Pension plans and other postretirement benefits (Tables)

12 Months Ended

Dec. 31, 2021

Compensation And Retirement Disclosure [Abstract]

Net Periodic Pension Expense for Defined Benefit Plans

Net periodic pension expense for defined benefit plans consisted of the following:

	Year Ended December 31
	2021			2020			2019
	(In thousands)
Service cost	$	20,513		$	19,944		$	17,294
Interest cost on benefit obligation		61,873			71,421			81,579
Expected return on plan assets		(143,448	)		(125,512	)		(122,139	)
Amortization of prior service cost		553			557			557
Recognized net actuarial loss		89,017			58,096			21,992
Net periodic pension cost (benefit)	$	28,508		$	24,506		$	(717	)

Net other postretirement benefits expense for defined benefit plans consisted of the following:

	Year Ended December 31
	2021			2020			2019
	(In thousands)
Service cost	$	1,014		$	970		$	859
Interest cost on benefit obligation		1,311			1,741			2,344
Amortization of prior service credit		(4,738	)		(4,738	)		(4,730	)
Recognized net actuarial gain		(1,295	)		(1,236	)		(1,247	)
Net other postretirement benefits	$	(3,708	)	$	(3,263	)	$	(2,774	)

Data Relating to Funding Position of Defined Benefit Plans

Data relating to the funding position of the defined benefit plans were as follows:

	Pension Benefits						Other Postretirement Benefits
	2021			2020			2021			2020
	(In thousands)
Change in benefit obligation:
Benefit obligation at beginning of year	$	2,521,292		$	2,247,329		$	55,281		$	56,492
Service cost		20,513			19,944			1,014			970
Interest cost		61,873			71,421			1,311			1,741
Plan participants’ contributions		—			—			2,553			2,386
Actuarial (gain) loss		(69,230	)		288,944			(2,232	)		2,371
Medicare Part D reimbursement		—			—			540			574
Benefits paid		(114,235	)		(106,346	)		(6,621	)		(9,253	)
Benefit obligation at end of year		2,420,213			2,521,292			51,846			55,281
Change in plan assets:
Fair value of plan assets at beginning of year		2,420,582			2,037,940			—			—
Actual return on plan assets		278,260			178,610			—			—
Employer contributions		11,231			310,378			3,528			6,293
Plan participants’ contributions		—			—			2,553			2,386
Medicare Part D reimbursement		—			—			540			574
Benefits paid		(114,235	)		(106,346	)		(6,621	)		(9,253	)
Fair value of plan assets at end of year		2,595,838			2,420,582			—			—
Funded status	$	175,625		$	(100,710	)	$	(51,846	)	$	(55,281	)
Prepaid asset recognized in the    consolidated balance sheet		332,197			64,670			—			—
Accrued liability recognized in the    consolidated balance sheet		(156,572	)		(165,380	)		(51,846	)		(55,281	)
Net accrued asset (liability)    recognized in the consolidated    balance sheet	$	175,625		$	(100,710	)	$	(51,846	)	$	(55,281	)
Amounts recognized in accumulated other comprehensive income (“AOCI”) were:
Net loss (gain)	$	391,721		$	684,780		$	(14,638	)	$	(13,701	)
Net prior service cost (credit)		724			1,277			(17,531	)		(22,269	)
Pre-tax adjustment to AOCI		392,445			686,057			(32,169	)		(35,970	)
Taxes		(101,447	)		(178,375	)		8,316			9,352
Net adjustment to AOCI	$	290,998		$	507,682		$	(23,853	)	$	(26,618	)

Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income

The table below reflects the changes in plan assets and benefit obligations recognized in other comprehensive income related to the Company’s postretirement benefit plans.

	Pension Plans			Other Postretirement Benefit Plans			Total
	(In thousands)
2021
Net loss (gain)	$	(204,042	)	$	(2,232	)	$	(206,274	)
Amortization of prior service (cost) credit		(553	)		4,738			4,185
Amortization of actuarial (loss) gain		(89,017	)		1,295			(87,722	)
Total recognized in other comprehensive income,    pre-tax	$	(293,612	)	$	3,801		$	(289,811	)
2020
Net loss (gain)	$	235,847		$	2,371		$	238,218
Amortization of prior service (cost) credit		(557	)		4,738			4,181
Amortization of actuarial (loss) gain		(58,096	)		1,236			(56,860	)
Total recognized in other comprehensive income,    pre-tax	$	177,194		$	8,345		$	185,539

Assumed Weighted-Average Rates Used to Determine Benefit Obligations

The assumed weighted-average rates used to determine benefit obligations at December 31 were:

	Pension Benefits						Other Postretirement Benefits
	2021			2020			2021			2020
Discount rate		2.75	%		2.50	%		2.75	%		2.50	%
Rate of increase in future compensation levels		3.35	%		3.37	%		—			—

