Fair Value of Financial Instruments (Components Of The Transfers In And Out Of Level 3) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	$ 66	$ 200
Transfers Out of Level 3	(298)	(53)
Transfers In or Out of Level 3, Net	(232)	147
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	40	160
Transfers Out of Level 3	(33)	(29)
Transfers In or Out of Level 3, Net	7	131
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]
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]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Out of Level 3	(12)
Transfers In or Out of Level 3, Net	(12)
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	(91)	(15)
Transfers In or Out of Level 3, Net	(91)	15
State and municipal bonds [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
Equity AFS Securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Out of Level 3	(162)
Transfers In or Out of Level 3, Net	(162)
Trading securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3		3
Transfers In or Out of Level 3, Net		$ 3
Equity Securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	26
Transfers In or Out of Level 3, Net	$ 26