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
		Mar. 31, 2018	Mar. 31, 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]	$ 653	$ 659
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		281	(74)
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		(4)	(14)
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		$ 376	$ 747

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