Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Oct. 02, 2020	Sep. 27, 2019
Deferred tax assets:
Inventory	$ 12,100	$ 10,100
Bad debts	100	200
Accrued compensation and benefits	10,100	5,900
Product returns, allowances and warranty	400	300
Restructuring	0	600
Share-based and other deferred compensation	25,900	21,200
Net operating loss carry forwards	7,400	11,300
Federal tax credits	16,500	20,700
State tax credits	115,500	106,400
Deferred Tax Assets, Property, Plant and Equipment	24,300	17,700
Other - net	5,800	5,900
Deferred tax assets	261,500	200,300
Less valuation allowance	(137,400)	(129,100)
Net deferred tax assets	124,100	71,200
Deferred Tax Liabilities, Prepaid Expenses	900	500
Deferred tax liabilities:
Prepaid insurance	(6,600)	(6,300)
Property, plant and equipment	(26,400)	(19,300)
Intangible assets	(7,600)	(17,400)
Deferred Tax Liabilities, Net	83,000	43,500
Total deferred tax assets	41,100	27,700
Deferred Tax Liabilities, Leasing Arrangements	(41,500)	0
deferred tax asset, leasing arrangements	$ 43,400	$ 0