Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net sales	$ 537,619	$ 720,355
Costs and expenses:
Cost of goods sold	401,640	534,917
Selling, general and administrative expenses	56,111	62,045
Research and development costs	31,996	36,846
Impairment of assets sold		37,902
Interest expense	8,906	9,009
Interest income	(495)	(487)
Other (income) expense, net	(8,123)	(21,425)
Total costs and expenses	490,035	658,807
Earnings before income taxes	47,584	61,548
Income tax expense	6,014	8,175
Net earnings	$ 41,570	$ 53,373
Earnings per share:
Basic earnings per share	$ 0.66	$ 0.86
Diluted earnings per share	$ 0.64	$ 0.83
Weighted Average Common Shares Outstanding:
Basic	62,812	61,991
Diluted	64,892	64,673