LOANS AND LEASES - Loans Held For Sale (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	$ 1,750	$ 1,219
Other loans held for sale	455	101
Residential loans held for sale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	1,615	967
Other loans held for sale	0	0
Commercial real estate loans held for sale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	135	252
Other loans held for sale	$ 455	$ 101