Derivatives and Hedging Activities - Summary of Open Foreign Currency Contracts (Details) £ in Thousands, SFr in Thousands, CAD in Thousands, $ in Thousands	Jul. 31, 2016 USD ($)	Jul. 31, 2016 GBP (£)	Jul. 31, 2016 CAD	Jul. 31, 2016 CHF (SFr)
Derivative [Line Items]
Number of Instruments	18	18	18	18
Sell USD/Buy CHF Forward Contract [Member]
Derivative [Line Items]
Number of Instruments	6	6	6	6
Sell USD/Buy CAD Forward Contract [Member]
Derivative [Line Items]
Number of Instruments	6	6	6	6
Sell USD/Buy GBP Forward Contract [Member]
Derivative [Line Items]
Number of Instruments	6	6	6	6
Short [Member] | Sell USD/Buy CHF Forward Contract [Member]
Derivative [Line Items]
Notional Value	$ 5,451
Short [Member] | Sell USD/Buy CAD Forward Contract [Member]
Derivative [Line Items]
Notional Value	9,387
Short [Member] | Sell USD/Buy GBP Forward Contract [Member]
Derivative [Line Items]
Notional Value	$ 5,129
Long [Member] | Sell USD/Buy CHF Forward Contract [Member]
Derivative [Line Items]
Notional Value | SFr				SFr 5,344
Long [Member] | Sell USD/Buy CAD Forward Contract [Member]
Derivative [Line Items]
Notional Value | CAD			CAD 13,129
Long [Member] | Sell USD/Buy GBP Forward Contract [Member]
Derivative [Line Items]
Notional Value | £		£ 3,508