Hancock Whitney (HWC) 10-Q 4 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Oct. 31, 2020
Cover [Abstract]
Entity Registrant Name	HANCOCK WHITNEY CORPORATION
Entity Filer Category	Large Accelerated Filer
Entity Central Index Key	0000750577
Amendment Flag	false
Document Type	10-Q
Document Fiscal Period Focus	Q3
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	001-36872
Entity Tax Identification Number	64-0693170
Entity Address, Address Line One	Hancock Whitney Plaza
Entity Address, Address Line Two	2510 14th Street
Entity Address, City or Town	Gulfport
Entity Address, State or Province	MS
Entity Address, Postal Zip Code	39501
City Area Code	(228)
Local Phone Number	868-4000
Entity Common Stock, Shares Outstanding		86,412,669
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	MS
Title of 12(b) Security	Common stock, par value $3.33 per share
Trading Symbol	HWC
Security Exchange Name	NASDAQ

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
ASSETS
Cash and due from banks	$ 484,315	$ 432,104
Interest-bearing bank deposits	778,363	109,961
Federal funds sold	694	268
Securities available for sale, at fair value (amortized cost of $5,410,502 and $4,637,610)	5,647,315	4,675,304
Securities held to maturity (fair value of $1,517,688 and $1,611,004)	1,408,961	1,568,009
Loans held for sale	103,566	55,864
Loans	22,240,204	21,212,755
Less: allowance for loan losses	(448,674)	(191,251)
Loans, net	21,791,530	21,021,504
Property and equipment, net of accumulated depreciation of $266,241 and $249,527	384,329	380,209
Right of use assets, net of accumulated amortization of $20,309 and $12,194	114,420	110,023
Prepaid expenses	40,003	40,178
Other real estate and foreclosed assets, net	11,640	30,405
Accrued interest receivable	112,686	92,037
Goodwill	855,453	855,453
Other intangible assets, net	91,505	106,807
Life insurance contracts	611,713	608,063
Funded pension assets, net	191,946	185,791
Other assets	564,885	328,777
Total assets	33,193,324	30,600,757
Deposits
Noninterest-bearing	11,881,548	8,775,632
Interest-bearing	15,149,111	15,027,943
Total deposits	27,030,659	23,803,575
Short-term borrowings	1,906,895	2,714,872
Long-term debt	385,887	233,462
Accrued interest payable	7,336	10,200
Lease liabilities	134,007	127,703
Deferred tax liability, net	46,665	37,721
Other liabilities	306,231	205,539
Total liabilities	29,817,680	27,133,072
Stockholders' equity:
Common stock	309,513	309,513
Capital surplus	1,755,315	1,736,664
Retained earnings	1,211,878	1,476,232
Accumulated other comprehensive income (loss), net	98,938	(54,724)
Total stockholders' equity	3,375,644	3,467,685
Total liabilities and stockholders' equity	$ 33,193,324	$ 30,600,757
Preferred shares authorized (par value of $20.00 per share)	50,000,000	50,000,000
Common shares authorized (par value of $3.33 per share)	350,000,000	350,000,000
Common shares issued	92,947,000	92,947,000
Common shares outstanding	86,400,000	87,515,000

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 5,410,502	$ 4,637,610
Securities held to maturity, fair value	1,517,688	1,611,004
Property and equipment, accumulated depreciation	266,241	249,527
Right of use assets, accumulated amortization	$ 20,309	$ 12,194
Preferred stock, par value per share	$ 20	$ 20
Common stock, par value per share	$ 3.33	$ 3.33

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income:
Loans, including fees	$ 220,392	$ 243,875	$ 688,032	$ 725,390
Loans held for sale	833	592	2,104	1,189
Securities-taxable	30,863	32,724	95,172	94,107
Securities-tax exempt	4,831	5,058	14,629	15,715
Short-term investments	124	915	791	3,424
Total interest income	257,043	283,164	800,728	839,825
Interest expense:
Deposits	14,783	49,220	76,349	145,201
Short-term borrowings	1,673	7,729	8,388	23,658
Long-term debt	5,404	3,276	11,754	8,905
Total interest expense	21,860	60,225	96,491	177,764
Net interest income	235,183	222,939	704,237	662,061
Provision for credit losses	24,999	12,421	578,690	38,552
Net interest income (loss) after provision for credit losses	210,184	210,518	125,547	623,509
Noninterest income:
Other income	14,799	16,325	44,112	40,773
Total noninterest income	83,748	83,230	242,078	232,983
Noninterest expense:
Compensation expense	97,095	93,858	286,922	265,573
Employee benefits	20,761	18,622	64,892	57,240
Personnel expense	117,856	112,480	351,814	322,813
Net occupancy expense	13,191	13,156	39,272	38,101
Equipment expense	5,355	4,685	14,724	13,706
Data processing expense	21,888	21,532	65,185	60,951
Professional services expense	14,372	17,704	35,098	35,537
Amortization of intangible assets	4,788	4,889	15,302	15,074
Deposit insurance and regulatory fees	4,108	3,995	15,039	14,156
Other real estate and foreclosed asset (income) expense	(482)	2,055	9,188	1,459
Other expense	14,698	33,058	50,026	71,024
Total noninterest expense	195,774	213,554	595,648	572,821
Income (loss) before income taxes	98,158	80,194	(228,023)	283,671
Income taxes expense (benefit)	18,802	12,387	(79,274)	48,423
Net income (loss)	$ 79,356	$ 67,807	$ (148,749)	$ 235,248
Earnings (loss) per common share-basic	$ 0.90	$ 0.77	$ (1.73)	$ 2.69
Earnings (loss) per common share-diluted	0.90	0.77	(1.73)	2.69
Dividends paid per share	$ 0.27	$ 0.27	$ 0.81	$ 0.81
Weighted average shares outstanding-basic	86,358	86,377	86,614	85,934
Weighted average shares outstanding-diluted	86,400	86,462	86,614	86,010
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 18,440	$ 21,892	$ 56,795	$ 62,982
Trust fees
Noninterest income:
Service charges on deposit accounts	14,424	15,098	43,390	46,126
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	17,222	17,154	50,541	49,063
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	5,988	7,048	18,504	20,167
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 12,875	$ 5,713	$ 28,736	$ 13,872

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 79,356	$ 67,807	$ (148,749)	$ 235,248
Other comprehensive income (loss) before income taxes:
Net change in unrealized gain or loss on securities available for sale and cash flow hedges	425	34,159	217,254	160,627
Reclassification of net gain or loss realized and included in earnings	(4,076)	3,280	(6,593)	11,483
Valuation adjustment to employee benefit plan		(7,015)	(10,251)	(7,015)
Amortization of unrealized net loss or gain on securities transferred to held to maturity	(89)	954	(378)	2,435
Other comprehensive income (loss) before income taxes	(3,740)	31,378	200,032	167,530
Income tax expense	48	7,331	46,370	37,977
Other comprehensive income (loss) net of income taxes	(3,788)	24,047	153,662	129,553
Comprehensive income	$ 75,568	$ 91,854	$ 4,913	$ 364,801

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Retained Earnings [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]
Balance at Dec. 31, 2018	$ 3,081,340		$ 292,716	$ 1,725,741	$ 1,243,592		$ (180,709)
Balance, Shares Issued at Dec. 31, 2018			87,903
Net income (loss)	235,248				235,248
Other comprehensive income (loss)	129,553						129,553
Comprehensive income	364,801				235,248		129,553
Cash dividends declared	(70,771)				(70,771)
Common stock issued in business combination	193,849		$ 16,797	177,052
Common stock issued in business combination, Shares Issued			5,044
Common stock activity, long-term incentive plans	14,469			14,355	114
Issuance of stock from dividend reinvestment and stock purchase plans	2,692			2,692
Balance at Sep. 30, 2019	3,586,380		$ 309,513	1,919,840	1,408,183		(51,156)
Balance, Shares Issued at Sep. 30, 2019			92,947
Balance at Jun. 30, 2019	3,318,915		$ 292,716	1,737,492	1,363,910		(75,203)
Balance, Shares Issued at Jun. 30, 2019			87,903
Net income (loss)	67,807				67,807
Other comprehensive income (loss)	24,047						24,047
Comprehensive income	91,854				67,807		24,047
Cash dividends declared	(23,597)				(23,597)
Common stock issued in business combination	193,849		$ 16,797	177,052
Common stock issued in business combination, Shares Issued			5,044
Common stock activity, long-term incentive plans	4,470			4,407	63
Issuance of stock from dividend reinvestment and stock purchase plans	889			889
Balance at Sep. 30, 2019	3,586,380		$ 309,513	1,919,840	1,408,183		(51,156)
Balance, Shares Issued at Sep. 30, 2019			92,947
Balance at Dec. 31, 2019	$ 3,467,685	$ (44,087)	$ 309,513	1,736,664	1,476,232	$ (44,087)	(54,724)
Balance, Shares Issued at Dec. 31, 2019	92,947		92,947
Net income (loss)	$ (148,749)				(148,749)
Other comprehensive income (loss)	153,662						153,662
Comprehensive income	4,913				(148,749)		153,662
Cash dividends declared	(71,620)				(71,620)
Common stock activity, long-term incentive plans	16,261			16,159	102
Net settlement of accelerated share repurchase agreement (1,001,472 shares)	12,110			12,110
Repurchase of common stock	(12,716)			(12,716)
Issuance of stock from dividend reinvestment and stock purchase plans	3,098			3,098
Balance at Sep. 30, 2020	$ 3,375,644		$ 309,513	1,755,315	1,211,878		98,938
Balance, Shares Issued at Sep. 30, 2020	92,947		92,947
Balance at Jun. 30, 2020	$ 3,316,157		$ 309,513	1,747,640	1,156,278		102,726
Balance, Shares Issued at Jun. 30, 2020			92,947
Net income (loss)	79,356				79,356
Other comprehensive income (loss)	(3,788)						(3,788)
Comprehensive income	75,568				79,356		(3,788)
Cash dividends declared	(23,803)				(23,803)
Common stock activity, long-term incentive plans	6,642			6,595	47
Issuance of stock from dividend reinvestment and stock purchase plans	1,080			1,080
Balance at Sep. 30, 2020	$ 3,375,644		$ 309,513	$ 1,755,315	$ 1,211,878		$ 98,938
Balance, Shares Issued at Sep. 30, 2020	92,947		92,947

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net settlement of accelerated share repurchase agreement, shares			1,001,472
Retained Earnings [Member]
Cash dividends declared, per common share	$ 0.27	$ 0.27	$ 0.81	$ 0.81

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (148,749)	$ 235,248
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	22,869	22,867
Provision for credit losses	578,690	38,552
Loss on other real estate and foreclosed assets	9,252	852
Gain on sale of securities	(488)
Deferred tax expense (benefit)	(28,949)	30,136
Increase in cash surrender value of life insurance contracts	(14,443)	(10,792)
(Gain) loss on disposal of other assets	(556)	70
Net increase in loans held for sale	(46,691)	(46,727)
Net amortization of securities premium/discount	30,576	23,133
Amortization of intangible assets	15,302	15,074
Stock-based compensation expense	16,661	15,497
Net change in liability from variation margin collateral	(102,501)	(42,500)
Contribution to pension plan		(100,000)
Increase (decrease) in interest payable and other liabilities	11,369	(1,632)
Increase in other assets	(97,265)	(10,631)
Other, net	(17,607)	(2,854)
Net cash provided by operating activities	227,470	166,293
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of available for sale securities	211,919	143,334
Proceeds from maturities of securities available for sale	662,269	204,391
Purchases of securities available for sale	(1,667,476)	(810,198)
Proceeds from maturities of securities held to maturity	169,863	297,150
Purchases of securities held to maturity	(20,884)	(183,626)
Net (increase) decrease in short-term investments	(668,828)	383,970
Proceeds from sales of loans and leases	301,609	111,141
Net increase in loans	(1,657,939)	(353,971)
Purchase of life insurance contracts		(32,788)
Purchases of property and equipment	(31,214)	(33,746)
Proceeds from sales of other real estate	15,299	20,764
Cash acquired in stock-based business combination		28,060
Final cash settlement for acquisition of business		(1,112)
Other, net	(4,412)	(19,815)
Net cash used in investing activities	(2,689,794)	(246,446)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in deposits	3,227,084	(229,964)
Net increase (decrease) in short-term borrowings	(807,977)	452,691
Proceeds from the issuance of long-term debt, net of issuance costs	166,425	11,649
Repayments of long-term debt	(230)	(226)
Dividends paid	(71,620)	(70,771)
Payroll tax remitted on net share settlement of equity awards	(1,639)	(1,594)
Proceeds from exercise of stock options		367
Proceeds from dividend reinvestment and stock purchase plans	3,098	2,692
Settlement of forward contract portion of accelerated share repurchase	12,110
Repurchase of shares	(12,716)
Net cash provided by financing activities	2,514,535	164,844
NET INCREASE IN CASH AND DUE FROM BANKS	52,211	84,691
CASH AND DUE FROM BANKS, BEGINNING	432,104	383,372
CASH AND DUE FROM BANKS, ENDING	484,315	468,063
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Value of stock-based consideration in business combination		193,849
Assets acquired in settlement of loans	$ 5,459	$ 14,170

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	1. Basis of Presentation The consolidated financial statements include the accounts of Hancock Whitney Corporation and all other entities in which it has a controlling interest (the “Company”). The financial statements include all adjustments that are, in the opinion of management, necessary to fairly state the Company’s financial condition, results of operations, changes in stockholders’ equity and cash flows for the interim periods presented. The Company has also evaluated all subsequent events for potential recognition and disclosure through the date of the filing of this Quarterly Report on Form 10-Q. Some financial information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) have been condensed or omitted in this Quarterly Report on Form 10-Q pursuant to Securities and Exchange Commission rules and regulations. These financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. Financial information reported in these financial statements is not necessarily indicative of the Company’s financial condition, results of operations, or cash flows for any other interim or annual period. Certain prior period amounts have been reclassified to conform to the current period presentation. These changes in presentation did not have a material impact on the Company’s financial condition or operating results. Use of Estimates The accounting principles the Company follows and the methods for applying these principles conform to GAAP and general practices followed by the banking industry. These accounting principles require management to make estimates and assumptions about future events that affect the amounts reported in the consolidated financial statements and the accompanying notes. Actual results could differ from those estimates. Critical Accounting Policies and Estimates On January 1, 2020, the Company adopted Accounting Standards Codification (“ASC”) 326, “Financial Instruments – Credit Losses,” more commonly referred to as CECL, on a modified retrospective basis. The provisions of this guidance require a material change to the manner in which the Company estimates and reports losses on financial instruments, including loans and unfunded lending commitments, select securities and other assets carried at amortized cost. Results for reporting periods beginning after January 1, 2020 are presented under ASC 326, while prior period amounts continue to be reported in accordance with previously applicable GAAP. Changes to the Company’s accounting policies related to CECL are described below. Further, the Company performed an interim test of goodwill impairment using a quantitative assessment, as described below. There were no other material changes or developments during the reporting period with respect to methodologies that the Company uses when applying what management believes are critical accounting policies and developing critical accounting estimates as disclosed in its Annual Report on Form 10-K for the year ended December 31, 2019. Refer to Note 16 – Recent Accounting Pronouncements for a discussion of accounting standards adopted during the nine months ended September 30, 2020 and the impact to the Company’s financial statements. Accounting Policy Updates Allowance for Credit Losses on Loans, Leases Held for Investment and Unfunded Exposures For reporting periods beginning on or after January 1, 2020, the Allowance for Credit Losses (ACL) is comprised of the Allowance for Loan and Lease Losses (ALLL), a valuation account available to absorb losses on loans and leases held for investment, and the Reserve for Unfunded Lending Commitments, a liability established to absorb credit losses for the expected life of the contractual term of on and off-balance sheet exposures as of the date of the determination. Quarterly, management estimates losses in the portfolio and unfunded exposures based on a number of factors, including the Company’s past loan loss experience, known and potential risks in the portfolio, adverse situations that may affect the borrowers’ ability to repay, the estimated value of any underlying collateral, and current and forecasted economic conditions. The analysis and methodology for estimating the ACL includes two primary elements: a collective approach for pools of loans that have similar risk characteristics using a loss rate analysis, and a specific reserve analysis for credits individually evaluated for credit loss. For the collective approach, the Company segments loans into commercial non-real estate, commercial real estate – owner occupied, commercial real estate – income producing, construction and land development, residential mortgage and consumer, with further segmentation by region and sub-portfolio, as deemed appropriate. Both quantitative and qualitative factors are applied at the portfolio segment levels. The Company applies the practical expedient that permits the exclusion of the accrued interest receivable balance from amortized cost basis of financing receivables. For the collectively evaluated portfolios, the Company utilizes internally developed credit models and third party economic forecasts for the calculation of expected credit loss over the reasonable and supportable forecast period for the majority of the portfolio and other methods, generally historical loss based, for select portfolios. The Company calculates collective allowance for a two-year reasonable and supportable forecast period utilizing probability weighted multiple macroeconomic scenarios, and then reverts on a linear basis over four quarters to an average historical loss rate for the remaining term . The credit models consist primarily of multivariate regression and autoregressive models that correlate our historical net charge-off rates to select macroeconomic variables at a collective level. Forward-looking macroeconomic forecasts are applied as inputs to the regression equations to estimate quarterly collective net charge-off rates over the reasonable and supportable period. The net charge-off rates from the credit models for the reasonable and supportable period, the linear reversion rates, and the average loss rates for the post reasonable and supportable periods are applied to forecasted balance runoff for the estimated remaining term. The balance runoff incorporates prepayment assumptions developed from historical experience that are applied to the multiple macroeconomic forecasts. Forecasted net charge-off rates are also applied to forecasted draws and subsequent runoff of unfunded commitments in the calculation of the reserve for unfunded lending commitments. Qualitative adjustments to the output of quantitative calculations are made when management deems it necessary to reflect differences in current and forecasted conditions as compared to those during the historical loss period used in model development. Conditions to be considered include, but are not limited to, problem loan trends, current business and economic conditions, credit concentrations, lending policies and procedures, lending staff, collateral values, loan profiles and volumes, loan review quality, changes in competition and regulations, and other adjustments for model limitations or other variables not specifically captured. The Company establishes specific reserves using an individually evaluated approach for nonaccrual loans, loans modified in troubled debt restructures, loans for which a troubled debt restructure is reasonably expected, and other financial instruments that are deemed to not share risk characteristics with other collectively evaluated financial assets. For loans individually evaluated, a specific allowance is recognized for any shortfall between the loan’s value and its recorded investment. The loan’s value is measured by either the loan’s observable market price, the fair value of the collateral of the loan (less liquidation costs) if it is collateral dependent, or by the present value of expected future cash flows discounted at the loan’s effective interest rate. The Company applies the practical expedient and defines collateral dependent loans as those where the borrower is experiencing financial difficulty and on which repayment is expected to be provided substantially through the operation or sale of the collateral. Loans individually analyzed are not incorporated into the pool analysis to avoid double counting. The Company limits the individually evaluated specific reserve analysis to include commercial and residential mortgage loans with relationship balances of $1 million or greater and all loans classified as troubled debt restructurings. Acquired Loans and Other Financial Assets Acquired loans and other financial assets within the scope of CECL are segregated between those purchased with credit deterioration (“PCD”) and those that are not (“non PCD”). Assets considered PCD include those individual financial assets (or groups of financial assets with similar risk characteristics) that as of the date of acquisition are assessed as having experienced a more-than-insignificant deterioration in credit quality since origination. The assessment of what is more-than-insignificant credit deterioration since origination considers information including, but not limited to, financial assets that are delinquent, on nonaccrual and/or otherwise adversely risk rated as of the acquisition date, those that have been downgraded since origination, and those for which, after origination, credit spreads have widened beyond the threshold specified in policy. The Company bifurcates the fair value discount between the credit and noncredit components and records an allowance for credit losses for PCD assets by adding the credit portion of the fair value discount to the initial amortized cost basis and increasing the allowance for credit losses at the date of acquisition. Any noncredit discount or premium resulting from acquiring assets with credit deterioration is allocated to each individual asset. All non PCD financial assets acquired are recorded at the estimated fair value of the asset at acquisition, with the estimated allowance for credit loss recorded as a provision for credit losses through earnings in the period in which the acquisition has occurred. The noncredit discount or premium for PCD assets and full discount for non PCD assets will be accreted to interest income using the interest method based on the effective interest rate at the acquisition date. Under the transition provisions for application of CECL, the Company has classified all purchased credit impaired loans (“PCI”) previously accounted for under Financial Accounting Standard Subtopic 310-30 to be classified as PCD, without reassessing whether the financial assets meet the criteria of PCD as of the date of adoption. The application of these provisions resulted in an adjustment to the amortized cost basis of the financial asset to reflect the addition of the allowance for credit losses at the date of adoption. The Company elected not to maintain pools of loans accounted for under Subtopic 310-30 at adoption. The Company was also not required to reassess whether modifications to individual acquired financial assets accounted for in pools were troubled debt restructurings as of the date of adoption. The noncredit discount, after the adjustment for the allowance for credit losses, will be accreted to interest income using the interest method based on the effective interest rate determined after the adjustment for credit losses at the adoption date. Allowance for Credit Losses on Securities The CECL standard also requires an assessment of the Company’s held to maturity debt securities for expected credit losses and the available for sale debt securities for credit-related impairment. The Company applies the practical expedient to exclude the accrued interest receivable balance from amortized cost basis of financing receivables. The allowance for credit losses on held to maturity debt securities is estimated at the individual security level when there is a more than inconsequential risk of default. The assessment uses probability of default and loss given default models based on public ratings, where available, or mapped internally developed risk grades to public ratings and forecasted cash flows using the same economic forecasts and probability weighting as used for the Company’s evaluation of the loan portfolio. Qualitative adjustments to the output of the quantitative calculation are made when management deems it necessary to reflect differences in current and forecasted conditions as compared to those during the historical loss period used in model development. The Company evaluates credit impairment on available for sale debt securities at an individual security level. This evaluation is done for securities whose fair value is below amortized cost with a more than inconsequential risk of default and where the Company has assessed the decline in fair value is significant enough to suggest a credit event occurred. Credit events are generally assessed based on adverse conditions specifically related to the security, an industry, or geographic area, changes in the financial condition of the issuer of the security, or in the case of an asset-backed debt security, changes in the financial condition of the underlying loan obligors. The allowance for credit losses for such securities is measured using a discounted cash flow methodology, through which management compares the present value of expected cash flows with the amortized cost basis of the security. The allowance for credit loss is limited to the amount by which the fair value is less than the amortized cost basis. The Company reassesses the potential for credit losses at each reporting period and records subsequent changes in the allowance for credit losses on securities with a corresponding adjustment recorded in the provision for credit loss expense. If the Company intends to sell the debt security, or more likely than not will be required to sell the security before recovery of its amortized cost basis, the security is charged down to fair value against the allowance for credit losses, with any incremental impairment reported in earnings. Critical Accounting Estimates Goodwill Impairment Testing Goodwill, which represents the excess of cost over the fair value of the net assets of an acquired business, is not amortized but is assessed for impairment on an annual basis, or more often if events or circumstances indicate that it is more likely than not that a goodwill impairment exists. The impairment test compares the estimated fair value of a reporting unit with its net book value. If the unit’s fair value is less than its carrying value, an impairment is recognized. The Company completed its annual impairment test of goodwill as of September 30, 2019 by performing a qualitative (“Step Zero”) assessment. The qualitative assessment involved the examination of changes in macroeconomic conditions, industry and market conditions, overall financial performance, cost factors and other relevant entity-specific events, including changes in management and other key personnel and changes in the share price of the Company’s common stock. As a result of the assessment, the Company concluded that its goodwill was not impaired. During the third quarter of 2020, the Company assessed the indicators of goodwill impairment and noted certain events that indicated that The Company used multiple approaches to measure its fair value at September 30, 2020. The primary approaches included an income approach using the discounted net present value of estimated future cash flows and a market approach using transaction or price-to-forward earnings multiples methodology using the actual price paid in recent acquisition transactions for similar entities, discounted for the current recessionary environment, neither of which resulted in impairment. The results from each of the primary approaches were weighted equally, with the valuation of the reporting unit approximately 14% in excess of net book value at September 30, 2020. Both valuation techniques employed by the Company require significant assumptions. Depending upon the specific approach, assumptions are made regarding the economic environment, expected net interest margins, growth rates, discount rate used to present value future cash flows, asset quality metrics, control premiums, and price-to-forward earnings multiples. Changes to any one of these assumptions could result in significantly different results. Changes in the amount and/or timing of the Company’s expected future cash flows or estimated growth rates, lack of improvement and/or further decline in the price of the Company’s common stock relative to our book value per share, and/or further deterioration in the economic environment beyond current estimates could result in an impairment charge to goodwill in future reporting periods. Annual impairment testing will be performed in the fourth quarter of 2020 in coordination with our annual strategic planning process, and interim testing is expected to continue until indicators of goodwill impairment no longer exist.

