Investments - Amortized Cost Basis of Mortgage Loans for Each Credit Quality Indicator by Year of Origination (Details) - Commercial mortgage-backed $ in Millions	Sep. 30, 2026 USD ($)
Credit Quality Information [Abstract]
2026	$ 34
2025	226
2024	101
2023	91
2022	158
Prior	414
Total	1,024
DSCR Greater than or Equal to 1.6x, LTV Less than 55%
Credit Quality Information [Abstract]
2026
2025	38
2024
2023	15
2022	19
Prior	227
Total	299
DSCR Greater than or Equal to 1.6x, LTV 55% to 65%
Credit Quality Information [Abstract]
2026
2025	37
2024
2023	12
2022	12
Prior
Total	61
DSCR Greater than or Equal to 1.6x, LTV Greater than 65%
Credit Quality Information [Abstract]
2026
2025
2024
2023
2022
Prior	13
Total	13
DSCR Between 1.2 to 1.6x, LTV Less than 55%
Credit Quality Information [Abstract]
2026	29
2025	11
2024	68
2023	46
2022
Prior	77
Total	231
DSCR Between 1.2 to 1.6x, LTV 55% to 65%
Credit Quality Information [Abstract]
2026
2025	96
2024	33
2023	18
2022	51
Prior	19
Total	217
DSCR Between 1.2 to 1.6x, LTV Greater than 65%
Credit Quality Information [Abstract]
2026	5
2025	7
2024
2023
2022	15
Prior
Total	27
DSCR Less than or Equal to 1.2x, LTV Less than 55%
Credit Quality Information [Abstract]
2026
2025	37
2024
2023
2022	37
Prior	32
Total	106
DSCR Less than or Equal to 1.2x, LTV 55% to 65%
Credit Quality Information [Abstract]
2026
2025
2024
2023
2022	7
Prior
Total	7
DSCR Less than or Equal to 1.2x, LTV Greater than 65%
Credit Quality Information [Abstract]
2026
2025
2024
2023
2022	17
Prior	46
Total	$ 63

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Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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-Topic 326
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-Topic 326
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