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, 2024	Jan. 31, 2023	Jan. 31, 2024	Jan. 31, 2023
Earnings Per Share [Line Items]
Net income	$ 43,628	$ 37,986	$ 90,869	$ 77,427
Denominator for basic income per share for both Class A and Class B	48,374	49,745	48,440	49,806
Plus: Effect of dilutive equity awards	351	264	328	243
Denominator for diluted income per share for both Class A and Class B	48,725	50,009	48,768	50,049
Class A Nonvoting Common Stock
Earnings Per Share [Line Items]
Basic	$ 0.90	$ 0.76	$ 1.88	$ 1.55
Diluted	$ 0.90	$ 0.76	$ 1.86	$ 1.55
Class B Voting Common Stock
Earnings Per Share [Line Items]
Preferential dividends	$ 0	$ 0	$ 748	$ 769
Preferential dividends on dilutive stock options	0	0	(5)	(4)
Numerator for basic and diluted income per Class B Voting Common Share	$ 43,628	$ 37,986	$ 90,116	$ 76,654
Basic	$ 0.90	$ 0.76	$ 1.86	$ 1.54
Diluted	$ 0.90	$ 0.76	$ 1.85	$ 1.53