INVESTMENT SECURITIES - Continuous unrealized loss position (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($)
Securities available for sale:
Less than 12 Months, Fair value	$ 77,523	$ 115,677
Less than 12 Months, Unrealized loss	2,169	737
12 Months or more, Fair value	1,255	11,085
12 Months or more, Unrealized loss	7	137
Total, Fair value	78,778	126,762
Total, Unrealized loss	2,176	874
Allowance for credit losses on investment securities available-for-sale
Ending balance	$ 75
Unrealized loss
Investment securities available for sale unrealized losses | item	74
Aggregate depreciation	0.0281%
U.S. government sponsored entities and U.S. agency securities
Securities available for sale:
Less than 12 Months, Fair value		7,200
Less than 12 Months, Unrealized loss		22
Total, Fair value		7,200
Total, Unrealized loss		22
Agency mortgage-backed securities
Securities available for sale:
Less than 12 Months, Fair value	$ 10,175	75,336
Less than 12 Months, Unrealized loss	42	170
12 Months or more, Fair value	1,255	7,170
12 Months or more, Unrealized loss	7	64
Total, Fair value	11,430	82,506
Total, Unrealized loss	49	234
State and municipal securities
Securities available for sale:
Less than 12 Months, Fair value		1,813
Less than 12 Months, Unrealized loss		11
Total, Fair value		1,813
Total, Unrealized loss		11
Allowance for credit losses on investment securities available-for-sale
Additions for securities for which no previous expected credit losses were recognized	19
Ending balance	19
Corporate Securities
Securities available for sale:
Less than 12 Months, Fair value	41,499	20,269
Less than 12 Months, Unrealized loss	1,287	481
12 Months or more, Fair value		3,915
12 Months or more, Unrealized loss		73
Total, Fair value	41,499	24,184
Total, Unrealized loss	1,287	554
Allowance for credit losses on investment securities available-for-sale
Additions for securities for which no previous expected credit losses were recognized	56
Ending balance	56
Non-agency mortgage-backed securities
Securities available for sale:
Less than 12 Months, Fair value	25,849	11,059
Less than 12 Months, Unrealized loss	840	53
Total, Fair value	25,849	11,059
Total, Unrealized loss	$ 840	$ 53