Fair Value of Assets and Liabilities - Schedule of Fair Value Assumptions for Borrower Loans, Loans Held for Sale and Notes (Details) $ in Thousands	6 Months Ended
Jun. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value	$ 258,205	$ 309,737
Notes, at Fair Value	221,070	243,900
Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes, at Fair Value	221,070	243,900
Level 3 Inputs
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value	258,205	309,737
Notes, at Fair Value	221,070	243,900
Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value	222,766	245,337
Notes, at Fair Value	221,070	243,900
Prosper Funding LLC \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes, at Fair Value	221,070	243,900
Prosper Funding LLC \| Level 3 Inputs
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value	222,766	245,337
Notes, at Fair Value	221,070	243,900
Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes, at Fair Value	221,070	243,900
Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes, at Fair Value	221,070	243,900
Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value	258,205	309,737
Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value	$ 222,766	245,337
Prepayment rate assumption \| Applying a 1.1 multiplier to prepayment rate \| Servicing Assets
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate increase	1.10%
Prepayment rate assumption \| Applying a 0.9 multiplier to prepayment rate \| Servicing Assets
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate decrease	0.90%
Discount rate assumption \| 100 basis point increase \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 219,093	241,752
Discount rate assumption \| 100 basis point increase \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	219,093	241,752
Discount rate assumption \| 100 basis point increase \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	255,899	307,014
Discount rate assumption \| 100 basis point increase \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	220,777	243,180
Discount rate assumption \| 200 basis point incease \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	217,163	239,655
Discount rate assumption \| 200 basis point incease \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	217,163	239,655
Discount rate assumption \| 200 basis point incease \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	253,648	304,354
Discount rate assumption \| 200 basis point incease \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	218,835	241,073
Discount rate assumption \| 100 basis point decrease \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	223,093	246,096
Discount rate assumption \| 100 basis point decrease \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	223,093	246,096
Discount rate assumption \| 100 basis point decrease \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	260,567	312,526
Discount rate assumption \| 100 basis point decrease \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	224,804	247,547
Discount rate assumption \| 200 basis point decrease \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	225,171	248,352
Discount rate assumption \| 200 basis point decrease \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	225,171	248,352
Discount rate assumption \| 200 basis point decrease \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	262,988	315,384
Discount rate assumption \| 200 basis point decrease \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 226,893	249,810
Default rate assumption \| Applying a 1.1 multiplier to default rate \| Servicing Assets
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate increase	1.10%
Default rate assumption \| Applying a 1.1 multiplier to default rate \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 219,297	241,944
Default rate assumption \| Applying a 1.1 multiplier to default rate \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	256,134	307,253
Default rate assumption \| Applying a 1.2 multiplier to default rate \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	217,523	239,987
Default rate assumption \| Applying a 1.2 multiplier to default rate \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 254,061	304,767
Default rate assumption \| Applying a 0.9 multiplier to default rate \| Servicing Assets
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate decrease	0.90%
Default rate assumption \| Applying a 0.9 multiplier to default rate \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 222,842	245,853
Default rate assumption \| Applying a 0.9 multiplier to default rate \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	260,275	312,219
Default rate assumption \| Applying a 0.8 multiplier to default rate \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	224,615	247,806
Default rate assumption \| Applying a 0.8 multiplier to default rate \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 262,347	314,699
Default rate assumption \| 10 percent increase \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate increase	110.00%
Default rate assumption \| 10 percent increase \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 219,297	241,944
Default rate assumption \| 10 percent increase \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate increase	110.00%
Default rate assumption \| 10 percent increase \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 220,980	243,371
Default rate assumption \| 20 percent increase \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate decrease	120.00%
Default rate assumption \| 20 percent increase \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 217,523	239,987
Default rate assumption \| 20 percent increase \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate decrease	120.00%
Default rate assumption \| 20 percent increase \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 219,192	241,402
Default rate assumption \| 10 percent decrease \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate increase	90.00%
Default rate assumption \| 10 percent decrease \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 222,842	245,853
Default rate assumption \| 10 percent decrease \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate increase	90.00%
Default rate assumption \| 10 percent decrease \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 224,553	247,304
Default rate assumption \| 20 percent decrease \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate decrease	80.00%
Default rate assumption \| 20 percent decrease \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 224,615	247,806
Default rate assumption \| 20 percent decrease \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate decrease	80.00%
Default rate assumption \| 20 percent decrease \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 226,340	$ 249,269
Discount rate \| 100 basis point increase in both discount rates \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rates increase	100
Discount rate \| 200 basis point increase in both discount rates \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rates increase	200
Discount rate \| 100 basis point decrease in both discount rates \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rates increase	100
Discount rate \| 200 basis point decrease in both discount rates \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rates increase	200
Discount rate \| Discount rate assumption \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.0939	0.0867
Discount rate \| Discount rate assumption \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.0939	0.0867
Discount rate \| Discount rate assumption \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.0925	0.0853
Discount rate \| Discount rate assumption \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.0939	0.0867
Default rate \| Applying a 1.1 multiplier to default rate \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate increase	1.10%
Default rate \| Applying a 1.1 multiplier to default rate \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate decrease	110.00%
Default rate \| Applying a 0.9 multiplier to default rate \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate decrease	0.90%
Default rate \| Applying a 0.9 multiplier to default rate \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate decrease	90.00%
Default rate \| Applying a 0.8 multiplier to default rate \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate decrease	80.00%
Default rate \| Default rate assumption \| Notes \| Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.1117	0.1148
Default rate \| Default rate assumption \| Notes \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.1117	0.1148
Default rate \| Default rate assumption \| Borrower Loans
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.1137	0.1179
Default rate \| Default rate assumption \| Borrower Loans \| Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions	0.1117	0.1148
Prepayment rate \| Applying a 1.1 multiplier to prepayment rate \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate increase	1.10%
Prepayment rate \| Applying a 1.1 multiplier to prepayment rate \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate increase	110.00%
Prepayment rate \| Applying a 1.2 multiplier to default rate \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate decrease	120.00%
Prepayment rate \| Applying a 0.9 multiplier to prepayment rate \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate decrease	0.90%
Prepayment rate \| Applying a 0.9 multiplier to prepayment rate \| Prosper Funding LLC \| Credit Card Derivative
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment rate increase	90.00%