Fair Value of Assets and Liabilities - Summary Of Book Value And Estimated Fair Value Of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Short-term financial assets:
Interest-bearing deposits with banks	$ 14,907	$ 8,351
Securities purchased under agreements to resell	488	380
Trading securities:	1,601	1,176
Loans held-for-sale	1,172	1,022
Securities held to maturity (fair value of $705 and $10, respectively)	712	10
Gross amounts of recognized assets	323	765
Other assets:
Total assets	89,092	84,209
Liabilities:
Trading liabilities	426	353
Short-term financial liabilities:
Securities sold under agreements to repurchase	1,247	1,187
Term borrowings:
Other long term borrowings	1,590	1,670
Gross amounts of recognized liabilities	103	125
Total liabilities	80,598	75,902
Level 3 | FHLB-Cincinnati Stock
Term borrowings:
Restricted investments	29	61
Level 3 | FRB Stock
Term borrowings:
Restricted investments	203	202
Reported Value Measurement
Assets
Total loans, net of unearned income and allowance for loan losses	54,189	57,269
Short-term financial assets:
Interest-bearing deposits with banks	14,907	8,351
Federal funds sold	153	65
Securities purchased under agreements to resell	488	380
Total short-term financial assets	15,548	8,796
Trading securities:	1,601	1,176
Loans held-for-sale	1,172	1,022
Securities available for sale at fair value	8,707	8,047
Securities held to maturity (fair value of $705 and $10, respectively)	712	10
Gross amounts of recognized assets	324	769
Other assets:
Tax credit investments	456	400
Deferred compensation mutual funds	125	118
Equity, mutual funds, and other	257	288
Total other assets	838	806
Total assets	83,091	77,895
Liabilities:
Defined maturity	3,500	5,070
Trading liabilities	426	353
Short-term financial liabilities:
Federal funds purchased	775	845
Securities sold under agreements to repurchase	1,247	1,187
Other short-term borrowings	102	166
Total short-term financial liabilities	2,124	2,198
Term borrowings:
Real estate investment trust-preferred	46	46
Term borrowings—new market tax credit investment	59	45
Secured borrowings	6	15
Junior subordinated debentures	148	238
Other long term borrowings	1,331	1,326
Total term borrowings	1,590	1,670
Gross amounts of recognized liabilities	128	149
Total liabilities	7,768	9,440
Reported Value Measurement | Commercial and industrial
Assets
Total loans, net of unearned income and allowance for loan losses	30,734	32,651
Reported Value Measurement | Commercial real estate
Assets
Total loans, net of unearned income and allowance for loan losses	11,955	12,033
Reported Value Measurement | Consumer real estate
Assets
Total loans, net of unearned income and allowance for loan losses	10,609	11,483
Reported Value Measurement | Credit Card and Other
Assets
Total loans, net of unearned income and allowance for loan losses	891	1,102
Reported Value Measurement | Mortgage Loans
Short-term financial assets:
Loans held-for-sale	258	405
Reported Value Measurement | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale	853	509
Reported Value Measurement | Other
Short-term financial assets:
Loans held-for-sale	24	31
Reported Value Measurement | Mortgage Loan - LOCOM
Short-term financial assets:
Loans held-for-sale	37	77
Estimate of Fair Value Measurement
Assets
Total loans, net of unearned income and allowance for loan losses	55,023	57,695
Short-term financial assets:
Interest-bearing deposits with banks	14,907	8,351
Federal funds sold	153	65
Securities purchased under agreements to resell	488	380
Total short-term financial assets	15,548	8,796
Trading securities:	1,601	1,176
Loans held-for-sale	1,175	1,025
Securities available for sale at fair value	8,707	8,047
Securities held to maturity (fair value of $705 and $10, respectively)	705	10
Gross amounts of recognized assets	324	769
Other assets:
Tax credit investments	450	371
Deferred compensation mutual funds	125	118
Equity, mutual funds, and other	257	288
Total other assets	832	777
Total assets	83,915	78,295
Liabilities:
Defined maturity	3,524	5,083
Trading liabilities	426	353
Short-term financial liabilities:
Federal funds purchased	775	845
Securities sold under agreements to repurchase	1,247	1,187
Other short-term borrowings	102	166
Total short-term financial liabilities	2,124	2,198
Term borrowings:
Real estate investment trust-preferred	47	47
Term borrowings—new market tax credit investment	58	45
Secured borrowings	6	15
Junior subordinated debentures	150	223
Other long term borrowings	1,452	1,455
Total term borrowings	1,713	1,785
Gross amounts of recognized liabilities	128	149
Total liabilities	7,915	9,568
Loan commitments	1	2
Standby and other commitments	6	6
Estimate of Fair Value Measurement | Commercial and industrial
Assets
Total loans, net of unearned income and allowance for loan losses	31,020	32,582
Estimate of Fair Value Measurement | Commercial real estate
Assets
Total loans, net of unearned income and allowance for loan losses	11,986	12,079
Estimate of Fair Value Measurement | Consumer real estate
Assets
Total loans, net of unearned income and allowance for loan losses	11,111	11,903
Estimate of Fair Value Measurement | Credit Card and Other
Assets
Total loans, net of unearned income and allowance for loan losses	906	1,131
Estimate of Fair Value Measurement | Mortgage Loans
Short-term financial assets:
Loans held-for-sale	258	405
Estimate of Fair Value Measurement | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale	856	512
Estimate of Fair Value Measurement | Other
Short-term financial assets:
Loans held-for-sale	24	31
Estimate of Fair Value Measurement | Mortgage Loan - LOCOM
Short-term financial assets:
Loans held-for-sale	37	77
Estimate of Fair Value Measurement | Level 1
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Short-term financial assets:
