Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments (Narrative) (Details)

v3.5.0.2
Financial Instruments (Narrative) (Details) - Level 1 - USD ($)
$ in Millions
Jun. 25, 2016
Dec. 26, 2015
Money Market Funds    
Schedule of Investments [Line Items]    
Available-for-sale investments used as collateral $ 3 $ 1
Mutual Funds    
Schedule of Investments [Line Items]    
Restricted investments $ 14 $ 15