EARNINGS PER SHARE - Earnings per Share (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ 1,878,703	$ 1,551,671	$ 1,394,170	$ 1,474,767	$ 3,430,374	$ 2,868,937
Less dividends:
Common stock	1,870,754	1,870,416	1,776,575	1,658,136	3,741,170	3,434,711
Preferred stock	3,750	$ 3,750	3,792	$ 480,472	7,500	484,264
Deemed dividend on preferred stock related to redemption	0		0		0	3,093,028
Dividends	1,874,504		1,780,367		3,748,670	7,012,003
Undistributed earnings (deficit)	$ 4,199		$ (386,197)		$ (318,296)	$ (4,143,066)
Common Stock
Less dividends:
Distributed earnings (in dollars per share)	$ 0.08		$ 0.07		$ 0.15	$ 0.14
Undistributed earnings (deficit) (in dollars per share)	0		(0.01)		(0.01)	(0.17)
Total (in dollars per share)	0.08		0.06		0.14	(0.03)
Unvested Share-Based Payment Awards
Less dividends:
Distributed earnings (in dollars per share)	0.08		0.07		0.15	0.14
Undistributed earnings (deficit) (in dollars per share)	0		0		0	0
Total (in dollars per share)	$ 0.08		$ 0.07		$ 0.15	$ 0.14