Pension plans and other postretirement benefits (Tables)

12 Months Ended

Dec. 31, 2015

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
	2015			2014			2013
	(In thousands)
Service cost	$	24,372		$	20,520		$	24,360
Interest cost on benefit obligation		72,731			69,162			60,130
Expected return on plan assets		(96,155	)		(91,568	)		(87,353	)
Amortization of prior service credit		(6,005	)		(6,552	)		(6,556	)
Recognized net actuarial loss		44,825			14,494			41,076
Net periodic pension expense	$	39,768		$	6,056		$	31,657

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

	Year Ended December 31
	2015			2014			2013
	(In thousands)
Service cost	$	914		$	605		$	742
Interest cost on benefit obligation		2,995			2,778			2,691
Amortization of prior service credit		(1,359	)		(1,359	)		(1,359	)
Recognized net actuarial loss		106			—			360
Net other postretirement benefits expense	$	2,656		$	2,024		$	2,434

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
	2015			2014			2015			2014
	(In thousands)
Change in benefit obligation:
Benefit obligation at beginning of year	$	1,813,409		$	1,484,193		$	67,502		$	60,592
Service cost		24,372			20,520			914			605
Interest cost		72,731			69,162			2,995			2,778
Plan participants’ contributions		—			—			2,619			3,498
Amendments		—			4,619			—			—
Actuarial (gain) loss		(83,593	)		300,444			(2,431	)		7,793
Business combinations		247,340			—			56,539			—
Medicare Part D reimbursement		—			—			420			495
Benefits paid		(69,728	)		(65,529	)		(7,061	)		(8,259	)
Benefit obligation at end of year		2,004,531			1,813,409			121,497			67,502
Change in plan assets:
Fair value of plan assets at beginning of year		1,505,661			1,506,684			—			—
Actual return on plan assets		(14,069	)		56,430			—			—
Employer contributions		8,367			8,076			4,022			4,266
Plan participants’ contributions		—			—			2,619			3,498
Business combinations		194,903			—			—			—
Medicare Part D reimbursement		—			—			420			495
Benefits and other payments		(69,728	)		(65,529	)		(7,061	)		(8,259	)
Fair value of plan assets at end of year		1,625,134			1,505,661			—			—
Funded status	$	(379,397	)	$	(307,748	)	$	(121,497	)	$	(67,502	)
Accrued liabilities recognized in the consolidated balance sheet	$	(379,397	)	$	(307,748	)	$	(121,497	)	$	(67,502	)
Amounts recognized in accumulated other comprehensive income (“AOCI”) were:
Net loss	$	494,279		$	512,473		$	4,200		$	6,737
Net prior service cost		277			(5,728	)		(9,096	)		(10,455	)
Pre-tax adjustment to AOCI		494,556			506,745			(4,896	)		(3,718	)
Taxes.		(194,608	)		(198,897	)		1,927			1,459
Net adjustment to AOCI.	$	299,948		$	307,848		$	(2,969	)	$	(2,259	)

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)
2015
Net loss (gain)	$	26,631		$	(2,431	)	$	24,200
Amortization of prior service credit		6,005			1,359			7,364
Amortization of loss		(44,825	)		(106	)		(44,931	)
Total recognized in other comprehensive income, pre-tax	$	(12,189	)	$	(1,178	)	$	(13,367	)
2014
Net loss	$	335,581		$	7,793		$	343,374
Prior service cost		4,619			—			4,619
Amortization of prior service credit		6,552			1,359			7,911
Amortization of loss		(14,494	)		—			(14,494	)
Total recognized in other comprehensive income, pre-tax	$	332,258		$	9,152		$	341,410

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 2016:

	Pension Plans			Other Postretirement Benefit Plans
	(In thousands)
Amortization of net prior service credit	$	(3,228	)	$	(1,359	)
Amortization of net loss		30,912			8

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
	2015			2014			2015			2014
Discount rate		4.25	%		4.00	%		4.25	%		4.00	%
Rate of increase in future compensation levels		4.37	%		4.39	%		—			—

