Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 24, 2021	Sep. 25, 2020	Sep. 27, 2019	Sep. 28, 2018
Tax Credit Carryforward [Line Items]
Foreign earnings repatriated	$ 200,000
Undistributed earnings of foreign subsidiaries	239,000
Net operating loss carryovers for federal tax purposes	3,600
Net operating loss carryovers for California tax purposes	7,200
NOL's not subject to expiration	9,800
R&D tax credit carryforwards	13,000
Valuation allowance, deferred tax assets, california	25,700
Valuation Allowance recorded against federal foreign tax credit deferred tax assets	2,000
Valuation allowance, deferred tax assets, foreign	$ 5,600
Effective tax rate	10.30%	3.40%	9.50%
Provision for income taxes	$ 36,689	$ 8,096	$ 26,802
Unrecognized tax benefits, gross	66,106	60,691	$ 108,539	$ 102,009
Unrecognized tax benefits if recognized, would affect our effective tax rate	43,600
Increase in interest expense for current tax provision	1,000	$ (6,300)
Foreign Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	7,900
California Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	34,300
Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 3,000