Contingent Liabilities, Commitments and Legal Matters (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jan. 31, 2022	Jan. 31, 2022	Jul. 31, 2021
Loss Contingencies [Line Items]
Standby repurchase obligations amount	$ 3,396,455	$ 3,396,455	$ 1,821,012
Term of commitments		18 months
Repurchase and guarantee reserve balances	9,883	$ 9,883	$ 6,023
Selling, General and Administrative Expenses
Loss Contingencies [Line Items]
Expenses recorded related to product recall costs	$ 13,000	$ 35,000