Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2012

Retirement Benefits [Abstract]

Components of net periodic benefit cost

Components of Net Periodic Benefit Cost (in thousands of dollars)

	Pension Benefits						Other Benefits
Three Months Ended March 31,	2012			2011			2012			2011
Service cost	$	2,151		$	1,672		$	57		$	48
Interest cost		2,905			3,012			74			77
Expected return on plan assets		(3,230	)		(3,404	)		-			-
Amortization of prior service cost		232			236			13			13
Amortization of unrecognized net loss (gain)		2,203			909			(45	)		(61	)
Net periodic benefit cost	$	4,261		$	2,425		$	99		$	77