Hancock Whitney (HWC) 10-Q 8 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 03, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	HANCOCK HOLDING CO
Entity Filer Category	Large Accelerated Filer
Entity Central Index Key	750,577
Trading Symbol	hbhc
Amendment Flag	false
Document Type	10-Q
Document Fiscal Period Focus	Q3
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		85,180,800

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 333,775	$ 372,689
Interest-bearing bank deposits	105,428	77,235
Federal funds sold	6,297	942
Securities available for sale, at fair value (amortized cost of $2,879,343 and $2,562,000)	2,855,278	2,516,908
Securities held to maturity (fair value of $2,768,148 and $2,470,117)	2,769,274	2,500,220
Loans held for sale	23,236	34,064
Loans	18,786,285	16,752,151
Less: allowance for loan losses	(223,122)	(229,418)
Loans, net	18,563,163	16,522,733
Property and equipment, net of accumulated depreciation of $226,410 and $231,127	365,145	361,612
Prepaid expenses	25,084	18,038
Other real estate, net	21,154	18,884
Accrued interest receivable	78,011	65,887
Goodwill	739,403	621,193
Other intangible assets, net	96,525	87,757
Life insurance contracts	539,232	480,406
FDIC loss share receivable		16,219
Deferred tax asset, net	83,615	104,435
Other assets	212,135	176,080
Total assets	26,816,755	23,975,302
Deposits:
Noninterest-bearing	7,896,384	7,658,203
Interest-bearing	13,637,475	11,766,063
Total deposits	21,533,859	19,424,266
Short-term borrowings	1,737,151	1,225,406
Long-term debt	331,179	436,280
Accrued interest payable	9,014	9,574
Other liabilities	342,277	160,008
Total liabilities	23,953,480	21,255,534
Stockholders' equity:
Common Stock	291,358	291,358
Capital surplus	1,721,477	1,698,253
Retained earnings	948,591	850,689
Accumulated other comprehensive loss, net	(98,151)	(120,532)
Total stockholders' equity	2,863,275	2,719,768
Total liabilities and stockholders' equity	$ 26,816,755	$ 23,975,302
Common shares authorized (par value of 3.33 per share)	350,000	350,000
Common shares issued	87,495	87,495
Common shares outstanding	84,767	84,235

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Consolidated Balance Sheets [Abstract]
Securities available for sale, amortized cost	$ 2,879,343	$ 2,562,000
Securities held to maturity, fair value	2,768,148	2,470,117
Property and equipment, accumulated depreciation	$ 226,410	$ 231,127
Common stock, par value per share	$ 3.33	$ 3.33

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest income:
Loans, including fees	$ 199,702	$ 155,761	$ 566,663	$ 466,591
Loans held for sale	216	323	669	731
Securities-taxable	26,616	21,782	74,385	68,788
Securities-tax exempt	5,608	3,780	16,643	8,593
Short-term investments	574	507	3,048	1,597
Total interest income	232,716	182,153	661,408	546,300
Interest expense:
Deposits	21,789	12,590	52,972	36,926
Short-term borrowings	4,425	1,040	11,598	2,942
Long-term debt	3,645	5,010	12,573	15,114
Total interest expense	29,859	18,640	77,143	54,982
Net interest income	202,857	163,513	584,265	491,318
Provision for loan losses	13,040	18,972	43,982	96,204
Net interest income after provision for loan losses	189,817	144,541	540,283	395,114
Noninterest income:
Service charges on deposit accounts	21,444	18,716	60,711	55,493
Trust fees	10,742	11,512	33,459	34,825
Bank card and ATM fees	13,390	11,808	39,545	35,110
Investment and annuity fees	5,570	4,289	15,440	14,265
Secondary mortgage market operations	4,157	4,917	11,965	12,005
Insurance commissions and fees	660	1,088	2,499	3,635
Amortization of FDIC loss share receivable		(1,539)	(2,427)	(4,678)
Other income	11,152	11,866	36,901	32,768
Securities transactions		351		1,465
Total noninterest income	67,115	63,008	198,093	184,888
Noninterest expense:
Compensation expense	82,242	70,290	237,486	213,524
Employee benefits	12,499	12,873	44,019	42,591
Personnel expense	94,741	83,163	281,505	256,115
Net occupancy expense	12,448	10,068	36,285	30,818
Equipment expense	3,779	3,349	11,457	10,203
Data processing expense	16,798	14,590	48,993	43,167
Professional services expense	10,062	6,584	31,691	21,917
Amortization of intangibles	6,070	4,886	16,532	15,015
Telecommunications and postage	3,876	3,284	11,081	9,917
Deposit insurance and regulatory fees	7,883	5,969	21,356	17,415
Other real estate (income) expense, net	199	(5,214)	(2,329)	(4,096)
Other expense	21,760	22,379	68,057	55,561
Total noninterest expense	177,616	149,058	524,628	456,032
Income before income taxes	79,316	58,491	213,748	123,970
Income taxes	20,414	11,772	53,565	26,505
Net income	$ 58,902	$ 46,719	$ 160,183	$ 97,465
Earnings per common share-basic	$ 0.68	$ 0.59	$ 1.85	$ 1.23
Earnings per common share-diluted	0.68	0.59	1.85	1.23
Dividends paid per share	$ 0.24	$ 0.24	$ 0.72	$ 0.72
Weighted average shares outstanding-basic	84,749	77,550	84,577	77,525
Weighted average shares outstanding-diluted	84,980	77,677	84,818	77,653

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Consolidated Statements of Comprehensive Income [Abstract]
Net income		$ 58,902	$ 46,719	$ 160,183	$ 97,465
Other comprehensive income:
Net change in unrealized gain/loss on securities available for sale and hedges		5,949	(5,604)	19,794	39,997
Reclassification of net losses realized and included in earnings		1,374	1,158	4,479	2,960
Valuation adjustment for pension plan amendment	[1]			17,315
Other valuation adjustments for employee benefit plans		1,597	(6,347)	(9,185)	(6,347)
Amortization of unrealized net loss on securities transferred to held to maturity		977	1,108	2,726	2,736
Other comprehensive income/loss before income taxes		9,897	(9,685)	35,129	39,346
Income tax expense (benefit)		3,609	(3,537)	12,748	14,440
Other comprehensive income/loss net of income taxes		6,288	(6,148)	22,381	24,906
Comprehensive income		$ 65,190	$ 40,571	$ 182,564	$ 122,371
[1]	For further discussion of the pension plan amendment, see Note 11 - Retirement Plans.

