INVESTMENT SECURITIES - Securities with unrealized losses (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	$ 8,294	$ 4,369
Less than 12 months, Unrealized Losses	(39)	(51)
12 months or Longer, Fair Value	556	566
12 months or Longer, Unrealized Losses	(18)	(13)
Total Fair Value	8,850	4,935
Total Unrealized Losses	(57)	(64)
U.S. Treasury debt
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	249
Less than 12 months, Unrealized Losses	(1)
Total Fair Value	249
Total Unrealized Losses	(1)
Government National Mortgage Association ("GNMA") mortgage-backed securities - residential
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	7,555
Less than 12 months, Unrealized Losses	(28)
Total Fair Value	7,555
Total Unrealized Losses	(28)
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	490	3,489
Less than 12 months, Unrealized Losses	(10)	(11)
Total Fair Value	490	3,489
Total Unrealized Losses	(10)	(11)
Corporate collateralized mortgage obligations ("CMO") and MBS
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value		880
Less than 12 months, Unrealized Losses		(40)
12 months or Longer, Fair Value	556	566
12 months or Longer, Unrealized Losses	(18)	(13)
Total Fair Value	556	1,446
Total Unrealized Losses	$ (18)	$ (53)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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