Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating activities:
Net loss	$ (26,451)	$ (21,320)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,110	3,321
Long-lived assets write-off due to restructuring	1,011
Change in fair value of contingent liability		(1,210)
Loss on disposal of equipment and improvements		161
Provision for doubtful accounts and other adjustments to accounts receivable	459	578
Provision for excess and obsolete inventory	62	41
Non-cash compensation related to stock options, ESPP and restricted stock	2,747	3,052
Change in operating accounts:
Accounts receivable	1,479	(1,395)
Income tax receivable	1	750
Inventories	(48)	44
Prepaid expenses and other assets	(335)	(159)
Accounts payable and accrued liabilities	4,603	(1,881)
Net cash used in operating activities	(13,362)	(18,018)
Investing activities:
Capital expenditures	(820)	(277)
Sales of short-term investments	6,136	21,564
Net cash provided by investing activities	5,316	21,287
Financing activities:
Cash received from stock sale for employee stock purchase plan	36	66
Cash received from exercise of stock options		16
Repurchase of common stock		(753)
Net cash provided by (used in) financing activities	36	(671)
Net increase (decrease) in cash and cash equivalents	(8,010)	2,598
Cash and cash equivalents, beginning of period	18,873	7,475
Cash and cash equivalents, end of period	10,863	10,073
Supplemental disclosures of cash flow information:
Cash paid for income taxes	$ 163	$ 199