Iberiabank (IBKC) 10-Q 8 May 20 2020 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-37532
Entity Registrant Name	IBERIABANK Corp
Entity Incorporation, State or Country Code	LA
Entity Address, Address Line One	200 West Congress Street
Entity Address, City or Town	Lafayette,
Entity Address, State or Province	LA
Entity Tax Identification Number	72-1280718
Entity Address, Postal Zip Code	70501
City Area Code	337
Local Phone Number	521-4003
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		52,663,861
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000933141
Current Fiscal Year End Date	--12-31
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock (par value $1.00 per share)
Trading Symbol	IBKC
Security Exchange Name	NASDAQ
Series B Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/400th Interest in
Trading Symbol	IBKCP
Security Exchange Name	NASDAQ
Series C Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/400th Interest in
Trading Symbol	IBKCO
Security Exchange Name	NASDAQ
Series D Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/400th Interest in
Trading Symbol	IBKCN
Security Exchange Name	NASDAQ

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets
Cash and due from banks	$ 279,388	$ 289,794
Interest-bearing deposits in other banks	665,674	604,929
Total cash and cash equivalents	945,062	894,723
Securities available for sale, at fair value	3,914,960	3,933,360
Securities held to maturity (fair values of $186,396 and $189,899, respectively)	177,960	182,961
Mortgage loans held for sale, at fair value	207,845	213,357
Loans and leases, net of unearned income	24,541,632	24,021,499
Allowance for loan and lease losses	(286,685)	(146,588)
Loans and leases, net	24,254,947	23,874,911
Premises and equipment, net	297,551	296,688
Goodwill	1,235,533	1,235,533
Other intangible assets	72,140	77,168
Other assets	1,133,985	1,004,749
Total Assets	32,239,983	31,713,450
Deposits:
Non-interest-bearing	6,628,901	6,319,806
Interest-bearing	18,897,336	18,899,543
Total deposits	25,526,237	25,219,349
Short-term borrowings	390,747	204,208
Long-term debt	1,288,172	1,343,687
Other liabilities	687,720	609,472
Total Liabilities	27,892,876	27,376,716
Shareholders’ Equity
Preferred stock, $1 par value - 5,000,000 shares authorized Non-cumulative perpetual, liquidation preference $10,000 per share; 23,750 shares issued and outstanding, respectively, including related surplus	228,485	228,485
Common stock, $1 par value - 100,000,000 shares authorized; 52,618,287 and 52,419,519 shares issued and outstanding, respectively	52,618	52,420
Additional paid-in capital	2,691,522	2,688,263
Retained earnings	1,263,298	1,322,805
Accumulated other comprehensive income (loss)	111,184	44,761
Total Shareholders’ Equity	4,347,107	4,336,734
Total Liabilities and Shareholders’ Equity	$ 32,239,983	$ 31,713,450

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Securities held to maturity, fair values	$ 186,396	$ 189,899
Preferred stock, par value (in usd per share)	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Liquidation preference (per share)	$ 10,000	$ 10,000
Preferred stock, shares issued	23,750	23,750
Preferred stock, shares outstanding	23,750	23,750
Common stock, par value (in usd per share)	$ 1	$ 1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	52,618,287	52,419,519
Common stock, shares outstanding	52,618,287	52,419,519

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest and dividend income
Loans and leases, including fees	$ 271,746	$ 284,879
Mortgage loans held for sale, including fees	1,678	1,054
Taxable securities	23,481	33,916
Tax-exempt securities	1,921	2,209
Other	4,103	4,026
Total interest and dividend income	302,929	326,084
Interest expense
Deposits	63,676	60,235
Short-term borrowings	266	5,716
Long-term debt	8,645	9,649
Total interest expense	72,587	75,600
Net interest income	230,342	250,484
Provision for expected credit losses	68,971	13,763
Net interest income after provision for expected credit losses	161,371	236,721
Non-interest income
Income from bank owned life insurance	1,822	1,797
Other non-interest income	4,451	4,051
Total non-interest income	64,656	52,509
Non-interest expense
Salaries and employee benefits	102,545	98,296
Net occupancy and equipment	19,984	18,564
Communication and delivery	3,677	3,700
Marketing and business development	3,710	4,118
Computer services expense	10,167	9,157
Professional services	5,322	4,450
Credit and other loan-related expense	3,643	2,859
Insurance	4,559	4,186
Travel and entertainment	2,740	2,430
Amortization of acquisition intangibles	4,187	5,009
Impairment of long-lived assets and other losses	3,317	1,064
Other non-interest expense	13,576	4,920
Total non-interest expense	177,427	158,753
Income before income tax expense	48,600	130,477
Income tax expense	12,175	30,346
Net income	36,425	100,131
Less: Preferred stock dividends	3,598	3,598
Net income available to common shareholders	32,827	96,533
Less: Earnings allocated to unvested restricted stock	367	933
Earnings allocated to common shareholders	$ 32,460	$ 95,600
Earnings per common share - Basic (in usd per share)	$ 0.62	$ 1.76
Earnings per common share - Diluted (in usd per share)	0.62	1.75
Cash dividends declared per common share (in usd per share)	$ 0.47	$ 0.43
Comprehensive income
Net income	$ 36,425	$ 100,131
Unrealized gains on securities:
Unrealized holding gains arising during the period (net of tax effects of $17,342 and $10,675, respectively)	56,424	41,408
Unrealized gains on securities, net of tax	56,424	41,408
Fair value of derivative instruments designated as cash flow hedges:
Change in fair value of derivative instruments designated as cash flow hedges during the period (net of tax effects of $3,209 and $471, respectively)	10,441	(2,185)
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $136 and $75, respectively)	442	(227)
Fair value of derivative instruments designated as cash flow hedges, net of tax	9,999	(1,958)
Other comprehensive income (loss), net of tax	66,423	39,450
Comprehensive income	102,848	139,581
Mortgage income
Non-interest income
Non-interest income	23,245	11,849
Service charges on deposit accounts
Non-interest income
Non-interest income	12,525	12,810
Title revenue
Non-interest income
Non-interest income	5,936	5,225
Commission income
Non-interest income
Non-interest income	4,191	4,664
Broker commissions
Non-interest income
Non-interest income	2,127	1,953
ATM and debit card fee income
Non-interest income
Non-interest income	2,838	2,582
Credit card and merchant-related income
Non-interest income
Non-interest income	3,295	3,411
Trust department income
Non-interest income
Non-interest income	$ 4,226	$ 4,167

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Unrealized holding gains (losses) arising during the period, tax expense (benefit)	$ 17,342	$ 10,675
Change in fair value of derivative instruments designated as cash flow hedges, tax expense	3,209	(471)
Reclassification adjustment for gains (losses) included in net income, tax expense (benefit)	$ (136)	$ (75)

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2018		13,750	54,796,231
Beginning balance at Dec. 31, 2018	$ 4,056,277	$ 132,097	$ 54,796	$ 2,869,416	$ 1,042,718	$ (42,750)
Increase (Decrease) in Shareholders' Equity
Net income	100,131				100,131
Other comprehensive income (loss)	39,450					39,450
Cash dividends declared	(23,457)				(23,457)
Preferred stock dividends	(3,598)				(3,598)
Common stock issued under incentive plans, net of shares surrendered in payment (in shares)			142,954
Common stock issued under incentive plans, net of shares surrendered in payment	(4,445)		$ 143	(4,588)
Common stock repurchases (in shares)			(387,921)
Common stock repurchases	(29,946)		$ (388)	(29,558)
Share-based compensation expense	5,572			5,572
Ending balance (in shares) at Mar. 31, 2019		13,750	54,551,264
Ending balance at Mar. 31, 2019	4,141,831	$ 132,097	$ 54,551	2,840,842	1,117,641	(3,300)
Beginning balance (in shares) at Dec. 31, 2019		23,750	52,419,519
Beginning balance at Dec. 31, 2019	4,336,734	$ 228,485	$ 52,420	2,688,263	1,322,805	44,761
Increase (Decrease) in Shareholders' Equity
Net income	36,425				36,425
Other comprehensive income (loss)	66,423					66,423
Cash dividends declared	(24,729)				(24,729)
Preferred stock dividends	(3,598)				(3,598)
Common stock issued under incentive plans, net of shares surrendered in payment (in shares)			198,768
Common stock issued under incentive plans, net of shares surrendered in payment	(3,575)		$ 198	(3,773)
Share-based compensation expense	7,032			7,032
Ending balance (in shares) at Mar. 31, 2020		23,750	52,618,287
Ending balance at Mar. 31, 2020	$ 4,347,107	$ 228,485	$ 52,618	$ 2,691,522	$ 1,263,298	$ 111,184

Consolidated Statements of Sh_2

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per common share (in usd per share)	$ 0.47	$ 0.43

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows from Operating Activities
Net income	$ 36,425	$ 100,131
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion, including amortization of purchase accounting adjustments and market value adjustments	8,427	4,018
Provision for expected credit losses	68,971	13,763
Share-based compensation expense - equity awards	7,032	5,572
(Gain) loss on sale of OREO and long-lived assets, net of impairment	(956)	278
Deferred income tax expense	8,529	17,861
Originations of mortgage loans held for sale	(533,032)	(326,244)
Proceeds from sales of mortgage loans held for sale	563,199	320,853
Realized and unrealized gain on mortgage loans held for sale, net	(24,656)	(11,593)
Other operating activities, net	(43,782)	152,430
Net Cash Provided by Operating Activities	90,157	277,069
Cash Flows from Investing Activities
Proceeds from maturities, prepayments and calls of securities available for sale	242,074	136,627
Purchases of securities available for sale	(156,706)	(179,565)
Proceeds from maturities, prepayments and calls of securities held to maturity	4,316	7,787
Purchases of equity securities	0	(14,753)
Proceeds from sales of equity securities	0	3,637
Increase in loans	(517,085)	(446,284)
Proceeds from sales of premises and equipment	402	91
Purchases of premises and equipment	(7,065)	(3,182)
Proceeds from dispositions of OREO	12,237	1,980
Cash paid for additional investment in tax credit entities	(673)	(2,828)
Other investing activities, net	(100)	0
Net Cash Used in Investing Activities	(422,600)	(496,490)
Cash Flows from Financing Activities
Increase in deposits	306,888	328,631
Net change in short-term borrowings	186,539	(376,751)
Proceeds from long-term debt	0	400,000
Repayments of long-term debt	(55,430)	(90,560)
Cash dividends paid on common stock	(48,042)	(22,466)
Cash dividends paid on preferred stock	(3,598)	(3,598)
Net share-based compensation stock transactions	(3,575)	(4,445)
Payments to repurchase common stock	0	(29,946)
Net Cash Provided by Financing Activities	382,782	200,865
Net Increase (Decrease) In Cash and Cash Equivalents	50,339	(18,556)
Cash and Cash Equivalents at Beginning of Period	894,723	690,453
Cash and Cash Equivalents at End of Period	945,062	671,897
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	524	2,727
Supplemental Disclosures
Interest on deposits and borrowings	$ 76,890	$ 71,010

