ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Aging Of The Amortized Cost In Past Due Loans (Details) $ in Thousands	Mar. 31, 2021 USD ($)
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	$ 4,473,876
Total Accruing	4,462,924
Total Nonaccrual	11,707
Nonaccrual With No Allowance For Credit Loss	4,534
Total	4,474,631
Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	737
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	18
Commercial and industrial loans | Working capital lines of credit loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	574,696
Total Accruing	574,096
Total Nonaccrual	600
Nonaccrual With No Allowance For Credit Loss	173
Total	574,696
Commercial and industrial loans | Working capital lines of credit loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Commercial and industrial loans | Working capital lines of credit loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Commercial and industrial loans | Non-working capital loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	1,093,471
Total Accruing	1,088,338
Total Nonaccrual	5,133
Nonaccrual With No Allowance For Credit Loss	610
Total	1,093,471
Commercial and industrial loans | Non-working capital loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Commercial and industrial loans | Non-working capital loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Commercial real estate and multi-family residential loans | Construction and land development loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	369,633
Total Accruing	369,633
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	369,633
Commercial real estate and multi-family residential loans | Construction and land development loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Commercial real estate and multi-family residential loans | Construction and land development loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Commercial real estate and multi-family residential loans | Owner occupied loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	668,934
Total Accruing	663,855
Total Nonaccrual	5,079
Nonaccrual With No Allowance For Credit Loss	3,396
Total	668,934
Commercial real estate and multi-family residential loans | Owner occupied loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Commercial real estate and multi-family residential loans | Owner occupied loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Commercial real estate and multi-family residential loans | Nonowner Occupied Loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	605,036
Total Accruing	605,036
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	605,036
Commercial real estate and multi-family residential loans | Nonowner Occupied Loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Commercial real estate and multi-family residential loans | Nonowner Occupied Loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Commercial real estate and multi-family residential loans | Multifamily Loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	300,996
Total Accruing	300,996
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	300,996
Commercial real estate and multi-family residential loans | Multifamily Loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Commercial real estate and multi-family residential loans | Multifamily Loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Agri-business and agricultural loans | Loans Secured By Farmland
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	154,786
Total Accruing	154,358
Total Nonaccrual	428
Nonaccrual With No Allowance For Credit Loss	283
Total	154,786
Agri-business and agricultural loans | Loans Secured By Farmland | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Agri-business and agricultural loans | Loans Secured By Farmland | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Agri-business and agricultural loans | Loans For Agricultural Production
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	192,412
Total Accruing	192,412
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	192,412
Agri-business and agricultural loans | Loans For Agricultural Production | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Agri-business and agricultural loans | Loans For Agricultural Production | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Agri-business and agricultural loans | Other commercial loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	86,379
Total Accruing	86,379
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	86,379
Agri-business and agricultural loans | Other commercial loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Agri-business and agricultural loans | Other commercial loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Consumer 1-4 family loans | Closed end first mortgage loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	160,677
Total Accruing	160,773
Total Nonaccrual	467
Nonaccrual With No Allowance For Credit Loss	72
Total	161,240
Consumer 1-4 family loans | Closed end first mortgage loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	545
Consumer 1-4 family loans | Closed end first mortgage loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	18
Consumer 1-4 family loans | Open end and junior lien loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	158,924
Total Accruing	159,034
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	159,034
Consumer 1-4 family loans | Open end and junior lien loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	110
Consumer 1-4 family loans | Open end and junior lien loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Consumer 1-4 family loans | Residential construction loans
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	9,179
Total Accruing	9,179
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	9,179
Consumer 1-4 family loans | Residential construction loans | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	0
Consumer 1-4 family loans | Residential construction loans | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	0
Consumer 1-4 family loans | Other Consumer Loans [Member]
Financing Receivable, Amortized Cost, Aging [Abstract]
Loans Not past Due	98,753
Total Accruing	98,835
Total Nonaccrual	0
Nonaccrual With No Allowance For Credit Loss	0
Total	98,835
Consumer 1-4 family loans | Other Consumer Loans [Member] | Financial Asset, 30 to 89 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
30-89 Days Past Due	82
Consumer 1-4 family loans | Other Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable, Amortized Cost, Aging [Abstract]
Greater than 89 days Past Due and Accruing	$ 0