LOANS AND LEASES - Summary of Loans and Leases Portfolio (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases commercial	$ 43,982,000,000		$ 43,226,000,000
Loans and leases retail	50,512,000,000		50,184,000,000
Loans and leases	94,494,000,000		93,410,000,000
Loans held for sale	322,000,000		256,000,000
Banking Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans serviced for others by the Company's subsidiaries	18,000,000,000		17,900,000,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases commercial	32,249,000,000		31,431,000,000
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases commercial	7,863,000,000		7,809,000,000
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases commercial	3,870,000,000		3,986,000,000
Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	11,808,000,000		11,832,000,000
Loans held for sale	322,000,000		256,000,000
Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	3,212,000,000		3,424,000,000
Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	15,127,000,000		15,423,000,000
Home equity loans serviced by others
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	1,192,000,000	[1]	1,228,000,000	[1]
Home equity lines of credit serviced by others
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	544,000,000	[1]	550,000,000	[1]
Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	13,179,000,000		12,706,000,000
Student
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	2,852,000,000		2,256,000,000
Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	1,588,000,000		1,693,000,000
Other retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases retail	1,010,000,000		1,072,000,000
Residential mortgage and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	376,000,000		281,000,000
Total Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 94,494,000,000	[2],[3]	$ 93,410,000,000	[2],[3]

[1] The Company’s SBO portfolio consists of home equity loans and lines that were originally serviced by others. The Company now services a portion of this portfolio internally.

[2] Excluded from the table above are loans held for sale totaling $376 million as of March 31, 2015 and $281 million as of December 31, 2014.

[3] Mortgage loans serviced for others by the Company’s subsidiaries are not included above, and amounted to $18.0 billion and $17.9 billion at March 31, 2015 and December 31, 2014, respectively.