Investments (Schedule Of Sources Of Net Investment Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Investment Income [Line Items]
Gross investment income	$ 2,264	$ 2,300	$ 2,337
Investment expenses	(120)	(119)	(95)
Net investment income	2,144	2,181	2,242
Fixed Maturities [Member]
Net Investment Income [Line Items]
Gross investment income	2,093	2,134	2,196
Short-term investments
Net Investment Income [Line Items]
Gross investment income	29	28	43
Equity securities
Net Investment Income [Line Items]
Gross investment income	37	34	36
Other Investments [Member]
Net Investment Income [Line Items]
Gross investment income	$ 105	$ 104	$ 62