Business Segment Information (Schedule Of Depreciation And Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Depreciation and Amortization	$ 37,755	$ 32,229	$ 23,568
Filtration [Member]
Depreciation and Amortization	7,600	6,600	4,000
Test [Member]
Depreciation and Amortization	4,500	3,600	3,600
USG [Member]
Depreciation and Amortization	11,000	9,800	8,100
Technical Packaging [Member]
Depreciation and Amortization	4,100	3,500	2,900
Corporate [Member]
Depreciation and Amortization	$ 10,600	$ 8,700	$ 5,000