Acquisition and Equity-Method Investment - Equity Method Investment Narrative (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 29, 2020	Sep. 29, 2019	Mar. 31, 2019	Dec. 31, 2019	Jul. 31, 2019
Schedule of Equity Method Investments [Line Items]
Gain on completion of Consumer Healthcare JV transaction	[1]	$ 6		$ 0
Equity-method investments	[2]	15,524			$ 17,133
GSK Consumer Healthcare [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage						32.00%
Gain on completion of Consumer Healthcare JV transaction			$ 8,100
Gain on completion of Consumer Healthcare JV transaction, after-tax			$ 5,400
Equity-method investments		15,400			17,000
Equity method investment earnings		$ 11
Fair value of equity method investment						$ 15,700
Underlying equity in net assets					11,000	11,200
Difference between carrying amount and underlying equity					$ 4,800	$ 4,500
Excess basis amortization period		17 years
GSK [Member] | GSK Consumer Healthcare [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage						68.00%
OID [Member] | GSK Consumer Healthcare [Member]
Schedule of Equity Method Investments [Line Items]
Excess basis amortization		$ 44
Consumer Healthcare [Member] | Held-for-sale [Member]
Schedule of Equity Method Investments [Line Items]
Pre-tax income attributable to disposal group				$ 281

[1] Amounts may not add due to rounding.

[2] Amounts may not add due to rounding.