Variable Interest Entities - Nonconsolidated VIEs (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Securitization investments	$ 407,782	$ 496,935
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Securitization investments	407,782	496,935
Variable Interest Entity, Not Primary Beneficiary \| Personal loans
Variable Interest Entity [Line Items]
Securitization investments	43,257	71,115
Variable Interest Entity, Not Primary Beneficiary \| Student loans
Variable Interest Entity [Line Items]
Securitization investments	$ 364,525	$ 425,820

The carrying amount (fair value) as of the balance sheet date of the transferor's interests in transferred financial assets (typically securitized receivables, generally not involved in the collection of principal) following transfer of significant portions of such financial instruments to other parties. Such interests could be ancillary cash flows and interest-only strips.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

Name:	us-gaap_InterestsContinuedToBeHeldByTransferorFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant