LOANS - Troubled debt restructurings (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($) Integer	Jun. 30, 2016 USD ($) Integer
Business Activities Loans - Residential real estate
Quantity of troubled debt restructurings | Integer		3
Pre-modification balance		$ 316
Post-modification balance		$ 316
Business Activities Loans - Commercial real estate
Quantity of troubled debt restructurings | Integer	1	1
Pre-modification balance	$ 600	$ 1,863
Post-modification balance	$ 600	$ 1,863
Business Activities Loans - Troubled debt restructurings
Quantity of troubled debt restructurings | Integer	1	4
Pre-modification balance	$ 600	$ 2,179
Post-modification balance	$ 600	$ 2,179
Business Activities Loans - Rate reduction and term extension
Quantity of troubled debt restructurings | Integer		2
Pre-modification balance		$ 262
Post-modification balance		$ 262
Business Activities Loans - Debt consolidation
Quantity of troubled debt restructurings | Integer		1
Pre-modification balance		$ 1,863
Post-modification balance		$ 1,863
Business Activities Loans - Term extension
Quantity of troubled debt restructurings | Integer	1	1
Pre-modification balance	$ 600	$ 54
Post-modification balance	$ 600	$ 54