Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended							1 Months Ended
	Oct. 31, 2013	Apr. 30, 2013	Nov. 30, 2008	Nov. 30, 2008 Standby Letters of Credit	Oct. 31, 2013 Unused lines of Credit	Apr. 30, 2013 Unused lines of Credit	Oct. 31, 2013 Revolving Credit Facility Amendment Five	Oct. 31, 2013 Combined Letter Of Credit And Credit Card Services Subfacility	Jul. 31, 2007 Line of Credit
Debt Instrument [Line Items]
Revolving line of credit with a borrowing capacity							$ 30.0	$ 2.7
Line of credit facility current borrowing capacity percentage							100.00%
Loan and security agreement, issue date									Jul. 18, 2007
Loan and security agreement, expiration date									Jan. 31, 2015
Letter of credit drawn	1.6	2.0
Unused revolving line of credit					28.4	28.0
Standby letter of credit in favor of its landlord			$ 0.5	$ 0.1