Revenue Recognition (Details)	3 Months Ended		6 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Revenue Recognition (Details) [Line Items]
Percentage of total revenues		76.00%		75.00%
Clinical Services Revenue [Member]
Revenue Recognition (Details) [Line Items]
Percentage of total revenues	70.00%		72.00%