Business Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Business Combinations	2. Business Combination On September 21, 2019, the Company completed the acquisition of MidSouth Bancorp, Inc. (“MidSouth”) (NYSE: MSL), parent company of MidSouth Bank, N.A. The transaction provides the Company opportunity for both enhanced growth in several of its current markets, such as MidSouth’s home market of Lafayette, Louisiana, as well as opportunities for expansion into new markets in Louisiana and Texas. The transaction was accounted for as a business combination whereby the Company acquired net assets with an estimated fair value of $130.5 million and recorded goodwill of $63.4 million. In consideration for the net assets acquired, the Company issued approximately 5.0 million shares of our common stock, resulting in a transaction value of $193.8 million. The following table sets forth the acquisition date fair value of the assets acquired and liabilities assumed, and the resulting goodwill. The goodwill is not deductible for federal income tax purposes. (in thousands) ASSETS Cash and due from banks $ 28,059 Interest bearing bank deposits 276,911 Federal funds sold 3,475 Securities available for sale 272,240 Loans 787,628 Property and equipment 34,288 Other real estate 343 Identifiable intangible assets 31,500 Other assets 79,888 Total identifiable assets 1,514,332 LIABILITIES Deposit liabilities 1,280,947 Short term borrowings 66,996 Long term debt 13,919 Other liabilities 21,990 Total liabilities 1,383,852 Net assets acquired 130,480 Value of stock 193,849 Goodwill $ 63,369 The results of the acquired business were included in the Company’s consolidated results of operations from the date of acquisition. The results of the acquired business are not material to the Company’s consolidated results of operations and, as such, neither supplemental pro forma information of the combined entity nor revenue and earnings contributed by the acquired business since the date of acquisition are presented. Goodwill Resulting from Business Combinations Goodwill represents the excess of the consideration transferred over the fair value of the net assets acquired. It is comprised of estimated future economic benefits arising from the transaction that cannot be individually identified or do not qualify for separate recognition. These benefits include expanded presence in existing markets and entry into new markets, and expected earnings streams and operational efficiencies that the Company believes will result from this business combination. The following table presents the change in the Company’s goodwill during the year ended December 31, 2019. No measurement period adjustments were recorded during the nine months ended September 30, 2020. (in thousands) Goodwill balance at December 31, 2018 $ 790,972 Final settlement of cash consideration - acquisition of trust and asset management business 1,112 Initial goodwill recorded in the acquisition of MidSouth Bancorp, Inc. 69,207 Measurement period adjustments - acquisition of MidSouth Bancorp, Inc. (5,838 ) Goodwill balance at December 31, 2019 $ 855,453 Goodwill balance at September 30, 2020 $ 855,453

Securities

Securities	9 Months Ended
	Sep. 30, 2020
Investments Debt And Equity Securities [Abstract]
Securities	3. Securities The following tables set forth the amortized cost, gross unrealized gains and losses, and estimated fair value of debt securities classified as available for sale and held to maturity at September 30, 2020 and December 31, 2019. Amortized cost of securities does not include accrued interest which is reflected in the accrued interest line item on the consolidated balance sheets totaling $23.2 million and $23.9 million at September 30, 2020 and December 31, 2019, respectively. September 30, 2020 December 31, 2019 Gross Gross Gross Gross Securities Available for Sale Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair (in thousands) Cost Gains Losses Value Cost Gains Losses Value U.S. Treasury and government agency securities $ 192,077 $ 6,664 $ 125 $ 198,616 $ 98,320 $ 652 $ 300 $ 98,672 Municipal obligations 297,712 16,291 347 313,656 242,016 7,789 — 249,805 Residential mortgage-backed securities 2,536,999 70,222 531 2,606,690 1,910,909 20,268 7,020 1,924,157 Commercial mortgage-backed securities 1,965,664 136,056 720 2,101,000 1,570,765 19,880 4,178 1,586,467 Collateralized mortgage obligations 410,050 9,141 21 419,170 807,600 3,757 3,142 808,215 Corporate debt securities 8,000 185 2 8,183 8,000 21 33 7,988  $ 5,410,502 $ 238,559 $ 1,746 $ 5,647,315 $ 4,637,610 $ 52,367 $ 14,673 $ 4,675,304 September 30, 2020 December 31, 2019 Gross Gross Gross Gross Securities Held to Maturity Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair (in thousands) Cost Gains Losses Value Cost Gains Losses Value U.S. Treasury and government agency securities $ — $ — $ — $ — $ 50,000 $ 3 $ — $ 50,003 Municipal obligations 630,894 49,348 17 680,225 641,019 27,146 69 668,096 Residential mortgage-backed securities 24,041 1,641 — 25,682 29,687 883 — 30,570 Commercial mortgage-backed securities 550,201 53,253 — 603,454 539,371 12,474 581 551,264 Collateralized mortgage obligations 203,825 4,502 — 208,327 307,932 3,597 458 311,071  $ 1,408,961 $ 108,744 $ 17 $ 1,517,688 $ 1,568,009 $ 44,103 $ 1,108 $ 1,611,004 The following tables present the amortized cost and estimated fair value of debt securities available for sale and held to maturity at September 30, 2020 by contractual maturity. Actual maturities will differ from contractual maturities because of rights to call or repay obligations with or without penalties and scheduled and unscheduled principal payments on mortgage-backed securities and collateralized mortgage obligations. Debt Securities Available for Sale Amortized Fair (in thousands) Cost Value Due in one year or less $ 14,492 $ 14,540 Due after one year through five years 239,148 258,655 Due after five years through ten years 2,066,697 2,196,332 Due after ten years 3,090,165 3,177,788 Total available for sale debt securities $ 5,410,502 $ 5,647,315 Debt Securities Held to Maturity Amortized Fair (in thousands) Cost Value Due in one year or less $ 2,196 $ 2,191 Due after one year through five years 189,141 201,869 Due after five years through ten years 636,976 701,345 Due after ten years 580,648 612,283 Total held to maturity securities $ 1,408,961 $ 1,517,688 The Company held no securities classified as trading at September 30, 2020 and December 31, 2019. The following table presents the proceeds from, gross gain on, and gross losses on sales of securities during the nine months ended September 30, 2020 and 2019. Nine Months Ended September 30, (in thousands) 2020 2019 Proceeds $ 211,919 $ 143,304 Gross gains 1,984 — Gross losses 1,496 — Securities with carrying values totaling $3.2 billion and $3.3 billion were pledged as collateral at September 30, 2020 and December 31, 2019 respectively, primarily to secure public deposits or securities sold under agreements to repurchase. Credit Quality The Company’s policy is to invest only in securities of investment grade quality. These investments are largely limited to U.S. agency securities and municipal securities. Management has concluded, based on the long history of no credit losses, that the expectation of nonpayment of the held to maturity securities carried at amortized cost is zero for securities that are backed by the full faith and credit of and/or guaranteed by the U.S. government. As such, no allowance for credit losses has been recorded for these securities. The municipal portfolio is analyzed separately for allowance for credit loss in accordance with the applicable guidance for each portfolio as noted below. Effective January 1, 2020, in conjunction with the adoption of CECL, and again at September 30, 2020, the Company evaluated credit impairment for individual securities available for sale whose fair value was below amortized cost with a more than inconsequential risk of default and where the Company had assessed the decline in fair value significant enough to suggest a credit event occurred. There were no securities that met the criteria of a credit loss event and therefore, no allowance for credit loss was recorded for either period. The fair value and gross unrealized losses for securities classified as available for sale with unrealized losses for the periods indicated follow. Available for Sale September 30, 2020 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. Treasury and government agency securities $ 44,039 $ 125 $ — $ — $ 44,039 $ 125 Municipal obligations 26,010 347 — — 26,010 347 Residential mortgage-backed securities 229,662 529 367 2 230,029 531 Commercial mortgage-backed securities 252,858 720 — — 252,858 720 Collateralized mortgage obligations 3,300 21 — — 3,300 21 Corporate debt securities 3,498 2 — — 3,498 2  $ 559,367 $ 1,744 $ 367 $ 2 $ 559,734 $ 1,746 Available for Sale December 31, 2019 Losses < 12 months Losses 12 months or > Total Gross Gross Gross Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) Value Losses Value Losses Value Losses U.S. Treasury and government agency securities $ 28,235 300 $ — $ — $ 28,235 $ 300 Municipal obligations — — — — — — Residential mortgage-backed securities 420,066 5,042 399,787 1,978 819,853 7,020 Commercial mortgage-backed securities 458,855 3,971 14,896 207 473,751 4,178 Collateralized mortgage obligations 89,689 1,315 184,389 1,827 274,078 3,142 Corporate debt securities 1,467 33 — — 1,467 33  $ 998,312 $ 10,661 $ 599,072 $ 4,012 $ 1,597,384 $ 14,673 Effective January 1, 2020 and in conjunction with the adoption of CECL, and again as of September 30, 2020, the Company evaluated its held to maturity municipal obligation portfolio for credit loss using probability of default and loss given default models. The models were run using a long-term average probability of default migration and with a probability weighting of Moody’s economic forecasts. The economic forecasts were largely weighted to a baseline scenario with some weight given to other scenarios. The September 30, 2020 forecast was further stressed by running a more severe probability of default migration. The resulting credit loss was negligible for both periods and no allowance for credit loss was recorded. The fair value and gross unrealized losses for securities classified as held to maturity with unrealized losses for the periods indicated follow. Held to Maturity September 30, 2020 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) Value Losses Value Losses Value Losses U.S. Treasury and government agency securities $ — $ — $ — $ — $ — $ — Municipal obligations 523 2 2,890 15 3,413 17 Residential mortgage-backed securities — — — — — — Commercial mortgage-backed securities 222 — — — 222 — Collateralized mortgage obligations — — — — — —  $ 745 $ 2 $ 2,890 $ 15 $ 3,635 $ 17 Held to Maturity December 31, 2019 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) Value Losses Value Losses Value Losses U.S. Treasury and government agency securities $ — $ — $ — $ — $ — $ — Municipal obligations 4,735 38 3,143 31 7,878 69 Residential mortgage-backed securities — — — — — — Commercial mortgage-backed securities 28,426 581 — — 28,426 581 Collateralized mortgage obligations — — 49,110 458 49,110 458  $ 33,161 $ 619 $ 52,253 $ 489 $ 85,414 $ 1,108 As of September 30, 2020 the Company had 40 securities with market values below their cost basis. Unrealized losses in both portfolios relate primarily to changes in interest rates on fixed rate debt securities since the respective purchase dates. In all cases, the indicated impairment on these debt securities would be recovered no later than the security’s maturity date or possibly earlier if the market price for the security increases with a reduction in the yield required by the market. None of the unrealized losses relate to the marketability of the securities or the issuers’ abilities to meet contractual obligations. The Company had adequate liquidity as of September 30, 2020 and December 31, 2019 and did not intend to nor believe that it would be required to sell these securities before recovery of the indicated impairment. The unrealized losses on these securities were determined to be non-credit related as of December 31, 2019 and as noted above, no allowance for credit losses was recorded as of January 1, 2020 or September 30, 2020.

Loans and Allowance for Credit

Loans and Allowance for Credit Losses	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Loans and Allowance for Credit Losses	4. Loans and Allowance for Credit Losses The Company generally makes loans in its market areas of south and central Mississippi; southern and central Alabama; northwest, central and south Louisiana; the northern, central, and panhandle regions of Florida; certain areas of east and northeast Texas, including Houston, Beaumont and Dallas; and Nashville, Tennessee. Loans, net of unearned income, by portfolio are presented at amortized cost basis in the table below. Amortized cost does not include accrued interest, which is reflected in the accrued interest line item in the Consolidated Balance Sheets, totaling $86.0 million and $67.7 million at September 30, 2020 and December 31, 2019, respectively. September 30, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 10,257,788 $ 9,166,947 Commercial real estate - owner occupied 2,779,407 2,738,460 Total commercial and industrial 13,037,195 11,905,407 Commercial real estate - income producing 3,406,554 2,994,448 Construction and land development 1,096,149 1,157,451 Residential mortgages 2,754,388 2,990,631 Consumer 1,945,918 2,164,818 Total loans $ 22,240,204 $ 21,212,755 The following briefly describes the composition of each loan category. Commercial and industrial Commercial and industrial loans are made available to businesses for working capital (including financing of inventory and receivables), business expansion, to facilitate the acquisition of a business, and the purchase of equipment and machinery, including equipment leasing. These loans are primarily made based on the identified cash flows of the borrower and, when secured, have the added strength of the underlying collateral. Commercial non-real estate loans may be secured by the assets being financed or other tangible or intangible business assets such as accounts receivable, inventory, ownership, enterprise value or commodity interests, and may incorporate a personal or corporate guarantee; however, some short-term loans may be made on an unsecured basis, including a small portfolio of corporate credit cards, generally issued as a part of overall customer relationships. Commercial non-real estate loans also include loans made under the Small Business Administration’s (SBA) Paycheck Protection Program (PPP). PPP loans are guaranteed by the SBA and are forgivable to the debtor upon satisfaction of certain criteria. The loans bear interest at 1% per annum and have two or five year terms, depending on the date of origination. These loans also earn an origination fee of 1% to 5%, depending on the loan size, that is deferred and amortized over the estimated life of the loan using the effective yield method. Commercial real estate – owner occupied loans consist of commercial mortgages on properties where repayment is generally dependent on the cash flow from the ongoing operations and activities of the borrower. Like commercial non-real estate, these loans are primarily made based on the identified cash flows of the borrower, but also have the added strength of the value of underlying real estate collateral. Commercial real estate – income producing Commercial real estate – income producing loans consist of loans secured by commercial mortgages on properties where the loan is made to real estate developers or investors and repayment is dependent on the sale, refinance, or income generated from the operation of the property. Properties financed include retail, office, multifamily, senior housing, hotel/motel, skilled nursing facilities and other commercial properties. Construction and land development Construction and land development loans are made to facilitate the acquisition, development, improvement and construction of both commercial and residential-purpose properties. Such loans are made to builders and investors where repayment is expected to be made from the sale, refinance or operation of the property or to businesses to be used in their business operations. This portfolio also includes a small amount of residential construction loans and loans secured by raw land not yet under development. Residential mortgages Residential mortgages consist of closed-end loans secured by first liens on 1- 4 family residential properties. The portfolio includes both fixed and adjustable rate loans, although most longer term, fixed rate loans originated are sold in the secondary mortgage market. Consumer Consumer loans include second lien mortgage home loans, home equity lines of credit and nonresidential consumer purpose loans. Nonresidential consumer loans include both direct and indirect loans. Direct nonresidential consumer loans are made to finance the purchase of personal property, including automobiles, recreational vehicles and boats, and for other personal purposes (secured and unsecured), and deposit account secured loans. Indirect nonresidential consumer loans include automobile financing provided to the consumer through an agreement with automobile dealerships. Consumer loans also include a small portfolio of credit card receivables issued on the basis of applications received through referrals from the Bank’s branches, online and other marketing efforts. Allowance for Credit Losses The following tables show activity in the allowance for credit losses by portfolio class for the nine months ended September 30, 2020 and 2019, as well as the corresponding recorded investment in loans at the end of each period. Effective January 1, 2020, the Company adopted the provisions of ASC 326 (CECL) using a modified retrospective basis. The difference between the December 31, 2019 incurred allowance and the CECL allowance is reflected as a cumulative effect of change in accounting principle in the table below. For further discussion of the day one impact of the CECL adoption, refer to Note 16 – Recent Accounting Pronouncements. Commercial Total Commercial Commercial real estate- commercial real estate- Construction non-real owner and income and land Residential (in thousands) estate occupied industrial producing development mortgages Consumer Total Nine Months Ended September 30, 2020 Allowance for credit losses Allowance for loan losses: Beginning balance $ 106,432 $ 10,977 $ 117,409 $ 20,869 $ 9,350 $ 20,331 $ 23,292 $ 191,251 Cumulative effect of change in accounting principle (244 ) 14,877 14,633 7,287 7,478 12,921 7,092 49,411 Charge-offs (364,123 ) (1,828 ) $ (365,951 ) (2,211 ) (7 ) (170 ) (13,640 ) (381,979 ) Recoveries 4,831 659 $ 5,490 46 549 1,078 4,360 11,523 Net provision for loan losses 401,155 41,336 $ 442,491 78,661 12,325 17,613 27,378 578,468 Ending balance - allowance for loan losses $ 148,051 $ 66,021 $ 214,072 $ 104,652 $ 29,695 $ 51,773 $ 48,482 $ 448,674 Reserve for unfunded lending commitments: Beginning balance $ 3,974 $ — $ 3,974 $ — $ — $ — $ — $ 3,974 Cumulative effect of change in accounting principle 5,772 288 6,060 449 15,658 17 5,146 27,330 Provision for losses on unfunded commitments (3,786 ) 187 (3,599 ) 1,599 6,046 (11 ) (3,813 ) 222 Ending balance - reserve for unfunded lending commitments 5,960 475 6,435 2,048 21,704 6 1,333 31,526 Total allowance for credit losses $ 154,011 $ 66,496 $ 220,507 $ 106,700 $ 51,399 $ 51,779 $ 49,815 $ 480,200 Allowance for loan losses: Individually evaluated $ 27,304 $ 1,344 $ 28,648 $ 24 $ 169 $ 416 $ 456 $ 29,713 Collectively evaluated 120,747 64,677 185,424 104,628 29,526 51,357 48,026 418,961 Allowance for loan losses $ 148,051 $ 66,021 $ 214,072 $ 104,652 $ 29,695 $ 51,773 $ 48,482 $ 448,674 Reserve for unfunded lending commitments: Individually evaluated $ 992 $ — $ 992 $ — $ — $ — $ 5 $ 997 Collectively evaluated 4,968 475 5,443 2,048 21,704 6 1,328 30,529 Reserve for unfunded lending commitments: $ 5,960 $ 475 $ 6,435 $ 2,048 $ 21,704 $ 6 $ 1,333 $ 31,526 Total allowance for credit losses $ 154,011 $ 66,496 $ 220,507 $ 106,700 $ 51,399 $ 51,779 $ 49,815 $ 480,200 Loans: Individually evaluated $ 73,139 $ 11,124 $ 84,263 $ 5,549 $ 1,837 $ 6,064 $ 3,924 $ 101,637 Collectively evaluated 10,184,649 2,768,283 12,952,932 3,401,005 1,094,312 2,748,324 1,941,994 22,138,567 Total loans $ 10,257,788 $ 2,779,407 $ 13,037,195 $ 3,406,554 $ 1,096,149 $ 2,754,388 $ 1,945,918 $ 22,240,204 Commercial Total Commercial Commercial real estate- commercial real estate- Construction non-real owner and income and land Residential (in thousands) estate occupied industrial producing development mortgages Consumer Total Nine Months Ended September 30, 2019 Allowance for loan losses: Beginning balance $ 97,752 $ 13,757 $ 111,509 $ 17,638 $ 15,647 $ 23,782 $ 25,938 $ 194,514 Charge-offs (33,382 ) (137 ) (33,519 ) (10 ) (7 ) (660 ) (13,169 ) (47,365 ) Recoveries 5,662 284 5,946 518 108 433 2,866 9,871 Net provision for loan losses 29,267 545 29,812 7,604 (5,982 ) (2,076 ) 9,194 38,552 Ending balance $ 99,299 $ 14,449 $ 113,748 $ 25,750 $ 9,766 $ 21,479 $ 24,829 $ 195,572 Ending balance: Allowance: Individually evaluated for impairment $ 11,535 $ 57 $ 11,592 $ 49 $ 29 $ 183 $ 365 $ 12,218 Amounts related to purchased credit impaired loans 135 172 307 40 144 8,032 300 8,823 Collectively evaluated for impairment 87,629 14,220 101,849 25,661 9,593 13,264 24,164 174,531 Total allowance $ 99,299 $ 14,449 $ 113,748 $ 25,750 $ 9,766 $ 21,479 $ 24,829 $ 195,572 Loans: Individually evaluated for impairment $ 201,979 $ 11,109 $ 213,088 $ 2,781 $ 3,385 $ 4,301 $ 1,583 $ 225,138 Purchased credit impaired loans 33,040 45,124 78,164 27,281 23,431 93,450 6,294 228,620 Collectively evaluated for impairment 8,657,985 2,678,146 11,336,131 3,030,506 1,163,902 2,907,207 2,144,448 20,582,194 Total loans $ 8,893,004 $ 2,734,379 $ 11,627,383 $ 3,060,568 $ 1,190,718 $ 3,004,958 $ 2,152,325 $ 21,035,952 The calculation of the allowance for credit losses under CECL is performed using two primary approaches: a collective approach for pools of loans that have similar risk characteristics using a loss rate analysis, and a specific reserve analysis for credits individually evaluated. The increase in the allowance for credit losses for the nine months ended September 30, 2020 reflects the impact of the economic shutdown in response to the pandemic and the significant drop in oil prices. The allowance for credit losses was developed using multiple Moody’s macroeconomic forecasts applied to internally developed credit models for a two year reasonable and supportable period. The Company weighted the baseline economic forecast, which Moody’s defines as the “most likely outcome” based on current conditions and its view of where the economy is headed, at 50%. Following the sharp recession in the first half of 2020, the baseline scenario assumes a gradual recovery beginning in the second half of 2020, with the most meaningful growth occurring after a vaccine for the coronavirus becomes widely available in the second quarter of 2021. The upside scenario S-1 and the downside scenario S-2 were each weighted 25% to incorporate reasonably possible alternative outcomes. The S-1 scenario reflects reasonably possible improving conditions and a quicker recovery in 2020 and in 2021 compared to the baseline. The S-2 scenario reflects reasonably possible slower economic recovery, with higher instances of infection and death, and restrictions on travel and business winding down somewhat more slowly as compared to the baseline. The degradation in economic conditions during the nine months ended September 30, 2020 created the need for an increased allowance across all portfolios. The allowance for credit loss activity for the nine months ended September 30, 2020 also reflects the impact the sale of $497 million of energy-related loans. The write-down to loans’ observable market value plus cost to sell resulted in charge-offs of $242.6 million and a reserve release of $82.5 million, for a net provision for credit losses impact of $160.1 million, which is mostly reflected in the commercial non-real estate portfolio. Detail of the individually evaluated allowance is provided in the impaired loans section that follows. Impaired Loans The following table shows the composition of nonaccrual loans by portfolio class. Prior to the adoption of CECL, purchased credit impaired loans accounted for in pools with an accretable yield were considered to be performing. Such loans totaled $17.5 million at December 31, 2019. September 30, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 78,184 $ 178,678 Commercial real estate - owner occupied 14,683 7,708 Total commercial and industrial 92,867 186,386 Commercial real estate - income producing 7,028 2,594 Construction and land development 3,234 1,217 Residential mortgages 43,596 39,262 Consumer 24,737 16,374 Total loans $ 171,462 $ 245,833 For the nine months ended September 30, 2020 and 2019, the estimated amount of interest income that would have been recorded had the loans not been assigned nonaccrual status was $10.6 million and $9.9 million, respectively. Nonaccrual loans include nonaccruing loans modified in troubled debt restructurings (“TDRs”) of $39.9 million and $132.5 million at September 30, 2020 and December 31, 2019, respectively. Total TDRs, both accruing and nonaccruing, were $49.1 million at September 30, 2020 and $193.7 million at December 31, 2019. All TDRs are individually evaluated for credit loss. At September 30, 2020 and December 31, 2019, the Company had unfunded commitments of $1.0 million and $2.4 million, respectively, to borrowers whose loan terms have been modified in a TDR. The tables below detail by portfolio class TDRs that were modified during the three and nine months ended September 30, 2020 and 2019: Three Months Ended ($ in thousands) September 30, 2020 September 30, 2019 Pre- Modification Post- Modification Pre- Modification Post- Modification Number Outstanding Outstanding Number Outstanding Outstanding of Recorded Recorded of Recorded Recorded Troubled Debt Restructurings: Contracts Investment Investment Contracts Investment Investment Commercial non-real estate — $ — $ — 2 $ 13,083 $ 6,271 Commercial real estate - owner occupied — — — — — — Total commercial and industrial — — — 2 13,083 6,271 Commercial real estate - income producing — — — 1 123 123 Construction and land development — — — 3 323 323 Residential mortgages 5 1,358 1,358 3 297 297 Consumer 2 25 25 4 70 70 Total loans 7 $ 1,383 $ 1,383 13 $ 13,896 $ 7,084 Nine Months Ended ($ in thousands) September 30, 2020 September 30, 2019 Troubled Debt Restructurings: Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial non-real estate 3 $ 745 $ 745 10 $ 27,220 $ 20,408 Commercial real estate - owner occupied — — — 1 167 167 Total commercial and industrial 3 745 745 11 27,387 20,575 Commercial real estate - income producing — — — 1 123 123 Construction and land development 1 15 15 3 323 323 Residential mortgages 14 3,424 3,424 10 2,199 2,199 Consumer 7 89 89 6 116 116 Total loans 25 4,273 4,273 31 $ 30,148 $ 23,336 The TDRs modified during the nine months ended September 30, 2020 reflected in the table above include $0.7 million of loans with extended amortization terms or other payment concessions, $1.1 million with reduced interest rates, $0.4 million with significant covenant waivers and $2.1 million with other modifications. The TDRs modified during the nine months ended September 30, 2019 include $0.6 million of loans with extended amortization terms or other payment concessions, $22.1 million with significant covenant waivers and $7.4 million with other modifications. One commercial non-real estate loan totaling $0.4 million, one residential mortgage loan totaling $0.6 million, and two consumer loans totaling $0.2 million that defaulted during the nine months ended September 30, 2020 had been modified in a TDR during the twelve months prior to default. The tables below present loans that are individually evaluated by portfolio class at September 30, 2020 and December 31, 2019. Loans individually evaluated include nonaccrual loans, TDRs and other loans that do not share common characteristics with loans evaluated on a collective basis that have aggregate relationship balances of $1 million or more. September 30, 2020 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance for loan loss Commercial non-real estate $ 20,689 $ 52,450 $ 125,893 $ 27,304 Commercial real estate - owner occupied 6,900 4,224 14,029 1,344 Total commercial and industrial 27,589 56,674 139,922 28,648 Commercial real estate - income producing 5,453 96 7,016 24 Construction and land development 667 1,170 1,838 169 Residential mortgages 2,890 3,174 6,869 416 Consumer 1,592 2,332 3,924 456 Total loans $ 38,191 $ 63,446 $ 159,569 $ 29,713 December 31, 2019 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance for loan loss Commercial non-real estate $ 134,191 $ 98,247 $ 270,078 $ 21,733 Commercial real estate - owner occupied 2,665 1,716 7,793 104 Total commercial and industrial 136,856 99,963 277,871 21,837 Commercial real estate - income producing 373 1,525 1,959 18 Construction and land development — 277 322 21 Residential mortgages 3,383 1,791 5,709 217 Consumer 479 1,004 1,906 292 Total loans $ 141,091 $ 104,560 $ 287,767 $ 22,385 The tables below present the average balances and interest income for individually evaluated loans for the three and nine months ended September 30, 2020 and 2019. Interest income recognized represents interest on accruing loans modified in a TDR. Three Months Ended September 30, 2020 September 30, 2019 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial non-real estate $ 81,227 $ 37 $ 213,291 $ 1,062 Commercial real estate - owner occupied 10,553 — 14,439 45 Total commercial and industrial 91,780 37 227,730 1,107 Commercial real estate - income producing 5,886 6 2,331 7 Construction and land development 1,422 3 1,702 2 Residential mortgages 5,887 22 4,195 2 Consumer 3,947 21 1,552 21 Total loans $ 108,922 $ 89 $ 237,510 $ 1,139 Nine Months Ended September 30, 2020 September 30, 2019 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial non-real estate $ 190,622 $ 776 $ 225,597 $ 4,202 Commercial real estate - owner occupied 7,306 — 17,044 196 Total commercial and industrial 197,928 776 242,641 4,398 Commercial real estate - income producing 5,749 18 2,430 21 Construction and land development 1,805 7 597 2 Residential mortgages 5,318 43 4,525 9 Consumer 2,651 67 1,442 55 Total loans $ 213,451 $ 911 $ 251,635 $ 4,485 The TDR disclosure above does not include loans modified under Section 4013 of the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) signed into law on March 27, 2020, which allows financial institutions to exclude eligible modifications from TDR assessment. Eligible modification must be (1) related to COVID-19, (2) executed on a loan that was not more than 30 days past due as of December 31, 2019 and (3) executed between March 1, 2020 and the earlier of 60 days after the date of the termination of the national emergency or December 31, 2020. At September 30, 2020, there were 817 loans totaling $564.8 million with active short-term payment deferrals of principal, interest or both, or other qualifying CARES Act modifications. These loans are reported in the aging analysis that follows based on the modified terms. Aging Analysis The tables below present the aging analysis of past due loans by portfolio class at September 30, 2020 and December 31, 2019. Prior to the adoption of CECL, purchased credit impaired loans accounted for in pools under ASC 310-30 with an accretable yield were considered to be current in the table below as of December 31, 2019. These loans totaled $6.1 million for 30-59 days past due, $2.0 million for 60-89 days past due and $8.3 September 30, 2020 30-59 days past due 60-89 days past due Greater than 90 days past due Total past due Current Total Loans Recorded investment > 90 days and still accruing (in thousands) Commercial non-real estate $ 6,026 $ 14,277 $ 65,705 $ 86,008 $ 10,171,780 $ 10,257,788 $ 5,110 Commercial real estate - owner occupied 535 2,276 11,708 14,519 2,764,888 2,779,407 113 Total commercial and industrial 6,561 16,553 77,413 100,527 12,936,668 13,037,195 5,223 Commercial real estate - income producing 165 30,238 8,701 39,104 3,367,450 3,406,554 2,490 Construction and land development 1,076 237 3,178 4,491 1,091,658 1,096,149 393 Residential mortgages 3,164 11,779 32,908 47,851 2,706,537 2,754,388 1,818 Consumer 9,451 4,621 12,920 26,992 1,918,926 1,945,918 515 Total $ 20,417 $ 63,428 $ 135,120 $ 218,965 $ 22,021,239 $ 22,240,204 $ 10,439 December 31, 2019 30-59 days past due 60-89 days past due Greater than 90 days past due Total past due Current Total Loans Recorded investment > 90 days and still accruing (in thousands) Commercial non-real estate $ 20,893 $ 13,445 $ 100,806 $ 135,144 $ 9,031,803 9,166,947 $ 1,537 Commercial real estate - owner occupied 4,862 556 7,268 12,686 2,725,774 2,738,460 830 Total commercial and industrial 25,755 14,001 108,074 147,830 11,757,577 11,905,407 2,367 Commercial real estate - income producing 738 703 2,910 4,351 2,990,097 2,994,448 450 Construction and land development 5,747 680 2,480 8,907 1,148,544 1,157,451 2,042 Residential mortgages 32,867 8,584 23,577 65,028 2,925,603 2,990,631 85 Consumer 18,586 6,215 9,901 34,702 2,130,116 2,164,818 1,638 Total $ 83,693 $ 30,183 $ 146,942 $ 260,818 $ 20,951,937 $ 21,212,755 $ 6,582 Credit Quality Indicators The following tables present the credit quality indicators by segments and portfolio class of loans held for investment at September 30, 2020 and December 31, 2019. The Company routinely assesses the ratings of loans in its portfolio through an established and comprehensive portfolio management process. In addition, the Company often examines portfolios of loans to determine if there are areas of risk not specifically identified in its loan by loan approach. As a result, several loans were downgraded to pass-watch in 2020 in reaction to the economic downturn caused by the pandemic and other environmental factors. In alignment with regulatory guidance, the Company has been working with its customers to manage through this period of severe uncertainty and economic stress, including providing various types of loan deferrals. While a significant number of these deferrals have expired, our ability to predict future cash flow is limited due to the economic uncertainty, and we expect that further risk rating adjustments may be required. September 30, 2020 (in thousands) Commercial non-real estate Commercial real estate - owner- occupied Total commercial and industrial Commercial real estate - income producing Construction and land development Total commercial Grade: Pass $ 9,617,743 $ 2,562,635 $ 12,180,378 $ 3,278,116 $ 1,062,252 $ 16,520,746 Pass-Watch 368,292 127,688 495,980 83,736 27,851 607,567 Special Mention 85,096 37,299 122,395 2,021 210 124,626 Substandard 186,657 51,785 238,442 42,681 5,836 286,959 Doubtful — — — — — — Total $ 10,257,788 $ 2,779,407 $ 13,037,195 $ 3,406,554 $ 1,096,149 $ 17,539,898 December 31, 2019 (in thousands) Commercial non-real estate Commercial real estate - owner- occupied Total commercial and industrial Commercial real estate - income producing Construction and land development Total commercial Grade: Pass $ 8,492,113 $ 2,517,448 $ 11,009,561 2,883,553 $ 1,120,997 $ 15,014,111 Pass-Watch 220,850 146,266 367,116 69,765 25,621 462,502 Special Mention 71,654 14,651 86,305 14,995 283 101,583 Substandard 382,330 60,095 442,425 26,135 10,550 479,110 Doubtful — — — — — — Total $ 9,166,947 $ 2,738,460 $ 11,905,407 $ 2,994,448 $ 1,157,451 $ 16,057,306 September 30, 2020 December 31, 2019 (in thousands) Residential mortgage Consumer Total Residential mortgage Consumer Total Performing $ 2,708,484 $ 1,920,049 $ 4,628,533 $ 2,950,854 $ 2,147,312 $ 5,098,166 Nonperforming 45,904 25,869 71,773 39,777 17,506 57,283 Total $ 2,754,388 $ 1,945,918 $ 4,700,306 $ 2,990,631 $ 2,164,818 $ 5,155,449 Below are the definitions of the Company’s internally assigned grades: Commercial: • Pass – loans properly approved, documented, collateralized, and performing which do not reflect an abnormal credit risk. • Pass-Watch – credits in this category are of sufficient risk to cause concern. This category is reserved for credits that display negative performance trends. The “Watch” grade should be regarded as a transition category. • Special Mention – a criticized asset category defined as having potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may, at some future date, result in the deterioration of the repayment prospects for the credit or the institution’s credit position. Special mention credits are not considered part of the Classified credit categories and do not expose the institution to sufficient risk to warrant adverse classification. • Substandard – an asset that is inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified must have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the institution will sustain some loss if the deficiencies are not corrected. • Doubtful – an asset that has all the weaknesses inherent in one classified Substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. • Loss – credits classified as Loss are considered uncollectable and are charged off promptly once so classified. Residential and Consumer: • Performing – accruing loans that have not been modified in a troubled debt restructuring. • Nonperforming – loans for which there are good reasons to doubt that payments will be made in full. All loans with nonaccrual status and all loans that have been modified in a troubled debt restructuring are classified as nonperforming. Vintage Analysis The following table presents credit quality disclosures of amortized cost by class and vintage for term loans and by revolving and revolving converted to amortizing at September 30, 2020. The Company defines vintage as the later of origination, renewal or restructure date. Term Loans Amortized Cost Basis by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Commercial Loans: Pass $ 4,980,953 $ 3,098,996 $ 1,979,152 $ 1,508,213 $ 1,067,144 $ 1,417,583 $ 2,385,763 $ 82,942 $ 16,520,746 Pass-Watch 70,389 101,741 56,681 78,598 53,259 116,413 125,134 5,352 607,567 Special Mention 5,687 13,763 24,805 17,888 31,355 2,268 25,960 2,900 124,626 Substandard 76,243 21,552 24,505 37,104 18,231 50,571 48,004 10,749 286,959 Doubtful — — — — — — — — — Total Commercial Loans $ 5,133,272 $ 3,236,052 $ 2,085,143 $ 1,641,803 $ 1,169,989 $ 1,586,835 $ 2,584,861 $ 101,943 $ 17,539,898 Residential Mortgage and Consumer Loans: Performing $ 351,828 $ 501,172 $ 489,007 $ 629,621 $ 536,380 $ 901,979 $ 1,212,937 $ 5,609 4,628,533 Nonperforming 1,244 4,540 6,181 10,422 5,178 35,169 3,039 6,000 71,773 Total Consumer Loans $ 353,072 $ 505,712 $ 495,188 $ 640,043 $ 541,558 $ 937,148 $ 1,215,976 $ 11,609 $ 4,700,306 Purchased Credit Impaired Loans Under the transition provisions for the application of CECL, the Company has classified all loans previously accounted for as purchased credit impaired under ASC 310-30 to be classified as purchased credit deteriorated. The application of these provisions resulted in an increase of $19.8 million to the amortized cost basis of the financial asset and the allowance for credit losses at the date of adoption, representing the remaining credit portion of the purchased discount. The Company elected not to maintain pools of loans accounted for under Subtopic 310-30 with the adoption of CECL. The remaining noncredit discount was allocated to the individual loans and will be accreted to interest income using the interest method based on the effective interest rate. Changes in the carrying amount of purchased credit impaired loans and related accretable yield are presented in the following table for the year ended December 31, 2019. December 31, 2019 (in thousands) Carrying Amount of Loans Accretable Yield Balance at beginning of period $ 129,596 $ 37,294 Additions 120,562 6,246 Payments received, net (48,076 ) (4,601 ) Accretion 13,163 (13,163 ) Decrease in expected cash flows based on actual cash flows and changes in cash flow assumptions — 4,170 Balance at end of period $ 215,245 $ 29,946 Residential Mortgage Loans in Process of Foreclosure Loans in process of foreclosure include those for which formal foreclosure proceedings are in process according to local requirements of the applicable jurisdiction. Included in loans at September 30, 2020 and December 31, 2019 was $11.2 million and $8.6 million of consumer loans secured by single family residential real estate that were in process of foreclosure. In March 2020, in light of the economic deterioration stemming from the COVID-19 pandemic, the Company placed all active residential mortgage foreclosures on hold and suspended the filing of new foreclosures. On September 1, 2020 the Company resumed foreclosure activity in all states except Florida, where the moratorium expired on September 30 and foreclosure activity resumed October 1, 2020. In addition to the single family residential real estate loans in process of foreclosure, the Company also held $3.6 million and $6.3 million of foreclosed single family residential properties in other real estate owned at September 30, 2020 and December 31, 2019, respectively. Loans Held for Sale At September 30, 2020 and December 31, 2019, loans held for sale was comprised only of mortgage loans originated for sale in the secondary market.