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]	Total
Balance at Dec. 31, 2015	$ 291,346	$ 1,424,448	$ 777,944	$ (80,595)	$ 2,413,143
Balance, Shares Issued at Dec. 31, 2015	87,491
Net income			97,465		97,465
Other comprehensive income				24,906	24,906
Comprehensive income			97,465	24,906	122,371
Cash dividends declared ($0.72 per common share)			(57,349)		(57,349)
Common stock activity, long-term incentive plan	$ 6	10,135			10,141
Common stock activity, long-term incentive plan, Shares issued	2
Issuance of stock from dividend reinvestment and stock purchase plan		821			821
Balance at Sep. 30, 2016	$ 291,352	1,435,404	818,060	(55,689)	2,489,127
Balance, Shares Issued at Sep. 30, 2016	87,493
Balance at Dec. 31, 2016	$ 291,358	1,698,253	850,689	(120,532)	$ 2,719,768
Balance, Shares Issued at Dec. 31, 2016	87,495				87,495,000
Net income			160,183		$ 160,183
Other comprehensive income				22,381	22,381
Comprehensive income			160,183	22,381	182,564
Cash dividends declared ($0.72 per common share)			(62,400)		(62,400)
Common stock activity, long-term incentive plan		20,910	119		21,029
Issuance of stock from dividend reinvestment and stock purchase plan		2,314			2,314
Balance at Sep. 30, 2017	$ 291,358	$ 1,721,477	$ 948,591	$ (98,151)	$ 2,863,275
Balance, Shares Issued at Sep. 30, 2017	87,495				87,495,000

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Retained Earnings [Member]
Cash dividends declared, per common share	$ 0.72	$ 0.72

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 160,183	$ 97,465
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	20,942	21,350
Provision for loan losses	43,982	96,204
Gain on other real estate owned	(1,865)	(5,145)
Deferred tax expense (benefit)	8,072	(14,713)
Increase in cash surrender value of life insurance contracts	(10,855)	(8,807)
(Gain) loss on disposal of other assets	1,662	(6,014)
Net (increase) decrease in loans held for sale	11,583	(21,698)
Net amortization of securities premium/discount	24,119	20,836
Amortization of intangible assets	16,532	15,015
Amortization of FDIC indemnification asset	2,427	4,678
Stock-based compensation expense	12,370	10,555
Increase (decrease) in interest payable and other liabilities	(5,038)	8,946
Net cash receipts from (payments to) FDIC for loss share claims	2,300	(436)
Decrease in FDIC loss share receivable	8,613	3,487
Increase in payable to FDIC for loan servicing	180,882
Decrease in other assets	11,446	40,693
Other, net	17,723	6,572
Net cash provided by operating activities	505,078	268,988
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of securities available for sale	213,877	141,716
Proceeds from maturities of securities available for sale	249,270	298,810
Purchases of securities available for sale	(578,690)	(720,241)
Proceeds from maturities of securities held to maturity	276,073	307,633
Purchases of securities held to maturity	(554,442)	(371,657)
Net decrease in short-term investments	331,746	436,635
Proceeds from sales of loans		166,922
Net increase in loans	(725,228)	(591,696)
Purchase of life insurance contracts	(50,000)	(40,000)
Purchases of property and equipment	(16,086)	(10,817)
Proceeds from sales of property and equipment	389	677
Proceeds from sales of other real estate	15,357	20,709
Net of cash paid for FNBC I acquisition	(322,708)
Net cash received for FNBC II acquisition	799,509
Other, net	(28,976)	(3,651)
Net cash used in investing activities	(389,909)	(364,960)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposits	181,084	536,581
Net decrease in short-term borrowings	(84,890)	(347,688)
Repayments of long-term debt	(198,690)	(16,796)
Net proceeds from issuance of long-term debt	124	6,796
Dividends paid	(62,400)	(57,349)
Taxes paid related to nets share settlement of equity awards	(3,235)	(444)
Proceeds from exercise of stock options	11,610	49
Proceeds from dividend reinvestment and stock purchase plan	2,314	821
Net cash provided by (used in) financing activities	(154,083)	121,970
NET (DECREASE) INCREASE IN CASH AND DUE FROM BANKS	(38,914)	25,998
CASH AND DUE FROM BANKS, BEGINNING	372,689	303,874
CASH AND DUE FROM BANKS, ENDING	333,775	329,872
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 4,770	$ 12,012

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Basis of Presentation [Abstract]
Basis of Presentation	HANCOCK HOLDING COMPANY AND SUBSIDIARIES NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS  1. Basis of Presentation The consolidated financial statements include the accounts of Hancock Holding Company and all other entities in which it has a controlling interest (the “Company”). The financial statements include all adjustments that are, in the opinion of management, necessary to fairly state the Company’s financial condition, results of operations, changes in stockholders’ equity and cash flows for the interim periods presented. The Company has also evaluated all subsequent events for potential recognition and disclosure through the date of the filing of this Quarterly Report on Form 10-Q. Some financial information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) have been condensed or omitted in this Quarterly Report on Form 10-Q pursuant to Securities and Exchange Commission rules and regulations. These financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016. Financial information reported in these financial statements is not necessarily indicative of the Company’s financial condition, results of operations, or cash flows for any other interim or annual period. Certain prior period amounts have been reclassified to conform to the current period presentation. Select Stockholders’ Equity line items in the Consolidated Balance Sheets and Statements of Changes in Stockholders’ Equity have been modified to simplify the presentation as discussed in Note 7 – Stockholders’ Equity. Presentation of derivatives contracts cleared through a central clearing counterparty has been revised prospectively to reflect netting of variation margin as settlements to the derivative assets and liabilities rather than collateral, effective January 3, 2017, as discussed in Note 6 – Derivatives. These changes in presentation did not have a material impact on the Company’s financial condition or operating results. Use of Estimates The accounting principles the Company follows and the methods for applying these principles conform to GAAP and general practices followed by the banking industry. These accounting principles require management to make estimates and assumptions about future events that affect the amounts reported in the consolidated financial statements and the accompanying notes. Actual results could differ from those estimates. Critical Accounting Policies and Estimates  There were no material changes or developments during the reporting period with respect to methodologies that the Company uses when applying what management believes are critical accounting policies and developing critical accounting estimates as disclosed in its Annual Report on Form 10-K for the year ended December 31, 2016. Refer to Note 14 – Recent Accounting Pronouncements for a discussion of accounting standards adopted in 2017. 

