Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2012	Apr. 01, 2011
Cash flows from operating activities:
Net income (loss)	$ (7,528)	$ 516
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Amortization of intangibles	7,539	7,371
Depreciation	3,798	3,403
Stock-based compensation	4,800	6,002
Net loss on disposal of fixed assets		61
Deferred income taxes	(1,262)	76
Provision for inventories	915	2,640
Allowance for doubtful accounts, returns and discounts	(684)	(510)
Other non-cash adjustments, net	(8)	121
Changes in assets and liabilities, net of effect of acquisitions:
Accounts receivable	(1,179)	(9,767)
Inventories	4,189	(3,372)
Prepaid expenses and other assets	1,892	998
Accounts payable	936	(3,616)
Deferred revenue	2,740	4,430
Income taxes payable	(929)	(6,748)
Accrued and other liabilities	(7,255)	(9,288)
Net cash provided by (used in) operating activities	7,964	(7,683)
Cash flows from investing activities:
Purchases of investments	(36,654)	(41,813)
Proceeds from maturities of investments	18,791	6,873
Proceeds from sales of investments	1,042	1,026
Acquisition of property and equipment	(3,715)	(4,957)
Net cash used in investing activities	(20,536)	(38,871)
Cash flows from financing activities:
Proceeds from issuance of common stock, net	2,479	9,570
Net cash provided by financing activities	2,479	9,570
Effect of exchange rate changes on cash and cash equivalents	129	123
Net decrease in cash and cash equivalents	(9,964)	(36,861)
Cash and cash equivalents at beginning of period	90,983	96,533
Cash and cash equivalents at end of period	$ 81,019	$ 59,672