Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common stock	Additional paid-in capital	Accumulated other comprehensive income	Accumulated deficit	Total
Balance at Beginning of period at Dec. 31, 2019	$ 11	$ 198,829	$ (19)	$ (167,859)	$ 30,962
Balance at Beginning of period (in shares) at Dec. 31, 2019	11,406,221
Vesting of common stock previously subject to repurchase (in shares)	90
Vesting of common stock previously subject to repurchase		1			1
Exercise of stock options (in shares)	1,289
Exercise of stock options		8			8
Foreign currency translation adjustment			27		27
Stock-based compensation expense		449			449
Net loss				(7,220)	(7,220)
Balance at Ending period at Mar. 31, 2020	$ 11	199,287	8	(175,079)	24,227
Balance at Ending period (in shares) at Mar. 31, 2020	11,407,600
Balance at Beginning of period at Dec. 31, 2020	$ 14	245,736	(71)	(196,653)	$ 49,026
Balance at Beginning of period (in shares) at Dec. 31, 2020	14,437,107
Vesting of common stock previously subject to repurchase (in shares)	46
Exercise of stock options (in shares)	3,122				3,122
Exercise of stock options		36			$ 36
Foreign currency translation adjustment			(11)		(11)
Stock-based compensation expense		694			694
Reclassification of liability-classified stock-based compensation		82			82
Net loss				(8,136)	(8,136)
Balance at Ending period at Mar. 31, 2021	$ 14	$ 246,548	$ (82)	$ (204,789)	$ 41,691
Balance at Ending period (in shares) at Mar. 31, 2021	14,440,275