Investments (Credit Losses Recognized In Earnings Related To OTTI Losses Recognized In Accumulated Other Comprehensive Income (Loss)) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Other than temporary impairment credit lossesfor available for sale securities rollforward [Abstract]
Beginning Balance	$ 186		$ 269		$ 197		$ 341
Additions For Credit Loss Impairments Recognized In The Current Period On Securities Previously Impaired	0		5		0		8
Reductions For Credit Loss Impairments Previously Recognized On Securities Sold During The Period	(4)		(2)		(14)		(18)
Reductions For Credit Loss Impairments Previously Recognized On Securities Impaired To Fair Value During The Period	0	[1]	(52)	[1]	0	[1]	(111)	[1]
Reductions For Increases In Cash Flows Expected To Be Collected Over The Remaining Life Of The Security	(4)		0		(5)		0
Ending Balance	$ 178		$ 220		$ 178		$ 220

[1] Represents circumstances where the Company determined in the current period that it intends to sell the security or it is more likely than not that it will be required to sell the security before recovery of the security's amortized cost.