EARNINGS PER SHARE - Basic earnings per share of common stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Basic and diluted earnings per share:
Net income (loss)	$ 480	$ (96)	$ 1,074	$ 174
Weighted average common shares outstanding, basic	2,847,191	2,832,974	2,845,493	2,831,174
Weighted average common shares outstanding, diluted	2,847,191	2,832,974	2,845,493	2,831,174
Basic net income (loss) per share (in dollars per share)	$ 0.17	$ (0.03)	$ 0.38	$ 0.06
Diluted net income (loss) per share (in dollars per share)	$ 0.17	$ (0.03)	$ 0.38	$ 0.06
Options outstanding	0	0	0	0