Condensed Consolidated Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid - In Capital [Member]	Retained Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
BALANCE at beginning of year at Dec. 31, 2018	$ 69,606	$ 18	$ 133,859	$ (64,055)	$ (216)
Stock-based compensation expense	3,246	0	3,246	0	0
Issuance of shares for stock purchase plans and stock options	730	1	729	0	0
Cancellation of shares for payment of withholding tax	(754)	0	(754)	0	0
Dividends paid	(3,046)	0	(3,046)	0	0
Net income	1,952	0	0	1,952	0
Change in cumulative translation adjustment, net	(256)	0	0	0	(256)
BALANCE at end of year at Sep. 30, 2019	71,478	19	134,034	(62,103)	(472)
BALANCE at beginning of year at Jun. 30, 2019	70,129	18	133,753	(63,431)	(211)
Stock-based compensation expense	918	0	918	0	0
Issuance of shares for stock purchase plans and stock options	392	1	391	0	0
Cancellation of shares for payment of withholding tax	(11)	0	(11)	0	0
Dividends paid	(1,017)	0	(1,017)	0	0
Net income	1,328	0	0	1,328	0
Change in cumulative translation adjustment, net	(261)	0	0	0	(261)
BALANCE at end of year at Sep. 30, 2019	71,478	19	134,034	(62,103)	(472)
BALANCE at beginning of year at Dec. 31, 2019	73,350	19	133,954	(60,305)	(318)
Stock-based compensation expense	1,996	1	1,995	0	0
Issuance of shares for stock purchase plans and stock options	504	0	504	0	0
Cancellation of shares for payment of withholding tax	(1,108)	0	(1,108)	0	0
Repurchase of common stock	(2,000)	(1)	(1,999)	0	0
Dividends paid	(3,079)	0	(3,079)	0	0
Net income	1,546	0	0	1,546	0
Change in cumulative translation adjustment, net	132	0	0	0	132
BALANCE at end of year at Sep. 30, 2020	71,341	19	130,267	(58,759)	(186)
BALANCE at beginning of year at Jun. 30, 2020	70,679	19	130,853	(59,801)	(392)
Stock-based compensation expense	433	0	433	0	0
Issuance of shares for stock purchase plans and stock options	8	0	8	0	0
Cancellation of shares for payment of withholding tax	(2)	0	(2)	0	0
Dividends paid	(1,025)	0	(1,025)	0	0
Net income	1,042	0	0	1,042	0
Change in cumulative translation adjustment, net	206	0	0	0	206
BALANCE at end of year at Sep. 30, 2020	$ 71,341	$ 19	$ 130,267	$ (58,759)	$ (186)