Consolidated Statement of Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2013	$ 643,912	$ 174	$ 211,440	$ 462,131	$ (29,833)
Beginning Balance, Shares at Dec. 31, 2013	86,831,000	86,831,000
Issuance of common stock under stock option plans, shares		648,000
Issuance of common stock under stock option plans	9,026	0	9,026
Repurchase of common stock, shares		(740,000)
Repurchase of common stock	(27,004)	0		(27,004)
Stock-based compensation expense	7,960		7,960
Excess tax benefit from stock option exercises	3,481		3,481
Net income	44,454			44,454
Net unrealized loss on cash flow hedges, net of tax of $6	(235)				(235)
Reclassification adjustments for loss (gain) included in net income	57				57
Net unrealized gain on available-for-sale investments, net of tax of $182	1,561				1,561
Reclassification of net realized gain on the sale of available-for-sale investments	(606)				(606)
Foreign currency translation adjustment, net of tax of $60	(99)				(99)
Ending Balance at Jun. 29, 2014	$ 682,507	$ 174	$ 231,907	$ 479,581	$ (29,155)
Ending Balance, Shares at Jun. 29, 2014	86,739,000	86,739,000