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, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 7,801	$ 10,836	$ 24,335	$ 27,234
% of Net finance receivables	0.40%	0.50%	1.10%	1.30%
Interest Rate Reduction [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 5,927	$ 7,905	$ 18,768	$ 18,840
% of Net finance receivables	0.30%	0.30%	0.90%	0.90%
Interest Rate Reduction and Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 1,242	$ 1,718	$ 4,364	$ 6,407
% of Net finance receivables	0.10%	0.10%	0.20%	0.30%
Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 448	$ 1,060	$ 769	$ 1,451
% of Net finance receivables		0.10%
Principal Forgiveness, Interest Rate Reduction, & Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	184	$ 153	434	536
Large Loans [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 6,317	$ 8,464	$ 19,422	$ 21,410
% of Net finance receivables	0.40%	0.60%	1.10%	1.40%
Large Loans [Member] \| Interest Rate Reduction [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 4,667	$ 6,011	$ 14,701	$ 14,350
% of Net finance receivables	0.30%	0.40%	0.90%	0.90%
Large Loans [Member] \| Interest Rate Reduction and Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 1,088	$ 1,421	$ 3,676	$ 5,331
% of Net finance receivables	0.10%	0.10%	0.20%	0.40%
Large Loans [Member] \| Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 378	$ 885	$ 626	$ 1,211
% of Net finance receivables		0.10%		0.10%
Large Loans [Member] \| Principal Forgiveness, Interest Rate Reduction, & Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	184	$ 147	419	$ 518
Small Loans [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 1,484	$ 2,372	$ 4,913	$ 5,824
% of Net finance receivables	0.30%	0.40%	1.00%	1.10%
Small Loans [Member] \| Interest Rate Reduction [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 1,260	$ 1,894	$ 4,067	$ 4,490
% of Net finance receivables	0.30%	0.30%	0.90%	0.90%
Small Loans [Member] \| Interest Rate Reduction and Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 154	$ 297	$ 688	$ 1,076
% of Net finance receivables		0.10%	0.10%	0.20%
Small Loans [Member] \| Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis	$ 70	$ 175	$ 143	$ 240
Small Loans [Member] \| Principal Forgiveness, Interest Rate Reduction, & Term Extension [Member]
Financing Receivable, Modified [Line Items]
Amortized cost basis		$ 6	$ 15	$ 18