Product, Geographic and Other Revenue Information - Revenues By Products (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jul. 04, 2021	Jun. 28, 2020	Jul. 04, 2021	Jun. 28, 2020
Revenue from External Customer [Line Items]
Revenues	[1]	$ 18,977	$ 9,864	$ 33,559	$ 19,947
Total Alliance revenues [Member]
Revenue from External Customer [Line Items]
Revenues		1,880	1,404	3,650	2,786
Total Biosimilars [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	559	289	1,089	578
Total Sterile Injectable Pharmaceuticals [Member]
Revenue from External Customer [Line Items]
Revenues	[3]	1,381	1,233	2,863	2,634
Vaccines [Member]
Revenue from External Customer [Line Items]
Revenues		9,234	1,247	14,127	2,857
Vaccines [Member] | BNT162b2 direct sales and alliance revenues [Member]
Revenue from External Customer [Line Items]
Revenues		7,838	0	11,300	0
Vaccines [Member] | Prevnar 13/Prevenar 13 [Member]
Revenue from External Customer [Line Items]
Revenues		1,241	1,116	2,524	2,566
Vaccines [Member] | FSME/IMMUN-TicoVac [Member]
Revenue from External Customer [Line Items]
Revenues		61	45	114	93
Vaccines [Member] | Nimenrix [Member]
Revenue from External Customer [Line Items]
Revenues		49	56	95	130
Vaccines [Member] | All other Vaccines [Member]
Revenue from External Customer [Line Items]
Revenues		46	30	94	68
Oncology [Member]
Revenue from External Customer [Line Items]
Revenues		3,145	2,647	6,007	5,082
Oncology [Member] | Ibrance [Member]
Revenue from External Customer [Line Items]
Revenues		1,404	1,349	2,657	2,598
Oncology [Member] | Xtandi alliance revenues [Member]
Revenue from External Customer [Line Items]
Revenues		303	266	570	475
Oncology [Member] | Inlyta [Member]
Revenue from External Customer [Line Items]
Revenues		257	195	486	364
Oncology [Member] | Sutent [Member]
Revenue from External Customer [Line Items]
Revenues		194	209	394	414
Oncology [Member] | Bosulif [Member]
Revenue from External Customer [Line Items]
Revenues		136	113	259	213
Oncology [Member] | Xalkori [Member]
Revenue from External Customer [Line Items]
Revenues		120	138	255	287
Oncology [Member] | Ruxience [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	120	11	218	19
Oncology [Member] | Zirabev [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	129	9	215	15
Oncology [Member] | Retacrit [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	103	87	212	176
Oncology [Member] | Lorbrena [Member]
Revenue from External Customer [Line Items]
Revenues		66	46	126	88
Oncology [Member] | Aromasin [Member]
Revenue from External Customer [Line Items]
Revenues		51	39	103	72
Oncology [Member] | Besponsa [Member]
Revenue from External Customer [Line Items]
Revenues		45	46	95	90
Oncology [Member] | Braftovi [Member]
Revenue from External Customer [Line Items]
Revenues		42	36	89	74
Oncology [Member] | Mektovi [Member]
Revenue from External Customer [Line Items]
Revenues		36	32	71	69
Oncology [Member] | All other Oncology [Member]
Revenue from External Customer [Line Items]
Revenues		138	69	257	128
Internal Medicine [Member]
Revenue from External Customer [Line Items]
Revenues		2,403	2,279	4,997	4,610
Internal Medicine [Member] | Eliquis [Member]
Revenue from External Customer [Line Items]
Revenues		1,481	1,272	3,124	2,572
Internal Medicine [Member] | Chantix / Champix [Member]
Revenue from External Customer [Line Items]
Revenues		184	235	401	505
Internal Medicine [Member] | Premarin family [Member]
Revenue from External Customer [Line Items]
Revenues		128	152	271	304
Internal Medicine [Member] | Toviaz [Member]
Revenue from External Customer [Line Items]
Revenues		62	64	119	124
Internal Medicine [Member] | BMP2 [Member]
Revenue from External Customer [Line Items]
Revenues		66	57	115	127
Internal Medicine [Member] | Pristiq [Member]
Revenue from External Customer [Line Items]
Revenues		42	43	101	84
Internal Medicine [Member] | All other Internal Medicine [Member]
Revenue from External Customer [Line Items]
Revenues		440	455	865	894
Hospital [Member]
Revenue from External Customer [Line Items]
Revenues	[1]	2,259	1,863	4,602	3,951
Hospital [Member] | Sulperazon [Member]
