Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 23,542	$ 30,164
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	7,372	5,959
Share-based compensation	2,146	3,800
Excess tax benefit from share-based compensation	(358)	(66)
Loss on sale of property and equipment	136	83
Deferred income taxes	990	(391)
Changes in assets and liabilities:
Accounts receivable, net	(516)	(1,862)
Inventories, net	6,943	7,169
Other assets	(137)	9,395
Accounts payable	(7,119)	(3,378)
Accrued liabilities	(12,787)	(16,881)
Deferred revenue	1,618	1,151
Income taxes	649	6,135
Other operating activities	1,685	(4,725)
Net cash provided by operating activities	24,164	36,553
Cash flows from investing activities:
Purchases of property and equipment	(1,952)	(7,654)
Proceeds from the sale of business	0	13,790
Acquisition of intangible assets	(500)	0
Acquisition of long-term equity investment	(604)	0
Purchases of investments and marketable securities	(106,947)	(132,390)
Maturities of investments and marketable securities	3,144	81,189
Proceeds from sales of investments and marketable securities	65,094	21,748
Net cash used in investing activities	(41,765)	(23,317)
Cash flows from financing activities:
Purchase of treasury stock	(3,888)	(9,775)
Proceeds from exercise of stock options and stock purchase plan purchases	5,913	1,998
Excess tax benefit from share-based compensation	358	66
Net cash provided by (used in) financing activities	2,383	(7,711)
Effect of exchange rate changes on cash	70	0
Net increase (decrease) in cash and cash equivalents	(15,148)	5,525
Cash and cash equivalents at beginning of period	64,740	36,418
Cash and cash equivalents at end of period	49,592	41,943
Supplemental disclosures of cash flow information:
Income taxes paid, net	$ 2,271	$ 7,956