Revenue (Schedule of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total net sales	$ 758,844	$ 548,249	$ 1,411,655	$ 1,018,397
United States
Disaggregation of Revenue [Line Items]
Total net sales	405,327		741,964
Germany
Disaggregation of Revenue [Line Items]
Total net sales	88,793		164,906
Europe, excluding Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales	113,913		212,873
Asia [Member]
Disaggregation of Revenue [Line Items]
Total net sales	108,755		212,179
Other Countries [Member]
Disaggregation of Revenue [Line Items]
Total net sales	42,056		79,733
Aerospace [Member]
Disaggregation of Revenue [Line Items]
Total net sales	482,954		875,841
Aerospace [Member] \| United States
Disaggregation of Revenue [Line Items]
Total net sales	351,763		638,508
Aerospace [Member] \| Germany
Disaggregation of Revenue [Line Items]
Total net sales	25,068		37,817
Aerospace [Member] \| Europe, excluding Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales	48,782		88,394
Aerospace [Member] \| Asia [Member]
Disaggregation of Revenue [Line Items]
Total net sales	23,292		47,298
Aerospace [Member] \| Other Countries [Member]
Disaggregation of Revenue [Line Items]
Total net sales	34,049		63,824
Aerospace [Member] \| Commercial OEM [Member]
Disaggregation of Revenue [Line Items]
Total net sales	174,343		314,851
Aerospace [Member] \| Commercial Aftermarket [Member]
Disaggregation of Revenue [Line Items]
Total net sales	139,708		251,056
Aerospace [Member] \| Defense OEM [Member]
Disaggregation of Revenue [Line Items]
Total net sales	123,006		224,842
Aerospace [Member] \| Defense Aftermarket [Member]
Disaggregation of Revenue [Line Items]
Total net sales	45,897		85,092
Industrial [Member]
Disaggregation of Revenue [Line Items]
Total net sales	275,890		535,814
Industrial [Member] \| United States
Disaggregation of Revenue [Line Items]
Total net sales	53,564		103,456
Industrial [Member] \| Germany
Disaggregation of Revenue [Line Items]
Total net sales	63,725		127,089
Industrial [Member] \| Europe, excluding Germany [Member]
Disaggregation of Revenue [Line Items]
Total net sales	65,131		124,479
Industrial [Member] \| Asia [Member]
Disaggregation of Revenue [Line Items]
Total net sales	85,463		164,881
Industrial [Member] \| Other Countries [Member]
Disaggregation of Revenue [Line Items]
Total net sales	8,007		15,909
Industrial [Member] \| Reciprocating Engines [Member]
Disaggregation of Revenue [Line Items]
Total net sales	209,257		405,387
Industrial [Member] \| Industrial Turbines [Member]
Disaggregation of Revenue [Line Items]
Total net sales	52,187		101,699
Industrial [Member] \| Renewables [Member]
Disaggregation of Revenue [Line Items]
Total net sales	$ 14,446		$ 28,728