SECURITIES - Amortized cost, fair value and tax equivalent yield of securities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Municipal bonds - Within 1 year
Amortized cost	$ 529
Fair value	$ 530
Yield	5.01%
Municipal bonds - After 1 year but within 5 years
Amortized cost	$ 259
Fair value	$ 260
Yield	3.84%
Municipal bonds - After 10 years but within 15 years
Amortized cost	$ 2,184
Fair value	$ 2,188
Yield	6.09%
Municipal bonds - After 15 years
Amortized cost
Fair value
Yield
Municipal bonds - Total
Amortized cost	$ 2,972
Fair value	$ 2,978
Yield	5.70%
Mortgage-backed securities - U.S. Government agency and U.S. Government-sponsored enterprises
Amortized cost	$ 44,315
Fair value	$ 43,737
Yield	2.38%
Collateralized mortgage obligations - U.S. Government agency and U.S. Government-sponsored enterprises
Amortized cost	$ 10,160
Fair value	$ 9,882
Yield	2.80%
Collateralized mortgage obligations - Non-agency
Amortized cost	$ 1,714
Fair value	$ 2,066
Yield	3.58%
SBA bonds
Amortized cost	$ 18,020
Fair value	$ 17,764
Yield	3.00%
Corporate bonds - After 5 years but within 10 years
Amortized cost	$ 3,500
Fair value	$ 3,479
Yield	5.57%
Fair value
Amortized cost	$ 80,681
Fair value	$ 79,906
Yield	2.85%