Derivative financial instruments - Summary of Fair Values Of Net Investment Contracts (Details)	Jul. 31, 2023 USD ($)
Prepaid expenses and other current assets
Investments, All Other Investments [Abstract]
Net investment contracts	$ 2,977,000
Derivative [Line Items]
Net investment contracts	2,977,000
Other assets
Investments, All Other Investments [Abstract]
Net investment contracts	59,000
Derivative [Line Items]
Net investment contracts	59,000
Accrued liabilities
Investments, All Other Investments [Abstract]
Net investment contracts	841,000
Derivative [Line Items]
Net investment contracts	841,000
Other long-term liabilities
Investments, All Other Investments [Abstract]
Net investment contracts	3,760,000
Derivative [Line Items]
Net investment contracts	$ 3,760,000