Notes and Residual Certificates held by Third-party Investors

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Securitization Note and Certificate Holder Payables, Fair Value Disclosure

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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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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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

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No definition available.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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- Definition

This is the principal amount outstanding for securitized loans only (across all types of loans).

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Weighted average maturity (weighted by amount of the agreement) of repurchase agreements with the counterparty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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Carrying value, as of the balance sheet date, of securities sold under agreements to repurchase where the transferor maintains effective control over the assets, accounting for them as secured debt.

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Fair value of financial instrument held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions.

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Amount, before counterparty netting, of cash proceeds received in transfers of derecognized financial assets from transactions which comprise an initial transfer and an agreement entered into in contemplation of the initial transfer resulting in retention of substantially all of the exposure to the economic return throughout the term of the transaction.

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Debt (Detail) - USD ($)	12 Months Ended
Debt (Detail) - USD ($)	Dec. 31, 2019	Jan. 15, 2020	Nov. 07, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 17, 2015
Minimum
Debt Instrument [Line Items]
Weighted-average estimated life of repurchase agreements	1 year 1 month 6 days
Maximum
Debt Instrument [Line Items]
Weighted-average estimated life of repurchase agreements	1 year 4 months 24 days
Revolving Credit Facility
Debt Instrument [Line Items]
Current borrowing capacity						$ 120,000,000.0
Outstanding principal	$ 60,000,000.0			$ 95,000,000.0
Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Commitment fee	0.25%
Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Commitment fee	0.375%
Revolving Credit Facility \| London Interbank Offered Rate (LIBOR) \| Minimum
Debt Instrument [Line Items]
Basis spread	1.75%
Revolving Credit Facility \| London Interbank Offered Rate (LIBOR) \| Maximum
Debt Instrument [Line Items]
Basis spread	2.00%
Revolving Credit Facility \| Fed Funds Effective Rate \| Minimum
Debt Instrument [Line Items]
Basis spread	0.50%
Revolving Credit Facility \| Adjusted Eurocurrency Rate \| Minimum
Debt Instrument [Line Items]
Basis spread	1.00%
Revolving Credit Facility \| Adjusted Eurocurrency Rate Plus 1% \| Minimum
Debt Instrument [Line Items]
Basis spread	0.75%
Revolving Credit Facility \| Adjusted Eurocurrency Rate Plus 1% \| Maximum
Debt Instrument [Line Items]
Basis spread	1.00%
Personal Loan Warehouse Credit Facilities \| Revolving Credit Facility
Debt Instrument [Line Items]
Current borrowing capacity	$ 750,000,000.0
Personal Loan Warehouse Credit Facilities \| Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Monthly unused commitment fee (percent)	0.375%
Personal Loan Warehouse Credit Facilities \| Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Monthly unused commitment fee (percent)	1.25%
Auto Loan Warehouse Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Outstanding principal	$ 14,300,000
Auto Loan Warehouse Credit Facility \| Term Loan
Debt Instrument [Line Items]
Current borrowing capacity	34,200,000
Personal Loan and Auto Loan Warehouse Credit Facilities \| Revolving Credit Facility
Debt Instrument [Line Items]
Outstanding principal	387,300,000			306,800,000
Restricted cash pledged as collateral	$ 25,100,000			25,200,000
Personal Loan and Auto Loan Warehouse Credit Facilities \| Revolving Credit Facility \| London Interbank Offered Rate (LIBOR) \| Minimum
Debt Instrument [Line Items]
Basis spread	1.85%
Personal Loan and Auto Loan Warehouse Credit Facilities \| Revolving Credit Facility \| London Interbank Offered Rate (LIBOR) \| Maximum
Debt Instrument [Line Items]
Basis spread	2.50%
Securities Sold Under Repurchase Agreements \| London Interbank Offered Rate (LIBOR) \| Minimum
Debt Instrument [Line Items]
Basis spread	0.65%
Securities Sold Under Repurchase Agreements \| London Interbank Offered Rate (LIBOR) \| Maximum
Debt Instrument [Line Items]
Basis spread	2.50%
Payables to Securitization Holders
Debt Instrument [Line Items]
Restricted cash pledged as collateral				9,300,000
Loans Held for Sale \| Personal Loan and Auto Loan Warehouse Credit Facilities
Debt Instrument [Line Items]
Loans pledged as collateral	$ 551,500,000			453,000,000.0
Loans Held for Sale \| Payables to Securitization Holders
Debt Instrument [Line Items]
Loans pledged as collateral				286,300,000
Unconsolidated Securitization Trusts
Debt Instrument [Line Items]
Outstanding principal balance			$ 44,700,000
Assets Sold under Repurchase Agreements
Debt Instrument [Line Items]
Securities pledged as collateral	174,800,000			64,100,000
Securities Sold under Repurchase Agreements
Debt Instrument [Line Items]
Debt outstanding under Repurchase Agreements	140,200,000			57,000,000.0
Securities Sold under Repurchase Agreements \| Contractual Repurchase Dates Ranging from February 2020 to December 2026
Debt Instrument [Line Items]
Debt outstanding under Repurchase Agreements	64,500,000
Securities Sold under Repurchase Agreements \| Contractual Repurchase Date in March 2020
Debt Instrument [Line Items]
Debt outstanding under Repurchase Agreements	75,700,000
Payable to Securitization Note and Residual Certificate Holders \| Unconsolidated Securitization Trusts
Debt Instrument [Line Items]
Notes and residual certificates held by third-party investors				256,400,000
Third-party Investor \| Unconsolidated Securitization Trusts
Debt Instrument [Line Items]
Notes sold to third-party investors			$ 42,500,000
Subsequent Event \| Personal Loan Warehouse Credit Facilities \| Revolving Credit Facility
Debt Instrument [Line Items]
Current borrowing capacity		$ 700,000,000.0
Consolidated VIEs \| Loans Related to Consolidation of Securitization Trust \| Loans Held for Investment
Debt Instrument [Line Items]
Payable to securitization note and certificate holders	40,600,000
Fair value of loans invested in by the Company	40,300,000
Loans Invested in by Company
Debt Instrument [Line Items]
Fair value of loans invested in by the Company	766,048,000			842,604,000	$ 597,055,000
Loans Invested in by Company \| Consolidated VIEs \| Loans Related to Consolidation of Securitization Trust
Debt Instrument [Line Items]
Restricted cash pledged as collateral	2,900,000
Fair value of loans invested in by the Company	$ 40,300,000			$ 286,300,000