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]
Balance at Dec. 31, 2018	$ 27,323	$ 49	$ 41,023	$ (13,169)	$ (580)
Balance (in shares) at Dec. 31, 2018		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
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
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
Balance at Dec. 31, 2019	$ 34,893	$ 50	41,576	(6,153)	(580)
Balance (in shares) at Dec. 31, 2019	4,933,063	4,933,063
Net income	$ 183			183
Exercise of stock options	58		58
Exercise of stock options (in shares)		14,000
At-the-market stock sales, net of costs	3,254	$ 3	3,251
At-the-market stock sales, net of costs (in shares)		263,725
Stock-based compensation	10		10
Balance at Mar. 31, 2020	38,398	$ 53	44,895	(5,970)	(580)
Balance (in shares) at Mar. 31, 2020		5,210,788
Balance at Dec. 31, 2019	$ 34,893	$ 50	41,576	(6,153)	(580)
Balance (in shares) at Dec. 31, 2019	4,933,063	4,933,063
Net income	$ 438
Balance at Jun. 30, 2020	$ 38,695	$ 53	44,937	(5,715)	(580)
Balance (in shares) at Jun. 30, 2020	5,212,054	5,212,054
Balance at Mar. 31, 2020	$ 38,398	$ 53	44,895	(5,970)	(580)
Balance (in shares) at Mar. 31, 2020		5,210,788
Net income	255			255
Exercise of stock options	5		5
Exercise of stock options (in shares)		1,266
Stock-based compensation	37		37
Balance at Jun. 30, 2020	$ 38,695	$ 53	$ 44,937	$ (5,715)	$ (580)
Balance (in shares) at Jun. 30, 2020	5,212,054	5,212,054