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		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
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]	$ 1,624	$ 679	$ (427)
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		(266)	(431)	(102)
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		(14)	(16)	(84)
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		$ 1,904	1,122	(244)
VIEs' liabilities - derivative instruments [Member] | Net Investment Income [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			$ 4	9
Credit Default Swaps [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				$ (6)

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