Pension And Other Postretirement Benefit Plans (Tables)

3 Months Ended

Jun. 30, 2011

Pension And Other Postretirement Benefit Plans

Components Of Company's Net Periodic Benefit Cost

	Pension Benefits						Other Postretirement Benefits
	Three Months Ended						Three Months Ended
	June 30,						June 30,
(in thousands of dollars)	2011			2010			2011			2010
Service cost	$	1,290		$	1,240		$	189		$	204
Interest cost		3,451			3,547			578			624
Expected return on plan assets		(3,709	)		(3,696	)		(34	)		(36	)
Net amortization and deferral		1,342			996			(58	)		(78	)
Net periodic benefit cost	$	2,374		$	2,087		$	675		$	714