Investments and Derivative Instruments (Details 12) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
GMWB reinsurance contracts
Notional Amount	$ 183,278	$ 205,854
Fair Value	(1,551)	(1,448)
UNITED STATES | GMWB hedging instruments [Member]
GMWB reinsurance contracts
Notional Amount	19,131	18,622
Fair Value	158	572
UNITED STATES | GMWB Hedging Instruments [Member] | Interest Rate Swaps and Futures [Member]
GMWB reinsurance contracts
Notional Amount	6,924	5,705
Fair Value	(60)	67
UNITED STATES | GMWB Hedging Instruments [Member] | Equity Swaps, Options and Futures [Member]
GMWB reinsurance contracts
Notional Amount	4,548	5,130
Fair Value	107	267
UNITED STATES | GMWB Hedging Instruments [Member] | Customized Swaps [Member]
GMWB reinsurance contracts
Notional Amount	7,659	7,787
Fair Value	111	238
UNITED STATES | Macro Hedge Program [Member]
GMWB reinsurance contracts
Notional Amount	6,599	7,442
Fair Value	181	286
UNITED STATES | Macro Hedge Program [Member] | Equity Futures [Member]
GMWB reinsurance contracts
Notional Amount	0	0
Fair Value	0	0
UNITED STATES | Macro Hedge Program [Member] | Equity Options [Member]
GMWB reinsurance contracts
Notional Amount	6,599	7,442
Fair Value	$ 181	$ 286