Pension Plan and Employee Benefits - Schedule of Net Periodic Pension and Other Benefits Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Pension Plan
Components of periodic benefit costs
Service cost	$ 966	$ 1,114	$ 2,899	$ 3,490
Interest cost	6,776	6,535	20,329	19,605
Amortizations
Expected return on plan assets	(8,292)	(7,607)	(24,876)	(22,821)
Net periodic benefit (income) cost	(550)	42	(1,648)	274
Other Benefits Plan
Components of periodic benefit costs
Service cost	395	475	1,184	1,375
Interest cost	586	583	1,757	1,750
Amortizations
Net loss (gain)	74	156	222	367
Net periodic benefit (income) cost	1,055	1,214	3,163	3,492
SERP Benefits
Components of periodic benefit costs
Service cost	14	34	43	101
Interest cost	864	836	2,591	2,507
Amortizations
Prior period service credit	(54)	(54)	(161)	(161)
Net loss (gain)	(35)	(21)	(104)	(61)
Net periodic benefit cost	$ 789	$ 795	$ 2,369	$ 2,386