Intangible Assets, Net (Schedule of Finite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Sep. 30, 2015
Gross Carrying Value	$ 443,489		$ 443,489		$ 445,256
Accumulated Amortization	(232,200)		(232,200)		(220,118)
Net Carrying Amount	211,289		211,289		225,138
Amortization expense	6,926	$ 7,227	13,872	$ 14,802
Process Technology [Member]
Gross Carrying Value	99,582		99,582		99,529
Accumulated Amortization	(55,749)		(55,749)		(52,032)
Net Carrying Amount	43,833		43,833		47,497
Customer Relationships [Member]
Gross Carrying Value	323,217		323,217		323,634
Accumulated Amortization	(158,190)		(158,190)		(149,123)
Net Carrying Amount	165,027		165,027		174,511
Intellectual Property [Member]
Gross Carrying Value	19,431		19,431		19,445
Accumulated Amortization	(17,471)		(17,471)		(16,921)
Net Carrying Amount	1,960		1,960		2,524
Other Intangibles [Member]
Gross Carrying Value	1,259		1,259		2,648
Accumulated Amortization	(790)		(790)		(2,042)
Net Carrying Amount	469		469		606
Aerospace [Member]
Gross Carrying Value	358,830		358,830		360,230
Accumulated Amortization	(165,515)		(165,515)		(154,943)
Net Carrying Amount	193,315		193,315		205,287
Aerospace [Member] \| Process Technology [Member]
Gross Carrying Value	76,605		76,605		76,605
Accumulated Amortization	(40,321)		(40,321)		(37,411)
Net Carrying Amount	36,284		36,284		39,194
Aerospace [Member] \| Customer Relationships [Member]
Gross Carrying Value	282,225		282,225		282,225
Accumulated Amortization	(125,194)		(125,194)		(116,232)
Net Carrying Amount	157,031		157,031		165,993
Aerospace [Member] \| Intellectual Property [Member]
Gross Carrying Value	0		0		0
Accumulated Amortization	0		0		0
Net Carrying Amount	0		0		0
Aerospace [Member] \| Other Intangibles [Member]
Gross Carrying Value					1,400
Accumulated Amortization					(1,300)
Net Carrying Amount	0		0		100
Industrial [Member]
Gross Carrying Value	84,659		84,659		85,026
Accumulated Amortization	(66,685)		(66,685)		(65,175)
Net Carrying Amount	17,974		17,974		19,851
Industrial [Member] \| Process Technology [Member]
Gross Carrying Value	22,977		22,977		22,924
Accumulated Amortization	(15,428)		(15,428)		(14,621)
Net Carrying Amount	7,549		7,549		8,303
Industrial [Member] \| Customer Relationships [Member]
Gross Carrying Value	40,992		40,992		41,409
Accumulated Amortization	(32,996)		(32,996)		(32,891)
Net Carrying Amount	7,996		7,996		8,518
Industrial [Member] \| Intellectual Property [Member]
Gross Carrying Value	19,431		19,431		19,445
Accumulated Amortization	(17,471)		(17,471)		(16,921)
Net Carrying Amount	1,960		1,960		2,524
Industrial [Member] \| Other Intangibles [Member]
Gross Carrying Value	1,259		1,259		1,248
Accumulated Amortization	(790)		(790)		(742)
Net Carrying Amount	$ 469		$ 469		$ 506

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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-Section 50
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