Shares and Stockholders' Equity (Components And Changes In Accumulated OCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			$ 1,566
(Increases) attributable to:
Gross OTTI recognized in OCI during the period	$ (1)	$ (12)	(1)	$ (48)
Less:
Balance as of end-of-period	2,859		2,859
Unrealized Gain (Loss) on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			1,784	991
Unrealized holding gains (losses) arising during the year			2,385	5,827
Change in foreign currency exchange rate adjustment			112	(47)
Change in DAC, VOBA, DSI, future contract benefits and other contract holder funds			(468)	(1,733)
Income tax benefit (expense)			(717)	(1,429)
Less:
Reclassification adjustment for gains (losses) included in net income (loss)			(26)	(131)
Associated amortization of DAC, VOBA, DSI, and DFEL			(16)	(14)
Income tax benefit (expense)			15	51
Less:
Balance as of end-of-period	3,123	3,703	3,123	3,703
Unrealized OTTI on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			25	26
(Increases) attributable to:
Gross OTTI recognized in OCI during the period			(1)	(48)
Change in DAC, VOBA, DSI and DFEL				11
Income tax benefit (expense)				12
Decreases attributable to
Changes in fair value, sales, maturities or other settlements of AFS securities			29	40
Change in DAC, VOBA, DSI, and DFEL			(5)	(8)
Income tax benefit (expense)			(8)	(11)
Less:
Balance as of end-of-period	40	22	40	22
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			49	132
Unrealized holding gains (losses) arising during the year			31	(297)
Change in foreign currency exchange rate adjustment			(119)	42
Decreases attributable to
Change in DAC, VOBA, DSI and DFEL			(3)
Income tax benefit (expense)			32	89
Less:
Reclassification adjustment for gains (losses) included in net income (loss)			7	12
Associated amortization of DAC, VOBA, DSI and DFEL			(1)	(1)
Income tax benefit (expense)			(2)	(4)
Balance as of end-of-period	(14)	(41)	(14)	(41)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			(27)	(5)
Change in foreign currency exchange rate adjustment			11	(15)
Less:
Balance as of end-of-period	(16)	(20)	(16)	(20)
Funded Status of Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			(265)	(299)
Less:
Adjustment arising during the period			(9)	12
Balance as of end-of-period	$ (274)	$ (287)	$ (274)	$ (287)