Benefits

9 Months Ended

Sep. 30, 2012

General Discussion of Pension and Other Postretirement Benefits [Abstract]

BENEFITS

BENEFITS

The components of our net periodic pension and Other Post-Retirement Employee Benefits (OPEB) costs for the three and nine months ended September 30 were as follows:

	Pension Costs
	Three Months Ended September 30						Nine Months Ended September 30
Benefit Plan Cost Components	2012			2011			2012			2011
	(Millions of Dollars)
Net Periodic Benefit Cost
Service cost	$	5.5		$	4.0		$	16.3		$	11.9
Interest cost	16.4			16.9			49.2			50.7
Expected return on plan assets	(22.5		)	(20.5		)	(67.3		)	(61.6		)
Amortization of:
Prior service cost	0.5			0.6			1.7			1.7
Actuarial loss	10.2			8.4			30.4			25.5
Net Periodic Benefit Cost	$	10.1		$	9.4		$	30.3		$	28.2

	OPEB Costs
	Three Months Ended September 30						Nine Months Ended September 30
Benefit Plan Cost Components	2012			2011			2012			2011
	(Millions of Dollars)
Net Periodic Benefit Cost
Service cost	$	2.6		$	2.6		$	7.8		$	7.8
Interest cost	5.1			5.2			15.3			15.6
Expected return on plan assets	(4.8		)	(4.3		)	(14.4		)	(12.7		)
Amortization of:
Transition obligation	—			—			0.2			0.2
Prior service (credit)	(0.5		)	(0.4		)	(1.4		)	(1.4		)
Actuarial loss	1.9			1.7			5.4			4.7
Net Periodic Benefit Cost	$	4.3		$	4.8		$	12.9		$	14.2

During the first nine months of 2012 and 2011, we contributed $100.0 million and $257.4 million, respectively, to our qualified benefit plans. Future contributions to the plans will be dependent upon many factors, including the performance of existing plan assets and long-term discount rates.

Postemployment Benefits:   Postemployment benefits provided to former or inactive employees are recognized when an event occurs. The estimated liability for such benefits was $5.2 million as of September 30, 2012 and $15.3 million as of December 31, 2011.