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	BASIS OF PRESENTATION, AND CHANGES IN SIGNIFICANT ACCOUNTING POLICIES IBERIABANK Corporation is a financial holding company based in Lafayette, Louisiana. The accompanying unaudited consolidated financial statements include the accounts of IBERIABANK Corporation and its consolidated subsidiaries (the Company). Through its subsidiaries, the Company provides a full range of commercial and consumer banking services, including private banking, small business, wealth and trust management, retail brokerage, mortgage, commercial leasing and equipment financing, and title insurance services through locations in Louisiana, Arkansas, Tennessee, Alabama, Texas, Florida, Georgia, South Carolina, North Carolina, Mississippi, Missouri, and New York. The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all information and notes necessary for complete financial statements in accordance with GAAP. In the opinion of management, the accompanying unaudited consolidated financial statements contain all the significant adjustments, consisting of normal and recurring items, considered necessary for fair presentation. These interim financial statements should be read in conjunction with the Company's audited consolidated financial statements and notes in the Annual Report on Form 10-K for the year ended December 31, 2019 . Operating results for the interim period are not necessarily indicative of the results that may be expected for the full year. All significant intercompany balances and transactions have been eliminated in consolidation. Certain amounts reported in prior periods have been reclassified to conform to the current period presentation. See the Glossary of Defined Terms included in this Report for terms used herein. Pending Merger As previously disclosed, on November 3, 2019, the Company entered into a merger agreement to combine with First Horizon National Corporation (First Horizon) in an all-stock merger of equals. On April 24, 2020, the Company received shareholder approval for the merger. The merger is expected to be completed in the second quarter of 2020, pending receipt of the remaining regulatory approvals and other customary closing conditions. Changes in Significant Accounting Policies On January 1, 2020, the Company adopted ASU No. 2016-13, “ Financial Instruments - Credit Losses (Topic 326) ,” (ASC 326) which significantly changed the measurement of credit losses for certain financial investments, such as loans (including unfunded loan commitments) and investment securities. See Note, 2, Recent Accounting Pronouncements, in the accompanying consolidated financial statements for a complete discussion. The adoption of ASC 326 impacts the accounting policies for the following: Investment Securities; Loans and Leases; and Allowance for Expected Credit Losses. Other than the accounting policy updates below, there have been no changes to the accounting policies as described in the Company’s 2019 Form 10-K. Investment Securities Management determines the appropriate accounting classification of debt and equity securities at the time of acquisition and re-evaluates such designations at least quarterly. Debt securities that management has the ability and intent to hold to maturity are classified as HTM and carried at cost, adjusted for amortization of premiums and accretion of discounts using methods approximating the interest method. Securities acquired with the intent of recognizing short-term profits or which are actively bought and sold are classified as trading securities and reported at fair value. Securities not classified as HTM or trading are classified as AFS and reported at fair value. The Company evaluates its investment securities portfolio for impairment on a quarterly basis as follows: HTM Securities: The Company maintains an allowance for expected credit losses appropriate to absorb estimated lifetime credit losses for HTM securities where there is a risk of credit loss. HTM securities where there is a risk of credit loss are segmented by credit rating and duration and an allowance for expected credit losses is calculated based on external historical loss data, taking into consideration management’s forecast of future economic conditions. The allowance of expected credit losses, if required, is recognized on the consolidated balance sheet with a corresponding adjustment to earnings. AFS Securities: Declines in the fair value of individual AFS securities below their amortized cost basis are reviewed to determine if the decline is due to credit-related factors. Impairment that is not credit-related is recognized in other comprehensive income, net of applicable taxes. Credit-related impairment is recognized as an allowance for expected credit losses on the consolidated balance sheet with a corresponding adjustment to earnings. However, if the Company intends to sell the impaired AFS security or it is more likely than not that the Company will be required to sell such a security before recovering the amortized cost basis of the security, the AFS security’s amortized cost basis is reduced by the decline in fair value with the entire credit loss recognized in the consolidated statement of income. Prior to January 1, 2020, investment securities were evaluated for indicators of other than temporary impairment (OTTI) on a quarterly basis. Declines in the fair value of individual HTM and AFS securities below their amortized cost basis were reviewed to determine whether the declines were other than temporary. In estimating OTTI losses, management considered 1) the length of time and the extent to which the fair value had been less than the amortized cost basis, 2) the financial condition and near-term prospects of the issuer, 3) its intent to sell and whether it was more likely than not that the Company would be required to sell those securities before the anticipated recovery of the amortized cost basis, and 4) for debt securities, the recovery of contractual principal and interest. For securities that the Company did not expect to sell, or it was not more likely than not it would be required to sell prior to recovery of its amortized cost basis, the credit component of an OTTI was recognized in earnings and the non-credit component was recognized in OCI. For securities that the Company did expect to sell, or it was more likely than not that it would be required to sell prior to recovery of its amortized cost basis, both the credit and non-credit component of an OTTI were recognized in earnings. Subsequent to recognition of OTTI, an increase in expected cash flows was recognized as a yield adjustment over the remaining expected life of the security based on an evaluation of the nature of the increase. Other equity securities primarily consist of stock acquired for regulatory purposes, such as Federal Home Loan Bank stock and Federal Reserve Bank stock and are included in “other assets." Gains or losses on securities sold are recorded on the trade date, using the specific identification method. Loans and Leases Loans The Company offers commercial and consumer loans for its customers. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at amortized cost, which represents the principal amount outstanding less charge-offs, net of any unearned income, unamortized net loan origination fees and direct costs on originated loans, and net premiums or discounts on acquired loans. Interest income is accrued as earned over the term of the loans based on the principal balance outstanding. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield. Accrued interest is reported within other assets in the consolidated balance sheet. Acquired loans are recorded at fair value on the acquisition date. The determination of fair value includes credit risk assumptions and any resulting credit discounts as well as estimates related to discount rates, expected prepayments, and the amount and timing of undiscounted expected principal, interest, and other cash flows. Additionally, at the time of acquisition, acquired loans are classified as either purchased credit deteriorated (PCD) or non-purchased credit deteriorated (non-PCD). Acquired loans which have experienced more-than-insignificant deterioration in credit since origination are classified as PCD Loans. All acquired loans not considered to be purchased credit deteriorated loans are classified as acquired non-PCD Loans. An initial allowance for expected credit losses (AECL) is established at the acquisition date for acquired loans and the classification of PCD or non-PCD determines how the initial AECL is recorded. For PCD Loans, the AECL is recorded with a corresponding increase to the amortized cost basis of the loan by reducing the purchase premium or discount recognized on the acquired loan. For acquired non-PCD loans, the AECL is recorded with a corresponding charge to earnings. Subsequent to acquisition, the AECL for both PCD Loans and acquired non-PCD loans is determined using the same methodology as originated loans. The non-credit related purchase premium or discount on acquired loans is amortized or accreted to income over the estimated life of the loans as an adjustment to yield using the effective interest rate calculated at the acquisition date. Prior to January 1, 2020, acquired loans that reflected credit deterioration since origination to the extent that it was probable that the Company would be unable to collect all contractually required payments were classified as purchased impaired loans (“acquired impaired loans”). All other acquired loans were classified as purchased non-impaired loans (“acquired non-impaired loans”). At the time of acquisition, acquired impaired loans were accounted for individually or aggregated into loan pools with similar characteristics. From these pools, the Company used certain loan information to estimate the expected cash flows for each loan pool. For acquired impaired loans, the expected cash flows at the acquisition date in excess of the fair value of loans were recorded as interest income over the life of the loans using a level yield method if the timing and amount of future cash flows was reasonably estimable. For acquired non-impaired loans, the difference between the fair value and unpaid principal balance of the loan at acquisition, referred to as a purchase premium or discount, was amortized or accreted to income over the estimated life of the loans as an adjustment to yield. Subsequent to acquisition, the Company performed cash flow re-estimations at least quarterly for each acquired impaired loan or loan pool. Increases in estimated cash flows above those expected at the time of acquisition were recognized on a prospective basis as interest income over the remaining life of the loan and/or pool. Decreases in expected cash flows subsequent to acquisition generally resulted in recognition of a provision for credit loss. The measurement of cash flows involved several assumptions and judgments, including prepayments, default rates and loss severity among other factors. All of these factors were inherently subjective and significant changes in the cash flow estimations could result over the life of the loan. Leases The Company leases equipment to commercial customers primarily through direct financing and sales-type leases. Equipment financing leases are reported at the net lease investment, which represents the sum of minimum lease payments over the lease term and the estimated residual value, less unearned interest income. Interest income is accrued as earned over the term of the lease based on the net investment in leases. Fees incurred to originate the lease are deferred and recognized as an adjustment of the yield on the lease. Portfolio Segmentation The Company’s loan portfolio is disaggregated into two portfolio segments: commercial loans and leases and consumer loans. The Company further disaggregates the commercial loans and leases and the consumer loans portfolio segment into receivable classes for purposes of monitoring and assessing credit quality. Receivable classes within the commercial loan and lease portfolio segment include commercial real estate-construction, commercial real estate-owner occupied, commercial real estate-non-owner occupied, and commercial and industrial, which includes equipment financing leases. Receivable classes within the consumer loan portfolio segment include residential mortgage, home equity, and other consumer. Prior to January 1, 2020, the Company’s loan portfolio was disaggregated into three portfolio segments: commercial, residential mortgage, and consumer and other loans. Receivable classes within the commercial loan portfolio segment included commercial real estate-construction, commercial real estate-owner-occupied, commercial real estate-non-owner occupied, and commercial and industrial. Receivable classes within the consumer and other loans portfolio segment included home equity, indirect automobile, credit card and other. Troubled Debt Restructurings The Company periodically grants concessions to its customers in an attempt to protect as much of its investment as possible and minimize risk of loss. These concessions may include restructuring the terms of a loan to alleviate the burden of the customer’s near-term cash requirements. In order to be classified as a TDR, the Company must conclude that the restructuring constitutes a concession and the customer is experiencing financial difficulties. The Company defines a concession to the customer as a modification of existing terms for economic or legal reasons that it would otherwise not consider. The concession is either granted through an agreement with the customer or is imposed by a court of law. Concessions include modifying original loan terms to reduce or defer cash payments required as part of the loan agreement, including but not limited to: • a reduction of the stated interest rate for the remaining original life of the loan, • extension of the maturity date or dates at a stated interest rate lower than the current market rate for new loans with similar risk characteristics, • reduction of the face amount or maturity amount of the loan as stated in the agreement, or • reduction of accrued interest receivable on the loan. In its determination of whether the customer is experiencing financial difficulties, the Company considers numerous indicators, including, but not limited to: • whether the customer is currently in default on its existing loan(s), or is in an economic position where it is probable the customer will be in default on its loan(s) in the foreseeable future without a modification, • whether the customer has declared bankruptcy, • whether there is substantial doubt about the customer’s ability to continue as a going concern, • whether, based on its projections of the customer’s current capabilities, the Company believes the customer’s future cash flows will be insufficient to service the loan, including interest, in accordance with the contractual terms of the existing agreement for the foreseeable future, and • whether the customer cannot obtain sufficient funds from other sources at an effective interest rate equal to the current market rate for a similar loan for a non-troubled debtor. If the Company concludes that both a concession has been granted and the customer is experiencing financial difficulties, the Company identifies the loan as a TDR. Prior to January 2020, all TDRs were considered impaired loans and acquired impaired loans accounted for within pools were not reviewed for TDR classification if modified. Non-accrual and Past Due Loans and Leases (Including Loan Charge-offs) Loans and leases are generally considered past due when contractual payments of principal and interest have not been received within 30 days after the contractual due date. Residential mortgage loans are considered past due when contractual payments have not been received for two consecutive payment dates. Loans and leases are placed on non-accrual status when any of the following occur: 1) the loan or lease is maintained on a cash basis because of deterioration in the financial condition of the borrower; 2) collection of the full contractual amount of principal and interest is not expected even if the loan or lease is currently paying as agreed; or 3) when principal or interest has been in default for a period of 90 days or more, unless the loan or lease is both well-secured and in the process of collection. Factors considered in determining the collection of the full contractual amount of principal and interest include assessment of the borrower’s cash flow, valuation of underlying collateral, and the ability and willingness of guarantors to provide credit support. Certain commercial loans and leases are also placed on non-accrual status when payment is not past due and full payment of principal and interest is expected, but the Company has doubt about the borrower’s ability to comply with existing repayment terms. Consideration will be given to placing a loan or lease on non-accrual due to the deterioration of the debtor’s repayment ability, the repayment of the loan or lease becoming dependent on the liquidation of collateral, an existing collateral deficiency, the loan or lease being classified as "doubtful" or "loss," the client filing for bankruptcy, and/or foreclosure being initiated. For all commercial loans and leases, the determination of a borrower’s ability to make the required principal and interest payments is based on an examination of the borrower’s current financial statements, industry, management capabilities, and other qualitative factors. Loans and leases are evaluated for potential charge-off in accordance with the parameters discussed in the following paragraph or when the loan or lease is placed on non-accrual status, whichever is earlier. Prior to January 1, 2020, acquired impaired loans were placed on non-accrual status when the Company could not reasonably estimate cash flows on the loan or loan pool. Loans and leases within the commercial portfolio are generally evaluated for charge-off at 90 days past due, unless both well-secured and in the process of collection. Closed and open-end consumer loans and leases are evaluated for charge-off no later than 120 days past due. Any outstanding loan balance in excess of the fair value of the collateral less costs to sell is charged-off no later than 120 days past due for loans secured by real estate. For non-real estate secured loans and leases, in lieu of charging off the entire balance, loans or leases may be written down to the fair value of the collateral less costs to sell if repossession of collateral is assured and in process. Prior to January 1, 2020, acquired impaired loans were not generally evaluated for charge-off. The accrual of interest, as well as the amortization/accretion of any remaining unamortized net deferred fees or costs and discount or premium, is discontinued at the time the loan or lease is placed on non-accrual status. Accrued but uncollected interest for all loans and leases that are placed on non-accrual status is generally reversed through interest income at 90 days past due. As accrued but uncollected interest is reversed on a timely basis, the Company does not estimate an AECL for accrued interest. Cash receipts received on non-accrual loans or leases are generally applied against principal until the loan or lease has been collected in full, after which time any additional cash receipts are recognized as interest income (i.e., cost recovery method). However, interest may be accounted for under the cash-basis method as long as the remaining recorded investment in the loan is deemed fully collectible. Loans and leases are returned to accrual status when the borrower has demonstrated a capacity to continue payment of the debt (generally a minimum of six months of sustained repayment performance) and collection of contractually required principal and interest associated with the debt is reasonably assured. Additionally, for a non-accrual TDR to be returned to accrual status, a current, well-documented credit analysis is required and the borrower must have complied with all terms of the modification. At such time, the accrual of interest and amortization/accretion of any remaining unamortized net deferred fees or costs and discount or premium shall resume. Any interest income which was applied to the principal balance shall not be reversed and subsequently will be recognized as an adjustment to yield over the remaining life of the loan. Individually Assessed Loans and Leases/Impaired Loans When a loan or lease no longer shares risk characteristics with other loans or leases, it is individually assessed for impairment. While management considers a variety of factors in determining when a loan no longer shares risk characteristics with other loans, generally all TDR and non-accrual loans above certain thresholds are considered to meet this requirement and are individually assessed for impairment. Impairment losses are measured on a loan-by-loan basis for these commercial and consumer loans and leases, based on either the present value of expected future cash flows discounted at the loan or lease’s effective interest rate or the fair value of the collateral if the loan or lease is collateral-dependent. This measurement requires significant judgment and use of estimates, and the actual loss ultimately recognized by the Company may differ significantly from the estimates. Prior to January 1, 2020, a loan was considered to be impaired when, based on current information and events, it was probable that the Company would be unable to collect the scheduled payments of principal and/or interest in accordance with the contractual terms of the loan agreement. Generally all TDRs regardless of the outstanding balance amount or portfolio classification, and all acquired impaired loans were considered to be impaired. Loans that experienced insignificant payment delays and payment shortfalls generally were not classified as impaired. Impairment losses were measured on a loan-by-loan basis for commercial and certain residential mortgage or consumer loans, based on either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s observable market price, or the fair value of the collateral if the loan was collateral-dependent. Allowance for Expected Credit Losses The Company maintains the AECL at a level that management believes appropriate to absorb estimated lifetime credit losses, including losses associated with unfunded commitments. The AECL includes the allowance for loan and lease losses (ALLL) (contra asset) and the reserve for unfunded commitments (liability). Determination of the appropriate AECL involves a high degree of complexity and requires significant judgment regarding the credit quality of the loan portfolio and management’s view of future economic conditions. Several factors are taken into consideration in the determination of the overall AECL which include, but are not limited to, the overall risk profiles of the loan and lease portfolios, net charge-off experience, the level of loans and leases that require an individual assessment for impairment, the level of non-performing loans and leases, the level of 90 days past due loans and leases, the value of collateral, among other factors. The Company also considers forecasts of future national and regional economic conditions, overall asset quality trends, changes in lending practices and procedures, trends in the nature and volume of the loan portfolio (including the existence and effect of any portfolio concentrations), changes in experience and depth of lending staff, the Company’s legal, regulatory and competitive environment, and data availability and applicability that might impact the portfolio or the manner in which it estimates losses, risk rating accuracy, and risk identification. The Company has developed multiple current expected credit loss models (ECL Models) which segment the Company’s loan and lease portfolio by borrower type (i.e. commercial and consumer) and loan or lease type to estimate lifetime expected credit losses for loans and leases that share similar risk characteristics. These ECL Models primarily use a probability-of-default methodology to estimate expected credit losses for all loan and lease commitments. Within each ECL Model, PDs and LGDs are established at the individual loan or lease commitment level based on various loan or lease specific characteristics. For commercial loans and leases, these characteristics include customer size, industry sector, geographic region, risk rating and collateral/property type, among others. For consumer loans, these characteristics include geographic region, loan size, customer size, fixed or variable rate, lien position, and FICO score, among others. The ECL Models use both internal and external historical loss data, as appropriate, for all available historical periods and a blend of multiple economic forecasts as approved by ALCO to estimate expected credit losses over a reasonable and supportable forecast period. The ECL Models then revert to longer term historical loss experience on a straight-line basis to arrive at lifetime expected credit losses. The selection of the economic forecasts, the forecast period and reversion period and methodology are reviewed and approved quarterly. The ECL Models also take into consideration the effects of prepayments and draw-down assumptions for any unfunded commitments, as applicable. Qualitative adjustments are incorporated into the ECL Model-based estimate of expected credit losses to accommodate for the imprecision of certain assumptions and uncertainties inherent in the calculation. Loans or leases that no longer share similar risk characteristics with other loans or leases in the portfolio must be individually evaluated for impairment. For these loans and leases, the AECL is determined on an individual loan and lease commitment basis, taking into consideration facts and circumstances specific to each borrower. As discussed above, the AECL for individually assessed loans or leases is based on the difference between the recorded investment in the loan or lease and either the estimated net present value of projected cash flows or the estimated value of the collateral associated with a collateral-dependent loan, less cost to sell. The overall AECL is allocated between the ALLL and the reserve for unfunded commitments based on the loan’s percentage funded and the future funding expectations of the loan. Prior to January 1, 2020, the allowance for credit losses was maintained at a level appropriate to absorb estimated probable credit losses incurred in the loan portfolio, including unfunded commitments as of the consolidated balance sheet date. The manner in which the allowance for credit losses was determined was based on 1) the accounting method applied to the underlying loans and 2) whether the loan was required to be measured for impairment. The Company delineated between loans accounted for under the contractual yield method, legacy loans (originated loans), acquired non-impaired loans, and acquired impaired loans. Further, for legacy and acquired non-impaired loans, the Company attributed portions of the allowance for credit losses to loans and loan commitments that it measured individually, and groups of homogeneous loans and loan commitments that it measured collectively for impairment. Prior to January 1, 2020, the allowance for loan losses for all impaired loans (excluding acquired impaired loans) was determined on an individual loan basis, considering the facts and circumstances specific to each borrower. The allowance was based on the difference between the recorded investment in the loan and generally either the estimated net present value of projected cash flows or the estimated value of the collateral associated with a collateral-dependent loan. The determination of the allowance for loan losses for acquired impaired loans prior to January 1, 2020 is further discussed in the “Loans” section of this footnote. Prior to January 1, 2020, the allowance for loan losses for all non-impaired loans (excluding acquired impaired loans) was calculated based on pools of loans with similar characteristics. The pool-level allowance was calculated through the application of PD and LGD factors for each individual loan. PDs and LGDs were determined based on historical default and loss information for similar loans. For purposes of establishing estimated loss percentages for pools of loans that shared common risk characteristics, the Company’s loan portfolio was segmented by various loan characteristics including loan type, risk rating for commercial, Vantage or FICO score for residential mortgage and consumer, past due status for residential mortgage and consumer and call report code. The default and loss information was measured over an appropriate period for each loan pool and adjusted as deemed appropriate. Qualitative adjustments were incorporated into the pool-level analysis to accommodate for the imprecision of certain assumptions and uncertainties inherent in the calculation.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2020
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Pronouncements adopted during the quarter ended March 31, 2020: ASU No. 2016-13, ASU No. 2019-04 (portion related to ASC 326), ASU No. 2019-05, ASU No. 2019-11, and ASU No. 2020-03 In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments. The guidance, along with subsequent related updates issued during 2019, introduces an impairment model that is based on expected credit losses (ECL) rather than incurred losses, to estimate credit losses on certain types of financial instruments, such as loans and held-to-maturity (HTM) securities, including certain off-balance sheet financial instruments, such as loan commitments. The measurement of ECL should consider historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments, over the contractual term. Financial instruments with similar risk characteristics must be grouped together when estimating ECL. In addition, ASC 326 expands credit quality disclosures. ASC 326 also provides for a simplified accounting model for purchased financial assets with a more-than-insignificant amount of credit deterioration since their origination (purchased credit deteriorated). The initial estimate of expected credit losses for purchase credit deteriorated financial assets is recognized as an AECL with an offset (i.e., increase) to the cost basis of the related financial asset at acquisition. Additionally, ASC 326 amends the current AFS security impairment model for debt securities. The new model will require an estimate of ECL when the fair value is below the amortized cost of the asset. The credit-related impairment (and subsequent recoveries) are recognized as an allowance on the balance sheet with a corresponding adjustment to the income statement. Non-credit related losses will continue to be recognized through OCI. The Company adopted these ASUs as of January 1, 2020 through a cumulative-effect adjustment to opening retaining earnings. Estimation Methodology The Company has developed multiple current expected credit loss models (ECL Models) which segment the Company’s loan and lease portfolio by borrower type (i.e. commercial and consumer) and loan type to estimate lifetime expected credit losses for loans and leases. The ECL Models primarily use a probability-of-default methodology to estimate expected credit losses. Within each ECL Model, loans and leases are further segregated based on additional risk characteristics specific to that loan or leases type, such as risk rating, industry sector, company and/or loan size, collateral type, geographic location and FICO score. The Company uses both internal and external historical loss data in the ECL Models, as appropriate. The estimate of expected credit losses is inherently subjective, as it requires management to exercise judgment in determining appropriate factors to be used to determine the allowance. Following are some of the most significant factors used to estimate expected credit losses under ASC 326: Economic Forecasts : Management selected economic variables it believes to be the most relevant for estimating losses based on the composition of the loan and leases portfolio and customer base, including property values, employment and unemployment levels, oil prices and other key economic measures. The Company considers a variety of economic forecasts and selects multiple economic forecasts it believes represent future changes in macroeconomic conditions. The Company uses a blend of the selected economic forecasts to estimate credit losses. Forecast Period : Management believes that it can reasonably forecast credit losses over an eighteen month period, taking into consideration historical information, current information, and reasonable and supportable economic forecasts. Management will re-evaluate the forecast period on a quarterly basis and may adjust the forecast period in response to changes in the economic environment and other factors. Reversion Methodology : For contractual periods beyond the eighteen month forecast period, the Company reverts over a twelve-month period to longer term historical loss experience on a straight-line basis to arrive at lifetime expected credit losses. Management will re-evaluate the reversion methodology on a quarterly basis. Credit losses for loans and leases which no longer share risk characteristics with other loans or leases, primarily non-accrual and TDR loans are individually assessed for impairment. A specific allowance is determined for these loans and leases determined using either the present value of expected cash flows or the fair value of the underlying collateral. The AECL calculated by the ECL Models for the Company’s loan and lease portfolio is allocated between the ALLL and the reserve for unfunded commitments based on the loan’s percentage funded and future funding expectations of the loan. The Company elected not to measure an allowance for expected credit losses for accrued interest as its reverses uncollectible accrued interest through interest income in a timely manner. Accrued interest will continue to be reported within other assets in the consolidated balance sheet. The Company did not elect the one-time fair value option transition expedient for financial instruments recorded at amortized cost. Additionally, the Company elected to discontinue the use of pools to account for purchased credit deteriorated financial assets. ASC 326 also requires an estimate of expected credit losses on the HTM and AFS debt securities portfolios. Most of these portfolios consist of agency-backed securities that inherently have an immaterial risk of loss. For non-agency-backed HTM securities, the Company estimates expected credit losses by segmenting the portfolio by credit rating and duration and applying external historical loss data, taking into consideration management's forecast of future economic conditions, as discussed above. For non-agency-backed AFS securities where amortized cost exceeds fair value, the Company reviews each security to determine if any portion of the unrealized loss is credit-related. Impact of Adoption The impact of the adoption of ASC 326 on the Company's loan and lease portfolio was as follows: (in thousands) December 31, 2019 CECL Adoption January 1, 2020 Allowance for Expected Credit Losses Real estate - construction $ 9,993 $ 3,332 $ 13,325 Real estate - owner-occupied 16,115 (7,536 ) 8,579 Real estate - non-owner occupied 38,170 28,859 67,029 Commercial & industrial 62,112 (14,656 ) 47,456 Residential mortgage 10,209 71,264 81,473 Home equity 14,231 2,808 17,039 Other consumer loans 12,395 (1,752 ) 10,643 Total $ 163,225 $ 82,319 $ 245,544 Retained Earnings Increase in allowance for expected credit losses $ 82,319 Balance sheet reclassification 5,987 Total pre-tax effect 88,306 Tax effect 20,701 Decrease to retained earnings $ 67,605 The increase in the AECL primarily relates to required increases for loans previously classified as acquired non-impaired. The AECL for residential mortgage loans increased due to the requirement to estimate lifetime expected credit losses and the remaining length of time to maturity for these loans versus a loss emergence period. The AECL for non-owner-occupied commercial real estate loans also increased reflecting higher LGDs under the CECL model. The balance sheet reclassification represents the adjustment to the amortized cost basis of purchased credit deteriorated loans to reflect the addition of the allowance for expected credit losses at the date of adoption. At the time of adoption, the Company recognized the economy was vulnerable to major shocks, fiscal policy missteps, other geopolitical events and the outcome of the pending U.S. elections. The transition adjustment reflected the Company's view of a relatively stable macroeconomic environment over the next eighteen months. While ASC 326 results in a higher AECL, it does not change the overall credit risk in the Company’s loan and lease portfolios or the ultimate losses therein. The Company expects future changes in the AECL to be more volatile under ASC 326 as the AECL in future periods will be based on a variety of factors, including changes in loan and lease volumes, the credit quality of the loan and lease portfolio, and forecasts of future economic conditions, which are outside of the Company’s control. The adoption of ASC 326 for the Company’s HTM and AFS debt securities was not material. ASU No. 2018-13 In August 2018, the FASB released ASU No. 2018-13, Fair Value Measurement (ASC 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates, adds and modifies certain disclosure requirements for fair value measurements. The ASU is effective for fiscal years beginning after December 15, 2019, including interim periods, with early adoption permitted. The Company adopted ASU No. 2018-13 as of January 1, 2020. While adoption of this ASU will result in changes to existing disclosures, it did not have an impact on the Company’s financial position or results of operations. ASU No. 2018-17 In October 2018, the FASB released ASU No. 2018-17, Consolidation (ASC 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities, which improves the consistency of the application of the variable interest entity (VIE) related party guidance for common control arrangements. This ASU requires reporting entities to consider indirect interests held through related parties under common control on a proportional basis rather than as the equivalent of a direct interest in its entirety (as currently required in GAAP) when determining whether a decision-making fee is a variable interest. ASU No. 2018-17 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. The guidance will be applied retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Company adopted ASU No. 2018-17 as of January 1, 2020. The adoption of the ASU did not have a material impact to the Company’s consolidated financial statements. Based on the Company’s invested interests at adoption, no transition adjustment was needed. ASU No. 2019-04 In April 2019, the FASB released ASU No. 2019-04, Codification Improvements to Financial Instruments-Credit Losses (ASC 326), Derivatives and Hedging (ASC 815), and Financial Instruments (ASC 825) . The amendments in the ASU improve the Codification by eliminating inconsistencies and providing clarifications. The amendments related to the credit losses standard are discussed above under ASU 2016-13. With respect to hedge accounting, the ASU addresses partial-term fair value hedges, fair value hedge basis adjustments, and certain transition requirements, among other things. For recognizing and measuring financial instruments, the ASU addresses the scope of the guidance, the requirement for re-measurement under ASC 820 when using the measurement alternative, certain disclosure requirements and which equity securities have to be re- measured at historical exchange rates. Since the Company early adopted the guidance in ASU No. 2017-12, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities in 2018, the amended hedge accounting guidance in ASU No. 2019-04 is effective as of the beginning of the first annual reporting period beginning after April 25, 2019 with early adoption permitted on any date after the issuance of this ASU. The Company adopted ASU No. 2017-08 as of January 1, 2020. The adoption of the ASU did not have a material impact to the Company’s consolidated financial statements. Pronouncements issued but not yet adopted: ASU No. 2019-12 In December 2019, the FASB released ASU No. 2019-12, Income Taxes (ASC 740): Simplifying the Accounting for Income Taxes , as part of their initiative to reduce complexity in accounting standards. The ASU simplifies the accounting for income taxes by eliminating certain exceptions to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The ASU also simplifies aspects of the accounting for enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. ASU No. 2019-12 will be effective for fiscal years beginning after December 15, 2020, including interim periods, with early adoption permitted. The transition method for ASU No. 2019-12 varies between the simplification items. The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements. ASU No. 2020-01 In January 2020, the FASB released ASU No. 2020-01, Investments-Equity Securities (ASC 321), Investments- Equity Method and Joint Ventures (ASC 323), and Derivatives and Hedging (ASC 815): Clarifying the Interactions between ASC 321, ASC 323, and ASC 815 , a consensus of the FASB’s Emerging Issues Task Force (EITF). The ASU clarifies that a company should consider observable transactions that require a company to either apply or discontinue the equity method of accounting under ASC 323 for the purposes of applying the measurement alternative in accordance with ASC 321 immediately before applying or upon discontinuing the equity method. The ASU also clarifies that, when determining the accounting for certain forward contracts and purchased options, a company should not consider, whether upon settlement or exercise, if the underlying securities would be accounted for under the equity method or fair value option. ASU No. 2020-01 will be effective for fiscal years beginning after December 15, 2020, including interim periods, with early adoption permitted. The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements. ASU No. 2020-04 In March 2020, the FASB released ASU No. 2020-04, “ Reference Rate Reform (Topic 848) ,” which provides relief for entities preparing for discontinuation of interest rates such as LIBOR. The ASU provides optional expedients and exceptions to ease the accounting impacts associated with contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. For contracts, this ASU allows entities to account for certain contract modifications as a continuation of the existing contract without additional analysis. For hedging relationships, this ASU allows hedge accounting to continue when certain critical terms of a hedging relationship charge and assess effectiveness in ways that disregard certain potential sources of ineffectiveness. Additionally, the ASU allows entities to make a one-time sale and/or transfer of certain debt securities from held-to-maturity to available-for-sale or trading. ASU No. 2020-04 is effective from the beginning of the interim period that includes March 12, 2020. An entity may elect to apply the ASU prospectively through December 31, 2022. The expedients and exceptions provided by the ASU do not apply to contract modifications made or hedging relationships entered into or evaluated after December 31, 2022, with certain exceptions for hedging relationships existing as of December 31, 2022. The Company is currently evaluating the impact of the ASU on its consolidated financial statements.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Investment Securities	INVESTMENT SECURITIES The following table summarizes the amortized cost and estimated fair value of securities available for sale and securities held to maturity as of March 31, 2020 and December 31, 2019 , excluding accrued interest of $13.3 million and $15.1 million , respectively, which is included in other assets in the unaudited consolidated balance sheets, and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) and gross unrecognized gains and losses: March 31, 2020 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,944 $ 425 $ — $ 40,369 Obligations of state and political subdivisions 158,578 6,984 — 165,562 Mortgage-backed securities: Residential agency 2,797,087 82,191 (70 ) 2,879,208 Commercial agency 681,145 32,078 (13 ) 713,210 Other securities 113,621 3,230 (240 ) 116,611 Total securities available for sale $ 3,790,375 $ 124,908 $ (323 ) $ 3,914,960 Amortized Gross Gross Estimated Securities held to maturity: Obligations of state and political subdivisions $ 162,330 $ 8,233 $ — $ 170,563 Mortgage-backed securities: Residential agency 15,630 210 (7 ) 15,833 Total securities held to maturity $ 177,960 $ 8,443 $ (7 ) $ 186,396 December 31, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,916 $ 281 $ — $ 40,197 Obligations of state and political subdivisions 160,873 7,607 — 168,480 Mortgage-backed securities: Residential agency 2,876,069 27,423 (3,836 ) 2,899,656 Commercial agency 704,661 17,202 (404 ) 721,459 Other securities 101,022 2,779 (233 ) 103,568 Total securities available for sale $ 3,882,541 $ 55,292 $ (4,473 ) $ 3,933,360 Amortized Gross Gross Estimated Securities held to maturity: Obligations of state and political subdivisions $ 166,386 $ 7,147 $ — $ 173,533 Mortgage-backed securities: Residential agency 16,575 30 (239 ) 16,366 Total securities held to maturity $ 182,961 $ 7,177 $ (239 ) $ 189,899 Securities with carrying values of $2.4 billion and $2.2 billion were pledged to support repurchase transactions, public funds deposits, and certain long-term borrowings at March 31, 2020 and December 31, 2019 , respectively. Information pertaining to securities with gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous loss position, was as follows: March 31, 2020 Less Than Twelve Months Twelve Months or More Total (in thousands) Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Securities available for sale: Mortgage-backed securities: Residential agency $ (70 ) $ 8,684 $ — $ — $ (70 ) $ 8,684 Commercial agency (13 ) 5,039 — — (13 ) 5,039 Other securities (152 ) 19,848 (88 ) 4,168 (240 ) 24,016 Total securities available for sale $ (235 ) $ 33,571 $ (88 ) $ 4,168 $ (323 ) $ 37,739 Less Than Twelve Months Twelve Months or More Total Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Securities held to maturity: Mortgage-backed securities: Residential agency $ — $ 46 $ (7 ) $ 1,973 $ (7 ) $ 2,019 Total securities held to maturity $ — $ 46 $ (7 ) $ 1,973 $ (7 ) $ 2,019 December 31, 2019 Less Than Twelve Months Twelve Months or More Total (in thousands) Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Securities available for sale: Obligations of state and political subdivisions $ — $ 590 $ — $ — $ — $ 590 Mortgage-backed securities: Residential agency (1,893 ) 441,332 (1,943 ) 268,383 (3,836 ) 709,715 Commercial agency (252 ) 56,728 (152 ) 10,301 (404 ) 67,029 Other securities (133 ) 13,241 (100 ) 4,492 (233 ) 17,733 Total securities available for sale $ (2,278 ) $ 511,891 $ (2,195 ) $ 283,176 $ (4,473 ) $ 795,067 Less Than Twelve Months Twelve Months or More Total Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Securities held to maturity: Mortgage-backed securities: Residential agency $ (52 ) $ 6,308 $ (187 ) $ 9,074 $ (239 ) $ 15,382 Total securities held to maturity $ (52 ) $ 6,308 $ (187 ) $ 9,074 $ (239 ) $ 15,382 The Company held certain investment securities where amortized cost exceeded fair value, resulting in unrealized loss positions, as shown in the tables above. The Company evaluates its investment securities portfolio for impairment on a quarterly basis. For HTM securities, the Company maintains an allowance for expected credit losses appropriate to absorb estimated lifetime credit losses. HTM securities where there is a risk of credit loss are segmented by credit rating and duration and an allowance for expected credit losses is calculated based on external historical loss data, taking into consideration management's forecast of future economic conditions. The Company has assessed the risk of credit loss and has determined the allowance for expected credit losses for HTM securities to be immaterial as of March 31, 2020. For AFS securities, declines in the fair value of individual securities below their amortized cost basis are reviewed to determine if the decline is due to credit-related factors. As of March 31, 2020, unrealized losses on AFS securities have not been recognized into income because the issuers are of high credit quality, management does not intend to sell and it is likely that management will not be required to sell the securities prior to their anticipated recovery, and the decline in fair value is largely due to changes in interest rates and other market conditions. Therefore, no allowance for expected credit losses has been recorded for AFS securities as of March 31, 2020 and the unrealized losses are recognized in other comprehensive income. Prior to January 1, 2020, management evaluated HTM and AFS securities for other-than-temporary impairment. Impairment was considered to be other-than-temporary if the Company (1) intended to sell the security, (2) more likely than not would be required to sell the security before recovering its cost, or (3) did not expect to recover the security's entire amortized cost basis. As of December 31, 2019, the Company did not intend to sell any of these securities, did not expect to be required to sell these securities, and expected to recover the entire amortized cost of all these securities. As a result of the Company's analysis, no declines in the estimated fair value of the Company's investment securities were deemed to be other-than-temporary at December 31, 2019. At March 31, 2020 , 13 debt securities had unrealized losses of 0.82% of the securities’ amortized cost basis. At December 31, 2019 , 123 debt securities had unrealized losses of 0.58% of the securities’ amortized cost basis. Additional information on securities that were in a continuous loss position for over twelve months at March 31, 2020 and December 31, 2019 is presented in the following table. (in thousands) March 31, 2020 December 31, 2019 Number of securities Mortgage-backed securities: Residential agency 2 59 Commercial agency — 6 Other securities 4 4 6 69 Amortized Cost Basis Mortgage-backed securities: Residential agency $ 1,980 $ 279,587 Commercial agency — 10,453 Other securities 4,256 4,591 $ 6,236 $ 294,631 Unrealized Loss Mortgage-backed securities: Residential agency $ 7 $ 2,130 Commercial agency — 152 Other securities 88 100 $ 95 $ 2,382 Credit Quality Indicators A substantial portion of the Company's HTM securities portfolio consists of obligations of state and political subdivisions. The Company monitors the credit quality of these securities through the use of credit ratings on a quarterly basis. The following table summarizes the amortized cost of HTM obligations of state and political subdivisions at March 31, 2020, aggregated by credit quality indicator: March 31, 2020 Securities Held to Maturity Credit Rating Obligations of State and Political Subdivisions Aaa / AAA $ 80,815 Aa1 / AA+ 33,066 Aa2/ AA 38,317 Aa3 / AA- 8,292 A2 / A 1,840 Total $ 162,330 At March 31, 2020, the Company also held HTM residential agency mortgage-backed securities with an amortized cost of $15.6 million . This portfolio includes Frannie Mae and Freddie Mac securities which are considered to be government sponsored enterprises (GSEs). While securities issued by GSEs do carry credit risk, the company considered the risks and determined that the risk of credit loss for these securities was zero. There were no HTM securities on non-accrual or past due status as of March 31, 2020. The amortized cost and estimated fair value of investment securities by maturity at March 31, 2020 are presented in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. Weighted average yields are calculated on the basis of the yield to maturity based on the amortized cost of each security. Securities Available for Sale Securities Held to Maturity (in thousands) Weighted Amortized Estimated Weighted Amortized Estimated Within one year or less 2.62 % $ 41,572 $ 41,999 3.00 % $ 245 $ 245 One through five years 2.60 180,356 187,480 2.59 5,329 5,380 After five through ten years 2.68 641,404 671,014 2.37 56,038 58,524 Over ten years 2.59 2,927,043 3,014,467 2.56 116,348 122,247 2.61 % $ 3,790,375 $ 3,914,960 2.50 % $ 177,960 $ 186,396 Gains or losses on securities sold are recorded on the trade date, using the specific identification method. For the three months ended March 31, 2020 and 2019, the Company did not have any realized gains or losses from the sale of securities classified as available for sale. The Company did not realize any gains on calls of securities held to maturity for the three months ended March 31, 2020 and 2019. Other Equity Securities The Company accounts for the following securities at cost less impairment plus or minus any observable price changes, which approximates fair value, with the exception of CRA and Community Development Investment Funds, which are recorded at fair value. Other equity securities, which are presented in other assets on the consolidated balance sheets, were as follows: (in thousands) March 31, 2020 December 31, 2019 Federal Home Loan Bank stock $ 70,914 $ 70,386 Federal Reserve Bank stock 85,630 85,630 CRA and Community Development Investment Funds 1,988 1,948 Other investments 22,098 21,118 $ 180,630 $ 179,082

Loans and Leases

Loans and Leases	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Loans and Leases	LOANS AND LEASES The following is the amortized cost of loans and leases as of March 31, 2020 and December 31, 2019 , excluding accrued interest of $65.9 million and $65.7 million , which is included in other assets in the unaudited consolidated balance sheets: (in thousands) March 31, 2020 December 31, 2019 Commercial loans and leases: Real estate - construction $ 1,322,627 $ 1,321,663 Real estate - owner-occupied 2,424,139 2,475,326 Real estate - non-owner-occupied 6,484,257 6,267,106 Commercial and industrial (C&I) (1) 6,909,841 6,547,538 17,140,864 16,611,633 Consumer and other loans: Residential mortgage 4,849,119 4,739,075 Home equity 1,926,753 1,987,336 Other 624,896 683,455 7,400,768 7,409,866 Total loans and leases $ 24,541,632 $ 24,021,499 (1) Includes equipment financing leases Net deferred loan and lease origination fees were $36.4 million and $36.8 million at March 31, 2020 and December 31, 2019 , respectively. Total net discount on the Company's loans and leases was $88.3 million and $89.3 million at March 31, 2020 and December 31, 2019 , respectively, of which $53.7 million and $56.4 million was related to non-impaired loans and leases. In addition to loans issued in the normal course of business, the Company considers overdrafts on customer deposit accounts to be loans and reclassifies these overdrafts as loans in its consolidated balance sheets. At March 31, 2020 and December 31, 2019 , overdrafts of $5.5 million and $7.7 million , respectively, had been reclassified to loans. Loans and leases with carrying values of $8.7 billion and $8.6 billion were pledged as collateral for borrowings at March 31, 2020 and December 31, 2019 , respectively. Certain acquired loans are to customers with addresses outside of the United States. Foreign loans, denominated in U.S. dollars, totaled $181.0 million and $182.4 million at March 31, 2020 and December 31, 2019 , respectively. Past Due Status Loans and leases are generally considered past due when contractual payments of principal and interest have not been received within 30 days after the contractual due date. Residential mortgage loans are considered past due when contractual payments have not been received for two consecutive payment dates. The following tables provide an analysis of the aging of loans and leases as of March 31, 2020 and December 31, 2019 . March 31, 2020 Age Analysis of Past Due Loans and Leases (in thousands) 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Past Due Total Past Due Current Total Accruing Loans Greater Than 90 Days Past Due Real estate- construction $ 5,466 $ — $ 69 $ 5,535 $ 1,317,092 $ 1,322,627 $ — Real estate- owner-occupied 5,714 6,302 12,810 24,826 2,399,313 2,424,139 1,328 Real estate- non-owner-occupied 4,525 8,318 14,451 27,294 6,456,963 6,484,257 1,679 Commercial and industrial 16,505 10,357 7,811 34,673 6,875,168 6,909,841 169 Residential mortgage 23,664 1,131 34,748 59,543 4,789,576 4,849,119 7,787 Home equity 20,719 3,014 18,254 41,987 1,884,766 1,926,753 — Other 5,195 2,751 2,572 10,518 614,378 624,896 — Total $ 81,788 $ 31,873 $ 90,715 $ 204,376 $ 24,337,256 $ 24,541,632 $ 10,963 December 31, 2019 Age Analysis of Past Due Loans and Leases (in thousands) 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Past Due Total Past Due Current Total Accruing Loans Greater Than 90 Days Past Due Real estate- construction $ 244 $ — $ 1,377 $ 1,621 $ 1,320,042 $ 1,321,663 $ — Real estate- owner-occupied 18,387 2,770 9,175 30,332 2,444,994 2,475,326 1,035 Real estate- non-owner-occupied 5,418 2,459 10,450 18,327 6,248,779 6,267,106 58 Commercial and industrial 6,805 1,523 15,601 23,929 6,523,609 6,547,538 887 Residential mortgage 4,008 17,297 23,055 44,360 4,694,715 4,739,075 1,277 Home equity 14,001 3,113 14,332 31,446 1,955,890 1,987,336 — Other 3,935 1,267 2,500 7,702 675,753 683,455 — Total $ 52,798 $ 28,429 $ 76,490 $ 157,717 $ 23,863,782 $ 24,021,499 $ 3,257 Additional information on non-accrual loans and leases as of March 31, 2020 and December 31, 2019 is presented in the following table. Amortized Cost of Non-accrual Loans and Leases Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses Interest Income Recognized on Non-accrual Loans and Leases (in thousands) March 31, 2020 December 31, 2019 December 31, 2018 March 31, 2020 December 31, 2019 Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 Real estate- construction $ 133 $ 1,394 $ 1,094 $ 4 $ 929 $ — $ — Real estate- owner-occupied 23,428 17,817 10,260 19,968 11,469 135 70 Real estate- non-owner-occupied 20,383 15,440 15,898 18,120 8,610 159 54 Commercial and industrial 40,768 41,636 57,860 34,432 9,590 122 352 Residential mortgage 48,067 34,833 30,396 26,013 19,500 49 60 Home equity 30,319 24,404 18,830 5,915 3,200 64 67 Other 3,465 3,381 2,846 1,190 — 13 2 Total $ 166,563 $ 138,905 $ 137,184 $ 105,642 $ 53,298 $ 542 $ 605 When a loan or lease is placed on non-accrual status, accrued but uncollected interest is reversed through interest income. During the three months ended March 31, 2020 , the Company reversed an immaterial amount of uncollectible accrued interest on both commercial loans and leases and consumer loans. Collateral-Dependent Loans Collateral-dependent loans are defined as loans for which repayment is expected to be derived substantially through the operation or sale of the collateral and where the borrower is experiencing financial difficulty. Collateral-dependent commercial loans are primarily secured by commercial real estate and to a lesser extent other business assets and residential real estate. The loan-to-value ratio, taking into consideration cost to sell the collateral for commercial collateral-dependent loans is approximately 75% at March 31, 2020 . Collateral-dependent consumer loans are secured by residential real estate with a loan-to-value ratio of 70% , taking into consideration the cost to sell the collateral at March 31, 2020 . As of March 31, 2020 , the Company did not have any collateral-dependent leases. Acquired Loans The Company did not acquire any loans during the three months ended March 31, 2020 . Prior to January 1, 2020, the Company accounted for acquired impaired loans in accordance with ASC 310-30. The following is a summary of changes in the accretable difference for all loans accounted for under ASC 310-30 during the three months ended March 31 , 2019: (in thousands) 2019 Balance at beginning of period $ 133,342 Transfers from non-accretable difference to accretable yield (3,640 ) Accretion (10,086 ) Changes in expected cash flows not affecting non-accretable differences (1) (272 ) Balance at end of period $ 119,344 (1) Includes changes in cash flows expected to be collected due to the impact of changes in actual or expected timing of liquidation events, modifications, changes in interest rates and changes in prepayment assumptions. Troubled Debt Restructurings After the adoption of ASC 326, all loans, including acquired loans, meeting the criteria for classification as a TDR since January 1, 2020 are included in the disclosures below. Prior to January 1, 2020, modifications of loans that were accounted for within a pool under ASC Topic 310-30 were not classified or reported as TDRs. As a result, all such acquired loans that would otherwise meet the criteria for classification as a TDR prior to January 1, 2020 were excluded from the disclosures below, which impacts comparability between periods. As of March 31, 2020 and December 31, 2019, there were no leases which met the criteria to be classified as a TDR. TDRs totaling $9.8 million and $31.4 million occurred during the three months ended March 31, 2020 and 2019, respectively, through modification of the original loan terms. The following table provides information on how the TDRs were modified during the periods indicated: Three Months Ended March 31, (in thousands) 2020 2019 Extended maturities $ 2,450 $ 9,014 Maturity and interest rate adjustment 706 468 Movement to or extension of interest-rate only payments 46 12 Interest rate adjustment 3,878 — Forbearance 1,111 6,510 Other concession(s) (1) 1,604 15,425 Total $ 9,795 $ 31,429 (1) Other concessions may include covenant waivers, forgiveness of principal or interest associated with a customer bankruptcy, or a combination of any of the above concessions. Of the $9.8 million of TDRs occurring during the three months ended March 31, 2020 , $6.8 million were on accrual status and $3.0 million were on non-accrual status. Of the $31.4 million of TDRs occurring during the three months ended March 31 2019 , $16.5 million were on accrual status and $14.9 million were on non-accrual status. The following table presents the end of period balance for loans modified in a TDR during the periods indicated: Three Months Ended March 31, 2020 2019 (in thousands, except number of loans) Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Real estate- construction 1 $ 154 $ 86 1 $ 39 $ 39 Real estate- owner-occupied 4 2,520 2,558 4 6,904 4,661 Real estate- non-owner-occupied 5 3,944 3,820 7 2,990 2,968 Commercial and industrial 14 1,844 1,367 23 17,382 17,040 Residential mortgage 6 750 413 10 1,741 1,738 Home equity 16 1,507 1,482 33 4,277 4,233 Other 5 71 69 38 787 750 Total 51 $ 10,790 $ 9,795 116 $ 34,120 $ 31,429 Information detailing TDRs that defaulted during the three-month periods ended March 31, 2020 and 2019 , and were modified in the previous twelve months (i.e., the twelve months prior to the default) is presented in the following tables. The Company has defined a default as any loan with a payment that is currently past due greater than 30 days , or was past due greater than 30 days at any point during the respective periods, or since the date of modification, whichever is shorter. Three Months Ended March 31, 2020 2019 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 9,212 1 $ 939 Real estate- owner-occupied 5 1,898 3 640 Real estate- non-owner-occupied 11 5,287 7 825 Commercial and industrial 33 7,862 10 3,933 Residential mortgage 15 1,190 13 1,108 Home equity 23 2,189 16 2,891 Other 20 208 20 261 Total 108 $ 27,846 70 $ 10,597

