FAIR VALUE - Summary of assets measured at fair value on recurring basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	$ 61,491	$ 43,695
U.S. Treasury debt
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	255	250
Securities issued by U.S. government sponsored entities and agencies
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale		4,302
Recurring
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	61,491	43,695
Equity securities not available-for-sale	718	693
Recurring | U.S. Treasury debt
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	255	250
Recurring | Securities issued by U.S. government sponsored entities and agencies
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale		4,302
Recurring | Corporate collateralized mortgage obligations and mortgage-backed securities
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	12,192	1,271
Recurring | Interest rate lock and forward delivery commitments
Summary of assets measured on a recurring and nonrecurring basis
Derivative asset, Fair value	2,148	890
Recurring | GNMA
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	45,735	34,002
Recurring | FNMA
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	3,309	3,870
Level 1 | Recurring
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	255	250
Equity securities not available-for-sale	718	693
Level 1 | Recurring | U.S. Treasury debt
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	255	250
Level 2 | Recurring
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	61,236	43,445
Level 2 | Recurring | Securities issued by U.S. government sponsored entities and agencies
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale		4,302
Level 2 | Recurring | Corporate collateralized mortgage obligations and mortgage-backed securities
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	12,192	1,271
Level 2 | Recurring | Interest rate lock and forward delivery commitments
Summary of assets measured on a recurring and nonrecurring basis
Derivative asset, Fair value	2,148	890
Level 2 | Recurring | GNMA
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	45,735	34,002
Level 2 | Recurring | FNMA
Summary of assets measured on a recurring and nonrecurring basis
Total securities available-for-sale	$ 3,309	$ 3,870