Summary of the Balance Sheet Classification of the Derivative Fair Value Amounts, as well as the Gross Asset and Liability Fair Value Amounts (Detail) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	$ 5,855	$ 6,174
Net Derivatives Fair Value	(89)	(177)
Asset Derivatives Fair Value	495	564
Liability Derivatives Fair Value	(584)	(741)
Cash flow hedges
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	823	860
Net Derivatives Fair Value	70	168
Asset Derivatives Fair Value	94	180
Liability Derivatives Fair Value	(24)	(12)
Cash flow hedges | Interest rate swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	248	245
Net Derivatives Fair Value	(1)	(2)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	(1)	(2)
Cash flow hedges | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	575	615
Net Derivatives Fair Value	71	170
Asset Derivatives Fair Value	94	180
Liability Derivatives Fair Value	(23)	(10)
Non-qualifying strategies
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	5,032	5,314
Net Derivatives Fair Value	(159)	(345)
Asset Derivatives Fair Value	401	384
Liability Derivatives Fair Value	(560)	(729)
Non-qualifying strategies | Interest rate swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	546	743
Net Derivatives Fair Value	121	56
Asset Derivatives Fair Value	125	124
Liability Derivatives Fair Value	(4)	(68)
Non-qualifying strategies | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	3,927	3,815
Net Derivatives Fair Value	(27)	(58)
Asset Derivatives Fair Value	276	260
Liability Derivatives Fair Value	(303)	(318)
Non-qualifying strategies | Credit default swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	559	756
Net Derivatives Fair Value	(253)	(343)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	(253)	(343)
Cash flow hedges and non-qualifying strategies
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	5,855	6,174
Net Derivatives Fair Value	(89)	(177)
Asset Derivatives Fair Value	495	564
Liability Derivatives Fair Value	(584)	(741)
Other assets
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	2,267	2,364
Net Derivatives Fair Value	495	564
Asset Derivatives Fair Value	495	564
Liability Derivatives Fair Value	0	0
Other Liabilities
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	3,588	3,810
Net Derivatives Fair Value	(584)	(741)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	$ (584)	$ (741)