Iberiabank (IBKC) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	001-37532
Entity Registrant Name	IBERIABANK Corp
Entity Incorporation, State or Country Code	LA
Entity Address, Address Line One	200 West Congress Street
Entity Address, City or Town	Lafayette,
Entity Address, State or Province	LA
Entity Tax Identification Number	72-1280718
Entity Address, Postal Zip Code	70501
City Area Code	337
Local Phone Number	521-4003
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		52,656,199
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000933141
Current Fiscal Year End Date	--12-31
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock (par value $1.00 per share)
Trading Symbol	IBKC
Security Exchange Name	NASDAQ
Series B Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/400th Interest in
Trading Symbol	IBKCP
Security Exchange Name	NASDAQ
Series C Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/400th Interest in
Trading Symbol	IBKCO
Security Exchange Name	NASDAQ
Series D Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/400th Interest
Trading Symbol	IBKCN
Security Exchange Name	NASDAQ

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 289,502	$ 294,186
Interest-bearing deposits in other banks	499,813	396,267
Total cash and cash equivalents	789,315	690,453
Securities available for sale, at fair value	4,455,308	4,783,579
Securities held to maturity (fair values of $198,012 and $204,277, respectively)	192,917	207,446
Mortgage loans held for sale, at fair value	187,987	107,734
Loans and leases, net of unearned income	23,355,311	22,519,815
Allowance for loan and lease losses	(146,386)	(140,571)
Loans and leases, net	23,208,925	22,379,244
Premises and equipment, net	295,897	300,507
Goodwill	1,235,533	1,235,533
Other intangible assets	81,618	88,736
Other assets	999,032	1,039,783
Total Assets	31,446,532	30,833,015
Deposits:
Non-interest-bearing	6,474,394	6,542,490
Interest-bearing	17,820,937	17,220,941
Total deposits	24,295,331	23,763,431
Short-term borrowings	997,507	1,482,882
Long-term debt	1,374,759	1,166,151
Other liabilities	540,935	364,274
Total Liabilities	27,208,532	26,776,738
Shareholders’ Equity
Preferred stock, $1 par value - 5,000,000 shares authorized Non-cumulative perpetual, liquidation preference $10,000 per share; 23,750 and 13,750 shares issued and outstanding, respectively, including related surplus	228,485	132,097
Common stock, $1 par value - 100,000,000 shares authorized; 52,805,461 and 54,796,231 shares issued and outstanding, respectively	52,805	54,796
Additional paid-in capital	2,714,074	2,869,416
Retained earnings	1,195,546	1,042,718
Accumulated other comprehensive income (loss)	47,090	(42,750)
Total Shareholders’ Equity	4,238,000	4,056,277
Total Liabilities and Shareholders’ Equity	$ 31,446,532	$ 30,833,015

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities held to maturity, fair values	$ 198,012	$ 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	23,750	13,750
Preferred stock, shares outstanding	23,750	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	52,805,461	54,796,231
Common stock, shares outstanding	52,805,461	54,796,231

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest and dividend income
Loans and leases, including fees	$ 296,686	$ 270,476	$ 581,565	$ 508,545
Mortgage loans held for sale, including fees	1,588	836	2,642	1,990
Taxable securities	31,662	26,617	65,578	51,945
Tax-exempt securities	2,141	2,708	4,350	5,474
Other	3,890	3,186	7,916	6,412
Total interest and dividend income	335,967	303,823	662,051	574,366
Interest Expense
Deposits	65,866	36,159	126,101	64,403
Short-term borrowings	5,197	3,327	10,913	5,851
Long-term debt	9,565	8,224	19,214	15,110
Total interest expense	80,628	47,710	156,228	85,364
Net interest income	255,339	256,113	505,823	489,002
Provision for credit losses	10,755	7,696	24,518	15,907
Net interest income after provision for credit losses	244,584	248,417	481,305	473,095
Non-interest income
Income from bank owned life insurance	1,750	1,261	3,547	2,543
Securities (losses) gains, net	(1,014)	3	(1,014)	(56)
Other non-interest income	4,250	4,299	8,301	7,387
Total non-interest income	58,825	53,940	111,334	98,506
Non-interest expense
Salaries and employee benefits	103,375	107,445	201,671	212,031
Net occupancy and equipment	18,999	19,931	37,563	39,978
Communication and delivery	3,597	4,213	7,297	8,115
Marketing and business development	3,370	4,895	7,488	9,647
Computer services expense	9,383	9,309	18,540	21,702
Professional services	6,244	7,160	10,694	14,551
Credit and other loan related expense	4,141	5,089	7,000	9,482
Insurance	4,265	6,946	8,451	14,051
Travel and entertainment	2,738	2,797	5,168	6,034
Amortization of acquisition intangibles	4,786	6,111	9,795	11,213
Impairment of long-lived assets and other losses	496	15,700	1,560	24,457
Other non-interest expense	8,224	7,180	13,144	13,586
Total non-interest expense	169,618	196,776	328,371	384,847
Income before income tax expense	133,791	105,581	264,268	186,754
Income tax expense	32,193	30,457	62,539	48,009
Net income	101,598	75,124	201,729	138,745
Less: Preferred stock dividends	949	949	4,547	4,547
Net income available to common shareholders	100,649	74,175	197,182	134,198
Less: Earnings allocated to unvested restricted stock	999	767	1,931	1,409
Earnings allocated to common shareholders	$ 99,650	$ 73,408	$ 195,251	$ 132,789
Earnings per common share - Basic (in usd per share)	$ 1.87	$ 1.31	$ 3.63	$ 2.42
Earnings per common share - Diluted (in usd per share)	1.86	1.30	3.61	2.41
Cash dividends declared per common share (in usd per share)	$ 0.43	$ 0.38	$ 0.86	$ 0.76
Comprehensive income
Net income	$ 101,598	$ 75,124	$ 201,729	$ 138,745
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) arising during the period (net of tax effects of $14,836, $4,449, $25,511, and $18,672, respectively)	45,108	(16,734)	86,516	(70,240)
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $251, $1, $251, and $12, respectively)	(763)	2	(763)	(44)
Unrealized gains (losses) on securities, net of tax	45,871	(16,736)	87,279	(70,196)
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 $1,461, $371, $990, and $1,048, respectively)	4,441	1,395	2,256	3,944
Less: Reclassification adjustment for gains (losses) included in net income (net of tax effects of $26, $11, $100, and $42, respectively)	(78)	(40)	(305)	(156)
Fair value of derivative instruments designated as cash flow hedges, net of tax	4,519	1,435	2,561	4,100
Other comprehensive income (loss), net of tax	50,390	(15,301)	89,840	(66,096)
Comprehensive income	151,988	59,823	291,569	72,649
Mortgage income
Non-interest income
Non-interest income	18,444	13,721	30,293	23,316
Service charges on deposit accounts
Non-interest income
Non-interest income	12,847	12,950	25,657	25,858
Title revenue
Non-interest income
Non-interest income	6,895	6,846	12,120	11,873
Broker commissions
Non-interest income
Non-interest income	2,044	2,396	3,997	4,617
ATM and debit card fee income
Non-interest income
Non-interest income	3,032	2,925	5,614	5,558
Credit card and merchant-related income
Non-interest income
Non-interest income	3,226	3,326	6,637	6,233
Trust department income
Non-interest income
Non-interest income	4,388	4,243	8,555	7,669
Commission income
Non-interest income
Non-interest income	$ 2,963	$ 1,970	$ 7,627	$ 3,508

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Unrealized holding gains (losses) arising during the period, tax expense (benefit)	$ 14,836	$ (4,449)	$ 25,511	$ (18,672)
Reclassification adjustment for gains (losses) included in net income, tax expense (benefit)	(251)	1	(251)	(12)
Change in fair value of derivative instruments designated as cash flow hedges, tax expense	1,461	371	990	1,048
Reclassification adjustment for gains (losses) included in net income, tax expense (benefit)	$ (26)	$ (11)	$ (100)	$ (42)

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	138,745				138,745
Other comprehensive income (loss)	(66,096)					(66,096)
Cash dividends declared	(43,006)				(43,006)
Preferred stock dividends	(4,547)				(4,547)
Common stock issued under incentive plans, net of shares surrendered in payment (in shares)			130,342
Common stock issued under incentive plans, net of shares surrendered in payment	(2,102)		$ 130	(2,232)
Common stock issued for acquisitions (in shares)			2,787,773
Common stock issued for acquisitions	214,659		$ 2,788	211,871
Common stock repurchases (in shares)			(400,000)
Common stock repurchases	(30,670)		$ (400)	(30,270)
Share-based compensation expense	9,980			9,980
Ending balance (in shares) at Jun. 30, 2018		13,750	56,390,387
Ending balance at Jun. 30, 2018	3,913,409	$ 132,097	$ 56,390	2,976,833	860,073	(111,984)
Beginning balance (in shares) at Mar. 31, 2018		13,750	56,778,841
Beginning balance at Mar. 31, 2018	3,900,907	$ 132,097	$ 56,779	3,001,389	807,325	(96,683)
Increase (Decrease) in Shareholders' Equity
Net income	75,124				75,124
Other comprehensive income (loss)	(15,301)					(15,301)
Cash dividends declared	(21,427)				(21,427)
Preferred stock dividends	(949)				(949)
Common stock issued under incentive plans, net of shares surrendered in payment (in shares)			11,546
Common stock issued under incentive plans, net of shares surrendered in payment	479		$ 11	468
Common stock repurchases (in shares)			(400,000)
Common stock repurchases	(30,670)		$ (400)	(30,270)
Share-based compensation expense	5,246			5,246
Ending balance (in shares) at Jun. 30, 2018		13,750	56,390,387
Ending balance at Jun. 30, 2018	3,913,409	$ 132,097	$ 56,390	2,976,833	860,073	(111,984)
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	201,729				201,729
Other comprehensive income (loss)	89,840					89,840
Cash dividends declared	(46,201)				(46,201)
Preferred stock dividends	(4,547)				(4,547)
Common stock issued under incentive plans, net of shares surrendered in payment (in shares)			157,000
Common stock issued under incentive plans, net of shares surrendered in payment	(4,448)		$ 157	(4,605)
Common stock issued for acquisitions (in shares)		10,000
Common stock issued for acquisitions	96,388	$ 96,388
Common stock repurchases (in shares)			(2,147,770)
Common stock repurchases	(164,724)		$ (2,148)	(162,576)
Share-based compensation expense	11,839			11,839
Ending balance (in shares) at Jun. 30, 2019		23,750	52,805,461
Ending balance at Jun. 30, 2019	4,238,000	$ 228,485	$ 52,805	2,714,074	1,195,546	47,090
Beginning balance (in shares) at Mar. 31, 2019		13,750	54,551,264
Beginning balance at Mar. 31, 2019	4,141,831	$ 132,097	$ 54,551	2,840,842	1,117,641	(3,300)
Increase (Decrease) in Shareholders' Equity
Net income	101,598				101,598
Other comprehensive income (loss)	50,390					50,390
Cash dividends declared	(22,744)				(22,744)
Preferred stock dividends	(949)				(949)
Common stock issued under incentive plans, net of shares surrendered in payment (in shares)			14,046
Common stock issued under incentive plans, net of shares surrendered in payment	(3)		$ 14	(17)
Common stock issued for acquisitions (in shares)		10,000
Common stock issued for acquisitions	96,388	$ 96,388
Common stock repurchases (in shares)			(1,759,849)
Common stock repurchases	(134,778)		$ (1,760)	(133,018)
Share-based compensation expense	6,267			6,267
Ending balance (in shares) at Jun. 30, 2019		23,750	52,805,461
Ending balance at Jun. 30, 2019	$ 4,238,000	$ 228,485	$ 52,805	$ 2,714,074	$ 1,195,546	$ 47,090

Consolidated Statements of Sh_2

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Cash dividends declared per common share (in usd per share)	$ 0.43	$ 0.38	$ 0.86	$ 0.76

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash Flows from Operating Activities
Net income	$ 201,729	$ 138,745
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	4,811	(562)
Provision for credit losses	24,518	15,907
Share-based compensation expense - equity awards	11,839	9,980
(Gain) loss on sale of OREO and long-lived assets, net of impairment	(1,270)	5,131
Securities losses, net	1,014	56
Deferred income tax expense	35,044	11,715
Originations of mortgage loans held for sale	(864,324)	(774,849)
Proceeds from sales of mortgage loans held for sale	815,728	848,116
Realized and unrealized (gain) on mortgage loans held for sale, net	(29,425)	(22,688)
Other operating activities, net	164,193	13,977
Net Cash Provided by Operating Activities	363,857	245,528
Cash Flows from Investing Activities
Proceeds from sales of available for sale securities	299,513	18,867
Proceeds from maturities, prepayments and calls of available for sale securities	316,982	311,340
Purchases of available for sale securities, net of available for sale securities acquired	(186,554)	(511,074)
Proceeds from maturities, prepayments and calls of held to maturity securities	13,123	4,746
Purchases of equity securities, net of equity securities acquired	(15,154)	(11,545)
Proceeds from sales of equity securities	3,637	70,371
Increase in loans, net of loans acquired	(824,675)	(501,618)
Proceeds from sales of premises and equipment	101	2,003
Purchases of premises and equipment, net of premises and equipment acquired	(7,819)	(8,304)
Proceeds from dispositions of OREO	8,247	11,431
Cash paid for additional investment in tax credit entities	(4,790)	(1,831)
Cash received for acquisition of a business, net of cash paid	0	99,318
Purchase of bank owned life insurance policies	0	(50,000)
Other investing activities, net	249	554
Net Cash Used in Investing Activities	(397,140)	(565,742)
Cash Flows from Financing Activities
Increase in deposits, net of deposits acquired	531,900	899,752
Net change in short-term borrowings	(485,375)	62,916
Proceeds from long-term debt, net of long-term debt acquired	400,000	440,299
Repayments of long-term debt	(191,123)	(902,262)
Cash dividends paid on common stock	(45,926)	(41,508)
Cash dividends paid on preferred stock	(4,547)	(4,547)
Net share-based compensation stock transactions	(4,448)	(2,102)
Payments to repurchase common stock	(164,724)	(30,670)
Net proceeds from issuance of preferred stock	96,388	0
Net Cash Provided by Financing Activities	132,145	421,878
Net Increase In Cash and Cash Equivalents	98,862	101,664
Cash and Cash Equivalents at Beginning of Period	690,453	625,724
Cash and Cash Equivalents at End of Period	789,315	727,388
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	5,055	2,722
Common stock issued in acquisitions	0	214,659
Cash paid (received) for:
Interest on deposits and borrowings, net of acquired	149,638	83,057
Income taxes, net	$ (152,950)	$ 19,006

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 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	6 Months Ended
	Jun. 30, 2019
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Pronouncements adopted during the six months ended June 30, 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 shortens 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, ASU No. 2019-04 (portion related to ASC 326), and ASU No. 2019-05 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 expands credit quality disclosures. Additionally, ASU No. 2016-13 amends the current AFS security impairment model for debt securities. The new model will require an estimate of ECL when the fair value is below the amortized cost of the asset. The credit-related impairment (and subsequent recoveries) are recognized as an allowance on the balance sheet with a corresponding adjustment to the income statement. Non-credit related losses will continue to be recognized through OCI. In addition, ASU No. 2016-13 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. This 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. During 2019, the FASB issued ASU No. 2019-04, Codification Improvements to Financial Instruments-Credit Losses (ASC 326), Derivatives and Hedging (ASC 815), and Financial Instruments (ASC 825), which clarified the scope of ASU No. 2016-13 and addressed various issues, including accrued interest receivable balances, recoveries, variable interest rates and prepayments, and ASU No. 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief , which clarified certain implementation issues. The effective date for the portion of ASU No. 2019-04 related to credit losses and ASU No. 2019-05 are the same as ASU No. 2016-13. 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. Implementation efforts are underway, including model development, fulfillment of additional data needs for new disclosure and reporting requirements, and drafting of accounting policies. Substantial progress has been made in model development. Model validation commenced in the second quarter of 2019. User acceptance testing and parallel runs are scheduled to begin in the third quarter of 2019. The Company expects that these ASUs will result in an increase to ACL as of January 1, 2020 given the requirement to estimate lifetime expected credit losses for the loan portfolio, although the extent of the increase to ACL is not yet known. The transition adjustment to increase ACL is expected to result in a decrease to shareholders' equity and to a lesser extent, discounts on acquired loans. While these ASUs are expected to increase ACL, they do not change the overall credit risk in the Company's loan and lease portfolios or the ultimate losses therein. The ultimate impact of the adoption of these ASUs will depend on the composition of the loan, lease 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 an impact on the Company’s financial position or results of operations. ASU No. 2018-17 In October 2018, the FASB released ASU No. 2018-17, Consolidation (ASC 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities, which improves the consistency of the application of the variable interest entity (VIE) related party guidance for common control arrangements. This ASU requires reporting entities to consider indirect interests held through related parties under common control on a proportional basis rather than as the equivalent of a direct interest in its entirety (as currently required in GAAP) when determining whether a decision-making fee is a variable interest. ASU No. 2018-17 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 will 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. The amendments related to the credit losses standard are discussed above under ASU 2016-13. With respect to hedge accounting, the ASU addresses partial-term fair value hedges, fair value hedge basis adjustments, and certain transition requirements, among other things. For recognizing and measuring financial instruments, the ASU addresses the scope of the guidance, the requirement for re-measurement under ASC 820 when using the measurement alternative, certain disclosure requirements and which equity securities have to be re-measured at historical exchange rates. Since the Company early adopted the guidance in ASU No. 2017-12, Derivatives and Hedging (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	6 Months Ended
	Jun. 30, 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: June 30, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,859 $ 341 $ — $ 40,200 Obligations of state and political subdivisions 172,160 6,698 — 178,858 Mortgage-backed securities: Residential agency 3,341,602 32,909 (6,364 ) 3,368,147 Commercial agency 742,760 17,383 (1,107 ) 759,036 Other securities 105,620 3,539 (92 ) 109,067 Total securities available for sale $ 4,402,001 $ 60,870 $ (7,563 ) $ 4,455,308 Securities held to maturity: Obligations of state and political subdivisions $ 175,281 $ 5,407 $ — $ 180,688 Mortgage-backed securities: Residential agency 17,636 30 (342 ) 17,324 Total securities held to maturity $ 192,917 $ 5,437 $ (342 ) $ 198,012 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 $2.2 billion and $2.4 billion were pledged to support repurchase transactions, public funds deposits, and certain long-term borrowings at June 30, 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, was as follows: June 30, 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: Mortgage-backed securities: Residential agency $ — $ — $ (6,364 ) $ 1,026,095 $ (6,364 ) $ 1,026,095 Commercial agency — — (1,107 ) 122,450 (1,107 ) 122,450 Other securities — — (92 ) 5,015 (92 ) 5,015 Total securities available for sale $ — $ — $ (7,563 ) $ 1,153,560 $ (7,563 ) $ 1,153,560 Securities held to maturity: Mortgage-backed securities: Residential agency $ — $ — $ (342 ) $ 17,039 $ (342 ) $ 17,039 Total securities held to maturity $ — $ — $ (342 ) $ 17,039 $ (342 ) $ 17,039 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 June 30, 2019 , the Company did not intend to sell any of these securities, did not expect to be required to sell these securities, and expected to recover the entire amortized cost of all these securities. At June 30, 2019 , 189 debt securities had unrealized losses of 0.67% 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 were in a continuous loss position for over twelve months at June 30, 2019 and December 31, 2018 is presented in the following table. (in thousands) June 30, 2019 December 31, 2018 Number of securities Mortgage-backed securities: Residential agency 159 302 Commercial agency 26 72 Obligations of state and political subdivisions — 60 Other securities 4 7 189 441 Amortized Cost Basis Mortgage-backed securities: Residential agency $ 1,049,840 $ 2,268,608 Commercial agency 123,557 498,321 Obligations of state and political subdivisions — 185,175 Other securities 5,107 33,270 $ 1,178,504 $ 2,985,374 Unrealized Loss Mortgage-backed securities: Residential agency $ 6,706 $ 57,268 Commercial agency 1,107 14,756 Obligations of state and political subdivisions — 3,208 Other securities 92 693 $ 7,905 $ 75,925 The amortized cost and estimated fair value of investment securities by maturity at June 30, 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 3.67 % $ 1,554 $ 1,558 2.34 % $ 952 $ 955 One through five years 2.66 112,248 113,915 2.63 4,484 4,524 After five through ten years 2.72 769,216 789,351 2.43 45,338 46,508 Over ten years 2.84 3,518,983 3,550,484 2.60 142,143 146,025 2.82 % $ 4,402,001 $ 4,455,308 2.56 % $ 192,917 $ 198,012 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 June 30, Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Realized gains $ 1,297 $ 30 $ 1,297 $ 39 Realized losses (2,311 ) (27 ) (2,311 ) (95 ) $ (1,014 ) $ 3 $ (1,014 ) $ (56 ) 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, were as follows: (in thousands) June 30, 2019 December 31, 2018 Federal Home Loan Bank stock $ 108,396 $ 95,213 Federal Reserve Bank stock 85,630 85,630 CRA and Community Development Investment Funds 2,192 1,884 Other investments 15,319 9,709 $ 211,537 $ 192,436

Loans and Leases

Loans and Leases	6 Months Ended
	Jun. 30, 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) June 30, 2019 December 31, 2018 Commercial loans and leases: Real estate - construction $ 1,342,984 $ 1,196,366 Real estate - owner-occupied 2,373,143 2,395,822 Real estate - non-owner-occupied 6,102,143 5,796,117 Commercial and industrial (1) 6,161,759 5,737,017 Total commercial loans and leases 15,980,029 15,125,322 Residential mortgage loans 4,538,194 4,359,156 Consumer and other loans: Home equity 2,147,897 2,304,694 Other 689,191 730,643 Total consumer and other loans 2,837,088 3,035,337 Total loans and leases $ 23,355,311 $ 22,519,815 (1) Includes equipment financing leases Net deferred loan origination fees were $30.1 million and $30.2 million at June 30, 2019 and December 31, 2018 , respectively. Total net discount on the Company's loans was $114.3 million and $136.8 million at June 30, 2019 and December 31, 2018 , respectively, of which $71.6 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 June 30, 2019 and December 31, 2018 , overdrafts of $5.6 million and $9.2 million , respectively, had been reclassified to loans. Loans with carrying values of $8.0 billion and $7.6 billion were pledged as collateral for borrowings at June 30, 2019 and December 31, 2018 , respectively. Aging Analysis The following tables provide an analysis of the aging of loans and leases as of June 30, 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. June 30, 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 $ 1,322,728 $ 207 $ — $ — $ 207 $ 1,188 $ 18,861 $ 1,342,984 Real estate- owner-occupied 2,285,316 7,274 — — 7,274 15,789 64,764 2,373,143 Real estate- non-owner-occupied 6,007,594 2,456 6,345 — 8,801 22,028 63,720 6,102,143 Commercial and industrial 6,086,983 3,035 437 — 3,472 48,747 22,557 6,161,759 Residential mortgage 4,393,649 4,914 5,941 851 11,706 50,046 82,793 4,538,194 Consumer - home equity 2,067,280 7,123 1,616 — 8,739 18,646 53,232 2,147,897 Consumer - other 680,595 2,972 701 — 3,673 2,548 2,375 689,191 Total $ 22,844,145 $ 27,981 $ 15,040 $ 851 $ 43,872 $ 158,992 $ 308,302 $ 23,355,311 (1) Of the total non-accrual loans at June 30, 2019 , $11.3 million were past due 30-59 days, $4.2 million were past due 60-89 days, and $68.6 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 $200.9 million and $202.6 million at June 30, 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 six months ended June 30 : (in thousands) 2019 2018 Balance at beginning of period $ 133,342 $ 152,623 Additions — 2,371 Transfers from non-accretable difference to accretable yield (2,563 ) (467 ) Accretion (19,580 ) (25,140 ) Changes in expected cash flows not affecting non-accretable differences (1) (4,341 ) 7,597 Balance at end of period $ 106,858 $ 136,984 (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 June 30, 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 $37.4 million and $46.7 million occurred during the six months ended June 30, 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 June 30, Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Extended maturities $ 7,633 $ 1,790 $ 11,175 $ 7,193 Maturity and interest rate adjustment 224 — 617 102 Movement to or extension of interest-rate only payments 1,771 1,316 1,783 1,364 Interest rate adjustment 74 — 74 103 Forbearance — 1,405 5,742 13,936 Other concession(s) (1) 10,950 15,597 18,018 23,993 Total $ 20,652 $ 20,108 $ 37,409 $ 46,691 (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 $37.4 million of TDRs occurring during the six months ended June 30, 2019 , $13.9 million were on accrual status and $23.5 million were on non-accrual status. Of the $46.7 million of TDRs occurring during the six months ended June 30, 2018 , $20.6 million were on accrual status and $26.1 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 June 30, 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- owner-occupied 4 $ 339 $ 338 5 $ 2,230 $ 2,201 Real estate- non-owner-occupied 7 4,687 4,628 5 823 780 Commercial and industrial 19 13,757 13,607 16 21,103 13,618 Residential mortgage 10 847 836 7 688 633 Consumer - home equity 22 1,159 1,056 19 2,361 2,350 Consumer - other 20 210 187 35 556 526 Total 82 $ 20,999 $ 20,652 87 $ 27,761 $ 20,108 Six Months Ended June 30, 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 $ 37 1 $ 1,950 $ 1,013 Real estate- owner-occupied 6 1,435 1,402 7 12,921 11,290 Real estate- non-owner-occupied 13 7,756 7,651 14 1,912 1,854 Commercial and industrial 38 29,785 20,670 32 35,338 26,684 Residential mortgage 19 1,687 1,669 7 688 633 Consumer - home equity 54 5,312 5,137 33 4,170 4,133 Consumer - other 51 918 843 51 1,126 1,084 Total 182 $ 46,932 $ 37,409 145 $ 58,105 $ 46,691 Information detailing TDRs that defaulted during the three-month and six-month periods ended June 30, 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 June 30, 2019 2018 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 37 — $ — Real estate- owner-occupied 4 1,232 5 461 Real estate- non-owner-occupied 11 2,341 9 1,448 Commercial and industrial 17 5,475 8 1,437 Residential mortgage 12 1,012 7 775 Consumer - home equity 17 1,411 11 1,129 Consumer - other 34 515 21 232 Total 96 $ 12,023 61 $ 5,482 Six Months Ended June 30, 2019 2018 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 37 — $ — Real estate- owner-occupied 6 1,232 6 9,455 Real estate- non-owner-occupied 17 2,913 15 1,813 Commercial and industrial 25 6,152 21 7,100 Residential mortgage 21 1,597 10 1,081 Consumer - home equity 27 2,401 26 2,242 Consumer - other 41 591 48 1,003 Total 138 $ 14,923 126 $ 22,694

Allowance for Credit Losses and

Allowance for Credit Losses and Credit Quality	6 Months Ended
	Jun. 30, 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 six months ended June 30 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 24,067 15,581 Transfer of balance to OREO and other (2,863 ) (3,943 ) Charge-offs (19,194 ) (22,734 ) Recoveries 3,805 6,781 Allowance for loan and lease losses at end of period $ 146,386 $ 136,576 Reserve for unfunded commitments at beginning of period $ 14,830 $ 13,208 Balance created in acquisition accounting — 900 Provision for unfunded lending commitments 451 325 Reserve for unfunded commitments at end of period $ 15,281 $ 14,433 Allowance for credit losses at end of period $ 161,667 $ 151,009 A summary of changes in the allowance for credit losses, by loan portfolio type, for the six months ended June 30 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 (Reversal of) loan and lease losses 15,204 5,077 (584 ) 4,370 24,067 Transfer of balance to OREO and other (256 ) (1 ) (2,862 ) 256 (2,863 ) Charge-offs (641 ) (11,880 ) (168 ) (6,505 ) (19,194 ) Recoveries 318 1,796 157 1,534 3,805 Allowance for loan and lease losses at end of period $ 66,431 $ 49,088 $ 9,541 $ 21,326 $ 146,386 Reserve for unfunded commitments at beginning of period $ 4,869 $ 6,198 $ 866 $ 2,897 $ 14,830 Provision for (Reversal of) unfunded commitments 603 (313 ) (206 ) 367 451 Reserve for unfunded commitments at end of period $ 5,472 $ 5,885 $ 660 $ 3,264 $ 15,281 Allowance on loans individually evaluated for impairment $ 4,673 $ 7,656 $ 349 $ 3,176 $ 15,854 Allowance on loans collectively evaluated for impairment 56,251 39,854 5,127 18,008 119,240 Allowance on loans acquired with deteriorated credit quality 5,507 1,578 4,065 142 11,292 Loans and leases, net of unearned income: Balance at end of period $ 9,818,270 $ 6,161,759 $ 4,538,194 $ 2,837,088 $ 23,355,311 Balance at end of period individually evaluated for impairment 74,331 54,860 41,363 39,127 209,681 Balance at end of period collectively evaluated for impairment 9,596,594 6,084,342 4,414,038 2,742,354 22,837,328 Balance at end of period acquired with deteriorated credit quality 147,345 22,557 82,793 55,607 308,302 2018 (in thousands) Commercial Real Estate Commercial and Industrial Residential Mortgage Consumer and Other Total Allowance for loan and lease losses at beginning of period $ 54,201 $ 53,916 $ 9,117 $ 23,657 $ 140,891 Provision for (Reversal of) loan and lease losses (3,404 ) 10,083 1,112 7,790 15,581 Transfer of balance to OREO and other (506 ) (18 ) 6 (3,425 ) (3,943 ) Charge-offs (1,258 ) (13,575 ) (196 ) (7,705 ) (22,734 ) Recoveries 384 4,403 44 1,950 6,781 Allowance for loan and lease losses at end of period $ 49,417 $ 54,809 $ 10,083 $ 22,267 $ 136,576 Reserve for unfunded commitments at beginning of period $ 4,531 $ 5,309 $ 555 $ 2,813 $ 13,208 Balance created in acquisition accounting 129 81 — 690 900 Provision for (Reversal of) unfunded commitments 467 (306 ) 160 4 325 Reserve for unfunded commitments at end of period $ 5,127 $ 5,084 $ 715 $ 3,507 $ 14,433 Allowance on loans individually evaluated for impairment $ 2,274 $ 11,946 $ 168 $ 3,199 $ 17,587 Allowance on loans collectively evaluated for impairment 40,763 40,540 3,816 18,742 103,861 Allowance on loans acquired with deteriorated credit quality 6,380 2,323 6,099 326 15,128 Loans and leases, net of unearned income: Balance at end of period $ 9,292,304 $ 5,512,416 $ 4,124,538 $ 3,146,525 $ 22,075,783 Balance at end of period individually evaluated for impairment 84,217 66,683 5,873 35,550 192,323 Balance at end of period collectively evaluated for impairment 9,017,756 5,415,093 3,984,086 3,029,027 21,445,962 Balance at end of period acquired with deteriorated credit quality 190,331 30,640 134,579 81,948 437,498 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 commercial 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 commercial 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 June 30, 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. June 30, 2019 December 31, 2018 (in thousands) Pass Special Mention Sub- Doubtful Total Pass Special Mention Sub- Doubtful Total Real estate - construction $ 1,320,007 $ 12,262 $ 10,715 $ — $ 1,342,984 $ 1,182,554 $ 1,062 $ 12,740 $ 10 $ 1,196,366 Real estate - owner-occupied 2,308,176 25,114 37,126 2,727 2,373,143 2,328,999 25,526 41,297 — 2,395,822 Real estate - non-owner-occupied 6,011,800 48,323 39,832 2,188 6,102,143 5,687,963 78,009 26,512 3,633 5,796,117 Commercial and industrial 6,018,866 53,075 73,667 16,151 6,161,759 5,586,482 52,632 73,853 24,050 5,737,017 Total $ 15,658,849 $ 138,774 $ 161,340 $ 21,066 $ 15,980,029 $ 14,785,998 $ 157,229 $ 154,402 $ 27,693 $ 15,125,322 June 30, 2019 December 31, 2018 (in thousands) Current 30+ Days Past Due Total Current 30+ Days Past Due Total Residential mortgage $ 4,459,706 $ 78,488 $ 4,538,194 $ 4,290,152 $ 69,004 $ 4,359,156 Consumer - home equity 2,113,237 34,660 2,147,897 2,258,659 46,035 2,304,694 Consumer - other 682,860 6,331 689,191 721,231 9,412 730,643 Total $ 7,255,803 $ 119,479 $ 7,375,282 $ 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. June 30, 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 27,142 27,064 — 25,037 19,044 — Real estate - non-owner-occupied 21,234 20,271 — 15,265 14,288 — Commercial and industrial 33,989 30,157 — 55,554 43,886 — Residential mortgage 32,448 31,645 — 1,244 1,221 — Consumer - home equity 1,995 1,998 — 4,183 4,176 — Consumer - other — — — — — — With an allowance recorded: Real estate - construction 140 127 (2 ) 228 140 (11 ) Real estate - owner-occupied 8,811 8,248 (4,061 ) 5,032 4,773 (520 ) Real estate - non-owner-occupied 7,683 7,482 (610 ) 6,445 6,398 (105 ) Commercial and industrial 37,969 24,703 (7,656 ) 46,387 27,915 (12,646 ) Residential mortgage 10,366 9,718 (349 ) 5,870 5,358 (145 ) Consumer - home equity 33,194 32,702 (2,662 ) 29,284 28,818 (2,427 ) Consumer - other 4,743 4,427 (514 ) 4,956 4,446 (488 ) Total $ 231,852 $ 209,681 $ (15,854 ) $ 209,746 $ 169,725 $ (16,342 ) Total commercial loans and leases $ 149,106 $ 129,191 $ (12,329 ) $ 164,209 $ 125,706 $ (13,282 ) Total residential mortgage loans 42,814 41,363 (349 ) 7,114 6,579 (145 ) Total consumer and other loans 39,932 39,127 (3,176 ) 38,423 37,440 (2,915 ) Three Months Ended June 30, 2019 Three Months Ended June 30, 2018 Six Months Ended June 30, 2019 Six Months Ended June 30, 2018 Average Interest Average Interest Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (in thousands) With no related allowance recorded: Real estate - construction $ 21,339 $ 341 $ 12,952 $ 198 $ 21,340 $ 678 $ 12,597 $ 393 Real estate - owner-occupied 24,134 326 30,899 209 27,314 569 31,265 609 Real estate - non-owner-occupied 20,305 100 15,929 121 20,360 207 16,558 250 Commercial and industrial 29,315 151 37,859 389 29,816 331 37,806 836 Residential mortgage 27,129 235 1,272 13 18,804 374 1,280 27 Consumer - home equity 1,998 22 1,910 28 1,943 44 1,922 52 With an allowance recorded: Real estate - construction 131 1 152 — 135 2 152 — Real estate - owner-occupied 8,578 57 19,582 82 8,628 116 19,696 192 Real estate - non-owner-occupied 7,557 42 1,631 14 7,643 122 1,705 39 Commercial and industrial 23,891 177 38,134 158 21,400 371 38,981 357 Residential mortgage 9,833 73 4,657 47 9,881 169 4,678 92 Consumer - home equity 32,885 332 28,595 304 32,341 656 28,173 600 Consumer - other 4,533 63 5,220 67 4,597 128 5,267 139 Total $ 211,628 $ 1,920 $ 198,792 $ 1,630 $ 204,202 $ 3,767 $ 200,080 $ 3,586 Total commercial loans and leases $ 135,250 $ 1,195 $ 157,138 $ 1,171 $ 136,636 $ 2,396 $ 158,760 $ 2,676 Total residential mortgage loans 36,962 308 5,929 60 28,685 543 5,958 119 Total consumer and other loans 39,416 417 35,725 399 38,881 828 35,362 791 As of June 30, 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	6 Months Ended
	Jun. 30, 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 six months ended June 30, 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, June 30, 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 six months ended June 30, 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: June 30, 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 $ 16,885 $ (5,486 ) $ 11,399 $ 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 June 30, 2019 and December 31, 2018 . No events or changes in circumstances occurred during the six months ended June 30, 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: June 30, 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 $ (72,870 ) $ 63,313 $ 136,183 $ (63,213 ) $ 72,970 Customer relationship intangible asset 1,385 (1,354 ) 31 1,385 (1,323 ) 62 Non-compete agreement 206 (94 ) 112 206 (72 ) 134 Total $ 137,774 $ (74,318 ) $ 63,456 $ 137,774 $ (64,608 ) $ 73,166

Derivative Instruments and Othe

Derivative Instruments and Other Hedging Activities	6 Months Ended
	Jun. 30, 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) June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 21,015 $ 3,469 $ — $ — Total derivatives designated as hedging instruments $ 21,015 $ 3,469 $ — $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 24 $ 474 $ 5,041 $ 191 Customer swaps - downstream 76,944 16,946 1,760 17,812 Foreign exchange contracts — 18 — 18 Forward sales contracts 146 630 1,834 750 Written and purchased options 9,574 5,490 3,871 3,310 Other contracts 44 21 93 43 Total derivatives not designated as hedging instruments $ 86,732 $ 23,579 $ 12,599 $ 22,124 Total $ 107,747 $ 27,048 $ 12,599 $ 22,124 Derivative Assets - Notional Amount Derivative Liabilities - Notional Amount (in thousands) June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 800,000 $ 408,500 $ 108,500 $ — Total derivatives designated as hedging instruments $ 800,000 $ 408,500 $ 108,500 $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 375,805 $ 919,653 $ 1,885,919 $ 701,257 Customer swaps - downstream 1,885,919 701,257 375,805 919,653 Foreign exchange contracts — 1,202 — 1,202 Forward sales contracts 46,143 1,140 262,566 143,179 Written and purchased options 350,875 229,333 137,167 140,645 Other contracts 54,568 50,527 113,396 85,623 Total derivatives not designated as hedging instruments $ 2,713,310 $ 1,903,112 $ 2,774,853 $ 1,991,559 Total $ 3,513,310 $ 2,311,612 $ 2,883,353 $ 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 $113.4 million and $85.6 million at June 30, 2019 and December 31, 2018 , respectively. Assuming all underlying third party customers referenced in the swap contracts defaulted at June 30, 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 June 30, 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 June 30, 2019 and December 31, 2018 , the Company was required to post $78.4 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 June 30, 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 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. June 30, 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 $ 21,015 $ — $ — $ 21,015 Interest rate contracts not designated as hedging instruments 76,968 (5,129 ) — 71,839 Written and purchased options 3,832 — — 3,832 Total derivative assets subject to master netting arrangements $ 101,815 $ (5,129 ) $ — $ 96,686 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 6,801 $ (5,129 ) $ — $ 1,672 Written and purchased options 3,832 — — 3,832 Total derivative liabilities subject to master netting arrangements $ 10,633 $ (5,129 ) $ — $ 5,504 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 and six months ended June 30, 2019 and 2018 , the Company did not reclassify into earnings any gain or loss as a result of the discontinuance of cash flow hedges because it was probable the original forecasted transaction would not occur by the end of the originally specified term. At June 30, 2019 , the Company did not expect to reclassify a material amount from accumulated other comprehensive income into interest income over the next twelve months for derivatives that will be settled. At June 30, 2019 and 2018 , and for the three and six months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements was as follows: Amount of Gain (Loss) Recognized in OCI, net of taxes Location of Gain (Loss) Reclassified from AOCI into Income Amount of Gain (Loss) Reclassified from AOCI into Income, net of taxes Location of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Amount of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Total Including Component Excluding Component Total Including Component Excluding Component Total Including Component Excluding Component (in thousands) For the Three Months Ended June 30, Derivatives in Cash Flow Hedging Relationships 2019 2019 2019 Interest rate contracts $ 4,441 $ 5,982 $ (1,541 ) Interest expense $ (78 ) $ 179 $ (257 ) Interest expense $ — $ — $ — 2018 2018 2018 Interest rate contracts $ 1,395 $ 1,395 $ — Interest expense $ (40 ) $ (40 ) $ — 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 Six Months Ended June 30, Derivatives in Cash Flow Hedging Relationships 2019 2019 2019 Interest rate contracts $ 2,256 $ 2,884 $ (628 ) Interest expense $ (305 ) $ 110 $ (415 ) Interest expense $ — $ — $ — 2018 2018 2018 Interest rate contracts $ 3,944 $ 3,944 $ — Interest expense $ (156 ) $ (156 ) $ — Interest expense $ — $ — $ — Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of June 30, was as follows: Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives For the Three Months Ended June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Interest rate contracts (1) Commission income $ 2,513 $ 1,458 $ 6,694 $ 2,507 Foreign exchange contracts Other income 1 5 6 10 Forward sales contracts Mortgage income (3,111 ) 228 (6,320 ) 3,615 Written and purchased options Mortgage income 1,660 517 3,523 1,165 Other contracts Other income (18 ) (2 ) (27 ) (5 ) Total $ 1,045 $ 2,206 $ 3,876 $ 7,292 (1) Includes fees associated with customer interest rate contracts.

