Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Operating Activities
Net income	$ 20,034	$ 14,320
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation of property and equipment	3,297	3,543
Amortization of other intangible assets and other assets	2,840	2,280
Stock-based compensation expense	6,260	6,693
Income tax benefit (detriment) from employee stock-based awards	(363)	2,656
Excess income tax benefit from employee stock-based awards	(217)	(2,426)
Deferred income taxes	7,521	3,101
Changes in operating assets and liabilities:
Accounts receivable	5,256	(6,074)
Inventories	(7,350)	447
Prepaid expenses and other assets	4,620	4,581
Accounts payable	2,356	4,209
Accrued expenses	(4,330)	(5,087)
Deferred income on shipments to distributors	(598)	3,307
Income taxes	(9,818)	(5,403)
Net cash provided by operating activities	29,508	26,147
Investing Activities
Purchases of available-for-sale investments	(78,851)	(82,845)
Proceeds from sales and maturities of available-for-sale investments	25,674	60,518
Purchases of property and equipment	(3,898)	(2,428)
Purchases of other assets	(1,228)	(850)
Net cash used in investing activities	(58,303)	(25,605)
Financing Activities
Proceeds from issuance of common stock, net of shares withheld for taxes	4,915	106
Excess income tax benefit from employee stock-based awards	217	2,426
Payments on debt	(2,500)
Net cash provided by financing activities	2,632	2,532
Increase (decrease) in cash and cash equivalents	(26,163)	3,074
Cash and cash equivalents at beginning of period	105,426	94,964
Cash and cash equivalents at end of period	$ 79,263	$ 98,038