Investments and Derivative Instruments (Details 13) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Macro hedge program
Notional Amount	$ 181,764		$ 205,854
Fair Value	(1,746)		(1,448)
International [Member]
Macro hedge program
Notional Amount	53,400		43,800
International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	55,210		48,448
Fair Value	(175)		(105)
Other Credit Derivatives [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	350		350
Fair Value	23		28
Currency Forwards [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	5,757	[1]	9,327	[1]
Fair Value	0	[1]	(87)	[1]
Currency options [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	10,099		9,710
Fair Value	(22)		(49)
Equity futures [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	945		1,206
Fair Value	0		0
Equity options [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	2,147		2,621
Fair Value	(128)		(105)
Equity swaps [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	4,075		2,683
Fair Value	(30)		(12)
Customized Swaps [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	0		899
Fair Value	0		(11)
Interest rate futures [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	0		634
Fair Value	0		0
Interest Rate Swaps and Swaptions [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	31,837		21,018
Fair Value	$ (18)		$ 131

[1] As of June 30, 2013 and December 31, 2012 net notional amounts are $2.2 billion and $0.1 billion, respectively, which include $4.0 billion and $4.7 billion, respectively, related to long positions and $1.8 billion and $4.6 billion, respectively, related to short positions.