LOANS AND LEASES - Summary of Loans and Leases Portfolio (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 124,071	$ 119,088
Loans held for sale, at fair value	3,587	1,946
Other loans held for sale	127	1,384
SBA Loans Serviced For Others \| CBNA and Other Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	44	33
Mortgage loans serviced for others \| CBNA and Other Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	80,700	77,500
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	62,362	57,538
Commercial \| Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	45,185	41,479
Commercial \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,889	13,522
Commercial \| Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	2,288	2,537
Commercial \| SBA Guaranteed PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	4,700
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	61,709	61,550
Retail \| Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	19,633	19,083
Retail \| Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	12,322	13,154
Retail \| Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	12,035	12,120
Retail \| Education
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	11,631	10,347
Retail \| Other retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 6,088	$ 6,846

The amount of other loans receivable that will be sold to other entities.

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- Definition

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+ References

No definition available.

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- Definition

Amount, before valuation allowance, of financing receivable classified as held-for-sale.

+ References

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- Definition

Amount, before allowance for credit loss, of financing receivable.

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