Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Schedule Of Significant Accounting Policies [Line Items]
Accounts receivable collection period (days)	30 days
LIFO balance sheet reserves	$ 152,000,000	$ 130,000,000
Effect of LIFO reserves on cost of goods sold increase (decrease)	22,000,000	0	$ 14,000,000
Shipping and handling costs	$ 1,800,000,000	$ 1,700,000,000	$ 1,600,000,000
Minimum
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets	3 years
Risk reduction strategy	$ 1,000,000
Maximum
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets	40 years
Risk reduction strategy	$ 10,000,000
Maximum | Employee Stock Purchase Plan
Schedule Of Significant Accounting Policies [Line Items]
Purchase of common stock discount, percentage	15.00%