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

3 Months Ended

Mar. 31, 2012

Other Postretirement Benefits [Member]

Net Periodic Pension and Other Postretirement Benefit Costs Table

	Pension Benefits
	For the three months ended
	March 31,
	2012	2011
	(in thousands)
Service cost	$                 2,736	$                 2,331
Interest cost	1,013	917
Expected return on plan assets	(1,357)	(1,099)
Amortization of prior service cost	71	86
Amortization of net loss	305	214
Net periodic benefit cost	$                 2,768	$                 2,449
	Other Postretirement Benefits
	For the three months ended
	March 31,
	2012		2011
	(in thousands)
Service cost	$                    458		$                    338
Interest cost	100		63
Amortization of transition obligation	16		16
Amortization of prior service cost	3		4
Amortization of net loss	23		3
Net periodic benefit cost	$                    600		$                    424