FAIR VALUE - Summary of assets measured at fair value on recurring basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	$ 30,843	$ 36,666
Mortgage loans held for sale	176,644	161,843
U.S. Treasury debt
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	253	254
Corporate bonds
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	6,088	6,044
Recurring
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	30,843	36,666
Equity securities	717	730
Guarantee asset	188	232
Mortgage loans held for sale	176,644	161,843
Recurring | U.S. Treasury debt
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	253	254
Recurring | Corporate bonds
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	6,088	6,044
Recurring | Corporate collateralized mortgage obligations and mortgage-backed securities
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	2,852	4,087
Recurring | IRLC,net
Summary of assets measured on a recurring and nonrecurring basis
Derivative asset, Fair value	2,105	9,841
Recurring | Forward Commitment
Summary of assets measured on a recurring and nonrecurring basis
Derivative asset, Fair value	5,309	(2,623)
Recurring | GNMA | mortgage-backed securities - residential
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	19,980	24,604
Recurring | FNMA
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value		1,677
Recurring | FNMA | mortgage-backed securities - residential
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	1,670
Level 1 | Recurring
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	253	254
Equity securities	717	730
Level 1 | Recurring | U.S. Treasury debt
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	253	254
Level 2 | Recurring
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	30,590	36,412
Mortgage loans held for sale	176,644	161,843
Level 2 | Recurring | Corporate bonds
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	6,088	6,044
Level 2 | Recurring | Corporate collateralized mortgage obligations and mortgage-backed securities
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	2,852	4,087
Level 2 | Recurring | Forward Commitment
Summary of assets measured on a recurring and nonrecurring basis
Derivative asset, Fair value	5,482	(2,534)
Level 2 | Recurring | GNMA | mortgage-backed securities - residential
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	19,980	24,604
Level 2 | Recurring | FNMA
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value		1,677
Level 2 | Recurring | FNMA | mortgage-backed securities - residential
Summary of assets measured on a recurring and nonrecurring basis
Available-for-sale securities, at fair value	1,670
Level 3 | Recurring
Summary of assets measured on a recurring and nonrecurring basis
Guarantee asset	188	232
Level 3 | Recurring | IRLC,net
Summary of assets measured on a recurring and nonrecurring basis
Derivative asset, Fair value	2,105	9,841
Level 3 | Recurring | Forward Commitment
Summary of assets measured on a recurring and nonrecurring basis
Derivative asset, Fair value	$ (173)	$ (89)