Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Components of accrued liabilities
Accrued compensation and related charges	$ 4,083	$ 5,115
Preferred stock dividends payable	2,901	2,901
Accrued income taxes	1,447	539
Payable in connection with construction in progress	861	2,974
Accrued product warranty	839	743
Advances from customers	757	946
Other tax payable	576	392
Accrued professional services	562	880
Current portion of operating lease liabilities	498	488
Other personnel-related costs	267	279
Accrual for sales returns	27	48
Other accrued liabilities	1,763	1,752
Accrued liabilities, Total	$ 14,581	$ 17,057