Derivative Instruments and Hedging Activities - Schedule of Derivative Gains and Losses (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
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Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
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| Interest Rate Contracts (Interest expense) | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Unrealized gain (loss) on derivatives, net of tax | $ 70 | $ (8) | $ 77 | $ (40) |
| Energy-Related Commodity Contracts (Mark-to-market for economic hedging activities included in Total operating revenues) | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Unrealized gain (loss) on derivatives, net of tax | 3 | (4) | 38 | (25) |
| Energy-Related Commodity Contracts (Mark-to-market for economic hedging activities included in Cost of operations) | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Unrealized gain (loss) on derivatives, net of tax | $ 0 | $ (1) | $ (1) | $ (1) |
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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. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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