FAIR VALUE - Summary of assets measured at fair value on Non recurring basis (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Summary of assets measured on a recurring and nonrecurring basis
Other real estate owned	$ 658,000		$ 658,000
Impaired loans	9,768,000		11,437,000
Other real estate owned, gross			2,400,000
Other real estate owned valuation allowance			1,700,000
Impaired loans carrying value	4,138,000		4,412,000
Allowance for loans	8,242,000		7,875,000
Provision for loan losses	400,000	$ 200,000
Bank charged off	0		200,000
Level 3
Summary of assets measured on a recurring and nonrecurring basis
Impaired loans carrying value	4,100,000		4,400,000
Allowance for loans	700,000		800,000
Provision for loan losses	700,000		800,000
Commercial properties
Summary of assets measured on a recurring and nonrecurring basis
Other real estate owned	700,000
Commercial properties | Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Other real estate owned	658,000		658,000
Commercial properties | Level 3 | Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Other real estate owned	658,000		658,000
Commercial and Industrial | Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Impaired loans	3,455,000		3,579,000
Commercial and Industrial | Level 3 | Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Impaired loans	$ 3,455,000		$ 3,579,000