Consolidated Statement of Shareholders' Equity (USD $) In Thousands	Total		Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2012	$ 572,285	[1]	$ 172	$ 165,162	$ 436,466	$ (29,515)
Beginning Balance, Shares at Dec. 31, 2012	86,110	[1]	86,110
Issuance of common stock under stock option plans	25,990		4	25,986
Issuance of common stock under stock option plans, shares	2,275		2,270
Repurchase of common stock	(28,059)		(1)		(28,058)
Repurchase of common stock, shares			(1,099)
Stock-based compensation expense	8,299			8,299
Excess tax benefit from stock option exercises	6,584			6,584
Tax benefit for research and development credits as a result of stock option accounting	121			121
Net income	53,130				53,130
Net unrealized loss on available-for-sale investments, net of tax of $124	(342)					(342)
Reclassification of net realized gain on the sale of available-for-sale investments	(103)					(103)
Foreign currency translation adjustment, net of tax of $121	(181)					(181)
Ending Balance at Sep. 29, 2013	$ 637,724	[1]	$ 175	$ 206,152	$ 461,538	$ (30,141)
Ending Balance, Shares at Sep. 29, 2013	87,281	[1]	87,281

[1] Prior period amounts have been adjusted to reflect the two-for-one stock split effected in the form of a stock dividend which occurred in September 2013.