Derivative Financial Instruments (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial 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] | Foreign currency [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	525	493
Estimated Fair Value Assets	4	2
Estimated Fair Value Liabilities	4	0
Non-derivative hedging instruments [Member] | Foreign currency [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	0	169
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	0	185
Equity options [Member] | Equity market [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial 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] | Equity market [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	6,015	8,794
Estimated Fair Value Assets	10	21
Estimated Fair Value Liabilities	94	9
Interest rate futures [Member] | Interest rate [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial 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] | Equity market [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	1,862	1,547
Estimated Fair Value Assets	1	0
Estimated Fair Value Liabilities	2	0
Variance swaps [Member] | Equity market [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	18,719	18,022
Estimated Fair Value Assets	152	198
Estimated Fair Value Liabilities	169	118
Credit default swaps [Member] | Credit [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	12,266	10,957
Estimated Fair Value Assets	159	173
Estimated Fair Value Liabilities	94	104
Credit forwards [Member] | Credit [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	121	90
Estimated Fair Value Assets	2	2
Estimated Fair Value Liabilities	3	3
Currency options [Member] | Foreign currency [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	2,191	5,426
Estimated Fair Value Assets	16	50
Estimated Fair Value Liabilities	1	0
Foreign currency forwards [Member] | Foreign currency [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	10,038	10,443
Estimated Fair Value Assets	80	119
Estimated Fair Value Liabilities	84	91
Foreign currency swaps [Member] | Foreign currency [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	17,455	17,626
Estimated Fair Value Assets	1,404	1,616
Estimated Fair Value Liabilities	1,391	1,282
Synthetic GICs [Member] | Interest rate [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	4,392	4,397
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	0	0
Interest rate forwards [Member] | Interest rate [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	8,637	10,374
Estimated Fair Value Assets	31	106
Estimated Fair Value Liabilities	125	135
Interest rate options [Member] | Interest rate [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	16,635	8,761
Estimated Fair Value Assets	186	144
Estimated Fair Value Liabilities	49	23
Interest rate caps [Member] | Interest rate [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	37,726	35,412
Estimated Fair Value Assets	189	176
Estimated Fair Value Liabilities	0	1
Interest rate floors [Member] | Interest rate [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	23,866	23,866
Estimated Fair Value Assets	623	630
Estimated Fair Value Liabilities	78	66
Interest rate swaps [Member] | Interest rate [Member]
Notional amount, estimated fair value and primary underlying risk exposure in derivative financial instruments
Notional Amount	69,893	54,803
Estimated Fair Value Assets	3,112	2,654
Estimated Fair Value Liabilities	$ 1,349	$ 1,516