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Summary of Significant Accounting Policies and Other Matters - Narrative (Details) $ in Millions | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
May 31, 2021 USD ($) | Jan. 31, 2016 mi | Mar. 31, 2022 | Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Dec. 30, 2021 USD ($) | Jun. 30, 2021 USD ($) | Mar. 31, 2021 USD ($) | Dec. 30, 2020 USD ($) | Dec. 31, 2019 USD ($)
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Investment loss/impairment |  |  |  | $ 0 | $ 211 |  |  |  |  |  |  |
Stagecoach Gas Services LLC |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Goodwill, impairment loss |  |  |  |  | 414 |  |  |  |  |  |  |
Stagecoach Gas Services LLC |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Goodwill, impairment loss |  |  |  |  | 211 |  |  |  |  |  |  |
Goodwill, impairment loss, after-tax |  |  |  |  | $ 147 |  |  |  |  |  |  |
Equity method investments |  |  |  |  |  |  |  |  | $ 630 | $ 667 |  |
Stagecoach Gas Services LLC | Con Edison Transmission | Subsidiaries |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sale | $ 1,225 |  |  |  |  |  |  |  |  |  |  |
Ownership percentage | 50.00% |  |  | 0.00% |  | 0.00% |  |  |  |  |  |
Stagecoach Gas Services LLC | CET Gas | Subsidiaries |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sale | $ 629 |  |  |  |  |  |  |  |  |  |  |
Mountain Valley Pipeline LLC | Con Edison Gas Pipeline and Storage, LLC |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership percentage |  |  |  | 9.70% |  | 10.20% | 11.30% |  |  |  |  |
Equity method investments |  |  |  |  |  |  |  |  |  |  |  | $ 530
Number of miles in pipeline construction | mi |  | 300 |  |  |  |  |  |  |  |  |  |
Equity method investment, ownership percentage, expected percentage |  |  |  | 0.08 |  |  |  |  |  |  |  |
Equity method investment, project percent completion |  |  |  |  |  | 94.00% | 92.00% |  |  |  |  |
Long term firm transportation contract period |  |  | 20 years |  |  |  |  |  |  |  |  |
Cash flows discount rate |  |  | 8.30% |  |  |  |  |  |  |  |  |
Investment loss/impairment |  |  |  |  |  | $ 231 | $ 320 |  |  |  |  |
Equity method investment, other than temporary impairment, net of tax |  |  |  |  |  | 162 | 223 |  |  |  |  |
Equity method investments, fair value disclosure |  |  |  |  |  | 111 | 342 | $ 342 |  |  | $ 662 |
Deferred tax assets, net |  |  |  | $ 130 |  | 130 | $ 53 |  |  |  |  |
Increase (decrease) in deferred tax assets |  |  |  |  |  | $ 77 |  |  |  |  |  |
Mountain Valley Pipeline LLC | Con Edison Gas Pipeline and Storage, LLC | Mountain Valley Pipeline LLC |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership percentage |  | 12.50% |  |  |  |  |  |  |  |  |  |

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