LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES - Impaired Financing Receivables (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves	$ 438,000	$ 1,671,000
Unpaid Principal Balance with specific reserves	438,000	1,699,000
Interest Income Recognized with specific reserves	11,000	5,000
Specific Reserve with specific reserves	282,000	782,000
Recorded Investment	486,000	1,740,000
Recorded Investment with no specific reserve	2,688,000	2,643,000
Unpaid Principal Balance with no specific reserve	3,424,000	3,411,000
Interest Income Recognized with no specific reserve	38,000	50,000
Specific Reserve	223,000
Average Recorded Investment with no specific reserve	3,589,000	3,528,000
Consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves	231,000	160,000
Unpaid Principal Balance with specific reserves	231,000	160,000
Interest Income Recognized with specific reserves	5,000	5,000
Specific Reserve with specific reserves	74,000	52,000
Recorded Investment	274,000	205,000
Recorded Investment with no specific reserve	104,000	49,000
Unpaid Principal Balance with no specific reserve	104,000	49,000
Interest Income Recognized with no specific reserve	1,000
Average Recorded Investment with no specific reserve	50,000
Indirect
Financing Receivable, Impaired [Line Items]
Recorded Investment with no specific reserve	108,000	88,000
Unpaid Principal Balance with no specific reserve	108,000	88,000
Specific Reserve	282,000
Commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves	208,000	217,000
Unpaid Principal Balance with specific reserves	208,000	217,000
Interest Income Recognized with specific reserves	6,000
Specific Reserve with specific reserves	208,000	217,000
Recorded Investment	212,000	223,000
Recorded Investment with no specific reserve		2,000
Unpaid Principal Balance with no specific reserve		2,000
Specific Reserve	208,000
Average Recorded Investment with no specific reserve		2,000
Construction
Financing Receivable, Impaired [Line Items]
Recorded Investment with no specific reserve	228,000	318,000
Unpaid Principal Balance with no specific reserve	228,000	318,000
Average Recorded Investment with no specific reserve	236,000	322,000
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Recorded Investment with no specific reserve	1,158,000	1,194,000
Unpaid Principal Balance with no specific reserve	1,468,000	1,194,000
Interest Income Recognized with no specific reserve	27,000	39,000
Average Recorded Investment with no specific reserve	1,643,000	1,632,000
Residential Real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves		1,294,000
Unpaid Principal Balance with specific reserves		1,322,000
Specific Reserve with specific reserves		513,000
Recorded Investment		1,312,000
Recorded Investment with no specific reserve	1,090,000	992,000
Unpaid Principal Balance with no specific reserve	1,516,000	1,760,000
Interest Income Recognized with no specific reserve	10,000	11,000
Average Recorded Investment with no specific reserve	$ 1,660,000	$ 1,572,000