Pension Plan and Other Postretirement Benefits

3 Months Ended

Mar. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Pension Plan and Other Postretirement Benefits

The Company provides a qualified, defined-benefit, non-contributory pension plan for substantially all employees. The Company makes annual contributions to fund the amounts accrued for in the qualified pension plan. The Company also maintains an unfunded, non-qualified, supplemental executive retirement plan. The costs of the plans are charged to expense or are capitalized in utility plant as appropriate.

The Company offers medical, dental, vision, and life insurance benefits for retirees and their spouses and dependents. Participants are required to pay a premium, which offsets a portion of the cost.

Cash contributions by the Company related to pension plans were $7.3 million and $5.5 million for the three months ended March 31, 2016 and March 31, 2015, respectively. There were no contributions to the other postretirement benefit plans for the three months ended March 31, 2016 and March 31, 2015, respectively. The 2016 estimated cash contribution to the pension plans is $27.3 million and to the other postretirement benefit plans is $13.4 million.

The following table lists components of net periodic benefit costs for the pension plans and other postretirement benefits. The data listed under “pension plan” includes the qualified pension plan and the non-qualified supplemental executive retirement plan. The data listed under “other benefits” is for all other postretirement benefits.



	Three Months Ended March 31
	Pension Plan						Other Benefits
	2016			2015			2016			2015
Service cost	$	5,067		$	5,632		$	2,304		$	2,500
Interest cost	5,453			5,003			1,800			1,614
Expected return on plan assets	(5,454		)	(4,792		)	(1,046		)	(876		)
Amortization of prior service cost	1,555			1,502			11			11
Recognized net actuarial loss	1,293			2,400			1,261			1,458
Net periodic benefit cost	$	7,914		$	9,745		$	4,330		$	4,707