Employee Benefit Plans and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2022

Retirement Benefits [Abstract]

Schedule of obligation and funded status

The changes in the benefit obligation, fair value of plan assets and the funded status of the Company’s pension and SERPA plans and the postretirement healthcare plans as of the Company’s measurement dates of December 31, were as follows (in thousands):

	Pension and SERPA Benefits				Postretirement Healthcare Benefits
	2022		2021		2022		2021
Change in benefit obligation:
Benefit obligation, beginning of period	$	2,174,595	$	2,390,435	$	286,301	$	315,245
Service cost	19,052		24,570		4,642		5,147
Interest cost	61,890		61,988		7,617		6,505
Actuarial gains	(561,142)		(92,157)		(67,903)		(24,190)
Plan participant contributions	—		—		2,029		2,337
Benefits paid	(137,645)		(138,043)		(16,657)		(18,743)
Net curtailments and settlements	(2,838)		(72,198)		(5,218)		—
Benefit obligation, end of period	1,553,912		2,174,595		210,811		286,301
Change in plan assets:
Fair value of plan assets, beginning of period	2,486,467		2,433,975		262,945		244,035
Return on plan assets	(539,800)		189,974		(48,257)		30,504
Plan participant contributions	—		—		2,029		2,337
Benefits paid	(137,124)		(137,482)		(10,914)		(13,931)
Fair value of plan assets, end of period	1,809,543		2,486,467		205,803		262,945
Funded status of the plan	$	255,631	$	311,872	$	(5,008)	$	(23,356)

	Pension and SERPA Benefits				Postretirement Healthcare Benefits
	2022		2021		2022		2021
Funded status as recognized on the Consolidated balance sheets:
Pension and postretirement assets	$	268,317	$	332,586	$	51,816	$	53,566
Accrued liabilities	(1,331)		(1,976)		(224)		(361)
Pension and postretirement liabilities	(11,355)		(18,738)		(56,600)		(76,561)
	$	255,631	$	311,872	$	(5,008)	$	(23,356)
Amounts included in Accumulated other comprehensive loss, net of tax:
Prior service credits	$	3,461	$	2,457	$	(1,884)	$	(3,661)
Actuarial losses (gains)	289,340		232,622		(39,699)		(36,905)
	$	292,801	$	235,079	$	(41,583)	$	(40,566)

Schedule of amounts recognized in balance sheet

The changes in the benefit obligation, fair value of plan assets and the funded status of the Company’s pension and SERPA plans and the postretirement healthcare plans as of the Company’s measurement dates of December 31, were as follows (in thousands):

	Pension and SERPA Benefits				Postretirement Healthcare Benefits
	2022		2021		2022		2021
Change in benefit obligation:
Benefit obligation, beginning of period	$	2,174,595	$	2,390,435	$	286,301	$	315,245
Service cost	19,052		24,570		4,642		5,147
Interest cost	61,890		61,988		7,617		6,505
Actuarial gains	(561,142)		(92,157)		(67,903)		(24,190)
Plan participant contributions	—		—		2,029		2,337
Benefits paid	(137,645)		(138,043)		(16,657)		(18,743)
Net curtailments and settlements	(2,838)		(72,198)		(5,218)		—
Benefit obligation, end of period	1,553,912		2,174,595		210,811		286,301
Change in plan assets:
Fair value of plan assets, beginning of period	2,486,467		2,433,975		262,945		244,035
Return on plan assets	(539,800)		189,974		(48,257)		30,504
Plan participant contributions	—		—		2,029		2,337
Benefits paid	(137,124)		(137,482)		(10,914)		(13,931)
Fair value of plan assets, end of period	1,809,543		2,486,467		205,803		262,945
Funded status of the plan	$	255,631	$	311,872	$	(5,008)	$	(23,356)

