Investments and Derivative Instruments (Details 13) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Derivative [Line Items]
Notional Amount	$ 126,446	$ 136,854
Fair Value	(404)	(547)
Long equity options, swaps and futures [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	8,650	13,332
Fair Value	231	205
Short equity options, swaps and futures [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	2,116	1,168
Fair Value	23	0
Long currency forward contracts [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	196	1,791
Fair Value	(4)	64
Short currency forward contracts [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	2,778	1,441
Fair Value	56	29
Foreign interest rate swaps [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	2,192	2,182
Fair Value	30	21
Cross-currency equity options [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	121	1,000
Fair Value	4	3
Long currency options [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	2,155	3,075
Fair Value	139	67
Short currency options [Member] | Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	465	2,221
Fair Value	(8)	(5)
Macro hedge program [Member]
Derivative [Line Items]
Notional Amount	18,673	26,210
Fair Value	$ 471	$ 384