LOANS AND ASSET QUALITY - Risk ratings of loans by categories of loans (Details 5) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017 USD ($) Account Loans	Dec. 31, 2016 USD ($) Account Loans	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)
Financing Receivable, Recorded Investment [Line Items]
Total	$ 272,031	$ 266,106
Non-accrual	3,527	3,751	$ 3,751	$ 3,779
Troubled debt restructures	$ 302	$ 312
Number of TDRs accounts | Account	3	3
Non-performing TDRs | Loans	80	84
Non-performing TDRs accounts | Account	2	2
Pass
Financing Receivable, Recorded Investment [Line Items]
Total	$ 265,712	$ 256,733
Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	1,675	4,698
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	4,584	4,461
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total	60	214
Loss
Financing Receivable, Recorded Investment [Line Items]
Total
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	3,739	4,679
Non-accrual
Troubled debt restructures	$ 222	$ 228
Number of TDRs accounts | Account	1	1
Non-performing TDRs | Loans
Non-performing TDRs accounts | Account
Commercial and industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total	$ 3,517	$ 4,357
Commercial and industrial | Special mention
Financing Receivable, Recorded Investment [Line Items]
Total		94
Commercial and industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	222	228
Commercial and industrial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total
Commercial and industrial | Loss
Financing Receivable, Recorded Investment [Line Items]
Total
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	65,655	69,422
Non-accrual	640	647	647	300
Troubled debt restructures
Number of TDRs accounts | Account
Non-performing TDRs | Loans
Non-performing TDRs accounts | Account
Commercial real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total	$ 63,837	$ 64,208
Commercial real estate | Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	334	3,801
Commercial real estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	1,484	1,413
Commercial real estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total
Commercial real estate | Loss
Financing Receivable, Recorded Investment [Line Items]
Total
Consumer and indirect
Financing Receivable, Recorded Investment [Line Items]
Total	95,509	83,582
Non-accrual	331	456
Troubled debt restructures	$ 33	$ 36
Number of TDRs accounts | Account	1	1
Non-performing TDRs | Loans	33	36
Non-performing TDRs accounts | Account	1	1
Consumer and indirect | Pass
Financing Receivable, Recorded Investment [Line Items]
Total	$ 94,194	$ 82,943
Consumer and indirect | Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	848	276
Consumer and indirect | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	407	327
Consumer and indirect | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total	60	36
Consumer and indirect | Loss
Financing Receivable, Recorded Investment [Line Items]
Total
Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Total	107,128	108,423
Non-accrual	2,556	2,648	$ 2,648	$ 2,883
Troubled debt restructures	$ 47	$ 48
Number of TDRs accounts | Account	1	1
Non-performing TDRs | Loans	47	48
Non-performing TDRs accounts | Account	1	1
Residential real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total	$ 104,164	$ 105,225
Residential real estate | Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	493	527
Residential real estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	2,471	2,493
Residential real estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total		178
Residential real estate | Loss
Financing Receivable, Recorded Investment [Line Items]
Total