Other (Income)/Deductions - Net - Schedule of Other (Income)/Deductions - Net (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Oct. 03, 2021	Sep. 27, 2020	Oct. 03, 2021	Sep. 27, 2020
Other Income and Expenses [Abstract]
Interest income		$ (10)	$ (15)	$ (21)	$ (68)
Interest expense		325	345	975	1,102
Net interest expense		315	330	954	1,034
Royalty-related income		(261)	(214)	(649)	(524)
Net (gains)/losses on asset disposals		(1)	(2)	(99)	0
Net (gains)/losses recognized during the period on equity securities	[1],[2]	(400)	70	(1,601)	(408)
Income from collaborations, out-licensing arrangements and sales of compound/product rights	[3]	(65)	(30)	(317)	(245)
Net periodic benefit costs/(credits) other than service costs	[4]	(1,132)	1,043	(1,635)	749
Certain legal matters, net	[5]	38	(17)	458	5
Certain asset impairments	[6]	0	900	0	900
Consumer Healthcare JV equity method (income)/loss	[7]	(105)	(103)	(307)	(196)
Other, net		(84)	(99)	(501)	(202)
Other (income)/deductions––net		$ (1,696)	$ 1,878	$ (3,697)	$ 1,114

[1] Reported in Other (income)/deductions––net. See Note 4.

[2] The gains in the third quarter and first nine months of 2021 include, among other things, unrealized gains of $420 million and $1.5 billion, respectively, related to investments in BioNTech and Cerevel Therapeutics, LLC. The losses in the third quarter of 2020 included, among other things, unrealized losses of $131 million related to our investment in Allogene. The gains in the first nine months of 2020 included, among other things, unrealized gains of $397 million related to our investments in Allogene and BioNTech.

[3] The first nine months of 2021 includes, among other things, $188 million of net collaboration income from BioNTech in the first quarter of 2021 related to the COVID-19 vaccine. The first nine months of 2020 mainly included, among other things, (i) an upfront payment to us of $75 million from our sale of our CK1 assets to Biogen, Inc., (ii) $40 million of milestone income from Puma Biotechnology, Inc. related to Neratinib regulatory approvals in the EU and (iii) $30 million of milestone income from Lilly related to the first commercial sale in the U.S. of LOXO-292 for the treatment of RET fusion-positive NSCLC.

[4] Amounts include the impact of a change in accounting principle. See Notes 1C and 10.

[5] The first nine months of 2021 primarily includes an amount to resolve a Multi-District Litigation relating to EpiPen pending against the Company in the U.S. District Court for the District of Kansas for $345 million, which remains subject to court approval. See Note 12A5.

[6] The third quarter and first nine months of 2020 included intangible asset impairment charges of $900 million related to IPR&D assets for unapproved indications of certain cancer medicines, acquired in our Array acquisition, and reflected, among other things, updated commercial forecasts.

[7] See Note 2B