Product and Geographic Information - Sales of Company's Products (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue from External Customer [Line Items]
Sales	$ 1,600	$ 1,613	$ 4,701	$ 4,919
Nexplanon/Implanon NXT
Revenue from External Customer [Line Items]
Sales	175	189	543	515
Follistim AQ
Revenue from External Customer [Line Items]
Sales	61	50	178	135
NuvaRing
Revenue from External Customer [Line Items]
Sales	49	58	147	184
Ganirelix Acetate Injection
Revenue from External Customer [Line Items]
Sales	25	25	85	55
Cerazette
Revenue from External Customer [Line Items]
Sales	18	18	53	51
Other Womens Health
Revenue from External Customer [Line Items]
Sales	53	84	191	224
Renflexis
Revenue from External Customer [Line Items]
Sales	54	38	136	96
Ontruzant
Revenue from External Customer [Line Items]
Sales	56	37	101	78
Brenzys
Revenue from External Customer [Line Items]
Sales	14	23	35	52
Other Biosimilars
Revenue from External Customer [Line Items]
Sales	16	1	34	1
Zetia
Revenue from External Customer [Line Items]
Sales	91	103	282	384
Vytorin
Revenue from External Customer [Line Items]
Sales	41	47	127	139
Atozet
Revenue from External Customer [Line Items]
Sales	114	111	347	348
Rosuzet
Revenue from External Customer [Line Items]
Sales	87	91	265	291
Cozaar/Hyzaar
Revenue from External Customer [Line Items]
Sales	15	32	48	94
Zocor
Revenue from External Customer [Line Items]
Sales	18	18	49	57
Other Cardiovascular
Revenue from External Customer [Line Items]
Sales	31	37	99	124
Singulair
Revenue from External Customer [Line Items]
Sales	100	82	300	338
Nasonex
Revenue from External Customer [Line Items]
Sales	48	41	144	160
Dulera
Revenue from External Customer [Line Items]
Sales	56	59	146	181
Clarinex
Revenue from External Customer [Line Items]
Sales	28	25	83	109
Asmanex
Revenue from External Customer [Line Items]
Sales	15	21	48	64
Other Respiratory
Revenue from External Customer [Line Items]
Sales	3	11	16	26
Arcoxia
Revenue from External Customer [Line Items]
Sales	65	68	184	204
Fosamax
Revenue from External Customer [Line Items]
Sales	46	46	132	140
Diprospan
Revenue from External Customer [Line Items]
Sales	34	33	92	87
Diprosone
Revenue from External Customer [Line Items]
Sales	22	22	65	59
Other Non-Opiod Pain, Bone and Dermatology
Revenue from External Customer [Line Items]
Sales	57	52	148	144
Proscar
Revenue from External Customer [Line Items]
Sales	27	60	92	154
Propecia
Revenue from External Customer [Line Items]
Sales	34	32	101	91
Sinemet
Revenue from External Customer [Line Items]
Sales	17	18	54	47
Remeron
Revenue from External Customer [Line Items]
Sales	19	16	51	58
Other
Revenue from External Customer [Line Items]
Sales	59	63	157	179
Other
Revenue from External Customer [Line Items]
Sales	52	2	168	50
U.S.
Revenue from External Customer [Line Items]
Sales	346	371	1,035	1,068
U.S. | Nexplanon/Implanon NXT
Revenue from External Customer [Line Items]
Sales	120	137	389	374
U.S. | Follistim AQ
Revenue from External Customer [Line Items]
Sales	29	20	81	60
U.S. | NuvaRing
Revenue from External Customer [Line Items]
Sales	21	25	68	86
U.S. | Ganirelix Acetate Injection
Revenue from External Customer [Line Items]
Sales	5	4	19	7
U.S. | Cerazette
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Other Womens Health
Revenue from External Customer [Line Items]
Sales	18	45	80	121
U.S. | Renflexis
Revenue from External Customer [Line Items]
Sales	48	34	119	88
U.S. | Ontruzant
Revenue from External Customer [Line Items]
Sales	9	0	20	1
U.S. | Brenzys
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Other Biosimilars
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Zetia
Revenue from External Customer [Line Items]
Sales	1	(1)	6	(4)
U.S. | Vytorin
Revenue from External Customer [Line Items]
Sales	3	3	8	9
U.S. | Atozet
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Rosuzet
Revenue from External Customer [Line Items]
Sales	3	5	9	17
U.S. | Cozaar/Hyzaar
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Zocor
Revenue from External Customer [Line Items]
Sales	1	1	3	1
U.S. | Other Cardiovascular
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Singulair
Revenue from External Customer [Line Items]
Sales	2	4	10	14
U.S. | Nasonex
Revenue from External Customer [Line Items]
Sales	0	0	3	9
U.S. | Dulera
