Madison Gas and Electric Company Consolidated Statements of Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Revenues:
Regulated electric revenues	$ 392,365	$ 375,858	$ 360,729
Regulated gas revenues	139,727	165,271	165,915
Nonregulated revenues	9,231	5,253	5,947
Total Operating Revenues	541,323	546,382	532,591
Operating Expenses:
Fuel for electric generation	46,499	50,819	41,947
Purchased power	73,842	64,085	71,239
Cost of gas sold	78,156	99,465	103,784
Other operations and maintenance	172,996	165,859	164,001
Depreciation and amortization	38,707	40,942	37,960
Other general taxes	18,360	17,344	17,058
Total Operating Expenses	428,560	438,514	435,989
Operating Income	112,763	107,868	96,602
Other Income and Deductions:
Equity earnings in ATC	9,079	8,615	8,501
Total Other Income and Deductions	10,069	9,214	11,093
Interest Expense:
Net Interest Expense	19,467	20,162	16,157
Net Income	64,446	60,928	57,718
MGE [Member]
Operating Revenues:
Regulated electric revenues	392,365	375,858	360,729
Regulated gas revenues	139,727	165,271	165,915
Nonregulated revenues	9,231	5,253	5,947
Total Operating Revenues	541,323	546,382	532,591
Operating Expenses:
Fuel for electric generation	46,499	50,819	41,947
Purchased power	73,842	64,085	71,239
Cost of gas sold	78,156	99,465	103,784
Other operations and maintenance	171,965	164,903	163,168
Depreciation and amortization	38,707	40,942	37,960
Other general taxes	18,360	17,344	17,058
Income tax provision	35,334	32,287	29,556
Total Operating Expenses	462,863	469,845	464,712
Operating Income	78,460	76,537	67,879
Other Income and Deductions:
AFUDC - equity funds	1,731	413	301
Equity earnings in ATC	9,079	8,615	8,501
Income tax provision	(4,101)	(3,752)	(4,749)
Other income, net	(263)	(321)	2,715
Total Other Income and Deductions	6,446	4,955	6,768
Income before interest expense	84,906	81,492	74,647
Interest Expense:
Interest on long-term debt	20,386	20,634	18,800
Other interest, net	(82)	(226)	(2,500)
AFUDC - borrowed funds	(704)	(168)	(118)
Net Interest Expense	19,600	20,240	16,182
Net Income Including Noncontrolling Interest	65,306	61,252	58,465
Less Net Income Attributable to Noncontrolling Interest, net of tax	(24,489)	(23,970)	(20,740)
Net Income	$ 40,817	$ 37,282	$ 37,725