Fair Value of Assets & Liabilities - Summary Of Book Value And Estimated Fair Value Of Financial Instruments (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		$ 31,067,684	$ 27,355,108
Short-term financial assets:
Interest-bearing cash		364,412	1,277,611
Federal funds sold		48,747	237,591
Securities purchased under agreements to resell		697,214	386,443
Trading securities		1,395,043	1,448,168
Loans held-for-sale	[1]	554,843	679,149
Securities available-for-sale		4,415,845	4,626,470
Securities held-to-maturity		10,000	10,000
Other assets:
Total assets		43,717,684	40,832,258
Liabilities:
Trading Liabilities		719,777	335,380
Short-term financial liabilities:
Federal funds purchased		936,837	256,567
Securities sold under agreements to repurchase		735,226	762,592
Other short-term borrowings		2,276,139	114,764
Term borrowings:
Other long term borrowings		1,195,096	1,170,963
Derivative liabilities		83,530	133,713
Total liabilities		38,721,641	36,046,878
Fair Value, Inputs, Level 3 | FHLB-Cincinnati Stock
Term borrowings:
Restricted investments		73,000	87,900
Fair Value, Inputs, Level 3 | FRB Stock
Term borrowings:
Restricted investments		130,700	130,700
Reported Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		31,067,684	27,355,108
Short-term financial assets:
Interest-bearing cash		364,412	1,277,611
Federal funds sold		48,747	237,591
Securities purchased under agreements to resell		697,214	386,443
Total short-term financial assets		1,110,373	1,901,645
Trading securities		1,395,043	1,448,168
Loans held-for-sale		554,843	679,149
Securities available-for-sale		4,415,845	4,626,470
Securities held-to-maturity		10,000	10,000
Derivative assets		250,786	81,475
Other assets:
Tax credit investments		196,451	163,300
Deferred compensation assets		43,826	37,771
Equity, mutual funds, and other		226,146	240,780
Total other assets		466,423	441,851
Total assets		39,270,997	36,543,866
Liabilities:
Defined maturity		4,176,267	4,105,777
Trading Liabilities		719,777	335,380
Short-term financial liabilities:
Federal funds purchased		936,837	256,567
Securities sold under agreements to repurchase		735,226	762,592
Other short-term borrowings		2,276,139	114,764
Short Term Financial Liabilities		3,948,202	1,133,923
Term borrowings:
Real estate investment trust-preferred		46,219	46,168
Term borrowings - new market tax credit investment		2,699	2,699
Secured Borrowings		24,432	19,588
Junior subordinated debentures		144,259	143,255
Other long term borrowings		977,487	959,253
Total term borrowings		1,195,096	1,170,963
Derivative liabilities		83,530	133,713
Total liabilities		10,122,872	6,879,756
Reported Value Measurement | Commercial, financial, and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		20,179,800	16,415,381
Reported Value Measurement | Commercial Real Estate (a)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		4,192,973	3,999,559
Reported Value Measurement | Consumer Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		6,040,992	6,223,077
Reported Value Measurement | Permanent Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		173,630	211,448
Reported Value Measurement | Credit Card and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		480,289	505,643
Reported Value Measurement | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held-for-sale		14,409	16,273
Reported Value Measurement | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale		449,111	578,291
Reported Value Measurement | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		5,479	25,134
Reported Value Measurement | Mortgage loans- LOCOM
Short-term financial assets:
Loans held-for-sale		85,844	59,451
Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		31,350,892	27,364,329
Short-term financial assets:
Interest-bearing cash		364,412	1,277,611
Federal funds sold		48,747	237,591
Securities purchased under agreements to resell		697,214	386,443
Total short-term financial assets		1,110,373	1,901,645
Trading securities		1,395,043	1,448,168
Loans held-for-sale		559,582	684,349
Securities available-for-sale		4,415,845	4,626,470
Securities held-to-maturity		9,987	9,843
Derivative assets		250,786	81,475
Other assets:
Tax credit investments		194,226	159,452
Deferred compensation assets		43,826	37,771
Equity, mutual funds, and other		226,146	240,780
Total other assets		464,198	438,003
Total assets		39,556,706	36,554,282
Liabilities:
Defined maturity		4,200,490	4,082,822
Trading Liabilities		719,777	335,380
Short-term financial liabilities:
Federal funds purchased		936,837	256,567
Securities sold under agreements to repurchase		735,226	762,592
Other short-term borrowings		2,276,139	114,764
Short Term Financial Liabilities		3,948,202	1,133,923
Term borrowings:
Real estate investment trust-preferred		47,000	47,000
Term borrowings - new market tax credit investment		2,696	2,664
Secured Borrowings		24,432	19,588
Junior subordinated debentures		138,947	134,266
Other long term borrowings		973,506	960,483
Total term borrowings		1,186,581	1,164,001
Derivative liabilities		83,530	133,713
Total liabilities		10,138,580	6,849,839
Loan commitments		3,187	2,551
Standby and other commitments		5,258	5,043
Estimate of Fair Value Measurement | Commercial, financial, and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		20,373,976	16,438,272
Estimate of Fair Value Measurement | Commercial Real Estate (a)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		4,203,482	3,997,736
Estimate of Fair Value Measurement | Consumer Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		6,100,503	6,194,066
Estimate of Fair Value Measurement | Permanent Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		188,433	227,254
Estimate of Fair Value Measurement | Credit Card and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		484,498	507,001
Estimate of Fair Value Measurement | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held-for-sale		14,409	16,273
Estimate of Fair Value Measurement | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale		453,850	583,491
Estimate of Fair Value Measurement | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		5,479	25,134
Estimate of Fair Value Measurement | Mortgage loans- LOCOM
