Derivative Financial Instruments (Details) (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] | Interest rate [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	72,828	54,803
Estimated Fair Value Assets	7,717	2,654
Estimated Fair Value Liabilities	2,092	1,516
Interest rate floors [Member] | Interest rate [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] | Interest rate [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] | Interest rate [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] | Interest rate [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] | Interest rate [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	16,812	10,374
Estimated Fair Value Assets	300	106
Estimated Fair Value Liabilities	94	135
Synthetic GICs [Member] | Interest rate [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] | Foreign currency [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	16,823	17,626
Estimated Fair Value Assets	1,311	1,616
Estimated Fair Value Liabilities	1,042	1,282
Foreign currency forwards [Member] | Foreign currency [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	10,029	10,443
Estimated Fair Value Assets	361	119
Estimated Fair Value Liabilities	54	91
Currency futures [Member] | Foreign currency [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] | Foreign currency [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	2,502	5,426
Estimated Fair Value Assets	13	50
Estimated Fair Value Liabilities	0	0
Non-derivative hedging instruments [Member] | Foreign currency [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	0	169
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	0	185
Credit default swaps [Member] | Credit [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	13,450	10,957
Estimated Fair Value Assets	383	173
Estimated Fair Value Liabilities	173	104
Credit forwards [Member] | Credit [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	20	90
Estimated Fair Value Assets	3	2
Estimated Fair Value Liabilities	0	3
Equity futures [Member] | Equity market [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] | Equity market [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] | Equity market [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] | Equity market [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,612	1,547
Estimated Fair Value Assets	31	0
Estimated Fair Value Liabilities	$ 0	$ 0