Fair Value Measurements - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended					1 Months Ended	3 Months Ended
	Dec. 19, 2012	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013 Trade Name [Member]	Aug. 31, 2013 Accrued Expenses and Other [Member]	Aug. 31, 2013 Other Long Term Liabilities [Member]	Aug. 31, 2013 Fair Value, Measurements, Recurring [Member]	Aug. 25, 2013 Fair Value, Measurements, Recurring [Member]	Dec. 19, 2012 AutoAnything [Member]	Aug. 31, 2013 AutoAnything [Member]	Aug. 31, 2013 AutoAnything [Member] Trade Name [Member]	Dec. 19, 2012 AutoAnything [Member] Maximum [Member]	Dec. 19, 2012 AutoAnything [Member] First Year [Member]	Dec. 19, 2012 AutoAnything [Member] Second Year [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term marketable securities							$ 16,410,000	$ 22,515,000
Long-term marketable securities							65,751,000	53,699,000
Acquisition of assets and liabilities									150,000,000
Initial cash payment	115,000,000								115,000,000
Holdback payment for working capital true-ups	5,000,000								5,000,000
Contingent payments, total									30,000,000			30,000,000	10,000,000	30,000,000
Contingent consideration adjusted to reflect fair value		200,000	200,000		100,000	100,000			22,700,000	200,000
Decrease in contingent consideration liability		23,300,000								23,300,000
Goodwill impairment charge			18,300,000							18,300,000
Impairment charge				$ 4,100,000							$ 4,100,000