Iberiabank (IBKC) 10-Q 8 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	IBKC
Entity Registrant Name	IBERIABANK CORP
Entity Central Index Key	0000933141
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 280,680	$ 294,186
Interest-bearing deposits in other banks	391,217	396,267
Total cash and cash equivalents	671,897	690,453
Securities available for sale, at fair value	4,873,778	4,783,579
Securities held to maturity (fair values of $200,568 and $204,277, respectively)	198,958	207,446
Mortgage loans held for sale, at fair value	128,451	107,734
Loans and leases, net of unearned income	22,968,295	22,519,815
Allowance for loan and lease losses	(142,966)	(140,571)
Loans and leases, net	22,825,329	22,379,244
Premises and equipment, net	297,342	300,507
Goodwill	1,235,533	1,235,533
Other intangible assets	84,459	88,736
Other assets	944,442	1,039,783
Total Assets	31,260,189	30,833,015
Deposits:
Non-interest-bearing	6,448,613	6,542,490
Interest-bearing	17,643,449	17,220,941
Total deposits	24,092,062	23,763,431
Short-term borrowings	1,106,131	1,482,882
Long-term debt	1,475,455	1,166,151
Other liabilities	444,710	364,274
Total Liabilities	27,118,358	26,776,738
Shareholders’ Equity
Preferred stock, $1 par value - 5,000,000 shares authorized Non-cumulative perpetual, liquidation preference $10,000 per share; 13,750 and 13,750 shares issued and outstanding, including related surplus	132,097	132,097
Common stock, $1 par value - 100,000,000 shares authorized; 54,551,264 and 54,796,231 shares issued and outstanding, respectively	54,551	54,796
Additional paid-in capital	2,840,842	2,869,416
Retained earnings	1,117,641	1,042,718
Accumulated other comprehensive income (loss)	(3,300)	(42,750)
Total Shareholders’ Equity	4,141,831	4,056,277
Total Liabilities and Shareholders’ Equity	$ 31,260,189	$ 30,833,015

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities held to maturity, fair values	$ 200,568	$ 204,277
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	13,750	13,750
Preferred stock, shares outstanding	13,750	13,750
Common stock, par value (in usd per share)	$ 1	$ 1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	54,551,264	54,796,231
Common stock, shares outstanding	54,551,264	54,796,231

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest and dividend income
Loans and leases, including fees	$ 284,879	$ 238,069
Mortgage loans held for sale, including fees	1,054	1,154
Taxable securities	33,916	25,328
Tax-exempt securities	2,209	2,766
Other	4,026	3,226
Total interest and dividend income	326,084	270,543
Interest Expense
Deposits	60,235	28,244
Short-term borrowings	5,716	2,524
Long-term debt	9,649	6,886
Total interest expense	75,600	37,654
Net interest income	250,484	232,889
Provision for credit losses	13,763	8,211
Net interest income after provision for credit losses	236,721	224,678
Non-interest income
Income from bank owned life insurance	1,797	1,282
Securities gains (losses), net	0	(59)
Other non-interest income	4,051	3,089
Total non-interest income	52,509	44,566
Non-interest expense
Salaries and employee benefits	98,296	104,586
Net occupancy and equipment	18,564	20,047
Communication and delivery	3,700	3,902
Marketing and business development	4,118	4,752
Computer services expense	9,157	12,393
Professional services	4,450	7,391
Credit and other loan related expense	2,859	4,393
Insurance	4,186	7,105
Travel and entertainment	2,430	3,237
Amortization of acquisition intangibles	5,009	5,102
Impairment of long-lived assets and other losses	1,064	8,757
Other non-interest expense	4,920	6,406
Total non-interest expense	158,753	188,071
Income before income tax expense	130,477	81,173
Income tax expense	30,346	17,552
Net income	100,131	63,621
Less: Preferred stock dividends	3,598	3,598
Net income available to common shareholders	96,533	60,023
Less: Earnings allocated to unvested restricted stock	933	639
Earnings allocated to common shareholders	$ 95,600	$ 59,384
Earnings per common share - Basic (in usd per share)	$ 1.76	$ 1.11
Earnings per common share - Diluted (in usd per share)	1.75	1.10
Cash dividends declared per common share (in usd per share)	$ 0.43	$ 0.38
Comprehensive income
Net income	$ 100,131	$ 63,621
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) arising during the period (net of tax effects of $10,675 and $14,223, respectively)	41,408	(53,506)
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $0 and $13, respectively)	0	(46)
Unrealized gains (losses) on securities, net of tax	41,408	(53,460)
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 $471 and $678, respectively)	(2,185)	2,549
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $75 and $31, respectively)	(227)	(116)
Fair value of derivative instruments designated as cash flow hedges, net of tax	(1,958)	2,665
Other comprehensive income (loss), net of tax	39,450	(50,795)
Comprehensive income	139,581	12,826
Mortgage income
Non-interest income
Non-interest income	11,849	9,595
Service charges on deposit accounts
Non-interest income
Non-interest income	12,810	12,908
Title income
Non-interest income
Non-interest income	5,225	5,027
Broker commissions
Non-interest income
Non-interest income	1,953	2,221
ATM and debit card fee income
Non-interest income
Non-interest income	2,582	2,633
Credit card and merchant-related income
Non-interest income
Non-interest income	3,411	2,907
Trust department income
Non-interest income
Non-interest income	4,167	3,426
Commission Income [Member]
Non-interest income
Non-interest income	$ 4,664	$ 1,537

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Unrealized holding gains (losses), arising during the period taxes	$ 10,675	$ 14,223
Reclassification adjustment for gains (losses) included in net income, taxes	0	13
Change in fair value of derivative instruments designated as cash flow hedges, taxes	471	678
Reclassification adjustment for gains (losses) included in net income, taxes	$ 75	$ 31

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, 2017		13,750	53,872,272
Beginning balance at Dec. 31, 2017	$ 3,696,791	$ 132,097	$ 53,872	$ 2,787,484	$ 769,226	$ (45,888)
Increase (Decrease) in Shareholders' Equity
Net income	63,621				63,621
Other comprehensive income (loss)	(50,795)					(50,795)
Cash dividends declared	(21,579)				(21,579)
Preferred stock dividends	(3,598)				(3,598)
Common stock issued under incentive plans, net of shares surrendered in payment (in shares)			118,796
Common stock issued under incentive plans, net of shares surrendered in payment	(2,581)		$ 119	(2,700)
Common stock issued for acquisitions (in shares)			2,787,773
Common stock issued for acquisitions	214,659		$ 2,788	211,871
Share-based compensation expense	4,734			4,734
Ending balance (in shares) at Mar. 31, 2018		13,750	56,778,841
Ending balance at Mar. 31, 2018	3,900,907	$ 132,097	$ 56,779	3,001,389	807,325	(96,683)
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)

Consolidated Statements of Sh_2

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash dividends declared per common share (in usd per share)	$ 0.43	$ 0.38
Retained Earnings
Cash dividends declared per common share (in usd per share)	$ 0.43	$ 0.38

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows from Operating Activities
Net income	$ 100,131	$ 63,621
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	4,018	(309)
Provision for credit losses	13,763	8,211
Share-based compensation cost - equity awards	5,572	4,734
Loss on sale of OREO and long-lived assets, net of impairment	278	670
Securities loss, net	0	59
Deferred income tax expense	17,861	10,992
Originations of mortgage loans held for sale	(326,244)	(336,400)
Proceeds from sales of mortgage loans held for sale	320,853	367,487
Realized and unrealized (gain) on mortgage loans held for sale, net	(11,593)	(9,320)
Other operating activities, net	152,430	(13,338)
Net Cash Provided by Operating Activities	277,069	96,407
Cash Flows from Investing Activities
Proceeds from maturities, prepayments and calls of available for sale securities	136,627	149,987
Purchases of available for sale securities, net of available for sale securities acquired	(179,565)	(194,543)
Proceeds from maturities, prepayments and calls of held to maturity securities	7,787	2,288
Purchases of equity securities, net of equity securities acquired	(14,753)	(2,452)
Proceeds from sales of equity securities	3,637	61,038
Increase in loans, net of loans acquired	(446,284)	(145,201)
Proceeds from sales of premises and equipment	91	1,408
Purchases of premises and equipment, net of premises and equipment acquired	(3,182)	(5,798)
Proceeds from dispositions of OREO	1,980	5,318
Cash paid for additional investment in tax credit entities	(2,828)	(750)
Cash received (paid) for acquisition of a business, net of cash paid	0	99,312
Other investing activities, net	0	(745)
Net Cash Used in Investing Activities	(496,490)	(30,138)
Cash Flows from Financing Activities
Increase in deposits, net of deposits acquired	328,631	440,470
Net change in short-term borrowings, net of borrowings acquired	(376,751)	(90,802)
Proceeds from long-term debt, net of long-term debt acquired	400,000	200,227
Repayments of long-term debt	(90,560)	(651,684)
Cash dividends paid on common stock	(22,466)	(19,933)
Cash dividends paid on preferred stock	(3,598)	(3,598)
Net share-based compensation stock transactions	(4,445)	(2,581)
Payments to repurchase common stock	(29,946)	0
Net Cash Provided by Financing Activities	200,865	(127,901)
Net Increase (Decrease) In Cash and Cash Equivalents	(18,556)	(61,632)
Cash and Cash Equivalents at Beginning of Period	690,453	625,724
Cash and Cash Equivalents at End of Period	671,897	564,092
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	2,727	1,757
Common stock issued in acquisitions	0	214,659
Cash paid for:
Interest on deposits and borrowings, net of acquired	71,010	37,035
Income taxes, net	$ 0	$ 101

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	BASIS OF PRESENTATION 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, 2018. 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.

Recent Accounting Pronouncement

Recent Accounting Pronouncements Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Pronouncements adopted during the three months ended March 31, 2019: ASU No. 2016-02, ASU No. 2018-11, ASU No. 2018-20, and ASU 2019-01 In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842) which requires lessees to recognize ROU assets and lease liabilities on the balance sheet for most leases, including operating leases. The lessor accounting model was relatively unchanged by this ASU. Additional quantitative and qualitative disclosures are also required. During 2018 and early 2019, the FASB issued ASU No. 2018-11, Targeted Improvements , ASU No. 2018-20, Narrow-Scope Improvements for Lessors , and ASU No. 2019-01, Codification Improvements , which clarified certain implementation issues, provided an additional optional transition method and clarified the disclosure requirements during the period of adopting ASC 842, among others. The Company adopted ASU No. 2016-02 and the related ASUs discussed above effective January 1, 2019 using the optional transition method. The Company elected the package of practical expedients that does not require the reassessment of whether expired or existing contracts contain leases, the reassessment of the lease classification for any expired or existing leases, or the reassessment of initial direct costs for existing leases. Additionally, the Company did not elect the hindsight practical expedient. The Company conducted a review of all existing lease contracts and service contracts which might contain embedded leases. Some of the Company’s leases contain variable lease payments, the majority of which depend on an index or rate, such as the Consumer Price Index. At transition, the present value of variable payments was based on the index or rate as of January 1, 2019. To determine the present value of lease payments at transition, the Company applied a portfolio approach utilizing an FHLB Advance rate based on the weighted average remaining term of the Company’s existing leases as of January 1, 2019. As a result of adopting ASC 842, the Company established an ROU asset and a lease liability as of January 1, 2019 of $94.2 million and $118.9 million , respectively. Additionally, as part of the adoption of ASC 842, $24.7 million in pre-existing liabilities were reclassified to the ROU asset on January 1, 2019. This resulted in a gross-up of the balance sheet of $94.2 million as a result of recognizing lease liabilities and corresponding right-of-use assets for operating leases. The adoption of ASC 842 also required the recognition of previously deferred gains on sale-leaseback transactions which resulted in an insignificant increase to retained earnings on January 1, 2019. The related impact on the Company’s regulatory capital ratios was not significant. The Company does not expect material changes to the recognition of lease expense in future periods as a result of the adoption of ASC 842. See Note 8, Leases, for additional disclosures required by ASC 842. ASU No. 2018-16 In October 2018, the FASB released ASU No. 2018-16, Derivatives and Hedging (ASC 815): Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes , which permits the use of the OIS rate based on SOFR as a U.S. benchmark interest rate for hedge accounting purposes under ASC 815 in addition to the interest rates on direct Treasury obligations of the UST, the LIBOR swap rate, the OIS Rate based on the Fed Funds Effective Rate, and the SIFMA Municipal Swap Rate. The required effective date of this ASU was dependent upon when an entity adopted the provisions of ASU No. 2017-12. The Company adopted ASU No. 2018-16 effective January 1, 2019 on a prospective basis for qualifying new or redesignated hedging relations as ASU No. 2017-12 had previously been adopted on January 1, 2018. The implementation of this ASU did not have a significant impact on the Company’s consolidated financial statements. ASU No. 2017-08 In March 2017, the FASB issued ASU No. 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities, which will shorten the amortization period for callable debt securities held at a premium to the earliest call date instead of the maturity date. The amendments do not require an accounting change for securities held at a discount, which will continue to be amortized to the maturity date. The Company adopted ASU No. 2017-08 effective January 1, 2019. 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. 2016-13 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 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 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. The ASU also 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 through the use of an allowance to record estimated credit losses (and subsequent recoveries). Non-credit related losses will continue to be recognized through OCI. In addition, the guidance provides for a simplified accounting model for purchased financial assets with a more-than-insignificant amount of credit deterioration since their origination. The initial estimate of expected credit losses would be recognized through an ALLL with an offset (i.e., increase) to the cost basis of the related financial asset at acquisition. ASU No. 2016-13 will be effective for fiscal years beginning after December 15, 2019, including interim periods. The ASU will be applied through a modified-retrospective approach, resulting in a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. A prospective transition approach is required for debt securities for which OTTI had been recognized before the effective date. Amounts previously recognized in AOCI as of the date of adoption that relate to improvements in cash flows expected to be collected should continue to be accreted into income over the remaining life of the asset. Recoveries of amounts previously written off relating to improvements in cash flows after the date of adoption should be recorded in earnings when received. The Company has established a cross-function implementation team and engaged third-party consultants who have jointly developed a project plan to provide implementation oversight. The Company is in the process of developing and implementing current expected credit loss models that satisfy the requirements of the ASU and continues to identify key interpretive issues. The Company expects that this ASU will result in an increase to ALLL given the change to estimate losses over the full remaining estimated life of the loan portfolio as well as the adoption of an allowance for debt securities. The extent of the increase in the ALLL is not yet known and will depend on the composition of our loan and securities portfolios, finalization of credit loss models, macroeconomic conditions and forecasts at the adoption date. 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 will be effective for fiscal years beginning after December 15, 2019, including interim periods, with early adoption permitted. The Company is currently evaluating the impact of the ASU. While adoption of this ASU will result in changes to existing disclosures, it will not have any impact on our financial position or results of operation. 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 will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. The guidance should be applied retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements. 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. ASU No. 2019-04 clarifies the scope of the credit losses standard and addresses various issues including, accrued interest receivable balances, recoveries, variable interest rates and prepayments. 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 remeasurement under ASC 820 when using the measurement alternative, certain disclosure requirements and which equity securities have to be remeasured at historical exchange rates. The amended guidance in this ASU related to the credit losses and the recognition and measurement of financial instruments will be effective for fiscal years and interim periods beginning after December 15, 2019 with early adoption in any interim period permitted. Since the Company early adopted the guidance in ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities in 2018, the amended hedge accounting guidance in ASU No. 2019-04 will be 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 is currently evaluating the impact of the ASU on the Company’s consolidated financial statements.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	INVESTMENT SECURITIES The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following: March 31, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 40,822 $ 130 $ — $ 40,952 Obligations of state and political subdivisions 175,271 4,740 (32 ) 179,979 Mortgage-backed securities: Residential agency 3,757,469 16,972 (29,763 ) 3,744,678 Commercial agency 779,487 6,656 (7,716 ) 778,427 Other securities 128,380 1,876 (514 ) 129,742 Total securities available for sale $ 4,881,429 $ 30,374 $ (38,025 ) $ 4,873,778 Securities held to maturity: Obligations of state and political subdivisions $ 180,472 $ 2,365 $ (42 ) $ 182,795 Mortgage-backed securities: Residential agency 18,486 29 (742 ) 17,773 Total securities held to maturity $ 198,958 $ 2,394 $ (784 ) $ 200,568 December 31, 2018 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 995 $ 3 $ — $ 998 Obligations of state and political subdivisions 177,566 2,045 (723 ) 178,888 Mortgage-backed securities: Residential agency 3,837,584 8,886 (57,073 ) 3,789,397 Commercial agency 730,148 2,363 (14,799 ) 717,712 Other securities 97,020 351 (787 ) 96,584 Total securities available for sale $ 4,843,313 $ 13,648 $ (73,382 ) $ 4,783,579 Securities held to maturity: Obligations of state and political subdivisions $ 188,684 $ 309 $ (2,497 ) $ 186,496 Mortgage-backed securities: Residential agency 18,762 30 (1,011 ) 17,781 Total securities held to maturity $ 207,446 $ 339 $ (3,508 ) $ 204,277 Securities with carrying values of $2.3 billion and $2.4 billion were pledged to support repurchase transactions, public funds deposits, and certain long-term borrowings at March 31, 2019 and December 31, 2018 , 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, is as follows: March 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 $ — $ — $ (32 ) $ 11,925 $ (32 ) $ 11,925 Mortgage-backed securities: Residential agency (71 ) 40,608 (29,692 ) 2,081,552 (29,763 ) 2,122,160 Commercial agency (5 ) 7,001 (7,711 ) 434,500 (7,716 ) 441,501 Other securities (4 ) 4,382 (510 ) 33,543 (514 ) 37,925 Total securities available for sale $ (80 ) $ 51,991 $ (37,945 ) $ 2,561,520 $ (38,025 ) $ 2,613,511 Securities held to maturity: Obligations of state and political subdivisions $ — $ — $ (42 ) $ 13,160 $ (42 ) $ 13,160 Mortgage-backed securities: Residential agency — — (742 ) 17,480 (742 ) 17,480 Total securities held to maturity $ — $ — $ (784 ) $ 30,640 $ (784 ) $ 30,640 December 31, 2018 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 $ (9 ) $ 4,112 $ (714 ) $ 30,268 $ (723 ) $ 34,380 Mortgage-backed securities: Residential agency (816 ) 197,057 (56,257 ) 2,193,862 (57,073 ) 2,390,919 Commercial agency (43 ) 18,190 (14,756 ) 483,565 (14,799 ) 501,755 Other securities (94 ) 18,025 (693 ) 32,577 (787 ) 50,602 Total securities available for sale $ (962 ) $ 237,384 $ (72,420 ) $ 2,740,272 $ (73,382 ) $ 2,977,656 Securities held to maturity: Obligations of state and political subdivisions $ (3 ) $ 2,059 $ (2,494 ) $ 151,699 $ (2,497 ) $ 153,758 Mortgage-backed securities: Residential agency — — (1,011 ) 17,478 (1,011 ) 17,478 Total securities held to maturity $ (3 ) $ 2,059 $ (3,505 ) $ 169,177 $ (3,508 ) $ 171,236 The Company held certain investment securities where amortized cost exceeded fair value, resulting in unrealized loss positions, as shown in the tables above. Management evaluates securities for other-than-temporary impairment on at least a quarterly basis, and more frequently when economic or market concerns warrant such evaluation. Impairment is considered to be other-than-temporary if the Company (1) intends to sell the security, (2) more likely than not will be required to sell the security before recovering its cost, or (3) does not expect to recover the security's entire amortized cost basis. As of March 31, 2019 , the Company does not intend to sell any of these securities, does not expect to be required to sell these securities, and expects to recover the entire amortized cost of all these securities. At March 31, 2019 , 389 debt securities had unrealized losses of 1.45% of the securities’ amortized cost basis. At December 31, 2018 , 488 debt securities had unrealized losses of 2.38% of the securities’ amortized cost basis. The unrealized losses for each of the securities related to market interest rate changes and not credit concerns of the issuers. Additional information on securities that have been in a continuous loss position for over twelve months at March 31, 2019 and December 31, 2018 is presented in the following table. (in thousands) March 31, 2019 December 31, 2018 Number of securities Mortgage-backed securities: Residential agency 289 302 Commercial agency 65 72 Obligations of state and political subdivisions 17 60 Other securities 8 7 379 441 Amortized Cost Basis Mortgage-backed securities: Residential agency $ 2,129,466 $ 2,268,608 Commercial agency 442,211 498,321 Obligations of state and political subdivisions 25,159 185,175 Other securities 34,053 33,270 $ 2,630,889 $ 2,985,374 Unrealized Loss Mortgage-backed securities: Residential agency $ 30,434 $ 57,268 Commercial agency 7,711 14,756 Obligations of state and political subdivisions 74 3,208 Other securities 510 693 $ 38,729 $ 75,925 The amortized cost and estimated fair value of investment securities by maturity at March 31, 2019 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 3.86 % $ 2,536 $ 2,542 2.33 % $ 955 $ 959 One through five years 2.66 113,924 114,533 2.42 6,100 6,114 After five through ten years 2.71 863,166 867,609 2.58 42,885 43,419 Over ten years 2.97 3,901,803 3,889,094 2.63 149,018 150,076 2.92 % $ 4,881,429 $ 4,873,778 2.61 % $ 198,958 $ 200,568 The following is a summary of realized gains and losses from the 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. Three Months Ended March 31, (in thousands) 2019 2018 Realized gains $ — $ 9 Realized losses — (68 ) $ — $ (59 ) In addition to the gains above, the Company realized certain gains on calls of securities held to maturity that were not significant to the consolidated financial statements. 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, are as follows: (in thousands) March 31, 2019 December 31, 2018 Federal Home Loan Bank stock $ 107,122 $ 95,213 Federal Reserve Bank stock 85,630 85,630 CRA and Community Development Investment Funds 1,914 1,884 Other investments 13,864 9,709 $ 208,530 $ 192,436

