CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Class A Nonvoting Common Stock [Member]	Class B Voting Common Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Class A Nonvoting Common Stock [Member]	Retained Earnings [Member] Class B Voting Common Stock [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]
Beginning balance at Jul. 31, 2020	$ 863,072			$ 548	$ 331,761	$ 704,456			$ (107,216)	$ (66,477)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	101,632					101,632
Other Comprehensive Income (Loss), Net of Tax	17,929									17,929
Issuance of shares of Class A Common Stock under stock plan	(1,158)				(2,839)				(1,681)
Tax benefit and withholdings from deferred compensation distributions	32				32
Stock-based compensation expense	8,003				8,003
Repurchase of shares of Class A Common Stock	(3,593)								(3,593)
Dividends, Common Stock, Cash		$ (32,013)	$ (2,278)				$ (32,013)	$ (2,278)
Ending balance at Apr. 30, 2021	951,626			548	336,957	771,797			(109,128)	(48,548)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared							$ 0.6600	$ 0.6434
Beginning balance at Jul. 31, 2021	963,028			548	339,125	788,369			(109,061)	(55,953)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	108,915					108,915
Other Comprehensive Income (Loss), Net of Tax	(42,935)									(42,935)
Issuance of shares of Class A Common Stock under stock plan	(4,407)				(4,539)				132
Tax benefit and withholdings from deferred compensation distributions	115				115
Stock-based compensation expense	9,153				9,153
Repurchase of shares of Class A Common Stock	(84,930)								(84,930)
Dividends, Common Stock, Cash		(32,370)	$ (2,331)				$ (32,370)	$ (2,331)
Ending balance at Apr. 30, 2022	914,238			548	343,854	862,583			(193,859)	(98,888)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared			$ 0.6584				$ 0.6750
Beginning balance at Jan. 31, 2022	966,568			548	341,889	833,981			(130,911)	(78,939)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,054					40,054
Other Comprehensive Income (Loss), Net of Tax	(19,949)									(19,949)
Issuance of shares of Class A Common Stock under stock plan	244				(18)				262
Stock-based compensation expense	1,983				1,983
Repurchase of shares of Class A Common Stock	(63,210)								(63,210)
Dividends, Common Stock, Cash		$ (10,655)	$ (797)				$ (10,655)	$ (797)
Ending balance at Apr. 30, 2022	$ 914,238			$ 548	$ 343,854	$ 862,583			$ (193,859)	$ (98,888)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared							$ 0.2250	$ 0.2250