Stock-Based Compensation - Schedule of Stock Based Compensation Included in Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 298	$ 317	$ 1,093	$ 993
Income Statement Location [Axis]: us-gaap:GeneralAndAdministrativeExpense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	237	274	850	860
Income Statement Location [Axis]: us-gaap:SellingAndMarketingExpense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	19	17	52	52
Income Statement Location [Axis]: prosper:OriginationAndServicing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 42	$ 26	$ 191	$ 81

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details