Stockholders' Equity (Deficit) - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Stock-Based Compensation Expense
Total stock-based compensation expense	$ 764	$ 742
Cost of goods sold
Stock-Based Compensation Expense
Total stock-based compensation expense	44	60
Research and development
Stock-Based Compensation Expense
Total stock-based compensation expense	103	107
Selling and marketing
Stock-Based Compensation Expense
Total stock-based compensation expense	40	35
General and administrative
Stock-Based Compensation Expense
Total stock-based compensation expense	$ 577	$ 540