Fair Value of Financial Instruments (Components Of The Transfers In And Out Of Level 3) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	$ 117	$ 150	$ 336	$ 484
Transfers Out of Level 3	(124)	(129)	(303)	(833)
Transfers In or Out of Level 3, Net	(7)	21	33	(349)
Corporate bonds [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	116	147	277	476
Transfers Out of Level 3	(57)	(81)	(88)	(188)
Transfers In or Out of Level 3, Net	59	66	189	288
ABS [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3			15	4
Transfers Out of Level 3	(15)	(27)	(21)	(27)
Transfers In or Out of Level 3, Net	(15)	(27)	(6)	(23)
U.S. government bonds [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3			5
Transfers In or Out of Level 3, Net			5
RMBS [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3		3		3
Transfers Out of Level 3		(16)		(16)
Transfers In or Out of Level 3, Net		(13)		(13)
CMBS [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3			3
Transfers Out of Level 3	(14)		(59)
Transfers In or Out of Level 3, Net	(14)		(56)
CLOs [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3			30
Transfers Out of Level 3	(28)	(5)	(116)	(591)
Transfers In or Out of Level 3, Net	(28)	$ (5)	(86)	(591)
State and municipal bonds [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3			2
Transfers Out of Level 3			(1)
Transfers In or Out of Level 3, Net			1
Hybrid and redeemable preferred securities [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Out of Level 3	(9)		(14)
Transfers In or Out of Level 3, Net	(9)		(14)
Equity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Out of Level 3	(1)		(1)
Transfers In or Out of Level 3, Net	(1)		(1)
Trading securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	1		4	1
Transfers Out of Level 3			(3)	(11)
Transfers In or Out of Level 3, Net	$ 1		$ 1	$ (10)

Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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