SHAREHOLDERS' EQUITY AND EMPLOYEE BENEFIT PLANS (Total equity-based compensation expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	$ 3,722	$ 3,301	$ 7,331	$ 7,174
Relative TSR PSU [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	896	818	1,302	2,193
Time-based RSUs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	2,349	2,131	4,764	4,272
Special/Growth PSUs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	255	157	821	319
Common Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	222	195	444	390
Cost of sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	183	160	415	310
Selling, general and administrative (1) [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	2,695	2,330	5,430	5,255
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	$ 844	$ 811	$ 1,486	$ 1,609