LOANS AND LEASES - Impaired Loans and Lease (Detail) - Originated Loans And Leases [Member] $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($)
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	$ 114
Recorded Investment With No Specific Reserve	86
Recorded Investment With Specific Reserve	2
Total Recorded Investment	88
Specific Reserve	4
Average Recorded Investment	87
Commercial Real Estate [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	30
Recorded Investment With No Specific Reserve	25
Recorded Investment With Specific Reserve	2
Total Recorded Investment	27
Specific Reserve	2
Average Recorded Investment	26
Commercial and Industrial [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	35
Recorded Investment With No Specific Reserve	21
Recorded Investment With Specific Reserve	0
Total Recorded Investment	21
Specific Reserve	2
Average Recorded Investment	22
Commercial Leases [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	1
Recorded Investment With No Specific Reserve	1
Recorded Investment With Specific Reserve	0
Total Recorded Investment	1
Specific Reserve	0
Average Recorded Investment	1
Total Commercial Loans and Leases [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	66
Recorded Investment With No Specific Reserve	47
Recorded Investment With Specific Reserve	2
Total Recorded Investment	49
Specific Reserve	4
Average Recorded Investment	49
Direct Installment [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	16
Recorded Investment With No Specific Reserve	13
Recorded Investment With Specific Reserve	0
Total Recorded Investment	13
Specific Reserve	0
Average Recorded Investment	13
Residential Mortgages [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	20
Recorded Investment With No Specific Reserve	18
Recorded Investment With Specific Reserve	0
Total Recorded Investment	18
Specific Reserve	0
Average Recorded Investment	17
Indirect Installment [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	5
Recorded Investment With No Specific Reserve	3
Recorded Investment With Specific Reserve	0
Total Recorded Investment	3
Specific Reserve	0
Average Recorded Investment	3
Consumer Lines of Credit [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	7
Recorded Investment With No Specific Reserve	5
Recorded Investment With Specific Reserve	0
Total Recorded Investment	5
Specific Reserve	0
Average Recorded Investment	5
Consumer Loan [Member]
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	48
Recorded Investment With No Specific Reserve	39
Recorded Investment With Specific Reserve	0
Total Recorded Investment	39
Specific Reserve	0
Average Recorded Investment	$ 38

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953550-111524

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