CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2018		63,916,437
Beginning balance at Dec. 31, 2018	$ 73,192	$ 6	$ 218,284	$ 542	$ (145,640)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(15,216)				(15,216)
Issuance of common stock to directors (in shares)		3,461
Vesting of restricted stock units (in shares)		482,444
Exercise of stock options (in shares)		278,680
Exercise of stock options	1,073		1,073
Stock-based compensation expense	7,225		7,225
Other comprehensive income	296			296
Ending balance (in shares) at Mar. 31, 2019		64,681,022
Ending balance at Mar. 31, 2019	127,511	$ 6	226,582	838	(99,915)
Beginning balance (in shares) at Dec. 31, 2019		67,468,022
Beginning balance at Dec. 31, 2019	205,237	$ 6	340,929	(285)	(135,413)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	$ (11,669)				(11,669)
Issuance of common stock to directors (in shares)		1,946
Vesting of restricted stock units (in shares)		46,031
Exercise of stock options (in shares)	129,082	129,082
Exercise of stock options	$ 670		670
Stock-based compensation expense	3,476		3,476
Other comprehensive income	17			17
Ending balance (in shares) at Mar. 31, 2020		67,645,081
Ending balance at Mar. 31, 2020	$ 197,731	$ 6	$ 345,075	$ (268)	$ (147,082)