Benefit Plans and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2011

Benefit Plans and Other Postretirement Benefits

Schedule of net cost for pension benefits and other postretirement benefits

	Pension Benefits						Other Postretirement Benefits
	Three months ended June 30,
	2011			2010			2011		2010
Service cost	$	1,354		$	1,435		$	45	$	41
Interest cost	4,587			5,631			201		197
Expected return on plan assets	(4,415		)	(5,628		)	—		—
Amortization of transition obligation	(29		)	(27		)	16		16
Amortization of prior service cost	412			888			—		—
Amortization of net actuarial losses	2,456			2,625			311		221
Net pension expense	$	4,365		$	4,924		$	573	$	475

	Pension Benefits						Other Postretirement Benefits
	Six months ended June 30,
	2011			2010			2011		2010
Service cost	$	2,967		$	2,894		$	100	$	82
Interest cost	10,391			11,341			424		394
Expected return on plan assets	(10,453		)	(11,274		)	—		—
Amortization of transition obligation	(56		)	(54		)	31		32
Amortization of prior service cost	990			1,776			—		—
Amortization of net actuarial losses	5,890			5,258			651		442
Net pension expense	$	9,729		$	9,941		$	1,206	$	950