Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Accounts receivable
Trade accounts receivable	$ 10,498,000	$ 8,140,000
Unbilled accounts receivable	551,000	450,000
Allowance for product returns and price adjustments	(384,000)	(397,000)
Accounts receivable, net	$ 10,665,000	$ 8,193,000