Finance Receivables - Schedule of Modified Financing Receivables To Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Personal Loans
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 215	$ 212	$ 409	$ 448
Modifications as a percent of net finance receivables by class	1.03%	1.05%	1.96%	2.23%
Personal Loans \| Interest rate reduction and term extension
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 93	$ 102	$ 180	$ 233
Personal Loans \| Interest rate reduction and principal forgiveness
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	122	110	229	215
Auto Finance
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 6	$ 5	$ 12	$ 9
Modifications as a percent of net finance receivables by class	0.26%	0.29%	0.54%	0.51%
Auto Finance \| Interest rate reduction and term extension
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 6	$ 5	$ 12	$ 9
Auto Finance \| Interest rate reduction and principal forgiveness
Financing Receivable, Modified [Line Items]
Total modifications to borrowers experiencing financial difficulties	$ 0	$ 0	$ 0	$ 0