Loss And Loss Adjustment Expense Reserves (RMBS Recoveries) (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended				9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Aug. 31, 2013 Rmbs And Heloc And Ces [Member]	May 23, 2013 Rmbs And Heloc And Ces [Member]	Sep. 30, 2013 Second-Lien RMBS Ineligible Mortgage Loans [Member]	Sep. 30, 2013 Second-Lien RMBS Ineligible Mortgage Loans [Member] Minimum [Member]	Sep. 30, 2013 Second-Lien RMBS Ineligible Mortgage Loans [Member] Maximum [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Federal statutory rate	35.00%	35.00%
Estimated insurance recoveries, after income taxes	$ 737	$ 2,300
Percentage of recognized estimated recoveries in relationship to consolidated total shareholder's equity	23.00%	73.00%
Current risk-free rate associated with underlying transaction, range, minimum					1.40%
Current risk-free rate associated with underlying transaction, range, maximum					2.70%
Remaining weighted average contract period (in years)	9 years 9 months 18 days	8 years 8 months 12 days				5 years 0 months 0 days	10 years 4 months 24 days
ResCap settlement amount per term sheet				796
ResCap recovery per disclosure statement			$ 828