Employee and Retiree Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

Schedule of Plans' Benefit Obligations and Fair Value of Assets and Statement of Funded Status

The tables that follow provide a reconciliation of the changes in the plans’ benefit obligations, fair value of assets and funded status for the respective periods presented.

	Pension Benefits				Other Postretirement Benefits
(Thousands of dollars)	2023		2022		2023		2022
Change in benefit obligation
Obligation at January 1	$	663,073	$	939,380	$	67,679	$	96,133
Service cost	6,542		7,875		495		968
Interest cost	34,140		22,747		3,241		2,211
Participant contributions	–		–		2,629		2,283
Actuarial loss (gain)	26,625		(238,407)		(5,567)		(29,533)
Medicare Part D subsidy	–		–		299		331
Exchange rate changes	6,089		(21,018)		2		(20)
Benefits paid	(56,296)		(47,504)		(4,970)		(4,694)
Plan amendments 1	18,978		–		–		–
Obligation at December 31	699,151		663,073		63,808		67,679
Change in plan assets
Fair value of plan assets at January 1	450,944		611,302		–		–
Actual return on plan assets	39,953		(133,395)		–		–
Employer contributions	37,546		41,145		2,042		2,080
Participant contributions	–		–		2,629		2,283
Medicare Part D subsidy	–		–		299		331
Exchange rate changes	5,662		(20,604)		–		–
Benefits paid	(56,296)		(47,504)		(4,970)		(4,694)
Fair value of plan assets at December 31	477,809		450,944		–		–
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Deferred charges and other assets	3,192		3,584		–		–
Other accrued liabilities	(10,219)		(9,693)		(4,433)		(4,830)
Deferred credits and other liabilities	(214,315)		(206,020)		(59,375)		(62,849)
Fund Status and net plan liability recognized at December 31	$	(221,342)	$	(212,129)	$	(63,808)	$	(67,679)

1 At December 31, 2023, the Company recognized an increase to its domestic plan benefit obligation related to a plan amendment. The amendment provides a permanent increase to benefits for retirees and beneficiaries who commenced payments prior to 2020.

The preceding tables in this note include the following amounts related to foreign benefit plans.

	Pension Benefits				Other Postretirement Benefits
(Thousands of dollars)	2023		2022		2023		2022
Benefit obligation at December 31	$	133,822	$	122,915	$	115	$	107
Fair value of plan assets at December 31	119,236		115,862		–		–
Net plan liabilities recognized	(14,586)		(7,053)		(115)		(107)
Net periodic benefit expense (benefit)	1,387		(5,322)		(44)		62

Schedule of Amounts Included in Accumulated Other Comprehensive Loss Not Recognized in Net Periodic Benefit Expense

At December 31, 2023, amounts included in “Accumulated other comprehensive loss” (AOCL) in the Consolidated Balance Sheets, before reduction for associated deferred income taxes, which have not been

recognized in net periodic benefit expense are shown in the following table.

(Thousands of dollars)	Pension Benefits		Other Postretirement Benefits
Net actuarial gain (loss)	$	(202,868)	$	44,165
Prior service (credit) cost	(20,561)		3,937
	$	(223,429)	$	48,102

Schedule of Projected Benefit Obligations, Accumulated Benefit Obligations and Fair Value of Plan Assets

The table that follows includes projected benefit obligations, accumulated benefit obligations and fair value of plan assets for plans where the accumulated benefit obligation exceeded the fair value of plan assets.

	Projected Benefit Obligations				Accumulated Benefit Obligations				Fair Value of Plan Assets
(Thousands of dollars)	2023		2022		2023		2022		2023		2022
Funded qualified plans where accumulated benefit obligation exceeds fair value of plan assets	$	534,751	$	511,375	$	523,096	$	499,338	$	461,363	$	434,283
Unfunded nonqualified and directors’ plans where accumulated benefit obligation exceeds fair value of plan assets	151,146		141,917		148,661		139,634		–		–
Unfunded other postretirement plans	63,808		67,679		63,808		67,679		–		–

Schedule of Components of Net Periodic Benefit Expense

The table that follows provides the components of net periodic benefit expense for each of the three years presented.

	Pension Benefits						Other Postretirement Benefits
(Thousands of dollars)	2023		2022		2021		2023		2022		2021
Service cost	$	6,542	$	7,875	$	8,199	$	495	$	968	$	1,295
Interest cost	34,140		22,747		14,784		3,241		2,211		2,071
Expected return on plan assets	(32,839)		(36,458)		(19,222)		–		–		–
Amortization of prior service cost (credit)	620		(684)		591		(532)		(532)		–
Recognized actuarial (gain) loss	9,776		16,098		20,565		(3,512)		(615)		(29)
Net periodic benefit expense	18,239		9,578		24,917		(308)		2,032		3,337
Curtailment expense	219		–		–		–		–		–
Total net periodic benefit expense	$	18,458	$	9,578	$	24,917	$	(308)	$	2,032	$	3,337

Schedule of Weighted-Average Assumptions used in Measurement of Benefit Obligations and Net Periodic Benefit Expense

The following table provides the weighted-average assumptions used in the measurement of the Company’s benefit obligations at December 31, 2023 and 2022 and net periodic benefit expense for 2023 and 2022.

