Fair Value Measurements (Reconciliation of the Beginning and Ending Balances for Level 3 Liabilities) (Details) (Significant Unobservable Inputs (Level 3) [Member], Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 23, 2013
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of December 29, 2012	$ 21.8
Unrealized losses	0.6
Payments	(0.5)
Balance as of March 23, 2013	$ 21.9