LOAN PERFORMANCE - Nonaccrual loans, segregated by loan class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Nonaccrual loans
Nonaccrual loans	$ 5,769	$ 7,646
Commercial and industrial
Nonaccrual loans
Nonaccrual loans	2,533	3,280
Commercial real estate
Nonaccrual loans
Nonaccrual loans	2,217	3,216
Construction and development
Nonaccrual loans
Nonaccrual loans	233	252
1-4 family residential
Nonaccrual loans
Nonaccrual loans	765	$ 898
Consumer
Nonaccrual loans
Nonaccrual loans	$ 21