Consolidated Statements of Shareholders' Equity (USD $)	Common stock	Additional paid-in capital	Accumulated deficit	Total
Beginning balances at Dec. 31, 2012	$ 25,000	$ 442,560,000	$ (437,531,000)	$ 5,054,000
Beginning balances, shares at Dec. 31, 2012	25,237,000
Share-based compensation expense	0	1,589,000	0	1,589,000
Share-based compensation expense, shares	323,000
Exercise of options	0	41,000	0	41,000
Exercise of options, shares	23,000
Sales of common stock and warrants	7,000	4,255,000	0	4,262,000
Sales of common stock and warrants, shares	6,128,000
Exchange of warrants	0	536,000	0	536,000
Exchange of warrants, shares	358,000
Net loss	0	0	(13,178,000)	(13,178,000)
Ending balances at Dec. 31, 2013	32,000	448,981,000	(450,709,000)	(1,696,000)
Ending balances, shares at Dec. 31, 2013	32,069,000
Share-based compensation expense	0	705,000	0	705,000
Share-based compensation expense, shares	105,000
Sales of common stock and warrants	9,000	16,105,000	0	16,114,000
Sales of common stock and warrants, shares	8,871,000
Exchange of warrants	4,000	9,865,000	0	9,869,000
Exchange of warrants, shares	3,713,000
Net loss	0	0	(18,120,000)	(18,120,000)
Ending balances at Dec. 31, 2014	$ 45,000	$ 475,656,000	$ (468,829,000)	$ 6,872,000
Ending balances, shares at Dec. 31, 2014	44,758,000