Leases

Leases	6 Months Ended
	Jun. 30, 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, 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 June 30, 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, utilities, and janitorial services, are based on the stand-alone price of the services and expensed as incurred. Operating lease expense for the three and six months ended June 30, 2019 totaled $6.9 million and $13.6 million , respectively. During the three and six months ended June 30, 2019 , the Company paid $7.7 million and $14.4 million , respectively, for amounts included in the measurement of lease liabilities and $8.0 million and $13.2 million , respectively, to obtain ROU assets. The following summarizes the ROU asset and lease liabilities as of June 30, 2019 : (in thousands) June 30, 2019 Right-of-use assets $ 98,723 Lease liabilities 119,463 Weighted average remaining lease term 7.9 years Weighted average discount rate 3.3 % Maturities of operating lease liabilities as of June 30, 2019 were as follows: (in thousands) 2019 $ 13,345 2020 25,055 2021 21,221 2022 18,154 2023 13,522 2024 and thereafter 45,371 Total operating lease payments $ 136,668 Less: Imputed interest 17,205 Total lease liabilities $ 119,463 As of June 30, 2019 , the Company had not entered into any material leases that had 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 contains terms of 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 the 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 were as follows: (in thousands) June 30, 2019 Lease payment receivable $ 259,103 Unguaranteed residual assets 28,903 Total net investment in leases $ 288,006 For the three and six months ended June 30, 2019 , interest income for direct financing or sales-type leases totaled $2.3 million and $4.3 million . During the three and six months ended June 30, 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 June 30, 2019 were as follows: (in thousands) 2019 $ 21,556 2020 42,696 2021 42,619 2022 37,866 2023 30,344 2024 and thereafter 93,482 Total future minimum lease payments $ 268,563 Less: Imputed interest 9,460 Lease receivables $ 259,103
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, 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 June 30, 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, utilities, and janitorial services, are based on the stand-alone price of the services and expensed as incurred. Operating lease expense for the three and six months ended June 30, 2019 totaled $6.9 million and $13.6 million , respectively. During the three and six months ended June 30, 2019 , the Company paid $7.7 million and $14.4 million , respectively, for amounts included in the measurement of lease liabilities and $8.0 million and $13.2 million , respectively, to obtain ROU assets. The following summarizes the ROU asset and lease liabilities as of June 30, 2019 : (in thousands) June 30, 2019 Right-of-use assets $ 98,723 Lease liabilities 119,463 Weighted average remaining lease term 7.9 years Weighted average discount rate 3.3 % Maturities of operating lease liabilities as of June 30, 2019 were as follows: (in thousands) 2019 $ 13,345 2020 25,055 2021 21,221 2022 18,154 2023 13,522 2024 and thereafter 45,371 Total operating lease payments $ 136,668 Less: Imputed interest 17,205 Total lease liabilities $ 119,463 As of June 30, 2019 , the Company had not entered into any material leases that had 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 contains terms of 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 the 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 were as follows: (in thousands) June 30, 2019 Lease payment receivable $ 259,103 Unguaranteed residual assets 28,903 Total net investment in leases $ 288,006 For the three and six months ended June 30, 2019 , interest income for direct financing or sales-type leases totaled $2.3 million and $4.3 million . During the three and six months ended June 30, 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 June 30, 2019 were as follows: (in thousands) 2019 $ 21,556 2020 42,696 2021 42,619 2022 37,866 2023 30,344 2024 and thereafter 93,482 Total future minimum lease payments $ 268,563 Less: Imputed interest 9,460 Lease receivables $ 259,103
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, 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 June 30, 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, utilities, and janitorial services, are based on the stand-alone price of the services and expensed as incurred. Operating lease expense for the three and six months ended June 30, 2019 totaled $6.9 million and $13.6 million , respectively. During the three and six months ended June 30, 2019 , the Company paid $7.7 million and $14.4 million , respectively, for amounts included in the measurement of lease liabilities and $8.0 million and $13.2 million , respectively, to obtain ROU assets. The following summarizes the ROU asset and lease liabilities as of June 30, 2019 : (in thousands) June 30, 2019 Right-of-use assets $ 98,723 Lease liabilities 119,463 Weighted average remaining lease term 7.9 years Weighted average discount rate 3.3 % Maturities of operating lease liabilities as of June 30, 2019 were as follows: (in thousands) 2019 $ 13,345 2020 25,055 2021 21,221 2022 18,154 2023 13,522 2024 and thereafter 45,371 Total operating lease payments $ 136,668 Less: Imputed interest 17,205 Total lease liabilities $ 119,463 As of June 30, 2019 , the Company had not entered into any material leases that had 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 contains terms of 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 the 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 were as follows: (in thousands) June 30, 2019 Lease payment receivable $ 259,103 Unguaranteed residual assets 28,903 Total net investment in leases $ 288,006 For the three and six months ended June 30, 2019 , interest income for direct financing or sales-type leases totaled $2.3 million and $4.3 million . During the three and six months ended June 30, 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 June 30, 2019 were as follows: (in thousands) 2019 $ 21,556 2020 42,696 2021 42,619 2022 37,866 2023 30,344 2024 and thereafter 93,482 Total future minimum lease payments $ 268,563 Less: Imputed interest 9,460 Lease receivables $ 259,103

Shareholders' Equity, Capital R

Shareholders' Equity, Capital Ratios and Other Regulatory Matters	6 Months Ended
	Jun. 30, 2019
Banking and Thrift [Abstract]
Shareholders' Equity, Capital Ratios and Other Regulatory Matters	SHAREHOLDERS' EQUITY, CAPITAL RATIOS AND OTHER REGULATORY MATTERS Preferred Stock 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. The following table presents a summary of the Company's non-cumulative perpetual preferred stock: June 30, 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 Series D Preferred Stock 4/4/2019 5/1/2024 6.100 % 100,000 96,388 — $ 237,500 $ 228,485 $ 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. During the second quarter of 2019, the Company repurchased 1,759,849 common shares for approximately $134.8 million at a weighted average cost of $76.59 per share. For the six months ended June 30, 2019 , the Company repurchased 2,147,770 common shares for approximately $164.7 million at a weighted average cost of $76.70 per share. During the six months ended June 30 2018 , the Company repurchased 400,000 common shares for approximately $30.7 million at a weighted average cost of $76.67 per share. At June 30, 2019 , the remaining common shares that could be repurchased under the plan approved by the Board in 2018 was 117,230 shares. Subsequent to quarter-end, the Company repurchased the remaining shares available and announced in July 2019 a new Board-approved share repurchase program for up to 1,600,000 shares, or approximately 3% of total common shares outstanding at June 30, 2019. 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 third quarter of 2021. The program may be extended, modified, suspended, or discontinued at any time. Subsequent to quarter-end and through August 6, 2019, the Company repurchased 307,230 common shares for approximately $23.0 million . 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 June 30, 2019 , the Company and IBERIABANK met all capital adequacy requirements to which they are subject. As of June 30, 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 June 30, 2019 and December 31, 2018 are presented in the following tables: (in thousands) June 30, 2019 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,199,612 4.00 % N/A N/A $ 2,913,362 9.71 % IBERIABANK 1,196,979 4.00 1,496,224 5.00 2,857,238 9.55 Common Equity Tier 1 (CET1) Consolidated $ 1,164,678 4.50 % N/A N/A $ 2,684,877 10.38 % IBERIABANK 1,161,409 4.50 1,677,591 6.50 2,857,238 11.07 Tier 1 Risk-Based Capital Consolidated $ 1,552,904 6.00 % N/A N/A $ 2,913,362 11.26 % IBERIABANK 1,548,546 6.00 2,064,728 8.00 2,857,238 11.07 Total Risk-Based Capital Consolidated $ 2,070,539 8.00 % N/A N/A $ 3,191,529 12.33 % IBERIABANK 2,064,728 8.00 2,580,910 10.00 3,018,905 11.70 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 June 30, 2019 , the required minimum capital conservation buffer was 2.50% . At June 30, 2019 , the capital conservation buffers of the Company and IBERIABANK were 4.33% and 3.70% , respectively.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 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 June 30, Six Months Ended June 30, (in thousands, except per share data) 2019 2018 2019 2018 Earnings Per Common Share - Basic: Net income $ 101,598 $ 75,124 $ 201,729 $ 138,745 Less: Preferred stock dividends 949 949 4,547 4,547 Less: Dividends and undistributed earnings allocated to unvested restricted shares 999 767 1,931 1,409 Earnings allocated to common shareholders - basic $ 99,650 $ 73,408 $ 195,251 $ 132,789 Weighted average common shares outstanding 53,345 55,931 53,758 54,780 Earnings per common share - basic $ 1.87 $ 1.31 $ 3.63 $ 2.42 Earnings Per Common Share - Diluted: Earnings allocated to common shareholders - basic $ 99,650 $ 73,408 $ 195,251 $ 132,789 Adjustment for undistributed earnings allocated to unvested restricted shares 24 (7 ) (21 ) (26 ) Earnings allocated to common shareholders - diluted $ 99,674 $ 73,401 $ 195,230 $ 132,763 Weighted average common shares outstanding 53,345 55,931 53,758 54,780 Dilutive potential common shares 328 356 346 353 Weighted average common shares outstanding - diluted 53,674 56,287 54,104 55,133 Earnings per common share - diluted $ 1.86 $ 1.30 $ 3.61 $ 2.41 For the three months ended June 30, 2019 and 2018 , the calculations for basic shares outstanding excluded weighted average shares owned by the RRP of 521,591 and 595,856 , respectively. For the six months ended June 30 2019 and 2018 , the calculations for basic shares outstanding excluded weighted average shares owned by the RRP of 542,769 and 601,018 , respectively. The effects from the assumed exercises of 154,780 and 156,988 stock options were not included in the computation of diluted earnings per share for the three months ended June 30, 2019 and 2018 , respectively, because they were antidilutive. For the six months ended June 30, 2019 and 2018 , the effects from the assumed exercises of 154,780 and 156,988

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2019
Share-based Payment Arrangement [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 June 30, 2019, awards of 3,448,650 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 June 30, 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 96,507 81.99 Exercised (34,745 ) 53.48 Forfeited or expired (22,524 ) 66.80 Outstanding options, June 30, 2018 725,604 $ 61.36 Exercisable options, June 30, 2018 505,477 $ 56.55 Outstanding options, December 31, 2018 714,420 $ 61.41 Granted 127,090 70.34 Exercised (21,575 ) 53.98 Forfeited or expired (8,787 ) 70.80 Outstanding options, June 30, 2019 811,148 $ 62.90 Exercisable options, June 30, 2019 561,789 $ 58.26 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 Six Months Ended June 30, 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 5.8 Weighted-average grant-date fair value $ 14.44 $ 18.44 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 June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Compensation expense related to stock options $ 336 $ 319 $ 685 $ 631 Income tax benefit related to stock options 24 23 50 46 At June 30, 2019 , there was $2.7 million of unrecognized compensation expense related to stock options that is expected to be recognized over a weighted-average period of 2.9 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 June 30, 2019 and 2018, unrecognized share-based compensation expense associated with these awards totaled $28.1 million and $35.5 million , respectively. The unrecognized compensation expense related to restricted stock awards at June 30, 2019 is expected to be recognized over a weighted-average period of 1.4 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 June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Compensation expense related to restricted stock awards and restricted share units $ 5,931 $ 4,927 $ 11,154 $ 9,349 Income tax benefit related to restricted stock awards and restricted share units 1,245 1,035 2,342 1,963 The following table represents unvested restricted stock award and restricted share unit activity for the following periods: For the Six Months Ended June 30, 2019 2018 Number of shares at beginning of period 700,628 738,187 Granted 212,038 224,170 Forfeited (15,199 ) (56,653 ) Vested (199,156 ) (138,952 ) Number of shares at end of period 698,311 766,752 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 June 30 of the periods indicated and the current market price of the Company’s stock at that time: For the Three Months Ended June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Compensation expense related to phantom stock $ 2,451 $ 2,017 $ 5,645 $ 5,013 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 140,804 10,673 Forfeited share equivalents (45,821 ) 3,473 Vested share equivalents (126,019 ) 10,519 Balance, June 30, 2018 362,808 $ 27,501 Balance, December 31, 2018 353,407 $ 22,717 Granted 174,991 13,273 Forfeited share equivalents (20,407 ) 1,548 Vested share equivalents (101,318 ) 7,647 Balance, June 30, 2019 406,673 $ 30,846 (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 $75.85 and $75.80 on June 30, 2019 , and 2018, respectively.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 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 June 30, 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. June 30, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 4,455,308 $ — $ 4,455,308 Mortgage loans held for sale — 187,987 — 187,987 Mortgage loans held for investment, at fair value option — — 1,945 1,945 Derivative instruments — 107,747 — 107,747 Total $ — $ 4,751,042 $ 1,945 $ 4,752,987 Liabilities Derivative instruments $ — $ 12,599 $ — $ 12,599 Total $ — $ 12,599 $ — $ 12,599 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 six months ended June 30, 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 June 30, 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. June 30, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 73,003 $ 73,003 OREO, net — — 5,076 5,076 Total $ — $ — $ 78,079 $ 78,079 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 GAAP and were not re-measured during the periods presented unless specifically required by GAAP. Acquisition date fair values represent either Level 2 fair value measurements (investment securities, deposits, and premises 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 June 30, 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 which continue to be accounted for at fair value at June 30, 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: June 30, 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 $ 187,987 $ 181,067 $ 6,920 $ 107,734 $ 104,345 $ 3,389 Mortgage loans held for investment, at fair value 1,945 2,099 (154 ) 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 and six months ended June 30, 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 June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Fair value option Mortgage loans held for sale, at fair value $ 2,879 $ (331 ) $ 3,531 $ (1,472 ) Mortgage loans held for investment, at fair value (104 ) (172 ) 87 (921 )

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 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. June 30, 2019 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 4,455,308 $ 4,455,308 $ — $ 4,455,308 $ — Mortgage loans held for sale 187,987 187,987 — 187,987 — Mortgage loans held for investment, at fair value option 1,945 1,945 — — 1,945 Derivative instruments 107,747 107,747 — 107,747 — Financial Liabilities Derivative instruments 12,599 12,599 — 12,599 — Amortized Cost Financial Assets Cash and cash equivalents $ 789,315 $ 789,315 $ 789,315 $ — $ — Securities held to maturity 192,917 198,012 — 198,012 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 23,206,980 22,939,128 — — 22,939,128 Financial Liabilities Deposits 24,295,331 24,295,695 — 24,295,695 — Short-term borrowings 997,507 997,507 184,507 813,000 — Long-term debt 1,374,759 1,381,572 — — 1,381,572 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 June 30, 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	6 Months Ended
	Jun. 30, 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 June 30, 2019 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 334,055 $ 1,912 $ — $ 335,967 Interest expense 80,628 — — 80,628 Net interest income 253,427 1,912 — 255,339 Provision for (reversal of) credit losses 10,742 13 — 10,755 Mortgage income — 18,444 — 18,444 Title revenue — — 6,895 6,895 Other non-interest income (expense) 33,496 (10 ) — 33,486 Allocated expenses (income) (4,414 ) 3,250 1,164 — Non-interest expense 151,139 13,590 4,889 169,618 Income before income tax expense 129,456 3,493 842 133,791 Income tax expense 31,134 836 223 32,193 Net income $ 98,322 $ 2,657 $ 619 $ 101,598 Total loans, leases, and loans held for sale, net of unearned income $ 23,330,738 $ 212,560 $ — $ 23,543,298 Total assets 31,165,205 255,106 26,221 31,446,532 Total deposits 24,279,416 15,915 — 24,295,331 Average assets 31,024,832 221,891 25,099 31,271,822 Three Months Ended June 30, 2018 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 302,387 $ 1,436 $ — $ 303,823 Interest expense 47,710 — — 47,710 Net interest income 254,677 1,436 — 256,113 Provision for (reversal of) credit losses 7,715 (19 ) — 7,696 Mortgage income — 13,721 — 13,721 Title revenue — — 6,846 6,846 Other non-interest income (expense) 33,481 (105 ) (3 ) 33,373 Allocated expenses (income) (3,873 ) 2,868 1,005 — Non-interest expense 179,831 11,966 4,979 196,776 Income before income tax expense 104,485 237 859 105,581 Income tax expense 30,211 17 229 30,457 Net income $ 74,274 $ 220 $ 630 $ 75,124 Total loans, leases, and loans held for sale, net of unearned income $ 22,026,914 $ 127,712 $ — $ 22,154,626 Total assets 29,928,360 173,415 24,387 30,126,162 Total deposits 23,419,382 11,076 — 23,430,458 Average assets 29,599,468 148,210 23,174 29,770,852 Six Months Ended June 30, 2019 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 658,699 $ 3,351 $ 1 $ 662,051 Interest expense 156,228 — — 156,228 Net interest income 502,471 3,351 1 505,823 Provision for (reversal of) credit losses 24,565 (47 ) — 24,518 Mortgage income — 30,293 — 30,293 Title revenue — — 12,120 12,120 Other non-interest income (expense) 68,959 (22 ) (16 ) 68,921 Allocated expenses (income) (6,447 ) 4,750 1,697 — Non-interest expense 294,894 24,131 9,346 328,371 Income before income tax expense 258,418 4,788 1,062 264,268 Income tax expense 61,109 1,143 287 62,539 Net income $ 197,309 $ 3,645 $ 775 $ 201,729 Total loans, leases, and loans held for sale, net of unearned income $ 23,330,738 $ 212,560 $ — $ 23,543,298 Total assets 31,165,205 255,106 26,221 31,446,532 Total deposits 24,279,416 15,915 — 24,295,331 Average assets 30,838,856 190,205 24,811 31,053,872 Six Months Ended June 30, 2018 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 571,162 $ 3,203 $ 1 $ 574,366 Interest expense 85,364 — — 85,364 Net interest income 485,798 3,203 1 489,002 Provision for (reversal of) credit losses 15,931 (24 ) — 15,907 Mortgage income — 23,316 — 23,316 Title revenue — — 11,873 11,873 Other non-interest income (expense) 63,387 (67 ) (3 ) 63,317 Allocated expenses (income) (5,352 ) 4,034 1,318 — Non-interest expense 351,422 23,882 9,543 384,847 Income (loss) before income tax expense 187,184 (1,440 ) 1,010 186,754 Income tax expense (benefit) 48,751 (393 ) (349 ) 48,009 Net income (loss) $ 138,433 $ (1,047 ) $ 1,359 $ 138,745 Total loans, leases, and loans held for sale, net of unearned income $ 22,026,914 $ 127,712 $ — $ 22,154,626 Total assets 29,928,360 173,415 24,387 30,126,162 Total deposits 23,419,382 11,076 — 23,430,458 Average assets 28,766,655 166,872 22,535 28,956,062

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 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 June 30, 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 June 30, 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) June 30, 2019 December 31, 2018 Commitments to extend credit $ 690,267 $ 642,162 Unfunded commitments under lines of credit 7,149,479 6,883,963 Commercial and standby letters of credit 246,622 240,436 Reserve for unfunded lending commitments 15,281 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 the Company is 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 June 30, 2019 is not material.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 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 June 30, 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 June 30, 2019 . Deposits from related parties held by the Company were not material at June 30, 2019 and December 31, 2018 .

