Loss And Loss Adjustment Expense Reserves (Schedule Of Losses And Loss Adjustment Expenses) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Loss And Loss Adjustment Expense Reserves [Line Items]
Losses and LAE related to expected payments	$ 23
Recoveries of expected payments	28
Gross losses incurred	51
Reinsurance	(1)
Losses and LAE	50		(194)
Second-Lien RMBS [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Losses and LAE related to expected payments	7
Recoveries of expected payments	18
Gross losses incurred	25
Reinsurance	0
Losses and LAE	25
First-Lien RMBS [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Losses and LAE related to expected payments	28
Recoveries of expected payments	2
Gross losses incurred	30
Reinsurance	0
Losses and LAE	30
Other [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Losses and LAE related to expected payments	(12)	[1]
Recoveries of expected payments	8	[1]
Gross losses incurred	(4)	[1]
Reinsurance	(1)	[1]
Losses and LAE	$ (5)	[1]

[1] Includes ABS CDOs, CMBS, U.S. public finance and other issues.