Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments (Details) (Narrative)

v3.2.0.727
Financial Instruments (Details) (Narrative) - USD ($)
$ in Millions
Jun. 27, 2015
Dec. 27, 2014
Money Market Funds    
Financial Instruments [Line Items]    
Available-for-sale investments used as collateral   $ 10
Mutual Funds    
Financial Instruments [Line Items]    
Restricted investments $ 16 $ 16