LOANS - Troubled debt restructurings (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Integer	Dec. 31, 2017 USD ($) Integer
Business Activities Loans - Residential real estate
Quantity of troubled debt restructurings | Integer	1	1
Pre-modification balance	$ 68	$ 222
Post-modification balance	$ 68	$ 222
Business Activities Loans - Commercial real estate
Quantity of troubled debt restructurings | Integer	1	1
Pre-modification balance	$ 566	$ 600
Post-modification balance	$ 566	$ 600
Business Activities Loans - Commercial and industrial
Quantity of troubled debt restructurings | Integer		2
Pre-modification balance		$ 182
Post-modification balance		$ 182
Totals
Quantity of troubled debt restructurings | Integer	2	4
Pre-modification balance	$ 634	$ 1,004
Post-modification balance	$ 634	$ 1,004
Business Activities Loans - Rate reduction and term extension
Quantity of troubled debt restructurings | Integer		3
Pre-modification balance		$ 404
Post-modification balance		$ 404
Business Activities Loans - Rate reduction
Quantity of troubled debt restructurings | Integer	2
Pre-modification balance	$ 634
Post-modification balance	$ 634
Business Activities Loans - Term extension
Quantity of troubled debt restructurings | Integer		1
Pre-modification balance		$ 600
Post-modification balance		$ 600