Pension and Other Postretirement Benefit Plans

The components of net periodic benefit cost (income) for the Corporation’s qualified and nonqualified pension plans and nonqualified postretirement benefit plan are as follows:



	Three Months Ended September 30,						Nine Months Ended September 30,
	2013			2012			2013			2012
	(In thousands)
Defined Benefit Pension Plans
Service cost	$	326		$	304		$	976		$	910
Interest cost	1,166			1,214			3,500			3,644
Expected return on plan assets	(1,949		)	(1,731		)	(5,845		)	(5,194		)
Amortization of prior service credit	—			—			(1		)	(1		)
Amortization of unrecognized net loss	946			614			2,838			1,843
Net periodic benefit cost	$	489		$	401		$	1,468		$	1,202
Postretirement Benefit Plan
Service cost	$	5		$	—		$	14		$	—
Interest cost	36			37			108			110
Amortization of prior service cost (credit)	27			(75		)	233			(225		)
Amortization of unrecognized net gain	(18		)	(7		)	(55		)	(21		)
Net periodic benefit cost (income)	$	50		$	(45	)	$	300		$	(136	)

The Corporation’s pension plan does not have a contribution requirement in 2013. The Corporation made a voluntary $15.0 million contribution to the pension plan during the first quarter of 2013. The discount rate used to compute the Corporation's pension plan expense for 2013 is 4.08%.

401(k) Savings Plan expense for the Corporation’s match of participants’ base compensation contributions and a 4% of eligible pay contribution to certain employees who are not grandfathered under the pension plan was $0.9 million and $0.8 million for the three months ended September 30, 2013 and 2012, respectively, and $2.7 million and $2.3 million for the nine months ended September 30, 2013 and 2012, respectively.