Summary of significant accounting policies (Details)	3 Months Ended
Oct. 31, 2022 item
Significant Accounting Policies [Line Items]
Number of reporting units	1

Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

No definition available.

Name:	us-gaap_NumberOfReportingUnits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration