Derivative Financial Instruments (Details Textual) $ in Thousands		3 Months Ended
		Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)	Apr. 30, 2017 CHF (SFr)	Apr. 30, 2017 EUR (€)	Apr. 30, 2017 GBP (£)	Apr. 30, 2017 JPY (¥)
Derivatives Fair Value [Line Items]
Net change in effective portion of hedging contracts		$ 100	$ 200
Net change in effective portion of hedging contracts, tax		$ 0	100
Maximum length of time hedged in cash flow hedge		24 months
Amounts reclassified from accumulated other comprehensive income	[1]	$ 77	126
Net Unrealized Income (Loss) On Hedging Contracts
Derivatives Fair Value [Line Items]
Amounts reclassified from accumulated other comprehensive income	[1]	$ 77	126
Accumulated other comprehensive income, tax			$ 0
Foreign Exchange Forward
Derivatives Fair Value [Line Items]
Net forward contracts hedging portfolio				SFr 21,000,000	€ 11,700,000	£ 5,900,000	¥ 30,000,000
Maximum
Derivatives Fair Value [Line Items]
Expiry dates ranging		Oct. 05, 2017

[1] Amounts reclassified to earnings in the Consolidated Statements of Operations.