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 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 six months ended June 30, 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 shortens 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, ASU No. 2019-04 (portion related to ASC 326), and ASU No. 2019-05 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 expands credit quality disclosures. Additionally, ASU No. 2016-13 amends the current AFS security impairment model for debt securities. The new model will require an estimate of ECL when the fair value is below the amortized cost of the asset. The credit-related impairment (and subsequent recoveries) are recognized as an allowance on the balance sheet with a corresponding adjustment to the income statement. Non-credit related losses will continue to be recognized through OCI. In addition, ASU No. 2016-13 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. This 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. During 2019, the FASB issued ASU No. 2019-04, Codification Improvements to Financial Instruments-Credit Losses (ASC 326), Derivatives and Hedging (ASC 815), and Financial Instruments (ASC 825), which clarified the scope of ASU No. 2016-13 and addressed various issues, including accrued interest receivable balances, recoveries, variable interest rates and prepayments, and ASU No. 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief , which clarified certain implementation issues. The effective date for the portion of ASU No. 2019-04 related to credit losses and ASU No. 2019-05 are the same as ASU No. 2016-13. 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. Implementation efforts are underway, including model development, fulfillment of additional data needs for new disclosure and reporting requirements, and drafting of accounting policies. Substantial progress has been made in model development. Model validation commenced in the second quarter of 2019. User acceptance testing and parallel runs are scheduled to begin in the third quarter of 2019. The Company expects that these ASUs will result in an increase to ACL as of January 1, 2020 given the requirement to estimate lifetime expected credit losses for the loan portfolio, although the extent of the increase to ACL is not yet known. The transition adjustment to increase ACL is expected to result in a decrease to shareholders' equity and to a lesser extent, discounts on acquired loans. While these ASUs are expected to increase ACL, they do not change the overall credit risk in the Company's loan and lease portfolios or the ultimate losses therein. The ultimate impact of the adoption of these ASUs will depend on the composition of the loan, lease 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 an impact on the Company’s financial position or results of operations. ASU No. 2018-17 In October 2018, the FASB released ASU No. 2018-17, Consolidation (ASC 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities, which improves the consistency of the application of the variable interest entity (VIE) related party guidance for common control arrangements. This ASU requires reporting entities to consider indirect interests held through related parties under common control on a proportional basis rather than as the equivalent of a direct interest in its entirety (as currently required in GAAP) when determining whether a decision-making fee is a variable interest. ASU No. 2018-17 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 will 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. The amendments related to the credit losses standard are discussed above under ASU 2016-13. With respect to hedge accounting, the ASU addresses partial-term fair value hedges, fair value hedge basis adjustments, and certain transition requirements, among other things. For recognizing and measuring financial instruments, the ASU addresses the scope of the guidance, the requirement for re-measurement under ASC 820 when using the measurement alternative, certain disclosure requirements and which equity securities have to be re-measured at historical exchange rates. Since the Company early adopted the guidance in ASU No. 2017-12, Derivatives and Hedging (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)	6 Months Ended
	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Available-for-sale 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, was as follows: June 30, 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: Mortgage-backed securities: Residential agency $ — $ — $ (6,364 ) $ 1,026,095 $ (6,364 ) $ 1,026,095 Commercial agency — — (1,107 ) 122,450 (1,107 ) 122,450 Other securities — — (92 ) 5,015 (92 ) 5,015 Total securities available for sale $ — $ — $ (7,563 ) $ 1,153,560 $ (7,563 ) $ 1,153,560 Securities held to maturity: Mortgage-backed securities: Residential agency $ — $ — $ (342 ) $ 17,039 $ (342 ) $ 17,039 Total securities held to maturity $ — $ — $ (342 ) $ 17,039 $ (342 ) $ 17,039 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: June 30, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,859 $ 341 $ — $ 40,200 Obligations of state and political subdivisions 172,160 6,698 — 178,858 Mortgage-backed securities: Residential agency 3,341,602 32,909 (6,364 ) 3,368,147 Commercial agency 742,760 17,383 (1,107 ) 759,036 Other securities 105,620 3,539 (92 ) 109,067 Total securities available for sale $ 4,402,001 $ 60,870 $ (7,563 ) $ 4,455,308 Securities held to maturity: Obligations of state and political subdivisions $ 175,281 $ 5,407 $ — $ 180,688 Mortgage-backed securities: Residential agency 17,636 30 (342 ) 17,324 Total securities held to maturity $ 192,917 $ 5,437 $ (342 ) $ 198,012 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
Held-to-maturity Securities	The amortized cost and fair values of investment securities, with gross unrealized gains and losses, consist of the following: June 30, 2019 (in thousands) Amortized Gross Gross Estimated Securities available for sale: U.S. Government-sponsored enterprise obligations $ 39,859 $ 341 $ — $ 40,200 Obligations of state and political subdivisions 172,160 6,698 — 178,858 Mortgage-backed securities: Residential agency 3,341,602 32,909 (6,364 ) 3,368,147 Commercial agency 742,760 17,383 (1,107 ) 759,036 Other securities 105,620 3,539 (92 ) 109,067 Total securities available for sale $ 4,402,001 $ 60,870 $ (7,563 ) $ 4,455,308 Securities held to maturity: Obligations of state and political subdivisions $ 175,281 $ 5,407 $ — $ 180,688 Mortgage-backed securities: Residential agency 17,636 30 (342 ) 17,324 Total securities held to maturity $ 192,917 $ 5,437 $ (342 ) $ 198,012 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, was as follows: June 30, 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: Mortgage-backed securities: Residential agency $ — $ — $ (6,364 ) $ 1,026,095 $ (6,364 ) $ 1,026,095 Commercial agency — — (1,107 ) 122,450 (1,107 ) 122,450 Other securities — — (92 ) 5,015 (92 ) 5,015 Total securities available for sale $ — $ — $ (7,563 ) $ 1,153,560 $ (7,563 ) $ 1,153,560 Securities held to maturity: Mortgage-backed securities: Residential agency $ — $ — $ (342 ) $ 17,039 $ (342 ) $ 17,039 Total securities held to maturity $ — $ — $ (342 ) $ 17,039 $ (342 ) $ 17,039 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
Additional Information on Securities in a Continuous Loss Position	Additional information on securities that were in a continuous loss position for over twelve months at June 30, 2019 and December 31, 2018 is presented in the following table. (in thousands) June 30, 2019 December 31, 2018 Number of securities Mortgage-backed securities: Residential agency 159 302 Commercial agency 26 72 Obligations of state and political subdivisions — 60 Other securities 4 7 189 441 Amortized Cost Basis Mortgage-backed securities: Residential agency $ 1,049,840 $ 2,268,608 Commercial agency 123,557 498,321 Obligations of state and political subdivisions — 185,175 Other securities 5,107 33,270 $ 1,178,504 $ 2,985,374 Unrealized Loss Mortgage-backed securities: Residential agency $ 6,706 $ 57,268 Commercial agency 1,107 14,756 Obligations of state and political subdivisions — 3,208 Other securities 92 693 $ 7,905 $ 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 June 30, 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 3.67 % $ 1,554 $ 1,558 2.34 % $ 952 $ 955 One through five years 2.66 112,248 113,915 2.63 4,484 4,524 After five through ten years 2.72 769,216 789,351 2.43 45,338 46,508 Over ten years 2.84 3,518,983 3,550,484 2.60 142,143 146,025 2.82 % $ 4,402,001 $ 4,455,308 2.56 % $ 192,917 $ 198,012
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 June 30, Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Realized gains $ 1,297 $ 30 $ 1,297 $ 39 Realized losses (2,311 ) (27 ) (2,311 ) (95 ) $ (1,014 ) $ 3 $ (1,014 ) $ (56 )
Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets	The Company accounts for the following securities at cost less impairment plus or minus any observable price changes, which approximates fair value, with the exception of CRA and Community Development Investment Funds, which are recorded at fair value. Other equity securities, which are presented in other assets on the consolidated balance sheets, were as follows: (in thousands) June 30, 2019 December 31, 2018 Federal Home Loan Bank stock $ 108,396 $ 95,213 Federal Reserve Bank stock 85,630 85,630 CRA and Community Development Investment Funds 2,192 1,884 Other investments 15,319 9,709 $ 211,537 $ 192,436

Loans and Leases (Tables)

Loans and Leases (Tables)	6 Months Ended
	Jun. 30, 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) June 30, 2019 December 31, 2018 Commercial loans and leases: Real estate - construction $ 1,342,984 $ 1,196,366 Real estate - owner-occupied 2,373,143 2,395,822 Real estate - non-owner-occupied 6,102,143 5,796,117 Commercial and industrial (1) 6,161,759 5,737,017 Total commercial loans and leases 15,980,029 15,125,322 Residential mortgage loans 4,538,194 4,359,156 Consumer and other loans: Home equity 2,147,897 2,304,694 Other 689,191 730,643 Total consumer and other loans 2,837,088 3,035,337 Total loans and leases $ 23,355,311 $ 22,519,815 (1) Includes equipment financing leases
Schedule of Aging of Loans	The following tables provide an analysis of the aging of loans and leases as of June 30, 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. June 30, 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 $ 1,322,728 $ 207 $ — $ — $ 207 $ 1,188 $ 18,861 $ 1,342,984 Real estate- owner-occupied 2,285,316 7,274 — — 7,274 15,789 64,764 2,373,143 Real estate- non-owner-occupied 6,007,594 2,456 6,345 — 8,801 22,028 63,720 6,102,143 Commercial and industrial 6,086,983 3,035 437 — 3,472 48,747 22,557 6,161,759 Residential mortgage 4,393,649 4,914 5,941 851 11,706 50,046 82,793 4,538,194 Consumer - home equity 2,067,280 7,123 1,616 — 8,739 18,646 53,232 2,147,897 Consumer - other 680,595 2,972 701 — 3,673 2,548 2,375 689,191 Total $ 22,844,145 $ 27,981 $ 15,040 $ 851 $ 43,872 $ 158,992 $ 308,302 $ 23,355,311 (1) Of the total non-accrual loans at June 30, 2019 , $11.3 million were past due 30-59 days, $4.2 million were past due 60-89 days, and $68.6 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 six months ended June 30 : (in thousands) 2019 2018 Balance at beginning of period $ 133,342 $ 152,623 Additions — 2,371 Transfers from non-accretable difference to accretable yield (2,563 ) (467 ) Accretion (19,580 ) (25,140 ) Changes in expected cash flows not affecting non-accretable differences (1) (4,341 ) 7,597 Balance at end of period $ 106,858 $ 136,984 (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 June 30, Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Extended maturities $ 7,633 $ 1,790 $ 11,175 $ 7,193 Maturity and interest rate adjustment 224 — 617 102 Movement to or extension of interest-rate only payments 1,771 1,316 1,783 1,364 Interest rate adjustment 74 — 74 103 Forbearance — 1,405 5,742 13,936 Other concession(s) (1) 10,950 15,597 18,018 23,993 Total $ 20,652 $ 20,108 $ 37,409 $ 46,691 (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 June 30, 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- owner-occupied 4 $ 339 $ 338 5 $ 2,230 $ 2,201 Real estate- non-owner-occupied 7 4,687 4,628 5 823 780 Commercial and industrial 19 13,757 13,607 16 21,103 13,618 Residential mortgage 10 847 836 7 688 633 Consumer - home equity 22 1,159 1,056 19 2,361 2,350 Consumer - other 20 210 187 35 556 526 Total 82 $ 20,999 $ 20,652 87 $ 27,761 $ 20,108 Six Months Ended June 30, 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 $ 37 1 $ 1,950 $ 1,013 Real estate- owner-occupied 6 1,435 1,402 7 12,921 11,290 Real estate- non-owner-occupied 13 7,756 7,651 14 1,912 1,854 Commercial and industrial 38 29,785 20,670 32 35,338 26,684 Residential mortgage 19 1,687 1,669 7 688 633 Consumer - home equity 54 5,312 5,137 33 4,170 4,133 Consumer - other 51 918 843 51 1,126 1,084 Total 182 $ 46,932 $ 37,409 145 $ 58,105 $ 46,691 Information detailing TDRs that defaulted during the three-month and six-month periods ended June 30, 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 June 30, 2019 2018 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 37 — $ — Real estate- owner-occupied 4 1,232 5 461 Real estate- non-owner-occupied 11 2,341 9 1,448 Commercial and industrial 17 5,475 8 1,437 Residential mortgage 12 1,012 7 775 Consumer - home equity 17 1,411 11 1,129 Consumer - other 34 515 21 232 Total 96 $ 12,023 61 $ 5,482 Six Months Ended June 30, 2019 2018 (in thousands, except number of loans) Number of Loans Recorded Investment Number of Loans Recorded Investment Real estate- construction 1 $ 37 — $ — Real estate- owner-occupied 6 1,232 6 9,455 Real estate- non-owner-occupied 17 2,913 15 1,813 Commercial and industrial 25 6,152 21 7,100 Residential mortgage 21 1,597 10 1,081 Consumer - home equity 27 2,401 26 2,242 Consumer - other 41 591 48 1,003 Total 138 $ 14,923 126 $ 22,694

Allowance for Credit Losses a_2

Allowance for Credit Losses and Credit Quality (Tables)	6 Months Ended
	Jun. 30, 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 six months ended June 30 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 24,067 15,581 Transfer of balance to OREO and other (2,863 ) (3,943 ) Charge-offs (19,194 ) (22,734 ) Recoveries 3,805 6,781 Allowance for loan and lease losses at end of period $ 146,386 $ 136,576 Reserve for unfunded commitments at beginning of period $ 14,830 $ 13,208 Balance created in acquisition accounting — 900 Provision for unfunded lending commitments 451 325 Reserve for unfunded commitments at end of period $ 15,281 $ 14,433 Allowance for credit losses at end of period $ 161,667 $ 151,009 A summary of changes in the allowance for credit losses, by loan portfolio type, for the six months ended June 30 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 (Reversal of) loan and lease losses 15,204 5,077 (584 ) 4,370 24,067 Transfer of balance to OREO and other (256 ) (1 ) (2,862 ) 256 (2,863 ) Charge-offs (641 ) (11,880 ) (168 ) (6,505 ) (19,194 ) Recoveries 318 1,796 157 1,534 3,805 Allowance for loan and lease losses at end of period $ 66,431 $ 49,088 $ 9,541 $ 21,326 $ 146,386 Reserve for unfunded commitments at beginning of period $ 4,869 $ 6,198 $ 866 $ 2,897 $ 14,830 Provision for (Reversal of) unfunded commitments 603 (313 ) (206 ) 367 451 Reserve for unfunded commitments at end of period $ 5,472 $ 5,885 $ 660 $ 3,264 $ 15,281 Allowance on loans individually evaluated for impairment $ 4,673 $ 7,656 $ 349 $ 3,176 $ 15,854 Allowance on loans collectively evaluated for impairment 56,251 39,854 5,127 18,008 119,240 Allowance on loans acquired with deteriorated credit quality 5,507 1,578 4,065 142 11,292 Loans and leases, net of unearned income: Balance at end of period $ 9,818,270 $ 6,161,759 $ 4,538,194 $ 2,837,088 $ 23,355,311 Balance at end of period individually evaluated for impairment 74,331 54,860 41,363 39,127 209,681 Balance at end of period collectively evaluated for impairment 9,596,594 6,084,342 4,414,038 2,742,354 22,837,328 Balance at end of period acquired with deteriorated credit quality 147,345 22,557 82,793 55,607 308,302 2018 (in thousands) Commercial Real Estate Commercial and Industrial Residential Mortgage Consumer and Other Total Allowance for loan and lease losses at beginning of period $ 54,201 $ 53,916 $ 9,117 $ 23,657 $ 140,891 Provision for (Reversal of) loan and lease losses (3,404 ) 10,083 1,112 7,790 15,581 Transfer of balance to OREO and other (506 ) (18 ) 6 (3,425 ) (3,943 ) Charge-offs (1,258 ) (13,575 ) (196 ) (7,705 ) (22,734 ) Recoveries 384 4,403 44 1,950 6,781 Allowance for loan and lease losses at end of period $ 49,417 $ 54,809 $ 10,083 $ 22,267 $ 136,576 Reserve for unfunded commitments at beginning of period $ 4,531 $ 5,309 $ 555 $ 2,813 $ 13,208 Balance created in acquisition accounting 129 81 — 690 900 Provision for (Reversal of) unfunded commitments 467 (306 ) 160 4 325 Reserve for unfunded commitments at end of period $ 5,127 $ 5,084 $ 715 $ 3,507 $ 14,433 Allowance on loans individually evaluated for impairment $ 2,274 $ 11,946 $ 168 $ 3,199 $ 17,587 Allowance on loans collectively evaluated for impairment 40,763 40,540 3,816 18,742 103,861 Allowance on loans acquired with deteriorated credit quality 6,380 2,323 6,099 326 15,128 Loans and leases, net of unearned income: Balance at end of period $ 9,292,304 $ 5,512,416 $ 4,124,538 $ 3,146,525 $ 22,075,783 Balance at end of period individually evaluated for impairment 84,217 66,683 5,873 35,550 192,323 Balance at end of period collectively evaluated for impairment 9,017,756 5,415,093 3,984,086 3,029,027 21,445,962 Balance at end of period acquired with deteriorated credit quality 190,331 30,640 134,579 81,948 437,498
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 June 30, 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. June 30, 2019 December 31, 2018 (in thousands) Pass Special Mention Sub- Doubtful Total Pass Special Mention Sub- Doubtful Total Real estate - construction $ 1,320,007 $ 12,262 $ 10,715 $ — $ 1,342,984 $ 1,182,554 $ 1,062 $ 12,740 $ 10 $ 1,196,366 Real estate - owner-occupied 2,308,176 25,114 37,126 2,727 2,373,143 2,328,999 25,526 41,297 — 2,395,822 Real estate - non-owner-occupied 6,011,800 48,323 39,832 2,188 6,102,143 5,687,963 78,009 26,512 3,633 5,796,117 Commercial and industrial 6,018,866 53,075 73,667 16,151 6,161,759 5,586,482 52,632 73,853 24,050 5,737,017 Total $ 15,658,849 $ 138,774 $ 161,340 $ 21,066 $ 15,980,029 $ 14,785,998 $ 157,229 $ 154,402 $ 27,693 $ 15,125,322 June 30, 2019 December 31, 2018 (in thousands) Current 30+ Days Past Due Total Current 30+ Days Past Due Total Residential mortgage $ 4,459,706 $ 78,488 $ 4,538,194 $ 4,290,152 $ 69,004 $ 4,359,156 Consumer - home equity 2,113,237 34,660 2,147,897 2,258,659 46,035 2,304,694 Consumer - other 682,860 6,331 689,191 721,231 9,412 730,643 Total $ 7,255,803 $ 119,479 $ 7,375,282 $ 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. June 30, 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 27,142 27,064 — 25,037 19,044 — Real estate - non-owner-occupied 21,234 20,271 — 15,265 14,288 — Commercial and industrial 33,989 30,157 — 55,554 43,886 — Residential mortgage 32,448 31,645 — 1,244 1,221 — Consumer - home equity 1,995 1,998 — 4,183 4,176 — Consumer - other — — — — — — With an allowance recorded: Real estate - construction 140 127 (2 ) 228 140 (11 ) Real estate - owner-occupied 8,811 8,248 (4,061 ) 5,032 4,773 (520 ) Real estate - non-owner-occupied 7,683 7,482 (610 ) 6,445 6,398 (105 ) Commercial and industrial 37,969 24,703 (7,656 ) 46,387 27,915 (12,646 ) Residential mortgage 10,366 9,718 (349 ) 5,870 5,358 (145 ) Consumer - home equity 33,194 32,702 (2,662 ) 29,284 28,818 (2,427 ) Consumer - other 4,743 4,427 (514 ) 4,956 4,446 (488 ) Total $ 231,852 $ 209,681 $ (15,854 ) $ 209,746 $ 169,725 $ (16,342 ) Total commercial loans and leases $ 149,106 $ 129,191 $ (12,329 ) $ 164,209 $ 125,706 $ (13,282 ) Total residential mortgage loans 42,814 41,363 (349 ) 7,114 6,579 (145 ) Total consumer and other loans 39,932 39,127 (3,176 ) 38,423 37,440 (2,915 ) Three Months Ended June 30, 2019 Three Months Ended June 30, 2018 Six Months Ended June 30, 2019 Six Months Ended June 30, 2018 Average Interest Average Interest Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (in thousands) With no related allowance recorded: Real estate - construction $ 21,339 $ 341 $ 12,952 $ 198 $ 21,340 $ 678 $ 12,597 $ 393 Real estate - owner-occupied 24,134 326 30,899 209 27,314 569 31,265 609 Real estate - non-owner-occupied 20,305 100 15,929 121 20,360 207 16,558 250 Commercial and industrial 29,315 151 37,859 389 29,816 331 37,806 836 Residential mortgage 27,129 235 1,272 13 18,804 374 1,280 27 Consumer - home equity 1,998 22 1,910 28 1,943 44 1,922 52 With an allowance recorded: Real estate - construction 131 1 152 — 135 2 152 — Real estate - owner-occupied 8,578 57 19,582 82 8,628 116 19,696 192 Real estate - non-owner-occupied 7,557 42 1,631 14 7,643 122 1,705 39 Commercial and industrial 23,891 177 38,134 158 21,400 371 38,981 357 Residential mortgage 9,833 73 4,657 47 9,881 169 4,678 92 Consumer - home equity 32,885 332 28,595 304 32,341 656 28,173 600 Consumer - other 4,533 63 5,220 67 4,597 128 5,267 139 Total $ 211,628 $ 1,920 $ 198,792 $ 1,630 $ 204,202 $ 3,767 $ 200,080 $ 3,586 Total commercial loans and leases $ 135,250 $ 1,195 $ 157,138 $ 1,171 $ 136,636 $ 2,396 $ 158,760 $ 2,676 Total residential mortgage loans 36,962 308 5,929 60 28,685 543 5,958 119 Total consumer and other loans 39,416 417 35,725 399 38,881 828 35,362 791

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 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 six months ended June 30, 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, June 30, 2019 $ 1,203,810 $ 23,178 $ 8,545 $ 1,235,533
Schedule of Mortgage Servicing Rights	Mortgage servicing rights had the following carrying values as of the periods indicated: June 30, 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 $ 16,885 $ (5,486 ) $ 11,399 $ 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: June 30, 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 $ (72,870 ) $ 63,313 $ 136,183 $ (63,213 ) $ 72,970 Customer relationship intangible asset 1,385 (1,354 ) 31 1,385 (1,323 ) 62 Non-compete agreement 206 (94 ) 112 206 (72 ) 134 Total $ 137,774 $ (74,318 ) $ 63,456 $ 137,774 $ (64,608 ) $ 73,166

