CREDIT QUALITY ASSESSMENT - Credit Quality of Loan Portfolio by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Total loans	$ 11,396,706	$ 9,967,091
Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	11,357,347	9,918,281
Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	34,782	46,086
Loans greater than 90 days past due	1,002	557
Restructured loans	3,575	2,167
Total loans	39,359	48,810
Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	11,312,130	9,901,309
30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	32,576	12,475
60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	12,641	4,497
Commercial investor real estate
Financing Receivable, Past Due [Line Items]
Total loans	5,130,094	4,141,346
Commercial owner-occupied real estate
Financing Receivable, Past Due [Line Items]
Total loans	1,775,037	1,690,881
Commercial AD&C
Financing Receivable, Past Due [Line Items]
Total loans	1,090,028	1,088,094
Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans	1,287,933	937,570
Residential construction
Financing Receivable, Past Due [Line Items]
Total loans	224,772	197,652
Commercial real estate: | Commercial investor real estate
Financing Receivable, Past Due [Line Items]
Total loans	5,130,094	4,141,346
Commercial real estate: | Commercial investor real estate | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	5,120,151	4,128,857
Commercial real estate: | Commercial investor real estate | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	9,943	12,489
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	9,943	12,489
Commercial real estate: | Commercial investor real estate | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	5,104,204	4,127,009
Commercial real estate: | Commercial investor real estate | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	9,735	1,656
Commercial real estate: | Commercial investor real estate | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	6,212	192
Commercial real estate: | Commercial owner-occupied real estate
Financing Receivable, Past Due [Line Items]
Total loans	1,775,037	1,690,881
Commercial real estate: | Commercial owner-occupied real estate | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,768,882	1,681,575
Commercial real estate: | Commercial owner-occupied real estate | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	5,019	9,306
Loans greater than 90 days past due	0	0
Restructured loans	1,136	0
Total loans	6,155	9,306
Commercial real estate: | Commercial owner-occupied real estate | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,767,875	1,680,635
Commercial real estate: | Commercial owner-occupied real estate | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,007	86
Commercial real estate: | Commercial owner-occupied real estate | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	0	854
Commercial real estate: | Commercial AD&C
Financing Receivable, Past Due [Line Items]
Total loans	1,090,028	1,088,094
Commercial real estate: | Commercial AD&C | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,090,028	1,087,444
Commercial real estate: | Commercial AD&C | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	0	650
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	0	650
Commercial real estate: | Commercial AD&C | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,090,028	1,085,642
Commercial real estate: | Commercial AD&C | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	0	1,802
Commercial real estate: | Commercial AD&C | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	0	0
Commercial Business
Financing Receivable, Past Due [Line Items]
Total loans	9,451,044	8,402,155
Commercial Business | Commercial business
Financing Receivable, Past Due [Line Items]
Total loans	1,455,885	1,481,834
Commercial Business | Commercial business | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,446,609	1,472,801
Commercial Business | Commercial business | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	7,322	8,420
Loans greater than 90 days past due	1,002	0
Restructured loans	952	613
Total loans	9,276	9,033
Commercial Business | Commercial business | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,443,012	1,471,669
Commercial Business | Commercial business | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	3,556	753
Commercial Business | Commercial business | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	41	379
Residential real estate: | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans	1,287,933	937,570
Residential real estate: | Residential mortgage | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,279,007	927,018
Residential real estate: | Residential mortgage | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	7,439	8,441
Loans greater than 90 days past due	0	557
Restructured loans	1,487	1,554
Total loans	8,926	10,552
Residential real estate: | Residential mortgage | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,261,878	919,199
Residential real estate: | Residential mortgage | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	11,307	5,157
Residential real estate: | Residential mortgage | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	5,822	2,662
Residential real estate: | Residential construction
Financing Receivable, Past Due [Line Items]
Total loans	224,772	197,652
Residential real estate: | Residential construction | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	224,772	197,597
Residential real estate: | Residential construction | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	0	55
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	0	55
Residential real estate: | Residential construction | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	222,144	197,597
Residential real estate: | Residential construction | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	2,628	0
Residential real estate: | Residential construction | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	0	0
Consumer
Financing Receivable, Past Due [Line Items]
Total loans	432,957	429,714
Consumer | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	427,898	422,989
Consumer | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	5,059	6,725
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	5,059	6,725
Consumer | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	422,989	419,558
Consumer | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	4,343	3,021
Consumer | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	$ 566	$ 410