Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Convertible Preferred Stock
Balance at Dec. 31, 2018	$ (36,161)	$ 10	$ 4,008	$ (40,179)
Balance, shares at Dec. 31, 2018					33,645,447
Balance at Dec. 31, 2018					$ 69,114
Balance, shares at Dec. 31, 2018		10,091,100
Stock-based compensation expense	146		146
Net loss	(2,193)			(2,193)
Balance at Mar. 31, 2019	(38,208)	$ 10	4,154	(42,372)
Balance, shares at Mar. 31, 2019					33,645,447
Balance at Mar. 31, 2019					$ 69,114
Balance, shares at Mar. 31, 2019		10,091,100
Balance at Dec. 31, 2018	(36,161)	$ 10	4,008	(40,179)
Balance, shares at Dec. 31, 2018					33,645,447
Balance at Dec. 31, 2018					$ 69,114
Balance, shares at Dec. 31, 2018		10,091,100
Net loss	(9,379)
Balance at Sep. 30, 2019	(45,090)	$ 10	4,458	(49,558)
Balance, shares at Sep. 30, 2019					33,645,447
Balance at Sep. 30, 2019					$ 69,114
Balance, shares at Sep. 30, 2019		10,091,100
Balance at Mar. 31, 2019	(38,208)	$ 10	4,154	(42,372)
Balance, shares at Mar. 31, 2019					33,645,447
Balance at Mar. 31, 2019					$ 69,114
Balance, shares at Mar. 31, 2019		10,091,100
Stock-based compensation expense	147		147
Net loss	(3,554)			(3,554)
Balance at Jun. 30, 2019	(41,615)	$ 10	4,301	(45,926)
Balance, shares at Jun. 30, 2019					33,645,447
Balance at Jun. 30, 2019					$ 69,114
Balance, shares at Jun. 30, 2019		10,091,100
Stock-based compensation expense	157		157
Net loss	(3,632)			(3,632)
Balance at Sep. 30, 2019	(45,090)	$ 10	4,458	(49,558)
Balance, shares at Sep. 30, 2019					33,645,447
Balance at Sep. 30, 2019					$ 69,114
Balance, shares at Sep. 30, 2019		10,091,100
Balance at Dec. 31, 2019	$ (49,571)	$ 10	4,632	(54,213)
Balance, shares at Dec. 31, 2019	33,645,447				33,645,447
Balance at Dec. 31, 2019	$ 69,114				$ 69,114
Balance, shares at Dec. 31, 2019		10,091,100
Stock-based compensation expense	189		189
Net loss	(3,988)			(3,988)
Balance at Mar. 31, 2020	(53,370)	$ 10	4,821	(58,201)
Balance, shares at Mar. 31, 2020					33,645,447
Balance at Mar. 31, 2020					$ 69,114
Balance, shares at Mar. 31, 2020		10,091,100
Balance at Dec. 31, 2019	$ (49,571)	$ 10	4,632	(54,213)
Balance, shares at Dec. 31, 2019	33,645,447				33,645,447
Balance at Dec. 31, 2019	$ 69,114				$ 69,114
Balance, shares at Dec. 31, 2019		10,091,100
Issuance of common stock for exercise of stock options, shares	18,747
Net loss	$ (31,603)
Balance at Sep. 30, 2020	$ (76,511)	$ 10	9,295	(85,816)
Balance, shares at Sep. 30, 2020	48,958,829				48,958,829
Balance at Sep. 30, 2020	$ 175,745				$ 175,745
Balance, shares at Sep. 30, 2020		10,109,847
Balance at Mar. 31, 2020	(53,370)	$ 10	4,821	(58,201)
Balance, shares at Mar. 31, 2020					33,645,447
Balance at Mar. 31, 2020					$ 69,114
Balance, shares at Mar. 31, 2020		10,091,100
Issuance of Series D convertible preferred stock, net of issuance costs of $869					$ 106,631
Issuance of Series D convertible preferred stock, net of issuance costs of $869, shares					15,313,382
Issuance of common stock for exercise of stock options	27		27
Issuance of common stock for exercise of stock options, shares		18,747
Stock-based compensation expense	209		209
Net loss	(9,993)			(9,993)
Balance at Jun. 30, 2020	(63,127)	$ 10	5,057	(68,194)
Balance, shares at Jun. 30, 2020					48,958,829
Balance at Jun. 30, 2020					$ 175,745
Balance, shares at Jun. 30, 2020		10,109,847
Stock-based compensation expense	4,238		4,238
Net loss	(17,622)			(17,622)
Balance at Sep. 30, 2020	$ (76,511)	$ 10	$ 9,295	$ (85,816)
Balance, shares at Sep. 30, 2020	48,958,829				48,958,829
Balance at Sep. 30, 2020	$ 175,745				$ 175,745
Balance, shares at Sep. 30, 2020		10,109,847