Income Taxes (Details) - USD ($)	3 Months Ended
	Oct. 31, 2015	Oct. 31, 2014
Income Tax Disclosure [Abstract]
Effective tax rate	27.90%	27.60%
Unrecognized tax benefits	$ 18,700,000
Accrued interest and penalties on unrecognized tax benefits	$ 2,000,000
Statute of limitations period, average, years	5 years
Maximum possible reduction in amount of unrecognized tax benefits	$ 1,100,000.0
Unrecognized tax benefits potential expiration period	12 months