LOANS - Troubled debt restructurings (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) Integer	Mar. 31, 2016 USD ($) Integer
Business Activities Loans - Residential real estate
Quantity of troubled debt restructurings | Integer		1
Pre-modification balance		$ 89
Post-modification balance		$ 89
Business Activities Loans - Commercial real estate
Quantity of troubled debt restructurings | Integer
Pre-modification balance
Post-modification balance
Business Activities Loans - Home equity lines of credit
Quantity of troubled debt restructurings | Integer
Pre-modification balance
Post-modification balance
Business Activities Loans - Troubled debt restructurings
Quantity of troubled debt restructurings | Integer		1
Pre-modification balance		$ 89
Post-modification balance		$ 89
Business Activities Loans - Refinance
Quantity of troubled debt restructurings | Integer		1
Pre-modification balance		$ 89
Post-modification balance		$ 89
Business Activities Loans - Rate reduction and term extension
Quantity of troubled debt restructurings | Integer
Pre-modification balance
Post-modification balance
Business Activities Loans - Debt consolidation and term extension
Quantity of troubled debt restructurings | Integer
Pre-modification balance
Post-modification balance
Business Activities Loans - Debt consolidation, rate reduction, term extension and note bifurcation
Quantity of troubled debt restructurings | Integer
Pre-modification balance
Post-modification balance
Business Activities Loans - Term extension
Quantity of troubled debt restructurings | Integer
Pre-modification balance
Post-modification balance