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Investments - Summary of Net Investment Income (Details) - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2023 | Mar. 31, 2022
Investment [Line Items] |  |
Equity Securities, FV-NI, Realized Gain (Loss) | $ 2 | $ (3)
Interest and Dividend Income, Securities, Operating, Available-for-Sale | 21 | 14
Short-term Investments [Member] |  |
Investment [Line Items] |  |
Gross Investment Income, Operating | 6 | 0
Fixed Income Investments [Member] |  |
Investment [Line Items] |  |
Gross Investment Income, Operating | 17 | 15
Fixed Income Securities, Trading |  |
Investment [Line Items] |  |
Gross Investment Income, Operating | $ 0 | $ (9)

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- Definition Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117546-209714 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(3)(d)) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 + Details
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- Definition Amount, before investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.2) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 + Details
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- Definition Amount of operating dividend and interest income, including amortization and accretion of premiums and discounts, on available-for-sale securities. + References No definition available. + Details
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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. + References No definition available. + Details
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