Derivative Instruments (Change In Unrealized Gain On Derivative Instruments In Accumulated OCI) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Change in our unrealized gain on derivative instruments in accumulated OCI
Balance as of beginning-of-year	$ 5,836
Income tax benefit (expense)	(99)	$ 15
Balance as of end-of-period	3,773
Unrealized Gain (Loss) on Derivative Instruments [Member]
Change in our unrealized gain on derivative instruments in accumulated OCI
Balance as of beginning-of-year	181	119
Change in foreign currency exchange rate adjustment	153	(14)
Change in DAC, VOBA, DSI and DFEL	(48)	4
Income tax benefit (expense)	(140)	(9)
Reclassification adjustment for gains (losses) included in net income (loss)	12	9
Associated amortization of DAC, VOBA, DSI and DFEL	(1)	(3)
Income tax benefit (expense)	(2)	(1)
Balance as of end-of-period	690	148
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	241	42
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
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	312	11
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	11	7
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	$ 1	$ 1