Acquisitions - Identified Intangible Assets (Detail) - American Railcar Industries - USD ($) $ in Thousands	12 Months Ended
Aug. 31, 2021	Jul. 26, 2019
Business Acquisition [Line Items]
Identified intangible assets subject to amortization	$ 35,571
Other identified intangible assets not subject to amortization	860
Total identified intangible assets	36,431	$ 36,785
Trademarks and patents
Business Acquisition [Line Items]
Identified intangible assets subject to amortization	$ 19,500
Identified intangible assets subject to amortization,Useful Life	9 years
Customer and supplier relationships
Business Acquisition [Line Items]
Identified intangible assets subject to amortization	$ 16,071
Identified intangible assets subject to amortization,Useful Life	7 years

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

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- Definition

Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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- Definition

The amount of identifiable intangible assets recognized as of the acquisition date.

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