LOANS (Details 8) (USD $) In Millions, unless otherwise specified		3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2011	Jun. 30, 2012 Corporate	Jun. 30, 2011 Corporate	Jun. 30, 2012 Corporate	Jun. 30, 2011 Corporate	Dec. 31, 2011 Corporate	Jun. 30, 2012 Corporate Commercial and industrial	Jun. 30, 2012 Corporate Commercial and industrial	Dec. 31, 2011 Corporate Commercial and industrial	Jun. 30, 2012 Corporate Loans to financial institutions	Dec. 31, 2011 Corporate Loans to financial institutions	Jun. 30, 2012 Corporate Mortgage and real estate	Jun. 30, 2012 Corporate Mortgage and real estate	Dec. 31, 2011 Corporate Mortgage and real estate	Jun. 30, 2012 Corporate Lease financing	Jun. 30, 2012 Corporate Lease financing	Dec. 31, 2011 Corporate Lease financing	Jun. 30, 2012 Corporate Other	Jun. 30, 2012 Corporate Other	Dec. 31, 2011 Corporate Other
Financing receivable impaired
Recorded investment	$ 1,170	$ 2,571		$ 2,571		$ 3,236	$ 1,023	$ 1,023	$ 1,134	$ 537	$ 763	$ 779	$ 779	$ 1,039	$ 7	$ 7	$ 13	$ 225	$ 225	$ 287
Unpaid principal balance		3,683		3,683		4,488	1,378	1,378	1,455	581	1,127	1,129	1,129	1,245	16	16	21	579	579	640
Related specific allowance	467	417		417		420	252	252	186	16	28	114	114	151				35	35	55
Average Carrying Value				3,239		4,434		1,186	1,446	791	1,056		983	1,487		13	25		266	420
Interest Income Recognized		37	33	63	46		28	35				3	21		1	1		5	6
Impaired financing receivable with specific allowance		1,107		1,107		1,239	530	530	501	43	78	422	422	540				112	112	120
Impaired financing receivable without specific allowance		$ 1,464		$ 1,464		$ 1,997	$ 493	$ 493	$ 633	$ 494	$ 685	$ 357	$ 357	$ 499	$ 7	$ 7	$ 13	$ 113	$ 113	$ 167
Number of months in sustained period of repayment performance for cash-basis loans to return to an accrual status		6 months		6 months		6 months