Allowance for Expected Credit L

Allowance for Expected Credit Losses and Credit Quality	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Allowance for Expected Credit Losses and Credit Quality	ALLOWANCE FOR EXPECTED CREDIT LOSSES AND CREDIT QUALITY Allowance for Expected Credit Losses Activity On January 1, 2020, the Company adopted ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments . ASC 326 replaced the incurred loss model for determining the allowance for credit losses with a current expected credit loss model for financial assets carried at amortized cost, including loans, leases, and loan commitments. ASC 326 requires recognition of lifetime expected credit losses that takes into consideration all available relevant information including details of past events, current conditions and reasonable and supportable forecasts of future economic conditions. The transition adjustment on January 1, 2020 resulted in an increase of the AECL of $82.3 million . The increase in the AECL at transition primarily relates to required increases for residential mortgage loans to establish an estimate of lifetime expected credit losses for these longer dated loans as well as an increase on non-owner-occupied commercial real estate loans reflecting higher LGDs under the CECL model. See Note 2, Recent Accounting Pronouncements, for additional discussion on the adoption of ASC 326. As a result of the adoption of ASC 326, the AECL as of March 31, 2020 and the provision for expected credit losses for the three months ended March 31, 2020 are not comparable to historical periods. A summary of changes in the allowance for expected credit losses for the three months ended March 31 was as follows: (in thousands) 2020 2019 Allowance for loan and lease losses at beginning of period $ 146,588 $ 140,571 Transition adjustment for ASC 326 83,194 — Allowance for loan and lease losses, as adjusted 229,782 140,571 Provision for loan and lease losses 66,431 12,612 Transfer of balance to OREO and other — (2,885 ) Charge-offs (12,119 ) (8,918 ) Recoveries 2,591 1,586 Allowance for loan and lease losses at end of period $ 286,685 $ 142,966 Reserve for unfunded commitments at beginning of period $ 16,637 $ 14,830 Transition adjustment for ASC 326 (875 ) — Reserve for unfunded lending commitments, as adjusted 15,762 14,830 Provision for unfunded lending commitments 2,540 1,151 Reserve for unfunded commitments at end of period $ 18,302 $ 15,981 Allowance for expected credit losses at end of period $ 304,987 $ 158,947 The AECL at March 31, 2020 reflects a blend of economic forecasts to estimate expected credit losses over an eighteen month reasonable and supportable forecast period and then reverts to historical loss experience to arrive at lifetime expected credit losses. At January 1, 2020, the Company’s economic forecast assumed a relatively stable macroeconomic environment over the reasonable and supportable forecast period while recognizing that the economy was vulnerable to major shocks, fiscal policy missteps, other geopolitical events and the outcome of the pending U.S. elections. During the latter part of the first quarter of 2020, the global and U.S. economies experienced substantial disruptions as a result of the COVID-19 pandemic as well as continued pressure on oil prices. In light of the deteriorating economic conditions, the U.S. government has taken numerous actions through multiple stimulus packages to support both individuals and businesses during the unprecedented freeze on commerce in the U.S. Uncertainty remains as to the length of the COVID-19 pandemic as well as the success of the various stimulus packages to both support the economy during the pandemic as well as restore economic conditions when the pandemic subsides. As a result, the Company has updated its economic forecast to reflect the expected impact of COVID-19 and the possibility of recessionary conditions over the reasonable and supportable forecast period which has resulted in an increase in the AECL at March 31, 2020 . A summary of changes in the allowance for expected credit losses, by loan portfolio type, for the three months ended March 31 was as follows: Three Months Ended March 31, 2020 Commercial Real Estate Consumer (in thousands) Construction Owner-occupied Non-owner-occupied Commercial and Industrial Residential Mortgage Home Equity Other Total Allowance for loan and lease losses at beginning of period $ 5,983 $ 15,770 $ 36,541 $ 55,634 $ 9,647 $ 12,153 $ 10,860 $ 146,588 Transition adjustment for ASC 326 2,307 (8,163 ) 29,850 (14,659 ) 70,521 3,620 (282 ) 83,194 Allowance for loan and lease losses, as adjusted 8,290 7,607 66,391 40,975 80,168 15,773 10,578 229,782 Provision for loan and lease losses 940 2,603 30,500 11,833 10,535 7,313 2,707 66,431 Charge-offs (14 ) — (240 ) (7,895 ) (450 ) (1,435 ) (2,085 ) (12,119 ) Recoveries 219 25 132 1,037 329 386 463 2,591 Allowance for loan and lease losses at end of period $ 9,435 $ 10,235 $ 96,783 $ 45,950 $ 90,582 $ 22,037 $ 11,663 $ 286,685 Reserve for unfunded lending commitments at beginning of period $ 4,010 $ 345 $ 1,629 $ 6,478 $ 562 $ 2,078 $ 1,535 $ 16,637 Transition adjustment for ASC 326 1,025 627 (991 ) 3 743 (812 ) (1,470 ) (875 ) Reserve for unfunded lending commitments, as adjusted 5,035 972 638 6,481 1,305 1,266 65 15,762 Provision for (reversal of) unfunded commitments 492 418 91 925 215 433 (34 ) 2,540 Reserve for unfunded lending commitments at end of period 5,527 1,390 729 7,406 1,520 1,699 31 18,302 Allowance for expected credit losses at end of period $ 14,962 $ 11,625 $ 97,512 $ 53,356 $ 92,102 $ 23,736 $ 11,694 $ 304,987 Three Months Ended March 31, 2019 Commercial Real Estate Consumer (in thousands) Construction Owner-occupied Non-owner-occupied Commercial and Industrial Residential Mortgage Home Equity Other Total Allowance for loan and lease losses at beginning of period $ 4,743 $ 12,549 $ 34,514 $ 54,096 $ 12,998 $ 10,181 $ 11,490 $ 140,571 Provision for loan and lease losses 936 1,303 4,648 2,876 1,749 1,056 44 12,612 Transfer of balance to OREO and other — — — — (2,881 ) (4 ) — (2,885 ) Charge-offs — (72 ) — (4,931 ) (28 ) (1,401 ) (2,486 ) (8,918 ) Recoveries 3 35 65 446 32 314 691 1,586 Allowance for loan and lease losses at end of period $ 5,682 $ 13,815 $ 39,227 $ 52,487 $ 11,870 $ 10,146 $ 9,739 $ 142,966 Reserve for unfunded commitments at beginning of period $ 3,249 $ 316 $ 1,304 $ 6,198 $ 866 $ 1,783 $ 1,114 $ 14,830 Provision for unfunded commitments 333 60 401 128 22 28 179 1,151 Reserve for unfunded commitments at end of period 3,582 376 1,705 6,326 888 1,811 1,293 15,981 Allowance for credit losses at end of period $ 9,264 $ 14,191 $ 40,932 $ 58,813 $ 12,758 $ 11,957 $ 11,032 $ 158,947 Portfolio Segment Risk Factors Commercial loans and leases include commercial real estate loans, commercial and industrial loans, and equipment financing leases. Commercial real estate loans include loans to commercial customers for medium-term financing of land and buildings or for land development or construction of a building. These loans are repaid from revenues through operations of the businesses, rents of properties, sales of properties and refinances. Commercial and industrial loans and leases represent loans to commercial customers to finance general working capital needs, equipment purchases and leases and other projects where repayment is derived from cash flows resulting from business operations. The Company originates commercial and industrial loans on a secured and, to a lesser extent, unsecured basis. Consumer loans are offered by the Company in order to provide a full range of retail financial services to its customers and include residential mortgages, home equity, credit card and other direct consumer installment loans. Residential mortgage loans consist of loans to consumers to finance a primary or secondary residence. The vast majority of the residential mortgage loan portfolio is comprised of non-conforming 1-4 family mortgage loans secured by properties located in the Company's market areas and originated under terms and documentation that permit their sale in a secondary market. The Company originates substantially all of its consumer loans in its primary market areas. Loans in the consumer segment are sensitive to property values, unemployment levels, and other key consumer economic measures. Prior to January 1, 2020, residential mortgage loans were in a separate portfolio segment. Credit Quality Indicators For commercial loans and leases, the Company utilizes regulatory classification ratings to monitor credit quality. Loans with a "pass" rating are those that the Company believes will be fully repaid in accordance with the contractual loan terms. Commercial loans and leases that are "criticized" are those that have some weakness or potential weakness that indicate an increased probability of future loss. "Criticized" loans are grouped into three categories: "special mention", "substandard", and "doubtful". Special mention loans and leases have potential weaknesses that, if left uncorrected, may result in deterioration of the Company's credit position at some future date. Substandard commercial loans and leases have well-defined weaknesses and are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Doubtful commercial loans and leases have the same weaknesses as substandard loans and leases with the added characteristics that the probability of loss is high and collection of the full amount is improbable. Substandard and doubtful loans are collectively referred to as "classified" loans and leases. Regulatory classification ratings for commercial loans and leases are updated annually. For consumer loans, the Company utilizes FICO scores to monitor credit quality as these are widely accepted measures of a borrower's risk of non-repayment over the life of a loan. FICO scores are updated quarterly. Prior to January 1, 2020, the Company’s primary credit quality indicator for residential mortgage and consumer loans was the loan’s payment and delinquency status. The Company’s investment in loans by credit quality indicator and year of origination is presented in the following tables. Asset risk classifications for commercial loans and leases reflect the classification as of March 31, 2020 . FICO scores for consumer loans are updated on a quarterly basis. Credit quality information in the tables reflects the amortized cost basis of all loans, excluding $65.9 million of accrued interest, which is included as a component of other assets in the unaudited consolidated balance sheet. Term Loans (in thousands) 2020 2019 2018 2017 2016 Prior Revolving loans Revolving loans Converted to Term Total Commercial loans and leases Real Estate- Construction Pass $ 45,117 $ 336,900 $ 599,002 $ 172,612 $ 65,200 $ 51,622 $ 40,147 $ — $ 1,310,600 Special Mention — — — — 10 105 2,156 — 2,271 Substandard — — 9,213 — — 475 65 — 9,753 Doubtful — — — — — 3 — — 3 Total Real Estate- Construction 45,117 336,900 608,215 172,612 65,210 52,205 42,368 — 1,322,627 Real Estate- Owner- occupied Pass 69,996 379,882 319,249 357,057 274,226 895,032 66,866 — 2,362,308 Special Mention — — 7,306 681 399 13,419 400 — 22,205 Substandard — 234 1,011 8,204 3,518 23,856 387 — 37,210 Doubtful — — — — — 2,416 — — 2,416 Total Real Estate- Owner-occupied 69,996 380,116 327,566 365,942 278,143 934,723 67,653 — 2,424,139 Real Estate- Non-owner-occupied Pass 261,614 1,323,506 961,036 987,814 867,303 1,867,101 130,929 — 6,399,303 Special Mention — — 806 1,497 10,248 14,561 1,900 — 29,012 Substandard — 591 2,059 10,066 6,038 31,481 635 — 50,870 Doubtful — — 104 — — 4,968 — — 5,072 Total Real Estate- Non-owner-occupied 261,614 1,324,097 964,005 999,377 883,589 1,918,111 133,464 — 6,484,257 Commercial and Industrial (1) Pass 649,228 1,957,486 1,307,679 455,600 218,485 551,933 1,635,017 — 6,775,428 Special Mention 259 1,463 23,811 500 8,093 1,436 7,896 — 43,458 Substandard 4,102 16,838 3,023 20,486 1,151 19,194 5,846 — 70,640 Doubtful — 5,323 9,517 2,353 648 2,474 — — 20,315 Total Commercial and Industrial 653,589 1,981,110 1,344,030 478,939 228,377 575,037 1,648,759 — 6,909,841 Total Commercial Loans and Leases $ 1,030,316 $ 4,022,223 $ 3,243,816 $ 2,016,870 $ 1,455,319 $ 3,480,076 $ 1,892,244 $ — $ 17,140,864 (1) Includes equipment financing leases Term Loans (in thousands) 2020 2019 2018 2017 2016 Prior Revolving loans Revolving loans Converted to Term Total Consumer Loans: Residential Mortgage 781 and above $ 45,204 $ 332,402 $ 263,099 $ 185,336 $ 153,118 $ 387,923 $ — $ — $ 1,367,082 723-780 72,666 452,401 360,319 233,243 199,457 410,212 — — 1,728,298 700-722 14,430 94,286 93,264 49,705 47,736 116,470 — — 415,891 660-699 8,549 103,361 83,700 37,108 54,661 144,238 — — 431,617 620-659 3,273 39,018 26,883 15,701 15,481 94,296 — — 194,652 580-619 — 13,756 11,717 8,358 11,281 51,387 — — 96,499 579 and below 101,641 52,459 53,362 58,542 84,198 264,878 — — 615,080 Total Residential Mortgage 245,763 1,087,683 892,344 587,993 565,932 1,469,404 — — 4,849,119 Home Equity 781 and above 2,052 8,710 28,297 16,579 15,903 56,995 374,502 21,481 524,519 723-780 1,160 13,680 25,948 19,278 25,677 81,172 498,082 27,061 692,058 700-722 103 2,226 7,915 7,696 5,276 18,320 130,949 13,029 185,514 660-699 747 3,823 10,975 6,434 6,112 32,755 163,267 17,238 241,351 620-659 351 1,418 1,894 4,355 3,630 19,419 73,928 13,822 118,817 580-619 2,735 875 5,331 2,006 2,581 13,452 27,526 6,484 60,990 579 and below 5,988 2,742 10,009 5,850 2,592 18,201 45,334 12,788 103,504 Total Home Equity 13,136 33,474 90,369 62,198 61,771 240,314 1,313,588 111,903 1,926,753 Other Consumer Loans 781 and above 3,357 11,136 8,566 14,957 5,938 22,047 69,402 — 135,403 723-780 5,717 11,388 22,356 12,895 5,490 32,481 76,717 — 167,044 700-722 1,089 22,224 4,560 3,345 4,133 11,551 16,713 — 63,615 660-699 1,803 4,688 5,120 4,057 1,113 18,128 20,797 — 55,706 620-659 751 4,245 2,432 1,702 3,745 8,142 13,553 — 34,570 580-619 337 1,754 2,689 674 1,611 4,922 8,499 — 20,486 579 and below 22,670 2,038 3,282 3,137 2,585 106,144 8,216 — 148,072 Total Other Consumer 35,724 57,473 49,005 40,767 24,615 203,415 213,897 — 624,896 Total Consumer Loans 294,623 1,178,630 1,031,718 690,958 652,318 1,913,133 1,527,485 111,903 7,400,768 Total Loans and Leases $ 1,324,939 $ 5,200,853 $ 4,275,534 $ 2,707,828 $ 2,107,637 $ 5,393,209 $ 3,419,729 $ 111,903 $ 24,541,632 During the three months ended March 31, 2020 , the Company converted $6.6 million

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill Goodwill allocated to each reporting unit at March 31, 2020 and December 31, 2019 is provided in the following table: (in thousands) March 31, 2020 December 31, 2019 IBERIABANK $ 1,203,810 $ 1,203,810 Mortgage 23,178 23,178 LTC 8,545 8,545 Total $ 1,235,533 $ 1,235,533 The Company performed the required annual goodwill impairment test as of October 1, 2019. The Company’s annual impairment test did not indicate impairment in any of the Company’s reporting units as of the testing date. During the first quarter of 2020 and through the date of the filing of this Quarterly Report on Form 10-Q for the quarter ended March 31, 2020, management evaluated the events and changes in certain circumstances that could indicate that goodwill might be impaired. In light of the COVID-19 pandemic and its impact on macroeconomic conditions, the unprecedented economic uncertainty, and the significant declines in the Company's stock price and overall prices in the equity markets, management concluded that an interim quantitative test was necessary for all reporting units. The Company factored in multiple economic scenarios, in an effort to take into account the unprecedented economic uncertainty, and determined that the estimated fair value of each reporting unit exceeded its carrying value. Therefore, the goodwill of each reporting unit was considered not to be impaired as of the testing date. The goodwill impairment evaluation requires management to utilize significant judgments and assumptions which are based on the best information available at the time. Results of future tests, if required, could vary in subsequent reporting periods if conditions differ substantially from the assumptions utilized in completing the evaluations. The conclusion that no impairment exists may change if the pandemic continues for an extended period of time or a recovery in economic activity is delayed. Mortgage Servicing Rights Mortgage servicing rights are recorded at the lower of cost or market value in other intangible assets on the Company's consolidated balance sheets and amortized over the remaining servicing life of the loans, with consideration given to prepayment assumptions. Mortgage servicing rights had the following carrying values as of the periods indicated: March 31, 2020 December 31, 2019 Gross Carrying Amount Valuation Allowance Accumulated Amortization Net Carrying Amount Gross Carrying Amount Valuation Allowance Accumulated Amortization Net Carrying Amount (in thousands) Mortgage servicing rights $ 24,870 $ (2,657 ) $ (7,451 ) $ 14,762 $ 22,476 $ (250 ) $ (6,621 ) $ 15,605 Intangible assets subject to amortization Definite-lived intangible assets included in other intangible assets on the Company’s consolidated balance sheets had the following carrying values as of the periods indicated: March 31, 2020 December 31, 2019 (in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Core deposit intangible assets $ 121,277 $ (70,758 ) $ 50,519 $ 136,183 $ (81,493 ) $ 54,690 Customer relationship intangible asset 1,348 (1,341 ) 7 1,385 (1,371 ) 14 Non-compete agreement 206 (118 ) 88 206 (110 ) 96 Total $ 122,831 $ (72,217 ) $ 50,614 $ 137,774 $ (82,974 ) $ 54,800

Derivative Instruments and Othe

Derivative Instruments and Other Hedging Activities	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Other Hedging Activities	DERIVATIVE INSTRUMENTS AND OTHER HEDGING ACTIVITIES The Company enters into derivative financial instruments to manage interest rate risk, exposures related to liquidity and credit risk, and to facilitate customer transactions. The primary types of derivatives utilized by the Company for its risk management strategies include interest rate swap agreements, interest rate collars, interest rate floors, interest rate lock commitments, forward sales commitments, written and purchased options, and credit derivatives. All derivative instruments are recognized on the consolidated balance sheets as other assets or other liabilities at fair value, regardless of whether a right of offset exists. Cash flow hedge relationships mitigate exposure to the variability of future cash flows or other forecasted transactions. The Company enters into interest rate swap agreements in a cash flow hedge to convert forecasted variable interest payments to a fixed rate on its junior subordinated debt. In addition, the Company has entered into interest rate collars and interest rate floors and designated the instruments as cash flow hedges of the risk of fluctuations in interest rates, thereby reducing the Company's exposure to variability in cash flows from variable-rate loans. For cash flow hedges, the effective and ineffective portions of the gain or loss related to the derivative instrument is initially reported as a component of other comprehensive income and subsequently reclassified into earnings when the forecasted transaction affects earnings or when the hedge is terminated. In applying hedge accounting for derivatives, the Company establishes and documents a method for assessing the effectiveness of the hedging derivative and a measurement approach for determining the ineffective aspect of the hedge upon the inception of the hedge. For derivative instruments that are not designated as hedging instruments, changes in the fair value of the derivatives are recognized in earnings immediately. Information pertaining to outstanding derivative instruments was as follows: Derivative Assets - Fair Value Derivative Liabilities - Fair Value (in thousands) March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Derivatives designated as hedging instruments: Interest rate contracts $ 41,200 $ 18,967 $ 11 $ — Total derivatives designated as hedging instruments $ 41,200 $ 18,967 $ 11 $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 18 $ 9 $ 10,510 $ 5,055 Customer swaps - downstream 222,769 77,934 18 1,680 Forward sales contracts 1,987 420 10,656 986 Written and purchased options 17,364 6,755 1,849 3,899 Other contracts 187 66 754 179 Total derivatives not designated as hedging instruments $ 242,325 $ 85,184 $ 23,787 $ 11,799 Total $ 283,525 $ 104,151 $ 23,798 $ 11,799 Derivative Assets - Notional Amount Derivative Liabilities - Notional Amount (in thousands) March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Derivatives designated as hedging instruments: Interest rate contracts $ 800,000 $ 800,000 $ 108,500 $ 108,500 Total derivatives designated as hedging instruments $ 800,000 $ 800,000 $ 108,500 $ 108,500 Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 48,215 $ 430,808 $ 2,855,442 $ 2,237,542 Customer swaps - downstream 2,855,442 2,237,542 48,215 430,808 Forward sales contracts 196,388 44,011 463,108 230,998 Written and purchased options 699,162 268,590 136,043 121,981 Other contracts 114,755 108,008 251,173 183,243 Total derivatives not designated as hedging instruments $ 3,913,962 $ 3,088,959 $ 3,753,981 $ 3,204,572 Total $ 4,713,962 $ 3,888,959 $ 3,862,481 $ 3,313,072 The Company has entered into risk participation agreements with counterparties to transfer or assume credit exposures related to interest rate derivatives. The notional amounts of risk participation agreements sold were $251.2 million and $183.2 million at March 31, 2020 and December 31, 2019 , respectively. Assuming all underlying third party customers referenced in the swap contracts defaulted at March 31, 2020 and December 31, 2019 , the exposure from these agreements would not be material based on the fair value of the underlying swaps. The Company is party to collateral agreements with certain derivative counterparties. Such agreements require that the Company maintain collateral based on the fair values of individual derivative transactions. In the event of default by the Company, the counterparty would be entitled to the collateral. At March 31, 2020 and December 31, 2019 , the Company was required to post $226.8 million and $79.6 million , respectively, in variation margin payments for its derivative transactions, which is required to be netted against the fair value of the derivatives in other assets or other liabilities on the consolidated balance sheets. The Company does not anticipate additional assets will be required to be posted as collateral, nor does it believe additional assets would be required to settle its derivative instruments immediately if contingent features were triggered at March 31, 2020 . The Company’s master netting agreements represent written, legally enforceable bilateral agreements that (1) create a single legal obligation for all individual transactions covered by the master agreement and (2) in the event of default, provide the non-defaulting counterparty the right to accelerate, terminate, and close-out on a net basis all transactions under the agreement and to promptly liquidate or set-off collateral posted by the defaulting counterparty. The Company does not offset fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral against recognized fair value amounts of derivatives executed with the same counterparty under a master netting agreement. The following table reconciles the gross amounts presented in the consolidated balance sheets to the net amounts that would result in the event of offset. March 31, 2020 Gross Amounts Presented in the Balance Sheet Gross Amounts Not Offset in the Balance Sheet Net (in thousands) Derivatives Collateral Derivatives subject to master netting arrangements Derivative assets Interest rate contracts designated as hedging instruments $ 41,200 $ — $ — $ 41,200 Interest rate contracts not designated as hedging instruments 222,787 (9,490 ) — 213,297 Written and purchased options 1,602 — — 1,602 Total derivative assets subject to master netting arrangements $ 265,589 $ (9,490 ) $ — $ 256,099 Derivative liabilities Interest rate contracts designated as hedging instruments $ 11 $ — $ — $ 11 Interest rate contracts not designated as hedging instruments 10,528 (9,490 ) — 1,038 Written and purchased options 1,602 — — 1,602 Total derivative liabilities subject to master netting arrangements $ 12,141 $ (9,490 ) $ — $ 2,651 December 31, 2019 Gross Amounts Presented in the Balance Sheet Gross Amounts Not Offset in the Balance Sheet Net (in thousands) Derivatives Collateral Derivatives subject to master netting arrangements Derivative assets Interest rate contracts designated as hedging instruments $ 18,967 $ — $ — $ 18,967 Interest rate contracts not designated as hedging instruments 77,943 (5,111 ) — 72,832 Written and purchased options 3,871 — — 3,871 Total derivative assets subject to master netting arrangements $ 100,781 $ (5,111 ) $ — $ 95,670 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 6,735 $ (5,111 ) $ — $ 1,624 Written and purchased options 3,871 — — 3,871 Total derivative liabilities subject to master netting arrangements $ 10,606 $ (5,111 ) $ — $ 5,495 During the three months ended March 31, 2020 and 2019 , the Company did not reclassify into earnings any gain or loss as a result of the discontinuance of cash flow hedges because it was probable the original forecasted transaction would not occur by the end of the originally specified term. At March 31, 2020 , the Company did not expect to reclassify a material amount from accumulated other comprehensive income into interest income over the next twelve months for derivatives that will be settled. At March 31, 2020 and 2019 , and for the three months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements was as follows: Amount of Gain (Loss) Recognized in OCI, net of taxes Location of Gain (Loss) Reclassified from AOCI into Income Amount of Gain (Loss) Reclassified from AOCI into Income, net of taxes Location of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Amount of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Total Including Component Excluding Component Total Including Component Excluding Component Total Including Component Excluding Component (in thousands) For the Three Months Ended March 31, Derivatives in Cash Flow Hedging Relationships 2020 2020 2020 Interest rate contracts $ 10,441 $ 10,628 $ (187 ) Interest expense $ 442 $ 707 $ (265 ) Interest expense $ — $ — $ — 2019 2019 2019 Interest rate contracts $ (2,185 ) $ (3,098 ) $ 913 Interest expense $ (227 ) $ (69 ) $ (158 ) Interest expense $ — $ — $ — Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of March 31, was as follows: Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives For the Three Months Ended March 31, (in thousands) 2020 2019 Interest rate contracts (1) Commission income $ 3,759 $ 4,181 Foreign exchange contracts Other income — 5 Forward sales contracts Mortgage income (10,910 ) (3,209 ) Written and purchased options Mortgage income 12,659 1,863 Other contracts Other income (454 ) (9 ) Total $ 5,054 $ 2,831 (1) Includes fees associated with customer interest rate contracts

Shareholders' Equity, Capital R

Shareholders' Equity, Capital Ratios and Other Regulatory Matters	3 Months Ended
	Mar. 31, 2020
Banking and Thrift [Abstract]
Shareholders' Equity, Capital Ratios and Other Regulatory Matters	SHAREHOLDERS' EQUITY, CAPITAL RATIOS AND OTHER REGULATORY MATTERS Preferred Stock The following table presents a summary of the Company's non-cumulative perpetual preferred stock: March 31, 2020 December 31, 2019 (in thousands) Issuance Date Earliest Redemption Date Annual Dividend Rate Liquidation Amount Carrying Amount Carrying Amount Series B Preferred Stock 8/5/2015 8/1/2025 6.625 % $ 80,000 $ 76,812 $ 76,812 Series C Preferred Stock 5/9/2016 5/1/2026 6.600 % 57,500 55,285 55,285 Series D Preferred Stock 4/4/2019 5/1/2024 6.100 % 100,000 96,388 96,388 $ 237,500 $ 228,485 $ 228,485 Common Stock In 2019, the Company announced a Board-approved share repurchase program for up to 1,600,000 shares, or approximately 3% of total common shares outstanding at the time of the announcement. The Company did not repurchase any common shares during the three months ended March 31, 2020 . At March 31, 2020 , there were 1,165,000 remaining shares that could be repurchased under the current plan. No further common stock repurchases are expected due to the pending merger with First Horizon. During the three months ended March 31, 2019 , the Company repurchased 387,921 common shares for approximately $29.9 million at a weighted average cost of $77.19 per share. Regulatory Capital The Company and IBERIABANK are subject to various regulatory capital requirements administered by federal and state banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy regulations and the regulatory framework for prompt corrective action, the Company and IBERIABANK, as applicable, must meet specific capital guidelines that involve quantitative measures of their assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. As of March 31, 2020 , the Company and IBERIABANK met all capital adequacy requirements to which they are subject. As of March 31, 2020 , the most recent notification from the FRB categorized IBERIABANK as well-capitalized under the regulatory framework for prompt corrective action (the prompt corrective action requirements are not applicable to the Company). To be categorized as well-capitalized, an institution must maintain minimum Total risk-based, Tier 1 risk-based, Common Equity Tier 1, and Tier 1 leverage ratios as set forth in the following table. There are no conditions or events since the notification that management believes have changed that categorization. In response to the COVID-19 pandemic, during the first quarter of 2020, the joint federal bank regulatory agencies issued an interim final rule that allows financial institutions to mitigate the effects of the adoption of CECL on regulatory capital. Because the Company adopted CECL as of January 1, 2020, it has elected to mitigate the estimated cumulative effects of adoption on regulatory capital for two years, after which the effects of adoption will be phased-in over a three-year period from January 1, 2022 through December 31, 2024. Under the interim final rule, the adjustments to regulatory capital that are deferred until the phase-in period include both the initial impact of the adoption of CECL at January 1, 2020 on retained earnings, as well as 25% of the subsequent change in the Company's total allowance for expected credit losses during each three-month period of the two-year period ending December 31, 2021. Capital amounts and ratios at March 31, 2020 in the table below reflect the adoption of the CECL regulatory capital adjustment. The Company’s and IBERIABANK’s actual capital amounts and ratios as of March 31, 2020 and December 31, 2019 are presented in the following tables: (in thousands) March 31, 2020 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,228,618 4.00 % N/A N/A $ 3,051,243 9.93 % IBERIABANK 1,225,516 4.00 1,531,895 5.00 3,008,038 9.82 Common Equity Tier 1 (CET1) Consolidated $ 1,216,954 4.50 % N/A N/A $ 2,822,758 10.44 % IBERIABANK 1,212,501 4.50 1,751,390 6.50 3,008,038 11.16 Tier 1 Risk-Based Capital Consolidated $ 1,622,605 6.00 % N/A N/A $ 3,051,243 11.28 % IBERIABANK 1,616,668 6.00 2,155,557 8.00 3,008,038 11.16 Total Risk-Based Capital Consolidated $ 2,163,474 8.00 % N/A N/A $ 3,375,550 12.48 % IBERIABANK 2,155,557 8.00 2,694,446 10.00 3,215,845 11.94 (in thousands) December 31, 2019 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,220,289 4.00 % N/A N/A $ 3,021,004 9.90 % IBERIABANK 1,217,638 4.00 1,522,048 5.00 2,949,533 9.69 Common Equity Tier 1 (CET1) Consolidated $ 1,194,765 4.50 % N/A N/A $ 2,792,520 10.52 % IBERIABANK 1,191,062 4.50 1,720,423 6.50 2,949,533 11.14 Tier 1 Risk-Based Capital Consolidated $ 1,593,020 6.00 % N/A N/A $ 3,021,004 11.38 % IBERIABANK 1,588,083 6.00 2,117,444 8.00 2,949,533 11.14 Total Risk-Based Capital Consolidated $ 2,124,026 8.00 % N/A N/A $ 3,300,730 12.43 % IBERIABANK 2,117,444 8.00 2,648,805 10.00 3,112,758 11.76 Minimum capital ratios are subject to a capital conservation buffer. In order to avoid limitations on distributions, including dividend payments, and certain discretionary bonus payments to executive officers, an institution must hold a capital conservation buffer above its minimum risk-based capital requirements. This capital conservation buffer is calculated as the lowest of the differences between the actual CET1 ratio, Tier 1 Risk-Based Capital Ratio, and Total Risk-Based Capital ratio and the corresponding minimum ratios. At March 31, 2020 , the required minimum capital conservation buffer was 2.50% . At March 31, 2020 , the capital conservation buffers of the Company and IBERIABANK were 4.48% and 3.94% , respectively.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The computations of basic and diluted earnings per share were as follows: Three Months Ended March 31, (in thousands, except per share data) 2020 2019 Earnings Per Common Share - Basic: Net income $ 36,425 $ 100,131 Preferred stock dividends (3,598 ) (3,598 ) Dividends and undistributed earnings allocated to unvested restricted shares (367 ) (933 ) Earnings allocated to common shareholders - basic $ 32,460 $ 95,600 Weighted average common shares outstanding 51,979 54,177 Earnings per common share - basic $ 0.62 $ 1.76 Earnings Per Common Share - Diluted: Earnings allocated to common shareholders - basic $ 32,460 $ 95,600 Adjustment for undistributed earnings allocated to unvested restricted shares (3 ) (42 ) Earnings allocated to common shareholders - diluted $ 32,457 $ 95,558 Weighted average common shares outstanding 51,979 54,177 Dilutive potential common shares 217 362 Weighted average common shares outstanding - diluted 52,196 54,539 Earnings per common share - diluted $ 0.62 $ 1.75 For the three months ended March 31, 2020 and 2019 , the calculations for basic shares outstanding excluded weighted average shares owned by the RRP of 608,128 and 564,188 , respectively. The effects from the assumed exercises of 517,900 and 155,757 stock options were not included in the computation of diluted earnings per share for the three months ended March 31, 2020 and 2019

