Pension plans and other postretirement benefits (Tables)

12 Months Ended

Dec. 31, 2019

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
	2019			2018			2017
	(In thousands)
Service cost	$	17,294		$	20,346		$	20,193
Interest cost on benefit obligation		81,579			74,704			79,270
Expected return on plan assets		(122,139	)		(123,127	)		(108,524	)
Amortization of prior service cost		557			557			557
Recognized net actuarial loss		21,992			43,793			29,263
Net periodic pension cost (benefit)	$	(717	)	$	16,273		$	20,759

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

	Year Ended December 31
	2019			2018			2017
	(In thousands)
Service cost	$	859		$	938		$	1,172
Interest cost on benefit obligation		2,344			2,293			3,716
Amortization of prior service credit		(4,730	)		(4,729	)		(1,359	)
Recognized net actuarial gain		(1,247	)		(826	)		(988	)
Net other postretirement benefits cost (benefit)	$	(2,774	)	$	(2,324	)	$	2,541

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
	2019			2018			2019			2018
	(In thousands)
Change in benefit obligation:
Benefit obligation at beginning of year	$	1,949,613		$	2,188,736		$	59,991		$	68,637
Service cost		17,294			20,346			859			938
Interest cost		81,579			74,704			2,344			2,293
Plan participants’ contributions		—			—			2,749			2,974
Actuarial (gain) loss		298,713			(228,897	)		(687	)		(4,758	)
Medicare Part D reimbursement		—			—			370			508
Benefits paid		(99,870	)		(105,276	)		(9,134	)		(10,601	)
Benefit obligation at end of year		2,247,329			1,949,613			56,492			59,991
Change in plan assets:
Fair value of plan assets at beginning of    year		1,833,833			2,014,891			—			—
Actual return on plan assets		293,546			(90,657	)		—			—
Employer contributions		10,431			14,875			6,015			7,119
Plan participants’ contributions		—			—			2,749			2,974
Medicare Part D reimbursement		—			—			370			508
Benefits paid		(99,870	)		(105,276	)		(9,134	)		(10,601	)
Fair value of plan assets at end of year		2,037,940			1,833,833			—			—
Funded status	$	(209,389	)	$	(115,780	)	$	(56,492	)	$	(59,991	)
Accrued liabilities recognized in the    consolidated balance sheet	$	(209,389	)	$	(115,780	)	$	(56,492	)	$	(59,991	)
Amounts recognized in accumulated other    comprehensive income (“AOCI”) were:
Net loss (gain)	$	507,029		$	401,716		$	(17,308	)	$	(17,868	)
Net prior service cost (credit)		1,834			2,391			(27,007	)		(31,737	)
Pre-tax adjustment to AOCI		508,863			404,107			(44,315	)		(49,605	)
Taxes		(133,779	)		(106,240	)		11,650			13,041
Net adjustment to AOCI	$	375,084		$	297,867		$	(32,665	)	$	(36,564	)

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)
2019
Net loss (gain)	$	127,305		$	(687	)	$	126,618
Amortization of prior service (cost) credit		(557	)		4,730			4,173
Amortization of actuarial (loss) gain		(21,992	)		1,247			(20,745	)
Total recognized in other comprehensive income,    pre-tax	$	104,756		$	5,290		$	110,046
2018
Net gain	$	(15,113	)	$	(4,758	)	$	(19,871	)
Amortization of prior service (cost) credit		(557	)		4,729			4,172
Amortization of actuarial (loss) gain		(43,793	)		826			(42,967	)
Total recognized in other comprehensive income,    pre-tax	$	(59,463	)	$	797		$	(58,666	)

Amortization of Amounts in Accumulated Other Comprehensive Income Expected to be Recognized as Components of Net Periodic Benefit Expense

The following table reflects the amortization of amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit expense during 2020:

	Pension Plans		Other Postretirement Benefit Plans
	(In thousands)
Amortization of net prior service cost (credit)	$	557	$	(4,738	)
Amortization of net loss (gain)		55,851		(1,223	)

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
	2019			2018			2019			2018
Discount rate		3.25	%		4.25	%		3.25	%		4.25	%
Rate of increase in future compensation levels		4.29	%		4.31	%		—			—

