Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	ATM Facility	Common Stock	Common Stock ATM Facility	Additional Paid-in Capital	Additional Paid-in Capital ATM Facility	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 31, 2018	$ 64,935		$ 1		$ 80,441		$ 5	$ (15,512)
Balance, Shares at Dec. 31, 2018			17,376,236
Vesting of restricted stock liability	19				19
Stock-based compensation expense	446				446
Other comprehensive income (loss)	44						44
Net loss	(5,950)							(5,950)
Balance at Mar. 31, 2019	59,494		$ 1		80,906		49	(21,462)
Balance, Shares at Mar. 31, 2019			17,376,236
Balance at Dec. 31, 2018	64,935		$ 1		80,441		5	(15,512)
Balance, Shares at Dec. 31, 2018			17,376,236
Other comprehensive income (loss)	75
Net loss	(18,033)
Balance at Sep. 30, 2019	48,959		$ 1		82,423		80	(33,545)
Balance, Shares at Sep. 30, 2019			17,376,236
Balance at Mar. 31, 2019	59,494		$ 1		80,906		49	(21,462)
Balance, Shares at Mar. 31, 2019			17,376,236
Vesting of restricted stock liability	19				19
Stock-based compensation expense	581				581
Other comprehensive income (loss)	38						38
Net loss	(6,069)							(6,069)
Balance at Jun. 30, 2019	54,063		$ 1		81,506		87	(27,531)
Balance, Shares at Jun. 30, 2019			17,376,236
Vesting of restricted stock liability	18				18
Stock-based compensation expense	633				633
Issuance of common stock warrants	266				266
Other comprehensive income (loss)	(7)						(7)
Net loss	(6,014)							(6,014)
Balance at Sep. 30, 2019	48,959		$ 1		82,423		80	(33,545)
Balance, Shares at Sep. 30, 2019			17,376,236
Balance at Dec. 31, 2019	41,848		$ 1		82,938		21	(41,112)
Balance, Shares at Dec. 31, 2019			17,425,654
Issuance of common stock	252	$ 825			252	$ 825
Issuance of common stock, Shares			83,662	174,649
Vesting of restricted stock liability	18				18
Stock-based compensation expense	787				787
Other comprehensive income (loss)	453						453
Net loss	(7,837)							(7,837)
Balance at Mar. 31, 2020	36,346		$ 1		84,820		474	(48,949)
Balance, Shares at Mar. 31, 2020			17,683,965
Balance at Dec. 31, 2019	41,848		$ 1		82,938		21	(41,112)
Balance, Shares at Dec. 31, 2019			17,425,654
Other comprehensive income (loss)	(50)
Net loss	(20,895)
Balance at Sep. 30, 2020	78,126		$ 2		140,161		(30)	(62,007)
Balance, Shares at Sep. 30, 2020			24,724,544
Balance at Mar. 31, 2020	36,346		$ 1		84,820		474	(48,949)
Balance, Shares at Mar. 31, 2020			17,683,965
Issuance of common stock pursuant to employeestock purchase plan	96				96
Issuance of common stock pursuant to employee stock purchase plan, Shares			39,885
Vesting of restricted stock liability	18				18
Stock-based compensation expense	1,350				1,350
Other comprehensive income (loss)	(377)						(377)
Net loss	(6,461)							(6,461)
Balance at Jun. 30, 2020	30,972		$ 1		86,284		97	(55,410)
Balance, Shares at Jun. 30, 2020			17,723,850
Issuance of common stock	35,723	$ 17,290	$ 1		35,722	$ 17,290
Issuance of common stock, Shares			5,461,169	1,539,525
Vesting of restricted stock liability	18				18
Stock-based compensation expense	847				847
Other comprehensive income (loss)	(127)						(127)
Net loss	(6,597)							(6,597)
Balance at Sep. 30, 2020	$ 78,126		$ 2		$ 140,161		$ (30)	$ (62,007)
Balance, Shares at Sep. 30, 2020			24,724,544