Unaudited Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Temporary equity, Balance at Dec. 31, 2019		$ 122,465
Temporary equity, Balance, shares at Dec. 31, 2019		85,093,688
Balance at Dec. 31, 2019	$ (78,237)			$ 5,164	$ 41	$ (83,442)
Balance, shares at Dec. 31, 2019			2,484,848
Stock-based compensation	503			503
Exercise of stock options	3			3
Exercise of stock options, shares			955
Vesting of early exercised stock options	24			24
Vesting of early exercised stock options, shares			48,766
Unrealized loss on investment securities	(68)				(68)
Net loss	(8,112)					(8,112)
Temporary equity, Balance at Mar. 31, 2020		$ 122,465
Temporary equity, Balance, shares at Mar. 31, 2020		85,093,688
Balance at Mar. 31, 2020	(85,887)			5,694	(27)	(91,554)
Balance, shares at Mar. 31, 2020			2,534,569
Balance at Dec. 31, 2020	$ 89,279		$ 3	210,021	1	(120,746)
Balance, shares at Dec. 31, 2020	25,969,442		25,969,442
Stock-based compensation	$ 1,520			1,520
Exercise of stock options	$ 623			623
Exercise of stock options, shares	228,678		228,678
Vesting of early exercised stock options	$ 8			8
Vesting of early exercised stock options, shares			11,207
Unrealized loss on investment securities	(2)				(2)
Net loss	(14,768)					(14,768)
Balance at Mar. 31, 2021	$ 76,660		$ 3	$ 212,172	$ (1)	$ (135,514)
Balance, shares at Mar. 31, 2021	26,209,327		26,209,327