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
	2019			2018			2017			2019			2018			2017
Discount rate		4.25	%		3.50	%		4.00	%		4.25	%		3.50	%		4.00	%
Long-term rate of return on plan assets		6.50	%		6.50	%		6.50	%		—			—			—
Rate of increase in future compensation    levels		4.31	%		4.33	%		4.39	%		—			—			—

Effects on One-Percentage Point Change in Assumed Health Care Cost Trend Rates

A one-percentage point change in assumed health care cost trend rates would have had the following effects:

	+1%			-1%
	(In thousands)
Increase (decrease) in:
Service and interest cost	$	49	$	(45	)
Accumulated postretirement benefit obligation		834		(747	)

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

The fair values of the Company’s pension plan assets at December 31, 2019 and 2018, by asset category, were as follows:

	Fair Value Measurement of Plan Assets At December 31, 2019
	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	$	38,461	$	33,870	$	4,591	$	—
Equity securities:
M&T		148,603		148,603		—		—
Domestic(a)		219,663		219,663		—		—
International(b)		10,476		10,476		—		—
Mutual funds:
Domestic(a)		238,872		238,872		—		—
International(b)		381,433		381,433		—		—
		999,047		999,047		—		—
Debt securities:
Corporate(c)		112,783		—		112,783		—
Government		190,679		—		190,679		—
International		6,648		—		6,648		—
Mutual funds:
Domestic(d)		249,075		249,075		—		—
		559,185		249,075		310,110		—
Other:
Diversified mutual fund		86,980		86,980		—		—
Real estate partnerships		21,905		3,939		—		17,966
Private equity / debt		87,966		—		—		87,966
Hedge funds		231,807		116,029		—		115,778
Guaranteed deposit fund		10,527		—		—		10,527
		439,185		206,948		—		232,237
Total(e)	$	2,035,878	$	1,488,940	$	314,701	$	232,237

	Fair Value Measurement of Plan Assets At December 31, 2018
	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	$	23,049	$	10,794	$	12,255	$	—
Equity securities:
M&T		125,299		125,299		—		—
Domestic(a)		191,640		191,640		—		—
International(b)		7,752		7,752		—		—
Mutual funds:
Domestic(a)		216,523		216,523		—		—
International(b)		316,923		316,923		—		—
		858,137		858,137		—		—
Debt securities:
Corporate(c)		103,672		—		103,672		—
Government		182,034		—		182,034		—
International		2,140		—		2,140		—
Mutual funds:
Domestic(d)		280,902		280,902		—		—
International		20,661		20,661		—		—
		589,409		301,563		287,846		—
Other:
Diversified mutual fund		74,446		74,446		—		—
Real estate partnerships		11,807		2,791		—		9,016
Private equity / debt		63,699		—		—		63,699
Hedge funds		200,811		125,309		—		75,502
Guaranteed deposit fund		10,415		—		—		10,415
		361,178		202,546		—		158,632
Total(e)	$	1,831,773	$	1,373,040	$	300,101	$	158,632

(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 80% of the mutual funds were invested in investment grade bonds and 20% in high-yielding bonds at December 31, 2019. Approximately 77% of the mutual funds were invested in investment grade bonds and 23% in high-yielding bonds at December 31, 2018.  The holdings within the funds were spread across diverse industries.

(e) Excludes dividends and interest receivable totaling $2 million at each of December 31, 2019 and 2018.

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, 2019 were as follows:

	Balance – January 1, 2019		Purchases (Sales)		Total Realized/ Unrealized Gains (Losses)		Balance – December 31, 2019
	(In thousands)
Other
Real estate partnerships	$	9,016	$	7,623	$	1,327	$	17,966
Private equity/debt		63,699		9,531		14,736		87,966
Hedge funds		75,502		27,000		13,276		115,778
Guaranteed deposit fund		10,415		—		112		10,527
Total	$	158,632	$	44,154	$	29,451	$	232,237

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:
2020	$	100,800	$	6,622
2021		104,385		4,036
2022		107,368		3,972
2023		111,990		3,904
2024		115,962		3,829
2025 through 2029		619,663		17,919