Shares and Stockholders' Equity (Components And Changes In Accumulated OCI) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Balance as of beginning-of-year	$ 845
Increases Attributable To
Gross OTTI recognized in OCI during the year	(26)	$ (9)
Less:
Balance as of end-of-period	1,931
Unrealized Gain (Loss) on AFS Securities [Member]
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Balance as of beginning-of-year	991	3,213
Unrealized holding gains (losses) arising during the year	2,469	1,150
Change in foreign currency exchange rate adjustment	7	(34)
Change in DAC, VOBA, DSI, future contract benefits and other contract holder funds	(661)	(200)
Income tax benefit (expense)	(641)	(322)
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	(44)	184
Associated amortization of DAC, VOBA, DSI, and DFEL	(2)	(7)
Income tax benefit (expense)	16	(62)
Less:
Balance as of end-of-period	2,195	3,692
Unrealized OTTI on AFS Securities [Member]
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Balance as of beginning-of-year	26	26
Increases Attributable To
Gross OTTI recognized in OCI during the year	(26)	(9)
Change in DAC, VOBA, DSI and DFEL	6	2
Income tax benefit (expense)	7	3
Decreases attributable to
Changes in fair value, sales, maturities or other settlements of AFS securities	(14)	(3)
Change in DAC, VOBA, DSI, and DFEL	4	(2)
Income tax benefit (expense)	3	2
Less:
Balance as of end-of-period	6	19
Unrealized Gain (Loss) on Derivative Instruments [Member]
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Balance as of beginning-of-year	132	139
Change in foreign currency exchange rate adjustment	(11)	37
Decreases attributable to
Unrealized holding gains (losses) arising during the year	(129)	$ (108)
Change in DAC, VOBA, DSI and DFEL	(4)
Income tax benefit (expense)	50	$ 25
Less:
Reclassification adjustment for gains (losses) included in net income (loss)	7	(194)
Associated amortization of DAC, VOBA, DSI and DFEL	(1)	1
Income tax benefit (expense)	(2)	68
Balance as of end-of-period	34	218
Foreign Currency Translation Adjustment [Member]
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Balance as of beginning-of-year	(5)	(3)
Change in foreign currency exchange rate adjustment	(2)	(1)
Less:
Balance as of end-of-period	(7)	(4)
Funded Status of Employee Benefit Plans [Member]
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Balance as of beginning-of-year	(299)	(279)
Less:
Adjustment arising during the period	2	8
Income tax benefit (expense)		(1)
Balance as of end-of-period	$ (297)	$ (272)