CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 134,537	$ 149,613
Restricted cash	1,492	1,562
Accounts receivable	10,850	7,455
Inventories	4,317	9,134
Prepaid expenses and other	2,952	3,841
Total current assets	154,148	171,605
Noncurrent assets:
Fixed assets, net	7,623	5,880
Goodwill	3,275	3,275
Intangible assets, net	2,914	2,974
Other assets	5,050	5,332
Total Assets	173,010	189,066
Current liabilities:
Accounts payable	1,245	2,550
Accrued liabilities	17,245	16,859
Common stock warrant liability	766	711
Note payable, current portion	12,000	9,000
Total current liabilities	31,256	29,120
Noncurrent liabilities:
Note payable, net of current portion	48,000	51,000
Convertible debt	60,000	60,000
Total liabilities	139,256	140,120
Stockholders' equity:
Preferred stock, $0.001 par value per share, 15,000,000 shares authorized, zero shares issued and outstanding	0	0
Common stock, $0.001 par value per share, 150,000,000 shares authorized, 69,394,765 and 68,861,366 shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	69	69
Additional paid-in capital	311,870	306,832
Accumulated other comprehensive loss	(607)	(60)
Accumulated deficit	(277,578)	(257,895)
Total stockholders' equity	33,754	48,946
Total Liabilities and Stockholders' Equity	$ 173,010	$ 189,066