Loans and Leases

Loans and Leases	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Loans and Leases	LOANS AND LEASES Loans and leases by portfolio segment and class consist of the following for the periods indicated: (in thousands) March 31, 2019 December 31, 2018 Commercial loans and leases: Real estate - construction $ 1,219,647 $ 1,196,366 Real estate - owner-occupied 2,408,079 2,395,822 Real estate - non-owner-occupied 6,147,864 5,796,117 Commercial and industrial (1) 5,852,568 5,737,017 Total commercial loans and leases 15,628,158 15,125,322 Residential mortgage loans 4,415,267 4,359,156 Consumer and other loans: Home equity 2,220,648 2,304,694 Other 704,222 730,643 Total consumer and other loans 2,924,870 3,035,337 Total loans and leases $ 22,968,295 $ 22,519,815 (1) Includes equipment financing leases Net deferred loan origination fees were $30.8 million and $30.2 million at March 31, 2019 and December 31, 2018 , respectively. Total net discount on the Company's loans was $130.1 million and $136.8 million at March 31, 2019 and December 31, 2018 , respectively, of which $79.0 million and $81.6 million was related to non-impaired loans. 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, 2019 and December 31, 2018 , overdrafts of $6.4 million and $9.2 million , respectively, have been reclassified to loans. Loans with carrying values of $7.8 billion and $7.6 billion were pledged as collateral for borrowings at March 31, 2019 and December 31, 2018 , respectively. Aging Analysis The following tables provide an analysis of the aging of loans and leases as of March 31, 2019 and December 31, 2018 . Past due and non-accrual loan amounts exclude acquired impaired loans, even if contractually past due or if the Company does not expect to receive payment in full, as the Company is currently accreting interest income over the expected life of the loans. For additional information on the determination of past due status and the Company's policies for recording payments received, placing loans and leases on non-accrual status, and the resumption of interest accrual on non-accruing loans and leases, see Note 1, Summary of Significant Accounting Policies, in the 2018 10-K. March 31, 2019 Accruing (in thousands) Current or Less Than 30 days Past Due 30-59 days 60-89 days > 90 days Total Past Due Non-accrual (1) Acquired Impaired Total Real estate- construction $ 1,197,063 $ 305 $ — $ — $ 305 $ 1,072 $ 21,207 $ 1,219,647 Real estate- owner-occupied 2,324,441 2,510 67 3,139 5,716 8,630 69,292 2,408,079 Real estate- non-owner-occupied 6,054,340 2,213 91 863 3,167 19,984 70,373 6,147,864 Commercial and industrial 5,766,811 8,881 725 109 9,715 51,447 24,595 5,852,568 Residential mortgage 4,269,617 10,884 4,756 — 15,640 45,473 84,537 4,415,267 Consumer - home equity 2,134,340 9,511 2,178 — 11,689 18,719 55,900 2,220,648 Consumer - other 695,940 2,303 910 — 3,213 2,731 2,338 704,222 Total $ 22,442,552 $ 36,607 $ 8,727 $ 4,111 $ 49,445 $ 148,056 $ 328,242 $ 22,968,295 (1) Of the total non-accrual loans at March 31, 2019 , $9.0 million were past due 30-59 days, $4.6 million were past due 60-89 days, and $53.7 million were past due more than 90 days. December 31, 2018 Accruing (in thousands) Current or Less Than 30 days Past Due 30-59 days 60-89 days > 90 days Total Past Due Non-accrual (1) Acquired Impaired Total Real estate- construction $ 1,167,795 $ 1,054 $ — $ — $ 1,054 $ 1,094 $ 26,423 $ 1,196,366 Real estate- owner-occupied 2,305,743 7,167 — — 7,167 10,260 72,652 2,395,822 Real estate- non-owner-occupied 5,703,131 7,473 360 — 7,833 15,898 69,255 5,796,117 Commercial and industrial 5,645,304 5,139 1,320 553 7,012 57,860 26,841 5,737,017 Residential mortgage 4,218,146 2,768 13,063 1,575 17,406 30,396 93,208 4,359,156 Consumer - home equity 2,200,517 10,283 2,409 — 12,692 18,830 72,655 2,304,694 Consumer - other 719,122 4,695 1,601 — 6,296 2,846 2,379 730,643 Total $ 21,959,758 $ 38,579 $ 18,753 $ 2,128 $ 59,460 $ 137,184 $ 363,413 $ 22,519,815 (1) Of the total non-accrual loans at December 31, 2018 , $7.0 million were past due 30-59 days, $3.7 million were past due 60-89 days, and $66.9 million were past due more than 90 days. Acquired Loans The Company acquired certain loans from Sabadell United to customers with addresses outside of the United States. Foreign loans, denominated in U.S. dollars, totaled $205.2 million and $202.6 million at March 31, 2019 and December 31, 2018, respectively. 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 : (in thousands) 2019 2018 Balance at beginning of period $ 133,342 $ 152,623 Additions — 2,371 Transfers from non-accretable difference to accretable yield (3,640 ) (279 ) Accretion (10,086 ) (13,154 ) Changes in expected cash flows not affecting non-accretable differences (1) (272 ) 9,687 Balance at end of period $ 119,344 $ 151,248 (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 Information about the Company’s TDRs at March 31, 2019 and 2018 is presented in the following tables. Modifications of loans that are accounted for within a pool under ASC Topic 310-30 are excluded as TDRs. Accordingly, such modifications do not result in the removal of those loans from the pool, even if the modification of those loans would otherwise be considered a TDR. As a result, all such acquired loans that would otherwise meet the criteria for classification as a TDR are excluded from the tables below. TDRs totaling $31.4 million and $27.2 million occurred during the three months ended March 31, 2019 and 2018, 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) 2019 2018 Extended maturities $ 9,014 $ 5,619 Maturity and interest rate adjustment 468 108 Movement to or extension of interest-rate only payments 12 48 Interest rate adjustment — 105 Forbearance 6,510 12,886 Other concession(s) (1) 15,425 8,434 Total $ 31,429 $ 27,200 (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 $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. Of the $27.2 million of TDRs occurring during the three months ended March 31, 2018 , $12.9 million were on accrual status and $14.3 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, 2019 2018 (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 $ 39 $ 39 1 $ 1,950 $ 1,049 Real estate- owner-occupied 4 6,904 4,661 2 10,691 9,324 Real estate- non-owner-occupied 7 2,990 2,968 9 1,089 1,091 Commercial and industrial 23 17,382 17,040 18 14,429 13,314 Residential mortgage 10 1,741 1,738 — — — Consumer - home equity 33 4,277 4,233 14 1,809 1,795 Consumer - other 38 787 750 21 648 627 Total 116 $ 34,120 $ 31,429 65 $ 30,616 $ 27,200 Information detailing TDRs that defaulted during the three-month periods ended March 31, 2019 and 2018 , 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, 2019 2018 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 939 — $ — Real estate- owner-occupied 3 640 3 10,187 Real estate- non-owner-occupied 7 825 9 492 Commercial and industrial 10 3,933 29 9,708 Residential mortgage 13 1,108 6 598 Consumer - home equity 16 2,891 24 2,331 Consumer - other 20 261 51 1,357 Total 70 $ 10,597 122 $ 24,673

Allowance for Credit Losses and

Allowance for Credit Losses and Credit Quality	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Allowance for Credit Losses and Credit Quality	ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY Allowance for Credit Losses Activity A summary of changes in the allowance for credit losses for the three months ended March 31 is as follows: (in thousands) 2019 2018 Allowance for loan and lease losses at beginning of period $ 140,571 $ 140,891 Provision for loan and lease losses 12,612 7,987 Transfer of balance to OREO and other (2,885 ) (48 ) Charge-offs (8,918 ) (9,116 ) Recoveries 1,586 4,813 Allowance for loan and lease losses at end of period $ 142,966 $ 144,527 Reserve for unfunded commitments at beginning of period $ 14,830 $ 13,208 Provision for unfunded lending commitments 1,151 224 Reserve for unfunded commitments at end of period $ 15,981 $ 13,432 Allowance for credit losses at end of period $ 158,947 $ 157,959 A summary of changes in the allowance for credit losses, by loan portfolio type, for the three months ended March 31 is as follows: 2019 (in thousands) Commercial Real Estate Commercial and Industrial Residential Mortgage Consumer and Other Total Allowance for loan and lease losses at beginning of period $ 51,806 $ 54,096 $ 12,998 $ 21,671 $ 140,571 Provision for loan and lease losses 6,887 2,876 1,749 1,100 12,612 Transfer of balance to OREO and other — — (2,881 ) (4 ) (2,885 ) Charge-offs (72 ) (4,931 ) (28 ) (3,887 ) (8,918 ) Recoveries 103 446 32 1,005 1,586 Allowance for loan and lease losses at end of period $ 58,724 $ 52,487 $ 11,870 $ 19,885 $ 142,966 Reserve for unfunded commitments at beginning of period $ 4,869 $ 6,198 $ 866 $ 2,897 $ 14,830 Provision for unfunded commitments 794 128 22 207 1,151 Reserve for unfunded commitments at end of period $ 5,663 $ 6,326 $ 888 $ 3,104 $ 15,981 Allowance on loans individually evaluated for impairment $ 3,078 $ 10,988 $ 258 $ 2,624 $ 16,948 Allowance on loans collectively evaluated for impairment 50,210 39,997 7,404 17,087 114,698 Allowance on loans acquired with deteriorated credit quality 5,436 1,502 4,208 174 11,320 Loans and leases, net of unearned income: Balance at end of period $ 9,775,590 $ 5,852,568 $ 4,415,267 $ 2,924,870 $ 22,968,295 Balance at end of period individually evaluated for impairment 67,909 63,889 7,679 35,835 175,312 Balance at end of period collectively evaluated for impairment 9,546,809 5,764,084 4,323,051 2,830,797 22,464,741 Balance at end of period acquired with deteriorated credit quality 160,872 24,595 84,537 58,238 328,242 2018 (in thousands) Commercial Real Estate Commercial and Industrial Residential Mortgage Consumer and Other Total Allowance for loan losses at beginning of period $ 54,201 $ 53,916 $ 9,117 $ 23,657 $ 140,891 Provision for (Reversal of) loan and lease losses 6,378 294 (686 ) 2,001 7,987 Transfer of balance to OREO and other (48 ) — — — (48 ) Charge-offs (114 ) (5,378 ) (105 ) (3,519 ) (9,116 ) Recoveries 191 3,698 22 902 4,813 Allowance for loan losses at end of period $ 60,608 $ 52,530 $ 8,348 $ 23,041 $ 144,527 Reserve for unfunded commitments at beginning of period $ 4,531 $ 5,309 $ 555 $ 2,813 $ 13,208 Provision for (Reversal of) unfunded commitments 1,476 (1,004 ) (15 ) (233 ) 224 Reserve for unfunded commitments at end of period $ 6,007 $ 4,305 $ 540 $ 2,580 $ 13,432 Allowance on loans individually evaluated for impairment $ 2,506 $ 14,040 $ 178 $ 2,974 $ 19,698 Allowance on loans collectively evaluated for impairment 35,871 36,208 2,073 16,544 90,696 Allowance on loans acquired with deteriorated credit quality 22,231 2,282 6,097 3,523 34,133 Loans, net of unearned income: Balance at end of period $ 9,248,951 $ 5,325,682 $ 3,971,067 $ 3,160,390 $ 21,706,090 Balance at end of period individually evaluated for impairment 78,489 78,725 6,041 33,277 196,532 Balance at end of period collectively evaluated for impairment 8,946,138 5,211,736 3,826,721 3,043,085 21,027,680 Balance at end of period acquired with deteriorated credit quality 224,324 35,221 138,305 84,028 481,878 Portfolio Segment Risk Factors Commercial real estate loans include loans to commercial customers for long-term financing of land and buildings or for land development or construction of a building. These loans are repaid through revenues from 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 business loans on a secured and, to a lesser extent, unsecured basis. Residential mortgage loans consist of loans to consumers to finance a primary 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. Consumer loans are offered by the Company in order to provide a full range of retail financial services to its customers and include home equity, credit card and other direct consumer installment loans. The Company originates substantially all of its consumer loans in its primary market areas. Loans in the consumer segment are sensitive to unemployment and other key consumer economic measures. 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 have potential weaknesses that, if left uncorrected, may result in deterioration of the Company's credit position at some future date. Substandard loans 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 loans have the same weaknesses as substandard loans 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. For residential mortgage loans and consumer loans, the Company primarily uses the loan's payment and delinquency status to monitor credit quality. These credit quality indicators are continually updated and monitored. The recorded investment in loans and leases by credit quality indicator is presented in the following tables. Asset risk classifications for commercial loans and leases reflect the classification as of March 31, 2019 and December 31, 2018 . Credit quality information in the tables below includes total loans acquired (including acquired impaired loans) at the net loan balance, after the application of premiums and discounts. Loan premiums and discounts represent the adjustment of acquired loans to fair value at the acquisition date, as adjusted for income accretion and changes in cash flow estimates in subsequent periods. March 31, 2019 December 31, 2018 (in thousands) Pass Special Mention Sub- Doubtful Total Pass Special Mention Sub- Doubtful Total Real estate - construction $ 1,213,202 $ 147 $ 6,289 $ 9 $ 1,219,647 $ 1,182,554 $ 1,062 $ 12,740 $ 10 $ 1,196,366 Real estate - owner-occupied 2,332,819 33,359 41,087 814 2,408,079 2,328,999 25,526 41,297 — 2,395,822 Real estate - non-owner-occupied 6,028,301 82,839 34,015 2,709 6,147,864 5,687,963 78,009 26,512 3,633 5,796,117 Commercial and industrial 5,696,564 46,384 87,385 22,235 5,852,568 5,586,482 52,632 73,853 24,050 5,737,017 Total $ 15,270,886 $ 162,729 $ 168,776 $ 25,767 $ 15,628,158 $ 14,785,998 $ 157,229 $ 154,402 $ 27,693 $ 15,125,322 March 31, 2019 December 31, 2018 (in thousands) Current 30+ Days Past Due Total Current 30+ Days Past Due Total Residential mortgage $ 4,335,779 $ 79,488 $ 4,415,267 $ 4,290,152 $ 69,004 $ 4,359,156 Consumer - home equity 2,184,204 36,444 2,220,648 2,258,659 46,035 2,304,694 Consumer - other 698,074 6,148 704,222 721,231 9,412 730,643 Total $ 7,218,057 $ 122,080 $ 7,340,137 $ 7,270,042 $ 124,451 $ 7,394,493 Impaired Loans Information on the Company’s investment in impaired loans, which include all TDRs and all other non-accrual loans evaluated or measured individually for impairment for purposes of determining the ALLL, is presented in the following tables as of and for the periods indicated. March 31, 2019 December 31, 2018 Unpaid Principal Balance Recorded Investment Related Allowance Unpaid Principal Balance Recorded Investment Related Allowance (in thousands) With no related allowance recorded: Real estate - construction $ 12,138 $ 11,139 $ — $ 10,261 $ 9,262 $ — Real estate - owner-occupied 33,670 27,732 — 25,037 19,044 — Real estate - non-owner-occupied 12,352 11,515 — 15,265 14,288 — Commercial and industrial 52,821 32,380 — 55,554 43,886 — Residential mortgage 1,456 1,456 — 1,244 1,221 — Consumer - home equity 1,783 1,783 — 4,183 4,176 — Consumer - other — — — — — — With an allowance recorded: Real estate - construction 224 134 (11 ) 228 140 (11 ) Real estate - owner-occupied 5,553 5,393 (613 ) 5,032 4,773 (520 ) Real estate - non-owner-occupied 12,113 11,996 (2,454 ) 6,445 6,398 (105 ) Commercial and industrial 36,243 31,509 (10,988 ) 46,387 27,915 (12,646 ) Residential mortgage 6,745 6,223 (258 ) 5,870 5,358 (145 ) Consumer - home equity 30,847 29,861 (2,132 ) 29,284 28,818 (2,427 ) Consumer - other 4,574 4,191 (492 ) 4,956 4,446 (488 ) Total $ 210,519 $ 175,312 $ (16,948 ) $ 209,746 $ 169,725 $ (16,342 ) Total commercial loans and leases $ 165,114 $ 131,798 $ (14,066 ) $ 164,209 $ 125,706 $ (13,282 ) Total residential mortgage loans 8,201 7,679 (258 ) 7,114 6,579 (145 ) Total consumer and other loans 37,204 35,835 (2,624 ) 38,423 37,440 (2,915 ) Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 Average Interest Average Interest (in thousands) With no related allowance recorded: Real estate - construction $ 11,142 $ 169 $ 10,470 $ 144 Real estate - owner-occupied 27,865 301 36,277 334 Real estate - non-owner-occupied 11,566 69 10,557 98 Commercial and industrial 37,185 461 27,832 385 Residential mortgage 1,463 17 1,090 12 Consumer - home equity 1,204 10 32 — With an allowance recorded: Real estate - construction 136 — 153 1 Real estate - owner-occupied 5,433 8 17,608 112 Real estate - non-owner-occupied 12,042 79 3,302 10 Commercial and industrial 28,624 202 44,056 196 Residential mortgage 6,274 59 4,974 44 Consumer - home equity 30,345 292 28,203 292 Consumer - other 4,314 58 5,200 67 Total $ 177,593 $ 1,725 $ 189,754 $ 1,695 Total commercial loans and leases $ 133,993 $ 1,289 $ 150,255 $ 1,280 Total residential mortgage loans 7,737 76 6,064 56 Total consumer and other loans 35,863 360 33,435 359 As of March 31, 2019 and December 31, 2018 , the Company was not committed to lend a material amount of additional funds to any customer whose loan was classified as impaired or as a TDR.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill Changes to the carrying amount of goodwill by reporting unit for the three months ended March 31, 2019, and the year ended December 31, 2018 are provided in the following table: (in thousands) IBERIABANK Mortgage LTC Total Balance, December 31, 2017 $ 1,160,559 $ 23,178 $ 5,165 $ 1,188,902 Goodwill acquired and adjustments during the year 43,251 — 3,380 46,631 Balance, December 31, 2018 $ 1,203,810 $ 23,178 $ 8,545 $ 1,235,533 Goodwill acquired and adjustments during the year — — — — Balance, March 31, 2019 $ 1,203,810 $ 23,178 $ 8,545 $ 1,235,533 The goodwill acquired and adjustments made during 2018 were the result of the Sabadell United, Gibraltar, and SolomonParks acquisitions. There were no changes to goodwill during the three months ended March 31, 2019. The Company performed the required annual goodwill impairment test as of October 1, 2018. The Company’s annual impairment test did not indicate impairment in any of the Company’s reporting units as of the testing date. Following the testing date, management evaluated the events and changes that could indicate that goodwill might be impaired and concluded that a subsequent interim test was not necessary. 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, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (in thousands) Mortgage servicing rights $ 14,636 $ (5,102 ) $ 9,534 $ 13,612 $ (4,806 ) $ 8,806 Title Plant The Company held title plant assets recorded in other intangible assets on the Company's consolidated balance sheets totaling $6.8 million at both March 31, 2019 and December 31, 2018. No events or changes in circumstances occurred during the three months ended March 31, 2019 to suggest the carrying value of the title plant was not recoverable. Intangible assets subject to amortization Definite-lived intangible assets had the following carrying values included in other intangible assets on the Company’s consolidated balance sheets as of the periods indicated: March 31, 2019 December 31, 2018 (in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Core deposit intangible assets $ 136,183 $ (68,189 ) $ 67,994 $ 136,183 $ (63,213 ) $ 72,970 Customer relationship intangible asset 1,385 (1,340 ) 45 1,385 (1,323 ) 62 Non-compete agreement 206 (84 ) 122 206 (72 ) 134 Total $ 137,774 $ (69,613 ) $ 68,161 $ 137,774 $ (64,608 ) $ 73,166

Derivative Instruments and Othe

Derivative Instruments and Other Hedging Activities	3 Months Ended
	Mar. 31, 2019
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, foreign exchange contracts, 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 is as follows: Derivative Assets - Fair Value Derivative Liabilities - Fair Value (in thousands) March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 6,920 $ 3,469 $ — $ — Total derivatives designated as hedging instruments $ 6,920 $ 3,469 $ — $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream 237 474 1,040 191 Customer swaps - downstream 35,265 16,946 9,766 17,812 Foreign exchange contracts 7 18 7 18 Forward sales contracts 143 630 1,440 750 Written and purchased options 8,488 5,490 4,446 3,310 Other contracts 26 21 57 43 Total derivatives not designated as hedging instruments $ 44,166 $ 23,579 $ 16,756 $ 22,124 Total $ 51,086 $ 27,048 $ 16,756 $ 22,124 Derivative Assets - Notional Amount Derivative Liabilities - Notional Amount (in thousands) March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 500,000 $ 408,500 $ 108,500 $ — Total derivatives designated as hedging instruments $ 500,000 $ 408,500 $ 108,500 $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream 634,998 919,653 1,290,051 701,257 Customer swaps - downstream 1,290,051 701,257 634,998 919,653 Foreign exchange contracts 903 1,202 903 1,202 Forward sales contracts 43,567 1,140 205,278 143,179 Written and purchased options 324,345 229,333 141,430 140,645 Other contracts 50,050 50,527 98,858 85,623 Total derivatives not designated as hedging instruments $ 2,343,914 $ 1,903,112 $ 2,371,518 $ 1,991,559 Total $ 2,843,914 $ 2,311,612 $ 2,480,018 $ 1,991,559 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 $98.9 million and $85.6 million at March 31, 2019 and December 31, 2018, respectively. Assuming all underlying third party customers referenced in the swap contracts defaulted at March 31, 2019 and December 31, 2018, 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, 2019 and December 31, 2018, the Company was not required to post collateral due to the Company's derivative position at the balance sheet date. At March 31, 2019 and December 31, 2018, the Company was required to post $44.7 million and $35.8 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, 2019. 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. As permitted by U.S. GAAP, 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, 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 $ 6,920 $ — $ — $ 6,920 Interest rate contracts not designated as hedging instruments 35,502 (824 ) — 34,678 Written and purchased options 4,406 — — 4,406 Total derivative assets subject to master netting arrangements $ 46,828 $ (824 ) $ — $ 46,004 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 10,806 $ (824 ) $ — $ 9,982 Written and purchased options 4,406 — — 4,406 Total derivative liabilities subject to master netting arrangements $ 15,212 $ (824 ) $ — $ 14,388 December 31, 2018 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 $ 3,469 $ — $ — $ 3,469 Interest rate contracts not designated as hedging instruments 17,420 (619 ) — 16,801 Written and purchased options 3,285 — — 3,285 Total derivative assets subject to master netting arrangements $ 24,174 $ (619 ) $ — $ 23,555 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 18,003 $ (619 ) $ — $ 17,384 Written and purchased options 3,285 — — 3,285 Total derivative liabilities subject to master netting arrangements $ 21,288 $ (619 ) $ — $ 20,669 During the three months ended March 31, 2019 and 2018 , the Company has not reclassified 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, 2019 , the Company does 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, 2019 and 2018 , and for the three months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements is 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 2019 2019 2019 Total Interest rate contracts $ (2,185 ) $ (3,098 ) $ 913 Interest expense $ (227 ) $ (69 ) $ (158 ) Interest expense $ — $ — $ — 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 2018 2018 2018 Total Interest rate contracts $ 2,549 $ 2,549 $ — Interest expense $ (116 ) $ (116 ) $ — Interest expense $ — $ — $ — Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of March 31, is 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) 2019 2018 Interest rate contracts (1) Other income $ 4,181 $ 1,049 Foreign exchange contracts Other income 5 5 Forward sales contracts Mortgage income (3,209 ) 3,387 Written and purchased options Mortgage income 1,863 648 Other contracts Other income (9 ) (3 ) Total $ 2,831 $ 5,086 (1) Includes fees associated with customer interest rate contracts.

