Business Segments (Schedule Of Business Segments Detailed Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 153,915	$ 181,486	$ 307,856	$ 338,942
Gross profit	31,715	34,237	65,499	54,615
Income (loss) before income taxes	8,910	11,976	19,864	11,841
Depreciation and amortization expense	2,348	3,254	5,421	6,427
Electrical Power Products [Member]
Segment Reporting Information [Line Items]
Revenues	145,259	173,974	291,395	324,638
Gross profit	29,592	32,533	61,969	51,526
Income (loss) before income taxes	8,830	11,665	19,984	11,644
Depreciation and amortization expense	2,328	3,229	5,381	6,414
Process Control Systems [Member]
Segment Reporting Information [Line Items]
Revenues	8,656	7,512	16,461	14,304
Gross profit	2,123	1,704	3,530	3,089
Income (loss) before income taxes	80	311	(120)	197
Depreciation and amortization expense	$ 20	$ 25	$ 40	$ 13

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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- Definition

Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

+ 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=6880815&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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