FAIR VALUE OF ASSETS AND LIABILITIES - Summary of assets and liabilities (Details) - USD ($) $ in Thousands	1 Months Ended
	Mar. 31, 2020	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		$ 274,462	$ 244,587
Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges	$ 1,400
Real estate held for sale	624
Certain premises and real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges	12,800
Real estate held for sale	$ 5,300
U.S. Treasury Note
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		6,608	10,000
Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		66,448	59,341
U.S. Government agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		22,859	19,675
Obligations issued by U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		22,456	24,795
Residential one-to-four family
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		108,629	72,716
Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		47,462	58,060
Measured on a recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets		274,462	244,587
Financial Liabilities		(935)	(5,545)
Measured on a recurring basis: | U.S. Treasury Note
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		6,608	10,000
Measured on a recurring basis: | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		66,448	59,341
Measured on a recurring basis: | U.S. Government agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		22,859	19,675
Measured on a recurring basis: | Obligations issued by U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		22,456	24,795
Measured on a recurring basis: | Residential one-to-four family
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		108,629	72,716
Measured on a recurring basis: | Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		47,462	58,060
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets		18,706	22,417
Financial Liabilities		0	0
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets | U.S. Treasury Note
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		6,608	10,000
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets | U.S. Government agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		12,098	12,417
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets | Obligations issued by U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets | Residential one-to-four family
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets | Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Significant Other Observable Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets		255,755	222,170
Financial Liabilities		(935)	(5,545)
Measured on a recurring basis: | Significant Other Observable Inputs | U.S. Treasury Note
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Significant Other Observable Inputs | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		66,448	59,341
Measured on a recurring basis: | Significant Other Observable Inputs | U.S. Government agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		10,760	7,258
Measured on a recurring basis: | Significant Other Observable Inputs | Obligations issued by U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		22,456	24,795
Measured on a recurring basis: | Significant Other Observable Inputs | Residential one-to-four family
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		108,629	72,716
Measured on a recurring basis: | Significant Other Observable Inputs | Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		47,462	58,060
Measured on a recurring basis: | Significant Unobservable Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets		0	0
Financial Liabilities		0	0
Measured on a recurring basis: | Significant Unobservable Inputs | U.S. Treasury Note
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Significant Unobservable Inputs | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Significant Unobservable Inputs | U.S. Government agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Significant Unobservable Inputs | Obligations issued by U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Significant Unobservable Inputs | Residential one-to-four family
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a recurring basis: | Significant Unobservable Inputs | Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale:		0	0
Measured on a nonrecurring basis: | Assets held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		5,156	5,295
Measured on a nonrecurring basis: | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		624	624
Measured on a nonrecurring basis: | Quoted Prices in Active Markets for Identical Assets | Assets held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		0	0
Measured on a nonrecurring basis: | Quoted Prices in Active Markets for Identical Assets | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		0	0
Measured on a nonrecurring basis: | Significant Other Observable Inputs | Assets held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		5,156	5,295
Measured on a nonrecurring basis: | Significant Other Observable Inputs | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		624	624
Measured on a nonrecurring basis: | Significant Unobservable Inputs | Assets held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		0	0
Measured on a nonrecurring basis: | Significant Unobservable Inputs | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonfinancial assets		$ 0	$ 0