Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 60,090	$ 63,309
Marketable securities, available-for-sale	30,618	30,588
Accounts receivable, net	7,663	9,131
Inventories	4,779	6,516
Other current assets and prepaid expenses	5,446	12,112
Total current assets	108,596	121,656
Property, equipment and leasehold improvements, net	13,750	15,348
Goodwill	10,007	10,007
Intangible assets, net	10,457	11,247
Other assets	2,640	2,813
Total assets	145,450	161,071
Liabilities and stockholders' deficit
Accounts payable	5,381	6,089
Accrued expenses	15,303	22,155
Long-term debt and obligations, current portion	2,313	4,144
Other current liabilities	1,212	2,581
Deferred gain on pooled patents agreement	0	21,000
Total current liabilities	24,209	55,969
Long-term debt and obligations, less current portion	5,524	5,602
Convertible senior notes	130,000	130,000
Other long-term liabilities	812	664
Total liabilities	160,545	192,235
Commitments and contingencies
Stockholders' deficit:
Convertible preferred stock, par value $0.001; 5,000 shares authorized, no shares issued or outstanding at March 31, 2015 and December 31, 2014	0	0
Common stock, par value $0.001; 185,000 shares authorized, 118,071 and 117,434 shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	118	117
Additional paid-in capital	983,647	981,929
Accumulated other comprehensive income	153	87
Accumulated deficit	(999,013)	(1,013,297)
Total stockholders' deficit	(15,095)	(31,164)
Total liabilities and stockholders' deficit	$ 145,450	$ 161,071