Retirement Plans - Other information on retirement plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Retirement Plans
Percentage of eligible compensation contributed by employer to Retirement Account Plan	2.00%
Additional percentage of eligible compensation contributed annually by employer to defined contribution plan for employees hired after January 1, 2010	4.00%
Cost recognized for defined contribution plans	$ 125	$ 123	$ 110
Portion of contribution related to Retirement Account Plan	$ 13	$ 13	$ 10