Business Combinations (Details) (USD $)									12 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012	Nov. 30, 2013 Pick A Part, Inc. store	Dec. 31, 2012 Ralphs Auto Supply (B.C.) Ltd store	Dec. 31, 2012 U-Pick-It store	Dec. 31, 2012 Freetown - Millis Used Auto Parts store	Jun. 30, 2013 Bill’s Auto Parts, Inc. and Perkins Horshoe Works, Inc. store	Aug. 31, 2013 Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Number of Stores				1	4	2	2	1
Consideration Transferred									$ 26,000,000
Goodwill	325,903,000	327,264,000	635,491,000						20,000,000
Goodwill, Expected Tax Deductible Amount									18,000,000
Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual									11,000,000
Pro Forma Information, Operating Income (Loss) of Acquiree since Acquisition Date, Actual									$ (4,000,000)