LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Impaired Loans (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded	$ 8,468		$ 5,717
Unpaid Principal Balance, With related allowance recorded	1,291		623
Unpaid Principal Balance	9,759		6,340
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded	8,468		5,717
Recorded Investment, With related allowance recorded	1,291		623
Recorded Investment	9,759		6,340
Related Allowance [Abstract]
Related Allowance	345		134
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded	3,319		6,786
Average Recorded Investment, With related allowance recorded	421		1,953
Average Recorded Investment	3,740		8,739
Interest income	0	$ 0
Cash-based interest income	0	$ 0
Commercial and industrial
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded	684		437
Unpaid Principal Balance, With related allowance recorded	392		26
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded	684		437
Recorded Investment, With related allowance recorded	392		26
Related Allowance [Abstract]
Related Allowance	209		17
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded	331		434
Average Recorded Investment, With related allowance recorded	58		315
Construction and development
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded			0
Unpaid Principal Balance, With related allowance recorded			0
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded			0
Recorded Investment, With related allowance recorded			0
Related Allowance [Abstract]
Related Allowance			0
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded			311
Average Recorded Investment, With related allowance recorded			7
Commercial real estate
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded	6,024		3,979
Unpaid Principal Balance, With related allowance recorded	506		279
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded	6,024		3,979
Recorded Investment, With related allowance recorded	506		279
Related Allowance [Abstract]
Related Allowance	49		27
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded	2,196		4,230
Average Recorded Investment, With related allowance recorded	188		505
Farmland
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded	73		6
Unpaid Principal Balance, With related allowance recorded	149		157
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded	73		6
Recorded Investment, With related allowance recorded	149		157
Related Allowance [Abstract]
Related Allowance	78		85
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded	32		90
Average Recorded Investment, With related allowance recorded	75		131
1-4 family residential
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded	1,194		681
Unpaid Principal Balance, With related allowance recorded	244		161
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded	1,194		681
Recorded Investment, With related allowance recorded	244		161
Related Allowance [Abstract]
Related Allowance	9		5
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded	470		1,096
Average Recorded Investment, With related allowance recorded	48		754
Multi-family residential
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded	0		217
Unpaid Principal Balance, With related allowance recorded			0
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded	0		217
Recorded Investment, With related allowance recorded			0
Related Allowance [Abstract]
Related Allowance			0
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded	53		180
Average Recorded Investment, With related allowance recorded			19
Consumer
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded			0
Unpaid Principal Balance, With related allowance recorded			0
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded			0
Recorded Investment, With related allowance recorded			0
Related Allowance [Abstract]
Related Allowance			0
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded			61
Average Recorded Investment, With related allowance recorded			42
Agricultural
Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, With no related allowance recorded	493		397
Unpaid Principal Balance, With related allowance recorded	0		0
Recorded Investment [Abstract]
Recorded Investment, With no related allowance recorded	493		397
Recorded Investment, With related allowance recorded	0		0
Related Allowance [Abstract]
Related Allowance	0		0
Average Recorded Investment [Abstract]
Average Recorded Investment, With no related allowance recorded	237		384
Average Recorded Investment, With related allowance recorded	$ 52		$ 180