Pension and Other Postretirement Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2013

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 (income) for the Corporation’s qualified and nonqualified pension plans and nonqualified postretirement benefit plan are as follows:

	Three Months Ended June 30,						Six Months Ended June 30,
	2013			2012			2013			2012
	(In thousands)
Defined Benefit Pension Plans
Service cost	$	325		$	303		$	650		$	606
Interest cost	1,167			1,215			2,334			2,430
Expected return on plan assets	(1,948		)	(1,732		)	(3,896		)	(3,463		)
Amortization of prior service credit	(1		)	(1		)	(1		)	(1		)
Amortization of unrecognized net loss	946			615			1,892			1,229
Net periodic benefit cost	$	489		$	400		$	979		$	801
Postretirement Benefit Plan
Service cost	$	4		$	—		$	9		$	—
Interest cost	36			36			72			73
Amortization of prior service credit	153			(75		)	206			(150		)
Amortization of unrecognized net gain	(18		)	(7		)	(37		)	(14		)
Net periodic benefit cost (income)	$	175		$	(46	)	$	250		$	(91	)