Securities Sold under Agreement

Securities Sold under Agreements to Repurchase	9 Months Ended
	Sep. 30, 2020
Brokers And Dealers [Abstract]
Securities Sold under Agreements to Repurchase	5. Securities Sold under Agreements to Repurchase Included in short-term borrowings are customer securities sold under agreements to repurchase that mature daily and are secured by U.S. agency securities totaling $806.6 million and $484.4 million at September 30, 2020 and December 31, 2019, respectively. The Company borrows funds on a secured basis by selling securities under agreements to repurchase, mainly in connection with treasury management services offered to its deposit customers. As the Company maintains effective control over assets sold under agreements to repurchase, the securities continue to be carried on the consolidated statements of financial condition. Because the Company acts as borrower transferring assets to the counterparty, and the agreements mature daily, the Company’s risk is limited.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Long-Term Debt	6. Long Term Debt At September 30, 2020 and December 31, 2019, long-term debt was comprised of the following: September 30, December 31, (in thousands) 2020 2019 Subordinated notes payable, maturing June 2045 $ 150,000 $ 150,000 Subordinated notes payable, maturing June 2060 172,500 — Other long-term debt 73,709 87,890 Less: unamortized debt issuance costs (10,322 ) (4,428 ) Total long-term debt $ 385,887 $ 233,462 The following table sets forth unamortized debt issuance costs associated with the respective debt instruments at September 30, 2020: Unamortized Debt Issuance (in thousands) Principal Costs Subordinated notes payable, maturing June 2045 $ 150,000 $ 4,296 Subordinated notes payable, maturing June 2060 172,500 6,026 Other long-term debt 73,709 — Total $ 396,209 $ 10,322 On June 9, 2020, the Company completed the issuance of subordinated notes payable with an aggregate principal amount of $172.5 million with a stated maturity of June 15, 2060. The notes accrue interest at a fixed rate of 6.25% per annum, with quarterly interest payments that began September 15, 2020. Subject to prior approval by the Federal Reserve, the Company may redeem the notes in whole or in part on any interest payment date on or after June 15, 2025. This debt qualifies as tier 2 capital in the calculation of certain regulatory capital ratios. The proceeds from the issuance are intended for general corporate purposes, including providing capital to Hancock Whitney Bank if and when deemed appropriate. On March 9, 2015, the Company completed the issuance of subordinated notes payable with an aggregate principal amount of $150 million with a stated maturity of June 15, 2045. These notes accrue interest at a fixed rate of 5.95% per annum, with quarterly interest payments that began in June 2015. Subject to prior approval by the Federal Reserve, the Company may redeem the notes in whole or in part on any interest payment date on or after June 15, 2020. This debt qualifies as tier 2 capital in the calculation of certain regulatory capital ratios. Substantially all of the Company’s other long-term debt consists of borrowings associated with tax credit fund activities. Although these borrowings have indicated maturities through 2053, each is expected to be satisfied at the end of the seven-year

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivatives	7. Derivatives Risk Management Objective of Using Derivatives The Company enters into derivative financial instruments to manage risks related to differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments, currently associated with fixed rate brokered deposits, certain investment securities and select pools of variable rate loans. The Company also enters into interest rate derivative agreements as a service to certain qualifying customers. A matched book is managed with respect to these customer derivatives in order to minimize its net interest rate risk exposure resulting from such agreements. The Company also enters into risk participation agreements under which it may either sell or buy credit risk associated with a customer’s performance under certain interest rate derivative contracts related to loans in which participation interests have been sold to or purchased from other banks. Fair Values of Derivative Instruments on the Balance Sheet The table below presents the notional or contractual amounts and fair values of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets at September 30, 2020 and December 31, 2019. September 30, 2020 December 31, 2019 Derivative (1) Derivative (1) (in thousands) Type of Hedge Notional or Contractual Amount Assets Liabilities Notional or Contractual Amount Assets Liabilities Derivatives designated as hedging instruments: Interest rate swaps - variable rate loans Cash Flow $ 1,175,000 $ 57,412 — $ 1,175,000 $ 24,172 $ 337 Interest rate swaps - securities Fair Value 762,650 842 24,203 441,400 1,474 1,759 Interest rate swaps - brokered deposits Fair Value — — — 43,000 — 9 1,937,650 58,254 24,203 1,659,400 25,646 2,105 Derivatives not designated as hedging instruments: Interest rate swaps (2) N/A 4,560,306 164,273 168,207 3,759,232 54,512 55,664 Risk participation agreements N/A 205,787 78 136 254,825 21 45 Forward commitments to sell residential mortgage loans N/A 345,871 82 3,584 145,623 651 744 Interest rate-lock commitments on residential mortgage loans N/A 265,957 2,452 59 83,224 369 375 Foreign exchange forward contracts N/A 81,492 1,937 1,888 64,632 303 366 Visa Class B derivative contract N/A 43,565 — 4,616 43,753 — 5,704 5,502,978 168,822 178,490 4,351,289 55,856 62,898 Total derivatives $ 7,440,628 $ 227,076 $ 202,693 $ 6,010,689 $ 81,502 $ 65,003 Less: netting adjustment (3) (58,254 ) (146,415 ) (27,056 ) (43,914 ) Total derivative assets/liabilities $ 168,822 $ 56,278 $ 54,446 $ 21,089 (1) Derivative assets and liabilities are reported at fair value in other assets or other liabilities, respectively, in the consolidated balance sheets. (2) The notional amount represents both the customer accommodation agreements and offsetting agreements with unrelated financial institutions. (3) Represents balance sheet netting of derivative assets and liabilities for variation margin collateral held or placed with the same central clearing counterparty. See offsetting assets and liabilities for further information. Cash Flow Hedges of Interest Rate Risk The Company is party to various interest rate swap agreements designated and qualifying as cash flow hedges of the Company’s forecasted variable cash flows for pools of variable rate loans. For each agreement, the Company receives interest at a fixed rate and pays at a variable rate. Amortization of other comprehensive loss on terminated cash flow hedges totaled $1.4 Fair Value Hedges of Interest Rate Risk Interest rate swaps on securities available for sale The Company is party to forward-starting fixed payer swaps that convert the latter portion of the term of certain available for sale securities to a floating rate. These derivative instruments are designated as fair value hedges of interest rate risk. This strategy provides the Company with a fixed rate coupon during the front-end unhedged tenor of the bonds and results in a floating rate security during the back-end hedged tenor with hedged start dates between August 2023 through September 2025, and maturity dates from January 2028 through March 2031. The fair value of the hedged item attributable to interest rate risk will be presented in interest income along with the change in the fair value of the hedging instrument. The majority of the hedged available for sale securities is a closed portfolio of pre-payable commercial mortgage backed securities. In accordance with ASC 815, prepayment risk may be excluded when measuring the change in fair value of such hedged items attributable to interest rate risk under the last-of-layer approach. At September 30, 2020, the amortized cost basis of the closed portfolio of pre-payable commercial mortgage backed securities totaled $823.6 million. The amount that represents the hedged items was $752.5 million and the basis adjustment associated with the hedged items totaled $23.8 million. Interest rate swaps on brokered deposits Prior to January 2020, the Company was party to certain interest rate swap agreements that modified the Company’s exposure to interest rate risk by effectively converting a portion of the Company’s brokered certificates of deposit from fixed rates to variable rates. The maturities and call features of these interest rate swaps matched the features of the hedged deposits. As interest rates declined or increased, the corresponding movement in the value of the certificates of deposit were offset by the change in the value of the interest rate swaps, resulting in no impact to earnings. Interest expense was adjusted by the difference between the fixed and floating rates for the period the swaps are in effect. Derivatives Not Designated as Hedges Customer interest rate derivative program The Company enters into interest rate derivative agreements, primarily rate swaps, with commercial banking customers to facilitate their risk management strategies. The Bank enters into offsetting agreements with unrelated financial institutions, thereby mitigating its net risk exposure resulting from such transactions. Because the interest rate derivatives associated with this program do not meet hedge accounting requirements, changes in the fair value of both the customer derivatives and the offsetting derivatives are recognized directly in earnings. The Company has offered customers a deferral of the monthly derivative payment/settlement if the associated loan was on deferral. At September 30, 2020, the Company had a receivable totaling $0.1 million related to these deferrals. Risk participation agreements The Company also enters into risk participation agreements under which it may either assume or sell credit risk associated with a borrower’s performance under certain interest rate derivative contracts. In those instances where the Bank has assumed credit risk, it is not a direct counterparty to the derivative contract with the borrower and has entered into the risk participation agreement because it is a party to the related loan agreement with the borrower. In those instances in which the Bank has sold credit risk, it is the sole counterparty to the derivative contract with the borrower and has entered into the risk participation agreement because other banks participate in the related loan agreement. The Bank manages its credit risk under risk participation agreements by monitoring the creditworthiness of the borrower, based on the Bank’s normal credit review process. Mortgage banking derivatives The Company also enters into certain derivative agreements as part of its mortgage banking activities. These agreements include interest rate lock commitments on prospective residential mortgage loans and forward commitments to sell these loans to investors on a best efforts delivery basis. Customer foreign exchange forward contract derivatives The Company enters into foreign exchange forward derivative agreements, primarily forward foreign currency contracts, with commercial banking customers to facilitate their risk management strategies. The Bank manages its risk exposure from such transactions by entering into offsetting agreements with unrelated financial institutions. Because the foreign exchange forward contract derivatives associated with this program do not meet hedge accounting requirements, changes in the fair value of both the customer derivatives and the offsetting derivatives are recognized directly in earnings. Visa Class B derivative contract The Company is a member of Visa USA. During the fourth quarter of 2018, the Company sold the majority of its Visa Class B holdings, at which time it entered into a derivative agreement with the purchaser whereby the Company will make or receive cash payments whenever the conversion ratio of the Visa Class B shares into Visa Class A shares is adjusted. The conversion ratio changes when Visa deposits funds to a litigation escrow account established by Visa to pay settlements for certain litigation, for which Visa is indemnified by Visa USA members. The Company is also required to make periodic financing payments to the purchaser until all of Visa’s covered litigation matters are resolved. Thus, the derivative contract extends until the end of Visa’s covered litigation matters, the timing of which is uncertain. The contract includes a contingent accelerated termination clause based on the credit ratings of the Company. At September 30, 2020 and December 31, 2019 the fair value of the liability associated with this contract was $4.6 million and $5.7 million, respectively. Effect of Derivative Instruments on the The effects of derivative instruments on the consolidated statements of income for the nine months ended September 30, 2020 and 2019 are presented in the table below. Interest income or the reduction of interest income attributable to cash flow hedges includes amortization of accumulated other comprehensive loss that resulted from termination of interest rate swap contracts. Three Months Ended Nine Months Ended September 30, September 30, Derivative Instruments: Location of Gain (Loss) Recognized in the Statement of Income: 2020 2019 2020 2019 Cash flow hedges - variable rate loans Interest income $ 5,788 $ (956 ) $ 11,249 $ (4,632 ) Fair value hedges - securities Interest income (7 ) 15 33 15 Fair value hedges - brokered deposits Interest expense — (243 ) 46 (1,692 ) All other instruments Other noninterest income 1,739 4,324 9,718 8,733 Total gain $ 7,520 $ 3,140 $ 21,046 $ 2,424 Credit Risk-Related Contingent Features Certain of the Company’s derivative instruments contain provisions allowing the financial institution counterparty to terminate the contracts in certain circumstances, such as a downgrade of the Bank’s credit ratings below specified levels, a default by the Bank on its indebtedness, or the failure of the Bank to maintain specified minimum regulatory capital ratios or its regulatory status as a well-capitalized institution. These derivative agreements also contain provisions regarding the posting of collateral by each party. At September 30, 2020, the Company was not in violation of any such provisions. The aggregate fair value of derivative instruments with credit risk-related contingent features that were in a net liability position at September 30, 2020 and December 31, 2019 was $47.1 million and $12.9 million, respectively, for which the Company had posted collateral of $47.8 million and $12.4 million, respectively. Offsetting Assets and Liabilities The Company’s derivative instruments with certain counterparties contain legally enforceable netting provisions that allow for net settlement of multiple transactions to a single amount, which may be positive, negative, or zero. Agreements with certain bilateral counterparties require both parties to maintain collateral in the event that the fair values of derivative instruments exceed established exposure thresholds. For centrally cleared derivatives, the Company is subject to initial margin posting and daily variation margin exchange with the central clearinghouses. Offsetting information in regards to all derivative assets and liabilities, including accrued interest, subject to these master netting agreements at September 30, 2020 and December 31, 2019 is presented in the following tables. (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Financial Condition Description Gross Amounts Recognized Offset in the Statement of Financial Condition Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Net Amount As of September 30, 2020 Derivative Assets $ 60,231 $ (60,231 ) $ — $ — $ — $ — Derivative Liabilities $ 195,780 $ (148,738 ) $ 47,042 $ — $ 87,926 $ (40,884 ) (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Financial Condition Description Gross Amounts Recognized Offset in the Statement of Financial Condition Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Net Amount As of December 31, 2019 Derivative Assets $ 27,938 $ (27,915 ) $ 23 $ 23 $ — $ — Derivative Liabilities $ 56,523 $ (44,570 ) $ 11,953 $ 23 $ 35,113 $ (23,183 ) The Company has excess collateral compared to total exposure due to initial margin requirements for day-to-day rate volatility.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2020
Stockholders Equity Note [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Common Shares Outstanding Common shares outstanding excludes treasury shares totaling 5.2 million at September 30, 2020 and 4.0 million at December 31, 2019, with a first-in-first-out cost basis of $176.1 million and $135.8 million at September 30, 2020 and December 31, 2019, respectively. Shares outstanding also excludes unvested restricted share awards totaling 1.4 million at both September 30, 2020 and December 31, 2019. Shares Issued as Consideration in Business Combination On September 21, 2019, the Company issued approximately 5.0 million shares of common stock at a market value of $38.42 per share as consideration for its acquisition of MidSouth. Refer to Note 2 – Business Combination for further information. Stock Buyback Program On September 23, 2019, the Company’s board of directors approved a stock buyback program that authorized the Company to repurchase up to 5.5 million shares of its common stock through the expiration date of December 31, 2020. The program allows the Company to repurchase its common shares in the open market, by block purchase, through accelerated share repurchase programs, in privately negotiated transactions, or as otherwise determined by the Company in one or more transactions. The Company is not obligated to purchase any shares under this program, and the board of directors may terminate or amend the program at any time prior to the expiration date. On October 18, 2019, the Company entered into an accelerated share repurchase agreement (“ASR”) with Morgan Stanley & Co. LLC (“Morgan Stanley”) to repurchase $185 million of the Company’s common stock. Pursuant to the ASR, the Company made a $185 million payment to Morgan Stanley on October 21, 2019, and received from Morgan Stanley an initial delivery of 3,611,870 shares of the Company’s common stock, which represented 75% of the estimated total number of shares to be repurchased based on the October 18, 2019 closing price of the Company’s common stock. The value of the remaining shares to be exchanged upon final settlement was accounted for as a forward contract until settlement. Final settlement of the ASR agreement occurred on March 18, 2020. Pursuant to the terms of the settlement, the Company received cash of approximately $12.1 million and a final delivery of 1.0 million shares. In January 2020, the Company repurchased 315,851 shares of its common stock at a price of $40.26 in a privately negotiated transaction. In total, the Company repurchased 4.9 million of the 5.5 million authorized shares under the buyback program at an average price of $37.65 per share. The Company has suspended the repurchase of shares under its stock buyback program. Accumulated Other Comprehensive Income (Loss) The components of Accumulated Other Comprehensive Income (Loss) and changes in those components are presented in the following table.  Available for Sale Securities HTM Securities Transferred from AFS Employee Benefit Plans Cash Flow Hedges Equity Method Investment Total (in thousands) Balance, December 31, 2018 $ (50,125 ) $ (12,044 ) $ (110,247 ) $ (8,293 ) $ — $ (180,709 ) Net change in unrealized loss 125,589 — — 35,472 (434 ) 160,627 Reclassification of net loss realized and included in earnings — — 6,851 4,632 — 11,483 Valuation adjustment to employee benefit plans — — (7,015 ) — — (7,015 ) Amortization of unrealized net loss on securities transferred to HTM — 2,435 — — — 2,435 Income tax expense (benefit) 28,395 551 (37 ) 9,068 — 37,977 Balance, September 30, 2019 $ 47,069 $ (10,160 ) $ (110,374 ) $ 22,743 $ (434 ) $ (51,156 ) Balance, December 31, 2019 $ 28,950 $ 639 $ (101,278 ) $ 17,399 $ (434 ) $ (54,724 ) Net change in unrealized gain or loss 176,009 — — 46,180 (4,935 ) 217,254 Reclassification of net income or loss realized and included in earnings — — 4,656 (11,249 ) — (6,593 ) Valuation adjustment to employee benefit plans — — (10,251 ) — — (10,251 ) Amortization of unrealized net gain on securities transferred to HTM — (378 ) — — — (378 ) Income tax expense (benefit) 39,817 (85 ) (1,265 ) 7,903 — 46,370 Balance, September 30, 2020 $ 165,142 $ 346 $ (105,608 ) $ 44,427 $ (5,369 ) $ 98,938 Accumulated Other Comprehensive Income or Loss (“AOCI”) is reported as a component of stockholders’ equity. AOCI can include, among other items, unrealized holding gains and losses on securities available for sale (“AFS”), including the Company’s share of unrealized gains and losses reported by a partnership accounted for under the equity method, gains and losses associated with pension or other post-retirement benefits that are not recognized immediately as a component of net periodic benefit cost, and gains and losses on derivative instruments that are designated as, and qualify as, cash flow hedges. Net unrealized gains and losses on AFS securities reclassified as securities held to maturity (“HTM”) also continue to be reported as a component of AOCI and will be amortized over the estimated remaining life of the securities as an adjustment to interest income. Subject to certain thresholds, unrealized losses on employee benefit plans will be reclassified into income as pension and post-retirement costs are recognized over the remaining service period of plan participants. Accumulated gains or losses on the cash flow hedge of the variable rate loans described in Note 7 will be reclassified into income over the life of the hedge. Accumulated other comprehensive loss resulting from the terminated interest rate swaps will be amortized over the remaining maturities of the designated instruments. Gains and losses within AOCI are net of deferred income taxes, where applicable. The following table shows the line items of the consolidated statements of income affected by amounts reclassified from AOCI.  Nine Months Ended Amount reclassified from AOCI (a) September 30, Affected line item on (in thousands) 2020 2019 the statement of income Amortization of unrealized net gain or loss or gain on securities transferred to HTM $ 378 $ (2,435 ) Interest income Tax effect (85 ) 551 Income taxes Net of tax 293 (1,884 ) Net income Amortization of defined benefit pension and post-retirement items (4,656 ) (6,851 ) Other noninterest expense (b) Tax effect 1,053 1,546 Income taxes Net of tax (3,603 ) (5,305 ) Net income Reclassification of unrealized gain (loss) on cash flow hedges 12,602 (1,200 ) Interest income Tax effect (2,851 ) 271 Income taxes Net of tax 9,751 (929 ) Net income Amortization of loss on terminated cash flow hedges (1,353 ) (3,432 ) Interest income Tax effect 306 776 Income taxes Net of tax (1,047 ) (2,656 ) Net income Total reclassifications, net of tax $ 5,394 $ (10,774 ) Net income (a) Amounts in parentheses indicate reduction in net income. (b) These AOCI components are included in the computation of net periodic pension and post-retirement cost that is reported with other noninterest expense (see Note 12 – Retirement Plans for additional details). On March 27, 2020, the Office of the Comptroller of the Currency (OCC), the Board of Governors of the Federal Reserve System, and the Federal Deposit Insurance Corporation issued an interim final rule that provides an option to delay the estimated impact on regulatory capital stemming from the implementation CECL for a transition period of five years. The five-year rule provides a full delay of the estimated impact of CECL on regulatory capital transition (0%) for the first two years, followed by a three-year transition (25% of the impact included in 2022, 50% in 2023, 75% in 2024 and 100% thereafter). The two-year delay includes the full impact of day one CECL plus the estimated impact of current CECL activity calculated quarterly as 25% of the current ACL over the day one balance (“modified transition amount”). The modified transition amount will be recalculated each quarter in 2020 and 2021, with the December 31, 2021 impact carrying through the remaining three years of the transition. The Company elected the five-year transition period option upon issuance of the interim final rule.

Other Noninterest Income

Other Noninterest Income	9 Months Ended
	Sep. 30, 2020
Other Income Disclosure Nonoperating [Abstract]
Other Noninterest Income	9. Other Noninterest Income Components of other noninterest income are as follows: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2020 2019 2020 2019 Income from bank-owned life insurance $ 6,628 $ 4,147 $ 14,211 $ 11,495 Credit related fees 2,911 2,988 8,585 8,520 Income from derivatives 1,739 4,324 9,718 8,733 Other miscellaneous 3,521 4,866 11,598 12,025 Total other noninterest income $ 14,799 $ 16,325 $ 44,112 $ 40,773

Other Noninterest Expense

Other Noninterest Expense	9 Months Ended
	Sep. 30, 2020
Other Expense Disclosure Nonoperating [Abstract]
Other Noninterest Expense	10. Other Noninterest Expense Components of other noninterest expense are as follows: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2020 2019 2020 2019 Advertising $ 3,159 $ 5,435 $ 10,089 $ 11,768 Corporate value and franchise taxes 4,872 4,109 13,649 12,366 Telecommunications and postage 4,043 3,610 11,483 10,439 Entertainment and contributions 1,315 2,765 7,146 8,215 Travel expense 309 1,172 1,816 3,614 Printing and supplies 1,271 1,459 4,006 3,720 Tax credit investment amortization 961 1,286 2,882 3,658 Net other retirement expense (income) (6,337 ) (4,152 ) (18,796 ) (12,409 ) Other miscellaneous 5,105 17,374 17,751 29,653 Total other noninterest expense $ 14,698 $ 33,058 $ 50,026 $ 71,024

Earnings (Loss) Per Common Shar

Earnings (Loss) Per Common Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share	11. Earnings (Loss) Per The Company calculates earnings (loss) per share using the two-class method. The two-class method allocates net income or loss to each class of common stock and participating security according to common dividends declared and participation rights in undistributed earnings. For reporting periods in which a net loss is recorded, net loss is not allocated to participating securities because the holders of such securities bear no contractual obligation to fund or otherwise share in the losses. Participating securities consist of nonvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents. A summary of the information used in the computation of earnings (loss) per common share follows. Three Months Ended Nine Months Ended September 30, September 30, (in thousands, except per share data) 2020 2019 2020 2019 Numerator: Net income (loss) to common shareholders $ 79,356 $ 67,807 $ (148,749 ) $ 235,248 Net dividends or income allocated to participating securities - basic and diluted 1,435 1,141 1,278 3,980 Net income (loss) allocated to common shareholders - basic and diluted $ 77,921 $ 66,666 $ (150,027 ) $ 231,268 Denominator: Weighted-average common shares - basic 86,358 86,377 $ 86,614 $ 85,934 Dilutive potential common shares 42 85 — 76 Weighted-average common shares - diluted 86,400 86,462 $ 86,614 $ 86,010 Earnings (loss) per common share: Basic $ 0.90 $ 0.77 $ (1.73 ) $ 2.69 Diluted $ 0.90 $ 0.77 $ (1.73 ) $ 2.69 Potential common shares consist of stock options, nonvested performance-based awards, and nonvested restricted share awards deferred under the Company’s nonqualified deferred compensation plan. These potential common shares do not enter into the calculation of diluted earnings per share if the impact would be antidilutive, i.e., increase earnings per share or reduce a loss per share. For reporting periods in which a net loss is reported, no effect is given to potentially dilutive common shares in the computation of loss per common share as any impact from such shares would be antidilutive. Potentially dilutive common shares with weighted averages of 78,867 for the three months ended September 30, 2020 and 43,794 and 37,680 for the three and nine months ended September 30, 2019, respectively, were excluded from the calculation of earnings per common share, as the effect would have been antidilutive.

