Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Beginning Balance at Dec. 31, 2018	$ 39	$ 496,544	$ (247,003)	$ (199)	$ 249,381
Beginning Balance, Shares at Dec. 31, 2018	38,604
Impact of equity compensation plans		1,858			1,858
Impact of equity compensation plans, Shares	162
Other comprehensive loss				45	45
Net loss			(9,736)		(9,736)
Ending Balance at Jun. 30, 2019	$ 39	498,402	(256,739)	(154)	241,548
Ending Balance, Shares at Jun. 30, 2019	38,766
Beginning Balance at Mar. 31, 2019	$ 39	492,177	(252,638)	(286)	239,292
Beginning Balance, Shares at Mar. 31, 2019	38,658
Impact of equity compensation plans		6,225			6,225
Impact of equity compensation plans, Shares	108
Other comprehensive loss				132	132
Net loss			(4,101)		(4,101)
Ending Balance at Jun. 30, 2019	$ 39	498,402	(256,739)	(154)	241,548
Ending Balance, Shares at Jun. 30, 2019	38,766
Beginning Balance at Dec. 31, 2019	$ 40	529,658	(282,197)	(158)	247,343
Beginning Balance, Shares at Dec. 31, 2019	39,655
Issuance of common stock through public offering	$ 5	188,953			188,958
Issuance of common stock through public offering, Shares	4,574
Impact of equity compensation plans		5,143			5,143
Impact of equity compensation plans, Shares	710
Other comprehensive loss				62	62
Net loss			(24,644)		(24,644)
Ending Balance at Jun. 30, 2020	$ 45	723,754	(306,841)	(96)	416,862
Ending Balance, Shares at Jun. 30, 2020	44,939
Beginning Balance at Mar. 31, 2020	$ 40	526,302	(298,605)	(371)	227,366
Beginning Balance, Shares at Mar. 31, 2020	40,077
Issuance of common stock through public offering	$ 5	188,953			188,958
Issuance of common stock through public offering, Shares	4,574
Impact of equity compensation plans		8,499			8,499
Impact of equity compensation plans, Shares	288
Other comprehensive loss				275	275
Net loss			(8,236)		(8,236)
Ending Balance at Jun. 30, 2020	$ 45	$ 723,754	$ (306,841)	$ (96)	$ 416,862
Ending Balance, Shares at Jun. 30, 2020	44,939