Employee Benefit Plans and Collective Bargaining Agreements (Fair Value Measured Using Significant Unobservable Inputs (Level 3) 2011) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 2.8	$ 3.8
Purchases, sales, settlements, net	0.4	(0.5)
Unrealized gains	0.8	(0.5)
Ending Balance	4.0	2.8
Corporate bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2.7	3.1
Purchases, sales, settlements, net	(0.1)	0.1
Unrealized gains	0.8	(0.5)
Ending Balance	3.4	2.7
Mortgage and other asset backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0
Purchases, sales, settlements, net	0.5
Unrealized gains	0
Ending Balance	0.5
U.S. government securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0.1	0.7
Purchases, sales, settlements, net	0	(0.6)
Unrealized gains	0	0
Ending Balance	$ 0.1	$ 0.1