| **Financial Instruments - Investments - Unrealized Gains and Losses Related to Equity Securities - Footnotes (Details) $ in Millions** | Jun. 30, 2024 USD ($) |
|----------------------------------------------------------------------------------------------------------------------------------------|-----------------------|
| **Fair Value Disclosures [Abstract]**                                                                                                  |                  |
| Cumulative impairment losses and downward price adjustments on equity securities                                                       | $ 306                 |
| Cumulative upward price adjustments on equity securities                                                                               | $ 214                 |

| X                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Equity Securities Without Readily Determinable Fair Value, Impairment Loss And Downward Price Adjustment, Cumulative Amount
+ References
No definition available.
+ Details**Name:**pfe_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAndDownwardPriceAdjustmentCumulativeAmount**Namespace Prefix:**pfe_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cumulative gain from upward price adjustment on investment in equity security without readily determinable fair value.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 321 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479536/321-10-50-3
+ Details**Name:**us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentCumulativeAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
No definition available.
+ Details**Name:**us-gaap_FairValueDisclosuresAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |