Finance Receivables - Schedule of Modified Financing Receivables To Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Personal Loans
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 216	$ 205	$ 552	$ 565
Modifications as a percent of net finance receivables by class	0.98%	0.96%	2.50%	2.66%
Personal Loans \| Interest rate reduction and term extension
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 96	$ 89	$ 278	$ 248
Personal Loans \| Interest rate reduction and principal forgiveness
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	120	116	274	317
Auto Finance
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 14	$ 10	$ 30	$ 20
Modifications as a percent of net finance receivables by class	0.47%	0.40%	1.06%	0.85%
Auto Finance \| Interest rate reduction and term extension
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 13	$ 9	$ 28	$ 19
Auto Finance \| Interest rate reduction and principal forgiveness
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 1	$ 1	$ 2	$ 1