Segment Information (Summary of Consolidated Net Sales and Earnings by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Total net sales	$ 581,321	$ 720,220	$ 1,118,940	$ 1,440,575
Interest expense, net	(7,966)	(8,280)	(16,377)	(16,802)
Consolidated earnings before income taxes	78,487	107,199	126,071	168,747
Aerospace [Member]
Segment Reporting Information [Line Items]
Total net sales	364,706	474,236	686,373	948,161
Industrial [Member]
Segment Reporting Information [Line Items]
Total net sales	216,615	245,984	432,567	492,414
Operating Segments [Member] | Aerospace [Member]
Segment Reporting Information [Line Items]
Total net sales	364,706	474,236	686,373	948,161
Segment earnings (loss)	69,008	117,638	115,474	210,549
Operating Segments [Member] | Industrial [Member]
Segment Reporting Information [Line Items]
Total net sales	216,615	245,984	432,567	492,414
Segment earnings (loss)	27,871	25,972	60,759	54,202
Unallocated Corporate [Member]
Segment Reporting Information [Line Items]
Segment earnings (loss)	$ (10,426)	$ (28,131)	$ (33,785)	$ (79,202)