Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Receivables, Net
Reserve for uncollectible accounts receivable	$ 7,050	$ 6,940
Reserve for uncollectible other accounts receivable	$ 1,323	$ 1,364
Common shareholders' equity
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	36,163,000	36,163,000
Common stock, shares outstanding	36,163,000	36,163,000
MGE [Member]
Receivables, Net
Reserve for uncollectible accounts receivable	$ 7,050	$ 6,940
Reserve for uncollectible other accounts receivable	$ 1,323	$ 1,364
Common shareholders' equity
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares outstanding	17,348,000	17,348,000