7. Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Common Stock
Beginning balance, shares	13,962,366	13,929,381
Beginning balance, amount	$ 8,377	$ 8,357
Common stock issued under restricted stock units, shares	24,505
Common stock issued under restricted stock units, amount	$ 15
Ending balance, shares	13,986,871	13,929,381
Ending balance, amount	$ 8,392	$ 8,357
Additional Paid-in Capital
Beginning balance, amount	26,346	26,095
Common stock issued under restricted stock units, amount	(15)
Share-based compensation expense-stock options	32	30
Share-based compensation expense-restricted stock units	103	21
Dividends declared ($0.02 per share)
Net loss
Ending balance, amount	26,466	26,146
Accumulated Deficit
Beginning balance, amount	(6,797)	(6,043)
Share-based compensation expense-stock options
Share-based compensation expense-restricted stock units
Dividends declared ($0.02 per share)	(251)	(250)
Net loss	(694)	(1,192)
Ending balance, amount	(7,742)	(7,485)
Treasury Stock
Beginning balance, amount	(5,402)	(5,133)
Share-based compensation expense-stock options
Share-based compensation expense-restricted stock units
Dividends declared ($0.02 per share)
Net loss
Repurchase of common stock		(243)
Ending balance, amount	(5,402)	(5,376)
Beginning balance, amount	22,524	23,276
Share-based compensation expense-stock options	32	30
Share-based compensation expense-restricted stock units	103	21
Dividends declared ($0.02 per share)	(251)	(250)
Net loss	(694)	(1,192)
Repurchase of common stock	0	(243)
Ending balance, amount	$ 21,714	$ 21,642