v3.26.1
Fair value measurements - Schedule of Range and Weighted‑Average of Significant Unobservable Inputs Used in Level 3 Fair Value Measurements by Asset (Details)
Apr. 30, 2026
Jan. 31, 2026
Minimum    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Cardholder receivables, Unobservable Input, Discount rate (as a percent) 14.20% 14.21%
Cardholder receivables, Unobservable Input, Default rate (as a percent) 27.00% 27.00%
Deferred purchase price receivable, Unobservable Input, Discount rate (as a percent) 7.25% 7.25%
Deferred purchase price receivable, Unobservable Input, Funded monthly repayment rate (as a percent) 4.50% 4.50%
Maximum    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Cardholder receivables, Unobservable Input, Discount rate (as a percent) 15.20% 15.21%
Cardholder receivables, Unobservable Input, Default rate (as a percent) 33.00% 33.00%
Deferred purchase price receivable, Unobservable Input, Discount rate (as a percent) 10.75% 10.75%
Deferred purchase price receivable, Unobservable Input, Funded monthly repayment rate (as a percent) 5.50% 5.50%
Weighted Average    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Cardholder receivables, Unobservable Input, Discount rate (as a percent) 14.70% 14.71%
Cardholder receivables, Unobservable Input, Default rate (as a percent) 30.00% 30.00%
Deferred purchase price receivable, Unobservable Input, Discount rate (as a percent) 9.00% 9.00%
Deferred purchase price receivable, Unobservable Input, Funded monthly repayment rate (as a percent) 5.00% 5.00%