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2017
Acquisitions [Abstract]
Acquisitions	2. Acquisitions  On March 10, 2017, the Company , through its banking subsidiary, Whitney Bank (“Whitney”), completed the acquisition of certain assets and liabilities, including nine branches, from First NBC Bank (“FNBC”), referred to as the FNBC I transaction. Whitney paid approximately $323 million in cash consideration ( $326 million cash paid net of $3 million in branch cash acquired), including a $41.6 million transaction premium for the earnings stream acquired.  On April 28, 2017, the Louisiana Office of Financial Institutions (“OFI”) closed FNBC and appointed the FDIC as receiver. Whitney entered into a purchase and assumption agreement with the FDIC , referred to as the FNBC II transaction . Pursuant to the agreement, Whitney acquired selected assets and liabilities of the former FNBC , including substantially all of the transaction and savings deposits, and con tinued to operate its 29 branch locations ( 24 in Louisiana and five in Florida). Whitney also had the option to purchase (or assume the leases for) the branch and non-branch locations, including furniture, fixtures, and equipment subsequent to the date of the transaction. This option was exercised for seven branch locations. Whitney paid a premium of $35 million to the FDIC for the earnings stream acquired and received approximately $ 800 million in cash ( $64 2 million from the FDIC for the net liabilities assumed and $158 million in branch cash acquired).  The FNBC I and FNBC II transactions were accounted for as business combinations and therefore, assets acquired and liabilities assumed were recorded at estimated fair values on the acquisition dates. The following table sets forth the preliminary acquisition date fair value of the assets acquired and liabilities assumed, the consideration paid or received, and the resulting goodwill recorded in each of the FNBC I and FNBC II transactions, and in the aggregate. The Company recorded certain p urchase accounting adjustments and a cash settlement with the FDIC during the third quarter of 2017. The Company expects to finalize acquisition date fair values and the resulting goodwill in the fourth quarter of 2017.    FNBC I FNBC II  (in thousands) March 10, 2017 April 28, 2017 Total  ASSETS  Cash and due from banks $ 2,856 $ 157,932 $ 160,788  Interest-bearing time deposits with other banks — 382,622 382,622  Fed funds sold and other short-term investments — 148 148  Securities — 213,877 213,877  Total loans 1,211,523 165,577 1,377,100  Property and equipment 11,837 8,988 20,825  Accrued interest receivable 2,969 885 3,854  Identifiable intangible assets 3,900 21,400 25,300  Other assets 63 4,150 4,213  Total identifiable assets 1,233,148 955,579 2,188,727   LIABILITIES  Deposits 398,171 1,530,338 1,928,509  Short-term borrowings 510,749 85,886 596,635  Long-term debt 93,120 — 93,120  Other liabilities 1,607 3,079 4,686  Total liabilities 1,003,647 1,619,303 2,622,950  Net identifiable assets acquired (liabilities assumed) 229,501 (663,724) (434,223)   Consideration (Paid) Received (325,564) 641,577 316,013  Goodwill $ 96,063 $ 22,147 $ 118,210  The loans acquired were recorded at estimated fair value at the acquisition dates with no carryover of the related allowance for loan losses. Substantially all of the loans acquired were considered to be performing (“purchased credit performing”) based on such factors as past due status and nonaccrual status, and were accounted for under Accounting Standards Codification (“ASC”) 310-20. The unpaid principal balance of the performing loans acquired totaled $1. 4 billion , of which $ 31.7 million is not expected to be collected. The difference at the acquisition dates between the fair value and the contractual amounts due (the “fair value discount”) of $ 41.0 million will be accreted into income over the estimated lives of the loan pools established in the valuation. Loans with an unpaid principal balance of $39.9 million and a fair value of $23.4 million were considered to be purchased credit impaired and were accounted for under ASC 310-30 using the cost recovery method; as such, the related fair value discount of $16.5 million will not be accreted into income .  The Company assumed approximately $604 million of borrowings in the FNBC I transaction, consisting of both short-term and long-term Federal Home Loan Bank (“FHLB”) borrowings. The short-term borrowings consisted of $460 million in variable rate term notes, of which $200 million mature in 2025 and $260 million mature in 2026 . These notes reprice quarterly and may be repaid at the Company’s option, either in full or in part, on any quarterly repricing date. Also included in short-term borrowings are $51 million in fixed rate term notes. The long-term borrowings include $93.1 million in fixed rate term notes, of which $88 million mature in 2018 , $3.2 million mature in 2019 , and $1.9 million mature in 2023 . Short-term borrowings assumed in the FNBC II transaction consisted of securities sold under repurchase agreements. No long-term borrowings were assumed in the FNBC II transaction.  Identifiable intangible assets consist of core deposit intangibles totaling $ 2 5.3 million that are being amortized using sum of years’ digits over the asset’s life of eight years for the FNBC I transaction and eleven years for the FNBC II transaction. Goodwill totaling $ 11 8 million represents the excess of the consideration paid over the fair value of the net assets acquired, or the excess of the fair value of the net liabilities assumed over the consideration received. It is comprised of estimated future economic benefits arising from these transactions that cannot not be individually identified or do not qualify for separate recognition. These benefits include increased market share in the Greater New Orleans and Florida Panhandle market areas, expected earnings streams, and operational efficiencies that the Company believes will result from these business combinations . The tax basis of the goodwill generated from these transactions is expected to be deductible for federal income tax purposes.     Goodwill balance at December 31, 2016 $ 621,193  Additions:  Initial goodwill recorded in FNBC I transaction 95,568  Measurement period adjustments - FNBC I transaction 495  Initial goodwill recorded in FNBC II transaction 23,009  Measurement period adjustments - FNBC II transaction (862)  Goodwill balance at September 30, 2017 $ 739,403 The operating results of the Company for the three and nine months ended September 30, 2017 include the results from the operations acquired in the FNBC transactions since the respective acquisition dates. Estimating reliable historical financial information is impracticable as only selected components of the businesses, as historically operated, were acquired. A number of post-acquisition events, including the consolidation of certain branch locations and the integration of operations, cash and investments acquired make quantifying discrete earnings contributions of the businesses acquired impracticable. As such, neither supplemental pro forma financial information of the combined entity, nor revenue and earnings contributed by the businesses acquired since the dates of acquisition are presented.  The Company incurred merger-related costs in connection with the FNBC I and FNBC II transactions. The following table reflects the merger-related costs for the three and nine months ended September 30, 2017 for both the FNBC I and FNBC II transactions combined. The Company does not expect to incur any additional merger-related costs related to the FNBC transactions in any subsequent period .     (in thousands) Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017  Personnel expense $ 2,120 $ 3,662  Net occupancy and equipment expense 500 777  Professional services expense 2,854 9,681  Data processing expense 929 974  Other real estate - (1,511)  Advertising expense 358 1,389  Other expense 2,132 4,398  Total merger-related expenses $ 8,893 $ 19,370 