Interest-bearing deposits with banks	14,907	8,351
Federal funds sold	0	0
Securities purchased under agreements to resell	0	0
Total short-term financial assets	14,907	8,351
Trading securities:	0	0
Loans held-for-sale	0	0
Securities available for sale at fair value	0	0
Securities held to maturity (fair value of $705 and $10, respectively)	0	0
Gross amounts of recognized assets	12	63
Other assets:
Tax credit investments	0	0
Deferred compensation mutual funds	125	118
Equity, mutual funds, and other	25	25
Total other assets	150	143
Total assets	15,069	8,557
Liabilities:
Defined maturity	0	0
Trading liabilities	0	0
Short-term financial liabilities:
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
Term borrowings:
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
Gross amounts of recognized liabilities	11	71
Total liabilities	11	71
Estimate of Fair Value Measurement | Level 1 | Commercial and industrial
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 1 | Commercial real estate
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 1 | Consumer real estate
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 1 | Credit Card and Other
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 1 | Mortgage Loans
Short-term financial assets:
Loans held-for-sale	0	0
Estimate of Fair Value Measurement | Level 1 | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale	0	0
Estimate of Fair Value Measurement | Level 1 | Other
Short-term financial assets:
Loans held-for-sale	0	0
Estimate of Fair Value Measurement | Level 1 | Mortgage Loan - LOCOM
Short-term financial assets:
Loans held-for-sale	0	0
Estimate of Fair Value Measurement | Level 2
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Short-term financial assets:
Interest-bearing deposits with banks	0	0
Federal funds sold	153	65
Securities purchased under agreements to resell	488	380
Total short-term financial assets	641	445
Trading securities:	1,563	1,176
Loans held-for-sale	1,109	935
Securities available for sale at fair value	8,707	8,015
Securities held to maturity (fair value of $705 and $10, respectively)	705	0
Gross amounts of recognized assets	312	706
Other assets:
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	13,037	11,277
Liabilities:
Defined maturity	3,524	5,083
Trading liabilities	426	353
Short-term financial liabilities:
Federal funds purchased	775	845
Securities sold under agreements to repurchase	1,247	1,187
Other short-term borrowings	102	166
Total short-term financial liabilities	2,124	2,198
Term borrowings:
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	1,452	1,455
Total term borrowings	1,452	1,455
Gross amounts of recognized liabilities	94	64
Total liabilities	7,620	9,153
Estimate of Fair Value Measurement | Level 2 | Commercial and industrial
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 2 | Commercial real estate
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 2 | Consumer real estate
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 2 | Credit Card and Other
Assets
Total loans, net of unearned income and allowance for loan losses	0	0
Estimate of Fair Value Measurement | Level 2 | Mortgage Loans
Short-term financial assets:
Loans held-for-sale	230	393
Estimate of Fair Value Measurement | Level 2 | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale	855	511
Estimate of Fair Value Measurement | Level 2 | Other
Short-term financial assets:
Loans held-for-sale	24	31
Estimate of Fair Value Measurement | Level 2 | Mortgage Loan - LOCOM
Short-term financial assets:
Loans held-for-sale	0	0
Estimate of Fair Value Measurement | Level 3
Assets
Total loans, net of unearned income and allowance for loan losses	55,023	57,695
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:	38	0
Loans held-for-sale	66	90
Securities available for sale at fair value	0	32
Securities held to maturity (fair value of $705 and $10, respectively)	0	10
Gross amounts of recognized assets	0	0
Other assets:
Tax credit investments	450	371
Deferred compensation mutual funds	0	0
Equity, mutual funds, and other	232	263
Total other assets	682	634
Total assets	55,809	58,461
Liabilities:
Defined maturity	0	0
Trading liabilities	0	0
Short-term financial liabilities:
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
Term borrowings:
Real estate investment trust-preferred	47	47
Term borrowings—new market tax credit investment	58	45
Secured borrowings	6	15
Junior subordinated debentures	150	223
Other long term borrowings	0	0
Total term borrowings	261	330
Gross amounts of recognized liabilities	23	14
Total liabilities	284	344
Estimate of Fair Value Measurement | Level 3 | Commercial and industrial
Assets
Total loans, net of unearned income and allowance for loan losses	31,020	32,582
Estimate of Fair Value Measurement | Level 3 | Commercial real estate
Assets
Total loans, net of unearned income and allowance for loan losses	11,986	12,079
Estimate of Fair Value Measurement | Level 3 | Consumer real estate
Assets
Total loans, net of unearned income and allowance for loan losses	11,111	11,903
Estimate of Fair Value Measurement | Level 3 | Credit Card and Other
Assets
Total loans, net of unearned income and allowance for loan losses	906	1,131
Estimate of Fair Value Measurement | Level 3 | Mortgage Loans
Short-term financial assets:
Loans held-for-sale	28	12
Estimate of Fair Value Measurement | Level 3 | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale	1	1
Estimate of Fair Value Measurement | Level 3 | Other
Short-term financial assets:
Loans held-for-sale	0	0
Estimate of Fair Value Measurement | Level 3 | Mortgage Loan - LOCOM
Short-term financial assets:
Loans held-for-sale	37	77
Contractual Amount
Term borrowings:
Loan commitments	24,229	20,796
Standby and other commitments	$ 810	$ 751