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	LEASES IBERIABANK as Lessee The Company leases certain branch and corporate offices, land and ATM facilities through operating leases with terms ranging from less than one year to 45 years. The Company has no financing leases (formerly capital leases). As discussed in Note 2, Recent Accounting Pronouncements, the Company adopted new guidance for leases on January 1, 2019 which requires that leases, whether classified as operating leases or financing leases, are to be accounted for as the acquisition of a right-of-use asset (ROU asset) and a related lease liability recorded at the present value of the lease payments less any lease incentives. The ROU asset represents the Company’s right to use an underlying asset for the lease term and is included in other assets on the Company’s consolidated balance sheets. The lease liability represents the Company’s obligation to make lease payments and is included in other liabilities in the Company’s consolidated balance sheets. The cost of the lease is recognized on a straight-line basis over the lease term as lease expense. Prior to January 1, 2019, operating leases were not recorded on the balance sheet. See Note 2, Recent Accounting Pronouncements, for further discussion of the adoption of this new guidance. Subsequent to the adoption of ASC 842 on January 1, 2019, the Company reviews new lease and service contracts to determine if the contracts contain an embedded lease. For leases that do not provide an implicit rate, the Company uses the corresponding FHLB Advance rate based on the lease term at commencement in determining the present value of lease payments. For leases with variable lease payments, the present value will be determined using the index at the lease commencement date. Changes in variable rent payments due to subsequent changes in the index or rate do not result in a re-measurement of the ROU asset or lease liability, but are recognized as expense in the period in which they occur. Certain of the Company’s leases contain options to either renew, extend or terminate the lease. As of March 31, 2019, no material extensions or terminations were considered reasonably certain, and as such, were not included in the measurement of the lease liability and ROU asset. The Company also has lease agreements with lease and non-lease components, which are generally accounted for separately. Non-lease components, which primarily consist of common area maintenance (“CAM”), utilities, and janitorial services, are based on the stand-alone price of the services and expensed as incurred. Operating lease expense for the three months ended March 31, 2019 totaled $6.8 million . During the three months ended March 31, 2019, the Company paid $6.7 million for amounts included in the measurement of lease liabilities and $5.2 million to obtain ROU assets. The following summarizes the ROU asset and lease liabilities as of March 31, 2019: (in thousands) March 31, 2019 Right-of-use assets $ 95,581 Total lease liabilities 118,430 Weighted Average Remaining Lease Term 7.4 years Weighted Average Discount Rate 3.4 % Maturities of operating lease liabilities as of March 31, 2019 is as follows: (in thousands) 2019 $ 20,059 2020 25,441 2021 22,038 2022 18,730 2023 12,394 2024 and thereafter 36,015 Total operating lease payments $ 134,677 Less: Imputed interest 16,247 Total lease liabilities $ 118,430 As of March 31, 2019, the Company has not entered into any material leases that have not yet commenced. IBERIABANK as Lessor As a lessor, the Company engages in the leasing of equipment to commercial customers primarily through direct financing and sales-type leases. Direct financing and sales-type leases are similar to other forms of installment lending in that lessors generally do not retain benefits and risks incidental to ownership of the property subject to leases. Such arrangements are essentially financing transactions that permit lessees to acquire and use property. The new guidance on leases discussed above did not have a significant impact on the lessor model of accounting. As lessor, the sum of all minimum lease payments over the lease term and the estimated residual value, less unearned interest income, is recorded as the net investment in the lease on the commencement date and is included in loans and leases, net of unearned income in the consolidated balance sheet. 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 on the commencement date and recognized as an adjustment of the yield on the lease. The Company’s portfolio of direct financing and sales-type leases contain remaining terms from 4 to 20 years. Some of these leases contain options to extend the leases for up to 12 months and/or to terminate the lease within one year. These direct financing and sales-type leases typically include a payment structure set at lease inception and do not provide any additional services. Expenses associated with the leased equipment, such as maintenance and insurance, are paid by the lessee directly to third parties. The lease agreement typically contains an option for the purchase of the leased property by the lessee at the end of the lease term at either the property’s residual value or a specified price. In all cases, the Company expects to sell or re-lease the equipment at the end of the lease term. Due to the nature and structure of the Company’s direct financing and sales-type leases, there is no selling profit or loss on these transactions. At a lease’s inception, the Company determines the expected residual value of the leased property at end of the lease term based on the type of equipment leased, location and usage, as well as the contractual return provisions in the lease agreement. Additionally, the Company utilizes multiple market sources of data to establish equipment values and in many cases engages certified appraisers to provide valuation analyses. In order to manage the risk associated with the residual value of its leased assets, lease agreements typically include various provisions designed to protect the value of the leased property, such as contractual equipment maintenance, use and return provisions; remarketing agreements; and lessee guarantees. In a few cases, the Company also obtains third-party guarantees to further manage residual risk in the portfolio. On an annual basis, leased properties with material residual values are reviewed for impairment. The components of the Company’s net investment in leases is as follows: (in thousands) March 31, 2019 Lease payment receivable $ 199,760 Unguaranteed residual assets 22,243 Total net investment in leases $ 222,003 For the three months ended March 31, 2019, interest income for direct financing or sales-type leases totaled $2.0 million . During the three months ended March 31, 2019, there was no profit or loss recognized at the commencement date for direct financing or sales-type leases. Maturities of the Company's lease receivables as of March 31, 2019 is as follows: (in thousands) 2019 $ 23,873 2020 31,495 2021 31,431 2022 28,869 2023 22,414 2024 and thereafter 75,940 Total future minimum lease payments $ 214,022 Less: Imputed interest 14,262 Lease receivables $ 199,760
Leases	LEASES IBERIABANK as Lessee The Company leases certain branch and corporate offices, land and ATM facilities through operating leases with terms ranging from less than one year to 45 years. The Company has no financing leases (formerly capital leases). As discussed in Note 2, Recent Accounting Pronouncements, the Company adopted new guidance for leases on January 1, 2019 which requires that leases, whether classified as operating leases or financing leases, are to be accounted for as the acquisition of a right-of-use asset (ROU asset) and a related lease liability recorded at the present value of the lease payments less any lease incentives. The ROU asset represents the Company’s right to use an underlying asset for the lease term and is included in other assets on the Company’s consolidated balance sheets. The lease liability represents the Company’s obligation to make lease payments and is included in other liabilities in the Company’s consolidated balance sheets. The cost of the lease is recognized on a straight-line basis over the lease term as lease expense. Prior to January 1, 2019, operating leases were not recorded on the balance sheet. See Note 2, Recent Accounting Pronouncements, for further discussion of the adoption of this new guidance. Subsequent to the adoption of ASC 842 on January 1, 2019, the Company reviews new lease and service contracts to determine if the contracts contain an embedded lease. For leases that do not provide an implicit rate, the Company uses the corresponding FHLB Advance rate based on the lease term at commencement in determining the present value of lease payments. For leases with variable lease payments, the present value will be determined using the index at the lease commencement date. Changes in variable rent payments due to subsequent changes in the index or rate do not result in a re-measurement of the ROU asset or lease liability, but are recognized as expense in the period in which they occur. Certain of the Company’s leases contain options to either renew, extend or terminate the lease. As of March 31, 2019, no material extensions or terminations were considered reasonably certain, and as such, were not included in the measurement of the lease liability and ROU asset. The Company also has lease agreements with lease and non-lease components, which are generally accounted for separately. Non-lease components, which primarily consist of common area maintenance (“CAM”), utilities, and janitorial services, are based on the stand-alone price of the services and expensed as incurred. Operating lease expense for the three months ended March 31, 2019 totaled $6.8 million . During the three months ended March 31, 2019, the Company paid $6.7 million for amounts included in the measurement of lease liabilities and $5.2 million to obtain ROU assets. The following summarizes the ROU asset and lease liabilities as of March 31, 2019: (in thousands) March 31, 2019 Right-of-use assets $ 95,581 Total lease liabilities 118,430 Weighted Average Remaining Lease Term 7.4 years Weighted Average Discount Rate 3.4 % Maturities of operating lease liabilities as of March 31, 2019 is as follows: (in thousands) 2019 $ 20,059 2020 25,441 2021 22,038 2022 18,730 2023 12,394 2024 and thereafter 36,015 Total operating lease payments $ 134,677 Less: Imputed interest 16,247 Total lease liabilities $ 118,430 As of March 31, 2019, the Company has not entered into any material leases that have not yet commenced. IBERIABANK as Lessor As a lessor, the Company engages in the leasing of equipment to commercial customers primarily through direct financing and sales-type leases. Direct financing and sales-type leases are similar to other forms of installment lending in that lessors generally do not retain benefits and risks incidental to ownership of the property subject to leases. Such arrangements are essentially financing transactions that permit lessees to acquire and use property. The new guidance on leases discussed above did not have a significant impact on the lessor model of accounting. As lessor, the sum of all minimum lease payments over the lease term and the estimated residual value, less unearned interest income, is recorded as the net investment in the lease on the commencement date and is included in loans and leases, net of unearned income in the consolidated balance sheet. 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 on the commencement date and recognized as an adjustment of the yield on the lease. The Company’s portfolio of direct financing and sales-type leases contain remaining terms from 4 to 20 years. Some of these leases contain options to extend the leases for up to 12 months and/or to terminate the lease within one year. These direct financing and sales-type leases typically include a payment structure set at lease inception and do not provide any additional services. Expenses associated with the leased equipment, such as maintenance and insurance, are paid by the lessee directly to third parties. The lease agreement typically contains an option for the purchase of the leased property by the lessee at the end of the lease term at either the property’s residual value or a specified price. In all cases, the Company expects to sell or re-lease the equipment at the end of the lease term. Due to the nature and structure of the Company’s direct financing and sales-type leases, there is no selling profit or loss on these transactions. At a lease’s inception, the Company determines the expected residual value of the leased property at end of the lease term based on the type of equipment leased, location and usage, as well as the contractual return provisions in the lease agreement. Additionally, the Company utilizes multiple market sources of data to establish equipment values and in many cases engages certified appraisers to provide valuation analyses. In order to manage the risk associated with the residual value of its leased assets, lease agreements typically include various provisions designed to protect the value of the leased property, such as contractual equipment maintenance, use and return provisions; remarketing agreements; and lessee guarantees. In a few cases, the Company also obtains third-party guarantees to further manage residual risk in the portfolio. On an annual basis, leased properties with material residual values are reviewed for impairment. The components of the Company’s net investment in leases is as follows: (in thousands) March 31, 2019 Lease payment receivable $ 199,760 Unguaranteed residual assets 22,243 Total net investment in leases $ 222,003 For the three months ended March 31, 2019, interest income for direct financing or sales-type leases totaled $2.0 million . During the three months ended March 31, 2019, there was no profit or loss recognized at the commencement date for direct financing or sales-type leases. Maturities of the Company's lease receivables as of March 31, 2019 is as follows: (in thousands) 2019 $ 23,873 2020 31,495 2021 31,431 2022 28,869 2023 22,414 2024 and thereafter 75,940 Total future minimum lease payments $ 214,022 Less: Imputed interest 14,262 Lease receivables $ 199,760
Leases	LEASES IBERIABANK as Lessee The Company leases certain branch and corporate offices, land and ATM facilities through operating leases with terms ranging from less than one year to 45 years. The Company has no financing leases (formerly capital leases). As discussed in Note 2, Recent Accounting Pronouncements, the Company adopted new guidance for leases on January 1, 2019 which requires that leases, whether classified as operating leases or financing leases, are to be accounted for as the acquisition of a right-of-use asset (ROU asset) and a related lease liability recorded at the present value of the lease payments less any lease incentives. The ROU asset represents the Company’s right to use an underlying asset for the lease term and is included in other assets on the Company’s consolidated balance sheets. The lease liability represents the Company’s obligation to make lease payments and is included in other liabilities in the Company’s consolidated balance sheets. The cost of the lease is recognized on a straight-line basis over the lease term as lease expense. Prior to January 1, 2019, operating leases were not recorded on the balance sheet. See Note 2, Recent Accounting Pronouncements, for further discussion of the adoption of this new guidance. Subsequent to the adoption of ASC 842 on January 1, 2019, the Company reviews new lease and service contracts to determine if the contracts contain an embedded lease. For leases that do not provide an implicit rate, the Company uses the corresponding FHLB Advance rate based on the lease term at commencement in determining the present value of lease payments. For leases with variable lease payments, the present value will be determined using the index at the lease commencement date. Changes in variable rent payments due to subsequent changes in the index or rate do not result in a re-measurement of the ROU asset or lease liability, but are recognized as expense in the period in which they occur. Certain of the Company’s leases contain options to either renew, extend or terminate the lease. As of March 31, 2019, no material extensions or terminations were considered reasonably certain, and as such, were not included in the measurement of the lease liability and ROU asset. The Company also has lease agreements with lease and non-lease components, which are generally accounted for separately. Non-lease components, which primarily consist of common area maintenance (“CAM”), utilities, and janitorial services, are based on the stand-alone price of the services and expensed as incurred. Operating lease expense for the three months ended March 31, 2019 totaled $6.8 million . During the three months ended March 31, 2019, the Company paid $6.7 million for amounts included in the measurement of lease liabilities and $5.2 million to obtain ROU assets. The following summarizes the ROU asset and lease liabilities as of March 31, 2019: (in thousands) March 31, 2019 Right-of-use assets $ 95,581 Total lease liabilities 118,430 Weighted Average Remaining Lease Term 7.4 years Weighted Average Discount Rate 3.4 % Maturities of operating lease liabilities as of March 31, 2019 is as follows: (in thousands) 2019 $ 20,059 2020 25,441 2021 22,038 2022 18,730 2023 12,394 2024 and thereafter 36,015 Total operating lease payments $ 134,677 Less: Imputed interest 16,247 Total lease liabilities $ 118,430 As of March 31, 2019, the Company has not entered into any material leases that have not yet commenced. IBERIABANK as Lessor As a lessor, the Company engages in the leasing of equipment to commercial customers primarily through direct financing and sales-type leases. Direct financing and sales-type leases are similar to other forms of installment lending in that lessors generally do not retain benefits and risks incidental to ownership of the property subject to leases. Such arrangements are essentially financing transactions that permit lessees to acquire and use property. The new guidance on leases discussed above did not have a significant impact on the lessor model of accounting. As lessor, the sum of all minimum lease payments over the lease term and the estimated residual value, less unearned interest income, is recorded as the net investment in the lease on the commencement date and is included in loans and leases, net of unearned income in the consolidated balance sheet. 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 on the commencement date and recognized as an adjustment of the yield on the lease. The Company’s portfolio of direct financing and sales-type leases contain remaining terms from 4 to 20 years. Some of these leases contain options to extend the leases for up to 12 months and/or to terminate the lease within one year. These direct financing and sales-type leases typically include a payment structure set at lease inception and do not provide any additional services. Expenses associated with the leased equipment, such as maintenance and insurance, are paid by the lessee directly to third parties. The lease agreement typically contains an option for the purchase of the leased property by the lessee at the end of the lease term at either the property’s residual value or a specified price. In all cases, the Company expects to sell or re-lease the equipment at the end of the lease term. Due to the nature and structure of the Company’s direct financing and sales-type leases, there is no selling profit or loss on these transactions. At a lease’s inception, the Company determines the expected residual value of the leased property at end of the lease term based on the type of equipment leased, location and usage, as well as the contractual return provisions in the lease agreement. Additionally, the Company utilizes multiple market sources of data to establish equipment values and in many cases engages certified appraisers to provide valuation analyses. In order to manage the risk associated with the residual value of its leased assets, lease agreements typically include various provisions designed to protect the value of the leased property, such as contractual equipment maintenance, use and return provisions; remarketing agreements; and lessee guarantees. In a few cases, the Company also obtains third-party guarantees to further manage residual risk in the portfolio. On an annual basis, leased properties with material residual values are reviewed for impairment. The components of the Company’s net investment in leases is as follows: (in thousands) March 31, 2019 Lease payment receivable $ 199,760 Unguaranteed residual assets 22,243 Total net investment in leases $ 222,003 For the three months ended March 31, 2019, interest income for direct financing or sales-type leases totaled $2.0 million . During the three months ended March 31, 2019, there was no profit or loss recognized at the commencement date for direct financing or sales-type leases. Maturities of the Company's lease receivables as of March 31, 2019 is as follows: (in thousands) 2019 $ 23,873 2020 31,495 2021 31,431 2022 28,869 2023 22,414 2024 and thereafter 75,940 Total future minimum lease payments $ 214,022 Less: Imputed interest 14,262 Lease receivables $ 199,760

Shareholders' Equity, Capital R

Shareholders' Equity, Capital Ratios and Other Regulatory Matters	3 Months Ended
	Mar. 31, 2019
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, 2019 December 31, 2018 Issuance Date Earliest Redemption Date Annual Dividend Rate Liquidation Amount Carrying Amount Carrying Amount (in thousands) 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 $ 137,500 $ 132,097 $ 132,097 Common Stock In 2018, the Company's Board of Directors authorized the repurchase of up to 2,765,000 shares of IBERIABANK Corporation's outstanding common stock. Stock repurchases under this program will be made from time to time, on the open market or in privately negotiated transactions. The timing of these repurchases will depend on market conditions and other requirements. The share repurchase program does not obligate the Company to repurchase any dollar amount or number of shares, and expires during the fourth quarter of 2020. The program may be extended, modified, suspended, or discontinued at any time. During the first three months of 2019, the Company repurchased 387,921 common shares for approximately $29.9 million at a weighted average cost of $77.19 per share. At March 31, 2019 , the remaining common shares that could be repurchased under the current Board-approved plan was 1,877,079 shares. Subsequent to quarter-end and through May 7, 2019, the Company repurchased 353,200 common shares for approximately $28.2 million . The Company did not repurchase any shares during the quarter ended March 31, 2018. Regulatory Capital The Company and IBERIABANK are subject to various regulatory capital requirements administered by the 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, 2019 , the Company and IBERIABANK met all capital adequacy requirements to which they are subject. As of March 31, 2019 , 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 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. The Company’s and IBERIABANK’s actual capital amounts and ratios as of March 31, 2019 and December 31, 2018 are presented in the following tables: (in thousands) March 31, 2019 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,184,075 4.00 % N/A N/A $ 2,863,388 9.67 % IBERIABANK 1,181,108 4.00 1,476,386 5.00 2,795,498 9.47 Common Equity Tier 1 (CET1) Consolidated $ 1,145,643 4.50 % N/A N/A $ 2,731,291 10.73 % IBERIABANK 1,143,315 4.50 1,651,455 6.50 2,795,498 11.00 Tier 1 Risk-Based Capital Consolidated $ 1,527,524 6.00 % N/A N/A $ 2,863,388 11.25 % IBERIABANK 1,524,420 6.00 2,032,560 8.00 2,795,498 11.00 Total Risk-Based Capital Consolidated $ 2,036,699 8.00 % N/A N/A $ 3,138,835 12.33 % IBERIABANK 2,032,560 8.00 2,540,700 10.00 2,954,445 11.63 December 31, 2018 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,168,343 4.00 % N/A N/A $ 2,812,863 9.63 % IBERIABANK 1,165,537 4.00 1,456,921 5.00 2,733,099 9.38 Common Equity Tier 1 (CET1) Consolidated $ 1,125,405 4.50 % N/A N/A $ 2,680,766 10.72 % IBERIABANK 1,122,712 4.50 1,621,695 6.50 2,733,099 10.95 Tier 1 Risk-Based Capital Consolidated $ 1,500,540 6.00 % N/A N/A $ 2,812,863 11.25 % IBERIABANK 1,496,949 6.00 1,995,932 8.00 2,733,099 10.95 Total Risk-Based Capital Consolidated $ 2,000,720 8.00 % N/A N/A $ 3,084,764 12.33 % IBERIABANK 1,995,932 8.00 2,494,915 10.00 2,888,500 11.58 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, 2019 , the required minimum capital conservation buffer was 2.50% . At March 31, 2019 , the capital conservation buffers of the Company and IBERIABANK were 4.33% and 3.63% , respectively.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2019
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) 2019 2018 Earnings Per Common Share - Basic: Net income $ 100,131 $ 63,621 Less: Preferred stock dividends 3,598 3,598 Less: Dividends and undistributed earnings allocated to unvested restricted shares 933 639 Net income allocated to common shareholders - basic $ 95,600 $ 59,384 Weighted average common shares outstanding 54,177 53,616 Earnings per common share - basic 1.76 1.11 Earnings Per Common Share - Diluted: Earnings allocated to common shareholders - basic $ 95,600 $ 59,384 Adjustment for undistributed earnings allocated to unvested restricted shares (42 ) (18 ) Earnings allocated to common shareholders - diluted $ 95,558 $ 59,366 Weighted average common shares outstanding 54,177 53,616 Dilutive potential common shares 362 351 Weighted average common shares outstanding - diluted 54,539 53,967 Earnings per common share - diluted $ 1.75 $ 1.10 For the three months ended March 31, 2019 , and 2018 , the calculations for basic shares outstanding excluded weighted average shares owned by the RRP of 564,188 and 606,442 , respectively. The effects from the assumed exercises of 155,757 and 156,737 stock options were not included in the computation of diluted earnings per share for the three months ended March 31, 2019 and 2018 , respectively, because they were antidilutive.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	SHARE-BASED COMPENSATION The Company has various types of share-based compensation plans that permit the granting of awards in the form of stock options, restricted stock, restricted share units and phantom stock. These plans are administered by the Compensation Committee of the Board of Directors, which selects persons eligible to receive awards and determines the terms, conditions and other provisions of the awards. At March 31, 2019, awards of 675,556 shares could be made under approved incentive compensation plans. The Company issues shares to fulfill stock option exercises and restricted share units and restricted stock awards vesting from available authorized common shares. At March 31, 2019, the Company believes there are adequate authorized shares to satisfy anticipated stock option exercises and restricted share unit and restricted stock award vesting. Stock option awards The Company issues stock options under various plans to directors, officers and other key employees. The option exercise price cannot be less than the fair value of the underlying common stock as of the date of the option grant and the maximum option term cannot exceed ten years . The following table represents the activity related to stock options during the periods indicated: Number of Shares Weighted Average Exercise Price Outstanding options, December 31, 2017 686,366 $ 58.24 Granted 92,162 82.20 Exercised (21,212 ) 52.10 Forfeited or expired (14,513 ) 65.27 Outstanding options, March 31, 2018 742,803 $ 61.25 Exercisable options, March 31, 2018 519,496 $ 56.53 Outstanding options, December 31, 2018 714,420 $ 61.41 Granted 126,405 70.32 Exercised (19,620 ) 54.44 Forfeited or expired (5,564 ) 69.58 Outstanding options, March 31, 2019 815,641 $ 62.90 Exercisable options, March 31, 2019 563,084 $ 58.22 The Company uses the Black-Scholes option pricing model to estimate the fair value of stock option awards. The following weighted-average assumptions were used for option awards issued during the following periods: For the Three Months Ended March 31, 2019 2018 Expected dividends 2.3 % 1.8 % Expected volatility 24.5 % 24.3 % Risk-free interest rate 2.5 % 2.7 % Expected term (in years) 5.7 5.7 Weighted-average grant-date fair value $ 14.44 $ 18.36 The assumptions above are based on multiple factors, including historical stock option exercise patterns and post-vesting employment termination behaviors, expected future exercise patterns and the expected volatility of the Company’s stock price. The following table represents the compensation expense that is included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to stock options for the following periods: For the Three Months Ended March 31, (in thousands) 2019 2018 Compensation expense related to stock options $ 349 $ 312 Income tax benefit related to stock options 26 23 At March 31, 2019, there was $3.0 million of unrecognized compensation expense related to stock options that is expected to be recognized over a weighted-average period of 3.1 years . Restricted stock awards The Company issues restricted stock under various plans for certain officers and directors. The restricted stock awards may not be sold or otherwise transferred until certain restrictions have lapsed. The holders of the restricted stock receive dividends and have the right to vote the shares. The compensation expense for these awards is determined based on the market price of the Company's common stock at the date of grant applied to the total number of shares granted and is recognized over the vesting period (generally three to five years). As of March 31, 2019 and 2018, unrecognized share-based compensation expense associated with these awards totaled $31.1 million and $39.0 million , respectively. The unrecognized compensation expense related to restricted stock awards at March 31, 2019 is expected to be recognized over a weighted-average period of 1.5 years . Restricted share units The Company issues restricted share units to certain of its executive officers. Restricted share units vest after the end of a three year performance period, based on satisfaction of the market and performance conditions set forth in the restricted share unit agreements. Recipients do not possess voting or investment power over the common stock underlying such units until vesting. The grant date fair value of these restricted share units is the same as the value of the corresponding number of shares of common stock, adjusted for assumptions surrounding the market-based conditions contained in the respective agreements. See Note 1, Summary of Significant Accounting Policies, in the 2018 Annual Report on Form 10-K for the year ended December 31, 2018, for further discussion of restricted share units with market or performance conditions. The following table represents the compensation expense that was included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to restricted stock awards and restricted share units for the periods indicated: For the Three Months Ended March 31, (in thousands) 2019 2018 Compensation expense related to restricted stock awards and restricted share units $ 5,223 $ 4,422 Income tax benefit related to restricted stock awards and restricted share units 1,097 929 The following table represents unvested restricted stock award and restricted share unit activity for the following periods: For the Three Months Ended March 31, 2019 2018 Number of shares at beginning of period 700,628 738,187 Granted 190,726 199,958 Forfeited (8,337 ) (43,405 ) Vested (182,947 ) (115,877 ) Number of shares at end of period 700,070 778,863 Phantom stock awards The Company issues phantom stock awards to certain key officers and employees. The awards are subject to a vesting period of five years and are paid out in cash upon vesting. The amount paid per vesting period is calculated as the number of vested “share equivalents” multiplied by the closing market price of a share of the Company’s common stock on the vesting date. Share equivalents are calculated on the date of grant as the total award’s dollar value divided by the closing market price of a share of the Company’s common stock on the grant date. The following table represents compensation expense recorded for phantom stock based on the number of share equivalents vested at March 31 of the periods indicated and the current market price of the Company’s stock at that time: For the Three Months Ended March 31, (in thousands) 2019 2018 Compensation expense related to phantom stock $ 3,194 $ 2,996 The following table represents phantom stock award activity during the periods indicated: (in thousands) Number of share equivalents (1) Value of share equivalents (2) Balance, December 31, 2017 393,844 $ 30,523 Granted 129,234 10,080 Forfeited share equivalents (24,460 ) 1,908 Vested share equivalents (121,758 ) 10,187 Balance, March 31, 2018 376,860 $ 29,395 Balance, December 31, 2018 353,407 $ 22,717 Granted 161,273 11,565 Forfeited share equivalents (13,680 ) 981 Vested share equivalents (96,995 ) 7,316 Balance, March 31, 2019 404,005 $ 28,971 (1) Number of share equivalents includes all reinvested dividend equivalents for the periods indicated. (2) Except for share equivalents at the beginning of each period, which are based on the value at that time, and vested share payments, which are based on the cash paid at the time of vesting, the value of share equivalents is calculated based on the market price of the Company’s stock at the end of the respective periods. The market price of the Company’s stock was $71.71 and $78.00 on March 31, 2019, and 2018, respectively.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
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, 2019 and December 31, 2018 and their classification within the fair value hierarchy. See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2018, for a description of how fair value measurements are determined. March 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 4,873,778 $ — $ 4,873,778 Mortgage loans held for sale — 128,451 — 128,451 Mortgage loans held for investment, at fair value option — — 550 550 Derivative instruments — 51,086 — 51,086 Total $ — $ 5,053,315 $ 550 $ 5,053,865 Liabilities Derivative instruments $ — $ 16,756 $ — $ 16,756 Total $ — $ 16,756 $ — $ 16,756 December 31, 2018 Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 4,783,579 $ — $ 4,783,579 Mortgage loans held for sale — 107,734 — 107,734 Mortgage loans held for investment, at fair value option — — 3,143 3,143 Derivative instruments — 27,048 — 27,048 Total $ — $ 4,918,361 $ 3,143 $ 4,921,504 Liabilities Derivative instruments $ — $ 22,124 $ — $ 22,124 Total $ — $ 22,124 $ — $ 22,124 During the three months ended March 31, 2019 , there were no transfers between the Level 1 and Level 2 fair value categories. Non-recurring fair value measurements The Company holds certain assets that are measured at fair value, but 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, 2019 and December 31, 2018 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 Annual Report on Form 10-K for the year ended December 31, 2018, for a description of how fair value measurements are determined. March 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 63,145 $ 63,145 OREO, net — — 8,875 8,875 Total $ — $ — $ 72,020 $ 72,020 December 31, 2018 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 65,914 $ 65,914 OREO, net — — 6,433 6,433 Total $ — $ — $ 72,347 $ 72,347 The tables above exclude the initial measurement of assets and liabilities that were acquired as part of business combinations. These assets and liabilities were recorded at their fair value upon acquisition in accordance with U.S. GAAP and were not re-measured during the periods presented unless specifically required by U.S. GAAP. Acquisition date fair values represent either Level 2 fair value measurements (investment securities, deposits, property, and equipment) or Level 3 fair value measurements (loans, core deposit intangible assets, and debt). Refer to Note 3, Acquisition Activity, in the Annual Report on Form 10-K for the year ended December 31, 2018, for further detail. 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, 2019 and December 31, 2018 . 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 continue to be accounted for at fair value at March 31, 2019 and December 31, 2018, 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, 2019 December 31, 2018 (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 $ 128,451 $ 124,410 $ 4,041 $ 107,734 $ 104,345 $ 3,389 Mortgage loans held for investment, at fair value 550 599 (49 ) 3,143 3,595 (452 ) 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, 2019 and 2018. 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) 2019 2018 Fair value option Mortgage loans held for sale, at fair value $ 652 $ (749 ) Mortgage loans held for investment, at fair value 191 (1,142 )

