LOANS AND ALLOWANCE FOR CREDIT LOSSES - Summary of Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 6,212	$ 21,403
Current	2,527,942	2,541,482
Total loans	2,534,154	2,562,885
Past Due More Than 90 days and Accruing	620	267
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,148	12,307
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,149	4,263
90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,915	4,833
Total commercial real estate
Financing Receivable, Past Due [Line Items]
Total loans		1,084,381
Total commercial and industrial
Financing Receivable, Past Due [Line Items]
Total loans		441,069
Commercial construction \| Total commercial loans
Financing Receivable, Past Due [Line Items]
Total Past Due		75
Current	152,700	117,807
Total loans	152,700	117,882
Commercial construction \| Total commercial loans \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due		74
Commercial construction \| Total commercial loans \| 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due		1
Commercial real estate owner occupied \| Total commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	637	2,211
Current	253,155	217,006
Total loans	253,792	219,217
Past Due More Than 90 days and Accruing	366
Commercial real estate owner occupied \| Total commercial real estate \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due		1,309
Commercial real estate owner occupied \| Total commercial real estate \| 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	10	464
Commercial real estate owner occupied \| Total commercial real estate \| 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	627	438
Commercial real estate non-owner occupied \| Total commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	431	1,801
Current	732,922	714,975
Total loans	733,353	716,776
Commercial real estate non-owner occupied \| Total commercial real estate \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	314	503
Commercial real estate non-owner occupied \| Total commercial real estate \| 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due		674
Commercial real estate non-owner occupied \| Total commercial real estate \| 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	117	624
Tax exempt
Financing Receivable, Past Due [Line Items]
Current	42,448	47,862
Total loans	42,448	47,862
Commercial and industrial \| Total commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	392	354
Current	336,597	355,330
Total loans	336,989	355,684
Past Due More Than 90 days and Accruing	149
Commercial and industrial \| Total commercial and industrial \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	44	161
Commercial and industrial \| Total commercial and industrial \| 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	35
Commercial and industrial \| Total commercial and industrial \| 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	313	193
Residential mortgages \| Total residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	4,217	14,889
Current	913,084	980,327
Total loans	917,301	995,216
Past Due More Than 90 days and Accruing	105
Residential mortgages \| Total residential real estate \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	414	9,178
Residential mortgages \| Total residential real estate \| 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,007	2,511
Residential mortgages \| Total residential real estate \| 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	2,796	3,200
Home equity
Financing Receivable, Past Due [Line Items]
Total Past Due	501	2,051
Current	87,501	98,045
Total loans	88,002	100,096
Past Due More Than 90 days and Accruing		267
Home equity \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	344	1,062
Home equity \| 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	95	614
Home equity \| 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	62	375
Consumer other \| Total consumer
Financing Receivable, Past Due [Line Items]
Total Past Due	34	22
Current	9,535	10,130
Total loans	9,569	10,152
Consumer other \| Total consumer \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	32	20
Consumer other \| Total consumer \| 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 2
Consumer other \| Total consumer \| 90 Days or Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due		$ 2