LOANS AND LEASES - Troubled Debt Restructurings (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2022 USD ($) contract	Jun. 30, 2021 USD ($) contract	Jun. 30, 2022 USD ($) contract	Jun. 30, 2021 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	46	39	69	71
Pre- Modification Outstanding Recorded Investment	$ 8	$ 3	$ 9	$ 22
Post- Modification Outstanding Recorded Investment	$ 8	$ 3	$ 10	$ 22
Total commercial loans and leases
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	13	13	15	24
Pre- Modification Outstanding Recorded Investment	$ 4	$ 2	$ 4	$ 19
Post- Modification Outstanding Recorded Investment	$ 3	$ 2	$ 5	$ 19
Total commercial loans and leases \| Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	7	9	9	19
Pre- Modification Outstanding Recorded Investment	$ 3	$ 2	$ 3	$ 19
Post- Modification Outstanding Recorded Investment	$ 3	$ 2	$ 4	$ 19
Total commercial loans and leases \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	6	4	6	5
Pre- Modification Outstanding Recorded Investment	$ 1	$ 0	$ 1	$ 0
Post- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 1	$ 0
Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	33	26	54	47
Pre- Modification Outstanding Recorded Investment	$ 4	$ 1	$ 5	$ 3
Post- Modification Outstanding Recorded Investment	$ 5	$ 1	$ 5	$ 3
Total consumer loans \| Direct installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	13	9	26	19
Pre- Modification Outstanding Recorded Investment	$ 1	$ 0	$ 1	$ 1
Post- Modification Outstanding Recorded Investment	$ 1	$ 0	$ 1	$ 1
Total consumer loans \| Residential mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	15	2	20	3
Pre- Modification Outstanding Recorded Investment	$ 3	$ 0	$ 3	$ 0
Post- Modification Outstanding Recorded Investment	$ 3	$ 0	$ 3	$ 0
Total consumer loans \| Consumer lines of credit
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	5	15	8	25
Pre- Modification Outstanding Recorded Investment	$ 0	$ 1	$ 1	$ 2
Post- Modification Outstanding Recorded Investment	$ 1	$ 1	$ 1	$ 2

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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