FAIR VALUE MEASUREMENT (Details 5) (Nonrecurring, Level 3, USD $)													3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Other real estate owned	Mar. 31, 2013 Other real estate owned Price-based Minimum	Mar. 31, 2013 Other real estate owned Price-based Maximum	Mar. 31, 2013 Loans held-for-sale	Mar. 31, 2013 Loans held-for-sale Price-based Minimum	Mar. 31, 2013 Loans held-for-sale Price-based Maximum	Mar. 31, 2013 Loans Price-based	Mar. 31, 2013 Loans Price-based Minimum	Mar. 31, 2013 Loans Price-based Maximum	Mar. 31, 2013 Loans Cash flow	Mar. 31, 2013 Loans Cash flow Minimum	Mar. 31, 2013 Loans Cash flow Maximum	Mar. 31, 2013 Loans Model-based	Mar. 31, 2013 Loans Model-based Minimum	Mar. 31, 2013 Loans Model-based Maximum
Fair Value Inputs Assets Liabilities Quantitative Information
Fair value of assets as of the balance sheet date	$ 1,936,000,000	$ 2,239,000,000	$ 141,000,000			$ 1,226,000,000			$ 350,000,000			$ 86,000,000			$ 111,000,000
Price				$ 0.00	$ 102.00		$ 37.00	$ 100.00
Yield (as a percent)													0.50%	15.13%
Discount to price (as a percent)				25.00%	55.00%					25.00%	34.00%
Appraised Value				$ 39,774	$ 5,379,477											$ 436,610	$ 86,000,000