| **Investments (Credit quality indicator) (Details) - Mortgage loans $ in Millions** | Dec. 31, 2023 USD ($) |
|-------------------------------------------------------------------------------------|-----------------------|
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | $ 127                 |
| 2022                                                                                | 248                   |
| 2021                                                                                | 81                    |
| 2020                                                                                | 135                   |
| 2019                                                                                | 181                   |
| Prior                                                                               | 298                   |
| Total                                                                               | 1,070                 |
| DSCR ≥1.6x | LTV less than 55%                                                |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 33                    |
| 2022                                                                                | 9                     |
| 2021                                                                                | 8                     |
| 2020                                                                                | 98                    |
| 2019                                                                                | 60                    |
| Prior                                                                               | 238                   |
| Total                                                                               | 446                   |
| DSCR ≥1.6x | LTV 55% to 65%                                                   |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 0                     |
| 2022                                                                                | 0                     |
| 2021                                                                                | 5                     |
| 2020                                                                                | 0                     |
| 2019                                                                                | 8                     |
| Prior                                                                               | 0                     |
| Total                                                                               | 13                    |
| DSCR ≥1.6x | LTV greater than 65%                                             |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 0                     |
| 2022                                                                                | 31                    |
| 2021                                                                                | 11                    |
| 2020                                                                                | 0                     |
| 2019                                                                                | 0                     |
| Prior                                                                               | 0                     |
| Total                                                                               | 42                    |
| DSCR 1.2x - 1.6x | LTV less than 55%                                                |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 28                    |
| 2022                                                                                | 5                     |
| 2021                                                                                | 0                     |
| 2020                                                                                | 14                    |
| 2019                                                                                | 29                    |
| Prior                                                                               | 21                    |
| Total                                                                               | 97                    |
| DSCR 1.2x - 1.6x | LTV 55% to 65%                                                   |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 34                    |
| 2022                                                                                | 36                    |
| 2021                                                                                | 36                    |
| 2020                                                                                | 23                    |
| 2019                                                                                | 0                     |
| Prior                                                                               | 32                    |
| Total                                                                               | 161                   |
| DSCR 1.2x - 1.6x | LTV greater than 65%                                             |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 0                     |
| 2022                                                                                | 65                    |
| 2021                                                                                | 0                     |
| 2020                                                                                | 0                     |
| 2019                                                                                | 0                     |
| Prior                                                                               | 0                     |
| Total                                                                               | 65                    |
| DSCR ≤1.2 | LTV less than 55%                                                 |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 6                     |
| 2022                                                                                | 34                    |
| 2021                                                                                | 0                     |
| 2020                                                                                | 0                     |
| 2019                                                                                | 0                     |
| Prior                                                                               | 0                     |
| Total                                                                               | 40                    |
| DSCR ≤1.2 | LTV 55% to 65%                                                    |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 26                    |
| 2022                                                                                | 40                    |
| 2021                                                                                | 0                     |
| 2020                                                                                | 0                     |
| 2019                                                                                | 43                    |
| Prior                                                                               | 0                     |
| Total                                                                               | 109                   |
| DSCR ≤1.2 | LTV greater than 65%                                              |                  |
| **Debt Securities, Available-for-sale [Line Items]**                                |                  |
| 2023                                                                                | 0                     |
| 2022                                                                                | 28                    |
| 2021                                                                                | 21                    |
| 2020                                                                                | 0                     |
| 2019                                                                                | 41                    |
| Prior                                                                               | 7                     |
| Total                                                                               | $ 97                  |

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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amortized cost excluding accrued interest, of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.
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Amortized cost excluding accrued interest, of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease.
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Amortized cost excluding accrued interest, of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amortized cost excluding accrued interest, of financing receivable originated in current fiscal year. Excludes net investment in lease.
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Amortized cost excluding accrued interest, of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease.
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Amortized cost excluding accrued interest of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease.
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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.
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