Equity Securities - (Summary of Cumulative Gross Unrealized Gains and Cumulative Gross Unrealized Losses and Impairments) (Details) - Non Marketable Equity Securities - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
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| Equity Securities without Readily Determinable Fair Value [Line Items] | ||
| Cumulative gross unrealized gains | $ 280.8 | $ 280.1 |
| Cumulative gross unrealized losses and impairments | $ 405.1 | $ 360.8 |
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- Definition Amount of cumulative loss from downward price adjustment on investment in equity security without readily determinable fair value. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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/disclosureRef
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- Definition Amount of cumulative gain from upward price adjustment on investment in equity security without readily determinable fair value. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Details
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