LOANS AND LEASES - Changes in Other Real Estate Owned (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
FDIC indemnification asset	$ 0		$ 1,900
Balance at beginning of period	2,781	$ 6,284
Additions	629	287
Disposals	(2,222)	(1,162)
Write-downs	123	109
Balance at end of period	1,065	5,300
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additions	170	122
Disposals	(2,104)	(925)
Write-downs	97	46
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additions	459	165
Disposals	(118)	(237)
Write-downs	$ 26	$ 63