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS The estimated fair value of a financial instrument is the current amount that would be exchanged between willing parties, other than in a forced liquidation. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. ASC Topic 825, Financial Instruments , excludes certain financial instruments and all non-financial instruments from its disclosure requirements. Consequently, the aggregate fair value amounts presented may not necessarily represent the underlying fair value of the Company. 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, and Note 2, Recent Accounting Pronouncements, in the Annual Report on Form 10-K for the year ended December 31, 2018, for a description of how fair value measurements are determined. March 31, 2019 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 4,873,778 $ 4,873,778 $ — $ 4,873,778 $ — Mortgage loans held for sale 128,451 128,451 — 128,451 — Mortgage loans held for investment, at fair value option 550 550 — — 550 Derivative instruments 51,086 51,086 — 51,086 — Financial Liabilities Derivative instruments 16,756 16,756 — 16,756 — Amortized Cost Financial Assets Cash and cash equivalents $ 671,897 $ 671,897 $ 671,897 $ — $ — Securities held to maturity 198,958 200,568 — 200,568 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 22,824,780 22,547,830 — — 22,547,830 Financial Liabilities Deposits 24,092,062 24,086,321 — 24,086,321 — Short-term borrowings 1,106,131 1,106,131 261,131 845,000 — Long-term debt 1,475,455 1,471,292 — — 1,471,292 December 31, 2018 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 4,783,579 $ 4,783,579 $ — $ 4,783,579 $ — Mortgage loans held for sale 107,734 107,734 — 107,734 — Mortgage loans held for investment, at fair value option 3,143 3,143 — — 3,143 Derivative instruments 27,048 27,048 — 27,048 — Financial Liabilities Derivative instruments 22,124 22,124 — 22,124 — Amortized Cost Financial Assets Cash and cash equivalents $ 690,453 $ 690,453 $ 690,453 $ — $ — Securities held to maturity 207,446 204,277 — 204,277 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 22,376,101 22,088,236 — — 22,088,236 Financial Liabilities Deposits 23,763,431 23,752,139 — 23,752,139 — Short-term borrowings 1,482,882 1,482,882 315,882 1,167,000 — Long-term debt 1,166,151 1,154,062 — — 1,154,062 The fair value estimates presented herein are based upon pertinent information available to management as of March 31, 2019 and December 31, 2018 . 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, 2019
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, 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 income — — 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 (loss) before income tax expense 128,962 1,295 220 130,477 Income tax expense (benefit) 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 Three Months Ended March 31, 2018 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 268,775 $ 1,767 $ 1 $ 270,543 Interest expense 37,654 — — 37,654 Net interest income 231,121 1,767 1 232,889 Provision for (reversal of) credit losses 8,216 (5 ) — 8,211 Mortgage income — 9,595 — 9,595 Title income — — 5,027 5,027 Other non-interest income (expense) 29,906 38 — 29,944 Allocated expenses (income) (1,479 ) 1,166 313 — Non-interest expense 171,591 11,916 4,564 188,071 Income (loss) before income tax expense 82,699 (1,677 ) 151 81,173 Income tax expense (benefit) 18,540 (410 ) (578 ) 17,552 Net income (loss) $ 64,159 $ (1,267 ) $ 729 $ 63,621 Total loans, leases, and loans held for sale, net of unearned income $ 21,652,223 $ 164,215 $ — $ 21,816,438 Total assets 29,243,983 205,497 23,157 29,472,637 Total deposits 22,959,061 12,131 — 22,971,192 Average assets 27,924,587 185,742 21,890 28,132,219

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
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, 2019 and December 31, 2018, the fair value of guarantees under commercial and standby letters of credit was $2.4 million . This fair value will decrease as the existing commercial and standby letters of credit approach their expiration dates. At March 31, 2019 and December 31, 2018, respectively, the Company had the following financial instruments outstanding and related reserves, whose contract amounts represent credit risk: (in thousands) March 31, 2019 December 31, 2018 Commitments to extend credit $ 760,056 $ 642,162 Unfunded commitments under lines of credit 7,003,670 6,883,963 Commercial and standby letters of credit 241,516 240,436 Reserve for unfunded lending commitments 15,981 14,830 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 represent 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 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 has appealed that decision to the United States Court of Appeals for the Fifth Circuit. The appeal seeks reversal of the summary judgment such that the case can be remanded to the district court in an effort to recover the $11.7 million we are suing to recover. 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 position, consolidated results of operations, or consolidated cash flows. However, it is possible that the ultimate resolution of these matters, if unfavorable, may be material to the Company’s consolidated financial position, consolidated results of operations, or consolidated cash flows. As of the date of this filing, the Company believes the amount of losses associated with legal proceedings that it is reasonably possible to incur above amounts already accrued and reported as of March 31, 2019 is not material.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2019
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, 2019 and December 31, 2018. There were no outstanding loans to such related parties classified as non-accrual, past due, or troubled debt restructurings at March 31, 2019. Deposits from related parties held by the Company were not material at March 31, 2019 and December 31, 2018.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS On April 4, 2019, the Company issued and sold an aggregate of 4,000,000 depositary shares (the “Series D Depositary Shares”), each representing a 1/400th ownership interest in a share of the Company’s 6.100% Fixed-to-Floating Non-Cumulative Perpetual Preferred Stock, Series D, par value $1.00 per share, (“Series D Preferred Stock”), with a liquidation preference of $10,000 per share of Series D Preferred Stock (equivalent to $25 per depositary share), which represents $100 million in aggregate liquidation preference. Dividends will accrue and be payable on the Series D Preferred Stock, if declared by the Company's Board of Directors, and will be paid semi-annually on May 1 and November 1, in arrears, at an annual rate equal to (i) 6.100% for each period from the issuance date to May 1, 2024 and (ii) three-month LIBOR plus 3.859% for each period on or after August 1, 2024. The Company may redeem the Series D Preferred Stock at its option, subject to regulatory approval, as described in the Company’s Registration Statement on Form 8-A, filed with the Securities and Exchange Commission on April 4, 2019.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2019
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.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Pronouncements adopted during the three months ended March 31, 2019: ASU No. 2016-02, ASU No. 2018-11, ASU No. 2018-20, and ASU 2019-01 In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842) which requires lessees to recognize ROU assets and lease liabilities on the balance sheet for most leases, including operating leases. The lessor accounting model was relatively unchanged by this ASU. Additional quantitative and qualitative disclosures are also required. During 2018 and early 2019, the FASB issued ASU No. 2018-11, Targeted Improvements , ASU No. 2018-20, Narrow-Scope Improvements for Lessors , and ASU No. 2019-01, Codification Improvements , which clarified certain implementation issues, provided an additional optional transition method and clarified the disclosure requirements during the period of adopting ASC 842, among others. The Company adopted ASU No. 2016-02 and the related ASUs discussed above effective January 1, 2019 using the optional transition method. The Company elected the package of practical expedients that does not require the reassessment of whether expired or existing contracts contain leases, the reassessment of the lease classification for any expired or existing leases, or the reassessment of initial direct costs for existing leases. Additionally, the Company did not elect the hindsight practical expedient. The Company conducted a review of all existing lease contracts and service contracts which might contain embedded leases. Some of the Company’s leases contain variable lease payments, the majority of which depend on an index or rate, such as the Consumer Price Index. At transition, the present value of variable payments was based on the index or rate as of January 1, 2019. To determine the present value of lease payments at transition, the Company applied a portfolio approach utilizing an FHLB Advance rate based on the weighted average remaining term of the Company’s existing leases as of January 1, 2019. As a result of adopting ASC 842, the Company established an ROU asset and a lease liability as of January 1, 2019 of $94.2 million and $118.9 million , respectively. Additionally, as part of the adoption of ASC 842, $24.7 million in pre-existing liabilities were reclassified to the ROU asset on January 1, 2019. This resulted in a gross-up of the balance sheet of $94.2 million as a result of recognizing lease liabilities and corresponding right-of-use assets for operating leases. The adoption of ASC 842 also required the recognition of previously deferred gains on sale-leaseback transactions which resulted in an insignificant increase to retained earnings on January 1, 2019. The related impact on the Company’s regulatory capital ratios was not significant. The Company does not expect material changes to the recognition of lease expense in future periods as a result of the adoption of ASC 842. See Note 8, Leases, for additional disclosures required by ASC 842. ASU No. 2018-16 In October 2018, the FASB released ASU No. 2018-16, Derivatives and Hedging (ASC 815): Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes , which permits the use of the OIS rate based on SOFR as a U.S. benchmark interest rate for hedge accounting purposes under ASC 815 in addition to the interest rates on direct Treasury obligations of the UST, the LIBOR swap rate, the OIS Rate based on the Fed Funds Effective Rate, and the SIFMA Municipal Swap Rate. The required effective date of this ASU was dependent upon when an entity adopted the provisions of ASU No. 2017-12. The Company adopted ASU No. 2018-16 effective January 1, 2019 on a prospective basis for qualifying new or redesignated hedging relations as ASU No. 2017-12 had previously been adopted on January 1, 2018. The implementation of this ASU did not have a significant impact on the Company’s consolidated financial statements. ASU No. 2017-08 In March 2017, the FASB issued ASU No. 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities, which will shorten the amortization period for callable debt securities held at a premium to the earliest call date instead of the maturity date. The amendments do not require an accounting change for securities held at a discount, which will continue to be amortized to the maturity date. The Company adopted ASU No. 2017-08 effective January 1, 2019. 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. 2016-13 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 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 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. The ASU also 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 through the use of an allowance to record estimated credit losses (and subsequent recoveries). Non-credit related losses will continue to be recognized through OCI. In addition, the guidance provides for a simplified accounting model for purchased financial assets with a more-than-insignificant amount of credit deterioration since their origination. The initial estimate of expected credit losses would be recognized through an ALLL with an offset (i.e., increase) to the cost basis of the related financial asset at acquisition. ASU No. 2016-13 will be effective for fiscal years beginning after December 15, 2019, including interim periods. The ASU will be applied through a modified-retrospective approach, resulting in a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. A prospective transition approach is required for debt securities for which OTTI had been recognized before the effective date. Amounts previously recognized in AOCI as of the date of adoption that relate to improvements in cash flows expected to be collected should continue to be accreted into income over the remaining life of the asset. Recoveries of amounts previously written off relating to improvements in cash flows after the date of adoption should be recorded in earnings when received. The Company has established a cross-function implementation team and engaged third-party consultants who have jointly developed a project plan to provide implementation oversight. The Company is in the process of developing and implementing current expected credit loss models that satisfy the requirements of the ASU and continues to identify key interpretive issues. The Company expects that this ASU will result in an increase to ALLL given the change to estimate losses over the full remaining estimated life of the loan portfolio as well as the adoption of an allowance for debt securities. The extent of the increase in the ALLL is not yet known and will depend on the composition of our loan and securities portfolios, finalization of credit loss models, macroeconomic conditions and forecasts at the adoption date. 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 will be effective for fiscal years beginning after December 15, 2019, including interim periods, with early adoption permitted. The Company is currently evaluating the impact of the ASU. While adoption of this ASU will result in changes to existing disclosures, it will not have any impact on our financial position or results of operation. 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 will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. The guidance should be applied retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Company is currently evaluating the impact of the ASU on the Company’s consolidated financial statements. 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. ASU No. 2019-04 clarifies the scope of the credit losses standard and addresses various issues including, accrued interest receivable balances, recoveries, variable interest rates and prepayments. 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 remeasurement under ASC 820 when using the measurement alternative, certain disclosure requirements and which equity securities have to be remeasured at historical exchange rates. The amended guidance in this ASU related to the credit losses and the recognition and measurement of financial instruments will be effective for fiscal years and interim periods beginning after December 15, 2019 with early adoption in any interim period permitted. Since the Company early adopted the guidance in ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities in 2018, the amended hedge accounting guidance in ASU No. 2019-04 will be 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 is currently evaluating the impact of the ASU on the Company’s consolidated financial statements.

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities	The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following: March 31, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 40,822 $ 130 $ — $ 40,952 Obligations of state and political subdivisions 175,271 4,740 (32 ) 179,979 Mortgage-backed securities: Residential agency 3,757,469 16,972 (29,763 ) 3,744,678 Commercial agency 779,487 6,656 (7,716 ) 778,427 Other securities 128,380 1,876 (514 ) 129,742 Total securities available for sale $ 4,881,429 $ 30,374 $ (38,025 ) $ 4,873,778 Securities held to maturity: Obligations of state and political subdivisions $ 180,472 $ 2,365 $ (42 ) $ 182,795 Mortgage-backed securities: Residential agency 18,486 29 (742 ) 17,773 Total securities held to maturity $ 198,958 $ 2,394 $ (784 ) $ 200,568 December 31, 2018 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 995 $ 3 $ — $ 998 Obligations of state and political subdivisions 177,566 2,045 (723 ) 178,888 Mortgage-backed securities: Residential agency 3,837,584 8,886 (57,073 ) 3,789,397 Commercial agency 730,148 2,363 (14,799 ) 717,712 Other securities 97,020 351 (787 ) 96,584 Total securities available for sale $ 4,843,313 $ 13,648 $ (73,382 ) $ 4,783,579 Securities held to maturity: Obligations of state and political subdivisions $ 188,684 $ 309 $ (2,497 ) $ 186,496 Mortgage-backed securities: Residential agency 18,762 30 (1,011 ) 17,781 Total securities held to maturity $ 207,446 $ 339 $ (3,508 ) $ 204,277 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, is as follows: March 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 $ — $ — $ (32 ) $ 11,925 $ (32 ) $ 11,925 Mortgage-backed securities: Residential agency (71 ) 40,608 (29,692 ) 2,081,552 (29,763 ) 2,122,160 Commercial agency (5 ) 7,001 (7,711 ) 434,500 (7,716 ) 441,501 Other securities (4 ) 4,382 (510 ) 33,543 (514 ) 37,925 Total securities available for sale $ (80 ) $ 51,991 $ (37,945 ) $ 2,561,520 $ (38,025 ) $ 2,613,511 Securities held to maturity: Obligations of state and political subdivisions $ — $ — $ (42 ) $ 13,160 $ (42 ) $ 13,160 Mortgage-backed securities: Residential agency — — (742 ) 17,480 (742 ) 17,480 Total securities held to maturity $ — $ — $ (784 ) $ 30,640 $ (784 ) $ 30,640 December 31, 2018 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 $ (9 ) $ 4,112 $ (714 ) $ 30,268 $ (723 ) $ 34,380 Mortgage-backed securities: Residential agency (816 ) 197,057 (56,257 ) 2,193,862 (57,073 ) 2,390,919 Commercial agency (43 ) 18,190 (14,756 ) 483,565 (14,799 ) 501,755 Other securities (94 ) 18,025 (693 ) 32,577 (787 ) 50,602 Total securities available for sale $ (962 ) $ 237,384 $ (72,420 ) $ 2,740,272 $ (73,382 ) $ 2,977,656 Securities held to maturity: Obligations of state and political subdivisions $ (3 ) $ 2,059 $ (2,494 ) $ 151,699 $ (2,497 ) $ 153,758 Mortgage-backed securities: Residential agency — — (1,011 ) 17,478 (1,011 ) 17,478 Total securities held to maturity $ (3 ) $ 2,059 $ (3,505 ) $ 169,177 $ (3,508 ) $ 171,236
Held-to-maturity Securities	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, is as follows: March 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 $ — $ — $ (32 ) $ 11,925 $ (32 ) $ 11,925 Mortgage-backed securities: Residential agency (71 ) 40,608 (29,692 ) 2,081,552 (29,763 ) 2,122,160 Commercial agency (5 ) 7,001 (7,711 ) 434,500 (7,716 ) 441,501 Other securities (4 ) 4,382 (510 ) 33,543 (514 ) 37,925 Total securities available for sale $ (80 ) $ 51,991 $ (37,945 ) $ 2,561,520 $ (38,025 ) $ 2,613,511 Securities held to maturity: Obligations of state and political subdivisions $ — $ — $ (42 ) $ 13,160 $ (42 ) $ 13,160 Mortgage-backed securities: Residential agency — — (742 ) 17,480 (742 ) 17,480 Total securities held to maturity $ — $ — $ (784 ) $ 30,640 $ (784 ) $ 30,640 December 31, 2018 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 $ (9 ) $ 4,112 $ (714 ) $ 30,268 $ (723 ) $ 34,380 Mortgage-backed securities: Residential agency (816 ) 197,057 (56,257 ) 2,193,862 (57,073 ) 2,390,919 Commercial agency (43 ) 18,190 (14,756 ) 483,565 (14,799 ) 501,755 Other securities (94 ) 18,025 (693 ) 32,577 (787 ) 50,602 Total securities available for sale $ (962 ) $ 237,384 $ (72,420 ) $ 2,740,272 $ (73,382 ) $ 2,977,656 Securities held to maturity: Obligations of state and political subdivisions $ (3 ) $ 2,059 $ (2,494 ) $ 151,699 $ (2,497 ) $ 153,758 Mortgage-backed securities: Residential agency — — (1,011 ) 17,478 (1,011 ) 17,478 Total securities held to maturity $ (3 ) $ 2,059 $ (3,505 ) $ 169,177 $ (3,508 ) $ 171,236 The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following: March 31, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 40,822 $ 130 $ — $ 40,952 Obligations of state and political subdivisions 175,271 4,740 (32 ) 179,979 Mortgage-backed securities: Residential agency 3,757,469 16,972 (29,763 ) 3,744,678 Commercial agency 779,487 6,656 (7,716 ) 778,427 Other securities 128,380 1,876 (514 ) 129,742 Total securities available for sale $ 4,881,429 $ 30,374 $ (38,025 ) $ 4,873,778 Securities held to maturity: Obligations of state and political subdivisions $ 180,472 $ 2,365 $ (42 ) $ 182,795 Mortgage-backed securities: Residential agency 18,486 29 (742 ) 17,773 Total securities held to maturity $ 198,958 $ 2,394 $ (784 ) $ 200,568 December 31, 2018 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 995 $ 3 $ — $ 998 Obligations of state and political subdivisions 177,566 2,045 (723 ) 178,888 Mortgage-backed securities: Residential agency 3,837,584 8,886 (57,073 ) 3,789,397 Commercial agency 730,148 2,363 (14,799 ) 717,712 Other securities 97,020 351 (787 ) 96,584 Total securities available for sale $ 4,843,313 $ 13,648 $ (73,382 ) $ 4,783,579 Securities held to maturity: Obligations of state and political subdivisions $ 188,684 $ 309 $ (2,497 ) $ 186,496 Mortgage-backed securities: Residential agency 18,762 30 (1,011 ) 17,781 Total securities held to maturity $ 207,446 $ 339 $ (3,508 ) $ 204,277
Additional Information on Securities in a Continuous Loss Position	Additional information on securities that have been in a continuous loss position for over twelve months at March 31, 2019 and December 31, 2018 is presented in the following table. (in thousands) March 31, 2019 December 31, 2018 Number of securities Mortgage-backed securities: Residential agency 289 302 Commercial agency 65 72 Obligations of state and political subdivisions 17 60 Other securities 8 7 379 441 Amortized Cost Basis Mortgage-backed securities: Residential agency $ 2,129,466 $ 2,268,608 Commercial agency 442,211 498,321 Obligations of state and political subdivisions 25,159 185,175 Other securities 34,053 33,270 $ 2,630,889 $ 2,985,374 Unrealized Loss Mortgage-backed securities: Residential agency $ 30,434 $ 57,268 Commercial agency 7,711 14,756 Obligations of state and political subdivisions 74 3,208 Other securities 510 693 $ 38,729 $ 75,925
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, 2019 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 3.86 % $ 2,536 $ 2,542 2.33 % $ 955 $ 959 One through five years 2.66 113,924 114,533 2.42 6,100 6,114 After five through ten years 2.71 863,166 867,609 2.58 42,885 43,419 Over ten years 2.97 3,901,803 3,889,094 2.63 149,018 150,076 2.92 % $ 4,881,429 $ 4,873,778 2.61 % $ 198,958 $ 200,568
Schedule of Realized Gains and Losses from Sale of Securities Classified as Available for Sale	The following is a summary of realized gains and losses from the 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. Three Months Ended March 31, (in thousands) 2019 2018 Realized gains $ — $ 9 Realized losses — (68 ) $ — $ (59 )
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, are as follows: (in thousands) March 31, 2019 December 31, 2018 Federal Home Loan Bank stock $ 107,122 $ 95,213 Federal Reserve Bank stock 85,630 85,630 CRA and Community Development Investment Funds 1,914 1,884 Other investments 13,864 9,709 $ 208,530 $ 192,436

