Revenue (Schedule of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Total net sales		$ 2,245,832	$ 2,495,665	$ 2,900,197
United States [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		1,278,123	1,426,454	1,628,064
Germany [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		183,696	233,965	302,084
Europe, excluding Germany [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		291,941	336,971	431,416
China [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		214,269	209,885	214,829
Asia, excluding China [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		137,500	140,069	164,488
Other Countries [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		140,303	148,321	159,316
Aerospace [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		1,404,117	1,590,963	1,880,520
Aerospace [Member] | United States [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		1,103,373	1,231,004	1,415,880
Aerospace [Member] | Germany [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		31,005	52,635	72,907
Aerospace [Member] | Europe, excluding Germany [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		95,984	122,938	178,905
Aerospace [Member] | China [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		35,286	38,359	47,492
Aerospace [Member] | Asia, excluding China [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		23,363	27,068	37,991
Aerospace [Member] | Other Countries [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		115,106	118,959	127,345
Aerospace [Member] | Commercial OEM [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		386,543	434,306	659,336
Aerospace [Member] | Commercial Aftermarket [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		306,547	399,843	497,795
Aerospace [Member] | Defense OEM [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		509,815	526,264	529,940
Aerospace [Member] | Defense Aftermarket [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		201,212	230,550	193,449
Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		841,715	904,702	1,019,677
Industrial [Member] | United States [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		174,750	195,450	212,184
Industrial [Member] | Germany [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		152,691	181,330	229,177
Industrial [Member] | Europe, excluding Germany [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		195,957	214,033	252,511
Industrial [Member] | China [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		178,983	171,526	167,337
Industrial [Member] | Asia, excluding China [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		114,137	113,001	126,497
Industrial [Member] | Other Countries [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		25,197	29,362	31,971
Industrial [Member] | Reciprocating Engines [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		639,946	632,555	751,136
Industrial [Member] | Industrial Turbines [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		$ 201,769	222,366	210,064
Industrial [Member] | Renewables [Member]
Disaggregation Of Revenue [Line Items]
Total net sales	[1]		$ 49,781	$ 58,477

[1] Sales in the renewables market were discontinued as of May 1, 2020 following the closing of the divestiture of the disposal group (see Note 10, Sale of businesses).