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OPUC (Details 4) - OPUC [Member] - Gas Distribution [Member] - Cascade Natural Gas [Member] - USD ($) | Feb. 01, 2021 | Sep. 30, 2020 | Mar. 31, 2020
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Public Utilities, General Disclosures [Line Items] |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  |  | $ 4,900,000
Public Utilities, Requested Rate Increase (Decrease), Percentage |  |  | 7.20%
Environmental Remediation Deferred Costs Increase (Decrease) Amount |  |  | $ 364,000
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount |  | $ 3,200,000 |
Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage |  | 4.80% |
Subsequent Event [Member] |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount | $ 2,900,000 |  |
Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage | 4.30% |  |

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