Derivatives And Financial Instruments (Schedule Of Classification Of Gains And Losses On Derivative Instruments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Oct. 31, 2012		Oct. 31, 2011		Oct. 31, 2012		Oct. 31, 2011
Derivatives, Fair Value [Line Items]
Recognized in Other Comprehensive Income (Loss)	$ (1,670)		$ (985)		$ (868)		$ 1,037
Reclassified from Accumulated Other Comprehensive Income into Statement of Operations	(440)	[1]	(607)	[1]	(1,205)	[1]	1,179	[1]
Recognized in Other Income (Expense), Net	(254)		682		(123)		(1,225)
Derivatives Designated As Hedging Instruments | Foreign Currency Forward [Member]
Derivatives, Fair Value [Line Items]
Recognized in Other Comprehensive Income (Loss)	(1,670)		(985)		(868)		1,037
Reclassified from Accumulated Other Comprehensive Income into Statement of Operations	(440)	[1]	(607)	[1]	(1,205)	[1]	1,179	[1]
Recognized in Other Income (Expense), Net	0		0		0		0
Derivatives Not Designated As Hedging Instruments | Foreign Currency Forward [Member]
Derivatives, Fair Value [Line Items]
Recognized in Other Comprehensive Income (Loss)	0		0		0		0
Reclassified from Accumulated Other Comprehensive Income into Statement of Operations	0	[1]	0	[1]	0	[1]	0	[1]
Recognized in Other Income (Expense), Net	$ (254)		$ 682		$ (123)		$ (1,225)

[1] Amounts reclassified from accumulated other comprehensive income (“OCI”) into the statement of operations are classified as operating expenses.