Securities

Securities	9 Months Ended
	Sep. 30, 2017
Securities [Abstract]
Securities	 3 . Securities The amortized cost , gross unrealized gains and losses, and estimated fair value of securities classified as available for sale and held to maturity follow.      Securities Available for Sale  (in thousands) September 30, 2017 December 31, 2016  Gross Gross Gross Gross  Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair  Cost Gains Losses Value Cost Gains Losses Value  U.S. Treasury and government agency securities $ 75,019 $ 29 $ 1,606 $ 73,442 $ 56,751 $ — $ 1,923 $ 54,828  Municipal obligations 246,805 534 4,661 242,678 253,228 113 11,186 242,155  Residential mortgage-backed securities 1,795,397 9,701 11,672 1,793,426 1,620,191 10,592 19,428 1,611,355  Commercial mortgage-backed securities 584,503 569 16,719 568,353 425,750 — 23,159 402,591  Collateralized mortgage obligations 174,119 114 354 173,879 202,580 490 591 202,479  Corporate debt securities 3,500 — — 3,500 3,500 — — 3,500  $ 2,879,343 $ 10,947 $ 35,012 $ 2,855,278 $ 2,562,000 $ 11,195 $ 56,287 $ 2,516,908      Securities Held to Maturity  (in thousands) September 30, 2017 December 31, 2016  Gross Gross Gross Gross  Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair  Cost Gains Losses Value Cost Gains Losses Value  U.S. Treasury and government agency securities $ 50,000 $ — $ 63 $ 49,937 $ 50,000 $ — $ 44 $ 49,956  Municipal obligations 725,484 7,677 7,396 725,765 648,093 2,147 20,175 630,065  Residential mortgage-backed securities 760,158 8,896 776 768,278 862,162 4,329 3,068 863,423  Commercial mortgage-backed securities 75,688 — 2,592 73,096 75,739 — 4,038 71,701  Collateralized mortgage obligations 1,157,944 2,476 9,348 1,151,072 864,226 1,420 10,674 854,972  $ 2,769,274 $ 19,049 $ 20,175 $ 2,768,148 $ 2,500,220 $ 7,896 $ 37,999 $ 2,470,117  The following table presents the amortized cost and estimated fair value of debt securities available for sale and held to maturity at September 30, 2017 by contractual maturity. Actual maturities will differ from contractual maturities because of rights to call or repay obligations with or without penalties and scheduled and unscheduled principal payments on mortgage-backed securities and collateralized mortgage obligations.       (in thousands) Amortized Fair  Debt Securities Available for Sale Cost Value  Due in one year or less $ 5,392 $ 5,425  Due after one year through five years 46,852 47,394  Due after five years through ten years 1,097,850 1,082,709  Due after ten years 1,729,249 1,719,750  Total available for sale debt securities $ 2,879,343 $ 2,855,278   Amortized Fair  Debt Securities Held to Maturity Cost Value  Due in one year or less $ 10,081 $ 10,123  Due after one year through five years 108,164 108,726  Due after five years through ten years 837,353 833,465  Due after ten years 1,813,676 1,815,834  Total held to maturity debt securities $ 2,769,274 $ 2,768,148 The Company held no securities c lassified as trading at September 30 , 2017 or December 31, 2016. The fair value and gross unrealized losses for securities classified as available for sale with unrealized losses for the periods indicated follow.     Available for Sale  September 30, 2017 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 52,866 1,606 $ — $ — $ 52,866 $ 1,606  Municipal obligations 145,441 2,286 66,640 2,375 212,081 4,661  Residential mortgage-backed securities 1,255,266 11,514 5,360 158 1,260,626 11,672  Commercial mortgage-backed securities 465,596 15,366 30,151 1,353 495,747 16,719  Collateralized mortgage obligations 66,149 201 5,565 153 71,714 354  $ 1,985,318 $ 30,973 $ 107,716 $ 4,039 $ 2,093,034 $ 35,012       Available for Sale  December 31, 2016 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 54,788 $ 1,923 $ — $ — $ 54,788 $ 1,923  Municipal obligations 228,588 11,186 — — 228,588 11,186  Residential mortgage-backed securities 1,087,644 19,359 3,738 69 1,091,382 19,428  Commercial mortgage-backed securities 402,591 23,159 — — 402,591 23,159  Collateralized mortgage obligations 83,701 591 — — 83,701 591  $ 1,857,312 $ 56,218 $ 3,738 $ 69 $ 1,861,050 $ 56,287  The fair value and gross unrealized losses for securities classified as held to maturity with unrealized losses for the periods indicated follow.      Held to maturity  September 30, 2017 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 49,938 $ 63 $ — $ — $ 49,938 $ 63  Municipal obligations 275,874 2,975 98,976 4,421 374,850 7,396  Residential mortgage-backed securities 254,743 776 — — 254,743 776  Commercial mortgage-backed securities 73,096 2,592 — — 73,096 2,592  Collateralized mortgage obligations 559,859 3,852 232,697 5,496 792,556 9,348  $ 1,213,510 $ 10,258 $ 331,673 $ 9,917 $ 1,545,183 $ 20,175      Held to maturity  December 31, 2016 Losses < 12 months Losses 12 months or > Total   Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 49,956 $ 44 $ — $ — $ 49,956 $ 44  Municipal obligations 494,470 19,706 11,750 469 506,220 20,175  Residential mortgage-backed securities 278,369 3,068 — — 278,369 3,068  Commercial mortgage-backed securities 71,701 4,038 — — 71,701 4,038  Collateralized mortgage obligations 618,739 7,296 115,375 3,378 734,114 10,674  $ 1,513,235 $ 34,152 $ 127,125 $ 3,847 $ 1,640,360 $ 37,999 The unrealized losses primarily relate to c hanges in market rates on fixed rate debt securities since the respective purchase dates. In all cases, the indicated impairment on these debt securities would be recovered no later than the security’s maturity date or possibly earlier if the market price for the security increases with a reduction in the yield required by the market. None of the unrealized losses relate to the marketability o f the securities or the issuers’ abilities to meet contractual obligations. The Company believes it has adequate liquidity and, therefore, does not plan to and, more likely than not, will not be required to sell these securities before recovery of the indicated impairment. Accordingly, the unrealized losses on these securities have been determined to be temporary. Proceeds from the sales of securities were approximately $ 213.9 million with no gross gain or loss and $ 141.7 million with a gross gain of $ 1.5 million and no loss for the nine months ended September 30, 2 017 and 2016 , respectively . Securities with carrying values totaling $ 3.6 billion and $3.8 billion at September 30, 2017 and December 31, 2016, respectively, were pledged as collateral primarily to secure public deposits or securities sold under agreements to repurchase. 

