Fair Value Measurements (Gain/Loss Included in Earnings Relating to Assets Still Held at End of Period) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
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| Fair Value Disclosures [Abstract] | ||||||
| The amount of total (gain) loss for the period included in earnings attributable to the change in unrealized (gain) loss relating to liabilities still held at the end of period | [1] | $ 12 | $ (2) | $ 28 | $ 1 | |
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