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Acquisitions - Identified Intangible Assets (Detail) - American Railcar Industries - USD ($) $ in Thousands | 12 Months Ended |
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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 |

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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275 + Details
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- Definition Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472 + Details
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- Definition Amount of intangible assets, excluding goodwill, acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472 + Details
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