Shares and Stockholder's Equity (Components And Changes In Accumulated OCI) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	$ 5,836
Less:
Balance as of end-of-period	7,815
Unrealized Gain (Loss) on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	5,637	$ 536
Unrealized holding gains (losses) arising during the period	3,583	6,623
Change in foreign currency exchange rate adjustment	(94)	2
Change in DAC, VOBA, DSI, future contract benefits and other contract holder funds	(1,358)	(1,904)
Income tax benefit (expense)	(452)	(1,004)
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	(41)	(22)
Associated amortization of DAC, VOBA, DSI, and DFEL	50	(6)
Income tax benefit (expense)	(2)	6
Less:
Balance as of end-of-period	7,349	4,275
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	40
Unrealized OTTI on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	40	29
Income tax benefit (expense)		4
(Increases) attributable to:
Gross OTTI recognized in OCI during the period		(14)
Change in DAC, VOBA, DSI and DFEL		1
Decreases attributable to
Changes in fair value, sales, maturities or other settlements of AFS securities		17
Change in DAC, VOBA, DSI, and DFEL		(4)
Income tax benefit (expense)		(3)
Less:
Balance as of end-of-period		30
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	(40)
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	181	119
Unrealized holding gains (losses) arising during the period	421	189
Change in foreign currency exchange rate adjustment	97	(5)
Decreases attributable to
Change in DAC, VOBA, DSI and DFEL	(104)	(4)
Income tax benefit (expense)	(88)	(38)
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	31	21
Associated amortization of DAC, VOBA, DSI and DFEL	(7)	(1)
Income tax benefit (expense)	(5)	(4)
Balance as of end-of-period	488	245
Funded Status of Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(22)	(25)
Less:
Adjustment arising during the period
Balance as of end-of-period	$ (22)	$ (25)