Shares And Stockholders' Equity (Components And Changes In Accumulated OCI) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	$ 407
(Increases) attributable to:
Change in DAC, VOBA, DSI and DFEL	1
Less:
Balance as of end-of-period	6,248
Unrealized Gain (Loss) on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	557	$ 3,486
Cumulative effect from adoption of new accounting standards			$ 674
Unrealized holding gains (losses) arising during the period	9,849	(5,520)
Change in foreign currency exchange rate adjustment	(80)	(68)
Change in DAC, VOBA, DSI, future contract benefits and other contract holder funds	(2,271)	1,538
Income tax benefit (expense)	(1,596)	858
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	(18)	(35)
Associated amortization of DAC, VOBA, DSI, and DFEL	(11)	(15)
Income tax benefit (expense)	6	11
Less:
Balance as of end-of-period	6,482	1,007
Unrealized OTTI on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	33	44
Cumulative effect from adoption of new accounting standards			9
(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	21	(8)
Change in DAC, VOBA, DSI, and DFEL	(2)	(10)
Income tax benefit (expense)	(4)	4
Less:
Balance as of end-of-period	36	39
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	139	(29)
Cumulative effect from adoption of new accounting standards			(6)
Unrealized holding gains (losses) arising during the period	(152)	98
Change in foreign currency exchange rate adjustment	80	69
Decreases attributable to
Change in DAC, VOBA, DSI and DFEL	(3)	8
Income tax benefit (expense)	15	(37)
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	34	15
Associated amortization of DAC, VOBA, DSI and DFEL	(1)	(1)
Income tax benefit (expense)	(7)	(3)
Balance as of end-of-period	53	92
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(23)	(14)
Change in foreign currency exchange rate adjustment	(5)	(6)
Less:
Balance as of end-of-period	(28)	(20)
Funded Status of Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(299)	(257)
Cumulative effect from adoption of new accounting standards			$ (35)
Less:
Adjustment arising during the period	4	10
Balance as of end-of-period	$ (295)	$ (282)