ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses Roll Forward by Segment (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Dec. 31, 2015
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 12,626	$ 15,994
Charge-offs	(2,143)	(2,458)
Recoveries	419	501
Replenishment of net charge-offs	1,724	1,957
Net reserve builds (releases)	42	(91)
Net specific reserve releases	120	(111)
Other	(76)	(1,194)
Allowance for loan losses at end of period	12,712	14,598
Allowance for loan losses
Determined in accordance with ASC 450			$ 10,195	$ 10,184
Determined in accordance with ASC 310-10-35			2,505	2,426
Allowance for loan losses	12,626	15,994	12,712	12,626
Loans, net of unearned income
Loans collectively evaluated for impairment in accordance with ASC 450			601,349	600,367
Loans individually evaluated for impairment in accordance with ASC 310-10-35			12,446	11,995
Loans held at fair value			4,793	5,005
Loans, net of unearned income			618,824	617,617
Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Determined in accordance with ASC 310-30			12	16
Loans, net of unearned income
Loans acquired with deteriorated credit quality in accordance with ASC 310-30			236	250
Corporate
Allowance for credit losses
Allowance for loan losses at beginning of period	2,791	2,447
Charge-offs	(224)	(26)
Recoveries	13	33
Replenishment of net charge-offs	211	(7)
Net reserve builds (releases)	4	112
Net specific reserve releases	101	3
Other	9	(16)
Allowance for loan losses at end of period	2,905	2,546
Allowance for loan losses
Determined in accordance with ASC 450			2,418	2,408
Determined in accordance with ASC 310-10-35			483	380
Allowance for loan losses	2,791	2,447	2,905	2,791
Loans, net of unearned income
Loans collectively evaluated for impairment in accordance with ASC 450			293,631	285,053
Loans individually evaluated for impairment in accordance with ASC 310-10-35			2,527	1,803
Loans held at fair value			4,760	4,971
Loans, net of unearned income			300,924	291,832
Corporate \| Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Determined in accordance with ASC 310-30			4	3
Loans, net of unearned income
Loans acquired with deteriorated credit quality in accordance with ASC 310-30			6	5
Consumer
Allowance for credit losses
Allowance for loan losses at beginning of period	9,835	13,547
Charge-offs	(1,919)	(2,432)
Recoveries	406	468
Replenishment of net charge-offs	1,513	1,964
Net reserve builds (releases)	38	(203)
Net specific reserve releases	19	(114)
Other	(85)	(1,178)
Allowance for loan losses at end of period	9,807	12,052
Allowance for loan losses
Determined in accordance with ASC 450			7,777	7,776
Determined in accordance with ASC 310-10-35			2,022	2,046
Allowance for loan losses	$ 9,835	$ 13,547	9,807	9,835
Loans, net of unearned income
Loans collectively evaluated for impairment in accordance with ASC 450			307,718	315,314
Loans individually evaluated for impairment in accordance with ASC 310-10-35			9,919	10,192
Loans held at fair value			33	34
Loans, net of unearned income			317,900	325,785
Consumer \| Receivables Acquired with Deteriorated Credit Quality
Allowance for loan losses
Determined in accordance with ASC 310-30			8	13
Loans, net of unearned income
Loans acquired with deteriorated credit quality in accordance with ASC 310-30			$ 230	$ 245

Reflects the amount of replenishment of net charge-offs for credit losses.

No definition available.

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- Definition

Provision charged or released during the period against earnings for credit losses on loans and leases receivable that are expected and were collectively evaluated for impairment.

+ References

No definition available.

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- Definition

Provision charged or released during the period against earnings for credit losses on loans and leases receivable that are expected and were individually evaluated for impairment.

+ References

No definition available.

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- Definition

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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- Definition

Amount of other addition (reduction) in allowance reserve for credit loss.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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-Publisher FASB
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Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

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