Securitizations and Variable Interest Entities - Summary of Personal Whole Loan Securitizations and Sales (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Proceeds from sale of securities by consolidated VIE			$ 0	$ 106,192
Unconsolidated Trusts and Certificate Program Trusts
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Principal derecognized from loans securitized or sold	$ 0	$ 0	41,023	0
Net gains recognized from loans securitized or sold	0	0	259	0
Fair value of asset-backed senior and subordinated securities, and CLUB Certificate asset-backed securities retained upon settlement	0	0	2,180	0
Cash proceeds from servicing and other administrative fees on loans securitized or sold	1,782	5,152	7,294	19,600
Proceeds from sale of securities by consolidated VIE	0	0	5,320	0
Cash proceeds for interest received on senior securities and subordinated securities	$ 1,294	$ 975	$ 6,373	$ 6,586