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Investments (Entities That Calculate Net Asset Value Per Share) (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | $ 6,210 | $ 7,395
Private equities | 14,078 | 12,355
Financial [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | 364 | 505
Private equities | 1,241 | 1,074
Real Estate Funds [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | 445 | 681
Private equities | 2,137 | 2,166
Distressed Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | 936 | 755
Private equities | 1,206 | 1,048
Private Credit Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | 298 | 429
Private equities | 331 | 215
Private Equity Funds [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | 4,167 | 5,025
Private equities | 8,873 | 7,424
Vintage Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | 0 | 0
Private equities | 72 | 55
Investment Funds Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | 0 | 0
Private equities | $ 218 | $ 373
Minimum | Financial [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 2 years | 2 years
Minimum | Real Estate Funds [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 2 years | 2 years
Minimum | Distressed Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 2 years | 2 years
Minimum | Private Credit Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 3 years | 3 years
Minimum | Private Equity Funds [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 2 years | 2 years
Minimum | Vintage Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 1 year | 1 year
Maximum | Financial [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 10 years | 10 years
Maximum | Real Estate Funds [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 13 years | 13 years
Maximum | Distressed Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 8 years | 8 years
Maximum | Private Credit Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 8 years | 8 years
Maximum | Private Equity Funds [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 14 years | 14 years
Maximum | Vintage Alternative Investments [Member] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period | 3 years | 3 years

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- Definition Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 35 -Paragraph 54B -Publisher FASB -URI https://asc.fasb.org//1943274/2147482134/820-10-35-54B Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-6A + 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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- Definition Remaining period of expected liquidation by investee of underlying asset of investment measured at net asset value per share or unit. In 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-6A + Details
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- Definition The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 6A -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-6A + Details
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