Pension and Other Postretirement Benefit Plans - Schedule of Changes in Accumulated Postemployment Benefit Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in plan assets:
Fair value of plan assets at beginning of period	$ 540,225
Fair value of plan assets at end of period	549,571	$ 540,225
Funded status:
Salary Retirement	47,246	38,548
Pension Benefits
Change in benefit obligation:
Benefit obligation at beginning of period	524,212	723,006
Service cost	1,217	1,207	$ 1,114
Interest cost	27,027	16,539	14,230
Actuarial loss (gain)	14,061	(173,233)
Benefits and other payments	(41,431)	(43,307)
Benefit obligation at end of period	525,086	524,212	723,006
Change in plan assets:
Fair value of plan assets at beginning of period	540,225	733,966
Actual return on plan assets	49,239	(151,968)
Company contributions	1,538	1,534
Benefits and other payments	(41,431)	(43,307)
Fair value of plan assets at end of period	549,571	540,225	733,966
Funded status:
Salary Retirement	47,246	38,548
Current liabilities	(1,953)	(1,950)
Noncurrent liabilities	(20,808)	(20,585)
Net asset (obligation) recognized	24,485	16,013
Amounts recognized in accumulated other comprehensive (loss) income consist of:
Net actuarial loss (gain)	248,252	244,700
Prior service credit	0	0
Net amount recognized (before tax effect)	248,252	244,700
Other Postretirement Benefits
Change in benefit obligation:
Benefit obligation at beginning of period	255,029	353,297
Service cost	0	0	0
Interest cost	13,044	7,898	7,274
Actuarial loss (gain)	(20,776)	(84,810)
Benefits and other payments	(20,062)	(21,356)
Benefit obligation at end of period	227,235	255,029	353,297
Change in plan assets:
Fair value of plan assets at beginning of period	0	0
Actual return on plan assets	0	0
Company contributions	20,062	21,356
Benefits and other payments	(20,062)	(21,356)
Fair value of plan assets at end of period	0	0	$ 0
Funded status:
Salary Retirement	0	0
Current liabilities	(19,327)	(22,436)
Noncurrent liabilities	(207,908)	(232,593)
Net asset (obligation) recognized	(227,235)	(255,029)
Amounts recognized in accumulated other comprehensive (loss) income consist of:
Net actuarial loss (gain)	(26,249)	(5,473)
Prior service credit	(11,329)	(13,734)
Net amount recognized (before tax effect)	$ (37,578)	$ (19,207)