Derivative Financial Instruments and Off-balance sheet Financial Instruments (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 contract	Dec. 31, 2012 contract
Derivative Financial Instruments and Off-balance sheet Financial Instruments
Assumed recoveries under sale of credit protection	$ 0
Cash and securities pledged in the form of margin deposits	12
Derivatives, Fair Value
Total asset derivatives, Notional amount	2,784	7,961
Total liability derivatives, Notional amount	11,219	8,218
Total derivatives, Notional amount	14,003	16,179
Total asset derivatives, Number of contracts	12,017	13,489
Total liability derivatives, Number of contracts	10,035	12,619
Total derivatives, Number of contracts	22,052	26,108
Derivative assets net amount on balance sheet	267	158
Asset derivatives, Gross asset	279	182
Asset derivatives, Gross liability	(12)	(24)
Total liability derivatives, Fair value, net	(746)	(646)
Total derivatives, Fair value, net	(479)	(488)
Liability derivatives, Gross asset	15	23
Liability derivatives, Gross liability	(761)	(669)
Number of stock rights held by the company related to derivative contracts (in shares)	6,160	34,634
Number of stock warrants held by the company related to derivative contracts (in shares)	1,232,420	879,158
Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	2,768	7,945
Total liability derivatives, Notional amount	11,087	8,083
Total asset derivatives, Number of contracts	12,017	13,489
Total liability derivatives, Number of contracts	10,035	12,619
Derivative assets net amount on balance sheet	266	156
Asset derivatives, Gross asset	278	180
Asset derivatives, Gross liability	(12)	(24)
Total liability derivatives, Fair value, net	(731)	(627)
Liability derivatives, Gross asset	15	23
Liability derivatives, Gross liability	(746)	(650)
Interest rate swap agreements | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount		5,541
Derivative assets net amount on balance sheet		19
Asset derivatives, Gross asset		28
Asset derivatives, Gross liability		(9)
Interest rate swap agreements | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	85	1,185
Total liability derivatives, Fair value, net	4	16
Liability derivatives, Gross asset	4	18
Liability derivatives, Gross liability		(2)
Foreign currency swap agreements | Other investments | Derivatives designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	16	16
Derivative assets net amount on balance sheet	1	2
Asset derivatives, Gross asset	1	2
Foreign currency swap agreements | Other liabilities and accrued expenses | Derivatives designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	132	135
Total liability derivatives, Fair value, net	(15)	(19)
Liability derivatives, Gross liability	(15)	(19)
Interest rate swaption agreements | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	1,420
Interest rate swaption agreements | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	4,570	250
Total liability derivatives, Fair value, net	1
Liability derivatives, Gross asset	1
Interest rate cap agreements | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	61	372
Derivative assets net amount on balance sheet	2	1
Asset derivatives, Gross asset	2	1
Interest rate cap agreements | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	262	429
Total liability derivatives, Fair value, net	4	1
Liability derivatives, Gross asset	4	1
Financial futures contracts - Interest rate contracts | Other assets | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Number of contracts	550	2
Financial futures contracts - Interest rate contracts | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Number of contracts		357
Options | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	55
Total liability derivatives, Number of contracts	10,035
Total liability derivatives, Fair value, net	(165)
Liability derivatives, Gross asset	2
Liability derivatives, Gross liability	(167)
Options and warrants | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	3	146
Total asset derivatives, Number of contracts	10,035	12,400
Derivative assets net amount on balance sheet	263	125
Asset derivatives, Gross asset	263	125
Options and futures | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Number of contracts		12,262
Total liability derivatives, Fair value, net		(58)
Liability derivatives, Gross liability		(58)
Financial futures contracts - Equity and index contracts | Other assets | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Number of contracts	1,432	1,087
Derivative assets net amount on balance sheet	1	5
Asset derivatives, Gross asset	1	5
Foreign currency forwards | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	161
Derivative assets net amount on balance sheet	10
Asset derivatives, Gross asset	10
Foreign currency forwards | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	148
Total liability derivatives, Fair value, net	(3)
Liability derivatives, Gross asset	2
Liability derivatives, Gross liability	(5)
Foreign currency forwards and options | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount		258
Derivative assets net amount on balance sheet		6
Asset derivatives, Gross asset		6
Foreign currency forwards and options | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount		139
Total liability derivatives, Fair value, net		(1)
Liability derivatives, Gross asset		1
Liability derivatives, Gross liability		(2)
Conversion options | Fixed income securities | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount		5
Equity-indexed call options | Fixed income securities | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount		90
Derivative assets net amount on balance sheet		9
Asset derivatives, Gross asset		9
Credit default swaps | Fixed income securities | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	12	12
Derivative assets net amount on balance sheet	(12)	(12)
Asset derivatives, Gross liability	(12)	(12)
Guaranteed accumulation benefits | Contractholder funds | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	738	820
Total liability derivatives, Fair value, net	(43)	(86)
Liability derivatives, Gross liability	(43)	(86)
Guaranteed withdrawal benefits | Contractholder funds | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	506	554
Total liability derivatives, Fair value, net	(13)	(39)
Liability derivatives, Gross liability	(13)	(39)
Equity-indexed and forward starting options in life and annuity product contracts | Contractholder funds | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	1,693	3,916
Total liability derivatives, Fair value, net	(247)	(419)
Liability derivatives, Gross liability	(247)	(419)
Equity-indexed and forward starting options in life and annuity product contracts | Liabilities held for sale | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	2,363
Total liability derivatives, Fair value, net	(246)
Liability derivatives, Gross liability	(246)
Other embedded derivative financial instruments | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	1,000	1,000
Other embedded derivative financial instruments | Contractholder funds | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	85	85
Total liability derivatives, Fair value, net	(4)	(9)
Liability derivatives, Gross liability	(4)	(9)
Credit Default Swaps - Buying Protection | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	2	209
Asset derivatives, Gross asset		2
Asset derivatives, Gross liability		(2)
Credit Default Swaps - Buying Protection | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	397	420
Total liability derivatives, Fair value, net	(6)	(3)
Liability derivatives, Gross asset		2
Liability derivatives, Gross liability	(6)	(5)
Credit Default Swaps - Selling Protection | Other investments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	105	308
Derivative assets net amount on balance sheet	2	2
Asset derivatives, Gross asset	2	3
Asset derivatives, Gross liability		(1)
Credit Default Swaps - Selling Protection | Other liabilities and accrued expenses | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, Notional amount	185	285
Total liability derivatives, Fair value, net	(13)	(29)
Liability derivatives, Gross asset	2	1
Liability derivatives, Gross liability	(15)	(30)
Other contracts | Other assets | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, Notional amount	4	4
Derivative assets net amount on balance sheet		1
Asset derivatives, Gross asset		$ 1