Intangible Assets, Net (Schedule of Finite-Lived Intangible Assets by Major Class) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2013
Gross Carrying Value	$ 495,069		$ 495,069		$ 494,609
Accumulated Amortization	(223,182)		(223,182)		(205,834)
Net Carrying Amount	271,887		271,887		288,775
Amortization expense	8,657	9,813	17,141	17,480
Process Technology [Member]
Gross Carrying Value	100,349		100,349		100,176
Accumulated Amortization	(41,590)		(41,590)		(37,828)
Net Carrying Amount	58,759		58,759		62,348
Customer Relationships [Member]
Gross Carrying Value	324,381		324,381		324,233
Accumulated Amortization	(118,579)		(118,579)		(106,999)
Net Carrying Amount	205,802		205,802		217,234
Intellectual Property [Member]
Gross Carrying Value	20,310		20,310		20,218
Accumulated Amortization	(15,476)		(15,476)		(14,722)
Net Carrying Amount	4,834		4,834		5,496
Other Intangibles [Member]
Gross Carrying Value	50,029		50,029		49,982
Accumulated Amortization	(47,537)		(47,537)		(46,285)
Net Carrying Amount	2,492		2,492		3,697
Aerospace [Member]
Gross Carrying Value	406,374		406,374		406,294
Accumulated Amortization	(162,038)		(162,038)		(147,989)
Net Carrying Amount	244,336		244,336		258,305
Aerospace [Member] | Process Technology [Member]
Gross Carrying Value	76,740		76,740		76,718
Accumulated Amortization	(29,039)		(29,039)		(26,129)
Net Carrying Amount	47,701		47,701		50,589
Aerospace [Member] | Customer Relationships [Member]
Gross Carrying Value	282,270		282,270		282,225
Accumulated Amortization	(87,319)		(87,319)		(77,288)
Net Carrying Amount	194,951		194,951		204,937
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	47,364		47,364		47,351
Accumulated Amortization	(45,680)		(45,680)		(44,572)
Net Carrying Amount	1,684		1,684		2,779
Energy [Member]
Gross Carrying Value	88,695		88,695		88,315
Accumulated Amortization	(61,144)		(61,144)		(57,845)
Net Carrying Amount	27,551		27,551		30,470
Energy [Member] | Process Technology [Member]
Gross Carrying Value	23,609		23,609		23,458
Accumulated Amortization	(12,551)		(12,551)		(11,699)
Net Carrying Amount	11,058		11,058		11,759
Energy [Member] | Customer Relationships [Member]
Gross Carrying Value	42,111		42,111		42,008
Accumulated Amortization	(31,260)		(31,260)		(29,711)
Net Carrying Amount	10,851		10,851		12,297
Energy [Member] | Intellectual Property [Member]
Gross Carrying Value	20,310		20,310		20,218
Accumulated Amortization	(15,476)		(15,476)		(14,722)
Net Carrying Amount	4,834		4,834		5,496
Energy [Member] | Other Intangibles [Member]
Gross Carrying Value	2,665		2,665		2,631
Accumulated Amortization	(1,857)		(1,857)		(1,713)
Net Carrying Amount	$ 808		$ 808		$ 918