STOCK OPTIONS - Stock option activity (Details) - 2008 Stock Option Plan - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Shares
Outstanding at beginning of period	147,150	173,050	199,450
Exercised		(11,200)	(25,400)
Forfeited		(14,700)	(1,000)
Outstanding at end of period	147,150	147,150	173,050
Exercisable at end of period	147,150	147,150	173,050
Weighted Average Exercise Price (in $ per share)
Outstanding at beginning of period (in dollars per share)	$ 2.06	$ 2.06	$ 2.05
Exercised		1.23	1.91
Forfeited		2.75	2.75
Outstanding at end of period (in dollars per share)	2.06	2.06	2.06
Exercisable at end of period	$ 2.06	$ 2.06	$ 2.06