Retirement Plans

Retirement Plans	9 Months Ended
	Sep. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	12. Retirement Plans The Company sponsors a qualified defined benefit pension plan, the The Company also offers a defined contribution retirement benefit plan, the Hancock Whitney Corporation 401(k) Savings Plan (“401(k) Plan”), that covers substantially all associates who have been employed 60 days and meet a minimum age requirement and employment classification criteria. The Company matches 100% of the first 1% of compensation saved by a participant, and 50% of the next 5% of compensation saved. Newly eligible associates are automatically enrolled at an initial 3% savings rate unless the associate actively opts out of participation in the plan. Beginning January 1, 2018, the Company makes an additional basic contribution to associates hired or rehired after June 30, 2017 in an amount equal to 2% of the associate’s eligible compensation. For Pension Plan participants whose benefits were frozen as of January 1, 2018, the 401(k) Plan provides an enhanced Company contribution in the amount of 2%, 4% or 6% of such participant’s eligible compensation, based on the participant’s age and years of service with the Company. Participants vest in basic and enhanced Company contributions upon completion of three years of service. The Company sponsors a nonqualified defined benefit plan covering certain legacy Whitney employees that was frozen as of December 31, 2012 and no future benefits are accrued under this plan. The Company sponsors defined benefit postretirement plans for both legacy Hancock and legacy Whitney employees that provide health care and life insurance benefits. Benefits under the Hancock plan are not available to employees hired on or after January 1, 2000. Benefits under the Whitney plan are restricted to retirees who were already receiving benefits at the time of plan amendments in 2007 or active participants who were eligible to receive benefits as of December 31, 2007. The following tables show the components of net periodic benefits cost included in expense for the plans for the periods indicated.  Other Post- (in thousands) Pension Benefits Retirement Benefits For The Three Months Ended September 30, 2020 2019 2020 2019 Service cost $ 3,207 $ 2,735 $ 28 $ 22 Interest cost 3,892 4,659 106 165 Expected return on plan assets (12,047 ) (11,299 ) — — Amortization of net loss and prior service costs 1,854 2,553 (142 ) (229 ) Net reduction of periodic benefit cost $ (3,094 ) $ (1,352 ) $ (8 ) $ (42 )  Other Post- (in thousands) Pension Benefits Retirement Benefits For the Nine Months Ended September 30, 2020 2019 2020 2019 Service cost $ 9,690 $ 8,245 $ 78 $ 73 Interest cost 12,315 14,183 377 457 Expected return on plan assets (36,144 ) (33,899 ) — — Amortization of net loss and prior service costs 5,168 7,535 (512 ) (684 ) Net reduction of periodic benefit cost $ (8,971 ) $ (3,936 ) $ (57 ) $ (154 )

Share-Based Payment Arrangement

Share-Based Payment Arrangements	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Payment Arrangements	13. Share-Based Payment Arrangements The Company maintains incentive compensation plans that provide for awards of share-based compensation to employees and directors. These plans have been approved by the Company’s shareholders. Detailed descriptions of these plans were included in Note 18 to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. At September 30, 2020, the Company had 28,725 outstanding and exercisable stock options, with a weighted average exercise price of $34.11 and a weighted average remaining contractual term of 1.4 years. The options had no aggregate intrinsic value. There were no exercises of stock options during the nine months ended September 30, 2020. The total intrinsic value of options exercised during the nine months ended September 30, 2019 was $0.2 million. The Company’s restricted and performance-based share awards to certain employees and directors are subject to service requirements. A summary of the status of the Company’s nonvested restricted and performance-based share awards at September 30, 2020 are presented in the following table. Weighted Average Number of Grant Date Shares Fair Value Nonvested at January 1, 2020 1,596,258 $ 40.43 Granted 131,025 31.81 Vested (32,706 ) 41.39 Forfeited (55,814 ) 41.21 Nonvested at September 30, 2020 1,638,763 $ 39.70 At September 30, 2020, there was $44.8 million of total unrecognized compensation expense related to nonvested restricted and performance shares expected to vest in the future. This compensation is expected to be recognized in expense over a weighted average period of 3 years. The total fair value of shares which vested during the nine months ended September 30, 2020 and 2019 was $1.4 million and $1.3 million, respectively. During the nine months ended September 30, 2020, the Company granted 35,754 performance share awards subject to a total shareholder return (“TSR”) performance metric with a grant date fair value of $46.61 per share and 35,754 performance shares subject to an operating earnings per share performance metric with a grant date fair value of $39.39 per share to key members of executive management. The number of performance shares subject to TSR that ultimately vest at the end of the three-year two-year three-year

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	14. Commitments and Contingencies In the normal course of business, the Bank enters into financial instruments, such as commitments to extend credit and letters of credit, to meet the financing needs of its customers. Such instruments are not reflected in the accompanying consolidated financial statements until they are funded, although they expose the Bank to varying degrees of credit risk and interest rate risk in much the same way as funded loans. Under regulatory capital guidelines, the Company and Bank must include unfunded commitments meeting certain criteria in risk-weighted capital calculations. Commitments to extend credit include revolving commercial credit lines, nonrevolving loan commitments issued mainly to finance the acquisition and development or construction of real property or equipment, and credit card and personal credit lines. The availability of funds under commercial credit lines and loan commitments generally depends on whether the borrower continues to meet credit standards established in the underlying contract and has not violated other contractual conditions. Loan commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee by the borrower. Credit card and personal credit lines are generally subject to cancellation if the borrower’s credit quality deteriorates. A number of commercial and personal credit lines are used only partially or, in some cases, not at all before they expire, and the total commitment amounts do not necessarily represent future cash requirements of the Company. A substantial majority of the letters of credit are standby agreements that obligate the Bank to fulfill a customer’s financial commitments to a third party if the customer is unable to perform. The Bank issues standby letters of credit primarily to provide credit enhancement to its customers’ other commercial or public financing arrangements and to help them demonstrate financial capacity to vendors of essential goods and services. The contract amounts of these instruments reflect the Company’s exposure to credit risk. The Company undertakes the same credit evaluation in making loan commitments and assuming conditional obligations as it does for on-balance sheet instruments and may require collateral or other credit support. At September 30, 2020, the Company had a reserve for unfunded lending commitments of $31.5 million. The following table presents a summary of the Company’s off-balance sheet financial instruments as of September 30, 2020 and December 31, 2019:  September 30, December 31, (in thousands) 2020 2019 Commitments to extend credit $ 7,803,139 $ 7,530,143 Letters of credit 369,538 393,284 Legal Proceedings The Company is party to various legal proceedings arising in the ordinary course of business. Management does not believe that loss contingencies, if any, arising from pending litigation and regulatory matters will have a material adverse effect on the consolidated financial position or liquidity of the Company.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	15. Fair Value The Financial Accounting Standards Board (“FASB”) defines fair value as the exchange price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The FASB’s guidance also establishes a fair value hierarchy that prioritizes the inputs to these valuation techniques used to measure fair value, giving preference to quoted prices in active markets for identical assets or liabilities (“level 1”) and the lowest priority to unobservable inputs such as a reporting entity’s own data (“level 3”). Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in markets that are not active, observable inputs other than quoted prices, such as interest rates and yield curves, and inputs that are derived principally from or corroborated by observable market data by correlation or other means. Fair Value of Assets and Liabilities Measured on a Recurring Basis The following tables present for each of the fair value hierarchy levels the Company’s assets and liabilities that are measured at fair value on a recurring basis in the consolidated balance sheets at September 30, 2020 and December 31, 2019:  September 30, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 198,616 $ — $ 198,616 Municipal obligations — 313,656 — 313,656 Corporate debt securities — 8,183 — 8,183 Residential mortgage-backed securities — 2,606,690 — 2,606,690 Commercial mortgage-backed securities — 2,101,000 — 2,101,000 Collateralized mortgage obligations — 419,170 — 419,170 Total available for sale securities — 5,647,315 — 5,647,315 Derivative assets (1) — 168,822 — 168,822 Total recurring fair value measurements - assets $ — $ 5,816,137 $ — $ 5,816,137 Liabilities Derivative liabilities (1) $ — $ 51,662 $ 4,616 $ 56,278 Total recurring fair value measurements - liabilities $ — $ 51,662 $ 4,616 $ 56,278  December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 98,672 $ — $ 98,672 Municipal obligations — 249,805 — 249,805 Corporate debt securities — 7,988 — 7,988 Residential mortgage-backed securities — 1,924,157 — 1,924,157 Commercial mortgage-backed securities — 1,586,467 — 1,586,467 Collateralized mortgage obligations — 808,215 — 808,215 Total available for sale securities — 4,675,304 — 4,675,304 Derivative assets (1) — 54,446 — 54,446 Total recurring fair value measurements - assets $ — $ 4,729,750 $ — $ 4,729,750 Liabilities Derivative liabilities (1) $ — $ 15,385 $ 5,704 $ 21,089 Total recurring fair value measurements - liabilities $ — $ 15,385 $ 5,704 $ 21,089 (1) For further disaggregation of derivative assets and liabilities, see Note 7 - Derivatives. Securities classified as level 2 include obligations of U.S. Government agencies and U.S. Government-sponsored agencies, residential and commercial mortgage-backed securities and collateralized mortgage obligations that are issued or guaranteed by U.S. government agencies, and state and municipal bonds. The level 2 fair value measurements for investment securities are obtained quarterly from a third-party pricing service that uses industry-standard pricing models. Substantially all of the model inputs are observable in the marketplace or can be supported by observable data. The Company invests only in securities of investment grade quality with a targeted duration, for the overall portfolio, generally between two and five and a half years. Company policies generally limit investments to U.S. agency securities and municipal securities determined to be investment grade according to an internally generated score which generally includes a rating of not less than “Baa” or its equivalent by a nationally recognized statistical rating agency. For the Company’s derivative financial instruments designated as hedges and those under the customer interest rate program, the fair value is obtained from a third-party pricing service that uses an industry-standard discounted cash flow model that reli es on inputs, LIBOR swap curves and Overnight Index swap rate curves, all observable in the marketplace. To comply with the accounting guidance, credit valuation adjustments are incorporated in the fair values to appropriately reflect nonperformance risk for both the Company and the counterparties. Although the Company has determined that the majority of the inputs used to value these derivative instruments fall within level 2 of the fair value hierarchy, the credit value adjustments utilize level 3 inputs, such as estimates of current credit spreads. The Company has determined that the impact of the credit valuation adjustments is not significant to the overall valuation of these derivatives. As a result, the Company has classified its derivative valuations for these instruments in level 2 of the fair value hierarchy. The Company’s policy is to measure counterparty credit risk quarterly for all derivative instruments subject to master netting arrangements consistent with how market participants would price the net risk exposure at the measurement date. The Company also has certain derivative instruments associated with the Bank’s mortgage-banking activities. These derivative instruments include interest rate lock commitments on prospective residential mortgage loans and forward commitments to sell these loans to investors on a best efforts delivery basis. The fair value of these derivative instruments is measured using observable market prices for similar instruments and is classified as a level 2 measurement. The Company’s Level 3 liability consists of a derivative contract with the purchaser of 192,163 shares of Visa Class B common stock. Pursuant to the agreement, the Company retains the risks associated with the ultimate conversion of the Visa Class B common shares into shares of Visa Class A common stock, such that the counterparty will be compensated for any dilutive adjustments to the conversion ratio and the Company will be compensated for any anti-dilutive adjustments to the ratio. The agreement also requires periodic payments by the Company to the counterparty calculated by reference to the market price of Visa Class A common shares at the time of sale and a fixed rate of interest that steps up once after the eighth scheduled quarterly payment. The fair value of the liability is determined using a discounted cash flow methodology. The significant unobservable inputs used in the fair value measurement are the Company’s own assumptions about estimated changes in the conversion rate of the Visa Class B common shares into Visa Class A common shares, the date on which such conversion is expected to occur and the estimated growth rate of the Visa Class A common share price. Refer to Note 7 – Derivatives for information about the derivative contract with the counterparty. The Company believes its valuation methods for its assets and liabilities carried at fair value are appropriate; however, the use of different methodologies or assumptions, particularly as applied to Level 3 assets and liabilities, could have a material effect on the computation of their estimated fair values. Changes in Level 3 Fair Value Measurements and Quantitative Information about Level 3 Fair Value Measurements The table below presents a rollforward of the amounts on the consolidated balance sheets for the nine months ended September 30, 2020 and the year ended December 31, 2019 for financial instruments of a material nature that are classified within Level 3 of the fair value hierarchy and are measured at fair value on a recurring basis: (in thousands) Balance at December 31, 2018 $ 7,304 Cash settlement (1,900 ) Losses included in earnings 300 Balance at December 31, 2019 5,704 Cash settlement (1,243 ) Losses included in earnings 155 Balance at September 30, 2020 $ 4,616 The table below provides an overview of the valuation techniques and significant unobservable inputs used in those techniques to measure the financial instrument measured on a recurring basis and classified within Level 3 of the valuation. The range of sensitivities that management utilized in its fair value calculations is deemed acceptable in the industry with respect to the identified financial instrument. ($ in thousands)  Fair Value Level 3 Class September 30, 2020 December 31, 2019 Derivative liability $ 4,616 $ 5,704 Valuation technique Discounted cash flow Discounted cash flow Unobservable inputs: Visa Class A appreciation - range 6% - 18% 6% - 18% Visa Class A appreciation - weighted average 12% 12% Conversion rate - range 1.63x - 1.59x 1.63x - 1.59x Conversion rate -weighted average 1.6109x 1.616x Time until resolution 3-27 months 12 - 36 months Fair Value of Assets Measured on a Nonrecurring Basis Certain assets and liabilities are measured at fair value on a nonrecurring basis. Collateral-dependent impaired loans are level 2 assets measured at the fair value of the underlying collateral based on independent third-party appraisals that take into consideration market-based information such as recent sales activity for similar assets in the property’s market. Other real estate owned and foreclosed assets, including both foreclosed property and surplus banking property, are level 3 assets that are adjusted to fair value, less estimated selling costs, upon transfer from loans or property and equipment. Subsequently, other real estate owned and foreclosed assets is carried at the lower of carrying value or fair value less estimated selling costs. Fair values are determined by sales agreement or third-party appraisals as discounted for estimated selling costs, information from comparable sales, and marketability of the assets. The fair value information presented below is not as of the period end, rather it was as of the date the fair value adjustment was recorded during the twelve months for each of the dates presented below, and excludes nonrecurring fair value measurements of assets no longer on the balance sheet. The following tables present the Company’s financial assets that are measured at fair value on a nonrecurring basis for each of the fair value hierarchy levels.  September 30, 2020 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 91,819 $ — $ 91,819 Other real estate owned and foreclosed assets, net — — 11,219 11,219 Total nonrecurring fair value measurements $ — $ 91,819 $ 11,219 $ 103,038  December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 182,377 $ — $ 182,377 Other real estate owned and foreclosed assets, net — — 24,422 24,422 Total nonrecurring fair value measurements $ — $ 182,377 $ 24,422 $ 206,799 Accounting guidance from the FASB requires the disclosure of estimated fair value information about certain on- and off-balance sheet financial instruments, including those financial instruments that are not measured and reported at fair value on a recurring basis. The significant methods and assumptions used by the Company to estimate the fair value of financial instruments are discussed below. Cash, Short-Term Investments and Federal Funds Sold – For these short-term instruments, the carrying amount is a reasonable estimate of fair value. Securities – The fair value measurement for securities available for sale was discussed earlier in the note. The same measurement techniques were applied to the valuation of securities held to maturity. Loans, Net – The fair value measurement for certain impaired loans was discussed earlier in the note. For the remaining portfolio, fair values were generally determined by discounting scheduled cash flows using discount rates determined with reference to current market rates at which loans with similar terms would be made to borrowers of similar credit quality. Loans Held for Sale – These loans are recorded at fair value and carried at the lower of cost or market. The carrying amount is considered a reasonable estimate of fair value. Deposits – The accounting guidance requires that the fair value of deposits with no stated maturity, such as noninterest-bearing demand deposits, interest-bearing checking and savings accounts, be assigned fair values equal to amounts payable upon demand (“carrying amounts”). The fair value of fixed maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. Federal Funds Purchased and Securities Sold under Agreements to Repurchase – For these short-term liabilities, the carrying amount is a reasonable estimate of fair value. Short-Term FHLB Borrowings – The fair value at September 30, 2020 is estimated by discounting the future contractual cash flows using current market rates at which borrowings with similar terms and options could be obtained. The fair value at December 31, 2019 assumed that the carrying amount was a reasonable estimate of fair value given the relatively stable interest rate environment. Long-Term Debt – The fair value is estimated by discounting the future contractual cash flows using current market rates at which debt with similar terms could be obtained. Derivative Financial Instruments – The fair value measurement for derivative financial instruments was discussed earlier in the note. The following tables present the estimated fair values of the Company’s financial instruments by fair value hierarchy levels and the corresponding carrying amounts:  September 30, 2020  Total Fair Carrying (in thousands) Level 1 Level 2 Level 3 Value Amount Financial assets: Cash, interest-bearing bank deposits, and federal funds sold $ 1,263,372 $ — $ — $ 1,263,372 $ 1,263,372 Available for sale securities — 5,647,315 — 5,647,315 5,647,315 Held to maturity securities — 1,517,688 — 1,517,688 1,408,961 Loans, net — 91,819 21,970,946 22,062,765 21,791,530 Loans held for sale — 103,566 — 103,566 103,566 Derivative financial instruments — 168,822 — 168,822 168,822 Financial liabilities: Deposits — — 27,017,416 27,017,416 27,030,659 Federal funds purchased 250 — — 250 250 Securities sold under agreements to repurchase 806,645 — — 806,645 806,645 FHLB short-term borrowings — 1,161,666 — 1,161,666 1,100,000 Long-term debt — 434,597 — 434,597 385,887 Derivative financial instruments — 51,662 4,616 56,278 56,278  December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Fair Value Carrying Amount Financial assets: Cash, interest-bearing bank deposits, and federal funds sold $ 542,333 $ — $ — $ 542,333 $ 542,333 Available for sale securities — 4,675,304 — 4,675,304 4,675,304 Held to maturity securities — 1,611,004 — 1,611,004 1,568,009 Loans, net — 182,377 20,861,702 21,044,079 21,021,504 Loans held for sale — 55,864 — 55,864 55,864 Derivative financial instruments — 54,446 — 54,446 54,446 Financial liabilities: Deposits $ — $ — $ 23,786,775 $ 23,786,775 $ 23,803,575 Federal funds purchased 195,450 — — 195,450 195,450 Securities sold under agreements to repurchase 484,422 — — 484,422 484,422 FHLB short-term borrowings 2,035,000 — — 2,035,000 2,035,000 Long-term debt — 226,098 — 226,098 233,462 Derivative financial instruments — 15,385 5,704 21,089 21,089

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2020
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	16. Recent Accounting Pronouncements Accounting Standards Adopted in 2020 In June 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The ASU, more commonly referred to as Current Expected Credit Losses, or CECL, along with several subsequently issued related amendments, were codified as ASC 326. The provisions of ASC 326, which supersede the incurred loss methodology, require the measurement of expected credit losses over the life of financial assets based on historical experience, current conditions, and reasonable and supportable forecasts. As such, financial institutions and other organizations are required to use forward-looking information to inform their credit loss estimates. Many of the loss estimation techniques prescribed by previous guidance will still be permitted, although the inputs to those techniques will change to reflect the full amount of expected credit losses for the estimated remaining life of the instrument. An entity will continue to use judgment to determine which loss estimation methods are appropriate for its circumstances. In addition, ASC 326 amends the accounting for credit losses on both held to maturity and available for sale debt securities and purchased financial assets with credit deterioration. The Company adopted the provisions of ASC 326 on January 1, 2020, with a cumulative-effect adjustment to retained earnings for non-purchased credit impaired loans. For purchased credit impaired loans (as defined by ASC 310-30), there was no impact to retained earnings upon adoption; rather, a portion of the purchase accounting fair value mark was reclassified to allowance for credit losses. A more detailed discussion of the Company’s policy for accounting for credit losses under the provisions of ASC 326 is presented in Note 1 – Basis of Presentation. The following table reflects the impact of adoption reflected in the Company’s consolidated balance sheets. The increase in the allowance for loan losses represents a reduction in total assets, while the reserve for unfunded lending commitments represents an increase in total liabilities. (in thousands) December 31, 2019 January 1, 2020 CECL adoption impact Assets and Liabilities Allowance for loan and lease losses $ 191,251 $ 240,662 $ 49,411 Reserve for unfunded lending commitments 3,974 31,304 27,330 Allowance for credit losses $ 195,225 $ 271,966 $ 76,741 Retained Earnings Allowance for credit loss increase $ 76,741 Balance sheet reclassification (19,767 ) Total pretax impact 56,974 Income tax impact (12,888 ) Decrease to retained earnings $ 44,086 In March 2020, the FASB issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” The amendments in this Update provide optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The amendments in this Update are elective and apply to all entities, subject to meeting certain criteria, that have contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The amendments in this Update provide optional expedients and exceptions for applying generally accepted accounting principles (GAAP) to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this Update apply only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. The Company adopted this guidance upon its issuance; at adoption, the Company elected to amend the hedge documentation, without de-designating and re-designating, for all outstanding hedging relationships using the available expedient to assert probability of the hedged interest, regardless of any expected modification in terms related to reference rate reform. In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement.” The amendments in this Update modify certain disclosure requirements on fair value measurements set forth in Topic 820, Fair Value Measurements. In addition, the amendments in this Update eliminate the phrase “an entity shall disclose at a minimum” to promote the appropriate exercise of discretion by entities when considering fair value measurement disclosures to clarify that materiality is an appropriate consideration of entities and their auditors when evaluating disclosure requirements. The amendments in this Update are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 31, 2019, and the Company adopted the guidance effective January 1, 2020. Refer to Note 15 - Fair Value Measurements for the modified disclosures. Adoption of this guidance had no impact upon the Company’s results of operations or financial condition. Accounting Standards Issued But Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, “Simplifying the Accounting for Income Taxes (Topic 740).” The amendments in this update are meant to simplify the accounting for income taxes by removing certain exceptions to GAAP. The amendments also improve consistent application of and simplify GAAP by modifying and/or revising the accounting for certain income tax transactions and by clarifying certain existing codification. The amendments in the update are effective for public business entities for fiscal years and interim periods within those fiscal years beginning after December 15, 2020. The Company is currently assessing the impact of adoption of this guidance, but does not expect the update to have a material impact upon its financial position and results of operations. In August 2018, the FASB issued ASU 2018-14, “Compensation – Retirement Benefits – Defined Benefit Plans – General (Subtopic 715-20): Disclosure Framework – Changes to the Disclosure Requirements for Defined Benefit Plans.” The amendments in this Update modify certain disclosure requirements by removing disclosures that are no longer considered cost beneficial, clarifying specific requirements of disclosures, and adding disclosure requirements identified as relevant. The amendments in this Update are effective for fiscal years ending after December 15, 2020 for public business entities. Adoption of this guidance will have no impact upon the Company’s results of operations or financial condition.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of Hancock Whitney Corporation and all other entities in which it has a controlling interest (the “Company”). The financial statements include all adjustments that are, in the opinion of management, necessary to fairly state the Company’s financial condition, results of operations, changes in stockholders’ equity and cash flows for the interim periods presented. The Company has also evaluated all subsequent events for potential recognition and disclosure through the date of the filing of this Quarterly Report on Form 10-Q. Some financial information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) have been condensed or omitted in this Quarterly Report on Form 10-Q pursuant to Securities and Exchange Commission rules and regulations. These financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. Financial information reported in these financial statements is not necessarily indicative of the Company’s financial condition, results of operations, or cash flows for any other interim or annual period. Certain prior period amounts have been reclassified to conform to the current period presentation. These changes in presentation did not have a material impact on the Company’s financial condition or operating results.
Use of Estimates	Use of Estimates The accounting principles the Company follows and the methods for applying these principles conform to GAAP and general practices followed by the banking industry. These accounting principles require management to make estimates and assumptions about future events that affect the amounts reported in the consolidated financial statements and the accompanying notes. Actual results could differ from those estimates.
Critical Accounting Policies and Estimates	Critical Accounting Policies and Estimates On January 1, 2020, the Company adopted Accounting Standards Codification (“ASC”) 326, “Financial Instruments – Credit Losses,” more commonly referred to as CECL, on a modified retrospective basis. The provisions of this guidance require a material change to the manner in which the Company estimates and reports losses on financial instruments, including loans and unfunded lending commitments, select securities and other assets carried at amortized cost. Results for reporting periods beginning after January 1, 2020 are presented under ASC 326, while prior period amounts continue to be reported in accordance with previously applicable GAAP. Changes to the Company’s accounting policies related to CECL are described below. Further, the Company performed an interim test of goodwill impairment using a quantitative assessment, as described below. There were no other material changes or developments during the reporting period with respect to methodologies that the Company uses when applying what management believes are critical accounting policies and developing critical accounting estimates as disclosed in its Annual Report on Form 10-K for the year ended December 31, 2019. Refer to Note 16 – Recent Accounting Pronouncements for a discussion of accounting standards adopted during the nine months ended September 30, 2020 and the impact to the Company’s financial statements.
Accounting Policy Updates	Accounting Policy Updates Allowance for Credit Losses on Loans, Leases Held for Investment and Unfunded Exposures For reporting periods beginning on or after January 1, 2020, the Allowance for Credit Losses (ACL) is comprised of the Allowance for Loan and Lease Losses (ALLL), a valuation account available to absorb losses on loans and leases held for investment, and the Reserve for Unfunded Lending Commitments, a liability established to absorb credit losses for the expected life of the contractual term of on and off-balance sheet exposures as of the date of the determination. Quarterly, management estimates losses in the portfolio and unfunded exposures based on a number of factors, including the Company’s past loan loss experience, known and potential risks in the portfolio, adverse situations that may affect the borrowers’ ability to repay, the estimated value of any underlying collateral, and current and forecasted economic conditions. The analysis and methodology for estimating the ACL includes two primary elements: a collective approach for pools of loans that have similar risk characteristics using a loss rate analysis, and a specific reserve analysis for credits individually evaluated for credit loss. For the collective approach, the Company segments loans into commercial non-real estate, commercial real estate – owner occupied, commercial real estate – income producing, construction and land development, residential mortgage and consumer, with further segmentation by region and sub-portfolio, as deemed appropriate. Both quantitative and qualitative factors are applied at the portfolio segment levels. The Company applies the practical expedient that permits the exclusion of the accrued interest receivable balance from amortized cost basis of financing receivables. For the collectively evaluated portfolios, the Company utilizes internally developed credit models and third party economic forecasts for the calculation of expected credit loss over the reasonable and supportable forecast period for the majority of the portfolio and other methods, generally historical loss based, for select portfolios. The Company calculates collective allowance for a two-year reasonable and supportable forecast period utilizing probability weighted multiple macroeconomic scenarios, and then reverts on a linear basis over four quarters to an average historical loss rate for the remaining term . The credit models consist primarily of multivariate regression and autoregressive models that correlate our historical net charge-off rates to select macroeconomic variables at a collective level. Forward-looking macroeconomic forecasts are applied as inputs to the regression equations to estimate quarterly collective net charge-off rates over the reasonable and supportable period. The net charge-off rates from the credit models for the reasonable and supportable period, the linear reversion rates, and the average loss rates for the post reasonable and supportable periods are applied to forecasted balance runoff for the estimated remaining term. The balance runoff incorporates prepayment assumptions developed from historical experience that are applied to the multiple macroeconomic forecasts. Forecasted net charge-off rates are also applied to forecasted draws and subsequent runoff of unfunded commitments in the calculation of the reserve for unfunded lending commitments. Qualitative adjustments to the output of quantitative calculations are made when management deems it necessary to reflect differences in current and forecasted conditions as compared to those during the historical loss period used in model development. Conditions to be considered include, but are not limited to, problem loan trends, current business and economic conditions, credit concentrations, lending policies and procedures, lending staff, collateral values, loan profiles and volumes, loan review quality, changes in competition and regulations, and other adjustments for model limitations or other variables not specifically captured. The Company establishes specific reserves using an individually evaluated approach for nonaccrual loans, loans modified in troubled debt restructures, loans for which a troubled debt restructure is reasonably expected, and other financial instruments that are deemed to not share risk characteristics with other collectively evaluated financial assets. For loans individually evaluated, a specific allowance is recognized for any shortfall between the loan’s value and its recorded investment. The loan’s value is measured by either the loan’s observable market price, the fair value of the collateral of the loan (less liquidation costs) if it is collateral dependent, or by the present value of expected future cash flows discounted at the loan’s effective interest rate. The Company applies the practical expedient and defines collateral dependent loans as those where the borrower is experiencing financial difficulty and on which repayment is expected to be provided substantially through the operation or sale of the collateral. Loans individually analyzed are not incorporated into the pool analysis to avoid double counting. The Company limits the individually evaluated specific reserve analysis to include commercial and residential mortgage loans with relationship balances of $1 million or greater and all loans classified as troubled debt restructurings. Acquired Loans and Other Financial Assets Acquired loans and other financial assets within the scope of CECL are segregated between those purchased with credit deterioration (“PCD”) and those that are not (“non PCD”). Assets considered PCD include those individual financial assets (or groups of financial assets with similar risk characteristics) that as of the date of acquisition are assessed as having experienced a more-than-insignificant deterioration in credit quality since origination. The assessment of what is more-than-insignificant credit deterioration since origination considers information including, but not limited to, financial assets that are delinquent, on nonaccrual and/or otherwise adversely risk rated as of the acquisition date, those that have been downgraded since origination, and those for which, after origination, credit spreads have widened beyond the threshold specified in policy. The Company bifurcates the fair value discount between the credit and noncredit components and records an allowance for credit losses for PCD assets by adding the credit portion of the fair value discount to the initial amortized cost basis and increasing the allowance for credit losses at the date of acquisition. Any noncredit discount or premium resulting from acquiring assets with credit deterioration is allocated to each individual asset. All non PCD financial assets acquired are recorded at the estimated fair value of the asset at acquisition, with the estimated allowance for credit loss recorded as a provision for credit losses through earnings in the period in which the acquisition has occurred. The noncredit discount or premium for PCD assets and full discount for non PCD assets will be accreted to interest income using the interest method based on the effective interest rate at the acquisition date. Under the transition provisions for application of CECL, the Company has classified all purchased credit impaired loans (“PCI”) previously accounted for under Financial Accounting Standard Subtopic 310-30 to be classified as PCD, without reassessing whether the financial assets meet the criteria of PCD as of the date of adoption. The application of these provisions resulted in an adjustment to the amortized cost basis of the financial asset to reflect the addition of the allowance for credit losses at the date of adoption. The Company elected not to maintain pools of loans accounted for under Subtopic 310-30 at adoption. The Company was also not required to reassess whether modifications to individual acquired financial assets accounted for in pools were troubled debt restructurings as of the date of adoption. The noncredit discount, after the adjustment for the allowance for credit losses, will be accreted to interest income using the interest method based on the effective interest rate determined after the adjustment for credit losses at the adoption date. Allowance for Credit Losses on Securities The CECL standard also requires an assessment of the Company’s held to maturity debt securities for expected credit losses and the available for sale debt securities for credit-related impairment. The Company applies the practical expedient to exclude the accrued interest receivable balance from amortized cost basis of financing receivables. The allowance for credit losses on held to maturity debt securities is estimated at the individual security level when there is a more than inconsequential risk of default. The assessment uses probability of default and loss given default models based on public ratings, where available, or mapped internally developed risk grades to public ratings and forecasted cash flows using the same economic forecasts and probability weighting as used for the Company’s evaluation of the loan portfolio. Qualitative adjustments to the output of the quantitative calculation are made when management deems it necessary to reflect differences in current and forecasted conditions as compared to those during the historical loss period used in model development. The Company evaluates credit impairment on available for sale debt securities at an individual security level. This evaluation is done for securities whose fair value is below amortized cost with a more than inconsequential risk of default and where the Company has assessed the decline in fair value is significant enough to suggest a credit event occurred. Credit events are generally assessed based on adverse conditions specifically related to the security, an industry, or geographic area, changes in the financial condition of the issuer of the security, or in the case of an asset-backed debt security, changes in the financial condition of the underlying loan obligors. The allowance for credit losses for such securities is measured using a discounted cash flow methodology, through which management compares the present value of expected cash flows with the amortized cost basis of the security. The allowance for credit loss is limited to the amount by which the fair value is less than the amortized cost basis. The Company reassesses the potential for credit losses at each reporting period and records subsequent changes in the allowance for credit losses on securities with a corresponding adjustment recorded in the provision for credit loss expense. If the Company intends to sell the debt security, or more likely than not will be required to sell the security before recovery of its amortized cost basis, the security is charged down to fair value against the allowance for credit losses, with any incremental impairment reported in earnings.
Critical Accounting Estimates	Critical Accounting Estimates Goodwill Impairment Testing Goodwill, which represents the excess of cost over the fair value of the net assets of an acquired business, is not amortized but is assessed for impairment on an annual basis, or more often if events or circumstances indicate that it is more likely than not that a goodwill impairment exists. The impairment test compares the estimated fair value of a reporting unit with its net book value. If the unit’s fair value is less than its carrying value, an impairment is recognized. The Company completed its annual impairment test of goodwill as of September 30, 2019 by performing a qualitative (“Step Zero”) assessment. The qualitative assessment involved the examination of changes in macroeconomic conditions, industry and market conditions, overall financial performance, cost factors and other relevant entity-specific events, including changes in management and other key personnel and changes in the share price of the Company’s common stock. As a result of the assessment, the Company concluded that its goodwill was not impaired. During the third quarter of 2020, the Company assessed the indicators of goodwill impairment and noted certain events that indicated that The Company used multiple approaches to measure its fair value at September 30, 2020. The primary approaches included an income approach using the discounted net present value of estimated future cash flows and a market approach using transaction or price-to-forward earnings multiples methodology using the actual price paid in recent acquisition transactions for similar entities, discounted for the current recessionary environment, neither of which resulted in impairment. The results from each of the primary approaches were weighted equally, with the valuation of the reporting unit approximately 14% in excess of net book value at September 30, 2020. Both valuation techniques employed by the Company require significant assumptions. Depending upon the specific approach, assumptions are made regarding the economic environment, expected net interest margins, growth rates, discount rate used to present value future cash flows, asset quality metrics, control premiums, and price-to-forward earnings multiples. Changes to any one of these assumptions could result in significantly different results. Changes in the amount and/or timing of the Company’s expected future cash flows or estimated growth rates, lack of improvement and/or further decline in the price of the Company’s common stock relative to our book value per share, and/or further deterioration in the economic environment beyond current estimates could result in an impairment charge to goodwill in future reporting periods. Annual impairment testing will be performed in the fourth quarter of 2020 in coordination with our annual strategic planning process, and interim testing is expected to continue until indicators of goodwill impairment no longer exist.

