Receivables (Narrative) (Details) (USD $)	9 Months Ended
	Jan. 31, 2013	Apr. 30, 2012	Jan. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired non-accrual status term, days	60 days
Loans made to franchisees	$ 237,800,000	$ 171,100,000	$ 215,600,000
Maximum credit card limit	2,500
Allowance for credit card receivables, percentage of amounts outstanding	21.00%
Emerald Advance Lines Of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual status loans	30,700,000	31,400,000	41,400,000
Term Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans made to franchisees	144,500,000	127,000,000	150,400,000
Revolving Lines Of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans made to franchisees	$ 93,300,000	$ 44,100,000	$ 65,200,000