Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2012

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs

The components of net periodic benefit cost are as follows:

	Pension Benefits
	Three Months Ended September 30,						Nine Months Ended September 30,
	2012			2011			2012			2011
Components of Net Periodic Pension Cost
Service Cost	$	1,799		$	1,531		$	5,397		$	4,593
Interest Cost	2,965			2,860			8,895			8,580
Expected return on assets	(3,034		)	(3,328		)	(9,102		)	(9,984		)
Amortization of unrecognized prior service costs	97			98			291			294
Cumulative net loss	2,593			1,780			7,779			5,340
Net periodic pension cost	$	4,420		$	2,941		$	13,260		$	8,823

	Postretirement Benefits
	Three Months Ended September 30,					Nine Months Ended September 30,
	2012			2011		2012			2011
Components of Net Periodic Postretirement Cost
Service Cost	$	19		$	14	$	57		$	42
Interest Cost	174			221		522			663
Amortization of unrecognized prior service costs	(117		)	—		(351		)	—
Cumulative net loss	72			28		216			84
Net periodic postretirement cost	$	148		$	263	$	444		$	789