Pension Plan and Postretirement Benefits Other Than Pension (Tables)

6 Months Ended

Jun. 30, 2012

Pension Plan and Postretirement Benefits Other Than Pension

Schedule of components of net periodic pension and other postretirement costs and assumptions related to those costs

	Pension Benefits					Other Postretirement Benefits		Pension Benefits				Other Postretirement Benefits
	Three months ended June 30,					Three months ended June 30,		Six months ended June 30,				Six months ended June 30,
	2012			2011		2012	2011	2012		2011		2012	2011
	(in thousands)							(in thousands)
Components of net periodic benefit cost:
Service cost	$	2,478		1,850		173	140	4,687		3,551		346	279
Interest cost	1,973			1,861		100	100	3,785		3,598		200	201
Expected return on plan assets	(2,273		)	(2,196	)	—	—	(4,400	)	(4,382	)	—	—
Actuarial loss amortization	1,260			518		3	—	2,281		902		6	—
Prior service cost amortization	139			139		14	14	278		278		28	28
Transition obligation amortization	2			1		—	—	3		2		—	—
Total	$	3,579		2,173		290	254	6,634		3,949		580	508