Fair Value of Financial Instruments (Components Of The Transfers In And Out Of Level 3) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	$ 200	$ 164
Transfers Out of Level 3	(53)	(25)
Transfers In or Out of Level 3, Net	147	139
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	160	164
Transfers Out of Level 3	(29)	(24)
Transfers In or Out of Level 3, Net	131	140
ABS [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Out of Level 3	(5)
Transfers In or Out of Level 3, Net	(5)
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
CMBS [Member] \| Fixed maturity AFS securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Out of Level 3	(4)
Transfers In or Out of Level 3, Net	(4)
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	(15)
Transfers In or Out of Level 3, Net	15
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 In or Out of Level 3, Net	2
Trading 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		(1)
Transfers In or Out of Level 3, Net	$ 3	$ (1)

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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- Definition

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

+ References

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- Definition

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

+ References

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