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Recurring fair value measurements The following table presents information about the Company's assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2020 and December 31, 2019 and their classification within the fair value hierarchy. See Note 1, Summary of Significant Accounting Policies, in the 2019 10-K, for a description of how fair value measurements are determined. March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 3,914,960 $ — $ 3,914,960 Mortgage loans held for sale — 207,845 — 207,845 Mortgage loans held for investment, at fair value option — — 2,779 2,779 Derivative instruments — 283,525 — 283,525 Total $ — $ 4,406,330 $ 2,779 $ 4,409,109 Liabilities Derivative instruments $ — $ 23,798 $ — $ 23,798 Total $ — $ 23,798 $ — $ 23,798 December 31, 2019 Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 3,933,360 $ — $ 3,933,360 Mortgage loans held for sale — 213,357 — 213,357 Mortgage loans held for investment, at fair value option — — 2,792 2,792 Derivative instruments — 104,151 — 104,151 Total $ — $ 4,250,868 $ 2,792 $ 4,253,660 Liabilities Derivative instruments $ — $ 11,799 $ — $ 11,799 Total $ — $ 11,799 $ — $ 11,799 Non-recurring fair value measurements The Company holds certain assets that are measured at fair value only in certain circumstances, such as impairment. The following table presents information about the Company's assets that are measured at fair value and still held as of March 31, 2020 and December 31, 2019 for which a non-recurring fair value adjustment was recorded during the periods then ended. See Note 1, Summary of Significant Accounting Policies, in the 2019 10-K, for a description of how fair value measurements are determined. March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 87,227 $ 87,227 OREO, net — — 6,869 6,869 Total $ — $ — $ 94,096 $ 94,096 December 31, 2019 Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 74,763 $ 74,763 OREO, net — — 4,907 4,907 Total $ — $ — $ 79,670 $ 79,670 The Company did not record any liabilities at fair value for which measurement of the fair value was made on a non-recurring basis as of March 31, 2020 and December 31, 2019 . Fair value option The Company has elected the fair value option for originated residential mortgage loans held for sale, which allows for a more effective offset of the changes in fair values of the loans and the derivative instruments used to hedge them without the burden of complying with the requirements for hedge accounting. The Company also has a portion of mortgage loans held for investment for which the fair value option was elected upon origination and which continue to be accounted for at fair value at March 31, 2020 and December 31, 2019 , respectively. The following table summarizes the difference between the aggregate fair value and the aggregate unpaid principal balance for mortgage loans held for sale and mortgage loans held for investment measured at fair value: March 31, 2020 December 31, 2019 (in thousands) Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Unpaid Principal Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Unpaid Principal Mortgage loans held for sale, at fair value $ 207,845 $ 201,259 $ 6,586 $ 213,357 $ 207,481 $ 5,876 Mortgage loans held for investment, at fair value 2,779 2,804 (25 ) 2,792 2,922 (130 ) Interest income on mortgage loans held for sale and mortgage loans held for investment at fair value option is recognized based on contractual rates and is reflected in interest income on loans held for sale in the consolidated statements of comprehensive income. The following table details net gains (losses) resulting from the change in fair value of loans that were recorded in mortgage income in the consolidated statements of comprehensive income for the three months ended March 31, 2020 and 2019. The changes in fair value are mostly offset by economic hedging activities, with an insignificant portion of these changes attributable to changes in instrument-specific credit risk. Net Gains (Losses) Resulting From Changes in Fair Value For the Three Months Ended March 31, (in thousands) 2020 2019 Fair value option Mortgage loans held for sale, at fair value $ 711 $ 652 Mortgage loans held for investment, at fair value — 191

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS The carrying amount and estimated fair values of the Company’s financial instruments, as well as the level within the fair value hierarchy, are included in the tables below. See Note 1, Summary of Significant Accounting Policies, in the 2019 10-K, for a description of how fair value measurements are determined. March 31, 2020 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 3,914,960 $ 3,914,960 $ — $ 3,914,960 $ — Mortgage loans held for sale 207,845 207,845 — 207,845 — Mortgage loans held for investment, at fair value option 2,779 2,779 — — 2,779 Derivative instruments 283,525 283,525 — 283,525 — Financial Liabilities Derivative instruments 23,798 23,798 — 23,798 — Amortized Cost Financial Assets Cash and cash equivalents $ 945,062 $ 945,062 $ 945,062 $ — $ — Securities held to maturity 177,960 186,396 — 186,396 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 24,254,947 24,209,165 — — 24,209,165 Financial Liabilities Deposits 25,526,237 25,547,705 — 25,547,705 — Short-term borrowings 390,747 390,747 172,747 218,000 — Long-term debt 1,288,172 1,261,688 — — 1,261,688 December 31, 2019 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 3,933,360 $ 3,933,360 $ — $ 3,933,360 $ — Mortgage loans held for sale 213,357 213,357 — 213,357 — Mortgage loans held for investment, at fair value option 2,792 2,792 — — 2,792 Derivative instruments 104,151 104,151 — 104,151 — Financial Liabilities Derivative instruments 11,799 11,799 — 11,799 — Amortized Cost Financial Assets Cash and cash equivalents $ 894,723 $ 894,723 $ 894,723 $ — $ — Securities held to maturity 182,961 189,899 — 189,899 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 23,874,911 23,732,650 — — 23,732,650 Financial Liabilities Deposits 25,219,349 25,229,566 — 25,229,566 — Short-term borrowings 204,208 204,208 204,208 — — Long-term debt 1,343,687 1,296,696 — — 1,296,696 The fair value estimates presented herein are based upon pertinent information available to management as of March 31, 2020 and December 31, 2019 . Although management is not aware of any factors that would significantly affect the estimated fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since these dates and, therefore, current estimates of fair value may differ significantly from the amounts presented herein.

Business Segments

Business Segments	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Business Segments	BUSINESS SEGMENTS Each of the Company’s reportable operating segments serves the specific needs of the Company’s customers based on the products and services it offers. The reportable segments are based upon those revenue-producing components for which separate financial information is produced internally and primarily reflect the manner in which resources are allocated and performance is assessed. Further, the reportable operating segments are also determined based on the quantitative thresholds prescribed within ASC Topic 280, Segment Reporting , and consideration of the usefulness of the information to the users of the consolidated financial statements. The Company reports the results of its operations through three reportable segments: IBERIABANK, Mortgage, and LTC. The IBERIABANK segment represents the Company’s commercial and retail banking functions, including its lending, investment, and deposit activities. IBERIABANK also includes the Company’s wealth management, capital markets, and other corporate functions. The Mortgage segment represents the Company’s origination, funding, and subsequent sale of one-to-four family residential mortgage loans. The LTC segment represents the Company’s title insurance and loan closing services. Certain expenses not directly attributable to a specific reportable segment are allocated to segments based on pre-determined methods that reflect utilization. Also within IBERIABANK are certain reconciling items that translate reportable segment results into consolidated results. The following tables present certain information regarding operations by reportable segment, including a reconciliation of segment results to reported consolidated results for the periods presented. Reconciling items between segment results and reported results include: • Elimination of interest income and interest expense representing interest earned by IBERIABANK on interest-bearing checking accounts held by related companies, as well as the elimination of the related deposit balances at the IBERIABANK segment; • Elimination of investment in subsidiary balances on certain operating segments included in total and average segment assets; and • Elimination of intercompany due to and due from balances on certain operating segments that are included in total and average segment assets. Three Months Ended March 31, 2020 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 300,930 $ 1,999 $ — $ 302,929 Interest expense 72,587 — — 72,587 Net interest income 228,343 1,999 — 230,342 Provision for (reversal of) expected credit losses 68,960 11 — 68,971 Mortgage income — 23,245 — 23,245 Title revenue — — 5,936 5,936 Other non-interest income (expense) 35,465 10 — 35,475 Allocated expenses (income) (1,729 ) 1,305 424 — Non-interest expense 155,333 16,910 5,184 177,427 Income before income tax expense 41,244 7,028 328 48,600 Income tax expense 10,384 1,603 188 12,175 Net income $ 30,860 $ 5,425 $ 140 $ 36,425 Total loans, leases, and loans held for sale, net of unearned income $ 24,522,757 $ 226,720 $ — $ 24,749,477 Total assets 31,914,337 298,030 27,616 32,239,983 Total deposits 25,497,777 28,460 25,526,237 Average assets 31,694,266 264,341 27,532 31,986,139 Three Months Ended March 31, 2019 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 324,644 $ 1,439 $ 1 $ 326,084 Interest expense 75,600 — — 75,600 Net interest income 249,044 1,439 1 250,484 Provision for (reversal of) credit losses 13,823 (60 ) — 13,763 Mortgage income — 11,849 — 11,849 Title revenue — — 5,225 5,225 Other non-interest income (expense) 35,463 (12 ) (16 ) 35,435 Allocated expenses (income) (2,033 ) 1,500 533 — Non-interest expense 143,755 10,541 4,457 158,753 Income before income tax expense 128,962 1,295 220 130,477 Income tax expense 29,975 307 64 30,346 Net income $ 98,987 $ 988 $ 156 $ 100,131 Total loans, leases, and loans held for sale, net of unearned income $ 22,944,800 $ 151,946 $ — $ 23,096,746 Total assets 31,044,209 191,254 24,726 31,260,189 Total deposits 24,078,698 13,364 — 24,092,062 Average assets 30,660,806 148,174 24,520 30,833,500

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Off-balance sheet commitments In the normal course of business, to meet the financing needs of its customers, the Company is a party to credit-related financial instruments, with risk not reflected in the consolidated financial statements. These financial instruments include commitments to extend credit, standby letters of credit, and commercial letters of credit. Such commitments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated balance sheets. The credit policies used for these commitments are consistent with those used for on-balance sheet instruments. The Company’s exposure to credit loss in the event of non-performance by its customers under such commitments or letters of credit represents the contractual amount of the financial instruments as indicated in the table below. At March 31, 2020 and December 31, 2019 , the fair value of guarantees under commercial and standby letters of credit was $2.8 million and $3.3 million , respectively. This fair value will decrease as the existing commercial and standby letters of credit approach their expiration dates. At March 31, 2020 and December 31, 2019 , respectively, the Company had the following financial instruments outstanding and related reserves, whose contract amounts represent credit risk: (in thousands) March 31, 2020 December 31, 2019 Commitments to extend credit $ 677,297 $ 806,164 Unfunded commitments under lines of credit 7,006,974 7,240,808 Commercial and standby letters of credit 277,415 327,336 Reserve for unfunded lending commitments 18,302 16,637 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee by the borrower. Since many of the commitments are expected to be drawn upon, the total commitment amounts generally represents future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral, if any, is based on management’s credit evaluation of the customer. Unfunded commitments under commercial lines of credit, revolving credit lines, and overdraft protection agreements are commitments for possible future extensions of credit to existing customers. Many of these types of commitments do not contain a specified maturity date and may not be drawn upon to the total extent to which the Company is committed. See Note 5, Allowance for Expected Credit Losses and Credit Quality, for additional information related to the Company’s reserve for unfunded lending commitments. Commercial and standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. These guarantees are primarily issued to support public and private borrowing arrangements, including commercial paper issuance, bond financing, and similar transactions. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. When necessary, they are collateralized, generally in the form of marketable securities and cash equivalents. Legal proceedings The nature of the business of the Company’s banking and other subsidiaries ordinarily results in a certain amount of claims, litigation, investigations, and legal and administrative cases and proceedings, which are considered incidental to the normal conduct of business. Some of these claims are against entities or assets of which the Company is a successor or acquired in business acquisitions. The Company has asserted defenses to these claims and, with respect to such legal proceedings, intends to continue to defend itself vigorously, litigating or settling cases according to management’s judgment as to what is in the best interest of the Company and its shareholders. In July of 2016, the Company received a subpoena from the Office of Inspector General of the U.S. Department of Housing and Urban Development (“HUD”) requesting information on certain previously originated loans insured by the Federal Housing Administration ("FHA") as well as other documents regarding the Company's FHA-related policies and practices. After the Company complied with the subpoena, attorneys from the Department of Justice (“DOJ”) informed the Company in late March of 2017 that a civil qui tam suit had been filed against the Company in federal court involving the subject matter of the HUD subpoena. The HUD lawsuit was settled on December 11, 2017 in the amount of $11.7 million . On February 2, 2018, IBERIABANK filed a lawsuit in the United States District Court for the Eastern District of Louisiana (New Orleans) against Illinois Union Insurance Company and Travelers Casualty and Surety Company of America in an effort to recover the $11.7 million it paid to settle the HUD matter. IBERIABANK filed that lawsuit to recover the insurance proceeds to which it claims to be entitled under certain Bankers’ Professional Liability insurance policies issued by defendants Illinois Union and Travelers. More specifically, IBERIABANK alleges that the insurers have failed to honor their obligations under the policies to pay IBERIABANK’s losses in connection with the $11.7 million settlement of disputed allegations relating to IBERIABANK’s professional services in connection with certain mortgage loans insured by the FHA. The judge in the federal lawsuit granted motion for summary judgment thereby dismissing the case. The Company appealed that decision to the United States Court of Appeals for the Fifth Circuit. The appeal sought reversal of the summary judgment such that the case could be remanded to the district court in an effort to recover the $11.7 million . The United States Court of Appeals for the Fifth Circuit affirmed the decision in favor of Illinois Union Insurance Company and Travelers Casualty and Surety Company of America. Four purported holders of IBKC common stock have filed four putative stockholder class action complaints against IBKC and the members of IBKC’s board of directors. The complaints are captioned as follows: Wang v. IBKC, et al., No. 20-0105-LAP (S.D.N.Y filed January 6, 2020); Parshall v. IBKC, et al. , No.20-00027-LPS (D. Del. filed January 8, 2020, includes First Horizon as a Defendant); Hertz v. IBKC, et al., No. 20-00267-MKB-LB (E.D.N.Y filed January 16, 2020); and Cooksey v. IBKC, et al., No. 20-00431-FB-RER (E.D.N.Y. filed January 26, 2020). The complaints assert claims under Section 14(a) of the Exchange Act and Rule 14a-9 thereunder against IBKC and the members of IBKC’s Board of Directors and under Section 20(a) of the Exchange Act against the members of IBKC’s Board of Directors for allegedly disseminating a false and misleading registration statement on Form S-4, filed by First Horizon with the SEC on December 31, 2019. Among other remedies, the plaintiffs sought to enjoin the merger and any shareholder vote on the merger and rescind the merger or recover damages in the event the merger is completed. All four of these complaints against IBKC and the members of IBKC’s board of directors have recently been dismissed. The Company assesses its liabilities and contingencies in connection with outstanding legal proceedings utilizing the latest information available. Where it is probable that the Company will incur a loss and the amount of the loss can be reasonably estimated, the Company records a liability in its consolidated financial statements. These legal reserves may be increased or decreased to reflect any relevant developments on a quarterly basis. Where a loss is not probable or the amount of loss is not estimable, the Company does not accrue legal reserves. While the outcome of legal proceedings is inherently uncertain, based on information currently available and available insurance coverage, the Company’s management believes that it has established appropriate legal reserves. Any incremental liabilities arising from pending legal proceedings are not expected to have a material adverse effect on the Company’s consolidated financial statements. However, it is possible that the ultimate resolution of these matters, if unfavorable, may be material to the Company’s consolidated financial statements. As of the date of this filing, the Company believes the amount of losses associated with legal proceedings that is reasonably possible to incur above amounts already accrued and reported as of March 31, 2020 is not material.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS In the ordinary course of business, the Company may execute transactions with various related parties. Examples of such transactions may include lending or deposit arrangements, transfers of financial assets, services for administrative support, and other miscellaneous items. The Company has granted loans to executive officers and directors and their affiliates. These loans, including the related principal additions, principal payments, and unfunded commitments are not material to the consolidated financial statements at March 31, 2020 and December 31, 2019 . There were no outstanding loans to such related parties classified as non-accrual, past due, or troubled debt restructurings at March 31, 2020 and December 31, 2019. Deposits from related parties held by the Company were not material at March 31, 2020 and December 31, 2019 .

