Segment Information (Reconciliation Of Reportable Segments Operating Gain To Income Before Income Tax Expense Included In The Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting [Abstract]
Reportable segments operating gain	$ 1,249	$ 982	$ 4,676	$ 3,794
Net investment income	250	220	708	628
Net realized gains on financial instruments	27	115	5	138
Other-than-temporary impairment losses recognized in income	(6)	(6)	(18)	(21)
Interest expense	(188)	(150)	(564)	(575)
Amortization of other intangible assets	(91)	(42)	(265)	(124)
Gain (loss) on Extinguishment of Debt	1	0	(17)	0
Income before income tax expense	$ 1,242	$ 1,119	$ 4,525	$ 3,840