Business Combinations (Tables)

Business Combinations (Tables)	9 Months Ended
	Sep. 30, 2020
Business Acquisition [Line Items]
Schedule of Goodwill	(in thousands) Goodwill balance at December 31, 2018 $ 790,972 Final settlement of cash consideration - acquisition of trust and asset management business 1,112 Initial goodwill recorded in the acquisition of MidSouth Bancorp, Inc. 69,207 Measurement period adjustments - acquisition of MidSouth Bancorp, Inc. (5,838 ) Goodwill balance at December 31, 2019 $ 855,453 Goodwill balance at September 30, 2020 $ 855,453
MidSouth [Member]
Business Acquisition [Line Items]
Schedule of Fair Value of Net Assets Acquired and Liabilities Assumed	The following table sets forth the acquisition date fair value of the assets acquired and liabilities assumed, and the resulting goodwill. (in thousands) ASSETS Cash and due from banks $ 28,059 Interest bearing bank deposits 276,911 Federal funds sold 3,475 Securities available for sale 272,240 Loans 787,628 Property and equipment 34,288 Other real estate 343 Identifiable intangible assets 31,500 Other assets 79,888 Total identifiable assets 1,514,332 LIABILITIES Deposit liabilities 1,280,947 Short term borrowings 66,996 Long term debt 13,919 Other liabilities 21,990 Total liabilities 1,383,852 Net assets acquired 130,480 Value of stock 193,849 Goodwill $ 63,369

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2020
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Amortized Cost and Fair Value of Debt Securities Available for Sale	September 30, 2020 December 31, 2019 Gross Gross Gross Gross Securities Available for Sale Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair (in thousands) Cost Gains Losses Value Cost Gains Losses Value U.S. Treasury and government agency securities $ 192,077 $ 6,664 $ 125 $ 198,616 $ 98,320 $ 652 $ 300 $ 98,672 Municipal obligations 297,712 16,291 347 313,656 242,016 7,789 — 249,805 Residential mortgage-backed securities 2,536,999 70,222 531 2,606,690 1,910,909 20,268 7,020 1,924,157 Commercial mortgage-backed securities 1,965,664 136,056 720 2,101,000 1,570,765 19,880 4,178 1,586,467 Collateralized mortgage obligations 410,050 9,141 21 419,170 807,600 3,757 3,142 808,215 Corporate debt securities 8,000 185 2 8,183 8,000 21 33 7,988  $ 5,410,502 $ 238,559 $ 1,746 $ 5,647,315 $ 4,637,610 $ 52,367 $ 14,673 $ 4,675,304
Amortized Cost and Fair Value of Debt Securities Held to Maturity	September 30, 2020 December 31, 2019 Gross Gross Gross Gross Securities Held to Maturity Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair (in thousands) Cost Gains Losses Value Cost Gains Losses Value U.S. Treasury and government agency securities $ — $ — $ — $ — $ 50,000 $ 3 $ — $ 50,003 Municipal obligations 630,894 49,348 17 680,225 641,019 27,146 69 668,096 Residential mortgage-backed securities 24,041 1,641 — 25,682 29,687 883 — 30,570 Commercial mortgage-backed securities 550,201 53,253 — 603,454 539,371 12,474 581 551,264 Collateralized mortgage obligations 203,825 4,502 — 208,327 307,932 3,597 458 311,071  $ 1,408,961 $ 108,744 $ 17 $ 1,517,688 $ 1,568,009 $ 44,103 $ 1,108 $ 1,611,004
Proceeds from Gross Gains on and Gross Losses on Sale of Securities	The following table presents the proceeds from, gross gain on, and gross losses on sales of securities during the nine months ended September 30, 2020 and 2019. Nine Months Ended September 30, (in thousands) 2020 2019 Proceeds $ 211,919 $ 143,304 Gross gains 1,984 — Gross losses 1,496 —
Available for Sale Securities [Member]
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	Debt Securities Available for Sale Amortized Fair (in thousands) Cost Value Due in one year or less $ 14,492 $ 14,540 Due after one year through five years 239,148 258,655 Due after five years through ten years 2,066,697 2,196,332 Due after ten years 3,090,165 3,177,788 Total available for sale debt securities $ 5,410,502 $ 5,647,315
Securities with Unrealized Losses	Available for Sale September 30, 2020 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. Treasury and government agency securities $ 44,039 $ 125 $ — $ — $ 44,039 $ 125 Municipal obligations 26,010 347 — — 26,010 347 Residential mortgage-backed securities 229,662 529 367 2 230,029 531 Commercial mortgage-backed securities 252,858 720 — — 252,858 720 Collateralized mortgage obligations 3,300 21 — — 3,300 21 Corporate debt securities 3,498 2 — — 3,498 2  $ 559,367 $ 1,744 $ 367 $ 2 $ 559,734 $ 1,746 Available for Sale December 31, 2019 Losses < 12 months Losses 12 months or > Total Gross Gross Gross Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) Value Losses Value Losses Value Losses U.S. Treasury and government agency securities $ 28,235 300 $ — $ — $ 28,235 $ 300 Municipal obligations — — — — — — Residential mortgage-backed securities 420,066 5,042 399,787 1,978 819,853 7,020 Commercial mortgage-backed securities 458,855 3,971 14,896 207 473,751 4,178 Collateralized mortgage obligations 89,689 1,315 184,389 1,827 274,078 3,142 Corporate debt securities 1,467 33 — — 1,467 33  $ 998,312 $ 10,661 $ 599,072 $ 4,012 $ 1,597,384 $ 14,673
Held-to-maturity Securities [Member]
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	Debt Securities Held to Maturity Amortized Fair (in thousands) Cost Value Due in one year or less $ 2,196 $ 2,191 Due after one year through five years 189,141 201,869 Due after five years through ten years 636,976 701,345 Due after ten years 580,648 612,283 Total held to maturity securities $ 1,408,961 $ 1,517,688
Securities with Unrealized Losses	Held to Maturity September 30, 2020 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) Value Losses Value Losses Value Losses U.S. Treasury and government agency securities $ — $ — $ — $ — $ — $ — Municipal obligations 523 2 2,890 15 3,413 17 Residential mortgage-backed securities — — — — — — Commercial mortgage-backed securities 222 — — — 222 — Collateralized mortgage obligations — — — — — —  $ 745 $ 2 $ 2,890 $ 15 $ 3,635 $ 17 Held to Maturity December 31, 2019 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) Value Losses Value Losses Value Losses U.S. Treasury and government agency securities $ — $ — $ — $ — $ — $ — Municipal obligations 4,735 38 3,143 31 7,878 69 Residential mortgage-backed securities — — — — — — Commercial mortgage-backed securities 28,426 581 — — 28,426 581 Collateralized mortgage obligations — — 49,110 458 49,110 458  $ 33,161 $ 619 $ 52,253 $ 489 $ 85,414 $ 1,108

Loans and Allowance for Credi_2

Loans and Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2020
Accounts Notes And Loans Receivable [Line Items]
Loans, Net of Unearned Income	Loans, net of unearned income, by portfolio are presented at amortized cost basis in the table below. Amortized cost does not include accrued interest, which is reflected in the accrued interest line item in the Consolidated Balance Sheets, totaling $86.0 million and $67.7 million at September 30, 2020 and December 31, 2019, respectively. September 30, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 10,257,788 $ 9,166,947 Commercial real estate - owner occupied 2,779,407 2,738,460 Total commercial and industrial 13,037,195 11,905,407 Commercial real estate - income producing 3,406,554 2,994,448 Construction and land development 1,096,149 1,157,451 Residential mortgages 2,754,388 2,990,631 Consumer 1,945,918 2,164,818 Total loans $ 22,240,204 $ 21,212,755
Allowance for Credit Losses by Portfolio Class	The following tables show activity in the allowance for credit losses by portfolio class for the nine months ended September 30, 2020 and 2019, as well as the corresponding recorded investment in loans at the end of each period. Effective January 1, 2020, the Company adopted the provisions of ASC 326 (CECL) using a modified retrospective basis. The difference between the December 31, 2019 incurred allowance and the CECL allowance is reflected as a cumulative effect of change in accounting principle in the table below. For further discussion of the day one impact of the CECL adoption, refer to Note 16 – Recent Accounting Pronouncements Commercial Total Commercial Commercial real estate- commercial real estate- Construction non-real owner and income and land Residential (in thousands) estate occupied industrial producing development mortgages Consumer Total Nine Months Ended September 30, 2020 Allowance for credit losses Allowance for loan losses: Beginning balance $ 106,432 $ 10,977 $ 117,409 $ 20,869 $ 9,350 $ 20,331 $ 23,292 $ 191,251 Cumulative effect of change in accounting principle (244 ) 14,877 14,633 7,287 7,478 12,921 7,092 49,411 Charge-offs (364,123 ) (1,828 ) $ (365,951 ) (2,211 ) (7 ) (170 ) (13,640 ) (381,979 ) Recoveries 4,831 659 $ 5,490 46 549 1,078 4,360 11,523 Net provision for loan losses 401,155 41,336 $ 442,491 78,661 12,325 17,613 27,378 578,468 Ending balance - allowance for loan losses $ 148,051 $ 66,021 $ 214,072 $ 104,652 $ 29,695 $ 51,773 $ 48,482 $ 448,674 Reserve for unfunded lending commitments: Beginning balance $ 3,974 $ — $ 3,974 $ — $ — $ — $ — $ 3,974 Cumulative effect of change in accounting principle 5,772 288 6,060 449 15,658 17 5,146 27,330 Provision for losses on unfunded commitments (3,786 ) 187 (3,599 ) 1,599 6,046 (11 ) (3,813 ) 222 Ending balance - reserve for unfunded lending commitments 5,960 475 6,435 2,048 21,704 6 1,333 31,526 Total allowance for credit losses $ 154,011 $ 66,496 $ 220,507 $ 106,700 $ 51,399 $ 51,779 $ 49,815 $ 480,200 Allowance for loan losses: Individually evaluated $ 27,304 $ 1,344 $ 28,648 $ 24 $ 169 $ 416 $ 456 $ 29,713 Collectively evaluated 120,747 64,677 185,424 104,628 29,526 51,357 48,026 418,961 Allowance for loan losses $ 148,051 $ 66,021 $ 214,072 $ 104,652 $ 29,695 $ 51,773 $ 48,482 $ 448,674 Reserve for unfunded lending commitments: Individually evaluated $ 992 $ — $ 992 $ — $ — $ — $ 5 $ 997 Collectively evaluated 4,968 475 5,443 2,048 21,704 6 1,328 30,529 Reserve for unfunded lending commitments: $ 5,960 $ 475 $ 6,435 $ 2,048 $ 21,704 $ 6 $ 1,333 $ 31,526 Total allowance for credit losses $ 154,011 $ 66,496 $ 220,507 $ 106,700 $ 51,399 $ 51,779 $ 49,815 $ 480,200 Loans: Individually evaluated $ 73,139 $ 11,124 $ 84,263 $ 5,549 $ 1,837 $ 6,064 $ 3,924 $ 101,637 Collectively evaluated 10,184,649 2,768,283 12,952,932 3,401,005 1,094,312 2,748,324 1,941,994 22,138,567 Total loans $ 10,257,788 $ 2,779,407 $ 13,037,195 $ 3,406,554 $ 1,096,149 $ 2,754,388 $ 1,945,918 $ 22,240,204 Commercial Total Commercial Commercial real estate- commercial real estate- Construction non-real owner and income and land Residential (in thousands) estate occupied industrial producing development mortgages Consumer Total Nine Months Ended September 30, 2019 Allowance for loan losses: Beginning balance $ 97,752 $ 13,757 $ 111,509 $ 17,638 $ 15,647 $ 23,782 $ 25,938 $ 194,514 Charge-offs (33,382 ) (137 ) (33,519 ) (10 ) (7 ) (660 ) (13,169 ) (47,365 ) Recoveries 5,662 284 5,946 518 108 433 2,866 9,871 Net provision for loan losses 29,267 545 29,812 7,604 (5,982 ) (2,076 ) 9,194 38,552 Ending balance $ 99,299 $ 14,449 $ 113,748 $ 25,750 $ 9,766 $ 21,479 $ 24,829 $ 195,572 Ending balance: Allowance: Individually evaluated for impairment $ 11,535 $ 57 $ 11,592 $ 49 $ 29 $ 183 $ 365 $ 12,218 Amounts related to purchased credit impaired loans 135 172 307 40 144 8,032 300 8,823 Collectively evaluated for impairment 87,629 14,220 101,849 25,661 9,593 13,264 24,164 174,531 Total allowance $ 99,299 $ 14,449 $ 113,748 $ 25,750 $ 9,766 $ 21,479 $ 24,829 $ 195,572 Loans: Individually evaluated for impairment $ 201,979 $ 11,109 $ 213,088 $ 2,781 $ 3,385 $ 4,301 $ 1,583 $ 225,138 Purchased credit impaired loans 33,040 45,124 78,164 27,281 23,431 93,450 6,294 228,620 Collectively evaluated for impairment 8,657,985 2,678,146 11,336,131 3,030,506 1,163,902 2,907,207 2,144,448 20,582,194 Total loans $ 8,893,004 $ 2,734,379 $ 11,627,383 $ 3,060,568 $ 1,190,718 $ 3,004,958 $ 2,152,325 $ 21,035,952
Composition of Nonaccrual Loans by Portfolio Class	The following table shows the composition of nonaccrual loans by portfolio class. Prior to the adoption of CECL, purchased credit impaired loans accounted for in pools with an accretable yield were considered to be performing. Such loans totaled $17.5 million at December 31, 2019. September 30, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 78,184 $ 178,678 Commercial real estate - owner occupied 14,683 7,708 Total commercial and industrial 92,867 186,386 Commercial real estate - income producing 7,028 2,594 Construction and land development 3,234 1,217 Residential mortgages 43,596 39,262 Consumer 24,737 16,374 Total loans $ 171,462 $ 245,833
Troubled Debt Restructurings Modified by Portfolio Class	The tables below detail by portfolio class TDRs that were modified during the three and nine months ended September 30, 2020 and 2019: Three Months Ended ($ in thousands) September 30, 2020 September 30, 2019 Pre- Modification Post- Modification Pre- Modification Post- Modification Number Outstanding Outstanding Number Outstanding Outstanding of Recorded Recorded of Recorded Recorded Troubled Debt Restructurings: Contracts Investment Investment Contracts Investment Investment Commercial non-real estate — $ — $ — 2 $ 13,083 $ 6,271 Commercial real estate - owner occupied — — — — — — Total commercial and industrial — — — 2 13,083 6,271 Commercial real estate - income producing — — — 1 123 123 Construction and land development — — — 3 323 323 Residential mortgages 5 1,358 1,358 3 297 297 Consumer 2 25 25 4 70 70 Total loans 7 $ 1,383 $ 1,383 13 $ 13,896 $ 7,084 Nine Months Ended ($ in thousands) September 30, 2020 September 30, 2019 Troubled Debt Restructurings: Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial non-real estate 3 $ 745 $ 745 10 $ 27,220 $ 20,408 Commercial real estate - owner occupied — — — 1 167 167 Total commercial and industrial 3 745 745 11 27,387 20,575 Commercial real estate - income producing — — — 1 123 123 Construction and land development 1 15 15 3 323 323 Residential mortgages 14 3,424 3,424 10 2,199 2,199 Consumer 7 89 89 6 116 116 Total loans 25 4,273 4,273 31 $ 30,148 $ 23,336
Loans Individually Evaluated Disaggregated by Portfolio Class	The tables below present loans that are individually evaluated by portfolio class at September 30, 2020 and December 31, 2019. Loans individually evaluated include nonaccrual loans, TDRs and other loans that do not share common characteristics with loans evaluated on a collective basis that have aggregate relationship balances of $1 million or more. September 30, 2020 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance for loan loss Commercial non-real estate $ 20,689 $ 52,450 $ 125,893 $ 27,304 Commercial real estate - owner occupied 6,900 4,224 14,029 1,344 Total commercial and industrial 27,589 56,674 139,922 28,648 Commercial real estate - income producing 5,453 96 7,016 24 Construction and land development 667 1,170 1,838 169 Residential mortgages 2,890 3,174 6,869 416 Consumer 1,592 2,332 3,924 456 Total loans $ 38,191 $ 63,446 $ 159,569 $ 29,713 December 31, 2019 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance for loan loss Commercial non-real estate $ 134,191 $ 98,247 $ 270,078 $ 21,733 Commercial real estate - owner occupied 2,665 1,716 7,793 104 Total commercial and industrial 136,856 99,963 277,871 21,837 Commercial real estate - income producing 373 1,525 1,959 18 Construction and land development — 277 322 21 Residential mortgages 3,383 1,791 5,709 217 Consumer 479 1,004 1,906 292 Total loans $ 141,091 $ 104,560 $ 287,767 $ 22,385 The tables below present the average balances and interest income for individually evaluated loans for the three and nine months ended September 30, 2020 and 2019. Interest income recognized represents interest on accruing loans modified in a TDR. Three Months Ended September 30, 2020 September 30, 2019 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial non-real estate $ 81,227 $ 37 $ 213,291 $ 1,062 Commercial real estate - owner occupied 10,553 — 14,439 45 Total commercial and industrial 91,780 37 227,730 1,107 Commercial real estate - income producing 5,886 6 2,331 7 Construction and land development 1,422 3 1,702 2 Residential mortgages 5,887 22 4,195 2 Consumer 3,947 21 1,552 21 Total loans $ 108,922 $ 89 $ 237,510 $ 1,139 Nine Months Ended September 30, 2020 September 30, 2019 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial non-real estate $ 190,622 $ 776 $ 225,597 $ 4,202 Commercial real estate - owner occupied 7,306 — 17,044 196 Total commercial and industrial 197,928 776 242,641 4,398 Commercial real estate - income producing 5,749 18 2,430 21 Construction and land development 1,805 7 597 2 Residential mortgages 5,318 43 4,525 9 Consumer 2,651 67 1,442 55 Total loans $ 213,451 $ 911 $ 251,635 $ 4,485
Aging Analysis of Past Due Loans by Portfolio Class	The tables below present the aging analysis of past due loans by portfolio class at September 30, 2020 and December 31, 2019. Prior to the adoption of CECL, purchased credit impaired loans accounted for in pools under ASC 310-30 with an accretable yield were considered to be current in the table below as of December 31, 2019. These loans totaled $6.1 million for 30-59 days past due, $2.0 million for 60-89 days past due and $8.3 September 30, 2020 30-59 days past due 60-89 days past due Greater than 90 days past due Total past due Current Total Loans Recorded investment > 90 days and still accruing (in thousands) Commercial non-real estate $ 6,026 $ 14,277 $ 65,705 $ 86,008 $ 10,171,780 $ 10,257,788 $ 5,110 Commercial real estate - owner occupied 535 2,276 11,708 14,519 2,764,888 2,779,407 113 Total commercial and industrial 6,561 16,553 77,413 100,527 12,936,668 13,037,195 5,223 Commercial real estate - income producing 165 30,238 8,701 39,104 3,367,450 3,406,554 2,490 Construction and land development 1,076 237 3,178 4,491 1,091,658 1,096,149 393 Residential mortgages 3,164 11,779 32,908 47,851 2,706,537 2,754,388 1,818 Consumer 9,451 4,621 12,920 26,992 1,918,926 1,945,918 515 Total $ 20,417 $ 63,428 $ 135,120 $ 218,965 $ 22,021,239 $ 22,240,204 $ 10,439 December 31, 2019 30-59 days past due 60-89 days past due Greater than 90 days past due Total past due Current Total Loans Recorded investment > 90 days and still accruing (in thousands) Commercial non-real estate $ 20,893 $ 13,445 $ 100,806 $ 135,144 $ 9,031,803 9,166,947 $ 1,537 Commercial real estate - owner occupied 4,862 556 7,268 12,686 2,725,774 2,738,460 830 Total commercial and industrial 25,755 14,001 108,074 147,830 11,757,577 11,905,407 2,367 Commercial real estate - income producing 738 703 2,910 4,351 2,990,097 2,994,448 450 Construction and land development 5,747 680 2,480 8,907 1,148,544 1,157,451 2,042 Residential mortgages 32,867 8,584 23,577 65,028 2,925,603 2,990,631 85 Consumer 18,586 6,215 9,901 34,702 2,130,116 2,164,818 1,638 Total $ 83,693 $ 30,183 $ 146,942 $ 260,818 $ 20,951,937 $ 21,212,755 $ 6,582
Credit Quality Indicators by Segments and Portfolio Class	The following table presents credit quality disclosures of amortized cost by class and vintage for term loans and by revolving and revolving converted to amortizing at September 30, 2020. The Company defines vintage as the later of origination, renewal or restructure date. Term Loans Amortized Cost Basis by Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Commercial Loans: Pass $ 4,980,953 $ 3,098,996 $ 1,979,152 $ 1,508,213 $ 1,067,144 $ 1,417,583 $ 2,385,763 $ 82,942 $ 16,520,746 Pass-Watch 70,389 101,741 56,681 78,598 53,259 116,413 125,134 5,352 607,567 Special Mention 5,687 13,763 24,805 17,888 31,355 2,268 25,960 2,900 124,626 Substandard 76,243 21,552 24,505 37,104 18,231 50,571 48,004 10,749 286,959 Doubtful — — — — — — — — — Total Commercial Loans $ 5,133,272 $ 3,236,052 $ 2,085,143 $ 1,641,803 $ 1,169,989 $ 1,586,835 $ 2,584,861 $ 101,943 $ 17,539,898 Residential Mortgage and Consumer Loans: Performing $ 351,828 $ 501,172 $ 489,007 $ 629,621 $ 536,380 $ 901,979 $ 1,212,937 $ 5,609 4,628,533 Nonperforming 1,244 4,540 6,181 10,422 5,178 35,169 3,039 6,000 71,773 Total Consumer Loans $ 353,072 $ 505,712 $ 495,188 $ 640,043 $ 541,558 $ 937,148 $ 1,215,976 $ 11,609 $ 4,700,306
Changes in Carrying Amount of Purchased Credit Impaired Loans and Related Accretable Yield	Changes in the carrying amount of purchased credit impaired loans and related accretable yield are presented in the following table for the year ended December 31, 2019. December 31, 2019 (in thousands) Carrying Amount of Loans Accretable Yield Balance at beginning of period $ 129,596 $ 37,294 Additions 120,562 6,246 Payments received, net (48,076 ) (4,601 ) Accretion 13,163 (13,163 ) Decrease in expected cash flows based on actual cash flows and changes in cash flow assumptions — 4,170 Balance at end of period $ 215,245 $ 29,946
Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Credit Quality Indicators by Segments and Portfolio Class	The following tables present the credit quality indicators by segments and portfolio class of loans held for investment at September 30, 2020 and December 31, 2019. The Company routinely assesses the ratings of loans in its portfolio through an established and comprehensive portfolio management process. In addition, the Company often examines portfolios of loans to determine if there are areas of risk not specifically identified in its loan by loan approach. As a result, several loans were downgraded to pass-watch in 2020 in reaction to the economic downturn caused by the pandemic and other environmental factors. In alignment with regulatory guidance, the Company has been working with its customers to manage through this period of severe uncertainty and economic stress, including providing various types of loan deferrals. While a significant number of these deferrals have expired, our ability to predict future cash flow is limited due to the economic uncertainty, and we expect that further risk rating adjustments may be required. September 30, 2020 (in thousands) Commercial non-real estate Commercial real estate - owner- occupied Total commercial and industrial Commercial real estate - income producing Construction and land development Total commercial Grade: Pass $ 9,617,743 $ 2,562,635 $ 12,180,378 $ 3,278,116 $ 1,062,252 $ 16,520,746 Pass-Watch 368,292 127,688 495,980 83,736 27,851 607,567 Special Mention 85,096 37,299 122,395 2,021 210 124,626 Substandard 186,657 51,785 238,442 42,681 5,836 286,959 Doubtful — — — — — — Total $ 10,257,788 $ 2,779,407 $ 13,037,195 $ 3,406,554 $ 1,096,149 $ 17,539,898 December 31, 2019 (in thousands) Commercial non-real estate Commercial real estate - owner- occupied Total commercial and industrial Commercial real estate - income producing Construction and land development Total commercial Grade: Pass $ 8,492,113 $ 2,517,448 $ 11,009,561 2,883,553 $ 1,120,997 $ 15,014,111 Pass-Watch 220,850 146,266 367,116 69,765 25,621 462,502 Special Mention 71,654 14,651 86,305 14,995 283 101,583 Substandard 382,330 60,095 442,425 26,135 10,550 479,110 Doubtful — — — — — — Total $ 9,166,947 $ 2,738,460 $ 11,905,407 $ 2,994,448 $ 1,157,451 $ 16,057,306
Residential Mortgage and Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Credit Quality Indicators by Segments and Portfolio Class	September 30, 2020 December 31, 2019 (in thousands) Residential mortgage Consumer Total Residential mortgage Consumer Total Performing $ 2,708,484 $ 1,920,049 $ 4,628,533 $ 2,950,854 $ 2,147,312 $ 5,098,166 Nonperforming 45,904 25,869 71,773 39,777 17,506 57,283 Total $ 2,754,388 $ 1,945,918 $ 4,700,306 $ 2,990,631 $ 2,164,818 $ 5,155,449

