| **Acquisitions, Licensing Agreements, Collaborative Arrangements, Divestitures and Equity-Method Investments - Discontinued Operations - Net of Tax - Footnotes (Detail) (USD $)In Millions, unless otherwise specified** | 12 Months Ended                                                                      |
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| **Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]**                                                                                         |                                                                                 |   |   |
| Deferred income tax expense (benefit), net                                                                                                                                                                                | $ 3pfe_DisposalGroupIncludingDiscontinuedOperationDeferredIncomeTaxExpenseBenefitNet | $ 23pfe_DisposalGroupIncludingDiscontinuedOperationDeferredIncomeTaxExpenseBenefitNet | $ 23pfe_DisposalGroupIncludingDiscontinuedOperationDeferredIncomeTaxExpenseBenefitNet |
| Deferred income tax expense                                                                                                                                                                                               |                                                                                 |   | 42pfe_DisposalGroupIncludingDiscontinuedOperationDeferredIncomeTaxExpense |
| Legal Entity Reorganization [Member]                                                                                                                                                                                      |                                                                                 |   |   |
| **Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]**                                                                                         |                                                                                 |   |   |
| Deferred income tax expense                                                                                                                                                                                               |                                                                                 |   | 1,400pfe_DisposalGroupIncludingDiscontinuedOperationDeferredIncomeTaxExpense/ us-gaap_RestructuringPlanAxis= pfe_LegalEntityReorganizationMember |
| Foreign Tax Authority [Member] | Legal Entity Reorganization [Member]                                                                                                                                                     |                                                                                 |   |   |
| **Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]**                                                                                         |                                                                                 |   |   |
| Deferred income tax expense                                                                                                                                                                                               |                                                                                 |   | 2,200pfe_DisposalGroupIncludingDiscontinuedOperationDeferredIncomeTaxExpense/ us-gaap_IncomeTaxAuthorityAxis= us-gaap_ForeignCountryMember/ us-gaap_RestructuringPlanAxis= pfe_LegalEntityReorganizationMember |
| Legal Entity Reorganization [Member] | Legal Entity Reorganization [Member]                                                                                                                                               |                                                                                 |   |   |
| **Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]**                                                                                         |                                                                                 |   |   |
| Deferred income tax expense                                                                                                                                                                                               |                                                                                 | $ 122pfe_DisposalGroupIncludingDiscontinuedOperationDeferredIncomeTaxExpense/ us-gaap_RestructuringCostAndReserveAxis= pfe_LegalEntityReorganizationMember/ us-gaap_RestructuringPlanAxis= pfe_LegalEntityReorganizationMember |   |

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