MGE Energy Inc Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating Activities:
Net Income	$ 16,048	$ 17,783
Items not affecting cash:
Depreciation and amortization	9,624	10,016
Deferred income taxes	8,846	1,622
Provision for doubtful receivables	1,167	1,038
Employee benefit plan expenses	4,682	3,394
Equity earnings in ATC	(2,242)	(2,097)
Other items	660	178
Changes in working capital items:
Decrease in current assets	12,377	29,753
Decrease in current liabilities	(6,631)	(7,279)
Dividend income from ATC	1,740	1,682
Cash contributions to pension and other postretirement plans	(20,789)	(19,188)
Other noncurrent items, net	(746)	1,135
Cash Provided by Operating Activities	24,736	38,037
Investing Activities:
Capital expenditures	(15,467)	(9,843)
Capital contributions to investments	(355)	(425)
Purchase of investment - land	(3)	(1,794)
Other	109	(419)
Cash Used for Investing Activities	(15,716)	(12,481)
Financing Activities:
Cash dividends paid on common stock	(8,843)	(8,670)
Repayment of long-term debt	(667)	(500)
Issuance of long-term debt	0	30,000
Decrease in short-term debt	0	(22,500)
Other	(19)	(311)
Cash Used for Financing Activities	(9,529)	(1,981)
Change in Cash and Cash Equivalents:	(509)	23,575
Cash and cash equivalents at beginning of period	41,169	7,110
Cash and cash equivalents at end of period	40,660	30,685
Significant noncash investing activities [Abstract]
Accrued capital expenditures	$ 4,674	$ 1,146