Investments (Schedule Of Other Investments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Cost-method Investments [Line Items]
Other investments - Total at Fair Value	$ 2,716	$ 2,314
Other investments - Total at Cost	2,465	2,112
Fair Value
Schedule of Cost-method Investments [Line Items]
Investment funds	395	378
Limited partnerships	531	531
Partially owned investment companies	1,186	904
Life insurance policies	148	127
Policy loans	164	143
Trading securities	243	194
Other	49	37
Other investments - Total at Fair Value	2,716	2,314
Cost
Schedule of Cost-method Investments [Line Items]
Investment funds	278	277
Limited partnerships	398	429
Partially owned investment companies	1,187	904
Life insurance policies	148	127
Policy loans	164	143
Trading securities	242	195
Other	48	37
Other investments - Total at Cost	$ 2,465	$ 2,112