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Schedule of Non-Covered and Covered Loans	Loans and leases by portfolio segment and class consist of the following for the periods indicated: (in thousands) March 31, 2019 December 31, 2018 Commercial loans and leases: Real estate - construction $ 1,219,647 $ 1,196,366 Real estate - owner-occupied 2,408,079 2,395,822 Real estate - non-owner-occupied 6,147,864 5,796,117 Commercial and industrial (1) 5,852,568 5,737,017 Total commercial loans and leases 15,628,158 15,125,322 Residential mortgage loans 4,415,267 4,359,156 Consumer and other loans: Home equity 2,220,648 2,304,694 Other 704,222 730,643 Total consumer and other loans 2,924,870 3,035,337 Total loans and leases $ 22,968,295 $ 22,519,815 (1) Includes equipment financing leases Net deferred loan origination fees were $30.8 million and $30.2 million at March 31, 2019 and December 31, 2018 , respectively. Total net discount on the Company's loans was $130.1 million and $136.8 million at March 31, 2019 and December 31, 2018 , respectively, of which $79.0 million and $81.6 million was related to non-impaired loans. 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, 2019 and December 31, 2018 , overdrafts of $6.4 million and $9.2 million , respectively, have been reclassified to loans. Loans with carrying values of $7.8 billion and $7.6 billion were pledged as collateral for borrowings at March 31, 2019 and December 31, 2018 , respectively.
Schedule of Aging of Loans	The following tables provide an analysis of the aging of loans and leases as of March 31, 2019 and December 31, 2018 . Past due and non-accrual loan amounts exclude acquired impaired loans, even if contractually past due or if the Company does not expect to receive payment in full, as the Company is currently accreting interest income over the expected life of the loans. For additional information on the determination of past due status and the Company's policies for recording payments received, placing loans and leases on non-accrual status, and the resumption of interest accrual on non-accruing loans and leases, see Note 1, Summary of Significant Accounting Policies, in the 2018 10-K. March 31, 2019 Accruing (in thousands) Current or Less Than 30 days Past Due 30-59 days 60-89 days > 90 days Total Past Due Non-accrual (1) Acquired Impaired Total Real estate- construction $ 1,197,063 $ 305 $ — $ — $ 305 $ 1,072 $ 21,207 $ 1,219,647 Real estate- owner-occupied 2,324,441 2,510 67 3,139 5,716 8,630 69,292 2,408,079 Real estate- non-owner-occupied 6,054,340 2,213 91 863 3,167 19,984 70,373 6,147,864 Commercial and industrial 5,766,811 8,881 725 109 9,715 51,447 24,595 5,852,568 Residential mortgage 4,269,617 10,884 4,756 — 15,640 45,473 84,537 4,415,267 Consumer - home equity 2,134,340 9,511 2,178 — 11,689 18,719 55,900 2,220,648 Consumer - other 695,940 2,303 910 — 3,213 2,731 2,338 704,222 Total $ 22,442,552 $ 36,607 $ 8,727 $ 4,111 $ 49,445 $ 148,056 $ 328,242 $ 22,968,295 (1) Of the total non-accrual loans at March 31, 2019 , $9.0 million were past due 30-59 days, $4.6 million were past due 60-89 days, and $53.7 million were past due more than 90 days. December 31, 2018 Accruing (in thousands) Current or Less Than 30 days Past Due 30-59 days 60-89 days > 90 days Total Past Due Non-accrual (1) Acquired Impaired Total Real estate- construction $ 1,167,795 $ 1,054 $ — $ — $ 1,054 $ 1,094 $ 26,423 $ 1,196,366 Real estate- owner-occupied 2,305,743 7,167 — — 7,167 10,260 72,652 2,395,822 Real estate- non-owner-occupied 5,703,131 7,473 360 — 7,833 15,898 69,255 5,796,117 Commercial and industrial 5,645,304 5,139 1,320 553 7,012 57,860 26,841 5,737,017 Residential mortgage 4,218,146 2,768 13,063 1,575 17,406 30,396 93,208 4,359,156 Consumer - home equity 2,200,517 10,283 2,409 — 12,692 18,830 72,655 2,304,694 Consumer - other 719,122 4,695 1,601 — 6,296 2,846 2,379 730,643 Total $ 21,959,758 $ 38,579 $ 18,753 $ 2,128 $ 59,460 $ 137,184 $ 363,413 $ 22,519,815 (1) Of the total non-accrual loans at December 31, 2018 , $7.0 million were past due 30-59 days, $3.7 million were past due 60-89 days, and $66.9 million were past due more than 90 days.
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 : (in thousands) 2019 2018 Balance at beginning of period $ 133,342 $ 152,623 Additions — 2,371 Transfers from non-accretable difference to accretable yield (3,640 ) (279 ) Accretion (10,086 ) (13,154 ) Changes in expected cash flows not affecting non-accretable differences (1) (272 ) 9,687 Balance at end of period $ 119,344 $ 151,248 (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) 2019 2018 Extended maturities $ 9,014 $ 5,619 Maturity and interest rate adjustment 468 108 Movement to or extension of interest-rate only payments 12 48 Interest rate adjustment — 105 Forbearance 6,510 12,886 Other concession(s) (1) 15,425 8,434 Total $ 31,429 $ 27,200 (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, 2019 2018 (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 $ 39 $ 39 1 $ 1,950 $ 1,049 Real estate- owner-occupied 4 6,904 4,661 2 10,691 9,324 Real estate- non-owner-occupied 7 2,990 2,968 9 1,089 1,091 Commercial and industrial 23 17,382 17,040 18 14,429 13,314 Residential mortgage 10 1,741 1,738 — — — Consumer - home equity 33 4,277 4,233 14 1,809 1,795 Consumer - other 38 787 750 21 648 627 Total 116 $ 34,120 $ 31,429 65 $ 30,616 $ 27,200 Information detailing TDRs that defaulted during the three-month periods ended March 31, 2019 and 2018 , 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, 2019 2018 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 939 — $ — Real estate- owner-occupied 3 640 3 10,187 Real estate- non-owner-occupied 7 825 9 492 Commercial and industrial 10 3,933 29 9,708 Residential mortgage 13 1,108 6 598 Consumer - home equity 16 2,891 24 2,331 Consumer - other 20 261 51 1,357 Total 70 $ 10,597 122 $ 24,673

Allowance for Credit Losses a_2

Allowance for Credit Losses and Credit Quality (Tables)	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Schedule of Allowance for Loan Losses for Covered and Non-Covered Loan Portfolios	A summary of changes in the allowance for credit losses for the three months ended March 31 is as follows: (in thousands) 2019 2018 Allowance for loan and lease losses at beginning of period $ 140,571 $ 140,891 Provision for loan and lease losses 12,612 7,987 Transfer of balance to OREO and other (2,885 ) (48 ) Charge-offs (8,918 ) (9,116 ) Recoveries 1,586 4,813 Allowance for loan and lease losses at end of period $ 142,966 $ 144,527 Reserve for unfunded commitments at beginning of period $ 14,830 $ 13,208 Provision for unfunded lending commitments 1,151 224 Reserve for unfunded commitments at end of period $ 15,981 $ 13,432 Allowance for credit losses at end of period $ 158,947 $ 157,959 A summary of changes in the allowance for credit losses, by loan portfolio type, for the three months ended March 31 is as follows: 2019 (in thousands) Commercial Real Estate Commercial and Industrial Residential Mortgage Consumer and Other Total Allowance for loan and lease losses at beginning of period $ 51,806 $ 54,096 $ 12,998 $ 21,671 $ 140,571 Provision for loan and lease losses 6,887 2,876 1,749 1,100 12,612 Transfer of balance to OREO and other — — (2,881 ) (4 ) (2,885 ) Charge-offs (72 ) (4,931 ) (28 ) (3,887 ) (8,918 ) Recoveries 103 446 32 1,005 1,586 Allowance for loan and lease losses at end of period $ 58,724 $ 52,487 $ 11,870 $ 19,885 $ 142,966 Reserve for unfunded commitments at beginning of period $ 4,869 $ 6,198 $ 866 $ 2,897 $ 14,830 Provision for unfunded commitments 794 128 22 207 1,151 Reserve for unfunded commitments at end of period $ 5,663 $ 6,326 $ 888 $ 3,104 $ 15,981 Allowance on loans individually evaluated for impairment $ 3,078 $ 10,988 $ 258 $ 2,624 $ 16,948 Allowance on loans collectively evaluated for impairment 50,210 39,997 7,404 17,087 114,698 Allowance on loans acquired with deteriorated credit quality 5,436 1,502 4,208 174 11,320 Loans and leases, net of unearned income: Balance at end of period $ 9,775,590 $ 5,852,568 $ 4,415,267 $ 2,924,870 $ 22,968,295 Balance at end of period individually evaluated for impairment 67,909 63,889 7,679 35,835 175,312 Balance at end of period collectively evaluated for impairment 9,546,809 5,764,084 4,323,051 2,830,797 22,464,741 Balance at end of period acquired with deteriorated credit quality 160,872 24,595 84,537 58,238 328,242 2018 (in thousands) Commercial Real Estate Commercial and Industrial Residential Mortgage Consumer and Other Total Allowance for loan losses at beginning of period $ 54,201 $ 53,916 $ 9,117 $ 23,657 $ 140,891 Provision for (Reversal of) loan and lease losses 6,378 294 (686 ) 2,001 7,987 Transfer of balance to OREO and other (48 ) — — — (48 ) Charge-offs (114 ) (5,378 ) (105 ) (3,519 ) (9,116 ) Recoveries 191 3,698 22 902 4,813 Allowance for loan losses at end of period $ 60,608 $ 52,530 $ 8,348 $ 23,041 $ 144,527 Reserve for unfunded commitments at beginning of period $ 4,531 $ 5,309 $ 555 $ 2,813 $ 13,208 Provision for (Reversal of) unfunded commitments 1,476 (1,004 ) (15 ) (233 ) 224 Reserve for unfunded commitments at end of period $ 6,007 $ 4,305 $ 540 $ 2,580 $ 13,432 Allowance on loans individually evaluated for impairment $ 2,506 $ 14,040 $ 178 $ 2,974 $ 19,698 Allowance on loans collectively evaluated for impairment 35,871 36,208 2,073 16,544 90,696 Allowance on loans acquired with deteriorated credit quality 22,231 2,282 6,097 3,523 34,133 Loans, net of unearned income: Balance at end of period $ 9,248,951 $ 5,325,682 $ 3,971,067 $ 3,160,390 $ 21,706,090 Balance at end of period individually evaluated for impairment 78,489 78,725 6,041 33,277 196,532 Balance at end of period collectively evaluated for impairment 8,946,138 5,211,736 3,826,721 3,043,085 21,027,680 Balance at end of period acquired with deteriorated credit quality 224,324 35,221 138,305 84,028 481,878
Investment in Legacy and Acquired Loans by Credit Quality Indicator	The recorded investment in loans and leases by credit quality indicator is presented in the following tables. Asset risk classifications for commercial loans and leases reflect the classification as of March 31, 2019 and December 31, 2018 . Credit quality information in the tables below includes total loans acquired (including acquired impaired loans) at the net loan balance, after the application of premiums and discounts. Loan premiums and discounts represent the adjustment of acquired loans to fair value at the acquisition date, as adjusted for income accretion and changes in cash flow estimates in subsequent periods. March 31, 2019 December 31, 2018 (in thousands) Pass Special Mention Sub- Doubtful Total Pass Special Mention Sub- Doubtful Total Real estate - construction $ 1,213,202 $ 147 $ 6,289 $ 9 $ 1,219,647 $ 1,182,554 $ 1,062 $ 12,740 $ 10 $ 1,196,366 Real estate - owner-occupied 2,332,819 33,359 41,087 814 2,408,079 2,328,999 25,526 41,297 — 2,395,822 Real estate - non-owner-occupied 6,028,301 82,839 34,015 2,709 6,147,864 5,687,963 78,009 26,512 3,633 5,796,117 Commercial and industrial 5,696,564 46,384 87,385 22,235 5,852,568 5,586,482 52,632 73,853 24,050 5,737,017 Total $ 15,270,886 $ 162,729 $ 168,776 $ 25,767 $ 15,628,158 $ 14,785,998 $ 157,229 $ 154,402 $ 27,693 $ 15,125,322 March 31, 2019 December 31, 2018 (in thousands) Current 30+ Days Past Due Total Current 30+ Days Past Due Total Residential mortgage $ 4,335,779 $ 79,488 $ 4,415,267 $ 4,290,152 $ 69,004 $ 4,359,156 Consumer - home equity 2,184,204 36,444 2,220,648 2,258,659 46,035 2,304,694 Consumer - other 698,074 6,148 704,222 721,231 9,412 730,643 Total $ 7,218,057 $ 122,080 $ 7,340,137 $ 7,270,042 $ 124,451 $ 7,394,493
Schedule of Investment in Legacy Impaired Loans	Information on the Company’s investment in impaired loans, which include all TDRs and all other non-accrual loans evaluated or measured individually for impairment for purposes of determining the ALLL, is presented in the following tables as of and for the periods indicated. March 31, 2019 December 31, 2018 Unpaid Principal Balance Recorded Investment Related Allowance Unpaid Principal Balance Recorded Investment Related Allowance (in thousands) With no related allowance recorded: Real estate - construction $ 12,138 $ 11,139 $ — $ 10,261 $ 9,262 $ — Real estate - owner-occupied 33,670 27,732 — 25,037 19,044 — Real estate - non-owner-occupied 12,352 11,515 — 15,265 14,288 — Commercial and industrial 52,821 32,380 — 55,554 43,886 — Residential mortgage 1,456 1,456 — 1,244 1,221 — Consumer - home equity 1,783 1,783 — 4,183 4,176 — Consumer - other — — — — — — With an allowance recorded: Real estate - construction 224 134 (11 ) 228 140 (11 ) Real estate - owner-occupied 5,553 5,393 (613 ) 5,032 4,773 (520 ) Real estate - non-owner-occupied 12,113 11,996 (2,454 ) 6,445 6,398 (105 ) Commercial and industrial 36,243 31,509 (10,988 ) 46,387 27,915 (12,646 ) Residential mortgage 6,745 6,223 (258 ) 5,870 5,358 (145 ) Consumer - home equity 30,847 29,861 (2,132 ) 29,284 28,818 (2,427 ) Consumer - other 4,574 4,191 (492 ) 4,956 4,446 (488 ) Total $ 210,519 $ 175,312 $ (16,948 ) $ 209,746 $ 169,725 $ (16,342 ) Total commercial loans and leases $ 165,114 $ 131,798 $ (14,066 ) $ 164,209 $ 125,706 $ (13,282 ) Total residential mortgage loans 8,201 7,679 (258 ) 7,114 6,579 (145 ) Total consumer and other loans 37,204 35,835 (2,624 ) 38,423 37,440 (2,915 ) Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 Average Interest Average Interest (in thousands) With no related allowance recorded: Real estate - construction $ 11,142 $ 169 $ 10,470 $ 144 Real estate - owner-occupied 27,865 301 36,277 334 Real estate - non-owner-occupied 11,566 69 10,557 98 Commercial and industrial 37,185 461 27,832 385 Residential mortgage 1,463 17 1,090 12 Consumer - home equity 1,204 10 32 — With an allowance recorded: Real estate - construction 136 — 153 1 Real estate - owner-occupied 5,433 8 17,608 112 Real estate - non-owner-occupied 12,042 79 3,302 10 Commercial and industrial 28,624 202 44,056 196 Residential mortgage 6,274 59 4,974 44 Consumer - home equity 30,345 292 28,203 292 Consumer - other 4,314 58 5,200 67 Total $ 177,593 $ 1,725 $ 189,754 $ 1,695 Total commercial loans and leases $ 133,993 $ 1,289 $ 150,255 $ 1,280 Total residential mortgage loans 7,737 76 6,064 56 Total consumer and other loans 35,863 360 33,435 359

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Carrying Amount of Goodwill	Changes to the carrying amount of goodwill by reporting unit for the three months ended March 31, 2019, and the year ended December 31, 2018 are provided in the following table: (in thousands) IBERIABANK Mortgage LTC Total Balance, December 31, 2017 $ 1,160,559 $ 23,178 $ 5,165 $ 1,188,902 Goodwill acquired and adjustments during the year 43,251 — 3,380 46,631 Balance, December 31, 2018 $ 1,203,810 $ 23,178 $ 8,545 $ 1,235,533 Goodwill acquired and adjustments during the year — — — — Balance, March 31, 2019 $ 1,203,810 $ 23,178 $ 8,545 $ 1,235,533
Schedule of Mortgage Servicing Rights	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, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (in thousands) Mortgage servicing rights $ 14,636 $ (5,102 ) $ 9,534 $ 13,612 $ (4,806 ) $ 8,806
Schedule of Definite-Lived Intangible Assets	Definite-lived intangible assets had the following carrying values included in other intangible assets on the Company’s consolidated balance sheets as of the periods indicated: March 31, 2019 December 31, 2018 (in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Core deposit intangible assets $ 136,183 $ (68,189 ) $ 67,994 $ 136,183 $ (63,213 ) $ 72,970 Customer relationship intangible asset 1,385 (1,340 ) 45 1,385 (1,323 ) 62 Non-compete agreement 206 (84 ) 122 206 (72 ) 134 Total $ 137,774 $ (69,613 ) $ 68,161 $ 137,774 $ (64,608 ) $ 73,166

Derivative Instruments and Ot_2

Derivative Instruments and Other Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Outstanding Derivative Instruments	Information pertaining to outstanding derivative instruments is as follows: Derivative Assets - Fair Value Derivative Liabilities - Fair Value (in thousands) March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 6,920 $ 3,469 $ — $ — Total derivatives designated as hedging instruments $ 6,920 $ 3,469 $ — $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream 237 474 1,040 191 Customer swaps - downstream 35,265 16,946 9,766 17,812 Foreign exchange contracts 7 18 7 18 Forward sales contracts 143 630 1,440 750 Written and purchased options 8,488 5,490 4,446 3,310 Other contracts 26 21 57 43 Total derivatives not designated as hedging instruments $ 44,166 $ 23,579 $ 16,756 $ 22,124 Total $ 51,086 $ 27,048 $ 16,756 $ 22,124 Derivative Assets - Notional Amount Derivative Liabilities - Notional Amount (in thousands) March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 500,000 $ 408,500 $ 108,500 $ — Total derivatives designated as hedging instruments $ 500,000 $ 408,500 $ 108,500 $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream 634,998 919,653 1,290,051 701,257 Customer swaps - downstream 1,290,051 701,257 634,998 919,653 Foreign exchange contracts 903 1,202 903 1,202 Forward sales contracts 43,567 1,140 205,278 143,179 Written and purchased options 324,345 229,333 141,430 140,645 Other contracts 50,050 50,527 98,858 85,623 Total derivatives not designated as hedging instruments $ 2,343,914 $ 1,903,112 $ 2,371,518 $ 1,991,559 Total $ 2,843,914 $ 2,311,612 $ 2,480,018 $ 1,991,559
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, 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 $ 6,920 $ — $ — $ 6,920 Interest rate contracts not designated as hedging instruments 35,502 (824 ) — 34,678 Written and purchased options 4,406 — — 4,406 Total derivative assets subject to master netting arrangements $ 46,828 $ (824 ) $ — $ 46,004 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 10,806 $ (824 ) $ — $ 9,982 Written and purchased options 4,406 — — 4,406 Total derivative liabilities subject to master netting arrangements $ 15,212 $ (824 ) $ — $ 14,388 December 31, 2018 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 $ 3,469 $ — $ — $ 3,469 Interest rate contracts not designated as hedging instruments 17,420 (619 ) — 16,801 Written and purchased options 3,285 — — 3,285 Total derivative assets subject to master netting arrangements $ 24,174 $ (619 ) $ — $ 23,555 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 18,003 $ (619 ) $ — $ 17,384 Written and purchased options 3,285 — — 3,285 Total derivative liabilities subject to master netting arrangements $ 21,288 $ (619 ) $ — $ 20,669
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, 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 $ 6,920 $ — $ — $ 6,920 Interest rate contracts not designated as hedging instruments 35,502 (824 ) — 34,678 Written and purchased options 4,406 — — 4,406 Total derivative assets subject to master netting arrangements $ 46,828 $ (824 ) $ — $ 46,004 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 10,806 $ (824 ) $ — $ 9,982 Written and purchased options 4,406 — — 4,406 Total derivative liabilities subject to master netting arrangements $ 15,212 $ (824 ) $ — $ 14,388 December 31, 2018 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 $ 3,469 $ — $ — $ 3,469 Interest rate contracts not designated as hedging instruments 17,420 (619 ) — 16,801 Written and purchased options 3,285 — — 3,285 Total derivative assets subject to master netting arrangements $ 24,174 $ (619 ) $ — $ 23,555 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 18,003 $ (619 ) $ — $ 17,384 Written and purchased options 3,285 — — 3,285 Total derivative liabilities subject to master netting arrangements $ 21,288 $ (619 ) $ — $ 20,669
Effect of Derivatives on the Consolidated Financial Statements	At March 31, 2019 and 2018 , and for the three months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements is 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 2019 2019 2019 Total Interest rate contracts $ (2,185 ) $ (3,098 ) $ 913 Interest expense $ (227 ) $ (69 ) $ (158 ) Interest expense $ — $ — $ — 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 2018 2018 2018 Total Interest rate contracts $ 2,549 $ 2,549 $ — Interest expense $ (116 ) $ (116 ) $ — Interest expense $ — $ — $ — Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of March 31, is 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) 2019 2018 Interest rate contracts (1) Other income $ 4,181 $ 1,049 Foreign exchange contracts Other income 5 5 Forward sales contracts Mortgage income (3,209 ) 3,387 Written and purchased options Mortgage income 1,863 648 Other contracts Other income (9 ) (3 ) Total $ 2,831 $ 5,086 (1) Includes fees associated with customer interest rate contracts.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Assets And Liabilities, Leases	The following summarizes the ROU asset and lease liabilities as of March 31, 2019: (in thousands) March 31, 2019 Right-of-use assets $ 95,581 Total lease liabilities 118,430 Weighted Average Remaining Lease Term 7.4 years Weighted Average Discount Rate 3.4 %
Lessee, Operating Lease, Liability, Maturity	Maturities of operating lease liabilities as of March 31, 2019 is as follows: (in thousands) 2019 $ 20,059 2020 25,441 2021 22,038 2022 18,730 2023 12,394 2024 and thereafter 36,015 Total operating lease payments $ 134,677 Less: Imputed interest 16,247 Total lease liabilities $ 118,430
Lessor, Net Investment in in Leases	The components of the Company’s net investment in leases is as follows: (in thousands) March 31, 2019 Lease payment receivable $ 199,760 Unguaranteed residual assets 22,243 Total net investment in leases $ 222,003
Sales-type and Direct Financing Leases, Lease Receivable, Maturity	Maturities of the Company's lease receivables as of March 31, 2019 is as follows: (in thousands) 2019 $ 23,873 2020 31,495 2021 31,431 2022 28,869 2023 22,414 2024 and thereafter 75,940 Total future minimum lease payments $ 214,022 Less: Imputed interest 14,262 Lease receivables $ 199,760

