Product, Geographic and Other Revenue Information - Revenues By Products (Detail) - USD ($) $ in Millions		3 Months Ended
		Apr. 04, 2021	Mar. 29, 2020
Revenue from External Customer [Line Items]
Revenues	[1]	$ 14,582	$ 10,083
Total Alliance revenues [Member]
Revenue from External Customer [Line Items]
Revenues		1,770	1,382
Total Biosimilars [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	530	288
Total Sterile Injectable Pharmaceuticals [Member]
Revenue from External Customer [Line Items]
Revenues	[3]	1,482	1,401
Vaccines [Member]
Revenue from External Customer [Line Items]
Revenues		4,894	1,611
Vaccines [Member] | BNT162b2 alliance revenues and direct sales [Member]
Revenue from External Customer [Line Items]
Revenues		3,462	0
Vaccines [Member] | Prevnar 13/Prevenar 13 [Member]
Revenue from External Customer [Line Items]
Revenues		1,284	1,450
Vaccines [Member] | FSME/IMMUN-TicoVac [Member]
Revenue from External Customer [Line Items]
Revenues		53	48
Vaccines [Member] | Nimenrix [Member]
Revenue from External Customer [Line Items]
Revenues		46	75
Vaccines [Member] | All other Vaccines [Member]
Revenue from External Customer [Line Items]
Revenues		49	38
Oncology [Member]
Revenue from External Customer [Line Items]
Revenues		2,862	2,435
Oncology [Member] | Ibrance [Member]
Revenue from External Customer [Line Items]
Revenues		1,254	1,248
Oncology [Member] | Xtandi alliance revenues [Member]
Revenue from External Customer [Line Items]
Revenues		267	209
Oncology [Member] | Inlyta [Member]
Revenue from External Customer [Line Items]
Revenues		229	169
Oncology [Member] | Sutent [Member]
Revenue from External Customer [Line Items]
Revenues		200	205
Oncology [Member] | Xalkori [Member]
Revenue from External Customer [Line Items]
Revenues		134	149
Oncology [Member] | Bosulif [Member]
Revenue from External Customer [Line Items]
Revenues		123	100
Oncology [Member] | Retacrit [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	109	89
Oncology [Member] | Ruxience [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	98	7
Oncology [Member] | Zirabev [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	86	6
Oncology [Member] | Lorbrena [Member]
Revenue from External Customer [Line Items]
Revenues		60	42
Oncology [Member] | Aromasin [Member]
Revenue from External Customer [Line Items]
Revenues		52	34
Oncology [Member] | Besponsa [Member]
Revenue from External Customer [Line Items]
Revenues		50	44
Oncology [Member] | Braftovi [Member]
Revenue from External Customer [Line Items]
Revenues		47	37
Oncology [Member] | Mektovi [Member]
Revenue from External Customer [Line Items]
Revenues		35	37
Oncology [Member] | All other Oncology [Member]
Revenue from External Customer [Line Items]
Revenues		119	59
Internal Medicine [Member]
Revenue from External Customer [Line Items]
Revenues		2,594	2,332
Internal Medicine [Member] | Eliquis [Member]
Revenue from External Customer [Line Items]
Revenues		1,643	1,300
Internal Medicine [Member] | Chantix / Champix [Member]
Revenue from External Customer [Line Items]
Revenues		217	270
Internal Medicine [Member] | Premarin family [Member]
Revenue from External Customer [Line Items]
Revenues		143	152
Internal Medicine [Member] | Pristiq [Member]
Revenue from External Customer [Line Items]
Revenues		60	41
Internal Medicine [Member] | Toviaz [Member]
Revenue from External Customer [Line Items]
Revenues		57	60
Internal Medicine [Member] | All other Internal Medicine [Member]
Revenue from External Customer [Line Items]
Revenues		474	509
Hospital [Member]
Revenue from External Customer [Line Items]
Revenues	[1]	2,343	2,088
Hospital [Member] | Sulperazon [Member]
Revenue from External Customer [Line Items]
Revenues		192	187
Hospital [Member] | Medrol [Member]
Revenue from External Customer [Line Items]
Revenues		99	129
Hospital [Member] | Zavicefta [Member]
Revenue from External Customer [Line Items]
Revenues		94	49
Hospital [Member] | Zithromax [Member]
Revenue from External Customer [Line Items]
Revenues		89	138
Hospital [Member] | Vfend [Member]
Revenue from External Customer [Line Items]
Revenues		80	74
Hospital [Member] | Fragmin [Member]
Revenue from External Customer [Line Items]
Revenues		71	59
Hospital [Member] | EpiPen [Member]
Revenue from External Customer [Line Items]
Revenues		66	84
Hospital [Member] | Zyvox [Member]
Revenue from External Customer [Line Items]
Revenues		55	70
Hospital [Member] | Precedex [Member]
Revenue from External Customer [Line Items]
Revenues		55	42
Hospital [Member] | IVIg Products [Member]
Revenue from External Customer [Line Items]
Revenues	[4]	105	98
Hospital [Member] | Pfizer CentreOne [Member]
Revenue from External Customer [Line Items]
Revenues	[5]	391	152
Hospital [Member] | All other Anti-infectives [Member]
Revenue from External Customer [Line Items]
Revenues		397	395
Hospital [Member] | All other Hospital [Member]
Revenue from External Customer [Line Items]
Revenues		648	610
Inflammation and Immunology (I&I) [Member]
Revenue from External Customer [Line Items]
Revenues		1,065	978
Inflammation and Immunology (I&I) [Member] | Xeljanz [Member]
Revenue from External Customer [Line Items]
Revenues		538	451
Inflammation and Immunology (I&I) [Member] | Enbrel (Outside the U.S. and Canada) [Member]
Revenue from External Customer [Line Items]
Revenues		319	347
Inflammation and Immunology (I&I) [Member] | Inflectra/Remsima [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	177	158
Inflammation and Immunology (I&I) [Member] | All other I & I [Member]
Revenue from External Customer [Line Items]
Revenues		31	22
Rare Disease [Member]
Revenue from External Customer [Line Items]
Revenues		824	639
Rare Disease [Member] | Vyndaqel/Vyndamax [Member]
Revenue from External Customer [Line Items]
Revenues		453	231
Rare Disease [Member] | BeneFIX [Member]
Revenue from External Customer [Line Items]
Revenues		112	121
Rare Disease [Member] | ReFacto AF/Xyntha [Member]
Revenue from External Customer [Line Items]
Revenues		89	89
Rare Disease [Member] | Genotropin [Member]
Revenue from External Customer [Line Items]
Revenues		80	103
Rare Disease [Member] | Somavert [Member]
Revenue from External Customer [Line Items]
Revenues		65	64
Rare Disease [Member] | All other Rare Disease [Member]
Revenue from External Customer [Line Items]
Revenues		$ 26	$ 31

[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, Retacrit, Ruxience and Zirabev

[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.