Fair Value of Financial Instruments (Fair Value of Assets and Liabilities on a Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2016		Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		$ 231,399		$ 217,146
Liabilities measured at fair value		(5,810)		(4,200)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		1,631		1,889
Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		225,455		211,094
Liabilities measured at fair value		(2,314)		(1,836)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		4,313		4,163
Liabilities measured at fair value		(3,496)		(2,364)
Corporate bonds [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		80,253		72,931
Corporate bonds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value				60
Corporate bonds [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		77,822		70,878
Corporate bonds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		2,431		1,993
ABS [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		1,116		1,101
ABS [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		1,081		1,056
ABS [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		35		45
U.S. government bonds [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		458		429
U.S. government bonds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		446		412
U.S. government bonds [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		4		17
U.S. government bonds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		8
Foreign government bonds [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		530		524
Foreign government bonds [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		417		413
Foreign government bonds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		113		111
RMBS [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		3,703		3,728
RMBS [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		3,649		3,727
RMBS [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		54		1
CMBS [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		316		376
CMBS [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		278		366
CMBS [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		38		10
CLOs [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		686		589
CLOs [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		612		38
CLOs [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		74		551
State and municipal bonds [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		4,939		4,480
State and municipal bonds [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		4,939		4,480
Hybrid and redeemable preferred securities [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		631		806
Hybrid and redeemable preferred securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		63		48
Hybrid and redeemable preferred securities [Member] | Significant Observable Inputs (Level 2) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		480		664
Hybrid and redeemable preferred securities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		88		94
VIEs' fixed maturity securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		600		598
VIEs' fixed maturity securities [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		600		598
Equity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		273		237
Equity AFS securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		13		8
Equity AFS securities [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		97		65
Equity AFS securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		163		164
Trading securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		1,808		1,854
Trading securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		103		160
Trading securities [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		1,629		1,621
Trading securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		76		73
Other investments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		149	[1]	148
Other investments [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		148	[1]	148
Other investments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value	[1]	1
Derivative investments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value	[2]	3,426		2,312
Derivative investments [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value	[2]	2,668		1,459
Derivative investments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value	[2]	758		853
Invested cash [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		3,444		3,146
Invested cash [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		3,444		3,146
Reinsurance recoverable [Member] | Other assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		474		268
Reinsurance recoverable [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		474		268
Separate Account Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		128,593		123,619
Separate Account Assets [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		858		1,053
Separate Account Assets [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		127,735		122,566
Indexed annuity and IUL contracts embedded derivatives [Member] | Future contract benefits [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		(1,125)		(1,100)
Indexed annuity and IUL contracts embedded derivatives [Member] | Significant Unobservable Inputs (Level 3) [Member] | Future contract benefits [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		(1,125)		(1,100)
Long-term Debt [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		(1,203)		(1,203)
Long-term Debt [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		(1,203)		(1,203)
Reinsurance related [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		(137)		(87)
Reinsurance related [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		(137)		(87)
VIEs' liabilities - derivative instruments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value				(4)
VIEs' liabilities - derivative instruments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value				(4)
Credit default swaps [Member] | Other liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value				(9)
Credit default swaps [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value				(9)
Derivative Financial Instruments, Liabilities [Member] | Other liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value	[2]	(1,468)		(844)
Derivative Financial Instruments, Liabilities [Member] | Significant Observable Inputs (Level 2) [Member] | Other liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value	[2]	(974)		(546)
Derivative Financial Instruments, Liabilities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value	[2]	(494)		(298)
GLB reserves embedded derivatives [Member] | Other liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		(1,877)		(953)
GLB reserves embedded derivatives [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Liabilities measured at fair value		$ (1,877)		$ (953)

[1] Includes credit default swaps in an asset position associated with consolidated VIEs.

[2] Derivative investment assets and liabilities presented within the fair value hierarchy are presented on a gross basis by derivative type and not on a master netting basis by counterparty.