Derivative Financial Instruments (Details 2) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Derivatives, Fair Value [Line Items]
Notional Amount	$ 278,891	$ 254,253
Estimated Fair Value Assets	16,284	7,777
Estimated Fair Value Liabilities	3,959	4,747
Interest rate swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	64,293	46,133
Estimated Fair Value Assets	4,969	1,729
Estimated Fair Value Liabilities	1,988	1,231
Interest rate floors [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	23,866	23,866
Estimated Fair Value Assets	1,231	630
Estimated Fair Value Liabilities	165	66
Interest rate caps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	38,727	35,412
Estimated Fair Value Assets	70	176
Estimated Fair Value Liabilities	0	1
Interest rate futures [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	15,429	9,385
Estimated Fair Value Assets	16	43
Estimated Fair Value Liabilities	28	17
Interest rate options [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	18,088	8,761
Estimated Fair Value Assets	1,100	144
Estimated Fair Value Liabilities	20	23
Interest rate forwards [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	15,802	9,234
Estimated Fair Value Assets	96	106
Estimated Fair Value Liabilities	94	28
Synthetic GICs [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	4,420	4,397
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	0	0
Foreign currency swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	7,154	7,546
Estimated Fair Value Assets	356	496
Estimated Fair Value Liabilities	663	790
Foreign currency forwards [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	8,114	8,508
Estimated Fair Value Assets	214	110
Estimated Fair Value Liabilities	53	65
Currency futures [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	633	493
Estimated Fair Value Assets	1	2
Estimated Fair Value Liabilities	1	0
Currency options [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	2,502	5,426
Estimated Fair Value Assets	13	50
Estimated Fair Value Liabilities	0	0
Credit default swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	13,450	10,957
Estimated Fair Value Assets	383	173
Estimated Fair Value Liabilities	173	104
Equity futures [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	6,845	8,794
Estimated Fair Value Assets	163	21
Estimated Fair Value Liabilities	19	9
Equity Options [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	17,413	33,688
Estimated Fair Value Assets	3,207	1,843
Estimated Fair Value Liabilities	204	1,197
Variance swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	19,394	18,022
Estimated Fair Value Assets	377	198
Estimated Fair Value Liabilities	67	118
Total rate of return swaps [Member] | Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,612	1,547
Estimated Fair Value Assets	31	0
Estimated Fair Value Liabilities	0	0
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	257,742	232,169
Estimated Fair Value Assets	12,227	5,721
Estimated Fair Value Liabilities	$ 3,475	$ 3,649