Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Oct. 31, 2015	Jan. 31, 2015
ASSETS:
Derivatives, assets	$ 6,280	$ 15,542
LIABILITIES:
Derivatives, liabilities	263	270
Derivatives designated as hedging instruments: | Foreign exchange currency contracts | Other current assets/Other assets | Cash flow hedges
ASSETS:
Derivatives, assets	4,307	6,597
Derivatives designated as hedging instruments: | Foreign exchange currency contracts | Accrued expenses | Cash flow hedges
LIABILITIES:
Derivatives, liabilities	36	0
Derivatives not designated as hedging instruments:
LIABILITIES:
Derivatives, liabilities	227	270
Derivatives not designated as hedging instruments: | Foreign exchange currency contracts | Other current assets
ASSETS:
Derivatives, assets	1,973	8,945
Derivatives not designated as hedging instruments: | Foreign exchange currency contracts | Accrued expenses
LIABILITIES:
Derivatives, liabilities	109	0
Derivatives not designated as hedging instruments: | Interest rate swaps | Accrued expenses/Other long-term liabilities
LIABILITIES:
Derivatives, liabilities	$ 118	$ 270