Pension and Postretirement Benefits

3 Months Ended

Mar. 31, 2017

Compensation And Retirement Disclosure [Abstract]

Pension and Postretirement Benefits

7. Pension and Postretirement Benefits

The estimated components of the recorded net periodic benefit cost (credit) for pension and postretirement benefits are as follows:

	Three Months Ended March 31,
	Pension						Postretirement Benefits
	2017			2016			2017			2016
	(Dollars in Thousands)
Service cost	$	6,572		$	5,507		$	24		$	34
Interest cost		9,008			8,871			185			238
Expected return on assets		(9,936	)		(9,434	)		—			—
Amortization of:
Prior service cost (credit)		78			88			(435	)		(462	)
Actuarial loss (gain)		3,524			2,831			(72	)		(99	)
Settlement charge		—			59			—			—
Special termination benefit		—			126			—			—
Net periodic benefit cost (credit)	$	9,246		$	8,048		$	(298	)	$	(289	)

The components of net periodic benefit cost (credit), other than the service cost component, are included in the line item Other nonoperating (income) and expenses, net, in the Consolidated Statements of Earnings and Comprehensive Earnings.