Loans Receivable at Amortized Cost, Net Troubled Debt Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 0	$ 0
Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	0	3,254
Financing Receivable, Troubled Debt Restructuring, Subsequent Interest and Fees Charged Off	$ 0	$ 419

Interest and fees related to troubled debt restructurings which were written off during the period.

No definition available.

Name:	oprt_FinancingReceivableTroubledDebtRestructuringSubsequentInterestandFeesChargedOff
Namespace Prefix:	oprt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reflects the amount of the write-down related to a troubled debt restructuring.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: