Hancock Whitney (HWC) 10-Q 7 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 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	Q1
Document Period End Date	Mar. 31, 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		86,283,006
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	Mar. 31, 2020	Dec. 31, 2019
ASSETS
Cash and due from banks	$ 476,811	$ 432,104
Interest-bearing bank deposits	876,058	109,961
Federal funds sold	256	268
Securities available for sale, at fair value (amortized cost of $4,709,075 and $4,637,610)	4,893,996	4,675,304
Securities held to maturity (fair value of $1,562,577 and $1,611,004)	1,480,494	1,568,009
Loans held for sale	67,587	55,864
Loans	21,515,681	21,212,755
Less: allowance for loan losses	(426,003)	(191,251)
Loans, net	21,089,678	21,021,504
Property and equipment, net of accumulated depreciation of $252,459 and $249,527	377,638	380,209
Right of use assets, net of accumulated amortization of $14,719 and $12,194	116,809	110,023
Prepaid expenses	43,772	40,178
Other real estate and foreclosed assets, net	18,460	30,405
Accrued interest receivable	96,167	92,037
Goodwill	855,453	855,453
Other intangible assets, net	101,463	106,807
Life insurance contracts	604,812	608,063
Funded pension assets, net	190,166	185,791
Other assets	472,073	328,777
Total assets	31,761,693	30,600,757
Deposits
Noninterest-bearing	9,204,631	8,775,632
Interest-bearing	15,803,865	15,027,943
Total deposits	25,008,496	23,803,575
Short-term borrowings	2,673,283	2,714,872
Long-term debt	225,606	233,462
Accrued interest payable	11,513	10,200
Lease liabilities	134,908	127,703
Deferred tax liability, net	32,063	37,721
Other liabilities	254,760	205,539
Total liabilities	28,340,629	27,133,072
Stockholders' equity:
Common stock	309,513	309,513
Capital surplus	1,741,156	1,736,664
Retained earnings	1,297,129	1,476,232
Accumulated other comprehensive income (loss), net	73,266	(54,724)
Total stockholders' equity	3,421,064	3,467,685
Total liabilities and stockholders' equity	$ 31,761,693	$ 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	86,275,000	87,515,000

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 4,709,075	$ 4,637,610
Securities held to maturity, fair value	1,562,577	1,611,004
Property and equipment, accumulated depreciation	252,459	249,527
Right of use assets, accumulated amortization	$ 14,719	$ 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
	Mar. 31, 2020	Mar. 31, 2019
Interest income:
Loans, including fees	$ 238,723	$ 238,282
Loans held for sale	621	253
Securities-taxable	32,607	31,139
Securities-tax exempt	4,944	5,446
Short-term investments	448	1,163
Total interest income	277,343	276,283
Interest expense:
Deposits	38,937	46,138
Short-term borrowings	4,462	8,082
Long-term debt	2,756	2,809
Total interest expense	46,155	57,029
Net interest income	231,188	219,254
Provision for credit losses	246,793	18,043
Net interest income (loss) after provision for credit losses	(15,605)	201,211
Noninterest income:
Other income	16,179	9,468
Total noninterest income	84,387	70,503
Noninterest expense:
Compensation expense	91,071	83,968
Employee benefits	22,478	19,730
Personnel expense	113,549	103,698
Net occupancy expense	12,522	11,984
Equipment expense	4,617	4,679
Data processing expense	22,047	19,331
Professional services expense	9,741	8,168
Amortization of intangible assets	5,345	5,138
Deposit insurance and regulatory fees	5,815	5,406
Other real estate and foreclosed assets (income) expense	10,130	(991)
Other expense	19,569	18,287
Total noninterest expense	203,335	175,700
Income (loss) before income taxes	(134,553)	96,014
Income taxes expense (benefit)	(23,520)	16,850
Net income (loss)	$ (111,033)	$ 79,164
Earnings (loss) per common share-basic	$ (1.28)	$ 0.91
Earnings (loss) per common share-diluted	(1.28)	0.91
Dividends paid per share	$ 0.27	$ 0.27
Weighted average shares outstanding-basic	87,186	85,688
Weighted average shares outstanding-diluted	87,186	85,800
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 22,837	$ 20,367
Trust fees
Noninterest income:
Service charges on deposit accounts	14,806	15,124
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	17,362	15,290
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	7,150	6,528
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 6,053	$ 3,726

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (111,033)	$ 79,164
Other comprehensive income/loss before income taxes:
Net change in unrealized gain/loss on securities available for sale and cash flow hedges	165,297	57,243
Reclassification of net losses realized and included in earnings	368	4,219
Amortization of unrealized net loss or gain on securities transferred to held to maturity	(195)	591
Other comprehensive income before income taxes	165,470	62,053
Income tax expense	37,480	13,853
Other comprehensive income net of income taxes	127,990	48,200
Comprehensive income	$ 16,957	$ 127,364

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [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)	79,164			79,164
Other comprehensive income (loss)	48,200				48,200
Comprehensive income	127,364			79,164	48,200
Cash dividends declared	(23,581)			(23,581)
Common stock activity, long-term incentive plan	4,573		4,528	45
Issuance of stock from dividend reinvestment and stock purchase plans	879		879
Balance at Mar. 31, 2019	3,190,575	$ 292,716	1,731,148	1,299,220	(132,509)
Balance, Shares Issued at Mar. 31, 2019		87,903
Balance at Dec. 31, 2019	$ 3,467,685	$ 309,513	1,736,664	1,476,232	(54,724)
Balance, Shares Issued at Dec. 31, 2019	92,947	92,947
Net income (loss)	$ (111,033)			(111,033)
Other comprehensive income (loss)	127,990				127,990
Comprehensive income	16,957			(111,033)	127,990
Cumulative effect of change in accounting principle	(44,087)			(44,087)
Cash dividends declared	(24,028)			(24,028)
Common stock activity, long-term incentive plan	4,159		4,114	45
Repurchase of common stock	(12,716)		(12,716)
Net settlement of forward contract portion of accelerated share repurchase agreement (1,001,472 shares)	12,110		12,110
Issuance of stock from dividend reinvestment and stock purchase plans	984		984
Balance at Mar. 31, 2020	$ 3,421,064	$ 309,513	$ 1,741,156	$ 1,297,129	$ 73,266
Balance, Shares Issued at Mar. 31, 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
	Mar. 31, 2020	Mar. 31, 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

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (111,033)	$ 79,164
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,880	7,516
Provision for credit losses	246,793	18,043
(Gain) loss on other real estate and foreclosed assets	10,550	(991)
Gain on sale of securities	(112)
Deferred tax expense (benefit)	(34,279)	30,829
Increase in cash surrender value of life insurance contracts	(646)	(3,772)
Net (increase) decrease in loans held for sale	(5,709)	5,714
Net amortization of securities premium/discount	9,349	7,009
Amortization of intangible assets	5,345	5,138
Stock-based compensation expense	5,583	5,181
Net change in liability from variation margin collateral	(105,921)	(3,820)
Contribution to pension plan		(100,000)
Decrease in interest payable and other liabilities	(18,641)	(11,658)
(Increase) decrease in other assets	9,887	(23,335)
Other, net	(7,521)	(1,595)
Net cash provided by operating activities	11,525	13,423
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of available for sale securities	124,122
Proceeds from maturities of securities available for sale	166,265	55,596
Purchases of securities available for sale	(367,944)	(1,502)
Proceeds from maturities of securities held to maturity	84,176	79,533
Net increase in short-term investments	(766,085)	(52,668)
Proceeds from sales of loans and leases	2,608	42,059
Net increase in loans	(339,888)	(148,073)
Purchases of property and equipment	(9,460)	(12,435)
Proceeds from sales of other real estate	3,007	4,613
Final cash settlement for acquisition of business		(1,112)
Other, net	(1,731)	(8,863)
Net cash used in investing activities	(1,104,930)	(42,852)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposits	1,204,921	230,109
Net decrease in short-term borrowings	(41,589)	(200,393)
Repayments of long-term debt	(76)	(75)
Dividends paid	(24,028)	(23,581)
Payroll tax remitted on net share settlement of equity awards	(1,494)	(688)
Proceeds from dividend reinvestment and stock purchase plans	984	879
Settlement of forward contract portion of accelerated share repurchase	12,110
Repurchase of shares	(12,716)
Net cash provided by financing activities	1,138,112	6,251
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	44,707	(23,178)
CASH AND DUE FROM BANKS, BEGINNING	432,104	383,372
CASH AND DUE FROM BANKS, ENDING	476,811	360,194
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 1,612	$ 4,273

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 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. 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 15 – Recent Accounting Pronouncements for a discussion of accounting standards adopted during the three months ended March 31, 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 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 the weighted average of multiple macroeconomic scenarios, and then reverts on a linear basis over four quarters to an average historical loss rate for the remaining life. 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 loans estimated fair value 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 prospective 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 prospective application 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 securit y. The allowance for credit loss is limited to the amount by which the fair value is less than the amortized cost basis. The Company reassess the 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.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 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 resulting in a transaction value of $193.8 million. The following table sets forth the preliminary 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 three months ended March 31, 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 March 31, 2020 $ 855,453

Securities

Securities	3 Months Ended
	Mar. 31, 2020
Investments Debt And Equity Securities [Abstract]
Securities	3. Securities The amortized cost, gross unrealized gains and losses, and estimated fair value of securities classified as available for sale and held to maturity at March 31, 2020 and December 31, 2019 as follow. Amortized cost of securities does not include accrued interest which is reflected in the accrued interest line item on the Consolidated Balance Sheets totaling $22.8 million and $23.9 million at March 31, 2020 and December 31, 2019, respectively. Securities Available for Sale (in thousands) March 31, 2020 December 31, 2019 Gross Gross Gross Gross Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair Cost Gains Losses Value Cost Gains Losses Value U.S. Treasury and government agency securities $ 107,750 1,676 223 $ 109,203 $ 98,320 $ 652 $ 300 $ 98,672 Municipal obligations 241,050 8,643 — 249,693 242,016 7,789 — 249,805 Residential mortgage-backed securities 2,061,777 62,764 10 2,124,531 1,910,909 20,268 7,020 1,924,157 Commercial mortgage-backed securities 1,648,643 94,268 105 1,742,806 1,570,765 19,880 4,178 1,586,467 Collateralized mortgage obligations 641,855 17,712 — 659,567 807,600 3,757 3,142 808,215 Corporate debt securities 8,000 218 22 8,196 8,000 21 33 7,988  $ 4,709,075 $ 185,281 $ 360 $ 4,893,996 $ 4,637,610 $ 52,367 $ 14,673 $ 4,675,304 March 31, 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 627,185 29,093 20 656,258 641,019 27,146 69 668,096 Residential mortgage-backed securities 28,236 1,309 — 29,545 29,687 883 — 30,570 Commercial mortgage-backed securities 538,865 41,782 — 580,647 539,371 12,474 581 551,264 Collateralized mortgage obligations 286,208 9,921 2 296,127 307,932 3,597 458 311,071  $ 1,480,494 $ 82,105 $ 22 $ 1,562,577 $ 1,568,009 $ 44,103 $ 1,108 $ 1,611,004 The following table s present the amortized cost and estimated fair value of debt securities available f or s ale and held to maturity at March 31, 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 $ 14,698 $ 14,850 Due after one year through five years 135,349 141,030 Due after five years through ten years 1,765,040 1,865,926 Due after ten years 2,793,988 2,872,190 Total available for sale debt securities $ 4,709,075 $ 4,893,996 Debt Securities Held to Maturity Amortized Fair (in thousands) Cost Value Due in one year or less $ — $ — Due after one year through five years 136,494 141,840 Due after five years through ten years 668,437 718,740 Due after ten years 675,563 701,997 Total held to maturity securities $ 1,480,494 $ 1,562,577 The Company held no securities classified as trading at March 31, 2020 and December 31, 2019. During the three months ended March 31, 2020, proceeds from the sales of securities totaled $124.1 million, with gross gains of $1.1 million and gross losses of $1.0 million. There were no sales of securities during the three months ended March 31, 2019. Securities with carrying values totaling $4.8 billion and $3.3 billion at March 31, 2020 and December 31, 2019, respectively, were pledged as collateral, primarily to secure public deposits or securities sold under agreements to repurchase and, at March 31, 2020, to provide enhanced liquidity through additional borrowing capacity at the Federal Reserve. 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 March 31, 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 March 31, 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 $ 7,807 $ 223 $ — $ — $ 7,807 $ 223 Municipal obligations — — — — — — Residential mortgage-backed securities 714 5 1,688 5 2,402 10 Commercial mortgage-backed securities 25,196 105 — — 25,196 105 Collateralized mortgage obligations — — — — — — Corporate debt securities 778 22 — — 778 22  $ 34,495 $ 355 $ 1,688 $ 5 $ 36,183 $ 360 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 March 31, 2020, the Company evaluated its 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 forecast. The economic forecast was largely weighted to a baseline forecast with some weight given to downside scenarios for both periods. The March 31, 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 March 31, 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 — — 2,894 20 2,894 20 Residential mortgage-backed securities — — — — — — Commercial mortgage-backed securities — — — — — — Collateralized mortgage obligations — — 1,287 2 1,287 2  $ — $ — $ 4,181 $ 22 $ 4,181 $ 22 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 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 March 31, 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 March 31, 2020.

Loans and Allowance for Credit

Loans and Allowance for Credit Losses	3 Months Ended
	Mar. 31, 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 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 $ 72.2 million and $67.7 million at March 31, 2020 and December 31, 2019, respectively. March 31, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 9,321,340 $ 9,166,947 Commercial real estate - owner occupied 2,731,320 2,738,460 Total commercial and industrial 12,052,660 11,905,407 Commercial real estate - income producing 3,232,783 2,994,448 Construction and land development 1,098,726 1,157,451 Residential mortgages 2,979,985 2,990,631 Consumer 2,151,527 2,164,818 Total loans $ 21,515,681 $ 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 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 three months ended March 31, 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 prospective 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 15 – 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 Three Months Ended March 31, 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 (40,713 ) (514 ) (41,227 ) (830 ) — (141 ) (5,540 ) (47,738 ) Recoveries 2,226 81 2,307 7 234 212 1,214 3,974 Net provision for loan losses 119,297 23,414 142,711 37,627 16,761 14,877 17,129 229,105 Ending balance - allowance for loan losses $ 186,998 $ 48,835 $ 235,833 $ 64,960 $ 33,823 $ 48,200 $ 43,187 $ 426,003 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 5,182 289 5,471 280 13,205 — (1,268 ) 17,688 Ending balance - reserve for unfunded lending commitments 14,928 577 15,505 729 28,863 17 3,878 48,992 Total allowance for credit losses $ 201,926 $ 49,412 $ 251,338 $ 65,689 $ 62,686 $ 48,217 $ 47,065 $ 474,995 Allowance for loan losses: Individually evaluated $ 67,404 $ 102 $ 67,506 $ 458 $ 23 $ 312 $ 195 $ 68,494 Collectively evaluated 119,594 48,733 168,327 64,502 33,800 47,888 42,992 357,509 Allowance for loan losses $ 186,998 $ 48,835 $ 235,833 $ 64,960 $ 33,823 $ 48,200 $ 43,187 $ 426,003 Reserve for unfunded lending commitments: Individually evaluated $ 7,215 $ — $ 7,215 $ — $ — $ — $ — $ 7,215 Collectively evaluated 7,713 577 8,290 729 28,863 17 3,878 41,777 Reserve for unfunded lending commitments: $ 14,928 $ 577 $ 15,505 $ 729 $ 28,863 $ 17 $ 3,878 $ 48,992 Total allowance for credit losses $ 201,926 $ 49,412 $ 251,338 $ 65,689 $ 62,686 $ 48,217 $ 47,065 $ 474,995 Loans: Individually evaluated $ 253,790 $ 4,184 $ 257,974 $ 7,300 $ 3,350 $ 4,625 $ 1,280 $ 274,529 Collectively evaluated 9,067,550 2,727,136 11,794,686 3,225,483 1,095,376 2,975,360 2,150,247 21,241,152 Total loans $ 9,321,340 $ 2,731,320 $ 12,052,660 $ 3,232,783 $ 1,098,726 $ 2,979,985 $ 2,151,527 $ 21,515,681 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 Three Months Ended March 31, 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 (16,344 ) — (16,344 ) (10 ) — (406 ) (4,231 ) (20,991 ) Recoveries 1,926 17 1,943 2 11 162 1,004 3,122 Net provision for loan losses 14,186 33 14,219 3,173 (1,631 ) (3 ) 2,285 18,043 Ending balance $ 97,520 $ 13,807 $ 111,327 $ 20,803 $ 14,027 $ 23,535 $ 24,996 $ 194,688 Ending balance: Allowance: Individually evaluated for impairment $ 1,775 $ 205 $ 1,980 $ 143 $ 1 $ 219 $ 347 $ 2,690 Amounts related to purchased credit impaired loans 288 185 473 35 78 9,162 341 10,089 Collectively evaluated for impairment 95,457 13,417 108,874 20,625 13,948 14,154 24,308 181,909 Total allowance $ 97,520 $ 13,807 $ 111,327 $ 20,803 $ 14,027 $ 23,535 $ 24,996 $ 194,688 Loans: Individually evaluated for impairment $ 231,506 $ 16,974 $ 248,480 $ 2,668 $ 19 $ 5,397 $ 1,508 $ 258,072 Purchased credit impaired loans 6,445 5,472 11,917 4,267 2,897 102,199 3,615 124,895 Collectively evaluated for impairment 8,418,375 2,492,982 10,911,357 2,556,459 1,337,151 2,825,655 2,099,249 19,729,871 Total loans $ 8,656,326 $ 2,515,428 $ 11,171,754 $ 2,563,394 $ 1,340,067 $ 2,933,251 $ 2,104,372 $ 20,112,838 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 three months ended March 31, 2020 reflects the impact of the unprecedented economic shutdown caused by 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 80% which includes a sharp recession in the first and second quarters of 2020, with a relatively quick recovery in the second half of 2020. The more severe downside scenarios S-3 and S-4 were weighted at 15% and 5%, respectively, to capture the risk a prolonged downturn might have on our markets, which is more heavily concentrated in tourism, oil and gas and certain areas of healthcare that are more severely impacted by the widespread shutdown and market turmoil. These downside scenarios include double-dip recessions with a more prolonged recovery, with the S-4 scenario having a more severe immediate impact and a longer, more gradual recovery compared to S-3. The degradation in economic conditions created the need for an increased allowance across all portfolios. See the detail of the individually evaluated allowance 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. March 31, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 175,166 $ 178,678 Commercial real estate - owner occupied 8,143 7,708 Total commercial and industrial 183,309 186,386 Commercial real estate - income producing 5,659 2,594 Construction and land development 4,321 1,217 Residential mortgages 42,866 39,262 Consumer 17,903 16,374 Total loans $ 254,058 $ 245,833 For the three months ended March 31, 2020 and 2019, the estimated amount of interest income that would have been recorded had the loans not been assigned nonaccrual status was $4.3 million and $2.9 million, respectively. Nonaccrual loans include nonaccruing loans modified in troubled debt restructurings (“TDRs”) of $117.9 million and $132.5 million at March 31, 2020 and December 31, 2019, respectively. Total TDRs, both accruing and nonaccruing, were $153.1 million at March 31, 2020 and $193.7 million at December 31, 2019. All TDRs are individually evaluated for credit loss. At March 31, 2020 and December 31, 2019 , the Company had unfunded commitments of $ 8.1 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 months ended March 31, 2020 and 2019: Three Months Ended ($ in thousands) March 31, 2020 March 31, 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 1 $ 395 $ 395 7 $ 13,803 $ 13,803 Commercial real estate - owner occupied — — — 1 167 167 Total commercial and industrial 1 395 395 8 13,970 13,970 Commercial real estate - income producing — — — — — — Construction and land development — — — — — — Residential mortgages 1 256 256 5 1,264 1,264 Consumer 3 34 34 2 46 46 Total loans 5 $ 685 $ 685 15 $ 15,280 $ 15,280 The TDRs modified during the three months ended March 31, 2020 reflected in the table above include $0.3 million of loans with extended amortization terms or other payment concessions and $0.4 million with significant covenant waivers. The TDRs modified during the three months ended March 31, 2019 include $0.1 million of loans with extended amortization terms or other payment concessions, $8.8 million with significant covenant waivers and $6.4 million with other modifications. There were no defaults on loans during the three months ended March 31, 2020 or 2019 that had been modified in a TDR during the prior twelve months. The tables below present loans that are individually evaluated disaggregated by portfolio class at March 31, 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. March 31, 2020 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance Commercial non-real estate $ 34,003 $ 219,787 $ 316,651 $ 67,404 Commercial real estate - owner occupied 1,608 2,576 6,954 102 Total commercial and industrial 35,611 222,363 323,605 67,506 Commercial real estate - income producing 2,407 4,893 8,136 458 Construction and land development 3,192 158 3,949 23 Residential mortgages 2,598 2,027 5,160 312 Consumer 136 1,144 1,668 195 Total loans $ 43,944 $ 230,585 $ 342,518 $ 68,494 December 31, 2019 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance 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 months ended March 31, 2020 and 201 9 . Interest income recognized represents interest on accruing loans modified in a TDR. Three Months Ended March 31, 2020 March 31, 2019 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial non-real estate $ 243,114 $ 522 $ 235,445 $ 1,696 Commercial real estate - owner occupied 4,283 — 19,320 80 Total commercial and industrial 247,397 522 254,765 1,776 Commercial real estate - income producing 4,599 6 2,685 7 Construction and land development 1,814 2 70 — Residential mortgages 4,900 4 4,637 5 Consumer 1,382 23 1,258 16 Total loans $ 260,092 $ 557 $ 263,415 $ 1,804 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 reporting. 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. As of March 31, 2020, there were 1,618 customers with loans totaling $839.4 million with payment deferral modifications of principal, interest or both that are eligible to be excluded from TDR reporting requirements. These loans are also excluded from reporting in the aging analysis that follows as delinquency is tracked under the modified terms. Aging Analysis The tables below present the aging analysis of past due loans by portfolio class at March 31, 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 March 31, 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 $ 23,478 $ 7,629 $ 116,763 $ 147,870 $ 9,173,470 $ 9,321,340 $ 6,832 Commercial real estate - owner occupied 5,294 803 11,298 17,395 2,713,925 2,731,320 4,747 Total commercial and industrial 28,772 8,432 128,061 165,265 11,887,395 12,052,660 11,579 Commercial real estate - income producing 8,727 80 9,430 18,237 3,214,546 3,232,783 4,221 Construction and land development 6,289 344 4,406 11,039 1,087,687 1,098,726 667 Residential mortgages 46,695 1,305 23,484 71,484 2,908,501 2,979,985 64 Consumer 24,002 7,870 9,451 41,323 2,110,204 2,151,527 1,259 Total $ 114,485 $ 18,031 $ 174,832 $ 307,348 $ 21,208,333 $ 21,515,681 $ 17,790 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 at March 31, 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 looks at 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 at March 31, 2020 to reflect the potential risk from 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. The Company expects that further risk rating adjustments will likely be required in the future to account for stresses on individual accounts. March 31, 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 $ 8,391,474 $ 2,533,020 $ 10,924,494 $ 3,119,828 $ 1,064,747 $ 15,109,069 Pass-Watch 507,455 136,808 644,263 75,823 24,883 744,969 Special Mention 61,397 11,677 73,074 11,330 970 85,374 Substandard 346,065 49,815 395,880 25,802 8,126 429,808 Doubtful 14,949 — 14,949 — — 14,949 Total $ 9,321,340 $ 2,731,320 $ 12,052,660 $ 3,232,783 $ 1,098,726 $ 16,384,169 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 March 31, 2020 December 31, 2019 (in thousands) Residential mortgage Consumer Total Residential mortgage Consumer Total Performing $ 2,936,218 $ 2,132,482 $ 5,068,700 $ 2,950,854 $ 2,147,312 $ 5,098,166 Nonperforming 43,767 19,045 62,812 39,777 17,506 57,283 Total $ 2,979,985 $ 2,151,527 $ 5,131,512 $ 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 tables further disaggregates credit quality disclosures by amortized cost by class and vintage for term loans and by revolving and revolving converted to amortizing as of March 31, 2020. We define 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 $ 1,200,289 $ 3,482,650 $ 2,316,675 $ 1,817,884 $ 1,268,500 $ 1,815,527 $ 3,166,739 $ 40,805 $ 15,109,069 Pass-Watch 45,483 89,492 50,169 73,719 45,264 45,098 393,676 2,068 744,969 Special Mention 1,106 2,754 11,838 26,324 699 20,130 21,204 1,319 85,374 Substandard 25,939 58,802 86,630 30,860 30,772 49,519 127,734 19,552 429,808 Doubtful — — 12,980 — — — 1,969 — 14,949 Loss — — — — — — — — — Total Commercial Loans $ 1,272,817 $ 3,633,698 $ 2,478,292 $ 1,948,787 $ 1,345,235 $ 1,930,274 $ 3,711,322 $ 63,744 $ 16,384,169 Consumer Loans: Performing $ 172,403 $ 528,274 $ 577,525 $ 771,724 $ 622,557 $ 1,096,363 $ 1,295,598 $ 4,256 5,068,700 Nonperforming 547 2,521 3,962 6,800 4,114 41,575 1,817 1,476 62,812 Total Consumer Loans $ 172,950 $ 530,795 $ 581,487 $ 778,524 $ 626,671 $ 1,137,938 $ 1,297,415 $ 5,732 $ 5,131,512 Purchased Credit Impaired Loans Under the transition provisions for prospective 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 prospective application 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 December 31, 2019 was $8.6 million of consumer loans secured by single family residential real estate that were in process of foreclosure. In light of the economic conditions stemming from the pandemic, the Company placed all active foreclosures on hold and suspended the filing of new foreclosures. In addition to the single family residential real estate loans in process of foreclosure, the Company also held $5.6 million and $6.3 million of foreclosed single family residential properties in other real estate owned at March 31, 2020 and December 31, 2019, respectively.

Securities Sold under Agreement

Securities Sold under Agreements to Repurchase	3 Months Ended
	Mar. 31, 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 $483.0

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivatives	6. 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 Bank also enters into interest rate derivative agreements as a service to certain qualifying customers. The Bank manages a matched book with respect to these customer derivatives in order to minimize its net interest rate risk exposure resulting from such agreements. The Bank 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 March 31, 2020 and December 31, 2019. March 31, 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 $ 63,742 $ — $ 1,175,000 $ 24,172 $ 337 Interest rate swaps - securities Fair Value 479,900 — 23,453 441,400 1,474 1,759 Interest rate swaps - brokered deposits Fair Value — — — 43,000 — 9 1,654,900 63,742 23,453 1,659,400 25,646 2,105 Derivatives not designated as hedging instruments: Interest rate swaps (2) N/A 4,284,812 161,835 165,934 3,759,232 54,512 55,664 Risk participation agreements N/A 248,423 72 82 254,825 21 45 Forward commitments to sell residential mortgage loans N/A 278,632 3,224 404 145,623 651 744 Interest rate-lock commitments on residential mortgage loans N/A 229,364 319 2,659 83,224 369 375 Foreign exchange forward contracts N/A 83,094 1,419 1,367 64,632 303 366 Visa Class B derivative contract N/A 43,272 — 5,345 43,753 — 5,704 5,167,597 166,869 175,791 4,351,289 55,856 62,898 Total derivatives $ 6,822,497 $ 230,611 $ 199,244 $ 6,010,689 $ 81,502 $ 65,003 Less: netting adjustment (3) (63,742 ) (149,835 ) (27,056 ) (43,914 ) Total derivative assets/liabilities $ 166,869 $ 49,409 $ 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 $0.7 million and $1.4 million for the three months ended March 31, 2020 and 2019. The notional amounts of the swap agreements in place at March 31, 2020 expire as follows: $50 million in 2021; $475 million in 2022; $550 million in 2023; and $100 million in 2024. Fair 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. Interest rate swaps on securities available for sale The Company is party to forward starting fixed payer swaps that convert the latter portion of pools of available for sale securities to a floating rate. These instruments were designated as last-of-layer fair value hedges against the select closed pools of prepayable commercial mortgage backed securities. 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 January 2025 and maturity dates from January 2028 through January 2029. In accordance with ASC 815, an entity may exclude prepayment risk when measuring the change in fair value of the hedged item attributable to interest rate risk under the last-of-layer approach. 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. At March 31, 2020, the amortized cost basis of the closed portfolio of prepayable commercial mortgage backed securities totaled $473.2 million. The amount that represents the hedged items was $479.9 million and the basis adjustment associated with the hedged items totaled $23.5 million. Derivatives Not Designated as Hedges Customer interest rate derivative program The Bank 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. Risk participation agreements The Bank 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 Bank 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 Bank 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 March 31, 2020 and December 31, 2019 the fair value of the liability associated with this contract was $5.3 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 three months ended March 31, 2020 and 2019 are presented in the table below. For the three months ended March 31, 2020 and 2019, interest income or the reduction of interest income attributable to cash flow hedges, respectively, includes amortization of accumulated other comprehensive loss that resulted from termination of interest rate swap contracts. Three Months Ended March 31, Derivative Instruments: Location of Gain (Loss) Recognized in the Statement of Income: 2020 2019 Cash flow hedges - variable rate loans Interest income $ 864 $ (2,016 ) Fair value hedges – securities Interest income 41 — Fair value hedges - brokered deposits Interest expense 46 (988 ) All other instruments Other noninterest income 3,871 809 Total $ 4,822 $ (2,195 ) Credit Risk-Related Contingent Features Certain of the Bank’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 March 31, 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 March 31, 2020 and December 31, 2019 was $40.0 million and $12.9 million, respectively, for which the Company had posted collateral of $40.0 million and $12.4 million, respectively. Offsetting Assets and Liabilities The Bank’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 March 31, 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 Income Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income Financial Instruments Cash Collateral Net Amount As of March 31, 2020 Derivative Assets $ 64,413 $ (64,409 ) $ 4 $ 4 $ — $ — Derivative Liabilities $ 188,984 $ (150,673 ) $ 38,311 $ 4 $ 75,670 $ (37,363 ) (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Income Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income 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	3 Months Ended
	Mar. 31, 2020
Stockholders Equity Note [Abstract]
Stockholders' Equity	7. Stockholders’ Equity Common Shares Outstanding Common shares outstanding excludes treasury shares totaling 5.3 million at March 31, 2020 and 4.0 million at December 31, 2019, with a first-in-first-out cost basis of $180.9 million and $135.8 million at March 31, 2020 and December 31, 2019, respectively. Shares outstanding also excludes unvested restricted share awards totaling 1.4 million at both March 31, 2020 and December 31, 2019. Shares Issued as Consideration in Business Combination On September 20, 2019, the Company issued approximately 5.0 million shares of common stock at $38.42 as consideration in 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 was expected to occur as early as the second quarter of 2020 and no later than the third quarter of 2020. However, on March 18, 2020, pursuant to the terms of the ASR, the contract was settled; in the settlement, the Company received from Morgan Stanley on March 20, 2020 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 shares of the 5.5 million authorized shares under the buyback program at an average price of $37.65 per share through the ASR and a privately negotiated transaction. Refer to Part II, Item 2 of this report for tabular presentation of share repurchase activity during the three months ended March 31, 2020. The Company 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 gain or loss 46,984 — — 9,475 784 57,243 Reclassification of net loss realized and included in earnings — — 2,203 2,016 — 4,219 Amortization of unrealized net loss on securities transferred to HTM — 591 — — — 591 Income tax expense (benefit) 10,623 134 498 2,598 — 13,853 Balance, March 31, 2019 $ (13,764 ) $ (11,587 ) $ (108,542 ) $ 600 $ 784 $ (132,509 ) Balance, December 31, 2019 $ 28,950 $ 639 $ (101,278 ) $ 17,399 $ (434 ) $ (54,724 ) Net change in unrealized gain or loss 124,018 — — 41,476 (197 ) 165,297 Reclassification of net income or loss realized and included in earnings — — 1,232 (864 ) — 368 Amortization of unrealized net gain on securities transferred to HTM — (195 ) — — — (195 ) Income tax expense (benefit) 28,056 (44 ) 279 9,189 — 37,480 Balance, March 31, 2020 $ 124,912 $ 488 $ (100,325 ) $ 48,822 $ (631 ) $ 73,266 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.  Three Months Ended Amount reclassified from AOCI (a) March 31, Affected line item on (in thousands) 2020 2019 the statement of income Amortization of unrealized net loss or gain on securities transferred to HTM $ 195 $ (591 ) Interest income Tax effect (44 ) 134 Income taxes Net of tax 151 (457 ) Net income Amortization of defined benefit pension and post-retirement items (1,232 ) (2,203 ) Other noninterest expense (b) Tax effect 279 498 Income taxes Net of tax (953 ) (1,705 ) Net income Reclassification of unrealized gain (loss) on cash flow hedges 1,569 (610 ) Interest income Tax effect (355 ) 138 Income taxes Net of tax 1,214 (472 ) Net income Amortization of loss on terminated cash flow hedges (705 ) (1,406 ) Interest income Tax effect 159 318 Income taxes Net of tax (546 ) (1,088 ) Net income Total reclassifications, net of tax $ (134 ) $ (3,722 ) 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 employee benefits expense (see Note 11 – Retirement Plans for additional details). On March 27, 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 for 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	3 Months Ended
	Mar. 31, 2020
Other Income Disclosure Nonoperating [Abstract]
Other Noninterest Income	8. Other Noninterest Income Components of other noninterest income are as follows: Three Months Ended March 31, (in thousands) 2020 2019 Income from bank-owned life insurance $ 4,266 $ 3,265 Credit related fees 3,065 2,595 Income from derivatives 3,871 809 Other miscellaneous 4,977 2,799 Total other noninterest income $ 16,179 $ 9,468

Other Noninterest Expense

Other Noninterest Expense	3 Months Ended
	Mar. 31, 2020
Other Expense Disclosure Nonoperating [Abstract]
Other Noninterest Expense	9. Other Noninterest Expense Components of other noninterest expense are as follows: Three Months Ended March 31, (in thousands) 2020 2019 Advertising $ 4,234 $ 3,080 Corporate value and franchise taxes 4,296 4,042 Printing and supplies 1,108 1,169 Telecommunications and postage 4,065 3,466 Travel expense 1,111 1,098 Entertainment and contributions 2,447 2,708 Tax credit investment amortization 961 1,138 Other retirement expense (6,122 ) (4,105 ) Other miscellaneous 7,469 5,691 Total other noninterest expense $ 19,569 $ 18,287

Earnings (Loss) Per Common Shar

Earnings (Loss) Per Common Share	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share	10. 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 March 31, (in thousands, except per share data) 2020 2019 Numerator: Net income (loss) to common shareholders $ (111,033 ) $ 79,164 Net dividends or income allocated to participating securities - basic and diluted 427 1,337 Net income (loss) allocated to common shareholders - basic and diluted $ (111,460 ) $ 77,827 Denominator: Weighted-average common shares - basic 87,186 85,688 Dilutive potential common shares — 112 Weighted-average common shares - diluted 87,186 85,800 Earnings (loss) per common share: Basic $ (1.28 ) $ 0.91 Diluted $ (1.28 ) $ 0.91 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 recorded, 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 a weighted average of 1,281 were excluded from the calculation of earnings per common share for the three months ended March 31, 2019 as the effect would have been antidilutive.

Retirement Plans

Retirement Plans	3 Months Ended
	Mar. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	11. 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 March 31, 2020 2019 2020 2019 Service cost $ 3,275 $ 2,775 $ 22 $ 29 Interest cost 3,782 4,863 164 128 Expected return on plan assets (11,300 ) (11,300 ) — — Amortization of net loss and prior service costs 1,461 2,430 (229 ) (227 ) Net periodic benefit cost (reduction of cost) $ (2,782 ) $ (1,232 ) $ (43 ) $ (70 )

Share-Based Payment Arrangement

Share-Based Payment Arrangements	3 Months Ended
	Mar. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Payment Arrangements	12. 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. A summary of stock option activity for the three months ended March 31, 2020 is presented below: Weighted Weighted Average Average Remaining Aggregate Number of Exercise Contractual Intrinsic Options Shares Price Term (Years) Value ($000) Outstanding at January 1, 2020 28,725 $ 34.11 2.2 $ 296 Exercised/Released — — — Cancelled/Forfeited — — — Expired — — — Outstanding at March 31, 2020 28,725 $ 34.11 1.9 $ — Exercisable at March 31, 2020 28,725 $ 34.11 1.9 $ — The total intrinsic value of options exercised during the three months ended March 31, 2019 was $0.5 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 March 31, 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 75,607 42.88 Vested (3,839 ) 42.64 Forfeited (29,567 ) 41.65 Nonvested at March 31, 2020 1,638,459 $ 40.52 As of March 31, 2020, there was $55.3 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 3.3 years. The total fair value of shares which vested during the three months ended March 31, 2020 and 2019 was $0.2 million and $0.1 million, respectively. During the three months ended March 31, 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	3 Months Ended
	Mar. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. 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. The following table presents a summary of the Company’s off-balance sheet financial instruments as of March 31, 2020 and December 31, 2019:  March 31, December 31, (in thousands) 2020 2019 Commitments to extend credit $ 7,591,029 $ 7,530,143 Letters of credit 366,112 393,284 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	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	14. 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 March 31, 2020 and December 31, 2019:  March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 109,203 $ — $ 109,203 Municipal obligations — 249,693 — 249,693 Corporate debt securities — 8,196 — 8,196 Residential mortgage-backed securities — 2,124,531 — 2,124,531 Commercial mortgage-backed securities — 1,742,806 — 1,742,806 Collateralized mortgage obligations — 659,567 — 659,567 Total available for sale securities — 4,893,996 — 4,893,996 Derivative assets (1) — 166,869 — 166,869 Total recurring fair value measurements - assets — $ 5,060,865 — $ 5,060,865 Liabilities Derivative liabilities (1) $ — $ 44,064 $ 5,345 $ 49,409 Total recurring fair value measurements - liabilities $ — $ 44,064 $ 5,345 $ 49,409  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 relies on inputs, LIBOR swap curves, 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 6 – 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 three months ended March 31, 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 (413 ) Losses included in earnings 54 Balance at March 31, 2020 $ 5,345 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 March 31, 2020 December 31, 2019 Derivative liability $ 5,345 $ 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 1.616x 1.616x Time until resolution 9 - 33 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.  March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 281,121 $ — $ 281,121 Other real estate owned and foreclosed assets, net — — 18,425 18,425 Total nonrecurring fair value measurements $ — $ 281,121 $ 18,425 $ 299,546  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 paya ble upon demand (“carrying amou nts”). The fair value of fixed maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. Securities Sold under Agreements to Repurchase, Federal Funds Purchased, and FHLB Borrowings – For these short-term liabilities, the carrying amount is a reasonable estimate of fair value. 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:  March 31, 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 $ 1,353,125 $ — $ — $ 1,353,125 $ 1,353,125 Available for sale securities — 4,893,996 — 4,893,996 4,893,996 Held to maturity securities — 1,562,577 — 1,562,577 1,480,494 Loans, net — 281,121 21,107,746 21,388,867 21,089,678 Loans held for sale — 67,587 — 67,587 67,587 Derivative financial instruments — 166,869 — 166,869 166,869 Financial liabilities: Deposits $ — $ — $ 25,003,807 $ 25,003,807 $ 25,008,496 Federal funds purchased 330,330 — — 330,330 330,330 Securities sold under agreements to repurchase 482,953 — — 482,953 482,953 FHLB short-term borrowings 1,860,000 — — 1,860,000 1,860,000 Long-term debt — 231,044 — 231,044 225,606 Derivative financial instruments — 44,064 5,345 49,409 49,409  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 $ 23,788,775 $ 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	3 Months Ended
	Mar. 31, 2020
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	15. 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, Company elected to amend the hedge documentation, without dedesignating and redesignating, 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 14 - 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)	3 Months Ended
	Mar. 31, 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. 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 15 – Recent Accounting Pronouncements for a discussion of accounting standards adopted during the three months ended March 31, 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 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 the weighted average of multiple macroeconomic scenarios, and then reverts on a linear basis over four quarters to an average historical loss rate for the remaining life. 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 loans estimated fair value 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 prospective 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 prospective application 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 securit y. The allowance for credit loss is limited to the amount by which the fair value is less than the amortized cost basis. The Company reassess the 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.

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 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 preliminary 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)	3 Months Ended
	Mar. 31, 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 Securities Available for Sale	Securities Available for Sale (in thousands) March 31, 2020 December 31, 2019 Gross Gross Gross Gross Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair Cost Gains Losses Value Cost Gains Losses Value U.S. Treasury and government agency securities $ 107,750 1,676 223 $ 109,203 $ 98,320 $ 652 $ 300 $ 98,672 Municipal obligations 241,050 8,643 — 249,693 242,016 7,789 — 249,805 Residential mortgage-backed securities 2,061,777 62,764 10 2,124,531 1,910,909 20,268 7,020 1,924,157 Commercial mortgage-backed securities 1,648,643 94,268 105 1,742,806 1,570,765 19,880 4,178 1,586,467 Collateralized mortgage obligations 641,855 17,712 — 659,567 807,600 3,757 3,142 808,215 Corporate debt securities 8,000 218 22 8,196 8,000 21 33 7,988  $ 4,709,075 $ 185,281 $ 360 $ 4,893,996 $ 4,637,610 $ 52,367 $ 14,673 $ 4,675,304
Amortized Cost and Fair Value of Securities Held to Maturity	March 31, 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 627,185 29,093 20 656,258 641,019 27,146 69 668,096 Residential mortgage-backed securities 28,236 1,309 — 29,545 29,687 883 — 30,570 Commercial mortgage-backed securities 538,865 41,782 — 580,647 539,371 12,474 581 551,264 Collateralized mortgage obligations 286,208 9,921 2 296,127 307,932 3,597 458 311,071  $ 1,480,494 $ 82,105 $ 22 $ 1,562,577 $ 1,568,009 $ 44,103 $ 1,108 $ 1,611,004
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 $ 14,698 $ 14,850 Due after one year through five years 135,349 141,030 Due after five years through ten years 1,765,040 1,865,926 Due after ten years 2,793,988 2,872,190 Total available for sale debt securities $ 4,709,075 $ 4,893,996
Securities with Unrealized Losses	Available for Sale March 31, 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 $ 7,807 $ 223 $ — $ — $ 7,807 $ 223 Municipal obligations — — — — — — Residential mortgage-backed securities 714 5 1,688 5 2,402 10 Commercial mortgage-backed securities 25,196 105 — — 25,196 105 Collateralized mortgage obligations — — — — — — Corporate debt securities 778 22 — — 778 22  $ 34,495 $ 355 $ 1,688 $ 5 $ 36,183 $ 360 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 $ — $ — Due after one year through five years 136,494 141,840 Due after five years through ten years 668,437 718,740 Due after ten years 675,563 701,997 Total held to maturity securities $ 1,480,494 $ 1,562,577
Securities with Unrealized Losses	Held to maturity March 31, 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 — — 2,894 20 2,894 20 Residential mortgage-backed securities — — — — — — Commercial mortgage-backed securities — — — — — — Collateralized mortgage obligations — — 1,287 2 1,287 2  $ — $ — $ 4,181 $ 22 $ 4,181 $ 22 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)	3 Months Ended
	Mar. 31, 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 $ 72.2 million and $67.7 million at March 31, 2020 and December 31, 2019, respectively. March 31, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 9,321,340 $ 9,166,947 Commercial real estate - owner occupied 2,731,320 2,738,460 Total commercial and industrial 12,052,660 11,905,407 Commercial real estate - income producing 3,232,783 2,994,448 Construction and land development 1,098,726 1,157,451 Residential mortgages 2,979,985 2,990,631 Consumer 2,151,527 2,164,818 Total loans $ 21,515,681 $ 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 three months ended March 31, 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 prospective 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 15 – 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 Three Months Ended March 31, 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 (40,713 ) (514 ) (41,227 ) (830 ) — (141 ) (5,540 ) (47,738 ) Recoveries 2,226 81 2,307 7 234 212 1,214 3,974 Net provision for loan losses 119,297 23,414 142,711 37,627 16,761 14,877 17,129 229,105 Ending balance - allowance for loan losses $ 186,998 $ 48,835 $ 235,833 $ 64,960 $ 33,823 $ 48,200 $ 43,187 $ 426,003 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 5,182 289 5,471 280 13,205 — (1,268 ) 17,688 Ending balance - reserve for unfunded lending commitments 14,928 577 15,505 729 28,863 17 3,878 48,992 Total allowance for credit losses $ 201,926 $ 49,412 $ 251,338 $ 65,689 $ 62,686 $ 48,217 $ 47,065 $ 474,995 Allowance for loan losses: Individually evaluated $ 67,404 $ 102 $ 67,506 $ 458 $ 23 $ 312 $ 195 $ 68,494 Collectively evaluated 119,594 48,733 168,327 64,502 33,800 47,888 42,992 357,509 Allowance for loan losses $ 186,998 $ 48,835 $ 235,833 $ 64,960 $ 33,823 $ 48,200 $ 43,187 $ 426,003 Reserve for unfunded lending commitments: Individually evaluated $ 7,215 $ — $ 7,215 $ — $ — $ — $ — $ 7,215 Collectively evaluated 7,713 577 8,290 729 28,863 17 3,878 41,777 Reserve for unfunded lending commitments: $ 14,928 $ 577 $ 15,505 $ 729 $ 28,863 $ 17 $ 3,878 $ 48,992 Total allowance for credit losses $ 201,926 $ 49,412 $ 251,338 $ 65,689 $ 62,686 $ 48,217 $ 47,065 $ 474,995 Loans: Individually evaluated $ 253,790 $ 4,184 $ 257,974 $ 7,300 $ 3,350 $ 4,625 $ 1,280 $ 274,529 Collectively evaluated 9,067,550 2,727,136 11,794,686 3,225,483 1,095,376 2,975,360 2,150,247 21,241,152 Total loans $ 9,321,340 $ 2,731,320 $ 12,052,660 $ 3,232,783 $ 1,098,726 $ 2,979,985 $ 2,151,527 $ 21,515,681 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 Three Months Ended March 31, 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 (16,344 ) — (16,344 ) (10 ) — (406 ) (4,231 ) (20,991 ) Recoveries 1,926 17 1,943 2 11 162 1,004 3,122 Net provision for loan losses 14,186 33 14,219 3,173 (1,631 ) (3 ) 2,285 18,043 Ending balance $ 97,520 $ 13,807 $ 111,327 $ 20,803 $ 14,027 $ 23,535 $ 24,996 $ 194,688 Ending balance: Allowance: Individually evaluated for impairment $ 1,775 $ 205 $ 1,980 $ 143 $ 1 $ 219 $ 347 $ 2,690 Amounts related to purchased credit impaired loans 288 185 473 35 78 9,162 341 10,089 Collectively evaluated for impairment 95,457 13,417 108,874 20,625 13,948 14,154 24,308 181,909 Total allowance $ 97,520 $ 13,807 $ 111,327 $ 20,803 $ 14,027 $ 23,535 $ 24,996 $ 194,688 Loans: Individually evaluated for impairment $ 231,506 $ 16,974 $ 248,480 $ 2,668 $ 19 $ 5,397 $ 1,508 $ 258,072 Purchased credit impaired loans 6,445 5,472 11,917 4,267 2,897 102,199 3,615 124,895 Collectively evaluated for impairment 8,418,375 2,492,982 10,911,357 2,556,459 1,337,151 2,825,655 2,099,249 19,729,871 Total loans $ 8,656,326 $ 2,515,428 $ 11,171,754 $ 2,563,394 $ 1,340,067 $ 2,933,251 $ 2,104,372 $ 20,112,838
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. March 31, December 31, (in thousands) 2020 2019 Commercial non-real estate $ 175,166 $ 178,678 Commercial real estate - owner occupied 8,143 7,708 Total commercial and industrial 183,309 186,386 Commercial real estate - income producing 5,659 2,594 Construction and land development 4,321 1,217 Residential mortgages 42,866 39,262 Consumer 17,903 16,374 Total loans $ 254,058 $ 245,833 For the three months ended March 31, 2020 and 2019, the estimated amount of interest income that would have been recorded had the loans not been assigned nonaccrual status was $4.3 million and $2.9 million, respectively.
Troubled Debt Restructurings Modified by Portfolio Class	The tables below detail by portfolio class TDRs that were modified during the three months ended March 31, 2020 and 2019: Three Months Ended ($ in thousands) March 31, 2020 March 31, 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 1 $ 395 $ 395 7 $ 13,803 $ 13,803 Commercial real estate - owner occupied — — — 1 167 167 Total commercial and industrial 1 395 395 8 13,970 13,970 Commercial real estate - income producing — — — — — — Construction and land development — — — — — — Residential mortgages 1 256 256 5 1,264 1,264 Consumer 3 34 34 2 46 46 Total loans 5 $ 685 $ 685 15 $ 15,280 $ 15,280
Loans Individually Evaluated Disaggregated by Portfolio Class	The tables below present loans that are individually evaluated disaggregated by portfolio class at March 31, 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. March 31, 2020 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance Commercial non-real estate $ 34,003 $ 219,787 $ 316,651 $ 67,404 Commercial real estate - owner occupied 1,608 2,576 6,954 102 Total commercial and industrial 35,611 222,363 323,605 67,506 Commercial real estate - income producing 2,407 4,893 8,136 458 Construction and land development 3,192 158 3,949 23 Residential mortgages 2,598 2,027 5,160 312 Consumer 136 1,144 1,668 195 Total loans $ 43,944 $ 230,585 $ 342,518 $ 68,494 December 31, 2019 (in thousands) Recorded investment without an allowance Recorded investment with an allowance Unpaid principal balance Related allowance 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 months ended March 31, 2020 and 201 9 . Interest income recognized represents interest on accruing loans modified in a TDR. Three Months Ended March 31, 2020 March 31, 2019 (in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial non-real estate $ 243,114 $ 522 $ 235,445 $ 1,696 Commercial real estate - owner occupied 4,283 — 19,320 80 Total commercial and industrial 247,397 522 254,765 1,776 Commercial real estate - income producing 4,599 6 2,685 7 Construction and land development 1,814 2 70 — Residential mortgages 4,900 4 4,637 5 Consumer 1,382 23 1,258 16 Total loans $ 260,092 $ 557 $ 263,415 $ 1,804
Aging Analysis of Past Due Loans by Portfolio Class	The tables below present the aging analysis of past due loans by portfolio class at March 31, 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 March 31, 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 $ 23,478 $ 7,629 $ 116,763 $ 147,870 $ 9,173,470 $ 9,321,340 $ 6,832 Commercial real estate - owner occupied 5,294 803 11,298 17,395 2,713,925 2,731,320 4,747 Total commercial and industrial 28,772 8,432 128,061 165,265 11,887,395 12,052,660 11,579 Commercial real estate - income producing 8,727 80 9,430 18,237 3,214,546 3,232,783 4,221 Construction and land development 6,289 344 4,406 11,039 1,087,687 1,098,726 667 Residential mortgages 46,695 1,305 23,484 71,484 2,908,501 2,979,985 64 Consumer 24,002 7,870 9,451 41,323 2,110,204 2,151,527 1,259 Total $ 114,485 $ 18,031 $ 174,832 $ 307,348 $ 21,208,333 $ 21,515,681 $ 17,790 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 tables further disaggregates credit quality disclosures by amortized cost by class and vintage for term loans and by revolving and revolving converted to amortizing as of March 31, 2020. We define 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 $ 1,200,289 $ 3,482,650 $ 2,316,675 $ 1,817,884 $ 1,268,500 $ 1,815,527 $ 3,166,739 $ 40,805 $ 15,109,069 Pass-Watch 45,483 89,492 50,169 73,719 45,264 45,098 393,676 2,068 744,969 Special Mention 1,106 2,754 11,838 26,324 699 20,130 21,204 1,319 85,374 Substandard 25,939 58,802 86,630 30,860 30,772 49,519 127,734 19,552 429,808 Doubtful — — 12,980 — — — 1,969 — 14,949 Loss — — — — — — — — — Total Commercial Loans $ 1,272,817 $ 3,633,698 $ 2,478,292 $ 1,948,787 $ 1,345,235 $ 1,930,274 $ 3,711,322 $ 63,744 $ 16,384,169 Consumer Loans: Performing $ 172,403 $ 528,274 $ 577,525 $ 771,724 $ 622,557 $ 1,096,363 $ 1,295,598 $ 4,256 5,068,700 Nonperforming 547 2,521 3,962 6,800 4,114 41,575 1,817 1,476 62,812 Total Consumer Loans $ 172,950 $ 530,795 $ 581,487 $ 778,524 $ 626,671 $ 1,137,938 $ 1,297,415 $ 5,732 $ 5,131,512
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 at March 31, 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 looks at 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 at March 31, 2020 to reflect the potential risk from 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. The Company expects that further risk rating adjustments will likely be required in the future to account for stresses on individual accounts. March 31, 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 $ 8,391,474 $ 2,533,020 $ 10,924,494 $ 3,119,828 $ 1,064,747 $ 15,109,069 Pass-Watch 507,455 136,808 644,263 75,823 24,883 744,969 Special Mention 61,397 11,677 73,074 11,330 970 85,374 Substandard 346,065 49,815 395,880 25,802 8,126 429,808 Doubtful 14,949 — 14,949 — — 14,949 Total $ 9,321,340 $ 2,731,320 $ 12,052,660 $ 3,232,783 $ 1,098,726 $ 16,384,169 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	March 31, 2020 December 31, 2019 (in thousands) Residential mortgage Consumer Total Residential mortgage Consumer Total Performing $ 2,936,218 $ 2,132,482 $ 5,068,700 $ 2,950,854 $ 2,147,312 $ 5,098,166 Nonperforming 43,767 19,045 62,812 39,777 17,506 57,283 Total $ 2,979,985 $ 2,151,527 $ 5,131,512 $ 2,990,631 $ 2,164,818 $ 5,155,449

