SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts
Schedule of Valuation and Qualifying Accounts [Roll Forward]
Balance at Beginning of Year	$ 708	$ 770
Additions Charged to Costs and Expenses	208	82
Additions Charged to other Accounts	0	0
Deductions	(99)	(144)
Balance at End of Year	817	708
Allowance for obsolete inventories
Schedule of Valuation and Qualifying Accounts [Roll Forward]
Balance at Beginning of Year	874	524
Additions Charged to Costs and Expenses	506	986
Additions Charged to other Accounts	0	0
Deductions	(909)	(636)
Balance at End of Year	471	874
Valuation allowance for deferred tax assets
Schedule of Valuation and Qualifying Accounts [Roll Forward]
Balance at Beginning of Year	12,375	12,793
Additions Charged to Costs and Expenses	(442)	(418)
Additions Charged to other Accounts	0	0
Deductions	0	0
Balance at End of Year	11,933	12,375
Reserve for sales returns
Schedule of Valuation and Qualifying Accounts [Roll Forward]
Balance at Beginning of Year	68	76
Additions Charged to Costs and Expenses	1,033	1,068
Additions Charged to other Accounts	0	0
Deductions	(1,030)	(1,076)
Balance at End of Year	$ 71	$ 68