Net Income per Common Share - Reconciliation of Numerator and Denominator of Basic and Diluted Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2022	Apr. 30, 2021
Earnings Per Share [Line Items]
Net income	$ 40,054	$ 37,291	$ 108,915	$ 101,632
Denominator for basic income per share for both Class A and Class B	51,326	52,050	51,700	52,030
Plus: Effect of dilutive equity awards	242	399	355	311
Denominator for diluted income per share for both Class A and Class B	51,568	52,449	52,055	52,341
Class A Nonvoting Common Stock [Member]
Earnings Per Share [Line Items]
Basic	$ 0.78	$ 0.72	$ 2.11	$ 1.95
Diluted	$ 0.78	$ 0.71	$ 2.09	$ 1.94
Class B Voting Common Stock [Member]
Earnings Per Share [Line Items]
Preferential dividends	$ 0	$ 0	$ 803	$ 808
Preferential dividends on dilutive stock options	0	0	8	(4)
Numerator for basic and diluted income per Class B Voting Common Share	$ 40,054	$ 37,291	$ 108,104	$ 100,820
Basic	$ 0.78	$ 0.72	$ 2.09	$ 1.94
Diluted	$ 0.78	$ 0.71	$ 2.08	$ 1.93