Loss And Loss Adjustment Expense Reserves (Schedule Of Insurance Loss Reserves And Recoverables For Insured Obligations) (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Loss Reserves (Claim Liability) [Member] | Classified [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss adjustment expense reserves	$ 873	$ 1,059
LAE Reserves [Member] | Classified [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss adjustment expense reserves	59	70
Reinsurance recoverable	0	1
Loss And LAE Reserves [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss adjustment expense reserves	932	1,129
Loss And LAE Reserves [Member] | Classified [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss adjustment expense reserves	932	1,129
Insurance Loss Recoverable [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Insurance claim loss recoverable	1,900
Insurance Loss Recoverable [Member] | Classified [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Insurance claim loss recoverable	(2,761)	(2,531)
LAE insurance loss recoverable	(9)
Insurance loss recoverable	(2,770)	(2,531)
Reinsurance recoverable	16	14
Reinsurance recoverable on paid losses	2	0
Reinsurance recoverable on paid and unpaid losses	$ 18	$ 15