
Employee Benefit Plans (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension and SERPA Benefits:        
Defined Benefit Plan Disclosure        
Service cost $ 878 $ 963 $ 1,756 $ 1,926
Interest cost 19,944 20,501 39,892 41,002
Expected return on plan assets (30,444) (32,799) (60,888) (65,598)
Amortization of unrecognized: Prior service cost 252 380 504 760
Amortization of unrecognized: Net gain (loss) 1,054 (174) 2,108 (348)
Special retirement benefit cost 2,952 0 2,952 0
Net periodic benefit income (5,364) (11,129) (13,676) (22,258)
Postretirement Healthcare Benefits:        
Defined Benefit Plan Disclosure        
Service cost 532 643 1,064 1,286
Interest cost 2,243 2,618 4,486 5,236
Expected return on plan assets (4,736) (4,675) (9,472) (9,350)
Amortization of unrecognized: Prior service cost 149 149 298 298
Amortization of unrecognized: Net gain (loss) (1,562) (1,369) (3,124) (2,738)
Net periodic benefit income $ (3,374) $ (2,634) $ (6,748) $ (5,268)