MORTGAGE BANKING AND OTHER - Other Serviced Loans (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 128,163	$ 123,090
Education Loans Serviced For Others
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	761	974
SBA Loans Serviced For Others \| CBNA and Other Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 80	$ 51

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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