Retirement Benefits

3 Months Ended

Mar. 31, 2013

Retirement Benefits

Retirement Benefits

Note 8 — Retirement Benefits

Net periodic benefit cost, some of which is capitalized as a component of labor cost and some of which is deferred as a regulatory asset, is comprised of the following components and is shown for our noncontributory defined benefit pension plan, our supplemental retirement program (SERP) and other postretirement benefits (OPEB) (in thousands):

	Three months ended March 31,
	Pension						SERP						OPEB
	2013			2012			2013			2012			2013			2012
Service cost	$	1,868		$	1,628		$	15		$	7		$	755		$	565
Interest cost	2,509			2,551			63			56			992			1,032
Expected return on plan assets	(3,125		)	(3,076		)	—			—			(1,099		)	(1,041		)
Amortization of prior service cost (1)	133			133			(2		)	(2		)	(253		)	(253		)
Amortization of net actuarial loss (1)	2,590			1,950			104			76			649			468
Net periodic benefit cost	$	3,975		$	3,186		$	180		$	137		$	1,044		$	771

	Twelve months ended March 31,
	Pension						SERP						OPEB
	2013			2012			2013			2012			2013			2012
Service cost	$	6,500		$	5,830		$	59		$	81		$	2,591		$	2,205
Interest cost	10,215			10,366			270			198			3,996			4,286
Expected return on plan assets	(12,358		)	(11,534		)	—			—			(4,193		)	(4,148		)
Amortization of prior service cost (1)	532			532			(8		)	(8		)	(1,011		)	(1,011		)
Amortization of net actuarial loss (1)	8,576			6,091			416			213			1,844			1,729
Net periodic benefit cost	$	13,465		$	11,285		$	737		$	484		$	3,227		$	3,061

(1) Amounts are amortized from our regulatory asset originally recorded upon recognizing our net pension liability on the balance sheet.

In accordance with our regulatory agreements, our pension funding policy is to make contributions that are at least equal to the greater of either the minimum funding requirements of ERISA or the accrued cost of the plan. We expect to make pension contributions of approximately $15.9 million during 2013. The actual minimum funding requirements will be determined based on the results of the actuarial valuations. Our OPEB funding policy is to contribute annually an amount at least equal to the actuarial cost of postretirement benefits.