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MNPUC (Details) - Pending Rate Case [Member] - MNPUC [Member] - Gas Distribution [Member] - Great Plains Natural Gas Co. [Member] - USD ($) $ in Millions | Oct. 26, 2020 | Jan. 01, 2020 | Sep. 27, 2019
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Public Utilities, General Disclosures [Line Items] |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  |  | $ 2.9
Public Utilities, Requested Rate Increase (Decrease), Percentage |  |  | 12.00%
Public Utilities, Interim Rate Increase (Decrease), Amount |  | $ 2.6 |
Public Utilities, Interim Rate Increase (Decrease), Percentage |  | 11.00% |
Public Utilities, Approved Rate Increase (Decrease), Amount | $ 2.6 |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage | 11.50% |  |

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