Retirement Plans and Other Postretirement Benefits - Schedule of Net Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Amortization of:
Portion of benefit charged to expense	$ (24,673)	$ (28,135)	$ (73,739)	$ (84,101)
Pension Benefits
Retirement Plans and Other Benefits
Service cost — benefits earned during the period	13,868	15,309	41,605	45,927
Interest cost on benefit obligation	26,873	24,641	80,619	73,924
Expected return on plan assets	(46,443)	(50,657)	(139,331)	(151,971)
Amortization of:
Prior service credit	0	0	0	0
Net actuarial loss (gain)	4,379	3,987	13,136	11,961
Net periodic benefit	(1,323)	(6,720)	(3,971)	(20,159)
Portion of benefit charged to expense	(4,246)	(7,803)	(12,258)	(24,428)
Other Benefits
Retirement Plans and Other Benefits
Service cost — benefits earned during the period	4,117	4,449	12,352	13,347
Interest cost on benefit obligation	4,372	4,128	13,118	12,385
Expected return on plan assets	(11,510)	(10,361)	(34,531)	(31,083)
Amortization of:
Prior service credit	(9,447)	(9,425)	(28,341)	(28,279)
Net actuarial loss (gain)	(3,209)	(2,523)	(9,627)	(7,569)
Net periodic benefit	(15,677)	(13,732)	(47,029)	(41,199)
Portion of benefit charged to expense	$ (11,318)	$ (9,765)	$ (33,736)	$ (28,901)