Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments (Cash and Cash Equivalents Fair Value Measurements) (Details)

v3.8.0.1
Financial Instruments (Cash and Cash Equivalents Fair Value Measurements) (Details) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 30, 2017
Schedule of Investments [Line Items]    
Total $ 1,045 $ 1,185
Level 1    
Schedule of Investments [Line Items]    
Total 45 395
Level 2    
Schedule of Investments [Line Items]    
Total 887 682
Cash    
Schedule of Investments [Line Items]    
Total 113 108
Government money market funds | Level 1    
Schedule of Investments [Line Items]    
Total 45 395
Commercial paper | Level 2    
Schedule of Investments [Line Items]    
Total $ 887 $ 682