Segment Reporting - Sales of Company's Products (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Sales	$ 59,283	$ 48,704	$ 41,518
Increase (decrease) in revenue hedging activities	810	(203)	(19)
Revenue related to the sale of the marketing rights	165	218	54
Operating Segments
Segment Reporting Information [Line Items]
Sales	57,555	48,322	41,336
Operating Segments | Pharmaceutical segment
Segment Reporting Information [Line Items]
Sales	52,005	42,754	36,610
Operating Segments | Pharmaceutical segment | Keytruda
Segment Reporting Information [Line Items]
Sales	20,937	17,186	14,380
Operating Segments | Pharmaceutical segment | Alliance revenue - Lynparza
Segment Reporting Information [Line Items]
Sales	1,116	989	725
Operating Segments | Pharmaceutical segment | Alliance revenue - Lenvima
Segment Reporting Information [Line Items]
Sales	876	704	580
Operating Segments | Pharmaceutical segment | Alliance revenue - Reblozyl
Segment Reporting Information [Line Items]
Sales	166	17	0
Operating Segments | Pharmaceutical segment | Gardasil/Gardasil 9
Segment Reporting Information [Line Items]
Sales	6,897	5,673	3,938
Operating Segments | Pharmaceutical segment | ProQuad/M-M-R II/Varivax
Segment Reporting Information [Line Items]
Sales	2,241	2,135	1,878
Operating Segments | Pharmaceutical segment | RotaTeq
Segment Reporting Information [Line Items]
Sales	783	807	797
Operating Segments | Pharmaceutical segment | Pneumovax 23
Segment Reporting Information [Line Items]
Sales	602	893	1,087
Operating Segments | Pharmaceutical segment | Vaqta
Segment Reporting Information [Line Items]
Sales	173	179	170
Operating Segments | Pharmaceutical segment | Bridion
Segment Reporting Information [Line Items]
Sales	1,685	1,532	1,198
Operating Segments | Pharmaceutical segment | Prevymis
Segment Reporting Information [Line Items]
Sales	428	370	281
Operating Segments | Pharmaceutical segment | Dificid
Segment Reporting Information [Line Items]
Sales	263	175	110
Operating Segments | Pharmaceutical segment | Primaxin
Segment Reporting Information [Line Items]
Sales	239	259	251
Operating Segments | Pharmaceutical segment | Noxafil
Segment Reporting Information [Line Items]
Sales	238	259	329
Operating Segments | Pharmaceutical segment | Invanz
Segment Reporting Information [Line Items]
Sales	189	202	211
Operating Segments | Pharmaceutical segment | Cancidas
Segment Reporting Information [Line Items]
Sales	174	212	213
Operating Segments | Pharmaceutical segment | Zerbaxa
Segment Reporting Information [Line Items]
Sales	169	(1)	130
Operating Segments | Pharmaceutical segment | Alliance revenue - Adempas/Verquvo
Segment Reporting Information [Line Items]
Sales	341	342	281
Operating Segments | Pharmaceutical segment | Adempas
Segment Reporting Information [Line Items]
Sales	238	252	220
Operating Segments | Pharmaceutical segment | Lagevrio
Segment Reporting Information [Line Items]
Sales	5,684	952	0
Operating Segments | Pharmaceutical segment | Isentress/Isentress HD
Segment Reporting Information [Line Items]
Sales	633	769	857
Operating Segments | Pharmaceutical segment | Belsomra
Segment Reporting Information [Line Items]
Sales	258	318	327
Operating Segments | Pharmaceutical segment | Simponi
Segment Reporting Information [Line Items]
Sales	706	825	838
Operating Segments | Pharmaceutical segment | Remicade
Segment Reporting Information [Line Items]
Sales	207	299	330
Operating Segments | Pharmaceutical segment | Januvia
Segment Reporting Information [Line Items]
Sales	2,813	3,324	3,306
Operating Segments | Pharmaceutical segment | Janumet
Segment Reporting Information [Line Items]
Sales	1,700	1,964	1,971
Operating Segments | Pharmaceutical segment | Other pharmaceutical
Segment Reporting Information [Line Items]
Sales	2,249	2,118	2,202
Operating Segments | Animal Health
Segment Reporting Information [Line Items]
Sales	5,550	5,568	4,703
Operating Segments | Animal Health | Livestock
Segment Reporting Information [Line Items]
Sales	3,300	3,295	2,939
Operating Segments | Animal Health | Companion Animals
Segment Reporting Information [Line Items]
Sales	2,250	2,273	1,764
Operating Segments | Other segments
Segment Reporting Information [Line Items]
Sales	0	0	23
Other
Segment Reporting Information [Line Items]
Sales	1,728	382	182
United States
Segment Reporting Information [Line Items]
Sales	27,206	22,425	19,588
United States | Operating Segments
