Retirement Benefits (Tables)

9 Months Ended

Sep. 30, 2011

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 September 30,	2011			2010			2011			2010
Service cost	$	1,723		$	1,414		$	32		$	23
Interest cost		2,959			2,896			87			88
Expected return on plan assets		(3,400	)		(3,188	)		-			-
Amortization of prior service cost		236			196			13			13
Amortization of unrecognized net loss (gain)		979			928			(56	)		(73	)
Net periodic benefit cost	$	2,497		$	2,246		$	76		$	51

	Pension Benefits						Other Benefits
Nine Months Ended September 30,	2011			2010			2011			2010
Service cost	$	5,168		$	4,242		$	96		$	69
Interest cost		8,878			8,689			260			263
Expected return on plan assets		(10,199	)		(9,564	)		-			-
Amortization of prior service cost		709			589			38			38
Amortization of unrecognized net loss (gain)		2,936			2,784			(167	)		(218	)
Net periodic benefit cost	$	7,492		$	6,740		$	227		$	152