Shareholders' Equity, Capital_2

Shareholders' Equity, Capital Ratios and Other Regulatory Matters (Tables)	3 Months Ended
	Mar. 31, 2019
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, 2019 December 31, 2018 Issuance Date Earliest Redemption Date Annual Dividend Rate Liquidation Amount Carrying Amount Carrying Amount (in thousands) 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 $ 137,500 $ 132,097 $ 132,097
Actual Capital Amounts and Ratios	The Company’s and IBERIABANK’s actual capital amounts and ratios as of March 31, 2019 and December 31, 2018 are presented in the following tables: (in thousands) March 31, 2019 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,184,075 4.00 % N/A N/A $ 2,863,388 9.67 % IBERIABANK 1,181,108 4.00 1,476,386 5.00 2,795,498 9.47 Common Equity Tier 1 (CET1) Consolidated $ 1,145,643 4.50 % N/A N/A $ 2,731,291 10.73 % IBERIABANK 1,143,315 4.50 1,651,455 6.50 2,795,498 11.00 Tier 1 Risk-Based Capital Consolidated $ 1,527,524 6.00 % N/A N/A $ 2,863,388 11.25 % IBERIABANK 1,524,420 6.00 2,032,560 8.00 2,795,498 11.00 Total Risk-Based Capital Consolidated $ 2,036,699 8.00 % N/A N/A $ 3,138,835 12.33 % IBERIABANK 2,032,560 8.00 2,540,700 10.00 2,954,445 11.63 December 31, 2018 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,168,343 4.00 % N/A N/A $ 2,812,863 9.63 % IBERIABANK 1,165,537 4.00 1,456,921 5.00 2,733,099 9.38 Common Equity Tier 1 (CET1) Consolidated $ 1,125,405 4.50 % N/A N/A $ 2,680,766 10.72 % IBERIABANK 1,122,712 4.50 1,621,695 6.50 2,733,099 10.95 Tier 1 Risk-Based Capital Consolidated $ 1,500,540 6.00 % N/A N/A $ 2,812,863 11.25 % IBERIABANK 1,496,949 6.00 1,995,932 8.00 2,733,099 10.95 Total Risk-Based Capital Consolidated $ 2,000,720 8.00 % N/A N/A $ 3,084,764 12.33 % IBERIABANK 1,995,932 8.00 2,494,915 10.00 2,888,500 11.58 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, 2019 , the required minimum capital conservation buffer was 2.50% . At March 31, 2019 , the capital conservation buffers of the Company and IBERIABANK were 4.33% and 3.63% , respectively.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
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) 2019 2018 Earnings Per Common Share - Basic: Net income $ 100,131 $ 63,621 Less: Preferred stock dividends 3,598 3,598 Less: Dividends and undistributed earnings allocated to unvested restricted shares 933 639 Net income allocated to common shareholders - basic $ 95,600 $ 59,384 Weighted average common shares outstanding 54,177 53,616 Earnings per common share - basic 1.76 1.11 Earnings Per Common Share - Diluted: Earnings allocated to common shareholders - basic $ 95,600 $ 59,384 Adjustment for undistributed earnings allocated to unvested restricted shares (42 ) (18 ) Earnings allocated to common shareholders - diluted $ 95,558 $ 59,366 Weighted average common shares outstanding 54,177 53,616 Dilutive potential common shares 362 351 Weighted average common shares outstanding - diluted 54,539 53,967 Earnings per common share - diluted $ 1.75 $ 1.10

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award	The following table represents the activity related to stock options during the periods indicated: Number of Shares Weighted Average Exercise Price Outstanding options, December 31, 2017 686,366 $ 58.24 Granted 92,162 82.20 Exercised (21,212 ) 52.10 Forfeited or expired (14,513 ) 65.27 Outstanding options, March 31, 2018 742,803 $ 61.25 Exercisable options, March 31, 2018 519,496 $ 56.53 Outstanding options, December 31, 2018 714,420 $ 61.41 Granted 126,405 70.32 Exercised (19,620 ) 54.44 Forfeited or expired (5,564 ) 69.58 Outstanding options, March 31, 2019 815,641 $ 62.90 Exercisable options, March 31, 2019 563,084 $ 58.22 The following table represents unvested restricted stock award and restricted share unit activity for the following periods: For the Three Months Ended March 31, 2019 2018 Number of shares at beginning of period 700,628 738,187 Granted 190,726 199,958 Forfeited (8,337 ) (43,405 ) Vested (182,947 ) (115,877 ) Number of shares at end of period 700,070 778,863 The following table represents phantom stock award activity during the periods indicated: (in thousands) Number of share equivalents (1) Value of share equivalents (2) Balance, December 31, 2017 393,844 $ 30,523 Granted 129,234 10,080 Forfeited share equivalents (24,460 ) 1,908 Vested share equivalents (121,758 ) 10,187 Balance, March 31, 2018 376,860 $ 29,395 Balance, December 31, 2018 353,407 $ 22,717 Granted 161,273 11,565 Forfeited share equivalents (13,680 ) 981 Vested share equivalents (96,995 ) 7,316 Balance, March 31, 2019 404,005 $ 28,971 (1) Number of share equivalents includes all reinvested dividend equivalents for the periods indicated. (2) Except for share equivalents at the beginning of each period, which are based on the value at that time, and vested share payments, which are based on the cash paid at the time of vesting, the value of share equivalents is calculated based on the market price of the Company’s stock at the end of the respective periods. The market price of the Company’s stock was $71.71 and $78.00 on March 31, 2019, and 2018, respectively.
Schedule of Valuation Assumptions	The following weighted-average assumptions were used for option awards issued during the following periods: For the Three Months Ended March 31, 2019 2018 Expected dividends 2.3 % 1.8 % Expected volatility 24.5 % 24.3 % Risk-free interest rate 2.5 % 2.7 % Expected term (in years) 5.7 5.7 Weighted-average grant-date fair value $ 14.44 $ 18.36
Schedule of Allocation for Share-based Compensation Expense	The following table represents the compensation expense that was included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to restricted stock awards and restricted share units for the periods indicated: For the Three Months Ended March 31, (in thousands) 2019 2018 Compensation expense related to restricted stock awards and restricted share units $ 5,223 $ 4,422 Income tax benefit related to restricted stock awards and restricted share units 1,097 929 The following table represents the compensation expense that is included in non-interest expense and related income tax benefits in the accompanying consolidated statements of comprehensive income related to stock options for the following periods: For the Three Months Ended March 31, (in thousands) 2019 2018 Compensation expense related to stock options $ 349 $ 312 Income tax benefit related to stock options 26 23 The following table represents compensation expense recorded for phantom stock based on the number of share equivalents vested at March 31 of the periods indicated and the current market price of the Company’s stock at that time: For the Three Months Ended March 31, (in thousands) 2019 2018 Compensation expense related to phantom stock $ 3,194 $ 2,996

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Financial Asset and Liabilities Measured at Fair Value on Recurring Basis	See Note 1, Summary of Significant Accounting Policies, in the Annual Report on Form 10-K for the year ended December 31, 2018, for a description of how fair value measurements are determined. March 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 4,873,778 $ — $ 4,873,778 Mortgage loans held for sale — 128,451 — 128,451 Mortgage loans held for investment, at fair value option — — 550 550 Derivative instruments — 51,086 — 51,086 Total $ — $ 5,053,315 $ 550 $ 5,053,865 Liabilities Derivative instruments $ — $ 16,756 $ — $ 16,756 Total $ — $ 16,756 $ — $ 16,756 December 31, 2018 Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 4,783,579 $ — $ 4,783,579 Mortgage loans held for sale — 107,734 — 107,734 Mortgage loans held for investment, at fair value option — — 3,143 3,143 Derivative instruments — 27,048 — 27,048 Total $ — $ 4,918,361 $ 3,143 $ 4,921,504 Liabilities Derivative instruments $ — $ 22,124 $ — $ 22,124 Total $ — $ 22,124 $ — $ 22,124
Financial Asset and Liabilities Measured at Fair Value on Nonrecurring Basis	The Company holds certain assets that are measured at fair value, but 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, 2019 and December 31, 2018 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 Annual Report on Form 10-K for the year ended December 31, 2018, for a description of how fair value measurements are determined. March 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 63,145 $ 63,145 OREO, net — — 8,875 8,875 Total $ — $ — $ 72,020 $ 72,020 December 31, 2018 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 65,914 $ 65,914 OREO, net — — 6,433 6,433 Total $ — $ — $ 72,347 $ 72,347
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, 2019 December 31, 2018 (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 $ 128,451 $ 124,410 $ 4,041 $ 107,734 $ 104,345 $ 3,389 Mortgage loans held for investment, at fair value 550 599 (49 ) 3,143 3,595 (452 )
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, 2019 and 2018. 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) 2019 2018 Fair value option Mortgage loans held for sale, at fair value $ 652 $ (749 ) Mortgage loans held for investment, at fair value 191 (1,142 )

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
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, and Note 2, Recent Accounting Pronouncements, in the Annual Report on Form 10-K for the year ended December 31, 2018, for a description of how fair value measurements are determined. March 31, 2019 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 4,873,778 $ 4,873,778 $ — $ 4,873,778 $ — Mortgage loans held for sale 128,451 128,451 — 128,451 — Mortgage loans held for investment, at fair value option 550 550 — — 550 Derivative instruments 51,086 51,086 — 51,086 — Financial Liabilities Derivative instruments 16,756 16,756 — 16,756 — Amortized Cost Financial Assets Cash and cash equivalents $ 671,897 $ 671,897 $ 671,897 $ — $ — Securities held to maturity 198,958 200,568 — 200,568 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 22,824,780 22,547,830 — — 22,547,830 Financial Liabilities Deposits 24,092,062 24,086,321 — 24,086,321 — Short-term borrowings 1,106,131 1,106,131 261,131 845,000 — Long-term debt 1,475,455 1,471,292 — — 1,471,292 December 31, 2018 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 4,783,579 $ 4,783,579 $ — $ 4,783,579 $ — Mortgage loans held for sale 107,734 107,734 — 107,734 — Mortgage loans held for investment, at fair value option 3,143 3,143 — — 3,143 Derivative instruments 27,048 27,048 — 27,048 — Financial Liabilities Derivative instruments 22,124 22,124 — 22,124 — Amortized Cost Financial Assets Cash and cash equivalents $ 690,453 $ 690,453 $ 690,453 $ — $ — Securities held to maturity 207,446 204,277 — 204,277 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 22,376,101 22,088,236 — — 22,088,236 Financial Liabilities Deposits 23,763,431 23,752,139 — 23,752,139 — Short-term borrowings 1,482,882 1,482,882 315,882 1,167,000 — Long-term debt 1,166,151 1,154,062 — — 1,154,062

Business Segments (Tables)

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2019
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, 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 income — — 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 (loss) before income tax expense 128,962 1,295 220 130,477 Income tax expense (benefit) 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 Three Months Ended March 31, 2018 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 268,775 $ 1,767 $ 1 $ 270,543 Interest expense 37,654 — — 37,654 Net interest income 231,121 1,767 1 232,889 Provision for (reversal of) credit losses 8,216 (5 ) — 8,211 Mortgage income — 9,595 — 9,595 Title income — — 5,027 5,027 Other non-interest income (expense) 29,906 38 — 29,944 Allocated expenses (income) (1,479 ) 1,166 313 — Non-interest expense 171,591 11,916 4,564 188,071 Income (loss) before income tax expense 82,699 (1,677 ) 151 81,173 Income tax expense (benefit) 18,540 (410 ) (578 ) 17,552 Net income (loss) $ 64,159 $ (1,267 ) $ 729 $ 63,621 Total loans, leases, and loans held for sale, net of unearned income $ 21,652,223 $ 164,215 $ — $ 21,816,438 Total assets 29,243,983 205,497 23,157 29,472,637 Total deposits 22,959,061 12,131 — 22,971,192 Average assets 27,924,587 185,742 21,890 28,132,219

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Summary of Financial Instruments Outstanding	At March 31, 2019 and December 31, 2018, respectively, the Company had the following financial instruments outstanding and related reserves, whose contract amounts represent credit risk: (in thousands) March 31, 2019 December 31, 2018 Commitments to extend credit $ 760,056 $ 642,162 Unfunded commitments under lines of credit 7,003,670 6,883,963 Commercial and standby letters of credit 241,516 240,436 Reserve for unfunded lending commitments 15,981 14,830

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Mar. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	$ 94,200	$ 95,581
Liabilities reclassed to right-of-used assets	24,700
Lease liability	$ 118,900	$ 118,430

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, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities
Amortized Cost	$ 4,881,429	$ 4,843,313
Gross Unrealized Gains	30,374	13,648
Gross Unrealized Losses	(38,025)	(73,382)
Estimated Fair Value	4,873,778	4,783,579
Schedule of Held-to-maturity Securities
Amortized Cost	198,958	207,446
Gross Unrealized Gains	2,394	339
Gross Unrealized Losses	(784)	(3,508)
Estimated Fair Value	200,568	204,277
Fair value of securities held as collateral	2,300,000	2,400,000
U.S. Government-sponsored enterprise obligations
Schedule of Available-for-sale Securities
Amortized Cost	40,822	995
Gross Unrealized Gains	130	3
Gross Unrealized Losses	0	0
Estimated Fair Value	40,952	998
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities
Amortized Cost	175,271	177,566
Gross Unrealized Gains	4,740	2,045
Gross Unrealized Losses	(32)	(723)
Estimated Fair Value	179,979	178,888
Schedule of Held-to-maturity Securities
Amortized Cost	180,472	188,684
Gross Unrealized Gains	2,365	309
Gross Unrealized Losses	(42)	(2,497)
Estimated Fair Value	182,795	186,496
Mortgage-backed securities: Residential agency
Schedule of Available-for-sale Securities
Amortized Cost	3,757,469	3,837,584
Gross Unrealized Gains	16,972	8,886
Gross Unrealized Losses	(29,763)	(57,073)
Estimated Fair Value	3,744,678	3,789,397
Schedule of Held-to-maturity Securities
Amortized Cost	18,486	18,762
Gross Unrealized Gains	29	30
Gross Unrealized Losses	(742)	(1,011)
Estimated Fair Value	17,773	17,781
Mortgage-backed securities: Commercial agency
Schedule of Available-for-sale Securities
Amortized Cost	779,487	730,148
Gross Unrealized Gains	6,656	2,363
Gross Unrealized Losses	(7,716)	(14,799)
Estimated Fair Value	778,427	717,712
Other securities
Schedule of Available-for-sale Securities
Amortized Cost	128,380	97,020
Gross Unrealized Gains	1,876	351
Gross Unrealized Losses	(514)	(787)
Estimated Fair Value	$ 129,742	$ 96,584

Investment Securities - Sched_2

Investment Securities - Schedule of Securities with Gross Unrealized Losses Aggregated by Investment Category (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Gross Unrealized Losses
Less Than Twelve Months	$ (80)	$ (962)
Twelve Months or More	(37,945)	(72,420)
Total	(38,025)	(73,382)
Estimated Fair Value
Less Than Twelve Months	51,991	237,384
Twelve Months or More	2,561,520	2,740,272
Total	2,613,511	2,977,656
Gross Unrealized Losses
Less than twelve months	0	(3)
Over twelve months	(784)	(3,505)
Total	(784)	(3,508)
Estimated Fair Value
Less than twelve months	0	2,059
Over twelve months	30,640	169,177
Total	30,640	171,236
Obligations of state and political subdivisions
Gross Unrealized Losses
Less Than Twelve Months	0	(9)
Twelve Months or More	(32)	(714)
Total	(32)	(723)
Estimated Fair Value
Less Than Twelve Months	0	4,112
Twelve Months or More	11,925	30,268
Total	11,925	34,380
Gross Unrealized Losses
Less than twelve months	0	(3)
Over twelve months	(42)	(2,494)
Total	(42)	(2,497)
Estimated Fair Value
Less than twelve months	0	2,059
Over twelve months	13,160	151,699
Total	13,160	153,758
Mortgage-backed securities: Residential agency
Gross Unrealized Losses
Less Than Twelve Months	(71)	(816)
Twelve Months or More	(29,692)	(56,257)
Total	(29,763)	(57,073)
Estimated Fair Value
Less Than Twelve Months	40,608	197,057
Twelve Months or More	2,081,552	2,193,862
Total	2,122,160	2,390,919
Gross Unrealized Losses
Less than twelve months	0	0
Over twelve months	(742)	(1,011)
Total	(742)	(1,011)
Estimated Fair Value
Less than twelve months	0	0
Over twelve months	17,480	17,478
Total	17,480	17,478
Mortgage-backed securities: Commercial agency
Gross Unrealized Losses
Less Than Twelve Months	(5)	(43)
Twelve Months or More	(7,711)	(14,756)
Total	(7,716)	(14,799)
Estimated Fair Value
Less Than Twelve Months	7,001	18,190
Twelve Months or More	434,500	483,565
Total	441,501	501,755
Other securities
Gross Unrealized Losses
Less Than Twelve Months	(4)	(94)
Twelve Months or More	(510)	(693)
Total	(514)	(787)
Estimated Fair Value
Less Than Twelve Months	4,382	18,025
Twelve Months or More	33,543	32,577
Total	$ 37,925	$ 50,602

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, 2019USD ($)Security	Dec. 31, 2018USD ($)Security
Schedule of Available-for-sale Securities
Number of debt securities with unrealized losses | Security	389	488
Debt securities with unrealized losses (percentage of amortized cost)	1.45%	2.38%
Number of securities | Security	379	441
Amortized cost basis	$ 2,630,889	$ 2,985,374
Unrealized loss	$ 38,729	$ 75,925
Mortgage-backed securities: Residential agency
Schedule of Available-for-sale Securities
Number of securities | Security	289	302
Amortized cost basis	$ 2,129,466	$ 2,268,608
Unrealized loss	$ 30,434	$ 57,268
Mortgage-backed securities: Commercial agency
Schedule of Available-for-sale Securities
Number of securities | Security	65	72
Amortized cost basis	$ 442,211	$ 498,321
Unrealized loss	$ 7,711	$ 14,756
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities
Number of securities | Security	17	60
Amortized cost basis	$ 25,159	$ 185,175
Unrealized loss	$ 74	$ 3,208
Other securities
Schedule of Available-for-sale Securities
Number of securities | Security	8	7
Amortized cost basis	$ 34,053	$ 33,270
Unrealized loss	$ 510	$ 693

Investment Securities - Sched_3

Investment Securities - Schedule of Amortized Cost and Estimated Fair Value of Investment Securities by Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Weighted Average Yield
Within one year or less	3.86%
One through five years	2.66%
After five through ten years	2.71%
Over ten years	2.97%
Weighted average yield	2.92%
Amortized Cost
Within one year or less	$ 2,536
One through five years	113,924
After five through ten years	863,166
Over ten years	3,901,803
Amortized Cost	4,881,429	$ 4,843,313
Estimated Fair Value
Within one year or less	2,542
One through five years	114,533
After five through ten years	867,609
Over ten years	3,889,094
Estimated fair value	$ 4,873,778	4,783,579
Weighted Average Yield
Within one year or less	2.33%
One through five years	2.42%
After five through ten years	2.58%
Over ten years	2.63%
Weighted average yield	2.61%
Amortized Cost
Within one year or less	$ 955
One through five years	6,100
After five through ten years	42,885
Over ten years	149,018
Amortized Cost	198,958	207,446
Estimated Fair Value
Within one year or less	959
One through five years	6,114
After five through ten years	43,419
Over ten years	150,076
Estimated fair value	$ 200,568	$ 204,277

Investment Securities - Sched_4

Investment Securities - Schedule of Realized Gains and Losses from Sale of Securities Classified as Available for Sale (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Realized gains	$ 0	$ 9
Realized losses	0	(68)
Realized gains (losses)	$ 0	$ (59)

Investment Securities - Sched_5

Investment Securities - Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank (FHLB) stock	$ 107,122	$ 95,213
Federal Reserve Bank Stock	85,630	85,630
CRA and Community Development Investment Funds	1,914	1,884
Other Investments	13,864	9,709
Marketable Securities	$ 208,530	$ 192,436

Loans and Leases - Schedule of

Loans and Leases - Schedule of Non-Covered Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 22,968,295	$ 22,519,815
Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	15,628,158	15,125,322
Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	1,219,647	1,196,366
Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,408,079	2,395,822
Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	6,147,864	5,796,117
Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	5,852,568	5,737,017
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	4,415,267	4,359,156
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,924,870	3,035,337
Consumer and Other Loans | Home Equity
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,220,648	2,304,694
Consumer and Other Loans | Other
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 704,222	$ 730,643

Loans (Detail)

Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable
Net deferred loan origination fees	$ 30,800		$ 30,200
Net discount	130,100		136,800
Deposit liabilities reclassified as loans receivable	6,400		9,200
Loans with carrying value pledged to secure public deposits and other borrowings	7,800,000		7,600,000
Loans acquired with no evidence of deteriorated credit quality	550		3,143
Acquired Loans
Accounts, Notes, Loans and Financing Receivable
Net discount	79,000		81,600
Sabadell United | Non-US
Accounts, Notes, Loans and Financing Receivable
Covered loans acquired	205,200		$ 202,600
TDRs Occurring during the Period | TDRs
Accounts, Notes, Loans and Financing Receivable
TDRs during period	31,429	$ 27,200
TDRs during period on accrual status	16,500	12,900
TDRs during period on non-accrual status	$ 14,900	$ 14,300

