Investments and Derivative Instruments (Details 13) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Macro hedge program
Notional Amount	$ 211,239		$ 196,608
Fair Value	(1,495)		(1,044)
International [Member]
Macro hedge program
Notional Amount	46,600		28,000
International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	52,683		28,719
Fair Value	204		542
Currency Forwards [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	15,565	[1]	8,622	[1]
Fair Value	33	[1]	446	[1]
Currency options [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	10,230		7,038
Fair Value	73		72
Equity futures [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	2,614		2,691
Fair Value	0		0
Equity options [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	2,719		1,120
Fair Value	(45)		(3)
Equity swaps [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	1,910	[2]	392	[2]
Fair Value	21	[2]	(8)	[2]
Interest rate futures [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	983		739
Fair Value	0		0
Interest Rate Swaps and Swaptions [Member] | International Program Hedging Instruments [Member]
Macro hedge program
Notional Amount	18,662		8,117
Fair Value	$ 122		$ 35

[1] As of June 30, 2012 and December 31, 2011 net notional amounts are $5.0 billion and $7.2 billion, respectively, which include $10.3 billion and $7.9 billion, respectively, related to long positions and $5.3 billion and $0.7 billion, respectively, related to short positions.

[2] As of June 30, 2012 the net notional amount is $0.3 billion which includes $1.1 billion related to long positions and $0.8 billion related to short positions. As of December 31, 2011 the net notional amount of $0.4 billion related to long positions only.