Employee Benefit Plans - Components of Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net periodic benefit cost	$ 5,326	$ 4,295
Defined benefit plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	5,602	5,935
Expected return on plan assets, net of expenses	(6,018)	(6,306)
Amortization of actuarial loss and prior service cost	5	5
Total for defined benefit pension plan	(411)	(366)
SERPs
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net periodic benefit cost	234	232
Defined contribution plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net periodic benefit cost	$ 5,503	$ 4,429