Fair Value of Financial Instruments (Components Of The Transfers In And Out Of Level 3) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3	$ 19	$ 170	$ 219	$ 334
Transfers Out of Level 3	(126)	(679)	(179)	(704)
Transfers In or Out of Level 3, Net	(107)	(509)	40	(370)
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	1	165	161	329
Transfers Out of Level 3	(2)	(83)	(31)	(107)
Transfers In or Out of Level 3, Net	(1)	82	130	222
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	15	4
Transfers Out of Level 3	(1)		(6)
Transfers In or Out of Level 3, Net	14	4	9	4
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 In to Level 3	3		3
Transfers Out of Level 3	(41)		(45)
Transfers In or Out of Level 3, Net	(38)		(42)
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	(73)	(586)	(88)	(586)
Transfers In or Out of Level 3, Net	(73)	(586)	(58)	(586)
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)		(1)
Transfers In or Out of Level 3, Net	(1)		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	(5)		(5)
Transfers In or Out of Level 3, Net	(5)		(5)
Trading securities [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers In to Level 3		1	3	1
Transfers Out of Level 3	(3)	(10)	$ (3)	(11)
Transfers In or Out of Level 3, Net	$ (3)	$ (9)		$ (10)