Investments and Derivative Instruments (Details 13) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Derivative [Line Items]
Notional Amount	$ 134,480	$ 136,854
Fair Value	(164)	(547)
Currency forwards [Member] | Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	5,049	3,232
Fair Value	406	93
Currency Options [Member] | Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	7,153	5,296
Fair Value	151	62
Equity Futures [Member] | Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	4,195	1,168
Fair Value	0	0
Equity options [Member] | Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	6,703	13,963
Fair Value	468	207
Equity swaps [Member] | Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	402	369
Fair Value	(45)	1
Interest Rate Futures [Member] | Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	695	0
Fair Value	0	0
Interest rate swaps [Member] | Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	5,579	2,182
Fair Value	95	21
Macro Hedge Program [Member]
Derivative [Line Items]
Notional Amount	29,776	26,210
Fair Value	$ 1,075	$ 384