INCOME TAXES - Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Allowance for loan losses	$ 7,222	$ 6,704
Deferred compensation	3,467	1,494
Deferred gain on interest rate swap	56	114
Unrealized loss on interest rate swap	0	80
Nonaccrual interest	107	5
Purchase accounting adjustments	13,144	5,631
Goodwill and intangible assets	0	4,909
Other real estate owned	2,980	3,203
Net operating loss tax carryforward	19,277	17,853
AMT credit carryforward	1,339	813
Unrealized loss on securities available for sale	2,792	508
FDIC-assisted transaction adjustments	2,501	0
Capitalized costs, accrued expenses and other	2,851	1,144
Deferred tax assets, net of valuation allowance, total	55,736	42,458
Deferred tax liabilities
Premises and equipment	4,597	4,064
Mortgage servicing rights	3,716	1,885
Subordinated debentures	5,259	5,147
FDIC-assisted transaction adjustments	0	3,042
Goodwill and intangible assets	7,017	0
Unrealized gain on interest rate swap	21	0
Deferred tax liabilities, net	20,610	14,138
Net deferred tax asset	$ 35,126	$ 28,320