Long-Term Debt - Mortgages (Schedule of Long-term Debt) (Details) - USD ($)		6 Months Ended
		Jan. 31, 2021		Jul. 31, 2020	Mar. 31, 2020	Nov. 30, 2019
Mortgage:
Deferred financing costs		$ (149,911)		$ (168,967)
Net		$ 8,080,454		8,627,965
Bond St. Building Brooklyn NY Two [Member]
Mortgage:
Current Annual Interest Rate		4.375%	[1]			4.375%
Final Payment Date	[1]	Dec. 01, 2024
Long term loan	[1]	$ 4,330,054		4,829,832
Fishkill, New York Property [Member]
Mortgage:
Current Annual Interest Rate		3.98%	[2]		3.98%
Final Payment Date	[2]	Apr. 01, 2025
Long term loan	[2]	$ 3,900,311		$ 3,967,100

[1] In November 2019, the Company refinanced the remaining balance of a $6,000,000, 3.54% interest rate loan with another bank for $5,255,920 plus an additional $144,080 for a total of $5,400,000. The interest rate on the new loan is fixed at 4.375%. The loan is self-liquidating over a period of five years and secured by the Nine Bond Street building in Brooklyn, New York.

[2] In March 2020, the Company obtained a loan with a bank in the amount of $4,000,000 to finance renovations and brokerage commissions relating to space leased to a community college at the Fishkill, New York building. The loan is secured by the Fishkill, New York building; amortized over a 20-year period with an interest rate of 3.98% and is due in five years.