Business Segment Information (Schedule Of Net Sales And Earnings Before Income Tax) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Dec. 31, 2012 segment	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of reporting segments	3
Net sales	$ 145,265	$ 152,925
Consolidated EBIT	860	8,833
Less: Interest expense	(563)	(491)
Earnings before income taxes	297	8,342
USG [Member]
Segment Reporting Information [Line Items]
Net sales	62,618	70,349
Consolidated EBIT	(2,208)	4,966
Test [Member]
Segment Reporting Information [Line Items]
Net sales	36,295	39,354
Consolidated EBIT	519	1,947
Filtration [Member]
Segment Reporting Information [Line Items]
Net sales	46,352	43,222
Consolidated EBIT	8,801	8,236
Corporate (Loss) [Member]
Segment Reporting Information [Line Items]
Consolidated EBIT	$ (6,252)	$ (6,316)

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h)(1)(i))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Subparagraph 1(i)

-Article 4

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- Definition

This element represents the income or loss from continuing operations (before interest income and interest expense) 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 interest income, interest expense, income taxes, extraordinary items, and noncontrolling interest.

+ References

No definition available.

+ Details

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- Definition

The net amount of operating interest income (expense).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.10)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 10

-Article 9

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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ 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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