Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net loss attributable to common stockholders	$ (14,430)	$ (9,901)	$ (8,380)	$ (6,990)	$ (6,174)	$ (4,686)	$ (32,711)	$ (17,850)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	1,475,170			1,139,647			1,352,721	1,078,783
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (9.78)			$ (6.13)			$ (24.18)	$ (16.55)
Numerator:
Net loss attributable to common stockholders	$ (14,430)	$ (9,901)	$ (8,380)	$ (6,990)	$ (6,174)	$ (4,686)	$ (32,711)	$ (17,850)
Denominator:
Weighted-average common shares outstanding, diluted (in shares)	1,475,170			1,139,647			1,352,721	1,078,783
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (9.78)			$ (6.13)			$ (24.18)	$ (16.55)