FAIR VALUE MEASUREMENT (Details 4) (Level 3, USD $)	6 Months Ended
	Jun. 30, 2012 correlation
Interest-bearing deposits
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	$ 698,000,000
Interest-bearing deposits | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean Reversion	1.00%
Forward Price	0.43
Commodity Volatility (as a percent)	4.00%
Commodity Correlation	(0.7600)
Interest-bearing deposits | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean Reversion	20.00%
Forward Price	4.23
Commodity Volatility (as a percent)	128.00%
Commodity Correlation	0.9500
Federal funds purchased and securities loaned or sold under agreements to repurchase
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	1,045,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest Rate (as a percent)	0.63%
Federal funds purchased and securities loaned or sold under agreements to repurchase | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Interest Rate (as a percent)	2.28%
Short-term borrowings and long-term debt
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	6,314,000,000
Short-term borrowings and long-term debt | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.47
IR-IR Correlation	(0.9800)
IR Volatility (as a percent)	8.59%
Equity Volatility	10.40%
Short-term borrowings and long-term debt | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	115.00
IR-IR Correlation	0.4000
IR Volatility (as a percent)	85.00%
Equity Volatility	101.21%
Short-term borrowings and long-term debt | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean Reversion	1.00%
Short-term borrowings and long-term debt | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean Reversion	20.00%
Federal funds sold and securities borrowed or purchased under agreements to resell
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	4,414,000,000
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)	1.15%
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)	1.52%
Trading and investment securities
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	32,062,000,000
Loans
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	4,737,000,000
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	104.19
Loans | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	0.90%
Credit Spread (as a percent)	0.32%
Loans | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	4.93%
Credit Spread (as a percent)	4.86%
Mortgage servicing rights
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,117,000,000
Mortgage servicing rights | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	0.00%
Prepayment period	2.25
Mortgage servicing rights | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	29.60%
Prepayment period	7.79
Interest rate contracts | Derivatives, assets
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	3,329,000,000
Interest rate contracts | Derivatives, assets | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit Spread (as a percent)	0.03%
Interest rate contracts | Derivatives, assets | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit Spread (as a percent)	6.75%
Interest rate contracts | Derivatives, assets | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
Yield (as a percent)	1.75%
IR-IR Correlation	(0.5000)
Interest rate contracts | Derivatives, assets | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	145.00
Yield (as a percent)	2.60%
IR-IR Correlation	1.0000
Interest rate contracts | Derivatives, assets | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean Reversion	1.00%
Interest rate contracts | Derivatives, assets | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Mean Reversion	20.00%
Foreign exchange contracts | Derivatives, assets
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	1,814,000,000
Foreign exchange contracts | Derivatives, assets | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Volatility (as a percent)	8.59%
Foreign exchange contracts | Derivatives, assets | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
IR Volatility (as a percent)	62.92%
Equity contracts | Derivatives, assets
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	4,283,000,000
Equity contracts | Derivatives, assets | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	8.19%
Equity-Equity Correlation	0.2530
Equity contracts | Derivatives, assets | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	108.60%
Equity-Equity Correlation	0.9800
Commodity contracts | Derivatives, assets
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,482,000,000
Commodity contracts | Derivatives, assets | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward Price	0.43
Commodity Volatility (as a percent)	4.00%
Commodity Correlation	(0.7600)
Commodity contracts | Derivatives, assets | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Forward Price	4.23
Commodity Volatility (as a percent)	128.00%
Commodity Correlation	0.9500
Credit derivatives | Derivatives, assets
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	12,044,000,000
Credit derivatives | Derivatives, assets | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
Credit Spread (as a percent)	0.01%
Credit Correlation	0.0500
Upfront points	5.00
Credit derivatives | Derivatives, assets | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	145.00
Credit Spread (as a percent)	11.64%
Credit Correlation	0.9500
Upfront points	45.00
Credit derivatives | Derivatives, assets | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Recovery Rate (as a percent)	9.00%
Credit derivatives | Derivatives, assets | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Recovery Rate (as a percent)	75.00%
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) | Derivatives
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	2,377,000,000
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) | Derivatives | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	100.00
Nontrading derivatives and other financial assets and liabilities measured on a recurring basis (gross) | Derivatives | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	100.00
Mortgage-backed securities | Trading and investment securities
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	4,971,000,000
Mortgage-backed securities | Trading and investment securities | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	2.31%
Prepayment period	2.25
Mortgage-backed securities | Trading and investment securities | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	30.00%
Prepayment period	7.79
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	113.89
Equity securities | Trading and investment securities
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	1,397,000,000
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)	25.00%
Asset-backed securities | Trading and investment securities
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	7,606,000,000
Asset-backed securities | Trading and investment securities | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	0.00%
Asset-backed securities | Trading and investment securities | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Yield (as a percent)	76.10%
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	115.48
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	6,309,000,000
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Cash flow | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit Spread (as a percent)	1.00%
State and municipal, foreign government, corporate, and other debt securities | Trading and investment securities | Cash flow | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Credit Spread (as a percent)	2.00%
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
Yield (as a percent)	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	159.63
Yield (as a percent)	23.42%
Non-marketable equity securities | Trading and investment securities
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	6,278,000,000
Non-marketable equity securities | Trading and investment securities | Price-based | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Adjustment factor	0.00
Non-marketable equity securities | Trading and investment securities | Price-based | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Adjustment factor	0.50
Non-marketable equity securities | Trading and investment securities | Comparables Analysis | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	0.00
EBITDA multiples	0.00
Fund NAV	7.962
Non-marketable equity securities | Trading and investment securities | Comparables Analysis | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Price	3.70
EBITDA multiples	14.50
Fund NAV	353,130.553
Securities sold, not yet purchased | Trading account liabilities
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of liabilities as of the balance sheet date	$ 148,000,000
Securities sold, not yet purchased | Trading account liabilities | Internal Model | Minimum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	10.40%
Equity-Equity Correlation	0.2530
Equity Forward	0.74%
Equity-FX Correlation	(0.7600)
Securities sold, not yet purchased | Trading account liabilities | Internal Model | Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Equity Volatility	60.50%
Equity-Equity Correlation	0.9480
Equity Forward	1.43%
Equity-FX Correlation	0.6000