Business Segment Information (Schedule Of Capital Expenditures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Capital Expenditures	$ 29,728	$ 13,843	$ 12,444
Filtration [Member]
Capital Expenditures	10,200	3,300	5,000
Test [Member]
Capital Expenditures	4,500	3,300	3,100
USG [Member]
Capital Expenditures	7,600	3,300	3,300
Technical Packaging [Member]
Capital Expenditures	7,400	3,900	1,000
Corporate [Member]
Capital Expenditures	$ 0	$ 0	$ 0