Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 26, 2014	Sep. 27, 2013	Sep. 26, 2014	Sep. 27, 2013
Income Statement [Abstract]
Net sales	$ 499,606	$ 445,945	$ 1,452,216	$ 1,278,205
Cost of sales	166,019	141,525	480,279	402,712
Gross margin	333,587	304,420	971,937	875,493
Research and development expense	112,078	95,336	310,856	278,542
Selling, general, and administrative expense	77,724	78,907	231,205	235,376
Amortization of acquisition-related intangible assets	2,465	1,846	7,394	2,974
Compensation (benefit)/expense — deferred compensation plan	(487)	3,462	4,093	6,724
Loss/(gain) on deferred compensation plan securities	487	(3,462)	(4,093)	(6,724)
Interest income and other	(4,558)	(2,214)	(18,362)	(6,651)
Gain reclassified from other comprehensive (loss)/income	(59)	(33)	(150)	(129)
Interest expense	10,774	2,511	32,139	8,365
Income before income taxes	135,163	128,067	408,855	357,016
Income tax expense	17,154	8,635	47,328	15,885
Net income	118,009	119,432	361,527	341,131
Unrealized holding (loss)/gain on investments:
Unrealized holding (loss)/gain on investments arising during period, net of tax of ($6), $30, $41 and ($12)	(4,929)	2,419	22,102	(6,613)
Less: Reclassification adjustments for gain on investments included in net income, net of tax of $11, $11, $21 and $21	(48)	(22)	(129)	(108)
Other comprehensive (loss)/income	(4,977)	2,397	21,973	(6,721)
Comprehensive income	$ 113,032	$ 121,829	$ 383,500	$ 334,410
Net income per share (in dollars per share):
Basic (in dollars per share)	$ 0.38	$ 0.37	$ 1.16	$ 1.07
Diluted (in dollars per share)	$ 0.38	$ 0.37	$ 1.15	$ 1.05
Shares used in computing per share amounts (in shares):
Basic (in shares)	308,215	320,445	311,853	320,266
Diluted (in shares)	310,184	323,505	314,130	323,355
Dividends per common share	$ 0.18	$ 0.15	$ 0.48	$ 0.35