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation	All significant intercompany balances and transactions have been eliminated in consolidation.
Reclassification	Certain amounts reported in prior periods have been reclassified to conform to the current period presentation.
Investment Securities	Management determines the appropriate accounting classification of debt and equity securities at the time of acquisition and re-evaluates such designations at least quarterly. Debt securities that management has the ability and intent to hold to maturity are classified as HTM and carried at cost, adjusted for amortization of premiums and accretion of discounts using methods approximating the interest method. Securities acquired with the intent of recognizing short-term profits or which are actively bought and sold are classified as trading securities and reported at fair value. Securities not classified as HTM or trading are classified as AFS and reported at fair value. The Company evaluates its investment securities portfolio for impairment on a quarterly basis as follows: HTM Securities: The Company maintains an allowance for expected credit losses appropriate to absorb estimated lifetime credit losses for HTM securities where there is a risk of credit loss. HTM securities where there is a risk of credit loss are segmented by credit rating and duration and an allowance for expected credit losses is calculated based on external historical loss data, taking into consideration management’s forecast of future economic conditions. The allowance of expected credit losses, if required, is recognized on the consolidated balance sheet with a corresponding adjustment to earnings. AFS Securities: Declines in the fair value of individual AFS securities below their amortized cost basis are reviewed to determine if the decline is due to credit-related factors. Impairment that is not credit-related is recognized in other comprehensive income, net of applicable taxes. Credit-related impairment is recognized as an allowance for expected credit losses on the consolidated balance sheet with a corresponding adjustment to earnings. However, if the Company intends to sell the impaired AFS security or it is more likely than not that the Company will be required to sell such a security before recovering the amortized cost basis of the security, the AFS security’s amortized cost basis is reduced by the decline in fair value with the entire credit loss recognized in the consolidated statement of income. Prior to January 1, 2020, investment securities were evaluated for indicators of other than temporary impairment (OTTI) on a quarterly basis. Declines in the fair value of individual HTM and AFS securities below their amortized cost basis were reviewed to determine whether the declines were other than temporary. In estimating OTTI losses, management considered 1) the length of time and the extent to which the fair value had been less than the amortized cost basis, 2) the financial condition and near-term prospects of the issuer, 3) its intent to sell and whether it was more likely than not that the Company would be required to sell those securities before the anticipated recovery of the amortized cost basis, and 4) for debt securities, the recovery of contractual principal and interest. For securities that the Company did not expect to sell, or it was not more likely than not it would be required to sell prior to recovery of its amortized cost basis, the credit component of an OTTI was recognized in earnings and the non-credit component was recognized in OCI. For securities that the Company did expect to sell, or it was more likely than not that it would be required to sell prior to recovery of its amortized cost basis, both the credit and non-credit component of an OTTI were recognized in earnings. Subsequent to recognition of OTTI, an increase in expected cash flows was recognized as a yield adjustment over the remaining expected life of the security based on an evaluation of the nature of the increase. Other equity securities primarily consist of stock acquired for regulatory purposes, such as Federal Home Loan Bank stock and Federal Reserve Bank stock and are included in “other assets." Gains or losses on securities sold are recorded on the trade date, using the specific identification method.
Loans, Leases and Portfolio Segmentation	Loans The Company offers commercial and consumer loans for its customers. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at amortized cost, which represents the principal amount outstanding less charge-offs, net of any unearned income, unamortized net loan origination fees and direct costs on originated loans, and net premiums or discounts on acquired loans. Interest income is accrued as earned over the term of the loans based on the principal balance outstanding. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield. Accrued interest is reported within other assets in the consolidated balance sheet. Acquired loans are recorded at fair value on the acquisition date. The determination of fair value includes credit risk assumptions and any resulting credit discounts as well as estimates related to discount rates, expected prepayments, and the amount and timing of undiscounted expected principal, interest, and other cash flows. Additionally, at the time of acquisition, acquired loans are classified as either purchased credit deteriorated (PCD) or non-purchased credit deteriorated (non-PCD). Acquired loans which have experienced more-than-insignificant deterioration in credit since origination are classified as PCD Loans. All acquired loans not considered to be purchased credit deteriorated loans are classified as acquired non-PCD Loans. An initial allowance for expected credit losses (AECL) is established at the acquisition date for acquired loans and the classification of PCD or non-PCD determines how the initial AECL is recorded. For PCD Loans, the AECL is recorded with a corresponding increase to the amortized cost basis of the loan by reducing the purchase premium or discount recognized on the acquired loan. For acquired non-PCD loans, the AECL is recorded with a corresponding charge to earnings. Subsequent to acquisition, the AECL for both PCD Loans and acquired non-PCD loans is determined using the same methodology as originated loans. The non-credit related purchase premium or discount on acquired loans is amortized or accreted to income over the estimated life of the loans as an adjustment to yield using the effective interest rate calculated at the acquisition date. Prior to January 1, 2020, acquired loans that reflected credit deterioration since origination to the extent that it was probable that the Company would be unable to collect all contractually required payments were classified as purchased impaired loans (“acquired impaired loans”). All other acquired loans were classified as purchased non-impaired loans (“acquired non-impaired loans”). At the time of acquisition, acquired impaired loans were accounted for individually or aggregated into loan pools with similar characteristics. From these pools, the Company used certain loan information to estimate the expected cash flows for each loan pool. For acquired impaired loans, the expected cash flows at the acquisition date in excess of the fair value of loans were recorded as interest income over the life of the loans using a level yield method if the timing and amount of future cash flows was reasonably estimable. For acquired non-impaired loans, the difference between the fair value and unpaid principal balance of the loan at acquisition, referred to as a purchase premium or discount, was amortized or accreted to income over the estimated life of the loans as an adjustment to yield. Subsequent to acquisition, the Company performed cash flow re-estimations at least quarterly for each acquired impaired loan or loan pool. Increases in estimated cash flows above those expected at the time of acquisition were recognized on a prospective basis as interest income over the remaining life of the loan and/or pool. Decreases in expected cash flows subsequent to acquisition generally resulted in recognition of a provision for credit loss. The measurement of cash flows involved several assumptions and judgments, including prepayments, default rates and loss severity among other factors. All of these factors were inherently subjective and significant changes in the cash flow estimations could result over the life of the loan. Leases The Company leases equipment to commercial customers primarily through direct financing and sales-type leases. Equipment financing leases are reported at the net lease investment, which represents the sum of minimum lease payments over the lease term and the estimated residual value, less unearned interest income. Interest income is accrued as earned over the term of the lease based on the net investment in leases. Fees incurred to originate the lease are deferred and recognized as an adjustment of the yield on the lease. Portfolio Segmentation The Company’s loan portfolio is disaggregated into two portfolio segments: commercial loans and leases and consumer loans. The Company further disaggregates the commercial loans and leases and the consumer loans portfolio segment into receivable classes for purposes of monitoring and assessing credit quality. Receivable classes within the commercial loan and lease portfolio segment include commercial real estate-construction, commercial real estate-owner occupied, commercial real estate-non-owner occupied, and commercial and industrial, which includes equipment financing leases. Receivable classes within the consumer loan portfolio segment include residential mortgage, home equity, and other consumer. Prior to January 1, 2020, the Company’s loan portfolio was disaggregated into three portfolio segments: commercial, residential mortgage, and consumer and other loans. Receivable classes within the commercial loan portfolio segment included commercial real estate-construction, commercial real estate-owner-occupied, commercial real estate-non-owner occupied, and commercial and industrial. Receivable classes within the consumer and other loans portfolio segment included home equity, indirect automobile, credit card and other.
Troubled Debt Restructurings	Troubled Debt Restructurings The Company periodically grants concessions to its customers in an attempt to protect as much of its investment as possible and minimize risk of loss. These concessions may include restructuring the terms of a loan to alleviate the burden of the customer’s near-term cash requirements. In order to be classified as a TDR, the Company must conclude that the restructuring constitutes a concession and the customer is experiencing financial difficulties. The Company defines a concession to the customer as a modification of existing terms for economic or legal reasons that it would otherwise not consider. The concession is either granted through an agreement with the customer or is imposed by a court of law. Concessions include modifying original loan terms to reduce or defer cash payments required as part of the loan agreement, including but not limited to: • a reduction of the stated interest rate for the remaining original life of the loan, • extension of the maturity date or dates at a stated interest rate lower than the current market rate for new loans with similar risk characteristics, • reduction of the face amount or maturity amount of the loan as stated in the agreement, or • reduction of accrued interest receivable on the loan. In its determination of whether the customer is experiencing financial difficulties, the Company considers numerous indicators, including, but not limited to: • whether the customer is currently in default on its existing loan(s), or is in an economic position where it is probable the customer will be in default on its loan(s) in the foreseeable future without a modification, • whether the customer has declared bankruptcy, • whether there is substantial doubt about the customer’s ability to continue as a going concern, • whether, based on its projections of the customer’s current capabilities, the Company believes the customer’s future cash flows will be insufficient to service the loan, including interest, in accordance with the contractual terms of the existing agreement for the foreseeable future, and • whether the customer cannot obtain sufficient funds from other sources at an effective interest rate equal to the current market rate for a similar loan for a non-troubled debtor. If the Company concludes that both a concession has been granted and the customer is experiencing financial difficulties, the Company identifies the loan as a TDR. Prior to January 2020, all TDRs were considered impaired loans and acquired impaired loans accounted for within pools were not reviewed for TDR classification if modified.
Non-accrual and Past Due Loans and Leases	Non-accrual and Past Due Loans and Leases (Including Loan Charge-offs) Loans and leases are generally considered past due when contractual payments of principal and interest have not been received within 30 days after the contractual due date. Residential mortgage loans are considered past due when contractual payments have not been received for two consecutive payment dates. Loans and leases are placed on non-accrual status when any of the following occur: 1) the loan or lease is maintained on a cash basis because of deterioration in the financial condition of the borrower; 2) collection of the full contractual amount of principal and interest is not expected even if the loan or lease is currently paying as agreed; or 3) when principal or interest has been in default for a period of 90 days or more, unless the loan or lease is both well-secured and in the process of collection. Factors considered in determining the collection of the full contractual amount of principal and interest include assessment of the borrower’s cash flow, valuation of underlying collateral, and the ability and willingness of guarantors to provide credit support. Certain commercial loans and leases are also placed on non-accrual status when payment is not past due and full payment of principal and interest is expected, but the Company has doubt about the borrower’s ability to comply with existing repayment terms. Consideration will be given to placing a loan or lease on non-accrual due to the deterioration of the debtor’s repayment ability, the repayment of the loan or lease becoming dependent on the liquidation of collateral, an existing collateral deficiency, the loan or lease being classified as "doubtful" or "loss," the client filing for bankruptcy, and/or foreclosure being initiated. For all commercial loans and leases, the determination of a borrower’s ability to make the required principal and interest payments is based on an examination of the borrower’s current financial statements, industry, management capabilities, and other qualitative factors. Loans and leases are evaluated for potential charge-off in accordance with the parameters discussed in the following paragraph or when the loan or lease is placed on non-accrual status, whichever is earlier. Prior to January 1, 2020, acquired impaired loans were placed on non-accrual status when the Company could not reasonably estimate cash flows on the loan or loan pool. Loans and leases within the commercial portfolio are generally evaluated for charge-off at 90 days past due, unless both well-secured and in the process of collection. Closed and open-end consumer loans and leases are evaluated for charge-off no later than 120 days past due. Any outstanding loan balance in excess of the fair value of the collateral less costs to sell is charged-off no later than 120 days past due for loans secured by real estate. For non-real estate secured loans and leases, in lieu of charging off the entire balance, loans or leases may be written down to the fair value of the collateral less costs to sell if repossession of collateral is assured and in process. Prior to January 1, 2020, acquired impaired loans were not generally evaluated for charge-off. The accrual of interest, as well as the amortization/accretion of any remaining unamortized net deferred fees or costs and discount or premium, is discontinued at the time the loan or lease is placed on non-accrual status. Accrued but uncollected interest for all loans and leases that are placed on non-accrual status is generally reversed through interest income at 90 days past due. As accrued but uncollected interest is reversed on a timely basis, the Company does not estimate an AECL for accrued interest. Cash receipts received on non-accrual loans or leases are generally applied against principal until the loan or lease has been collected in full, after which time any additional cash receipts are recognized as interest income (i.e., cost recovery method). However, interest may be accounted for under the cash-basis method as long as the remaining recorded investment in the loan is deemed fully collectible. Loans and leases are returned to accrual status when the borrower has demonstrated a capacity to continue payment of the debt (generally a minimum of six months of sustained repayment performance) and collection of contractually required principal and interest associated with the debt is reasonably assured. Additionally, for a non-accrual TDR to be returned to accrual status, a current, well-documented credit analysis is required and the borrower must have complied with all terms of the modification. At such time, the accrual of interest and amortization/accretion of any remaining unamortized net deferred fees or costs and discount or premium shall resume. Any interest income which was applied to the principal balance shall not be reversed and subsequently will be recognized as an adjustment to yield over the remaining life of the loan.
Individually Assessed Loans and Leases/Impaired Loans	Individually Assessed Loans and Leases/Impaired Loans When a loan or lease no longer shares risk characteristics with other loans or leases, it is individually assessed for impairment. While management considers a variety of factors in determining when a loan no longer shares risk characteristics with other loans, generally all TDR and non-accrual loans above certain thresholds are considered to meet this requirement and are individually assessed for impairment. Impairment losses are measured on a loan-by-loan basis for these commercial and consumer loans and leases, based on either the present value of expected future cash flows discounted at the loan or lease’s effective interest rate or the fair value of the collateral if the loan or lease is collateral-dependent. This measurement requires significant judgment and use of estimates, and the actual loss ultimately recognized by the Company may differ significantly from the estimates. Prior to January 1, 2020, a loan was considered to be impaired when, based on current information and events, it was probable that the Company would be unable to collect the scheduled payments of principal and/or interest in accordance with the contractual terms of the loan agreement. Generally all TDRs regardless of the outstanding balance amount or portfolio classification, and all acquired impaired loans were considered to be impaired. Loans that experienced insignificant payment delays and payment shortfalls generally were not classified as impaired. Impairment losses were measured on a loan-by-loan basis for commercial and certain residential mortgage or consumer loans, based on either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s observable market price, or the fair value of the collateral if the loan was collateral-dependent.
Allowance for Credit Losses	Allowance for Expected Credit Losses The Company maintains the AECL at a level that management believes appropriate to absorb estimated lifetime credit losses, including losses associated with unfunded commitments. The AECL includes the allowance for loan and lease losses (ALLL) (contra asset) and the reserve for unfunded commitments (liability). Determination of the appropriate AECL involves a high degree of complexity and requires significant judgment regarding the credit quality of the loan portfolio and management’s view of future economic conditions. Several factors are taken into consideration in the determination of the overall AECL which include, but are not limited to, the overall risk profiles of the loan and lease portfolios, net charge-off experience, the level of loans and leases that require an individual assessment for impairment, the level of non-performing loans and leases, the level of 90 days past due loans and leases, the value of collateral, among other factors. The Company also considers forecasts of future national and regional economic conditions, overall asset quality trends, changes in lending practices and procedures, trends in the nature and volume of the loan portfolio (including the existence and effect of any portfolio concentrations), changes in experience and depth of lending staff, the Company’s legal, regulatory and competitive environment, and data availability and applicability that might impact the portfolio or the manner in which it estimates losses, risk rating accuracy, and risk identification. The Company has developed multiple current expected credit loss models (ECL Models) which segment the Company’s loan and lease portfolio by borrower type (i.e. commercial and consumer) and loan or lease type to estimate lifetime expected credit losses for loans and leases that share similar risk characteristics. These ECL Models primarily use a probability-of-default methodology to estimate expected credit losses for all loan and lease commitments. Within each ECL Model, PDs and LGDs are established at the individual loan or lease commitment level based on various loan or lease specific characteristics. For commercial loans and leases, these characteristics include customer size, industry sector, geographic region, risk rating and collateral/property type, among others. For consumer loans, these characteristics include geographic region, loan size, customer size, fixed or variable rate, lien position, and FICO score, among others. The ECL Models use both internal and external historical loss data, as appropriate, for all available historical periods and a blend of multiple economic forecasts as approved by ALCO to estimate expected credit losses over a reasonable and supportable forecast period. The ECL Models then revert to longer term historical loss experience on a straight-line basis to arrive at lifetime expected credit losses. The selection of the economic forecasts, the forecast period and reversion period and methodology are reviewed and approved quarterly. The ECL Models also take into consideration the effects of prepayments and draw-down assumptions for any unfunded commitments, as applicable. Qualitative adjustments are incorporated into the ECL Model-based estimate of expected credit losses to accommodate for the imprecision of certain assumptions and uncertainties inherent in the calculation. Loans or leases that no longer share similar risk characteristics with other loans or leases in the portfolio must be individually evaluated for impairment. For these loans and leases, the AECL is determined on an individual loan and lease commitment basis, taking into consideration facts and circumstances specific to each borrower. As discussed above, the AECL for individually assessed loans or leases is based on the difference between the recorded investment in the loan or lease and either the estimated net present value of projected cash flows or the estimated value of the collateral associated with a collateral-dependent loan, less cost to sell. The overall AECL is allocated between the ALLL and the reserve for unfunded commitments based on the loan’s percentage funded and the future funding expectations of the loan. Prior to January 1, 2020, the allowance for credit losses was maintained at a level appropriate to absorb estimated probable credit losses incurred in the loan portfolio, including unfunded commitments as of the consolidated balance sheet date. The manner in which the allowance for credit losses was determined was based on 1) the accounting method applied to the underlying loans and 2) whether the loan was required to be measured for impairment. The Company delineated between loans accounted for under the contractual yield method, legacy loans (originated loans), acquired non-impaired loans, and acquired impaired loans. Further, for legacy and acquired non-impaired loans, the Company attributed portions of the allowance for credit losses to loans and loan commitments that it measured individually, and groups of homogeneous loans and loan commitments that it measured collectively for impairment. Prior to January 1, 2020, the allowance for loan losses for all impaired loans (excluding acquired impaired loans) was determined on an individual loan basis, considering the facts and circumstances specific to each borrower. The allowance was based on the difference between the recorded investment in the loan and generally either the estimated net present value of projected cash flows or the estimated value of the collateral associated with a collateral-dependent loan. The determination of the allowance for loan losses for acquired impaired loans prior to January 1, 2020 is further discussed in the “Loans” section of this footnote. Prior to January 1, 2020, the allowance for loan losses for all non-impaired loans (excluding acquired impaired loans) was calculated based on pools of loans with similar characteristics. The pool-level allowance was calculated through the application of PD and LGD factors for each individual loan. PDs and LGDs were determined based on historical default and loss information for similar loans. For purposes of establishing estimated loss percentages for pools of loans that shared common risk characteristics, the Company’s loan portfolio was segmented by various loan characteristics including loan type, risk rating for commercial, Vantage or FICO score for residential mortgage and consumer, past due status for residential mortgage and consumer and call report code. The default and loss information was measured over an appropriate period for each loan pool and adjusted as deemed appropriate. Qualitative adjustments were incorporated into the pool-level analysis to accommodate for the imprecision of certain assumptions and uncertainties inherent in the calculation.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Pronouncements adopted during the quarter ended March 31, 2020: ASU No. 2016-13, ASU No. 2019-04 (portion related to ASC 326), ASU No. 2019-05, ASU No. 2019-11, and ASU No. 2020-03 In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments. The guidance, along with subsequent related updates issued during 2019, introduces an impairment model that is based on expected credit losses (ECL) rather than incurred losses, to estimate credit losses on certain types of financial instruments, such as loans and held-to-maturity (HTM) securities, including certain off-balance sheet financial instruments, such as loan commitments. The measurement of ECL should consider historical information, current information, and reasonable and supportable forecasts, including estimates of prepayments, over the contractual term. Financial instruments with similar risk characteristics must be grouped together when estimating ECL. In addition, ASC 326 expands credit quality disclosures. ASC 326 also provides for a simplified accounting model for purchased financial assets with a more-than-insignificant amount of credit deterioration since their origination (purchased credit deteriorated). The initial estimate of expected credit losses for purchase credit deteriorated financial assets is recognized as an AECL with an offset (i.e., increase) to the cost basis of the related financial asset at acquisition. Additionally, ASC 326 amends the current AFS security impairment model for debt securities. The new model will require an estimate of ECL when the fair value is below the amortized cost of the asset. The credit-related impairment (and subsequent recoveries) are recognized as an allowance on the balance sheet with a corresponding adjustment to the income statement. Non-credit related losses will continue to be recognized through OCI. The Company adopted these ASUs as of January 1, 2020 through a cumulative-effect adjustment to opening retaining earnings. Estimation Methodology The Company has developed multiple current expected credit loss models (ECL Models) which segment the Company’s loan and lease portfolio by borrower type (i.e. commercial and consumer) and loan type to estimate lifetime expected credit losses for loans and leases. The ECL Models primarily use a probability-of-default methodology to estimate expected credit losses. Within each ECL Model, loans and leases are further segregated based on additional risk characteristics specific to that loan or leases type, such as risk rating, industry sector, company and/or loan size, collateral type, geographic location and FICO score. The Company uses both internal and external historical loss data in the ECL Models, as appropriate. The estimate of expected credit losses is inherently subjective, as it requires management to exercise judgment in determining appropriate factors to be used to determine the allowance. Following are some of the most significant factors used to estimate expected credit losses under ASC 326: Economic Forecasts : Management selected economic variables it believes to be the most relevant for estimating losses based on the composition of the loan and leases portfolio and customer base, including property values, employment and unemployment levels, oil prices and other key economic measures. The Company considers a variety of economic forecasts and selects multiple economic forecasts it believes represent future changes in macroeconomic conditions. The Company uses a blend of the selected economic forecasts to estimate credit losses. Forecast Period : Management believes that it can reasonably forecast credit losses over an eighteen month period, taking into consideration historical information, current information, and reasonable and supportable economic forecasts. Management will re-evaluate the forecast period on a quarterly basis and may adjust the forecast period in response to changes in the economic environment and other factors. Reversion Methodology : For contractual periods beyond the eighteen month forecast period, the Company reverts over a twelve-month period to longer term historical loss experience on a straight-line basis to arrive at lifetime expected credit losses. Management will re-evaluate the reversion methodology on a quarterly basis. Credit losses for loans and leases which no longer share risk characteristics with other loans or leases, primarily non-accrual and TDR loans are individually assessed for impairment. A specific allowance is determined for these loans and leases determined using either the present value of expected cash flows or the fair value of the underlying collateral. The AECL calculated by the ECL Models for the Company’s loan and lease portfolio is allocated between the ALLL and the reserve for unfunded commitments based on the loan’s percentage funded and future funding expectations of the loan. The Company elected not to measure an allowance for expected credit losses for accrued interest as its reverses uncollectible accrued interest through interest income in a timely manner. Accrued interest will continue to be reported within other assets in the consolidated balance sheet. The Company did not elect the one-time fair value option transition expedient for financial instruments recorded at amortized cost. Additionally, the Company elected to discontinue the use of pools to account for purchased credit deteriorated financial assets. ASC 326 also requires an estimate of expected credit losses on the HTM and AFS debt securities portfolios. Most of these portfolios consist of agency-backed securities that inherently have an immaterial risk of loss. For non-agency-backed HTM securities, the Company estimates expected credit losses by segmenting the portfolio by credit rating and duration and applying external historical loss data, taking into consideration management's forecast of future economic conditions, as discussed above. For non-agency-backed AFS securities where amortized cost exceeds fair value, the Company reviews each security to determine if any portion of the unrealized loss is credit-related. Impact of Adoption The impact of the adoption of ASC 326 on the Company's loan and lease portfolio was as follows: (in thousands) December 31, 2019 CECL Adoption January 1, 2020 Allowance for Expected Credit Losses Real estate - construction $ 9,993 $ 3,332 $ 13,325 Real estate - owner-occupied 16,115 (7,536 ) 8,579 Real estate - non-owner occupied 38,170 28,859 67,029 Commercial & industrial 62,112 (14,656 ) 47,456 Residential mortgage 10,209 71,264 81,473 Home equity 14,231 2,808 17,039 Other consumer loans 12,395 (1,752 ) 10,643 Total $ 163,225 $ 82,319 $ 245,544 Retained Earnings Increase in allowance for expected credit losses $ 82,319 Balance sheet reclassification 5,987 Total pre-tax effect 88,306 Tax effect 20,701 Decrease to retained earnings $ 67,605 The increase in the AECL primarily relates to required increases for loans previously classified as acquired non-impaired. The AECL for residential mortgage loans increased due to the requirement to estimate lifetime expected credit losses and the remaining length of time to maturity for these loans versus a loss emergence period. The AECL for non-owner-occupied commercial real estate loans also increased reflecting higher LGDs under the CECL model. The balance sheet reclassification represents the adjustment to the amortized cost basis of purchased credit deteriorated loans to reflect the addition of the allowance for expected credit losses at the date of adoption. At the time of adoption, the Company recognized the economy was vulnerable to major shocks, fiscal policy missteps, other geopolitical events and the outcome of the pending U.S. elections. The transition adjustment reflected the Company's view of a relatively stable macroeconomic environment over the next eighteen months. While ASC 326 results in a higher AECL, it does not change the overall credit risk in the Company’s loan and lease portfolios or the ultimate losses therein. The Company expects future changes in the AECL to be more volatile under ASC 326 as the AECL in future periods will be based on a variety of factors, including changes in loan and lease volumes, the credit quality of the loan and lease portfolio, and forecasts of future economic conditions, which are outside of the Company’s control. The adoption of ASC 326 for the Company’s HTM and AFS debt securities was not material. ASU No. 2018-13 In August 2018, the FASB released ASU No. 2018-13, Fair Value Measurement (ASC 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates, adds and modifies certain disclosure requirements for fair value measurements. The ASU is effective for fiscal years beginning after December 15, 2019, including interim periods, with early adoption permitted. The Company adopted ASU No. 2018-13 as of January 1, 2020. While adoption of this ASU will result in changes to existing disclosures, it did not have an impact on the Company’s financial position or results of operations. ASU No. 2018-17 In October 2018, the FASB released ASU No. 2018-17, Consolidation (ASC 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities, which improves the consistency of the application of the variable interest entity (VIE) related party guidance for common control arrangements. This ASU requires reporting entities to consider indirect interests held through related parties under common control on a proportional basis rather than as the equivalent of a direct interest in its entirety (as currently required in GAAP) when determining whether a decision-making fee is a variable interest. ASU No. 2018-17 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. The guidance will be applied retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Company adopted ASU No. 2018-17 as of January 1, 2020. The adoption of the ASU did not have a material impact to the Company’s consolidated financial statements. Based on the Company’s invested interests at adoption, no transition adjustment was needed. ASU No. 2019-04 In April 2019, the FASB released ASU No. 2019-04, Codification Improvements to Financial Instruments-Credit Losses (ASC 326), Derivatives and Hedging (ASC 815), and Financial Instruments (ASC 825) . The amendments in the ASU improve the Codification by eliminating inconsistencies and providing clarifications. The amendments related to the credit losses standard are discussed above under ASU 2016-13. With respect to hedge accounting, the ASU addresses partial-term fair value hedges, fair value hedge basis adjustments, and certain transition requirements, among other things. For recognizing and measuring financial instruments, the ASU addresses the scope of the guidance, the requirement for re-measurement under ASC 820 when using the measurement alternative, certain disclosure requirements and which equity securities have to be re- measured at historical exchange rates. Since the Company early adopted the guidance in ASU No. 2017-12, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities in 2018, the amended hedge accounting guidance in ASU No. 2019-04 is effective as of the beginning of the first annual reporting period beginning after April 25, 2019 with early adoption permitted on any date after the issuance of this ASU. The Company adopted ASU No. 2017-08 as of January 1, 2020. The adoption of the ASU did not have a material impact to the Company’s consolidated financial statements. Pronouncements issued but not yet adopted: ASU No. 2019-12 In December 2019, the FASB released ASU No. 2019-12, Income Taxes (ASC 740): Simplifying the Accounting for Income Taxes , as part of their initiative to reduce complexity in accounting standards. The ASU simplifies the accounting for income taxes by eliminating certain exceptions to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The ASU also simplifies aspects of the accounting for enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. ASU No. 2019-12 will be effective for fiscal years beginning after December 15, 2020, including interim periods, with early adoption permitted. The transition method for ASU No. 2019-12 varies between the simplification items. The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements. ASU No. 2020-01 In January 2020, the FASB released ASU No. 2020-01, Investments-Equity Securities (ASC 321), Investments- Equity Method and Joint Ventures (ASC 323), and Derivatives and Hedging (ASC 815): Clarifying the Interactions between ASC 321, ASC 323, and ASC 815 , a consensus of the FASB’s Emerging Issues Task Force (EITF). The ASU clarifies that a company should consider observable transactions that require a company to either apply or discontinue the equity method of accounting under ASC 323 for the purposes of applying the measurement alternative in accordance with ASC 321 immediately before applying or upon discontinuing the equity method. The ASU also clarifies that, when determining the accounting for certain forward contracts and purchased options, a company should not consider, whether upon settlement or exercise, if the underlying securities would be accounted for under the equity method or fair value option. ASU No. 2020-01 will be effective for fiscal years beginning after December 15, 2020, including interim periods, with early adoption permitted. The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements. ASU No. 2020-04 In March 2020, the FASB released ASU No. 2020-04, “ Reference Rate Reform (Topic 848) ,” which provides relief for entities preparing for discontinuation of interest rates such as LIBOR. The ASU provides optional expedients and exceptions to ease the accounting impacts associated with contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. For contracts, this ASU allows entities to account for certain contract modifications as a continuation of the existing contract without additional analysis. For hedging relationships, this ASU allows hedge accounting to continue when certain critical terms of a hedging relationship charge and assess effectiveness in ways that disregard certain potential sources of ineffectiveness. Additionally, the ASU allows entities to make a one-time sale and/or transfer of certain debt securities from held-to-maturity to available-for-sale or trading. ASU No. 2020-04 is effective from the beginning of the interim period that includes March 12, 2020. An entity may elect to apply the ASU prospectively through December 31, 2022. The expedients and exceptions provided by the ASU do not apply to contract modifications made or hedging relationships entered into or evaluated after December 31, 2022, with certain exceptions for hedging relationships existing as of December 31, 2022. The Company is currently evaluating the impact of the ASU on its consolidated financial statements.

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	3 Months Ended
	Mar. 31, 2020
Accounting Changes and Error Corrections [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The impact of the adoption of ASC 326 on the Company's loan and lease portfolio was as follows: (in thousands) December 31, 2019 CECL Adoption January 1, 2020 Allowance for Expected Credit Losses Real estate - construction $ 9,993 $ 3,332 $ 13,325 Real estate - owner-occupied 16,115 (7,536 ) 8,579 Real estate - non-owner occupied 38,170 28,859 67,029 Commercial & industrial 62,112 (14,656 ) 47,456 Residential mortgage 10,209 71,264 81,473 Home equity 14,231 2,808 17,039 Other consumer loans 12,395 (1,752 ) 10,643 Total $ 163,225 $ 82,319 $ 245,544 Retained Earnings Increase in allowance for expected credit losses $ 82,319 Balance sheet reclassification 5,987 Total pre-tax effect 88,306 Tax effect 20,701 Decrease to retained earnings $ 67,605

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities	The following table summarizes the amortized cost and estimated fair value of securities available for sale and securities held to maturity as of March 31, 2020 and December 31, 2019 , excluding accrued interest of $13.3 million and $15.1 million , respectively, which is included in other assets in the unaudited consolidated balance sheets, and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) and gross unrecognized gains and losses: March 31, 2020 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,944 $ 425 $ — $ 40,369 Obligations of state and political subdivisions 158,578 6,984 — 165,562 Mortgage-backed securities: Residential agency 2,797,087 82,191 (70 ) 2,879,208 Commercial agency 681,145 32,078 (13 ) 713,210 Other securities 113,621 3,230 (240 ) 116,611 Total securities available for sale $ 3,790,375 $ 124,908 $ (323 ) $ 3,914,960 Amortized Gross Gross Estimated Securities held to maturity: Obligations of state and political subdivisions $ 162,330 $ 8,233 $ — $ 170,563 Mortgage-backed securities: Residential agency 15,630 210 (7 ) 15,833 Total securities held to maturity $ 177,960 $ 8,443 $ (7 ) $ 186,396 December 31, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,916 $ 281 $ — $ 40,197 Obligations of state and political subdivisions 160,873 7,607 — 168,480 Mortgage-backed securities: Residential agency 2,876,069 27,423 (3,836 ) 2,899,656 Commercial agency 704,661 17,202 (404 ) 721,459 Other securities 101,022 2,779 (233 ) 103,568 Total securities available for sale $ 3,882,541 $ 55,292 $ (4,473 ) $ 3,933,360 Amortized Gross Gross Estimated Securities held to maturity: Obligations of state and political subdivisions $ 166,386 $ 7,147 $ — $ 173,533 Mortgage-backed securities: Residential agency 16,575 30 (239 ) 16,366 Total securities held to maturity $ 182,961 $ 7,177 $ (239 ) $ 189,899 Information pertaining to securities with gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous loss position, was as follows: March 31, 2020 Less Than Twelve Months Twelve Months or More Total (in thousands) Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Securities available for sale: Mortgage-backed securities: Residential agency $ (70 ) $ 8,684 $ — $ — $ (70 ) $ 8,684 Commercial agency (13 ) 5,039 — — (13 ) 5,039 Other securities (152 ) 19,848 (88 ) 4,168 (240 ) 24,016 Total securities available for sale $ (235 ) $ 33,571 $ (88 ) $ 4,168 $ (323 ) $ 37,739 Less Than Twelve Months Twelve Months or More Total Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Securities held to maturity: Mortgage-backed securities: Residential agency $ — $ 46 $ (7 ) $ 1,973 $ (7 ) $ 2,019 Total securities held to maturity $ — $ 46 $ (7 ) $ 1,973 $ (7 ) $ 2,019 December 31, 2019 Less Than Twelve Months Twelve Months or More Total (in thousands) Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Securities available for sale: Obligations of state and political subdivisions $ — $ 590 $ — $ — $ — $ 590 Mortgage-backed securities: Residential agency (1,893 ) 441,332 (1,943 ) 268,383 (3,836 ) 709,715 Commercial agency (252 ) 56,728 (152 ) 10,301 (404 ) 67,029 Other securities (133 ) 13,241 (100 ) 4,492 (233 ) 17,733 Total securities available for sale $ (2,278 ) $ 511,891 $ (2,195 ) $ 283,176 $ (4,473 ) $ 795,067 Less Than Twelve Months Twelve Months or More Total Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Securities held to maturity: Mortgage-backed securities: Residential agency $ (52 ) $ 6,308 $ (187 ) $ 9,074 $ (239 ) $ 15,382 Total securities held to maturity $ (52 ) $ 6,308 $ (187 ) $ 9,074 $ (239 ) $ 15,382
Held-to-maturity Securities	The following table summarizes the amortized cost and estimated fair value of securities available for sale and securities held to maturity as of March 31, 2020 and December 31, 2019 , excluding accrued interest of $13.3 million and $15.1 million , respectively, which is included in other assets in the unaudited consolidated balance sheets, and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) and gross unrecognized gains and losses: March 31, 2020 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,944 $ 425 $ — $ 40,369 Obligations of state and political subdivisions 158,578 6,984 — 165,562 Mortgage-backed securities: Residential agency 2,797,087 82,191 (70 ) 2,879,208 Commercial agency 681,145 32,078 (13 ) 713,210 Other securities 113,621 3,230 (240 ) 116,611 Total securities available for sale $ 3,790,375 $ 124,908 $ (323 ) $ 3,914,960 Amortized Gross Gross Estimated Securities held to maturity: Obligations of state and political subdivisions $ 162,330 $ 8,233 $ — $ 170,563 Mortgage-backed securities: Residential agency 15,630 210 (7 ) 15,833 Total securities held to maturity $ 177,960 $ 8,443 $ (7 ) $ 186,396 December 31, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,916 $ 281 $ — $ 40,197 Obligations of state and political subdivisions 160,873 7,607 — 168,480 Mortgage-backed securities: Residential agency 2,876,069 27,423 (3,836 ) 2,899,656 Commercial agency 704,661 17,202 (404 ) 721,459 Other securities 101,022 2,779 (233 ) 103,568 Total securities available for sale $ 3,882,541 $ 55,292 $ (4,473 ) $ 3,933,360 Amortized Gross Gross Estimated Securities held to maturity: Obligations of state and political subdivisions $ 166,386 $ 7,147 $ — $ 173,533 Mortgage-backed securities: Residential agency 16,575 30 (239 ) 16,366 Total securities held to maturity $ 182,961 $ 7,177 $ (239 ) $ 189,899 Information pertaining to securities with gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous loss position, was as follows: March 31, 2020 Less Than Twelve Months Twelve Months or More Total (in thousands) Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Securities available for sale: Mortgage-backed securities: Residential agency $ (70 ) $ 8,684 $ — $ — $ (70 ) $ 8,684 Commercial agency (13 ) 5,039 — — (13 ) 5,039 Other securities (152 ) 19,848 (88 ) 4,168 (240 ) 24,016 Total securities available for sale $ (235 ) $ 33,571 $ (88 ) $ 4,168 $ (323 ) $ 37,739 Less Than Twelve Months Twelve Months or More Total Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Securities held to maturity: Mortgage-backed securities: Residential agency $ — $ 46 $ (7 ) $ 1,973 $ (7 ) $ 2,019 Total securities held to maturity $ — $ 46 $ (7 ) $ 1,973 $ (7 ) $ 2,019 December 31, 2019 Less Than Twelve Months Twelve Months or More Total (in thousands) Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Securities available for sale: Obligations of state and political subdivisions $ — $ 590 $ — $ — $ — $ 590 Mortgage-backed securities: Residential agency (1,893 ) 441,332 (1,943 ) 268,383 (3,836 ) 709,715 Commercial agency (252 ) 56,728 (152 ) 10,301 (404 ) 67,029 Other securities (133 ) 13,241 (100 ) 4,492 (233 ) 17,733 Total securities available for sale $ (2,278 ) $ 511,891 $ (2,195 ) $ 283,176 $ (4,473 ) $ 795,067 Less Than Twelve Months Twelve Months or More Total Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Gross Unrecognized Losses Estimated Fair Value Securities held to maturity: Mortgage-backed securities: Residential agency $ (52 ) $ 6,308 $ (187 ) $ 9,074 $ (239 ) $ 15,382 Total securities held to maturity $ (52 ) $ 6,308 $ (187 ) $ 9,074 $ (239 ) $ 15,382
Additional Information on Securities in a Continuous Loss Position	Additional information on securities that were in a continuous loss position for over twelve months at March 31, 2020 and December 31, 2019 is presented in the following table. (in thousands) March 31, 2020 December 31, 2019 Number of securities Mortgage-backed securities: Residential agency 2 59 Commercial agency — 6 Other securities 4 4 6 69 Amortized Cost Basis Mortgage-backed securities: Residential agency $ 1,980 $ 279,587 Commercial agency — 10,453 Other securities 4,256 4,591 $ 6,236 $ 294,631 Unrealized Loss Mortgage-backed securities: Residential agency $ 7 $ 2,130 Commercial agency — 152 Other securities 88 100 $ 95 $ 2,382
Debt Securities, Held-to-maturity, Credit Quality Indicator [Table Text Block]	March 31, 2020 Securities Held to Maturity Credit Rating Obligations of State and Political Subdivisions Aaa / AAA $ 80,815 Aa1 / AA+ 33,066 Aa2/ AA 38,317 Aa3 / AA- 8,292 A2 / A 1,840 Total $ 162,330
Schedule of Amortized Cost and Estimated Fair Value of Investment Securities by Maturity	The amortized cost and estimated fair value of investment securities by maturity at March 31, 2020 are presented in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. Weighted average yields are calculated on the basis of the yield to maturity based on the amortized cost of each security. Securities Available for Sale Securities Held to Maturity (in thousands) Weighted Amortized Estimated Weighted Amortized Estimated Within one year or less 2.62 % $ 41,572 $ 41,999 3.00 % $ 245 $ 245 One through five years 2.60 180,356 187,480 2.59 5,329 5,380 After five through ten years 2.68 641,404 671,014 2.37 56,038 58,524 Over ten years 2.59 2,927,043 3,014,467 2.56 116,348 122,247 2.61 % $ 3,790,375 $ 3,914,960 2.50 % $ 177,960 $ 186,396
Schedule of Realized Gains and Losses from Sale of Securities Classified as Available for Sale	Gains or losses on securities sold are recorded on the trade date, using the specific identification method. For the three months ended March 31, 2020 and 2019, the Company did not have any realized gains or losses from the sale of securities classified as available for sale. The Company did not realize any gains on calls of securities held to maturity for the three months ended March 31, 2020 and 2019.
Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets	The Company accounts for the following securities at cost less impairment plus or minus any observable price changes, which approximates fair value, with the exception of CRA and Community Development Investment Funds, which are recorded at fair value. Other equity securities, which are presented in other assets on the consolidated balance sheets, were as follows: (in thousands) March 31, 2020 December 31, 2019 Federal Home Loan Bank stock $ 70,914 $ 70,386 Federal Reserve Bank stock 85,630 85,630 CRA and Community Development Investment Funds 1,988 1,948 Other investments 22,098 21,118 $ 180,630 $ 179,082

Loans and Leases (Tables)

