CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 9,591	$ 22,063
Restricted cash	795	794
Marketable securities	56,617	73,472
Interest and other receivables	555	752
Prepaid assets	844	1,336
Total current assets	68,402	98,417
Property and equipment, net	116	974
Deposits and other assets	195	410
Total assets	68,713	99,801
Current liabilities:
Accounts payable	1,547	3,429
Accrued compensation and benefits	2,886	5,216
Accrued restructuring charges	161	1,972
Accrued liabilities	1,985	3,480
Fair value of derivatives	258	51
Total current liabilities	6,837	14,148
Commitments and contingencies
Stockholders' equity:
Common stock	129	130
Additional paid-in capital	945,241	939,867
Accumulated deficit	(883,482)	(854,384)
Accumulated other comprehensive (loss) income	(12)	40
Total stockholders' equity	61,876	85,653
Total liabilities and stockholders' equity	$ 68,713	$ 99,801