Summary of Financial Information by Reportable Segment and Product Line (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Nov. 30, 2013 Segment	Nov. 30, 2012	Aug. 31, 2013
Segment Reporting Information [Line Items]
Number of reportable segments	3
Net sales	$ 339,556	$ 307,809
Operating profit (Loss)	43,647	43,474
Assets	2,163,865		2,119,332
Assets of discontinued operations	270,106		272,606
Industrial
Segment Reporting Information [Line Items]
Net sales	98,641	101,122
Operating profit (Loss)	26,897	27,006
Assets	287,705		280,110
Energy
Segment Reporting Information [Line Items]
Net sales	107,925	90,769
Operating profit (Loss)	8,923	15,387
Assets	833,032		812,444
Engineered Solutions
Segment Reporting Information [Line Items]
Net sales	132,990	115,918
Operating profit (Loss)	13,190	7,625
Assets	675,785		652,581
Vehicle Systems
Segment Reporting Information [Line Items]
Net sales	71,649	58,029
Other
Segment Reporting Information [Line Items]
Net sales	61,341	57,889
General Corporate
Segment Reporting Information [Line Items]
Operating profit (Loss)	(5,363)	(6,544)
Assets	$ 97,237		$ 101,591

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 18

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

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-Subparagraph (SX 210.5-02.18)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section S99

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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Concepts (CON)

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-Paragraph 25

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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The aggregate value (measured at the lower of net carrying value or fair value less cost of disposal) for current assets (assets with expected useful life shorter than one year or one operating cycle, whichever is longer) of a disposal group, including a component of the entity (discontinued operation), to be sold or that has subsequently been disposed of through sale, as of the financial statement date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 20

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 46

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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