Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 29, 2012
Information about Litigation Matters
Number of Vendors, EPA Compliance Issue	1
Letters of Credit
Letters of Credit Outstanding, Amount	$ 41.4
Letter of credit outstanding outside of the Senior credit facility	6.2
Construction Projects [Member]
Construction Commitments
Property and construction commitments	5.6
DC Construction Projects [Member]
Construction Commitments
Property and construction commitments	30
Store Previously Under Lease [Member]
Construction Commitments
Property and construction commitments	$ 1.8
Number of stores, commitment to purchase	1