Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income (loss)	$ (28,730)	$ 10,653	$ (2,434)
Adjustments to reconcile net loss to net cash, provided by (used in) operating activities:
Bad debt expense	62	39	103
Income tax benefit	(86)	(15,067)	0
Depreciation and amortization	2,729	2,444	2,765
Stock-based compensation	4,136	2,546	3,092
Change in fair value of contingent consideration related to acquisition (Note 10)	10,500	0	0
Gain on sale of equipment	(141)	0	0
Changes in operating assets and liabilities:
Accounts receivable	(3,392)	(3,909)	(2,074)
Inventories	(9,801)	(2,964)	1,686
Prepaid expenses and other current assets	(153)	(672)	29
Accounts payable	700	2,098	353
Accrued payroll	1,597	498	2,183
Accrued expenses and other current liabilities	189	243	(712)
Deferred rent	8	(22)	6
Net cash provided by (used in) operating activities	(22,382)	(4,113)	4,997
Cash flows from investing activities:
Decrease in restricted cash equivalents	0	0	500
Cash acquired in Nellix acquisition	0	698	0
Purchases of property and equipment	(3,033)	(861)	(598)
Net cash used in investing activities	(3,033)	(163)	(98)
Cash flows from financing activities:
Proceeds from sale of common stock, net of expenses	0	14,990	14,777
Proceeds from sale of common stock under employee stock purchase plan	1,965	1,118	786
Proceeds from exercise of stock options	5,324	2,347	782
Repayments of long-term debt	0	(79)	162
Proceeds (repayment) under term loan and line of credit facilities	0	0	(5,000)
Net cash provided by financing activities	7,289	18,376	11,507
Effect of exchange rate changes on cash and cash equivalents	(30)	26	48
Net decrease (decrease) in cash and cash equivalents	(18,156)	14,126	16,454
Cash and cash equivalents, beginning of period	38,191	24,065	7,611
Cash and cash equivalents, end of period	20,035	38,191	24,065
Supplemental Disclosure of Cash Flow Activities:
Cash paid during the year for interest	32	16	192
Non-cash investing and financing activities:
Shares issued for acquisition (Note 10)	$ 0	$ 19,388	$ 0