Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	12 Months Ended
	Jan. 02, 2022 USD ($) Segment Employee	Jan. 03, 2021 USD ($)	Dec. 29, 2019 USD ($)	Dec. 30, 2018	Dec. 31, 2017
Concentration of Credit Risk [Line Items]
Number of employees | Employee	141,700
Number of business segments | Segment	3
Minimum reverse repurchase agreement collateral (as a percent)	102.00%
Accrued Rebates Returns And Promotions	$ 12,095	$ 11,513
Sales return reserve (as a percent)	1.00%	1.00%	1.00%
Percentage of profit share payments (less than)	3.00%	3.00%	3.00%
Cost of products sold	$ 29,855	$ 28,427	$ 27,556
Shipping and handling costs as a percent of sales	0.50%	0.50%	0.50%
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets, noncurrent	Other assets, noncurrent
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities, Current	Accrued Liabilities, Current
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Operating lease, right-of-use asset	$ 900	$ 1,000
Operating lease liabilities	1,000	1,100
Operating lease costs	300	300	$ 300
Cash paid for operating leases	300	300	300
Advertising expense	$ 2,700	$ 2,100	$ 2,200
U.S. statutory rate	21.00%	21.00%	21.00%	21.00%	35.00%
TCJA, undistributed foreign earnings percent related to cash and cash equivalents				15.50%
TCJA, undistributed foreign earnings percent related to earnings other than cash and cash equivalents				8.00%
TCJA, provisional liability	$ 6,900
TJCA , provisional liability, non-current	6,100
Repatriation of foreign earnings amount	$ 700
Minimum | Software Development
Concentration of Credit Risk [Line Items]
Estimated useful lives of the assets	3 years
Maximum | Software Development
Concentration of Credit Risk [Line Items]
Estimated useful lives of the assets	8 years
R&D Expense | Project Concentration Risk
Concentration of Credit Risk [Line Items]
Concentration risk, threshold percentage (as a percent)	0.05	0.05	0.05
Shipping and Handling
Concentration of Credit Risk [Line Items]
Cost of products sold	$ 1,100	$ 1,000	$ 1,000
Pharmaceutical
Concentration of Credit Risk [Line Items]
Accrued Rebates Returns And Promotions	$ 7,700	$ 7,200