Loans and Leases - Schedule o_2

Loans and Leases - Schedule of Aging of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable
Accruing	$ 49,445	$ 59,460
Non-accrual Loans	148,056	137,184
Acquired Impaired Loans	175,312	169,725
Total Loans	22,968,295	22,519,815
Financing Receivable, Nonaccrual Loans, Thirty To Fifty-Nine Days Past Due, Amount	9,000	7,000
Financing Receivable, Nonaccrual Loans, Sixty to Eighty-Nine Days Past Due, Amount	4,600	3,700
Financing Receivable, Nonacrrual Loans, Over Ninety Days Past Due, Amount	53,700	66,900
Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	131,798	125,706
Total Loans	15,628,158	15,125,322
Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	305	1,054
Non-accrual Loans	1,072	1,094
Total Loans	1,219,647	1,196,366
Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	5,716	7,167
Non-accrual Loans	8,630	10,260
Total Loans	2,408,079	2,395,822
Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	3,167	7,833
Non-accrual Loans	19,984	15,898
Total Loans	6,147,864	5,796,117
Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	9,715	7,012
Non-accrual Loans	51,447	57,860
Total Loans	5,852,568	5,737,017
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	7,679	6,579
Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Current	4,335,779	4,290,152
Accruing	15,640	17,406
Non-accrual Loans	45,473	30,396
Total Loans	4,415,267	4,359,156
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	35,835	37,440
Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Current	2,184,204	2,258,659
Accruing	11,689	12,692
Non-accrual Loans	18,719	18,830
Total Loans	2,220,648	2,304,694
Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Current	698,074	721,231
Accruing	3,213	6,296
Non-accrual Loans	2,731	2,846
Total Loans	704,222	730,643
Current or Less Than 30 days past due
Accounts, Notes, Loans and Financing Receivable
Current	22,442,552	21,959,758
Current or Less Than 30 days past due | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Current	1,197,063	1,167,795
Current or Less Than 30 days past due | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Current	2,324,441	2,305,743
Current or Less Than 30 days past due | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Current	6,054,340	5,703,131
Current or Less Than 30 days past due | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Current	5,766,811	5,645,304
Current or Less Than 30 days past due | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Current	4,269,617	4,218,146
Current or Less Than 30 days past due | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Current	2,134,340	2,200,517
Current or Less Than 30 days past due | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Current	695,940	719,122
30-59 days
Accounts, Notes, Loans and Financing Receivable
Accruing	36,607	38,579
30-59 days | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	305	1,054
30-59 days | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	2,510	7,167
30-59 days | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	2,213	7,473
30-59 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	8,881	5,139
30-59 days | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	10,884	2,768
30-59 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	9,511	10,283
30-59 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	2,303	4,695
60-89 days
Accounts, Notes, Loans and Financing Receivable
Accruing	8,727	18,753
60-89 days | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
60-89 days | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	67	0
60-89 days | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	91	360
60-89 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	725	1,320
60-89 days | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	4,756	13,063
60-89 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	2,178	2,409
60-89 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	910	1,601
Greater than 90 days
Accounts, Notes, Loans and Financing Receivable
Accruing	4,111	2,128
Greater than 90 days | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Greater than 90 days | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	3,139	0
Greater than 90 days | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	863	0
Greater than 90 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	109	553
Greater than 90 days | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	0	1,575
Greater than 90 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Greater than 90 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Acquired Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	328,242	363,413
Acquired Loans | Commercial Loans | Commercial real estate - Construction
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	21,207	26,423
Acquired Loans | Commercial Loans | Commercial real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	69,292	72,652
Acquired Loans | Commercial Loans | Commercial real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	70,373	69,255
Acquired Loans | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	24,595	26,841
Acquired Loans | Residential Mortgage | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	84,537	93,208
Acquired Loans | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	55,900	72,655
Acquired Loans | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	$ 2,338	$ 2,379

Loans and Leases - Schedule o_3

Loans and Leases - Schedule of Carrying Amount of Loans Acquired (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Accounts, Notes, Loans and Financing Receivable
Expected losses and foregone interest	$ (158,947)		$ (157,959)
Loans acquired with no evidence of deteriorated credit quality	550	$ 3,143
Related allowance	$ (16,948)	$ (16,342)

Loans and Leases - Summary of C

Loans and Leases - Summary of Changes in Accretable Yields of Acquired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 133,342	$ 152,623
Additions	0	2,371
Transfers from non-accretable difference to accretable yield	(3,640)	(279)
Accretion	(10,086)	(13,154)
Changes in expected cash flows not affecting non-accretable differences	(272)	9,687
Balance at end of period	$ 119,344	$ 151,248

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, 2019	Mar. 31, 2018
Financing Receivable, Modifications
TDRs during period on accrual status	$ 16,500	$ 12,900
TDRs during period on non-accrual status	14,900	14,300
Extended maturities	9,014	5,619
Maturity and interest rate adjustment	468	108
Movement to or extension of interest-rate only payments	12	48
Interest rate adjustment	0	105
Financing Receivable Modifications Forbearance	6,510	12,886
Other concession(s)	15,425	8,434
TDRs during period	31,429	27,200
Commercial Loans | Commercial real estate - Construction
Financing Receivable, Modifications
TDRs during period	39	1,049
Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Modifications
TDRs during period	4,661	9,324
Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Modifications
TDRs during period	2,968	1,091
Commercial Loans | Commercial and industrial
Financing Receivable, Modifications
TDRs during period	17,040	13,314
Residential Mortgage | Residential mortgage
Financing Receivable, Modifications
TDRs during period	1,738	0
Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Modifications
TDRs during period	4,233	1,795
Consumer and Other Loans | Consumer - Other
Financing Receivable, Modifications
TDRs during period	$ 750	$ 627

Loans and Leases - Schedule o_5

Loans and Leases - Schedule of Subsequently Defaulted TDRs (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)SecurityLoan	Mar. 31, 2018USD ($)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	116	65
Pre-modification Outstanding Recorded Investment	$ 34,120	$ 30,616
Post-modification Outstanding Recorded Investment	$ 31,429	$ 27,200
Number of loans | SecurityLoan	70	122
Recorded investment	$ 10,597	$ 24,673
TDRs | Commercial Loans | Commercial 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	$ 39	$ 1,950
Post-modification Outstanding Recorded Investment	$ 39	$ 1,049
Number of loans | SecurityLoan	1	0
Recorded investment	$ 939	$ 0
TDRs | Commercial Loans | Commercial real estate - owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	4	2
Pre-modification Outstanding Recorded Investment	$ 6,904	$ 10,691
Post-modification Outstanding Recorded Investment	$ 4,661	$ 9,324
Number of loans | SecurityLoan	3	3
Recorded investment	$ 640	$ 10,187
TDRs | Commercial Loans | Commercial real estate - non-owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	7	9
Pre-modification Outstanding Recorded Investment	$ 2,990	$ 1,089
Post-modification Outstanding Recorded Investment	$ 2,968	$ 1,091
Number of loans | SecurityLoan	7	9
Recorded investment	$ 825	$ 492
TDRs | Commercial Loans | Commercial and industrial | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	23	18
Pre-modification Outstanding Recorded Investment	$ 17,382	$ 14,429
Post-modification Outstanding Recorded Investment	$ 17,040	$ 13,314
Number of loans | SecurityLoan	10	29
Recorded investment	$ 3,933	$ 9,708
TDRs | Residential Mortgage | Residential mortgage | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	10	0
Pre-modification Outstanding Recorded Investment	$ 1,741	$ 0
Post-modification Outstanding Recorded Investment	$ 1,738	$ 0
Number of loans | SecurityLoan	13	6
Recorded investment	$ 1,108	$ 598
TDRs | Consumer and Other Loans | Consumer - Home equity | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	33	14
Pre-modification Outstanding Recorded Investment	$ 4,277	$ 1,809
Post-modification Outstanding Recorded Investment	$ 4,233	$ 1,795
Number of loans | SecurityLoan	16	24
Recorded investment	$ 2,891	$ 2,331
TDRs | Consumer and Other Loans | Consumer - Other | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	38	21
Pre-modification Outstanding Recorded Investment	$ 787	$ 648
Post-modification Outstanding Recorded Investment	$ 750	$ 627
Number of loans | SecurityLoan	20	51
Recorded investment	$ 261	$ 1,357

Allowance for Credit Losses a_3

Allowance for 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, 2019	Mar. 31, 2018
Allowance for credit losses
Allowance for loan losses at beginning of period	$ 140,571	$ 140,891
Provision for loan and lease losses	12,612	7,987
Transfer of balance to OREO and other	(2,885)	(48)
Loans charged-off	(8,918)	(9,116)
Recoveries	1,586	4,813
Allowance for loan losses at end of period	142,966	144,527
Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	14,830	13,208
Provision For Unfunded Commitments	1,151	224
Reserve for unfunded commitments at end of period	15,981	13,432
Allowance for credit losses at end of period	$ 158,947	$ 157,959

Allowance for Credit Losses a_4

Allowance for Credit Losses and Credit Quality - Schedule of Allowance for Loan Losses for Legacy and Acquired Loans, by Loan Portfolio (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	$ 140,571	$ 140,891
Provision for (Reversal of) loan losses	12,612	7,987
Transfer of balance to OREO and other	(2,885)	(48)
Loans charged-off	(8,918)	(9,116)
Recoveries	1,586	4,813
Allowance for loan losses at end of period	142,966	144,527
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	14,830	13,208
Provision for (Reversal of) unfunded commitments	1,151	224
Reserve for unfunded commitments at end of period	15,981	13,432
Allowance on loans individually evaluated for impairment	16,948	19,698
Allowance on loans collectively evaluated for impairment	114,698	90,696
Allowance on loans acquired with deteriorated credit quality	158,947	157,959
Loans, net of unearned income:
Loans, net of unearned income	22,968,295	21,706,090
Balance at end of period individually evaluated for impairment	175,312	196,532
Balance at end of period collectively evaluated for impairment	22,464,741	21,027,680
Commercial Loans | Real Estate
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	51,806	54,201
Provision for (Reversal of) loan losses	6,887	6,378
Transfer of balance to OREO and other	0	(48)
Loans charged-off	(72)	(114)
Recoveries	103	191
Allowance for loan losses at end of period	58,724	60,608
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	4,869	4,531
Provision for (Reversal of) unfunded commitments	794	1,476
Reserve for unfunded commitments at end of period	5,663	6,007
Allowance on loans individually evaluated for impairment	3,078	2,506
Allowance on loans collectively evaluated for impairment	50,210	35,871
Loans, net of unearned income:
Loans, net of unearned income	9,775,590	9,248,951
Balance at end of period individually evaluated for impairment	67,909	78,489
Balance at end of period collectively evaluated for impairment	9,546,809	8,946,138
Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	54,096	53,916
Provision for (Reversal of) loan losses	2,876	294
Transfer of balance to OREO and other	0	0
Loans charged-off	(4,931)	(5,378)
Recoveries	446	3,698
Allowance for loan losses at end of period	52,487	52,530
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	6,198	5,309
Provision for (Reversal of) unfunded commitments	128	(1,004)
Reserve for unfunded commitments at end of period	6,326	4,305
Allowance on loans individually evaluated for impairment	10,988	14,040
Allowance on loans collectively evaluated for impairment	39,997	36,208
Loans, net of unearned income:
Loans, net of unearned income	5,852,568	5,325,682
Balance at end of period individually evaluated for impairment	63,889	78,725
Balance at end of period collectively evaluated for impairment	5,764,084	5,211,736
Residential Mortgage
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	12,998	9,117
Provision for (Reversal of) loan losses	1,749	(686)
Transfer of balance to OREO and other	(2,881)	0
Loans charged-off	(28)	(105)
Recoveries	32	22
Allowance for loan losses at end of period	11,870	8,348
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	866	555
Provision for (Reversal of) unfunded commitments	22	(15)
Reserve for unfunded commitments at end of period	888	540
Allowance on loans individually evaluated for impairment	258	178
Allowance on loans collectively evaluated for impairment	7,404	2,073
Loans, net of unearned income:
Loans, net of unearned income	4,415,267	3,971,067
Balance at end of period individually evaluated for impairment	7,679	6,041
Balance at end of period collectively evaluated for impairment	4,323,051	3,826,721
Consumer and Other Loans
Financing Receivable, Allowance for Credit Losses
Allowance for loan losses at beginning of period	21,671	23,657
Provision for (Reversal of) loan losses	1,100	2,001
Transfer of balance to OREO and other	(4)	0
Loans charged-off	(3,887)	(3,519)
Recoveries	1,005	902
Allowance for loan losses at end of period	19,885	23,041
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	2,897	2,813
Provision for (Reversal of) unfunded commitments	207	(233)
Reserve for unfunded commitments at end of period	3,104	2,580
Allowance on loans individually evaluated for impairment	2,624	2,974
Allowance on loans collectively evaluated for impairment	17,087	16,544
Loans, net of unearned income:
Loans, net of unearned income	2,924,870	3,160,390
Balance at end of period individually evaluated for impairment	35,835	33,277
Balance at end of period collectively evaluated for impairment	2,830,797	3,043,085
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	11,320	34,133
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	328,242	481,878
Receivables Acquired with Deteriorated Credit Quality | Commercial Loans | Real Estate
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	5,436	22,231
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	160,872	224,324
Receivables Acquired with Deteriorated Credit Quality | Commercial Loans | Commercial and industrial
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	1,502	2,282
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	24,595	35,221
Receivables Acquired with Deteriorated Credit Quality | Residential Mortgage
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	4,208	6,097
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	84,537	138,305
Receivables Acquired with Deteriorated Credit Quality | Consumer and Other Loans
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	174	3,523
Loans, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	$ 58,238	$ 84,028

Allowance for Credit Losses a_5

Allowance for Credit Losses and Credit Quality - Investment in Legacy and Acquired Loans by Credit Quality Indicator (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses
Total Loans	$ 22,968,295	$ 22,519,815
Commercial Loans
Financing Receivable, Allowance for Credit Losses
Total Loans	15,628,158	15,125,322
Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Total Loans	1,219,647	1,196,366
Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Total Loans	2,408,079	2,395,822
Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Total Loans	6,147,864	5,796,117
Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Total Loans	5,852,568	5,737,017
Residential and Consumer Portfolio
Financing Receivable, Allowance for Credit Losses
Current	7,218,057	7,270,042
30 or more days past due	122,080	124,451
Total Loans	7,340,137	7,394,493
Residential Mortgage | Residential mortgage
Financing Receivable, Allowance for Credit Losses
Current	4,335,779	4,290,152
30 or more days past due	79,488	69,004
Total Loans	4,415,267	4,359,156
Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Allowance for Credit Losses
Current	2,184,204	2,258,659
30 or more days past due	36,444	46,035
Total Loans	2,220,648	2,304,694
Consumer and Other Loans | Consumer - Other
Financing Receivable, Allowance for Credit Losses
Current	698,074	721,231
30 or more days past due	6,148	9,412
Total Loans	704,222	730,643
Pass | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	15,270,886	14,785,998
Pass | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	1,213,202	1,182,554
Pass | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	2,332,819	2,328,999
Pass | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	6,028,301	5,687,963
Pass | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	5,696,564	5,586,482
Special Mention | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	162,729	157,229
Special Mention | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	147	1,062
Special Mention | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	33,359	25,526
Special Mention | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	82,839	78,009
Special Mention | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	46,384	52,632
Substandard | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	168,776	154,402
Substandard | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	6,289	12,740
Substandard | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	41,087	41,297
Substandard | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	34,015	26,512
Substandard | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	87,385	73,853
Doubtful | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	25,767	27,693
Doubtful | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	9	10
Doubtful | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	814	0
Doubtful | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	2,709	3,633
Doubtful | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	$ 22,235	$ 24,050

Allowance for Credit Losses a_6

Allowance for Credit Losses and Credit Quality - Schedule of Investment in Legacy Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Impaired
Unpaid Principal Balance	$ 210,519		$ 209,746
Recorded Investment	175,312		169,725
Related allowance	(16,948)		(16,342)
Average Recorded Investment	177,593	$ 189,754
Interest Income Recognized	1,725	1,695
Commercial Loans
Financing Receivable, Impaired
Unpaid Principal Balance	165,114		164,209
Recorded Investment	131,798		125,706
Related allowance	(14,066)		(13,282)
Average Recorded Investment	133,993	150,255
Interest Income Recognized	1,289	1,280
Residential Mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	8,201		7,114
Recorded Investment	7,679		6,579
Related allowance	(258)		(145)
Average Recorded Investment	7,737	6,064
Interest Income Recognized	76	56
Consumer and Other Loans
Financing Receivable, Impaired
Unpaid Principal Balance	37,204		38,423
Recorded Investment	35,835		37,440
Related allowance	(2,624)		(2,915)
Average Recorded Investment	35,863	33,435
Interest Income Recognized	360	359
With No Related Allowance Recorded [Member] | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Impaired
Unpaid Principal Balance	12,138		10,261
Recorded Investment	11,139		9,262
Average Recorded Investment		10,470	11,142
Interest Income Recognized	169	144
With No Related Allowance Recorded [Member] | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	33,670		25,037
Recorded Investment	27,732		19,044
Average Recorded Investment	27,865	36,277
Interest Income Recognized	301	334
With No Related Allowance Recorded [Member] | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	12,352		15,265
Recorded Investment	11,515		14,288
Average Recorded Investment	11,566	10,557
Interest Income Recognized	69	98
With No Related Allowance Recorded [Member] | Commercial Loans | Commercial and industrial
Financing Receivable, Impaired
Unpaid Principal Balance	52,821		55,554
Recorded Investment	32,380		43,886
Average Recorded Investment	37,185	27,832
Interest Income Recognized	461	385
With No Related Allowance Recorded [Member] | Commercial Loans | Residential mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	1,456		1,244
Recorded Investment	1,456		1,221
Average Recorded Investment	1,463	1,090
Interest Income Recognized	17	12
With No Related Allowance Recorded [Member] | Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Impaired
Unpaid Principal Balance	1,783		4,183
Recorded Investment	1,783		4,176
Average Recorded Investment	1,204	32
Interest Income Recognized	10	0
With No Related Allowance Recorded [Member] | Consumer and Other Loans | Consumer - Other
Financing Receivable, Impaired
Unpaid Principal Balance	0		0
Recorded Investment	0		0
With An Allowance Recorded | Commercial Loans | Commercial real estate - Construction
Financing Receivable, Impaired
Unpaid Principal Balance	224		228
Recorded Investment	134		140
Related allowance	(11)		(11)
Average Recorded Investment	136	153
Interest Income Recognized	0	1
With An Allowance Recorded | Commercial Loans | Commercial real estate - owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	5,553		5,032
Recorded Investment	5,393		4,773
Related allowance	(613)		(520)
Average Recorded Investment	5,433	17,608
Interest Income Recognized	8	112
With An Allowance Recorded | Commercial Loans | Commercial real estate - non-owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	12,113		6,445
Recorded Investment	11,996		6,398
Related allowance	(2,454)		(105)
Average Recorded Investment	12,042	3,302
Interest Income Recognized	79	10
With An Allowance Recorded | Commercial Loans | Commercial and industrial
Financing Receivable, Impaired
Unpaid Principal Balance	36,243		46,387
Recorded Investment	31,509		27,915
Related allowance	(10,988)		(12,646)
Average Recorded Investment	28,624	44,056
Interest Income Recognized	202	196
With An Allowance Recorded | Residential Mortgage | Residential mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	6,745		5,870
Recorded Investment	6,223		5,358
Related allowance	(258)		(145)
Average Recorded Investment	6,274	4,974
Interest Income Recognized	59	44
With An Allowance Recorded | Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Impaired
Unpaid Principal Balance	30,847		29,284
Recorded Investment	29,861		28,818
Related allowance	(2,132)		(2,427)
Average Recorded Investment	30,345	28,203
Interest Income Recognized	292	292
With An Allowance Recorded | Consumer and Other Loans | Consumer - Other
Financing Receivable, Impaired
Unpaid Principal Balance	4,574		4,956
Recorded Investment	4,191		4,446
Related allowance	(492)		$ (488)
Average Recorded Investment	4,314	5,200
Interest Income Recognized	$ 58	$ 67

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Schedule of Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Goodwill
Balance at beginning of the period	$ 1,235,533	$ 1,188,902
Goodwill acquired and adjustments during the year	0	46,631
Balance at end of the period	1,235,533	1,235,533
Operating Segments | IBERIABANK
Goodwill
Balance at beginning of the period	1,203,810	1,160,559
Goodwill acquired and adjustments during the year	0	43,251
Balance at end of the period	1,203,810	1,203,810
Operating Segments | IMC
Goodwill
Balance at beginning of the period	23,178	23,178
Goodwill acquired and adjustments during the year	0	0
Balance at end of the period	23,178	23,178
Operating Segments | LTC
Goodwill
Balance at beginning of the period	8,545	5,165
Goodwill acquired and adjustments during the year	0	3,380
Balance at end of the period	$ 8,545	$ 8,545

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Narrative (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Title plant assets	$ 6.8	$ 6.8

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Schedule of Mortgage Servicing Rights at Carrying Value (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 137,774	$ 137,774
Finite-Lived Intangible Assets, Accumulated Amortization	69,613	64,608
Finite-Lived Intangible Assets, Net	68,161	73,166
Mortgage servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	14,636	13,612
Finite-Lived Intangible Assets, Accumulated Amortization	5,102	4,806
Finite-Lived Intangible Assets, Net	$ 9,534	$ 8,806

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Schedule of Definite-Lived Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 137,774	$ 137,774
Accumulated Amortization	(69,613)	(64,608)
Net Carrying Amount	68,161	73,166
Core deposit intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	136,183	136,183
Accumulated Amortization	(68,189)	(63,213)
Net Carrying Amount	67,994	72,970
Customer relationship intangible asset
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,385	1,385
Accumulated Amortization	(1,340)	(1,323)
Net Carrying Amount	45	62
Non-compete agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	206	206
Accumulated Amortization	(84)	(72)
Net Carrying Amount	$ 122	$ 134

Derivative Instruments and Ot_3

Derivative Instruments and Other Hedging Activities - Schedule of Outstanding Derivative Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value of Derivatives
Derivative instruments	$ 51,086	$ 27,048
Derivative Liability	16,756	22,124
Notional Amount of Derivatives
Derivative assets	2,843,914	2,311,612
Derivative liabilities	2,480,018	1,991,559
Designated as Hedging Instruments
Fair Value of Derivatives
Derivative instruments	6,920	3,469
Derivative Liability	0	0
Notional Amount of Derivatives
Derivative assets	500,000	408,500
Derivative liabilities	108,500	0
Designated as Hedging Instruments | Interest rate contracts
Notional Amount of Derivatives
Derivative assets	500,000	408,500
Derivative liabilities	108,500	0
Designated as Hedging Instruments | Interest rate contracts | Other Assets
Fair Value of Derivatives
Derivative instruments	6,920	3,469
Designated as Hedging Instruments | Interest rate contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	0	0
Not Designated as Hedging Instruments
Notional Amount of Derivatives
Derivative assets	2,343,914	1,903,112
Derivative liabilities	2,371,518	1,991,559
Not Designated as Hedging Instruments | Other Assets
Fair Value of Derivatives
Derivative instruments	44,166	23,579
Not Designated as Hedging Instruments | Other Liabilities
Fair Value of Derivatives
Derivative Liability	16,756	22,124
Not Designated as Hedging Instruments | Interest rate contracts
Notional Amount of Derivatives
Derivative assets	1,290,051	701,257
Derivative liabilities	634,998	919,653
Not Designated as Hedging Instruments | Interest rate contracts | Other Assets
Fair Value of Derivatives
Derivative instruments	35,265	16,946
Not Designated as Hedging Instruments | Interest rate contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	9,766	17,812
Not Designated as Hedging Instruments | Customer swaps - upstream
Notional Amount of Derivatives
Derivative assets	634,998	919,653
Derivative liabilities	1,290,051	701,257
Not Designated as Hedging Instruments | Customer swaps - upstream | Other Assets
Fair Value of Derivatives
Derivative instruments	237	474
Not Designated as Hedging Instruments | Customer swaps - upstream | Other Liabilities
Fair Value of Derivatives
Derivative Liability	1,040	191
Not Designated as Hedging Instruments | Foreign exchange contracts
Notional Amount of Derivatives
Derivative assets	903	1,202
Derivative liabilities	903	1,202
Not Designated as Hedging Instruments | Foreign exchange contracts | Other Assets
Fair Value of Derivatives
Derivative instruments	7	18
Not Designated as Hedging Instruments | Foreign exchange contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	7	18
Not Designated as Hedging Instruments | Forward sales contracts
Notional Amount of Derivatives
Derivative assets	43,567	1,140
Derivative liabilities	205,278	143,179
Not Designated as Hedging Instruments | Forward sales contracts | Other Assets
Fair Value of Derivatives
Derivative instruments	143	630
Not Designated as Hedging Instruments | Forward sales contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	1,440	750
Not Designated as Hedging Instruments | Written and purchased options
Notional Amount of Derivatives
Derivative assets	324,345	229,333
Derivative liabilities	141,430	140,645
Not Designated as Hedging Instruments | Written and purchased options | Other Assets
Fair Value of Derivatives
Derivative instruments	8,488	5,490
Not Designated as Hedging Instruments | Written and purchased options | Other Liabilities
Fair Value of Derivatives
Derivative Liability	4,446	3,310
Not Designated as Hedging Instruments | Other contracts
Notional Amount of Derivatives
Derivative assets	50,050	50,527
Derivative liabilities	98,858	85,623
Not Designated as Hedging Instruments | Other contracts | Other Assets
Fair Value of Derivatives
Derivative instruments	26	21
Not Designated as Hedging Instruments | Other contracts | Other Liabilities
Fair Value of Derivatives
Derivative Liability	$ 57	$ 43

