Litigation And Related Contingencies (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Oct. 31, 2012 item	Apr. 30, 2012
Loss Contingencies [Line Items]
Accrued obligations under indemnifications	$ 20.8	$ 79.0
Expected payment for settlement of litigation, minimum	0
Expected payment for settlement of litigation, maximum	118.0
Percentage of losses related to discontinued operations	78.00%
Number of securitization transactions	38
SCC [Member]
Loss Contingencies [Line Items]
Number of securities originated and securitized	2
Number of loans sold	96
Number of lawsuits	12
Jeanne Drake, Et Al. V. Option Onve Mortgage Corp., Et Al. [Member]
Loss Contingencies [Line Items]
Damages sought	8
American International Group, Inc. [Member]
Loss Contingencies [Line Items]
Damages sought	650
Federal Home Loan Banks Of Chicago V. Bank Of America Funding Corporation, Et Al. [Member] | Pending Or Threatened Litigation [Member]
Loss Contingencies [Line Items]
Initial principal on loans securitized	50
Principal outstanding on loans securitized	41
Lemus Case [Member]
Loss Contingencies [Line Items]
Expected payment for settlement of litigation, maximum	35.0
Williams Case [Member]
Loss Contingencies [Line Items]
Expected payment for settlement of litigation, maximum	$ 7.5