Benefit Plans (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension and Supplemental Executive Retirement Plans
Components of Net Periodic Benefit Cost [Abstract]
Service cost		$ 1,869	$ 2,152	$ 3,626	$ 3,816
Interest cost		2,848	2,779	5,725	5,589
Expected return on plan assets		(4,864)	(5,256)	(9,816)	(10,458)
Amortization of net actuarial losses (gains)		1,349	1,255	2,532	2,805
Amortization of prior service cost (credit)		(53)	(59)	(106)	(119)
Net periodic benefit cost (benefit)		1,149	871	1,961	1,633
Other Postretirement Benefit Plans
Components of Net Periodic Benefit Cost [Abstract]
Service cost		306	390	654	754
Interest cost		171	160	348	324
Expected return on plan assets		(2,626)	(2,216)	(5,251)	(4,431)
Amortization of net actuarial losses (gains)		(798)	(409)	(1,552)	(848)
Amortization of prior service cost (credit)		122	53	244	106
Net periodic benefit cost (benefit)		$ (2,825)	$ (2,022)	$ (5,557)	$ (4,095)
Pension Plan | Subsequent Event
Components of Net Periodic Benefit Cost [Abstract]
Company contribution to qualified pension plan	$ 6,300