Pension Plan and Other Postretirement Benefits (Tables) (Other Postretirement Benefits [Member])

9 Months Ended

Sep. 30, 2011

Other Postretirement Benefits [Member]

Net Periodic Pension and Other Postretirement Benefit Costs Table

	Pension Benefits
	For the three months ended		For the nine months ended
	September 30,		September 30,
	2011	2010	2011	2010
	(in thousands)
Service cost	$            2,330	$            1,774	$            6,992	$            5,322
Interest cost	918	812	2,753	2,436
Expected return on plan assets	(1,099)	(876)	(3,298)	(2,628)
Amortization of prior service cost	86	87	258	260
Amortization of net loss	214	201	642	605
Net periodic benefit cost	$            2,449	$            1,998	$            7,347	$            5,995
	Postretirement Benefits
	For the three months ended		For the nine months ended
	September 30,		September 30,
	2011	2010	2011	2010
	(in thousands)
Service cost	$               338	$               272	$             1,015	$               816
Interest cost	63	49	189	147
Amortization of transition obligation	16	16	48	48
Amortization of prior service cost	4	3	11	11
Amortization of net loss	2	6	8	16
Net periodic benefit cost	$               423	$               346	$              1,271	$            1,038