Income Tax (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 24, 2011		Sep. 25, 2010		Sep. 24, 2011		Sep. 25, 2010		Dec. 25, 2010
Income Tax
Effective tax rate (as a percent)	14.00%		19.00%		15.00%		18.00%
Nonoperating Income (Expense)	$ (2.3)		$ 41.6		$ (4.8)		$ 54.4
Uncertain tax benefits	90.2				90.2				84.1
Uncertain tax benefits, change in period					6.1
Non Cash Income Tax Benefit	18.6
Gain loss from Foster's swap and related financial instruments [Member]
Income Tax
Nonoperating Income (Expense)	$ 0	[1]	$ 42.3	[1]	$ 0.8	[1]	$ 57.3	[1]

[1] During January 2011, we settled the remaining Foster's total return swap and related financial instruments.