LOANS AND LEASES - Summary of Loans and Leases Portfolio (Details) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[1],[2]	$ 110,151	$ 107,669
Loans receivable held for sale		1,200	625
Mortgage loans serviced for others | Banking Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		17,700	17,300
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		52,381	51,651
Commercial | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		37,706	37,274
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		11,426	10,624
Commercial | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		3,249	3,753
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		57,770	56,018
Retail | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		16,619	15,115
Retail | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		1,483	1,858
Retail | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		13,555	14,100
Retail | Home equity loans serviced by others
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		599	750
Retail | Home equity lines of credit serviced by others
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		166	219
Retail | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		13,311	13,938
Retail | Education
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[3]	8,014	6,610
Retail | Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		1,754	1,691
Retail | Other retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		$ 2,269	$ 1,737

[1] Excluded from the table above are loans held for sale totaling $1.2 billion and $625 million as of September 30, 2017 and December 31, 2016, respectively.

[2] Mortgage loans serviced for others by the Company’s subsidiaries are not included above, and amounted to $17.7 billion and $17.3 billion at September 30, 2017 and December 31, 2016, respectively.

[3] During first quarter 2017, student loans were renamed “education” loans. Refer to Note 1 “Basis of Presentation” for more information.