Assumed Weighted-Average Rates Used to Determine Net Benefit Expense

The assumed weighted-average rates used to determine net benefit expense for the years ended December 31 were:

	Pension Benefits									Other Postretirement Benefits
	2021			2020			2019			2021			2020			2019
Discount rate		2.50	%		3.25	%		4.25	%		2.50	%		3.25	%		4.25	%
Long-term rate of return on plan assets		6.25	%		6.50	%		6.50	%		—			—			—
Rate of increase in future compensation    levels		3.37	%		4.29	%		4.31	%		—			—			—

Fair Values of Company's Pension Plan Assets by Asset Category

The fair values of the Company’s pension plan assets at December 31, 2021 and 2020, by asset category, were as follows:

	Fair Value Measurement of Plan Assets At December 31, 2021
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(In thousands)
Asset category:
Money-market investments	$	82,751	$	43,616	$	39,135	$	—
Equity securities:
M&T		134,447		134,447		—		—
Domestic(a)		369,283		369,283		—		—
International(b)		14,835		14,835		—		—
Mutual funds:
Domestic(a)		280,347		280,347		—		—
International(b)		461,304		461,304		—		—
		1,260,216		1,260,216		—		—
Debt securities:
Corporate(c)		178,528		—		178,528		—
Government		206,540		—		206,540		—
International		12,933		—		12,933		—
Mutual funds:
Domestic(d)		315,424		315,424		—		—
		713,425		315,424		398,001		—
Other:
Diversified mutual fund		108,239		108,239		—		—
Real estate partnerships		16,620		5,264		—		11,356
Private equity / debt		151,550		—		—		151,550
Hedge funds		250,691		74,599		—		176,092
Guaranteed deposit fund		10,041		—		—		10,041
		537,141		188,102		—		349,039
Total(e)	$	2,593,533	$	1,807,358	$	437,136	$	349,039

	Fair Value Measurement of Plan Assets At December 31, 2020
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(In thousands)
Asset category:
Money-market investments	$	65,263	$	48,322	$	16,941	$	—
Equity securities:
M&T		111,441		111,441		—		—
Domestic(a)		308,220		308,220		—		—
International(b)		13,648		13,648		—		—
Mutual funds:
Domestic(a)		302,094		302,094		—		—
International(b)		422,601		422,601		—		—
		1,158,004		1,158,004		—		—
Debt securities:
Corporate(c)		172,762		—		172,762		—
Government		234,232		—		234,232		—
International		6,413		—		6,413		—
Mutual funds:
Domestic(d)		302,635		302,635		—		—
		716,042		302,635		413,407		—
Other:
Diversified mutual fund		83,507		83,507		—		—
Real estate partnerships		26,847		3,616		—		23,231
Private equity / debt		97,124		—		—		97,124
Hedge funds		261,417		108,516		—		152,901
Guaranteed deposit fund		10,498		—		—		10,498
		479,393		195,639		—		283,754
Total(e)	$	2,418,702	$	1,704,600	$	430,348	$	283,754

(a) This category is mainly comprised of equities of companies primarily within the small-cap, mid-cap and large-cap sectors of the U.S. economy and range across diverse industries.

(b) This category is comprised of equities in companies primarily within the mid-cap and large-cap sectors of international markets mainly in developed and emerging markets in Europe and the Pacific Rim.

(c) This category represents investment grade bonds of U.S. issuers from diverse industries.

(d) Approximately 72% of the mutual funds were invested in investment grade bonds and 28% in high-yielding bonds at December 31, 2021. Approximately 78% of the mutual funds were invested in investment grade bonds and 22% in high-yielding bonds at December 31, 2020.  The holdings within the funds were spread across diverse industries.

(e) Excludes dividends and interest receivable totaling $2 million at each of December 31, 2021 and 2020.

Changes in Level 3 Pension Plan Assets Measured at Fair Value on Recurring Basis

The changes in Level 3 pension plan assets measured at estimated fair value on a recurring basis during the year ended December 31, 2021 were as follows:

	Balance – January 1, 2021		Purchases (Sales)			Total Realized/ Unrealized Gains (Losses)			Balance – December 31, 2021
	(In thousands)
Other
Real estate partnerships	$	23,231	$	(31,299	)	$	19,424		$	11,356
Private equity/debt		97,124		27,170			27,256			151,550
Hedge funds		152,901		(2,322	)		25,513			176,092
Guaranteed deposit fund		10,498		—			(457	)		10,041
Total	$	283,754	$	(6,451	)	$	71,736		$	349,039

Defined Benefit Plan Estimated Future Benefit Payments

Estimated benefits expected to be paid in future years related to the Company’s defined benefit pension and other postretirement benefits plans are as follows:

	Pension Benefits		Other Postretirement Benefits
	(In thousands)
Year ending December 31:
2022	$	110,113	$	3,219
2023		114,022		3,112
2024		118,641		2,983
2025		121,602		2,829
2026		125,469		2,656
2027 through 2031		649,845		11,534