Product, Geographic and Other Revenue Information - Revenues By Geographic Area (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Oct. 03, 2021	Sep. 27, 2020	Oct. 03, 2021	Sep. 27, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	[1]	$ 24,094	$ 10,277	$ 57,653	$ 30,224
Percentage Change In Revenue		134.00%		91.00%
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues		$ 7,079	5,425	$ 22,269	15,827
Percentage Change In Revenue		30.00%		41.00%
Developed Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues		$ 6,221	1,864	$ 13,836	5,437
Percentage Change In Revenue		234.00%		154.00%
Developed Rest Of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues		$ 4,498	1,065	$ 8,617	2,974
Percentage Change In Revenue		322.00%		190.00%
Emerging Markets [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues		$ 6,296	$ 1,923	$ 12,930	$ 5,986
Percentage Change In Revenue		227.00%		116.00%

[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.