Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension and Supplemental Executive Retirement Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	$ 0	$ 1,869	$ 0	$ 3,626
Interest cost	3,299	2,848	6,981	5,725
Expected return on plan assets	(3,425)	(4,864)	(7,006)	(9,816)
Net actuarial losses (gains)	530	1,349	1,127	2,532
Prior service cost (credit)	86	(53)	172	(106)
Cost of settlements and curtailments	1,000	0	8,847	0
Net periodic benefit cost (benefit)	1,490	1,149	10,121	1,961
Other Postretirement Benefit Plans
Components of Net Periodic Benefit Cost [Abstract]
Company service cost	362	306	748	654
Interest cost	418	171	816	348
Expected return on plan assets	(2,054)	(2,626)	(4,117)	(5,251)
Net actuarial losses (gains)	(11)	(798)	(75)	(1,552)
Prior service cost (credit)	466	122	931	244
Cost of settlements and curtailments	0	0	0	0
Net periodic benefit cost (benefit)	$ (819)	$ (2,825)	$ (1,697)	$ (5,557)