LOANS AND LEASES - Loans Held For Sale (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at fair value	$ 1,377	$ 2,733
Other loans held for sale	2,078	735
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at fair value		76
Other loans held for sale	1,590	735
Residential Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at fair value		2,657
Other loans held for sale	0	$ 0
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other loans held for sale	488
Residential loans held for sale | Residential Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at fair value	1,278
Other retail | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at fair value	0
Commercial loans held for sale | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at fair value	$ 99