Stockholders' Equity and Stock-based Compensation (Details 3)	3 Months Ended		9 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014	Apr. 30, 2013
Summary of assumptions for fair value of employee stock option estimates
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum
Summary of assumptions for fair value of employee stock option estimates
Expected life (in years)	5 years 3 months	6 years 1 month 6 days	5 years	5 years 1 month 6 days
Risk-free interest rate, minimum	1.70%	1.20%	1.50%	0.60%
Expected volatility, minimum	42.30%	46.90%	41.30%	45.10%
Maximum
Summary of assumptions for fair value of employee stock option estimates
Expected life (in years)	5 years 3 months	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days
Risk-free interest rate, maximum	1.70%	1.20%	2.00%	1.20%
Expected volatility, maximum	42.30%	46.90%	46.20%	48.70%