ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses Roll Forward (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 12,315	$ 12,355
Gross credit losses	(2,345)	(2,296)
Gross recoveries	397	429
Net credit losses (NCLs)	(1,948)	(1,867)
Net reserve builds (releases)	67	102
Net specific reserve builds (releases)	(71)	(166)
Total provision for loan losses	1,944	1,803
Other, net	18	63
Allowance for loan losses at end of period	12,329	12,354
Allowance for credit losses on unfunded lending commitments
Allowance for credit losses on unfunded lending commitments at beginning of period	1,367	1,258
Provision (release) for unfunded lending commitments	24	28
Other, net	0	4
Allowance for credit losses on unfunded lending commitments at end of period	1,391	1,290
Total allowance for loans, leases and unfunded lending commitments	13,720	13,644
Sales or transfers of various consumer loan portfolios to HFS
Other, net	18	63
Consumer
Allowance for credit losses
Allowance for loan losses at beginning of period	9,950	9,869
Gross credit losses	(2,272)	(2,157)
Gross recoveries	380	386
Net credit losses (NCLs)	(1,892)	(1,771)
Net reserve builds (releases)	60	121
Net specific reserve builds (releases)	(10)	(11)
Other, net	26	60
Allowance for loan losses at end of period	10,026	10,039
Sales or transfers of various consumer loan portfolios to HFS
Transfer of real estate loan portfolios	0	(53)
Transfer of other loan portfolios	0	(2)
Sales or transfers of various consumer loan portfolios to HFS	0	(55)
FX translation, consumer	26	118
Other, net	26	60
Corporate
Allowance for credit losses
Allowance for loan losses at beginning of period	2,365	2,486
Gross credit losses	(73)	(139)
Gross recoveries	17	43
Net credit losses (NCLs)	(56)	(96)
Net reserve builds (releases)	7	(19)
Net specific reserve builds (releases)	(61)	(155)
Other, net	(8)	3
Allowance for loan losses at end of period	2,303	2,315
Sales or transfers of various consumer loan portfolios to HFS
Other	(8)	0
Other, net	$ (8)	$ 3

Allowance For Loan And Lease Losses, Loans Transferred To Other Loan Portfolios

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- Definition

Allowance For Loan And Lease Losses, Loans Transferred To Real Estate Loan Portfolio

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No definition available.

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Allowance for Loan and Lease Losses, Adjustments, Miscellaneous Other

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No definition available.

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- Definition

The reserve to cover probable credit losses related to loans and leases receivable and unfunded lending commitments as of the balance sheet date.

+ References

No definition available.

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Provision charged or released during the period against earnings for unfunded lending commitments other net.

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No definition available.

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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.

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No definition available.

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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.

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No definition available.

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The reserve to cover probable credit losses related to unfunded lending commitments as of the balance sheet date.

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Unfunded Lending Commitments Allowance For Credit Losses, Adjustments, Net

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

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Amount of gain (loss) from converting allowance reserve for credit loss to currency of reporting entity from amount denominated or measured in a different currency, which decreases (increases) the allowance for loan and lease losses.

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Amount of reduction of allowance reserve for credit loss arising from sale of loan and lease portfolios.

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

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Amount, after recoveries, of loans and leases that have been written-off.

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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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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 of expense related to loss from loan transactions.

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