Fair Value of Financial Instruments (Fair Value of Assets and Liabilities on a Recurring Basis) (Details) - USD ($) $ in Millions		Mar. 31, 2016		Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		$ 221,516		$ 217,146
Liabilities measured at fair value		(5,936)		(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		1,802		1,889
Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		215,187		211,094
Liabilities measured at fair value		(2,292)		(1,836)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		4,527		4,163
Liabilities measured at fair value		(3,644)		(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		75,897		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		73,712		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		2,185		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		1,059		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		1,015		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		44		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		450		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		436		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		14		17
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		532		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		421		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		111		111
RMBS [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		3,679		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		3,678		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		1		1
CMBS [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		349		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		340		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		9		10
CLOs [Member] | Fixed maturity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		628		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		37		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		591		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		4,744		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		4,744		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		726		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		48		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		586		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		92		94
VIEs' fixed maturity securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		599		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		599		598
Equity AFS securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		245		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		9		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		69		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		167		164
Trading securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		1,864		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		162		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		1,628		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		74		73
Other investments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		153	[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		151	[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]	2
Derivative investments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value	[2]	3,475		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]	2,657		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]	818		853
Invested cash [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		3,177		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		3,177		3,146
Other assets - reinsurance recoverable [Member] | Other assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		433		268
Other assets - 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		433		268
Separate Account Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Assets measured at fair value		123,506		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		996		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		122,510		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		(1,088)		(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		(1,088)		(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		(111)		(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		(111)		(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		(12)		(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		(12)		(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]	(1,606)		(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]	(978)		(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]	(628)		(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		(1,916)		(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		$ (1,916)		$ (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.