Business Segments (Schedule Of Business Segments Detailed Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Segment Reporting Information [Line Items]
Revenues									$ 717,194	$ 562,397	$ 550,692
Gross profit	41,480	43,843	34,237	20,378	27,324	21,864	24,877	25,865	139,938	99,930	142,057
Income before income taxes									48,234	3,997	45,061
Depreciation and amortization expense									13,065	15,350	13,630
Electrical Power Products [Member]
Segment Reporting Information [Line Items]
Revenues									686,581	533,339	517,069
Gross profit									132,458	91,730	129,780
Income before income taxes									48,055	3,888	41,378
Depreciation and amortization expense									13,010	15,188	13,453
Process Control Systems [Member]
Segment Reporting Information [Line Items]
Revenues									30,613	29,058	33,623
Gross profit									7,480	8,200	12,277
Income before income taxes									179	109	3,683
Depreciation and amortization expense									$ 55	$ 162	$ 177