Pension plans and other postretirement benefits (Tables)

12 Months Ended

Dec. 31, 2018

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
	2018			2017			2016
	(In thousands)
Service cost	$	20,346		$	20,193		$	25,037
Interest cost on benefit obligation		74,704			79,270			83,410
Expected return on plan assets		(123,127	)		(108,524	)		(108,473	)
Amortization of prior service cost (credit)		557			557			(3,228	)
Recognized net actuarial loss		43,793			29,263			30,145
Net periodic pension expense	$	16,273		$	20,759		$	26,891

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

	Year Ended December 31
	2018			2017			2016
	(In thousands)
Service cost	$	938		$	1,172		$	1,595
Interest cost on benefit obligation		2,293			3,716			4,971
Amortization of prior service credit		(4,729	)		(1,359	)		(1,359	)
Recognized net actuarial (gain) loss		(826	)		(988	)		60
Net other postretirement benefits expense	$	(2,324	)	$	2,541		$	5,267

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
	2018			2017			2018			2017
	(In thousands)
Change in benefit obligation:
Benefit obligation at beginning of year	$	2,188,736		$	2,007,158		$	68,637		$	109,922
Service cost		20,346			20,193			938			1,172
Interest cost		74,704			79,270			2,293			3,716
Plan participants’ contributions		—			—			2,974			2,929
Amendments and curtailments		—			—			—			(30,088	)
Actuarial (gain) loss		(228,897	)		172,180			(4,758	)		(8,511	)
Medicare Part D reimbursement		—			—			508			630
Benefits paid		(105,276	)		(90,065	)		(10,601	)		(11,133	)
Benefit obligation at end of year		1,949,613			2,188,736			59,991			68,637
Change in plan assets:
Fair value of plan assets at beginning of year		2,014,891			1,642,131			—			—
Actual return on plan assets		(90,657	)		251,381			—			—
Employer contributions		14,875			211,444			7,119			7,574
Plan participants’ contributions		—			—			2,974			2,929
Medicare Part D reimbursement		—			—			508			630
Benefits paid		(105,276	)		(90,065	)		(10,601	)		(11,133	)
Fair value of plan assets at end of year		1,833,833			2,014,891			—			—
Funded status	$	(115,780	)	$	(173,845	)	$	(59,991	)	$	(68,637	)
Accrued liabilities recognized in the consolidated    balance sheet	$	(115,780	)	$	(173,845	)	$	(59,991	)	$	(68,637	)
Amounts recognized in accumulated other    comprehensive income (“AOCI”) were:
Net loss (gain)	$	401,716		$	460,622		$	(17,868	)	$	(13,936	)
Net prior service cost (credit)		2,391			2,948			(31,737	)		(36,466	)
Pre-tax adjustment to AOCI		404,107			463,570			(49,605	)		(50,402	)
Taxes		(106,240	)		(121,873	)		13,041			13,251
Net adjustment to AOCI	$	297,867		$	341,697		$	(36,564	)	$	(37,151	)

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)
2018
Net loss (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	)
2017
Net loss (gain)	$	29,323		$	(8,511	)	$	20,812
Amendments and curtailments		—			(30,088	)		(30,088	)
Amortization of prior service (cost) credit		(557	)		1,359			802
Amortization of actuarial (loss) gain		(29,263	)		988			(28,275	)
Total recognized in other comprehensive income,    pre-tax	$	(497	)	$	(36,252	)	$	(36,749	)

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 2019:

	Pension Plans		Other Postretirement Benefit Plans
	(In thousands)
Amortization of net prior service cost (credit)	$	557	$	(4,730	)
Amortization of net loss (gain)		17,755		1,168

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
	2018			2017			2018			2017
Discount rate		4.25	%		3.50	%		4.25	%		3.50	%
Rate of increase in future compensation levels		4.31	%		4.33	%		—			—

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
	2018			2017			2016			2018			2017			2016
Discount rate		3.50	%		4.00	%		4.25	%		3.50	%		4.00	%		4.25	%
Long-term rate of return on plan assets		6.50	%		6.50	%		6.50	%		—			—			—
Rate of increase in future compensation    levels		4.33	%		4.39	%		4.37	%		—			—			—

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	$	55	$	(50	)
Accumulated postretirement benefit obligation		1,204		(1,094	)

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

The fair values of the Company’s pension plan assets at December 31, 2018 and 2017, by asset category, were as follows:

	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		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

	Fair Value Measurement of Plan Assets At December 31, 2017
	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	$	117,648	$	62,706	$	54,942	$	—
Equity securities:
M&T		154,818		154,818		—		—
Domestic(a)		240,763		240,763		—		—
International(b)		13,349		13,349		—		—
Mutual funds:
Domestic(a)		205,509		205,509		—		—
International(b)		405,200		405,200		—		—
		1,019,639		1,019,639		—		—
Debt securities:
Corporate(c)		89,751		—		89,751		—
Government		235,984		—		235,984		—
International		2,176		—		2,176		—
Mutual funds:
Domestic(d)		243,456		243,456		—		—
		571,367		243,456		327,911		—
Other:
Diversified mutual fund		80,227		80,227		—		—
Real estate partnerships		3,747		842		—		2,905
Private equity		31,484		—		—		31,484
Hedge funds		178,080		125,966		—		52,114
Guaranteed deposit fund		10,925		—		—		10,925
		304,463		207,035		—		97,428
Total(e)	$	2,013,117	$	1,532,836	$	382,853	$	97,428

(a) This category is mainly comprised of equities of companies primarily within the 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 markets in Europe and the Pacific Rim.

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

(d) Approximately 77% of the mutual funds were invested in investment grade bonds and 23% in high-yielding bonds at December 31, 2018 and December 31, 2017. The holdings within the funds were spread across diverse industries.

(e) Excludes dividends and interest receivable totaling $2,060,000 and $1,774,000 at December 31, 2018 and 2017, respectively.

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, 2018 were as follows:

	Balance – January 1, 2018		Purchases (Sales)		Total Realized/ Unrealized Gains (Losses)			Balance – December 31, 2018
	(In thousands)
Other
Real estate partnerships	$	2,905	$	4,717	$	1,394		$	9,016
Private equity		31,484		30,396		1,819			63,699
Hedge funds		52,114		19,971		3,417			75,502
Guaranteed deposit fund		10,925		—		(510	)		10,415
Total	$	97,428	$	55,084	$	6,120		$	158,632

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:
2019	$	94,427	$	7,108
2020		99,361		6,975
2021		103,502		4,284
2022		106,270		4,196
2023		110,753		4,108
2024 through 2028		600,961		19,065