Benefit Plans and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2012

Benefit Plans and Other Postretirement Benefits [Abstract]

Components of Net Periodic Benefit Cost

Components of Net Periodic Benefit Cost

	Three Months Ended Sept. 30
	2012				2011				2012				2011
									Postretirement Health
(Thousands of Dollars)		Pension Benefits							Care Benefits
Service cost		$	1,142			$	1,067			$	5			$	4
Interest cost			1,918				2,007				268				287
Expected return on plan assets			(2,622	)			(2,871	)			(13	)			(19	)
Amortization of transition obligation			-				-				42				42
Amortization of prior service cost (credit)			442				473				(4	)			(4	)
Amortization of net loss			1,460				1,019				123				93
Net benefit cost recognized for financial reporting		$	2,340			$	1,695			$	421			$	403

	Nine Months Ended Sept. 30
	2012				2011				2012				2011
									Postretirement Health
(Thousands of Dollars)		Pension Benefits							Care Benefits
Service cost		$	3,426			$	3,203			$	15			$	13
Interest cost			5,753				6,023				806				859
Expected return on plan assets			(7,867	)			(8,613	)			(38	)			(56	)
Amortization of transition obligation			-				-				128				128
Amortization of prior service cost (credit)			1,328				1,421				(11	)			(11	)
Amortization of net loss			4,382				3,053				365				275
Net benefit cost recognized for financial reporting		$	7,022			$	5,087			$	1,265			$	1,208