GUARANTEES AND COMMITMENTS (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 item	Dec. 31, 2012
Maximum potential amount of future payments
Expire Within One Year	$ 183,300,000,000	$ 191,500,000,000
Expire After One Year	166,000,000,000	160,700,000,000
Total amount outstanding	349,300,000,000	352,200,000,000
Carrying value	2,704,500,000	3,210,100,000
Allowance for credit losses relating to letters of credit and unfunded lending commitments	1,132,000,000	1,119,000,000
Cash collateral available to reimburse losses realized under guarantees and indemnifications	45,000,000,000	39,000,000,000
Securities and other marketable assets held as collateral, the majority of which collateral is held to reimburse losses realized under securities lending indemnifications	42,000,000,000	51,000,000,000
Letters of credit in favor of the Company held as collateral	3,800,000,000	3,400,000,000
Number of trusts funded by the reinsurer	2
Fair value of securities in trusts funded by reinsurer relating to indemnification	5,300,000,000	4,900,000,000
Compensation for standard representations and warranties	0
Stated or notional amounts included in the indemnification clauses	0
Liability related to VTNs	0
Liability related to long-term care insurance indemnification	0
Investment grade
Maximum potential amount of future payments
Total amount outstanding	111,800,000,000	118,300,000,000
Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	15,600,000,000	14,100,000,000
Not rated
Maximum potential amount of future payments
Total amount outstanding	221,900,000,000	219,800,000,000
Financial standby letters of credit
Maximum potential amount of future payments
Expire Within One Year	22,200,000,000	22,300,000,000
Expire After One Year	75,700,000,000	79,800,000,000
Total amount outstanding	97,900,000,000	102,100,000,000
Carrying value	388,500,000	432,800,000
Financial standby letters of credit | Investment grade
Maximum potential amount of future payments
Total amount outstanding	73,300,000,000	80,900,000,000
Financial standby letters of credit | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	12,400,000,000	11,000,000,000
Financial standby letters of credit | Not rated
Maximum potential amount of future payments
Total amount outstanding	12,200,000,000	10,200,000,000
Performance guarantees
Maximum potential amount of future payments
Expire Within One Year	7,400,000,000	7,300,000,000
Expire After One Year	4,600,000,000	4,700,000,000
Total amount outstanding	12,000,000,000	12,000,000,000
Carrying value	41,200,000	41,600,000
Performance guarantees | Investment grade
Maximum potential amount of future payments
Total amount outstanding	7,100,000,000	7,300,000,000
Performance guarantees | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	3,100,000,000	3,000,000,000
Performance guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	1,800,000,000	1,700,000,000
Derivative instruments considered to be guarantees
Maximum potential amount of future payments
Expire Within One Year	11,600,000,000	11,200,000,000
Expire After One Year	53,800,000,000	45,500,000,000
Total amount outstanding	65,400,000,000	56,700,000,000
Carrying value	2,189,700,000	2,648,700,000
Derivative instruments considered to be guarantees | Not rated
Maximum potential amount of future payments
Total amount outstanding	65,400,000,000	56,700,000,000
Loans sold with recourse
Maximum potential amount of future payments
Expire After One Year	400,000,000	500,000,000
Total amount outstanding	400,000,000	500,000,000
Carrying value	85,100,000	87,000,000
Repurchase reserve for Consumer mortgages representations and warranties	1,415,000,000	1,565,000,000
Reasonably possible loss from whole loan sale representation and warranty claims in excess of amounts accrued due to modifying the key assumptions	(600,000,000)
Loans sold with recourse | Not rated
Maximum potential amount of future payments
Total amount outstanding	400,000,000	500,000,000
Securities lending indemnifications
Maximum potential amount of future payments
Expire Within One Year	76,200,000,000	80,400,000,000
Total amount outstanding	76,200,000,000	80,400,000,000
Securities lending indemnifications | Not rated
Maximum potential amount of future payments
Total amount outstanding	76,200,000,000	80,400,000,000
Credit card merchant processing
Maximum potential amount of future payments
Expire Within One Year	65,900,000,000	70,300,000,000
Total amount outstanding	65,900,000,000	70,300,000,000
Maximum potential contingent liability related to bankcard and private-label merchant processing services	66,000,000,000	70,000,000,000
Credit card merchant processing | Not rated
Maximum potential amount of future payments
Total amount outstanding	65,900,000,000	70,300,000,000
Custody indemnifications and other
Maximum potential amount of future payments
Expire After One Year	31,500,000,000	30,200,000,000
Total amount outstanding	31,500,000,000	30,200,000,000
Custody indemnifications and other | Investment grade
Maximum potential amount of future payments
Total amount outstanding	31,400,000,000	30,100,000,000
Custody indemnifications and other | Non-investment grade
Maximum potential amount of future payments
Total amount outstanding	$ 100,000,000	$ 100,000,000