Contingencies (Details 3) (Self Insured Property And Casualty Reserves [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011
Self Insured Property And Casualty Reserves [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ 140	$ 150
Expense	58	55
Payments	(56)	(65)
Ending balance	$ 142	$ 140