Loss And Loss Adjustment Expense Reserves (Schedule Of Expenses Related To Remedial Actions For Insured Obligations) (Detail) (Remedial Actions For Insured Obligations [Member], USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Remedial Actions For Insured Obligations [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss adjustment expense incurred, gross	$ 34	$ 33