Notes Receivable and Allowances for Credit Losses (Details) - USD ($) $ in Millions	6 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jul. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans purchased from originating bank partner, principal balance	$ 1,500	$ 748
Commitment to purchase, amount originated before period end	$ 25
Period of suspended accrued interest past due	120 days
Period past due considered delinquent	1 day
Notes receivable held for sale	$ 14		$ 3
Loans sold	237	$ 74
2023 Forward Flow Agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum commitment to sell participation interest in unsecured term loans, cumulatively	350
Notes receivable, remaining amount held for sale	225
2025 Forward Flow Agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, remaining amount held for sale	300
Minimum | 2023 Forward Flow Agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum commitment to sell participation interest in unsecured term loans, monthly	$ 8
Term of commitment	4 years
Minimum | 2025 Forward Flow Agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum commitment to sell participation interest in unsecured term loans, cumulatively	$ 300
Term of commitment	18 months
Maximum | 2025 Forward Flow Agreement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum commitment to sell participation interest in unsecured term loans, monthly	$ 45
Small Business Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, net	1,200		912
Refund Advance Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment to purchase, amount originated before period end	30
Notes receivable, net	$ 268		$ 4