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
	2015			2014			2013			2015			2014			2013
Discount rate		4.00	%		4.75	%		3.75	%		4.00	%		4.75	%		3.75	%
Long-term rate of return on plan assets		6.50	%		6.50	%		6.50	%		—			—			—
Rate of increase in future compensation levels		4.39	%		4.42	%		4.50	%		—			—			—

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	$	108	$	(96	)
Accumulated postretirement benefit obligation		3,180		(2,729	)

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

The fair values of the Company’s pension plan assets at December 31, 2015, by asset category, were as follows:

	Fair Value Measurement of Plan Assets At December 31, 2015
	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 funds	$	69,634	$	37,958	$	31,676	$	—
Equity securities:
M&T		148,800		148,800		—		—
Domestic(a)		106,993		106,993		—		—
International(b)		9,433		9,433		—		—
Mutual funds:
Domestic(a)		445,663		445,663		—		—
International(b)		348,869		348,869		—		—
		1,059,758		1,059,758		—		—
Debt securities:
Corporate(c)		105,499		—		105,499		—
Government		120,346		—		120,346		—
International		7,492		—		7,492		—
Mutual funds:
Domestic(d)		51,028		51,028		—		—
		284,365		51,028		233,337		—
Other:
Diversified mutual fund		70,343		70,343		—		—
Private real estate		2,787		—		—		2,787
Private equity		5,603		—		—		5,603
Hedge funds		119,549		81,861		—		37,688
Guaranteed deposit fund		11,596		—		—		11,596
		209,878		152,204		—		57,674
Total(e)	$	1,623,635	$	1,300,948	$	265,013	$	57,674

The fair values of the Company’s pension plan assets at December 31, 2014, by asset category, were as follows:

	Fair Value Measurement of Plan Assets At December 31, 2014
	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 funds	$	29,458	$	29,458	$	—	$	—
Equity securities:
M&T		154,252		154,252		—		—
Domestic(a)		214,127		214,127		—		—
International(b)		16,170		16,170		—		—
Mutual funds:
Domestic(a)		305,817		305,817		—		—
International(b)		381,101		381,101		—		—
		1,071,467		1,071,467		—		—
Debt securities:
Corporate(c)		102,848		—		102,848		—
Government		92,772		—		92,772		—
International		7,196		—		7,196		—
Mutual funds:
Domestic(d)		27,847		27,847		—		—
		230,663		27,847		202,816		—
Other:
Diversified mutual fund		96,936		96,936		—		—
Private real estate		2,162		—		—		2,162
Private equity		6,234		—		—		6,234
Hedge funds		66,694		42,430		—		24,264
		172,026		139,366		—		32,660
Total(e)	$	1,503,614	$	1,268,138	$	202,816	$	32,660

(a) This category is 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 33% of the mutual funds were invested in investment grade bonds and 67% in high-yielding bonds at December 31, 2015. Approximately 55% of the mutual funds were invested in investment grade bonds and 45% in high-yielding bonds at December 31, 2014. The holdings within the funds were spread across diverse industries.

(e) Excludes dividends and interest receivable totaling $1,499,000 and $2,047,000 at December 31, 2015 and 2014, 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, 2015 were as follows:

	Balance – January 1, 2015		Purchases (Sales)			Total Realized/ Unrealized Gains (Losses)			Balance – December 31, 2015
	(In thousands)
Other
Private real estate	$	2,162	$	(125	)	$	750		$	2,787
Private equity		6,234		(975	)		344			5,603
Hedge funds		24,264		14,258			(834	)		37,688
Guaranteed deposit fund		—		11,407			189			11,596
Total	$	32,660	$	24,565		$	449		$	57,674

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:
2016	$	77,923	$	8,771
2017		82,899		8,834
2018		87,480		8,952
2019		93,309		8,979
2020		98,138		8,973
2021 through 2025		561,736		44,338