CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 8,834	$ 22,063
Restricted cash	795	794
Marketable securities	61,966	73,472
Interest and other receivables	480	752
Prepaid assets	356	1,336
Total current assets	72,431	98,417
Property and equipment, net	566	974
Deposits and other assets	414	410
Total assets	73,411	99,801
Current liabilities:
Accounts payable	1,176	3,429
Accrued compensation and benefits	2,046	5,216
Accrued restructuring charges	374	1,972
Accrued liabilities	1,358	3,480
Fair value of derivatives	50	51
Total current liabilities	5,004	14,148
Commitments and contingencies
Stockholders' equity:
Common stock	130	130
Additional paid-in capital	943,518	939,867
Accumulated deficit	(875,228)	(854,384)
Accumulated other comprehensive (loss) income	(13)	40
Total stockholders' equity	68,407	85,653
Total liabilities and stockholders' equity	$ 73,411	$ 99,801