SHAREHOLDERS' EQUITY AND EMPLOYEE BENEFIT PLANS (Total equity-based compensation expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	$ 3,725	$ 3,597	$ 11,056	$ 10,772
Relative TSR PSU [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	908	1,020	2,210	3,213
Time-based RSUs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	2,366	2,182	7,130	6,455
Special/Growth PSUs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	266	173	1,087	492
Common Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	185	222	629	612
Cost of sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	182	161	597	471
Selling, general and administrative (1) [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	2,676	2,616	8,106	7,871
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	$ 867	$ 820	$ 2,353	$ 2,430