Fair Value of Financial Instruments (Changes In Unrealized Gains (Losses) Within Level 3 Financial Instruments Carried At Fair Value And Still Held) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Changes in unrealized gains (losses) within Level 3 financial instruments carried at fair value and still held
Change in unrealized gains (losses) included in net income	[1]	$ 564	$ 347	$ 1,351	$ 1,180
Derivative Investments [Member] | Realized Gain (Loss) [Member]
Changes in unrealized gains (losses) within Level 3 financial instruments carried at fair value and still held
Change in unrealized gains (losses) included in net income		(1)	(83)	105	(159)
Indexed Annuity And Embedded Derivatives [Member] | Realized Gain (Loss) [Member]
Changes in unrealized gains (losses) within Level 3 financial instruments carried at fair value and still held
Change in unrealized gains (losses) included in net income		(11)	2	(18)	(13)
GLB Embedded Derivatives [Member] | Realized Gain (Loss) [Member]
Changes in unrealized gains (losses) within Level 3 financial instruments carried at fair value and still held
Change in unrealized gains (losses) included in net income		$ 576	$ 428	$ 1,264	$ 1,352

[1] Included in realized gain (loss) on our Consolidated Statements of Comprehensive Income (Loss).