LOANS HELD FOR INVESTMENT, NET - Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Unpaid Principal Balance
With no related allowance recorded	$ 4,567
With related allowance recorded	12,502
Total	17,069
Recorded Investment
With no related allowance recorded	4,567
With related allowance recorded	12,502		$ 1,900
Total	17,069
Related Allowance
Valuation allowance	6,474
Average Recorded Investment
With no related allowance recorded	3,562	$ 4,189
Total	14,167	9,314
Interest Income Recognized
With no related allowance recorded	7	282
Total	8	295
One-to-four family residential and cooperative/condominium apartment
Average Recorded Investment
With no related allowance recorded	1,179	9
Interest Income Recognized
With no related allowance recorded		9
Multifamily residential and residential mixed-use
Unpaid Principal Balance
With no related allowance recorded	1,863
Recorded Investment
With no related allowance recorded	1,863
Average Recorded Investment
With no related allowance recorded	1,188	415
Interest Income Recognized
With no related allowance recorded	6	29
Commercial real estate ("CRE")
Unpaid Principal Balance
With no related allowance recorded	2,704
Recorded Investment
With no related allowance recorded	2,704
Average Recorded Investment
With no related allowance recorded	1,195	3,765
Interest Income Recognized
With no related allowance recorded	1	244
Commercial and Industrial ("C&I") Loans
Unpaid Principal Balance
With related allowance recorded	12,502
Recorded Investment
With related allowance recorded	12,502
Related Allowance
Valuation allowance	6,474
Average Recorded Investment
With related allowance recorded	10,605	5,125
Interest Income Recognized
With related allowance recorded	$ 1	$ 13