Fair Value - Schedule of Gain (Losses) Recorded for Financial Instruments Elected the Fair Value Option (Details) - Retirement Services - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Gain (loss) for fair value option instruments | $ 199 | $ (3,204) |
| Trading securities | ||
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Gain (loss) for fair value option instruments | 66 | (424) |
| Mortgage loans | ||
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Gain (loss) for fair value option instruments | 183 | (3,213) |
| Investment funds | ||
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Gain (loss) for fair value option instruments | 77 | 114 |
| Future policy benefits | ||
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Gain (loss) for fair value option instruments | (14) | 356 |
| Other liabilities | ||
| Fair Value, Option, Quantitative Disclosures [Line Items] | ||
| Gain (loss) for fair value option instruments | $ (113) | $ (37) |