Contingencies - Narrative (Details) $ in Millions	1 Months Ended	9 Months Ended
	Mar. 31, 2014 Case	Sep. 30, 2020 USD ($) Case Claim	Dec. 31, 2019 USD ($)
Legal Defense Costs
Loss Contingencies [Line Items]
Legal defense costs reserve | $		$ 255	$ 240
Zetia antitrust litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters) | Claim		35
Patents [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters)		3
Loss Contingency, Claims Settled, Number		5
Fosamax
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters)		3,590
Fosamax | Femur Fracture Litigation | Federal
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters)		970
Loss contingency, claims dismissed, number (in legal matters)	650
Loss contingency, claims on appeal, number (in legal matters)	515
Fosamax | Femur Fracture Litigation | New Jersey state court
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters)		2,340
Fosamax | Femur Fracture Litigation | California state court
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters)		275
Fosamax | Femur Fracture Litigation | Other state courts
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters)		4
Januvia
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters) | Claim		1,465
Januvia | Other state courts
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters) | Claim		6
Januvia | Cases Company Agreed To Toll Statute Of Limitations
Loss Contingencies [Line Items]
Loss contingency, pending claims, number (in legal matters) | Claim		50