	Pension and SERPA Benefits				Postretirement Healthcare Benefits
	2022		2021		2022		2021
Funded status as recognized on the Consolidated balance sheets:
Pension and postretirement assets	$	268,317	$	332,586	$	51,816	$	53,566
Accrued liabilities	(1,331)		(1,976)		(224)		(361)
Pension and postretirement liabilities	(11,355)		(18,738)		(56,600)		(76,561)
	$	255,631	$	311,872	$	(5,008)	$	(23,356)
Amounts included in Accumulated other comprehensive loss, net of tax:
Prior service credits	$	3,461	$	2,457	$	(1,884)	$	(3,661)
Actuarial losses (gains)	289,340		232,622		(39,699)		(36,905)
	$	292,801	$	235,079	$	(41,583)	$	(40,566)

Schedule of PBO in excess of fair value of plan assets

The funded status of the qualified pension plan and the SERPA plans are combined above. Plans with projected benefit obligations (PBO) or accumulated benefit obligations (ABO) in excess of the fair value of plan assets at December 31, is presented below (in thousands):

	2022		2021
Plans with PBO in excess of fair value of plan assets:
PBO	$	12,686	$	20,715
Fair value of plan assets	$	—	$	—
Plans with ABO in excess of fair value of plan assets:
ABO	$	12,643	$	18,165
Fair value of plan assets	$	—	$	—

Schedule of ABO in excess of fair value of plan assets

The funded status of the qualified pension plan and the SERPA plans are combined above. Plans with projected benefit obligations (PBO) or accumulated benefit obligations (ABO) in excess of the fair value of plan assets at December 31, is presented below (in thousands):

	2022		2021
Plans with PBO in excess of fair value of plan assets:
PBO	$	12,686	$	20,715
Fair value of plan assets	$	—	$	—
Plans with ABO in excess of fair value of plan assets:
ABO	$	12,643	$	18,165
Fair value of plan assets	$	—	$	—

Schedule of Components of net periodic benefit costs

Components of net periodic benefit costs for the Company's defined benefit plans for the years ended December 31, were as follows (in thousands):

	Pension and SERPA Benefits						Postretirement Healthcare Benefits
	2022		2021		2020		2022		2021		2020
Service cost	$	19,052	$	24,570	$	27,224	$	4,642	$	5,147	$	11,761
Interest cost	61,890		61,988		76,447		7,617		6,505		9,391
Expected return on plan assets	(125,904)		(131,494)		(135,056)		(15,237)		(13,978)		(13,870)
Amortization of unrecognized:
Prior service credit	(1,312)		(1,247)		(1,088)		(2,323)		(2,323)		(2,381)
Net loss	31,912		67,933		65,489		488		1,056		492
Special early retirement benefits	—		—		—		—		—		—
Curtailment (gain) loss	—		(10,562)		74		—		—		(392)
Settlement (gain) loss	(1,471)		722		2,742		(1,244)		—		—
Net periodic benefit cost	$	(15,833)	$	11,910	$	35,832	$	(6,057)	$	(3,593)	$	5,001

Schedule of assumptions used to determine net periodic benefit cost

Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost at December 31, were as follows:

	Pension and SERPA Benefits						Postretirement Healthcare Benefits
	2022		2021		2020		2022		2021		2020
Assumptions for benefit obligations:
Discount rate	5.45	%	2.89	%	2.62	%	5.42	%	2.72	%	2.11	%
Rate of compensation increase	4.00	%	3.49	%	3.34	%	n/a		n/a		n/a
Assumptions for net periodic benefit cost:
Discount rate	2.89	%	2.67	%	3.49	%	2.72	%	2.11	%	3.26	%
Expected return on plan assets	5.60	%	6.20	%	6.70	%	6.77	%	6.69	%	7.00	%
Rate of compensation increase	3.49	%	3.34	%	3.39	%	n/a		n/a		n/a

Schedule of allocation of plan assets

The fair values of the Company’s pension plan assets at December 31, 2022 were as follows (in thousands):

	Balance		Level 1		Level 2
Cash and cash equivalents	$	43,062	$	—	$	43,062
Equity holdings:
U.S. companies	537,587		537,548		39
Foreign companies	22,445		22,444		1
Pooled equity funds	241,412		241,412		—
Other	35		35		—
	801,479		801,439		40
Fixed-income holdings:
U.S. Treasuries	94,128		94,128		—
Federal agencies	11,054		—		11,054
Corporate bonds	640,875		—		640,875
Pooled fixed income funds	111,649		49,472		62,177
Foreign bonds	93,112		4		93,108
Municipal bonds	10,375		—		10,375
	961,193		143,604		817,589
Plan assets subject to fair value leveling	1,805,734		$	945,043	$	860,691
Plan assets measured at net asset value:
Private equity investments	799
Real estate investments	3,010
	3,809
	$	1,809,543

