Derivatives (Derivative Fair Values on the Condensed Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Oct. 31, 2015	Jan. 31, 2015
Foreign currency exchange forward contracts | Other current assets | Designated As Hedging Instrument
The location and amounts of derivative fair values on the Condensed Consolidated Balance Sheets
Other current assets	$ 1,688	$ 10,283
Foreign currency exchange forward contracts | Other current assets | Not Designated as Hedging Instruments
The location and amounts of derivative fair values on the Condensed Consolidated Balance Sheets
Other current assets	81	10
Foreign currency exchange forward contracts | Accrued expenses | Designated As Hedging Instrument
The location and amounts of derivative fair values on the Condensed Consolidated Balance Sheets
Other liabilities	305	0
Foreign currency exchange forward contracts | Accrued expenses | Not Designated as Hedging Instruments
The location and amounts of derivative fair values on the Condensed Consolidated Balance Sheets
Other liabilities	91	0
Fair Value, Measurements, Recurring
The location and amounts of derivative fair values on the Condensed Consolidated Balance Sheets
Other liabilities	396	0
Other current assets	1,769	10,293
Level 2 | Fair Value, Measurements, Recurring
The location and amounts of derivative fair values on the Condensed Consolidated Balance Sheets
Other liabilities	396	0
Other current assets	$ 1,769	$ 10,293