Condensed Consolidated Statements Of Stockholders' Equity/(Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Series B	Series F Preferred Stock	Preferred Stock Series B	Preferred Stock Series F Preferred Stock	Common Stock	Additional paid-in capital	Additional paid-in capital Series F Preferred Stock	Other Comprehensive Loss	Accumulated deficit	Accumulated deficit Series B
Balances, shares, beginning balance at Dec. 31, 2017				44	0	32,560
Balances, beginning balance at Dec. 31, 2017	$ 271,321			$ 0	$ 0	$ 326	$ 572,342		$ (315)	$ (301,032)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Declared and paid dividends on preferred stock		$ (32)									$ (32)
Common stock issued from exercise of rights offering, shares						200
Common stock issued from exercise of rights offering	4,720					$ 2	4,718
Options exercised, shares						3
Options exercised	50						50
Stock-based compensation	547						547
Comprehensive income	115								115
Stockholders' Equity, Other Shares						(27)
Stockholders' Equity, Other	(1,455)						(1,455)
Net loss	(26,233)									(26,233)
Balances, shares, endings balance at Mar. 31, 2018				44	0	32,736
Balances, ending balance at Mar. 31, 2018	248,979			$ 0	$ 0	$ 328	576,202		(200)	(327,351)
Balances, shares, beginning balance at Dec. 31, 2018				44	0	34,403
Balances, beginning balance at Dec. 31, 2018	211,839			$ 0	$ 1	$ 344	651,623		(219)	(439,910)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Declared and paid dividends on preferred stock		$ (32)									$ (32)
Stock issuance, shares						20
Stock issuance	0		$ 14,340					$ 14,340
Stock-based compensation	1,808						1,808
Comprehensive income	35								35
Stockholders' Equity, Other Shares						(10)
Stockholders' Equity, Other	(106)						(106)
Net loss	(37,575)									(37,575)
Balances, shares, endings balance at Mar. 31, 2019				44	0	34,413
Balances, ending balance at Mar. 31, 2019	$ 190,309			$ 0	$ 1	$ 344	$ 667,665		$ (184)	$ (477,517)