Investments and Derivative Instruments (Details 12) (UNITED STATES, USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
GMWB hedging instruments [Member]
GMWB reinsurance contracts
Notional Amount	$ 19,220	$ 18,622
Fair Value	346	572
GMWB Hedging Instruments [Member] | Interest Rate Swaps and Futures [Member]
GMWB reinsurance contracts
Notional Amount	6,405	5,705
Fair Value	31	67
GMWB Hedging Instruments [Member] | Equity Swaps, Options and Futures [Member]
GMWB reinsurance contracts
Notional Amount	4,903	5,130
Fair Value	139	267
GMWB Hedging Instruments [Member] | Customized Swaps [Member]
GMWB reinsurance contracts
Notional Amount	7,912	7,787
Fair Value	176	238
Macro Hedge Program [Member] | Equity Futures [Member]
GMWB reinsurance contracts
Notional Amount	391	0
Fair Value	0	0
Macro Hedge Program [Member] | Equity Options [Member]
GMWB reinsurance contracts
Notional Amount	6,158	7,442
Fair Value	$ 243	$ 286