SECURITIES - Amortized cost, fair value and tax equivalent yield of securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Municipal bonds - Within 1 year
Amortized cost	$ 353
Fair value	$ 353
Yield	6.17%
Municipal bonds - After 1 year but within 5 years
Amortized cost	$ 439
Fair value	$ 440
Yield	5.03%
Municipal bonds - After 10 years but within 15 years
Amortized cost	$ 1,494
Fair value	$ 1,500
Yield	7.15%
Municipal bonds - After 15 years
Amortized cost	$ 1,190
Fair value	$ 1,193
Yield	7.13%
Municipal bonds - Total
Amortized cost	$ 3,476
Fair value	$ 3,486
Yield	6.78%
Mortgage-backed securities - U.S. Government agency and U.S. Government-sponsored enterprises
Amortized cost	$ 45,983
Fair value	$ 45,868
Yield	2.33%
Collateralized mortgage obligations - U.S. Government agency and U.S. Government-sponsored enterprises
Amortized cost	$ 10,462
Fair value	$ 10,377
Yield	2.76%
Collateralized mortgage obligations - Non-agency
Amortized cost	$ 2,271
Fair value	$ 2,664
Yield	3.97%
SBA bonds
Amortized cost	$ 12,278
Fair value	$ 12,267
Yield	2.99%
CRA mutual funds
Amortized cost	$ 851
Fair value	$ 835
Yield	2.17%
Corporate bonds - After 5 years but within 10 years
Amortized cost	$ 3,500
Fair value	$ 3,550
Yield	5.57%
Securities available-for-sale
Amortized cost	$ 78,821
Fair value	$ 79,047
Yield	2.87%