Reserves in Addition to Account Balance, Based on Expected No-Lapse Guarantee Benefits and Expected Policy Assessments (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	$ 3,013	$ 3,068
Life policy reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	1,571	1,597
Investment contract reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	1,442	1,471
Term Life Insurance | Life policy reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	1,054	1,066	$ 1,011
Whole Life Insurance | Life policy reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	418	434	$ 427
Long-Duration Insurance, Other | Life policy reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	99	97
Long-Duration Insurance, Other | Investment contract reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	104	107
Deferred Fixed Annuity | Investment contract reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	631	656
Universal life | Investment contract reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	585	585
Structured Settlement Annuity | Investment contract reserves:
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	$ 122	$ 123