Pension and Other Postretirement Plans

3 Months Ended

Mar. 31, 2018

Compensation and Retirement Disclosure [Abstract]

Pension and Other Postretirement Plans - MGE Energy and MGE.

MGE maintains qualified and nonqualified pension plans, health care, and life insurance benefits. Additionally, MGE has defined contribution 401(k) benefit plans.

The components of net periodic benefit cost, other than the service cost component, are recorded in "Other income, net" on the consolidated statements of income. The service cost component is recorded in "Other operations and maintenance" on the consolidated statements of income. Prior to January 1, 2018, a portion of all net periodic benefit cost components were capitalized within the consolidated balance sheets. The FASB issued authoritative guidance within the codification's Compensation-Retirement Benefits topic that, beginning January 1, 2018, only allows the service cost component of net periodic benefit cost to be eligible for capitalization within the consolidated balance sheets. MGE has regulatory treatment and recognizes regulatory assets or liabilities for timing differences between when net periodic benefit costs are recovered and when costs are recognized.

The following table presents the components of net periodic benefit costs recognized for the three months ended March 31, 2018 and 2017.

		Three Months Ended
		March 31,
(In thousands)		2018		2017
Pension Benefits
Components of net periodic benefit cost:
Service cost	$	1,457	$	1,332
Interest cost		3,208		3,119
Expected return on assets		(6,568)		(5,742)
Amortization of:
Prior service credit		(11)		(4)
Actuarial loss		1,298		1,464
Net periodic benefit (credit) cost	$	(616)	$	169

Postretirement Benefits
Components of net periodic benefit cost:
Service cost	$	332	$	206
Interest cost		658		444
Expected return on assets		(802)		(472)
Amortization of:
Transition obligation		1		-
Prior service credit		(667)		(436)
Actuarial loss		128		129
Net periodic benefit (credit) cost	$	(350)	$	(129)