CONDENSED STATEMENTS OF PREFERRED STOCK AND STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Preferred Stock Series A Preferred Stock	Preferred Stock Series B Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balance at the beginning at Dec. 31, 2018			$ 1	$ 352		$ (47,297)	$ (46,944)
Balance at the beginning (in shares) at Dec. 31, 2018			1,374,812
Balance at the beginning at Dec. 31, 2018	$ 71,000	$ 91,223
Balance at the beginning (in shares) at Dec. 31, 2018	68,181,819	56,828,851
Increase (Decrease) in Stockholders' Deficit
Stock based compensation				383			383
Issuance of common stock				4			4
Issuance of common stock (in shares)			4,697
Net loss						(6,155)	(6,155)
Balance at the end at Mar. 31, 2019			$ 1	739		(53,452)	(52,712)
Balance at the end (in shares) at Mar. 31, 2019			1,379,509
Balance at the end at Mar. 31, 2019	$ 71,000	$ 91,223
Balance at the end (in shares) at Mar. 31, 2019	68,181,819	56,828,851
Balance at the beginning at Dec. 31, 2018			$ 1	352		(47,297)	(46,944)
Balance at the beginning (in shares) at Dec. 31, 2018			1,374,812
Balance at the beginning at Dec. 31, 2018	$ 71,000	$ 91,223
Balance at the beginning (in shares) at Dec. 31, 2018	68,181,819	56,828,851
Increase (Decrease) in Stockholders' Deficit
Net loss							(14,376)
Balance at the end at Jun. 30, 2019			$ 23	240,245		(61,673)	178,595
Balance at the end (in shares) at Jun. 30, 2019			22,714,765
Balance at the beginning at Mar. 31, 2019			$ 1	739		(53,452)	(52,712)
Balance at the beginning (in shares) at Mar. 31, 2019			1,379,509
Balance at the beginning at Mar. 31, 2019	$ 71,000	$ 91,223
Balance at the beginning (in shares) at Mar. 31, 2019	68,181,819	56,828,851
Increase (Decrease) in Stockholders' Deficit
Stock based compensation				412			412
Issuance of common stock			$ 1	42			43
Issuance of common stock (in shares)			24,687
Initial public offering, net of issuance costs of $9.4M			$ 6	76,844			76,850
Initial public offering, net of issuance costs of $9.4M (in shares)			5,750,000
Conversion of preferred stock to common stock	$ (71,000)	$ (91,223)	$ 15	162,208			162,223
Conversion of preferred stock to common stock (in shares)	(68,181,819)	(56,828,851)	15,560,569
Net loss						(8,221)	(8,221)
Balance at the end at Jun. 30, 2019			$ 23	240,245		(61,673)	178,595
Balance at the end (in shares) at Jun. 30, 2019			22,714,765
Balance at the beginning at Dec. 31, 2019			$ 27	402,529	$ (38)	(81,034)	$ 321,484
Balance at the beginning (in shares) at Dec. 31, 2019			27,499,260				27,499,260
Increase (Decrease) in Stockholders' Deficit
Stock based compensation				1,008			$ 1,008
Issuance of common stock			$ 1	36			37
Issuance of common stock (in shares)			17,142
Unrealized (loss) gain on marketable securities, net of tax $0					(505)		(505)
Net loss						9,733	9,733
Balance at the end at Mar. 31, 2020			$ 28	403,573	(543)	(71,301)	331,757
Balance at the end (in shares) at Mar. 31, 2020			27,516,402
Balance at the beginning at Dec. 31, 2019			$ 27	402,529	(38)	(81,034)	$ 321,484
Balance at the beginning (in shares) at Dec. 31, 2019			27,499,260				27,499,260
Increase (Decrease) in Stockholders' Deficit
Net loss							$ (4,775)
Balance at the end at Jun. 30, 2020			$ 28	405,763	1,935	(85,809)	$ 321,917
Balance at the end (in shares) at Jun. 30, 2020			27,520,650				27,520,650
Balance at the beginning at Mar. 31, 2020			$ 28	403,573	(543)	(71,301)	$ 331,757
Balance at the beginning (in shares) at Mar. 31, 2020			27,516,402
Increase (Decrease) in Stockholders' Deficit
Stock based compensation				2,187			2,187
Issuance of common stock				3			3
Issuance of common stock (in shares)			4,248
Unrealized (loss) gain on marketable securities, net of tax $0					2,478		2,478
Net loss						(14,508)	(14,508)
Balance at the end at Jun. 30, 2020			$ 28	$ 405,763	$ 1,935	$ (85,809)	$ 321,917
Balance at the end (in shares) at Jun. 30, 2020			27,520,650				27,520,650