Accrued Liabilities (Details) - Warranty reserve - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Product Warranty Liability [Line Items]
Balance at beginning of year	$ 438,000	$ 430,000
Provisions	115,000	149,000
Deductions	(173,000)	(141,000)
Balance at end of year	$ 380,000	$ 438,000