Investments - Mortgage Loans Credit Ratings Indicator (Details) - Commercial Real Estate - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	$ 1,523	$ 1,505
1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	5	8
2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	1,466	1,452
5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	52	45
7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2025
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	130
2025 | 1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
2025 | 2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	130
2025 | 5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
2025 | 7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0
2024
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	315	315
2024 | 1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2024 | 2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	315	315
2024 | 5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2024 | 7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2023
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	289	292
2023 | 1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2023 | 2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	289	292
2023 | 5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2023 | 7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2022
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	315	324
2022 | 1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2022 | 2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	285	320
2022 | 5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	30	4
2022 | 7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2021
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	189	218
2021 | 1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
2021 | 2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	172	205
2021 | 5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	17	13
2021 | 7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	0	0
Prior
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	285	356
Prior | 1
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	5	8
Prior | 2 to 4
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	275	320
Prior | 5 and 6
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	5	28
Prior | 7
Mortgage Loans on Real Estate [Line Items]
Mortgage loans	$ 0	$ 0