Contingencies and Certain Commitments (Patent Litigation) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Apr. 04, 2021 USD ($) patent	Dec. 31, 2019 patent	Dec. 31, 2017 patent defendant
Gain Contingencies [Line Items]
Threshold for disclosure of proceedings under environmental laws | $	$ 1
Pneumococcal Vaccine Patent Infringement [Member]
Gain Contingencies [Line Items]
Number of patents without court proceedings			2
Number of patents allegedly infringed upon	2
Other Patent Infringement [Member]
Gain Contingencies [Line Items]
Number of patents allegedly infringed upon	1
Pfizer Versus Generic Companies [Member] | Patent Infringement [Member] | Pending Litigation [Member]
Gain Contingencies [Line Items]
Number of patents allegedly infringed upon		2
Xeljanz [Member] | Pfizer Versus Zydus [Member] | Patent Infringement [Member] | Settled Litigation [Member]
Gain Contingencies [Line Items]
Number of patents allegedly infringed upon			3
Eliquis [Member] | Pfizer and BMS Versus Several Generic Manufacturers [Member] | Patent Infringement [Member] | Pending Litigation [Member]
Gain Contingencies [Line Items]
Number of patents allegedly infringed upon			3
Number of defendants | defendant			25
Number of patents allegedly infringed upon, expired December 2019			1