Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Lessee, Lease, Description [Line Items]
Operating Leases, Rent Expense			$ 771
Lessee, Operating Lease, Option to Extend	five years,
Lessee, Operating Lease, Option to Terminate	one year
Operating Lease, Cost	$ 539	$ 474
Variable Lease, Cost	111	101
Short-term Lease, Cost	436	379
lessee, operating lease, amortization amount included in operating lease cost	478	412
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	621	479
Operating Lease, Payments	555	478
Operating Lease, Right-of-Use Asset	$ 1,670	$ 1,548
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent
Operating Lease, Liability, Current	$ 460	$ 442
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLongTermDebtNoncurrent	us-gaap:OtherLongTermDebtNoncurrent
Operating Lease, Liability, Noncurrent	$ 1,233	$ 1,118
Operating Lease, Liability	$ 1,693
Operating Lease, Weighted Average Discount Rate, Percent	4.00%	4.00%
Operating Lease, Weighted Average Remaining Lease Term	6 years	6 years
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	$ 486
Lessee, Operating Lease, Liability, Payments, Due Year Two	385
Lessee, Operating Lease, Liability, Payments, Due Year Three	278
Lessee, Operating Lease, Liability, Payments, Due Year Four	194
Lessee, Operating Lease, Liability, Payments, Due Year Five	139
Lessee, Operating Lease, Liability, Payments, Due after Year Five	413
Lessee, Operating Lease, Liability, Payments, Due	1,895
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	$ (202)
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities
Sale and Leaseback Transaction, Gain (Loss), Net	$ 7	$ 77
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	20 years