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Long-Term Debt	At September 30, 2020 and December 31, 2019, long-term debt was comprised of the following: September 30, December 31, (in thousands) 2020 2019 Subordinated notes payable, maturing June 2045 $ 150,000 $ 150,000 Subordinated notes payable, maturing June 2060 172,500 — Other long-term debt 73,709 87,890 Less: unamortized debt issuance costs (10,322 ) (4,428 ) Total long-term debt $ 385,887 $ 233,462
Long-Term Debt with Related Unamortized Debt Issuance Cost	The following table sets forth unamortized debt issuance costs associated with the respective debt instruments at September 30, 2020: Unamortized Debt Issuance (in thousands) Principal Costs Subordinated notes payable, maturing June 2045 $ 150,000 $ 4,296 Subordinated notes payable, maturing June 2060 172,500 6,026 Other long-term debt 73,709 — Total $ 396,209 $ 10,322

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Fair Values of Derivative Financial Instruments	The table below presents the notional or contractual amounts and fair values of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets at September 30, 2020 and December 31, 2019. September 30, 2020 December 31, 2019 Derivative (1) Derivative (1) (in thousands) Type of Hedge Notional or Contractual Amount Assets Liabilities Notional or Contractual Amount Assets Liabilities Derivatives designated as hedging instruments: Interest rate swaps - variable rate loans Cash Flow $ 1,175,000 $ 57,412 — $ 1,175,000 $ 24,172 $ 337 Interest rate swaps - securities Fair Value 762,650 842 24,203 441,400 1,474 1,759 Interest rate swaps - brokered deposits Fair Value — — — 43,000 — 9 1,937,650 58,254 24,203 1,659,400 25,646 2,105 Derivatives not designated as hedging instruments: Interest rate swaps (2) N/A 4,560,306 164,273 168,207 3,759,232 54,512 55,664 Risk participation agreements N/A 205,787 78 136 254,825 21 45 Forward commitments to sell residential mortgage loans N/A 345,871 82 3,584 145,623 651 744 Interest rate-lock commitments on residential mortgage loans N/A 265,957 2,452 59 83,224 369 375 Foreign exchange forward contracts N/A 81,492 1,937 1,888 64,632 303 366 Visa Class B derivative contract N/A 43,565 — 4,616 43,753 — 5,704 5,502,978 168,822 178,490 4,351,289 55,856 62,898 Total derivatives $ 7,440,628 $ 227,076 $ 202,693 $ 6,010,689 $ 81,502 $ 65,003 Less: netting adjustment (3) (58,254 ) (146,415 ) (27,056 ) (43,914 ) Total derivative assets/liabilities $ 168,822 $ 56,278 $ 54,446 $ 21,089 (1) Derivative assets and liabilities are reported at fair value in other assets or other liabilities, respectively, in the consolidated balance sheets. (2) The notional amount represents both the customer accommodation agreements and offsetting agreements with unrelated financial institutions. (3) Represents balance sheet netting of derivative assets and liabilities for variation margin collateral held or placed with the same central clearing counterparty. See offsetting assets and liabilities for further information.
Effects of Derivative Instruments on the Statement of Income	Three Months Ended Nine Months Ended September 30, September 30, Derivative Instruments: Location of Gain (Loss) Recognized in the Statement of Income: 2020 2019 2020 2019 Cash flow hedges - variable rate loans Interest income $ 5,788 $ (956 ) $ 11,249 $ (4,632 ) Fair value hedges - securities Interest income (7 ) 15 33 15 Fair value hedges - brokered deposits Interest expense — (243 ) 46 (1,692 ) All other instruments Other noninterest income 1,739 4,324 9,718 8,733 Total gain $ 7,520 $ 3,140 $ 21,046 $ 2,424
Offsetting Derivative Assets and Liabilities Subject to Master Netting Arrangements	(in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Financial Condition Description Gross Amounts Recognized Offset in the Statement of Financial Condition Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Net Amount As of September 30, 2020 Derivative Assets $ 60,231 $ (60,231 ) $ — $ — $ — $ — Derivative Liabilities $ 195,780 $ (148,738 ) $ 47,042 $ — $ 87,926 $ (40,884 ) (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Financial Condition Description Gross Amounts Recognized Offset in the Statement of Financial Condition Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Net Amount As of December 31, 2019 Derivative Assets $ 27,938 $ (27,915 ) $ 23 $ 23 $ — $ — Derivative Liabilities $ 56,523 $ (44,570 ) $ 11,953 $ 23 $ 35,113 $ (23,183 )

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2020
Stockholders Equity Note [Abstract]
Components of Accumulated Other Comprehensive Income (Loss)	 Available for Sale Securities HTM Securities Transferred from AFS Employee Benefit Plans Cash Flow Hedges Equity Method Investment Total (in thousands) Balance, December 31, 2018 $ (50,125 ) $ (12,044 ) $ (110,247 ) $ (8,293 ) $ — $ (180,709 ) Net change in unrealized loss 125,589 — — 35,472 (434 ) 160,627 Reclassification of net loss realized and included in earnings — — 6,851 4,632 — 11,483 Valuation adjustment to employee benefit plans — — (7,015 ) — — (7,015 ) Amortization of unrealized net loss on securities transferred to HTM — 2,435 — — — 2,435 Income tax expense (benefit) 28,395 551 (37 ) 9,068 — 37,977 Balance, September 30, 2019 $ 47,069 $ (10,160 ) $ (110,374 ) $ 22,743 $ (434 ) $ (51,156 ) Balance, December 31, 2019 $ 28,950 $ 639 $ (101,278 ) $ 17,399 $ (434 ) $ (54,724 ) Net change in unrealized gain or loss 176,009 — — 46,180 (4,935 ) 217,254 Reclassification of net income or loss realized and included in earnings — — 4,656 (11,249 ) — (6,593 ) Valuation adjustment to employee benefit plans — — (10,251 ) — — (10,251 ) Amortization of unrealized net gain on securities transferred to HTM — (378 ) — — — (378 ) Income tax expense (benefit) 39,817 (85 ) (1,265 ) 7,903 — 46,370 Balance, September 30, 2020 $ 165,142 $ 346 $ (105,608 ) $ 44,427 $ (5,369 ) $ 98,938
Line Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income	The following table shows the line items of the consolidated statements of income affected by amounts reclassified from AOCI.  Nine Months Ended Amount reclassified from AOCI (a) September 30, Affected line item on (in thousands) 2020 2019 the statement of income Amortization of unrealized net gain or loss or gain on securities transferred to HTM $ 378 $ (2,435 ) Interest income Tax effect (85 ) 551 Income taxes Net of tax 293 (1,884 ) Net income Amortization of defined benefit pension and post-retirement items (4,656 ) (6,851 ) Other noninterest expense (b) Tax effect 1,053 1,546 Income taxes Net of tax (3,603 ) (5,305 ) Net income Reclassification of unrealized gain (loss) on cash flow hedges 12,602 (1,200 ) Interest income Tax effect (2,851 ) 271 Income taxes Net of tax 9,751 (929 ) Net income Amortization of loss on terminated cash flow hedges (1,353 ) (3,432 ) Interest income Tax effect 306 776 Income taxes Net of tax (1,047 ) (2,656 ) Net income Total reclassifications, net of tax $ 5,394 $ (10,774 ) Net income (a) Amounts in parentheses indicate reduction in net income. (b) These AOCI components are included in the computation of net periodic pension and post-retirement cost that is reported with other noninterest expense (see Note 12 – Retirement Plans for additional details).

Other Noninterest Income (Table

Other Noninterest Income (Tables)	9 Months Ended
	Sep. 30, 2020
Other Income Disclosure Nonoperating [Abstract]
Components of Other Noninterest Income	Components of other noninterest income are as follows: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2020 2019 2020 2019 Income from bank-owned life insurance $ 6,628 $ 4,147 $ 14,211 $ 11,495 Credit related fees 2,911 2,988 8,585 8,520 Income from derivatives 1,739 4,324 9,718 8,733 Other miscellaneous 3,521 4,866 11,598 12,025 Total other noninterest income $ 14,799 $ 16,325 $ 44,112 $ 40,773

Other Noninterest Expense (Tabl

Other Noninterest Expense (Tables)	9 Months Ended
	Sep. 30, 2020
Other Expense Disclosure Nonoperating [Abstract]
Components of Other Noninterest Expense	Components of other noninterest expense are as follows: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2020 2019 2020 2019 Advertising $ 3,159 $ 5,435 $ 10,089 $ 11,768 Corporate value and franchise taxes 4,872 4,109 13,649 12,366 Telecommunications and postage 4,043 3,610 11,483 10,439 Entertainment and contributions 1,315 2,765 7,146 8,215 Travel expense 309 1,172 1,816 3,614 Printing and supplies 1,271 1,459 4,006 3,720 Tax credit investment amortization 961 1,286 2,882 3,658 Net other retirement expense (income) (6,337 ) (4,152 ) (18,796 ) (12,409 ) Other miscellaneous 5,105 17,374 17,751 29,653 Total other noninterest expense $ 14,698 $ 33,058 $ 50,026 $ 71,024

Earnings (Loss) Per Common Sh_2

Earnings (Loss) Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Computation of Earnings (Loss) Per Common Share	A summary of the information used in the computation of earnings (loss) per common share follows. Three Months Ended Nine Months Ended September 30, September 30, (in thousands, except per share data) 2020 2019 2020 2019 Numerator: Net income (loss) to common shareholders $ 79,356 $ 67,807 $ (148,749 ) $ 235,248 Net dividends or income allocated to participating securities - basic and diluted 1,435 1,141 1,278 3,980 Net income (loss) allocated to common shareholders - basic and diluted $ 77,921 $ 66,666 $ (150,027 ) $ 231,268 Denominator: Weighted-average common shares - basic 86,358 86,377 $ 86,614 $ 85,934 Dilutive potential common shares 42 85 — 76 Weighted-average common shares - diluted 86,400 86,462 $ 86,614 $ 86,010 Earnings (loss) per common share: Basic $ 0.90 $ 0.77 $ (1.73 ) $ 2.69 Diluted $ 0.90 $ 0.77 $ (1.73 ) $ 2.69

Retirement Plans (Tables)

Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Components of Net Periodic Benefits Cost	The following tables show the components of net periodic benefits cost included in expense for the plans for the periods indicated.  Other Post- (in thousands) Pension Benefits Retirement Benefits For The Three Months Ended September 30, 2020 2019 2020 2019 Service cost $ 3,207 $ 2,735 $ 28 $ 22 Interest cost 3,892 4,659 106 165 Expected return on plan assets (12,047 ) (11,299 ) — — Amortization of net loss and prior service costs 1,854 2,553 (142 ) (229 ) Net reduction of periodic benefit cost $ (3,094 ) $ (1,352 ) $ (8 ) $ (42 )  Other Post- (in thousands) Pension Benefits Retirement Benefits For the Nine Months Ended September 30, 2020 2019 2020 2019 Service cost $ 9,690 $ 8,245 $ 78 $ 73 Interest cost 12,315 14,183 377 457 Expected return on plan assets (36,144 ) (33,899 ) — — Amortization of net loss and prior service costs 5,168 7,535 (512 ) (684 ) Net reduction of periodic benefit cost $ (8,971 ) $ (3,936 ) $ (57 ) $ (154 )

Share-Based Payment Arrangeme_2

Share-Based Payment Arrangements (Tables)	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Nonvested Restricted and Performance Shares	A summary of the status of the Company’s nonvested restricted and performance-based share awards at September 30, 2020 are presented in the following table. Weighted Average Number of Grant Date Shares Fair Value Nonvested at January 1, 2020 1,596,258 $ 40.43 Granted 131,025 31.81 Vested (32,706 ) 41.39 Forfeited (55,814 ) 41.21 Nonvested at September 30, 2020 1,638,763 $ 39.70

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Off-Balance Sheet Financial Instruments	The following table presents a summary of the Company’s off-balance sheet financial instruments as of September 30, 2020 and December 31, 2019:  September 30, December 31, (in thousands) 2020 2019 Commitments to extend credit $ 7,803,139 $ 7,530,143 Letters of credit 369,538 393,284

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables present for each of the fair value hierarchy levels the Company’s assets and liabilities that are measured at fair value on a recurring basis in the consolidated balance sheets at September 30, 2020 and December 31, 2019:  September 30, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 198,616 $ — $ 198,616 Municipal obligations — 313,656 — 313,656 Corporate debt securities — 8,183 — 8,183 Residential mortgage-backed securities — 2,606,690 — 2,606,690 Commercial mortgage-backed securities — 2,101,000 — 2,101,000 Collateralized mortgage obligations — 419,170 — 419,170 Total available for sale securities — 5,647,315 — 5,647,315 Derivative assets (1) — 168,822 — 168,822 Total recurring fair value measurements - assets $ — $ 5,816,137 $ — $ 5,816,137 Liabilities Derivative liabilities (1) $ — $ 51,662 $ 4,616 $ 56,278 Total recurring fair value measurements - liabilities $ — $ 51,662 $ 4,616 $ 56,278  December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 98,672 $ — $ 98,672 Municipal obligations — 249,805 — 249,805 Corporate debt securities — 7,988 — 7,988 Residential mortgage-backed securities — 1,924,157 — 1,924,157 Commercial mortgage-backed securities — 1,586,467 — 1,586,467 Collateralized mortgage obligations — 808,215 — 808,215 Total available for sale securities — 4,675,304 — 4,675,304 Derivative assets (1) — 54,446 — 54,446 Total recurring fair value measurements - assets $ — $ 4,729,750 $ — $ 4,729,750 Liabilities Derivative liabilities (1) $ — $ 15,385 $ 5,704 $ 21,089 Total recurring fair value measurements - liabilities $ — $ 15,385 $ 5,704 $ 21,089 (1) For further disaggregation of derivative assets and liabilities, see Note 7 - Derivatives.
Consolidated Balance Sheets for Financial Instruments of Material Nature Measured at Fair Value on Recurring Basis	The table below presents a rollforward of the amounts on the consolidated balance sheets for the nine months ended September 30, 2020 and the year ended December 31, 2019 for financial instruments of a material nature that are classified within Level 3 of the fair value hierarchy and are measured at fair value on a recurring basis: (in thousands) Balance at December 31, 2018 $ 7,304 Cash settlement (1,900 ) Losses included in earnings 300 Balance at December 31, 2019 5,704 Cash settlement (1,243 ) Losses included in earnings 155 Balance at September 30, 2020 $ 4,616
Overview of the Valuation Techniques and Significant Unobservable Inputs	($ in thousands)  Fair Value Level 3 Class September 30, 2020 December 31, 2019 Derivative liability $ 4,616 $ 5,704 Valuation technique Discounted cash flow Discounted cash flow Unobservable inputs: Visa Class A appreciation - range 6% - 18% 6% - 18% Visa Class A appreciation - weighted average 12% 12% Conversion rate - range 1.63x - 1.59x 1.63x - 1.59x Conversion rate -weighted average 1.6109x 1.616x Time until resolution 3-27 months 12 - 36 months
Financial Assets Measured at Fair Value on Nonrecurring Basis	The following tables present the Company’s financial assets that are measured at fair value on a nonrecurring basis for each of the fair value hierarchy levels.  September 30, 2020 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 91,819 $ — $ 91,819 Other real estate owned and foreclosed assets, net — — 11,219 11,219 Total nonrecurring fair value measurements $ — $ 91,819 $ 11,219 $ 103,038  December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 182,377 $ — $ 182,377 Other real estate owned and foreclosed assets, net — — 24,422 24,422 Total nonrecurring fair value measurements $ — $ 182,377 $ 24,422 $ 206,799
Estimated Fair Values of Financial Instruments	The following tables present the estimated fair values of the Company’s financial instruments by fair value hierarchy levels and the corresponding carrying amounts:  September 30, 2020  Total Fair Carrying (in thousands) Level 1 Level 2 Level 3 Value Amount Financial assets: Cash, interest-bearing bank deposits, and federal funds sold $ 1,263,372 $ — $ — $ 1,263,372 $ 1,263,372 Available for sale securities — 5,647,315 — 5,647,315 5,647,315 Held to maturity securities — 1,517,688 — 1,517,688 1,408,961 Loans, net — 91,819 21,970,946 22,062,765 21,791,530 Loans held for sale — 103,566 — 103,566 103,566 Derivative financial instruments — 168,822 — 168,822 168,822 Financial liabilities: Deposits — — 27,017,416 27,017,416 27,030,659 Federal funds purchased 250 — — 250 250 Securities sold under agreements to repurchase 806,645 — — 806,645 806,645 FHLB short-term borrowings — 1,161,666 — 1,161,666 1,100,000 Long-term debt — 434,597 — 434,597 385,887 Derivative financial instruments — 51,662 4,616 56,278 56,278  December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Fair Value Carrying Amount Financial assets: Cash, interest-bearing bank deposits, and federal funds sold $ 542,333 $ — $ — $ 542,333 $ 542,333 Available for sale securities — 4,675,304 — 4,675,304 4,675,304 Held to maturity securities — 1,611,004 — 1,611,004 1,568,009 Loans, net — 182,377 20,861,702 21,044,079 21,021,504 Loans held for sale — 55,864 — 55,864 55,864 Derivative financial instruments — 54,446 — 54,446 54,446 Financial liabilities: Deposits $ — $ — $ 23,786,775 $ 23,786,775 $ 23,803,575 Federal funds purchased 195,450 — — 195,450 195,450 Securities sold under agreements to repurchase 484,422 — — 484,422 484,422 FHLB short-term borrowings 2,035,000 — — 2,035,000 2,035,000 Long-term debt — 226,098 — 226,098 233,462 Derivative financial instruments — 15,385 5,704 21,089 21,089

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Changes And Error Corrections [Abstract]
Schedule of Impact of Adoption Reflected in Consolidated Balance Sheets	The following table reflects the impact of adoption reflected in the Company’s consolidated balance sheets. The increase in the allowance for loan losses represents a reduction in total assets, while the reserve for unfunded lending commitments represents an increase in total liabilities. (in thousands) December 31, 2019 January 1, 2020 CECL adoption impact Assets and Liabilities Allowance for loan and lease losses $ 191,251 $ 240,662 $ 49,411 Reserve for unfunded lending commitments 3,974 31,304 27,330 Allowance for credit losses $ 195,225 $ 271,966 $ 76,741 Retained Earnings Allowance for credit loss increase $ 76,741 Balance sheet reclassification (19,767 ) Total pretax impact 56,974 Income tax impact (12,888 ) Decrease to retained earnings $ 44,086

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details)	9 Months Ended
	Sep. 30, 2020USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Loan minimum balance included in specific reserve analysis	$ 1,000,000
Goodwill impairment	$ 0
Percentage of fair value of reporting unit in excess of net book value	14.00%

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) - USD ($) shares in Millions	Sep. 21, 2019	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill		$ 855,453,000	$ 855,453,000	$ 790,972,000
MidSouth [Member]
Business Acquisition [Line Items]
Net assets acquired	$ 130,500,000	130,480,000
Goodwill	$ 63,400,000	63,369,000
Shares issued	5
Business combination transaction value on an average of share price	$ 193,800,000
Goodwill, Measurement period adjustments		$ 0	$ (5,838,000)

Business Combinations (Schedule

Business Combinations (Schedule of Fair Value of Net Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 21, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 855,453	$ 855,453		$ 790,972
MidSouth [Member]
Business Acquisition [Line Items]
Cash and due from banks	28,059
Interest bearing bank deposits	276,911
Federal funds sold	3,475
Securities available for sale	272,240
Loans	787,628
Property and equipment	34,288
Other real estate	343
Identifiable intangible assets	31,500
Other assets	79,888
Total identifiable assets	1,514,332
Deposit liabilities	1,280,947
Short term borrowings	66,996
Long term debt	13,919
Other liabilities	21,990
Total liabilities	1,383,852
Net assets acquired	130,480		$ 130,500
Value of stock-based consideration	193,849
Goodwill	$ 63,369		$ 63,400

Business Combinations (Schedu_2

Business Combinations (Schedule of Goodwill) (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill, Beginning Balance	$ 855,453,000	$ 790,972,000
Goodwill, Ending Balance	855,453,000	855,453,000
MidSouth [Member]
Business Acquisition [Line Items]
Goodwill, Initial goodwill recorded		69,207,000
Goodwill, Measurement period adjustments	0	(5,838,000)
Goodwill, Ending Balance	$ 63,369,000
Trust and Asset Management Business [Member]
Business Acquisition [Line Items]
Final settlement of cash consideration - acquisition of trust and asset management business		$ 1,112,000

Securities (Narrative) (Details

Securities (Narrative) (Details)	Sep. 30, 2020USD ($)Security	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
Investments Debt And Equity Securities [Abstract]
Amortized cost of securities excluding accrued interest	$ 23,200,000		$ 23,900,000
Securities classified as trading	0		0
Securities pledged as collateral	3,200,000,000		$ 3,300,000,000
Allowance for credit loss	$ 0	$ 0
Securities that met the criteria of a credit loss event | Security	0
Number of securities with market values below their cost basis | Security	40

Securities (Amortized Cost and

Securities (Amortized Cost and Fair Value of Debt Securities Available for Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	$ 5,410,502	$ 4,637,610
Securities Available for Sale, Gross Unrealized Gains	238,559	52,367
Securities Available for Sale, Gross Unrealized Losses	1,746	14,673
Securities Available for Sale, Fair Value	5,647,315	4,675,304
U.S. Treasury And Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	192,077	98,320
Securities Available for Sale, Gross Unrealized Gains	6,664	652
Securities Available for Sale, Gross Unrealized Losses	125	300
Securities Available for Sale, Fair Value	198,616	98,672
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	297,712	242,016
Securities Available for Sale, Gross Unrealized Gains	16,291	7,789
Securities Available for Sale, Gross Unrealized Losses	347
Securities Available for Sale, Fair Value	313,656	249,805
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	2,536,999	1,910,909
Securities Available for Sale, Gross Unrealized Gains	70,222	20,268
Securities Available for Sale, Gross Unrealized Losses	531	7,020
Securities Available for Sale, Fair Value	2,606,690	1,924,157
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	1,965,664	1,570,765
Securities Available for Sale, Gross Unrealized Gains	136,056	19,880
Securities Available for Sale, Gross Unrealized Losses	720	4,178
Securities Available for Sale, Fair Value	2,101,000	1,586,467
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	410,050	807,600
Securities Available for Sale, Gross Unrealized Gains	9,141	3,757
Securities Available for Sale, Gross Unrealized Losses	21	3,142
Securities Available for Sale, Fair Value	419,170	808,215
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	8,000	8,000
Securities Available for Sale, Gross Unrealized Gains	185	21
Securities Available for Sale, Gross Unrealized Losses	2	33
Securities Available for Sale, Fair Value	$ 8,183	$ 7,988

Securities (Amortized Cost an_2

Securities (Amortized Cost and Fair Value of Debt Securities Held to Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	$ 1,408,961	$ 1,568,009
Securities Held to Maturity, Gross Unrealized Gains	108,744	44,103
Securities Held to Maturity, Gross Unrealized Losses	17	1,108
Securities Held to Maturity, Fair Value	1,517,688	1,611,004
U.S. Treasury And Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost		50,000
Securities Held to Maturity, Gross Unrealized Gains		3
Securities Held to Maturity, Fair Value		50,003
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	630,894	641,019
Securities Held to Maturity, Gross Unrealized Gains	49,348	27,146
Securities Held to Maturity, Gross Unrealized Losses	17	69
Securities Held to Maturity, Fair Value	680,225	668,096
Residential Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	24,041	29,687
Securities Held to Maturity, Gross Unrealized Gains	1,641	883
Securities Held to Maturity, Fair Value	25,682	30,570
Commercial Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	550,201	539,371
Securities Held to Maturity, Gross Unrealized Gains	53,253	12,474
Securities Held to Maturity, Gross Unrealized Losses		581
Securities Held to Maturity, Fair Value	603,454	551,264
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	203,825	307,932
Securities Held to Maturity, Gross Unrealized Gains	4,502	3,597
Securities Held to Maturity, Gross Unrealized Losses		458
Securities Held to Maturity, Fair Value	$ 208,327	$ 311,071

Securities (Amortized Cost an_3

Securities (Amortized Cost and Fair Value of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Debt Securities Available for Sale, Due in one year or less, Amortized Cost	$ 14,492
Debt Securities Available for Sale, Due after one year through five years, Amortized Cost	239,148
Debt Securities Available for Sale, Due after five years through ten years, Amortized Cost	2,066,697
Debt Securities Available for Sale, Due after ten years, Amortized Cost	3,090,165
Securities Available for Sale, Gross Amortized Cost	5,410,502	$ 4,637,610
Debt Securities Available for Sale, Due in one year or less, Fair Value	14,540
Debt Securities Available for Sale, Due after one year through five years, Fair Value	258,655
Debt Securities Available for Sale, Due after five years through ten years, Fair Value	2,196,332
Debt Securities Available for Sale, Due after ten years, Fair Value	3,177,788
Total available for sale debt securities, Fair Value	5,647,315	4,675,304
Debt Securities Held to Maturity, Due in one year or less, Amortized Cost	2,196
Debt Securities Held to Maturity, Due after one year through five years, Amortized Cost	189,141
Debt Securities Held to Maturity, Due after five years through ten years, Amortized Cost	636,976
Debt Securities Held to Maturity, Due after ten years, Amortized Cost	580,648
Total held to maturity debt securities, Amortized Cost	1,408,961	1,568,009
Debt Securities Held to Maturity, Due in one year or less, Fair Value	2,191
Debt Securities Held to Maturity, Due after one year through five years, Fair Value	201,869
Debt Securities Held to Maturity, Due after five years through ten years, Fair Value	701,345
Debt Securities Held to Maturity, Due after ten years, Fair Value	612,283
Total held to maturity debt securities, Fair Value	$ 1,517,688	$ 1,611,004

Securities (Proceeds from Gross

Securities (Proceeds from Gross Gains on and Gross Losses on Sale of Securities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Proceeds	$ 211,919	$ 143,304
Gross gains	1,984
Gross losses	$ 1,496

Securities (Securities Availabl

Securities (Securities Available for Sale with Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	$ 559,367	$ 998,312
Available for sale, Losses less than 12 months, Gross Unrealized Losses	1,744	10,661
Available for sale, Losses 12 months or longer, Fair Value	367	599,072
Available for sale, Losses 12 months or longer, Gross Unrealized Losses	2	4,012
Available for sale, Total, Fair Value	559,734	1,597,384
Available for sale, Total, Gross Unrealized Losses	1,746	14,673
U.S. Treasury And Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	44,039	28,235
Available for sale, Losses less than 12 months, Gross Unrealized Losses	125	300
Available for sale, Total, Fair Value	44,039	28,235
Available for sale, Total, Gross Unrealized Losses	125	300
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	26,010
Available for sale, Losses less than 12 months, Gross Unrealized Losses	347
Available for sale, Total, Fair Value	26,010
Available for sale, Total, Gross Unrealized Losses	347
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	229,662	420,066
Available for sale, Losses less than 12 months, Gross Unrealized Losses	529	5,042
Available for sale, Losses 12 months or longer, Fair Value	367	399,787
Available for sale, Losses 12 months or longer, Gross Unrealized Losses	2	1,978
Available for sale, Total, Fair Value	230,029	819,853
Available for sale, Total, Gross Unrealized Losses	531	7,020
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	252,858	458,855
Available for sale, Losses less than 12 months, Gross Unrealized Losses	720	3,971
Available for sale, Losses 12 months or longer, Fair Value		14,896
Available for sale, Losses 12 months or longer, Gross Unrealized Losses		207
Available for sale, Total, Fair Value	252,858	473,751
Available for sale, Total, Gross Unrealized Losses	720	4,178
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	3,300	89,689
Available for sale, Losses less than 12 months, Gross Unrealized Losses	21	1,315
Available for sale, Losses 12 months or longer, Fair Value		184,389
Available for sale, Losses 12 months or longer, Gross Unrealized Losses		1,827
Available for sale, Total, Fair Value	3,300	274,078
Available for sale, Total, Gross Unrealized Losses	21	3,142
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	3,498	1,467
Available for sale, Losses less than 12 months, Gross Unrealized Losses	2	33
Available for sale, Total, Fair Value	3,498	1,467
Available for sale, Total, Gross Unrealized Losses	$ 2	$ 33

