Fair Value of Assets and Liabilities - Summary Of Book Value And Estimated Fair Value Of Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	$ 55,905	$ 54,189
Short-term financial assets:
Interest-bearing deposits with banks	9,475	14,907
Securities Purchased under Agreements to Resell	423	488
Trading securities	1,392	1,601
Loans held for sale:	870	1,172
Securities available-for-sale	8,941	8,707
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	687	712
Derivative assets	187	323
Other Assets Financial Instruments [Abstract]
Total assets	85,132	89,092
Liabilities:
Trading liabilities	394	426
Short Term Financial Liabilities [Abstract]
Securities sold under agreements to repurchase	1,158	1,247
Long-Term Debt, Unclassified [Abstract]
Other long term borrowings	1,599	1,590
Derivative liabilities	578	103
Total liabilities	76,581	80,598
Fair Value, Inputs, Level 3 | FHLB-Cincinnati Stock
Long-Term Debt, Unclassified [Abstract]
Restricted investments	29	29
Fair Value, Inputs, Level 3 | FRB Stock
Long-Term Debt, Unclassified [Abstract]
Restricted investments	204	203
Reported Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	55,905	54,189
Short-term financial assets:
Interest-bearing deposits with banks	9,475	14,907
Federal funds sold	289	153
Securities Purchased under Agreements to Resell	423	488
Total short-term financial assets	10,187	15,548
Trading securities	1,392	1,601
Loans held for sale:	870	1,172
Securities available-for-sale	8,941	8,707
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	687	712
Derivative assets	189	324
Other Assets Financial Instruments [Abstract]
Tax credit investments	504	456
Deferred compensation mutual funds	115	125
Equity, mutual funds, and other	255	257
Total other assets	874	838
Total assets	79,045	83,091
Liabilities:
Defined maturity deposits	2,888	3,500
Trading liabilities	394	426
Short Term Financial Liabilities [Abstract]
Federal Funds Purchased	566	775
Securities sold under agreements to repurchase	1,158	1,247
Other short-term borrowings	229	102
Total short-term financial liabilities	1,953	2,124
Long-Term Debt, Unclassified [Abstract]
Real estate investment trust-preferred	46	46
Term borrowings—new market tax credit investment	66	59
Secured borrowings	7	6
Junior subordinated debentures	148	148
Other long term borrowings	1,332	1,331
Total term borrowings	1,599	1,590
Derivative liabilities	606	128
Total liabilities	7,440	7,768
Reported Value Measurement | Commercial, financial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	31,002	30,734
Reported Value Measurement | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	12,801	11,955
Reported Value Measurement | Consumer Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	11,258	10,609
Reported Value Measurement | Credit Card And Other Portfolio Segment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	844	891
Reported Value Measurement | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held for sale:	143	258
Reported Value Measurement | USDA & SBA loans - LOCOM
Short-term financial assets:
Loans held for sale:	690	853
Reported Value Measurement | Other loans - LOCOM
Short-term financial assets:
Loans held for sale:	3	24
Reported Value Measurement | Mortgage loans - LOCOM
Short-term financial assets:
Loans held for sale:	34	37
Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	56,624	55,023
Short-term financial assets:
Interest-bearing deposits with banks	9,475	14,907
Federal funds sold	289	153
Securities Purchased under Agreements to Resell	423	488
Total short-term financial assets	10,187	15,548
Trading securities	1,392	1,601
Loans held for sale:	870	1,175
Securities available-for-sale	8,941	8,707
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	601	705
Derivative assets	189	324
Other Assets Financial Instruments [Abstract]
Tax credit investments	498	450
Deferred compensation mutual funds	115	125
Equity, mutual funds, and other	255	257
Total other assets	868	832
Total assets	79,672	83,915
Liabilities:
Defined maturity deposits	2,893	3,524
Trading liabilities	394	426
Short Term Financial Liabilities [Abstract]
Federal Funds Purchased	566	775
Securities sold under agreements to repurchase	1,158	1,247
Other short-term borrowings	229	102
Total short-term financial liabilities	1,953	2,124
Long-Term Debt, Unclassified [Abstract]
Real estate investment trust-preferred	47	47
Term borrowings—new market tax credit investment	61	58
Secured borrowings	7	6
Junior subordinated debentures	150	150
Other long term borrowings	1,331	1,452
Total term borrowings	1,596	1,713
Derivative liabilities	606	128
Total liabilities	7,442	7,915
Unfunded Commitments [Abstract]
Loan commitments	1	1
Standby And Other Commitments	6	6
Estimate of Fair Value Measurement | Commercial, financial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	31,296	31,020
Estimate of Fair Value Measurement | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	13,191	11,986
Estimate of Fair Value Measurement | Consumer Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	11,252	11,111
Estimate of Fair Value Measurement | Credit Card And Other Portfolio Segment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	885	906
Estimate of Fair Value Measurement | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held for sale:	143	258
Estimate of Fair Value Measurement | USDA & SBA loans - LOCOM
Short-term financial assets:
Loans held for sale:	690	856
Estimate of Fair Value Measurement | Other loans - LOCOM
Short-term financial assets:
Loans held for sale:	3	24
Estimate of Fair Value Measurement | Mortgage loans - LOCOM
Short-term financial assets:
Loans held for sale:	34	37
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Short-term financial assets:
Interest-bearing deposits with banks	9,475	14,907
Federal funds sold	0	0
Securities Purchased under Agreements to Resell	0	0
Total short-term financial assets	9,475	14,907
