Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Aug. 31, 2011
Segment Reporting Information [Line Items]
Net Sales	$ 392,799	$ 318,412
Operating Profit	57,281	41,572
Assets	2,017,554		2,056,681
Industrial [Member]
Segment Reporting Information [Line Items]
Net Sales	100,253	87,392
Operating Profit	27,934	20,187
Assets	269,332		263,680
Energy [Member]
Segment Reporting Information [Line Items]
Net Sales	80,421	70,743
Operating Profit	13,217	11,858
Assets	504,263		517,428
Electrical [Member]
Segment Reporting Information [Line Items]
Net Sales	82,833	55,396
Operating Profit	4,977	3,760
Assets	529,022		547,556
Engineered Solutions [Member]
Segment Reporting Information [Line Items]
Net Sales	129,292	104,881
Operating Profit	18,999	13,802
Assets	622,110		632,242
Vehicle Systems [Member]
Segment Reporting Information [Line Items]
Net Sales	76,363	76,741
Other [Member]
Segment Reporting Information [Line Items]
Net Sales	52,929	28,140
General Corporate [Member]
Segment Reporting Information [Line Items]
Operating Profit	(7,846)	(8,035)
Assets	$ 92,827		$ 95,775