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2017
Loans and Allowance for Loan Losses [Abstract]
Loans and Allowance for Loan Losses	4. Loans and Allowance for Loan Losses The Company generally makes loans in its market areas of south Mississippi, southern and central Alabama, south Lou isiana, the Houston, Texas area and the northern, central and panhandle regions of Florida. Loans, net of unearned income, by portfolio are p resented in the table below.      September 30, December 31,  (in thousands) 2017 2016  Commercial non-real estate $ 8,129,429 $ 7,613,917  Commercial real estate - owner occupied 2,076,014 1,906,821  Total commercial & industrial 10,205,443 9,520,738  Commercial real estate - income producing 2,511,808 2,013,890  Construction and land development 1,373,048 1,010,879  Residential mortgages 2,596,692 2,146,713  Consumer 2,099,294 2,059,931  Total loans $ 18,786,285 $ 16,752,151  The following briefly describes the composition of each loan category.  Commercial and industrial  Commercial and industrial loans are made available to businesses for working capital (including financing of inventory and receivables), business expansion, to facilitate the acquisition of a business, and the purchase of equipment and machinery, including equipment leasing. These loans are primarily made based on the identified cash flows of the borrower and, when secured, have the added strength of the underlying collateral.  Commercial non-real estate loans may be secured by the assets being financed or other business assets such as accounts receivable, inventory, ownership or commodity interests, and may incorporate a personal or corporate guarantee; however, some short-term loans may be made on an unsecured basis, including a small portfolio of corporate credit cards, generally issued as a part of overall customer relationships.  Commercial real estate – owner occupied loans consist of commercial mortgages on properties where repayment is generally dependent on the cash flow from the ongoing operations and activities of the borrower. Like commercial non-real estate, these loans are primarily made based on the identified cash flows of the borrower, but also have the added strength of the value of underlying real estate collateral.  Commercial real estate – income producing  Commercial real estate – income producing loans consist of loans secured by commercial mortgages on properties where the loan is made to real estate developers or investors and repayment is dependent on the sale, refinance, or income generated from the operation of the property. Properties financed include retail, office, multifamily, senior housing, hotel/motel, skilled nursing facilities and other commercial properties.  Construction and land development  C onstruction and land development loans are made to facilitate t he acquisition, development, improvement and construction of both commercial and residential-purpose properties. Such loans are made to builders and investors where repayment is expected to be made from the sale, refinance or operation of the property or to businesses to be used in their business operations. This portfolio also includes a small amount of residential construction loans and loans secured by raw land not yet under development.  Residential Mortgages  Residential mortgages consist of closed-end loans secured by first liens on 1- 4 family residential properties. The portfolio includes both fixed and adjustable rate loans, although most longer term, fixed rate loans originated are sold in the secondary mortgage market .  Consumer  Consumer loans include second lien mortgage home loans, home equity lines of credit and nonresidential consumer purpose loans. Nonresidential consumer loans include both direct and indirect loans. Direct nonresidential consumer loans are made to finance the purchase of personal property, including automobiles, recreational vehicles and boats, and for other personal purposes (secured and unsecured), and deposit account secured loans. Indirect nonresidential consumer loans include automobile financing provided to the consumer through an agreement with automobile dealerships. Consumer loans also include a small portfolio of credit card receivables issued on the basis of applications received through referrals from the Bank’s branches, online and other marketing efforts.  Allowance for Loan Losses The following schedule shows activity in the allowance for loan losses by portfolio class for the nine months ended September 30, 2017 and 2016, as well as the corresponding recorded investment in loans at the end of each period.      Commercial Commercial  Commercial real estate- Total real estate- Construction  non-real owner commercial & income and land Residential  (in thousands) estate occupied industrial producing development mortgages Consumer Total  Nine Months Ended September 30, 2017  Allowance for loan losses:  Beginning balance $ 147,052 $ 11,083 $ 158,135 $ 13,509 $ 6,271 $ 25,361 $ 26,142 $ 229,418  Purchased credit impaired activity:  Charge-offs — — — — (77) (102) (153) (332)  Recoveries 5 110 115 — 49 23 72 259  Net provision for loan losses (27) (220) (247) (54) (124) 175 (192) (442)  Decrease in FDIC loss share receivable (47) — (47) — — (2,344) (135) (2,526)  Non-purchased credit impaired activity:  Charge-offs (35,247) (527) (35,774) (160) (593) (2,383) (22,691) (61,601)  Recoveries 6,437 337 6,774 655 1,001 316 5,176 13,922  Net provision for loan losses 15,922 2,776 18,698 540 54 3,988 21,144 44,424  Ending balance $ 134,095 $ 13,559 $ 147,654 $ 14,490 $ 6,581 $ 25,034 $ 29,363 $ 223,122  Ending balance:  Allowance:  Individually evaluated for impairment $ 20,880 $ 477 $ 21,357 $ 1,321 $ 1 $ 406 $ 405 $ 23,490  Amounts related to purchased credit impaired loans 417 784 1,201 199 254 12,795 863 15,312  Collectively evaluated for impairment 112,798 12,298 125,096 12,970 6,326 11,833 28,095 184,320  Total allowance $ 134,095 $ 13,559 $ 147,654 $ 14,490 $ 6,581 $ 25,034 $ 29,363 $ 223,122  Loans:  Individually evaluated for impairment $ 271,024 $ 6,351 $ 277,375 $ 14,295 $ 480 $ 8,942 $ 1,306 $ 302,397  Purchased credit impaired loans 20,186 13,021 33,207 5,353 6,670 123,244 7,637 176,111  Collectively evaluated for impairment 7,838,219 2,056,642 9,894,861 2,492,160 1,365,898 2,464,506 2,090,351 18,307,777  Total loans $ 8,129,429 $ 2,076,014 $ 10,205,443 $ 2,511,808 $ 1,373,048 $ 2,596,692 $ 2,099,294 $ 18,786,285        Commercial Commercial  Commercial real estate- Total real estate- Construction  non-real owner commercial & income and land Residential  (in thousands) estate occupied industrial producing development mortgages Consumer Total  Nine Months Ended September 30, 2016  Allowance for loan losses:  Beginning balance $ 109,428 $ 9,858 $ 119,286 $ 6,041 $ 5,642 $ 25,353 $ 24,857 $ 181,179  Purchased credit impaired activity:  Charge-offs — (28) (28) (1) (18) (91) (8) (146)  Recoveries 76 163 239 2 98 33 112 484  Net provision for loan losses 54 (140) (86) (436) (253) 1,685 (1,633) (723)  (Decrease) increase in FDIC loss share receivable (2) — (2) — — (3,341) 316 (3,027)  Non-purchased credit impaired activity:  Charge-offs (27,504) (1,660) (29,164) (191) (827) (908) (17,403) (48,493)  Recoveries 2,709 287 2,996 673 1,422 497 4,272 9,860  Net provision for loan losses 74,500 2,303 76,803 4,862 (216) 964 14,514 96,927  Ending balance $ 159,261 $ 10,783 $ 170,044 $ 10,950 $ 5,848 $ 24,192 $ 25,027 $ 236,061  Ending balance:  Allowance:  Individually evaluated for impairment $ 20,665 $ 223 $ 20,888 $ 57 $ 6 $ 94 $ 85 $ 21,130  Amounts related to purchased credit impaired loans 574 1,088 1,662 279 484 15,949 1,334 19,708  Collectively evaluated for impairment 138,022 9,472 147,494 10,614 5,358 8,149 23,608 195,223  Total allowance $ 159,261 $ 10,783 $ 170,044 $ 10,950 $ 5,848 $ 24,192 $ 25,027 $ 236,061  Loans:  Individually evaluated for impairment $ 235,039 $ 6,458 $ 241,497 $ 7,655 $ 2,062 $ 3,864 $ 1,485 $ 256,563  Purchased credit impaired loans 11,534 16,417 27,951 8,087 8,436 145,273 12,045 201,792  Collectively evaluated for impairment 6,887,355 1,878,950 8,766,305 1,974,567 936,094 1,888,025 2,047,475 15,612,466  Total loans $ 7,133,928 $ 1,901,825 $ 9,035,753 $ 1,990,309 $ 946,592 $ 2,037,162 $ 2,061,005 $ 16,070,821   Impaired Loans The following table shows the composition of nonaccrual loans by portfolio class. Purchased credit impaired loans accounted for in pools with an accretable yield are considered to be performing and are excluded from the table.     September 30, December 31,  (in thousands) 2017 2016  Commercial non-real estate $ 188,982 $ 249,037  Commercial real estate - owner occupied 14,305 14,413  Total commercial & industrial 203,287 263,450  Commercial real estate - income producing 14,360 13,954  Construction and land development 3,292 4,550  Residential mortgages 34,674 23,665  Consumer 14,063 12,351  Total loans $ 269,676 $ 317,970  Nonaccrual loans include nonaccruing loans modified in troubled debt restructurings (“TDRs”) of $ 119.3 million and $81.9 million at September 30, 2017 and December 31, 2016, respectively. Total TDRs, both accruing and nonaccruing, were $ 216.0 million as of September 30, 2017 and $121.7 million at December 31, 2016. All TDRs are individually evaluated for impairment. The table below details by portfolio class TDRs that were modified during the nine months ended September 30, 2017 and 2016 .      Nine Months Ended  ($ in thousands) September 30, 2017 September 30, 2016  Pre-Modification Post-Modification Pre-Modification Post-Modification  Outstanding Outstanding Outstanding Outstanding  Number of Recorded Recorded Number of Recorded Recorded  Troubled Debt Restructurings: Contracts Investment Investment Contracts Investment Investment  Commercial non-real estate 50 $ 135,926 $ 135,926 17 $ 57,915 $ 57,915  Commercial real estate - owner occupied 4 3,734 3,734 — — —  Total commercial & industrial 54 139,660 139,660 17 57,915 57,915  Commercial real estate - income producing 5 5,684 5,684 — — —  Construction and land development — — — — — —  Residential mortgages 13 2,068 2,068 6 532 532  Consumer 1 40 42 — — —  Total loans 73 $ 147,452 $ 147,454 23 $ 58,447 $ 58,447  The TDRs modified during the nine months ended September 30, 2017 reflected in the table above include $ 96.1 million of loans with extended amortization terms or other payment concessions, $ 50.1 million of loans with significant covenant waivers and $ 1.3 million with other modifications. The TDRs modified during the nine months ended September 30, 2016 include $43.4 million of loans with extended amortization terms or other payment concessions , $14.7 million of loans with significant covenant waivers and $ 0.4 million of other modifications. No TDRs recorded during the nine months ended September 30, 2017 and 2016 subsequently defaulted within twelve months of modification. The tables below present loans that are individually evaluated for impairment disaggregated by portfolio class at September 30, 2017 and December 31, 2016. Loans individually evaluated for impairment include TDRs and loans that are determined to be impaired and have aggregate relationship balances of $1 million or more.      September 30, 2017  Recorded investment Recorded investment Unpaid  (in thousands) without an allowance with an allowance principal balance Related allowance  Commercial non-real estate $ 92,583 $ 178,441 $ 276,879 $ 20,880  Commercial real estate - owner occupied 3,599 2,752 6,353 477  Total commercial & industrial 96,182 181,193 283,232 21,357  Commercial real estate - income producing 5,160 9,135 14,451 1,321  Construction and land development 464 16 1,445 1  Residential mortgages 6,311 2,630 11,961 406  Consumer 1 1,305 1,308 405  Total loans $ 108,118 $ 194,279 $ 312,397 $ 23,490    December 31, 2016  Recorded investment Recorded investment Unpaid  (in thousands) without an allowance with an allowance principal balance Related allowance  Commercial non-real estate $ 150,650 $ 120,612 $ 295,445 $ 28,187  Commercial real estate - owner occupied 4,261 2,007 6,646 246  Total commercial & industrial 154,911 122,619 302,091 28,433  Commercial real estate - income producing 10,447 4,929 15,708 466  Construction and land development 1,106 832 2,903 38  Residential mortgages 2,877 1,470 4,865 91  Consumer — 2,154 2,155 267  Total loans $ 169,341 $ 132,004 $ 327,722 $ 29,295 The tables below present the average balances and interest income for total impaired loans for the three and nine months ended September 30, 2017 and 2016. Interest income recognized represents interest on accruing loans modified in a TDR.      Three Months Ended  September 30, 2017 September 30, 2016  Average Interest Average Interest  recorded income recorded income  (in thousands) investment recognized investment recognized  Commercial non-real estate $ 260,640 $ 872 $ 233,913 $ 155  Commercial real estate - owner occupied 6,916 24 6,374 10  Total commercial & industrial 267,556 896 240,287 165  Commercial real estate - income producing 14,604 35 7,729 24  Construction and land development 663 1 1,655 —  Residential mortgages 6,204 7 2,466 3  Consumer 1,179 4 826 2  Total loans $ 290,206 $ 943 $ 252,963 $ 194      Nine Months Ended  September 30, 2017 September 30, 2016  Average Interest Average Interest  recorded income recorded income  (in thousands) investment recognized investment recognized  Commercial non-real estate $ 251,129 $ 1,806 $ 197,382 $ 1,002  Commercial real estate - owner occupied 5,895 46 6,015 39  Total commercial & industrial 257,024 1,852 203,397 1,041  Commercial real estate - income producing 14,449 112 8,624 67  Construction and land development 1,216 1 7,821 —  Residential mortgages 4,449 12 1,444 7  Consumer 1,644 9 348 4  Total loans $ 278,782 $ 1,986 $ 221,634 $ 1,119    Aging Analysis The tables below present the age analysis of past due loans by portfolio class at September 30, 2017 and December 31, 2016. Purchased credit impaired loans accounted for in pools with an accretable yield are considered to be current.      