The fair values of the Company’s postretirement healthcare plan assets at December 31, 2022 were as follows (in thousands): 

	Balance		Level 1		Level 2
Cash and cash equivalents	$	7,998	$	—	$	7,998
Equity holdings:
U.S. companies	95,014		95,014		—
Foreign companies	20,784		20,784		—
Pooled equity funds	24,181		24,181		—
Other	5		5		—
	139,984		139,984		—
Fixed-income holdings:
U.S. Treasuries	287		287		—
Federal agencies	34		—		34
Corporate bonds	1,938		—		1,938
Pooled fixed income funds	40,043		39,855		188
Foreign bonds	282		—		282
Municipal bonds	31		—		31
	42,615		40,142		2,473
Plan assets subject to fair value leveling	190,597		$	180,126	$	10,471
Plan assets measured at net asset value:
Private equity investments	$	13,502
Real estate investments	1,704
	$	205,803

The fair values of the Company’s pension plan assets at December 31, 2021 were as follows (in thousands):

	Balance		Level 1		Level 2
Cash and cash equivalents	$	55,192	$	—	$	55,192
Equity holdings:
U.S. companies	949,787		942,297		7,490
Foreign companies	67,111		63,245		3,866
Pooled equity funds	350,356		350,356		—
Other	63		63		—
	1,367,317		1,355,961		11,356
Fixed-income holdings:
U.S. Treasuries	76,943		76,943		—
Federal agencies	14,680		—		14,680
Corporate bonds	690,319		—		690,319
Pooled fixed income funds	148,860		54,302		94,558
Foreign bonds	112,293		207		112,086
Municipal bonds	12,549		—		12,549
	1,055,644		131,452		924,192
Plan assets subject to fair value leveling	2,478,153		$	1,487,413	$	990,740
Plan assets measured at net asset value:
Private equity investments	509
Real estate investments	7,805
	8,314
	$	2,486,467

The fair values of the Company’s postretirement healthcare plan assets at December 31, 2021 were as follows (in thousands):

	Balance		Level 1		Level 2
Cash and cash equivalents	$	6,081	$	—	$	6,081
Equity holdings:
U.S. companies	132,812		132,790		22
Foreign companies	25,062		25,051		11
Pooled equity funds	30,302		30,302		—
Other	6		6		—
	188,182		188,149		33
Fixed-income holdings:
U.S. Treasuries	221		221		—
Federal agencies	42		—		42
Corporate bonds	1,967		—		1,967
Pooled fixed income funds	46,150		45,878		272
Foreign bonds	320		1		319
Municipal bonds	36		—		36
	48,736		46,100		2,636
Plan assets subject to fair value leveling	242,999		$	234,249	$	8,750
Plan assets measured at net asset value:
Limited partnership interests	$	15,593
Real estate investments	4,353
	$	262,945

Schedule of weighted average health care cost trend rate

The weighted-average healthcare cost trend rates used in determining the accumulated postretirement benefit obligation of the healthcare plans were as follows:

	2022		2021
Healthcare cost trend rate for next year	7.00	%	6.75	%
Rate to which the cost trend rate is assumed to decline (the ultimate rate)	5.00	%	5.00	%
Year that the rate reaches the ultimate trend rate	2032		2029

Schedule of expected benefit payments for next five years and thereafter

The Company's future expected benefit payments as of December 31, 2022 were as follows (in thousands):

	Pension Benefits		SERPA Benefits		Postretirement Healthcare Benefits
2023	$	111,175	$	1,368	$	19,152
2024	$	112,243	$	1,355	$	19,674
2025	$	112,042	$	1,299	$	20,141
2026	$	113,778	$	1,253	$	20,507
2027	$	114,354	$	1,105	$	20,886
2028-2032	$	572,258	$	4,727	$	103,202