FAIR VALUE MEASUREMENT (Details 3) (Level 3, USD $)	3 Months Ended
	Mar. 31, 2013
Interest-bearing deposits | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	834,000,000
Interest-bearing deposits | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	11.78%
Equity-Equity Correlation	50.00%
Equity Forward	87.08%
Commodity Volatility (as a percent)	5.00%
Forward Price	70.30%
Commodity Correlation	(77.00%)
Equity-IR Correlation	0.2500
Mean Reversion	1.00%
Interest-bearing deposits | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	70.77%
Equity-Equity Correlation	98.00%
Equity Forward	118.53%
Commodity Volatility (as a percent)	124.00%
Forward Price	233.80%
Commodity Correlation	95.00%
Equity-IR Correlation	0.5450
Mean Reversion	20.00%
Federal funds purchased and securities loaned or sold under agreements to repurchase | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	201,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	853,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	0.70%
Federal funds purchased and securities loaned or sold under agreements to repurchase | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	2.77%
Short-term borrowings and long-term debt
Fair Value Inputs Assets Liabilities Quantitative Information
Price	82.86
Short-term borrowings and long-term debt | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	1,029,000,000
Short-term borrowings and long-term debt | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Volatility (as a percent)	0.07%
Short-term borrowings and long-term debt | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Volatility (as a percent)	85.00%
Short-term borrowings and long-term debt | Yield analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	674,000,000
Short-term borrowings and long-term debt | Yield analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	4.43%
Price	0.00
Equity Volatility	7.81%
Equity-FX correlation	(86.38%)
Short-term borrowings and long-term debt | Yield analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	15.00%
Price	104.42
Equity Volatility	64.97%
Equity-FX correlation	60.00%
Short-term borrowings and long-term debt | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	5,194,000,000
Short-term borrowings and long-term debt | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	0.07%
Short-term borrowings and long-term debt | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	3.00%
Federal funds sold and securities borrowed or purchased under agreements to resell | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	4,099,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	1.22%
Federal funds sold and securities borrowed or purchased under agreements to resell | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	1.67%
Loans
Fair Value Inputs Assets Liabilities Quantitative Information
Price	90.26
Loans | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,239,000,000
Loans | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
Loans | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	105.35
Loans | Yield analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	1,418,000,000
Loans | Yield analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	0.47%
Loans | Yield analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	3.50%
Loans | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	585,000,000
Mortgage servicing rights | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,119,000,000
Mortgage servicing rights | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	0.00%
WAL	3 years 8 months 16 days
Mortgage servicing rights | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	51.48%
WAL	7 years 1 month 28 days
Interest rate contracts | Derivatives, assets | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	7,585,000,000
Interest rate contracts | Derivatives, assets | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Volatility (as a percent)	40.00%
Credit spread (as a percent)	0.73%
Interest rate contracts | Derivatives, assets | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Volatility (as a percent)	85.00%
Credit spread (as a percent)	3.75%
Foreign exchange contracts | Derivatives, assets | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,504,000,000
Foreign exchange contracts | Derivatives, assets | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	3.75%
Credit spread (as a percent)	0.28%
Foreign exchange (FX) volatility (as a Percent)	11.00%
IR-FX correlation	40.00%
IR-IR Correlation	40.00%
Foreign exchange contracts | Derivatives, assets | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest rate (as a percent)	15.00%
Credit spread (as a percent)	4.19%
Foreign exchange (FX) volatility (as a Percent)	20.00%
IR-FX correlation	60.00%
IR-IR Correlation	40.00%
Equity contracts | Derivatives, assets | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	4,553,000,000
Equity contracts | Derivatives, assets | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	10.20%
Equity-Equity Correlation	1.00%
Equity Forward	87.08%
Equity-FX correlation	(95.00%)
Equity contracts | Derivatives, assets | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	77.68%
Equity-Equity Correlation	99.90%
Equity Forward	118.53%
Equity-FX correlation	78.00%
Commodity contracts | Derivatives, assets | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,060,000,000
Commodity contracts | Derivatives, assets | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Commodity Volatility (as a percent)	5.00%
Forward Price	70.30%
Commodity Correlation	(77.00%)
Commodity contracts | Derivatives, assets | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Commodity Volatility (as a percent)	124.00%
Forward Price	233.80%
Commodity Correlation	95.00%
Credit derivatives | Derivatives, assets | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,133,000,000
Credit derivatives | Derivatives, assets | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	0.00%
Credit Correlation	5.00%
Credit derivatives | Derivatives, assets | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit spread (as a percent)	25.42%
