Derivative Financial Instruments (Details 2) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	$ 259,441	$ 254,253
Estimated Fair Value Assets	7,693	7,777
Estimated Fair Value Liabilities	3,821	4,747
Currency futures [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	525	493
Estimated Fair Value Assets	4	2
Estimated Fair Value Liabilities	4	0
Equity options [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	16,330	33,688
Estimated Fair Value Assets	1,679	1,843
Estimated Fair Value Liabilities	342	1,197
Equity futures [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	6,015	8,794
Estimated Fair Value Assets	10	21
Estimated Fair Value Liabilities	94	9
Interest rate futures [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	12,770	9,385
Estimated Fair Value Assets	45	43
Estimated Fair Value Liabilities	36	17
Total rate of return swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	1,862	1,547
Estimated Fair Value Assets	1	0
Estimated Fair Value Liabilities	2	0
Variance swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	18,719	18,022
Estimated Fair Value Assets	152	198
Estimated Fair Value Liabilities	169	118
Credit default swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	12,266	10,957
Estimated Fair Value Assets	159	173
Estimated Fair Value Liabilities	94	104
Currency options [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	2,191	5,426
Estimated Fair Value Assets	16	50
Estimated Fair Value Liabilities	1	0
Foreign currency forwards [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	8,275	8,508
Estimated Fair Value Assets	75	110
Estimated Fair Value Liabilities	67	65
Foreign currency swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	7,243	7,546
Estimated Fair Value Assets	285	496
Estimated Fair Value Liabilities	894	790
Synthetic GICs [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	4,392	4,397
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	0	0
Interest rate forwards [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	7,497	9,234
Estimated Fair Value Assets	31	106
Estimated Fair Value Liabilities	24	28
Interest rate options [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	16,635	8,761
Estimated Fair Value Assets	186	144
Estimated Fair Value Liabilities	49	23
Interest rate caps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	37,726	35,412
Estimated Fair Value Assets	189	176
Estimated Fair Value Liabilities	0	1
Interest rate floors [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	23,866	23,866
Estimated Fair Value Assets	623	630
Estimated Fair Value Liabilities	78	66
Interest rate swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	59,523	46,133
Estimated Fair Value Assets	2,080	1,729
Estimated Fair Value Liabilities	1,081	1,231
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Notional amount and estimated fair value of derivatives designated and not designated as hedging instruments
Notional Amount	235,835	232,169
Estimated Fair Value Assets	5,535	5,721
Estimated Fair Value Liabilities	$ 2,935	$ 3,649