Financial Instruments - Outstanding Currency, Forward Exchange Contracts (Detail) $ in Thousands	Jul. 31, 2015 USD ($)
Derivative [Line Items]
Fair Market Value of foreign currency derivative contracts	$ 312
Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	533,016
Fair Market Value of foreign currency derivative contracts	522,821
Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	595,465
Fair Market Value of foreign currency derivative contracts	585,582
Euro [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	370,973
Fair Market Value of foreign currency derivative contracts	361,188
Euro [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	355,289
Fair Market Value of foreign currency derivative contracts	348,063
British Pound [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	84,196
Fair Market Value of foreign currency derivative contracts	84,382
British Pound [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	64,146
Fair Market Value of foreign currency derivative contracts	64,046
Japanese Yen [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	28,212
Fair Market Value of foreign currency derivative contracts	27,741
Japanese Yen [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	19,589
Fair Market Value of foreign currency derivative contracts	19,209
Australian Dollar [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	192
Fair Market Value of foreign currency derivative contracts	183
Australian Dollar [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	7,583
Fair Market Value of foreign currency derivative contracts	7,001
Hong Kong Dollar [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	46,624
Fair Market Value of foreign currency derivative contracts	46,611
Hong Kong Dollar [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	108,693
Fair Market Value of foreign currency derivative contracts	108,663
Singapore Dollar [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	10,850
Fair Market Value of foreign currency derivative contracts	10,533
Others [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	2,819
Fair Market Value of foreign currency derivative contracts	2,716
Others [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	29,315
Fair Market Value of foreign currency derivative contracts	$ 28,067