Shares And Stockholder's Equity (Schedule of Reclassifications Out Of AOCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income	$ 4,962	$ 4,844	$ 4,760
Total realized gain (loss)	(828)	(92)	(456)
Commissions and other expenses	(5,065)	(4,583)	(3,967)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gain (Loss) on AFS Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)	(26)	(44)	(40)
Reclassifications before income tax benefit (expense)	(37)	(63)	(59)
Income tax benefit (expense)	8	13	21
Reclassifications, net of income tax	(29)	(50)	(38)
Reclassification out of Accumulated Other Comprehensive Income [Member] | 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)	(11)	(19)	(19)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized OTTI on AFS Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)	4	7	5
Reclassifications before income tax benefit (expense)	4	7	4
Income tax benefit (expense)	(1)	(1)	(1)
Reclassifications, net of income tax	3	6	3
Reclassification out of Accumulated Other Comprehensive Income [Member] | 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)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gain (Loss) on Derivative Instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total gross reclassifications	47	31	31
Reclassifications before income tax benefit (expense)	45	28	29
Income tax benefit (expense)	(9)	(6)	(10)
Reclassifications, net of income tax	36	22	19
Reclassification out of Accumulated Other Comprehensive Income [Member] | 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	4	4
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gain (Loss) on Derivative Instruments [Member] | Foreign currency contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income	35	27	18
Total realized gain (loss)	9		9
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gain (Loss) on Derivative Instruments [Member] | Change In DAC, VOBA, DSI, And DFEL [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Commissions and other expenses	$ (2)	$ (3)	$ (2)