Litigation And Related Contingencies (Details) (USD $)	9 Months Ended
	Jan. 31, 2013	Apr. 30, 2012
Loss Contingencies [Line Items]
Accrued obligations under indemnifications	$ 18,900,000	$ 79,000,000
Expected payment for settlement of litigation, minimum	0
Expected payment for settlement of litigation, maximum	119,000,000
Percentage of losses related to discontinued operations	78.00%
SCC [Member]
Loss Contingencies [Line Items]
Number of securities originated and securitized	2
Number of loans sold	96
Number of lawsuits	14
Value of original investments	14,000,000,000
Jeanne Drake, Et Al. V. Option Onve Mortgage Corp., Et Al. [Member]
Loss Contingencies [Line Items]
Damages sought	8,000,000
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	50,000,000
Principal outstanding on loans securitized	40,000,000
Williams Case [Member]
Loss Contingencies [Line Items]
Expected payment for settlement of litigation, maximum	$ 7,500,000