Segments of Business and Geographic Areas - Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas (Details) $ in Millions	12 Months Ended
	Jan. 03, 2021 USD ($)	Dec. 29, 2019 USD ($) Segment	Dec. 30, 2018 USD ($) Segment	Oct. 31, 2020 USD ($)	Oct. 31, 2019 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 82,584	$ 82,059	$ 81,581
Identifiable Assets	174,894	157,728
Gain (Loss) on Disposition of Assets			1,200
Contingent consideration reversal	(1,148)	$ 0	$ 0
Number of segments | Segment		3	3
Restructuring charges	247	$ 266	$ 251
In-process research and development (Note 5)	$ 181	$ 890	1,126
Percentage Change In Sales By Segment Of Business	0.60%	0.60%
Pending Litigation
Revenues from External Customers and Long-Lived Assets [Line Items]
Loss contingency, estimate of possible loss				$ 5,000	$ 4,000
Medical Devices
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 22,959	$ 25,963	26,994
Restructuring charges	300	400
Regulation charge	100
In-process research and development (Note 5)	200
Litigation expense	$ 300	$ 400	1,700
Restructuring Charge, Net of Accrual Adjustment			600
Percentage Change In Sales By Segment Of Business	(11.60%)	(3.80%)
Medical Devices | Interventional Solutions
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 3,046	$ 2,997	2,646
Percentage Change In Sales By Segment Of Business	1.60%	13.30%
Medical Devices | Diabetes Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers			1,009
Consumer
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 14,053	$ 13,898	13,853
Restructuring charges		100
Litigation expense	$ 3,900	$ 400	300
Percentage Change In Sales By Segment Of Business	1.10%	0.30%
Consumer | Baby Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,517	$ 1,675	1,858
Percentage Change In Sales By Segment Of Business	(9.40%)	(9.90%)
Consumer | OTC
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 4,824	$ 4,444	4,334
Percentage Change In Sales By Segment Of Business	8.50%	2.50%
Consumer | Skin health/Beauty
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 4,450	$ 4,593	4,382
Percentage Change In Sales By Segment Of Business	(3.10%)	4.80%
Consumer | Oral Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,641	$ 1,528	1,555
Percentage Change In Sales By Segment Of Business	7.40%	(1.70%)
Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 45,572	$ 42,198	40,734
Unrealized loss on securities			200
Restructuring charges	100	100
In-process research and development (Note 5)		900
Litigation expense	$ 800	4,300
Research and Development Expense		$ 300
Percentage Change In Sales By Segment Of Business	8.00%	3.60%
Pharmaceutical | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 15,055	$ 13,950	13,120
Percentage Change In Sales By Segment Of Business	7.90%	6.30%
Pharmaceutical | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 12,367	$ 10,692	9,844
Percentage Change In Sales By Segment Of Business	15.70%	8.60%
Pharmaceutical | Pulmonary Hypertension
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 3,148	$ 2,623	2,573
Percentage Change In Sales By Segment Of Business	20.00%	1.90%
Pharmaceutical | Stelara | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 7,707	$ 6,361	5,156
Percentage Change In Sales By Segment Of Business	21.10%	23.40%
Pharmaceutical | Tremfya | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,347	$ 1,012	544
Percentage Change In Sales By Segment Of Business	33.20%	85.90%
Pharmaceutical | Erleada | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 760	$ 332	124
Pharmaceutical | IMBRUVICA | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 4,128	$ 3,411	2,615
Percentage Change In Sales By Segment Of Business	21.00%	30.40%
Pharmaceutical | DARZALEX | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 4,190	$ 2,998	2,025
Percentage Change In Sales By Segment Of Business	39.80%	48.00%
Pharmaceutical | OPSUMIT | Pulmonary Hypertension
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,639	$ 1,327	1,215
Percentage Change In Sales By Segment Of Business	23.50%	9.20%
Property, Plant and Equipment
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 18,766	$ 17,658
Other Intangible Assets
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	89,795	81,282
Ci:z Holdings Co. Ltd. | Consumer
Revenues from External Customers and Long-Lived Assets [Line Items]
Gain (Loss) on Sale of Equity Investments		300
Alios Biopharma Inc and XO1 Limited | Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
In-process research and development (Note 5)			1,100
XO1
Revenues from External Customers and Long-Lived Assets [Line Items]
Contingent consideration reversal			(200)
Actelion | Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
Acquisition related costs		200	200
AMO | Medical Devices
