GUARANTEES AND COMMITMENTS (Details) (USD $)	Jun. 30, 2012 trust	Dec. 31, 2011
Maximum potential amount of future payments
Expire Within One Year	$ 218,400,000,000	$ 201,300,000,000
Expire After One Year	120,100,000,000	132,400,000,000
Total amount outstanding	338,500,000,000	333,700,000,000
Carrying value	2,924,400,000	2,647,600,000
Allowance for credit losses relating to letters of credit and unfunded lending commitments	1,104,000,000	1,136,000,000
Cash collateral available to reimburse losses realized under guarantees and indemnifications	39,000,000,000	35,000,000,000
Securities and other marketable assets held as collateral, the majority of which collateral is held to reimburse losses realized under securities lending indemnifications	65,000,000,000	65,000,000,000
Letters of credit in favor of the Company held as collateral	2,000,000,000	1,500,000,000
Number of trusts funded by the reinsurer	2
Fair value of securities in trusts funded by reinsurer relating to indemnification	4,900,000,000	4,400,000,000
Investment grade
Maximum potential amount of future payments
Total amount outstanding	109,600,000,000	126,200,000,000
Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	20,500,000,000	20,400,000,000
Not rated
Maximum potential amount of future payments
Total amount outstanding	208,400,000,000	187,100,000,000
Financial standby letters of credit
Maximum potential amount of future payments
Expire Within One Year	24,600,000,000	25,200,000,000
Expire After One Year	77,600,000,000	79,500,000,000
Total amount outstanding	102,200,000,000	104,700,000,000
Carrying value	322,200,000	417,500,000
Financial standby letters of credit | Investment grade
Maximum potential amount of future payments
Total amount outstanding	75,400,000,000	79,300,000,000
Financial standby letters of credit | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	17,400,000,000	17,200,000,000
Financial standby letters of credit | Not rated
Maximum potential amount of future payments
Total amount outstanding	9,400,000,000	8,200,000,000
Performance guarantees
Maximum potential amount of future payments
Expire Within One Year	7,300,000,000	7,800,000,000
Expire After One Year	4,300,000,000	4,500,000,000
Total amount outstanding	11,600,000,000	12,300,000,000
Carrying value	43,100,000	43,900,000
Performance guarantees | Investment grade
Maximum potential amount of future payments
Total amount outstanding	6,700,000,000	6,900,000,000
Performance guarantees | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	3,100,000,000	3,200,000,000
Performance guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	1,800,000,000	2,200,000,000
Derivative instruments considered to be guarantees
Maximum potential amount of future payments
Expire Within One Year	17,700,000,000	7,200,000,000
Expire After One Year	10,300,000,000	8,000,000,000
Total amount outstanding	28,000,000,000	15,200,000,000
Carrying value	2,442,300,000	2,065,900,000
Derivative instruments considered to be guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	28,000,000,000	15,200,000,000
Loans sold with recourse
Maximum potential amount of future payments
Expire After One Year	400,000,000	400,000,000
Total amount outstanding	400,000,000	400,000,000
Carrying value	84,800,000	89,600,000
Repurchase reserve for Consumer mortgages representations and warranties	1,476,000,000	1,188,000,000
Increase in repurchase reserve due to 10% adverse change in significant assumptions	500,000,000
Loans sold with recourse | Not rated
Maximum potential amount of future payments
Total amount outstanding	400,000,000	400,000,000
Securities lending indemnifications
Maximum potential amount of future payments
Expire Within One Year	94,900,000,000	90,900,000,000
Total amount outstanding	94,900,000,000	90,900,000,000
Securities lending indemnifications | Not rated
Maximum potential amount of future payments
Total amount outstanding	94,900,000,000	90,900,000,000
Credit card merchant processing
Maximum potential amount of future payments
Expire Within One Year	73,900,000,000	70,200,000,000
Total amount outstanding	73,900,000,000	70,200,000,000
Maximum potential contingent liability related to bankcard and private-label merchant processing services	74,000,000,000	70,000,000,000
Credit card merchant processing | Not rated
Maximum potential amount of future payments
Total amount outstanding	73,900,000,000	70,200,000,000
Custody indemnifications and other
Maximum potential amount of future payments
Expire After One Year	27,500,000,000	40,000,000,000
Total amount outstanding	27,500,000,000	40,000,000,000
Carrying value	32,000,000	30,700,000
Custody indemnifications and other | Investment grade
Maximum potential amount of future payments
Total amount outstanding	$ 27,500,000,000	$ 40,000,000,000