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, 2020	Mar. 31, 2019
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	$ (4,033)	$ 162
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	(4,867)	481
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	895	(287)
Indexed Annuity And IUL Contracts [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	$ (61)	$ (32)