Intangible Assets and Goodwill - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Sep. 30, 2018	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Apr. 01, 2019
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)			$ 11,569	$ 9,190
Amortization expense of amortizable intangible assets			4,500	4,400	$ 3,000
Goodwill			$ 33,639	30,453	31,906
Patents And Trademarks
Finite-Lived Intangible Assets [Line Items]
Intangible assets useful life			12 years
Customer relationships and other intangible assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets useful life			21 years
Auris Health
Finite-Lived Intangible Assets [Line Items]
Goodwill						$ 2,000
Consumer
Finite-Lived Intangible Assets [Line Items]
Goodwill			$ 9,736	8,670	8,875
Medical Devices
Finite-Lived Intangible Assets [Line Items]
Goodwill			14,734	12,720	13,922
Pharmaceutical
Finite-Lived Intangible Assets [Line Items]
Goodwill			9,169	9,063	$ 9,109
Goodwill | AdvancedSterilizationProducts | Medical Devices
Finite-Lived Intangible Assets [Line Items]
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent				300
Goodwill | LifeScan | Medical Devices
Finite-Lived Intangible Assets [Line Items]
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent				1,000
Purchased in-process research and development
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)			$ 4,647	$ 2,253
Purchased in-process research and development | Alios Biopharma Inc
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	$ 900	$ 800