Pension Plan and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2013

Pension Plan And Other Postretirement Benefits [Abstract]

Net Periodic Pension and Other Postretirement Benefit Costs

	Pension Benefits
	For the three months ended				For the six months ended
	June 30,				June 30,
	2013		2012		2013		2012
	(in thousands)
Service cost	$	3,448	$	2,735	$	6,895	$	5,471
Interest cost		1,026		1,012		2,052		2,025
Expected return on plan assets		(1,534)		(1,356)		(3,068)		(2,713)
Amortization of prior service cost		26		72		52		143
Amortization of net loss		385		305		770		610
Net periodic benefit cost	$	3,351	$	2,768	$	6,701	$	5,536
	Postretirement Benefits
	For the three months ended				For the six months ended
	June 30,				June 30,
	2013		2012		2013		2012
	(in thousands)
Service cost	$	574	$	458	$	1,148	$	916
Interest cost		110		99		220		199
Amortization of transition obligation		–		16		–		32
Amortization of prior service cost		3		4		7		7
Amortization of net loss		30		23		60		46
Net periodic benefit cost	$	717	$	600	$	1,435	$	1,200