Securities (Securities Held to

Securities (Securities Held to Maturity with Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Losses less than 12 months, Fair Value	$ 745	$ 33,161
Held to Maturity, Losses less than 12 months, Gross Unrealized Losses	2	619
Held to Maturity, Losses 12 months or longer, Fair Value	2,890	52,253
Held to Maturity, Losses 12 months or longer, Gross Unrealized Losses	15	489
Held to Maturity, Total, Fair Value	3,635	85,414
Held to Maturity, Total, Gross Unrealized Losses	17	1,108
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Losses less than 12 months, Fair Value	523	4,735
Held to Maturity, Losses less than 12 months, Gross Unrealized Losses	2	38
Held to Maturity, Losses 12 months or longer, Fair Value	2,890	3,143
Held to Maturity, Losses 12 months or longer, Gross Unrealized Losses	15	31
Held to Maturity, Total, Fair Value	3,413	7,878
Held to Maturity, Total, Gross Unrealized Losses	17	69
Commercial Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Losses less than 12 months, Fair Value	222	28,426
Held to Maturity, Losses less than 12 months, Gross Unrealized Losses		581
Held to Maturity, Total, Fair Value	$ 222	28,426
Held to Maturity, Total, Gross Unrealized Losses		581
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Losses 12 months or longer, Fair Value		49,110
Held to Maturity, Losses 12 months or longer, Gross Unrealized Losses		458
Held to Maturity, Total, Fair Value		49,110
Held to Maturity, Total, Gross Unrealized Losses		$ 458

Loans and Allowance for Credi_3

Loans and Allowance for Credit Losses (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)Customer	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)loanCustomer	Sep. 30, 2019USD ($)loan	Dec. 31, 2019USD ($)
Accounts Notes And Loans Receivable [Line Items]
Accrued interest	$ 86,000		$ 86,000		$ 67,700
Weighted average percentage of forecast	50.00%		50.00%
Loans held for sale	$ 103,566		$ 103,566		55,864
Provision for credit losses	24,999	$ 12,421	578,690	$ 38,552
Nonaccrual loans	171,462		171,462		245,833
Estimated interest income from nonaccrual loans not assigned to nonaccrual status			10,600	$ 9,900
TDRs both accruing and nonaccruing	49,100		49,100		193,700
Unfunded commitment to borrowers related to modified TDR	$ 1,000		1,000		2,400
TDRs and loans impaired with minimum aggregate relationship balances			$ 1,000
Number of customer loans excluded from TDR | Customer	817		817
Loans excluded from TDR disclosure			$ 564,800
Total Past Due	$ 218,965		218,965		260,818
Recorded Investment > 90 Days and Accruing	10,439		10,439		6,582
Purchased with credit deterioration, increase			19,800
30-59 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	20,417		20,417		83,693
60-89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	63,428		63,428		30,183
Greater Than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	135,120		135,120		146,942
Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	39,900		39,900		132,500
Number of TDRs subsequently defaulted | loan				0
Troubled Debt Restructurings [Member] | Loans With Extended Amortization Terms Or Other Payment Concessions [Member]
Accounts Notes And Loans Receivable [Line Items]
Extended terms and other payment concessions			700	$ 600
Troubled Debt Restructurings [Member] | Loans With Reduction Of Interest Rate [Member]
Accounts Notes And Loans Receivable [Line Items]
Reduced interest rate			1,100
Troubled Debt Restructurings [Member] | Loans With Significant Covenant Waivers [Member]
Accounts Notes And Loans Receivable [Line Items]
Covenant waivers			400	22,100
Troubled Debt Restructurings [Member] | Loans With Other Modifications [Member]
Accounts Notes And Loans Receivable [Line Items]
Other modifications			2,100	$ 7,400
Prior to Adoption of CEFL [member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 17,500		$ 17,500
Recorded Investment > 90 Days and Accruing					8,300
Prior to Adoption of CEFL [member] | 30-59 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due					6,100
Prior to Adoption of CEFL [member] | 60-89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due					2,000
Prior to Adoption of CEFL [member] | Greater Than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due					8,300
Downside Scenario S-1 [Member]
Accounts Notes And Loans Receivable [Line Items]
Weighted average percentage of forecast	25.00%		25.00%
Downside Scenario S-2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Weighted average percentage of forecast	25.00%		25.00%
Energy Related Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale	$ 497,000		$ 497,000
Charge-off			242,600
Release of credit loss reserves			82,500
Provision for credit losses			160,100
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	24,737		24,737		16,374
Total Past Due	26,992		26,992		34,702
Recorded Investment > 90 Days and Accruing	515		515		1,638
Real estate in process of foreclosure	11,200		11,200		8,600
Real estate acquired through foreclosure	3,600		3,600		6,300
Consumer [Member] | 30-59 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	9,451		9,451		18,586
Consumer [Member] | 60-89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	4,621		4,621		6,215
Consumer [Member] | Greater Than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	12,920		$ 12,920		9,901
Consumer [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | loan			2
TDRs subsequently defaulted, amount			$ 200
Commercial Non-Real Estate [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | loan			1
TDRs subsequently defaulted, amount			$ 400
Residential Mortgages [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | loan			1
TDRs subsequently defaulted, amount			$ 600
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	92,867		92,867		186,386
Total Past Due	100,527		100,527		147,830
Recorded Investment > 90 Days and Accruing	5,223		5,223		2,367
Total Commercial And Industrial [Member] | Total Commercial [Member] | 30-59 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	6,561		6,561		25,755
Total Commercial And Industrial [Member] | Total Commercial [Member] | 60-89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	16,553		16,553		14,001
Total Commercial And Industrial [Member] | Total Commercial [Member] | Greater Than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	$ 77,413		$ 77,413		108,074
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans interest bearing rate	1.00%		1.00%
Nonaccrual loans	$ 78,184		$ 78,184		178,678
Total Past Due	86,008		86,008		135,144
Recorded Investment > 90 Days and Accruing	5,110		5,110		1,537
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | 30-59 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	6,026		6,026		20,893
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | 60-89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	14,277		14,277		13,445
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | Greater Than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	$ 65,705		$ 65,705		$ 100,806
Total Commercial And Industrial [Member] | Minimum [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans term			2 years
Loans percentage of origination fee	1.00%		1.00%
Total Commercial And Industrial [Member] | Maximum [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans term			5 years
Loans percentage of origination fee	5.00%		5.00%

Loans and Allowance for Credi_4

Loans and Allowance for Credit Losses (Loans, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 22,240,204	$ 21,212,755	$ 21,035,952
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	2,754,388	2,990,631	3,004,958
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,945,918	2,164,818	2,152,325
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	3,406,554	2,994,448	3,060,568
Construction and Land Development [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,096,149	1,157,451	1,190,718
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	13,037,195	11,905,407	11,627,383
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	10,257,788	9,166,947	8,893,004
Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 2,779,407	$ 2,738,460	$ 2,734,379

Loans and Allowance for Credi_5

Loans and Allowance for Credit Losses (Allowance for Credit Losses by Portfolio Class) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			$ 191,251	$ 194,514
Allowance for loan losses: Net provision for loan losses	$ 24,999	$ 12,421	578,690	38,552
Allowance for loan losses: Ending balance	448,674	195,572	448,674	195,572
Reserve for unfunded lending commitments: Beginning balance			3,974
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			27,330
Reserve for unfunded lending commitments: Provision for losses			222
Reserve for unfunded lending commitments: Ending balance	31,526		31,526
Total allowance for credit losses	480,200		480,200		$ 271,966	$ 195,225
Allowance for loan losses: Individually evaluated	29,713	12,218	29,713	12,218
Allowance for loan losses: Amounts related to purchased credit impaired loans		8,823		8,823
Allowance for loan losses: Collectively evaluated	418,961	174,531	418,961	174,531
Reserve for unfunded lending commitments: Individually evaluated	997		997
Reserve for unfunded lending commitments: Collectively evaluated	30,529		30,529
Loans: Individually evaluated	101,637	225,138	101,637	225,138
Loans: Purchased credit impaired loans		228,620		228,620
Purchased credit impaired loans	22,138,567	20,582,194	22,138,567	20,582,194
Loans receivable	22,240,204	21,035,952	22,240,204	21,035,952		21,212,755
Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			49,411
Allowance for loan losses: Charge-offs			(381,979)	(47,365)
Allowance for loan losses: Recoveries			11,523	9,871
Allowance for loan losses: Net provision for loan losses			578,468	38,552
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			20,869	17,638
Allowance for loan losses: Ending balance	104,652	25,750	104,652	25,750
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			449
Reserve for unfunded lending commitments: Provision for losses			1,599
Reserve for unfunded lending commitments: Ending balance	2,048		2,048
Total allowance for credit losses	106,700		106,700
Allowance for loan losses: Individually evaluated	24	49	24	49
Allowance for loan losses: Amounts related to purchased credit impaired loans		40		40
Allowance for loan losses: Collectively evaluated	104,628	25,661	104,628	25,661
Reserve for unfunded lending commitments: Collectively evaluated	2,048		2,048
Loans: Individually evaluated	5,549	2,781	5,549	2,781
Loans: Purchased credit impaired loans		27,281		27,281
Purchased credit impaired loans	3,401,005	3,030,506	3,401,005	3,030,506
Loans receivable	3,406,554	3,060,568	3,406,554	3,060,568		2,994,448
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			9,350	15,647
Allowance for loan losses: Ending balance	29,695	9,766	29,695	9,766
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			15,658
Reserve for unfunded lending commitments: Provision for losses			6,046
Reserve for unfunded lending commitments: Ending balance	21,704		21,704
Total allowance for credit losses	51,399		51,399
Allowance for loan losses: Individually evaluated	169	29	169	29
Allowance for loan losses: Amounts related to purchased credit impaired loans		144		144
Allowance for loan losses: Collectively evaluated	29,526	9,593	29,526	9,593
Reserve for unfunded lending commitments: Collectively evaluated	21,704		21,704
Loans: Individually evaluated	1,837	3,385	1,837	3,385
Loans: Purchased credit impaired loans		23,431		23,431
Purchased credit impaired loans	1,094,312	1,163,902	1,094,312	1,163,902
Loans receivable	1,096,149	1,190,718	1,096,149	1,190,718		1,157,451
Total Commercial [Member] | Non-Purchased Credit Impaired Loans [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			7,287
Allowance for loan losses: Charge-offs			(2,211)	(10)
Allowance for loan losses: Recoveries			46	518
Allowance for loan losses: Net provision for loan losses			78,661	7,604
Total Commercial [Member] | Non-Purchased Credit Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			7,478
Allowance for loan losses: Charge-offs			(7)	(7)
Allowance for loan losses: Recoveries			549	108
Allowance for loan losses: Net provision for loan losses			12,325	(5,982)
Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			117,409	111,509
Allowance for loan losses: Ending balance	214,072	113,748	214,072	113,748
Reserve for unfunded lending commitments: Beginning balance			3,974
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			6,060
Reserve for unfunded lending commitments: Provision for losses			(3,599)
Reserve for unfunded lending commitments: Ending balance	6,435		6,435
Total allowance for credit losses	220,507		220,507
Allowance for loan losses: Individually evaluated	28,648	11,592	28,648	11,592
Allowance for loan losses: Amounts related to purchased credit impaired loans		307		307
Allowance for loan losses: Collectively evaluated	185,424	101,849	185,424	101,849
Reserve for unfunded lending commitments: Individually evaluated	992		992
Reserve for unfunded lending commitments: Collectively evaluated	5,443		5,443
Loans: Individually evaluated	84,263	213,088	84,263	213,088
Loans: Purchased credit impaired loans		78,164		78,164
Purchased credit impaired loans	12,952,932	11,336,131	12,952,932	11,336,131
Loans receivable	13,037,195	11,627,383	13,037,195	11,627,383		11,905,407
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			106,432	97,752
Allowance for loan losses: Ending balance	148,051	99,299	148,051	99,299
Reserve for unfunded lending commitments: Beginning balance			3,974
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			5,772
Reserve for unfunded lending commitments: Provision for losses			(3,786)
Reserve for unfunded lending commitments: Ending balance	5,960		5,960
Total allowance for credit losses	154,011		154,011
Allowance for loan losses: Individually evaluated	27,304	11,535	27,304	11,535
Allowance for loan losses: Amounts related to purchased credit impaired loans		135		135
Allowance for loan losses: Collectively evaluated	120,747	87,629	120,747	87,629
Reserve for unfunded lending commitments: Individually evaluated	992		992
Reserve for unfunded lending commitments: Collectively evaluated	4,968		4,968
Loans: Individually evaluated	73,139	201,979	73,139	201,979
Loans: Purchased credit impaired loans		33,040		33,040
Purchased credit impaired loans	10,184,649	8,657,985	10,184,649	8,657,985
Loans receivable	10,257,788	8,893,004	10,257,788	8,893,004		9,166,947
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			10,977	13,757
Allowance for loan losses: Ending balance	66,021	14,449	66,021	14,449
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			288
Reserve for unfunded lending commitments: Provision for losses			187
Reserve for unfunded lending commitments: Ending balance	475		475
Total allowance for credit losses	66,496		66,496
Allowance for loan losses: Individually evaluated	1,344	57	1,344	57
Allowance for loan losses: Amounts related to purchased credit impaired loans		172		172
Allowance for loan losses: Collectively evaluated	64,677	14,220	64,677	14,220
Reserve for unfunded lending commitments: Collectively evaluated	475		475
Loans: Individually evaluated	11,124	11,109	11,124	11,109
Loans: Purchased credit impaired loans		45,124		45,124
Purchased credit impaired loans	2,768,283	2,678,146	2,768,283	2,678,146
Loans receivable	2,779,407	2,734,379	2,779,407	2,734,379		2,738,460
Total Commercial [Member] | Total Commercial And Industrial [Member] | Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			14,633
Allowance for loan losses: Charge-offs			(365,951)	(33,519)
Allowance for loan losses: Recoveries			5,490	5,946
Allowance for loan losses: Net provision for loan losses			442,491	29,812
Total Commercial [Member] | Total Commercial And Industrial [Member] | Non-Purchased Credit Impaired Loans [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			(244)
Allowance for loan losses: Charge-offs			(364,123)	(33,382)
Allowance for loan losses: Recoveries			4,831	5,662
Allowance for loan losses: Net provision for loan losses			401,155	29,267
Total Commercial [Member] | Total Commercial And Industrial [Member] | Non-Purchased Credit Impaired Loans [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			14,877
Allowance for loan losses: Charge-offs			(1,828)	(137)
Allowance for loan losses: Recoveries			659	284
Allowance for loan losses: Net provision for loan losses			41,336	545
Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			20,331	23,782
Allowance for loan losses: Ending balance	51,773	21,479	51,773	21,479
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			17
Reserve for unfunded lending commitments: Provision for losses			(11)
Reserve for unfunded lending commitments: Ending balance	6		6
Total allowance for credit losses	51,779		51,779
Allowance for loan losses: Individually evaluated	416	183	416	183
Allowance for loan losses: Amounts related to purchased credit impaired loans		8,032		8,032
Allowance for loan losses: Collectively evaluated	51,357	13,264	51,357	13,264
Reserve for unfunded lending commitments: Collectively evaluated	6		6
Loans: Individually evaluated	6,064	4,301	6,064	4,301
Loans: Purchased credit impaired loans		93,450		93,450
Purchased credit impaired loans	2,748,324	2,907,207	2,748,324	2,907,207
Loans receivable	2,754,388	3,004,958	2,754,388	3,004,958		2,990,631
Residential Mortgages [Member] | Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			12,921
Allowance for loan losses: Charge-offs			(170)	(660)
Allowance for loan losses: Recoveries			1,078	433
Allowance for loan losses: Net provision for loan losses			17,613	(2,076)
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			23,292	25,938
Allowance for loan losses: Ending balance	48,482	24,829	48,482	24,829
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle			5,146
Reserve for unfunded lending commitments: Provision for losses			(3,813)
Reserve for unfunded lending commitments: Ending balance	1,333		1,333
Total allowance for credit losses	49,815		49,815
Allowance for loan losses: Individually evaluated	456	365	456	365
Allowance for loan losses: Amounts related to purchased credit impaired loans		300		300
Allowance for loan losses: Collectively evaluated	48,026	24,164	48,026	24,164
Reserve for unfunded lending commitments: Individually evaluated	5		5
Reserve for unfunded lending commitments: Collectively evaluated	1,328		1,328
Loans: Individually evaluated	3,924	1,583	3,924	1,583
Loans: Purchased credit impaired loans		6,294		6,294
Purchased credit impaired loans	1,941,994	2,144,448	1,941,994	2,144,448
Loans receivable	$ 1,945,918	$ 2,152,325	1,945,918	2,152,325		$ 2,164,818
Consumer [Member] | Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Cumulative effect of change in accounting principle			7,092
Allowance for loan losses: Charge-offs			(13,640)	(13,169)
Allowance for loan losses: Recoveries			4,360	2,866
Allowance for loan losses: Net provision for loan losses			$ 27,378	$ 9,194

Loans and Allowance for Credi_6

Loans and Allowance for Credit Losses (Composition of Nonaccrual Loans by Portfolio Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 171,462	$ 245,833
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	7,028	2,594
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,234	1,217
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	43,596	39,262
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	24,737	16,374
Total Commercial And Industrial [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	92,867	186,386
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	78,184	178,678
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 14,683	$ 7,708

Loans and Allowance for Credi_7

Loans and Allowance for Credit Losses (Troubled Debt Restructurings Modified by Portfolio Class) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	7	13	25	31
Pre-Modification Outstanding Recorded Investment	$ 1,383	$ 13,896	$ 4,273	$ 30,148
Post-Modification Outstanding Recorded Investment	$ 1,383	$ 7,084	$ 4,273	$ 23,336
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract		1		1
Pre-Modification Outstanding Recorded Investment		$ 123		$ 123
Post-Modification Outstanding Recorded Investment		$ 123		$ 123
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract		3	1	3
Pre-Modification Outstanding Recorded Investment		$ 323	$ 15	$ 323
Post-Modification Outstanding Recorded Investment		$ 323	$ 15	$ 323
Residential Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	5	3	14	10
Pre-Modification Outstanding Recorded Investment	$ 1,358	$ 297	$ 3,424	$ 2,199
Post-Modification Outstanding Recorded Investment	$ 1,358	$ 297	$ 3,424	$ 2,199
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	2	4	7	6
Pre-Modification Outstanding Recorded Investment	$ 25	$ 70	$ 89	$ 116
Post-Modification Outstanding Recorded Investment	$ 25	$ 70	$ 89	$ 116
Total Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract		2	3	11
Pre-Modification Outstanding Recorded Investment		$ 13,083	$ 745	$ 27,387
Post-Modification Outstanding Recorded Investment		$ 6,271	$ 745	$ 20,575
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract		2	3	10
Pre-Modification Outstanding Recorded Investment		$ 13,083	$ 745	$ 27,220
Post-Modification Outstanding Recorded Investment		$ 6,271	$ 745	$ 20,408
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract				1
Pre-Modification Outstanding Recorded Investment				$ 167
Post-Modification Outstanding Recorded Investment				$ 167

Loans and Allowance for Credi_8

Loans and Allowance for Credit Losses (Loans Individually Evaluated Disaggregated by Portfolio Class) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	$ 38,191		$ 38,191		$ 141,091
Recorded investment with an allowance	63,446		63,446		104,560
Unpaid principal balance	159,569		159,569		287,767
Related allowance for loan loss	29,713		29,713		22,385
Average recorded investment	108,922	$ 237,510	213,451	$ 251,635
Interest income recognized	89	1,139	911	4,485
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	5,453		5,453		373
Recorded investment with an allowance	96		96		1,525
Unpaid principal balance	7,016		7,016		1,959
Related allowance for loan loss	24		24		18
Average recorded investment	5,886	2,331	5,749	2,430
Interest income recognized	6	7	18	21
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	667		667
Recorded investment with an allowance	1,170		1,170		277
Unpaid principal balance	1,838		1,838		322
Related allowance for loan loss	169		169		21
Average recorded investment	1,422	1,702	1,805	597
Interest income recognized	3	2	7	2
Residential Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	2,890		2,890		3,383
Recorded investment with an allowance	3,174		3,174		1,791
Unpaid principal balance	6,869		6,869		5,709
Related allowance for loan loss	416		416		217
Average recorded investment	5,887	4,195	5,318	4,525
Interest income recognized	22	2	43	9
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	1,592		1,592		479
Recorded investment with an allowance	2,332		2,332		1,004
Unpaid principal balance	3,924		3,924		1,906
Related allowance for loan loss	456		456		292
Average recorded investment	3,947	1,552	2,651	1,442
Interest income recognized	21	21	67	55
Total Commercial And Industrial [Member] | Total Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	27,589		27,589		136,856
Recorded investment with an allowance	56,674		56,674		99,963
Unpaid principal balance	139,922		139,922		277,871
Related allowance for loan loss	28,648		28,648		21,837
Average recorded investment	91,780	227,730	197,928	242,641
Interest income recognized	37	1,107	776	4,398
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	20,689		20,689		134,191
Recorded investment with an allowance	52,450		52,450		98,247
Unpaid principal balance	125,893		125,893		270,078
Related allowance for loan loss	27,304		27,304		21,733
Average recorded investment	81,227	213,291	190,622	225,597
Interest income recognized	37	1,062	776	4,202
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	6,900		6,900		2,665
Recorded investment with an allowance	4,224		4,224		1,716
Unpaid principal balance	14,029		14,029		7,793
Related allowance for loan loss	1,344		1,344		$ 104
Average recorded investment	$ 10,553	14,439	$ 7,306	17,044
Interest income recognized		$ 45		$ 196

Loans and Allowance for Credi_9

Loans and Allowance for Credit Losses (Aging Analysis of Past Due Loans by Portfolio Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 218,965	$ 260,818
Current	22,021,239	20,951,937
Total loans	22,240,204	21,212,755	$ 21,035,952
Recorded Investment > 90 Days and Accruing	10,439	6,582
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	20,417	83,693
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	63,428	30,183
Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	135,120	146,942
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	39,104	4,351
Current	3,367,450	2,990,097
Total loans	3,406,554	2,994,448	3,060,568
Recorded Investment > 90 Days and Accruing	2,490	450
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	165	738
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	30,238	703
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,701	2,910
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,491	8,907
Current	1,091,658	1,148,544
Total loans	1,096,149	1,157,451	1,190,718
Recorded Investment > 90 Days and Accruing	393	2,042
Total Commercial [Member] | Construction and Land Development [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,076	5,747
Total Commercial [Member] | Construction and Land Development [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	237	680
Total Commercial [Member] | Construction and Land Development [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,178	2,480
Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	100,527	147,830
Current	12,936,668	11,757,577
Total loans	13,037,195	11,905,407	11,627,383
Recorded Investment > 90 Days and Accruing	5,223	2,367
Total Commercial [Member] | Total Commercial And Industrial [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,561	25,755
Total Commercial [Member] | Total Commercial And Industrial [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	16,553	14,001
Total Commercial [Member] | Total Commercial And Industrial [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	77,413	108,074
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	86,008	135,144
Current	10,171,780	9,031,803
Total loans	10,257,788	9,166,947	8,893,004
Recorded Investment > 90 Days and Accruing	5,110	1,537
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,026	20,893
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	14,277	13,445
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	65,705	100,806
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	14,519	12,686
Current	2,764,888	2,725,774
Total loans	2,779,407	2,738,460	2,734,379
Recorded Investment > 90 Days and Accruing	113	830
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	535	4,862
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,276	556
Total Commercial [Member] | Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	11,708	7,268
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	47,851	65,028
Current	2,706,537	2,925,603
Total loans	2,754,388	2,990,631	3,004,958
Recorded Investment > 90 Days and Accruing	1,818	85
Residential Mortgages [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,164	32,867
Residential Mortgages [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	11,779	8,584
Residential Mortgages [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	32,908	23,577
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	26,992	34,702
Current	1,918,926	2,130,116
Total loans	1,945,918	2,164,818	$ 2,152,325
Recorded Investment > 90 Days and Accruing	515	1,638
Consumer [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	9,451	18,586
Consumer [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,621	6,215
Consumer [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 12,920	$ 9,901

Loans and Allowance for Cred_10

Loans and Allowance for Credit Losses (Credit Quality Indicators by Segments and Portfolio Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 17,539,898	$ 16,057,306
Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	13,037,195	11,905,407
Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	16,520,746	15,014,111
Total Commercial [Member] | Pass [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	12,180,378	11,009,561
Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	607,567	462,502
Total Commercial [Member] | Pass-Watch [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	495,980	367,116
Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	124,626	101,583
Total Commercial [Member] | Special Mention [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	122,395	86,305
Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	286,959	479,110
Total Commercial [Member] | Substandard [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	238,442	442,425
Residential Mortgages [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,754,388	2,990,631
Residential Mortgages [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,708,484	2,950,854
Residential Mortgages [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	45,904	39,777
Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,945,918	2,164,818
Consumer [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,920,049	2,147,312
Consumer [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	25,869	17,506
Residential Mortgage and Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,700,306	5,155,449
Residential Mortgage and Consumer [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,628,533	5,098,166
Residential Mortgage and Consumer [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	71,773	57,283
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	10,257,788	9,166,947
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Pass [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,617,743	8,492,113
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Pass-Watch [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	368,292	220,850
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Special Mention [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	85,096	71,654
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Substandard [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	186,657	382,330
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,779,407	2,738,460
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Pass [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,562,635	2,517,448
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Pass-Watch [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	127,688	146,266
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Special Mention [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	37,299	14,651
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Substandard [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	51,785	60,095
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,406,554	2,994,448
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,278,116	2,883,553
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	83,736	69,765
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,021	14,995
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	42,681	26,135
Construction and Land Development [Member] | Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,096,149	1,157,451
Construction and Land Development [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,062,252	1,120,997
Construction and Land Development [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	27,851	25,621
Construction and Land Development [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	210	283
Construction and Land Development [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 5,836	$ 10,550

Loans and Allowance for Cred_11

Loans and Allowance for Credit Losses (Disaggregation of Credit Quality Disclosures) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	$ 5,133,272
Term Loans, Amortized Cost Basis by Origination Year, 2019	3,236,052
Term Loans, Amortized Cost Basis by Origination Year, 2018	2,085,143
Term Loans, Amortized Cost Basis by Origination Year, 2017	1,641,803
Term Loans, Amortized Cost Basis by Origination Year, 2016	1,169,989
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,586,835
Revolving Loans	2,584,861
Revolving Loans Converted to Term Loans	101,943
Notes Receivable Gross	17,539,898	$ 16,057,306
Total Commercial [Member] | Pass [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	4,980,953
Term Loans, Amortized Cost Basis by Origination Year, 2019	3,098,996
Term Loans, Amortized Cost Basis by Origination Year, 2018	1,979,152
Term Loans, Amortized Cost Basis by Origination Year, 2017	1,508,213
Term Loans, Amortized Cost Basis by Origination Year, 2016	1,067,144
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,417,583
Revolving Loans	2,385,763
Revolving Loans Converted to Term Loans	82,942
Notes Receivable Gross	16,520,746	15,014,111
Total Commercial [Member] | Pass-Watch [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	70,389
Term Loans, Amortized Cost Basis by Origination Year, 2019	101,741
Term Loans, Amortized Cost Basis by Origination Year, 2018	56,681
Term Loans, Amortized Cost Basis by Origination Year, 2017	78,598
Term Loans, Amortized Cost Basis by Origination Year, 2016	53,259
Term Loans, Amortized Cost Basis by Origination Year, Prior	116,413
Revolving Loans	125,134
Revolving Loans Converted to Term Loans	5,352
Notes Receivable Gross	607,567	462,502
Total Commercial [Member] | Special Mention [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	5,687
Term Loans, Amortized Cost Basis by Origination Year, 2019	13,763
Term Loans, Amortized Cost Basis by Origination Year, 2018	24,805
Term Loans, Amortized Cost Basis by Origination Year, 2017	17,888
Term Loans, Amortized Cost Basis by Origination Year, 2016	31,355
Term Loans, Amortized Cost Basis by Origination Year, Prior	2,268
Revolving Loans	25,960
Revolving Loans Converted to Term Loans	2,900
Notes Receivable Gross	124,626	101,583
Total Commercial [Member] | Substandard [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	76,243
Term Loans, Amortized Cost Basis by Origination Year, 2019	21,552
Term Loans, Amortized Cost Basis by Origination Year, 2018	24,505
Term Loans, Amortized Cost Basis by Origination Year, 2017	37,104
Term Loans, Amortized Cost Basis by Origination Year, 2016	18,231
Term Loans, Amortized Cost Basis by Origination Year, Prior	50,571
Revolving Loans	48,004
Revolving Loans Converted to Term Loans	10,749
Notes Receivable Gross	286,959	479,110
Residential Mortgage and Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	353,072
Term Loans, Amortized Cost Basis by Origination Year, 2019	505,712
Term Loans, Amortized Cost Basis by Origination Year, 2018	495,188
Term Loans, Amortized Cost Basis by Origination Year, 2017	640,043
Term Loans, Amortized Cost Basis by Origination Year, 2016	541,558
Term Loans, Amortized Cost Basis by Origination Year, Prior	937,148
Revolving Loans	1,215,976
Revolving Loans Converted to Term Loans	11,609
Notes Receivable Gross	4,700,306	5,155,449
Residential Mortgage and Consumer [Member] | Performing [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	351,828
Term Loans, Amortized Cost Basis by Origination Year, 2019	501,172
Term Loans, Amortized Cost Basis by Origination Year, 2018	489,007
Term Loans, Amortized Cost Basis by Origination Year, 2017	629,621
Term Loans, Amortized Cost Basis by Origination Year, 2016	536,380
Term Loans, Amortized Cost Basis by Origination Year, Prior	901,979
Revolving Loans	1,212,937
Revolving Loans Converted to Term Loans	5,609
Notes Receivable Gross	4,628,533	5,098,166
Residential Mortgage and Consumer [Member] | Nonperforming [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	1,244
Term Loans, Amortized Cost Basis by Origination Year, 2019	4,540
Term Loans, Amortized Cost Basis by Origination Year, 2018	6,181
Term Loans, Amortized Cost Basis by Origination Year, 2017	10,422
Term Loans, Amortized Cost Basis by Origination Year, 2016	5,178
Term Loans, Amortized Cost Basis by Origination Year, Prior	35,169
Revolving Loans	3,039
Revolving Loans Converted to Term Loans	6,000
Notes Receivable Gross	$ 71,773	$ 57,283

