Shares And Stockholders' Equity (Schedule of Reclassifications Out Of AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)	$ (55)	$ (56)	$ (51)	$ (105)
Net investment income	1,271	1,239	3,736	3,738
Interest and debt expense	(69)	(63)	(228)	(190)
Commissions and other expenses	$ (1,367)	$ (1,020)	(3,600)	(3,068)
Unrealized Gain (Loss) on AFS Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)			(35)	(26)
Reclassifications before income tax benefit (expense)			(50)	(42)
Income tax benefit (expense)			11	15
Reclassifications, net of income tax			(39)	(27)
Unrealized Gain (Loss) on AFS Securities [Member] | Associated amortization of DAC, VOBA, DSI and DFEL [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)			(15)	(16)
Unrealized OTTI on AFS Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)			(1)	6
Reclassifications before income tax benefit (expense)			(1)	5
Income tax benefit (expense)				(2)
Reclassifications, net of income tax			(1)	3
Unrealized OTTI on AFS Securities [Member] | Change In DAC, VOBA, DSI, And DFEL [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)				(1)
Unrealized Gain (Loss) on Derivative Instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Nonoperating income expense			15	7
Reclassifications before income tax benefit (expense)			14	6
Income tax benefit (expense)			(3)	(2)
Reclassifications, net of income tax			11	4
Unrealized Gain (Loss) on Derivative Instruments [Member] | Interest rate contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income			3	3
Interest and debt expense			(6)	(13)
Unrealized Gain (Loss) on Derivative Instruments [Member] | Foreign currency contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)				5
Net investment income			18	12
Unrealized Gain (Loss) on Derivative Instruments [Member] | Associated amortization of DAC, VOBA, DSI and DFEL [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Commissions and other expenses			$ (1)	$ (1)