Shares And Stockholders' Equity (Schedule of Reclassifications Out Of AOCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total realized gain (loss)	$ 141	$ (170)	$ (339)
Net investment income	5,085	4,990	4,874
Interest and debt expense	(297)	(253)	(331)
Commissions and other expenses	(4,763)	(4,176)	(4,277)
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)	(42)	(39)	(158)
Reclassifications before income tax benefit (expense)	(62)	(59)	(181)
Income tax benefit (expense)	13	21	63
Reclassifications, net of income tax	(49)	(38)	(118)
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)	(20)	(20)	(23)
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)	8	5	3
Reclassifications before income tax benefit (expense)	8	4	3
Income tax benefit (expense)	(2)	(1)
Reclassifications, net of income tax	6	3	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	24	13	14
Reclassifications before income tax benefit (expense)	22	12	13
Income tax benefit (expense)	(5)	(4)	(5)
Reclassifications, net of income tax	17	8	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]
Total realized gain (loss)			1
Net investment income	4	4	5
Interest and debt expense	(7)	(18)	(10)
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	7
Net investment income	27	18	11
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	$ (2)	$ (1)	$ (1)