Investments - Mortgage Loans Credit Ratings Indicator (Details) - Commercial Real Estate - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	$ 1,311	$ 1,044
2023
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	302
2022
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	346	326
2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	244	247
2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	35	36
2019
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	11	11
Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	373	424
1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	11	15
1 | 2023
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
1 | 2022
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
1 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	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 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	11	15
2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	1,262	1,022
2 to 4 | 2023
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	302
2 to 4 | 2022
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	346	326
2 to 4 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	225	247
2 to 4 | 2020
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	35	36
2 to 4 | 2019
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	11	11
2 to 4 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	343	402
5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	32	7
5 and 6 | 2023
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
5 and 6 | 2022
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
5 and 6 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	13	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 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	19	7
7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	6	0
7 | 2023
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
7 | 2022
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
7 | 2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	6	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 | Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	$ 0	$ 0