Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2013

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,	2013			2012			2013			2012
Service cost	$	2,834		$	2,151		$	11		$	57
Interest cost		3,023			2,905			45			74
Expected return on plan assets		(3,547	)		(3,230	)		-			-
Amortization of prior service cost		221			232			(63	)		13
Amortization of unrecognized net loss (gain)		2,453			2,203			(25	)		(45	)
Net periodic benefit cost	$	4,984		$	4,261		$	(32	)	$	99