Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Debt Securities, Available-for-sale, Amortized Cost | $ 20,411 | $ 18,304 |
| Equity Securities, FV-NI, Cost | 4,273 | 4,155 |
| Short-term investments, available-for-sale, amortized cost basis | 144 | 148 |
| Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization | $ 381 | $ 367 |
| Common Stock, Par or Stated Value Per Share (in dollars per share) | $ 2 | $ 2 |
| Common Stock, Shares Authorized (in shares) | 500.0 | 500.0 |
| Common Stock, Shares, Issued (in shares) | 198.3 | 198.3 |
| Treasury Stock, Common, Shares (in shares) | 44.8 | 42.9 |
| X | ||||||||||
- Definition Amortized cost of short-term investments measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). No definition available.
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| X | ||||||||||
- Definition Amount of accumulated depreciation, depletion, and amortization of property, plant, and equipment. Includes, but is not limited to, land and land improvement; building; machinery and equipment; furniture and fixture; and work of art, historical treasure, or similar asset classified as collection. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Face amount or stated value per share of common stock. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amortized cost, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Number of previously issued common shares repurchased by the issuing entity and held in treasury. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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