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Regulatory Matters: Winter Storm Uri (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2022 | Jun. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021 | Dec. 31, 2021
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Regulatory assets | $ 706,206 |  |  | $ 706,206 |  | $ 796,599
Winter Storm Uri Incremental Costs in a Separately Tracked Mechanism |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Regulatory assets | 392,994 |  |  | 392,994 |  | 509,025
Winter Storm Uri |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Amount Recovered Through Regulatory Mechanism |  |  |  | $ 125,000 |  |
Winter Storm Uri | Winter Storm Uri Incremental Costs in a Separately Tracked Mechanism |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Regulatory assets |  |  |  |  |  | $ 546,000
Regulatory Asset, Amortization Period |  |  |  | 2 years 9 months 18 days |  | 3 years 6 months
Winter Storm Uri | Winter Storm Uri |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Storm Carrying Costs | $ 3,700 |  | $ 1,800 | $ 18,000 | $ 1,800 |
Storm Carrying Costs One Time True-up to Commission Authorized Rates |  | $ 10,000 |  |  |  |

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