REVENUES - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)
Revenue from Contract with Customer [Abstract]
Number of reportable segments | segment			1
Disaggregation of Revenue [Line Items]
Total revenues	$ 12,541	$ 12,641	$ 28,722	$ 26,012
Interchange and card revenue
Disaggregation of Revenue [Line Items]
Total revenues	2,284	1,458	5,699	4,424
Servicing fees
Disaggregation of Revenue [Line Items]
Total revenues	6,874	7,700	15,840	14,332
Account fees
Disaggregation of Revenue [Line Items]
Total revenues	1,805	1,910	3,900	4,050
University fees
Disaggregation of Revenue [Line Items]
Total revenues	1,469	1,373	3,081	2,879
Other revenue
Disaggregation of Revenue [Line Items]
Total revenues	109	200	202	327
Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	11,218	11,297	26,092	23,334
Revenue recognized at a point in time | Interchange and card revenue
Disaggregation of Revenue [Line Items]
Total revenues	2,284	1,458	5,699	4,424
Revenue recognized at a point in time | Servicing fees
Disaggregation of Revenue [Line Items]
Total revenues	6,874	7,700	15,840	14,332
Revenue recognized at a point in time | Account fees
Disaggregation of Revenue [Line Items]
Total revenues	1,805	1,910	3,900	4,050
Revenue recognized at a point in time | University fees
Disaggregation of Revenue [Line Items]
Total revenues	234	172	597	432
Revenue recognized at a point in time | Other revenue
Disaggregation of Revenue [Line Items]
Total revenues	21	57	56	96
Revenue recognized over time
Disaggregation of Revenue [Line Items]
Total revenues	1,323	1,344	2,630	2,678
Revenue recognized over time | University fees
Disaggregation of Revenue [Line Items]
Total revenues	1,235	1,201	2,484	2,447
Revenue recognized over time | Other revenue
Disaggregation of Revenue [Line Items]
Total revenues	$ 88	$ 143	$ 146	$ 231