Quarterly report pursuant to Section 13 or 15(d)

BORROWINGS - Narrative (Details)

v3.21.2
BORROWINGS - Narrative (Details) - USD ($)
$ in Millions
9 Months Ended
Aug. 15, 2031
Sep. 30, 2021
Aug. 16, 2021
Jun. 09, 2021
Dec. 31, 2020
Debt Instrument [Line Items]          
Long-term debt   $ 7,779     $ 8,352
Parent          
Debt Instrument [Line Items]          
Long-term debt   3,839     4,142
Bank          
Debt Instrument [Line Items]          
Long-term debt   3,264     3,766
Federal Home Loan Bank Advances          
Debt Instrument [Line Items]          
Long-term debt   216     3
Subordinated Notes | Parent          
Debt Instrument [Line Items]          
Long-term debt   1,037     507
Subordinated Notes | Bank          
Debt Instrument [Line Items]          
Long-term debt   813     233
Senior Notes | Parent          
Debt Instrument [Line Items]          
Long-term debt   2,802     3,635
Senior Notes | Bank          
Debt Instrument [Line Items]          
Long-term debt   $ 2,451     $ 3,533
TCF Financial Corporation          
Debt Instrument [Line Items]          
Long-term debt       $ 1,516  
TCF Financial Corporation | Parent | Minimum | London Interbank Offered Rate (LIBOR)          
Debt Instrument [Line Items]          
Basis spread on variable rate   2.85%      
TCF Financial Corporation | Bank | Minimum | London Interbank Offered Rate (LIBOR)          
Debt Instrument [Line Items]          
Basis spread on variable rate   0.64%      
TCF Financial Corporation | Bank | Maximum | London Interbank Offered Rate (LIBOR)          
Debt Instrument [Line Items]          
Basis spread on variable rate   3.75%      
TCF Financial Corporation | Federal Home Loan Bank Advances          
Debt Instrument [Line Items]          
Long-term debt   $ 213      
Debt stated interest rate   1.03%      
TCF Financial Corporation | Subordinated Notes          
Debt Instrument [Line Items]          
Long-term debt   $ 598      
TCF Financial Corporation | Subordinated Notes | Parent          
Debt Instrument [Line Items]          
Long-term debt   8      
TCF Financial Corporation | Subordinated Notes | Bank          
Debt Instrument [Line Items]          
Long-term debt   $ 590      
Huntington Bancshares Incorporated Senior Notes Due 2036 2.487 percent | Subordinated Notes | Parent          
Debt Instrument [Line Items]          
Debt stated interest rate     2.487%    
Debt face amount     $ 558    
Huntington Bancshares Incorporated Senior Notes Due 2036 2.487 percent | Subordinated Notes | Parent | Forecast          
Debt Instrument [Line Items]          
Basis spread on variable rate 1.17%        
3.55% Huntington Bancshares Incorporated subordinated notes due 2023 | Subordinated Notes | Parent          
Debt Instrument [Line Items]          
Debt stated interest rate   4.35%      
6.250% Huntington National Bank subordinated notes due 2022 | Subordinated Notes          
Debt Instrument [Line Items]          
Debt stated interest rate   6.25%      
4.600% Huntington National Bank subordinated notes due 2025 | Subordinated Notes          
Debt Instrument [Line Items]          
Debt stated interest rate   4.60%      
3.86% Huntington National Bank subordinated notes due 2026 | Subordinated Notes          
Debt Instrument [Line Items]          
Debt stated interest rate   4.27%