Derivative Instruments and Ot_4

Derivative Instruments and Other Hedging Activities Derivative Instruments and Other Hedging Activities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Notional amount of derivative liabilities	$ 2,480,018	$ 1,991,559
Cash Posted As Variation Margin for Derivatives	44,700	35,800
Not Designated as Hedging Instruments
Derivative [Line Items]
Notional amount of derivative liabilities	2,371,518	1,991,559
Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Notional amount of derivative liabilities	$ 98,858	$ 85,623

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, 2019	Dec. 31, 2018
Derivative assets
Gross derivative assets	$ 46,828	$ 24,174
Gross amounts not offset in the Balance Sheet, derivatives	(824)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	46,004	23,555
Derivative liabilities
Gross derivative liabilities	15,212	21,288
Gross amounts not offset in the Balance Sheet, derivatives	(824)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	14,388	20,669
Written and purchased options
Derivative assets
Gross derivative assets	4,406	3,285
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	4,406	3,285
Derivative liabilities
Gross derivative liabilities	4,406	3,285
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	4,406	3,285
Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets	6,920	3,469
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	6,920	3,469
Not Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets	35,502	17,420
Gross amounts not offset in the Balance Sheet, derivatives	(824)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	34,678	16,801
Derivative liabilities
Gross derivative liabilities	10,806	18,003
Gross amounts not offset in the Balance Sheet, derivatives	(824)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	$ 9,982	$ 17,384

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, 2019	Mar. 31, 2018
Designated as Hedging Instruments | Cash Flow Hedging | Interest rate contracts | Interest expense
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	$ (227)	$ (116)
Derivative, Included Component, Gain (Loss) Recognized in Earnings	(69)	(116)
Amount of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing)	(158)	0
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 Compnonent, Net	0	0
Not Designated as Hedging Instruments
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	2,831	5,086
Not Designated as Hedging Instruments | Interest rate contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	4,181	1,049
Not Designated as Hedging Instruments | Foreign exchange contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	5	5
Not Designated as Hedging Instruments | Forward sales contracts | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	(3,209)	3,387
Not Designated as Hedging Instruments | Written and purchased options | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	1,863	648
Not Designated as Hedging Instruments | Other contracts | Other income
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	(9)	(3)
OCI | Designated as Hedging Instruments | Cash Flow Hedging | Interest rate contracts
Derivative Instruments and Hedging Activities Disclosures
Amount of Gain (Loss) Recognized	(2,185)	2,549
Derivative, Included Component, Gain (Loss) Recognized in Earnings	(3,098)	2,549
Amount of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing)	$ 913	$ 0

Leases Additional Information (

Leases Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Lessor, Lease, Description [Line Items]
Lease receivables	$ 199,760
Lease expense	6,800
Amounts included in measurement of lease liabilities	6,700
Amount to obtain ROU assets	$ 5,200
Term of options to extend leases	12 months
Term for option to terminate leases	1 year
Interest income for sales-type and direct finance leases	$ 2,000
Minimum
Lessor, Lease, Description [Line Items]
Term of contract on operating lease	1 year
Remaining lease terms on sales type and direct finance leases	4 years
Maximum
Lessor, Lease, Description [Line Items]
Term of contract on operating lease	45 years
Remaining lease terms on sales type and direct finance leases	20 years

Leases Maturities of Operating

Leases Maturities of Operating Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019
Leases [Abstract]
2019	$ 20,059
2020	25,441
2021	22,038
2022	18,730
2023	12,394
2024 and thereafter	36,015
Total operating lease payments	134,677
Less: Imputed interest	16,247
Total lease liabilities	$ 118,430	$ 118,900

Leases Components of net invest

Leases Components of net investment in leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
Lease receivables	$ 199,760
Unguaranteed residual assets	22,243
Total net investment in leases	$ 222,003

Leases Direct Finance and Sales

Leases Direct Finance and Sales Type Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
2019	$ 23,873
2020	31,495
2021	31,431
2022	28,869
2023	22,414
2024 and thereafter	75,940
Total future minimum lease payments	214,022
Less: Imputed interest	14,262
Lease receivables	$ 199,760

Leases Right-of-use assets and

Leases Right-of-use assets and lease liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019
Leases [Abstract]
Right-of-use assets	$ 95,581	$ 94,200
Total lease liabilities	$ 118,430	$ 118,900
Weighted Average Remaining Lease Term	7 years 4 months 24 days
Weighted Average Discount Rate	3.40%

Income Taxes Schedule of Effect

Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income before income tax expense	$ 130,477	$ 81,173
Income tax expense	$ 30,346	$ 17,552

Shareholders' Equity, Capital_3

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	May 05, 2019	May 09, 2016	Aug. 05, 2015	Mar. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Liquidation preference value		$ 137,500
Carrying Amount				$ 132,097	$ 132,097
Number of shares authorized to be repurchased				2,765,000
Common stock repurchases				$ 29,946
Shares authorized to be repurchased				1,877,079
Series B Preferred Stock
Class of Stock [Line Items]
Ownership per share			6.625%
Liquidation preference value			$ 80,000
Carrying Amount				$ 76,812	76,812
Series C Preferred Stock
Class of Stock [Line Items]
Ownership per share		6.60%
Liquidation preference value		$ 57,500
Carrying Amount				$ 55,285	$ 55,285
Subsequent Event
Class of Stock [Line Items]
Common stock repurchases (in shares)	353,200
Treasury stock acquired	$ 28,200
Common Stock
Class of Stock [Line Items]
Common stock repurchases (in shares)				387,921
Common stock repurchases				$ 388
2016 and 2018 Share Repurchase Program
Class of Stock [Line Items]
Common stock repurchases				$ 29,900
Average cost of common stock shares repurchased (in usd per share)				$ 77.19
2016 and 2018 Share Repurchase Program | Common Stock
Class of Stock [Line Items]
Common stock repurchases (in shares)				387,921

Shareholders' Equity, Capital_4

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Actual Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Total Risk-Based Capital
Capital Conversion Buffer	4.33%
Consolidated
Tier 1 Leverage
Minimum amount	$ 1,184,075	$ 1,168,343
Minimum ratio	4.00%	4.00%
Actual amount	$ 2,863,388	$ 2,812,863
Actual ratio	9.67%	9.63%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,145,643	$ 1,125,405
Minimum ratio	4.50%	4.50%
Actual amount	$ 2,731,291	$ 2,680,766
Actual Ratio	10.73%	10.72%
Tier 1 Risk-Based Capital
Minimum amount	$ 1,527,524	$ 1,500,540
Minimum ratio	6.00%	6.00%
Actual amount	$ 2,863,388	$ 2,812,863
Actual ratio	11.25%	11.25%
Total Risk-Based Capital
Minimum amount	$ 2,036,699	$ 2,000,720
Minimum ratio	8.00%	8.00%
Actual amount	$ 3,138,835	$ 3,084,764
Actual ratio	12.33%	12.33%
IBERIABANK
Tier 1 Leverage
Minimum amount	$ 1,181,108	$ 1,165,537
Minimum ratio	4.00%	4.00%
Well capitalized amount	$ 1,476,386	$ 1,456,921
Well capitalized ratio	5.00%	5.00%
Actual amount	$ 2,795,498	$ 2,733,099
Actual ratio	9.47%	9.38%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,143,315	$ 1,122,712
Minimum ratio	4.50%	4.50%
Well capitalized amount	$ 1,651,455	$ 1,621,695
Well capitalized ratio	6.50%	6.50%
Actual amount	$ 2,795,498	$ 2,733,099
Actual Ratio	11.00%	10.95%
Tier 1 Risk-Based Capital
Minimum amount	$ 1,524,420	$ 1,496,949
Minimum ratio	6.00%	6.00%
Well capitalized amount	$ 2,032,560	$ 1,995,932
Well capitalized ratio	8.00%	8.00%
Actual amount	$ 2,795,498	$ 2,733,099
Actual ratio	11.00%	10.95%
Total Risk-Based Capital
Minimum amount	$ 2,032,560	$ 1,995,932
Minimum ratio	8.00%	8.00%
Well capitalized amount	$ 2,540,700	$ 2,494,915
Well capitalized ratio	10.00%	10.00%
Actual amount	$ 2,954,445	$ 2,888,500
Actual ratio	11.63%	11.58%
Capital Conversion Buffer	3.63%

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, 2019	Mar. 31, 2018
Earnings Per Common Share - Basic:
Net income	$ 100,131	$ 63,621
Less: Preferred stock dividends	3,598	3,598
Less: Dividends and undistributed earnings allocated to unvested restricted shares	933	639
Net income allocated to common shareholders - basic	$ 95,600	$ 59,384
Weighted average common shares outstanding	54,177	53,616
Earnings per common share - basic (in usd per share)	$ 1.76	$ 1.11
Earnings Per Common Share - Diluted:
Net income allocated to common shareholders - basic	$ 95,600	$ 59,384
Adjustment for undistributed earnings allocated to unvested restricted shares	(42)	(18)
Net income allocated to common shareholders - diluted	$ 95,558	$ 59,366
Weighted average common shares outstanding	54,177	53,616
Dilutive potential common shares	362	351
Weighted average common shares outstanding - diluted	54,539	53,967
Earnings per common share - diluted (in usd per share)	$ 1.75	$ 1.10

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Detail) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
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	564,188	606,442
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded from the computation of earnings per share	155,757	156,737

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards shares under approved incentive compensation plans	675,556
Share-based compensation maximum option term (in years)	10 years
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned share-based compensation associated with awards	$ 3
Unrecognized compensation cost related to stock options expected to be recognized over a weighted-average period	3 years 1 month
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned share-based compensation associated with awards	$ 31.1	$ 39
Unrecognized compensation cost related to stock options expected to be recognized over a weighted-average period	1 year 6 months
Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Phantom Stock Awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years

Share-Based Compensation - Acti

Share-Based Compensation - Activity Related to Stock Options (Detail) - Stock Option Awards - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Number of shares
Balance at beginning of the period (in shares)	714,420,000	686,366,000
Granted (in shares)	126,405,000	92,162,000
Exercised (in shares)	(19,620,000)	(21,212,000)
Forfeited or expired (in shares)	(5,564,000)	(14,513,000)
Balance at end of the period (in shares)	815,641,000	742,803,000
Exercisable at period end (in shares)	563,084,000	519,496,000
Weighted Average Exercise Price
Balance at beginning of the period (in usd per share)	$ 61.41	$ 58.24
Granted (in usd per share)	70.32	82.20
Exercised (in usd per share)	54.44	52.10
Forfeited or expired (in usd per share)	69.58	65.27
Balance at end of the period (in usd per share)	62.90	61.25
Exercisable at period end (in usd per share)	$ 58.22	$ 56.53

Share-Based Compensation - Esti

Share-Based Compensation - Estimate Fair Value of Stock Option Awards with Weighted-Average Assumptions (Detail) - Stock Option Awards - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends	2.30%	1.80%
Expected volatility	24.50%	24.30%
Risk-free interest rate	2.50%	2.70%
Expected term (in years)	5 years 8 months 18 days	5 years 8 months 18 days
Weighted-average grant-date fair value	$ 14.44	$ 18.36

Share-Based Compensation - Comp

Share-Based Compensation - Compensation Expense Included in Non-Interest Expense and Related Income Tax Benefits (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 349	$ 312
Income tax benefit	26	23
Restricted Stock And Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	5,223	4,422
Income tax benefit	1,097	929
Phantom Stock and Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 3,194	$ 2,996

Share-Based Compensation - Unve

Share-Based Compensation - Unvested Restricted Stock Award Activity (Detail) - Restricted Stock And Restricted Stock Units - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of the period (in shares)	700,628,000	738,187,000
Granted (in shares)	190,726,000	199,958,000
Forfeited (in shares)	(8,337,000)	(43,405,000)
Earned and issued (in shares)	(182,947,000)	(115,877,000)
Balance at end of the period (in shares)	700,070,000	778,863,000

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Share and Dividend Equivalent Share Award Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Value of share equivalents
Market price of Company's stock	$ 71.71	$ 78
Phantom Stock and Performance Stock Units
Number of share equivalents
Balance at beginning of the period (in shares)	353,407,000	393,844,000
Granted (in shares)	161,273,000	129,234,000
Forfeited share equivalents (in shares)	(13,680,000)	(24,460,000)
Vested share equivalents (in shares)	(96,995,000)	(121,758,000)
Balance at end of the period (in shares)	404,005,000	376,860,000
Value of share equivalents
Balance at beginning of the period (in shares)	$ 22,717	$ 30,523
Granted (in shares)	11,565	10,080
Forfeited share equivalents (in shares)	981	1,908
Vested share equivalents (in shares)	7,316	10,187
Balance at end of the period (in shares)	$ 28,971	$ 29,395

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Assets
Securities available for sale, at fair value	$ 4,873,778,000	$ 4,783,579,000
Mortgage loans held for sale	128,451,000	107,734,000
Mortgage loans held for investment, at fair value option	550,000	3,143,000
Derivative instruments	46,828,000	24,174,000
Liabilities
Derivative instruments	15,212,000	21,288,000
Fair value assets transferred from Level 1 to Level 2	0
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	4,873,778,000	4,783,579,000
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	550,000	3,143,000
Recurring
Assets
Securities available for sale, at fair value	4,873,778,000	4,783,579,000
Mortgage loans held for sale	128,451,000	107,734,000
Mortgage loans held for investment, at fair value option	550,000	3,143,000
Derivative instruments	51,086,000	27,048,000
Total, Assets	5,053,865,000	4,921,504,000
Liabilities
Derivative instruments	16,756,000	22,124,000
Total	16,756,000	22,124,000
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, Assets	0	0
Liabilities
Derivative instruments	0	0
Total	0	0
Recurring | Level 2
Assets
Securities available for sale, at fair value	4,873,778,000	4,783,579,000
Mortgage loans held for sale	128,451,000	107,734,000
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	51,086,000	27,048,000
Total, Assets	5,053,315,000	4,918,361,000
Liabilities
Derivative instruments	16,756,000	22,124,000
Total	16,756,000	22,124,000
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	550,000	3,143,000
Derivative instruments	0	0
Total, Assets	550,000	3,143,000
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, 2019	Dec. 31, 2018
Assets
Impaired loans	$ 63,145	$ 65,914
OREO, net	8,875	6,433
Total	72,020	72,347
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	63,145	65,914
OREO, net	8,875	6,433
Total	$ 72,020	$ 72,347

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, 2019	Dec. 31, 2018
Mortgage loans held for sale, at fair value
Aggregate Fair Value	$ 128,451	$ 107,734
Aggregate Unpaid Principal	124,410	104,345
Aggregate Fair Value Less Unpaid Principal	4,041	3,389
Mortgage loans held for investment, at fair value
Aggregate Fair Value	550	3,143
Aggregate Unpaid Principal	599	3,595
Aggregate Fair Value Less Unpaid Principal	$ (49)	$ (452)

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, 2019	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Net Gains (Losses) Resulting From Changes in Fair Value - Mortgage loans held for sale, at fair value	$ 652	$ (749)
Net Gains (Losses) Resulting From Changes in Fair Value - Mortgage loans held for investment, at fair value	$ 191	$ (1,142)

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, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Financial Assets
Securities available for sale, at fair value	$ 4,873,778	$ 4,783,579
Mortgage loans held for sale, at fair value	128,451	107,734
Mortgage loans held for investment, at fair value option	550	3,143
Derivative instruments	51,086	27,048
Cash and cash equivalents	671,897	690,453	$ 564,092	$ 625,724
Securities held to maturity	198,958	207,446
Financial Liabilities
Derivative instruments	16,756	22,124
Deposits	24,092,062	23,763,431	$ 22,971,192
Short-term borrowings	1,106,131	1,482,882
Long-term debt	1,475,455	1,166,151
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	671,897	690,453
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	261,131	315,882
Long-term debt	0	0
Level 2
Financial Assets
Securities available for sale, at fair value	4,873,778	4,783,579
Mortgage loans held for sale, at fair value	128,451	107,734
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	51,086	27,048
Cash and cash equivalents	0	0
Securities held to maturity	200,568	204,277
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	0	0
Financial Liabilities
Derivative instruments	16,756	22,124
Deposits	24,086,321	23,752,139
Short-term borrowings	845,000	1,167,000
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	550	3,143
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	22,547,830	22,088,236
Financial Liabilities
Derivative instruments	0	0
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	1,471,292	1,154,062
Carrying Amount
Financial Assets
Securities available for sale, at fair value	4,873,778	4,783,579
Mortgage loans held for sale, at fair value	128,451	107,734
Mortgage loans held for investment, at fair value option	550	3,143
Derivative instruments	51,086	27,048
Cash and cash equivalents	671,897	690,453
Securities held to maturity	198,958	207,446
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	22,824,780	22,376,101
Financial Liabilities
Derivative instruments	16,756	22,124
Deposits	24,092,062	23,763,431
Short-term borrowings	1,106,131	1,482,882
Long-term debt	1,475,455	1,166,151
Fair Value
Financial Assets
Securities available for sale, at fair value	4,873,778	4,783,579
Mortgage loans held for sale, at fair value	128,451	107,734
Mortgage loans held for investment, at fair value option	550	3,143
Derivative instruments	51,086	27,048
Cash and cash equivalents	671,897	690,453
Securities held to maturity	200,568	204,277
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	22,547,830	22,088,236
Financial Liabilities
Derivative instruments	16,756	22,124
Deposits	24,086,321	23,752,139
Short-term borrowings	1,106,131	1,482,882
Long-term debt	$ 1,471,292	$ 1,154,062

Business Segments (Detail)

Business Segments (Detail)	3 Months Ended
	Mar. 31, 2019Segment
Segment Reporting [Abstract]
Number of business segments	3

Business Segments - Schedule of

Business Segments - Schedule of Segment Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information
Interest and dividend income	$ 326,084	$ 270,543
Interest expense	75,600	37,654
Net interest income	250,484	232,889
Provision for/(reversal of) loan losses	13,763	8,211
Other non-interest income (expense)	35,435	29,944
Allocated expenses (income)	0	0
Non-interest expense	158,753	188,071
Income before income tax expense	130,477	81,173
Income tax expense	30,346	17,552
Net income	100,131	63,621
Total loans, leases, and loans held for sale, net of unearned income	23,096,746	21,816,438
Total assets	31,260,189	29,472,637	$ 30,833,015
Total deposits	24,092,062	22,971,192	$ 23,763,431
Average assets	30,833,500	28,132,219
Operating Segments | IBERIABANK
Segment Reporting Information
Interest and dividend income	324,644	268,775
Interest expense	75,600	37,654
Net interest income	249,044	231,121
Provision for/(reversal of) loan losses	13,823	8,216
Other non-interest income (expense)	35,463	29,906
Allocated expenses (income)	(2,033)	(1,479)
Non-interest expense	143,755	171,591
Income before income tax expense	128,962	82,699
Income tax expense	29,975	18,540
Net income	98,987	64,159
Total loans, leases, and loans held for sale, net of unearned income	22,944,800	21,652,223
Total assets	31,044,209	29,243,983
Total deposits	24,078,698	22,959,061
Average assets	30,660,806	27,924,587
Operating Segments | IMC
Segment Reporting Information
Interest and dividend income	1,439	1,767
Interest expense	0	0
Net interest income	1,439	1,767
Provision for/(reversal of) loan losses	(60)	(5)
Other non-interest income (expense)	(12)	38
Allocated expenses (income)	1,500	1,166
Non-interest expense	10,541	11,916
Income before income tax expense	1,295	(1,677)
Income tax expense	307	(410)
Net income	988	(1,267)
Total loans, leases, and loans held for sale, net of unearned income	151,946	164,215
Total assets	191,254	205,497
Total deposits	13,364	12,131
Average assets	148,174	185,742
Operating Segments | LTC
Segment Reporting Information
Interest and dividend income	1	1
Interest expense	0	0
Net interest income	1	1
Provision for/(reversal of) loan losses	0	0
Other non-interest income (expense)	(16)	0
Allocated expenses (income)	533	313
Non-interest expense	4,457	4,564
Income before income tax expense	220	151
Income tax expense	64	(578)
Net income	156	729
Total loans, leases, and loans held for sale, net of unearned income	0	0
Total assets	24,726	23,157
Total deposits	0	0
Average assets	24,520	21,890
Mortgage income
Segment Reporting Information
Non-interest income	11,849	9,595
Mortgage income | Operating Segments | IBERIABANK
Segment Reporting Information
Non-interest income	0	0
Mortgage income | Operating Segments | IMC
Segment Reporting Information
Non-interest income	11,849	9,595
Mortgage income | Operating Segments | LTC
Segment Reporting Information
Non-interest income	0	0
Title income
Segment Reporting Information
Non-interest income	5,225	5,027
Title income | Operating Segments | IBERIABANK
Segment Reporting Information
Non-interest income	0	0
Title income | Operating Segments | IMC
Segment Reporting Information
Non-interest income	0	0
Title income | Operating Segments | LTC
Segment Reporting Information
Non-interest income	$ 5,225	$ 5,027

Commitments and Contingencies_2

Commitments and Contingencies (Detail) - USD ($) $ in Millions	Dec. 11, 2017	Mar. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Fair value of guarantees under commercial and standby letters of credit		$ 2.4	$ 2.4
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, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments to extend credit	$ 760,056	$ 642,162
Unfunded commitments under lines of credit	7,003,670	6,883,963
Commercial and standby letters of credit	241,516	240,436
Reserve for unfunded lending commitments	$ 15,981	$ 14,830	$ 13,432	$ 13,208

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 01, 2024	Apr. 04, 2019	Mar. 31, 2019	Dec. 31, 2018	May 09, 2016
Subsequent Event [Line Items]
Preferred stock, shares issued			13,750	13,750
Preferred stock, par value (in usd per share)			$ 1	$ 1
Liquidation preference (per share)			$ 10,000	$ 10,000
Liquidation preference value					$ 137,500
Series D Depositary Shares | Subsequent Event
Subsequent Event [Line Items]
Preferred stock, shares issued		4,000,000
Liquidation preference (per share)		$ 25
Ownership interest per depositary share		0.25%
Series D Preferred Stock | Subsequent Event
Subsequent Event [Line Items]
Dividend rate per share		6.10%
Preferred stock, par value (in usd per share)		$ 1
Liquidation preference (per share)		$ 10,000
Liquidation preference value		$ 100,000
Variable dividend rate after August 1, 2024	3.859%

Uncategorized Items - ibkc-2019

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (345,000)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1	1,847,000	[1]
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(345,000)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1	$ 1,847,000	[1]
[1]	Cumulative-effect adjustment to beginning retained earnings for fair value adjustments related to the reclassification of certain equity investments in accordance with ASU 2016-01, adopted as of January 1, 2018.