Fair Value of Assets & Liabilities - Summary Of Book Value And Estimated Fair Value Of Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 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		$ 27,805,137	$ 27,355,108
Short-term financial assets:
Interest-bearing cash			1,277,611
Federal funds sold			237,591
Securities purchased under agreements to resell		474,679	386,443
Trading securities		1,681,727	1,448,168
Loans held-for-sale	[1]	594,662	679,149
Securities available-for-sale		4,616,322	4,626,470
Securities held-to-maturity		10,000	10,000
Derivative assets		118,128	81,475
Other assets:
Total assets		41,099,003	40,832,258
Liabilities:
Trading Liabilities			335,380
Short-term financial liabilities:
Federal funds purchased			256,567
Securities sold under agreements to repurchase		745,788	762,592
Other short-term borrowings			114,764
Term borrowings:
Other long term borrowings		1,177,926	1,170,963
Derivative liabilities		107,123	133,713
Total liabilities		36,252,482	36,046,878
Fair Value, Inputs, Level 3 | FHLB-Cincinnati Stock
Term borrowings:
Restricted investments		63,700	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		27,805,137	27,355,108
Short-term financial assets:
Interest-bearing cash		1,013,254	1,277,611
Federal funds sold		167,602	237,591
Securities purchased under agreements to resell		474,679	386,443
Total short-term financial assets		1,655,535	1,901,645
Trading securities		1,681,727	1,448,168
Loans held-for-sale		594,662	679,149
Securities available-for-sale		4,616,322	4,626,470
Securities held-to-maturity		10,000	10,000
Derivative assets		118,128	81,475
Other assets:
Tax credit investments		164,509	163,300
Deferred compensation assets		41,097	37,771
Equity, mutual funds, and other		216,684	240,780
Total other assets		422,290	441,851
Total assets		36,903,801	36,543,866
Liabilities:
Defined maturity		4,454,622	4,105,777
Trading Liabilities		429,669	335,380
Short-term financial liabilities:
Federal funds purchased		339,360	256,567
Securities sold under agreements to repurchase		745,788	762,592
Other short-term borrowings		140,832	114,764
Short Term Financial Liabilities		1,225,980	1,133,923
Term borrowings:
Real estate investment trust-preferred		46,185	46,168
Term borrowings - new market tax credit investment		2,699	2,699
Secured Borrowings		21,119	19,588
Junior subordinated debentures		143,589	143,255
Other long term borrowings		964,334	959,253
Total term borrowings		1,177,926	1,170,963
Derivative liabilities		107,123	133,713
Total liabilities		7,395,320	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		17,072,399	16,415,381
Reported Value Measurement | Commercial 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		3,912,561	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		6,127,430	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		199,179	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		493,568	505,643
Reported Value Measurement | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held-for-sale		15,751	16,273
Reported Value Measurement | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale		495,451	578,291
Reported Value Measurement | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		24,238	25,134
Reported Value Measurement | Mortgage loans- LOCOM
Short-term financial assets:
Loans held-for-sale		59,222	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		27,901,543	27,364,329
Short-term financial assets:
Interest-bearing cash		1,013,254	1,277,611
Federal funds sold		167,602	237,591
Securities purchased under agreements to resell		474,679	386,443
Total short-term financial assets		1,655,535	1,901,645
Trading securities		1,681,727	1,448,168
Loans held-for-sale		599,533	684,349
Securities available-for-sale		4,616,322	4,626,470
Securities held-to-maturity		9,889	9,843
Derivative assets		118,128	81,475
Other assets:
Tax credit investments		161,355	159,452
Deferred compensation assets		41,097	37,771
Equity, mutual funds, and other		216,684	240,780
Total other assets		419,136	438,003
Total assets		37,001,813	36,554,282
Liabilities:
Defined maturity		4,454,687	4,082,822
Trading Liabilities		429,669	335,380
Short-term financial liabilities:
Federal funds purchased		339,360	256,567
Securities sold under agreements to repurchase		745,788	762,592
Other short-term borrowings		140,832	114,764
Short Term Financial Liabilities		1,225,980	1,133,923
Term borrowings:
Real estate investment trust-preferred		47,000	47,000
Term borrowings - new market tax credit investment		2,678	2,664
Secured Borrowings		21,119	19,588
Junior subordinated debentures		138,947	134,266
Other long term borrowings		967,047	960,483
Total term borrowings		1,176,791	1,164,001
