Pension and Postretirement Benefits

9 Months Ended

Sep. 30, 2016

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 September 30,
	Pension						Postretirement Benefits
	2016			2015			2016			2015
	(Dollars in Thousands)
Service cost	$	5,542		$	5,752		$	22		$	34
Interest cost		8,970			8,287			216			232
Expected return on assets		(9,425	)		(9,095	)		—			—
Amortization of:
Prior service cost (credit)		87			106			(491	)		(574	)
Actuarial loss (gain)		3,018			3,223			(125	)		(77	)
Special termination benefit		—			382			—			—
Net periodic benefit cost (credit)	$	8,192		$	8,655		$	(378	)	$	(385	)

	Nine Months Ended September 30,
	Pension						Postretirement Benefits
	2016			2015			2016			2015
	(Dollars in Thousands)
Service cost	$	16,624		$	17,257		$	65		$	103
Interest cost		26,908			24,863			648			696
Expected return on assets		(28,272	)		(27,285	)		—			—
Amortization of:
Prior service cost (credit)		262			317			(1,471	)		(1,724	)
Actuarial loss (gain)		9,055			13,923			(374	)		(232	)
Settlement charge		59			—			—			—
Special termination benefit		764			1,844			(8	)		—
Net periodic benefit cost (credit)	$	25,400		$	30,919		$	(1,140	)	$	(1,157	)

The Corporation currently estimates that it will contribute $38,752,000 to its pension and SERP plans in 2016.