Restructuring, Impairment and Integration Charges (Summary of Charges) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Total Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	$ 289	$ 373	$ 316
2019 Productivity Plan
Total Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	289	370	138
2014 Productivity Plan
Total Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	0	0	170
Total restructuring and impairment charges
Total Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	289	370	308
Other productivity initiatives
Total Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	$ 0	$ 3	$ 8