LOANS - Past Due and Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	$ 308	$ 1,834
Nonaccrual Including 90 Days or More Past Due	2,808	6,955
Total Past Due and Nonaccrual	7,516	12,403
Current	3,261,256	3,085,850
Total Loans	3,268,772	3,098,253
30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	3,780	2,854
60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	620	760
Commercial Real Estate | Mortgage loans
Past Due and Nonaccrual Loans
Total Loans	1,373,556	1,293,906
Commercial Real Estate | Mortgage loans | Owner occupied
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	175
Nonaccrual Including 90 Days or More Past Due	253	2,205
Total Past Due and Nonaccrual	780	2,664
Current	509,618	469,985
Total Loans	510,398	472,649
Commercial Real Estate | Mortgage loans | Owner occupied | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	333	284
Commercial Real Estate | Mortgage loans | Owner occupied | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	194	0
Commercial Real Estate | Mortgage loans | Non-owner occupied
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	1,163
Nonaccrual Including 90 Days or More Past Due	885	0
Total Past Due and Nonaccrual	885	1,163
Current	862,273	820,094
Total Loans	863,158	821,257
Commercial Real Estate | Mortgage loans | Non-owner occupied | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	0	0
Multi-family | Mortgage loans
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	0
Nonaccrual Including 90 Days or More Past Due	0	0
Total Past Due and Nonaccrual	0	0
Current	585,827	595,280
Total Loans	585,827	595,280
Multi-family | Mortgage loans | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	0	0
Multi-family | Mortgage loans | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	0	0
Residential real estate mortgage loans | Mortgage loans
Past Due and Nonaccrual Loans
Total Loans	519,763	464,264
Residential real estate mortgage loans | Mortgage loans | Residential mortgage
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	0
Nonaccrual Including 90 Days or More Past Due	199	401
Total Past Due and Nonaccrual	1,321	2,873
Current	447,194	395,300
Total Loans	448,515	398,173
Residential real estate mortgage loans | Mortgage loans | Residential mortgage | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	892	2,074
Residential real estate mortgage loans | Mortgage loans | Residential mortgage | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	230	398
Residential real estate mortgage loans | Mortgage loans | Home equity
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	308	271
Nonaccrual Including 90 Days or More Past Due	624	161
Total Past Due and Nonaccrual	1,965	761
Current	69,283	65,330
Total Loans	71,248	66,091
Residential real estate mortgage loans | Mortgage loans | Home equity | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	1,033	329
Residential real estate mortgage loans | Mortgage loans | Home equity | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	0	0
Commercial, industrial and agricultural loans
Past Due and Nonaccrual Loans
Total Loans	645,724	616,003
Commercial, industrial and agricultural loans | Secured
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	225
Nonaccrual Including 90 Days or More Past Due	174	570
Total Past Due and Nonaccrual	700	949
Current	167,840	153,977
Total Loans	168,540	154,926
Commercial, industrial and agricultural loans | Secured | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	330	113
Commercial, industrial and agricultural loans | Secured | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	196	41
Commercial, industrial and agricultural loans | Unsecured
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	0
Nonaccrual Including 90 Days or More Past Due	621	3,618
Total Past Due and Nonaccrual	1,729	3,671
Current	475,455	457,406
Total Loans	477,184	461,077
Commercial, industrial and agricultural loans | Unsecured | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	1,108	18
Commercial, industrial and agricultural loans | Unsecured | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	0	35
Real estate construction and land loans
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	0
Nonaccrual Including 90 Days or More Past Due	0	0
Total Past Due and Nonaccrual	0	281
Current	123,393	107,478
Total Loans	123,393	107,759
Real estate construction and land loans | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	0	0
Real estate construction and land loans | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	0	281
Installment/consumer loans
Past Due and Nonaccrual Loans
>90 Days Past Due and Accruing	0	0
Nonaccrual Including 90 Days or More Past Due	52	0
Total Past Due and Nonaccrual	136	41
Current	20,373	21,000
Total Loans	20,509	21,041
Installment/consumer loans | 30-59 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	84	36
Installment/consumer loans | 60-89 Days Past Due
Past Due and Nonaccrual Loans
Total Past Due and Nonaccrual	$ 0	$ 5