Stock Plans and Share-Based Compensation - Share-Based Compensation and Related Income Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Share-based Compensation Expense	$ 51	$ 89	$ 37
Income Tax Benefit	26	42	15
Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Share-based Compensation Expense	28	49	17
Restricted Stock Units and Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Share-based Compensation Expense	6	15	11
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Share-based Compensation Expense	13	22	7
Stock Awards for Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Share-based Compensation Expense	2	3	2
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Share-based Compensation Expense	$ 2	$ 0	$ 0