Loss And Loss Adjustment Expense Reserves (Loss And LAE Activity) (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Abs Cdo Portfolio [Member]	Mar. 31, 2014 Second Lien Residential Mortgage Backed Securities And Reserves [Member]	Mar. 31, 2014 First Lien Residential Mortgage Backed Securities [Member]	Mar. 31, 2014 Financial Guarantee [Member]	Dec. 31, 2013 Financial Guarantee [Member]	Mar. 31, 2014 Financial Guarantee [Member] Variable Interest Entity Primary Beneficiary [Member]	Dec. 31, 2013 Financial Guarantee [Member] Variable Interest Entity Primary Beneficiary [Member]	Mar. 31, 2014 Loss And Lae Reserves [Member]	Dec. 31, 2013 Loss And Lae Reserves [Member]	Mar. 31, 2014 Recoveries On Unpaid Losses [Member]	Dec. 31, 2013 Recoveries On Unpaid Losses [Member]	Mar. 31, 2014 Insurance Loss Recoverable [Member]	Dec. 31, 2013 Insurance Loss Recoverable [Member]	Mar. 31, 2014 Insurance Loss Recoverable [Member] Classified [Member]	Dec. 31, 2013 Insurance Loss Recoverable [Member] Classified [Member]	Mar. 31, 2014 Loan Repurchase Commitments [Member] Second Lien Residential Mortgage Backed Securities And Reserves [Member] Ineligible Loan Recoveries [Member]	Dec. 31, 2013 Loan Repurchase Commitments [Member] Second Lien Residential Mortgage Backed Securities And Reserves [Member] Ineligible Loan Recoveries [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
ABS CDO exposure decrease since December 31,2007			96.00%
Aggregate ABS CDO Loss And LAE Reserves						$ 120	$ 115	$ 236	$ 226
Policyholder (Benefits) And Claims Incurred Net	50	(194)	6	25	30
Elimination Of Loss And LAE Expense As Result Of Consolidating VIE			10	12	2
Reserves for expected future claim payments										784	847
Expected recoveries of future payments										182	206	182	206
Weighted average risk-free rate used to discount claim liability	2.12%
Total estimated insurance recoveries																		364	359
Insurance claim loss recoverable																671	694
Insurance loss recoverable														671	694	671	694
Losses and LAE related to expected payments	$ 23			$ 7	$ 28