Subsequent Events Subsequent Events (Details) - Nonvoting Common Stock [Member] - $ / shares	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015	Oct. 31, 2017
Subsequent Event [Line Items]
Dividends	$ 0.83	$ 0.82	$ 0.81	$ 0.80
Dividends Payable, Amount Per Share					$ 0.2075
Percentage Increase In Dividend		1.20%