Finance Receivables - Schedule of Modified Financing Receivables To Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Personal Loans
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 198	$ 215	$ 376	$ 409
Modifications as a percent of net finance receivables by class	0.93%	1.03%	1.76%	1.96%
Personal Loans \| Interest rate reduction and term extension
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 101	$ 93	$ 201	$ 180
Personal Loans \| Interest rate reduction and principal forgiveness
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	97	122	175	229
Auto Finance
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 11	$ 6	$ 18	$ 12
Modifications as a percent of net finance receivables by class	0.39%	0.26%	0.68%	0.54%
Auto Finance \| Interest rate reduction and term extension
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 10	$ 6	$ 17	$ 12
Auto Finance \| Interest rate reduction and principal forgiveness
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 1	$ 0	$ 1	$ 0