Marketable Securities - Available-for-Sale Marketable Securities (Detail) (USD $) In Thousands, unless otherwise specified	May 10, 2014	Aug. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Marketable Securities, Amortized Cost Basis	$ 85,802	$ 82,198
Available-For-Sale Marketable Securities, Gross Unrealized Gains	296	240
Available-For-Sale Marketable Securities, Gross Unrealized Losses	(91)	(277)
Available-For-Sale Marketable Securities, Fair Value	86,007	82,161
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Marketable Securities, Amortized Cost Basis	27,164	27,803
Available-For-Sale Marketable Securities, Gross Unrealized Gains	176	148
Available-For-Sale Marketable Securities, Gross Unrealized Losses	(5)	(67)
Available-For-Sale Marketable Securities, Fair Value	27,335	27,884
Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Marketable Securities, Amortized Cost Basis	26,424	21,372
Available-For-Sale Marketable Securities, Gross Unrealized Gains	36	18
Available-For-Sale Marketable Securities, Gross Unrealized Losses	(3)	(67)
Available-For-Sale Marketable Securities, Fair Value	26,457	21,323
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Marketable Securities, Amortized Cost Basis	6,113	7,198
Available-For-Sale Marketable Securities, Gross Unrealized Gains	28	24
Available-For-Sale Marketable Securities, Gross Unrealized Losses	(83)	(138)
Available-For-Sale Marketable Securities, Fair Value	6,058	7,084
Asset-Backed Securities and Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Marketable Securities, Amortized Cost Basis	26,101	25,825
Available-For-Sale Marketable Securities, Gross Unrealized Gains	56	50
Available-For-Sale Marketable Securities, Gross Unrealized Losses		(5)
Available-For-Sale Marketable Securities, Fair Value	$ 26,157	$ 25,870