Derivative Financial Instruments (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013 contract	Jun. 30, 2012	Jun. 30, 2013 contract	Jun. 30, 2012	Dec. 31, 2012 contract
Derivative Financial Instruments
Cash flow hedge losses to be reclassified from AOCI during the next twelve months	$ 2		$ 2
Hedge ineffectiveness in realized gains	0	0	0	0
Hedge ineffectiveness in realized losses	0	0	0	0
Effective portion
Gain recognized in OCI on derivatives during the period	6	5	9
Loss recognized in OCI on derivatives during the term of the hedging relationship	(12)	(16)	(12)	(16)
Loss reclassified from AOCI into income (net investment income)	(1)		(1)
(Loss) gain reclassified from AOCI into income (realized capital gains and losses)				(1)
Derivative Instruments, Gain (Loss)
Total derivatives, Number of contracts	23,233		23,233		26,108
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	56	9	80	95
Total gain (loss) recognized in net income on derivatives				94
Fair value hedging | Derivatives designated as accounting hedging instruments
Derivative Instruments, Gain (Loss)
Total derivatives, Number of contracts	0		0
Net investment income
Derivative Instruments, Gain (Loss)
Total gain (loss) recognized in net income on derivatives				(1)
Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	14	7	10	29
Total gain (loss) recognized in net income on derivatives				29
Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	20	(17)	46	14
Total gain (loss) recognized in net income on derivatives				14
Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	20	24	18	41
Total gain (loss) recognized in net income on derivatives				41
Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	2	(5)	6	11
Total gain (loss) recognized in net income on derivatives				11
Interest rate contracts
Derivative Instruments, Gain (Loss)
Derivatives in fair value accounting hedging relationships, total gain (loss) recognized in net income on derivatives				(1)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	3	2	3	1
Interest rate contracts | Net investment income
Derivative Instruments, Gain (Loss)
Derivatives in fair value accounting hedging relationships, total gain (loss) recognized in net income on derivatives				(1)
Interest rate contracts | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	3	2	3	1
Equity and index contracts
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	15	(16)	55	47
Equity and index contracts | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	4	4	(5)	1
Equity and index contracts | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	9	(16)	47	37
Equity and index contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	2	(4)	13	9
Embedded derivative financial instruments
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	34	27	19	35
Embedded derivative financial instruments | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		4	(1)	19
Embedded derivative financial instruments | Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	20	(17)	46	14
Embedded derivative financial instruments | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	14	40	(26)	2
Foreign currency contracts
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(5)	(4)	(11)	2
Foreign currency contracts | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(5)	(3)	(4)
Foreign currency contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		(1)	(7)	2
Credit default swaps
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	12		17	8
Credit default swaps | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	12		17	8
Other contracts
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(3)		(3)	2
Other contracts | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	$ (3)		$ (3)	$ 2