Loans and Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Schedule of Non-Covered and Covered Loans	The following is the amortized cost of loans and leases as of March 31, 2020 and December 31, 2019 , excluding accrued interest of $65.9 million and $65.7 million , which is included in other assets in the unaudited consolidated balance sheets: (in thousands) March 31, 2020 December 31, 2019 Commercial loans and leases: Real estate - construction $ 1,322,627 $ 1,321,663 Real estate - owner-occupied 2,424,139 2,475,326 Real estate - non-owner-occupied 6,484,257 6,267,106 Commercial and industrial (C&I) (1) 6,909,841 6,547,538 17,140,864 16,611,633 Consumer and other loans: Residential mortgage 4,849,119 4,739,075 Home equity 1,926,753 1,987,336 Other 624,896 683,455 7,400,768 7,409,866 Total loans and leases $ 24,541,632 $ 24,021,499 (1) Includes equipment financing leases
Schedule of Aging of Loans	The following tables provide an analysis of the aging of loans and leases as of March 31, 2020 and December 31, 2019 . March 31, 2020 Age Analysis of Past Due Loans and Leases (in thousands) 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Past Due Total Past Due Current Total Accruing Loans Greater Than 90 Days Past Due Real estate- construction $ 5,466 $ — $ 69 $ 5,535 $ 1,317,092 $ 1,322,627 $ — Real estate- owner-occupied 5,714 6,302 12,810 24,826 2,399,313 2,424,139 1,328 Real estate- non-owner-occupied 4,525 8,318 14,451 27,294 6,456,963 6,484,257 1,679 Commercial and industrial 16,505 10,357 7,811 34,673 6,875,168 6,909,841 169 Residential mortgage 23,664 1,131 34,748 59,543 4,789,576 4,849,119 7,787 Home equity 20,719 3,014 18,254 41,987 1,884,766 1,926,753 — Other 5,195 2,751 2,572 10,518 614,378 624,896 — Total $ 81,788 $ 31,873 $ 90,715 $ 204,376 $ 24,337,256 $ 24,541,632 $ 10,963 December 31, 2019 Age Analysis of Past Due Loans and Leases (in thousands) 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days Past Due Total Past Due Current Total Accruing Loans Greater Than 90 Days Past Due Real estate- construction $ 244 $ — $ 1,377 $ 1,621 $ 1,320,042 $ 1,321,663 $ — Real estate- owner-occupied 18,387 2,770 9,175 30,332 2,444,994 2,475,326 1,035 Real estate- non-owner-occupied 5,418 2,459 10,450 18,327 6,248,779 6,267,106 58 Commercial and industrial 6,805 1,523 15,601 23,929 6,523,609 6,547,538 887 Residential mortgage 4,008 17,297 23,055 44,360 4,694,715 4,739,075 1,277 Home equity 14,001 3,113 14,332 31,446 1,955,890 1,987,336 — Other 3,935 1,267 2,500 7,702 675,753 683,455 — Total $ 52,798 $ 28,429 $ 76,490 $ 157,717 $ 23,863,782 $ 24,021,499 $ 3,257
Schedule of nonaccrual loans	Additional information on non-accrual loans and leases as of March 31, 2020 and December 31, 2019 is presented in the following table. Amortized Cost of Non-accrual Loans and Leases Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses Interest Income Recognized on Non-accrual Loans and Leases (in thousands) March 31, 2020 December 31, 2019 December 31, 2018 March 31, 2020 December 31, 2019 Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 Real estate- construction $ 133 $ 1,394 $ 1,094 $ 4 $ 929 $ — $ — Real estate- owner-occupied 23,428 17,817 10,260 19,968 11,469 135 70 Real estate- non-owner-occupied 20,383 15,440 15,898 18,120 8,610 159 54 Commercial and industrial 40,768 41,636 57,860 34,432 9,590 122 352 Residential mortgage 48,067 34,833 30,396 26,013 19,500 49 60 Home equity 30,319 24,404 18,830 5,915 3,200 64 67 Other 3,465 3,381 2,846 1,190 — 13 2 Total $ 166,563 $ 138,905 $ 137,184 $ 105,642 $ 53,298 $ 542 $ 605
Summary of Changes in Accretable Yields of Acquired Loans	The following is a summary of changes in the accretable difference for all loans accounted for under ASC 310-30 during the three months ended March 31 , 2019: (in thousands) 2019 Balance at beginning of period $ 133,342 Transfers from non-accretable difference to accretable yield (3,640 ) Accretion (10,086 ) Changes in expected cash flows not affecting non-accretable differences (1) (272 ) Balance at end of period $ 119,344 (1) Includes changes in cash flows expected to be collected due to the impact of changes in actual or expected timing of liquidation events, modifications, changes in interest rates and changes in prepayment assumptions.
Schedule of Modified TDRs	The following table provides information on how the TDRs were modified during the periods indicated: Three Months Ended March 31, (in thousands) 2020 2019 Extended maturities $ 2,450 $ 9,014 Maturity and interest rate adjustment 706 468 Movement to or extension of interest-rate only payments 46 12 Interest rate adjustment 3,878 — Forbearance 1,111 6,510 Other concession(s) (1) 1,604 15,425 Total $ 9,795 $ 31,429 (1) Other concessions may include covenant waivers, forgiveness of principal or interest associated with a customer bankruptcy, or a combination of any of the above concessions.
Schedule of Subsequently Defaulted TDRs	The following table presents the end of period balance for loans modified in a TDR during the periods indicated: Three Months Ended March 31, 2020 2019 (in thousands, except number of loans) Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Real estate- construction 1 $ 154 $ 86 1 $ 39 $ 39 Real estate- owner-occupied 4 2,520 2,558 4 6,904 4,661 Real estate- non-owner-occupied 5 3,944 3,820 7 2,990 2,968 Commercial and industrial 14 1,844 1,367 23 17,382 17,040 Residential mortgage 6 750 413 10 1,741 1,738 Home equity 16 1,507 1,482 33 4,277 4,233 Other 5 71 69 38 787 750 Total 51 $ 10,790 $ 9,795 116 $ 34,120 $ 31,429 Information detailing TDRs that defaulted during the three-month periods ended March 31, 2020 and 2019 , and were modified in the previous twelve months (i.e., the twelve months prior to the default) is presented in the following tables. The Company has defined a default as any loan with a payment that is currently past due greater than 30 days , or was past due greater than 30 days at any point during the respective periods, or since the date of modification, whichever is shorter. Three Months Ended March 31, 2020 2019 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 9,212 1 $ 939 Real estate- owner-occupied 5 1,898 3 640 Real estate- non-owner-occupied 11 5,287 7 825 Commercial and industrial 33 7,862 10 3,933 Residential mortgage 15 1,190 13 1,108 Home equity 23 2,189 16 2,891 Other 20 208 20 261 Total 108 $ 27,846 70 $ 10,597

Allowance for Expected Credit_2

Allowance for Expected Credit Losses and Credit Quality (Tables)	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Schedule of Allowance for Loan Losses for Covered and Non-Covered Loan Portfolios	A summary of changes in the allowance for expected credit losses for the three months ended March 31 was as follows: (in thousands) 2020 2019 Allowance for loan and lease losses at beginning of period $ 146,588 $ 140,571 Transition adjustment for ASC 326 83,194 — Allowance for loan and lease losses, as adjusted 229,782 140,571 Provision for loan and lease losses 66,431 12,612 Transfer of balance to OREO and other — (2,885 ) Charge-offs (12,119 ) (8,918 ) Recoveries 2,591 1,586 Allowance for loan and lease losses at end of period $ 286,685 $ 142,966 Reserve for unfunded commitments at beginning of period $ 16,637 $ 14,830 Transition adjustment for ASC 326 (875 ) — Reserve for unfunded lending commitments, as adjusted 15,762 14,830 Provision for unfunded lending commitments 2,540 1,151 Reserve for unfunded commitments at end of period $ 18,302 $ 15,981 Allowance for expected credit losses at end of period $ 304,987 $ 158,947 A summary of changes in the allowance for expected credit losses, by loan portfolio type, for the three months ended March 31 was as follows: Three Months Ended March 31, 2020 Commercial Real Estate Consumer (in thousands) Construction Owner-occupied Non-owner-occupied Commercial and Industrial Residential Mortgage Home Equity Other Total Allowance for loan and lease losses at beginning of period $ 5,983 $ 15,770 $ 36,541 $ 55,634 $ 9,647 $ 12,153 $ 10,860 $ 146,588 Transition adjustment for ASC 326 2,307 (8,163 ) 29,850 (14,659 ) 70,521 3,620 (282 ) 83,194 Allowance for loan and lease losses, as adjusted 8,290 7,607 66,391 40,975 80,168 15,773 10,578 229,782 Provision for loan and lease losses 940 2,603 30,500 11,833 10,535 7,313 2,707 66,431 Charge-offs (14 ) — (240 ) (7,895 ) (450 ) (1,435 ) (2,085 ) (12,119 ) Recoveries 219 25 132 1,037 329 386 463 2,591 Allowance for loan and lease losses at end of period $ 9,435 $ 10,235 $ 96,783 $ 45,950 $ 90,582 $ 22,037 $ 11,663 $ 286,685 Reserve for unfunded lending commitments at beginning of period $ 4,010 $ 345 $ 1,629 $ 6,478 $ 562 $ 2,078 $ 1,535 $ 16,637 Transition adjustment for ASC 326 1,025 627 (991 ) 3 743 (812 ) (1,470 ) (875 ) Reserve for unfunded lending commitments, as adjusted 5,035 972 638 6,481 1,305 1,266 65 15,762 Provision for (reversal of) unfunded commitments 492 418 91 925 215 433 (34 ) 2,540 Reserve for unfunded lending commitments at end of period 5,527 1,390 729 7,406 1,520 1,699 31 18,302 Allowance for expected credit losses at end of period $ 14,962 $ 11,625 $ 97,512 $ 53,356 $ 92,102 $ 23,736 $ 11,694 $ 304,987 Three Months Ended March 31, 2019 Commercial Real Estate Consumer (in thousands) Construction Owner-occupied Non-owner-occupied Commercial and Industrial Residential Mortgage Home Equity Other Total Allowance for loan and lease losses at beginning of period $ 4,743 $ 12,549 $ 34,514 $ 54,096 $ 12,998 $ 10,181 $ 11,490 $ 140,571 Provision for loan and lease losses 936 1,303 4,648 2,876 1,749 1,056 44 12,612 Transfer of balance to OREO and other — — — — (2,881 ) (4 ) — (2,885 ) Charge-offs — (72 ) — (4,931 ) (28 ) (1,401 ) (2,486 ) (8,918 ) Recoveries 3 35 65 446 32 314 691 1,586 Allowance for loan and lease losses at end of period $ 5,682 $ 13,815 $ 39,227 $ 52,487 $ 11,870 $ 10,146 $ 9,739 $ 142,966 Reserve for unfunded commitments at beginning of period $ 3,249 $ 316 $ 1,304 $ 6,198 $ 866 $ 1,783 $ 1,114 $ 14,830 Provision for unfunded commitments 333 60 401 128 22 28 179 1,151 Reserve for unfunded commitments at end of period 3,582 376 1,705 6,326 888 1,811 1,293 15,981 Allowance for credit losses at end of period $ 9,264 $ 14,191 $ 40,932 $ 58,813 $ 12,758 $ 11,957 $ 11,032 $ 158,947
Investment in Legacy and Acquired Loans by Credit Quality Indicator	Term Loans (in thousands) 2020 2019 2018 2017 2016 Prior Revolving loans Revolving loans Converted to Term Total Commercial loans and leases Real Estate- Construction Pass $ 45,117 $ 336,900 $ 599,002 $ 172,612 $ 65,200 $ 51,622 $ 40,147 $ — $ 1,310,600 Special Mention — — — — 10 105 2,156 — 2,271 Substandard — — 9,213 — — 475 65 — 9,753 Doubtful — — — — — 3 — — 3 Total Real Estate- Construction 45,117 336,900 608,215 172,612 65,210 52,205 42,368 — 1,322,627 Real Estate- Owner- occupied Pass 69,996 379,882 319,249 357,057 274,226 895,032 66,866 — 2,362,308 Special Mention — — 7,306 681 399 13,419 400 — 22,205 Substandard — 234 1,011 8,204 3,518 23,856 387 — 37,210 Doubtful — — — — — 2,416 — — 2,416 Total Real Estate- Owner-occupied 69,996 380,116 327,566 365,942 278,143 934,723 67,653 — 2,424,139 Real Estate- Non-owner-occupied Pass 261,614 1,323,506 961,036 987,814 867,303 1,867,101 130,929 — 6,399,303 Special Mention — — 806 1,497 10,248 14,561 1,900 — 29,012 Substandard — 591 2,059 10,066 6,038 31,481 635 — 50,870 Doubtful — — 104 — — 4,968 — — 5,072 Total Real Estate- Non-owner-occupied 261,614 1,324,097 964,005 999,377 883,589 1,918,111 133,464 — 6,484,257 Commercial and Industrial (1) Pass 649,228 1,957,486 1,307,679 455,600 218,485 551,933 1,635,017 — 6,775,428 Special Mention 259 1,463 23,811 500 8,093 1,436 7,896 — 43,458 Substandard 4,102 16,838 3,023 20,486 1,151 19,194 5,846 — 70,640 Doubtful — 5,323 9,517 2,353 648 2,474 — — 20,315 Total Commercial and Industrial 653,589 1,981,110 1,344,030 478,939 228,377 575,037 1,648,759 — 6,909,841 Total Commercial Loans and Leases $ 1,030,316 $ 4,022,223 $ 3,243,816 $ 2,016,870 $ 1,455,319 $ 3,480,076 $ 1,892,244 $ — $ 17,140,864 (1) Includes equipment financing leases Term Loans (in thousands) 2020 2019 2018 2017 2016 Prior Revolving loans Revolving loans Converted to Term Total Consumer Loans: Residential Mortgage 781 and above $ 45,204 $ 332,402 $ 263,099 $ 185,336 $ 153,118 $ 387,923 $ — $ — $ 1,367,082 723-780 72,666 452,401 360,319 233,243 199,457 410,212 — — 1,728,298 700-722 14,430 94,286 93,264 49,705 47,736 116,470 — — 415,891 660-699 8,549 103,361 83,700 37,108 54,661 144,238 — — 431,617 620-659 3,273 39,018 26,883 15,701 15,481 94,296 — — 194,652 580-619 — 13,756 11,717 8,358 11,281 51,387 — — 96,499 579 and below 101,641 52,459 53,362 58,542 84,198 264,878 — — 615,080 Total Residential Mortgage 245,763 1,087,683 892,344 587,993 565,932 1,469,404 — — 4,849,119 Home Equity 781 and above 2,052 8,710 28,297 16,579 15,903 56,995 374,502 21,481 524,519 723-780 1,160 13,680 25,948 19,278 25,677 81,172 498,082 27,061 692,058 700-722 103 2,226 7,915 7,696 5,276 18,320 130,949 13,029 185,514 660-699 747 3,823 10,975 6,434 6,112 32,755 163,267 17,238 241,351 620-659 351 1,418 1,894 4,355 3,630 19,419 73,928 13,822 118,817 580-619 2,735 875 5,331 2,006 2,581 13,452 27,526 6,484 60,990 579 and below 5,988 2,742 10,009 5,850 2,592 18,201 45,334 12,788 103,504 Total Home Equity 13,136 33,474 90,369 62,198 61,771 240,314 1,313,588 111,903 1,926,753 Other Consumer Loans 781 and above 3,357 11,136 8,566 14,957 5,938 22,047 69,402 — 135,403 723-780 5,717 11,388 22,356 12,895 5,490 32,481 76,717 — 167,044 700-722 1,089 22,224 4,560 3,345 4,133 11,551 16,713 — 63,615 660-699 1,803 4,688 5,120 4,057 1,113 18,128 20,797 — 55,706 620-659 751 4,245 2,432 1,702 3,745 8,142 13,553 — 34,570 580-619 337 1,754 2,689 674 1,611 4,922 8,499 — 20,486 579 and below 22,670 2,038 3,282 3,137 2,585 106,144 8,216 — 148,072 Total Other Consumer 35,724 57,473 49,005 40,767 24,615 203,415 213,897 — 624,896 Total Consumer Loans 294,623 1,178,630 1,031,718 690,958 652,318 1,913,133 1,527,485 111,903 7,400,768 Total Loans and Leases $ 1,324,939 $ 5,200,853 $ 4,275,534 $ 2,707,828 $ 2,107,637 $ 5,393,209 $ 3,419,729 $ 111,903 $ 24,541,632

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Carrying Amount of Goodwill	Goodwill allocated to each reporting unit at March 31, 2020 and December 31, 2019 is provided in the following table: (in thousands) March 31, 2020 December 31, 2019 IBERIABANK $ 1,203,810 $ 1,203,810 Mortgage 23,178 23,178 LTC 8,545 8,545 Total $ 1,235,533 $ 1,235,533
Schedule of Mortgage Servicing Rights	Mortgage servicing rights had the following carrying values as of the periods indicated: March 31, 2020 December 31, 2019 Gross Carrying Amount Valuation Allowance Accumulated Amortization Net Carrying Amount Gross Carrying Amount Valuation Allowance Accumulated Amortization Net Carrying Amount (in thousands) Mortgage servicing rights $ 24,870 $ (2,657 ) $ (7,451 ) $ 14,762 $ 22,476 $ (250 ) $ (6,621 ) $ 15,605
Schedule of Definite-Lived Intangible Assets	Definite-lived intangible assets included in other intangible assets on the Company’s consolidated balance sheets had the following carrying values as of the periods indicated: March 31, 2020 December 31, 2019 (in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Core deposit intangible assets $ 121,277 $ (70,758 ) $ 50,519 $ 136,183 $ (81,493 ) $ 54,690 Customer relationship intangible asset 1,348 (1,341 ) 7 1,385 (1,371 ) 14 Non-compete agreement 206 (118 ) 88 206 (110 ) 96 Total $ 122,831 $ (72,217 ) $ 50,614 $ 137,774 $ (82,974 ) $ 54,800

Derivative Instruments and Ot_2

Derivative Instruments and Other Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Outstanding Derivative Instruments	Information pertaining to outstanding derivative instruments was as follows: Derivative Assets - Fair Value Derivative Liabilities - Fair Value (in thousands) March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Derivatives designated as hedging instruments: Interest rate contracts $ 41,200 $ 18,967 $ 11 $ — Total derivatives designated as hedging instruments $ 41,200 $ 18,967 $ 11 $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 18 $ 9 $ 10,510 $ 5,055 Customer swaps - downstream 222,769 77,934 18 1,680 Forward sales contracts 1,987 420 10,656 986 Written and purchased options 17,364 6,755 1,849 3,899 Other contracts 187 66 754 179 Total derivatives not designated as hedging instruments $ 242,325 $ 85,184 $ 23,787 $ 11,799 Total $ 283,525 $ 104,151 $ 23,798 $ 11,799 Derivative Assets - Notional Amount Derivative Liabilities - Notional Amount (in thousands) March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Derivatives designated as hedging instruments: Interest rate contracts $ 800,000 $ 800,000 $ 108,500 $ 108,500 Total derivatives designated as hedging instruments $ 800,000 $ 800,000 $ 108,500 $ 108,500 Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 48,215 $ 430,808 $ 2,855,442 $ 2,237,542 Customer swaps - downstream 2,855,442 2,237,542 48,215 430,808 Forward sales contracts 196,388 44,011 463,108 230,998 Written and purchased options 699,162 268,590 136,043 121,981 Other contracts 114,755 108,008 251,173 183,243 Total derivatives not designated as hedging instruments $ 3,913,962 $ 3,088,959 $ 3,753,981 $ 3,204,572 Total $ 4,713,962 $ 3,888,959 $ 3,862,481 $ 3,313,072
Offsetting Assets	The following table reconciles the gross amounts presented in the consolidated balance sheets to the net amounts that would result in the event of offset. March 31, 2020 Gross Amounts Presented in the Balance Sheet Gross Amounts Not Offset in the Balance Sheet Net (in thousands) Derivatives Collateral Derivatives subject to master netting arrangements Derivative assets Interest rate contracts designated as hedging instruments $ 41,200 $ — $ — $ 41,200 Interest rate contracts not designated as hedging instruments 222,787 (9,490 ) — 213,297 Written and purchased options 1,602 — — 1,602 Total derivative assets subject to master netting arrangements $ 265,589 $ (9,490 ) $ — $ 256,099 Derivative liabilities Interest rate contracts designated as hedging instruments $ 11 $ — $ — $ 11 Interest rate contracts not designated as hedging instruments 10,528 (9,490 ) — 1,038 Written and purchased options 1,602 — — 1,602 Total derivative liabilities subject to master netting arrangements $ 12,141 $ (9,490 ) $ — $ 2,651 December 31, 2019 Gross Amounts Presented in the Balance Sheet Gross Amounts Not Offset in the Balance Sheet Net (in thousands) Derivatives Collateral Derivatives subject to master netting arrangements Derivative assets Interest rate contracts designated as hedging instruments $ 18,967 $ — $ — $ 18,967 Interest rate contracts not designated as hedging instruments 77,943 (5,111 ) — 72,832 Written and purchased options 3,871 — — 3,871 Total derivative assets subject to master netting arrangements $ 100,781 $ (5,111 ) $ — $ 95,670 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 6,735 $ (5,111 ) $ — $ 1,624 Written and purchased options 3,871 — — 3,871 Total derivative liabilities subject to master netting arrangements $ 10,606 $ (5,111 ) $ — $ 5,495
Offsetting Liabilities	The following table reconciles the gross amounts presented in the consolidated balance sheets to the net amounts that would result in the event of offset. March 31, 2020 Gross Amounts Presented in the Balance Sheet Gross Amounts Not Offset in the Balance Sheet Net (in thousands) Derivatives Collateral Derivatives subject to master netting arrangements Derivative assets Interest rate contracts designated as hedging instruments $ 41,200 $ — $ — $ 41,200 Interest rate contracts not designated as hedging instruments 222,787 (9,490 ) — 213,297 Written and purchased options 1,602 — — 1,602 Total derivative assets subject to master netting arrangements $ 265,589 $ (9,490 ) $ — $ 256,099 Derivative liabilities Interest rate contracts designated as hedging instruments $ 11 $ — $ — $ 11 Interest rate contracts not designated as hedging instruments 10,528 (9,490 ) — 1,038 Written and purchased options 1,602 — — 1,602 Total derivative liabilities subject to master netting arrangements $ 12,141 $ (9,490 ) $ — $ 2,651 December 31, 2019 Gross Amounts Presented in the Balance Sheet Gross Amounts Not Offset in the Balance Sheet Net (in thousands) Derivatives Collateral Derivatives subject to master netting arrangements Derivative assets Interest rate contracts designated as hedging instruments $ 18,967 $ — $ — $ 18,967 Interest rate contracts not designated as hedging instruments 77,943 (5,111 ) — 72,832 Written and purchased options 3,871 — — 3,871 Total derivative assets subject to master netting arrangements $ 100,781 $ (5,111 ) $ — $ 95,670 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 6,735 $ (5,111 ) $ — $ 1,624 Written and purchased options 3,871 — — 3,871 Total derivative liabilities subject to master netting arrangements $ 10,606 $ (5,111 ) $ — $ 5,495
Effect of Derivatives on the Consolidated Financial Statements	At March 31, 2020 and 2019 , and for the three months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements was as follows: Amount of Gain (Loss) Recognized in OCI, net of taxes Location of Gain (Loss) Reclassified from AOCI into Income Amount of Gain (Loss) Reclassified from AOCI into Income, net of taxes Location of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Amount of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Total Including Component Excluding Component Total Including Component Excluding Component Total Including Component Excluding Component (in thousands) For the Three Months Ended March 31, Derivatives in Cash Flow Hedging Relationships 2020 2020 2020 Interest rate contracts $ 10,441 $ 10,628 $ (187 ) Interest expense $ 442 $ 707 $ (265 ) Interest expense $ — $ — $ — 2019 2019 2019 Interest rate contracts $ (2,185 ) $ (3,098 ) $ 913 Interest expense $ (227 ) $ (69 ) $ (158 ) Interest expense $ — $ — $ — Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of March 31, was as follows: Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives For the Three Months Ended March 31, (in thousands) 2020 2019 Interest rate contracts (1) Commission income $ 3,759 $ 4,181 Foreign exchange contracts Other income — 5 Forward sales contracts Mortgage income (10,910 ) (3,209 ) Written and purchased options Mortgage income 12,659 1,863 Other contracts Other income (454 ) (9 ) Total $ 5,054 $ 2,831 (1) Includes fees associated with customer interest rate contracts

Shareholders' Equity, Capital_2

Shareholders' Equity, Capital Ratios and Other Regulatory Matters (Tables)	3 Months Ended
	Mar. 31, 2020
Banking and Thrift [Abstract]
Schedule of Preferred Stock	The following table presents a summary of the Company's non-cumulative perpetual preferred stock: March 31, 2020 December 31, 2019 (in thousands) Issuance Date Earliest Redemption Date Annual Dividend Rate Liquidation Amount Carrying Amount Carrying Amount Series B Preferred Stock 8/5/2015 8/1/2025 6.625 % $ 80,000 $ 76,812 $ 76,812 Series C Preferred Stock 5/9/2016 5/1/2026 6.600 % 57,500 55,285 55,285 Series D Preferred Stock 4/4/2019 5/1/2024 6.100 % 100,000 96,388 96,388 $ 237,500 $ 228,485 $ 228,485
Actual Capital Amounts and Ratios	The Company’s and IBERIABANK’s actual capital amounts and ratios as of March 31, 2020 and December 31, 2019 are presented in the following tables: (in thousands) March 31, 2020 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,228,618 4.00 % N/A N/A $ 3,051,243 9.93 % IBERIABANK 1,225,516 4.00 1,531,895 5.00 3,008,038 9.82 Common Equity Tier 1 (CET1) Consolidated $ 1,216,954 4.50 % N/A N/A $ 2,822,758 10.44 % IBERIABANK 1,212,501 4.50 1,751,390 6.50 3,008,038 11.16 Tier 1 Risk-Based Capital Consolidated $ 1,622,605 6.00 % N/A N/A $ 3,051,243 11.28 % IBERIABANK 1,616,668 6.00 2,155,557 8.00 3,008,038 11.16 Total Risk-Based Capital Consolidated $ 2,163,474 8.00 % N/A N/A $ 3,375,550 12.48 % IBERIABANK 2,155,557 8.00 2,694,446 10.00 3,215,845 11.94 (in thousands) December 31, 2019 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,220,289 4.00 % N/A N/A $ 3,021,004 9.90 % IBERIABANK 1,217,638 4.00 1,522,048 5.00 2,949,533 9.69 Common Equity Tier 1 (CET1) Consolidated $ 1,194,765 4.50 % N/A N/A $ 2,792,520 10.52 % IBERIABANK 1,191,062 4.50 1,720,423 6.50 2,949,533 11.14 Tier 1 Risk-Based Capital Consolidated $ 1,593,020 6.00 % N/A N/A $ 3,021,004 11.38 % IBERIABANK 1,588,083 6.00 2,117,444 8.00 2,949,533 11.14 Total Risk-Based Capital Consolidated $ 2,124,026 8.00 % N/A N/A $ 3,300,730 12.43 % IBERIABANK 2,117,444 8.00 2,648,805 10.00 3,112,758 11.76

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Schedule of Calculation of Basic and Diluted Earnings Per Share	The computations of basic and diluted earnings per share were as follows: Three Months Ended March 31, (in thousands, except per share data) 2020 2019 Earnings Per Common Share - Basic: Net income $ 36,425 $ 100,131 Preferred stock dividends (3,598 ) (3,598 ) Dividends and undistributed earnings allocated to unvested restricted shares (367 ) (933 ) Earnings allocated to common shareholders - basic $ 32,460 $ 95,600 Weighted average common shares outstanding 51,979 54,177 Earnings per common share - basic $ 0.62 $ 1.76 Earnings Per Common Share - Diluted: Earnings allocated to common shareholders - basic $ 32,460 $ 95,600 Adjustment for undistributed earnings allocated to unvested restricted shares (3 ) (42 ) Earnings allocated to common shareholders - diluted $ 32,457 $ 95,558 Weighted average common shares outstanding 51,979 54,177 Dilutive potential common shares 217 362 Weighted average common shares outstanding - diluted 52,196 54,539 Earnings per common share - diluted $ 0.62 $ 1.75

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Financial Asset and Liabilities Measured at Fair Value on Recurring Basis	The following table presents information about the Company's assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2020 and December 31, 2019 and their classification within the fair value hierarchy. See Note 1, Summary of Significant Accounting Policies, in the 2019 10-K, for a description of how fair value measurements are determined. March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 3,914,960 $ — $ 3,914,960 Mortgage loans held for sale — 207,845 — 207,845 Mortgage loans held for investment, at fair value option — — 2,779 2,779 Derivative instruments — 283,525 — 283,525 Total $ — $ 4,406,330 $ 2,779 $ 4,409,109 Liabilities Derivative instruments $ — $ 23,798 $ — $ 23,798 Total $ — $ 23,798 $ — $ 23,798 December 31, 2019 Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 3,933,360 $ — $ 3,933,360 Mortgage loans held for sale — 213,357 — 213,357 Mortgage loans held for investment, at fair value option — — 2,792 2,792 Derivative instruments — 104,151 — 104,151 Total $ — $ 4,250,868 $ 2,792 $ 4,253,660 Liabilities Derivative instruments $ — $ 11,799 $ — $ 11,799 Total $ — $ 11,799 $ — $ 11,799
Financial Asset and Liabilities Measured at Fair Value on Nonrecurring Basis	The following table presents information about the Company's assets that are measured at fair value and still held as of March 31, 2020 and December 31, 2019 for which a non-recurring fair value adjustment was recorded during the periods then ended. See Note 1, Summary of Significant Accounting Policies, in the 2019 10-K, for a description of how fair value measurements are determined. March 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 87,227 $ 87,227 OREO, net — — 6,869 6,869 Total $ — $ — $ 94,096 $ 94,096 December 31, 2019 Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 74,763 $ 74,763 OREO, net — — 4,907 4,907 Total $ — $ — $ 79,670 $ 79,670
Summary of Difference Between the Aggregate Fair Value and the Aggregate Unpaid Principal Balance for Mortgage Loans Held for Sale	The following table summarizes the difference between the aggregate fair value and the aggregate unpaid principal balance for mortgage loans held for sale and mortgage loans held for investment measured at fair value: March 31, 2020 December 31, 2019 (in thousands) Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Unpaid Principal Aggregate Fair Value Aggregate Unpaid Principal Aggregate Fair Value Less Unpaid Principal Mortgage loans held for sale, at fair value $ 207,845 $ 201,259 $ 6,586 $ 213,357 $ 207,481 $ 5,876 Mortgage loans held for investment, at fair value 2,779 2,804 (25 ) 2,792 2,922 (130 )
Fair Value Option, Disclosures	The following table details net gains (losses) resulting from the change in fair value of loans that were recorded in mortgage income in the consolidated statements of comprehensive income for the three months ended March 31, 2020 and 2019. The changes in fair value are mostly offset by economic hedging activities, with an insignificant portion of these changes attributable to changes in instrument-specific credit risk. Net Gains (Losses) Resulting From Changes in Fair Value For the Three Months Ended March 31, (in thousands) 2020 2019 Fair value option Mortgage loans held for sale, at fair value $ 711 $ 652 Mortgage loans held for investment, at fair value — 191

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Estimated Fair Values and Carrying Amounts of Financial Instruments	The carrying amount and estimated fair values of the Company’s financial instruments, as well as the level within the fair value hierarchy, are included in the tables below. See Note 1, Summary of Significant Accounting Policies, in the 2019 10-K, for a description of how fair value measurements are determined. March 31, 2020 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 3,914,960 $ 3,914,960 $ — $ 3,914,960 $ — Mortgage loans held for sale 207,845 207,845 — 207,845 — Mortgage loans held for investment, at fair value option 2,779 2,779 — — 2,779 Derivative instruments 283,525 283,525 — 283,525 — Financial Liabilities Derivative instruments 23,798 23,798 — 23,798 — Amortized Cost Financial Assets Cash and cash equivalents $ 945,062 $ 945,062 $ 945,062 $ — $ — Securities held to maturity 177,960 186,396 — 186,396 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 24,254,947 24,209,165 — — 24,209,165 Financial Liabilities Deposits 25,526,237 25,547,705 — 25,547,705 — Short-term borrowings 390,747 390,747 172,747 218,000 — Long-term debt 1,288,172 1,261,688 — — 1,261,688 December 31, 2019 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 3,933,360 $ 3,933,360 $ — $ 3,933,360 $ — Mortgage loans held for sale 213,357 213,357 — 213,357 — Mortgage loans held for investment, at fair value option 2,792 2,792 — — 2,792 Derivative instruments 104,151 104,151 — 104,151 — Financial Liabilities Derivative instruments 11,799 11,799 — 11,799 — Amortized Cost Financial Assets Cash and cash equivalents $ 894,723 $ 894,723 $ 894,723 $ — $ — Securities held to maturity 182,961 189,899 — 189,899 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 23,874,911 23,732,650 — — 23,732,650 Financial Liabilities Deposits 25,219,349 25,229,566 — 25,229,566 — Short-term borrowings 204,208 204,208 204,208 — — Long-term debt 1,343,687 1,296,696 — — 1,296,696

Business Segments (Tables)

