Finance Receivables, Credit Quality Information, and Allowance for Credit Losses - Summary of Modification Made to Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 10,836	$ 8,195	$ 27,234	$ 17,194
% of Net finance receivables	0.50%	0.50%	1.30%	0.90%
Interest Rate Reduction [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 7,905	$ 4,277	$ 18,840	$ 4,903
% of Net finance receivables	0.30%	0.20%	0.90%	0.30%
Interest Rate Reduction and Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 1,718	$ 2,496	$ 6,407	$ 9,331
% of Net finance receivables	0.10%	0.10%	0.30%	0.50%
Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 1,060	$ 1,307	$ 1,451	$ 2,552
% of Net finance receivables	0.10%	0.10%	0.10%	0.10%
Principal Forgiveness, Interest Rate Reduction, & Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 153	$ 115	$ 536	$ 408
Large Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 8,464	$ 6,271	$ 21,410	$ 13,902
% of Net finance receivables	0.60%	0.50%	1.40%	1.10%
Large Loans [Member] \| Interest Rate Reduction [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 6,011	$ 2,943	$ 14,350	$ 3,435
% of Net finance receivables	0.40%	0.20%	0.90%	0.30%
Large Loans [Member] \| Interest Rate Reduction and Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 1,421	$ 2,110	$ 5,331	$ 8,000
% of Net finance receivables	0.10%	0.20%	0.40%	0.60%
Large Loans [Member] \| Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 885	$ 1,108	$ 1,211	$ 2,082
% of Net finance receivables	0.10%	0.10%	0.10%	0.20%
Large Loans [Member] \| Principal Forgiveness, Interest Rate Reduction, & Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 147	$ 110	$ 518	$ 385
Small Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 2,372	$ 1,924	$ 5,824	$ 3,292
% of Net finance receivables	0.40%	0.40%	1.10%	0.60%
Small Loans [Member] \| Interest Rate Reduction [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 1,894	$ 1,334	$ 4,490	$ 1,468
% of Net finance receivables	0.30%	0.30%	0.90%	0.30%
Small Loans [Member] \| Interest Rate Reduction and Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 297	$ 386	$ 1,076	$ 1,331
% of Net finance receivables	0.10%	0.10%	0.20%	0.30%
Small Loans [Member] \| Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 175	$ 199	$ 240	$ 470
% of Net finance receivables		0.00%		0.10%
Small Loans [Member] \| Principal Forgiveness, Interest Rate Reduction, & Term Extension [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized cost basis	$ 6	$ 5	$ 18	$ 23