Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 28, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net loss	$ (33,782)	$ (16,433)
Adjustments to reconcile net loss to cash flows used in operating activities:
Depreciation and amortization of property and equipment	9,081	8,721
Amortization of intangible assets	904	300
Stock-based compensation	6,540	6,308
Loss on disposal of property and equipment	23	14
Changes in operating assets and liabilities:
Accounts receivable	13,020	8,762
Inventory	(3,868)	19,113
Other operating assets	(4,998)	9,763
Accounts payable	(1,753)	(7,234)
Accrued expenses and other long-term liabilities	(3,625)	(12,046)
Deferred revenue	(9,624)	(33,477)
Net cash used in operating activities	(28,082)	(16,209)
Cash flows from investing activities:
Purchases of property and equipment	(7,792)	(10,962)
Business acquisition, net of cash acquired	(35,508)
Purchases of marketable securities	(139,917)	(152,402)
Sale/maturities of marketable securities	200,380	192,769
Net cash provided by investing activities	17,163	29,405
Cash flows from financing activities:
Proceeds from sale of common stock in connection with employee stock purchase plan	1,693	1,513
Proceeds from exercise of stock options	151	818
Payment of tax withholding obligations related to net share settlements of restricted stock awards	(169)	(1,245)
Principal payments of capital lease obligations	(87)	(66)
Settlement of redeemable convertible subordinated debentures	(23,704)
Net cash (used in) provided by financing activities	(22,116)	1,020
Effect of exchange rate changes on cash and cash equivalents	192	(445)
Net (decrease) increase in cash and cash equivalents	(32,843)	13,771
Cash and cash equivalents, beginning of year	105,451	62,501
Cash and cash equivalents, end of period	72,608	76,272
Supplemental disclosure of cash flow information:
Interest paid	638	8
Income taxes paid	1,958	853
Income tax refunds received	42	564
Supplemental disclosure of non-cash investing activities:
Capital expenditures incurred, but not yet paid	861	803
Property and equipment acquired under operating lease	40	59
Business acquisition purchase consideration - assumed equity awards	$ 892