Goodwill and Other Intangible Assets (Schedule Of Changes In The Carrying Amount Of Goodwill Attributable To Business Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 377,879	$ 323,600
Acquisition activity	3,900	53,400
Foreign currency translation and other	(100)	900
Goodwill, Ending Balance	381,652	377,879
Filtration [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	73,700	43,900
Acquisition activity	0	29,800
Foreign currency translation and other	0	0
Goodwill, Ending Balance	73,700	73,700
Test [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	34,100	34,100
Acquisition activity	0	0
Foreign currency translation and other	0	0
Goodwill, Ending Balance	34,100	34,100
Utility Solutions [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	250,200	226,200
Acquisition activity	3,900	23,600
Foreign currency translation and other	0	400
Goodwill, Ending Balance	254,100	250,200
Technical Packaging [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	19,900	19,400
Acquisition activity	0	0
Foreign currency translation and other	(100)	500
Goodwill, Ending Balance	$ 19,800	$ 19,900