Quarterly report pursuant to Section 13 or 15(d)

VIEs - Trust preferred Securities (Details)

v3.10.0.1
VIEs - Trust preferred Securities (Details)
$ in Millions
 3 Months Ended
Sep. 30, 2018
USD ($)
Summary of Outstanding Trust Preferred Securities  
Principal amount of subordinated note/ debenture issued to trust $ 252
Investment in unconsolidated subsidiary $ 14
Huntington Capital I  
Summary of Outstanding Trust Preferred Securities  
Interest rate on Trust Preferred Securities 3.10%
Principal amount of subordinated note/ debenture issued to trust $ 70
Investment in unconsolidated subsidiary $ 6
Huntington Capital I | London Interbank Offered Rate (LIBOR)  
Summary of Outstanding Trust Preferred Securities (Textuals) [Abstract]  
Rate spread over three month LIBOR 0.70%
Huntington Capital II  
Summary of Outstanding Trust Preferred Securities  
Interest rate on Trust Preferred Securities 3.02%
Principal amount of subordinated note/ debenture issued to trust $ 32
Investment in unconsolidated subsidiary $ 3
Huntington Capital II | London Interbank Offered Rate (LIBOR)  
Summary of Outstanding Trust Preferred Securities (Textuals) [Abstract]  
Rate spread over three month LIBOR 0.625%
Sky Financial Capital Trust III  
Summary of Outstanding Trust Preferred Securities  
Interest rate on Trust Preferred Securities 3.80%
Principal amount of subordinated note/ debenture issued to trust $ 72
Investment in unconsolidated subsidiary $ 2
Sky Financial Capital Trust III | London Interbank Offered Rate (LIBOR)  
Summary of Outstanding Trust Preferred Securities (Textuals) [Abstract]  
Rate spread over three month LIBOR 1.40%
Sky Financial Capital Trust IV  
Summary of Outstanding Trust Preferred Securities  
Interest rate on Trust Preferred Securities 3.80%
Principal amount of subordinated note/ debenture issued to trust $ 74
Investment in unconsolidated subsidiary $ 2
Camco Financial Trust  
Summary of Outstanding Trust Preferred Securities  
Interest rate on Trust Preferred Securities 3.73%
Principal amount of subordinated note/ debenture issued to trust $ 4
Investment in unconsolidated subsidiary $ 1
Camco Financial Trust | London Interbank Offered Rate (LIBOR)  
Summary of Outstanding Trust Preferred Securities (Textuals) [Abstract]  
Rate spread over three month LIBOR 1.33%