Income Taxes - Foreign Jurisdiction Tax Attributes and Sale of Medicare Advantage and Related Businesses (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Deferred tax assets associated with foreign tax attributes	$ 1,800	$ 0
Valuation allowance against deferred tax assets associated with foreign tax attributes	772
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred loss - sale of business	584	0
Valuation allowance		$ 208
Held-for-Sale | Medicare Advantage and related Cigna Healthcare businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred loss - sale of business	584
Valuation allowance	$ 584