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IPUC (Details) - Pending Rate Case [Member] - IPUC - Intermountain Gas - Gas Distribution [Member] - USD ($) $ in Millions | Jun. 03, 2021 | Jan. 12, 2021
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Public Utilities, General Disclosures [Line Items] |  |
Depreciation and Amortization Rate Case |  | $ (2.9)
Depreciation and Amortization, Rate, Percent |  | 3.00%
Depreciation and Amortization, Requested Rate, Percent |  | 2.60%
Depreciation and Amortization Requested Rate Increase (Decrease), Amended Amount | $ (3.8) |
Depreciation and Amortization, Requested Rate, Amended, Percent | 2.40% |

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