7. Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Common Stock
Beginning balance, shares	13,883,937	13,882,937	13,844,584	13,844,584	13,882,937	13,844,584
Beginning balance, amount	$ 8,330	$ 8,330	$ 8,307	$ 8,307	$ 8,330	$ 8,307
Restricted stock units issued, shares	38,353		38,353
Restricted stock units issued, amount	$ 23		$ 23
Stock options exercised and issued, shares		1,000
Ending balance, shares	13,922,290	13,883,937	13,882,937	13,844,584	13,922,290	13,882,937
Ending balance, amount	$ 8,353	$ 8,330	$ 8,330	$ 8,307	$ 8,353	$ 8,330
Additional Paid In Capital
Beginning balance, amount	25,941	25,867	25,697	25,642	25,867	25,642
Restricted stock units issued, amount	(23)		(23)
Stock options exercised and issued, amount		2
Share-based compensation expense	37	31	17	21
Restricted stock unit compensation expense	33	41	39	34
Ending balance, amount	25,988	25,941	25,730	25,697	25,988	25,730
Accumulated Deficit
Beginning balance, amount	(3,965)	(2,393)	(1,846)	(5,450)	(2,393)	(5,450)
Dividends declared ($0.02 per share)	(255)	(254)	(271)	(271)
Net (loss) income	(247)	(1,318)	947	(443)
Effect of adoption of ASU 2016-01				4,318
Ending balance, amount	(4,467)	(3,965)	(1,171)	(1,846)	(4,467)	(1,171)
Accumulated Other Comprehensive Income
Beginning balance, amount	0	0	0	4,318	0	4,318
Effect of adoption of ASU 2016-01				(4,318)
Ending balance, amount	0	0	0	0	0	0
Treasury Stock
Beginning balance, amount	(4,429)	(4,092)	(1,167)	(810)	(4,092)	(810)
Repurchase of common stock	(213)	(337)	(259)	(357)
Ending balance, amount	(4,642)	(4,429)	(1,426)	(1,167)	(4,642)	(1,426)
Beginning balance, amount	25,877	27,712	30,991	32,007	$ 27,712	32,007
Restricted stock units issued, amount	0		0
Stock options exercised and issued, shares					1,000
Stock options exercised and issued, amount		2
Share-based compensation expense	37	31	17	21
Restricted stock unit compensation expense	33	41	39	34	$ 74	73
Dividends declared ($0.02 per share)	(255)	(254)	(271)	(271)
Net (loss) income	(247)	(1,318)	947	(443)	(1,565)	503
Effect of adoption of ASU 2016-01			0	0
Repurchase of common stock	(213)	(337)	(259)	(357)	(550)	(616)
Ending balance, amount	$ 25,232	$ 25,877	$ 31,463	$ 30,991	$ 25,232	$ 31,463