Share-Based Employee Compensation (Weighted-average Assumptions Used to Value Grants) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 23, 2013	Mar. 24, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based employee compensation	$ 13.6	$ 11.0
Expected stock volatility	33.00%	30.60%
Risk-free interest rate	1.30%	1.30%
Expected dividend yield during the expected term	3.80%	2.80%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	6 years 3 months	6 years 3 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	6 years 6 months	6 years 6 months