Income Taxes - U.S. Tax Reform (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
U.S. Tax Reform
U.S. federal statutory income tax rate (as a percent)		21.00%	21.00%	35.00%	35.00%
Income tax expense charge to reflect provisional estimate of the net impact of Tax Cuts and Jobs Act		$ 266
Remeasurement of U.S. deferred tax assets and liabilities		154
One-time transition tax on post-1986 earnings		112
Post-1986 earnings and profits previously deferred from U.S. income taxes used as basis for one-time transition tax		$ 1,600		$ 1,600
Post-1986 earnings and profits transition tax	$ 14		$ 14