Investments (Credit quality indicator) (Details) - Mortgage loans $ in Millions	Jun. 30, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
2021	$ 15
2020	161
2019	283
2018	92
2017	170
Prior	311
Total	1,032
DSCR ≥1.6x | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2021	0
2020	89
2019	33
2018	50
2017	113
Prior	183
Total	468
DSCR ≥1.6x | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2021	0
2020	0
2019	19
2018	0
2017	9
Prior	4
Total	32
DSCR ≥1.6x | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2021	5
2020	0
2019	6
2018	0
2017	0
Prior	24
Total	35
DSCR 1.2x - 1.6x | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2021	0
2020	0
2019	16
2018	0
2017	5
Prior	71
Total	92
DSCR 1.2x - 1.6x | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2021	10
2020	38
2019	39
2018	42
2017	27
Prior	0
Total	156
DSCR 1.2x - 1.6x | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2021	0
2020	34
2019	44
2018	0
2017	8
Prior	12
Total	98
DSCR ≤1.2 | LTV less than 55%
Debt Securities, Available-for-sale [Line Items]
2021	0
2020	0
2019	50
2018	0
2017	8
Prior	10
Total	68
DSCR ≤1.2 | LTV 55% to 65%
Debt Securities, Available-for-sale [Line Items]
2021	0
2020	0
2019	47
2018	0
2017	0
Prior	0
Total	47
DSCR ≤1.2 | LTV greater than 65%
Debt Securities, Available-for-sale [Line Items]
2021	0
2020	0
2019	29
2018	0
2017	0
Prior	7
Total	$ 36