LOANS AND ALLOWANCE FOR LOAN LOSSES - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) contract	Dec. 31, 2016 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased loan pools	$ 262,600	$ 328,200
Purchased loan pools principal balance	260,500	324,400
Purchased pool loans unamortized purchase premium	2,100	3,800
Allowance for loan and lease Losses, purchased loan pools	732	1,100
Loans modified that are not troubled debt restructurings	111,700	103,000
Troubled debt restructurings excluding purchased loans	11,000	15,600
Troubled debt restructurings, previous charge-offs	890	2,800
Allowance for loan losses allocated to troubled debt restructurings	820	1,400
Consumer Installment Home Improvement Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	399,900	273,700
Commercial Insurance Premium Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	413,500	482,500
Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,588,832	861,595
Purchased loans carrying value	2,590,000	861,600
Purchased loan pools, troubled debt restructuring amount		904
Nonaccrual loans	24,107	15,428
Troubled debt restructuring loans	2,499	3,635
Troubled debt restructurings, previous charge-offs	940	1,200
Troubled debt restructurings principal balances	2,500	3,600
Financing receivable, modifications, subsequent default, recorded investment	2,500	742
Troubled debt restructuring	22,200	$ 24,900
Financing receivable, modifications, number of contracts | contract		1
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	17,952	$ 14,202
Troubled debt restructuring loans	2,256	4,212
Troubled debt restructurings principal balances	2,300	4,200
Financing receivable, modifications, subsequent default, recorded investment	1,300	1,600
Minimum | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	100	100	$ 100
Troubled debt restructuring loans	$ 100	$ 100	$ 100