MGE Energy Inc Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities:
Net Income	$ 53,960	$ 51,544
Items not affecting cash:
Depreciation and amortization	29,042	30,669
Deferred income taxes	54,602	16,854
Provision for doubtful receivables	1,537	1,441
Employee benefit plan expenses	13,815	10,259
Equity earnings in ATC	(6,764)	(6,434)
Other items	1,632	1,044
Changes in working capital items:
(Increase) decrease in current assets	(9,002)	27,868
Decrease in current liabilities	(13,418)	(10,547)
Dividend income from ATC	5,300	5,012
Cash contributions to pension and other postretirement plans	(24,336)	(22,484)
Other noncurrent items, net	9,518	1,299
Cash Provided by Operating Activities	115,886	106,525
Investing Activities:
Capital expenditures	(65,909)	(44,859)
Capital contributions to investments	(1,988)	(958)
Purchase of investment - land	(2)	(2,152)
Other	(289)	80
Cash Used for Investing Activities	(68,188)	(47,889)
Financing Activities:
Cash dividends paid on common stock	(26,820)	(26,183)
Repayment of long-term debt	(30,000)	(1,834)
Issuance of long-term debt	28,000	30,000
Decrease in short-term debt	0	(22,500)
Other	(844)	(336)
Cash Used for Financing Activities	(29,664)	(20,853)
Change in Cash and Cash Equivalents:	18,034	37,783
Cash and cash equivalents at beginning of period	41,169	7,110
Cash and cash equivalents at end of period	59,203	44,893
Significant noncash investing activities [Abstract]
Accrued capital expenditures	$ 7,649	$ 2,606