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Investments Investments - Equity Investments (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2023 | Mar. 31, 2022 | Dec. 31, 2022
Schedule of Equity Method Investments [Line Items] |  |  |
Equity Securities Excluded From Fair Value Table | $ 12 |  | $ 12
Equity Securities, FV-NI, Realized Gain (Loss) | 2 | $ (3) |
Debt Securities, Available-for-sale, Allowance for Credit Loss | 1 | 1 | 0
Net Realized and Unrealized Gain (Loss) on Trading Securities | 7 | $ (13) |
Real Estate [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 22 |  | 22
Hedge Funds, Multi-strategy [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 178 |  | 186
Interest Rate Contract [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 84 |  | 80
Illiquid Investments [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 87 |  | 84
Insurance Linked [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 1 |  | 1
Equity [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 68 |  | 64
Credit Index Product [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 47 |  | 63
Private Equity Funds [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 49 |  | 47
Equity investments in pooled funds [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 545 |  | 556
Equity Securities Excluded From Fair Value |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 |  | 0
Convertibles and Bonds with Warrants Attached |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 9 |  |
Priced Through Pricing Vendors [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 65 |  | 61
Priced Through Pricing Vendors [Member] | Equity [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 57 |  | 53
Priced Through Pricing Vendors [Member] | Convertibles and Bonds with Warrants Attached |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 9 |  | $ 8
Commitments [Member] | Partnership Interest [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | $ 57 |  |

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