Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Income Tax Disclosure [Abstract]
Effective tax rate	24.00%	29.50%	24.90%	27.90%
Income tax expense (benefit)	$ 3,000,000		$ 3,000,000
Unrecognized tax benefits	16,800,000		16,800,000
Accrued interest and penalties on unrecognized tax benefits	$ 2,000,000		$ 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