Derivatives (Tables)

Derivatives (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2020 and December 31, 2019. March 31, 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 $ 63,742 $ — $ 1,175,000 $ 24,172 $ 337 Interest rate swaps - securities Fair Value 479,900 — 23,453 441,400 1,474 1,759 Interest rate swaps - brokered deposits Fair Value — — — 43,000 — 9 1,654,900 63,742 23,453 1,659,400 25,646 2,105 Derivatives not designated as hedging instruments: Interest rate swaps (2) N/A 4,284,812 161,835 165,934 3,759,232 54,512 55,664 Risk participation agreements N/A 248,423 72 82 254,825 21 45 Forward commitments to sell residential mortgage loans N/A 278,632 3,224 404 145,623 651 744 Interest rate-lock commitments on residential mortgage loans N/A 229,364 319 2,659 83,224 369 375 Foreign exchange forward contracts N/A 83,094 1,419 1,367 64,632 303 366 Visa Class B derivative contract N/A 43,272 — 5,345 43,753 — 5,704 5,167,597 166,869 175,791 4,351,289 55,856 62,898 Total derivatives $ 6,822,497 $ 230,611 $ 199,244 $ 6,010,689 $ 81,502 $ 65,003 Less: netting adjustment (3) (63,742 ) (149,835 ) (27,056 ) (43,914 ) Total derivative assets/liabilities $ 166,869 $ 49,409 $ 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 March 31, Derivative Instruments: Location of Gain (Loss) Recognized in the Statement of Income: 2020 2019 Cash flow hedges - variable rate loans Interest income $ 864 $ (2,016 ) Fair value hedges – securities Interest income 41 — Fair value hedges - brokered deposits Interest expense 46 (988 ) All other instruments Other noninterest income 3,871 809 Total $ 4,822 $ (2,195 )
Offsetting Derivative Assets and Liabilities Subject to Master Netting Arrangements	(in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Income Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income Financial Instruments Cash Collateral Net Amount As of March 31, 2020 Derivative Assets $ 64,413 $ (64,409 ) $ 4 $ 4 $ — $ — Derivative Liabilities $ 188,984 $ (150,673 ) $ 38,311 $ 4 $ 75,670 $ (37,363 ) (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Income Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income 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)	3 Months Ended
	Mar. 31, 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 gain or loss 46,984 — — 9,475 784 57,243 Reclassification of net loss realized and included in earnings — — 2,203 2,016 — 4,219 Amortization of unrealized net loss on securities transferred to HTM — 591 — — — 591 Income tax expense (benefit) 10,623 134 498 2,598 — 13,853 Balance, March 31, 2019 $ (13,764 ) $ (11,587 ) $ (108,542 ) $ 600 $ 784 $ (132,509 ) Balance, December 31, 2019 $ 28,950 $ 639 $ (101,278 ) $ 17,399 $ (434 ) $ (54,724 ) Net change in unrealized gain or loss 124,018 — — 41,476 (197 ) 165,297 Reclassification of net income or loss realized and included in earnings — — 1,232 (864 ) — 368 Amortization of unrealized net gain on securities transferred to HTM — (195 ) — — — (195 ) Income tax expense (benefit) 28,056 (44 ) 279 9,189 — 37,480 Balance, March 31, 2020 $ 124,912 $ 488 $ (100,325 ) $ 48,822 $ (631 ) $ 73,266
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.  Three Months Ended Amount reclassified from AOCI (a) March 31, Affected line item on (in thousands) 2020 2019 the statement of income Amortization of unrealized net loss or gain on securities transferred to HTM $ 195 $ (591 ) Interest income Tax effect (44 ) 134 Income taxes Net of tax 151 (457 ) Net income Amortization of defined benefit pension and post-retirement items (1,232 ) (2,203 ) Other noninterest expense (b) Tax effect 279 498 Income taxes Net of tax (953 ) (1,705 ) Net income Reclassification of unrealized gain (loss) on cash flow hedges 1,569 (610 ) Interest income Tax effect (355 ) 138 Income taxes Net of tax 1,214 (472 ) Net income Amortization of loss on terminated cash flow hedges (705 ) (1,406 ) Interest income Tax effect 159 318 Income taxes Net of tax (546 ) (1,088 ) Net income Total reclassifications, net of tax $ (134 ) $ (3,722 ) 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 employee benefits expense (see Note 11 – Retirement Plans for additional details).

Other Noninterest Income (Table

Other Noninterest Income (Tables)	3 Months Ended
	Mar. 31, 2020
Other Income Disclosure Nonoperating [Abstract]
Components of Other Noninterest Income	Components of other noninterest income are as follows: Three Months Ended March 31, (in thousands) 2020 2019 Income from bank-owned life insurance $ 4,266 $ 3,265 Credit related fees 3,065 2,595 Income from derivatives 3,871 809 Other miscellaneous 4,977 2,799 Total other noninterest income $ 16,179 $ 9,468

Other Noninterest Expense (Tabl

Other Noninterest Expense (Tables)	3 Months Ended
	Mar. 31, 2020
Other Expense Disclosure Nonoperating [Abstract]
Components of Other Noninterest Expense	Components of other noninterest expense are as follows: Three Months Ended March 31, (in thousands) 2020 2019 Advertising $ 4,234 $ 3,080 Corporate value and franchise taxes 4,296 4,042 Printing and supplies 1,108 1,169 Telecommunications and postage 4,065 3,466 Travel expense 1,111 1,098 Entertainment and contributions 2,447 2,708 Tax credit investment amortization 961 1,138 Other retirement expense (6,122 ) (4,105 ) Other miscellaneous 7,469 5,691 Total other noninterest expense $ 19,569 $ 18,287

Earnings (Loss) Per Common Sh_2

Earnings (Loss) Per Common Share (Tables)	3 Months Ended
	Mar. 31, 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 March 31, (in thousands, except per share data) 2020 2019 Numerator: Net income (loss) to common shareholders $ (111,033 ) $ 79,164 Net dividends or income allocated to participating securities - basic and diluted 427 1,337 Net income (loss) allocated to common shareholders - basic and diluted $ (111,460 ) $ 77,827 Denominator: Weighted-average common shares - basic 87,186 85,688 Dilutive potential common shares — 112 Weighted-average common shares - diluted 87,186 85,800 Earnings (loss) per common share: Basic $ (1.28 ) $ 0.91 Diluted $ (1.28 ) $ 0.91

Retirement Plans (Tables)

Retirement Plans (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2020 2019 2020 2019 Service cost $ 3,275 $ 2,775 $ 22 $ 29 Interest cost 3,782 4,863 164 128 Expected return on plan assets (11,300 ) (11,300 ) — — Amortization of net loss and prior service costs 1,461 2,430 (229 ) (227 ) Net periodic benefit cost (reduction of cost) $ (2,782 ) $ (1,232 ) $ (43 ) $ (70 )

Share-Based Payment Arrangeme_2

Share-Based Payment Arrangements (Tables)	3 Months Ended
	Mar. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Option Activity	A summary of stock option activity for the three months ended March 31, 2020 is presented below: Weighted Weighted Average Average Remaining Aggregate Number of Exercise Contractual Intrinsic Options Shares Price Term (Years) Value ($000) Outstanding at January 1, 2020 28,725 $ 34.11 2.2 $ 296 Exercised/Released — — — Cancelled/Forfeited — — — Expired — — — Outstanding at March 31, 2020 28,725 $ 34.11 1.9 $ — Exercisable at March 31, 2020 28,725 $ 34.11 1.9 $ —
Summary of Nonvested Restricted and Performance Shares	A summary of the status of the Company’s nonvested restricted and performance-based share awards at March 31, 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 75,607 42.88 Vested (3,839 ) 42.64 Forfeited (29,567 ) 41.65 Nonvested at March 31, 2020 1,638,459 $ 40.52

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2020 and December 31, 2019:  March 31, December 31, (in thousands) 2020 2019 Commitments to extend credit $ 7,591,029 $ 7,530,143 Letters of credit 366,112 393,284

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2020 and December 31, 2019:  March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 109,203 $ — $ 109,203 Municipal obligations — 249,693 — 249,693 Corporate debt securities — 8,196 — 8,196 Residential mortgage-backed securities — 2,124,531 — 2,124,531 Commercial mortgage-backed securities — 1,742,806 — 1,742,806 Collateralized mortgage obligations — 659,567 — 659,567 Total available for sale securities — 4,893,996 — 4,893,996 Derivative assets (1) — 166,869 — 166,869 Total recurring fair value measurements - assets — $ 5,060,865 — $ 5,060,865 Liabilities Derivative liabilities (1) $ — $ 44,064 $ 5,345 $ 49,409 Total recurring fair value measurements - liabilities $ — $ 44,064 $ 5,345 $ 49,409  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 three months ended March 31, 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 (413 ) Losses included in earnings 54 Balance at March 31, 2020 $ 5,345
Overview of the Valuation Techniques and Significant Unobservable Inputs	($ in thousands)  Fair Value Level 3 Class March 31, 2020 December 31, 2019 Derivative liability $ 5,345 $ 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 1.616x 1.616x Time until resolution 9 - 33 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.  March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 281,121 $ — $ 281,121 Other real estate owned and foreclosed assets, net — — 18,425 18,425 Total nonrecurring fair value measurements $ — $ 281,121 $ 18,425 $ 299,546  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:  March 31, 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 $ 1,353,125 $ — $ — $ 1,353,125 $ 1,353,125 Available for sale securities — 4,893,996 — 4,893,996 4,893,996 Held to maturity securities — 1,562,577 — 1,562,577 1,480,494 Loans, net — 281,121 21,107,746 21,388,867 21,089,678 Loans held for sale — 67,587 — 67,587 67,587 Derivative financial instruments — 166,869 — 166,869 166,869 Financial liabilities: Deposits $ — $ — $ 25,003,807 $ 25,003,807 $ 25,008,496 Federal funds purchased 330,330 — — 330,330 330,330 Securities sold under agreements to repurchase 482,953 — — 482,953 482,953 FHLB short-term borrowings 1,860,000 — — 1,860,000 1,860,000 Long-term debt — 231,044 — 231,044 225,606 Derivative financial instruments — 44,064 5,345 49,409 49,409  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 $ 23,788,775 $ 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)	3 Months Ended
	Mar. 31, 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) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Loan minimum balance included in specific reserve analysis	$ 1

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) - USD ($) shares in Millions	Sep. 21, 2019	Sep. 20, 2019	Mar. 31, 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	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	Mar. 31, 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 ($)	3 Months Ended	12 Months Ended
	Mar. 31, 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)	3 Months Ended
	Mar. 31, 2020USD ($)Security	Mar. 31, 2019USD ($)	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
Investments Debt And Equity Securities [Abstract]
Amortized cost of securities excluding accrued interest	$ 22,800,000			$ 23,900,000
Securities classified as trading	0			0
Proceeds from sales of securities	124,100,000	$ 0
Gross gains	1,100,000
Gross losses	1,000,000
Securities pledged as collateral	4,800,000,000			$ 3,300,000,000
Allowance for credit loss	$ 0		$ 0
Securities that met the criteria of a credit loss event | Security	0

Securities (Amortized Cost and

Securities (Amortized Cost and Fair Value of Securities Available for Sale) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	$ 4,709,075	$ 4,637,610	$ 4,637,610
Securities Available for Sale, Gross Unrealized Gains	185,281		52,367
Securities Available for Sale, Gross Unrealized Losses	360		14,673
Securities Available for Sale, Fair Value	4,893,996	$ 4,675,304	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	107,750		98,320
Securities Available for Sale, Gross Unrealized Gains	1,676		652
Securities Available for Sale, Gross Unrealized Losses	223		300
Securities Available for Sale, Fair Value	109,203		98,672
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	241,050		242,016
Securities Available for Sale, Gross Unrealized Gains	8,643		7,789
Securities Available for Sale, Fair Value	249,693		249,805
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	2,061,777		1,910,909
Securities Available for Sale, Gross Unrealized Gains	62,764		20,268
Securities Available for Sale, Gross Unrealized Losses	10		7,020
Securities Available for Sale, Fair Value	2,124,531		1,924,157
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	1,648,643		1,570,765
Securities Available for Sale, Gross Unrealized Gains	94,268		19,880
Securities Available for Sale, Gross Unrealized Losses	105		4,178
Securities Available for Sale, Fair Value	1,742,806		1,586,467
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Gross Amortized Cost	641,855		807,600
Securities Available for Sale, Gross Unrealized Gains	17,712		3,757
Securities Available for Sale, Gross Unrealized Losses			3,142
Securities Available for Sale, Fair Value	659,567		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	218		21
Securities Available for Sale, Gross Unrealized Losses	22		33
Securities Available for Sale, Fair Value	$ 8,196		$ 7,988

Securities (Amortized Cost an_2

Securities (Amortized Cost and Fair Value of Securities Held to Maturity) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	$ 1,480,494	$ 1,568,009
Securities Held to Maturity, Gross Unrealized Gains	82,105	44,103
Securities Held to Maturity, Gross Unrealized Losses	22	1,108
Securities Held to Maturity, Fair Value	1,562,577	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	627,185	641,019
Securities Held to Maturity, Gross Unrealized Gains	29,093	27,146
Securities Held to Maturity, Gross Unrealized Losses	20	69
Securities Held to Maturity, Fair Value	656,258	668,096
Residential Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	28,236	29,687
Securities Held to Maturity, Gross Unrealized Gains	1,309	883
Securities Held to Maturity, Fair Value	29,545	30,570
Commercial Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	538,865	539,371
Securities Held to Maturity, Gross Unrealized Gains	41,782	12,474
Securities Held to Maturity, Gross Unrealized Losses		581
Securities Held to Maturity, Fair Value	580,647	551,264
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Gross Amortized Cost	286,208	307,932
Securities Held to Maturity, Gross Unrealized Gains	9,921	3,597
Securities Held to Maturity, Gross Unrealized Losses	2	458
Securities Held to Maturity, Fair Value	$ 296,127	$ 311,071

