Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Tax Credit Carryforward [Line Items]
Deferred income tax withholding tax foreign earnings	$ 868,000
U.S. income taxes, adjusted for any foreign tax credits, and withholding taxes	224,800
Net operating loss carryovers for Federal tax purposes	2,200
Net operating loss carryovers for California tax purposes	$ 9,700
Effective tax rate	21.10%	21.00%	25.40%
Unrecognized tax benefits, gross	$ 98,665	$ 75,168	$ 65,161	$ 31,351
Unrecognized tax benefits if recognized, would affect our effective tax rate	85,000
Estimated decrease in unrecognized tax benefits due to lapse in statute of limitations	3,700
Increase in interest expense for current tax provision	1,800	400
Reduction in penalties for current tax provision		$ (500)
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration	7,900
Deferred Tax Assets, Tax Credit Carryforwards, Research	4,900
Foreign Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	7,700
California Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	20,900
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 1,500