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v3.20.2

Risk Management Activities (Narrative) (Details) - USD ($) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Dec. 31, 2019
Derivative [Line Items] |  |  |
Limit of GCA Volumes | 20.00% |  |
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net | $ 0 | $ 0 | $ 0
Interest Rate Swap |  |  |
Derivative [Line Items] |  |  |
Derivative, Notional Amount | $ 500,000,000.0 |  |
Minimum |  |  |
Derivative [Line Items] |  |  |
Commodity Contract Length | 5 years |  |
Maximum |  |  |
Derivative [Line Items] |  |  |
Commodity Contract Length | 10 years |  |

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