GUARANTEES AND COMMITMENTS (Details) (USD $)	Mar. 31, 2012 trust	Dec. 31, 2011
Maximum potential amount of future payments
Expire Within One Year	$ 210,900,000,000	$ 205,200,000,000
Expire After One Year	137,400,000,000	134,600,000,000
Total amount outstanding	348,300,000,000	339,800,000,000
Carrying value	3,309,500,000	3,151,400,000
Allowance for credit losses relating to letters of credit and unfunded lending commitments	1,097,000,000	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	1,500,000,000	1,500,000,000
Number of trusts funded by the reinsurer	2
Fair value of securities in trusts funded by reinsurer relating to indemnification	4,600,000,000	4,400,000,000
Investment grade
Maximum potential amount of future payments
Total amount outstanding	121,800,000,000	126,200,000,000
Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	22,000,000,000	20,400,000,000
Not rated
Maximum potential amount of future payments
Total amount outstanding	204,500,000,000	193,200,000,000
Financial standby letters of credit
Maximum potential amount of future payments
Expire Within One Year	24,200,000,000	25,200,000,000
Expire After One Year	80,700,000,000	79,500,000,000
Total amount outstanding	104,900,000,000	104,700,000,000
Carrying value	367,100,000	417,500,000
Financial standby letters of credit | Investment grade
Maximum potential amount of future payments
Total amount outstanding	77,100,000,000	79,300,000,000
Financial standby letters of credit | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	18,900,000,000	17,200,000,000
Financial standby letters of credit | Not rated
Maximum potential amount of future payments
Total amount outstanding	8,900,000,000	8,200,000,000
Performance guarantees
Maximum potential amount of future payments
Expire Within One Year	7,700,000,000	7,800,000,000
Expire After One Year	4,500,000,000	4,500,000,000
Total amount outstanding	12,200,000,000	12,300,000,000
Carrying value	45,600,000	43,900,000
Performance guarantees | Investment grade
Maximum potential amount of future payments
Total amount outstanding	6,900,000,000	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	2,200,000,000	2,200,000,000
Derivative instruments considered to be guarantees
Maximum potential amount of future payments
Expire Within One Year	16,900,000,000	11,100,000,000
Expire After One Year	13,900,000,000	10,200,000,000
Total amount outstanding	30,800,000,000	21,300,000,000
Carrying value	2,755,800,000	2,569,700,000
Derivative instruments considered to be guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	30,800,000,000	21,300,000,000
Loans sold with recourse
Maximum potential amount of future payments
Expire After One Year	500,000,000	400,000,000
Total amount outstanding	500,000,000	400,000,000
Carrying value	87,000,000	89,600,000
Repurchase reserve for Consumer mortgages representations and warranties	1,376,000,000	1,188,000,000
Increase in repurchase reserve due to 10% adverse change in significant assumptions	602,000,000
Loans sold with recourse | Not rated
Maximum potential amount of future payments
Total amount outstanding	500,000,000	400,000,000
Securities lending indemnifications
Maximum potential amount of future payments
Expire Within One Year	95,000,000,000	90,900,000,000
Total amount outstanding	95,000,000,000	90,900,000,000
Securities lending indemnifications | Not rated
Maximum potential amount of future payments
Total amount outstanding	95,000,000,000	90,900,000,000
Credit card merchant processing
Maximum potential amount of future payments
Expire Within One Year	67,100,000,000	70,200,000,000
Total amount outstanding	67,100,000,000	70,200,000,000
Maximum potential contingent liability related to bankcard and private-label merchant processing services	67,000,000,000	70,000,000,000
Credit card merchant processing | Not rated
Maximum potential amount of future payments
Total amount outstanding	67,100,000,000	70,200,000,000
Custody indemnifications and other
Maximum potential amount of future payments
Expire After One Year	37,800,000,000	40,000,000,000
Total amount outstanding	37,800,000,000	40,000,000,000
Carrying value	54,000,000	30,700,000
Custody indemnifications and other | Investment grade
Maximum potential amount of future payments
Total amount outstanding	$ 37,800,000,000	$ 40,000,000,000