Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (USD $)	Total	Redeemable Convertible Preferred Stock Series B [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Balances at Dec. 31, 2013	$ (22,625,000)	$ 707,000	$ 1,825,000	$ 360,665,000	$ (385,115,000)
Balances (in shares) at Dec. 31, 2013		8,859,978	182,535,562
Net income (loss)	23,109,000	0	0	0	23,109,000
Accretion of Series B convertible preferred stock to its redemption value	(1,285,000)	1,285,000	0	(1,285,000)	0
Warrants exercised	1,595,000	0	28,000	1,567,000	0
Warrants exercised (in shares)		0	2,734,151
Preferred shares converted to common stock	707,000	(2,000)	19,000	688,000	0
Preferred shares converted to common stock (in shares)		(188,938)	1,889,380
Stock-based compensation	775,000	0	0	775,000	0
Stock-based compensation - severance	1,161,000	0	0	1,161,000	0
Shares released from escrow	0	0	120,000	(120,000)	0
Shares released from escrow (in shares)		0	12,000,000
Balances at Dec. 31, 2014	3,437,000	1,990,000	1,992,000	363,451,000	(362,006,000)
Balances (in shares) at Dec. 31, 2014		8,671,040	199,159,093
Net income (loss)	(14,493,000)	0	0	0	(14,493,000)
Accretion of Series B convertible preferred stock to its redemption value	338,000	338,000	0	(338,000)	0
Net common stock issued in March 2015 financing	8,266,000	0	787,000	7,479,000	0
Net common stock issued in March 2015 financing (in shares)		0	78,787,880
Stock-based compensation	52,000		0	52,000	0
Balances at Mar. 31, 2015	$ (3,076,000)	$ 2,328,000	$ 2,779,000	$ 370,644,000	$ (376,499,000)
Balances (in shares) at Mar. 31, 2015		8,671,040	277,946,973