Investments (Credit quality indicator) (Details) - Mortgage loans $ in Millions	Mar. 31, 2022 USD ($)
Debt Securities, Available-for-sale [Line Items]
2022	$ 39
2021	95
2020	151
2019	237
2018	64
Prior	372
Total	958
DSCR ≥1.6x | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2022	0
2021	9
2020	94
2019	21
2018	54
Prior	247
Total	425
DSCR ≥1.6x | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2022	0
2021	5
2020	19
2019	8
2018	0
Prior	24
Total	56
DSCR ≥1.6x | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2022	18
2021	11
2020	0
2019	0
2018	0
Prior	0
Total	29
DSCR 1.2x - 1.6x | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2022	0
2021	13
2020	14
2019	95
2018	10
Prior	56
Total	188
DSCR 1.2x - 1.6x | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2022	21
2021	36
2020	24
2019	0
2018	0
Prior	8
Total	89
DSCR 1.2x - 1.6x | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2022	0
2021	0
2020	0
2019	0
2018	0
Prior	0
Total	0
DSCR ≤1.2 | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2022	0
2021	0
2020	0
2019	52
2018	0
Prior	30
Total	82
DSCR ≤1.2 | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2022	0
2021	0
2020	0
2019	55
2018	0
Prior	0
Total	55
DSCR ≤1.2 | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2022	0
2021	21
2020	0
2019	6
2018	0
Prior	7
Total	$ 34