Recorded  Greater than investment  30-59 days 60-89 days 90 days Total Total > 90 days and  September 30, 2017 past due past due past due past due Current Loans still accruing  (in thousands)  Commercial non-real estate $ 31,634 $ 3,880 $ 104,334 $ 139,848 $ 7,989,581 $ 8,129,429 $ 24,400  Commercial real estate - owner occupied 18,579 303 8,950 27,832 2,048,182 2,076,014 767  Total commercial & industrial 50,213 4,183 113,284 167,680 10,037,763 10,205,443 25,167  Commercial real estate - income producing 1,540 3,731 5,676 10,947 2,500,861 2,511,808 2,907  Construction and land development 5,018 1,031 2,861 8,910 1,364,138 1,373,048 417  Residential mortgages 39,081 10,575 24,415 74,071 2,522,621 2,596,692 41  Consumer 15,574 7,426 7,710 30,710 2,068,584 2,099,294 318  Total $ 111,426 $ 26,946 $ 153,946 $ 292,318 $ 18,493,967 $ 18,786,285 $ 28,850      Recorded  Greater than investment  30-59 days 60-89 days 90 days Total Total > 90 days and  December 31, 2016 past due past due past due past due Current Loans still accruing  (in thousands)  Commercial non-real estate $ 19,722 $ 1,909 $ 68,505 $ 90,136 $ 7,523,781 $ 7,613,917 $ 384  Commercial real estate - owner occupied 3,008 581 6,310 9,899 1,896,922 1,906,821 52  Total commercial & industrial 22,730 2,490 74,815 100,035 9,420,703 9,520,738 436  Commercial real estate - income producing 838 50 5,026 5,914 2,007,976 2,013,890 216  Construction and land development 694 171 5,300 6,165 1,004,714 1,010,879 1,563  Residential mortgages 24,599 8,816 14,369 47,784 2,098,929 2,146,713 1  Consumer 18,621 7,441 9,147 35,209 2,024,722 2,059,931 823  Total $ 67,482 $ 18,968 $ 108,657 $ 195,107 $ 16,557,044 $ 16,752,151 $ 3,039  Credit Quality Indicators The following tables present the credit quality indicators by segments and portfolio class of loans at September 30, 2017 and December 31, 2016.      September 30, 2017  (in thousands) Commercial non-real estate Commercial real estate - owner-occupied Total commercial & industrial Commercial real estate - income producing Construction and land development Total commercial  Grade:  Pass $ 6,941,591 $ 1,840,553 $ 8,782,144 $ 2,327,685 $ 1,278,648 $ 12,388,477  Pass-Watch 345,073 83,808 428,881 107,568 73,538 609,987  Special Mention 122,023 41,270 163,293 12,802 7,484 183,579  Substandard 717,436 110,383 827,819 63,744 13,378 904,941  Doubtful 3,306 — 3,306 9 — 3,315  Total $ 8,129,429 $ 2,076,014 $ 10,205,443 $ 2,511,808 $ 1,373,048 $ 14,090,299   December 31, 2016  (in thousands) Commercial non-real estate Commercial real estate - owner-occupied Total commercial & industrial Commercial real estate - income producing Construction and land development Total commercial  Grade:  Pass $ 6,364,348 $ 1,719,114 $ 8,083,462 $ 1,873,644 $ 968,505 $ 10,925,611  Pass-Watch 203,311 47,676 250,987 78,309 22,592 351,888  Special Mention 181,763 40,299 222,062 22,492 4,142 248,696  Substandard 846,793 99,732 946,525 39,434 15,640 1,001,599  Doubtful 17,702 — 17,702 11 — 17,713  Total $ 7,613,917 $ 1,906,821 $ 9,520,738 $ 2,013,890 $ 1,010,879 $ 12,545,507       September 30, 2017 December 31, 2016  (in thousands) Residential mortgage Consumer Total Residential mortgage Consumer Total  Performing $ 2,561,977 $ 2,084,913 $ 4,646,890 $ 2,123,048 $ 2,046,757 $ 4,169,805  Nonperforming 34,715 14,381 49,096 23,665 13,174 36,839  Total $ 2,596,692 $ 2,099,294 $ 4,695,986 $ 2,146,713 $ 2,059,931 $ 4,206,644 Below are the definitions of the Company’s internally assigned grades: Commercial : · Pass – loans properly approved, documented, collateralized, and performing which do not reflect an abnormal credit risk. · Pass-Watch – credits in this category are of sufficient risk to cause concern. This category is reserved for credits that display negative performance trends. The “Watch” grade should be regarded as a transition category. · Special Mention – a criticized asset category defined as having potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may, at some future date, result in the deterioration of the repayment prospects for the credit or the institution’s credit position. Special mention credits are not considered part of the Classified credit categories and do not expose the institution to sufficient risk to warrant adverse classification. · Substandard – an asset that is inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified must have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the institution will sustain some loss if the deficiencies are not corrected. · Doubtful – an asset that has all the weaknesses inherent in one classified Substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. · Loss – credits classified as Loss are considered uncollectable and are charged off promptly once so classified. Residential and Consumer: · Performing – loans on which payments of principal and interest are less than 90 days past due. · Nonperforming – a nonperforming loan is a loan that is in default or close to being in default and there are good reasons to doubt that payments will be made in full. All loans rated as nonaccrual loans are also classified as nonperforming.  Purchased Credit Impaired Loans Changes in the carrying amount of purchased credit impaired loans and related accretable yield are presented in the following table for the nine months ended September 30, 2017 and the year ended December 31, 2016.      September 30, 2017 December 31, 2016  Carrying Carrying  Amount Accretable Amount Accretable  (in thousands) of Loans Yield of Loans Yield  Balance at beginning of period $ 190,915 $ 113,686 $ 225,838 $ 129,488  Addition of cost recovery loans 23,431 — — —  Payments received, net (51,040) (6,651) (55,194) (11,024)  Accretion 12,805 (12,805) 20,271 (20,271)  Increase in expected cash flows based on actual cash flows and changes in cash flow assumptions — 4,149 — 5,358  Net transfers from nonaccretable difference to accretable yield — 8,095 — 10,135  Balance at end of period $ 176,111 $ 106,474 $ 190,915 $ 113,686  Loans Acquired in an FDIC-Assisted Transaction and the Related FDIC Loss Share Receivable  Loans purchased in the 2009 acquisition of Peoples First Community Bank were covered by two loss share agreements between the FDIC and the Company. In the third quarter of 2017, the Company terminated the agreement s with the FDIC on the remaining covered loan balances totaling $154 million at June 30, 2017. The indemnification asset was written down to the final settlement amount of $3.2 million in the second quarter of 2017. The final cash settlement was received from the FDIC in July 2017. The following schedule shows activity in the FDIC loss share receivable for the nine months ended September 30, 2017 and 2016 .      September 30, September 30,  (in thousands) 2017 2016  Beginning Balance $ 16,219 $ 29,868  Amortization (2,427) (4,678)  Charge-offs, write-downs and other recoveries (2,442) (5,569)  External expenses qualifying under loss share agreements 79 1,000  Adjustment due to changes in cash flow projections (2,526) (3,027)  Net payments to FDIC 934 436  Write-down for termination of loss share agreements (6,603) —  Cash received from FDIC for final settlement of agreements (3,234) —  Ending balance $ — $ 18,030  Residential Mortgage Loans in Process of Foreclosure  Included in loans are $8 .0 million and $10. 1 million of consumer loans secured by single family residential real estate that are in process of foreclosure as of September 30, 2017 and December 31, 2016, respectively. Loans in process of foreclosure include those for which formal foreclosure proceedings are in process according to local requirements of the applicable jurisdiction. In addition to the single family residential real estate loans in process of forec is losure, the Company also held $ 2. 5 million and $3.1 million of foreclosed single family residential properties in other real estate owned as of September 30, 2017 and December 31, 2016, respectively.

