Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2011

Compensation and Retirement Disclosure [Abstract]

Components of Net Periodic Benefit Cost

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

	Pension Benefits						Other Benefits
Three Months Ended June 30,	2011			2010			2011			2010
Service cost	$	1,775		$	1,239		$	17		$	(3	)
Interest cost		2,908			2,846			96			68
Expected return on plan assets		(3,397	)		(3,233	)		-			-
Amortization of prior service cost		236			197			13			13
Amortization of unrecognized net loss (gain)		1,049			628			(50	)		(111	)
Net periodic benefit cost (income)	$	2,571		$	1,677		$	76		$	(33	)
	Pension Benefits						Other Benefits
Six Months Ended June 30,		2011			2010			2011			2010
Service cost	$	3,447		$	2,828		$	64		$	46
Interest cost		5,920			5,793			173			176
Expected return on plan assets		(6,801	)		(6,376	)		-			-
Amortization of prior service cost		473			393			25			26
Amortization of unrecognized net loss (gain)		1,958			1,856			(111	)		(146	)
Net periodic benefit cost	$	4,997		$	4,494		$	151		$	102