INCOME TAXES - Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Allowance for credit losses	$ 50,132	$ 59,643
Deferred compensation	7,816	5,722
Deferred loan fees	1,593	5,224
Purchase accounting adjustments	14,008	17,266
Other real estate owned	334	2,647
Net operating loss tax carryforward	35,082	17,176
Tax credit carryforwards	315	931
Capitalized costs, accrued expenses and other	2,208	2,815
Lease liability	16,186	19,314
Deferred tax assets, net of valuation allowance, total	127,674	130,738
Deferred tax liabilities
Premises and equipment	13,130	14,337
Mortgage servicing rights	52,076	35,806
Subordinated debentures	6,818	6,169
Lease financing	42,865	0
Goodwill and intangible assets	29,393	13,165
Unrealized gain on securities available-for-sale	4,498	9,263
Right of use lease asset	14,001	18,684
Deferred tax liabilities	162,781	97,424
Net deferred tax asset (liability)	$ (35,107)
Net deferred tax asset (liability)		$ 33,314