Pension and Other Postretirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2014

Compensation and Retirement Disclosure [Abstract]

Components of net periodic benefit cost (income) for the Corporation's qualified and nonqualified pension plans and nonqualified postretirement benefits plan

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

	Three Months Ended March 31,
	2014			2013
	(In thousands)
Defined Benefit Pension Plans
Service cost	$	250		$	325
Interest cost	1,312			1,167
Expected return on plan assets	(2,078		)	(1,948		)
Amortization of unrecognized net loss	569			946
Net periodic benefit cost	$	53		$	490
Postretirement Benefit Plan
Service cost	$	5		$	—
Interest cost	35			75
Amortization of prior service cost	32			—
Amortization of unrecognized net gain	(26		)	—
Net periodic benefit cost	$	46		$	75