Fair Value Measurements (Narrative) (Details) (USD $)	Mar. 25, 2012	Dec. 31, 2011
Fair Value Measurements [Abstract]
Aggregate notional amount of outstanding foreign currency hedges	$ 1,500,000,000	$ 1,700,000,000
Aggregate notional amount of outstanding interest rate swaps	459,000,000	450,000,000
Estimated fair values of debt instruments	$ 8,000,000,000	$ 7,800,000,000