Regulatory Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2017

Regulatory Assets and Liabilities Disclosure [Abstract]

Regulatory Assets and Liabilities

The following regulatory assets and liabilities are reflected in MGE's consolidated balance sheets as of December 31:

(In thousands)		2017		2016
Regulatory Assets
Asset retirement obligation	$	8,328	$	5,563
Conservation costs		222		444
Debt related costs		9,749		10,211
Derivatives		41,958		49,281
Tax recovery related to AFUDC equity		5,497		9,403
Unfunded pension and other postretirement liability		84,342		86,475
Other		359		3,522
Total Regulatory Assets	$	150,455	$	164,899
Regulatory Liabilities
Deferred fuel savings	$	4,229	$	6,016
Elm Road		931		3,473
Income taxes		131,689		1,302
Non-ARO removal costs		18,536		16,415
Purchased gas adjustment		1,404		894
Renewable energy credits		454		339
Other		2,543		644
Total Regulatory Liabilities	$	159,786	$	29,083