Derivative Instruments and Ot_2

Derivative Instruments and Other Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 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) June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 21,015 $ 3,469 $ — $ — Total derivatives designated as hedging instruments $ 21,015 $ 3,469 $ — $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 24 $ 474 $ 5,041 $ 191 Customer swaps - downstream 76,944 16,946 1,760 17,812 Foreign exchange contracts — 18 — 18 Forward sales contracts 146 630 1,834 750 Written and purchased options 9,574 5,490 3,871 3,310 Other contracts 44 21 93 43 Total derivatives not designated as hedging instruments $ 86,732 $ 23,579 $ 12,599 $ 22,124 Total $ 107,747 $ 27,048 $ 12,599 $ 22,124 Derivative Assets - Notional Amount Derivative Liabilities - Notional Amount (in thousands) June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest rate contracts $ 800,000 $ 408,500 $ 108,500 $ — Total derivatives designated as hedging instruments $ 800,000 $ 408,500 $ 108,500 $ — Derivatives not designated as hedging instruments: Interest rate contracts: Customer swaps - upstream $ 375,805 $ 919,653 $ 1,885,919 $ 701,257 Customer swaps - downstream 1,885,919 701,257 375,805 919,653 Foreign exchange contracts — 1,202 — 1,202 Forward sales contracts 46,143 1,140 262,566 143,179 Written and purchased options 350,875 229,333 137,167 140,645 Other contracts 54,568 50,527 113,396 85,623 Total derivatives not designated as hedging instruments $ 2,713,310 $ 1,903,112 $ 2,774,853 $ 1,991,559 Total $ 3,513,310 $ 2,311,612 $ 2,883,353 $ 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. June 30, 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 $ 21,015 $ — $ — $ 21,015 Interest rate contracts not designated as hedging instruments 76,968 (5,129 ) — 71,839 Written and purchased options 3,832 — — 3,832 Total derivative assets subject to master netting arrangements $ 101,815 $ (5,129 ) $ — $ 96,686 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 6,801 $ (5,129 ) $ — $ 1,672 Written and purchased options 3,832 — — 3,832 Total derivative liabilities subject to master netting arrangements $ 10,633 $ (5,129 ) $ — $ 5,504 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. June 30, 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 $ 21,015 $ — $ — $ 21,015 Interest rate contracts not designated as hedging instruments 76,968 (5,129 ) — 71,839 Written and purchased options 3,832 — — 3,832 Total derivative assets subject to master netting arrangements $ 101,815 $ (5,129 ) $ — $ 96,686 Derivative liabilities Interest rate contracts not designated as hedging instruments $ 6,801 $ (5,129 ) $ — $ 1,672 Written and purchased options 3,832 — — 3,832 Total derivative liabilities subject to master netting arrangements $ 10,633 $ (5,129 ) $ — $ 5,504 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 June 30, 2019 and 2018 , and for the three and six months then ended, information pertaining to the effect of the hedging instruments on the consolidated financial statements was as follows: Amount of Gain (Loss) Recognized in OCI, net of taxes Location of Gain (Loss) Reclassified from AOCI into Income Amount of Gain (Loss) Reclassified from AOCI into Income, net of taxes Location of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Amount of Gain (Loss) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing) Total Including Component Excluding Component Total Including Component Excluding Component Total Including Component Excluding Component (in thousands) For the Three Months Ended June 30, Derivatives in Cash Flow Hedging Relationships 2019 2019 2019 Interest rate contracts $ 4,441 $ 5,982 $ (1,541 ) Interest expense $ (78 ) $ 179 $ (257 ) Interest expense $ — $ — $ — 2018 2018 2018 Interest rate contracts $ 1,395 $ 1,395 $ — Interest expense $ (40 ) $ (40 ) $ — 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 Six Months Ended June 30, Derivatives in Cash Flow Hedging Relationships 2019 2019 2019 Interest rate contracts $ 2,256 $ 2,884 $ (628 ) Interest expense $ (305 ) $ 110 $ (415 ) Interest expense $ — $ — $ — 2018 2018 2018 Interest rate contracts $ 3,944 $ 3,944 $ — Interest expense $ (156 ) $ (156 ) $ — Interest expense $ — $ — $ — Information pertaining to the effect of derivatives not designated as hedging instruments on the consolidated financial statements as of June 30, was as follows: Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives For the Three Months Ended June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Interest rate contracts (1) Commission income $ 2,513 $ 1,458 $ 6,694 $ 2,507 Foreign exchange contracts Other income 1 5 6 10 Forward sales contracts Mortgage income (3,111 ) 228 (6,320 ) 3,615 Written and purchased options Mortgage income 1,660 517 3,523 1,165 Other contracts Other income (18 ) (2 ) (27 ) (5 ) Total $ 1,045 $ 2,206 $ 3,876 $ 7,292 (1) Includes fees associated with customer interest rate contracts.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Assets And Liabilities, Leases	The following summarizes the ROU asset and lease liabilities as of June 30, 2019 : (in thousands) June 30, 2019 Right-of-use assets $ 98,723 Lease liabilities 119,463 Weighted average remaining lease term 7.9 years Weighted average discount rate 3.3 %
Lessee, Operating Lease, Liability, Maturity	Maturities of operating lease liabilities as of June 30, 2019 were as follows: (in thousands) 2019 $ 13,345 2020 25,055 2021 21,221 2022 18,154 2023 13,522 2024 and thereafter 45,371 Total operating lease payments $ 136,668 Less: Imputed interest 17,205 Total lease liabilities $ 119,463
Lessor, Net Investment in in Leases	The components of the Company’s net investment in leases were as follows: (in thousands) June 30, 2019 Lease payment receivable $ 259,103 Unguaranteed residual assets 28,903 Total net investment in leases $ 288,006
Sales-type and Direct Financing Leases, Lease Receivable, Maturity	Maturities of the Company's lease receivables as of June 30, 2019 were as follows: (in thousands) 2019 $ 21,556 2020 42,696 2021 42,619 2022 37,866 2023 30,344 2024 and thereafter 93,482 Total future minimum lease payments $ 268,563 Less: Imputed interest 9,460 Lease receivables $ 259,103

Shareholders' Equity, Capital_2

Shareholders' Equity, Capital Ratios and Other Regulatory Matters (Tables)	6 Months Ended
	Jun. 30, 2019
Banking and Thrift [Abstract]
Schedule of Preferred Stock	The following table presents a summary of the Company's non-cumulative perpetual preferred stock: June 30, 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 Series D Preferred Stock 4/4/2019 5/1/2024 6.100 % 100,000 96,388 — $ 237,500 $ 228,485 $ 132,097
Actual Capital Amounts and Ratios	The Company’s and IBERIABANK’s actual capital amounts and ratios as of June 30, 2019 and December 31, 2018 are presented in the following tables: (in thousands) June 30, 2019 Minimum Well-Capitalized Actual Amount Ratio Amount Ratio Amount Ratio Tier 1 Leverage Consolidated $ 1,199,612 4.00 % N/A N/A $ 2,913,362 9.71 % IBERIABANK 1,196,979 4.00 1,496,224 5.00 2,857,238 9.55 Common Equity Tier 1 (CET1) Consolidated $ 1,164,678 4.50 % N/A N/A $ 2,684,877 10.38 % IBERIABANK 1,161,409 4.50 1,677,591 6.50 2,857,238 11.07 Tier 1 Risk-Based Capital Consolidated $ 1,552,904 6.00 % N/A N/A $ 2,913,362 11.26 % IBERIABANK 1,548,546 6.00 2,064,728 8.00 2,857,238 11.07 Total Risk-Based Capital Consolidated $ 2,070,539 8.00 % N/A N/A $ 3,191,529 12.33 % IBERIABANK 2,064,728 8.00 2,580,910 10.00 3,018,905 11.70 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

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 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 June 30, Six Months Ended June 30, (in thousands, except per share data) 2019 2018 2019 2018 Earnings Per Common Share - Basic: Net income $ 101,598 $ 75,124 $ 201,729 $ 138,745 Less: Preferred stock dividends 949 949 4,547 4,547 Less: Dividends and undistributed earnings allocated to unvested restricted shares 999 767 1,931 1,409 Earnings allocated to common shareholders - basic $ 99,650 $ 73,408 $ 195,251 $ 132,789 Weighted average common shares outstanding 53,345 55,931 53,758 54,780 Earnings per common share - basic $ 1.87 $ 1.31 $ 3.63 $ 2.42 Earnings Per Common Share - Diluted: Earnings allocated to common shareholders - basic $ 99,650 $ 73,408 $ 195,251 $ 132,789 Adjustment for undistributed earnings allocated to unvested restricted shares 24 (7 ) (21 ) (26 ) Earnings allocated to common shareholders - diluted $ 99,674 $ 73,401 $ 195,230 $ 132,763 Weighted average common shares outstanding 53,345 55,931 53,758 54,780 Dilutive potential common shares 328 356 346 353 Weighted average common shares outstanding - diluted 53,674 56,287 54,104 55,133 Earnings per common share - diluted $ 1.86 $ 1.30 $ 3.61 $ 2.41

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Share-based Payment Arrangement [Abstract]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award	The following table represents unvested restricted stock award and restricted share unit activity for the following periods: For the Six Months Ended June 30, 2019 2018 Number of shares at beginning of period 700,628 738,187 Granted 212,038 224,170 Forfeited (15,199 ) (56,653 ) Vested (199,156 ) (138,952 ) Number of shares at end of period 698,311 766,752 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 140,804 10,673 Forfeited share equivalents (45,821 ) 3,473 Vested share equivalents (126,019 ) 10,519 Balance, June 30, 2018 362,808 $ 27,501 Balance, December 31, 2018 353,407 $ 22,717 Granted 174,991 13,273 Forfeited share equivalents (20,407 ) 1,548 Vested share equivalents (101,318 ) 7,647 Balance, June 30, 2019 406,673 $ 30,846 (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 $75.85 and $75.80 on June 30, 2019 , and 2018, respectively. 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 96,507 81.99 Exercised (34,745 ) 53.48 Forfeited or expired (22,524 ) 66.80 Outstanding options, June 30, 2018 725,604 $ 61.36 Exercisable options, June 30, 2018 505,477 $ 56.55 Outstanding options, December 31, 2018 714,420 $ 61.41 Granted 127,090 70.34 Exercised (21,575 ) 53.98 Forfeited or expired (8,787 ) 70.80 Outstanding options, June 30, 2019 811,148 $ 62.90 Exercisable options, June 30, 2019 561,789 $ 58.26
Schedule of Valuation Assumptions	The following weighted-average assumptions were used for option awards issued during the following periods: For the Six Months Ended June 30, 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 5.8 Weighted-average grant-date fair value $ 14.44 $ 18.44
Schedule of Allocation for Share-based Compensation Expense	The following table represents compensation expense recorded for phantom stock based on the number of share equivalents vested at June 30 of the periods indicated and the current market price of the Company’s stock at that time: For the Three Months Ended June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Compensation expense related to phantom stock $ 2,451 $ 2,017 $ 5,645 $ 5,013 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 June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Compensation expense related to restricted stock awards and restricted share units $ 5,931 $ 4,927 $ 11,154 $ 9,349 Income tax benefit related to restricted stock awards and restricted share units 1,245 1,035 2,342 1,963 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 June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Compensation expense related to stock options $ 336 $ 319 $ 685 $ 631 Income tax benefit related to stock options 24 23 50 46

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Financial Asset and Liabilities Measured at Fair Value on Recurring Basis	The following table presents information about the Company's assets and liabilities that are measured at fair value on a recurring basis as of June 30, 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. June 30, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Securities available for sale $ — $ 4,455,308 $ — $ 4,455,308 Mortgage loans held for sale — 187,987 — 187,987 Mortgage loans held for investment, at fair value option — — 1,945 1,945 Derivative instruments — 107,747 — 107,747 Total $ — $ 4,751,042 $ 1,945 $ 4,752,987 Liabilities Derivative instruments $ — $ 12,599 $ — $ 12,599 Total $ — $ 12,599 $ — $ 12,599 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 June 30, 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. June 30, 2019 (in thousands) Level 1 Level 2 Level 3 Total Assets Impaired loans $ — $ — $ 73,003 $ 73,003 OREO, net — — 5,076 5,076 Total $ — $ — $ 78,079 $ 78,079 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: June 30, 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 $ 187,987 $ 181,067 $ 6,920 $ 107,734 $ 104,345 $ 3,389 Mortgage loans held for investment, at fair value 1,945 2,099 (154 ) 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 and six months ended June 30, 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 June 30, For the Six Months Ended June 30, (in thousands) 2019 2018 2019 2018 Fair value option Mortgage loans held for sale, at fair value $ 2,879 $ (331 ) $ 3,531 $ (1,472 ) Mortgage loans held for investment, at fair value (104 ) (172 ) 87 (921 )

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 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. June 30, 2019 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Measurement Category Fair Value Financial Assets Securities available for sale $ 4,455,308 $ 4,455,308 $ — $ 4,455,308 $ — Mortgage loans held for sale 187,987 187,987 — 187,987 — Mortgage loans held for investment, at fair value option 1,945 1,945 — — 1,945 Derivative instruments 107,747 107,747 — 107,747 — Financial Liabilities Derivative instruments 12,599 12,599 — 12,599 — Amortized Cost Financial Assets Cash and cash equivalents $ 789,315 $ 789,315 $ 789,315 $ — $ — Securities held to maturity 192,917 198,012 — 198,012 — Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses 23,206,980 22,939,128 — — 22,939,128 Financial Liabilities Deposits 24,295,331 24,295,695 — 24,295,695 — Short-term borrowings 997,507 997,507 184,507 813,000 — Long-term debt 1,374,759 1,381,572 — — 1,381,572 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)	6 Months Ended
	Jun. 30, 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 June 30, 2019 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 334,055 $ 1,912 $ — $ 335,967 Interest expense 80,628 — — 80,628 Net interest income 253,427 1,912 — 255,339 Provision for (reversal of) credit losses 10,742 13 — 10,755 Mortgage income — 18,444 — 18,444 Title revenue — — 6,895 6,895 Other non-interest income (expense) 33,496 (10 ) — 33,486 Allocated expenses (income) (4,414 ) 3,250 1,164 — Non-interest expense 151,139 13,590 4,889 169,618 Income before income tax expense 129,456 3,493 842 133,791 Income tax expense 31,134 836 223 32,193 Net income $ 98,322 $ 2,657 $ 619 $ 101,598 Total loans, leases, and loans held for sale, net of unearned income $ 23,330,738 $ 212,560 $ — $ 23,543,298 Total assets 31,165,205 255,106 26,221 31,446,532 Total deposits 24,279,416 15,915 — 24,295,331 Average assets 31,024,832 221,891 25,099 31,271,822 Three Months Ended June 30, 2018 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 302,387 $ 1,436 $ — $ 303,823 Interest expense 47,710 — — 47,710 Net interest income 254,677 1,436 — 256,113 Provision for (reversal of) credit losses 7,715 (19 ) — 7,696 Mortgage income — 13,721 — 13,721 Title revenue — — 6,846 6,846 Other non-interest income (expense) 33,481 (105 ) (3 ) 33,373 Allocated expenses (income) (3,873 ) 2,868 1,005 — Non-interest expense 179,831 11,966 4,979 196,776 Income before income tax expense 104,485 237 859 105,581 Income tax expense 30,211 17 229 30,457 Net income $ 74,274 $ 220 $ 630 $ 75,124 Total loans, leases, and loans held for sale, net of unearned income $ 22,026,914 $ 127,712 $ — $ 22,154,626 Total assets 29,928,360 173,415 24,387 30,126,162 Total deposits 23,419,382 11,076 — 23,430,458 Average assets 29,599,468 148,210 23,174 29,770,852 Six Months Ended June 30, 2019 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 658,699 $ 3,351 $ 1 $ 662,051 Interest expense 156,228 — — 156,228 Net interest income 502,471 3,351 1 505,823 Provision for (reversal of) credit losses 24,565 (47 ) — 24,518 Mortgage income — 30,293 — 30,293 Title revenue — — 12,120 12,120 Other non-interest income (expense) 68,959 (22 ) (16 ) 68,921 Allocated expenses (income) (6,447 ) 4,750 1,697 — Non-interest expense 294,894 24,131 9,346 328,371 Income before income tax expense 258,418 4,788 1,062 264,268 Income tax expense 61,109 1,143 287 62,539 Net income $ 197,309 $ 3,645 $ 775 $ 201,729 Total loans, leases, and loans held for sale, net of unearned income $ 23,330,738 $ 212,560 $ — $ 23,543,298 Total assets 31,165,205 255,106 26,221 31,446,532 Total deposits 24,279,416 15,915 — 24,295,331 Average assets 30,838,856 190,205 24,811 31,053,872 Six Months Ended June 30, 2018 (in thousands) IBERIABANK Mortgage LTC Consolidated Interest and dividend income $ 571,162 $ 3,203 $ 1 $ 574,366 Interest expense 85,364 — — 85,364 Net interest income 485,798 3,203 1 489,002 Provision for (reversal of) credit losses 15,931 (24 ) — 15,907 Mortgage income — 23,316 — 23,316 Title revenue — — 11,873 11,873 Other non-interest income (expense) 63,387 (67 ) (3 ) 63,317 Allocated expenses (income) (5,352 ) 4,034 1,318 — Non-interest expense 351,422 23,882 9,543 384,847 Income (loss) before income tax expense 187,184 (1,440 ) 1,010 186,754 Income tax expense (benefit) 48,751 (393 ) (349 ) 48,009 Net income (loss) $ 138,433 $ (1,047 ) $ 1,359 $ 138,745 Total loans, leases, and loans held for sale, net of unearned income $ 22,026,914 $ 127,712 $ — $ 22,154,626 Total assets 29,928,360 173,415 24,387 30,126,162 Total deposits 23,419,382 11,076 — 23,430,458 Average assets 28,766,655 166,872 22,535 28,956,062

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Summary of Financial Instruments Outstanding	At June 30, 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) June 30, 2019 December 31, 2018 Commitments to extend credit $ 690,267 $ 642,162 Unfunded commitments under lines of credit 7,149,479 6,883,963 Commercial and standby letters of credit 246,622 240,436 Reserve for unfunded lending commitments 15,281 14,830

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Jun. 30, 2019
Accounting Changes and Error Corrections [Abstract]
Right-of-use assets	$ 94,200	$ 98,723
Lease liability	118,900	$ 119,463
Liabilities reclassed to right-of-used assets	$ 24,700

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	Jun. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities
Amortized Cost	$ 4,402,001	$ 4,843,313
Gross Unrealized Gains	60,870	13,648
Gross Unrealized Losses	(7,563)	(73,382)
Estimated Fair Value	4,455,308	4,783,579
Schedule of Held-to-maturity Securities
Amortized Cost	192,917	207,446
Gross Unrealized Gains	5,437	339
Gross Unrealized Losses	(342)	(3,508)
Estimated Fair Value	198,012	204,277
Fair value of securities held as collateral	2,200,000	2,400,000
U.S. Government-sponsored enterprise obligations
Schedule of Available-for-sale Securities
Amortized Cost	39,859	995
Gross Unrealized Gains	341	3
Gross Unrealized Losses	0	0
Estimated Fair Value	40,200	998
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities
Amortized Cost	172,160	177,566
Gross Unrealized Gains	6,698	2,045
Gross Unrealized Losses	0	(723)
Estimated Fair Value	178,858	178,888
Schedule of Held-to-maturity Securities
Amortized Cost	175,281	188,684
Gross Unrealized Gains	5,407	309
Gross Unrealized Losses	0	(2,497)
Estimated Fair Value	180,688	186,496
Mortgage-backed securities: Residential agency
Schedule of Available-for-sale Securities
Amortized Cost	3,341,602	3,837,584
Gross Unrealized Gains	32,909	8,886
Gross Unrealized Losses	(6,364)	(57,073)
Estimated Fair Value	3,368,147	3,789,397
Schedule of Held-to-maturity Securities
Amortized Cost	17,636	18,762
Gross Unrealized Gains	30	30
Gross Unrealized Losses	(342)	(1,011)
Estimated Fair Value	17,324	17,781
Mortgage-backed securities: Commercial agency
Schedule of Available-for-sale Securities
Amortized Cost	742,760	730,148
Gross Unrealized Gains	17,383	2,363
Gross Unrealized Losses	(1,107)	(14,799)
Estimated Fair Value	759,036	717,712
Other securities
Schedule of Available-for-sale Securities
Amortized Cost	105,620	97,020
Gross Unrealized Gains	3,539	351
Gross Unrealized Losses	(92)	(787)
Estimated Fair Value	$ 109,067	$ 96,584

Investment Securities - Sched_2

Investment Securities - Schedule of Securities with Gross Unrealized Losses Aggregated by Investment Category (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Gross Unrealized Losses
Less Than Twelve Months	$ 0	$ (962)
Twelve Months or More	(7,563)	(72,420)
Total	(7,563)	(73,382)
Estimated Fair Value
Less Than Twelve Months	0	237,384
Twelve Months or More	1,153,560	2,740,272
Total	1,153,560	2,977,656
Gross Unrealized Losses
Less than twelve months	0	(3)
Over twelve months	(342)	(3,505)
Total	(342)	(3,508)
Estimated Fair Value
Less than twelve months	0	2,059
Over twelve months	17,039	169,177
Total	17,039	171,236
Obligations of state and political subdivisions
Gross Unrealized Losses
Less Than Twelve Months		(9)
Twelve Months or More		(714)
Total		(723)
Estimated Fair Value
Less Than Twelve Months		4,112
Twelve Months or More		30,268
Total		34,380
Gross Unrealized Losses
Less than twelve months		(3)
Over twelve months		(2,494)
Total		(2,497)
Estimated Fair Value
Less than twelve months		2,059
Over twelve months		151,699
Total		153,758
Mortgage-backed securities: Residential agency
Gross Unrealized Losses
Less Than Twelve Months	0	(816)
Twelve Months or More	(6,364)	(56,257)
Total	(6,364)	(57,073)
Estimated Fair Value
Less Than Twelve Months	0	197,057
Twelve Months or More	1,026,095	2,193,862
Total	1,026,095	2,390,919
Gross Unrealized Losses
Less than twelve months	0	0
Over twelve months	(342)	(1,011)
Total	(342)	(1,011)
Estimated Fair Value
Less than twelve months	0	0
Over twelve months	17,039	17,478
Total	17,039	17,478
Mortgage-backed securities: Commercial agency
Gross Unrealized Losses
Less Than Twelve Months	0	(43)
Twelve Months or More	(1,107)	(14,756)
Total	(1,107)	(14,799)
Estimated Fair Value
Less Than Twelve Months	0	18,190
Twelve Months or More	122,450	483,565
Total	122,450	501,755
Other securities
Gross Unrealized Losses
Less Than Twelve Months	0	(94)
Twelve Months or More	(92)	(693)
Total	(92)	(787)
Estimated Fair Value
Less Than Twelve Months	0	18,025
Twelve Months or More	5,015	32,577
Total	$ 5,015	$ 50,602

