Financial Instruments (Fair Values of Financial Assets and Liabilities) (Details) $ in Millions	12 Months Ended
	Dec. 26, 2020 USD ($)	Dec. 28, 2019 USD ($)
Derivatives, Fair Value [Line Items]
Senior Notes	$ 200	$ 2,200
Short-term Investments	1,366	229
Total asset derivatives at fair value	79	41
Total liability derivatives at fair value	393	470
Total Financial Assets at Fair Value	328	287
Total Financial Liabilities at Fair Value	1,731	938
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	2	5
Business Combinations [Abstract]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	1,100
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	861
Business Combination, Contingent Consideration, Liability	861	0
Business Combination, Contingent Consideration, Asset	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances	882
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	$ 21
Duration of contingent consideration arrangement	15 years
Fair Value, Inputs, Level 3, estimated range of payments, low [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	40
Fair Value, Inputs, Level 3, estimated range of payments, high [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	110
Fair Value, Inputs, Level 3, estimated range of payments, average [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	70
Fair Value, Inputs, Level 3, estimated range of probabilities of acceleration, low [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.03
Fair Value, Inputs, Level 3, estimated range of probabilities of acceleration, high [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.25
Fair Value, Inputs, Level 3, weighted average payment period [Member]
Business Combinations [Abstract]
Duration of contingent consideration arrangement	4 years
Fair Value, Inputs, Level 3, estimated range of discount rates, low [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.01
Fair Value, Inputs, Level 3, estimated range of discount rates, high [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.05
Fair Value, Inputs, Level 3, weighted average discount rate [Member]
Business Combinations [Abstract]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.03
Derivatives Designated As Cash Flow Hedging Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives designated as hedging instruments, Assets, Total	$ 54	9
Derivatives Designated As Cash Flow Hedging Instruments Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives designated as hedging instruments, Liabilities, Total	378	432
Derivatives Not Designated As Hedging Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives not designated as hedging instruments, Assets, Total	23	32
Derivatives Not Designated As Hedging Instruments Liabilities [Member]
Derivatives, Fair Value [Line Items]
Other Derivatives Not Designated as Hedging Instruments Liabilities at Fair Value	15	33
Fair Value, Inputs, Level 1 [Member] | Derivatives Designated As Cash Flow Hedging Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Commodity contracts - other	0	2
Fair Value, Inputs, Level 1 [Member] | Derivatives Designated As Cash Flow Hedging Instruments Liabilities [Member]
Derivatives, Fair Value [Line Items]
Commodity contracts - other	0	5
Fair Value, Inputs, Level 1 [Member] | Derivatives Not Designated As Hedging Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Commodity contracts - other	0	23
Fair Value, Inputs, Level 1 [Member] | Derivatives Not Designated As Hedging Instruments Liabilities [Member]
Derivatives, Fair Value [Line Items]
Commodity contracts - other	0	7
Fair Value, Inputs, Level 2 [Member] | Derivatives Designated As Fair Value Hedging Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Interest rate derivatives	2	0
Fair Value, Inputs, Level 2 [Member] | Derivatives Designated As Fair Value Hedging Instruments Liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest rate derivatives	0	5
Fair Value, Inputs, Level 2 [Member] | Derivatives Designated As Cash Flow Hedging Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Foreign Exchange Forward contracts	9	5
Interest rate derivatives	13	0
Commodity contracts - other	32	2
Fair Value, Inputs, Level 2 [Member] | Derivatives Designated As Cash Flow Hedging Instruments Liabilities [Member]
Derivatives, Fair Value [Line Items]
Foreign Exchange Forward contracts	71	32
Interest rate derivatives	307	390
Commodity contracts - other	0	5
Fair Value, Inputs, Level 2 [Member] | Derivatives Not Designated As Hedging Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Foreign Exchange Forward contracts	4	3
Commodity contracts - other	19	6
Fair Value, Inputs, Level 2 [Member] | Derivatives Not Designated As Hedging Instruments Liabilities [Member]
Derivatives, Fair Value [Line Items]
Foreign Exchange Forward contracts	8	2
Commodity contracts - other	7	24
Fair Value, Inputs, Level 2 [Member] | Assets [Member]
Derivatives, Fair Value [Line Items]
Prepaid Forward Asset Fair Value	18	17
Deferred compensation	0	0
Fair Value, Inputs, Level 2 [Member] | Liability [Member]
Derivatives, Fair Value [Line Items]
Prepaid Forward Asset Fair Value	0	0
Deferred compensation	477	468
Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Short-term Investments	231	229
Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Short-term Investments	0	0
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 1,100	$ 1,100