Intangible Assets, Net (Schedule of Finite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2016
Gross Carrying Value	$ 442,443		$ 443,445
Accumulated Amortization	(251,510)		(245,795)
Net Carrying Amount	190,933		197,650
Amortization expense	6,458	$ 6,946
Process Technology [Member]
Gross Carrying Value	99,201		99,570
Accumulated Amortization	(61,047)		(59,429)
Net Carrying Amount	38,154		40,141
Customer Relationships [Member]
Gross Carrying Value	322,918		323,194
Accumulated Amortization	(171,938)		(167,667)
Net Carrying Amount	150,980		155,527
Intellectual Property [Member]
Gross Carrying Value	19,156		19,435
Accumulated Amortization	(17,734)		(17,876)
Net Carrying Amount	1,422		1,559
Other Intangibles [Member]
Gross Carrying Value	1,168		1,246
Accumulated Amortization	(791)		(823)
Net Carrying Amount	377		423
Aerospace [Member]
Gross Carrying Value	358,830		358,830
Accumulated Amortization	(183,111)		(177,387)
Net Carrying Amount	175,719		181,443
Aerospace [Member] | Process Technology [Member]
Gross Carrying Value	76,605		76,605
Accumulated Amortization	(44,703)		(43,229)
Net Carrying Amount	31,902		33,376
Aerospace [Member] | Customer Relationships [Member]
Gross Carrying Value	282,225		282,225
Accumulated Amortization	(138,408)		(134,158)
Net Carrying Amount	143,817		148,067
Aerospace [Member] | Intellectual Property [Member]
Gross Carrying Value	0		0
Accumulated Amortization	0		0
Net Carrying Amount	0		0
Aerospace [Member] | Other Intangibles [Member]
Gross Carrying Value	0		0
Accumulated Amortization	0		0
Net Carrying Amount	0		0
Industrial [Member]
Gross Carrying Value	83,613		84,615
Accumulated Amortization	(68,399)		(68,408)
Net Carrying Amount	15,214		16,207
Industrial [Member] | Process Technology [Member]
Gross Carrying Value	22,596		22,965
Accumulated Amortization	(16,344)		(16,200)
Net Carrying Amount	6,252		6,765
Industrial [Member] | Customer Relationships [Member]
Gross Carrying Value	40,693		40,969
Accumulated Amortization	(33,530)		(33,509)
Net Carrying Amount	7,163		7,460
Industrial [Member] | Intellectual Property [Member]
Gross Carrying Value	19,156		19,435
Accumulated Amortization	(17,734)		(17,876)
Net Carrying Amount	1,422		1,559
Industrial [Member] | Other Intangibles [Member]
Gross Carrying Value	1,168		1,246
Accumulated Amortization	(791)		(823)
Net Carrying Amount	$ 377		$ 423