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IPUC (Details) - IPUC - Intermountain Gas - Gas Distribution [Member] - USD ($) $ in Millions | Jan. 12, 2021 | Jan. 01, 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 , Approved Rate Increase (Decrease), Amount |  | $ (3.8)
Depreciation and Amortization, Approved Rate, Percent |  | 2.40%

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