Segment, Geographic and Other Revenue Information - Footnotes (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 29, 2020	Mar. 31, 2019
ViiV [Member]
Segment Reporting Information [Line Items]
Dividend income	$ 77	$ 64

Amount of dividend income on nonoperating securities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(a))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Name:	us-gaap_InvestmentIncomeDividend
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration