Investments and Derivative Instruments (Details 13) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 International [Member]	Dec. 31, 2012 International [Member]	Mar. 31, 2013 International Program Hedging Instruments [Member]	Dec. 31, 2012 International Program Hedging Instruments [Member]	Mar. 31, 2013 Other Credit Derivatives [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Other Credit Derivatives [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Currency options [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Currency options [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Equity futures [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Equity futures [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Equity options [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Equity options [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Equity swaps [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Equity swaps [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Interest rate futures [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Interest rate futures [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Interest Rate Swaps and Swaptions [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Interest Rate Swaps and Swaptions [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Net Hedge Position [Member] Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Net Hedge Position [Member] Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Long Hedge Position [Member] International [Member]	Dec. 31, 2012 Long Hedge Position [Member] International [Member]	Mar. 31, 2013 Long Hedge Position [Member] Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Long Hedge Position [Member] Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Mar. 31, 2013 Short Hedge Position [Member] Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Dec. 31, 2012 Short Hedge Position [Member] Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]
Derivative [Line Items]
Document Period End Date	Mar. 31, 2013
Macro hedge program
Notional Amount		$ 68,700	$ 58,500	$ 72,123	$ 63,085	$ 350	$ 350	$ 9,160	$ 9,327	$ 15,462	$ 10,342	$ 2,294	$ 2,332	$ 4,240	$ 3,952	$ 4,735	$ 2,617	$ 486	$ 634	$ 34,567	$ 32,632	$ 2,300	$ 100	$ 3,400	$ 4,600	$ 5,700	$ 4,700	$ 3,400	$ 4,600
Fair Value				$ 375	$ 169	$ 28	$ 28	$ 153	$ (87)	$ 9	$ (24)	$ 0	$ 0	$ (46)	$ 47	$ (7)	$ (12)	$ 0	$ 0	$ 258	$ 228