CREDIT QUALITY ASSESSMENT - Credit Quality of Loan Portfolio by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Total loans	$ 11,366,989	$ 11,396,706
Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	11,275,142	11,357,347
Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	91,485	34,782
Loans greater than 90 days past due	362	1,002
Restructured loans	0	3,575
Total loans	91,847	39,359
Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	11,248,749	11,312,130
30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	23,732	32,576
60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	2,661	12,641
Commercial Investor R/E
Financing Receivable, Past Due [Line Items]
Total loans	5,104,425	5,130,094
Commercial Owner- Occupied R/E
Financing Receivable, Past Due [Line Items]
Total loans	1,755,235	1,775,037
Commercial AD&C
Financing Receivable, Past Due [Line Items]
Total loans	988,967	1,090,028
Residential Mortgage
Financing Receivable, Past Due [Line Items]
Total loans	1,474,521	1,287,933
Residential Construction
Financing Receivable, Past Due [Line Items]
Total loans	121,419	224,772
Commercial Real Estate | Commercial Investor R/E
Financing Receivable, Past Due [Line Items]
Total loans	5,104,425	5,130,094
Commercial Real Estate | Commercial Investor R/E | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	5,045,767	5,120,151
Commercial Real Estate | Commercial Investor R/E | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	58,658	9,943
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	58,658	9,943
Commercial Real Estate | Commercial Investor R/E | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	5,044,647	5,104,204
Commercial Real Estate | Commercial Investor R/E | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,120	9,735
Commercial Real Estate | Commercial Investor R/E | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	0	6,212
Commercial Real Estate | Commercial Owner- Occupied R/E
Financing Receivable, Past Due [Line Items]
Total loans	1,755,235	1,775,037
Commercial Real Estate | Commercial Owner- Occupied R/E | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,750,595	1,768,882
Commercial Real Estate | Commercial Owner- Occupied R/E | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	4,640	5,019
Loans greater than 90 days past due	0	0
Restructured loans	0	1,136
Total loans	4,640	6,155
Commercial Real Estate | Commercial Owner- Occupied R/E | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,748,449	1,767,875
Commercial Real Estate | Commercial Owner- Occupied R/E | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	2,056	1,007
Commercial Real Estate | Commercial Owner- Occupied R/E | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	90	0
Commercial Real Estate | Commercial AD&C
Financing Receivable, Past Due [Line Items]
Total loans	988,967	1,090,028
Commercial Real Estate | Commercial AD&C | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	987,708	1,090,028
Commercial Real Estate | Commercial AD&C | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	1,259	0
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	1,259	0
Commercial Real Estate | Commercial AD&C | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	986,859	1,090,028
Commercial Real Estate | Commercial AD&C | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	849	0
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	9,353,507	9,451,044
Commercial Business | Commercial Business
Financing Receivable, Past Due [Line Items]
Total loans	1,504,880	1,455,885
Commercial Business | Commercial Business | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,494,809	1,446,609
Commercial Business | Commercial Business | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	10,051	7,322
Loans greater than 90 days past due	20	1,002
Restructured loans	0	952
Total loans	10,071	9,276
Commercial Business | Commercial Business | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,494,426	1,443,012
Commercial Business | Commercial Business | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	383	3,556
Commercial Business | Commercial Business | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	0	41
Residential Real Estate | Residential Mortgage
Financing Receivable, Past Due [Line Items]
Total loans	1,474,521	1,287,933
Residential Real Estate | Residential Mortgage | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,461,847	1,279,007
Residential Real Estate | Residential Mortgage | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	12,332	7,439
Loans greater than 90 days past due	342	0
Restructured loans	0	1,487
Total loans	12,674	8,926
Residential Real Estate | Residential Mortgage | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	1,445,785	1,261,878
Residential Real Estate | Residential Mortgage | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	14,026	11,307
Residential Real Estate | Residential Mortgage | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	2,036	5,822
Residential Real Estate | Residential Construction
Financing Receivable, Past Due [Line Items]
Total loans	121,419	224,772
Residential Real Estate | Residential Construction | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	120,976	224,772
Residential Real Estate | Residential Construction | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	443	0
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	443	0
Residential Real Estate | Residential Construction | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	118,976	222,144
Residential Real Estate | Residential Construction | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	2,000	2,628
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	417,542	432,957
Consumer | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	413,440	427,898
Consumer | Non-performing loans:
Financing Receivable, Past Due [Line Items]
Non-accrual loans	4,102	5,059
Loans greater than 90 days past due	0	0
Restructured loans	0	0
Total loans	4,102	5,059
Consumer | Current | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	409,607	422,989
Consumer | 30-59 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	3,298	4,343
Consumer | 60-89 days | Performing loans:
Financing Receivable, Past Due [Line Items]
Total loans	$ 535	$ 566