Future Policy Benefits - Schedule of Reconciliation of Net FPB to the Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Millions |
Sep. 30, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|---|
| Liability for Future Policy Benefit, Activity [Line Items] | |||
| Future policy benefits | $ 8,268 | $ 7,050 | |
| Traditional Life | |||
| Liability for Future Policy Benefit, Activity [Line Items] | |||
| Future policy benefits | 1,385 | 1,349 | |
| Immediate Annuities | |||
| Liability for Future Policy Benefit, Activity [Line Items] | |||
| Future policy benefits | 1,393 | 1,415 | |
| Deferred profit liability | 90 | 87 | $ 69 |
| PRT | |||
| Liability for Future Policy Benefit, Activity [Line Items] | |||
| Future policy benefits | 5,394 | 4,189 | |
| Deferred profit liability | 6 | 10 | $ 4 |
| Immediate annuities DPL | |||
| Liability for Future Policy Benefit, Activity [Line Items] | |||
| Deferred profit liability | 90 | 87 | |
| PRT DPL | |||
| Liability for Future Policy Benefit, Activity [Line Items] | |||
| Deferred profit liability | $ 6 | $ 10 |