Pension Plan and Employee Benefits - Schedule of Net Periodic Pension and Other Benefits Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Pension Plan
Components of periodic benefit costs
Service cost	$ 966	$ 1,186	$ 1,933	$ 2,375
Interest cost	6,776	6,535	13,553	13,070
Amortizations
Expected return on plan assets	(8,291)	(7,607)	(16,584)	(15,213)
Net periodic benefit (income) cost	(549)	114	(1,098)	232
Other Benefits Plan
Components of periodic benefit costs
Service cost	395	420	789	899
Interest cost	586	583	1,171	1,167
Amortizations
Net loss (gain)	73	49	148	212
Net periodic benefit (income) cost	1,054	1,052	2,108	2,278
SERP Benefits
Components of periodic benefit costs
Service cost	14	34	29	67
Interest cost	864	836	1,727	1,671
Amortizations
Prior period service credit	(54)	(54)	(107)	(107)
Net loss (gain)	(35)	(20)	(70)	(41)
Net periodic benefit cost	$ 789	$ 796	$ 1,579	$ 1,590