Segment Reporting Information [Line Items]
Sales	26,811	22,159	19,517
United States | Operating Segments | Pharmaceutical segment
Segment Reporting Information [Line Items]
Sales	24,989	20,401	18,010
United States | Operating Segments | Pharmaceutical segment | Keytruda
Segment Reporting Information [Line Items]
Sales	12,686	9,765	8,352
United States | Operating Segments | Pharmaceutical segment | Alliance revenue - Lynparza
Segment Reporting Information [Line Items]
Sales	584	515	417
United States | Operating Segments | Pharmaceutical segment | Alliance revenue - Lenvima
Segment Reporting Information [Line Items]
Sales	579	417	359
United States | Operating Segments | Pharmaceutical segment | Alliance revenue - Reblozyl
Segment Reporting Information [Line Items]
Sales	123	0	0
United States | Operating Segments | Pharmaceutical segment | Gardasil/Gardasil 9
Segment Reporting Information [Line Items]
Sales	2,065	1,881	1,755
United States | Operating Segments | Pharmaceutical segment | ProQuad/M-M-R II/Varivax
Segment Reporting Information [Line Items]
Sales	1,724	1,629	1,378
United States | Operating Segments | Pharmaceutical segment | RotaTeq
Segment Reporting Information [Line Items]
Sales	508	473	486
United States | Operating Segments | Pharmaceutical segment | Pneumovax 23
Segment Reporting Information [Line Items]
Sales	346	547	727
United States | Operating Segments | Pharmaceutical segment | Vaqta
Segment Reporting Information [Line Items]
Sales	95	100	103
United States | Operating Segments | Pharmaceutical segment | Bridion
Segment Reporting Information [Line Items]
Sales	922	762	583
United States | Operating Segments | Pharmaceutical segment | Prevymis
Segment Reporting Information [Line Items]
Sales	188	153	119
United States | Operating Segments | Pharmaceutical segment | Dificid
Segment Reporting Information [Line Items]
Sales	241	166	102
United States | Operating Segments | Pharmaceutical segment | Primaxin
Segment Reporting Information [Line Items]
Sales	1	2	2
United States | Operating Segments | Pharmaceutical segment | Noxafil
Segment Reporting Information [Line Items]
Sales	51	60	42
United States | Operating Segments | Pharmaceutical segment | Invanz
Segment Reporting Information [Line Items]
Sales	4	(5)	9
United States | Operating Segments | Pharmaceutical segment | Cancidas
Segment Reporting Information [Line Items]
Sales	6	4	7
United States | Operating Segments | Pharmaceutical segment | Zerbaxa
Segment Reporting Information [Line Items]
Sales	89	4	74
United States | Operating Segments | Pharmaceutical segment | Alliance revenue - Adempas/Verquvo
Segment Reporting Information [Line Items]
Sales	329	312	259
United States | Operating Segments | Pharmaceutical segment | Adempas
Segment Reporting Information [Line Items]
Sales	0	0	0
United States | Operating Segments | Pharmaceutical segment | Lagevrio
Segment Reporting Information [Line Items]
Sales	1,523	632	0
United States | Operating Segments | Pharmaceutical segment | Isentress/Isentress HD
Segment Reporting Information [Line Items]
Sales	274	294	326
United States | Operating Segments | Pharmaceutical segment | Belsomra
Segment Reporting Information [Line Items]
Sales	79	78	81
United States | Operating Segments | Pharmaceutical segment | Simponi
Segment Reporting Information [Line Items]
Sales	0	0	0
United States | Operating Segments | Pharmaceutical segment | Remicade
Segment Reporting Information [Line Items]
Sales	0	0	0
United States | Operating Segments | Pharmaceutical segment | Januvia
Segment Reporting Information [Line Items]
Sales	1,248	1,404	1,470
United States | Operating Segments | Pharmaceutical segment | Janumet
Segment Reporting Information [Line Items]
Sales	355	367	477
United States | Operating Segments | Pharmaceutical segment | Other pharmaceutical
Segment Reporting Information [Line Items]
Sales	969	841	882
United States | Operating Segments | Animal Health
Segment Reporting Information [Line Items]
Sales	1,822	1,758	1,484
United States | Operating Segments | Animal Health | Livestock
Segment Reporting Information [Line Items]
Sales	710	667	612
United States | Operating Segments | Animal Health | Companion Animals
Segment Reporting Information [Line Items]
Sales	1,112	1,091	872
United States | Operating Segments | Other segments
Segment Reporting Information [Line Items]
Sales	0	0	23
United States | Other