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The following tables present certain information regarding operations by reportable segment, including a reconciliation of segment results to reported consolidated results for the periods presented. Reconciling items between segment results and reported results include: • Elimination of interest income and interest expense representing interest earned by IBERIABANK on interest-bearing checking accounts held by related companies, as well as the elimination of the related deposit balances at the IBERIABANK segment; • Elimination of investment in subsidiary balances on certain operating segments included in total and average segment assets; and • Elimination of intercompany due to and due from balances on certain operating segments that are included in total and average segment assets. Three Months Ended March 31, 2020 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 300,930 $ 1,999 $ — $ 302,929 Interest expense 72,587 — — 72,587 Net interest income 228,343 1,999 — 230,342 Provision for (reversal of) expected credit losses 68,960 11 — 68,971 Mortgage income — 23,245 — 23,245 Title revenue — — 5,936 5,936 Other non-interest income (expense) 35,465 10 — 35,475 Allocated expenses (income) (1,729 ) 1,305 424 — Non-interest expense 155,333 16,910 5,184 177,427 Income before income tax expense 41,244 7,028 328 48,600 Income tax expense 10,384 1,603 188 12,175 Net income $ 30,860 $ 5,425 $ 140 $ 36,425 Total loans, leases, and loans held for sale, net of unearned income $ 24,522,757 $ 226,720 $ — $ 24,749,477 Total assets 31,914,337 298,030 27,616 32,239,983 Total deposits 25,497,777 28,460 25,526,237 Average assets 31,694,266 264,341 27,532 31,986,139 Three Months Ended March 31, 2019 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 324,644 $ 1,439 $ 1 $ 326,084 Interest expense 75,600 — — 75,600 Net interest income 249,044 1,439 1 250,484 Provision for (reversal of) credit losses 13,823 (60 ) — 13,763 Mortgage income — 11,849 — 11,849 Title revenue — — 5,225 5,225 Other non-interest income (expense) 35,463 (12 ) (16 ) 35,435 Allocated expenses (income) (2,033 ) 1,500 533 — Non-interest expense 143,755 10,541 4,457 158,753 Income before income tax expense 128,962 1,295 220 130,477 Income tax expense 29,975 307 64 30,346 Net income $ 98,987 $ 988 $ 156 $ 100,131 Total loans, leases, and loans held for sale, net of unearned income $ 22,944,800 $ 151,946 $ — $ 23,096,746 Total assets 31,044,209 191,254 24,726 31,260,189 Total deposits 24,078,698 13,364 — 24,092,062 Average assets 30,660,806 148,174 24,520 30,833,500

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Summary of Financial Instruments Outstanding	At March 31, 2020 and December 31, 2019 , respectively, the Company had the following financial instruments outstanding and related reserves, whose contract amounts represent credit risk: (in thousands) March 31, 2020 December 31, 2019 Commitments to extend credit $ 677,297 $ 806,164 Unfunded commitments under lines of credit 7,006,974 7,240,808 Commercial and standby letters of credit 277,415 327,336 Reserve for unfunded lending commitments 18,302 16,637

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			$ 163,225
Balance sheet reclassification	$ 5,987
Total pre-tax effect	88,306
Tax effect	20,701
Decrease to retained earnings	$ 67,605
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		$ 245,544
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		82,319	82,300
Residential mortgage
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			10,209
Residential mortgage | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		81,473
Residential mortgage | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		71,264
Real estate - construction | Commercial Loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			9,993
Real estate - construction | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		13,325
Real estate - construction | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		3,332
Real estate - owner-occupied | Commercial Loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			16,115
Real estate - owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		8,579
Real estate - owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		(7,536)
Real estate - non-owner-occupied | Commercial Loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			38,170
Real estate - non-owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		67,029
Real estate - non-owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		28,859
Commercial and industrial | Commercial Loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			62,112
Commercial and industrial | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		47,456
Commercial and industrial | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		(14,656)
Consumer - Home equity | Consumer and other loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			14,231
Consumer - Home equity | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		17,039
Consumer - Home equity | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		2,808
Other | Consumer and other loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses			$ 12,395
Other | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		10,643
Other | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		$ (1,752)

Investment Securities - Schedul

Investment Securities - Schedule of Amortized Cost and Fair Values of Investment Securities, with Gross Unrealized Gains and Losses (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Accrued interest on available-for-sale and held-to-maturity securities	$ 13,300	$ 15,100
Schedule of Available-for-sale Securities
Amortized Cost	3,790,375	3,882,541
Gross Unrealized Gains	124,908	55,292
Gross Unrealized Losses	(323)	(4,473)
Estimated Fair Value	3,914,960	3,933,360
Schedule of Held-to-maturity Securities
Amortized Cost	177,960	182,961
Gross Unrealized Gains	8,443	7,177
Gross Unrealized Losses	(7)	(239)
Estimated Fair Value	186,396	189,899
Fair value of securities held as collateral	2,400,000	2,200,000
U.S. Government-sponsored enterprise obligations
Schedule of Available-for-sale Securities
Amortized Cost	39,944	39,916
Gross Unrealized Gains	425	281
Gross Unrealized Losses	0	0
Estimated Fair Value	40,369	40,197
Schedule of Held-to-maturity Securities
Amortized Cost	15,600
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities
Amortized Cost	158,578	160,873
Gross Unrealized Gains	6,984	7,607
Gross Unrealized Losses	0	0
Estimated Fair Value	165,562	168,480
Schedule of Held-to-maturity Securities
Amortized Cost	162,330	166,386
Gross Unrealized Gains	8,233	7,147
Gross Unrealized Losses	0	0
Estimated Fair Value	170,563	173,533
Mortgage-backed securities: Residential agency
Schedule of Available-for-sale Securities
Amortized Cost	2,797,087	2,876,069
Gross Unrealized Gains	82,191	27,423
Gross Unrealized Losses	(70)	(3,836)
Estimated Fair Value	2,879,208	2,899,656
Schedule of Held-to-maturity Securities
Amortized Cost	15,630	16,575
Gross Unrealized Gains	210	30
Gross Unrealized Losses	(7)	(239)
Estimated Fair Value	15,833	16,366
Mortgage-backed securities: Commercial agency
Schedule of Available-for-sale Securities
Amortized Cost	681,145	704,661
Gross Unrealized Gains	32,078	17,202
Gross Unrealized Losses	(13)	(404)
Estimated Fair Value	713,210	721,459
Other securities
Schedule of Available-for-sale Securities
Amortized Cost	113,621	101,022
Gross Unrealized Gains	3,230	2,779
Gross Unrealized Losses	(240)	(233)
Estimated Fair Value	$ 116,611	$ 103,568

Investment Securities - Sched_2

Investment Securities - Schedule of Securities with Gross Unrealized Losses Aggregated by Investment Category (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Gross Unrealized Losses
Less Than Twelve Months	$ (235)	$ (2,278)
Twelve Months or More	(88)	(2,195)
Total	(323)	(4,473)
Estimated Fair Value
Less Than Twelve Months	33,571	511,891
Twelve Months or More	4,168	283,176
Total	37,739	795,067
Gross Unrealized Losses
Less than twelve months	0	(52)
Over twelve months	(7)	(187)
Total	(7)	(239)
Estimated Fair Value
Less than twelve months	46	6,308
Over twelve months	1,973	9,074
Total	2,019	15,382
Obligations of state and political subdivisions
Gross Unrealized Losses
Less Than Twelve Months		0
Twelve Months or More		0
Total		0
Estimated Fair Value
Less Than Twelve Months		590
Twelve Months or More		0
Total		590
Mortgage-backed securities: Residential agency
Gross Unrealized Losses
Less Than Twelve Months	(70)	(1,893)
Twelve Months or More	0	(1,943)
Total	(70)	(3,836)
Estimated Fair Value
Less Than Twelve Months	8,684	441,332
Twelve Months or More	0	268,383
Total	8,684	709,715
Gross Unrealized Losses
Less than twelve months	0	(52)
Over twelve months	(7)	(187)
Total	(7)	(239)
Estimated Fair Value
Less than twelve months	46	6,308
Over twelve months	1,973	9,074
Total	2,019	15,382
Mortgage-backed securities: Commercial agency
Gross Unrealized Losses
Less Than Twelve Months	(13)	(252)
Twelve Months or More	0	(152)
Total	(13)	(404)
Estimated Fair Value
Less Than Twelve Months	5,039	56,728
Twelve Months or More	0	10,301
Total	5,039	67,029
Other securities
Gross Unrealized Losses
Less Than Twelve Months	(152)	(133)
Twelve Months or More	(88)	(100)
Total	(240)	(233)
Estimated Fair Value
Less Than Twelve Months	19,848	13,241
Twelve Months or More	4,168	4,492
Total	$ 24,016	$ 17,733

Investment Securities - Additio

Investment Securities - Additional Information on Securities in a Continuous Loss Position (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020USD ($)Security	Dec. 31, 2019USD ($)Security
Schedule of Available-for-sale Securities
Number of debt securities with unrealized losses | Security	13	123
Debt securities with unrealized losses (percentage of amortized cost)	0.82%	0.58%
Number of securities | Security	6,000	69,000
Amortized cost basis	$ 6,236	$ 294,631
Unrealized loss	$ 95	$ 2,382
Mortgage-backed securities: Residential agency
Schedule of Available-for-sale Securities
Number of securities | Security	2,000	59,000
Amortized cost basis	$ 1,980	$ 279,587
Unrealized loss	$ 7	$ 2,130
Mortgage-backed securities: Commercial agency
Schedule of Available-for-sale Securities
Number of securities | Security	0	6,000
Amortized cost basis	$ 0	$ 10,453
Unrealized loss	$ 0	$ 152
Other securities
Schedule of Available-for-sale Securities
Number of securities | Security	4,000	4,000
Amortized cost basis	$ 4,256	$ 4,591
Unrealized loss	$ 88	$ 100

Investment Securities - Sched_3

Investment Securities - Schedule of Credit Quality Indicators (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	$ 177,960	$ 182,961
Obligations of state and political subdivisions
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	162,330	$ 166,386
Obligations of state and political subdivisions | Aaa / AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	80,815
Obligations of state and political subdivisions | Aa1 / AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	33,066
Obligations of state and political subdivisions | Aa2/ AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	38,317
Obligations of state and political subdivisions | Aa3 / AA-
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	8,292
Obligations of state and political subdivisions | A2 / A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	1,840
U.S. Government-sponsored enterprise obligations
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held to maturity	$ 15,600

Investment Securities - Sched_4

Investment Securities - Schedule of Amortized Cost and Estimated Fair Value of Investment Securities by Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Weighted Average Yield
Within one year or less	2.62%
One through five years	2.60%
After five through ten years	2.68%
Over ten years	2.59%
Weighted average yield	2.61%
Amortized Cost
Within one year or less	$ 41,572
One through five years	180,356
After five through ten years	641,404
Over ten years	2,927,043
Amortized Cost	3,790,375	$ 3,882,541
Estimated Fair Value
Within one year or less	41,999
One through five years	187,480
After five through ten years	671,014
Over ten years	3,014,467
Estimated fair value	$ 3,914,960	3,933,360
Weighted Average Yield
Within one year or less	3.00%
One through five years	2.59%
After five through ten years	2.37%
Over ten years	2.56%
Weighted average yield	2.50%
Amortized Cost
Within one year or less	$ 245
One through five years	5,329
After five through ten years	56,038
Over ten years	116,348
Amortized Cost	177,960	182,961
Estimated Fair Value
Within one year or less	245
One through five years	5,380
After five through ten years	58,524
Over ten years	122,247
Estimated fair value	$ 186,396	$ 189,899

Investment Securities - Sched_5

Investment Securities - Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank (FHLB) stock	$ 70,914	$ 70,386
Federal Reserve Bank Stock	85,630	85,630
CRA and Community Development Investment Funds	1,988	1,948
Other Investments	22,098	21,118
Marketable Securities	$ 180,630	$ 179,082

Loans and Leases - Schedule of

Loans and Leases - Schedule of Non-Covered Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 24,541,632	$ 24,021,499
Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	17,140,864	16,611,633
Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	1,322,627	1,321,663
Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,424,139	2,475,326
Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	6,484,257	6,267,106
Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	6,909,841	6,547,538
Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	4,849,119	4,739,075
Consumer and other loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	7,400,768	7,409,866
Consumer and other loans | Home equity
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	1,926,753	1,987,336
Consumer and other loans | Other
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 624,896	$ 683,455

Loans and Leases - Loans (Detai

Loans and Leases - Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable
Loan to value ratio	75.00%
Accrued interest	$ 65,900		$ 65,700
Net deferred loan origination fees	36,400		36,800
Net discount	88,300		89,300
Deposit liabilities reclassified as loans receivable	5,500		7,700
Loans with carrying value pledged to secure public deposits and other borrowings	8,700,000		8,600,000
Non-US
Accounts, Notes, Loans and Financing Receivable
Covered loans acquired	181,000		182,400
Acquired Loans
Accounts, Notes, Loans and Financing Receivable
Net discount	$ 53,700		$ 56,400
Consumer and other loans
Accounts, Notes, Loans and Financing Receivable
Loan to value ratio	70.00%
TDRs Occurring during the Period | TDRs
Accounts, Notes, Loans and Financing Receivable
TDRs during period	$ 9,795	$ 31,429
TDRs during period on accrual status	6,800	16,500
TDRs during period on non-accrual status	$ 3,000	$ 14,900

Loans and Leases - Schedule o_2

Loans and Leases - Schedule of Aging of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable
Past due	$ 204,376	$ 157,717
Current	24,337,256	23,863,782
Total Loans	24,541,632	24,021,499
Accruing Loans Greater Than 90 Days Past Due	10,963	3,257
Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Past due	5,535	1,621
Current	1,317,092	1,320,042
Total Loans	1,322,627	1,321,663
Accruing Loans Greater Than 90 Days Past Due	0	0
Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	24,826	30,332
Current	2,399,313	2,444,994
Total Loans	2,424,139	2,475,326
Accruing Loans Greater Than 90 Days Past Due	1,328	1,035
Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	27,294	18,327
Current	6,456,963	6,248,779
Total Loans	6,484,257	6,267,106
Accruing Loans Greater Than 90 Days Past Due	1,679	58
Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Past due	34,673	23,929
Current	6,875,168	6,523,609
Total Loans	6,909,841	6,547,538
Accruing Loans Greater Than 90 Days Past Due	169	887
Residential mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Past due	59,543	44,360
Current	4,789,576	4,694,715
Total Loans	4,849,119	4,739,075
Accruing Loans Greater Than 90 Days Past Due	7,787	1,277
Consumer and other loans | Home equity
Accounts, Notes, Loans and Financing Receivable
Past due	41,987	31,446
Current	1,884,766	1,955,890
Total Loans	1,926,753	1,987,336
Accruing Loans Greater Than 90 Days Past Due	0	0
Consumer and other loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Past due	10,518	7,702
Current	614,378	675,753
Total Loans	624,896	683,455
Accruing Loans Greater Than 90 Days Past Due	0	0
30-59 days
Accounts, Notes, Loans and Financing Receivable
Past due	81,788	52,798
30-59 days | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Past due	5,466	244
30-59 days | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	5,714	18,387
30-59 days | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	4,525	5,418
30-59 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Past due	16,505	6,805
30-59 days | Residential mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Past due	23,664	4,008
30-59 days | Consumer and other loans | Home equity
Accounts, Notes, Loans and Financing Receivable
Past due	20,719	14,001
30-59 days | Consumer and other loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Past due	5,195	3,935
60-89 days
Accounts, Notes, Loans and Financing Receivable
Past due	31,873	28,429
60-89 days | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Past due	0	0
60-89 days | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	6,302	2,770
60-89 days | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	8,318	2,459
60-89 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Past due	10,357	1,523
60-89 days | Residential mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Past due	1,131	17,297
60-89 days | Consumer and other loans | Home equity
Accounts, Notes, Loans and Financing Receivable
Past due	3,014	3,113
60-89 days | Consumer and other loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Past due	2,751	1,267
Greater than 90 days
Accounts, Notes, Loans and Financing Receivable
Past due	90,715	76,490
Greater than 90 days | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Past due	69	1,377
Greater than 90 days | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	12,810	9,175
Greater than 90 days | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Past due	14,451	10,450
Greater than 90 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Past due	7,811	15,601
Greater than 90 days | Residential mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Past due	34,748	23,055
Greater than 90 days | Consumer and other loans | Home equity
Accounts, Notes, Loans and Financing Receivable
Past due	18,254	14,332
Greater than 90 days | Consumer and other loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Past due	$ 2,572	$ 2,500

Loans and Leases - Schedule o_3

Loans and Leases - Schedule of Non-Accrual Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	$ 166,563		$ 138,905	$ 137,184
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	105,642		53,298
Interest Income Recognized on Non-accrual Loans and Leases	542	$ 605
Real estate - construction | Commercial Loans
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	133		1,394	1,094
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	4		929
Interest Income Recognized on Non-accrual Loans and Leases	0	0
Real estate - owner-occupied | Commercial Loans
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	23,428		17,817	10,260
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	19,968		11,469
Interest Income Recognized on Non-accrual Loans and Leases	135	70
Real estate - non-owner-occupied | Commercial Loans
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	20,383		15,440	15,898
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	18,120		8,610
Interest Income Recognized on Non-accrual Loans and Leases	159	54
Commercial and industrial | Commercial Loans
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	40,768		41,636	57,860
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	34,432		9,590
Interest Income Recognized on Non-accrual Loans and Leases	122	352
Residential mortgage | Residential mortgage
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	48,067		34,833	30,396
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	26,013		19,500
Interest Income Recognized on Non-accrual Loans and Leases	49	60
Consumer - Home equity | Consumer and other loans
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	30,319		24,404	18,830
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	5,915		3,200
Interest Income Recognized on Non-accrual Loans and Leases	64	67
Consumer - Other | Consumer and other loans
Financing Receivable, Nonaccrual [Line Items]
Amortized Cost of Non-accrual Loans and Leases	3,465		3,381	$ 2,846
Non-accrual Loans and Leases With No Related Allowance for Expected Credit Losses	1,190		$ 0
Interest Income Recognized on Non-accrual Loans and Leases	$ 13	$ 2

Loans and Leases - Summary of C

Loans and Leases - Summary of Changes in Accretable Yields of Acquired Loans (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 133,342
Transfers from non-accretable difference to accretable yield	(3,640)
Accretion	(10,086)
Changes in expected cash flows not affecting non-accretable differences	(272)
Balance at end of period	$ 119,344

Loans and Leases - Schedule o_4

Loans and Leases - Schedule of Modified TDRs (Detail) - TDRs Occurring during the Period - TDRs - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Financing Receivable, Modifications
Extended maturities	$ 2,450	$ 9,014
Maturity and interest rate adjustment	706	468
Movement to or extension of interest-rate only payments	46	12
Interest rate adjustment	3,878	0
Financing Receivable Modifications Forbearance	1,111	6,510
Other concession(s)	1,604	15,425
TDRs during period	9,795	31,429
Commercial Loans | Real estate - construction
Financing Receivable, Modifications
TDRs during period	86	39
Commercial Loans | Real estate - owner-occupied
Financing Receivable, Modifications
TDRs during period	2,558	4,661
Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Modifications
TDRs during period	3,820	2,968
Commercial Loans | Commercial and industrial
Financing Receivable, Modifications
TDRs during period	1,367	17,040
Residential mortgage | Residential mortgage
Financing Receivable, Modifications
TDRs during period	413	1,738
Consumer and other loans | Consumer - Home equity
Financing Receivable, Modifications
TDRs during period	1,482	4,233
Consumer and other loans | Consumer - Other
Financing Receivable, Modifications
TDRs during period	$ 69	$ 750

Loans and Leases - Schedule o_5

Loans and Leases - Schedule of Subsequently Defaulted TDRs (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)SecurityLoan	Mar. 31, 2019USD ($)SecurityLoan
Accounts, Notes, Loans and Financing Receivable
Threshold period for loans in default (in days)	30 days
TDRs | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	51	116
Pre-modification Outstanding Recorded Investment	$ 10,790	$ 34,120
Post-modification Outstanding Recorded Investment	$ 9,795	$ 31,429
Number of loans | SecurityLoan	108	70
Recorded investment	$ 27,846	$ 10,597
TDRs | Commercial Loans | Real estate - construction | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	1	1
Pre-modification Outstanding Recorded Investment	$ 154	$ 39
Post-modification Outstanding Recorded Investment	$ 86	$ 39
Number of loans | SecurityLoan	1	1
Recorded investment	$ 9,212	$ 939
TDRs | Commercial Loans | Real estate - owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	4	4
Pre-modification Outstanding Recorded Investment	$ 2,520	$ 6,904
Post-modification Outstanding Recorded Investment	$ 2,558	$ 4,661
Number of loans | SecurityLoan	5	3
Recorded investment	$ 1,898	$ 640
TDRs | Commercial Loans | Real estate - non-owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	5	7
Pre-modification Outstanding Recorded Investment	$ 3,944	$ 2,990
Post-modification Outstanding Recorded Investment	$ 3,820	$ 2,968
Number of loans | SecurityLoan	11	7
Recorded investment	$ 5,287	$ 825
TDRs | Commercial Loans | Commercial and industrial | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	14	23
Pre-modification Outstanding Recorded Investment	$ 1,844	$ 17,382
Post-modification Outstanding Recorded Investment	$ 1,367	$ 17,040
Number of loans | SecurityLoan	33	10
Recorded investment	$ 7,862	$ 3,933
TDRs | Residential mortgage | Residential mortgage | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	6	10
Pre-modification Outstanding Recorded Investment	$ 750	$ 1,741
Post-modification Outstanding Recorded Investment	$ 413	$ 1,738
Number of loans | SecurityLoan	15	13
Recorded investment	$ 1,190	$ 1,108
TDRs | Consumer and other loans | Consumer - Home equity | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	16	33
Pre-modification Outstanding Recorded Investment	$ 1,507	$ 4,277
Post-modification Outstanding Recorded Investment	$ 1,482	$ 4,233
Number of loans | SecurityLoan	23	16
Recorded investment	$ 2,189	$ 2,891
TDRs | Consumer and other loans | Consumer - Other | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	5	38
Pre-modification Outstanding Recorded Investment	$ 71	$ 787
Post-modification Outstanding Recorded Investment	$ 69	$ 750
Number of loans | SecurityLoan	20	20
Recorded investment	$ 208	$ 261

Allowance for Expected Credit_3

Allowance for Expected Credit Losses and Credit Quality - Schedule of Allowance for Loan Losses for Covered and Non-Covered Loan Portfolios (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	$ 146,588	$ 140,571
Provision for loan and lease losses	66,431	12,612
Transfer of balance to OREO and other	0	(2,885)
Charge-offs	(12,119)	(8,918)
Recoveries	2,591	1,586
Allowance for loan and lease losses at end of period	286,685	142,966
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	16,637	14,830
Provision for unfunded lending commitments	2,540	1,151
Reserve for unfunded commitments at end of period	18,302	15,981
Allowance for expected credit losses at end of period	304,987	158,947
Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	83,194	0
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	(875)	0
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	229,782	140,571
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	15,762	14,830
Real estate - construction | Commercial Loans
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	5,983	4,743
Provision for loan and lease losses	940	936
Transfer of balance to OREO and other		0
Charge-offs	(14)	0
Recoveries	219	3
Allowance for loan and lease losses at end of period	9,435	5,682
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	4,010	3,249
Provision for unfunded lending commitments	492	333
Reserve for unfunded commitments at end of period	5,527	3,582
Allowance for expected credit losses at end of period	14,962	9,264
Real estate - construction | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	2,307
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	1,025
Real estate - construction | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	8,290
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	5,035
Real estate - owner-occupied | Commercial Loans
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	15,770	12,549
Provision for loan and lease losses	2,603	1,303
Transfer of balance to OREO and other		0
Charge-offs	0	(72)
Recoveries	25	35
Allowance for loan and lease losses at end of period	10,235	13,815
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	345	316
Provision for unfunded lending commitments	418	60
Reserve for unfunded commitments at end of period	1,390	376
Allowance for expected credit losses at end of period	11,625	14,191
Real estate - owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	(8,163)
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	627
Real estate - owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	7,607
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	972
Real estate - non-owner-occupied | Commercial Loans
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	36,541	34,514
Provision for loan and lease losses	30,500	4,648
Transfer of balance to OREO and other		0
Charge-offs	(240)	0
Recoveries	132	65
Allowance for loan and lease losses at end of period	96,783	39,227
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	1,629	1,304
Provision for unfunded lending commitments	91	401
Reserve for unfunded commitments at end of period	729	1,705
Allowance for expected credit losses at end of period	97,512	40,932
Real estate - non-owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	29,850
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	(991)
Real estate - non-owner-occupied | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	66,391
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	638
Commercial and industrial | Commercial Loans
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	55,634	54,096
Provision for loan and lease losses	11,833	2,876
Transfer of balance to OREO and other		0
Charge-offs	(7,895)	(4,931)
Recoveries	1,037	446
Allowance for loan and lease losses at end of period	45,950	52,487
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	6,478	6,198
Provision for unfunded lending commitments	925	128
Reserve for unfunded commitments at end of period	7,406	6,326
Allowance for expected credit losses at end of period	53,356	58,813
Commercial and industrial | Commercial Loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	(14,659)
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	3
Commercial and industrial | Commercial Loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	40,975
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	6,481
Residential mortgage | Residential mortgage
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	9,647	12,998
Provision for loan and lease losses	10,535	1,749
Transfer of balance to OREO and other		(2,881)
Charge-offs	(450)	(28)
Recoveries	329	32
Allowance for loan and lease losses at end of period	90,582	11,870
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	562	866
Provision for unfunded lending commitments	215	22
Reserve for unfunded commitments at end of period	1,520	888
Allowance for expected credit losses at end of period	92,102	12,758
Residential mortgage | Residential mortgage | Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	70,521
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	743
Residential mortgage | Residential mortgage | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	80,168
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	1,305
Consumer - Home equity | Consumer and other loans
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	12,153	10,181
Provision for loan and lease losses	7,313	1,056
Transfer of balance to OREO and other		(4)
Charge-offs	(1,435)	(1,401)
Recoveries	386	314
Allowance for loan and lease losses at end of period	22,037	10,146
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	2,078	1,783
Provision for unfunded lending commitments	433	28
Reserve for unfunded commitments at end of period	1,699	1,811
Allowance for expected credit losses at end of period	23,736	11,957
Consumer - Home equity | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	3,620
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	(812)
Consumer - Home equity | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	15,773
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	1,266
Consumer - Other | Consumer and other loans
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	10,860	11,490
Provision for loan and lease losses	2,707	44
Transfer of balance to OREO and other		0
Charge-offs	(2,085)	(2,486)
Recoveries	463	691
Allowance for loan and lease losses at end of period	11,663	9,739
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	1,535	1,114
Provision for unfunded lending commitments	(34)	179
Reserve for unfunded commitments at end of period	31	1,293
Allowance for expected credit losses at end of period	11,694	$ 11,032
Consumer - Other | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	(282)
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	(1,470)
Consumer - Other | Consumer and other loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	10,578
Reserve for unfunded commitment
Reserve for unfunded commitments at beginning of period	$ 65

