INCOME TAXES - Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Allowance for loan losses	$ 9,596	$ 7,222
Deferred compensation	3,459	3,467
Deferred gain on interest rate swap	39	56
Nonaccrual interest	107	107
Purchase accounting adjustments	21,104	13,144
Other real estate owned	4,556	2,980
Net operating loss tax carryforward	18,775	19,277
Tax credit carryforwards	3,701	1,655
Unrealized loss on securities available for sale	0	2,792
FDIC-assisted transaction adjustments	2,060	2,501
Capitalized costs, accrued expenses and other	4,840	2,535
Lease liability	10,619
Deferred tax assets, net of valuation allowance, total	78,856	55,736
Deferred tax liabilities
Premises and equipment	12,211	4,597
Mortgage servicing rights	25,990	3,716
Subordinated debentures	7,226	5,259
Goodwill and intangible assets	15,756	7,017
Unrealized gain on securities available for sale	5,430	0
Unrealized gain on interest rate swap	0	21
Right of use lease asset	10,063
Deferred tax liabilities	76,676	20,610
Net deferred tax asset	$ 2,180	$ 35,126