Risk Management - Derivative Liabilities Input Level (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	$ (488)	$ (395)
Energy commodity derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	(162)	(113)
Contracts available for netting	25	16
Cash collateral posted	(15)	(85)
Net amount	(152)	(182)
Energy commodity derivative contracts \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	(12)	(17)
Energy commodity derivative contracts \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	(150)	(96)
Energy commodity derivative contracts \| Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	0	0
Interest rate contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	(309)	(278)
Contracts available for netting	0	0
Cash collateral posted	0	0
Net amount	(309)	(278)
Interest rate contracts \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	0	0
Interest rate contracts \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	(309)	(278)
Interest rate contracts \| Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	0	0
Foreign currency contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	(17)	(4)
Contracts available for netting	0	0
Cash collateral posted	0	0
Net amount	(17)	(4)
Foreign currency contracts \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	0	0
Foreign currency contracts \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	(17)	(4)
Foreign currency contracts \| Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross amount	$ 0	$ 0

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

Fair value of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and contract can be net settled by means outside contract or delivery of asset, subject to master netting arrangement or similar agreement and not elected or qualified to offset, deducted from derivative liability.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount of payable for negative price movement on derivative.

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