Allowance for Expected Credit_4

Allowance for Expected Credit Losses and Credit Quality - Credit Quality By Year (Details) $ in Thousands	Mar. 31, 2020USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 1,324,939
2019	5,200,853
2018	4,275,534
2017	2,707,828
2016	2,107,637
Prior	5,393,209
Revolving loans	3,419,729
Revolving loans Converted to Term	111,903
Total	24,541,632
Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,030,316
2019	4,022,223
2018	3,243,816
2017	2,016,870
2016	1,455,319
Prior	3,480,076
Revolving loans	1,892,244
Revolving loans Converted to Term	0
Total	17,140,864
Consumer and other loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	294,623
2019	1,178,630
2018	1,031,718
2017	690,958
2016	652,318
Prior	1,913,133
Revolving loans	1,527,485
Revolving loans Converted to Term	111,903
Total	7,400,768
Real estate - construction | Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	45,117
2019	336,900
2018	608,215
2017	172,612
2016	65,210
Prior	52,205
Revolving loans	42,368
Revolving loans Converted to Term	0
Total	1,322,627
Real estate - construction | Commercial Loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	45,117
2019	336,900
2018	599,002
2017	172,612
2016	65,200
Prior	51,622
Revolving loans	40,147
Revolving loans Converted to Term	0
Total	1,310,600
Real estate - construction | Commercial Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	10
Prior	105
Revolving loans	2,156
Revolving loans Converted to Term	0
Total	2,271
Real estate - construction | Commercial Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	9,213
2017	0
2016	0
Prior	475
Revolving loans	65
Revolving loans Converted to Term	0
Total	9,753
Real estate - construction | Commercial Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	3
Revolving loans	0
Revolving loans Converted to Term	0
Total	3
Real estate - owner-occupied | Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	69,996
2019	380,116
2018	327,566
2017	365,942
2016	278,143
Prior	934,723
Revolving loans	67,653
Revolving loans Converted to Term	0
Total	2,424,139
Real estate - owner-occupied | Commercial Loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	69,996
2019	379,882
2018	319,249
2017	357,057
2016	274,226
Prior	895,032
Revolving loans	66,866
Revolving loans Converted to Term	0
Total	2,362,308
Real estate - owner-occupied | Commercial Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	7,306
2017	681
2016	399
Prior	13,419
Revolving loans	400
Revolving loans Converted to Term	0
Total	22,205
Real estate - owner-occupied | Commercial Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	234
2018	1,011
2017	8,204
2016	3,518
Prior	23,856
Revolving loans	387
Revolving loans Converted to Term	0
Total	37,210
Real estate - owner-occupied | Commercial Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	2,416
Revolving loans	0
Revolving loans Converted to Term	0
Total	2,416
Real estate - non-owner-occupied | Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	261,614
2019	1,324,097
2018	964,005
2017	999,377
2016	883,589
Prior	1,918,111
Revolving loans	133,464
Revolving loans Converted to Term	0
Total	6,484,257
Real estate - non-owner-occupied | Commercial Loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	261,614
2019	1,323,506
2018	961,036
2017	987,814
2016	867,303
Prior	1,867,101
Revolving loans	130,929
Revolving loans Converted to Term	0
Total	6,399,303
Real estate - non-owner-occupied | Commercial Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	806
2017	1,497
2016	10,248
Prior	14,561
Revolving loans	1,900
Revolving loans Converted to Term	0
Total	29,012
Real estate - non-owner-occupied | Commercial Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	591
2018	2,059
2017	10,066
2016	6,038
Prior	31,481
Revolving loans	635
Revolving loans Converted to Term	0
Total	50,870
Real estate - non-owner-occupied | Commercial Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	104
2017	0
2016	0
Prior	4,968
Revolving loans	0
Revolving loans Converted to Term	0
Total	5,072
Commercial and industrial | Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	653,589
2019	1,981,110
2018	1,344,030
2017	478,939
2016	228,377
Prior	575,037
Revolving loans	1,648,759
Revolving loans Converted to Term	0
Total	6,909,841
Commercial and industrial | Commercial Loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	649,228
2019	1,957,486
2018	1,307,679
2017	455,600
2016	218,485
Prior	551,933
Revolving loans	1,635,017
Revolving loans Converted to Term	0
Total	6,775,428
Commercial and industrial | Commercial Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	259
2019	1,463
2018	23,811
2017	500
2016	8,093
Prior	1,436
Revolving loans	7,896
Revolving loans Converted to Term	0
Total	43,458
Commercial and industrial | Commercial Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	4,102
2019	16,838
2018	3,023
2017	20,486
2016	1,151
Prior	19,194
Revolving loans	5,846
Revolving loans Converted to Term	0
Total	70,640
Commercial and industrial | Commercial Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	5,323
2018	9,517
2017	2,353
2016	648
Prior	2,474
Revolving loans	0
Revolving loans Converted to Term	0
Total	20,315
Residential mortgage | Consumer and other loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	245,763
2019	1,087,683
2018	892,344
2017	587,993
2016	565,932
Prior	1,469,404
Revolving loans	0
Revolving loans Converted to Term	0
Total	4,849,119
Residential mortgage | Consumer and other loans | 781 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	45,204
2019	332,402
2018	263,099
2017	185,336
2016	153,118
Prior	387,923
Revolving loans	0
Revolving loans Converted to Term	0
Total	1,367,082
Residential mortgage | Consumer and other loans | 723-780
Financing Receivable, Credit Quality Indicator [Line Items]
2020	72,666
2019	452,401
2018	360,319
2017	233,243
2016	199,457
Prior	410,212
Revolving loans	0
Revolving loans Converted to Term	0
Total	1,728,298
Residential mortgage | Consumer and other loans | 700-722
Financing Receivable, Credit Quality Indicator [Line Items]
2020	14,430
2019	94,286
2018	93,264
2017	49,705
2016	47,736
Prior	116,470
Revolving loans	0
Revolving loans Converted to Term	0
Total	415,891
Residential mortgage | Consumer and other loans | 660-699
Financing Receivable, Credit Quality Indicator [Line Items]
2020	8,549
2019	103,361
2018	83,700
2017	37,108
2016	54,661
Prior	144,238
Revolving loans	0
Revolving loans Converted to Term	0
Total	431,617
Residential mortgage | Consumer and other loans | 620-659
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,273
2019	39,018
2018	26,883
2017	15,701
2016	15,481
Prior	94,296
Revolving loans	0
Revolving loans Converted to Term	0
Total	194,652
Residential mortgage | Consumer and other loans | 580-619
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	13,756
2018	11,717
2017	8,358
2016	11,281
Prior	51,387
Revolving loans	0
Revolving loans Converted to Term	0
Total	96,499
Residential mortgage | Consumer and other loans | 579 and below
Financing Receivable, Credit Quality Indicator [Line Items]
2020	101,641
2019	52,459
2018	53,362
2017	58,542
2016	84,198
Prior	264,878
Revolving loans	0
Revolving loans Converted to Term	0
Total	615,080
Consumer - Home equity | Consumer and other loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	13,136
2019	33,474
2018	90,369
2017	62,198
2016	61,771
Prior	240,314
Revolving loans	1,313,588
Revolving loans Converted to Term	111,903
Total	1,926,753
Consumer - Home equity | Consumer and other loans | 781 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,052
2019	8,710
2018	28,297
2017	16,579
2016	15,903
Prior	56,995
Revolving loans	374,502
Revolving loans Converted to Term	21,481
Total	524,519
Consumer - Home equity | Consumer and other loans | 723-780
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,160
2019	13,680
2018	25,948
2017	19,278
2016	25,677
Prior	81,172
Revolving loans	498,082
Revolving loans Converted to Term	27,061
Total	692,058
Consumer - Home equity | Consumer and other loans | 700-722
Financing Receivable, Credit Quality Indicator [Line Items]
2020	103
2019	2,226
2018	7,915
2017	7,696
2016	5,276
Prior	18,320
Revolving loans	130,949
Revolving loans Converted to Term	13,029
Total	185,514
Consumer - Home equity | Consumer and other loans | 660-699
Financing Receivable, Credit Quality Indicator [Line Items]
2020	747
2019	3,823
2018	10,975
2017	6,434
2016	6,112
Prior	32,755
Revolving loans	163,267
Revolving loans Converted to Term	17,238
Total	241,351
Consumer - Home equity | Consumer and other loans | 620-659
Financing Receivable, Credit Quality Indicator [Line Items]
2020	351
2019	1,418
2018	1,894
2017	4,355
2016	3,630
Prior	19,419
Revolving loans	73,928
Revolving loans Converted to Term	13,822
Total	118,817
Consumer - Home equity | Consumer and other loans | 580-619
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,735
2019	875
2018	5,331
2017	2,006
2016	2,581
Prior	13,452
Revolving loans	27,526
Revolving loans Converted to Term	6,484
Total	60,990
Consumer - Home equity | Consumer and other loans | 579 and below
Financing Receivable, Credit Quality Indicator [Line Items]
2020	5,988
2019	2,742
2018	10,009
2017	5,850
2016	2,592
Prior	18,201
Revolving loans	45,334
Revolving loans Converted to Term	12,788
Total	103,504
Consumer - Other | Consumer and other loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	35,724
2019	57,473
2018	49,005
2017	40,767
2016	24,615
Prior	203,415
Revolving loans	213,897
Revolving loans Converted to Term	0
Total	624,896
Consumer - Other | Consumer and other loans | 781 and above
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,357
2019	11,136
2018	8,566
2017	14,957
2016	5,938
Prior	22,047
Revolving loans	69,402
Revolving loans Converted to Term	0
Total	135,403
Consumer - Other | Consumer and other loans | 723-780
Financing Receivable, Credit Quality Indicator [Line Items]
2020	5,717
2019	11,388
2018	22,356
2017	12,895
2016	5,490
Prior	32,481
Revolving loans	76,717
Revolving loans Converted to Term	0
Total	167,044
Consumer - Other | Consumer and other loans | 700-722
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,089
2019	22,224
2018	4,560
2017	3,345
2016	4,133
Prior	11,551
Revolving loans	16,713
Revolving loans Converted to Term	0
Total	63,615
Consumer - Other | Consumer and other loans | 660-699
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,803
2019	4,688
2018	5,120
2017	4,057
2016	1,113
Prior	18,128
Revolving loans	20,797
Revolving loans Converted to Term	0
Total	55,706
Consumer - Other | Consumer and other loans | 620-659
Financing Receivable, Credit Quality Indicator [Line Items]
2020	751
2019	4,245
2018	2,432
2017	1,702
2016	3,745
Prior	8,142
Revolving loans	13,553
Revolving loans Converted to Term	0
Total	34,570
Consumer - Other | Consumer and other loans | 580-619
Financing Receivable, Credit Quality Indicator [Line Items]
2020	337
2019	1,754
2018	2,689
2017	674
2016	1,611
Prior	4,922
Revolving loans	8,499
Revolving loans Converted to Term	0
Total	20,486
Consumer - Other | Consumer and other loans | 579 and below
Financing Receivable, Credit Quality Indicator [Line Items]
2020	22,670
2019	2,038
2018	3,282
2017	3,137
2016	2,585
Prior	106,144
Revolving loans	8,216
Revolving loans Converted to Term	0
Total	$ 148,072

Allowance for Expected Credit_5

Allowance for Expected Credit Losses and Credit Quality - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest	$ 65,900		$ 65,700
Accounting Standards Update 2016-13
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses			163,225
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses		$ 82,319	82,300
Consumer Portfolio Segment [Member] | Consumer - Home equity
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans Converted to Term	$ 6,600
Allowance for credit losses			$ 14,231
Consumer Portfolio Segment [Member] | Consumer - Home equity | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses		$ 2,808

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Schedule of Carrying Amount of Goodwill (Detail) $ in Thousands	Mar. 31, 2020USD ($)
Goodwill [Roll Forward]
Balance at beginning of the period	$ 1,235,533
Balance at end of the period	1,235,533
Operating Segments
Goodwill [Roll Forward]
Balance at beginning of the period	1,235,533
Balance at end of the period	1,235,533
Operating Segments | IBERIABANK
Goodwill [Roll Forward]
Balance at beginning of the period	1,203,810
Balance at end of the period	1,203,810
Operating Segments | IMC
Goodwill [Roll Forward]
Balance at beginning of the period	23,178
Balance at end of the period	23,178
Operating Segments | LTC
Goodwill [Roll Forward]
Balance at beginning of the period	8,545
Balance at end of the period	$ 8,545

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Schedule of Mortgage Servicing Rights at Carrying Value (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 122,831	$ 137,774
Accumulated Amortization	(72,217)	(82,974)
Net Carrying Amount	50,614	54,800
Mortgage servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	24,870	22,476
Valuation Allowance	(2,657)	(250)
Accumulated Amortization	(7,451)	(6,621)
Net Carrying Amount	$ 14,762	$ 15,605

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Schedule of Definite-Lived Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 122,831	$ 137,774
Accumulated Amortization	(72,217)	(82,974)
Net Carrying Amount	50,614	54,800
Core deposit intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	121,277	136,183
Accumulated Amortization	(70,758)	(81,493)
Net Carrying Amount	50,519	54,690
Customer relationship intangible asset
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,348	1,385
Accumulated Amortization	(1,341)	(1,371)
Net Carrying Amount	7	14
Non-compete agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	206	206
Accumulated Amortization	(118)	(110)
Net Carrying Amount	$ 88	$ 96

Derivative Instruments and Ot_3

Derivative Instruments and Other Hedging Activities - Schedule of Outstanding Derivative Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative Assets - Fair Value	$ 283,525	$ 104,151
Derivative Liabilities - Fair Value	23,798	11,799
Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Fair Value	41,200	18,967
Derivative Liabilities - Fair Value	11	0
Other Assets | Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Fair Value	41,200	18,967
Other Assets | Not Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Fair Value	242,325	85,184
Other Assets | Not Designated as Hedging Instruments | Customer swaps - upstream
Derivative [Line Items]
Derivative Assets - Fair Value	18	9
Other Assets | Not Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Fair Value	222,769	77,934
Other Assets | Not Designated as Hedging Instruments | Forward sales contracts
Derivative [Line Items]
Derivative Assets - Fair Value	1,987	420
Other Assets | Not Designated as Hedging Instruments | Written and purchased options
Derivative [Line Items]
Derivative Assets - Fair Value	17,364	6,755
Other Assets | Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Derivative Assets - Fair Value	187	66
Other Liabilities | Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	11	0
Other Liabilities | Not Designated as Hedging Instruments
Derivative [Line Items]
Derivative Liabilities - Fair Value	23,787	11,799
Other Liabilities | Not Designated as Hedging Instruments | Customer swaps - upstream
Derivative [Line Items]
Derivative Liabilities - Fair Value	10,510	5,055
Other Liabilities | Not Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	18	1,680
Other Liabilities | Not Designated as Hedging Instruments | Forward sales contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	10,656	986
Other Liabilities | Not Designated as Hedging Instruments | Written and purchased options
Derivative [Line Items]
Derivative Liabilities - Fair Value	1,849	3,899
Other Liabilities | Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	$ 754	$ 179

Derivative Instruments and Ot_4

Derivative Instruments and Other Hedging Activities (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative Assets - Notional Amount	$ 4,713,962	$ 3,888,959
Derivative Liabilities - Notional Amount	3,862,481	3,313,072
Cash posted as variation margin for derivatives	226,800	79,600
Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Notional Amount	800,000	800,000
Derivative Liabilities - Notional Amount	108,500	108,500
Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	800,000	800,000
Derivative Liabilities - Notional Amount	108,500	108,500
Not Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Notional Amount	3,913,962	3,088,959
Derivative Liabilities - Notional Amount	3,753,981	3,204,572
Not Designated as Hedging Instruments | Customer swaps - upstream
Derivative [Line Items]
Derivative Assets - Notional Amount	48,215	430,808
Derivative Liabilities - Notional Amount	2,855,442	2,237,542
Not Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	2,855,442	2,237,542
Derivative Liabilities - Notional Amount	48,215	430,808
Not Designated as Hedging Instruments | Forward sales contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	196,388	44,011
Derivative Liabilities - Notional Amount	463,108	230,998
Not Designated as Hedging Instruments | Written and purchased options
Derivative [Line Items]
Derivative Assets - Notional Amount	699,162	268,590
Derivative Liabilities - Notional Amount	136,043	121,981
Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	114,755	108,008
Derivative Liabilities - Notional Amount	$ 251,173	$ 183,243

Derivative Instruments and Ot_5

Derivative Instruments and Other Hedging Activities - Reconciliation of Gross Amounts in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative assets
Gross derivative assets	$ 265,589	$ 100,781
Gross amounts not offset in the Balance Sheet, derivatives	(9,490)	(5,111)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	256,099	95,670
Derivative liabilities
Gross derivative liabilities	12,141	10,606
Gross amounts not offset in the Balance Sheet, derivatives	(9,490)	(5,111)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	2,651	5,495
Written and purchased options
Derivative assets
Gross derivative assets	1,602	3,871
Gross amounts not offset in the Balance Sheet, derivatives	0	0
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	1,602	3,871
Derivative liabilities
Gross derivative liabilities	1,602	3,871
Gross amounts not offset in the Balance Sheet, derivatives	0	0
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	1,602	3,871
Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets	41,200	18,967
Gross amounts not offset in the Balance Sheet, derivatives	0	0
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	41,200	18,967
Derivative liabilities
Gross derivative liabilities	11
Gross amounts not offset in the Balance Sheet, derivatives	0
Gross amounts not offset in the Balance Sheet, collateral	0
Net derivative liabilities	11
Not Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets	222,787	77,943
Gross amounts not offset in the Balance Sheet, derivatives	(9,490)	(5,111)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	213,297	72,832
Derivative liabilities
Gross derivative liabilities	10,528	6,735
Gross amounts not offset in the Balance Sheet, derivatives	(9,490)	(5,111)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	$ 1,038	$ 1,624

Derivative Instruments and Ot_6

Derivative Instruments and Other Hedging Activities - Effect of Hedging Instruments on Consolidated Financial Statements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Designated as Hedging Instruments | Cash Flow Hedging | Interest rate contracts | Interest expense
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	$ 442	$ (227)
Derivative, included component, gain (loss) recognized in earnings	707	(69)
Amount of gain (loss) recognized in income on derivatives (amount excluded from effectiveness testing)	(265)	(158)
Derivative instruments, gain (loss) recognized in income, ineffective portion and amount excluded from effectiveness testing, net	0	0
Derivative instruments, gain (loss) recognized in income, ineffective portion and amount excluded from effectiveness testing, included component net	0	0
Derivative instruments, gain (loss) recognized in income, ineffective portion and amount excluded from effectiveness testing, excluding component, net	0	0
Not Designated as Hedging Instruments
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	5,054	2,831
Not Designated as Hedging Instruments | Interest rate contracts | Commission income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	3,759	4,181
Not Designated as Hedging Instruments | Foreign exchange contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	0	5
Not Designated as Hedging Instruments | Forward sales contracts | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	(10,910)	(3,209)
Not Designated as Hedging Instruments | Written and purchased options | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	12,659	1,863
Not Designated as Hedging Instruments | Other contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	(454)	(9)
OCI | Designated as Hedging Instruments | Cash Flow Hedging | Interest rate contracts
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	10,441	(2,185)
Derivative, included component, gain (loss) recognized in earnings	10,628	(3,098)
Amount of gain (loss) recognized in income on derivatives (amount excluded from effectiveness testing)	$ (187)	$ 913

Shareholders' Equity, Capital_3

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2019
Class of Stock [Line Items]
Liquidation preference value	$ 237,500
Carrying Amount	$ 228,485			$ 228,485
Common stock repurchases			$ 29,946
Average cost of common stock shares repurchased (in usd per share)			$ 77.19
Shares authorized to be repurchased (in shares)	1,165,000
Series B Preferred Stock
Class of Stock [Line Items]
Annual Dividend Rate	6.625%
Liquidation preference value	$ 80,000
Carrying Amount	$ 76,812			76,812
Series C Preferred Stock
Class of Stock [Line Items]
Annual Dividend Rate	6.60%
Liquidation preference value	$ 57,500
Carrying Amount	$ 55,285			55,285
Series D Preferred Stock
Class of Stock [Line Items]
Annual Dividend Rate	6.10%
Liquidation preference value	$ 100,000
Carrying Amount	$ 96,388			$ 96,388
Common Stock
Class of Stock [Line Items]
Common stock repurchases (in shares)			387,921
Common stock repurchases			$ 388
2019 Share Repurchase Program | Common Stock
Class of Stock [Line Items]
Number of shares authorized to be repurchased		1,600,000
Percentage of outstanding common shares		3.00%

Shareholders' Equity, Capital_4

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Actual Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Total Risk-Based Capital
Capital Conversion Buffer	4.48%
Consolidated
Tier 1 Leverage
Minimum amount	$ 1,228,618	$ 1,220,289
Minimum ratio	4.00%	4.00%
Actual amount	$ 3,051,243	$ 3,021,004
Actual ratio	9.93%	9.90%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,216,954	$ 1,194,765
Minimum ratio	4.50%	4.50%
Actual amount	$ 2,822,758	$ 2,792,520
Actual Ratio	10.44%	10.52%
Tier 1 Risk-Based Capital
Minimum amount	$ 1,622,605	$ 1,593,020
Minimum ratio	6.00%	6.00%
Actual amount	$ 3,051,243	$ 3,021,004
Actual ratio	11.28%	11.38%
Total Risk-Based Capital
Minimum amount	$ 2,163,474	$ 2,124,026
Minimum ratio	8.00%	8.00%
Actual amount	$ 3,375,550	$ 3,300,730
Actual ratio	12.48%	12.43%
IBERIABANK
Tier 1 Leverage
Minimum amount	$ 1,225,516	$ 1,217,638
Minimum ratio	4.00%	4.00%
Well capitalized amount	$ 1,531,895	$ 1,522,048
Well capitalized ratio	5.00%	5.00%
Actual amount	$ 3,008,038	$ 2,949,533
Actual ratio	9.82%	9.69%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,212,501	$ 1,191,062
Minimum ratio	4.50%	4.50%
Well capitalized amount	$ 1,751,390	$ 1,720,423
Well capitalized ratio	6.50%	6.50%
Actual amount	$ 3,008,038	$ 2,949,533
Actual Ratio	11.16%	11.14%
Tier 1 Risk-Based Capital
Minimum amount	$ 1,616,668	$ 1,588,083
Minimum ratio	6.00%	6.00%
Well capitalized amount	$ 2,155,557	$ 2,117,444
Well capitalized ratio	8.00%	8.00%
Actual amount	$ 3,008,038	$ 2,949,533
Actual ratio	11.16%	11.14%
Total Risk-Based Capital
Minimum amount	$ 2,155,557	$ 2,117,444
Minimum ratio	8.00%	8.00%
Well capitalized amount	$ 2,694,446	$ 2,648,805
Well capitalized ratio	10.00%	10.00%
Actual amount	$ 3,215,845	$ 3,112,758
Actual ratio	11.94%	11.76%
Capital Conversion Buffer	3.94%

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Common Share - Basic:
Net income	$ 36,425	$ 100,131
Preferred stock dividends	(3,598)	(3,598)
Dividends and undistributed earnings allocated to unvested restricted shares	(367)	(933)
Earnings allocated to common shareholders	$ 32,460	$ 95,600
Weighted average common shares outstanding (in shares)	51,979	54,177
Earnings per common share - basic (in usd per share)	$ 0.62	$ 1.76
Earnings Per Common Share - Diluted:
Earnings allocated to common shareholders - basic	$ 32,460	$ 95,600
Adjustment for undistributed earnings allocated to unvested restricted shares	(3)	(42)
Earnings allocated to common shareholders - diluted	$ 32,457	$ 95,558
Weighted average common shares outstanding (in shares)	51,979	54,177
Dilutive potential common shares (in shares)	217	362
Weighted average common shares outstanding - diluted (in shares)	52,196	54,539
Earnings per common share - diluted (in usd per share)	$ 0.62	$ 1.75

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Detail) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share
Weighted average number of shares held by Recognition and Retention Plan excluded from the calculation for basic shares outstanding	608,128	564,188
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded from the computation of earnings per share	517,900	155,757

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets
Securities available for sale, at fair value	$ 3,914,960	$ 3,933,360
Mortgage loans held for sale	207,845	213,357
Mortgage loans held for investment, at fair value option	2,779	2,792
Derivative instruments	265,589	100,781
Liabilities
Derivative instruments	12,141	10,606
Level 1
Assets
Securities available for sale, at fair value	0	0
Mortgage loans held for investment, at fair value option	0	0
Level 2
Assets
Securities available for sale, at fair value	3,914,960	3,933,360
Mortgage loans held for investment, at fair value option	0	0
Level 3
Assets
Securities available for sale, at fair value	0	0
Mortgage loans held for investment, at fair value option	2,779	2,792
Recurring
Assets
Securities available for sale, at fair value	3,914,960	3,933,360
Mortgage loans held for sale	207,845	213,357
Mortgage loans held for investment, at fair value option	2,779	2,792
Derivative instruments	283,525	104,151
Total	4,409,109	4,253,660
Liabilities
Derivative instruments	23,798	11,799
Total	23,798	11,799
Recurring | Level 1
Assets
Securities available for sale, at fair value	0	0
Mortgage loans held for sale	0	0
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	0	0
Total	0	0
Liabilities
Derivative instruments	0	0
Total	0	0
Recurring | Level 2
Assets
Securities available for sale, at fair value	3,914,960	3,933,360
Mortgage loans held for sale	207,845	213,357
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	283,525	104,151
Total	4,406,330	4,250,868
Liabilities
Derivative instruments	23,798	11,799
Total	23,798	11,799
Recurring | Level 3
Assets
Securities available for sale, at fair value	0	0
Mortgage loans held for sale	0	0
Mortgage loans held for investment, at fair value option	2,779	2,792
Derivative instruments	0	0
Total	2,779	2,792
Liabilities
Derivative instruments	0	0
Total	$ 0	$ 0

Fair Value Measurements - Fin_2

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Detail) - Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets
Impaired loans	$ 87,227	$ 74,763
OREO, net	6,869	4,907
Total	94,096	79,670
Level 1
Assets
Impaired loans	0	0
OREO, net	0	0
Total	0	0
Level 2
Assets
Impaired loans	0	0
OREO, net	0	0
Total	0	0
Level 3
Assets
Impaired loans	87,227	74,763
OREO, net	6,869	4,907
Total	$ 94,096	$ 79,670

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Difference Between the Aggregate Fair Value and the Aggregate Unpaid Principal Balance for Mortgage Loans Held for Sale and Mortgage Loans Held for Investment (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Mortgage loans held for sale, at fair value
Aggregate Fair Value	$ 207,845	$ 213,357
Aggregate Unpaid Principal	201,259	207,481
Aggregate Fair Value Less Unpaid Principal	6,586	5,876
Mortgage loans held for investment, at fair value
Aggregate Fair Value	2,779	2,792
Aggregate Unpaid Principal	2,804	2,922
Aggregate Fair Value Less Unpaid Principal	$ (25)	$ (130)

Fair Value Measurements - Amoun

Fair Value Measurements - Amount of Net Gains (Losses) from Fair Value Changes (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Mortgage loans held for sale, at fair value	$ 711	$ 652
Mortgage loans held for investment, at fair value	$ 0	$ 191

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Estimated Fair Values and Carrying Amounts of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Financial Assets
Securities available for sale, at fair value	$ 3,914,960	$ 3,933,360
Mortgage loans held for sale, at fair value	207,845	213,357
Mortgage loans held for investment, at fair value option	2,779	2,792
Derivative instruments	283,525	104,151
Cash and cash equivalents	945,062	894,723
Securities held to maturity	177,960	182,961
Financial Liabilities
Derivative instruments	23,798	11,799
Deposits	25,526,237	25,219,349	$ 24,092,062
Short-term borrowings	390,747	204,208
Long-term debt	1,288,172	1,343,687
Level 1
Financial Assets
Securities available for sale, at fair value	0	0
Mortgage loans held for sale, at fair value	0	0
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	0	0
Cash and cash equivalents	945,062	894,723
Securities held to maturity	0	0
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	0	0
Financial Liabilities
Derivative instruments	0	0
Deposits	0	0
Short-term borrowings	172,747	204,208
Long-term debt	0	0
Level 2
Financial Assets
Securities available for sale, at fair value	3,914,960	3,933,360
Mortgage loans held for sale, at fair value	207,845	213,357
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	283,525	104,151
Cash and cash equivalents	0	0
Securities held to maturity	186,396	189,899
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	0	0
Financial Liabilities
Derivative instruments	23,798	11,799
Deposits	25,547,705	25,229,566
Short-term borrowings	218,000	0
Long-term debt	0	0
Level 3
Financial Assets
Securities available for sale, at fair value	0	0
Mortgage loans held for sale, at fair value	0	0
Mortgage loans held for investment, at fair value option	2,779	2,792
Derivative instruments	0	0
Cash and cash equivalents	0	0
Securities held to maturity	0	0
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	24,209,165	23,732,650
Financial Liabilities
Derivative instruments	0	0
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	1,261,688	1,296,696
Carrying Amount
Financial Assets
Securities available for sale, at fair value	3,914,960	3,933,360
Mortgage loans held for sale, at fair value	207,845	213,357
Mortgage loans held for investment, at fair value option	2,779	2,792
Derivative instruments	283,525	104,151
Cash and cash equivalents	945,062	894,723
Securities held to maturity	177,960	182,961
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	24,254,947	23,874,911
Financial Liabilities
Derivative instruments	23,798	11,799
Deposits	25,526,237	25,219,349
Short-term borrowings	390,747	204,208
Long-term debt	1,288,172	1,343,687
Fair Value
Financial Assets
Securities available for sale, at fair value	3,914,960	3,933,360
Mortgage loans held for sale, at fair value	207,845	213,357
Mortgage loans held for investment, at fair value option	2,779	2,792
Derivative instruments	283,525	104,151
Cash and cash equivalents	945,062	894,723
Securities held to maturity	186,396	189,899
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	24,209,165	23,732,650
Financial Liabilities
Derivative instruments	23,798	11,799
Deposits	25,547,705	25,229,566
Short-term borrowings	390,747	204,208
Long-term debt	$ 1,261,688	$ 1,296,696

Business Segments (Detail)

Business Segments (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)Segment	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Segment Reporting Information
Number of business segments | Segment	3
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	$ 302,929	$ 326,084
Interest expense	72,587	75,600
Net interest income	230,342	250,484
Other Income and Expenses [Abstract]
Provision for (reversal of) expected credit losses	68,971	13,763
Other non-interest income (expense)	35,475	35,435
Allocated expenses (income)	0	0
Non-interest expense	177,427	158,753
Income before income tax expense	48,600	130,477
Income tax expense	12,175	30,346
Net income	36,425	100,131
Total loans, leases, and loans held for sale, net of unearned income	24,749,477	23,096,746
Total assets	32,239,983	31,260,189	$ 31,713,450
Total deposits	25,526,237	24,092,062	$ 25,219,349
Average assets	31,986,139	30,833,500
Mortgage income
Other Income and Expenses [Abstract]
Non-interest income	23,245	11,849
Title revenue
Other Income and Expenses [Abstract]
Non-interest income	5,936	5,225
Operating Segments | IBERIABANK
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	300,930	324,644
Interest expense	72,587	75,600
Net interest income	228,343	249,044
Other Income and Expenses [Abstract]
Provision for (reversal of) expected credit losses	68,960	13,823
Other non-interest income (expense)	35,465	35,463
Allocated expenses (income)	(1,729)	(2,033)
Non-interest expense	155,333	143,755
Income before income tax expense	41,244	128,962
Income tax expense	10,384	29,975
Net income	30,860	98,987
Total loans, leases, and loans held for sale, net of unearned income	24,522,757	22,944,800
Total assets	31,914,337	31,044,209
Total deposits	25,497,777	24,078,698
Average assets	31,694,266	30,660,806
Operating Segments | IMC
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	1,999	1,439
Interest expense	0	0
Net interest income	1,999	1,439
Other Income and Expenses [Abstract]
Provision for (reversal of) expected credit losses	11	(60)
Other non-interest income (expense)	10	(12)
Allocated expenses (income)	1,305	1,500
Non-interest expense	16,910	10,541
Income before income tax expense	7,028	1,295
Income tax expense	1,603	307
Net income	5,425	988
Total loans, leases, and loans held for sale, net of unearned income	226,720	151,946
Total assets	298,030	191,254
Total deposits	28,460	13,364
Average assets	264,341	148,174
Operating Segments | LTC
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	0	1
Interest expense	0	0
Net interest income	0	1
Other Income and Expenses [Abstract]
Provision for (reversal of) expected credit losses	0	0
Other non-interest income (expense)	0	(16)
Allocated expenses (income)	424	533
Non-interest expense	5,184	4,457
Income before income tax expense	328	220
Income tax expense	188	64
Net income	140	156
Total loans, leases, and loans held for sale, net of unearned income	0	0
Total assets	27,616	24,726
Total deposits		0
Average assets	27,532	24,520
Operating Segments | Mortgage income | IBERIABANK
Other Income and Expenses [Abstract]
Non-interest income	0	0
Operating Segments | Mortgage income | IMC
Other Income and Expenses [Abstract]
Non-interest income	23,245	11,849
Operating Segments | Mortgage income | LTC
Other Income and Expenses [Abstract]
Non-interest income	0	0
Operating Segments | Title revenue | IBERIABANK
Other Income and Expenses [Abstract]
Non-interest income	0	0
Operating Segments | Title revenue | IMC
Other Income and Expenses [Abstract]
Non-interest income	0	0
Operating Segments | Title revenue | LTC
Other Income and Expenses [Abstract]
Non-interest income	$ 5,936	$ 5,225

Commitments and Contingencies_2

Commitments and Contingencies (Detail) - USD ($) $ in Millions	Feb. 02, 2018	Dec. 11, 2017	Mar. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Fair value of guarantees under commercial and standby letters of credit			$ 2.8	$ 3.3
Settled Litigation
Loss Contingencies [Line Items]
Settlement amount		$ 11.7
Pending Litigation
Loss Contingencies [Line Items]
Damages sought	$ 11.7

Commitments and Contingencies -

Commitments and Contingencies - Summary of Financial Instruments Outstanding (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments to extend credit	$ 677,297	$ 806,164
Unfunded commitments under lines of credit	7,006,974	7,240,808
Commercial and standby letters of credit	277,415	327,336
Reserve for unfunded lending commitments	$ 18,302	$ 16,637

Uncategorized Items - ibkc10-q3

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 1,847,000	[1]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(67,605,000)	[2]
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(67,605,000)	[2]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 1,847,000	[1]
[1]	Cumulative-effect adjustment to beginning retained earnings related to the recognition of pre-existing lease liabilities and previously deferred gains on sale-leaseback transactions in accordance with ASU 2016-02, adopted as of January 1, 2019.
[2]	Cumulative-effect adjustment to beginning retained earnings related to the adoption of the current expected credit loss (CECL) methodology for estimating credit losses in accordance with ASU 2016-13, adopted as of January 1, 2020.