Investment Securities - Additio

Investment Securities - Additional Information on Securities in a Continuous Loss Position (Detail) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)Security	Dec. 31, 2018USD ($)Security
Schedule of Available-for-sale Securities
Number of debt securities with unrealized losses | Security	189	488
Debt securities with unrealized losses (percentage of amortized cost)	0.67%	2.38%
Number of securities | Security	189	441
Amortized cost basis	$ 1,178,504	$ 2,985,374
Unrealized loss	$ 7,905	$ 75,925
Mortgage-backed securities: Residential agency
Schedule of Available-for-sale Securities
Number of securities | Security	159	302
Amortized cost basis	$ 1,049,840	$ 2,268,608
Unrealized loss	$ 6,706	$ 57,268
Mortgage-backed securities: Commercial agency
Schedule of Available-for-sale Securities
Number of securities | Security	26	72
Amortized cost basis	$ 123,557	$ 498,321
Unrealized loss	$ 1,107	$ 14,756
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities
Number of securities | Security	0	60
Amortized cost basis	$ 0	$ 185,175
Unrealized loss	$ 0	$ 3,208
Other securities
Schedule of Available-for-sale Securities
Number of securities | Security	4	7
Amortized cost basis	$ 5,107	$ 33,270
Unrealized loss	$ 92	$ 693

Investment Securities - Sched_3

Investment Securities - Schedule of Amortized Cost and Estimated Fair Value of Investment Securities by Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Weighted Average Yield
Within one year or less	3.67%
One through five years	2.66%
After five through ten years	2.72%
Over ten years	2.84%
Weighted average yield	2.82%
Amortized Cost
Within one year or less	$ 1,554
One through five years	112,248
After five through ten years	769,216
Over ten years	3,518,983
Amortized Cost	4,402,001	$ 4,843,313
Estimated Fair Value
Within one year or less	1,558
One through five years	113,915
After five through ten years	789,351
Over ten years	3,550,484
Estimated fair value	$ 4,455,308	4,783,579
Weighted Average Yield
Within one year or less	2.34%
One through five years	2.63%
After five through ten years	2.43%
Over ten years	2.60%
Weighted average yield	2.56%
Amortized Cost
Within one year or less	$ 952
One through five years	4,484
After five through ten years	45,338
Over ten years	142,143
Amortized Cost	192,917	207,446
Estimated Fair Value
Within one year or less	955
One through five years	4,524
After five through ten years	46,508
Over ten years	146,025
Estimated fair value	$ 198,012	$ 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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Realized gains	$ 1,297	$ 30	$ 1,297	$ 39
Realized losses	(2,311)	(27)	(2,311)	(95)
Realized gains (losses)	$ (1,014)	$ 3	$ (1,014)	$ (56)

Investment Securities - Sched_5

Investment Securities - Schedule of Securities in Other Assets on Company's Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank (FHLB) stock	$ 108,396	$ 95,213
Federal Reserve Bank Stock	85,630	85,630
CRA and Community Development Investment Funds	2,192	1,884
Other Investments	15,319	9,709
Marketable Securities	$ 211,537	$ 192,436

Loans and Leases - Schedule of

Loans and Leases - Schedule of Non-Covered Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 23,355,311	$ 22,519,815
Commercial loans and leases
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	15,980,029	15,125,322
Commercial loans and leases | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	1,342,984	1,196,366
Commercial loans and leases | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,373,143	2,395,822
Commercial loans and leases | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	6,102,143	5,796,117
Commercial loans and leases | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	6,161,759	5,737,017
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	4,538,194	4,359,156
Consumer and other loans
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,837,088	3,035,337
Consumer and other loans | Home equity
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	2,147,897	2,304,694
Consumer and other loans | Other
Accounts, Notes, Loans and Financing Receivable
Loans and leases, net of unearned income	$ 689,191	$ 730,643

Loans and Leases - Loans (Detai

Loans and Leases - Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable
Net deferred loan origination fees	$ 30,100		$ 30,100		$ 30,200
Net discount	114,300		114,300		136,800
Deposit liabilities reclassified as loans receivable	5,600		5,600		9,200
Loans with carrying value pledged to secure public deposits and other borrowings	8,000,000		8,000,000		7,600,000
Acquired Loans
Accounts, Notes, Loans and Financing Receivable
Net discount	71,600		71,600		81,600
Sabadell United | Non-US
Accounts, Notes, Loans and Financing Receivable
Covered loans acquired	200,900		200,900		$ 202,600
TDRs Occurring during the Period | TDRs
Accounts, Notes, Loans and Financing Receivable
TDRs during period	$ 20,652	$ 20,108	37,409	$ 46,691
TDRs during period on accrual status			13,900	20,600
TDRs during period on non-accrual status			$ 23,500	$ 26,100

Loans and Leases - Schedule o_2

Loans and Leases - Schedule of Aging of Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable
Accruing	$ 43,872	$ 59,460
Non-accrual Loans	158,992	137,184
Acquired Impaired Loans	209,681	169,725
Total Loans	23,355,311	22,519,815
Non-accrual loans 30-59 days past due	11,300	7,000
Non-accrual loans past due 60-89 days	4,200	3,700
Non-accrual loans over 90 days past due	68,600	66,900
Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	129,191	125,706
Total Loans	15,980,029	15,125,322
Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Accruing	207	1,054
Non-accrual Loans	1,188	1,094
Total Loans	1,342,984	1,196,366
Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	7,274	7,167
Non-accrual Loans	15,789	10,260
Total Loans	2,373,143	2,395,822
Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	8,801	7,833
Non-accrual Loans	22,028	15,898
Total Loans	6,102,143	5,796,117
Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	3,472	7,012
Non-accrual Loans	48,747	57,860
Total Loans	6,161,759	5,737,017
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	41,363	6,579
Residential mortgage loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Current	4,459,706	4,290,152
Accruing	11,706	17,406
Non-accrual Loans	50,046	30,396
Total Loans	4,538,194	4,359,156
Consumer and Other Loans
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	39,127	37,440
Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Current	2,113,237	2,258,659
Accruing	8,739	12,692
Non-accrual Loans	18,646	18,830
Total Loans	2,147,897	2,304,694
Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Current	682,860	721,231
Accruing	3,673	6,296
Non-accrual Loans	2,548	2,846
Total Loans	689,191	730,643
Current or Less Than 30 days past due
Accounts, Notes, Loans and Financing Receivable
Current	22,844,145	21,959,758
Current or Less Than 30 days past due | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Current	1,322,728	1,167,795
Current or Less Than 30 days past due | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Current	2,285,316	2,305,743
Current or Less Than 30 days past due | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Current	6,007,594	5,703,131
Current or Less Than 30 days past due | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Current	6,086,983	5,645,304
Current or Less Than 30 days past due | Residential mortgage loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Current	4,393,649	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	2,067,280	2,200,517
Current or Less Than 30 days past due | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Current	680,595	719,122
30-59 days
Accounts, Notes, Loans and Financing Receivable
Accruing	27,981	38,579
30-59 days | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Accruing	207	1,054
30-59 days | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	7,274	7,167
30-59 days | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	2,456	7,473
30-59 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	3,035	5,139
30-59 days | Residential mortgage loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	4,914	2,768
30-59 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	7,123	10,283
30-59 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	2,972	4,695
60-89 days
Accounts, Notes, Loans and Financing Receivable
Accruing	15,040	18,753
60-89 days | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
60-89 days | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
60-89 days | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	6,345	360
60-89 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	437	1,320
60-89 days | Residential mortgage loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	5,941	13,063
60-89 days | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Accruing	1,616	2,409
60-89 days | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Accruing	701	1,601
Greater than 90 days
Accounts, Notes, Loans and Financing Receivable
Accruing	851	2,128
Greater than 90 days | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Greater than 90 days | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Greater than 90 days | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Accruing	0	0
Greater than 90 days | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Accruing	0	553
Greater than 90 days | Residential mortgage loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Accruing	851	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	308,302	363,413
Acquired Loans | Commercial Loans | Real estate - construction
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	18,861	26,423
Acquired Loans | Commercial Loans | Real estate - owner-occupied
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	64,764	72,652
Acquired Loans | Commercial Loans | Real estate - non-owner-occupied
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	63,720	69,255
Acquired Loans | Commercial Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	22,557	26,841
Acquired Loans | Residential mortgage loans | Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	82,793	93,208
Acquired Loans | Consumer and Other Loans | Consumer - Home equity
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	53,232	72,655
Acquired Loans | Consumer and Other Loans | Consumer - Other
Accounts, Notes, Loans and Financing Receivable
Acquired Impaired Loans	$ 2,375	$ 2,379

Loans and Leases - Schedule o_3

Loans and Leases - Schedule of Carrying Amount of Loans Acquired (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Accounts, Notes, Loans and Financing Receivable
Expected losses and foregone interest	$ (161,667)		$ (151,009)
Loans acquired with no evidence of deteriorated credit quality	1,945	$ 3,143
Related allowance	$ (15,854)	$ (16,342)

Loans and Leases - Summary of C

Loans and Leases - Summary of Changes in Accretable Yields of Acquired Loans (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 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	(2,563)	(467)
Accretion	(19,580)	(25,140)
Changes in expected cash flows not affecting non-accretable differences	(4,341)	7,597
Balance at end of period	$ 106,858	$ 136,984

Loans and Leases - Schedule o_4

Loans and Leases - Schedule of Modified TDRs (Detail) - TDRs Occurring during the Period - TDRs $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)SecurityLoan	Jun. 30, 2018USD ($)SecurityLoan	Jun. 30, 2019USD ($)SecurityLoan	Jun. 30, 2018USD ($)SecurityLoan
Financing Receivable, Modifications
Number of Loans | SecurityLoan	82	87	182	145
Pre-modification Outstanding Recorded Investment	$ 20,999	$ 27,761	$ 46,932	$ 58,105
Recorded investment	$ 12,023	$ 5,482	$ 14,923	$ 22,694
Number of loans | SecurityLoan	96	61	138	126
Extended maturities	$ 7,633	$ 1,790	$ 11,175	$ 7,193
Maturity and interest rate adjustment	224	0	617	102
Movement to or extension of interest-rate only payments	1,771	1,316	1,783	1,364
Interest rate adjustment	74	0	74	103
Financing Receivable Modifications Forbearance	0	1,405	5,742	13,936
Other concession(s)	10,950	15,597	18,018	23,993
TDRs during period	20,652	20,108	$ 37,409	$ 46,691
Commercial Loans | Real estate - construction
Financing Receivable, Modifications
Number of Loans | SecurityLoan			1	1
Pre-modification Outstanding Recorded Investment			$ 39	$ 1,950
Recorded investment	$ 37	$ 0	$ 37	$ 0
Number of loans | SecurityLoan	1	0	1	0
TDRs during period			$ 37	$ 1,013
Commercial Loans | Real estate - owner-occupied
Financing Receivable, Modifications
Number of Loans | SecurityLoan	4	5	6	7
Pre-modification Outstanding Recorded Investment	$ 339	$ 2,230	$ 1,435	$ 12,921
Recorded investment	$ 1,232	$ 461	$ 1,232	$ 9,455
Number of loans | SecurityLoan	4	5	6	6
TDRs during period	$ 338	$ 2,201	$ 1,402	$ 11,290
Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Modifications
Number of Loans | SecurityLoan	7	5	13	14
Pre-modification Outstanding Recorded Investment	$ 4,687	$ 823	$ 7,756	$ 1,912
Recorded investment	$ 2,341	$ 1,448	$ 2,913	$ 1,813
Number of loans | SecurityLoan	11	9	17	15
TDRs during period	$ 4,628	$ 780	$ 7,651	$ 1,854
Commercial Loans | Commercial and industrial
Financing Receivable, Modifications
Number of Loans | SecurityLoan	19	16	38	32
Pre-modification Outstanding Recorded Investment	$ 13,757	$ 21,103	$ 29,785	$ 35,338
Recorded investment	$ 5,475	$ 1,437	$ 6,152	$ 7,100
Number of loans | SecurityLoan	17	8	25	21
TDRs during period	$ 13,607	$ 13,618	$ 20,670	$ 26,684
Residential mortgage loans | Residential mortgage
Financing Receivable, Modifications
Number of Loans | SecurityLoan	10	7	19	7
Pre-modification Outstanding Recorded Investment	$ 847	$ 688	$ 1,687	$ 688
Recorded investment	$ 1,012	$ 775	$ 1,597	$ 1,081
Number of loans | SecurityLoan	12	7	21	10
TDRs during period	$ 836	$ 633	$ 1,669	$ 633
Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Modifications
Number of Loans | SecurityLoan	22	19	54	33
Pre-modification Outstanding Recorded Investment	$ 1,159	$ 2,361	$ 5,312	$ 4,170
Recorded investment	$ 1,411	$ 1,129	$ 2,401	$ 2,242
Number of loans | SecurityLoan	17	11	27	26
TDRs during period	$ 1,056	$ 2,350	$ 5,137	$ 4,133
Consumer and Other Loans | Consumer - Other
Financing Receivable, Modifications
Number of Loans | SecurityLoan	20	35	51	51
Pre-modification Outstanding Recorded Investment	$ 210	$ 556	$ 918	$ 1,126
Recorded investment	$ 515	$ 232	$ 591	$ 1,003
Number of loans | SecurityLoan	34	21	41	48
TDRs during period	$ 187	$ 526	$ 843	$ 1,084

Loans and Leases - Schedule o_5

Loans and Leases - Schedule of Subsequently Defaulted TDRs (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)SecurityLoan	Jun. 30, 2018USD ($)SecurityLoan	Jun. 30, 2019USD ($)SecurityLoan	Jun. 30, 2018USD ($)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	82	87	182	145
Pre-modification Outstanding Recorded Investment	$ 20,999	$ 27,761	$ 46,932	$ 58,105
Post-modification Outstanding Recorded Investment	$ 20,652	$ 20,108	$ 37,409	$ 46,691
Number of loans | SecurityLoan	96	61	138	126
Recorded investment	$ 12,023	$ 5,482	$ 14,923	$ 22,694
TDRs | Commercial Loans | Real estate - construction | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan			1	1
Pre-modification Outstanding Recorded Investment			$ 39	$ 1,950
Post-modification Outstanding Recorded Investment			$ 37	$ 1,013
Number of loans | SecurityLoan	1	0	1	0
Recorded investment	$ 37	$ 0	$ 37	$ 0
TDRs | Commercial Loans | Real estate - owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	4	5	6	7
Pre-modification Outstanding Recorded Investment	$ 339	$ 2,230	$ 1,435	$ 12,921
Post-modification Outstanding Recorded Investment	$ 338	$ 2,201	$ 1,402	$ 11,290
Number of loans | SecurityLoan	4	5	6	6
Recorded investment	$ 1,232	$ 461	$ 1,232	$ 9,455
TDRs | Commercial Loans | Real estate - non-owner-occupied | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	7	5	13	14
Pre-modification Outstanding Recorded Investment	$ 4,687	$ 823	$ 7,756	$ 1,912
Post-modification Outstanding Recorded Investment	$ 4,628	$ 780	$ 7,651	$ 1,854
Number of loans | SecurityLoan	11	9	17	15
Recorded investment	$ 2,341	$ 1,448	$ 2,913	$ 1,813
TDRs | Commercial Loans | Commercial and industrial | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	19	16	38	32
Pre-modification Outstanding Recorded Investment	$ 13,757	$ 21,103	$ 29,785	$ 35,338
Post-modification Outstanding Recorded Investment	$ 13,607	$ 13,618	$ 20,670	$ 26,684
Number of loans | SecurityLoan	17	8	25	21
Recorded investment	$ 5,475	$ 1,437	$ 6,152	$ 7,100
TDRs | Residential mortgage loans | Residential mortgage | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	10	7	19	7
Pre-modification Outstanding Recorded Investment	$ 847	$ 688	$ 1,687	$ 688
Post-modification Outstanding Recorded Investment	$ 836	$ 633	$ 1,669	$ 633
Number of loans | SecurityLoan	12	7	21	10
Recorded investment	$ 1,012	$ 775	$ 1,597	$ 1,081
TDRs | Consumer and Other Loans | Consumer - Home equity | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	22	19	54	33
Pre-modification Outstanding Recorded Investment	$ 1,159	$ 2,361	$ 5,312	$ 4,170
Post-modification Outstanding Recorded Investment	$ 1,056	$ 2,350	$ 5,137	$ 4,133
Number of loans | SecurityLoan	17	11	27	26
Recorded investment	$ 1,411	$ 1,129	$ 2,401	$ 2,242
TDRs | Consumer and Other Loans | Consumer - Other | TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans | SecurityLoan	20	35	51	51
Pre-modification Outstanding Recorded Investment	$ 210	$ 556	$ 918	$ 1,126
Post-modification Outstanding Recorded Investment	$ 187	$ 526	$ 843	$ 1,084
Number of loans | SecurityLoan	34	21	41	48
Recorded investment	$ 515	$ 232	$ 591	$ 1,003

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	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Allowance for credit losses
Allowance for loan and lease losses at beginning of period	$ 140,571	$ 140,891
Provision for loan and lease losses	24,067	15,581
Transfer of balance to OREO and other	(2,863)	(3,943)
Charge-offs	(19,194)	(22,734)
Recoveries	3,805	6,781
Allowance for loan and lease losses at end of period	146,386	136,576
Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	14,830	13,208
Balance created in acquisition accounting	0	900
Provision for unfunded lending commitments	451	325
Reserve for unfunded commitments at end of period	15,281	14,433
Allowance for credit losses at end of period	$ 161,667	$ 151,009

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	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses at beginning of period	$ 140,571	$ 140,891
Provision for (Reversal of) loan and lease losses	24,067	15,581
Transfer of balance to OREO and other	(2,863)	(3,943)
Charge-offs	(19,194)	(22,734)
Recoveries	3,805	6,781
Allowance for loan and lease losses at end of period	146,386	136,576
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	14,830	13,208
Balance created in acquisition accounting		900
Provision for (Reversal of) unfunded commitments	451	325
Reserve for unfunded commitments at end of period	15,281	14,433
Allowance on loans individually evaluated for impairment	15,854	17,587
Allowance on loans collectively evaluated for impairment	119,240	103,861
Allowance on loans acquired with deteriorated credit quality	161,667	151,009
Loans and leases, net of unearned income:
Balance at end of period	23,355,311	22,075,783
Balance at end of period individually evaluated for impairment	209,681	192,323
Balance at end of period collectively evaluated for impairment	22,837,328	21,445,962
Commercial Loans | Real Estate
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses at beginning of period	51,806	54,201
Provision for (Reversal of) loan and lease losses	15,204	(3,404)
Transfer of balance to OREO and other	(256)	(506)
Charge-offs	(641)	(1,258)
Recoveries	318	384
Allowance for loan and lease losses at end of period	66,431	49,417
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	4,869	4,531
Balance created in acquisition accounting		129
Provision for (Reversal of) unfunded commitments	603	467
Reserve for unfunded commitments at end of period	5,472	5,127
Allowance on loans individually evaluated for impairment	4,673	2,274
Allowance on loans collectively evaluated for impairment	56,251	40,763
Loans and leases, net of unearned income:
Balance at end of period	9,818,270	9,292,304
Balance at end of period individually evaluated for impairment	74,331	84,217
Balance at end of period collectively evaluated for impairment	9,596,594	9,017,756
Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses at beginning of period	54,096	53,916
Provision for (Reversal of) loan and lease losses	5,077	10,083
Transfer of balance to OREO and other	(1)	(18)
Charge-offs	(11,880)	(13,575)
Recoveries	1,796	4,403
Allowance for loan and lease losses at end of period	49,088	54,809
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	6,198	5,309
Balance created in acquisition accounting		81
Provision for (Reversal of) unfunded commitments	(313)	(306)
Reserve for unfunded commitments at end of period	5,885	5,084
Allowance on loans individually evaluated for impairment	7,656	11,946
Allowance on loans collectively evaluated for impairment	39,854	40,540
Loans and leases, net of unearned income:
Balance at end of period	6,161,759	5,512,416
Balance at end of period individually evaluated for impairment	54,860	66,683
Balance at end of period collectively evaluated for impairment	6,084,342	5,415,093
Residential mortgage loans
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses at beginning of period	12,998	9,117
Provision for (Reversal of) loan and lease losses	(584)	1,112
Transfer of balance to OREO and other	(2,862)	6
Charge-offs	(168)	(196)
Recoveries	157	44
Allowance for loan and lease losses at end of period	9,541	10,083
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	866	555
Balance created in acquisition accounting		0
Provision for (Reversal of) unfunded commitments	(206)	160
Reserve for unfunded commitments at end of period	660	715
Allowance on loans individually evaluated for impairment	349	168
Allowance on loans collectively evaluated for impairment	5,127	3,816
Loans and leases, net of unearned income:
Balance at end of period	4,538,194	4,124,538
Balance at end of period individually evaluated for impairment	41,363	5,873
Balance at end of period collectively evaluated for impairment	4,414,038	3,984,086
Consumer and Other Loans
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses at beginning of period	21,671	23,657
Provision for (Reversal of) loan and lease losses	4,370	7,790
Transfer of balance to OREO and other	256	(3,425)
Charge-offs	(6,505)	(7,705)
Recoveries	1,534	1,950
Allowance for loan and lease losses at end of period	21,326	22,267
Financing Receivable, Reserve For Unfunded Commitments
Reserve for unfunded commitments at beginning of period	2,897	2,813
Balance created in acquisition accounting		690
Provision for (Reversal of) unfunded commitments	367	4
Reserve for unfunded commitments at end of period	3,264	3,507
Allowance on loans individually evaluated for impairment	3,176	3,199
Allowance on loans collectively evaluated for impairment	18,008	18,742
Loans and leases, net of unearned income:
Balance at end of period	2,837,088	3,146,525
Balance at end of period individually evaluated for impairment	39,127	35,550
Balance at end of period collectively evaluated for impairment	2,742,354	3,029,027
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	11,292	15,128
Loans and leases, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	308,302	437,498
Receivables Acquired with Deteriorated Credit Quality | Commercial Loans | Real Estate
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	5,507	6,380
Loans and leases, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	147,345	190,331
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	1,578	2,323
Loans and leases, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	22,557	30,640
Receivables Acquired with Deteriorated Credit Quality | Residential mortgage loans
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	4,065	6,099
Loans and leases, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	82,793	134,579
Receivables Acquired with Deteriorated Credit Quality | Consumer and Other Loans
Financing Receivable, Reserve For Unfunded Commitments
Allowance on loans acquired with deteriorated credit quality	142	326
Loans and leases, net of unearned income:
Balance at end of period acquired with deteriorated credit quality	$ 55,607	$ 81,948

