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Marketable Debt Securities - Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands | Feb. 15, 2020 | Aug. 31, 2019
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Schedule of Available-for-sale Securities [Line Items] |  |
Available-For-Sale Marketable Securities, Amortized Cost Basis | $ 123,708 | $ 138,173
Available-For-Sale Marketable Securities, Gross Unrealized Gains | 749 | 794
Available-For-Sale Marketable Securities, Gross Unrealized Losses | (10) | (41)
Available-For-Sale Marketable Securities, Fair Value | 124,447 | 138,926
Corporate Debt Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-For-Sale Marketable Securities, Amortized Cost Basis | 33,784 | 36,998
Available-For-Sale Marketable Securities, Gross Unrealized Gains | 62 | 29
Available-For-Sale Marketable Securities, Gross Unrealized Losses |  | (19)
Available-For-Sale Marketable Securities, Fair Value | 33,846 | 37,008
Government Bonds [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-For-Sale Marketable Securities, Amortized Cost Basis | 57,554 | 45,741
Available-For-Sale Marketable Securities, Gross Unrealized Gains | 662 | 763
Available-For-Sale Marketable Securities, Gross Unrealized Losses |  |
Available-For-Sale Marketable Securities, Fair Value | 58,216 | 46,504
Mortgage-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-For-Sale Marketable Securities, Amortized Cost Basis | 3,414 | 2,089
Available-For-Sale Marketable Securities, Gross Unrealized Gains | 12 | 2
Available-For-Sale Marketable Securities, Gross Unrealized Losses | (8) | (15)
Available-For-Sale Marketable Securities, Fair Value | 3,418 | 2,076
Asset-Backed Securities and Other [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-For-Sale Marketable Securities, Amortized Cost Basis | 28,956 | 53,345
Available-For-Sale Marketable Securities, Gross Unrealized Gains | 13 | 0
Available-For-Sale Marketable Securities, Gross Unrealized Losses | (2) | (7)
Available-For-Sale Marketable Securities, Fair Value | $ 28,967 | $ 53,338

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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
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- Definition Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
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- Definition Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References No definition available. + Details
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- Definition 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. + References No definition available. + Details
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