Accounts Receivable (Details) - USD ($)	9 Months Ended	12 Months Ended
	Apr. 30, 2024	Jul. 31, 2023
Statement [Line Items]
Total accounts receivable	$ 202,352,000	$ 165,248,000
Less allowance for doubtful accounts	2,706,000	2,089,000
Accounts receivable, net	$ 199,646,000	$ 163,159,000
Accounts Receivable | Customer Concentration Risk | U.S. government
Statement [Line Items]
Concentration risk, percentage	42.30%	35.30%
Accounts Receivable | Customer Concentration Risk | AT&T, Inc.
Statement [Line Items]
Concentration risk, percentage		11.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-05-01
Statement [Line Items]
Remaining performance obligations, period	24 months
Billed Receivables | Commercial and International Customers
Statement [Line Items]
Total accounts receivable	$ 39,770,000	$ 52,438,000
Billed Receivables | U.S. Government and Its Agencies
Statement [Line Items]
Total accounts receivable	21,316,000	31,149,000
Unbilled Receivables
Statement [Line Items]
Long-term receivables	417,000	2,993,000
Unbilled Receivables | Commercial and International Customers
Statement [Line Items]
Total accounts receivable	76,932,000	54,469,000
Unbilled Receivables | U.S. Government and Its Agencies
Statement [Line Items]
Total accounts receivable	$ 64,334,000	$ 27,192,000