Discontinued Operations (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2017 USD ($)	Feb. 29, 2016 USD ($)	Feb. 28, 2017 USD ($)	Feb. 29, 2016 USD ($)	Aug. 31, 2015 store	Feb. 28, 2015 store
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other asset impairment charges	$ 0	$ 18,458	$ 401	$ 18,458
Loss from discontinued operations, net of tax	(95)	(1,024)	(148)	(1,089)
Auto Parts Stores
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Stores | store					7	7
Auto Parts Stores | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Stores | store					6
Revenues	0	0	0	0
Loss from discontinued operations before income taxes	(109)	(1,015)	(158)	(1,094)
Income tax (expense) benefit	(14)	9	(10)	(5)
Loss from discontinued operations, net of tax	(95)	(1,024)	(148)	(1,089)
Income (Loss) from Discontinued Operations, Net of Tax
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other asset impairment charges	$ 0	$ 947	$ 0	$ 947