FAIR VALUE OF ASSETS AND LIABILITIES - Significant Unobservable Inputs (Details)	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Servicing Assets:
Market rate for collection fee	0.10%	0.07%
Prosper Funding LLC
Servicing Assets:
Market rate for collection fee	0.10%	0.07%
Weighted average market servicing rate		0.703%
Minimum
Servicing Assets:
Discount rate	15.00%	15.00%
Default rate	2.00%	2.60%
Prepayment rate	13.30%	8.30%
Market servicing rate	0.593%	0.633%
Weighted average market servicing rate		0.703%
Minimum \| Prosper Funding LLC
Servicing Assets:
Discount rate	15.00%	15.00%
Default rate	1.90%	2.90%
Prepayment rate	3.40%	13.60%
Market servicing rate	0.593%	0.633%
Weighted average market servicing rate	0.693%
Maximum
Servicing Assets:
Discount rate	25.00%	25.00%
Default rate	15.00%	22.60%
Prepayment rate	35.60%	29.80%
Market servicing rate	0.842%	0.842%
Weighted average market servicing rate		0.912%
Maximum \| Prosper Funding LLC
Servicing Assets:
Discount rate	25.00%	25.00%
Default rate	15.00%	22.60%
Prepayment rate	41.40%	28.10%
Market servicing rate	0.842%	0.842%
Weighted average market servicing rate	0.942%	0.912%
Discount rate \| Minimum
Borrower Loans and Notes:
Fair value assumptions	0.050	0.057
Loan Trailing Fee Liability:
Fair value assumptions	0.050	0.057
Discount rate \| Minimum \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.150	0.150
Loan Trailing Fee Liability:
Fair value assumptions	0.150	0.150
Discount rate \| Minimum \| Prosper Funding LLC
Borrower Loans and Notes:
Fair value assumptions	0.063	0.058
Loan Trailing Fee Liability:
Fair value assumptions	0.063	0.058
Discount rate \| Minimum \| Prosper Funding LLC \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.150	0.150
Loan Trailing Fee Liability:
Fair value assumptions	0.150	0.150
Discount rate \| Maximum
Borrower Loans and Notes:
Fair value assumptions	0.155	0.109
Loan Trailing Fee Liability:
Fair value assumptions	0.155	0.109
Discount rate \| Maximum \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.250	0.250
Loan Trailing Fee Liability:
Fair value assumptions	0.250	0.250
Discount rate \| Maximum \| Prosper Funding LLC
Borrower Loans and Notes:
Fair value assumptions	0.155	0.087
Loan Trailing Fee Liability:
Fair value assumptions	0.155	0.087
Discount rate \| Maximum \| Prosper Funding LLC \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.250	0.250
Loan Trailing Fee Liability:
Fair value assumptions	0.250	0.250
Default rate \| Minimum
Borrower Loans and Notes:
Fair value assumptions	0.019	0.026
Loan Trailing Fee Liability:
Fair value assumptions	0.019	0.026
Default rate \| Minimum \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.020	0.026
Loan Trailing Fee Liability:
Fair value assumptions	0.020	0.026
Default rate \| Minimum \| Prosper Funding LLC
Borrower Loans and Notes:
Fair value assumptions	0.023	0.029
Loan Trailing Fee Liability:
Fair value assumptions	0.023	0.029
Default rate \| Minimum \| Prosper Funding LLC \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.019	0.029
Loan Trailing Fee Liability:
Fair value assumptions	0.019	0.029
Default rate \| Maximum
Borrower Loans and Notes:
Fair value assumptions	0.145	0.226
Loan Trailing Fee Liability:
Fair value assumptions	0.145	0.226
Default rate \| Maximum \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.150	0.226
Loan Trailing Fee Liability:
Fair value assumptions	0.150	0.226
Default rate \| Maximum \| Prosper Funding LLC
Borrower Loans and Notes:
Fair value assumptions	0.145	0.226
Loan Trailing Fee Liability:
Fair value assumptions	0.145	0.226
Default rate \| Maximum \| Prosper Funding LLC \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.150	0.226
Loan Trailing Fee Liability:
Fair value assumptions	0.150	0.226
Prepayment rate \| Minimum \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.133	0.083
Loan Trailing Fee Liability:
Fair value assumptions	0.133	0.083
Prepayment rate \| Minimum \| Prosper Funding LLC \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.034	0.136
Loan Trailing Fee Liability:
Fair value assumptions	0.034	0.136
Prepayment rate \| Maximum \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.356	0.298
Loan Trailing Fee Liability:
Fair value assumptions	0.356	0.298
Prepayment rate \| Maximum \| Prosper Funding LLC \| Loan trailing fee liability
Borrower Loans and Notes:
Fair value assumptions	0.414	0.281
Loan Trailing Fee Liability:
Fair value assumptions	0.414	0.281

Borrower Loans, Loans Held for Sale, and Notes

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- Definition

Fair Value Assumptions, Collection Fee Market Rate

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Fair Value Assumptions, Weighted Average Market Servicing Rate

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- Definition

Loan Trailing Fee Liability

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- Definition

Servicing Assets

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- Definition

Servicing assets and servicing liabilities at fair value assumptions used to estimate fair value market servicing rate.

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- Definition

Value of input used to measure investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 103
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-103

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

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- Definition

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

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Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-2

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- Definition

Percentage of contractually collectible principal associated with a financial asset expected not to be collected due to default by the borrower.

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- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

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