Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Unrecognized Tax Benefits, Beginning Balance	$ 6,148	$ 5,482
Additions based on tax positions related to current year	2,706	1,982
Additions for tax positions of prior years	142	48
Reductions for tax positions of prior years	(47)	(192)
Reductions due to lapse of applicable statute of limitations	(1,411)	(1,172)
Settlements
Unrecognized Tax Benefits, Ending Balance	$ 7,538	$ 6,148