Business Segment Information (Schedule Of Depreciation And Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Depreciation and Amortization	$ 32,229	$ 23,568	$ 18,584
Filtration [Member]
Depreciation and Amortization	6,600	4,000	3,800
Test [Member]
Depreciation and Amortization	3,600	3,600	3,100
USG [Member]
Depreciation and Amortization	9,800	8,100	6,200
Technical Packaging [Member]
Depreciation and Amortization	3,500	2,900	1,400
Corporate [Member]
Depreciation and Amortization	$ 8,700	$ 5,000	$ 4,100