Segment Reporting Information [Line Items]
Sales	395	266	71
Int’l
Segment Reporting Information [Line Items]
Sales	32,077	26,279	21,930
Int’l | Operating Segments
Segment Reporting Information [Line Items]
Sales	30,744	26,163	21,819
Int’l | Operating Segments | Pharmaceutical segment
Segment Reporting Information [Line Items]
Sales	27,016	22,353	18,600
Int’l | Operating Segments | Pharmaceutical segment | Keytruda
Segment Reporting Information [Line Items]
Sales	8,251	7,421	6,028
Int’l | Operating Segments | Pharmaceutical segment | Alliance revenue - Lynparza
Segment Reporting Information [Line Items]
Sales	532	473	308
Int’l | Operating Segments | Pharmaceutical segment | Alliance revenue - Lenvima
Segment Reporting Information [Line Items]
Sales	297	287	220
Int’l | Operating Segments | Pharmaceutical segment | Alliance revenue - Reblozyl
Segment Reporting Information [Line Items]
Sales	43	17	0
Int’l | Operating Segments | Pharmaceutical segment | Gardasil/Gardasil 9
Segment Reporting Information [Line Items]
Sales	4,832	3,792	2,184
Int’l | Operating Segments | Pharmaceutical segment | ProQuad/M-M-R II/Varivax
Segment Reporting Information [Line Items]
Sales	518	506	500
Int’l | Operating Segments | Pharmaceutical segment | RotaTeq
Segment Reporting Information [Line Items]
Sales	275	334	311
Int’l | Operating Segments | Pharmaceutical segment | Pneumovax 23
Segment Reporting Information [Line Items]
Sales	256	346	359
Int’l | Operating Segments | Pharmaceutical segment | Vaqta
Segment Reporting Information [Line Items]
Sales	78	79	67
Int’l | Operating Segments | Pharmaceutical segment | Bridion
Segment Reporting Information [Line Items]
Sales	762	770	615
Int’l | Operating Segments | Pharmaceutical segment | Prevymis
Segment Reporting Information [Line Items]
Sales	240	218	162
Int’l | Operating Segments | Pharmaceutical segment | Dificid
Segment Reporting Information [Line Items]
Sales	22	10	7
Int’l | Operating Segments | Pharmaceutical segment | Primaxin
Segment Reporting Information [Line Items]
Sales	238	258	248
Int’l | Operating Segments | Pharmaceutical segment | Noxafil
Segment Reporting Information [Line Items]
Sales	187	199	287
Int’l | Operating Segments | Pharmaceutical segment | Invanz
Segment Reporting Information [Line Items]
Sales	185	207	202
Int’l | Operating Segments | Pharmaceutical segment | Cancidas
Segment Reporting Information [Line Items]
Sales	168	208	207
Int’l | Operating Segments | Pharmaceutical segment | Zerbaxa
Segment Reporting Information [Line Items]
Sales	79	(5)	56
Int’l | Operating Segments | Pharmaceutical segment | Alliance revenue - Adempas/Verquvo
Segment Reporting Information [Line Items]
Sales	12	30	22
Int’l | Operating Segments | Pharmaceutical segment | Adempas
Segment Reporting Information [Line Items]
Sales	238	252	220
Int’l | Operating Segments | Pharmaceutical segment | Lagevrio
Segment Reporting Information [Line Items]
Sales	4,161	320	0
Int’l | Operating Segments | Pharmaceutical segment | Isentress/Isentress HD
Segment Reporting Information [Line Items]
Sales	359	474	531
Int’l | Operating Segments | Pharmaceutical segment | Belsomra
Segment Reporting Information [Line Items]
Sales	179	241	247
Int’l | Operating Segments | Pharmaceutical segment | Simponi
Segment Reporting Information [Line Items]
Sales	706	825	838
Int’l | Operating Segments | Pharmaceutical segment | Remicade
Segment Reporting Information [Line Items]
Sales	207	299	330
Int’l | Operating Segments | Pharmaceutical segment | Januvia
Segment Reporting Information [Line Items]
Sales	1,565	1,920	1,836
Int’l | Operating Segments | Pharmaceutical segment | Janumet
Segment Reporting Information [Line Items]
Sales	1,344	1,597	1,494
Int’l | Operating Segments | Pharmaceutical segment | Other pharmaceutical
Segment Reporting Information [Line Items]
Sales	1,282	1,275	1,321
Int’l | Operating Segments | Animal Health
Segment Reporting Information [Line Items]
Sales	3,728	3,810	3,219
Int’l | Operating Segments | Animal Health | Livestock
Segment Reporting Information [Line Items]
Sales	2,590	2,628	2,327
Int’l | Operating Segments | Animal Health | Companion Animals
Segment Reporting Information [Line Items]
Sales	1,138	1,182	892
Int’l | Operating Segments | Other segments
Segment Reporting Information [Line Items]
Sales	0	0	0
Int’l | Other
Segment Reporting Information [Line Items]
Sales	$ 1,333	$ 116	$ 111