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Fair Value Measurements (Details) - USD ($)
3 Months Ended 6 Months Ended
Jan. 31, 2022
Jan. 31, 2021
Jan. 31, 2022
Jan. 31, 2021
Oct. 31, 2020
Fair Value Disclosures [Abstract]          
Investment hedge funds         $ 2,000,000
Investments in securities $ 500,000   $ 500,000    
Impairment loss $ 0 $ 0 $ 0 $ 700,000