Investments - Amortized Cost Basis of Mortgage Loans for Each Credit Quality Indicator by Year of Origination (Details) - Commercial mortgage-backed $ in Millions	Mar. 31, 2025 USD ($)
Credit Quality Information [Abstract]
2025	$ 37
2024	101
2023	127
2022	234
2021	76
Prior	509
Total	1,084
DSCR Greater than or Equal to 1.6x, LTV Less than 55%
Credit Quality Information [Abstract]
2025
2024
2023	33
2022	9
2021
Prior	209
Total	251
DSCR Greater than or Equal to 1.6x, LTV 55% to 65%
Credit Quality Information [Abstract]
2025
2024
2023
2022	15
2021	11
Prior	16
Total	42
DSCR Greater than or Equal to 1.6x, LTV Greater than 65%
Credit Quality Information [Abstract]
2025
2024
2023	12
2022	31
2021	12
Prior
Total	55
DSCR Between 1.2 to 1.6x, LTV Less than 55%
Credit Quality Information [Abstract]
2025
2024	60
2023	28
2022	5
2021	2
Prior	137
Total	232
DSCR Between 1.2 to 1.6x, LTV 55% to 65%
Credit Quality Information [Abstract]
2025
2024	41
2023	31
2022	20
2021	30
Prior	58
Total	180
DSCR Between 1.2 to 1.6x, LTV Greater than 65%
Credit Quality Information [Abstract]
2025
2024
2023
2022	46
2021
Prior
Total	46
DSCR Less than or Equal to 1.2x, LTV Less than 55%
Credit Quality Information [Abstract]
2025
2024
2023
2022
2021
Prior	21
Total	21
DSCR Less than or Equal to 1.2x, LTV 55% to 65%
Credit Quality Information [Abstract]
2025	37
2024
2023	23
2022	73
2021
Prior	20
Total	153
DSCR Less than or Equal to 1.2x, LTV Greater than 65%
Credit Quality Information [Abstract]
2025
2024
2023
2022	35
2021	21
Prior	48
Total	$ 104

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
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+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
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