Securities (Amortized Cost an_3

Securities (Amortized Cost and Fair Value of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Debt Securities Available for Sale, Due in one year or less, Amortized Cost	$ 14,698
Debt Securities Available for Sale, Due after one year through five years, Amortized Cost	135,349
Debt Securities Available for Sale, Due after five years through ten years, Amortized Cost	1,765,040
Debt Securities Available for Sale, Due after ten years, Amortized Cost	2,793,988
Total available for sale debt securities, Amortized Cost	4,709,075
Debt Securities Available for Sale, Due in one year or less, Fair Value	14,850
Debt Securities Available for Sale, Due after one year through five years, Fair Value	141,030
Debt Securities Available for Sale, Due after five years through ten years, Fair Value	1,865,926
Debt Securities Available for Sale, Due after ten years, Fair Value	2,872,190
Total available for sale debt securities, Fair Value	4,893,996
Debt Securities Held to Maturity, Due after one year through five years, Amortized Cost	136,494
Debt Securities Held to Maturity, Due after five years through ten years, Amortized Cost	668,437
Debt Securities Held to Maturity, Due after ten years, Amortized Cost	675,563
Total held to maturity debt securities, Amortized Cost	1,480,494	$ 1,568,009
Debt Securities Held to Maturity, Due after one year through five years, Fair Value	141,840
Debt Securities Held to Maturity, Due after five years through ten years, Fair Value	718,740
Debt Securities Held to Maturity, Due after ten years, Fair Value	701,997
Total held to maturity debt securities, Fair Value	$ 1,562,577	$ 1,611,004

Securities (Securities Availabl

Securities (Securities Available for Sale with Unrealized Losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	$ 34,495	$ 998,312
Available for sale, Losses less than 12 months, Gross Unrealized Losses	355	10,661
Available for sale, Losses 12 months or longer, Fair Value	1,688	599,072
Available for sale, Losses 12 months or longer, Gross Unrealized Losses	5	4,012
Available for sale, Total, Fair Value	36,183	1,597,384
Available for sale, Total, Gross Unrealized Losses	360	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	7,807	28,235
Available for sale, Losses less than 12 months, Gross Unrealized Losses	223	300
Available for sale, Total, Fair Value	7,807	28,235
Available for sale, Total, Gross Unrealized Losses	223	300
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	714	420,066
Available for sale, Losses less than 12 months, Gross Unrealized Losses	5	5,042
Available for sale, Losses 12 months or longer, Fair Value	1,688	399,787
Available for sale, Losses 12 months or longer, Gross Unrealized Losses	5	1,978
Available for sale, Total, Fair Value	2,402	819,853
Available for sale, Total, Gross Unrealized Losses	10	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	25,196	458,855
Available for sale, Losses less than 12 months, Gross Unrealized Losses	105	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	25,196	473,751
Available for sale, Total, Gross Unrealized Losses	105	4,178
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value		89,689
Available for sale, Losses less than 12 months, Gross Unrealized Losses		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		274,078
Available for sale, Total, Gross Unrealized Losses		3,142
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Losses less than 12 months, Fair Value	778	1,467
Available for sale, Losses less than 12 months, Gross Unrealized Losses	22	33
Available for sale, Total, Fair Value	778	1,467
Available for sale, Total, Gross Unrealized Losses	$ 22	$ 33

Securities (Securities Held to

Securities (Securities Held to Maturity with Unrealized Losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value		$ 33,161
Held to maturity, Losses less than 12 months, Gross Unrealized Losses		619
Held to maturity, Losses 12 months or longer, Fair Value	$ 4,181	52,253
Held to maturity, Losses 12 months or longer, Gross Unrealized Losses	22	489
Held to maturity, Total, Fair Value	4,181	85,414
Held to maturity, Total, Gross Unrealized Losses	22	1,108
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value		4,735
Held to maturity, Losses less than 12 months, Gross Unrealized Losses		38
Held to maturity, Losses 12 months or longer, Fair Value	2,894	3,143
Held to maturity, Losses 12 months or longer, Gross Unrealized Losses	20	31
Held to maturity, Total, Fair Value	2,894	7,878
Held to maturity, Total, Gross Unrealized Losses	20	69
Commercial Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value		28,426
Held to maturity, Losses less than 12 months, Gross Unrealized Losses		581
Held to maturity, Total, Fair Value		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	1,287	49,110
Held to maturity, Losses 12 months or longer, Gross Unrealized Losses	2	458
Held to maturity, Total, Fair Value	1,287	49,110
Held to maturity, Total, Gross Unrealized Losses	$ 2	$ 458

Loans and Allowance for Credi_3

Loans and Allowance for Credit Losses (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)loanCustomer	Mar. 31, 2019USD ($)loan	Dec. 31, 2019USD ($)
Accounts Notes And Loans Receivable [Line Items]
Accrued interest	$ 72,200		$ 67,700
Weighted average percentage of forecast	80.00%
Nonaccrual loans	$ 254,058		245,833
Estimated interest income from nonaccrual loans not assigned to nonaccrual status	4,300	$ 2,900
TDRs both accruing and nonaccruing	153,100		193,700
Unfunded commitment to borrowers related to modified TDR	8,100		2,400
TDRs and loans impaired with minimum aggregate relationship balances	$ 1,000
Number of customer loans excluded from TDR | Customer	1,618
Loans excluded from TDR disclosure	$ 839,400
Total Past Due	307,348		260,818
Recorded Investment > 90 Days and Accruing	17,790		6,582
Purchased with credit deterioration, increase	19,800
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	17,903		16,374
Total Past Due	41,323		34,702
Recorded Investment > 90 Days and Accruing	1,259		1,638
Real estate in process of foreclosure			8,600
Real estate acquired through foreclosure	5,600		6,300
30-59 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	114,485		83,693
30-59 Days Past Due [Member] | Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	24,002		18,586
60-89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	18,031		30,183
60-89 Days Past Due [Member] | Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	7,870		6,215
Greater Than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	174,832		146,942
Greater Than 90 Days Past Due [Member] | Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Past Due	9,451		9,901
Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 117,900		132,500
Number of TDRs subsequently defaulted | loan	0	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	$ 300	$ 100
Troubled Debt Restructurings [Member] | Loans With Significant Covenant Waivers [Member]
Accounts Notes And Loans Receivable [Line Items]
Covenant waivers	400	8,800
Troubled Debt Restructurings [Member] | Loans With Other Modifications [Member]
Accounts Notes And Loans Receivable [Line Items]
Other modifications		$ 6,400
Prior to Adoption of CEFL [member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 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-3 [Member]
Accounts Notes And Loans Receivable [Line Items]
Weighted average percentage of forecast	15.00%
Downside Scenario S-4 [Member]
Accounts Notes And Loans Receivable [Line Items]
Weighted average percentage of forecast	5.00%

Loans and Allowance for Credi_4

Loans and Allowance for Credit Losses (Loans, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 21,515,681	$ 21,212,755	$ 20,112,838
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	2,979,985	2,990,631	2,933,251
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	2,151,527	2,164,818	2,104,372
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	3,232,783	2,994,448	2,563,394
Construction and Land Development [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,098,726	1,157,451	1,340,067
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	12,052,660	11,905,407	11,171,754
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	9,321,340	9,166,947	8,656,326
Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 2,731,320	$ 2,738,460	$ 2,515,428

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
	Mar. 31, 2020	Mar. 31, 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	246,793	18,043
Allowance for loan losses: Ending balance	426,003	194,688
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	17,688
Reserve for unfunded lending commitments: Ending balance	48,992
Total allowance for credit losses	474,995		$ 271,966	$ 195,225
Allowance for loan losses: Individually evaluated	68,494	2,690
Allowance for loan losses: Amounts related to purchased credit impaired loans		10,089
Allowance for loan losses: Collectively evaluated	357,509	181,909
Reserve for unfunded lending commitments: Individually evaluated	7,215
Reserve for unfunded lending commitments: Collectively evaluated	41,777
Loans: Individually evaluated	274,529	258,072
Loans: Purchased credit impaired loans		124,895
Purchased credit impaired loans	21,241,152	19,729,871
Loans receivable	21,515,681	20,112,838		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	(47,738)	(20,991)
Allowance for loan losses: Recoveries	3,974	3,122
Allowance for loan losses: Net provision for loan losses	229,105	18,043
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	64,960	20,803
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle	449
Reserve for unfunded lending commitments: Provision for losses	280
Reserve for unfunded lending commitments: Ending balance	729
Total allowance for credit losses	65,689
Allowance for loan losses: Individually evaluated	458	143
Allowance for loan losses: Amounts related to purchased credit impaired loans		35
Allowance for loan losses: Collectively evaluated	64,502	20,625
Reserve for unfunded lending commitments: Collectively evaluated	729
Loans: Individually evaluated	7,300	2,668
Loans: Purchased credit impaired loans		4,267
Purchased credit impaired loans	3,225,483	2,556,459
Loans receivable	3,232,783	2,563,394		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	33,823	14,027
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle	15,658
Reserve for unfunded lending commitments: Provision for losses	13,205
Reserve for unfunded lending commitments: Ending balance	28,863
Total allowance for credit losses	62,686
Allowance for loan losses: Individually evaluated	23	1
Allowance for loan losses: Amounts related to purchased credit impaired loans		78
Allowance for loan losses: Collectively evaluated	33,800	13,948
Reserve for unfunded lending commitments: Collectively evaluated	28,863
Loans: Individually evaluated	3,350	19
Loans: Purchased credit impaired loans		2,897
Purchased credit impaired loans	1,095,376	1,337,151
Loans receivable	1,098,726	1,340,067		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	(830)	(10)
Allowance for loan losses: Recoveries	7	2
Allowance for loan losses: Net provision for loan losses	37,627	3,173
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: Recoveries	234	11
Allowance for loan losses: Net provision for loan losses	16,761	(1,631)
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	235,833	111,327
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	5,471
Reserve for unfunded lending commitments: Ending balance	15,505
Total allowance for credit losses	251,338
Allowance for loan losses: Individually evaluated	67,506	1,980
Allowance for loan losses: Amounts related to purchased credit impaired loans		473
Allowance for loan losses: Collectively evaluated	168,327	108,874
Reserve for unfunded lending commitments: Individually evaluated	7,215
Reserve for unfunded lending commitments: Collectively evaluated	8,290
Loans: Individually evaluated	257,974	248,480
Loans: Purchased credit impaired loans		11,917
Purchased credit impaired loans	11,794,686	10,911,357
Loans receivable	12,052,660	11,171,754		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	186,998	97,520
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	5,182
Reserve for unfunded lending commitments: Ending balance	14,928
Total allowance for credit losses	201,926
Allowance for loan losses: Individually evaluated	67,404	1,775
Allowance for loan losses: Amounts related to purchased credit impaired loans		288
Allowance for loan losses: Collectively evaluated	119,594	95,457
Reserve for unfunded lending commitments: Individually evaluated	7,215
Reserve for unfunded lending commitments: Collectively evaluated	7,713
Loans: Individually evaluated	253,790	231,506
Loans: Purchased credit impaired loans		6,445
Purchased credit impaired loans	9,067,550	8,418,375
Loans receivable	9,321,340	8,656,326		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	48,835	13,807
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle	288
Reserve for unfunded lending commitments: Provision for losses	289
Reserve for unfunded lending commitments: Ending balance	577
Total allowance for credit losses	49,412
Allowance for loan losses: Individually evaluated	102	205
Allowance for loan losses: Amounts related to purchased credit impaired loans		185
Allowance for loan losses: Collectively evaluated	48,733	13,417
Reserve for unfunded lending commitments: Collectively evaluated	577
Loans: Individually evaluated	4,184	16,974
Loans: Purchased credit impaired loans		5,472
Purchased credit impaired loans	2,727,136	2,492,982
Loans receivable	2,731,320	2,515,428		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	(41,227)	(16,344)
Allowance for loan losses: Recoveries	2,307	1,943
Allowance for loan losses: Net provision for loan losses	142,711	14,219
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	(40,713)	(16,344)
Allowance for loan losses: Recoveries	2,226	1,926
Allowance for loan losses: Net provision for loan losses	119,297	14,186
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	(514)
Allowance for loan losses: Recoveries	81	17
Allowance for loan losses: Net provision for loan losses	23,414	33
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	48,200	23,535
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle	17
Reserve for unfunded lending commitments: Ending balance	17
Total allowance for credit losses	48,217
Allowance for loan losses: Individually evaluated	312	219
Allowance for loan losses: Amounts related to purchased credit impaired loans		9,162
Allowance for loan losses: Collectively evaluated	47,888	14,154
Reserve for unfunded lending commitments: Collectively evaluated	17
Loans: Individually evaluated	4,625	5,397
Loans: Purchased credit impaired loans		102,199
Purchased credit impaired loans	2,975,360	2,825,655
Loans receivable	2,979,985	2,933,251		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	(141)	(406)
Allowance for loan losses: Recoveries	212	162
Allowance for loan losses: Net provision for loan losses	14,877	(3)
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	43,187	24,996
Reserve for unfunded lending commitments: Cumulative effect of change in accounting principle	5,146
Reserve for unfunded lending commitments: Provision for losses	(1,268)
Reserve for unfunded lending commitments: Ending balance	3,878
Total allowance for credit losses	47,065
Allowance for loan losses: Individually evaluated	195	347
Allowance for loan losses: Amounts related to purchased credit impaired loans		341
Allowance for loan losses: Collectively evaluated	42,992	24,308
Reserve for unfunded lending commitments: Collectively evaluated	3,878
Loans: Individually evaluated	1,280	1,508
Loans: Purchased credit impaired loans		3,615
Purchased credit impaired loans	2,150,247	2,099,249
Loans receivable	2,151,527	2,104,372		$ 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	(5,540)	(4,231)
Allowance for loan losses: Recoveries	1,214	1,004
Allowance for loan losses: Net provision for loan losses	$ 17,129	$ 2,285