Revenue from External Customer [Line Items]
Sales	48	51	121	155
U.S. | Clarinex
Revenue from External Customer [Line Items]
Sales	2	2	5	5
U.S. | Asmanex
Revenue from External Customer [Line Items]
Sales	14	20	43	58
U.S. | Other Respiratory
Revenue from External Customer [Line Items]
Sales	0	0	0	1
U.S. | Arcoxia
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Fosamax
Revenue from External Customer [Line Items]
Sales	1	1	3	3
U.S. | Diprospan
Revenue from External Customer [Line Items]
Sales	0	0	0	0
U.S. | Diprosone
Revenue from External Customer [Line Items]
Sales	0	0	1	1
U.S. | Other Non-Opiod Pain, Bone and Dermatology
Revenue from External Customer [Line Items]
Sales	9	3	11	5
U.S. | Proscar
Revenue from External Customer [Line Items]
Sales	0	0	1	1
U.S. | Propecia
Revenue from External Customer [Line Items]
Sales	1	2	5	7
U.S. | Sinemet
Revenue from External Customer [Line Items]
Sales	0	0	0	(1)
U.S. | Remeron
Revenue from External Customer [Line Items]
Sales	1	1	3	2
U.S. | Other
Revenue from External Customer [Line Items]
Sales	9	15	29	44
U.S. | Other
Revenue from External Customer [Line Items]
Sales	1	(1)	(2)	4
International
Revenue from External Customer [Line Items]
Sales	1,254	1,242	3,666	3,851
International | Nexplanon/Implanon NXT
Revenue from External Customer [Line Items]
Sales	55	52	154	142
International | Follistim AQ
Revenue from External Customer [Line Items]
Sales	32	31	97	75
International | NuvaRing
Revenue from External Customer [Line Items]
Sales	28	33	79	98
International | Ganirelix Acetate Injection
Revenue from External Customer [Line Items]
Sales	20	21	66	48
International | Cerazette
Revenue from External Customer [Line Items]
Sales	18	18	53	51
International | Other Womens Health
Revenue from External Customer [Line Items]
Sales	35	39	111	103
International | Renflexis
Revenue from External Customer [Line Items]
Sales	6	4	17	8
International | Ontruzant
Revenue from External Customer [Line Items]
Sales	47	37	81	77
International | Brenzys
Revenue from External Customer [Line Items]
Sales	14	23	35	52
International | Other Biosimilars
Revenue from External Customer [Line Items]
Sales	16	1	34	1
International | Zetia
Revenue from External Customer [Line Items]
Sales	90	103	276	389
International | Vytorin
Revenue from External Customer [Line Items]
Sales	38	44	119	130
International | Atozet
Revenue from External Customer [Line Items]
Sales	114	111	347	348
International | Rosuzet
Revenue from External Customer [Line Items]
Sales	84	86	256	274
International | Cozaar/Hyzaar
Revenue from External Customer [Line Items]
Sales	15	32	48	94
International | Zocor
Revenue from External Customer [Line Items]
Sales	17	17	46	56
International | Other Cardiovascular
Revenue from External Customer [Line Items]
Sales	31	37	99	124
International | Singulair
Revenue from External Customer [Line Items]
Sales	98	78	289	324
International | Nasonex
Revenue from External Customer [Line Items]
Sales	49	41	141	151
International | Dulera
Revenue from External Customer [Line Items]
Sales	8	8	25	26
International | Clarinex
Revenue from External Customer [Line Items]
Sales	27	23	78	104
International | Asmanex
Revenue from External Customer [Line Items]
Sales	2	1	5	5
International | Other Respiratory
Revenue from External Customer [Line Items]
Sales	3	11	15	25
International | Arcoxia
Revenue from External Customer [Line Items]
Sales	65	68	184	204
International | Fosamax
Revenue from External Customer [Line Items]
Sales	45	45	130	137
International | Diprospan
Revenue from External Customer [Line Items]
Sales	34	33	92	87
International | Diprosone
Revenue from External Customer [Line Items]
Sales	22	22	64	58
International | Other Non-Opiod Pain, Bone and Dermatology
Revenue from External Customer [Line Items]
Sales	47	49	137	140
International | Proscar
Revenue from External Customer [Line Items]
Sales	27	59	91	152
International | Propecia
Revenue from External Customer [Line Items]
Sales	33	30	96	83
International | Sinemet
Revenue from External Customer [Line Items]
Sales	17	18	54	46
International | Remeron
Revenue from External Customer [Line Items]
Sales	17	16	48	58
International | Other
Revenue from External Customer [Line Items]
Sales	49	48	128	135
International | Other
Revenue from External Customer [Line Items]
Sales	$ 51	$ 3	$ 171	$ 46