Commitments and Contingencies Obligation Reserves (Details) (USD $) In Millions	9 Months Ended
	Sep. 24, 2011	Dec. 25, 2010
Indemnification Agreement [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, at Carrying Value	$ 31.1	$ 33.7
Loss Contingency, Accrual Carrying Value, Foreign Exchange Impact	(2.6)
Kaiser Purchased Tax Credits Indemnity Reserve [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, at Carrying Value	21.9	23.7
Loss Contingency, Accrual Carrying Value, Foreign Exchange Impact	(1.8)
Kaiser Tax, Civil and Labor Indemnity Reserve [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, at Carrying Value	9.2	10.0
Loss Contingency, Accrual Carrying Value, Foreign Exchange Impact	$ (0.8)