Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments (Narrative) (Details)

v3.8.0.1
Financial Instruments (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Dec. 30, 2017
Foreign Currency Forward Contracts    
Schedule of Investments [Line Items]    
Contract maturity period 12 months  
Maximum length of time hedged in foreign currency cash flow hedges 12 months  
Cash Flow Hedging | Foreign Currency Forward Contracts    
Schedule of Investments [Line Items]    
Derivative, notional amount $ 336 $ 300
Level 1 | Government money market funds    
Schedule of Investments [Line Items]    
Investment in money market fund and bank guarantee 3 2
Level 1 | Bank guarantee    
Schedule of Investments [Line Items]    
Investment in money market fund and bank guarantee 3  
Level 1 | Mutual funds    
Schedule of Investments [Line Items]    
Restricted investments $ 18 $ 18