Retirement Plans and Other Postretirement Benefits - Schedule of Net Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Amortization of:
Portion of benefit charged to expense	$ (9,865)	$ (23,809)
Pension Benefits
Retirement Plans and Other Benefits
Service cost — benefits earned during the period	10,157	14,331
Interest cost on benefit obligation	38,362	27,023
Expected return on plan assets	(45,561)	(46,394)
Amortization of:
Prior service credit	0	0
Net actuarial loss (gain)	9,713	4,768
Net periodic cost/(benefit)	12,671	(272)
Portion of benefit charged to expense	7,227	(3,290)
Other Benefits
Retirement Plans and Other Benefits
Service cost — benefits earned during the period	2,120	4,218
Interest cost on benefit obligation	5,673	4,463
Expected return on plan assets	(10,872)	(11,510)
Amortization of:
Prior service credit	(9,447)	(9,447)
Net actuarial loss (gain)	(2,303)	(2,982)
Net periodic cost/(benefit)	(14,829)	(15,258)
Portion of benefit charged to expense	$ (10,737)	$ (10,895)