Shares And Stockholders' Equity (Components And Changes In Accumulated OCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	$ 5,673
Less:
Balance as of end-of-period	8,931	$ 5,673
Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			$ (6)
Unrealized Gain (Loss) on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	5,983	557	3,486
Unrealized holding gains (losses) arising during the period	7,925	9,267	(6,274)
Change in foreign currency exchange rate adjustment	180	46	(107)
Change in DAC, VOBA, DSI, future contract benefits and other contract holder funds	(3,569)	(2,462)	1,748
Income tax benefit (expense)	(970)	(1,457)	981
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	(53)	(28)	(42)
Associated amortization of DAC, VOBA, DSI, and DFEL	32	(12)	(20)
Income tax benefit (expense)	4	8	13
Less:
Balance as of end-of-period	9,611	5,983	557
Unrealized Gain (Loss) on AFS Securities [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	45		674
Less:
Balance as of end-of-period		45
Unrealized OTTI on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	45	33	44
(Increases) attributable to:
Gross OTTI recognized in OCI during the period		(16)
Change in DAC, VOBA, DSI and DFEL		1
Income tax benefit (expense)		3
Decreases attributable to
Changes in fair value, sales, maturities or other settlements of AFS securities		31	(19)
Change in DAC, VOBA, DSI, and DFEL		(1)	(6)
Income tax benefit (expense)		(6)	5
Less:
Balance as of end-of-period		45	33
Unrealized OTTI on AFS Securities [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(45)		9
Less:
Balance as of end-of-period		(45)
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(11)	139	(29)
Unrealized holding gains (losses) arising during the period	(257)	(93)	144
Change in foreign currency exchange rate adjustment	(174)	(52)	111
Decreases attributable to
Change in DAC, VOBA, DSI and DFEL	(17)	(4)	(13)
Income tax benefit (expense)	94	31	(51)
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	48	42	24
Associated amortization of DAC, VOBA, DSI and DFEL	(1)	(1)	(2)
Income tax benefit (expense)	(10)	(9)	(5)
Balance as of end-of-period	(402)	(11)	139
Unrealized Gain (Loss) on Derivative Instruments [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			(6)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(17)	(23)	(14)
Change in foreign currency exchange rate adjustment	5	6	(9)
Less:
Balance as of end-of-period	(12)	(17)	(23)
Funded Status of Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(327)	(299)	(257)
Less:
Adjustment arising during the period	74	(20)	(12)
Income tax benefit (expense)	(13)	(8)	5
Balance as of end-of-period	$ (266)	$ (327)	(299)
Funded Status of Employee Benefit Plans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			$ (35)