Deconsolidation of RBH (Details) $ in Millions, $ in Millions			3 Months Ended	9 Months Ended
	Mar. 01, 2019 USD ($) litigation_case	Mar. 01, 2019 CAD ($) litigation_case	Mar. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 litigation_case	Mar. 22, 2019 USD ($)
Loss Contingencies [Line Items]
Number of cases decided in favor of plaintiff | litigation_case					13
Marketing Administration And Research Costs [Member]
Loss Contingencies [Line Items]
Deconsolidation amount				$ 239
Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member]
Loss Contingencies [Line Items]
Pending litigation liabilities measurement input						0.08
Measurement Input, Terminal Growth Rate [Member] | Valuation Technique, Discounted Cash Flow [Member]
Loss Contingencies [Line Items]
Pending litigation liabilities measurement input						0.025
RBH [Member]
Loss Contingencies [Line Items]
Amount deconsolidated from balance sheet						$ 3,519
Equity securities						3,280
Tax benefit for reversal of deferred tax liabilities				49
RBH [Member] | Cash [Member]
Loss Contingencies [Line Items]
Amount deconsolidated from balance sheet						1,323
RBH [Member] | Goodwill [Member]
Loss Contingencies [Line Items]
Amount deconsolidated from balance sheet						1,463
RBH [Member] | Other Comprehensive Earnings [Member]
Loss Contingencies [Line Items]
Amount deconsolidated from balance sheet						529
RBH [Member] | Other Assets and Liabilities [Member]
Loss Contingencies [Line Items]
Amount deconsolidated from balance sheet						$ 204
Canada [Member] | Appellate Ruling [Member] | RBH [Member] | Smoking And Health Class Actions [Member] | Cecilia Letourneau & Conseil Quebecois Sur La Tabac Et La Sante and Jean-Yves Blais Cases [Member]
Loss Contingencies [Line Items]
Number of cases decided in favor of plaintiff | litigation_case	2	2
Amount of litigation charge			$ 194	$ 194
Amount of litigation charge net of tax			$ 142
Amount of security ordered, funded by defendant	$ 194	$ 257