Pension and Other Postretirement Plans

6 Months Ended

Jun. 30, 2017

Compensation and Retirement Disclosure [Abstract]

Pension and Other Postretirement Plans

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 following table presents the components of net periodic benefit costs recognized for the three and six months endedJune 30,2017 and 2016. A portion of the net periodic benefit cost is capitalized within the consolidated balance sheets.

		Three Months Ended				Six Months Ended
		June 30,				June 30,
(In thousands)		2017		2016		2017		2016
Pension Benefits
Components of net periodic benefit cost:
Service cost	$	1,360	$	1,564	$	2,692	$	2,945
Interest cost		3,194		3,494		6,313		6,583
Expected return on assets		(5,740)		(6,329)		(11,482)		(11,922)
Amortization of:
Prior service (credit) cost		(4)		3		(8)		5
Actuarial loss		1,711		1,534		3,175		2,890
Net periodic benefit cost	$	521	$	266	$	690	$	501
Postretirement Benefits
Components of net periodic benefit cost:
Service cost	$	423	$	399	$	629	$	723
Interest cost		912		831		1,356		1,505
Expected return on assets		(971)		(868)		(1,443)		(1,573)
Amortization of:
Transition obligation		1		1		1		2
Prior service credit		(898)		(822)		(1,334)		(1,489)
Actuarial loss		251		196		380		355
Net periodic benefit credit	$	(282)	$	(263)	$	(411)	$	(477)