Business Segment Information (Schedule Of Depreciation And Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Depreciation and Amortization	$ 18,584	$ 16,362	$ 14,805
Filtration [Member]
Depreciation and Amortization	5,200	5,200	4,200
Test [Member]
Depreciation and Amortization	3,100	2,700	2,500
USG [Member]
Depreciation and Amortization	6,200	4,800	4,600
Corporate [Member]
Depreciation and Amortization	$ 4,100	$ 3,700	$ 3,500