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, 2017	Sep. 30, 2016
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 323,616	$ 291,200
Acquisition activity	53,400	32,400
Foreign currency translation and other	900	0
Goodwill, Ending Balance	377,879	323,616
Filtration [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	43,900	26,000
Acquisition activity	29,800	17,900
Foreign currency translation and other	0	0
Goodwill, Ending Balance	73,700	43,900
Test [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	34,100	34,200
Acquisition activity	0	0
Foreign currency translation and other	0	(100)
Goodwill, Ending Balance	34,100	34,100
Utility Solutions [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	226,200	226,200
Acquisition activity	23,600	0
Foreign currency translation and other	400	0
Goodwill, Ending Balance	250,200	226,200
Technical Packaging [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	19,400	4,800
Acquisition activity	0	14,500
Foreign currency translation and other	500	100
Goodwill, Ending Balance	$ 19,900	$ 19,400