Investments (Supplemental Net Investment Income) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
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| Net Investment Income [Line Items] | ||||
| Debt and Equity Securities, Realized Gain (Loss) | $ (261) | $ (75) | $ (326) | $ (251) |
| Net Investment Income | 3,014 | 2,806 | 6,114 | 5,682 |
| Income (Loss) from Equity Method Investments | 89 | 119 | 356 | 251 |
| Income Statement Location [Axis]: us-gaap:RealizedInvestmentGainsLosses | ||||
| Net Investment Income [Line Items] | ||||
| Debt and Equity Securities, Realized Gain (Loss) | 0 | 0 | 0 | 0 |
| Debt and Equity Securities, Gain (Loss) | 132 | 84 | 99 | 70 |
| Income Statement Location [Axis]: mlic:FVOSecuritiesAndREJVsMember | ||||
| Net Investment Income [Line Items] | ||||
| Debt and Equity Securities, Unrealized Gain (Loss) | 132 | 84 | 99 | 70 |
| FVO Securities [Member] | ||||
| Net Investment Income [Line Items] | ||||
| Debt and Equity Securities, Realized Gain (Loss) | 0 | (18) | 0 | |
| Net Investment Income | $ 125 | $ 81 | $ 85 | $ 46 |
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- Definition Amount of unrealized and realized gain (loss) on investment in debt and equity securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of realized gain (loss) on investment in debt and equity securities. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of unrealized gain (loss) on investment in debt and equity securities. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of income (loss) for proportionate share of equity method investee's income (loss). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, after 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. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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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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