REVENUES (Schedule Of Revenues) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 193,949	$ 174,778	$ 376,546	$ 348,273
Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues	91,440		177,929
Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues	102,509		198,617
United States [Member]
Disaggregation of Revenue [Line Items]
Revenues	138,017		271,166
International [Member]
Disaggregation of Revenue [Line Items]
Revenues	55,932		105,380
Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	153,957		301,184
Government [Member]
Disaggregation of Revenue [Line Items]
Revenues	39,992		75,362
Filtration [Member]
Disaggregation of Revenue [Line Items]
Revenues	79,478	65,775	145,702	125,810
Filtration [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues	42,400		74,214
Filtration [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues	37,078		71,488
Filtration [Member] | United States [Member]
Disaggregation of Revenue [Line Items]
Revenues	66,068		120,833
Filtration [Member] | International [Member]
Disaggregation of Revenue [Line Items]
Revenues	13,410		24,869
Filtration [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	46,325		83,546
Filtration [Member] | Government [Member]
Disaggregation of Revenue [Line Items]
Revenues	33,153		62,156
Test [Member]
Disaggregation of Revenue [Line Items]
Revenues	42,875	40,805	84,161	78,334
Test [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues	12,166		22,608
Test [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues	30,709		61,553
Test [Member] | United States [Member]
Disaggregation of Revenue [Line Items]
Revenues	26,694		55,148
Test [Member] | International [Member]
Disaggregation of Revenue [Line Items]
Revenues	16,181		29,013
Test [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	37,451		73,688
Test [Member] | Government [Member]
Disaggregation of Revenue [Line Items]
Revenues	5,424		10,473
USG [Member]
Disaggregation of Revenue [Line Items]
Revenues	48,890	46,699	104,745	102,453
USG [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues	36,874		81,107
USG [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues	12,016		23,638
USG [Member] | United States [Member]
Disaggregation of Revenue [Line Items]
Revenues	33,798		73,879
USG [Member] | International [Member]
Disaggregation of Revenue [Line Items]
Revenues	15,092		30,866
USG [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	47,551		102,206
USG [Member] | Government [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,339		2,539
Technical Packaging [Member]
Disaggregation of Revenue [Line Items]
Revenues	22,706	$ 21,499	41,938	$ 41,676
Technical Packaging [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues	0		0
Technical Packaging [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues	22,706		41,938
Technical Packaging [Member] | United States [Member]
Disaggregation of Revenue [Line Items]
Revenues	11,457		21,306
Technical Packaging [Member] | International [Member]
Disaggregation of Revenue [Line Items]
Revenues	11,249		20,632
Technical Packaging [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	22,630		41,744
Technical Packaging [Member] | Government [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 76		$ 194