Revenue (Schedule of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total net sales		$ 720,220	$ 758,844	$ 1,440,575	$ 1,411,655
United States [Member]
Disaggregation of Revenue [Line Items]
Total net sales		409,016	405,327	824,021	741,964
Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales		74,052	88,793	142,768	164,906
Europe, excluding Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales		106,002	113,913	195,490	212,873
China
Disaggregation of Revenue [Line Items]
Total net sales		49,035	63,399	113,122	129,287
Asia, excluding China [Member]
Disaggregation of Revenue [Line Items]
Total net sales		40,250	45,356	79,143	82,892
Other Countries [Member]
Disaggregation of Revenue [Line Items]
Total net sales		41,865	42,056	86,031	79,733
Aerospace [Member]
Disaggregation of Revenue [Line Items]
Total net sales		474,236	482,954	948,161	875,841
Aerospace [Member] | United States [Member]
Disaggregation of Revenue [Line Items]
Total net sales		356,109	351,763	720,021	638,508
Aerospace [Member] | Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales		21,111	25,068	38,389	37,817
Aerospace [Member] | Europe, excluding Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales		40,600	48,782	79,587	88,394
Aerospace [Member] | China
Disaggregation of Revenue [Line Items]
Total net sales		11,487	9,502	21,698	25,140
Aerospace [Member] | Asia, excluding China [Member]
Disaggregation of Revenue [Line Items]
Total net sales		10,582	13,790	17,563	22,158
Aerospace [Member] | Other Countries [Member]
Disaggregation of Revenue [Line Items]
Total net sales		34,347	34,049	70,903	63,824
Aerospace [Member] | Commercial OEM [Member]
Disaggregation of Revenue [Line Items]
Total net sales		144,610	174,343	303,276	314,851
Aerospace [Member] | Commercial Aftermarket [Member]
Disaggregation of Revenue [Line Items]
Total net sales		134,042	139,708	259,970	251,056
Aerospace [Member] | Defense OEM [Member]
Disaggregation of Revenue [Line Items]
Total net sales		139,901	123,006	280,827	224,842
Aerospace [Member] | Defense Aftermarket [Member]
Disaggregation of Revenue [Line Items]
Total net sales		55,683	45,897	104,088	85,092
Industrial [Member]
Disaggregation of Revenue [Line Items]
Total net sales		245,984	275,890	492,414	535,814
Industrial [Member] | United States [Member]
Disaggregation of Revenue [Line Items]
Total net sales		52,907	53,564	104,000	103,456
Industrial [Member] | Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales		52,941	63,725	104,379	127,089
Industrial [Member] | Europe, excluding Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales		65,402	65,131	115,903	124,479
Industrial [Member] | China
Disaggregation of Revenue [Line Items]
Total net sales		37,548	53,897	91,424	104,147
Industrial [Member] | Asia, excluding China [Member]
Disaggregation of Revenue [Line Items]
Total net sales		29,668	31,566	61,580	60,734
Industrial [Member] | Other Countries [Member]
Disaggregation of Revenue [Line Items]
Total net sales		7,518	8,007	15,128	15,909
Industrial [Member] | Reciprocating Engines [Member]
Disaggregation of Revenue [Line Items]
Total net sales		163,555	209,257	338,208	405,387
Industrial [Member] | Industrial Turbines [Member]
Disaggregation of Revenue [Line Items]
Total net sales		59,678	52,187	111,177	101,699
Industrial [Member] | Renewables [Member]
Disaggregation of Revenue [Line Items]
Total net sales	[1]	$ 22,751	$ 14,446	$ 43,029	$ 28,728

[1] Sales in the renewables market will be discontinued as of May 1, 2020 following the closing of the divestiture of the disposal groups (see Note 10, Impairment of assets held for sale).