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Accounting Policies - Additional Information (Detail) $ in Millions			3 Months Ended
	Dec. 29, 2017	Dec. 22, 2017	Aug. 31, 2018 USD ($)
Significant Accounting Policies [Line Items]
Stock split ratio	1.33
Federal corporate tax rate		35.00%	21.00%
Deferred tax benefit			$ 6.0
Deferred tax benefit, net			4.8
Current tax expense			$ 1.2
Minimum
Significant Accounting Policies [Line Items]
Marketable securities, maturity period			91 days
Finite lived intangible assets, useful life			5 years
Maximum
Significant Accounting Policies [Line Items]
Marketable securities, maturity period			1 year
Finite lived intangible assets, useful life			25 years

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Marketable Securities Contractual Maturity Period

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Significant Accounting Policies [Line Items]

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Tax cuts and jobs act of 2017 change in tax rate deferred income tax expense benefit.

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Tax Cuts and Jobs Act of 2017 change in tax rate deferred income tax expense benefit net.

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Tax cuts and jobs act of 2017 change in tax rate repatriation of foreign earning.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I)
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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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