Investments and Derivative Instruments (Details 12) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
GMWB reinsurance contracts
Notional Amount	$ 167,102	$ 141,436
Fair Value	(610)	(458)
UNITED STATES | GMWB hedging instruments [Member]
GMWB reinsurance contracts
Notional Amount	18,153	16,406
Fair Value	810	894
UNITED STATES | Macro Hedge Program [Member]
GMWB reinsurance contracts
Notional Amount	5,278	6,819
Fair Value	180	357
UNITED STATES | Macro Hedge Program [Member] | Equity Futures [Member]
GMWB reinsurance contracts
Notional Amount	0	59
Fair Value	0	0
UNITED STATES | Macro Hedge Program [Member] | Stock Option [Member]
GMWB reinsurance contracts
Notional Amount	5,278	6,760
Fair Value	180	357
UNITED STATES | Customized swaps [Member] | GMWB hedging instruments [Member]
GMWB reinsurance contracts
Notional Amount	8,142	8,389
Fair Value	329	385
UNITED STATES | Equity swaps, options and futures [Member] | GMWB hedging instruments [Member]
GMWB reinsurance contracts
Notional Amount	5,621	5,320
Fair Value	385	498
UNITED STATES | Interest rate swaps and futures [Member] | GMWB hedging instruments [Member]
GMWB reinsurance contracts
Notional Amount	4,390	2,697
Fair Value	$ 96	$ 11