RETIREMENT AND OTHER EMPLOYEE BENEFITS (Tables)

3 Months Ended

Mar. 31, 2015

Retirement and other employee benefits

Schedule of net periodic benefit pension cost

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
	2015			2014			2015			2014			2015			2014
Service cost	$	1,883		$	1,627		$	43		$	29		$	920		$	607
Interest cost	2,503			2,733			92			87			1,164			1,080
Expected return on plan assets	(3,390		)	(3,322		)	—			—			(1,312		)	(1,196		)
Amortization of prior service cost (1)	(157		)	105			(11		)	(2		)	(253		)	(253		)
Amortization of net actuarial loss (1)	2,345			1,649			140			105			681			228
Net periodic benefit cost	$	3,184		$	2,792		$	264		$	219		$	1,200		$	466

	Twelve months ended March 31,
	Pension						SERP						OPEB
	2015			2014			2015			2014			2015			2014
Service cost	$	6,722		$	7,213		$	167		$	148		$	2,914		$	2,792
Interest cost	10,589			10,287			393			338			4,442			3,916
Expected return on plan assets	(13,173		)	(12,625		)	—			—			(4,916		)	(4,451		)
Amortization of prior service cost (1)	156			503			(17		)	(8		)	(1,011		)	(1,011		)
Amortization of net actuarial loss (1)	7,308			9,504			539			569			1,420			1,841
Net periodic benefit cost	$	11,602		$	14,882		$	1,082		$	1,047		$	2,849		$	3,087

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