Financial Instruments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		3 Months Ended		6 Months Ended
	Dec. 31, 2011	Jun. 29, 2012	Jun. 29, 2012 Not Designated as Hedging Instrument [Member]	Jul. 01, 2011 Not Designated as Hedging Instrument [Member]	Jun. 29, 2012 Not Designated as Hedging Instrument [Member]	Jul. 01, 2011 Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Number of derivative require collateral security	0	0
Collateral to secure the derivative liability positions	$ 0.7
Gain (loss) on derivative instruments not designated as cash flow hedges			(6.5)	0.4	(0.3)	6.4
Forward pricing agreements	36.3	35.8
Fair value forward pricing agreements	35.3	35.4
Unrealized gain (loss) related to forward pricing agreements	$ (1.0)	$ (0.4)