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	12 Months Ended
	Jul. 31, 2025	Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2021
Earnings Per Share [Line Items]
Net income	$ 189,256	$ 197,215	$ 174,857	$ 149,979	$ 129,659
Denominator for basic earnings per share for both Class A and Class B	47,641	48,119	49,591
Plus: Effect of dilutive stock options	451	377	278
Denominator for diluted earnings per share for both Class A and Class B	48,092	48,496	49,869
Class A Nonvoting Common Stock
Earnings Per Share [Line Items]
Basic	$ 3.97	$ 4.10	$ 3.53
Diluted	$ 3.94	$ 4.07	$ 3.51
Class B Voting Common Stock
Earnings Per Share [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic	$ 188,512	$ 196,462	$ 174,085
Cash dividends on Common Stock	736	748	769
Preferential dividends on dilutive stock options	$ 8	$ 5	$ 3
Basic	$ 3.96	$ 4.08	$ 3.51
Diluted	$ 3.92	$ 4.05	$ 3.49