Revenue - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Trailing fee liabilities	$ 4,852	$ 4,315
Servicing fees and other receivables	$ 46,652	55,518
Loans on non-accrual status	120 days
Accrued interest income	$ 12,800	$ 2,600
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Loans (at fair value)	Loans (at fair value)
Customer A \| Customer Concentration Risk \| Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk (in percent)	45.00%	56.00%	63.00%
Customer B \| Customer Concentration Risk \| Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk (in percent)	28.00%	27.00%	18.00%
Customer C \| Customer Concentration Risk \| Accounts Receivable
Disaggregation of Revenue [Line Items]
Concentration risk (in percent)	23.00%	25.00%
Customer D \| Customer Concentration Risk \| Accounts Receivable
Disaggregation of Revenue [Line Items]
Concentration risk (in percent)		33.00%
Platform and referral fees, net
Disaggregation of Revenue [Line Items]
Loan premium and loan trailing fees recognized	$ 27,700	$ 23,600	$ 8,300
Servicing fees and other receivables	$ 31,100	$ 44,800
Capitalized cost amortization term	3 years

Loan Premium Fees and Loan Trailing Fees

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Trailing Fee Liabilities, Fair Value Disclosure

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- Definition

For an unclassified balance sheet, the amount of fees and other revenue, excluding investment income receivable, earned but not yet received, which were recognized in conformity with revenue recognition criteria based on estimates or specific contractual terms.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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- Definition

Amortization period of cost capitalized in obtaining or fulfilling contract with customer, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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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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No definition available.

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Amount, after allowance for credit loss, of accrued interest on financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
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Indicates line item in statement of financial position that includes accrued interest, after allowance for credit loss, on financing receivable.

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Threshold period for when financing receivable is considered past due, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Excludes threshold period past due to write off as uncollectible.

+ References

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-Name Accounting Standards Codification
-Topic 326
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