	Benefit Obligations								Net Periodic Benefit Expense
	Pension Benefits				Other Postretirement Benefits				Pension Benefits				Other Postretirement Benefits
	December 31,				December 31,				Year				Year
	2023		2022		2023		2022		2023		2022		2023		2022
Discount rate on obligation, interest cost and service cost	5.03	%	5.30	%	5.15	%	5.41	%	5.27	%	3.13	%	5.41	%	2.86	%
Rate of compensation increase	3.52	%	3.50	%	–		–		3.52	%	3.00	%	–		–
Cash balance interest credit rate	3.20	%	3.20	%	–		–		–		–		–		–
Expected return on plan assets	–		–		–		–		7.35	%	6.24	%	–		–

Schedule of Benefit Payments Expected to be Paid in Future Years

Benefit payments, reflecting expected future service as appropriate, which are expected to be paid in future years from the assets of the plans or by the Company, are shown in the following table.

(Thousands of dollars)	Pension Benefits		Other Postretirement Benefits
2024	$	47,042	$	4,433
2025	47,424		4,456
2026	48,004		4,479
2027	48,481		4,491
2028	49,834		4,614
2029-2033	248,023		22,037

Schedule of Weighted Average Asset Allocation for Funded Pension Benefit Plans

The weighted average asset allocation for the Company’s funded pension benefit plans at the respective balance sheet dates are shown in the following table.

	December 31,
	2023		2022
Equity securities	62.6	%	65.7	%
Fixed income securities	29.1	%	23.4	%
Alternatives	5.1	%	7.3	%
Cash equivalents	3.2	%	3.6	%
	100.0	%	100.0	%

Schedule of Fair Value Measurements of Retirement Plan Assets

At December 31, 2023, the fair value measurements of retirement plan assets within the fair value hierarchy are included in the table that follows.

			Fair Value Measurements Using
(Thousands of dollars)	Fair Value at December 31, 2023		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Domestic Plans
Equity securities:
U.S. core equity	$	105,212	$	105,212	$	–	$	–
U.S. small/midcap	64,165		64,165		–		–
Other alternative strategies	3,831		–		–		3,831
International equity	31,820		31,820		–		–
Emerging market equity	10,525		10,525		–		–
Fixed income securities:
U.S. fixed income	132,608		56,381		76,227		–
Cash and equivalents	10,412		10,412		—		–
Total Domestic Plans	358,573		278,515		76,227		3,831
Foreign Plans
Equity securities funds	24,389		–		24,389		–
Fixed income securities funds	23,930		–		23,930		–
Diversified pooled fund	45,162		–		45,162		–
Other	20,623		–		–		20,623
Cash and equivalents	5,133		–		5,133		–
Total Foreign Plans	119,236		–		98,613		20,623
Total	$	477,809	$	278,515	$	174,841	$	24,454

At December 31, 2022, the fair value measurements of retirement plan assets within the fair value hierarchy are included in the table that follows.

			Fair Value Measurements Using
(Thousands of dollars)	Fair Value at December 31, 2022		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Domestic Plans
Equity securities:
U.S. core equity	$	96,433	$	96,433	$	–	$	–
U.S. small/midcap	64,421		64,421		–		–
Other alternative strategies	12,106		–		–		12,106
International equity	44,672		44,672		–		–
Emerging market equity	13,541		13,541		–		–
Fixed income securities:
U.S. fixed income	85,190		35,661		49,528		–
Cash and equivalents	18,719		18,719		–		–
Total Domestic Plans	335,082		273,447		49,528		12,106
Foreign Plans
Equity securities funds	23,877		–		23,877		–
Fixed income securities funds	30,727		–		30,727		–
Diversified pooled fund	31,246		–		31,246		–
Other	20,628		–		–		20,628
Cash and equivalents	9,384		–		9,384		–
Total Foreign Plans	115,862		–		95,234		20,628
Total	$	450,944	$	273,447	$	144,763	$	32,734

Schedule of Effects of Fair Value Measurements Using Significant Unobservable Inputs on Changes in Level 3 Plan Assets

The effects of fair value measurements using significant unobservable inputs on changes in Level 3 plan assets are outlined below:

(Thousands of dollars)	Hedged Funds and Other Alternative Strategies
Total at December 31, 2021	$	82,854
Actual return on plan assets:
Relating to assets held at the reporting date	(38,389)
Purchases, sales and settlements	(11,731)
Total at December 31, 2022	32,734
Actual return on plan assets:
Relating to assets held at the reporting date	711
Relating to assets sold during the period	(8,991)
Total at December 31, 2023	$	24,454