Derivative Instruments (Change In Unrealized Gain On Derivative Instruments In Accumulated OCI) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2017
Change in our unrealized gain on derivative instruments in accumulated OCI
Balance as of beginning-of-year		$ 659
Income tax expense (benefit)		(15)	$ 76
Balance as of end-of-period		2,654
Unrealized Gain (Loss) on Derivative Instruments [Member]
Change in our unrealized gain on derivative instruments in accumulated OCI
Balance as of beginning-of-year		119	27
Cumulative effect from adoption of new accounting standard				$ 6
Change in foreign currency exchange rate adjustment		(14)	(50)
Change in DAC, VOBA, DSI and DFEL		4	4
Income tax benefit (expense)		(9)	28
Associated amortization of DAC, VOBA, DSI and DFEL		(3)	(1)
Income tax expense (benefit)		(1)	(1)
Balance as of end-of-period		148	(72)
Unrealized Gain (Loss) on Derivative Instruments [Member] | Cash Flow Hedges [Member] | Interest rate contracts [Member]
Change in our unrealized gain on derivative instruments in accumulated OCI
Unrealized holding gains (losses) arising during the period		42	(46)
Unrealized Gain (Loss) on Derivative Instruments [Member] | Cash Flow Hedges [Member] | Interest rate contracts [Member] | Net Investment Income [Member]
Change in our unrealized gain on derivative instruments in accumulated OCI
Transfers from derivative instruments to bonds through basis adjustment	[1]	1	1
Unrealized Gain (Loss) on Derivative Instruments [Member] | Cash Flow Hedges [Member] | Foreign currency contracts [Member]
Change in our unrealized gain on derivative instruments in accumulated OCI
Unrealized holding gains (losses) arising during the period		11	(37)
Unrealized Gain (Loss) on Derivative Instruments [Member] | Cash Flow Hedges [Member] | Foreign currency contracts [Member] | Net Investment Income [Member]
Change in our unrealized gain on derivative instruments in accumulated OCI
Transfers from derivative instruments to bonds through basis adjustment	[1]	7	$ 5
Unrealized Gain (Loss) on Derivative Instruments [Member] | Cash Flow Hedges [Member] | Foreign currency contracts [Member] | Realized Gain (Loss) [Member]
Change in our unrealized gain on derivative instruments in accumulated OCI
Transfers from derivative instruments to bonds through basis adjustment	[2]	$ 1

[1] The OCI offset is reported within net investment income on our Consolidated Statements of Comprehensive Income (Loss).

[2] The OCI offset is reported within realized gain (loss) on our Consolidated Statements of Comprehensive Income (Loss).