Investments - Mortgage Loans Credit Ratings Indicator (Details) - Commercial Real Estate - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	$ 902	$ 1,047
2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	255
2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	48	46
2019
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	40	96
2018
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	75	94
2017
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	101	150
Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	383	661
1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	28	59
1 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
1 | 2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
1 | 2019
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
1 | 2018
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
1 | 2017
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	22
1 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	28	37
2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	861	952
2 to 4 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	255
2 to 4 | 2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	48	46
2 to 4 | 2019
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	40	96
2 to 4 | 2018
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	72	91
2 to 4 | 2017
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	97	124
2 to 4 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	349	595
5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	13	36
5 and 6 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
5 and 6 | 2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
5 and 6 | 2019
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
5 and 6 | 2018
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	3	3
5 and 6 | 2017
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	4	4
5 and 6 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	6	29
7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
7 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
7 | 2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
7 | 2019
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
7 | 2018
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
7 | 2017
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
7 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	$ 0	$ 0