Short-term financial assets:
Loans held-for-sale		85,844	59,451
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		0	0
Short-term financial assets:
Interest-bearing cash		364,412	1,277,611
Federal funds sold		0	0
Securities purchased under agreements to resell		0	0
Total short-term financial assets		364,412	1,277,611
Trading securities		0	0
Loans held-for-sale		0	0
Securities available-for-sale		0	0
Securities held-to-maturity		0	0
Derivative assets		35,518	28,826
Other assets:
Tax credit investments		0	0
Deferred compensation assets		43,826	37,771
Equity, mutual funds, and other		22,442	22,248
Total other assets		66,268	60,019
Total assets		466,198	1,366,456
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
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
Derivative liabilities		33,819	30,236
Total liabilities		33,819	30,236
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]
Total loans, net of unearned income and allowance for loan losses		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Commercial Real Estate (a)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		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]
Total loans, net of unearned income and allowance for loan losses		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Permanent Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Credit Card and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		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 | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1 | Other consumer 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]
Total loans, net of unearned income and allowance for loan losses		0	0
Short-term financial assets:
Interest-bearing cash		0	0
Federal funds sold		48,747	237,591
Securities purchased under agreements to resell		697,214	386,443
Total short-term financial assets		745,961	624,034
Trading securities		1,393,945	1,446,644
Loans held-for-sale		458,368	588,898
Securities available-for-sale		4,400,596	4,616,568
Securities held-to-maturity		0	0
Derivative assets		215,268	52,649
Other assets:
Tax credit investments		0	0
Deferred compensation assets		0	0
Equity, mutual funds, and other		0	0
Total other assets		0	0
Total assets		7,214,138	7,328,793
Liabilities:
Defined maturity		4,200,490	4,082,822
Trading Liabilities		719,777	335,380
Short-term financial liabilities:
Federal funds purchased		936,837	256,567
Securities sold under agreements to repurchase		735,226	762,592
Other short-term borrowings		2,276,139	114,764
Short Term Financial Liabilities		3,948,202	1,133,923
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		973,506	960,483
Total term borrowings		973,506	960,483
Derivative liabilities		21,626	71,937
Total liabilities		9,863,601	6,584,545
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]
Total loans, net of unearned income and allowance for loan losses		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Commercial Real Estate (a)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		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]
Total loans, net of unearned income and allowance for loan losses		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Permanent Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Credit Card and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		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		0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale		452,889	582,476
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		5,479	6,422
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]
Total loans, net of unearned income and allowance for loan losses		31,350,892	27,364,329
Short-term financial assets:
Interest-bearing cash		0	0
Federal funds sold		0	0
Securities purchased under agreements to resell		0	0
Total short-term financial assets		0	0
Trading securities		1,098	1,524
Loans held-for-sale		101,214	95,451
Securities available-for-sale		15,249	9,902
Securities held-to-maturity		9,987	9,843
Derivative assets		0	0
Other assets:
Tax credit investments		194,226	159,452
Deferred compensation assets		0	0
Equity, mutual funds, and other		203,704	218,532
Total other assets		397,930	377,984
Total assets		31,876,370	27,859,033
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
Short Term Financial Liabilities		0	0
Term borrowings:
Real estate investment trust-preferred		47,000	47,000
Term borrowings - new market tax credit investment		2,696	2,664
Secured Borrowings		24,432	19,588
Junior subordinated debentures		138,947	134,266
Other long term borrowings		0	0
Total term borrowings		213,075	203,518
Derivative liabilities		28,085	31,540
Total liabilities		241,160	235,058
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]
Total loans, net of unearned income and allowance for loan losses		20,373,976	16,438,272
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Commercial Real Estate (a)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		4,203,482	3,997,736
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]
Total loans, net of unearned income and allowance for loan losses		6,100,503	6,194,066
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Permanent Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		188,433	227,254
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Credit Card and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans, net of unearned income and allowance for loan losses		484,498	507,001
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held-for-sale		14,409	16,273
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale		961	1,015
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		0	18,712
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Mortgage loans- LOCOM
Short-term financial assets:
Loans held-for-sale		85,844	59,451
Contractual Amount
Term borrowings:
Loan commitments		11,397,521	10,884,975
Standby and other commitments		$ 430,226	$ 446,958

[1] September 30, 2019 and December 31, 2018 include $6.4 million and $8.4 million, respectively, of held-for-sale consumer mortgage loans secured by residential real estate in process of foreclosure.