Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Adjustment due to adoption of ASC 842, Leases	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit	Accumulated Deficit Adjustment due to adoption of ASC 842, Leases
Beginning balance (in shares) at Dec. 31, 2018			12,233		0
Beginning balance at Dec. 31, 2018	$ 196,427	$ (823)	$ 122	$ 303,463	$ 0	$ (107,158)	$ (823)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock to employees (in shares)			97
Issuance of common stock to employees	0		$ 1	(1)
Issuance of common stock for Rights Offering (in shares)			3,382
Issuance of common stock for Rights Offering	32,175		$ 34	32,141
Treasury stock acquired through surrender of shares for tax withholding (in shares)					(34)
Treasury stock acquired through surrender of shares for tax withholding	(373)				$ (373)
Stock-based compensation	852			852
Net loss	(6,355)					(6,355)
Ending balance (in shares) at Mar. 31, 2019			15,712		34
Ending balance at Mar. 31, 2019	221,903		$ 157	336,455	$ (373)	(114,336)
Beginning balance (in shares) at Dec. 31, 2018			12,233		0
Beginning balance at Dec. 31, 2018	196,427	$ (823)	$ 122	303,463	$ 0	(107,158)	$ (823)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(11,361)
Ending balance (in shares) at Jun. 30, 2019			15,746		37
Ending balance at Jun. 30, 2019	217,431		$ 157	337,018	$ (402)	(119,342)
Beginning balance (in shares) at Mar. 31, 2019			15,712		34
Beginning balance at Mar. 31, 2019	221,903		$ 157	336,455	$ (373)	(114,336)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock to employees (in shares)			34
Issuance of common stock to employees	0		$ 0
Treasury stock acquired through surrender of shares for tax withholding (in shares)					(3)
Treasury stock acquired through surrender of shares for tax withholding	(29)				$ (29)
Stock-based compensation	563			563
Net loss	(5,006)					(5,006)
Ending balance (in shares) at Jun. 30, 2019			15,746		37
Ending balance at Jun. 30, 2019	217,431		$ 157	337,018	$ (402)	(119,342)
Beginning balance (in shares) at Dec. 31, 2019			15,781		46
Beginning balance at Dec. 31, 2019	174,432		$ 158	337,628	$ (436)	(162,918)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock to employees (in shares)			40
Issuance of common stock to employees	0		$ 0
Treasury stock acquired through surrender of shares for tax withholding (in shares)					(14)
Treasury stock acquired through surrender of shares for tax withholding	(41)				$ (41)
Stock-based compensation	290			290
Net loss	(23,044)					(23,044)
Ending balance (in shares) at Mar. 31, 2020			15,821		60
Ending balance at Mar. 31, 2020	151,637		$ 158	337,918	$ (477)	(185,962)
Beginning balance (in shares) at Dec. 31, 2019			15,781		46
Beginning balance at Dec. 31, 2019	174,432		$ 158	337,628	$ (436)	(162,918)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(29,823)
Ending balance (in shares) at Jun. 30, 2020			15,821		60
Ending balance at Jun. 30, 2020	145,180		$ 158	338,240	$ (477)	(192,741)
Beginning balance (in shares) at Mar. 31, 2020			15,821		60
Beginning balance at Mar. 31, 2020	151,637		$ 158	337,918	$ (477)	(185,962)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock to employees	0
Treasury stock acquired through surrender of shares for tax withholding	0
Stock-based compensation	322			322
Net loss	(6,779)					(6,779)
Ending balance (in shares) at Jun. 30, 2020			15,821		60
Ending balance at Jun. 30, 2020	$ 145,180		$ 158	$ 338,240	$ (477)	$ (192,741)