LOANS - Recorded investment and number of modifications for TDRs (Details) $ in Thousands	Dec. 31, 2017 USD ($) Integer	Dec. 31, 2016 USD ($) Integer
Residential 1-4 family
Quanity, TDRs with Modifications that Subsequently Defaulted | Integer		1
Balance, TDRs with Modifications that Subsequently Defaulted | $		$ 52
Residential 5+ multifamily
Quanity, TDRs with Modifications that Subsequently Defaulted | Integer		1
Balance, TDRs with Modifications that Subsequently Defaulted | $		$ 163
Commercial real estate
Quanity, TDRs with Modifications that Subsequently Defaulted | Integer		1
Balance, TDRs with Modifications that Subsequently Defaulted | $		$ 1,793
Total
Quanity, TDRs with Modifications that Subsequently Defaulted | Integer		3
Balance, TDRs with Modifications that Subsequently Defaulted | $		$ 2,008