Stockholders’ Equity - Common and Preferred Shares Authorized (Details)	May 13, 2016 $ / shares shares	Jul. 31, 2016 $ / shares shares	Apr. 30, 2016 $ / shares shares
Authorized stock
Common and preferred stock, shares authorized	550,000,000
Common stock, shares authorized	500,000,000	500,000,000	500,000,000
Preferred stock, shares authorized	50,000,000	50,000,000	50,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Common Stock
Authorized stock
Stock split ratio	10.158