LOANS AND LEASES - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Nonaccrual Status	$ 6,000,000.0		$ 6,400,000
Write-downs	123,000	$ 109,000
Gain (loss) on sale of other real estate owned	(77,000)	(24,000)
Real Estate Acquired Through Foreclosure	1,065,000	5,300,000	2,781,000	$ 6,284,000
FDIC indemnification asset	0		$ 1,900,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum	250,000
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum	250,000
Write-downs	$ 26,000	$ 63,000