Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Common Stock [Member] February 2010 financing [Member]	Common Stock [Member] April 2010 financing [Member]	Common Stock [Member] June 2010 financing [Member]	Common Stock [Member] October 2010 financing [Member]	Common Stock [Member] February 2011 financing [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] February 2010 financing [Member]	Additional Paid-in Capital [Member] April 2010 financing [Member]	Additional Paid-in Capital [Member] June 2010 financing [Member]	Additional Paid-in Capital [Member] October 2010 financing [Member]	Additional Paid-in Capital [Member] February 2011 financing [Member]	Accumulated Deficit [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Total [Member]	Total [Member] February 2010 financing [Member]	Total [Member] April 2010 financing [Member]	Total [Member] June 2010 financing [Member]	Total [Member] October 2010 financing [Member]	Total [Member] February 2011 financing [Member]
Balance at Dec. 31, 2009		$ 8						$ 361,622						$ (357,280)	$ (3,054)	$ 0	$ 1,296
Balance (in shares) at Dec. 31, 2009		8,446													(21)
Comprehensive loss:
Net loss	(19,175)	0						0						(19,175)	0	0	(19,175)
Other comprehensive loss - unrealized gains on investments		0						0						0	0	0	0
Total comprehensive loss		0						0						0	0	0	(19,175)
Issuance of common stock, restricted stock awards (in shares)		155
Issuance of common stock, restricted stock awards		0						0						0	0	0	0
Issuance of common stock, 401(k) employer match (in shares)		61
Issuance of common stock, 401(k) employer match		1						223						0	0	0	224
Issuance of common stock, financing (in shares)			1,833	270	2,381	159
Issuance of common stock, financing			2	0	2	0			9,379	2,105	9,092	452		0	0	0		9,381	2,105	9,094	452
Issuance of common stock, CEFF financings (in shares)		517
Issuance of common stock, CEFF financings		1						1,242						0	0	0	1,243
Stock-based compensation expense		0						1,406						0	0	0	1,406
Balance at Dec. 31, 2010	6,026	14						385,521						(376,455)	(3,054)	0	6,026
Balance (in shares) at Dec. 31, 2010	13,801	13,822													(21)
Comprehensive loss:
Net loss	(20,965)	0						0						(20,965)	0	0	(20,965)
Other comprehensive loss - unrealized gains on investments		0						0						0	0	0	0
Total comprehensive loss		0						0						0	0	0	(20,965)
Issuance of common stock, restricted stock awards (in shares)		1
Issuance of common stock, restricted stock awards		0						0						0	0	0	0
Issuance of common stock, 401(k) employer match (in shares)		265
Issuance of common stock, 401(k) employer match		0						497						0	0	0	497
Issuance of common stock, financing (in shares)							10,000
Issuance of common stock, financing							10						13,513	0	0	0						13,523
Issuance of common stock, CEFF financings (in shares)		515
Issuance of common stock, CEFF financings		1						1,315						0	0	0	1,316
Stock-based compensation expense		0						867						0	0	0	867
Balance at Dec. 31, 2011	$ 1,264	$ 25						$ 401,713						$ (397,420)	$ (3,054)	$ 0	$ 1,264
Balance (in shares) at Dec. 31, 2011	24,582	24,603													(21)