Borrower Loans and Notes, at Fair Value - Schedule of Fair Value of Borrower Loans and Notes (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, at Fair value	$ 258,205	$ 309,737
Notes, at Fair value	221,070	243,900
Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, at Fair value	222,766	245,337
Notes, at Fair value	221,070	243,900
Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes, Aggregate principal balance and interest outstanding	233,817	256,929
Notes, Fair value adjustments	(12,747)	(13,029)
Notes, at Fair value	221,070	243,900
Notes \| Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes, Aggregate principal balance and interest outstanding	233,817	256,929
Notes, Fair value adjustments	(12,747)	(13,029)
Notes, at Fair value	221,070	243,900
Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, Aggregate principal balance and interest outstanding	270,738	324,505
Borrower Loans, Fair value adjustment	(12,533)	(14,768)
Borrower Loans, at Fair value	258,205	309,737
Borrower Loans \| Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, Aggregate principal balance and interest outstanding	232,661	255,132
Borrower Loans, Fair value adjustment	(9,895)	(9,795)
Borrower Loans, at Fair value	$ 222,766	$ 245,337

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