Stockholders' Equity - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018	Aug. 01, 2018
Schedule Of Stockholders Equity [Line Items]
Beginning balance	$ 803,381	$ 731,973	$ 752,112	$ 700,140
Net income	34,781	26,000	94,645	56,109
Other comprehensive loss, net of tax	(7,881)	(13,056)	(12,045)	(3,464)
Issuance of shares of Class A Common Stock under stock plan			(18,119)	(7,878)
Tax benefit and withholdings from deferred compensation distributions			209
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation				(209)
Stock-based compensation expense			10,311	7,581
Purchase of shares of Class A Common Stock			(3,182)
Cumulative adjustment for ASU 2014-09, net of tax (Note B)					$ (2,137)
Cash dividends on Class A common stock			(31,291)	(29,970)
Cash dividends on Class B common stock			(2,197)	(2,140)
Ending balance	824,544	734,647	824,544	734,647
Common Stock
Schedule Of Stockholders Equity [Line Items]
Beginning balance	548	548	548	548
Ending balance	548	548	548	548
Additional Paid-in Capital
Schedule Of Stockholders Equity [Line Items]
Beginning balance	328,978	325,733	325,631	322,608
Issuance of shares of Class A Common Stock under stock plan			(6,100)	(3,001)
Tax benefit and withholdings from deferred compensation distributions			209	213
Stock-based compensation expense			10,311	7,581
Ending balance	330,051	327,401	330,051	327,401
Retained Earnings
Schedule Of Stockholders Equity [Line Items]
Beginning balance	588,918	515,872	553,454	507,136
Net income			94,645	56,109
Cumulative adjustment for ASU 2014-09, net of tax (Note B)					$ (2,137)
Cash dividends on Class A common stock			(31,291)	(29,970)
Cash dividends on Class B common stock			(2,197)	(2,140)
Ending balance	612,474	531,135	612,474	531,135
Treasury Stock
Schedule Of Stockholders Equity [Line Items]
Beginning balance	(54,498)	(75,090)	(71,120)	(85,470)
Issuance of shares of Class A Common Stock under stock plan			(24,219)	(10,879)
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation				(422)
Purchase of shares of Class A Common Stock		1,278	3,182	1,278
Ending balance	(50,083)	(76,291)	(50,083)	(76,291)
Accumulated Other Comprehensive Loss
Schedule Of Stockholders Equity [Line Items]
Beginning balance	(60,565)	(35,090)	(56,401)	(44,682)
Other comprehensive loss, net of tax			(12,045)	(3,464)
Ending balance	$ (68,446)	$ (48,146)	$ (68,446)	$ (48,146)