FAIR VALUE - Gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	$ 41,090	$ 62,294
Less than 12 months Unrealized Loss	492	1,155
12 months or more Fair Value	15,156	10,589
12 months or more Unrealized Loss	411	293
Total Fair Value	56,246	72,883
Total Unrealized Loss	903	1,448
US Treasury
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	499
Less than 12 months Unrealized Loss	1
Total Fair Value	499
Total Unrealized Loss	1
Agency
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	1,992
Less than 12 months Unrealized Loss	7
12 months or more Fair Value	848	986
12 months or more Unrealized Loss	12	16
Total Fair Value	2,840	986
Total Unrealized Loss	19	16
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	5,133	19,200
Less than 12 months Unrealized Loss	62	580
12 months or more Fair Value	4,862
12 months or more Unrealized Loss	167
Total Fair Value	9,995	19,200
Total Unrealized Loss	229	580
Mortgage-backed
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	33,466	43,094
Less than 12 months Unrealized Loss	422	575
12 months or more Fair Value	9,446	9,603
12 months or more Unrealized Loss	232	277
Total Fair Value	42,912	52,697
Total Unrealized Loss	$ 654	$ 852