Identifiable Intangible Assets and Goodwill - Finite-lived and Indefinite-lived Intangible Assets (Detail) - USD ($) $ in Millions		Sep. 27, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount		$ 93,358	$ 91,425
Finite-lived intangible assets, accumulated amortization	[1]	(68,216)	(65,037)
Finite-lived intangible assets, net		25,142	26,387
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets		5,785	8,983
Intangible assets, gross carrying amount	[1]	99,143	100,408
Finite-lived intangible assets, accumulated amortization	[1]	(68,216)	(65,037)
Identifiable Intangible Assets, less Accumulated Amortization	[1]	30,927	35,370
Brands [Member]
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets		1,991	1,991
IPR&D [Member]
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	[2]	3,221	5,919
License Agreements and Other [Member]
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	[3]	573	1,073
Developed technology rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	[4]	90,052	88,730
Finite-lived intangible assets, accumulated amortization	[4]	(66,212)	(63,106)
Finite-lived intangible assets, net	[4]	23,840	25,625
Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets, accumulated amortization	[4]	(66,212)	(63,106)
Brands [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount		922	922
Finite-lived intangible assets, accumulated amortization		(766)	(741)
Finite-lived intangible assets, net		156	181
Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets, accumulated amortization		(766)	(741)
License Agreements and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	[3]	2,385	1,772
Finite-lived intangible assets, accumulated amortization	[3]	(1,238)	(1,191)
Finite-lived intangible assets, net	[3]	1,146	582
Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets, accumulated amortization	[3]	$ (1,238)	$ (1,191)

[1] The decrease is primarily due to amortization, the $900 million impairment of IPR&D, and measurement period adjustments related to the acquisition of Array.

[2] The changes in the gross carrying amount primarily reflect a $1.2 billion measurement period adjustment related to the acquisition of Array, a $900 million impairment of IPR&D (see Note 4), and the transfer of $600 million from IPR&D to Developed technology rights to reflect the approval of Braftovi in combination with Erbitux® (cetuximab), for the treatment of BRAFV600E-mutant metastatic colorectal cancer after prior therapy.

[3] The changes in the gross carrying amounts primarily reflect the transfer of $600 million from Indefinite-lived Licensing agreements and other to finite-lived Licensing agreements and other to reflect the approval in the U.S. of several products subject to out-licensing arrangements acquired from Array, as well as measurement period adjustments related to the acquisition of Array.

[4] The change in the gross carrying amount primarily reflect the transfer of $600 million from IPR&D to Developed technology rights to reflect the approval of Braftovi in combination with Erbitux® (cetuximab), for the treatment of BRAFV600E-mutant metastatic colorectal cancer after prior therapy and a $200 million measurement period adjustment related to the acquisition of Array (see Note 2A).