Stockholders' Equity - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Apr. 30, 2020
Apr. 30, 2019
Apr. 30, 2020
Apr. 30, 2019
Aug. 01, 2019
Jul. 31, 2019
Jul. 31, 2018
Schedule Of Stockholders Equity [Line Items]              
Accumulated other comprehensive loss $ (92,242)   $ (92,242)     $ (71,254) $ (56,401)
Beginning balance 899,924 $ 803,381 850,774 $ 752,112      
Net income 13,633 34,781 84,684 94,645      
Other comprehensive loss, net of tax (19,752) (7,881) (20,988) (12,045)      
Issuance of shares of Class A Common Stock under stock plan (426) (2,982) (2,620) (18,119)      
Tax benefit and withholdings from deferred compensation distributions     133        
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation       209      
Stock-based compensation expense 1,796 2,506 7,180 10,311      
Purchase of shares of Class A Common Stock       (3,182)      
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets         $ (2,137)    
Cash dividends on Class A common stock (10,542) (10,473) (32,197) (31,291)      
Cash dividends on Class B common stock (770) (752) (2,251) (2,197)      
Ending balance 820,602 824,544 820,602 824,544      
Treasury Stock, Value, Acquired, Cost Method (64,113)   (64,113)        
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 329,263 328,978 329,969 325,631      
Issuance of shares of Class A Common Stock under stock plan (91) (1,433) (6,314) (6,100)      
Tax benefit and withholdings from deferred compensation distributions     133 209      
Stock-based compensation expense 1,796 2,506 7,180 10,311      
Ending balance 330,968 330,051 330,968 330,051      
Retained Earnings              
Schedule Of Stockholders Equity [Line Items]              
Beginning balance 685,758 588,918 637,843 553,454      
Net income 13,633 34,781 84,684 94,645      
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets         $ (2,137)    
Cash dividends on Class A common stock (10,542) (10,473) (32,197) (31,291)      
Cash dividends on Class B common stock (770) (752) (2,251) (2,197)      
Ending balance 688,079 612,474 688,079 612,474      
Treasury Stock              
Schedule Of Stockholders Equity [Line Items]              
Beginning balance (43,155) (54,498) (46,332) (71,120)      
Issuance of shares of Class A Common Stock under stock plan (517) (4,415) (3,694) (24,219)      
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation       0      
Purchase of shares of Class A Common Stock       (3,182)      
Ending balance (106,751) (50,083) (106,751) (50,083)      
Treasury Stock, Value, Acquired, Cost Method (64,113)   (64,113)        
Accumulated Other Comprehensive Loss              
Schedule Of Stockholders Equity [Line Items]              
Accumulated other comprehensive loss   (68,446)   (68,446)      
Beginning balance (72,490) (60,565) (71,254) (56,401)      
Other comprehensive loss, net of tax (19,752) (7,881) (20,988) (12,045)      
Ending balance $ (92,242) $ (68,446) $ (92,242) $ (68,446)