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	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses
Total Loans	$ 23,355,311	$ 22,519,815
Commercial Loans
Financing Receivable, Allowance for Credit Losses
Total Loans	15,980,029	15,125,322
Commercial Loans | Real estate - construction
Financing Receivable, Allowance for Credit Losses
Total Loans	1,342,984	1,196,366
Commercial Loans | Real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Total Loans	2,373,143	2,395,822
Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Total Loans	6,102,143	5,796,117
Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Total Loans	6,161,759	5,737,017
Residential and Consumer Portfolio
Financing Receivable, Allowance for Credit Losses
Current	7,255,803	7,270,042
30 or more days past due	119,479	124,451
Total Loans	7,375,282	7,394,493
Residential mortgage loans | Residential mortgage
Financing Receivable, Allowance for Credit Losses
Current	4,459,706	4,290,152
30 or more days past due	78,488	69,004
Total Loans	4,538,194	4,359,156
Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Allowance for Credit Losses
Current	2,113,237	2,258,659
30 or more days past due	34,660	46,035
Total Loans	2,147,897	2,304,694
Consumer and Other Loans | Consumer - Other
Financing Receivable, Allowance for Credit Losses
Current	682,860	721,231
30 or more days past due	6,331	9,412
Total Loans	689,191	730,643
Pass | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	15,658,849	14,785,998
Pass | Commercial Loans | Real estate - construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	1,320,007	1,182,554
Pass | Commercial Loans | Real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	2,308,176	2,328,999
Pass | Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	6,011,800	5,687,963
Pass | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	6,018,866	5,586,482
Special Mention | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	138,774	157,229
Special Mention | Commercial Loans | Real estate - construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	12,262	1,062
Special Mention | Commercial Loans | Real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	25,114	25,526
Special Mention | Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	48,323	78,009
Special Mention | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	53,075	52,632
Substandard | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	161,340	154,402
Substandard | Commercial Loans | Real estate - construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	10,715	12,740
Substandard | Commercial Loans | Real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	37,126	41,297
Substandard | Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	39,832	26,512
Substandard | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	73,667	73,853
Doubtful | Commercial Loans
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	21,066	27,693
Doubtful | Commercial Loans | Real estate - construction
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	0	10
Doubtful | Commercial Loans | Real estate - owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	2,727	0
Doubtful | Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	2,188	3,633
Doubtful | Commercial Loans | Commercial and industrial
Financing Receivable, Allowance for Credit Losses
Gross loans and leases receivable	$ 16,151	$ 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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Financing Receivable, Impaired
Unpaid Principal Balance	$ 231,852		$ 231,852		$ 209,746
Recorded Investment	209,681		209,681		169,725
Related allowance	(15,854)		(15,854)		(16,342)
Average Recorded Investment	211,628	$ 198,792	204,202	$ 200,080
Interest Income Recognized	1,920	1,630	3,767	3,586
Commercial Loans
Financing Receivable, Impaired
Unpaid Principal Balance	149,106		149,106		164,209
Recorded Investment	129,191		129,191		125,706
Related allowance	(12,329)		(12,329)		(13,282)
Average Recorded Investment	135,250	157,138	136,636	158,760
Interest Income Recognized	1,195	1,171	2,396	2,676
Residential mortgage loans
Financing Receivable, Impaired
Unpaid Principal Balance	42,814		42,814		7,114
Recorded Investment	41,363		41,363		6,579
Related allowance	(349)		(349)		(145)
Average Recorded Investment	36,962	5,929	28,685	5,958
Interest Income Recognized	308	60	543	119
Consumer and Other Loans
Financing Receivable, Impaired
Unpaid Principal Balance	39,932		39,932		38,423
Recorded Investment	39,127		39,127		37,440
Related allowance	(3,176)		(3,176)		(2,915)
Average Recorded Investment	39,416	35,725	38,881	35,362
Interest Income Recognized	417	399	828	791
With No Related Allowance Recorded | Commercial Loans | Real estate - construction
Financing Receivable, Impaired
Unpaid Principal Balance	12,138		12,138		10,261
Recorded Investment	11,139		11,139		9,262
Average Recorded Investment	21,339	12,952	21,340	12,597
Interest Income Recognized	341	198	678	393
With No Related Allowance Recorded | Commercial Loans | Real estate - owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	27,142		27,142		25,037
Recorded Investment	27,064		27,064		19,044
Average Recorded Investment	24,134	30,899	27,314	31,265
Interest Income Recognized	326	209	569	609
With No Related Allowance Recorded | Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	21,234		21,234		15,265
Recorded Investment	20,271		20,271		14,288
Average Recorded Investment	20,305	15,929	20,360	16,558
Interest Income Recognized	100	121	207	250
With No Related Allowance Recorded | Commercial Loans | Commercial and industrial
Financing Receivable, Impaired
Unpaid Principal Balance	33,989		33,989		55,554
Recorded Investment	30,157		30,157		43,886
Average Recorded Investment	29,315	37,859	29,816	37,806
Interest Income Recognized	151	389	331	836
With No Related Allowance Recorded | Commercial Loans | Residential mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	32,448		32,448		1,244
Recorded Investment	31,645		31,645		1,221
Average Recorded Investment	27,129	1,272	18,804	1,280
Interest Income Recognized	235	13	374	27
With No Related Allowance Recorded | Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Impaired
Unpaid Principal Balance	1,995		1,995		4,183
Recorded Investment	1,998		1,998		4,176
Average Recorded Investment	1,998	1,910	1,943	1,922
Interest Income Recognized	22	28	44	52
With No Related Allowance Recorded | Consumer and Other Loans | Consumer - Other
Financing Receivable, Impaired
Unpaid Principal Balance	0		0		0
Recorded Investment	0		0		0
With An Allowance Recorded | Commercial Loans | Real estate - construction
Financing Receivable, Impaired
Unpaid Principal Balance	140		140		228
Recorded Investment	127		127		140
Related allowance	(2)		(2)		(11)
Average Recorded Investment	131	152	135	152
Interest Income Recognized	1	0	2	0
With An Allowance Recorded | Commercial Loans | Real estate - owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	8,811		8,811		5,032
Recorded Investment	8,248		8,248		4,773
Related allowance	(4,061)		(4,061)		(520)
Average Recorded Investment	8,578	19,582	8,628	19,696
Interest Income Recognized	57	82	116	192
With An Allowance Recorded | Commercial Loans | Real estate - non-owner-occupied
Financing Receivable, Impaired
Unpaid Principal Balance	7,683		7,683		6,445
Recorded Investment	7,482		7,482		6,398
Related allowance	(610)		(610)		(105)
Average Recorded Investment	7,557	1,631	7,643	1,705
Interest Income Recognized	42	14	122	39
With An Allowance Recorded | Commercial Loans | Commercial and industrial
Financing Receivable, Impaired
Unpaid Principal Balance	37,969		37,969		46,387
Recorded Investment	24,703		24,703		27,915
Related allowance	(7,656)		(7,656)		(12,646)
Average Recorded Investment	23,891	38,134	21,400	38,981
Interest Income Recognized	177	158	371	357
With An Allowance Recorded | Residential mortgage loans | Residential mortgage
Financing Receivable, Impaired
Unpaid Principal Balance	10,366		10,366		5,870
Recorded Investment	9,718		9,718		5,358
Related allowance	(349)		(349)		(145)
Average Recorded Investment	9,833	4,657	9,881	4,678
Interest Income Recognized	73	47	169	92
With An Allowance Recorded | Consumer and Other Loans | Consumer - Home equity
Financing Receivable, Impaired
Unpaid Principal Balance	33,194		33,194		29,284
Recorded Investment	32,702		32,702		28,818
Related allowance	(2,662)		(2,662)		(2,427)
Average Recorded Investment	32,885	28,595	32,341	28,173
Interest Income Recognized	332	304	656	600
With An Allowance Recorded | Consumer and Other Loans | Consumer - Other
Financing Receivable, Impaired
Unpaid Principal Balance	4,743		4,743		4,956
Recorded Investment	4,427		4,427		4,446
Related allowance	(514)		(514)		$ (488)
Average Recorded Investment	4,533	5,220	4,597	5,267
Interest Income Recognized	$ 63	$ 67	$ 128	$ 139

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Schedule of Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 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 - Schedule of Mortgage Servicing Rights at Carrying Value (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 137,774	$ 137,774
Accumulated Amortization	(74,318)	(64,608)
Net Carrying Amount	63,456	73,166
Mortgage servicing rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	16,885	13,612
Accumulated Amortization	(5,486)	(4,806)
Net Carrying Amount	$ 11,399	$ 8,806

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Narrative (Detail) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Title plant assets	$ 6.8	$ 6.8

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Schedule of Definite-Lived Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 137,774	$ 137,774
Accumulated Amortization	(74,318)	(64,608)
Net Carrying Amount	63,456	73,166
Core deposit intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	136,183	136,183
Accumulated Amortization	(72,870)	(63,213)
Net Carrying Amount	63,313	72,970
Customer relationship intangible asset
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,385	1,385
Accumulated Amortization	(1,354)	(1,323)
Net Carrying Amount	31	62
Non-compete agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	206	206
Accumulated Amortization	(94)	(72)
Net Carrying Amount	$ 112	$ 134

Derivative Instruments and Ot_3

Derivative Instruments and Other Hedging Activities - Schedule of Outstanding Derivative Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative Assets - Fair Value	$ 107,747	$ 27,048
Derivative Liabilities - Fair Value	12,599	22,124
Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Fair Value	21,015	3,469
Derivative Liabilities - Fair Value	0	0
Other Assets | Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Fair Value	21,015	3,469
Other Assets | Not Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Fair Value	86,732	23,579
Other Assets | Not Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Fair Value	76,944	16,946
Other Assets | Not Designated as Hedging Instruments | Customer swaps - upstream
Derivative [Line Items]
Derivative Assets - Fair Value	24	474
Other Assets | Not Designated as Hedging Instruments | Foreign exchange contracts
Derivative [Line Items]
Derivative Assets - Fair Value	0	18
Other Assets | Not Designated as Hedging Instruments | Forward sales contracts
Derivative [Line Items]
Derivative Assets - Fair Value	146	630
Other Assets | Not Designated as Hedging Instruments | Written and purchased options
Derivative [Line Items]
Derivative Assets - Fair Value	9,574	5,490
Other Assets | Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Derivative Assets - Fair Value	44	21
Other Liabilities | Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	0	0
Other Liabilities | Not Designated as Hedging Instruments
Derivative [Line Items]
Derivative Liabilities - Fair Value	12,599	22,124
Other Liabilities | Not Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	1,760	17,812
Other Liabilities | Not Designated as Hedging Instruments | Customer swaps - upstream
Derivative [Line Items]
Derivative Liabilities - Fair Value	5,041	191
Other Liabilities | Not Designated as Hedging Instruments | Foreign exchange contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	0	18
Other Liabilities | Not Designated as Hedging Instruments | Forward sales contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	1,834	750
Other Liabilities | Not Designated as Hedging Instruments | Written and purchased options
Derivative [Line Items]
Derivative Liabilities - Fair Value	3,871	3,310
Other Liabilities | Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Derivative Liabilities - Fair Value	$ 93	$ 43

Derivative Instruments and Ot_4

Derivative Instruments and Other Hedging Activities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative Assets - Notional Amount	$ 3,513,310	$ 2,311,612
Derivative Liabilities - Notional Amount	2,883,353	1,991,559
Cash posted as variation margin for derivatives	78,400	35,800
Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Notional Amount	800,000	408,500
Derivative Liabilities - Notional Amount	108,500	0
Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	800,000	408,500
Derivative Liabilities - Notional Amount	108,500	0
Not Designated as Hedging Instruments
Derivative [Line Items]
Derivative Assets - Notional Amount	2,713,310	1,903,112
Derivative Liabilities - Notional Amount	2,774,853	1,991,559
Not Designated as Hedging Instruments | Interest rate contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	1,885,919	701,257
Derivative Liabilities - Notional Amount	375,805	919,653
Not Designated as Hedging Instruments | Customer swaps - upstream
Derivative [Line Items]
Derivative Assets - Notional Amount	375,805	919,653
Derivative Liabilities - Notional Amount	1,885,919	701,257
Not Designated as Hedging Instruments | Other contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	54,568	50,527
Derivative Liabilities - Notional Amount	113,396	85,623
Not Designated as Hedging Instruments | Foreign exchange contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	0	1,202
Derivative Liabilities - Notional Amount	0	1,202
Not Designated as Hedging Instruments | Forward sales contracts
Derivative [Line Items]
Derivative Assets - Notional Amount	46,143	1,140
Derivative Liabilities - Notional Amount	262,566	143,179
Not Designated as Hedging Instruments | Written and purchased options
Derivative [Line Items]
Derivative Assets - Notional Amount	350,875	229,333
Derivative Liabilities - Notional Amount	$ 137,167	$ 140,645

Derivative Instruments and Ot_5

Derivative Instruments and Other Hedging Activities - Reconciliation of Gross Amounts in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative assets
Gross derivative assets	$ 101,815	$ 24,174
Gross amounts not offset in the Balance Sheet, derivatives	(5,129)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	96,686	23,555
Derivative liabilities
Gross derivative liabilities	10,633	21,288
Gross amounts not offset in the Balance Sheet, derivatives	(5,129)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	5,504	20,669
Written and purchased options
Derivative assets
Gross derivative assets	3,832	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	3,832	3,285
Derivative liabilities
Gross derivative liabilities	3,832	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	3,832	3,285
Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets	21,015	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	21,015	3,469
Not Designated as Hedging Instruments | Interest rate contracts
Derivative assets
Gross derivative assets	76,968	17,420
Gross amounts not offset in the Balance Sheet, derivatives	(5,129)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative assets	71,839	16,801
Derivative liabilities
Gross derivative liabilities	6,801	18,003
Gross amounts not offset in the Balance Sheet, derivatives	(5,129)	(619)
Gross amounts not offset in the Balance Sheet, collateral	0	0
Net derivative liabilities	$ 1,672	$ 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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Designated as Hedging Instruments | Cash Flow Hedging | Interest rate contracts | Interest expense
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	$ (78)	$ (40)	$ (305)	$ (156)
Derivative, included component, gain (loss) recognized in earnings	179	(40)	110	(156)
Amount of gain (loss) recognized in income on derivatives (amount excluded from effectiveness testing)	(257)	0	(415)	0
Derivative instruments, gain (loss) recognized in income, ineffective portion and amount excluded from effectiveness testing, net	0	0	0	0
Derivative instruments, gain (loss) recognized in income, ineffective portion and amount excluded from effectiveness testing, included component net	0	0	0	0
Derivative instruments, gain (loss) recognized in income, ineffective portion and amount excluded from effectiveness testing, excluding component, net	0	0	0	0
Not Designated as Hedging Instruments
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	1,045	2,206	3,876	7,292
Not Designated as Hedging Instruments | Interest rate contracts | Commission income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	2,513	1,458	6,694	2,507
Not Designated as Hedging Instruments | Foreign exchange contracts | Commission income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	1	5	6	10
Not Designated as Hedging Instruments | Forward sales contracts | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	(3,111)	228	(6,320)	3,615
Not Designated as Hedging Instruments | Written and purchased options | Mortgage income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	1,660	517	3,523	1,165
Not Designated as Hedging Instruments | Other contracts | Commission income
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	(18)	(2)	(27)	(5)
OCI | Designated as Hedging Instruments | Cash Flow Hedging | Interest rate contracts
Derivative Instruments and Hedging Activities Disclosures
Amount of gain (loss) recognized	4,441	1,395	2,256	3,944
Derivative, included component, gain (loss) recognized in earnings	5,982	1,395	2,884	3,944
Amount of gain (loss) recognized in income on derivatives (amount excluded from effectiveness testing)	$ (1,541)	$ 0	$ (628)	$ 0

Leases - Additional Information

Leases - Additional Information (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Lessor, Lease, Description [Line Items]
Lease expense	$ 6.9	$ 13.6
Amounts included in measurement of lease liabilities	7.7	14.4
Amount to obtain ROU assets	8	$ 13.2
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	$ 2.3	$ 4.3
Minimum
Lessor, Lease, Description [Line Items]
Term of contract on operating lease	1 year	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	45 years
Remaining lease terms on sales type and direct finance leases		20 years

Leases - Right-of-use Assets an

Leases - Right-of-use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
Leases [Abstract]
Right-of-use assets	$ 98,723	$ 94,200
Lease liabilities	$ 119,463	$ 118,900
Weighted average remaining lease term	7 years 10 months 24 days
Weighted average discount rate	3.30%

Leases - Maturities of Operatin

Leases - Maturities of Operating Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
Leases [Abstract]
2019	$ 13,345
2020	25,055
2021	21,221
2022	18,154
2023	13,522
2024 and thereafter	45,371
Total operating lease payments	136,668
Less: Imputed interest	17,205
Lease liabilities	$ 119,463	$ 118,900

Leases - Components of Net Inve

Leases - Components of Net Investment in Leases (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
Lease payment receivable	$ 259,103
Unguaranteed residual assets	28,903
Total net investment in leases	$ 288,006

Leases - Direct Finance and Sal

Leases - Direct Finance and Sales Type Leases (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
2019	$ 21,556
2020	42,696
2021	42,619
2022	37,866
2023	30,344
2024 and thereafter	93,482
Total future minimum lease payments	268,563
Less: Imputed interest	9,460
Lease receivables	$ 259,103

Shareholders' Equity, Capital_3

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 01, 2024	Apr. 04, 2019	May 09, 2016	Aug. 05, 2015	Aug. 06, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Class of Stock [Line Items]
Preferred stock, shares issued						23,750		23,750		13,750
Preferred stock, par value (in usd per share)						$ 1		$ 1		$ 1
Liquidation preference (per share)						$ 10,000		$ 10,000		$ 10,000
Liquidation preference value			$ 237,500
Carrying Amount						$ 228,485		$ 228,485		$ 132,097
Number of shares authorized to be repurchased										2,765,000
Common stock repurchases						$ 134,778	$ 30,670	$ 164,724	$ 30,670
Shares authorized to be repurchased						117,230		117,230
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		$ 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		55,285
Series D Preferred Stock
Class of Stock [Line Items]
Ownership per share		6.10%
Preferred stock, par value (in usd per share)		$ 1
Liquidation preference (per share)		$ 10,000
Liquidation preference value		$ 100,000
Carrying Amount						$ 96,388		$ 96,388		$ 0
Series D Depositary Shares
Class of Stock [Line Items]
Preferred stock, shares issued		4,000,000
Liquidation preference (per share)		$ 25
Common Stock
Class of Stock [Line Items]
Common stock repurchases (in shares)						1,759,849	400,000	2,147,770	400,000
Common stock repurchases						$ 1,760	$ 400	$ 2,148	$ 400
2016 and 2018 Share Repurchase Program
Class of Stock [Line Items]
Common stock repurchases						$ 134,800		$ 164,700
Average cost of common stock shares repurchased (in usd per share)						$ 76.59		$ 76.70	$ 76.67
2016 and 2018 Share Repurchase Program | Common Stock
Class of Stock [Line Items]
Common stock repurchases (in shares)						1,759,849		2,147,770	400,000
Common stock repurchases									$ 30,700
2019 Share Repurchase Program | Common Stock
Class of Stock [Line Items]
Number of shares authorized to be repurchased						1,600,000		1,600,000
Percentage of total common shares outstanding								3.00%
Forecast | Series D Preferred Stock
Class of Stock [Line Items]
Variable dividend rate after August 1, 2024	3.859%
Subsequent Event
Class of Stock [Line Items]
Common stock repurchases (in shares)					307,230
Treasury stock acquired					$ 23,000