Revenues from External Customers and Long-Lived Assets [Line Items]
Acquisition related costs			100
Auris Health
Revenues from External Customers and Long-Lived Assets [Line Items]
Contingent consideration reversal	(1,148)
Auris Health | Medical Devices | Other Income [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Contingent consideration reversal	(1,100)
Auris Health | Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
Acquisition related costs		100
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 43,133	$ 42,097	41,884
Percentage Change In Sales By Segment Of Business	2.50%	0.50%
United States | Medical Devices
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 11,036	$ 12,384	12,837
Percentage Change In Sales By Segment Of Business	(10.90%)	(3.50%)
United States | Medical Devices | Interventional Solutions
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,452	$ 1,443	1,283
Percentage Change In Sales By Segment Of Business	0.60%	12.50%
United States | Medical Devices | Diabetes Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers			371
United States | Consumer
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 6,362	$ 5,839	5,761
Percentage Change In Sales By Segment Of Business	9.00%	1.40%
United States | Consumer | Baby Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 376	$ 362	422
Percentage Change In Sales By Segment Of Business	3.70%	(14.20%)
United States | Consumer | OTC
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,460	$ 2,010	1,850
Percentage Change In Sales By Segment Of Business	22.40%	8.60%
United States | Consumer | Skin health/Beauty
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,350	$ 2,392	2,403
Percentage Change In Sales By Segment Of Business	(1.70%)	(0.40%)
United States | Consumer | Oral Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 683	$ 621	637
Percentage Change In Sales By Segment Of Business	9.90%	(2.50%)
United States | Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 25,735	$ 23,874	23,286
Percentage Change In Sales By Segment Of Business	7.80%	2.50%
United States | Pharmaceutical | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 10,175	$ 9,641	9,073
Percentage Change In Sales By Segment Of Business	5.50%	6.30%
United States | Pharmaceutical | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 5,092	$ 4,299	4,331
Percentage Change In Sales By Segment Of Business	18.50%	(0.70%)
United States | Pharmaceutical | Pulmonary Hypertension
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,133	$ 1,684	1,651
Percentage Change In Sales By Segment Of Business	26.60%	2.00%
United States | Pharmaceutical | OPSUMIT
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage Change In Sales By Segment Of Business		9.40%
United States | Pharmaceutical | Stelara | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 5,240	$ 4,346	3,469
Percentage Change In Sales By Segment Of Business	20.60%	25.30%
United States | Pharmaceutical | Tremfya | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 926	$ 764	453
Percentage Change In Sales By Segment Of Business	21.30%	68.50%
United States | Pharmaceutical | Erleada | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 583	$ 297	124
Percentage Change In Sales By Segment Of Business	96.10%
United States | Pharmaceutical | IMBRUVICA | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,821	$ 1,555	1,129
Percentage Change In Sales By Segment Of Business	17.10%	37.70%
United States | Pharmaceutical | DARZALEX | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,232	$ 1,567	1,203
Percentage Change In Sales By Segment Of Business	42.40%	30.30%
United States | Pharmaceutical | OPSUMIT | Pulmonary Hypertension
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,008	$ 766	700
Percentage Change In Sales By Segment Of Business	31.70%
Non-US
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 39,451	$ 39,962	39,697
Percentage Change In Sales By Segment Of Business	(1.30%)	0.70%
Non-US | Medical Devices
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 11,923	$ 13,579	14,157
Percentage Change In Sales By Segment Of Business	(12.20%)	(4.10%)
Non-US | Medical Devices | Interventional Solutions
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,594	$ 1,554	1,363
Percentage Change In Sales By Segment Of Business	2.60%	14.00%
Non-US | Medical Devices | Diabetes Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers			638
Non-US | Consumer
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 7,691	$ 8,059	8,092
Percentage Change In Sales By Segment Of Business	(4.60%)	(0.40%)
Non-US | Consumer | Baby Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,141	$ 1,313	1,436
Percentage Change In Sales By Segment Of Business	(13.10%)	(8.60%)
