Discontinued Operations (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended
	Jan. 31, 2012	Jan. 31, 2012
Net income tax expense (benefit)	$ (20,260,000)	$ (59,969,000)
RSM EquiCo, Inc. [Member]
Estimated aggregate fair value		6,000,000
Net income tax expense (benefit)		$ 20,500,000