Postretirement Benefits Other Than Pensions (Tables)

12 Months Ended

Dec. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Funded Status of Plans

The reconciliation of the beginning and ending balances of the projected benefit obligation and the fair value of plan assets for the years ended December 31, 2015 and 2014, and the funded status of the plans at December 31, 2015 and 2014 is as follows:

	December 31
	2015			2014
	(In thousands)
Change in benefit obligation:
Benefit obligation at beginning of year	$	345,766		$	293,850
Service cost	3,631			3,081
Interest cost	13,736			13,979
Plan participants’ contributions	10			13
Plan amendments	72			(411		)
Actuarial (gain) loss	(10,351		)	57,716
Benefits paid	(18,889		)	(22,462		)
Benefit obligation at end of year	333,975			345,766
Change in plan assets:
Fair value of plan assets at beginning of year	289,526			270,123
Actual return on plan assets	(6,716		)	28,980
Employer contributions	18,822			14,338
Plan participants’ contributions	10			13
Benefits paid	(18,889		)	(22,462		)
Plan settlements	—			(1,466		)
Fair value of plan assets at end of year	282,753			289,526
Funded status at end of year	$	(51,222	)	$	(56,240	)

The following table sets forth the funded status of these plans:

	December 31
	2015			2014
	(In thousands)
Change in benefit obligation:
Benefit obligation at beginning of year	$	39,126		$	37,230
Service cost	821			824
Interest cost	1,455			1,663
Employee contributions	389			380
Actuarial (gain) loss	(8,048		)	895
Benefits paid	(1,611		)	(1,866		)
Benefit obligation at end of year	32,132			39,126
Fair value of plan assets at end of year	—			—
Funded status	$	(32,132	)	$	(39,126	)

Summary of Actuarial Assumptions Used to Determine Benefit Obligations

A summary of our key actuarial assumptions used to determine the benefit obligation as of December 31, 2015 and 2014 follows:

	December 31
	2015		2014
Healthcare inflation:
Healthcare cost trend rate assumed for next year	7.27	%	7.70	%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	4.50	%	4.50	%
Year of ultimate rate achievement	2038		2029
Weighted average discount rate	4.27	%	3.85	%

A summary of our key actuarial assumptions used to determine net periodic benefit cost follows:

	Year Ended December 31
	2015		2014		2013
Healthcare inflation:
Healthcare cost trend rate assumed for next year	7.70	%	7.90	%	8.20	%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	4.50	%	4.50	%	4.50	%
Year of ultimate rate achievement	2029		2029		2029
Weighted average discount rate	3.85	%	4.64	%	3.38	%

Net Periodic Benefit Cost

	Year Ended December 31
	2015			2014			2013
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	3,631		$	3,081		$	3,692
Interest cost	13,736			13,979			12,496
Expected return on plan assets	(20,026		)	(18,761		)	(18,531		)
Amortizations:
Prior service cost	856			787			791
Unrecognized net loss	8,544			5,105			11,759
Effect of settlement	—			538			(136		)
Other	(147		)	—			329
Net periodic benefit cost	$	6,594		$	4,729		$	10,400

	Year Ended December 31
	2015		2014		2013
	(In thousands)
Components of net periodic benefit cost:
Service and interest cost	$	2,276	$	2,487	$	2,039
Amortizations:
Prior service cost	92		65		26
Unrecognized net loss	63		75		298
Other	—		98		2,286
Net periodic benefit cost	$	2,431	$	2,725	$	4,649

Effects of One Percent Change in Assumed Health Care Cost Trend Rates

A one percent change in assumed health care cost trend rates would have the following effects:

	1-Percentage- Point Increase		1-Percentage- Point Decrease
	(In thousands)
Effect on total of service and interest cost components	$	323	$	(268	)
Effect on postretirement obligation	3,155		(2,702		)

Estimated Pension Plan Benefit Payments to Participants for Next Ten Years

Estimated pension plan benefit payments to participants for the next ten years are as follows:

2016	$	19.5	million
2017	19.9		million
2018	20.1		million
2019	20.2		million
2020	20.4		million
Next five years	108.2		million

Estimated postretirement health care plan benefit payments for the next ten years are as follows:

2016	$	2.4	million
2017	2.3		million
2018	2.3		million
2019	2.4		million
2020	2.5		million
Next five years	12.7		million