This element represents the aggregate of the liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

Name:	us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Quantitative Information about Level 3 Fair Value Measurements of Liabilities (Detail) (Fair Value, Measurements, Recurring, USD $) In Millions, unless otherwise specified						3 Months Ended			3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Level 3	Dec. 31, 2011 Level 3	Mar. 31, 2012 Level 3 Trading Liabilities Structured Foreign Exchange Swaptions Option Pricing Model	Mar. 31, 2012 Level 3 Trading Liabilities Structured Foreign Exchange Swaptions Option Pricing Model Minimum	Mar. 31, 2012 Level 3 Trading Liabilities Structured Foreign Exchange Swaptions Option Pricing Model Maximum	Mar. 31, 2012 Level 3 Trading Liabilities Equity Options Option Pricing Model	Mar. 31, 2012 Level 3 Trading Liabilities Equity Options Option Pricing Model Minimum	Mar. 31, 2012 Level 3 Trading Liabilities Equity Options Option Pricing Model Maximum
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair value of liabilities	$ 17,559	$ 18,864	$ 246	$ 314	$ 178			$ 68
Correlation risk						0.00%	25.00%
Volatility						13.00%	18.00%		23.00%	32.00%