Contingencies (Details 1) (USD $) In Thousands, unless otherwise specified	0 Months Ended	3 Months Ended	9 Months Ended	20 Months Ended		9 Months Ended	0 Months Ended
	Dec. 29, 2010 TransWeb [Member]	Sep. 01, 2012 TransWeb [Member]	Sep. 01, 2012 TransWeb [Member]	Sep. 01, 2012 TransWeb [Member]	Sep. 01, 2012 TransWeb [Member] Purchase Price Withheld Remaining Current [Member]	Sep. 01, 2012 Legal Contingnecy - Donaldson [Member]	Oct. 07, 2011 Legal Contingency - Antitrust [Member]
Business Acquisition, Purchase Price Withheld Disclosures [Line Items]
Litigation Settlement, Gross						$ 531	$ 625
Business Acquisition, Effective Date of Acquisition	Dec. 29, 2010
Business Acquisition, Purchase Price Withheld	17,000
Business Acquisition, Legal Charges Applied Against Purchase Price Withheld		2,014	6,421	12,750
Business Acquisition, Purchase Price Withheld Remaining Balance					$ 4,250