CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2018	$ 7,157	$ 2	$ 243,022	$ (235,867)
Beginning Balance, shares at Dec. 31, 2018		2,148
Issuance of common stock for release of awards	(1)		(1)
Issuance of common stock for release of awards, shares		9
Stock-based compensation	(4)		(4)
Net income (loss)	10			10
Ending Balance at Mar. 31, 2019	7,162	$ 2	243,017	(235,857)
Ending Balance, shares at Mar. 31, 2019		2,157
Beginning Balance at Dec. 31, 2019	$ 4,836	$ 2	243,281	(238,447)
Beginning Balance, shares at Dec. 31, 2019	2,179	2,179
Issuance of common stock for release of awards	$ (1)		(1)
Issuance of common stock for release of awards, shares		20
Exercise of pre-funded warrants	2		2
Exercise of pre-funded warrants, shares		116
Stock-based compensation	68		68
Net income (loss)	(1,405)			(1,405)
Ending Balance at Mar. 31, 2020	$ 3,500	$ 2	$ 243,350	$ (239,852)
Ending Balance, shares at Mar. 31, 2020	2,315	2,315