Condensed Consolidated Statements of Stockholder's Equity - Unaudited - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]
Balance at Dec. 31, 2017	$ 24,928	$ 47	$ 40,035	$ (14,609)	$ (580)	$ 35
Balance (in shares) at Dec. 31, 2017		4,692,893
Net income	193			193
Cumulative effect adjustment from adoption of ASU | ASU 2016-01 [Member]				35		(35)
Exercise of stock options	22		22
Exercise of stock options (in shares)		5,500
Stock-based compensation	7		7
Balance at Mar. 31, 2018	25,150	$ 47	40,064	(14,381)	(580)
Balance (in shares) at Mar. 31, 2018		4,698,393
Balance at Dec. 31, 2017	24,928	$ 47	40,035	(14,609)	(580)	$ 35
Balance (in shares) at Dec. 31, 2017		4,692,893
Net income	665
Balance at Jun. 30, 2018	25,600	$ 47	40,042	(13,909)	(580)
Balance (in shares) at Jun. 30, 2018		4,698,393
Balance at Mar. 31, 2018	25,150	$ 47	40,064	(14,381)	(580)
Balance (in shares) at Mar. 31, 2018		4,698,393
Net income	472			472
Stock-based compensation	6		6
Issuance costs for rights offering	(28)		(28)
Balance at Jun. 30, 2018	25,600	$ 47	40,042	(13,909)	(580)
Balance (in shares) at Jun. 30, 2018		4,698,393
Balance at Dec. 31, 2018	$ 27,323	$ 49	41,023	(13,169)	(580)
Balance (in shares) at Dec. 31, 2018	4,831,178	4,831,178
Net income	$ 582			582
Exercise of stock options	71		71
Exercise of stock options (in shares)		14,250
Stock-based compensation	6		6
Balance at Mar. 31, 2019	27,982	$ 49	41,100	(12,587)	(580)
Balance (in shares) at Mar. 31, 2019		4,845,428
Balance at Dec. 31, 2018	$ 27,323	$ 49	41,023	(13,169)	(580)
Balance (in shares) at Dec. 31, 2018	4,831,178	4,831,178
Net income	$ 1,521
Balance at Jun. 30, 2019	$ 29,124	$ 49	41,303	(11,648)	(580)
Balance (in shares) at Jun. 30, 2019	4,886,478	4,886,478
Balance at Mar. 31, 2019	$ 27,982	$ 49	41,100	(12,587)	(580)
Balance (in shares) at Mar. 31, 2019		4,845,428
Net income	939			939
Exercise of stock options	197		197
Exercise of stock options (in shares)		41,050
Stock-based compensation	6		6
Balance at Jun. 30, 2019	$ 29,124	$ 49	$ 41,303	$ (11,648)	$ (580)
Balance (in shares) at Jun. 30, 2019	4,886,478	4,886,478