ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Balance In The Allowance For Loan Losses And The Recorded Investment In Loans By Portfolio Management (Details) - USD ($) $ in Thousands	Dec. 31, 2020		Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Ending allowance balance attributable to loans:
Individually evaluated for impairment	$ 8,041
Collectively evaluated for impairment	53,367
Total ending allowance balance	61,408	[1]	$ 60,747	$ 59,019	$ 50,652
Loans:
Loans individually evaluated for impairment	20,179
Loans collectively evaluated for impairment	4,628,977
Total	4,649,156
Commercial and industrial loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment	6,310
Collectively evaluated for impairment	22,023
Total ending allowance balance	28,333		28,363	26,744	25,789
Loans:
Loans individually evaluated for impairment	12,533
Loans collectively evaluated for impairment	1,772,393
Total	1,784,926
Commercial real estate and multi-family residential loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment	1,377
Collectively evaluated for impairment	21,530
Total ending allowance balance	22,907		21,415	21,063	15,796
Loans:
Loans individually evaluated for impairment	5,518
Loans collectively evaluated for impairment	1,887,054
Total	1,892,572
Agri-business and agricultural loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment	84
Collectively evaluated for impairment	2,959
Total ending allowance balance	3,043		3,097	3,408	3,869
Loans:
Loans individually evaluated for impairment	428
Loans collectively evaluated for impairment	429,234
Total	429,662
Other Commercial
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0
Collectively evaluated for impairment	416
Total ending allowance balance	416		572	542	447
Loans:
Loans individually evaluated for impairment	0
Loans collectively evaluated for impairment	93,912
Total	93,912
Consumer 1-4 family loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment	270
Collectively evaluated for impairment	2,349
Total ending allowance balance	2,619		3,318	3,434	2,086
Loans:
Loans individually evaluated for impairment	1,700
Loans collectively evaluated for impairment	342,999
Total	344,699
Other Consumer
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0
Collectively evaluated for impairment	951
Total ending allowance balance	951		830	774	345
Loans:
Loans individually evaluated for impairment	0
Loans collectively evaluated for impairment	103,385
Total	103,385
Unallocated
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0
Collectively evaluated for impairment	3,139
Total ending allowance balance	3,139		$ 3,152	$ 3,054	$ 2,320
Loans:
Loans individually evaluated for impairment	0
Loans collectively evaluated for impairment	0
Total	$ 0

[1] Beginning January 1, 2021 calculation is based on the current expected credit loss methodology. Prior to January 1, 2021 calculation was based on the incurred loss methodology.