Stock Based Compensation - Stock-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Stock Based Compensation
Total stock-based compensation expense	$ 3,974	$ 2,824
Research and development expense
Stock Based Compensation
Total stock-based compensation expense	1,319	749
Sales and marketing expense
Stock Based Compensation
Total stock-based compensation expense	319	220
General and administrative expense
Stock Based Compensation
Total stock-based compensation expense	2,336	$ 1,855
Stock options and RSUs
Stock Based Compensation
Unrecognized stock-based compensation expense	$ 3,900
Expected weighted average period to be recognized	1 year 10 months 13 days
Employee stock options
Estimated grant-date fair value of stock options calculated using the Black-Scholes option-pricing model
Expected term (years)	5 years	5 years
Minimum | Employee stock options
Estimated grant-date fair value of stock options calculated using the Black-Scholes option-pricing model
Volatility (as a percent)	163.80%	150.10%
Risk-free interest rate (as a percent)	0.50%	0.30%
Maximum | Employee stock options
Estimated grant-date fair value of stock options calculated using the Black-Scholes option-pricing model
Volatility (as a percent)	164.00%	167.90%
Risk-free interest rate (as a percent)	1.20%	0.50%