Trading securities	0	0
Loans held for sale:	0	0
Securities available-for-sale	0	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
Derivative assets	22	12
Other Assets Financial Instruments [Abstract]
Tax credit investments	0	0
Deferred compensation mutual funds	115	125
Equity, mutual funds, and other	22	25
Total other assets	137	150
Total assets	9,634	15,069
Liabilities:
Defined maturity deposits	0	0
Trading liabilities	0	0
Short Term Financial Liabilities [Abstract]
Federal Funds Purchased	0	0
Securities sold under agreements to repurchase	0	0
Other short-term borrowings	0	0
Total short-term financial liabilities	0	0
Long-Term Debt, Unclassified [Abstract]
Real estate investment trust-preferred	0	0
Term borrowings—new market tax credit investment	0	0
Secured borrowings	0	0
Junior subordinated debentures	0	0
Other long term borrowings	0	0
Total term borrowings	0	0
Derivative liabilities	21	11
Total liabilities	21	11
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Commercial, financial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Consumer Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Credit Card And Other Portfolio Segment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held for sale:	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | USDA & SBA loans - LOCOM
Short-term financial assets:
Loans held for sale:	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Other loans - LOCOM
Short-term financial assets:
Loans held for sale:	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Mortgage loans - LOCOM
Short-term financial assets:
Loans held for sale:	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Short-term financial assets:
Interest-bearing deposits with banks	0	0
Federal funds sold	289	153
Securities Purchased under Agreements to Resell	423	488
Total short-term financial assets	712	641
Trading securities	1,366	1,563
Loans held for sale:	802	1,109
Securities available-for-sale	8,941	8,707
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	601	705
Derivative assets	167	312
Other Assets Financial Instruments [Abstract]
Tax credit investments	0	0
Deferred compensation mutual funds	0	0
Equity, mutual funds, and other	0	0
Total other assets	0	0
Total assets	12,589	13,037
Liabilities:
Defined maturity deposits	2,893	3,524
Trading liabilities	394	426
Short Term Financial Liabilities [Abstract]
Federal Funds Purchased	566	775
Securities sold under agreements to repurchase	1,158	1,247
Other short-term borrowings	229	102
Total short-term financial liabilities	1,953	2,124
Long-Term Debt, Unclassified [Abstract]
Real estate investment trust-preferred	0	0
Term borrowings—new market tax credit investment	0	0
Secured borrowings	0	0
Junior subordinated debentures	0	0
Other long term borrowings	1,331	1,452
Total term borrowings	1,331	1,452
Derivative liabilities	557	94
Total liabilities	7,128	7,620
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Commercial, financial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Consumer Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Credit Card And Other Portfolio Segment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held for sale:	109	230
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | USDA & SBA loans - LOCOM
Short-term financial assets:
Loans held for sale:	690	855
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Other loans - LOCOM
Short-term financial assets:
Loans held for sale:	3	24
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Mortgage loans - LOCOM
Short-term financial assets:
Loans held for sale:	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	56,624	55,023
Short-term financial assets:
Interest-bearing deposits with banks	0	0
Federal funds sold	0	0
Securities Purchased under Agreements to Resell	0	0
Total short-term financial assets	0	0
Trading securities	26	38
Loans held for sale:	68	66
Securities available-for-sale	0	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
Derivative assets	0	0
Other Assets Financial Instruments [Abstract]
Tax credit investments	498	450
Deferred compensation mutual funds	0	0
Equity, mutual funds, and other	233	232
Total other assets	731	682
Total assets	57,449	55,809
Liabilities:
Defined maturity deposits	0	0
Trading liabilities	0	0
Short Term Financial Liabilities [Abstract]
Federal Funds Purchased	0	0
Securities sold under agreements to repurchase	0	0
Other short-term borrowings	0	0
Total short-term financial liabilities	0	0
Long-Term Debt, Unclassified [Abstract]
Real estate investment trust-preferred	47	47
Term borrowings—new market tax credit investment	61	58
Secured borrowings	7	6
Junior subordinated debentures	150	150
Other long term borrowings	0	0
Total term borrowings	265	261
Derivative liabilities	28	23
Total liabilities	293	284
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Commercial, financial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	31,296	31,020
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	13,191	11,986
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Consumer Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	11,252	11,111
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Credit Card And Other Portfolio Segment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net loans and leases	885	906
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held for sale:	34	28
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | USDA & SBA loans - LOCOM
Short-term financial assets:
Loans held for sale:	0	1
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Other loans - LOCOM
Short-term financial assets:
Loans held for sale:	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Mortgage loans - LOCOM
Short-term financial assets:
Loans held for sale:	34	37
Contractual Amount
Unfunded Commitments [Abstract]
Loan commitments	26,049	24,229
Standby And Other Commitments	$ 723	$ 810