Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	$ (386,022)	$ (371,274)
Net Carrying Amount - Finite-Lived Intangible	529,974
Intangible Assets, Gross, Total	981,180	983,266
Intangible Assets, Net, Total	595,158	611,992
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	694,327	689,366
Accumulated Amortization of Finite-Lived Intangible	(244,773)	(225,981)
Net Carrying Amount - Finite-Lived Intangible	449,554	463,385
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	15,750	19,201
Accumulated Amortization of Finite-Lived Intangible	(15,565)	(18,705)
Net Carrying Amount - Finite-Lived Intangible	185	496
Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	164,104	169,191
Accumulated Amortization of Finite-Lived Intangible	(83,938)	(84,839)
Net Carrying Amount - Finite-Lived Intangible	80,166	84,352
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	41,590	40,500
Accumulated Amortization of Finite-Lived Intangible	(41,590)	(40,500)
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	225	1,541
Accumulated Amortization of Finite-Lived Intangible	(156)	(1,249)
Net Carrying Amount - Finite-Lived Intangible	69	292
Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	65,184	63,467
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(255,836)	(241,908)
Intangible Assets, Gross, Total	358,054	358,054
Intangible Assets, Net, Total	102,218	116,146
Aerospace [Member] \| Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	281,683	281,683
Accumulated Amortization of Finite-Lived Intangible	(192,890)	(181,995)
Net Carrying Amount - Finite-Lived Intangible	88,793	99,688
Aerospace [Member] \| Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	76,371	76,371
Accumulated Amortization of Finite-Lived Intangible	(62,946)	(59,913)
Net Carrying Amount - Finite-Lived Intangible	13,425	16,458
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(130,186)	(129,366)
Intangible Assets, Gross, Total	623,126	625,212
Intangible Assets, Net, Total	492,940	495,846
Industrial [Member] \| Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	412,644	407,683
Accumulated Amortization of Finite-Lived Intangible	(51,883)	(43,986)
Net Carrying Amount - Finite-Lived Intangible	360,761	363,697
Industrial [Member] \| Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	15,750	19,201
Accumulated Amortization of Finite-Lived Intangible	(15,565)	(18,705)
Net Carrying Amount - Finite-Lived Intangible	185	496
Industrial [Member] \| Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	87,733	92,820
Accumulated Amortization of Finite-Lived Intangible	(20,992)	(24,926)
Net Carrying Amount - Finite-Lived Intangible	66,741	67,894
Industrial [Member] \| Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	41,590	40,500
Accumulated Amortization of Finite-Lived Intangible	(41,590)	(40,500)
Industrial [Member] \| Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	225	1,541
Accumulated Amortization of Finite-Lived Intangible	(156)	(1,249)
Net Carrying Amount - Finite-Lived Intangible	69	292
Industrial [Member] \| Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	$ 65,184	$ 63,467

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