Loans and Allowance for Credi_6

Loans and Allowance for Credit Losses (Composition of Nonaccrual Loans by Portfolio Class) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 254,058	$ 245,833
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	5,659	2,594
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	4,321	1,217
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	42,866	39,262
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	17,903	16,374
Total Commercial And Industrial [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	183,309	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	175,166	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	$ 8,143	$ 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
	Mar. 31, 2020USD ($)contract	Mar. 31, 2019USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	5	15
Pre-Modification Outstanding Recorded Investment	$ 685	$ 15,280
Post-Modification Outstanding Recorded Investment	$ 685	$ 15,280
Residential Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1	5
Pre-Modification Outstanding Recorded Investment	$ 256	$ 1,264
Post-Modification Outstanding Recorded Investment	$ 256	$ 1,264
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	3	2
Pre-Modification Outstanding Recorded Investment	$ 34	$ 46
Post-Modification Outstanding Recorded Investment	$ 34	$ 46
Total Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1	8
Pre-Modification Outstanding Recorded Investment	$ 395	$ 13,970
Post-Modification Outstanding Recorded Investment	$ 395	$ 13,970
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1	7
Pre-Modification Outstanding Recorded Investment	$ 395	$ 13,803
Post-Modification Outstanding Recorded Investment	$ 395	$ 13,803
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
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	$ 43,944		$ 141,091
Recorded investment with an allowance	230,585		104,560
Unpaid principal balance	342,518		287,767
Related allowance	68,494		22,385
Average recorded investment	260,092	$ 263,415
Interest income recognized	557	1,804
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	2,407		373
Recorded investment with an allowance	4,893		1,525
Unpaid principal balance	8,136		1,959
Related allowance	458		18
Average recorded investment	4,599	2,685
Interest income recognized	6	7
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	3,192
Recorded investment with an allowance	158		277
Unpaid principal balance	3,949		322
Related allowance	23		21
Average recorded investment	1,814	70
Interest income recognized	2
Residential Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	2,598		3,383
Recorded investment with an allowance	2,027		1,791
Unpaid principal balance	5,160		5,709
Related allowance	312		217
Average recorded investment	4,900	4,637
Interest income recognized	4	5
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	136		479
Recorded investment with an allowance	1,144		1,004
Unpaid principal balance	1,668		1,906
Related allowance	195		292
Average recorded investment	1,382	1,258
Interest income recognized	23	16
Total Commercial And Industrial [Member] | Total Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	35,611		136,856
Recorded investment with an allowance	222,363		99,963
Unpaid principal balance	323,605		277,871
Related allowance	67,506		21,837
Average recorded investment	247,397	254,765
Interest income recognized	522	1,776
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	34,003		134,191
Recorded investment with an allowance	219,787		98,247
Unpaid principal balance	316,651		270,078
Related allowance	67,404		21,733
Average recorded investment	243,114	235,445
Interest income recognized	522	1,696
Total Commercial And Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	1,608		2,665
Recorded investment with an allowance	2,576		1,716
Unpaid principal balance	6,954		7,793
Related allowance	102		$ 104
Average recorded investment	$ 4,283	19,320
Interest income recognized		$ 80

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	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 307,348	$ 260,818
Current	21,208,333	20,951,937
Total loans	21,515,681	21,212,755	$ 20,112,838
Recorded Investment > 90 Days and Accruing	17,790	6,582
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	114,485	83,693
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	18,031	30,183
Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	174,832	146,942
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	18,237	4,351
Current	3,214,546	2,990,097
Total loans	3,232,783	2,994,448	2,563,394
Recorded Investment > 90 Days and Accruing	4,221	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	8,727	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	80	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	9,430	2,910
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	11,039	8,907
Current	1,087,687	1,148,544
Total loans	1,098,726	1,157,451	1,340,067
Recorded Investment > 90 Days and Accruing	667	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	6,289	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	344	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	4,406	2,480
Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	165,265	147,830
Current	11,887,395	11,757,577
Total loans	12,052,660	11,905,407	11,171,754
Recorded Investment > 90 Days and Accruing	11,579	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	28,772	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	8,432	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	128,061	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	147,870	135,144
Current	9,173,470	9,031,803
Total loans	9,321,340	9,166,947	8,656,326
Recorded Investment > 90 Days and Accruing	6,832	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	23,478	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	7,629	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	116,763	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	17,395	12,686
Current	2,713,925	2,725,774
Total loans	2,731,320	2,738,460	2,515,428
Recorded Investment > 90 Days and Accruing	4,747	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	5,294	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	803	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	11,298	7,268
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	71,484	65,028
Current	2,908,501	2,925,603
Total loans	2,979,985	2,990,631	2,933,251
Recorded Investment > 90 Days and Accruing	64	85
Residential Mortgages [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	46,695	32,867
Residential Mortgages [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,305	8,584
Residential Mortgages [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	23,484	23,577
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	41,323	34,702
Current	2,110,204	2,130,116
Total loans	2,151,527	2,164,818	$ 2,104,372
Recorded Investment > 90 Days and Accruing	1,259	1,638
Consumer [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	24,002	18,586
Consumer [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7,870	6,215
Consumer [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 9,451	$ 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	Mar. 31, 2020	Dec. 31, 2019
Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 16,384,169	$ 16,057,306
Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	12,052,660	11,905,407
Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	15,109,069	15,014,111
Total Commercial [Member] | Pass [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	10,924,494	11,009,561
Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	744,969	462,502
Total Commercial [Member] | Pass-Watch [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	644,263	367,116
Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	85,374	101,583
Total Commercial [Member] | Special Mention [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	73,074	86,305
Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	429,808	479,110
Total Commercial [Member] | Substandard [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	395,880	442,425
Total Commercial [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	14,949
Total Commercial [Member] | Doubtful [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	14,949
Residential Mortgages [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,979,985	2,990,631
Residential Mortgages [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,936,218	2,950,854
Residential Mortgages [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	43,767	39,777
Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,151,527	2,164,818
Consumer [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,132,482	2,147,312
Consumer [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	19,045	17,506
Residential Mortgage and Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,131,512	5,155,449
Residential Mortgage and Consumer [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,068,700	5,098,166
Residential Mortgage and Consumer [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	62,812	57,283
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,321,340	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	8,391,474	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	507,455	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	61,397	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	346,065	382,330
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Doubtful [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	14,949
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,731,320	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	2,533,020	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	136,808	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	11,677	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	49,815	60,095
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,232,783	2,994,448
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,119,828	2,883,553
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	75,823	69,765
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	11,330	14,995
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	25,802	26,135
Construction and Land Development [Member] | Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,098,726	1,157,451
Construction and Land Development [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,064,747	1,120,997
Construction and Land Development [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	24,883	25,621
Construction and Land Development [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	970	283
Construction and Land Development [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 8,126	$ 10,550

Loans and Allowance for Cred_11

Loans and Allowance for Credit Losses (Disaggregation of Credit Quality Disclosures) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	$ 1,272,817
Term Loans, Amortized Cost Basis by Origination Year, 2019	3,633,698
Term Loans, Amortized Cost Basis by Origination Year, 2018	2,478,292
Term Loans, Amortized Cost Basis by Origination Year, 2017	1,948,787
Term Loans, Amortized Cost Basis by Origination Year, 2016	1,345,235
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,930,274
Revolving Loans	3,711,322
Revolving Loans Converted to Term Loans	63,744
Notes Receivable Gross	16,384,169	$ 16,057,306
Total Commercial [Member] | Pass [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	1,200,289
Term Loans, Amortized Cost Basis by Origination Year, 2019	3,482,650
Term Loans, Amortized Cost Basis by Origination Year, 2018	2,316,675
Term Loans, Amortized Cost Basis by Origination Year, 2017	1,817,884
Term Loans, Amortized Cost Basis by Origination Year, 2016	1,268,500
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,815,527
Revolving Loans	3,166,739
Revolving Loans Converted to Term Loans	40,805
Notes Receivable Gross	15,109,069	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	45,483
Term Loans, Amortized Cost Basis by Origination Year, 2019	89,492
Term Loans, Amortized Cost Basis by Origination Year, 2018	50,169
Term Loans, Amortized Cost Basis by Origination Year, 2017	73,719
Term Loans, Amortized Cost Basis by Origination Year, 2016	45,264
Term Loans, Amortized Cost Basis by Origination Year, Prior	45,098
Revolving Loans	393,676
Revolving Loans Converted to Term Loans	2,068
Notes Receivable Gross	744,969	462,502
Total Commercial [Member] | Special Mention [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	1,106
Term Loans, Amortized Cost Basis by Origination Year, 2019	2,754
Term Loans, Amortized Cost Basis by Origination Year, 2018	11,838
Term Loans, Amortized Cost Basis by Origination Year, 2017	26,324
Term Loans, Amortized Cost Basis by Origination Year, 2016	699
Term Loans, Amortized Cost Basis by Origination Year, Prior	20,130
Revolving Loans	21,204
Revolving Loans Converted to Term Loans	1,319
Notes Receivable Gross	85,374	101,583
Total Commercial [Member] | Substandard [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	25,939
Term Loans, Amortized Cost Basis by Origination Year, 2019	58,802
Term Loans, Amortized Cost Basis by Origination Year, 2018	86,630
Term Loans, Amortized Cost Basis by Origination Year, 2017	30,860
Term Loans, Amortized Cost Basis by Origination Year, 2016	30,772
Term Loans, Amortized Cost Basis by Origination Year, Prior	49,519
Revolving Loans	127,734
Revolving Loans Converted to Term Loans	19,552
Notes Receivable Gross	429,808	479,110
Total Commercial [Member] | Doubtful [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2018	12,980
Revolving Loans	1,969
Notes Receivable Gross	14,949
Residential Mortgage and Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2020	172,950
Term Loans, Amortized Cost Basis by Origination Year, 2019	530,795
Term Loans, Amortized Cost Basis by Origination Year, 2018	581,487
Term Loans, Amortized Cost Basis by Origination Year, 2017	778,524
Term Loans, Amortized Cost Basis by Origination Year, 2016	626,671
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,137,938
Revolving Loans	1,297,415
Revolving Loans Converted to Term Loans	5,732
Notes Receivable Gross	5,131,512	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	172,403
Term Loans, Amortized Cost Basis by Origination Year, 2019	528,274
Term Loans, Amortized Cost Basis by Origination Year, 2018	577,525
Term Loans, Amortized Cost Basis by Origination Year, 2017	771,724
Term Loans, Amortized Cost Basis by Origination Year, 2016	622,557
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,096,363
Revolving Loans	1,295,598
Revolving Loans Converted to Term Loans	4,256
Notes Receivable Gross	5,068,700	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	547
Term Loans, Amortized Cost Basis by Origination Year, 2019	2,521
Term Loans, Amortized Cost Basis by Origination Year, 2018	3,962
Term Loans, Amortized Cost Basis by Origination Year, 2017	6,800
Term Loans, Amortized Cost Basis by Origination Year, 2016	4,114
Term Loans, Amortized Cost Basis by Origination Year, Prior	41,575
Revolving Loans	1,817
Revolving Loans Converted to Term Loans	1,476
Notes Receivable Gross	$ 62,812	$ 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	Mar. 31, 2020	Dec. 31, 2019
Brokers And Dealers [Abstract]
Securities sold under agreements to repurchase	$ 483	$ 484.4

Derivatives (Fair Values of Der

Derivatives (Fair Values of Derivative Financial Instruments) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		$ 6,822,497	$ 6,010,689
Fair Values, Assets		4	23
Less: netting adjustment, Assets	[1],[2]	(63,742)	(27,056)
Fair Values, Liabilities		38,311	11,953
Less: netting adjustment, Liabilities	[1],[2]	(149,835)	(43,914)
Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	230,611	81,502
Total derivative assets/liabilities	[1]	166,869	54,446
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Total derivative assets/liabilities	[1]	49,409	21,089
Fair Values, Liabilities	[1]	199,244	65,003
Derivatives Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		1,654,900	1,659,400
Derivatives Designated as Hedging Instruments [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	63,742	25,646
Derivatives Designated as Hedging Instruments [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	23,453	2,105
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		5,167,597	4,351,289
Derivatives Not Designated as Hedging Instruments [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values, Assets	[1]	166,869	55,856
Derivatives Not Designated as Hedging Instruments [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	175,791	62,898
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount	[3]	4,284,812	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]	161,835	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]	165,934	55,664
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		248,423	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]	72	21
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair Values, Liabilities	[1]	82	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		278,632	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]	3,224	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]	404	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		229,364	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]	319	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]	2,659	375
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		83,094	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]	1,419	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]	1,367	366
Derivatives Not Designated as Hedging Instruments [Member] | Visa Class B derivative contract [Member]
Derivatives Fair Value [Line Items]
Notional or Contractual Amount		43,272	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]	5,345	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]	63,742	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		479,900	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]		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]	$ 23,453	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		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Derivative [Line Items]
Notional amount of derivatives		$ 6,822,497		$ 6,010,689
Available for sale debt securities, Amortized Cost		4,709,075
Fair Values, Liabilities		38,311		11,953
Fair value liability		5,300		5,700
Credit risk-related contingent features, net liability position		40,000		12,900
Credit risk-related contingent features, posted collateral		40,000		12,400
Other Liabilities [Member]
Derivative [Line Items]
Fair Values, Liabilities	[1]	199,244		65,003
Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional amount of derivatives		1,654,900		1,659,400
Derivatives Designated as Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Fair Values, Liabilities	[1]	23,453		2,105
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		700	$ 1,400
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		$ 479,900		441,400
Interest Rate Swaps - Securities [Member] | Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member] | Commercial Mortgage-Backed Securities [Member]
Derivative [Line Items]
Available for sale debt securities, Amortized Cost		473,200
Interest Rate Swaps - Securities [Member] | Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member] | Other Liabilities [Member]
Derivative [Line Items]
Fair Values, Liabilities	[1]	$ 23,453		$ 1,759
[1]	Derivative assets and liabilities are reported at fair value in other assets or other liabilities, respectively, in the consolidated balance sheets.

