DEBT Debt (Narrative) (Details) - USD ($)	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Debt Instrument
Shelf Notes	$ 75,000,000
Senior Notes Issued November 2010
Debt Instrument
Face amount	18,500,000
Repayments of Debt	3,100,000
Minimum overdue financial obligation considered as default	$ 5,000,000
Debt Instrument, Maturity Date Range, Start	Aug. 01, 2019
Debt Instrument, Maturity Date Range, End	Jul. 31, 2020
Debt Instrument, Interest Rate, Stated Percentage	3.96%
Series B Senior Notes
Debt Instrument
Face amount	$ 10,000,000
Minimum overdue financial obligation considered as default	5,000,000
Annual Principal Installments	$ 1,000,000
Debt Instrument, Maturity Date Range, Start	May 15, 2021
Debt Instrument, Maturity Date Range, End	May 15, 2030
Debt Instrument, Interest Rate, Stated Percentage	3.95%
Line of Credit, BMO Harris
Debt Instrument
Expiration date	Jan. 31, 2024
Maximum borrowing capacity	$ 45,000,000
Maximum borrowing capacity for letters of credit	$ 10,000,000
Variable interest rate, prime based	3.50%
Variable interest rate, LIBOR based	1.50%
Line of credit amount outstanding	$ 0	$ 0
Minimum overdue financial obligation considered as default	$ 1,000,000