Consolidated Condensed Statements of Earnings (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Income Statement [Abstract]
Net sales	$ 657,539	$ 740,969	$ 2,177,659	$ 2,139,456
Cost of sales	486,760	529,050	1,587,569	1,530,634
Inventory write-down	19,271	0	19,271	0
Gross profit	151,508	211,919	570,819	608,822
Research and development	27,407	31,298	82,303	94,518
Selling, general and administrative	96,899	103,655	302,517	299,841
Interest	9,440	9,780	29,923	29,401
Long-lived asset impairment	31,871	0	31,871	0
Restructuring	4,830	0	4,830	0
Other	4,415	7,168	14,294	14,645
Earnings (loss) before income taxes	(23,354)	60,018	105,081	170,417
Income taxes (benefit)	(10,764)	13,853	17,899	40,424
Net earnings (loss)	$ (12,590)	$ 46,165	$ 87,182	$ 129,993
Net earnings (loss) per share
Basic	$ (0.39)	$ 1.32	$ 2.60	$ 3.73
Diluted	(0.39)	1.31	2.59	3.69
Dividends declared per share	$ 0	$ 0.25	$ 0.50	$ 0.75
Average common shares outstanding
Basic	32,601,481	34,904,487	33,515,584	34,869,021
Diluted	32,601,481	35,239,834	33,722,723	35,202,519