Earnings Per Share (Details 1) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Shares excluded from the calculation of diluted earnings per share	1,078	1,554	1,595	1,554
Stock options [Member]
Shares excluded from the calculation of diluted earnings per share	937	1,301	1,330	1,301
Non-vested restricted Class B common stock [Member]
Shares excluded from the calculation of diluted earnings per share	141	253	172	253
Deferred stock units [Member]
Shares excluded from the calculation of diluted earnings per share			93