Non-US | Consumer | OTC
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,364	$ 2,434	2,484
Percentage Change In Sales By Segment Of Business	(2.90%)	(2.00%)
Non-US | Consumer | Skin health/Beauty
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,100	$ 2,201	1,979
Percentage Change In Sales By Segment Of Business	(4.60%)	11.20%
Non-US | Consumer | Oral Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 958	$ 906	918
Percentage Change In Sales By Segment Of Business	5.70%	(1.20%)
Non-US | Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 19,837	$ 18,324	17,448
Percentage Change In Sales By Segment Of Business	8.30%	5.00%
Non-US | Pharmaceutical | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 4,880	$ 4,309	4,047
Percentage Change In Sales By Segment Of Business	13.20%	6.50%
Non-US | Pharmaceutical | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 7,275	$ 6,393	5,513
Percentage Change In Sales By Segment Of Business	13.80%	16.00%
Non-US | Pharmaceutical | Pulmonary Hypertension
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,015	$ 939	922
Percentage Change In Sales By Segment Of Business	8.20%	1.90%
Non-US | Pharmaceutical | OPSUMIT
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage Change In Sales By Segment Of Business		9.00%
Non-US | Pharmaceutical | Stelara | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,467	$ 2,015	1,687
Percentage Change In Sales By Segment Of Business	22.40%	19.40%
Non-US | Pharmaceutical | Tremfya | Immunology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 421	$ 248	91
Percentage Change In Sales By Segment Of Business	69.90%
Non-US | Pharmaceutical | Erleada | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 176	35	0
Non-US | Pharmaceutical | IMBRUVICA | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 2,307	$ 1,856	1,486
Percentage Change In Sales By Segment Of Business	24.30%	24.90%
Non-US | Pharmaceutical | DARZALEX | Oncology
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 1,958	$ 1,430	822
Percentage Change In Sales By Segment Of Business	36.90%	73.90%
Non-US | Pharmaceutical | OPSUMIT | Pulmonary Hypertension
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	$ 631	$ 562	515
Percentage Change In Sales By Segment Of Business	12.30%
Corporate, Non-Segment
Revenues from External Customers and Long-Lived Assets [Line Items]
Other Non Long Lived Assets	$ 66,333	58,788
Corporate, Non-Segment | General Corporate
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	1,029	1,049
Identifiable Assets	31,803	25,356
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	82,584	82,059	81,581
Long-Lived Assets	107,532	97,891
Operating Segments | Medical Devices
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets	49,578	49,462
Operating Segments | Consumer
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets	27,355	26,618
Operating Segments | Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
Identifiable Assets	66,158	56,292
Unrealized Gain (Loss) on Securities	500	600
Operating Segments | NIZORAL | Consumer
Revenues from External Customers and Long-Lived Assets [Line Items]
Gain (Loss) on Disposition of Assets			300
Operating Segments | PANCREASE | Pharmaceutical
Revenues from External Customers and Long-Lived Assets [Line Items]
Gain (Loss) on Disposition of Assets			200
Operating Segments | LifeScan | Medical Devices
Revenues from External Customers and Long-Lived Assets [Line Items]
Gain (Loss) on Disposition of Business			500
Operating Segments | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	43,133	42,097	41,884
Long-Lived Assets	49,951	41,528
Operating Segments | Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	18,980	18,466	18,753
Long-Lived Assets	49,363	48,015
Operating Segments | Western Hemisphere excluding U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	5,335	5,941	6,113
Long-Lived Assets	2,734	2,862
Operating Segments | Asia-Pacific, Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to Customers	15,136	15,555	$ 14,831
Long-Lived Assets	$ 5,484	$ 5,486
Wholesaler 1 | Sales Revenue, Net
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk (as a percent)	16.00%	15.00%	14.00%
Wholesaler 2 | Sales Revenue, Net
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk (as a percent)	12.00%	12.00%	11.00%
Wholesaler 3 | Sales Revenue, Net
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk (as a percent)	12.00%	11.00%
AdvancedSterilizationProducts
Revenues from External Customers and Long-Lived Assets [Line Items]
Gain (Loss) on Disposition of Business		$ 2,000
AdvancedSterilizationProducts | Operating Segments | Medical Devices
Revenues from External Customers and Long-Lived Assets [Line Items]
Gain (Loss) on Disposition of Business		$ 2,000