Derivative Instruments and Foreign Currency Exposure (Details) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2013 Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2012 Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Jul. 31, 2013 Designated as Hedging Instrument [Member] Foreign Currency Cash Flow Hedge [Member]	Jul. 31, 2012 Designated as Hedging Instrument [Member] Foreign Currency Cash Flow Hedge [Member]	Jan. 31, 2013 Designated as Hedging Instrument [Member] Foreign Currency Cash Flow Hedge [Member]
Notional Value in USD	$ 1,000,000	$ 22,822,770	$ 5,587,136	$ 25,325,540
Gain and loss reported in current operating income (expense)	92,818	1,647	122,697	(55,614)
Notional Value in USD					300,000		6,944,040
Gain reported in equity as other comprehensive income					4,722		38,513
Gain reclassed from other comprehensive income into current earnings during three months ended July 31, 2013, reported in operating income					$ 160,032	$ 32,485