Benefit Plans and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2013

Benefit Plans and Other Postretirement Benefits [Abstract]

Components of Net Periodic Benefit Cost

Components of Net Periodic Benefit Cost

	Three Months Ended March 31
	2013			2012			2013			2012
							Postretirement Health
(Thousands of Dollars)	Pension Benefits						Care Benefits
Service cost	$	1,421		$	1,134		$	6		$	5
Interest cost		1,731			1,910			190			264
Expected return on plan assets		(2,499	)		(2,611	)		(11	)		(13	)
Amortization of transition obligation		-			-			-			43
Amortization of prior service cost (credit)		104			443			(88	)		(4	)
Amortization of net loss		1,981			1,435			241			114
Net benefit cost recognized for financial reporting	$	2,738		$	2,311		$	338		$	409