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		6 Months Ended
	Jan. 31, 2026	Jan. 31, 2025	Jan. 31, 2026	Jan. 31, 2025
Earnings Per Share [Line Items]
Net income	$ 48,051	$ 40,334	$ 101,987	$ 87,117
Denominator for basic income per share for both Class A and Class B	47,310	47,851	47,291	47,792
Plus: Effect of dilutive equity awards	428	455	443	469
Denominator for diluted income per share for both Class A and Class B	47,738	48,306	47,734	48,261
Class A Nonvoting Common Stock
Earnings Per Share [Line Items]
Basic	$ 1.02	$ 0.84	$ 2.16	$ 1.82
Diluted	$ 1.01	$ 0.83	$ 2.14	$ 1.81
Class B Voting Common Stock
Earnings Per Share [Line Items]
Preferential dividends	$ 0	$ 0	$ 728	$ 736
Preferential dividends on dilutive stock options	0	0	(8)	(8)
Numerator for basic and diluted income per Class B Voting Common Share	$ 48,051	$ 40,334	$ 101,251	$ 86,373
Basic	$ 1.02	$ 0.84	$ 2.14	$ 1.81
Diluted	$ 1.01	$ 0.83	$ 2.12	$ 1.79