Investments and Derivative Instruments (Details 12) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
GMWB reinsurance contracts
Notional Amount	$ 181,764	$ 205,854
Fair Value	(1,746)	(1,448)
UNITED STATES | GMWB hedging instruments [Member]
GMWB reinsurance contracts
Notional Amount	18,529	18,622
Fair Value	256	572
UNITED STATES | GMWB Hedging Instruments [Member] | Interest Rate Swaps and Futures [Member]
GMWB reinsurance contracts
Notional Amount	6,155	5,705
Fair Value	(77)	67
UNITED STATES | GMWB Hedging Instruments [Member] | Equity Swaps, Options and Futures [Member]
GMWB reinsurance contracts
Notional Amount	4,732	5,130
Fair Value	184	267
UNITED STATES | GMWB Hedging Instruments [Member] | Customized Swaps [Member]
GMWB reinsurance contracts
Notional Amount	7,642	7,787
Fair Value	149	238
UNITED STATES | Macro Hedge Program [Member]
GMWB reinsurance contracts
Notional Amount	5,489	7,442
Fair Value	210	286
UNITED STATES | Macro Hedge Program [Member] | Equity Futures [Member]
GMWB reinsurance contracts
Notional Amount	390	0
Fair Value	0	0
UNITED STATES | Macro Hedge Program [Member] | Equity Options [Member]
GMWB reinsurance contracts
Notional Amount	5,099	7,442
Fair Value	$ 210	$ 286