Segment and Geographic Information - Narrative (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Number of distribution centers	28		28
Number of distribution facilities operated as a third party logistics provider	2		2
Number of reportable segments			1
Number of geographical areas			2
United States [Member]
Segment Reporting Information [Line Items]
Number of distribution centers	24		24
Number of Consolidating Warehouses	3		3
Canada [Member]
Segment Reporting Information [Line Items]
Number of distribution centers	4		4
Net sales [Member] | Customer Concentration Risk [Member] | Couche-Tard [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	13.00%	13.00%	13.00%	13.00%