Notes Payable to Banks, Commercial Paper, and Lines of Credit (Tables)

12 Months Ended

Dec. 31, 2011

Notes Payable to Banks, Commercial Paper, and Lines of Credit (Tables) [Abstract]

Short-Term Borrowings

		As of December 31,
(In thousands)		2011		2010		2009
MGE Energy (a)
Available lines of credit	$	115,000	$	115,000	$	195,000
Short-term debt outstanding	$	0	$	22,500	$	64,500
Weighted-average interest rate		0.00%		1.36%		0.53%	(b)
During the year:
Maximum short-term borrowings	$	28,500	$	122,500	$	134,000
Average short-term borrowings	$	3,410	$	58,080	$	105,015	(b)
Weighted-average interest rate		1.43%		0.56%		0.63%	(b)
MGE
Available lines of credit	$	75,000	$	75,000	$	75,000
Commercial paper outstanding	$	0	$	3,500	$	33,500
Weighted-average interest rate		0.00%		0.25%		0.20%
During the year:
Maximum short-term borrowings	$	9,500	$	41,000	$	60,500
Average short-term borrowings	$	349	$	20,720	$	26,900
Weighted-average interest rate		0.25%		0.24%		0.31%