Summary of Financial Information by Reportable Segment and Product Line (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Feb. 28, 2015	Feb. 28, 2014	Feb. 28, 2015 Segment	Feb. 28, 2014	Aug. 31, 2014
Segment Reporting Information [Line Items]
Number of reportable segments			3us-gaap_NumberOfReportableSegments
Net sales	$ 301,005us-gaap_SalesRevenueNet	$ 327,770us-gaap_SalesRevenueNet	$ 628,770us-gaap_SalesRevenueNet	$ 667,326us-gaap_SalesRevenueNet
Operating profit (Loss)	(56,447)us-gaap_OperatingIncomeLoss	38,981us-gaap_OperatingIncomeLoss	(18,229)us-gaap_OperatingIncomeLoss	82,628us-gaap_OperatingIncomeLoss
Assets	1,636,819us-gaap_Assets		1,636,819us-gaap_Assets		1,856,879us-gaap_Assets
Industrial
Segment Reporting Information [Line Items]
Net sales	96,489	93,571	198,902	192,212
Operating profit (Loss)	23,517	26,477	50,221	53,374
Assets	286,529		286,529		307,058
Energy
Segment Reporting Information [Line Items]
Net sales	100,211	106,031	211,733	213,956
Operating profit (Loss)	(75,673)	9,504	(63,231)	18,427
Assets	618,346		618,346		788,915
Engineered Solutions
Segment Reporting Information [Line Items]
Net sales	104,305	128,168	218,135	261,158
Operating profit (Loss)	2,010	9,548	8,288	22,737
Assets	625,052		625,052		643,323
Vehicle Systems
Segment Reporting Information [Line Items]
Net sales	51,981	67,278	110,449	138,927
Other
Segment Reporting Information [Line Items]
Net sales	52,324	60,890	107,686	122,231
General Corporate
Segment Reporting Information [Line Items]
Operating profit (Loss)	(6,301)	(6,548)	(13,507)	(11,910)
Assets	$ 106,892		$ 106,892		$ 117,583

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 FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.18)

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

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

-Publisher FASB

-Name Accounting Standards Codification

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-Section S99

-Paragraph 1

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 7

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

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-Name Regulation S-X (SX)

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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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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

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

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