Revenue (Schedule of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Total net sales		$ 556,675	$ 523,826	$ 1,675,615	$ 1,964,401
Aerospace [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		340,912	306,494	1,027,285	1,254,655
Aerospace [Member] | Commercial OEM [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		96,290	63,804	274,278	367,080
Aerospace [Member] | Commercial Aftermarket [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		75,508	68,332	218,602	328,302
Aerospace [Member] | Defense OEM [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		117,204	111,667	384,097	392,494
Aerospace [Member] | Defense Aftermarket [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		51,910	62,691	150,308	166,779
Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		215,763	217,332	648,330	709,746
Industrial [Member] | Reciprocating Engines [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		166,143	158,804	494,099	497,012
Industrial [Member] | Industrial Turbines [Member]
Disaggregation Of Revenue [Line Items]
Total net sales		$ 49,620	53,486	$ 154,231	164,663
Industrial [Member] | Renewables [Member]
Disaggregation Of Revenue [Line Items]
Total net sales	[1]		$ 5,042		$ 48,071

[1] Sales in the renewables market were discontinued as of May 1, 2020 following the closing of the divestiture of the renewable power systems business and other related businesses (as described more fully in Note 10, Sale of businesses, and defined therein as the “disposal group”).