Employee Benefit Plans (Amounts Recoreded in Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 27, 2013		Dec. 28, 2012
Pension Plan, Defined Benefit [Member]
Amounts Recorded in Consolidated Balance Sheets [Abstract]
Long-term Assets	$ 44	[1]	$ 3	[1]
Current Liabilities	(14)		(15)
Long-term Liabilities	(209)		(648)
Net Amount Recognized in Consolidated Balance Sheet	(179)		(660)
Other Postretirement Benefit Plan, Defined Benefit [Member]
Amounts Recorded in Consolidated Balance Sheets [Abstract]
Long-term Assets	0		0
Current Liabilities	(38)		(41)
Long-term Liabilities	(312)		(374)
Net Amount Recognized in Consolidated Balance Sheet	$ (350)		$ (415)

[1] Long-term assets relate to two of the qualified pension plans whose assets exceed projected benefit obligations.