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Investments Investments - Equity Investments (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2022 | Mar. 31, 2021 | Dec. 31, 2021
Schedule of Equity Method Investments [Line Items] |  |  |
Equity Securities Excluded From Fair Value Table | $ 8 |  | $ 8
Equity Securities, FV-NI, Realized Gain (Loss) | (3) | $ 0 |
Debt Securities, Available-for-sale, Allowance for Credit Loss | 1 | $ 0 | 0
Real Estate [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 40 |  | 33
Hedge Funds, Multi-strategy [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 196 |  | 216
Interest Rate Contract [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 88 |  | 78
Illiquid Investments [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 87 |  | 88
Insurance Linked [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 1 |  | 2
Equity [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 91 |  | 98
Credit Index Product [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 90 |  | 107
Private Equity Funds [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 41 |  | 37
Emerging Market Debt [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 17 |  | 24
Equity investments in pooled funds [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 652 |  | 683
Equity Securities Excluded From Fair Value |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Debt Securities, Available-for-sale, Allowance for Credit Loss | 0 |  | 0
Priced Through Pricing Vendors [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 92 |  | 106
Priced Through Pricing Vendors [Member] | Equity [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 75 |  | 82
Priced Through Pricing Vendors [Member] | Emerging Market Debt [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | 17 |  | $ 24
Commitments [Member] | Partnership Interest [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Other investments | $ 70 |  |

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