Pension Plan and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2013

Pension Plan And Other Postretirement Benefits [Abstract]

Net Periodic Pension and Other Postretirement Benefit Costs

	Pension Benefits
	For the three months ended
	March 31,
	2013		2012
	(in thousands)
Service cost	$	3,447	$	2,736
Interest cost		1,026		1,013
Expected return on plan assets		(1,534)		(1,357)
Amortization of prior service cost		26		71
Amortization of net loss		385		305
Net periodic benefit cost	$	3,350	$	2,768
	Postretirement Benefits
	For the three months ended
	March 31,
	2013		2012
	(in thousands)
Service cost	$	574	$	458
Interest cost		110		100
Amortization of transition obligation		–		16
Amortization of prior service cost		4		3
Amortization of net loss		30		23
Net periodic benefit cost	$	718	$	600