Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total	$ 971,480	$ 983,266
Accumulated Amortization of Finite-Lived Intangible	(375,290)	(371,274)
Net Carrying Amount - Finite-Lived Intangible	532,156
Intangible Assets, Net, Total	596,190	611,992
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	64,034	63,467
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	687,770	689,366
Accumulated Amortization of Finite-Lived Intangible	(236,847)	(225,981)
Net Carrying Amount - Finite-Lived Intangible	450,923	463,385
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	15,703	19,201
Accumulated Amortization of Finite-Lived Intangible	(15,513)	(18,705)
Net Carrying Amount - Finite-Lived Intangible	190	496
Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	162,908	169,191
Accumulated Amortization of Finite-Lived Intangible	(81,929)	(84,839)
Net Carrying Amount - Finite-Lived Intangible	80,979	84,352
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	40,860	40,500
Accumulated Amortization of Finite-Lived Intangible	(40,860)	(40,500)
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	205	1,541
Accumulated Amortization of Finite-Lived Intangible	(141)	(1,249)
Net Carrying Amount - Finite-Lived Intangible	64	292
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total	358,054	358,054
Accumulated Amortization of Finite-Lived Intangible	(251,191)	(241,908)
Intangible Assets, Net, Total	106,863	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	(189,258)	(181,995)
Net Carrying Amount - Finite-Lived Intangible	92,425	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	(61,933)	(59,913)
Net Carrying Amount - Finite-Lived Intangible	14,438	16,458
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total	613,426	625,212
Accumulated Amortization of Finite-Lived Intangible	(124,099)	(129,366)
Intangible Assets, Net, Total	489,327	495,846
Industrial [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	64,034	63,467
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	406,087	407,683
Accumulated Amortization of Finite-Lived Intangible	(47,589)	(43,986)
Net Carrying Amount - Finite-Lived Intangible	358,498	363,697
Industrial [Member] | Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	15,703	19,201
Accumulated Amortization of Finite-Lived Intangible	(15,513)	(18,705)
Net Carrying Amount - Finite-Lived Intangible	190	496
Industrial [Member] | Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	86,537	92,820
Accumulated Amortization of Finite-Lived Intangible	(19,996)	(24,926)
Net Carrying Amount - Finite-Lived Intangible	66,541	67,894
Industrial [Member] | Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	40,860	40,500
Accumulated Amortization of Finite-Lived Intangible	(40,860)	(40,500)
Industrial [Member] | Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	205	1,541
Accumulated Amortization of Finite-Lived Intangible	(141)	(1,249)
Net Carrying Amount - Finite-Lived Intangible	$ 64	$ 292