Summary of Significant Accounting Policies - Details (Details) - Accounting Standards Update 2015-03
$ in Millions
Jul. 31, 2016
USD ($)
Other long-term assets  
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]  
Debt finance costs, net $ (1.6)
Long-term debt  
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]  
Debt finance costs, net $ 1.6