Summary of Financial Information by Reportable Segment and Product Line (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 1,249,254	$ 1,399,862	$ 1,279,742
Operating profit (loss)	53,554	203,108	190,145
Depreciation and amortization	53,239	60,635	53,902
Capital Expenditure	22,516	41,857	23,668
Assets	1,636,917	1,856,879
Industrial
Segment Reporting Information [Line Items]
Net sales	402,464	413,902	422,620
Operating profit (loss)	105,652	120,250	117,644
Depreciation and amortization	8,257	7,597	8,553
Capital Expenditure	1,249	3,349	3,524
Assets	293,738	307,058
Energy
Segment Reporting Information [Line Items]
Net sales	411,875	462,368	363,372
Operating profit (loss)	(41,351)	56,412	63,280
Depreciation and amortization	26,532	33,983	18,451
Capital Expenditure	11,864	26,787	9,417
Assets	601,521	788,915
Engineered Solutions
Segment Reporting Information [Line Items]
Net sales	434,915	523,592	493,750
Operating profit (loss)	19,789	55,430	40,328
Depreciation and amortization	16,652	17,602	16,949
Capital Expenditure	8,472	8,763	7,001
Assets	588,200	643,323
General Corporate
Segment Reporting Information [Line Items]
Operating profit (loss)	(30,536)	(28,984)	(31,107)
Depreciation and amortization	1,798	1,453	2,145
Capital Expenditure	931	2,956	867
Assets	153,458	117,583
Vehicle Systems
Segment Reporting Information [Line Items]
Net sales	220,889	272,201	253,073
Other
Segment Reporting Information [Line Items]
Net sales	214,026	251,391	240,677
Discontinued Operations
Segment Reporting Information [Line Items]
Depreciation and Amortization, Discontinued Operations	0	0	7,804
Capital Expenditure	$ 0	$ 2	$ 2,859