Investments in Equity Securities (Summary of Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Investments [Line Items]
Total	$ 19,529	$ 23,581
ABI [Member]
Investments [Line Items]
Equity method investments	16,651	18,071
JUUL [Member]
Investments [Line Items]
JUUL	1,705	4,205
Cronos [Member]
Investments [Line Items]
Equity method investments	1,173	1,305
Common Stock [Member] | Cronos [Member]
Investments [Line Items]
Equity method investments	1,010	1,002
Equity Contract, Warrant [Member] | Cronos [Member]
Investments [Line Items]
Fair value of assets	139	234
Equity Contract, Preemptive Rights [Member] | Cronos [Member]
Investments [Line Items]
Fair value of assets	24	69
Net Investment Hedging [Member]
Investments [Line Items]
Fair value of assets	163	349
Not Designated as Hedging Instrument [Member] | Net Investment Hedging [Member] | Investments In Equity Securities [Member] | Equity Contract, Warrant [Member]
Investments [Line Items]
Fair value of assets	139	234
Not Designated as Hedging Instrument [Member] | Net Investment Hedging [Member] | Investments In Equity Securities [Member] | Equity Contract, Preemptive Rights [Member]
Investments [Line Items]
Fair value of assets	$ 24	$ 69