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
	Oct. 31, 2025	Oct. 31, 2024
Earnings Per Share [Line Items]
Net income	$ 53,936	$ 46,783
Denominator for basic income per share for both Class A and Class B	47,273	47,732
Plus: Effect of dilutive equity awards	458	485
Denominator for diluted income per share for both Class A and Class B	47,731	48,217
Class A Nonvoting Common Stock
Earnings Per Share [Line Items]
Basic	$ 1.14	$ 0.98
Diluted	$ 1.13	$ 0.97
Class B Voting Common Stock
Earnings Per Share [Line Items]
Preferential dividends	$ (728)	$ (736)
Preferential dividends on dilutive stock options	(8)	(8)
Numerator for basic and diluted income per Class B Voting Common Share	$ 53,200	$ 46,039
Basic	$ 1.13	$ 0.96
Diluted	$ 1.11	$ 0.95