Revenue from External Customer [Line Items]
Revenues		141	102	334	289
Hospital [Member] | Medrol [Member]
Revenue from External Customer [Line Items]
Revenues		112	78	211	207
Hospital [Member] | Zavicefta [Member]
Revenue from External Customer [Line Items]
Revenues		104	46	198	95
Hospital [Member] | Vfend [Member]
Revenue from External Customer [Line Items]
Revenues		72	75	153	149
Hospital [Member] | Fragmin [Member]
Revenue from External Customer [Line Items]
Revenues		77	58	149	118
Hospital [Member] | EpiPen [Member]
Revenue from External Customer [Line Items]
Revenues		80	75	147	160
Hospital [Member] | Zithromax [Member]
Revenue from External Customer [Line Items]
Revenues		43	55	132	193
Hospital [Member] | Zyvox [Member]
Revenue from External Customer [Line Items]
Revenues		48	55	103	125
Hospital [Member] | Precedex [Member]
Revenue from External Customer [Line Items]
Revenues		42	114	97	156
Hospital [Member] | IVIg Products [Member]
Revenue from External Customer [Line Items]
Revenues	[4]	107	85	212	183
Hospital [Member] | Pfizer CentreOne [Member]
Revenue from External Customer [Line Items]
Revenues	[5]	437	224	827	376
Hospital [Member] | All other Anti-infectives [Member]
Revenue from External Customer [Line Items]
Revenues		425	321	823	717
Hospital [Member] | All other Hospital [Member]
Revenue from External Customer [Line Items]
Revenues		569	574	1,217	1,183
Inflammation and Immunology (I&I) [Member]
Revenue from External Customer [Line Items]
Revenues		1,041	1,149	2,107	2,127
Inflammation and Immunology (I&I) [Member] | Xeljanz [Member]
Revenue from External Customer [Line Items]
Revenues		586	635	1,124	1,086
Inflammation and Immunology (I&I) [Member] | Enbrel (Outside the U.S. and Canada) [Member]
Revenue from External Customer [Line Items]
Revenues		286	337	605	684
Inflammation and Immunology (I&I) [Member] | Inflectra/Remsima [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	136	150	313	308
Inflammation and Immunology (I&I) [Member] | All other I & I [Member]
Revenue from External Customer [Line Items]
Revenues		33	26	65	48
Rare Disease [Member]
Revenue from External Customer [Line Items]
Revenues		895	681	1,720	1,319
Rare Disease [Member] | Vyndaqel/Vyndamax [Member]
Revenue from External Customer [Line Items]
Revenues		501	277	953	508
Rare Disease [Member] | BeneFIX [Member]
Revenue from External Customer [Line Items]
Revenues		112	109	225	230
Rare Disease [Member] | Genotropin [Member]
Revenue from External Customer [Line Items]
Revenues		109	106	189	209
Rare Disease [Member] | ReFacto AF/Xyntha [Member]
Revenue from External Customer [Line Items]
Revenues		77	91	165	181
Rare Disease [Member] | Somavert [Member]
Revenue from External Customer [Line Items]
Revenues		68	67	133	131
Rare Disease [Member] | All other Rare Disease [Member]
Revenue from External Customer [Line Items]
Revenues		$ 29	$ 31	$ 55	$ 61

[1] On November 16, 2020, we completed the spin-off and the combination of our Upjohn Business with Mylan to form Viatris. See Note 1A. Beginning in the fourth quarter of 2020, the results of our Meridian subsidiary, which was previously included in our former Upjohn operating segment, are reported in the Hospital therapeutic area for all periods presented.

[2] Biosimilars are highly similar versions of approved and authorized biological medicines and primarily include revenues from Inflectra/Remsima, Ruxience, Zirabev and Retacrit

[3] Total Sterile Injectable Pharmaceuticals represents the total of all branded and generic injectable products in the Hospital therapeutic area, including anti-infective sterile injectable pharmaceuticals.

[4] Intravenous immunoglobulin (IVIg) products include the revenues from Panzyga, Octagam and Cutaquig.

[5] Pfizer CentreOne includes revenues from our contract manufacturing and active pharmaceutical ingredient sales operation, as well as revenues related to our manufacturing and supply agreements with former legacy Pfizer businesses/partnerships, including but not limited to, manufacturing and supply agreements with Viatris following the spin-off of the Upjohn Business.