Employee Benefit Plans

The following table shows the components of net periodic benefit cost (including amounts capitalized to our balance sheets) for our benefit plans:



	Pension Benefits						Other Postretirement Benefits
	Three Months Ended March 31						Three Months Ended March 31
(Millions)	2014			2013			2014			2013
Service cost	$	2.4		$	2.7		$	2.5		$	2.7
Interest cost	8.7			7.8			3.9			3.3
Expected return on plan assets	(16.2		)	(14.4		)	(4.6		)	(3.7		)
Amortization of prior service cost (credit)	0.1			0.9			(1.1		)	(0.5		)
Amortization of net actuarial loss	3.7			5.8			0.6			1.8
Net periodic benefit cost (credit)	$	(1.3	)	$	2.8		$	1.3		$	3.6

Prior service costs (credits), and net actuarial losses that have not yet been recognized as a component of net periodic benefit cost are recorded as net regulatory assets or liabilities.

On March 1, 2014, we remeasured the obligations of certain other postretirement benefit plans in which we both sponsor and participate in. The remeasurement was necessary because we will replace the current retiree medical plans for participants age 65 and older with a Medicare Advantage plan starting in 2015.

Our funding policy is to contribute at least the minimum amounts that are required to be funded under the Employee Retirement Income Security Act, but not more than the maximum amounts that are currently deductible for income tax purposes. During the three months ended March 31, 2014, we contributed $46.2 million to our pension plans. Amounts contributed to our other postretirement benefit plans were not significant. We do not expect to contribute any additional amounts to our pension plans during the remainder of 2014. We expect to contribute an additional $3.8 million to our other postretirement benefit plans during the remainder of 2014, dependent upon various factors affecting us, including our liquidity position and tax law changes.