Derivatives (Effects of Derivat

Derivatives (Effects of Derivative Instruments on the Statements of Income) (Details) - Interest Rate Swaps Designated as Hedges [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	$ 4,822	$ (2,195)
Other Noninterest Income [Member] | All Other Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	3,871	809
Cash Flow Hedge [Member] | Interest Income [Member] | Variable Rate Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	864	(2,016)
Fair Value Hedging [Member] | Interest Income [Member] | Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	41
Fair Value Hedging [Member] | Interest Expense [Member] | Brokered Deposits [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	$ 46	$ (988)

Derivatives (Offsetting Derivat

Derivatives (Offsetting Derivative Assets and Liabilities Subject to Master Netting Arrangements) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Gross Amounts Recognized, Derivative Assets	$ 64,413	$ 27,938
Gross Amounts Offset in the Statement of Income, Derivative Assets	(64,409)	(27,915)
Net Amounts Presented in the Statement of Income, Derivative Assets	4	23
Gross Amounts Not Offset in the Statement of Income - Financial Instruments, Derivative Assets	4	23
Gross Amounts Recognized, Derivative Liabilities	188,984	56,523
Gross Amounts Offset in the Statement of Income, Derivative Liabilities	(150,673)	(44,570)
Net Amounts Presented in the Statement of Income, Derivative Liabilities	38,311	11,953
Gross Amounts Not Offset in the Statement of Income - Financial Instruments, Derivative Liabilities	4	23
Gross Amounts Not offset in the Statement of Income - Cash Collateral, Derivative Liabilities	75,670	35,113
Net Amounts Presented in the Statement of Income, Derivative Liabilities	$ (37,363)	$ (23,183)

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 20, 2020	Oct. 21, 2019	Sep. 23, 2019	Sep. 21, 2019	Sep. 20, 2019	Jan. 31, 2020	Mar. 31, 2020	Mar. 27, 2020	Dec. 31, 2019	Oct. 18, 2019
Equity, Class of Treasury Stock [Line Items]
Treasury stock shares							5,300,000		4,000,000
Treasury stock, Cost basis							$ 180,900		$ 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	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
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (54,724)	$ (180,709)
Net change in unrealized gain or loss	165,297	57,243
Reclassification of net income or loss realized and included in earnings	368	4,219
Amortization of unrealized net loss (gain) on securities transferred to HTM	(195)	591
Income tax expense	37,480	13,853
Ending Balance	73,266	(132,509)
Equity Method Investment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(434)
Net change in unrealized gain or loss	(197)	784
Ending Balance	(631)	784
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	124,018	46,984
Income tax expense	28,056	10,623
Ending Balance	124,912	(13,764)
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	(195)	591
Income tax expense	(44)	134
Ending Balance	488	(11,587)
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	1,232	2,203
Income tax expense	279	498
Ending Balance	(100,325)	(108,542)
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	41,476	9,475
Reclassification of net income or loss realized and included in earnings	(864)	2,016
Income tax expense	9,189	2,598
Ending Balance	$ 48,822	$ 600

Stockholders' Equity (Line Item

Stockholders' Equity (Line Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income) (Details) - Reclassification out of Accumulated Other Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications, net of tax	[1]	$ (134)	$ (3,722)
Held to Maturity Securities Transferred from AFS [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of unrealized net loss or gain on securities transferred to HTM	[1]	195	(591)
Tax effect	[1]	(44)	134
Net of tax	[1]	151	(457)
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]	(1,232)	(2,203)
Tax effect	[1]	279	498
Net of tax	[1]	(953)	(1,705)
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]	1,569	(610)
Tax effect	[1]	(355)	138
Net of tax	[1]	1,214	(472)
Amortization of loss on terminated cash flow hedges	[1]	(705)	(1,406)
Tax effect	[1]	159	318
Net of tax	[1]	$ (546)	$ (1,088)
[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 employee benefits expense (see Note 11 – Retirement Plans for additional details).

Other Noninterest Income (Compo

Other Noninterest Income (Components of Other Noninterest Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Income Disclosure Nonoperating [Abstract]
Income from bank-owned life insurance	$ 4,266	$ 3,265
Credit related fees	3,065	2,595
Income from derivatives	3,871	809
Other miscellaneous	4,977	2,799
Total other noninterest income	$ 16,179	$ 9,468

Other Noninterest Expense (Deta

Other Noninterest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Expense Disclosure Nonoperating [Abstract]
Advertising	$ 4,234	$ 3,080
Corporate value and franchise taxes	4,296	4,042
Printing and supplies	1,108	1,169
Telecommunications and postage	4,065	3,466
Travel expense	1,111	1,098
Entertainment and contributions	2,447	2,708
Tax credit investment amortization	961	1,138
Other retirement expense	(6,122)	(4,105)
Other miscellaneous	7,469	5,691
Total other noninterest expense	$ 19,569	$ 18,287

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
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net income (loss) to common shareholders	$ (111,033)	$ 79,164
Net dividends or income allocated to participating securities - basic and diluted	427	1,337
Net income (loss) allocated to common shareholders - basic and diluted	$ (111,460)	$ 77,827
Weighted-average common shares - basic	87,186	85,688
Dilutive potential common shares		112
Weighted-average common shares - diluted	87,186	85,800
Earnings per common share: Basic	$ (1.28)	$ 0.91
Earnings per common share: Diluted	$ (1.28)	$ 0.91

Earnings (Loss) Per Common Sh_4

Earnings (Loss) Per Common Share (Narrative) (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Weighted-average anti-dilutive potential common shares	0	1,281

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
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
	Mar. 31, 2020	Mar. 31, 2019
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,275	$ 2,775
Interest cost	3,782	4,863
Expected return on plan assets	(11,300)	(11,300)
Amortization of net loss and prior service costs	1,461	2,430
Net periodic benefit cost (reduction of cost)	(2,782)	(1,232)
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	22	29
Interest cost	164	128
Amortization of net loss and prior service costs	(229)	(227)
Net periodic benefit cost (reduction of cost)	$ (43)	$ (70)

Share-Based Payment Arrangeme_3

Share-Based Payment Arrangements (Summary of Option Activity) (Details) - Options [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding at Beginning	28,725
Number of Shares, Outstanding at Ending	28,725	28,725
Number of Shares, Exercisable at Ending	28,725
Weighted Average Exercise Price, Outstanding at Beginning	$ 34.11
Weighted Average Exercise Price, Outstanding at Ending	34.11	$ 34.11
Weighted Average Exercise Price, Exercisable at Ending	$ 34.11
Weighted Average Remaining Contractual Term (Years)	1 year 10 months 24 days	2 years 2 months 12 days
Weighted Average Remaining Contractual Term (Years), Exercisable at Ending	1 year 10 months 24 days
Aggregate Intrinsic Value, Outstanding at Beginning	$ 296
Aggregate Intrinsic Value, Outstanding at Ending		$ 296

Share-Based Payment Arrangeme_4

Share-Based Payment Arrangements (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)entity$ / sharesshares	Mar. 31, 2019USD ($)
Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised | $		$ 0.5
Restricted and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense | $	$ 55.3
Weighted-average period	3 years 3 months 18 days
Total fair value of shares vested | $	$ 0.2	$ 0.1
Shares granted | shares	75,607
Grant date fair value per share | $ / shares	$ 42.88
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 | shares	35,754
Grant date fair value per share | $ / shares	$ 46.61
Vesting performance period	3 years
Number of peer group regional banks | entity	49
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 | shares	35,754
Grant date fair value per share | $ / shares	$ 39.39
Vesting performance period	2 years

Share-Based Payment Arrangeme_5

Share-Based Payment Arrangements (Summary of Nonvested Restricted and Performance Shares) (Details) - Restricted and Performance Shares [Member]	3 Months Ended
	Mar. 31, 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	75,607
Number of Shares, Vested | shares	(3,839)
Number of Shares, Forfeited | shares	(29,567)
Number of Shares, Nonvested at Ending | shares	1,638,459
Weighted Average Grant Date Fair Value, Nonvested at Beginning | $ / shares	$ 40.43
Weighted Average Grant Date Fair Value, Granted | $ / shares	42.88
Weighted Average Grant Date Fair Value, Vested | $ / shares	42.64
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	41.65
Weighted Average Grant Date Fair Value, Nonvested at Ending | $ / shares	$ 40.52

Commitments and Contingencies_2

Commitments and Contingencies (Off-Balance Sheet Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Commitments to Extend Credit [Member]
Loss Contingencies [Line Items]
Contract amounts	$ 7,591,029	$ 7,530,143
Letters of Credit [Member]
Loss Contingencies [Line Items]
Contract amounts	$ 366,112	$ 393,284

Fair Value Measurements (Financ

Fair Value Measurements (Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		$ 4,893,996	$ 4,675,304	$ 4,675,304
Derivative assets		4	23
Derivative liabilities		38,311	11,953
Total recurring fair value measurements - liabilities		5,300	5,700
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		4,893,996	4,675,304
Derivative assets	[1]	166,869	54,446
Total fair value measurements		5,060,865	4,729,750
Derivative liabilities	[1]	49,409	21,089
Total recurring fair value measurements - liabilities		49,409	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		109,203	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		249,693	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		8,196	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		2,124,531	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		1,742,806	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		659,567	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		4,893,996	4,675,304
Derivative assets	[1]	166,869	54,446
Total fair value measurements		5,060,865	4,729,750
Derivative liabilities	[1]	44,064	15,385
Total recurring fair value measurements - liabilities		44,064	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		109,203	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		249,693	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		8,196	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		2,124,531	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		1,742,806	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		659,567	808,215
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	[1]	5,345	5,704
Total recurring fair value measurements - liabilities		$ 5,345	$ 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]	Mar. 31, 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	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 5,704	$ 7,304
Cash settlement	(413)	(1,900)
Losses included in earnings	54	300
Ending balance	$ 5,345	$ 5,704

Fair Value Measurements (Overvi

Fair Value Measurements (Overview of the Valuation Techniques and Significant Unobservable Inputs) (Details) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Values, Liabilities		$ 38,311	$ 11,953
Recurring [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Values, Liabilities	[1]	49,409	21,089
Recurring [Member] | Level 3 [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Values, Liabilities	[1]	5,345	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		$ 5,345	$ 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		9 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		33 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		1.616	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	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral-dependent impaired loans	$ 281,121	$ 182,377
Other real estate owned and foreclosed assets, net	18,425	24,422
Total fair value measurements	299,546	206,799
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral-dependent impaired loans	281,121	182,377
Total fair value measurements	281,121	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	18,425	24,422
Total fair value measurements	$ 18,425	$ 24,422

Fair Value Measurements (Estima

Fair Value Measurements (Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available for sale securities	$ 4,893,996	$ 4,675,304	$ 4,675,304
Held to maturity securities	1,480,494	1,568,009
Derivative financial instruments	4	23
Derivative financial instruments	38,311	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	1,353,125	542,333
Available for sale securities	4,893,996	4,675,304
Held to maturity securities	1,562,577	1,611,004
Loans, net	21,388,867	21,044,079
Loans held for sale	67,587	55,864
Derivative financial instruments	166,869	54,446
Deposits	25,003,807	23,788,775
Federal funds purchased	330,330	195,450
Securities sold under agreements to repurchase	482,953	484,422
FHLB short-term borrowings	1,860,000	2,035,000
Long-term debt	231,044	226,098
Derivative financial instruments	49,409	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	1,353,125	542,333
Federal funds purchased	330,330	195,450
Securities sold under agreements to repurchase	482,953	484,422
FHLB short-term borrowings	1,860,000	2,035,000
Total Fair Value [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available for sale securities	4,893,996	4,675,304
Held to maturity securities	1,562,577	1,611,004
Loans, net	281,121	182,377
Loans held for sale	67,587	55,864
Derivative financial instruments	166,869	54,446
Long-term debt	231,044	226,098
Derivative financial instruments	44,064	15,385
Total Fair Value [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loans, net	21,107,746	20,861,702
Deposits	25,003,807	23,786,775
Derivative financial instruments	5,345	5,704
Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,353,125	542,333
Available for sale securities	4,893,996	4,675,304
Held to maturity securities	1,480,494	1,568,009
Loans, net	21,089,678	21,021,504
Loans held for sale	67,587	55,864
Derivative financial instruments	166,869	54,446
Deposits	25,008,496	23,803,575
Federal funds purchased	330,330	195,450
Securities sold under agreements to repurchase	482,953	484,422
FHLB short-term borrowings	1,860,000	2,035,000
Long-term debt	225,606	233,462
Derivative financial instruments	$ 49,409	$ 21,089

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Schedule of Impact of Adoption Reflected in Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Assets and Liabilities
Allowance for loan and lease losses	$ 240,662	$ 426,003	$ 191,251	$ 194,688	$ 194,514
Reserve for unfunded lending commitments	31,304	48,992	3,974
Total allowance for credit losses	271,966	474,995	$ 195,225
Retained Earnings
Decrease to retained earnings		$ (44,087)
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