Investment in ATC and ATC Holdco (Details-1) - USD ($) $ in Thousands |
1 Months Ended | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|---|
Oct. 31, 2026 |
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
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| Schedule of Equity Method Investments [Line Items] | |||||
| Equity earnings from investment | $ 11,261 | $ 9,586 | |||
| Dividends from investments | 8,499 | 8,411 | |||
| Capital contributions to investments | $ 4,300 | 12,072 | 9,208 | ||
| MGE Transco [Member] | ATC [Member] | |||||
| Schedule of Equity Method Investments [Line Items] | |||||
| Equity earnings from investment | $ 3,907 | $ 3,224 | 11,205 | 9,280 | |
| Dividends from investments | 2,954 | 2,403 | 8,404 | 8,035 | |
| Capital contributions to investments | $ 3,567 | $ 3,214 | $ 10,183 | $ 8,385 | |
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- Definition Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of income (loss) for proportionate share of equity method investee's income (loss). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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