Pension and Other Postretirement Plans

3 Months Ended

Mar. 31, 2019

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. The service cost component of net periodic benefit cost is 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.

		Three Months Ended
		March 31,
(In thousands)		2019		2018
Pension Benefits
Components of net periodic benefit cost:
Service cost	$	1,141	$	1,457
Interest cost		3,452		3,208
Expected return on assets		(5,547)		(6,568)
Amortization of:
Prior service credit		(28)		(11)
Actuarial loss		1,729		1,298
Net periodic benefit cost (credit)	$	747	$	(616)

Postretirement Benefits
Components of net periodic benefit cost:
Service cost	$	219	$	332
Interest cost		577		658
Expected return on assets		(681)		(802)
Amortization of:
Transition obligation		1		1
Prior service credit		(667)		(667)
Actuarial loss		106		128
Net periodic benefit (credit) cost	$	(445)	$	(350)