Madison Gas and Electric Company Consolidated Statements of Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Revenues:
Electric revenues		$ 414,274	$ 410,202	$ 420,291
Gas revenues		148,825	134,543	143,737
Total Operating Revenues		563,099	544,745	564,028
Operating Expenses:
Fuel for electric generation		53,029	60,736	53,858
Purchased power		58,690	56,313	81,224
Cost of gas sold		76,644	66,771	76,109
Other operations and maintenance		173,629	167,989	164,478
Depreciation and amortization		53,077	44,646	44,225
Other general taxes		19,294	20,062	19,879
Total Operating Expenses		434,363	416,517	439,773
Operating Income (Loss)		128,736	128,228	124,255
Other Income and Deductions:
Equity earnings in MGE Transco		10,125	8,428	7,728
Total Other Income and Deductions		10,288	9,711	8,613
Interest Expense:
Net Interest Expense		19,324	19,866	20,162
Net Income		97,606	75,560	71,343
MGE [Member]
Operating Revenues:
Electric revenues		414,277	410,226	420,313
Gas revenues		148,834	134,572	143,752
Total Operating Revenues		563,111	544,798	564,065
Operating Expenses:
Fuel for electric generation		53,031	60,745	53,866
Purchased power		58,692	56,327	81,237
Cost of gas sold		76,652	66,800	76,124
Other operations and maintenance		172,618	167,077	163,622
Depreciation and amortization		53,077	44,622	44,178
Other general taxes		19,294	20,062	19,879
Income tax provision		18,280	39,616	38,159
Total Operating Expenses		451,644	455,249	477,065
Operating Income (Loss)	[1]	111,467	89,549	87,000
Other Income and Deductions:
AFUDC - equity funds		1,222	1,207	712
Equity earnings in MGE Transco		0	6,366	7,728
Income tax provision		(710)	(2,175)	(3,247)
Other income (deductions), net		1,117	(217)	(345)
Total Other Income and Deductions	[1]	1,629	5,181	4,848
Income before interest expense		113,096	94,730	91,848
Interest Expense:
Interest on long-term debt		20,273	20,351	20,520
Other interest, net		163	182	94
AFUDC - borrowed funds		(412)	(395)	(231)
Net Interest Expense		20,024	20,138	20,383
Net Income Including Noncontrolling Interest		93,072	74,592	71,465
Less Net Income Attributable to Noncontrolling Interest, net of tax		(43,237)	(23,358)	(26,097)
Net Income		$ 49,835	$ 51,234	$ 45,368

[1] Amounts are shown net of the related tax expense, consistent with the presentation on the MGE Consolidated Statements of Income.