Income Taxes - Valuation Allowances (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Valuation Allowance [Line Items]
Deferred tax assets, impairment of equity securities and other unrealized investment losses.	$ 880
Deferred tax assets, impairment of equity securities	561	$ 0
Foreign tax attributes	1,800	1,800
Deferred loss - sale of business	773	584
Equity securities
Valuation Allowance [Line Items]
Deferred tax assets, impairment of equity securities	636
Impairment of equity securities
Valuation Allowance [Line Items]
Deferred tax assets, valuation allowance	636
Impairment of equity securities | Equity securities
Valuation Allowance [Line Items]
Deferred tax assets, valuation allowance	636
Foreign jurisdiction tax attributes
Valuation Allowance [Line Items]
Deferred tax assets, valuation allowance	772	772
Sale of Medicare Advantage and related businesses
Valuation Allowance [Line Items]
Deferred tax assets, valuation allowance	$ 715	$ 584