Credit Correlation	95.00%
Credit derivatives | Derivatives, assets | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	5,007,000,000
Credit derivatives | Derivatives, assets | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
Credit derivatives | Derivatives, assets | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	134.16
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) | Derivatives, assets | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,306,000,000
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) | Derivatives, assets | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	100.00
Redemption Rate (as a percent)	7.50%
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) | Derivatives, assets | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	100.00
Redemption Rate (as a percent)	99.50%
Structured debt securities with embedded derivatives | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	100
Mortgage-backed securities
Fair Value Inputs Assets Liabilities Quantitative Information
Price	91.72
Mortgage-backed securities | Trading and investment securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	5,137,000,000
Mortgage-backed securities | Trading and investment securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
Mortgage-backed securities | Trading and investment securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	126.12
Mortgage-backed securities | Trading and investment securities | Yield analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	988,000,000
Mortgage-backed securities | Trading and investment securities | Yield analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	0.00%
Mortgage-backed securities | Trading and investment securities | Yield analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	28.57%
Equity securities | Trading and investment securities | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	785,000,000
Equity securities | Trading and investment securities | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	9.00%
Equity securities | Trading and investment securities | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	9.00%
Equity securities | Trading and investment securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	175,000,000
Equity securities | Trading and investment securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	1.00
WAL	3 years
Equity securities | Trading and investment securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	17,123,129
WAL	3 years
Asset-backed securities
Fair Value Inputs Assets Liabilities Quantitative Information
Price	82.61
Asset-backed securities | Trading and investment securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	6,133,000,000
Asset-backed securities | Trading and investment securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
Asset-backed securities | Trading and investment securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	118.09
Asset-backed securities | Trading and investment securities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	1,696,000,000
State and municipal, foreign government, corporate, and other debt securities
Fair Value Inputs Assets Liabilities Quantitative Information
Price	88.43
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	1,234,000,000
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	0.00%
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	11.90%
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	3,086,000,000
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	135.98
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Yield analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	861,000,000
Non-marketable equity securities | Trading and investment securities | Cash flow
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	797,000,000
Non-marketable equity securities | Trading and investment securities | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price-to-book ratio	0.77
Discount to price (as a percent)	0.00%
Price-earnings ratio	8.7
Cost of capital	9.00%
Non-marketable equity securities | Trading and investment securities | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price-to-book ratio	1.5
Discount to price (as a percent)	75.00%
Price-earnings ratio	14.1
Cost of capital	20.00%
Non-marketable equity securities | Trading and investment securities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,701,000,000
Non-marketable equity securities | Trading and investment securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Fund NAV	611
Non-marketable equity securities | Trading and investment securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Fund NAV	477,311,897
Non-marketable equity securities | Trading and investment securities | Comparables Analysis
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	1,696,000,000
Non-marketable equity securities | Trading and investment securities | Comparables Analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
EBITDA multiples	4.5
Non-marketable equity securities | Trading and investment securities | Comparables Analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
EBITDA multiples	13.5
Securities sold, not yet purchased | Trading account liabilities | Price-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	69,000,000
Securities sold, not yet purchased | Trading account liabilities | Model-based
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	264,000,000
Securities sold, not yet purchased | Trading account liabilities | Model-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
Securities sold, not yet purchased | Trading account liabilities | Model-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	135.98
Fixed-income investments
Fair Value Inputs Assets Liabilities Quantitative Information
Price input for instrument valued at par	100
Fixed-income investments | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0
Fixed-income investments | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	100