Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net loss	$ (6,438)	$ (12,408)
Adjustments to reconcile net loss to cash flows used in operating activities:
Depreciation and amortization of property and equipment	2,900	2,850
Amortization of intangible assets	100	100
Stock-based compensation	2,117	2,026
(Gain) loss on disposal of property and equipment		(12)
Changes in operating assets and liabilities:
Accounts receivable	20,457	24,390
Inventory	(2,867)	10,425
Other operating assets	(9,541)	2,981
Accounts payable	(5,204)	900
Accrued expenses and other long-term liabilities	(4,137)	(11,281)
Deferred revenue	(906)	(22,624)
Net cash used in operating activities	(3,519)	(2,653)
Cash flows from investing activities:
Purchases of property and equipment	(2,120)	(3,165)
Purchases of marketable securities	(70,990)	(42,773)
Sale/maturities of marketable securities	82,851	72,487
Net cash provided by investing activities	9,741	26,549
Cash flows from financing activities:
Proceeds from sale of common stock in connection with employee stock purchase plan	993	754
Proceeds from exercise of stock options	39	665
Payment of tax withholding obligations related to net share settlements of restricted stock awards	(91)	(877)
Principal payments of capital lease obligations	(33)	(26)
Net cash provided by financing activities	908	516
Effect of exchange rate changes on cash and cash equivalents	78	239
Net increase in cash and cash equivalents	7,208	24,651
Cash and cash equivalents, beginning of year	105,451	62,501
Cash and cash equivalents, end of period	112,659	87,152
Supplemental disclosure of cash flow information:
Interest paid	9	3
Income taxes paid	636	197
Income tax refunds received	4	547
Supplemental disclosure of non-cash investing activities:
Capital expenditures incurred, but not yet paid	777	956
Property and equipment acquired under operating lease	$ 40