Income Taxes - Reconciliation (Details)	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Income tax reconciliation disclosure
Expected statutory tax	35.00%	35.00%	35.00%
Differential attributable to:
Foreign operations	0.60%	1.20%	(0.10%)
State and local taxes	3.20%	3.40%	3.20%
Domestic production deduction	(2.30%)	(2.40%)	(2.30%)
Acquisition related items, net (a)		(1.60%)	0.70%
Loss on sale of business		1.10%
R&E tax credit	(1.10%)	(0.50%)	(0.30%)
Change in foreign tax rates	(0.40%)
Other	1.20%	0.90%	0.70%
Consolidated effective tax rate (as a percent)	36.20%	37.10%	36.90%