SECURITIES - Securities Held to Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Amortized cost and estimated fair value of securities held to maturity [Abstract]
Amortized Cost	$ 3,640	$ 3,781
Unrealized Gains	0	0
Unrealized Losses	13	5
Securities held to maturity	3,627	3,776
Amortized Cost [Abstract]
Within one year	900
After one, but within five years	2,507
After five, but within ten years	233
After ten years	0
Total	3,640
Fair Value [Abstract]
Within one year	899
After one, but within five years	2,495
After five, but within ten years	233
After ten years	0
Total	3,627
Obligations of states and political subdivisions
Amortized cost and estimated fair value of securities held to maturity [Abstract]
Amortized Cost	1,805	1,946
Unrealized Gains	0	0
Unrealized Losses	0	0
Securities held to maturity	1,805	1,946
Time deposits with other financial institutions
Amortized cost and estimated fair value of securities held to maturity [Abstract]
Amortized Cost	1,835	1,835
Unrealized Gains	0	0
Unrealized Losses	13	5
Securities held to maturity	$ 1,822	$ 1,830