Investments (Credit quality indicator) (Details) - Mortgage loans $ in Millions	Mar. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
2023	$ 12
2022	249
2021	94
2020	149
2019	184
Prior	342
Total	1,030
DSCR ≥1.6x | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2023	0
2022	9
2021	13
2020	112
2019	41
Prior	280
Total	455
DSCR ≥1.6x | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	0
Total	0
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	0
2022	5
2021	49
2020	13
2019	43
Prior	47
Total	157
DSCR 1.2x - 1.6x | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2023	12
2022	44
2021	0
2020	24
2019	0
Prior	8
Total	88
DSCR 1.2x - 1.6x | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2023	0
2022	58
2021	0
2020	0
2019	0
Prior	0
Total	58
DSCR ≤1.2 | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2023	0
2022	34
2021	0
2020	0
2019	35
Prior	0
Total	69
DSCR ≤1.2 | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2023	0
2022	41
2021	0
2020	0
2019	43
Prior	0
Total	84
DSCR ≤1.2 | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2023	0
2022	27
2021	21
2020	0
2019	22
Prior	7
Total	$ 77