Segment Information (Summary of Consolidated Total Assets by Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Segment Reporting Information [Line Items]
Consolidated total assets	$ 3,959,505	$ 3,903,336
Property, plant and equipment, net	986,030	997,415
Other assets	271,621	265,435
Unallocated Corporate [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	103,830	106,380
Other assets	576,966	515,029
Aerospace [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated total assets	1,717,820	1,752,516
Industrial [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Consolidated total assets	$ 1,560,889	$ 1,529,411