Acquisition, Equity-Method Investment and Licensing Arrangements - Schedule of Equity-Method Investment (Details) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 28, 2020		Mar. 31, 2020	Jun. 30, 2019	Jun. 28, 2020		Mar. 31, 2020	Jun. 30, 2019	Mar. 29, 2020	Dec. 31, 2019		Mar. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Current assets	[1]	$ 46,424				$ 46,424					$ 32,803
Total assets	[1]	177,934				177,934					167,489
Current liabilities	[1]	32,723				32,723					37,304
Total liabilities	[1]	113,370				113,370					104,042
Equity attributable to shareholders	[1]	64,336				64,336					63,143
Equity attributable to noncontrolling interests	[1]	228				228					303
Total equity	[2]	64,564	[1]		$ 59,924	64,564	[1]		$ 59,924	$ 65,338	$ 63,447	[1]	$ 59,158	$ 63,758
Income from continuing operations	[3]	3,434			5,056	6,845			8,945
Net income before allocation to noncontrolling interests	[2],[3],[4],[5]	3,434			5,056	6,845			8,945
Income attributable to shareholders	[3]	$ 3,426			$ 5,046	$ 6,828			$ 8,929
GSK Consumer Healthcare [Member]
Schedule of Equity Method Investments [Line Items]
Current assets				$ 8,213				$ 8,213
Noncurrent assets				37,627				37,627
Total assets				45,840				45,840
Current liabilities				5,524				5,524
Noncurrent liabilities				5,152				5,152
Total liabilities				10,677				10,677
Equity attributable to shareholders				35,031				35,031
Equity attributable to noncontrolling interests				133				133
Total equity				35,163				35,163
Net sales				3,503				6,691
Cost of sales				(1,394)				(3,205)
Gross profit				2,109				3,486
Income from continuing operations				425				471
Net income before allocation to noncontrolling interests				425				471
Income attributable to shareholders				$ 405				$ 441

[1] Amounts may not add due to rounding.

[2] Amounts may not add due to rounding.

[3] Amounts may not add due to rounding.

[4] Amounts may not add due to rounding.

[5] Amounts may not add due to rounding.