Income Taxes (Summary Of Tax Effects Of The Temporary Differences Between Carrying Amounts And Amounts Used For Tax) (Details) - USD ($) $ in Thousands	Sep. 25, 2015	Sep. 26, 2014
Income Tax Disclosure [Abstract]
Investments	$ 977	$ 2,033
Inventories	8,800	3,607
Net operating loss	1,406	2,062
Accrued expenses	16,843	16,759
Stock-based compensation	32,359	30,455
Revenue recognition	52,282	55,453
Deferred Tax Assets, Goodwill and Intangible Assets	401
Depreciation and amortization	6,443	4,423
Research and development credits	7,977	5,153
Foreign tax credits	11,119	2,854
Deferred Tax Assets, Unrealized Currency Losses	719
Other	9,092	8,786
Total gross deferred income tax assets	148,418	131,585
Less: valuation allowance	0	0
Total deferred income tax assets	148,418	131,585
Translation adjustment	0	(579)
Intangibles	0	(450)
International earnings	(4,646)	(1,960)
Unrealized gain on investments	(493)	(405)
Deferred income tax assets, net	143,279	128,191
Current deferred income tax assets	97,101	86,445
Long-term deferred income tax assets, net	$ 46,178	$ 41,746