Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($)	Redeemable Convertible Preferred Stock Series B [Member] Series B redeemable convertible preferred stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balances at Dec. 31, 2013	$ 707,000	$ 36,000	$ 362,454,000	$ (385,115,000)	$ (22,625,000)
Balances (in shares) at Dec. 31, 2013	8,859,978	3,650,711
Net income (loss)				23,109,000	23,109,000
Accretion of dividends on Series B redeemable convertible preferred stock	$ 1,285,000		(1,285,000)		(1,285,000)
Warrants exercised		$ 1,000	1,594,000		1,595,000
Warrants exercised (in shares)		54,683
Conversion of Series B redeemable convertible preferred stock to common stock, value	$ (2,000)	$ 1,000	706,000		707,000
Conversion of Series B redeemable convertible preferred stock to common stock, shares	(188,938)	37,788
Stock-based compensation			775,000		775,000
Stock-based compensation - severance			1,161,000		1,161,000
Shares released from escrow		$ 2,000	(2,000)
Shares released from escrow (in shares)		240,000
Balances at Dec. 31, 2014	$ 1,990,000	$ 40,000	365,403,000	(362,006,000)	3,437,000
Balances (in shares) at Dec. 31, 2014	8,671,040	3,983,182
Net income (loss)				(516,000)	(516,000)
Accretion of dividends on Series B redeemable convertible preferred stock	$ 1,307,000		(1,307,000)		(1,307,000)
Amount reclassified to Series B redeemable convertible stock to accrete to its redemption value	8,971,000		(8,971,000)		(8,971,000)
Warrants exercised		$ 1,000	1,072,000		1,073,000
Warrants exercised (in shares)		56,645
Conversion of Series B redeemable convertible preferred stock to common stock, value	$ (378,000)	$ 2,000	1,504,000		1,506,000
Conversion of Series B redeemable convertible preferred stock to common stock, shares	(1,143,187)	228,637
Common stock issued in March 2015 financing, net of offering costs		$ 16,000	8,250,000		8,266,000
Common stock issued in March 2015 financing, net of offering costs (in shares)		1,575,758
Warrants reclassified from liabilities to equity due to amendment of warrants			5,462,000		5,462,000
Warrants reclassified from liabilities to equity due to increase in authorized shares			3,281,000		$ 3,281,000
Exercise of common stock options (shares)		39,281			214,815
Stock-based compensation			479,000		$ 479,000
Stock-based compensation - severance			4,000		4,000
Balances at Dec. 31, 2015	$ 11,890,000	$ 59,000	$ 375,177,000	$ (362,522,000)	$ 12,714,000
Balances (in shares) at Dec. 31, 2015	7,527,853	5,883,503