Litigation And Other Related Contingencies (Details) $ in Thousands	6 Months Ended
	Oct. 31, 2017 USD ($) loan securities lawsuit	Apr. 30, 2017 USD ($)	Oct. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)
Litigation And Related Contingencies [Abstract]
Loss Contingency Accrual	$ 2,500	$ 2,300	$ 2,300
Number of loans sold to the trust | loan	96
Loans Sold To Trust, With Claims of Breach of Contract and Indemnity | loan	649
Loss Contingencies [Line Items]
Securitization Transactions | securities	39
Principal Assets of SCC	$ 313,000
SCC [Member]
Litigation And Related Contingencies [Abstract]
Loss Contingency Accrual	4,500	$ 4,500	$ 25,500	$ 65,265
Loss Contingencies [Line Items]
Original Principal Amount of Loans Securitized	14,000,000
SCC [Member] | Claims with Knowledge of Outstanding Principal Amount [Member]
Loss Contingencies [Line Items]
Initial principal on loans securitized	$ 3,500,000
MGRID LLC v. Merrill Lynch Mortgage Lending Inc [Member]
Loss Contingencies [Line Items]
Number Of Lawsuits | lawsuit	21