Financing Arrangements (Details) (USD $)	3 Months Ended	12 Months Ended
	Apr. 30, 2013	Nov. 30, 2013	Jan. 31, 2013	Apr. 30, 2012
Debt Disclosure [Abstract]
Borrowing capacity under line of credit	$ 10,500,000
Maturity date of the line of credit		Nov. 30, 2013
Line of credit prime interest rate percentage	1.50%
Letters of credit issued, amount	850,000
Borrowing outstanding under line of credit	0		0	0
Remaining borrowing capacity under the line of credit	$ 9,650,000