BALANCE SHEET COMPONENTS (Components of significant balance sheet accounts) (Details) - USD ($) $ in Thousands	Dec. 30, 2023	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Short-term investments	$ 285,000	$ 230,000
Inventories, net:
Raw materials and supplies	119,077	114,827
Work in process	85,499	74,555
Finished goods	55,463	49,207
Inventory, gross	260,039	238,589
Inventory reserves	(23,481)	(21,285)
Inventories, net	236,558	217,304
Property, plant and equipment, net:
Land	2,182	2,182
Buildings and building improvements	23,213	23,105
Leasehold improvements	83,586	82,927
Data processing equipment and software	38,267	37,483
Machinery, equipment, furniture and fixtures	98,773	95,692
Construction in progress	11,345	11,099
Property, plant and equipment, gross	257,366	252,488
Accumulated depreciation	(150,093)	(142,437)
Property, plant and equipment, net	107,273	110,051
Accrued expenses and other current liabilities:
Accrued customer obligations	36,287	35,701
Wages and benefits	23,060	33,096
Dividends payable	11,303	10,710
Commissions and professional fees	4,270	4,091
Accrued leasehold renovations	10,013	11,005
Other	6,260	8,402
Accrued expenses and other current liabilities	$ 91,193	$ 103,005