Loans and Allowance for Cred_12

Loans and Allowance for Credit Losses (Changes in Carrying Amount of Purchased Credit Impaired Loans and Related Accretable Yield) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Receivables [Abstract]
Carrying Amount of Loans, Balance at beginning of period	$ 129,596
Carrying Amount of Loans, Additions	120,562
Carrying Amount of Loans, Payments received, net	(48,076)
Carrying Amount of Loans, Accretion	13,163
Carrying Amount of Loans, Balance at end of period	215,245
Accretable Yield, Balance at beginning of period	37,294
Accretable Yield, Additions	6,246
Accretable Yield, Payments received, net	(4,601)
Accretable Yield, Accretion	(13,163)
Accretable Yield, Decrease in expected cash flows based on actual cash flows and changes in cash flow assumptions	4,170
Accretable Yield, Balance at end of period	$ 29,946

Securities Sold under Agreeme_2

Securities Sold under Agreements to Repurchase (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Brokers And Dealers [Abstract]
Securities sold under agreements to repurchase	$ 806.6	$ 484.4

Long-Term Debt (Long-Term Debt)

Long-Term Debt (Long-Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Gross long-term debt	$ 396,209
Less: unamortized debt issuance costs	(10,322)	$ (4,428)
Total long-term debt	385,887	233,462
Subordinated Notes [Member] | Subordinated Notes Payable, Maturing June 2045 [Member]
Debt Instrument [Line Items]
Gross long-term debt	150,000	150,000
Less: unamortized debt issuance costs	(4,296)
Subordinated Notes [Member] | Subordinated Notes Payable, Maturing June 2060 [Member]
Debt Instrument [Line Items]
Gross long-term debt	172,500
Less: unamortized debt issuance costs	(6,026)
Other Long-Term Debt [Member]
Debt Instrument [Line Items]
Gross long-term debt	$ 73,709	$ 87,890

Long-Term Debt (Long-Term Debt

Long-Term Debt (Long-Term Debt with Related Unamortized Debt Issuance Cost) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Principal	$ 396,209
Unamortized Debt Issuance Costs	10,322	$ 4,428
Subordinated Notes [Member] | Subordinated Notes Payable, Maturing June 2045 [Member]
Debt Instrument [Line Items]
Principal	150,000	150,000
Unamortized Debt Issuance Costs	4,296
Subordinated Notes [Member] | Subordinated Notes Payable, Maturing June 2060 [Member]
Debt Instrument [Line Items]
Principal	172,500
Unamortized Debt Issuance Costs	6,026
Other Long-Term Debt [Member]
Debt Instrument [Line Items]
Principal	$ 73,709	$ 87,890

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Notes payable aggregate principal amount	$ 396,209
Other long-term debt maturity year	2053
Subordinated Notes [Member] | Subordinated Notes Payable, Maturing June 2060 [Member]
Debt Instrument [Line Items]
Notes payable issuance date	Jun. 9, 2020
Notes payable aggregate principal amount	$ 172,500
Notes payable maturity date	Jun. 15, 2060
Notes payable interest rate	6.25%
Notes payable beginning payment date	Sep. 15, 2020
Notes payable redemption start date	Jun. 15, 2025
Subordinated Notes [Member] | Subordinated Notes Payable, Maturing June 2045 [Member]
Debt Instrument [Line Items]
Notes payable issuance date	Mar. 9, 2015
Notes payable aggregate principal amount	$ 150,000	$ 150,000
Notes payable maturity date	Jun. 15, 2045
Notes payable interest rate	5.95%
Notes payable beginning payment date	2015-06
Notes payable redemption start date	Jun. 15, 2020
Other Long-Term Debt [Member]
Debt Instrument [Line Items]
Notes payable aggregate principal amount	$ 73,709	$ 87,890
Notes payable agreement period	7 years

Derivatives (Fair Values of Der

Derivatives (Fair Values of Derivative Financial Instruments) (Details) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2020	Dec. 31, 2019
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		$ 7,440,628	$ 6,010,689
Fair Values, Assets			23
Less: netting adjustment, Assets	[1],[2]	(58,254)	(27,056)
Fair Values, Liabilities		47,042	11,953
Less: netting adjustment, Liabilities	[1],[2]	(146,415)	(43,914)
Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	227,076	81,502
Total derivative assets/liabilities	[1]	168,822	54,446
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Total derivative assets/liabilities	[1]	56,278	21,089
Fair Values, Liabilities	[1]	202,693	65,003
Derivatives Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		1,937,650	1,659,400
Derivatives Designated as Hedging Instruments [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	58,254	25,646
Derivatives Designated as Hedging Instruments [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	24,203	2,105
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		5,502,978	4,351,289
Derivatives Not Designated as Hedging Instruments [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	168,822	55,856
Derivatives Not Designated as Hedging Instruments [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	178,490	62,898
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount	[3]	4,560,306	3,759,232
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1],[3]	164,273	54,512
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1],[3]	168,207	55,664
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		205,787	254,825
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	78	21
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	136	45
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		345,871	145,623
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	82	651
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	3,584	744
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		265,957	83,224
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	2,452	369
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	59	375
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		81,492	64,632
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	1,937	303
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	1,888	366
Derivatives Not Designated as Hedging Instruments [Member] | Visa Class B derivative contract [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		43,565	43,753
Derivatives Not Designated as Hedging Instruments [Member] | Visa Class B derivative contract [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	4,616	5,704
Cash Flow Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Variable Rate Loans [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		1,175,000	1,175,000
Cash Flow Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Variable Rate Loans [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	57,412	24,172
Cash Flow Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Variable Rate Loans [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]		337
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Securities [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		762,650	441,400
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Securities [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	842	1,474
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Securities [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	$ 24,203	1,759
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Brokered Deposits [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount			43,000
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps - Brokered Deposits [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]		$ 9
[1]	Derivative assets and liabilities are reported at fair value in other assets or other liabilities, respectively, in the consolidated balance sheets.
[2]	Represents balance sheet netting of derivative assets and liabilities for variation margin collateral held or placed with the same central clearing counterparty. See offsetting assets and liabilities for further information.
[3]	The notional amount represents both the customer accommodation agreements and offsetting agreements with unrelated financial institutions

Derivatives (Narrative) (Detail

Derivatives (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative [Line Items]
Notional amount of derivatives	$ 7,440,628		$ 6,010,689
Derivative instrument associated loans on deferrals, receivable amount	100
Fair value liability	4,600		5,700
Credit risk-related contingent features, net liability position	47,100		12,900
Credit risk-related contingent features, posted collateral	47,800		12,400
Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional amount of derivatives	1,937,650		1,659,400
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member]
Derivative [Line Items]
Amortization of accumulated other comprehensive loss on terminated cash flow hedges	1,400	$ 3,400
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Swap Agreement 4, Expires 2021 [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 50,000
Derivative maturity expiration year	2021
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Swap Agreement 1, Expires 2022 [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 475,000
Derivative maturity expiration year	2022
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Swap Agreement 2, Expires 2023 [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 550,000
Derivative maturity expiration year	2023
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Swap Agreement 3, Expires 2024 [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 100,000
Derivative maturity expiration year	2024
Interest Rate Swaps - Securities [Member] | Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 762,650		$ 441,400
Derivative hedged item	752,500
Basis adjustment associated with hedged items	23,800
Interest Rate Swaps - Securities [Member] | Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member] | Commercial Mortgage-Backed Securities [Member]
Derivative [Line Items]
Amortized cost basis of closed portfolio of pre-payable securities	$ 823,600

Derivatives (Effects of Derivat

Derivatives (Effects of Derivative Instruments on the Statements of Income) (Details) - Derivatives Designated as Hedging Instruments [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	$ 7,520	$ 3,140	$ 21,046	$ 2,424
Other Noninterest Income [Member] | All Other Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	1,739	4,324	9,718	8,733
Cash Flow Hedge [Member] | Interest Income [Member] | Variable Rate Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	5,788	(956)	11,249	(4,632)
Fair Value Hedging [Member] | Interest Income [Member] | Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	$ (7)	15	33	15
Fair Value Hedging [Member] | Interest Expense [Member] | Brokered Deposits [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement		$ (243)	$ 46	$ (1,692)

Derivatives (Offsetting Derivat

Derivatives (Offsetting Derivative Assets and Liabilities Subject to Master Netting Arrangements) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Gross Amounts Recognized, Derivative Assets	$ 60,231	$ 27,938
Gross Amounts Offset in the Statement of Financial Condition, Derivative Assets	(60,231)	(27,915)
Net Amounts Presented in the Statement of Financial Condition, Derivative Assets		23
Gross Amounts Not Offset in the Statement of Financial Condition - Financial Instruments, Derivative Assets		23
Gross Amounts Recognized, Derivative Liabilities	195,780	56,523
Gross Amounts Offset in the Statement of Financial Condition, Derivative Liabilities	(148,738)	(44,570)
Net Amounts Presented in the Statement of Financial Condition, Derivative Liabilities	47,042	11,953
Gross Amounts Not Offset in the Statement of Financial Condition - Financial Instruments, Derivative Liabilities		23
Gross Amounts Not offset in the Statement of Financial Condition - Cash Collateral, Derivative Liabilities	87,926	35,113
Net Amounts Presented in the Statement of Financial Condition, Derivative Liabilities	$ (40,884)	$ (23,183)

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 18, 2020	Oct. 21, 2019	Sep. 23, 2019	Sep. 21, 2019	Jan. 31, 2020	Sep. 30, 2020	Mar. 27, 2020	Dec. 31, 2019	Oct. 18, 2019
Equity, Class of Treasury Stock [Line Items]
Treasury stock shares						5,200,000		4,000,000
Treasury stock, Cost basis						$ 176,100		$ 135,800
Payments for repurchase of common stock						$ 12,716
Implementation CECL [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital modified transition amount percentage							25.00%
Implementation CECL [Member] | Regulatory Capital Transition For First Two Years [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage							0.00%
Implementation CECL [Member] | Regulatory Capital Three Year Transition, Year 2022 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage							25.00%
Implementation CECL [Member] | Regulatory Capital Three Year Transition, Year 2023 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage							50.00%
Implementation CECL [Member] | Regulatory Capital Three Year Transition, Year 2024 [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage							75.00%
Implementation CECL [Member] | Regulatory Capital Three Year Transition, Year 2024 and Thereafter [Member]
Equity, Class of Treasury Stock [Line Items]
Regulatory capital transition percentage							100.00%
Accelerated Share Repurchase Agreement | Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized for repurchase						5,500,000
Share repurchase, authorized amount									$ 185,000
Payments for repurchase of common stock		$ 185,000
Shares repurchased	1,000,000	3,611,870			315,851	4,900,000
Percentage of shares repurchased among authorized		75.00%
Proceeds from repurchase of common stock	$ 12,100
Shares purchased price per share					$ 40.26	$ 37.65
2018 Stock Buyback Program [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized for repurchase			5,500,000
Stock repurchase expiration date			Dec. 31, 2020
MidSouth [Member]
Equity, Class of Treasury Stock [Line Items]
Shares issued				5,000,000
Business combination, price per share				$ 38.42
Restricted Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares nonvested						1,400,000		1,400,000

Stockholders' Equity (Component

Stockholders' Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (54,724)	$ (180,709)
Net change in unrealized gain or loss	$ 425	$ 34,159	217,254	160,627
Reclassification of net income or loss realized and included in earnings	(4,076)	3,280	(6,593)	11,483
Valuation adjustment to employee benefit plans			(10,251)	(7,015)
Amortization of unrealized net loss (gain) on securities transferred to HTM	(89)	954	(378)	2,435
Income tax expense	48	7,331	46,370	37,977
Ending Balance	98,938	(51,156)	98,938	(51,156)
Equity Method Investment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(434)
Net change in unrealized gain or loss			(4,935)	(434)
Ending Balance	(5,369)	(434)	(5,369)	(434)
Accumulated Other Comprehensive Loss Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			28,950	(50,125)
Net change in unrealized gain or loss			176,009	125,589
Income tax expense			39,817	28,395
Ending Balance	165,142	47,069	165,142	47,069
Held to Maturity Securities Transferred from AFS [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			639	(12,044)
Amortization of unrealized net loss (gain) on securities transferred to HTM			(378)	2,435
Income tax expense			(85)	551
Ending Balance	346	(10,160)	346	(10,160)
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(101,278)	(110,247)
Reclassification of net income or loss realized and included in earnings			4,656	6,851
Valuation adjustment to employee benefit plans			(10,251)	(7,015)
Income tax expense			(1,265)	(37)
Ending Balance	(105,608)	(110,374)	(105,608)	(110,374)
Gains and Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			17,399	(8,293)
Net change in unrealized gain or loss			46,180	35,472
Reclassification of net income or loss realized and included in earnings			(11,249)	4,632
Income tax expense			7,903	9,068
Ending Balance	$ 44,427	$ 22,743	$ 44,427	$ 22,743

Stockholders' Equity (Line Item

Stockholders' Equity (Line Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items		$ (10,251)	$ (7,015)
Employee Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items		(10,251)	(7,015)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications, net of tax	[1]	5,394	(10,774)
Reclassification out of Accumulated Other Comprehensive Income | Held to Maturity Securities Transferred from AFS [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of unrealized net gain or loss or gain on securities transferred to HTM	[1]	378	(2,435)
Tax effect	[1]	(85)	551
Net of tax	[1]	293	(1,884)
Reclassification out of Accumulated Other Comprehensive Income | Employee Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items	[1],[2]	(4,656)	(6,851)
Tax effect	[1]	1,053	1,546
Net of tax	[1]	(3,603)	(5,305)
Reclassification out of Accumulated Other Comprehensive Income | Gains and Losses on Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification of unrealized gain (loss) on cash flow hedges	[1]	12,602	(1,200)
Tax effect	[1]	(2,851)	271
Net of tax	[1]	9,751	(929)
Amortization of loss on terminated cash flow hedges	[1]	(1,353)	(3,432)
Tax effect	[1]	306	776
Net of tax	[1]	$ (1,047)	$ (2,656)
[1]	Amounts in parentheses indicate reduction in net income.
[2]	These AOCI components are included in the computation of net periodic pension and post-retirement cost that is reported with other noninterest expense (see Note 12 – Retirement Plans for additional details).

Other Noninterest Income (Compo

Other Noninterest Income (Components of Other Noninterest Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Income Disclosure Nonoperating [Abstract]
Income from bank-owned life insurance	$ 6,628	$ 4,147	$ 14,211	$ 11,495
Credit related fees	2,911	2,988	8,585	8,520
Income from derivatives	1,739	4,324	9,718	8,733
Other miscellaneous	3,521	4,866	11,598	12,025
Total other noninterest income	$ 14,799	$ 16,325	$ 44,112	$ 40,773

Other Noninterest Expense (Deta

Other Noninterest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Expense Disclosure Nonoperating [Abstract]
Advertising	$ 3,159	$ 5,435	$ 10,089	$ 11,768
Corporate value and franchise taxes	4,872	4,109	13,649	12,366
Telecommunications and postage	4,043	3,610	11,483	10,439
Entertainment and contributions	1,315	2,765	7,146	8,215
Travel expense	309	1,172	1,816	3,614
Printing and supplies	1,271	1,459	4,006	3,720
Tax credit investment amortization	961	1,286	2,882	3,658
Net other retirement expense (income)	(6,337)	(4,152)	(18,796)	(12,409)
Other miscellaneous	5,105	17,374	17,751	29,653
Total other noninterest expense	$ 14,698	$ 33,058	$ 50,026	$ 71,024

Earnings (Loss) Per Common Sh_3

Earnings (Loss) Per Common Share (Computation of Earnings (Loss) Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income (loss) to common shareholders	$ 79,356	$ 67,807	$ (148,749)	$ 235,248
Net dividends or income allocated to participating securities - basic and diluted	1,435	1,141	1,278	3,980
Net income (loss) allocated to common shareholders - basic and diluted	$ 77,921	$ 66,666	$ (150,027)	$ 231,268
Weighted-average common shares - basic	86,358	86,377	86,614	85,934
Dilutive potential common shares	42	85		76
Weighted-average common shares - diluted	86,400	86,462	86,614	86,010
Earnings per common share: Basic	$ 0.90	$ 0.77	$ (1.73)	$ 2.69
Earnings per common share: Diluted	$ 0.90	$ 0.77	$ (1.73)	$ 2.69

Earnings (Loss) Per Common Sh_4

Earnings (Loss) Per Common Share (Narrative) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted-average anti-dilutive potential common shares	78,867	43,794	0	37,680

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2019	Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Contributed to pension plan	$ 100
Newly eligible associates initial savings rate		3.00%
First 1% Of Contribution Saved [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage		100.00%
Percentage of compensation saved		1.00%
Next 5% Of Contribution Saved [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage		50.00%
Percentage of compensation saved		5.00%
Amended Hancock 401K Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Additional matching percentage		2.00%
Period of employment for eligibility		3 years
Amended Hancock 401K Plan [Member] | 4% Of Contribution [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage		4.00%
Amended Hancock 401K Plan [Member] | 6% Of Contribution [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage		6.00%
Amended Hancock 401K Plan [Member] | 2% Of Contribution [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage		2.00%

Retirement Plans (Components of

Retirement Plans (Components of Net Periodic Benefits Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,207	$ 2,735	$ 9,690	$ 8,245
Interest cost	3,892	4,659	12,315	14,183
Expected return on plan assets	(12,047)	(11,299)	(36,144)	(33,899)
Amortization of net loss and prior service costs	1,854	2,553	5,168	7,535
Net reduction of periodic benefit cost	(3,094)	(1,352)	(8,971)	(3,936)
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	28	22	78	73
Interest cost	106	165	377	457
Amortization of net loss and prior service costs	(142)	(229)	(512)	(684)
Net reduction of periodic benefit cost	$ (8)	$ (42)	$ (57)	$ (154)

Share-Based Payment Arrangeme_3

Share-Based Payment Arrangements (Narrative) (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)entity$ / sharesshares	Sep. 30, 2019USD ($)
Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, outstanding	28,725
Number of shares, exercisable	28,725
Weighted average exercise price | $ / shares	$ 34.11
Weighted average remaining contractual term	1 year 4 months 24 days
Aggregate intrinsic value | $	$ 0
Stock options exercised	0
Intrinsic value of options exercised | $	$ 200
Restricted and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense | $	$ 44,800
Weighted-average period	3 years
Total fair value of shares vested | $	$ 1,400	$ 1,300
Shares granted	131,025
Grant date fair value per share | $ / shares	$ 31.81
Performance Shares [Member] | Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	3 years
Performance Shares [Member] | Total Shareholder Return [Member] | Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	35,754
Grant date fair value per share | $ / shares	$ 46.61
Vesting performance period	3 years
Number of peer group regional banks | entity	47
Performance Shares [Member] | Total Shareholder Return [Member] | Executive Management [Member] | Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of maximum number of shares vested	200.00%
Performance Shares [Member] | Operating Earnings Per Share [Member] | Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	35,754
Grant date fair value per share | $ / shares	$ 39.39
Vesting performance period	2 years

Share-Based Payment Arrangeme_4

Share-Based Payment Arrangements (Summary of Nonvested Restricted and Performance Shares) (Details) - Restricted and Performance Shares [Member]	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Nonvested at Beginning | shares	1,596,258
Number of Shares, Granted | shares	131,025
Number of Shares, Vested | shares	(32,706)
Number of Shares, Forfeited | shares	(55,814)
Number of Shares, Nonvested at Ending | shares	1,638,763
Weighted Average Grant Date Fair Value, Nonvested at Beginning | $ / shares	$ 40.43
Weighted Average Grant Date Fair Value, Granted | $ / shares	31.81
Weighted Average Grant Date Fair Value, Vested | $ / shares	41.39
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	41.21
Weighted Average Grant Date Fair Value, Nonvested at Ending | $ / shares	$ 39.70

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Reserve for unfunded lending commitments	$ 31,526	$ 31,304	$ 3,974

Commitments and Contingencies_3

Commitments and Contingencies (Off-Balance Sheet Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Commitments to Extend Credit [Member]
Loss Contingencies [Line Items]
Contract amounts	$ 7,803,139	$ 7,530,143
Letters of Credit [Member]
Loss Contingencies [Line Items]
Contract amounts	$ 369,538	$ 393,284

Fair Value Measurements (Financ

Fair Value Measurements (Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		$ 5,647,315	$ 4,675,304
Derivative assets			23
Derivative liabilities		47,042	11,953
Total recurring fair value measurements - liabilities		4,600	5,700
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		5,647,315	4,675,304
Derivative assets	[1]	168,822	54,446
Total fair value measurements		5,816,137	4,729,750
Derivative liabilities	[1]	56,278	21,089
Total recurring fair value measurements - liabilities		56,278	21,089
Recurring [Member] | U.S. Treasury And Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		198,616	98,672
Recurring [Member] | Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		313,656	249,805
Recurring [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		8,183	7,988
Recurring [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		2,606,690	1,924,157
Recurring [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		2,101,000	1,586,467
Recurring [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		419,170	808,215
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		5,647,315	4,675,304
Derivative assets	[1]	168,822	54,446
Total fair value measurements		5,816,137	4,729,750
Derivative liabilities	[1]	51,662	15,385
Total recurring fair value measurements - liabilities		51,662	15,385
Recurring [Member] | Level 2 [Member] | U.S. Treasury And Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		198,616	98,672
Recurring [Member] | Level 2 [Member] | Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		313,656	249,805
Recurring [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		8,183	7,988
Recurring [Member] | Level 2 [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		2,606,690	1,924,157
Recurring [Member] | Level 2 [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		2,101,000	1,586,467
Recurring [Member] | Level 2 [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		419,170	808,215
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	[1]	4,616	5,704
Total recurring fair value measurements - liabilities		$ 4,616	$ 5,704
[1]	For further disaggregation of derivative assets and liabilities, see Note 7 - Derivatives.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - Recurring [Member]	Sep. 30, 2020shares
Visa Inc [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Number of shares of Visa Class B common stock	192,163
Investment Securities [Member] | Minimum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Targeted duration	2 years
Investment Securities [Member] | Maximum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Targeted duration	5 years 6 months

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Level 3 Fair Value Rollforward) (Details) - Level 3 [Member] - Recurring [Member] - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 5,704	$ 7,304
Cash settlement	(1,243)	(1,900)
Losses included in earnings	155	300
Ending balance	$ 4,616	$ 5,704

Fair Value Measurements (Overvi

Fair Value Measurements (Overview of the Valuation Techniques and Significant Unobservable Inputs) (Details) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Values, Liabilities		$ 47,042	$ 11,953
Recurring [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Values, Liabilities	[1]	56,278	21,089
Recurring [Member] | Level 3 [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Values, Liabilities	[1]	4,616	5,704
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Values, Liabilities		$ 4,616	$ 5,704
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Minimum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Time until resolution		3 months	12 months
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Maximum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Time until resolution		27 months	36 months
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, VISA Class A Appreciation [Member] | Minimum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Values Utilized		6	6
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, VISA Class A Appreciation [Member] | Maximum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Values Utilized		18	18
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, VISA Class A Appreciation [Member] | Weighted Average [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Values Utilized		12	12
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Conversion Rate [Member] | Minimum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Values Utilized		1.63	1.63
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Conversion Rate [Member] | Maximum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Values Utilized		1.59	1.59
Recurring [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Conversion Rate [Member] | Weighted Average [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Values Utilized		1.6109	1.616
[1]	For further disaggregation of derivative assets and liabilities, see Note 7 - Derivatives.

Fair Value Measurements (Fina_2

Fair Value Measurements (Financial Assets Measured at Fair Value on Nonrecurring Basis) (Details) - Nonrecurring [Member] - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral-dependent impaired loans	$ 91,819	$ 182,377
Other real estate owned and foreclosed assets, net	11,219	24,422
Total fair value measurements	103,038	206,799
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral-dependent impaired loans	91,819	182,377
Total fair value measurements	91,819	182,377
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned and foreclosed assets, net	11,219	24,422
Total fair value measurements	$ 11,219	$ 24,422

Fair Value Measurements (Estima

Fair Value Measurements (Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available for sale securities	$ 5,647,315	$ 4,675,304
Held to maturity securities	1,408,961	1,568,009
Derivative financial instruments		23
Derivative financial instruments	47,042	11,953
Total Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,263,372	542,333
Available for sale securities	5,647,315	4,675,304
Held to maturity securities	1,517,688	1,611,004
Loans, net	22,062,765	21,044,079
Loans held for sale	103,566	55,864
Derivative financial instruments	168,822	54,446
Deposits	27,017,416	23,786,775
Federal funds purchased	250	195,450
Securities sold under agreements to repurchase	806,645	484,422
FHLB short-term borrowings	1,161,666	2,035,000
Long-term debt	434,597	226,098
Derivative financial instruments	56,278	21,089
Total Fair Value [Member] | Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,263,372	542,333
Federal funds purchased	250	195,450
Securities sold under agreements to repurchase	806,645	484,422
FHLB short-term borrowings		2,035,000
Total Fair Value [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available for sale securities	5,647,315	4,675,304
Held to maturity securities	1,517,688	1,611,004
Loans, net	91,819	182,377
Loans held for sale	103,566	55,864
Derivative financial instruments	168,822	54,446
FHLB short-term borrowings	1,161,666
Long-term debt	434,597	226,098
Derivative financial instruments	51,662	15,385
Total Fair Value [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loans, net	21,970,946	20,861,702
Deposits	27,017,416	23,786,775
Derivative financial instruments	4,616	5,704
Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,263,372	542,333
Available for sale securities	5,647,315	4,675,304
Held to maturity securities	1,408,961	1,568,009
Loans, net	21,791,530	21,021,504
Loans held for sale	103,566	55,864
Derivative financial instruments	168,822	54,446
Deposits	27,030,659	23,803,575
Federal funds purchased	250	195,450
Securities sold under agreements to repurchase	806,645	484,422
FHLB short-term borrowings	1,100,000	2,035,000
Long-term debt	385,887	233,462
Derivative financial instruments	$ 56,278	$ 21,089

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Narrative) (Details)	Sep. 30, 2020
ASU 2016-13 [Member]
Recent Accounting Pronouncements [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2020-04 [Member]
Recent Accounting Pronouncements [Line Items]
Change in accounting principle, accounting standards update, adopted	true
ASU 2018-13 [Member]
Recent Accounting Pronouncements [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect	true

Recent Accounting Pronounceme_4

Recent Accounting Pronouncements (Schedule of Impact of Adoption Reflected in Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Assets and Liabilities
Allowance for loan and lease losses	$ 240,662	$ 448,674	$ 191,251	$ 195,572	$ 194,514
Reserve for unfunded lending commitments	31,304	31,526	3,974
Total allowance for credit losses	271,966	480,200	195,225
Retained Earnings
Decrease to retained earnings		$ 1,211,878	$ 1,476,232
Implementation CECL [Member]
Assets and Liabilities
Allowance for loan and lease losses	49,411
Reserve for unfunded lending commitments	27,330
Total allowance for credit losses	76,741
Retained Earnings
Allowance for credit loss increase	76,741
Balance sheet reclassification	19,767
Total pretax impact	56,974
Income tax impact	(12,888)
Decrease to retained earnings	$ 44,086