Shares And Stockholders' Equity (Components And Changes In Accumulated OCI) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	$ 5,673
Less:
Balance as of end-of-period	3,004
Unrealized Gain (Loss) on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	5,983	$ 557
Cumulative effect from adoption of new accounting standards			$ 45
Unrealized holding gains (losses) arising during the period	(4,498)	3,556
Change in foreign currency exchange rate adjustment	(150)	14
Change in DAC, VOBA, DSI, future contract benefits and other contract holder funds	1,264	(928)
Income tax benefit (expense)	720	(563)
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	(2)	(15)
Associated amortization of DAC, VOBA, DSI, and DFEL	32	(1)
Income tax benefit (expense)	(6)	3
Less:
Balance as of end-of-period	3,340	2,649
Unrealized OTTI on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	45	33
Cumulative effect from adoption of new accounting standards			$ (45)
(Increases) attributable to:
Gross OTTI recognized in OCI during the period		(16)
Change in DAC, VOBA, DSI and DFEL		1
Income tax benefit (expense)		4
Decreases attributable to
Changes in fair value, sales, maturities or other settlements of AFS securities		6
Change in DAC, VOBA, DSI, and DFEL		(2)
Income tax benefit (expense)		(1)
Less:
Balance as of end-of-period		25
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(11)	139
Unrealized holding gains (losses) arising during the period	(71)	(36)
Change in foreign currency exchange rate adjustment	153	(14)
Decreases attributable to
Change in DAC, VOBA, DSI and DFEL	(53)	6
Income tax benefit (expense)	(8)	10
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	9	8
Associated amortization of DAC, VOBA, DSI and DFEL	(6)	(1)
Income tax benefit (expense)	(1)	(1)
Balance as of end-of-period	8	99
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(17)	(23)
Change in foreign currency exchange rate adjustment	(10)	3
Less:
Balance as of end-of-period	(27)	(20)
Funded Status of Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(327)	(299)
Less:
Adjustment arising during the period	10	(1)
Balance as of end-of-period	$ (317)	$ (300)