Business Segments (Schedule Of Business Segments Detailed Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting Information [Line Items]
Revenues									$ 674,772	$ 717,194	$ 562,397
Gross profit	42,852	38,485	31,715	33,784	41,480	43,843	34,237	20,378	146,836	139,938	99,930
Income before income taxes									50,732	48,234	3,997
Depreciation and amortization expense									10,190	13,065	15,350
Electrical Power Products
Segment Reporting Information [Line Items]
Revenues									635,253	686,581	533,339
Gross profit									137,756	132,458	91,730
Income before income taxes									49,421	48,055	3,888
Depreciation and amortization expense									10,103	13,010	15,188
Process Control Systems
Segment Reporting Information [Line Items]
Revenues									39,519	30,613	29,058
Gross profit									9,080	7,480	8,200
Income before income taxes									1,311	179	109
Depreciation and amortization expense									$ 87	$ 55	$ 162