|**Accumulated Other Comprehensive Loss, Excluding Noncontrolling Interests (Tables)**        | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|**Equity [Abstract]**                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Schedule of Changes in Accumulated Other Comprehensive Loss, Net of Tax                      | The following summarizes the changes, net of tax, inAccumulated other comprehensive loss(a):Net Unrealized Gains/(Losses)Benefit Plans(MILLIONS)Foreign Currency Translation AdjustmentsDerivative Financial InstrumentsAvailable-For-Sale SecuritiesPrior Service (Costs)/ Credits and OtherAccumulated Other Comprehensive Income/(Loss)Balance, January 1, 2019$(6,075)$167$(68)$728$(5,249)Other comprehensive income/(loss)(b)139(146)33(144)(118)Balance, December 31, 2019(5,936)20(35)584(5,367)Other comprehensive income/(loss)(b)883(448)151(106)480Distribution of Upjohn Business(c)(397)——(26)(423)Balance, December 31, 2020(5,450)(428)116452(5,310)Other comprehensive income/(loss)(b)(722)547(336)(75)(587)Balance, December 31, 2021$(6,172)$119$(220)$377$(5,897)(a)Amounts include the impact of a change in accounting principle. SeeNote 1C.(b)Amounts do not include foreign currency translation adjustments attributable to noncontrolling interests. Foreign currency translation adjustments include net losses in 2021 and net gains in 2020 and 2019 related to our equity-method investment in the Consumer Healthcare JV (seeNote 2C),and the impact of our net investment hedging program.(c)For more information, seeNote 2B.
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|The following summarizes the changes, net of tax, inAccumulated other comprehensive loss(a):
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|(MILLIONS)                                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Balance, January 1, 2019                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Other comprehensive income/(loss)(b)                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Balance, December 31, 2019                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Other comprehensive income/(loss)(b)                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Distribution of Upjohn Business(c)                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Balance, December 31, 2020                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Other comprehensive income/(loss)(b)                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Balance, December 31, 2021                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 

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