Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pension and Supplemental Executive Retirement Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	$ 0		$ 0	$ 0	$ 0
Interest cost	3,247		3,299	6,494	6,981
Expected return on plan assets	(3,644)		(3,425)	(7,288)	(7,006)
Net actuarial losses (gains)	523		530	1,046	1,127
Prior service cost (credit)	86		86	172	172
Cost of settlements and curtailments	0		1,000	0	8,847
Net periodic benefit cost (benefit)	212		1,490	424	10,121
Other Postretirement Benefit Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	417		362	834	748
Interest cost	375		418	750	816
Expected return on plan assets	(2,494)		(2,054)	(4,988)	(4,117)
Net actuarial losses (gains)	(380)		(11)	(760)	(75)
Prior service cost (credit)	453		466	906	931
Cost of settlements and curtailments	0		0	0	0
Net periodic benefit cost (benefit)	$ (1,629)		$ (819)	$ (3,258)	$ (1,697)
Pension Plan
Components of Net Periodic Benefit Cost [Abstract]
Company contribution to qualified pension plan		$ 23,000