Shareholders' Equity, Capital_4

Shareholders' Equity, Capital Ratios and Other Regulatory Matters - Actual Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Total Risk-Based Capital
Capital Conversion Buffer	4.33%
Consolidated
Tier 1 Leverage
Minimum amount	$ 1,199,612	$ 1,168,343
Minimum ratio	4.00%	4.00%
Actual amount	$ 2,913,362	$ 2,812,863
Actual ratio	9.71%	9.63%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,164,678	$ 1,125,405
Minimum ratio	4.50%	4.50%
Actual amount	$ 2,684,877	$ 2,680,766
Actual Ratio	10.38%	10.72%
Tier 1 Risk-Based Capital
Minimum amount	$ 1,552,904	$ 1,500,540
Minimum ratio	6.00%	6.00%
Actual amount	$ 2,913,362	$ 2,812,863
Actual ratio	11.26%	11.25%
Total Risk-Based Capital
Minimum amount	$ 2,070,539	$ 2,000,720
Minimum ratio	8.00%	8.00%
Actual amount	$ 3,191,529	$ 3,084,764
Actual ratio	12.33%	12.33%
IBERIABANK
Tier 1 Leverage
Minimum amount	$ 1,196,979	$ 1,165,537
Minimum ratio	4.00%	4.00%
Well capitalized amount	$ 1,496,224	$ 1,456,921
Well capitalized ratio	5.00%	5.00%
Actual amount	$ 2,857,238	$ 2,733,099
Actual ratio	9.55%	9.38%
Common Equity Tier 1 (CET1)
Minimum amount	$ 1,161,409	$ 1,122,712
Minimum ratio	4.50%	4.50%
Well capitalized amount	$ 1,677,591	$ 1,621,695
Well capitalized ratio	6.50%	6.50%
Actual amount	$ 2,857,238	$ 2,733,099
Actual Ratio	11.07%	10.95%
Tier 1 Risk-Based Capital
Minimum amount	$ 1,548,546	$ 1,496,949
Minimum ratio	6.00%	6.00%
Well capitalized amount	$ 2,064,728	$ 1,995,932
Well capitalized ratio	8.00%	8.00%
Actual amount	$ 2,857,238	$ 2,733,099
Actual ratio	11.07%	10.95%
Total Risk-Based Capital
Minimum amount	$ 2,064,728	$ 1,995,932
Minimum ratio	8.00%	8.00%
Well capitalized amount	$ 2,580,910	$ 2,494,915
Well capitalized ratio	10.00%	10.00%
Actual amount	$ 3,018,905	$ 2,888,500
Actual ratio	11.70%	11.58%
Capital Conversion Buffer	3.70%

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Common Share - Basic:
Net income	$ 101,598	$ 75,124	$ 201,729	$ 138,745
Less: Preferred stock dividends	949	949	4,547	4,547
Less: Dividends and undistributed earnings allocated to unvested restricted shares	999	767	1,931	1,409
Earnings allocated to common shareholders - basic	$ 99,650	$ 73,408	$ 195,251	$ 132,789
Weighted average common shares outstanding	53,345	55,931	53,758	54,780
Earnings per common share - basic (in usd per share)	$ 1.87	$ 1.31	$ 3.63	$ 2.42
Earnings Per Common Share - Diluted:
Earnings allocated to common shareholders - basic	$ 99,650	$ 73,408	$ 195,251	$ 132,789
Adjustment for undistributed earnings allocated to unvested restricted shares	24	(7)	(21)	(26)
Earnings allocated to common shareholders - diluted	$ 99,674	$ 73,401	$ 195,230	$ 132,763
Weighted average common shares outstanding	53,345	55,931	53,758	54,780
Dilutive potential common shares	328	356	346	353
Weighted average common shares outstanding - diluted	53,674	56,287	54,104	55,133
Earnings per common share - diluted (in usd per share)	$ 1.86	$ 1.30	$ 3.61	$ 2.41

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 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	521,591	595,856	542,769	601,018
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded from the computation of earnings per share	154,780	156,988	154,780	156,988

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards shares under approved incentive compensation plans	3,448,650
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	$ 2.7
Unrecognized compensation cost related to stock options expected to be recognized over a weighted-average period	2 years 10 months 24 days
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned share-based compensation associated with awards	$ 28.1	$ 35.5
Unrecognized compensation cost related to stock options expected to be recognized over a weighted-average period	1 year 4 months 24 days
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	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Number of shares
Balance at beginning of the period (in shares)	714,420,000	686,366,000
Granted (in shares)	127,090,000	96,507,000
Exercised (in shares)	(21,575,000)	(34,745,000)
Forfeited or expired (in shares)	(8,787,000)	(22,524,000)
Balance at end of the period (in shares)	811,148,000	725,604,000
Exercisable at period end (in shares)	561,789,000	505,477,000
Weighted Average Exercise Price
Balance at beginning of the period (in usd per share)	$ 61.41	$ 58.24
Granted (in usd per share)	70.34	81.99
Exercised (in usd per share)	53.98	53.48
Forfeited or expired (in usd per share)	70.80	66.80
Balance at end of the period (in usd per share)	62.90	61.36
Exercisable at period end (in usd per share)	$ 58.26	$ 56.55

Share-Based Compensation - Esti

Share-Based Compensation - Estimate Fair Value of Stock Option Awards with Weighted-Average Assumptions (Detail) - Stock Option Awards - $ / shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 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 12 days	5 years 9 months 18 days
Weighted-average grant-date fair value	$ 14.44	$ 18.44

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 336	$ 319	$ 685	$ 631
Income tax benefit	24	23	50	46
Restricted Stock And Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	5,931	4,927	11,154	9,349
Income tax benefit	1,245	1,035	2,342	1,963
Phantom Stock and Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 2,451	$ 2,017	$ 5,645	$ 5,013

Share-Based Compensation - Unve

Share-Based Compensation - Unvested Restricted Stock Award Activity (Detail) - Restricted Stock And Restricted Stock Units - shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 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)	212,038,000	224,170,000
Forfeited (in shares)	(15,199,000)	(56,653,000)
Vested (in shares)	(199,156,000)	(138,952,000)
Balance at end of the period (in shares)	698,311,000	766,752,000

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Share and Dividend Equivalent Share Award Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Value of share equivalents
Market price of Company's stock (in usd per share)	$ 75.85	$ 75.80
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)	174,991,000	140,804,000
Forfeited share equivalents (in shares)	(20,407,000)	(45,821,000)
Vested share equivalents (in shares)	(101,318,000)	(126,019,000)
Balance at end of the period (in shares)	406,673,000	362,808,000
Value of share equivalents
Balance at beginning of the period (in shares)	$ 22,717	$ 30,523
Granted (in shares)	13,273	10,673
Forfeited share equivalents (in shares)	1,548	3,473
Vested share equivalents (in shares)	7,647	10,519
Balance at end of the period (in shares)	$ 30,846	$ 27,501

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Assets
Securities available for sale, at fair value	$ 4,455,308,000	$ 4,783,579,000
Mortgage loans held for sale	187,987,000	107,734,000
Mortgage loans held for investment, at fair value option	1,945,000	3,143,000
Derivative instruments	101,815,000	24,174,000
Liabilities
Derivative instruments	10,633,000	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	4,455,308,000	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	1,945,000	3,143,000
Recurring
Assets
Securities available for sale, at fair value	4,455,308,000	4,783,579,000
Mortgage loans held for sale	187,987,000	107,734,000
Mortgage loans held for investment, at fair value option	1,945,000	3,143,000
Derivative instruments	107,747,000	27,048,000
Total	4,752,987,000	4,921,504,000
Liabilities
Derivative instruments	12,599,000	22,124,000
Total	12,599,000	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	0	0
Liabilities
Derivative instruments	0	0
Total	0	0
Recurring | Level 2
Assets
Securities available for sale, at fair value	4,455,308,000	4,783,579,000
Mortgage loans held for sale	187,987,000	107,734,000
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	107,747,000	27,048,000
Total	4,751,042,000	4,918,361,000
Liabilities
Derivative instruments	12,599,000	22,124,000
Total	12,599,000	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	1,945,000	3,143,000
Derivative instruments	0	0
Total	1,945,000	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	Jun. 30, 2019	Dec. 31, 2018
Assets
Impaired loans	$ 73,003	$ 65,914
OREO, net	5,076	6,433
Total	78,079	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	73,003	65,914
OREO, net	5,076	6,433
Total	$ 78,079	$ 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	Jun. 30, 2019	Dec. 31, 2018
Mortgage loans held for sale, at fair value
Aggregate Fair Value	$ 187,987	$ 107,734
Aggregate Unpaid Principal	181,067	104,345
Aggregate Fair Value Less Unpaid Principal	6,920	3,389
Mortgage loans held for investment, at fair value
Aggregate Fair Value	1,945	3,143
Aggregate Unpaid Principal	2,099	3,595
Aggregate Fair Value Less Unpaid Principal	$ (154)	$ (452)

Fair Value Measurements - Amoun

Fair Value Measurements - Amount of Net Gains (Losses) from Fair Value Changes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Mortgage loans held for sale, at fair value	$ 2,879	$ (331)	$ 3,531	$ (1,472)
Mortgage loans held for investment, at fair value	$ (104)	$ (172)	$ 87	$ (921)

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Estimated Fair Values and Carrying Amounts of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Financial Assets
Securities available for sale, at fair value	$ 4,455,308	$ 4,783,579
Mortgage loans held for sale, at fair value	187,987	107,734
Mortgage loans held for investment, at fair value option	1,945	3,143
Derivative instruments	107,747	27,048
Cash and cash equivalents	789,315	690,453	$ 727,388	$ 625,724
Securities held to maturity	192,917	207,446
Financial Liabilities
Derivative instruments	12,599	22,124
Deposits	24,295,331	23,763,431	$ 23,430,458
Short-term borrowings	997,507	1,482,882
Long-term debt	1,374,759	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	789,315	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	184,507	315,882
Long-term debt	0	0
Level 2
Financial Assets
Securities available for sale, at fair value	4,455,308	4,783,579
Mortgage loans held for sale, at fair value	187,987	107,734
Mortgage loans held for investment, at fair value option	0	0
Derivative instruments	107,747	27,048
Cash and cash equivalents	0	0
Securities held to maturity	198,012	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	12,599	22,124
Deposits	24,295,695	23,752,139
Short-term borrowings	813,000	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	1,945	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	22,939,128	22,088,236
Financial Liabilities
Derivative instruments	0	0
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	1,381,572	1,154,062
Carrying Amount
Financial Assets
Securities available for sale, at fair value	4,455,308	4,783,579
Mortgage loans held for sale, at fair value	187,987	107,734
Mortgage loans held for investment, at fair value option	1,945	3,143
Derivative instruments	107,747	27,048
Cash and cash equivalents	789,315	690,453
Securities held to maturity	192,917	207,446
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	23,206,980	22,376,101
Financial Liabilities
Derivative instruments	12,599	22,124
Deposits	24,295,331	23,763,431
Short-term borrowings	997,507	1,482,882
Long-term debt	1,374,759	1,166,151
Fair Value
Financial Assets
Securities available for sale, at fair value	4,455,308	4,783,579
Mortgage loans held for sale, at fair value	187,987	107,734
Mortgage loans held for investment, at fair value option	1,945	3,143
Derivative instruments	107,747	27,048
Cash and cash equivalents	789,315	690,453
Securities held to maturity	198,012	204,277
Loans and leases, carried at amortized cost, net of unearned income and allowance for loan and lease losses	22,939,128	22,088,236
Financial Liabilities
Derivative instruments	12,599	22,124
Deposits	24,295,695	23,752,139
Short-term borrowings	997,507	1,482,882
Long-term debt	$ 1,381,572	$ 1,154,062

Business Segments (Detail)

Business Segments (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)Segment	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Segment Reporting Information
Number of business segments | Segment			3
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	$ 335,967	$ 303,823	$ 662,051	$ 574,366
Interest expense	80,628	47,710	156,228	85,364
Net interest income	255,339	256,113	505,823	489,002
Other Income and Expenses [Abstract]
Provision for/(reversal of) loan losses	10,755	7,696	24,518	15,907
Other non-interest income (expense)	33,486	33,373	68,921	63,317
Allocated expenses (income)	0	0	0	0
Non-interest expense	169,618	196,776	328,371	384,847
Income before income tax expense	133,791	105,581	264,268	186,754
Income tax expense	32,193	30,457	62,539	48,009
Net income	101,598	75,124	201,729	138,745
Total loans, leases, and loans held for sale, net of unearned income	23,543,298	22,154,626	23,543,298	22,154,626
Total assets	31,446,532	30,126,162	31,446,532	30,126,162	$ 30,833,015
Deposits	24,295,331	23,430,458	24,295,331	23,430,458	$ 23,763,431
Average assets	31,271,822	29,770,852	31,053,872	28,956,062
Title revenue
Other Income and Expenses [Abstract]
Non-interest income	6,895	6,846	12,120	11,873
Mortgage income
Other Income and Expenses [Abstract]
Non-interest income	18,444	13,721	30,293	23,316
Operating Segments | IBERIABANK
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	334,055	302,387	658,699	571,162
Interest expense	80,628	47,710	156,228	85,364
Net interest income	253,427	254,677	502,471	485,798
Other Income and Expenses [Abstract]
Provision for/(reversal of) loan losses	10,742	7,715	24,565	15,931
Other non-interest income (expense)	33,496	33,481	68,959	63,387
Allocated expenses (income)	(4,414)	(3,873)	(6,447)	(5,352)
Non-interest expense	151,139	179,831	294,894	351,422
Income before income tax expense	129,456	104,485	258,418	187,184
Income tax expense	31,134	30,211	61,109	48,751
Net income	98,322	74,274	197,309	138,433
Total loans, leases, and loans held for sale, net of unearned income	23,330,738	22,026,914	23,330,738	22,026,914
Total assets	31,165,205	29,928,360	31,165,205	29,928,360
Deposits	24,279,416	23,419,382	24,279,416	23,419,382
Average assets	31,024,832	29,599,468	30,838,856	28,766,655
Operating Segments | IMC
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	1,912	1,436	3,351	3,203
Interest expense	0	0	0	0
Net interest income	1,912	1,436	3,351	3,203
Other Income and Expenses [Abstract]
Provision for/(reversal of) loan losses	13	(19)	(47)	(24)
Other non-interest income (expense)	(10)	(105)	(22)	(67)
Allocated expenses (income)	3,250	2,868	4,750	4,034
Non-interest expense	13,590	11,966	24,131	23,882
Income before income tax expense	3,493	237	4,788	(1,440)
Income tax expense	836	17	1,143	(393)
Net income	2,657	220	3,645	(1,047)
Total loans, leases, and loans held for sale, net of unearned income	212,560	127,712	212,560	127,712
Total assets	255,106	173,415	255,106	173,415
Deposits	15,915	11,076	15,915	11,076
Average assets	221,891	148,210	190,205	166,872
Operating Segments | LTC
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Interest and dividend income	0	0	1	1
Interest expense	0	0	0	0
Net interest income	0	0	1	1
Other Income and Expenses [Abstract]
Provision for/(reversal of) loan losses	0	0	0	0
Other non-interest income (expense)	0	(3)	(16)	(3)
Allocated expenses (income)	1,164	1,005	1,697	1,318
Non-interest expense	4,889	4,979	9,346	9,543
Income before income tax expense	842	859	1,062	1,010
Income tax expense	223	229	287	(349)
Net income	619	630	775	1,359
Total loans, leases, and loans held for sale, net of unearned income	0	0	0	0
Total assets	26,221	24,387	26,221	24,387
Deposits	0	0	0	0
Average assets	25,099	23,174	24,811	22,535
Operating Segments | Title revenue | IBERIABANK
Other Income and Expenses [Abstract]
Non-interest income	0	0	0	0
Operating Segments | Title revenue | IMC
Other Income and Expenses [Abstract]
Non-interest income	0	0	0	0
Operating Segments | Title revenue | LTC
Other Income and Expenses [Abstract]
Non-interest income	6,895	6,846	12,120	11,873
Operating Segments | Mortgage income | IBERIABANK
Other Income and Expenses [Abstract]
Non-interest income	0	0	0	0
Operating Segments | Mortgage income | IMC
Other Income and Expenses [Abstract]
Non-interest income	18,444	13,721	30,293	23,316
Operating Segments | Mortgage income | LTC
Other Income and Expenses [Abstract]
Non-interest income	$ 0	$ 0	$ 0	$ 0

Business Segments - Schedule of

Business Segments - Schedule of Segment Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Segment Reporting Information
Interest and dividend income	$ 335,967	$ 303,823	$ 662,051	$ 574,366
Interest expense	80,628	47,710	156,228	85,364
Net interest income	255,339	256,113	505,823	489,002
Provision for/(reversal of) loan losses	10,755	7,696	24,518	15,907
Other non-interest income (expense)	33,486	33,373	68,921	63,317
Allocated expenses (income)	0	0	0	0
Non-interest expense	169,618	196,776	328,371	384,847
Income before income tax expense	133,791	105,581	264,268	186,754
Income tax expense	32,193	30,457	62,539	48,009
Net income	101,598	75,124	201,729	138,745
Total loans, leases, and loans held for sale, net of unearned income	23,543,298	22,154,626	23,543,298	22,154,626
Total assets	31,446,532	30,126,162	31,446,532	30,126,162	$ 30,833,015
Total deposits	24,295,331	23,430,458	24,295,331	23,430,458	$ 23,763,431
Average assets	31,271,822	29,770,852	31,053,872	28,956,062
Operating Segments | IBERIABANK
Segment Reporting Information
Interest and dividend income	334,055	302,387	658,699	571,162
Interest expense	80,628	47,710	156,228	85,364
Net interest income	253,427	254,677	502,471	485,798
Provision for/(reversal of) loan losses	10,742	7,715	24,565	15,931
Other non-interest income (expense)	33,496	33,481	68,959	63,387
Allocated expenses (income)	(4,414)	(3,873)	(6,447)	(5,352)
Non-interest expense	151,139	179,831	294,894	351,422
Income before income tax expense	129,456	104,485	258,418	187,184
Income tax expense	31,134	30,211	61,109	48,751
Net income	98,322	74,274	197,309	138,433
Total loans, leases, and loans held for sale, net of unearned income	23,330,738	22,026,914	23,330,738	22,026,914
Total assets	31,165,205	29,928,360	31,165,205	29,928,360
Total deposits	24,279,416	23,419,382	24,279,416	23,419,382
Average assets	31,024,832	29,599,468	30,838,856	28,766,655
Operating Segments | IMC
Segment Reporting Information
Interest and dividend income	1,912	1,436	3,351	3,203
Interest expense	0	0	0	0
Net interest income	1,912	1,436	3,351	3,203
Provision for/(reversal of) loan losses	13	(19)	(47)	(24)
Other non-interest income (expense)	(10)	(105)	(22)	(67)
Allocated expenses (income)	3,250	2,868	4,750	4,034
Non-interest expense	13,590	11,966	24,131	23,882
Income before income tax expense	3,493	237	4,788	(1,440)
Income tax expense	836	17	1,143	(393)
Net income	2,657	220	3,645	(1,047)
Total loans, leases, and loans held for sale, net of unearned income	212,560	127,712	212,560	127,712
Total assets	255,106	173,415	255,106	173,415
Total deposits	15,915	11,076	15,915	11,076
Average assets	221,891	148,210	190,205	166,872
Operating Segments | LTC
Segment Reporting Information
Interest and dividend income	0	0	1	1
Interest expense	0	0	0	0
Net interest income	0	0	1	1
Provision for/(reversal of) loan losses	0	0	0	0
Other non-interest income (expense)	0	(3)	(16)	(3)
Allocated expenses (income)	1,164	1,005	1,697	1,318
Non-interest expense	4,889	4,979	9,346	9,543
Income before income tax expense	842	859	1,062	1,010
Income tax expense	223	229	287	(349)
Net income	619	630	775	1,359
Total loans, leases, and loans held for sale, net of unearned income	0	0	0	0
Total assets	26,221	24,387	26,221	24,387
Total deposits	0	0	0	0
Average assets	25,099	23,174	24,811	22,535
Mortgage income
Segment Reporting Information
Non-interest income	18,444	13,721	30,293	23,316
Mortgage income | Operating Segments | IBERIABANK
Segment Reporting Information
Non-interest income	0	0	0	0
Mortgage income | Operating Segments | IMC
Segment Reporting Information
Non-interest income	18,444	13,721	30,293	23,316
Mortgage income | Operating Segments | LTC
Segment Reporting Information
Non-interest income	0	0	0	0
Title revenue
Segment Reporting Information
Non-interest income	6,895	6,846	12,120	11,873
Title revenue | Operating Segments | IBERIABANK
Segment Reporting Information
Non-interest income	0	0	0	0
Title revenue | Operating Segments | IMC
Segment Reporting Information
Non-interest income	0	0	0	0
Title revenue | Operating Segments | LTC
Segment Reporting Information
Non-interest income	$ 6,895	$ 6,846	$ 12,120	$ 11,873

Commitments and Contingencies_2

Commitments and Contingencies (Detail) - USD ($) $ in Millions	Dec. 11, 2017	Jun. 30, 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	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments to extend credit	$ 690,267	$ 642,162
Unfunded commitments under lines of credit	7,149,479	6,883,963
Commercial and standby letters of credit	246,622	240,436
Reserve for unfunded lending commitments	$ 15,281	$ 14,830	$ 14,433	$ 13,208

Uncategorized Items - ibkc10-q6

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (345,000)	[1]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1	1,847,000	[2]
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(345,000)	[1]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1	$ 1,847,000	[2]
[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.
[2]	Cumulative-effect adjustment to beginning retained earnings related to the recognition of pre-existing lease liabilities and previously deferred gains on sale-leaseback transactions in accordance with ASU 2016-02, adopted as of January 1, 2019.