Income Taxes (Schedule Of Reconciliation Between Income Tax Provision And Statutory Federal Tax Rate) (Details)	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal income tax benefit	4.00%	4.20%	4.40%
Permanent differences	(0.10%)	0.50%	(0.60%)
Uncertain tax positions	(4.10%)	(0.60%)	1.20%
Net change in valuation allowance	(1.00%)	0.20%	(1.40%)
Other	(0.10%)	0.60%	(1.10%)
Effective tax rate	33.70%	39.90%	37.50%