Derivative liabilities		107,123	133,713
Total liabilities		7,394,250	6,849,839
Loan commitments		2,735	2,551
Standby and other commitments		5,052	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		17,166,407	16,438,272
Estimate of Fair Value Measurement | Commercial 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		3,916,819	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		6,112,800	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		210,387	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		495,130	507,001
Estimate of Fair Value Measurement | Mortgage loans (elected fair value)
Short-term financial assets:
Loans held-for-sale		15,751	16,273
Estimate of Fair Value Measurement | Government guaranteed loans (SBA and USDA)
Short-term financial assets:
Loans held-for-sale		500,322	583,491
Estimate of Fair Value Measurement | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		24,238	25,134
Estimate of Fair Value Measurement | Mortgage loans- LOCOM
Short-term financial assets:
Loans held-for-sale		59,222	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		1,013,254	1,277,611
Federal funds sold		0	0
Securities purchased under agreements to resell		0	0
Total short-term financial assets		1,013,254	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		36,976	28,826
Other assets:
Tax credit investments		0	0
Deferred compensation assets		41,097	37,771
Equity, mutual funds, and other		22,326	22,248
Total other assets		63,423	60,019
Total assets		1,113,653	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		36,688	30,236
Total liabilities		36,688	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
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		167,602	237,591
Securities purchased under agreements to resell		474,679	386,443
Total short-term financial assets		642,281	624,034
Trading securities		1,680,330	1,446,644
Loans held-for-sale		505,408	588,898
Securities available-for-sale		4,603,127	4,616,568
Securities held-to-maturity		0	0
Derivative assets		81,152	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		7,512,298	7,328,793
Liabilities:
Defined maturity		4,454,687	4,082,822
Trading Liabilities		429,669	335,380
Short-term financial liabilities:
Federal funds purchased		339,360	256,567
Securities sold under agreements to repurchase		745,788	762,592
Other short-term borrowings		140,832	114,764
Short Term Financial Liabilities		1,225,980	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		967,047	960,483
Total term borrowings		967,047	960,483
Derivative liabilities		41,465	71,937
Total liabilities		7,118,848	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
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		499,307	582,476
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		6,101	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		27,901,543	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		1,397	1,524
Loans held-for-sale		94,125	95,451
Securities available-for-sale		13,195	9,902
Securities held-to-maturity		9,889	9,843
Derivative assets		0	0
Other assets:
Tax credit investments		161,355	159,452
Deferred compensation assets		0	0
Equity, mutual funds, and other		194,358	218,532
Total other assets		355,713	377,984
Total assets		28,375,862	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		2,678	2,664
Secured Borrowings		21,119	19,588
Junior subordinated debentures		138,947	134,266
Other long term borrowings		0	0
Total term borrowings		209,744	203,518
Derivative liabilities		28,970	31,540
Total liabilities		238,714	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		17,166,407	16,438,272
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]
Total loans, net of unearned income and allowance for loan losses		3,916,819	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		6,112,800	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		210,387	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		495,130	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		15,751	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		1,015	1,015
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Other consumer loans- LOCOM
Short-term financial assets:
Loans held-for-sale		18,137	18,712
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3 | Mortgage loans- LOCOM
Short-term financial assets:
Loans held-for-sale		59,222	59,451
Contractual Amount
Term borrowings:
Loan commitments		11,000,220	10,884,975
Standby and other commitments		$ 404,249	$ 446,958

[1] March 31, 2019 and December 31, 2018 include $8.0 million and $8.4 million, respectively, of held-for-sale consumer mortgage loans secured by residential real estate in process of foreclosure.