Financial Instruments - Outstanding Currency, Forward Exchange Contracts (Detail) $ in Thousands	Jan. 31, 2017 USD ($)
Derivative [Line Items]
Fair Market Value of foreign currency derivative contracts	$ (253)
Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	190,649
Fair Market Value of foreign currency derivative contracts	192,604
Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	238,727
Fair Market Value of foreign currency derivative contracts	240,470
Euro [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	127,476
Fair Market Value of foreign currency derivative contracts	128,608
Euro [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	46,433
Fair Market Value of foreign currency derivative contracts	46,911
British Pound [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	34,612
Fair Market Value of foreign currency derivative contracts	35,266
British Pound [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	38,391
Fair Market Value of foreign currency derivative contracts	38,779
Japanese Yen [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	22,762
Fair Market Value of foreign currency derivative contracts	22,865
Japanese Yen [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	16,351
Fair Market Value of foreign currency derivative contracts	16,266
Australian Dollar [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	376
Fair Market Value of foreign currency derivative contracts	379
Australian Dollar [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	7,519
Fair Market Value of foreign currency derivative contracts	7,679
Hong Kong Dollar [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	82,435
Fair Market Value of foreign currency derivative contracts	82,321
Singapore Dollar [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	1,155
Fair Market Value of foreign currency derivative contracts	1,159
Singapore Dollar [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	11,497
Fair Market Value of foreign currency derivative contracts	11,580
Others [Member] | Foreign Currency Forward Contracts [Member] | Sell [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	4,268
Fair Market Value of foreign currency derivative contracts	4,327
Others [Member] | Foreign Currency Forward Contracts [Member] | Buy [Member]
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	36,101
Fair Market Value of foreign currency derivative contracts	$ 36,934