ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses Roll Forward by Segment (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Dec. 31, 2016
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 12,060	$ 12,626
Charge-offs	(2,144)	(2,143)
Recoveries	435	419
Replenishment of net charge-offs	1,709	1,724
Net reserve builds (releases)	(20)	42
Net specific reserve builds (releases)	(14)	120
Other	4	(76)
Allowance for loan losses at end of period	12,030	12,712
Allowance for loan losses
Determined in accordance with ASC 450			$ 10,074	$ 10,054
Determined in accordance with ASC 310-10-35			1,951	2,000
Determined in accordance with ASC 310-30			5	6
Total allowance for loan losses	12,060	12,626	12,030	12,060
Loans, net of unearned income
Loans collectively evaluated for impairment in accordance with ASC 450			614,322	610,266
Loans individually evaluated for impairment in accordance with ASC 310-10-35			10,044	10,430
Loans held at fair value			4,035	3,486
Loans, net of unearned income			628,595	624,369
Receivables Acquired with Deteriorated Credit Quality
Loans, net of unearned income
Loans acquired with deteriorated credit quality in accordance with ASC 310-30			194	187
Corporate
Allowance for credit losses
Allowance for loan losses at beginning of period	2,702	2,791
Charge-offs	(103)	(223)
Recoveries	66	13
Replenishment of net charge-offs	37	210
Net reserve builds (releases)	(166)	4
Net specific reserve builds (releases)	(12)	101
Other	11	9
Allowance for loan losses at end of period	2,535	2,905
Allowance for loan losses
Determined in accordance with ASC 450			2,153	2,310
Determined in accordance with ASC 310-10-35			382	392
Determined in accordance with ASC 310-30			0	0
Total allowance for loan losses	2,702	2,791	2,535	2,702
Loans, net of unearned income
Loans collectively evaluated for impairment in accordance with ASC 450			301,561	293,218
Loans individually evaluated for impairment in accordance with ASC 310-10-35			2,471	2,631
Loans held at fair value			4,007	3,457
Loans, net of unearned income			308,039	299,306
Corporate \| Receivables Acquired with Deteriorated Credit Quality
Loans, net of unearned income
Loans acquired with deteriorated credit quality in accordance with ASC 310-30			0	0
Consumer
Allowance for credit losses
Allowance for loan losses at beginning of period	9,358	9,835
Charge-offs	(2,041)	(1,920)
Recoveries	369	406
Replenishment of net charge-offs	1,672	1,514
Net reserve builds (releases)	146	38
Net specific reserve builds (releases)	(2)	19
Other	(7)	(85)
Allowance for loan losses at end of period	9,495	9,807
Allowance for loan losses
Determined in accordance with ASC 450			7,921	7,744
Determined in accordance with ASC 310-10-35			1,569	1,608
Determined in accordance with ASC 310-30			5	6
Total allowance for loan losses	$ 9,358	$ 9,835	9,495	9,358
Loans, net of unearned income
Loans collectively evaluated for impairment in accordance with ASC 450			312,761	317,048
Loans individually evaluated for impairment in accordance with ASC 310-10-35			7,573	7,799
Loans held at fair value			28	29
Loans, net of unearned income			320,556	325,063
Consumer \| Receivables Acquired with Deteriorated Credit Quality
Loans, net of unearned income
Loans acquired with deteriorated credit quality in accordance with ASC 310-30			$ 194	$ 187

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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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.

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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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No definition available.

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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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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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