Receivables and Financing Arrangements - Additional Information (Detail) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Receivables [Abstract]
Amount of the Credit Card Receivables	$ 53,160,000	$ 53,594,000
Percentage of Credit Card Receivables as recorded in accounts receivable considered current	98.00%	97.00%
Allowance for doubtful accounts for estimated losses associated with the Credit Card Receivables	1,500,000	2,000,000
Current portion of carrying amount of financing arrangements including accrued interest	7,065,000
Non-current portion of carrying amount of financing arrangements including accrued interest	$ 65,460,000	$ 59,576,000