Leases (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Leases [Abstract]
Net operating leases with initial term expiration dates ,description			The Company is the lessor of certain properties which are leased to tenants under net operating leases with initial term expiration dates ranging from 2021 to 2029.
Comprehensive loss	$ 0.9	$ 0.7	$ 1.7	$ 1.5
Related party leases expire, description			The Company has related party leases that expire in April 2025 for (i) an aggregate of 88,631 square feet, which includes two parking spots per thousand square feet of space leased at 520 Broad Street, Newark, New Jersey, and (ii) 3,595 square feet in Israel.
Annual rent			$ 2.0
Related parties terminate leases, description			The related parties have the right to terminate the domestic leases upon four months’ notice, and upon early termination will pay a termination penalty equal to 25% of the portion of the rent due over the course of the remaining term. A related party has the right to terminate the Israeli lease upon four months’ notice. IDT has the right to lease an additional 50,000 square feet, in 25,000-foot increments, in the building located at 520 Broad Street, Newark, New Jersey on the same terms as their base lease, and other rights should 25,000 square feet or less remain available to lessees in the building. Upon expiration of the lease, related parties have the right to renew the leases for another five years.

Net operating leases with initial term expiration dates ,description

The Company is the lessor of certain properties which are leased to tenants under net operating leases with initial term expiration dates ranging from 2021 to 2029.

The Company has related party leases that expire in April 2025 for (i) an aggregate of 88,631 square feet, which includes two parking spots per thousand square feet of space leased at 520 Broad Street, Newark, New Jersey, and (ii) 3,595 square feet in Israel.

The related parties have the right to terminate the domestic leases upon four months’ notice, and upon early termination will pay a termination penalty equal to 25% of the portion of the rent due over the course of the remaining term. A related party has the right to terminate the Israeli lease upon four months’ notice. IDT has the right to lease an additional 50,000 square feet, in 25,000-foot increments, in the building located at 520 Broad Street, Newark, New Jersey on the same terms as their base lease, and other rights should 25,000 square feet or less remain available to lessees in the building. Upon expiration of the lease, related parties have the right to renew the leases for another five years.