Stockholder's Investments - Schedule of Other Activity in Stockholders' Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Class of Stock [Line Items]
Sale Of Shares At Cost	$ 0	$ 0	$ 0
Purchase Of Shares At Cost	0	0	0
Ending Balance, Other Stockholders Equity	0	0	0	$ 0
Shares Held Rabbi Trust At Cost [Member]
Class of Stock [Line Items]
Sale Of Shares At Cost	(277)	(460)	(928)
Purchase Of Shares At Cost	(1,472)	(1,293)	(1,212)
Ending Balance, Other Stockholders Equity	$ (10,534)	$ (9,339)	$ (8,506)	$ (8,222)
Ending Balance, Other Stockholders Equity Shares	315,916	292,329	285,533	299,916
Deferred Compensation [Member]
Class of Stock [Line Items]
Sale Of Shares At Cost	$ (277)	$ (460)	$ (928)
Purchase Of Shares At Cost	(1,472)	(1,293)	(1,212)
Ending Balance, Other Stockholders Equity	$ 10,534	$ 9,339	$ 8,506	$ 8,222
Ending Balance, Other Stockholders Equity Shares	315,916	292,329	285,533	299,916