Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
May 07, 2011	Aug. 28, 2010
Available-for-sale marketable securities
Available-For-Sale Marketable Securities, Amortized Cost Basis	$ 74,527	$ 71,701
Available-For-Sale Marketable Securities, Gross Unrealized Gains	731	1,012
Available-For-Sale Marketable Securities, Gross Unrealized Losses	9	12
Available-For-Sale Marketable Securities, Fair Value	75,249	72,701
Marketable Securities (Textuals) [Abstract]
Available for sale securities debt maturity period range	Less than one year to approximately 3 years
Held to maturity securities in continuous unrealized loss position amount	9
Number of securities held in unrealized loss position	7
Corporate securities [Member]
Available-for-sale marketable securities
Available-For-Sale Marketable Securities, Amortized Cost Basis	25,895	28,707
Available-For-Sale Marketable Securities, Gross Unrealized Gains	297	490
Available-For-Sale Marketable Securities, Gross Unrealized Losses	2	1
Available-For-Sale Marketable Securities, Fair Value	26,190	29,196
Government bonds [Member]
Available-for-sale marketable securities
Available-For-Sale Marketable Securities, Amortized Cost Basis	29,919	24,560
Available-For-Sale Marketable Securities, Gross Unrealized Gains	180	283
Available-For-Sale Marketable Securities, Gross Unrealized Losses	7	0
Available-For-Sale Marketable Securities, Fair Value	30,092	24,843
Mortgage-backed securities [Member]
Available-for-sale marketable securities
Available-For-Sale Marketable Securities, Amortized Cost Basis	5,449	8,603
Available-For-Sale Marketable Securities, Gross Unrealized Gains	88	192
Available-For-Sale Marketable Securities, Gross Unrealized Losses	0	0
Available-For-Sale Marketable Securities, Fair Value	5,537	8,795
Asset-Backed securities and other [Member]
Available-for-sale marketable securities
Available-For-Sale Marketable Securities, Amortized Cost Basis	13,264	9,831
Available-For-Sale Marketable Securities, Gross Unrealized Gains	166	47
Available-For-Sale Marketable Securities, Gross Unrealized Losses	0	11
Available-For-Sale Marketable Securities, Fair Value	$ 13,430	$ 9,867

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

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- Definition

This item represents the excess of amortized cost basis over fair value of securities in a loss position and which are categorized as held-to-maturity.

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- Definition

Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity investments determined to be temporarily impaired.

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