Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data	Common stock	Additional paid-in capital	Accumulated deficit	Total
Beginning balances at Dec. 31, 2012	$ 25	$ 442,560	$ (437,531)	$ 5,054
Beginning balances, shares at Dec. 31, 2012	25,237,000
Share-based compensation expense	0	1,589	0	1,589
Share-based compensation expense, shares	323,000
Exercise of warrants and options	0	41	0	41
Exercise of warrants and options, shares	23,000
Sales of common stock and warrants	7	4,255	0	4,262
Sales of common stock and warrants, shares	6,128,000
Exchange of warrants	0	536	0	536
Exchange of warrants, shares	358,000
Net loss	0	0	(13,178)	(13,178)
Ending balances at Dec. 31, 2013	32	448,981	(450,709)	(1,696)
Ending balances, shares at Dec. 31, 2013	32,069,000
Share-based compensation expense	0	310	0	310
Share-based compensation expense, shares	19,000
Sales of common stock and warrants	7	12,841	0	12,848
Sales of common stock and warrants, shares	7,160,000
Exchange of warrants	4	9,865	0	9,869
Exchange of warrants, shares	3,713,000
Net loss	0	0	(8,018)	(8,018)
Ending balances at Mar. 31, 2014	$ 43	$ 471,997	$ (458,727)	$ 13,313
Ending balances, shares at Mar. 31, 2014	42,961,000