Loss Contingencies Arising From Representations and Warranties of Our Discontinued Mortgage Operations (Narrative) (Details) $ in Thousands	12 Months Ended				35 Months Ended	36 Months Ended	60 Months Ended	108 Months Ended
	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)	Apr. 30, 2015 USD ($)	Apr. 30, 2014 USD ($)	Nov. 30, 2007 item	Apr. 30, 2007	Apr. 30, 2013 USD ($)	Apr. 30, 2017 USD ($)
Loss Contingencies [Line Items]
Percentage of fraud on originated loans						68.00%
Claims received for loans								$ 2,600,000
Document Fiscal Year Focus	2017
Principal Assets of SCC	$ 318,000							318,000
Securitization transactions | item					39
SCC
Loss Contingencies [Line Items]
Claims received for loans							$ 1,900,000
Loss Contingency Accrual, Payments		$ 61,000	$ 88,500	$ 50,000
Accrued liability	$ 4,500		$ 65,265	$ 149,765			$ 183,765	$ 4,500