ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment
Total ending loans balance	$ 4,085,738	$ 4,065,828
Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	104,163	112,166
Commercial and Industrial Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	1,428,646	1,426,826
Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	730,848	709,983
Commercial and Industrial Loans [Member] | Non-working Capital Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	697,798	716,843
Commercial Real Estate and Multi-family Residential Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	1,758,212	1,670,840
Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	333,699	286,534
Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	571,738	573,359
Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans
Financing Receivable, Recorded Investment
Total ending loans balance	583,709	570,687
Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans
Financing Receivable, Recorded Investment
Total ending loans balance	269,066	240,260
Commercial Real Estate and Multi-family Residential Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance		573,359
Agri-business and Agricultural Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	329,497	379,631
Agri-business and Agricultural Loans [Member] | Loans Secured By Farmland
Financing Receivable, Recorded Investment
Total ending loans balance	145,554	174,389
Agri-business and Agricultural Loans [Member] | Loans For Agricultural Production
Financing Receivable, Recorded Investment
Total ending loans balance	183,943	205,242
Agri-business and Agricultural Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	104,163	112,166
Consumer 1-4 Family Mortgage Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	368,361	377,999
Consumer 1-4 Family Mortgage Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	96,859	98,366
Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	173,075	176,873
Consumer 1-4 Family Mortgage Loans [Member] | Open End And Junior Lien Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	183,180	188,204
Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	12,106	12,922
Pass
Financing Receivable, Recorded Investment
Total ending loans balance	3,516,048	3,490,863
Pass | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	651,403	631,728
Pass | Commercial and Industrial Loans [Member] | Non-working Capital Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	653,230	673,370
Pass | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	333,699	286,534
Pass | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	527,818
Pass | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans
Financing Receivable, Recorded Investment
Total ending loans balance	582,374	569,315
Pass | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans
Financing Receivable, Recorded Investment
Total ending loans balance	269,066	240,260
Pass | Commercial Real Estate and Multi-family Residential Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance		535,496
Pass | Agri-business and Agricultural Loans [Member] | Loans Secured By Farmland
Financing Receivable, Recorded Investment
Total ending loans balance	138,247	165,005
Pass | Agri-business and Agricultural Loans [Member] | Loans For Agricultural Production
Financing Receivable, Recorded Investment
Total ending loans balance	172,730	191,489
Pass | Agri-business and Agricultural Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	104,163	112,166
Pass | Consumer 1-4 Family Mortgage Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	27,439	27,250
Pass | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	44,863	47,405
Pass | Consumer 1-4 Family Mortgage Loans [Member] | Open End And Junior Lien Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	11,016	10,845
Pass | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Special Mention
Financing Receivable, Recorded Investment
Total ending loans balance	123,798	96,608
Special Mention | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	54,559	40,551
Special Mention | Commercial and Industrial Loans [Member] | Non-working Capital Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	17,834	18,782
Special Mention | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Special Mention | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	33,555
Special Mention | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans
Financing Receivable, Recorded Investment
Total ending loans balance	758	781
Special Mention | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Special Mention | Commercial Real Estate and Multi-family Residential Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance		14,804
Special Mention | Agri-business and Agricultural Loans [Member] | Loans Secured By Farmland
Financing Receivable, Recorded Investment
Total ending loans balance	5,879	7,952
Special Mention | Agri-business and Agricultural Loans [Member] | Loans For Agricultural Production
Financing Receivable, Recorded Investment
Total ending loans balance	11,213	13,738
Special Mention | Agri-business and Agricultural Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Special Mention | Consumer 1-4 Family Mortgage Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Special Mention | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Special Mention | Consumer 1-4 Family Mortgage Loans [Member] | Open End And Junior Lien Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Special Mention | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Substandard
Financing Receivable, Recorded Investment
Total ending loans balance	60,998	84,562
Substandard | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	24,527	37,278
Substandard | Commercial and Industrial Loans [Member] | Non-working Capital Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	21,406	19,381
Substandard | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Substandard | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	10,365
Substandard | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans
Financing Receivable, Recorded Investment
Total ending loans balance	577	591
Substandard | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Substandard | Commercial Real Estate and Multi-family Residential Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance		23,059
Substandard | Agri-business and Agricultural Loans [Member] | Loans Secured By Farmland
Financing Receivable, Recorded Investment
Total ending loans balance	1,428	1,432
Substandard | Agri-business and Agricultural Loans [Member] | Loans For Agricultural Production
Financing Receivable, Recorded Investment
Total ending loans balance	0	15
Substandard | Agri-business and Agricultural Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Substandard | Consumer 1-4 Family Mortgage Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	17
Substandard | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	1,960	1,976
Substandard | Consumer 1-4 Family Mortgage Loans [Member] | Open End And Junior Lien Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	683	762
Substandard | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	52	51
Doubtful
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Commercial and Industrial Loans [Member] | Non-working Capital Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0
Doubtful | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Commercial Real Estate and Multi-family Residential Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance		0
Doubtful | Agri-business and Agricultural Loans [Member] | Loans Secured By Farmland
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Agri-business and Agricultural Loans [Member] | Loans For Agricultural Production
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Agri-business and Agricultural Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Consumer 1-4 Family Mortgage Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Consumer 1-4 Family Mortgage Loans [Member] | Open End And Junior Lien Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Doubtful | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Not Rated
Financing Receivable, Recorded Investment
Total ending loans balance	384,894	393,795
Not Rated | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	359	426
Not Rated | Commercial and Industrial Loans [Member] | Non-working Capital Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	5,328	5,310
Not Rated | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Not Rated | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	0
Not Rated | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Not Rated | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Not Rated | Commercial Real Estate and Multi-family Residential Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance		0
Not Rated | Agri-business and Agricultural Loans [Member] | Loans Secured By Farmland
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Not Rated | Agri-business and Agricultural Loans [Member] | Loans For Agricultural Production
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Not Rated | Agri-business and Agricultural Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	0	0
Not Rated | Consumer 1-4 Family Mortgage Loans [Member] | Other Commercial Loans
Financing Receivable, Recorded Investment
Total ending loans balance	69,420	71,099
Not Rated | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	126,252	127,492
Not Rated | Consumer 1-4 Family Mortgage Loans [Member] | Open End And Junior Lien Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	171,481	176,597
Not Rated | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction and Land Development Loans [Member]
Financing Receivable, Recorded Investment
Total ending loans balance	$ 12,054	$ 12,871