BENEFITS

The components of our net periodic pension and Other Post-Retirement Employee Benefits (OPEB) costs for the three months ended March 31 were as follows:



	Pension Costs						OPEB Costs
Benefit Plan Cost Components	2014			2013			2014			2013
	(Millions of Dollars)
Net Periodic Benefit Cost
Service cost	$	2.7		$	4.2		$	2.2		$	2.7
Interest cost	17.1			15.1			4.5			3.9
Expected return on plan assets	(24.7		)	(24.0		)	(5.9		)	(5.3		)
Amortization of:
Prior service cost (credit)	0.5			0.6			(0.5		)	(0.5		)
Actuarial loss	9.1			13.6			0.2			0.9
Net Periodic Benefit Cost	$	4.7		$	9.5		$	0.5		$	1.7

We made no contributions to our qualified benefit plans during the first three months of 2014 and 2013. 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 $4.2 million as of March 31, 2014 and December 31, 2013.