LOANS AND ALLOWANCE FOR LOAN AND LEASE LOSSES - NON-PERFORMING LOANS (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Non-performing loans and non-performing assets disclosures
Loans on nonaccrual status	$ 14,849	$ 14,118
Loans past due 90 days or more and still on accrual	1,279	956
Total nonperforming loans	16,128	15,074
Other real estate owned	160	115
Total nonperforming assets	$ 16,288	$ 15,189
Credit Quality Ratios - Total Company:
Nonperforming loans to total loans (as percent)	0.40%	0.38%
Nonperforming assets to total loans (including OREO) (as percent)	0.40%	0.38%
Nonperforming assets to total assets (as percent)	0.32%	0.30%
Core Banking Activities
Non-performing loans and non-performing assets disclosures
Loans on nonaccrual status	$ 14,849	$ 14,118
Loans past due 90 days or more and still on accrual	$ 27	$ 19
Credit Quality Ratios - Total Company:
Nonperforming loans to total loans (as percent)	0.37%	0.36%
Nonperforming assets to total loans (including OREO) (as percent)	0.38%	0.36%
Nonperforming assets to total assets (as percent)	0.31%	0.28%