Supplemental Financial Information (Schedule of Supplemental Balance Sheet Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Accounts and notes receivable
Trade receivables	$ 6,892	$ 6,447
Other receivables	1,713	1,480
Total receivables	8,605	7,927
Analysis of valuation allowances
Allowance, beginning of year	105	101	$ 129
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification (Pre-Tax)	44	0	0
Net amounts charged to expense	79	22	16
Accounts Receivable, Credit Loss Expense (reversal) Novel Coronavirus (COVID-19) Impact	56
Deductions	(32)	(30)	(33)
Other	5	12	(11)
Allowance, end of year	201	105	101
Net receivables	8,404	7,822
Inventories (c)
Raw materials	1,720	1,395
Work-in-process	205	200
Finished goods	2,247	1,743
Inventories	4,172	3,338
Property, plant and equipment, net [Abstract]
Property, plant and equipment, gross	46,340	43,003
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	24,971	23,698
Property, Plant and Equipment, net	21,369	19,305
Depreciation	2,335	2,257	$ 2,241
Other assets
Other Assets, Noncurrent	(3,312)	(3,011)
Noncurrent notes and accounts receivable	109	85
Deferred marketplace spending	130	147
Prepaid Expense and Other Assets, Noncurrent	910	846
Operating Lease, Right-of-Use Asset	1,670	1,548
Other Assets, Miscellaneous	493	385
Accounts payable and other current liabilities
Accounts payable	8,853	8,013
Accrued marketplace spending	2,935	2,765
Accrued compensation and benefits	2,059	1,835
Dividends payable	1,430	1,351
Business Combination, Contingent Consideration, Liability	861	0
Operating Lease, Liability, Current	460	442
Other current liabilities	3,855	3,135
Accounts payable and other current liabilities	19,592	17,541
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 46,340	$ 43,003
Maximum [Member]
Property, Plant and Equipment [Line Items]
Percentage of LIFO Inventory	6.00%	7.00%
Percentage of LIFO Inventory	6.00%	7.00%
Land [Member]
Property, plant and equipment, net [Abstract]
Property, plant and equipment, gross	$ 1,171	$ 1,130
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,171	1,130
Buildings And Improvements
Property, plant and equipment, net [Abstract]
Property, plant and equipment, gross	10,214	9,314
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 10,214	9,314
Buildings And Improvements | Maximum
Property, Plant and Equipment [Line Items]
Average Useful Life (Years)	44 years
Buildings And Improvements | Minimum
Property, Plant and Equipment [Line Items]
Average Useful Life (Years)	15 years
Construction In Progress
Property, plant and equipment, net [Abstract]
Property, plant and equipment, gross	$ 3,679	3,169
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,679	3,169
Machinery And Equipment, Including Fleet And Software
Property, plant and equipment, net [Abstract]
Property, plant and equipment, gross	31,276	29,390
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 31,276	$ 29,390
Machinery And Equipment, Including Fleet And Software | Maximum
Property, Plant and Equipment [Line Items]
Average Useful Life (Years)	15 years
Machinery And Equipment, Including Fleet And Software | Minimum
Property, Plant and Equipment [Line Items]
Average Useful Life (Years)	5 years