Huntington Bancshares Incorporated Quarterly report pursuant to Section 13 or 15(d)

LOANS / LEASES AND ALLOWANCE FOR CREDIT LOSSES - Nonaccrual Loans by Loan Class (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	$ 383	$ 349
Commercial \| Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	190	161
Commercial \| Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	30	29
Consumer \| Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	5	6
Consumer \| Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	75	68
Consumer \| Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	82	84
Consumer \| RV and Marine FInance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	1	1
Consumer \| Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total nonaccrual loans	$ 0	$ 0