Bank Credit Facility (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Apr. 28, 2012 2011 Credit Agreement [Member]	Apr. 28, 2009 2009 Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 700	$ 500
Deferred Finance Costs, Gross	3.0
Line of Credit Facility, Canadian Swing Loan Sublimit	10
Line of Credit Facility, Swing Loan Sublimit	30
Line of Credit Facility, Letter of Credit Sublimit	150
Line of Credit Facility, Canadian Revolving Credit Loan Subfacility	200
Line of Credit Facility, Amount Outstanding	0
Line of Credit Facility, Letters of Credit Outstanding	56.9
Line of Credit Facility, Remaining Borrowing Capacity	$ 643.1