Shares And Stockholders' 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]
Total realized gain (loss)	$ (610)	$ 141	$ (170)
Net investment income	5,223	5,085	4,990
Interest and debt expense	(326)	(297)	(253)
Commissions and other expenses	(5,287)	(4,763)	(4,176)
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)	(28)	(42)	(39)
Reclassifications before income tax benefit (expense)	(40)	(62)	(59)
Income tax benefit (expense)	8	13	21
Reclassifications, net of income tax	(32)	(49)	(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)	(12)	(20)	(20)
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	8	5
Reclassifications before income tax benefit (expense)	4	8	4
Income tax benefit (expense)	(1)	(2)	(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]
Nonoperating income expense	42	24	13
Reclassifications before income tax benefit (expense)	41	22	12
Income tax benefit (expense)	(9)	(5)	(4)
Reclassifications, net of income tax	32	17	8
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
Interest and debt expense	(5)	(7)	(18)
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]
Total realized gain (loss)	9		9
Net investment income	35	27	18
Reclassification out of Accumulated Other Comprehensive Income [Member] | 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)	$ (2)	$ (1)