CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Cash flows from operating activities:
Net income	$ 69,163	$ 54,108
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	18,096	15,412
Share-based compensation	7,110	6,504
Excess tax benefit from share-based compensation	(3,947)	(3,727)
Loss on sale of property and equipment	49	182
Deferred income taxes	2,979	4,439
Loss of forward interest rate swaps	2,433	0
Changes in assets and liabilities:
Accounts receivable, net	11,359	(1,976)
Inventories, net	(5,061)	14,190
Other assets	2,583	1,313
Accounts payable	(5,336)	3,263
Accrued liabilities	3,535	(6,094)
Deferred revenue	502	1,585
Income taxes	4,706	476
Other operating activities	1,742	1,381
Net cash provided by operating activities	109,913	91,056
Cash flows from investing activities:
Purchases of property and equipment	(7,962)	(8,547)
Acquisition of intangible assets	0	(500)
Purchase of long-term investments	(1,213)	(604)
Purchase of investments and marketable securities	(276,400)	(231,174)
Maturities of investments and marketable securities	20,852	19,188
Proceeds from sales of investments and marketable securities	150,781	142,230
Net cash used in investing activities	(113,942)	(79,407)
Cash flows from financing activities:
Purchase of treasury stock	0	(28,563)
Proceeds from exercise of stock options and stock purchase plan purchases	7,711	4,104
Excess tax benefit from share-based compensation	3,947	3,727
Net cash provided by (used in) financing activities	11,658	(20,732)
Effect of exchange rate changes on cash	(107)	229
Net increase (decrease) in cash and cash equivalents	7,522	(8,854)
Cash and cash equivalents at beginning of period	62,827	64,740
Cash and cash equivalents at end of period	70,349	55,886
Supplemental disclosures of cash flow information:
Income taxes paid, net	$ 7,627	$ 5,346