Fair Value of Financial Instruments (Components Of The Transfers In And Out Of Level 3) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	$ 518	$ 613	$ 284
Transfers Out of Level 3	(331)	(997)	(196)
Transfers In or Out of Level 3, Net	187	(384)	88
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	458	605	224
Transfers Out of Level 3	(88)	(224)	(166)
Transfers In or Out of Level 3, Net	370	381	58
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	16	4
Transfers Out of Level 3	(21)	(28)
Transfers In or Out of Level 3, Net	(5)	(24)
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 Out of Level 3		(8)
Transfers In or Out of Level 3, Net	5	(8)
Foreign 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			4
Transfers Out of Level 3			(4)
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
Transfers Out of Level 3	(11)	(67)
Transfers In or Out of Level 3, Net	(11)	(64)
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	(59)	(31)
Transfers In or Out of Level 3, Net	(56)	(31)
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		4
Transfers Out of Level 3	(131)	(621)	(16)
Transfers In or Out of Level 3, Net	(101)	(621)	(12)
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 In to Level 3			48
Transfers Out of Level 3	(14)		(5)
Transfers In or Out of Level 3, Net	(14)		43
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	4	1	4
Transfers Out of Level 3	(5)	(18)	$ (4)
Transfers In or Out of Level 3, Net	$ (1)	$ (17)