SECURITIES - Aggreggate fair value and gross unrealized loss of securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Less Than 12 Months, Fair value
Available-for-sale
Municipal bonds		$ 479
Mortgage-backed securities	$ 22,537	15,914
Collateralized mortgage obligations, U.S. Government agencies	8,860	9,317
Collateralized mortgage obligations, Non-agency
SBA bonds	15,652	8,519
Corporate bonds	1,421	1,491
Total temporarily impaired securities	48,470	35,720
Other than temporarily impaired securities, Collateralized mortgage obligations, Non-agency	93	101
Total temporarily impaired and other-than-temporarily impaired securities	48,563	35,821
Less Than 12 Months, Unrealized losses
Available-for-sale
Municipal bonds		1
Mortgage-backed securities	303	99
Collateralized mortgage obligations, U.S. Government agencies	288	87
Collateralized mortgage obligations, Non-agency
SBA bonds	256	20
Corporate bonds	79	9
Total temporarily impaired securities	926	216
Other than temporarily impaired securities, Collateralized mortgage obligations, Non-agency	13	14
Total temporarily impaired and other-than-temporarily impaired securities	939	230
12 Months or Longer, Fair value
Available-for-sale
Municipal bonds
Mortgage-backed securities	16,091	17,892
Collateralized mortgage obligations, U.S. Government agencies
Collateralized mortgage obligations, Non-agency		77
SBA bonds
Corporate bonds
Total temporarily impaired securities	16,091	17,969
Other than temporarily impaired securities, Collateralized mortgage obligations, Non-agency
Total temporarily impaired and other-than-temporarily impaired securities	16,091	17,969
12 Months or Longer, Unrealized losses
Available-for-sale
Municipal bonds
Mortgage-backed securities	340	168
Collateralized mortgage obligations, U.S. Government agencies
Collateralized mortgage obligations, Non-agency		3
SBA bonds
Corporate bonds
Total temporarily impaired securities	340	171
Other than temporarily impaired securities, Collateralized mortgage obligations, Non-agency
Total temporarily impaired and other-than-temporarily impaired securities	340	171
Total, Fair value
Available-for-sale
Municipal bonds		479
Mortgage-backed securities	38,628	33,806
Collateralized mortgage obligations, U.S. Government agencies	8,860	9,317
Collateralized mortgage obligations, Non-agency		77
SBA bonds	15,652	8,519
Corporate bonds	1,421	1,491
Total temporarily impaired securities	64,561	53,689
Other than temporarily impaired securities, Collateralized mortgage obligations, Non-agency	93	101
Total temporarily impaired and other-than-temporarily impaired securities	64,654	53,790
Total, Unrealized losses
Available-for-sale
Municipal bonds		1
Mortgage-backed securities	643	267
Collateralized mortgage obligations, U.S. Government agencies	288	87
Collateralized mortgage obligations, Non-agency		3
SBA bonds	256	20
Corporate bonds	79	9
Total temporarily impaired securities	1,266	387
Other than temporarily impaired securities, Collateralized mortgage obligations, Non-agency	13	14
Total temporarily impaired and other-than-temporarily impaired securities	$ 1,279	$ 401

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- Definition

Accumulated other comprehensive loss related to portion of other than temporary impairment (OTTI) due to factors other than credit losses on debt securities categorized as available-for-sale that an entity does not intend to sell and which it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis of the debt security. The amount represented by this item is net of tax, as applicable.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 9A
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- Definition

Total of accumulated other comprehensive loss related to that portion of other than temporary impairment (OTTI) due to factors other than credit losses on debt securities categorized either as available-for-sale or held-to-maturity that an entity does not intend to sell and which it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis of the debt security. The amount represented by this item is net of tax, as applicable.

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- Definition

Investments in notes or bonds that are collateralized by a specific group of underlying assets owned by the issuer of the notes or bonds which are short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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Amount of securities that are debt instruments (corporate or municipal bonds) that typically have long-term nominal maturities for which the interest rate is reset through an auction process.

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- Definition

Amount of securities, mortgage loans, or other financial instruments pledged as collateral for deposits.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
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The aggregate fair value as of the balance sheet date of financial instruments and other positions owned by the entity including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities. Includes both pledged and unpledged holdings.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 320
-Section 45
-Paragraph 2
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Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale.

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Bonds or similar securities issued by state, city, or local governments or the agencies operated by state, city, or local governments which are short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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