NET DEFERRED TAX ASSET AND INCOME TAXES - Components of net deferred tax assets (Details) - Components of net deferred tax assets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Allowance for loan losses	$ 1,916	$ 1,499
Interest on non-performing loans	233	210
Accrued deferred compensation	334	248
Post-retirement benefits	11	11
Other real estate owned write-downs		6
Restricted stock awards	162	77
Mark-to-market purchase accounting adjustments		122
Net unrealized holding loss on available-for-sale securities	58
Write-down of securities	4	154
Other	282	51
Gross deferred tax assets	3,000	2,378
Deferred loan costs, net	(344)	(312)
Mark-to-market purchase accounting adjustments	(37)
Goodwill and core deposit intangible asset	(545)	(534)
Accelerated depreciation	(698)	(752)
Other real estate owned write-downs	(45)
Mortgage servicing rights	(55)	(56)
Net unrealized holding gain on available-for-sale securities		(47)
Gross deferred tax liabilities	(1,724)	(1,701)
Net deferred tax asset	$ 1,276	$ 677