Stockholders' Equity - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Stock-Based Compensation Expense
Total stock-based compensation expense	$ 669	$ 843	$ 1,433	$ 1,585
Cost of goods sold
Stock-Based Compensation Expense
Total stock-based compensation expense	31	75	75	135
Research and development
Stock-Based Compensation Expense
Total stock-based compensation expense	91	121	194	228
Selling and marketing
Stock-Based Compensation Expense
Total stock-based compensation expense	40	43	80	78
General and administrative
Stock-Based Compensation Expense
Total stock-based compensation expense	$ 507	$ 604	$ 1,084	$ 1,144