Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Sep. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total	$ 1,004,526	$ 1,016,456
Accumulated Amortization of Finite-Lived Intangible	(363,045)	(315,573)
Net Carrying Amount - Finite-Lived Intangible	575,548
Intangible Assets, Net, Total	641,481	700,883	[1]
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	65,933	67,335
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	703,559	711,563
Accumulated Amortization of Finite-Lived Intangible	(218,315)	(202,575)
Net Carrying Amount - Finite-Lived Intangible	485,244	508,988
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	19,354	19,448
Accumulated Amortization of Finite-Lived Intangible	(18,763)	(18,587)
Net Carrying Amount - Finite-Lived Intangible	591	861
Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	172,016	173,526
Accumulated Amortization of Finite-Lived Intangible	(82,644)	(75,247)
Net Carrying Amount - Finite-Lived Intangible	89,372	98,279
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	42,066	42,955
Accumulated Amortization of Finite-Lived Intangible	(42,066)	(18,006)
Net Carrying Amount - Finite-Lived Intangible	0	24,949
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	1,598	1,629
Accumulated Amortization of Finite-Lived Intangible	(1,257)	(1,158)
Net Carrying Amount - Finite-Lived Intangible	341	471
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total	358,054	358,055
Accumulated Amortization of Finite-Lived Intangible	(236,831)	(221,593)
Intangible Assets, Net, Total	121,223	136,462
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	(178,177)	(166,719)
Net Carrying Amount - Finite-Lived Intangible	103,506	114,964
Aerospace [Member] | Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	76,371	76,372
Accumulated Amortization of Finite-Lived Intangible	(58,654)	(54,874)
Net Carrying Amount - Finite-Lived Intangible	17,717	21,498
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total	646,472	658,401
Accumulated Amortization of Finite-Lived Intangible	(126,214)	(93,980)
Intangible Assets, Net, Total	520,258	564,421
Industrial [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	65,933	67,335
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	421,876	429,880
Accumulated Amortization of Finite-Lived Intangible	(40,138)	(35,856)
Net Carrying Amount - Finite-Lived Intangible	381,738	394,024
Industrial [Member] | Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	19,354	19,448
Accumulated Amortization of Finite-Lived Intangible	(18,763)	(18,587)
Net Carrying Amount - Finite-Lived Intangible	591	861
Industrial [Member] | Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	95,645	97,154
Accumulated Amortization of Finite-Lived Intangible	(23,990)	(20,373)
Net Carrying Amount - Finite-Lived Intangible	71,655	76,781
Industrial [Member] | Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	42,066	42,955
Accumulated Amortization of Finite-Lived Intangible	(42,066)	(18,006)
Net Carrying Amount - Finite-Lived Intangible	0	24,949
Industrial [Member] | Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	1,598	1,629
Accumulated Amortization of Finite-Lived Intangible	(1,257)	(1,158)
Net Carrying Amount - Finite-Lived Intangible	$ 341	$ 471

[1] The net book value of the backlog and customer relationships and contracts intangible assets was adjusted concurrent with the change in the timing of the associated revenue, resulting in a reduction in the net book value of these assets as of the date of adoption.