|**Other Financial Information (Tables)**               | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Other Financial Information [Abstract]**             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Schedule of Components of Inventories, Current         | The following summarizes the components ofInventories:As of December 31,(MILLIONS)20212020Finished goods$3,641$2,867Work in process4,4244,436Raw materials and supplies994716Inventories(a)$9,059$8,020Noncurrent inventories not included above(b)$939$890(a)The change from December 31, 2020 reflects increases for certain products, including inventory build for new product launches (primarily Comirnaty), network strategy and supply recovery, partially offset by decreases due to market demand.(b)Included inOther noncurrent assets. There are no recoverability issues for these amounts.
|                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|The following summarizes the components ofInventories:
|                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|(MILLIONS)                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Finished goods                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Work in process                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Raw materials and supplies                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Inventories(a)                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Noncurrent inventories not included above(b)           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Schedule of Component of Inventories, Noncurrent       | The following summarizes the components ofInventories:As of December 31,(MILLIONS)20212020Finished goods$3,641$2,867Work in process4,4244,436Raw materials and supplies994716Inventories(a)$9,059$8,020Noncurrent inventories not included above(b)$939$890(a)The change from December 31, 2020 reflects increases for certain products, including inventory build for new product launches (primarily Comirnaty), network strategy and supply recovery, partially offset by decreases due to market demand.(b)Included inOther noncurrent assets. There are no recoverability issues for these amounts.
|                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|The following summarizes the components ofInventories:
|                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|(MILLIONS)                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Finished goods                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Work in process                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Raw materials and supplies                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Inventories(a)                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Noncurrent inventories not included above(b)           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

X- DefinitionOther Financial Information
+ ReferencesNo definition available.
+ Details**Name:**
pfe_OtherFinancialInformationAbstract**Namespace Prefix:**
pfe_**Data Type:**
xbrli:stringItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionTabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.
+ ReferencesReference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(6)(c)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(6)(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(6)(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6361739&loc=d3e7789-107766
+ Details**Name:**
us-gaap_ScheduleOfInventoryCurrentTableTextBlock**Namespace Prefix:**
us-gaap_**Data Type:**
dtr-types:textBlockItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionTabular disclosure of inventories not expected to be converted to cash, sold or exchanged within the normal operating cycle including inventoried costs relating to long-term contracts or programs.
+ ReferencesReference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(6)(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(6)(d)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(6)(c)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(6)(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6361739&loc=d3e7789-107766
+ Details**Name:**
us-gaap_ScheduleOfInventoryNoncurrentTableTextBlock**Namespace Prefix:**
us-gaap_**Data Type:**
dtr-types:textBlockItemType**Balance Type:**
na**Period Type:**
duration