INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Allowance for credit losses and other contingent liabilities	$ 29,777	$ 13,261
Employee benefit plans		4,227
Tax effect of purchase accounting fair value adjustments		287
Tax effect of other components of income on derivatives		5,831
Tax effect of other components of income on securities available-for-sale	3,608
Operating lease liability	20,532	12,673
Other	1,976	2
Total deferred tax assets	55,893	36,281
Deferred tax liabilities:
Tax effect of other components of income on derivatives	1,371
Tax effect of other components of income on securities available-for-sale and derivatives		6,161
Employee benefit plans	2,803
Tax effect of purchase accounting fair value adjustments	3,945
Difference in book and tax carrying value of fixed assets	3,950	906
Difference in book and tax basis of unearned loan fees	2,413	2,490
Operating lease asset	19,871	10,774
Other	1,141	685
Total deferred tax liabilities	35,494	21,016
Net deferred tax asset (recorded in other assets)	$ 20,399	$ 15,265