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

6 Months Ended

Jun. 30, 2011

Other Postretirement Benefits [Member]

Net Periodic Pension and Other Postretirement Benefit Costs Table

	Pension Benefits
	For the three months ended		For the six months ended
	June 30,		June 30,
	2011	2010	2011	2010
	(in thousands)
Service cost	$            2,331	$            1,774	$            4,662	$            3,548
Interest cost	918	812	1,835	1,624
Expected return on plan assets	(1,100)	(876)	(2,199)	(1,752)
Amortization of prior service cost	86	87	172	173
Amortization of net loss	214	202	428	404
Net periodic benefit cost	$            2,449	$            1,999	$            4,898	$            3,997
	Postretirement Benefits
	For the three months ended		For the six months ended
	June 30,		June 30,
	2011	2010	2011	2010
	(in thousands)
Service cost	$               339	$               272	$               677	$               544
Interest cost	63	49	126	98
Amortization of transition obligation	16	16	32	32
Amortization of prior service cost	3	4	7	8
Amortization of net loss	3	5	6	10
Net periodic benefit cost	$               424	$               346	$               848	$               692