Basis of Presentation and Principles of Consolidation (Details) (Customer Concentration Risk [Member])			3 Months Ended
	Mar. 31, 2013 customers	Dec. 31, 2012 customers	Mar. 31, 2013 Couche-Tard [Member]	Mar. 31, 2012 Couche-Tard [Member]
Concentration Risk [Line Items]
Major customer percentage of net sales			13.40%	13.50%
Customer accounted for 10% or more of accounts receivable, number	0	0