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, 2017	$ 83,319	$ 18	$ 134,505	$ (51,258)	$ 54
Stock-based compensation expense	668	0	668	0	0
Issuance of shares for stock purchase plans	364	0	364	0	0
Cancellation of shares for payment of withholding tax	(289)	0	(289)	0	0
Dividends paid	(995)	0	(995)	0	0
Net loss	(858)	0	0	(858)	0
Change in cumulative translation adjustment, net	244	0	0	0	244
BALANCE at end of year at Mar. 31, 2018	82,545	18	134,253	(52,024)	298
Cumulative-effect adjustment resulting from adoption of ASU 2016-16 at Dec. 31, 2017	92			92
BALANCE at beginning of year, as adjusted at Dec. 31, 2017	83,411	18	134,505	(51,166)	54
BALANCE at beginning of year at Dec. 31, 2018	69,606	18	133,859	(64,055)	(216)
Stock-based compensation expense	882	0	882	0	0
Issuance of shares for stock purchase plans	338	0	338	0	0
Cancellation of shares for payment of withholding tax	(743)	0	(743)	0	0
Dividends paid	(1,016)	0	(1,016)	0	0
Net loss	(317)	0	0	(317)	0
Change in cumulative translation adjustment, net	153	0	0	0	153
BALANCE at end of year at Mar. 31, 2019	$ 68,903	$ 18	$ 133,320	$ (64,372)	$ (63)