Securities Sold under Agreement

Securities Sold under Agreements to Repurchase	9 Months Ended
	Sep. 30, 2017
Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	5. Securities Sold under Agreements to Repurchase Included in short-term borrowings are customer securities sold under agreements to repurchase (“repurchase agreements”) that mature daily and are secured by U.S. agency securities totaling $ 512.0 million and $358.1 million at September 30, 2017 and December 31, 2016, respectively . The Company borrows funds on a secured basis by selling securities under agreements to repurchase, mainly in connection with treasury management services offered to its deposit customers. As the Company maintains effective control over assets sold under agreements to repurchase, the securities continue to be carried on the consolidated statements of financial condition. Because the Company acts as borrower transferring assets to the counterparty, and the agreements mature daily, the Company’s risk is limited.

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2017
Derivatives [Abstract]
Derivatives	6 . Derivatives Risk Management Objective of Using Derivatives The Company enters into derivative financial instruments to manage risks related to differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments, currently related to select pools of variable rate loans and fixed rate brokered deposits. The Bank also enters into interest rate derivative agreements as a service to certain qualifying customers. The Bank manages a matched book with respect to these customer derivatives in order to minimize its net risk exposure resulting from such agreements. The Bank also enters into risk participation agreements under which it may either sell or buy credit risk associated with a customer’s performance under certain interest rate derivative contracts related to loans in which participation interests have been sold to or purchased from other banks. Fair Values of Derivative Instruments on the Balance Sheet The table below presents the notional or contractual amounts and fair values of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets as of September 30, 2017 and December 31, 2016. Effective January 3, 2017, the Company’s central clearing counterparty amended its rulebook to legally characterize variation margin accounts as settlements, rather than being reflected separately as collateral. As a result of that change, the Company began prospectively reflecting derivative assets and liabilities net of the central clearing counterparty derivative margin account.     September 30, 2017 December 31, 2016  Derivative (1) Derivative (1)  (in thousands) Type of Hedge Notional or Contractual Amount Assets Liabilities Notional or Contractual Amount Assets Liabilities  Derivatives designated as hedging instruments:  Interest rate swaps Cash Flow $ 875,000 $ — $ 7,924 $ 1,100,000 $ — $ 7,787  Interest rate swaps Fair Value 363,000 — 823 — — —  $ 1,238,000 $ — $ 8,747 $ 1,100,000 $ — $ 7,787  Derivatives not designated as hedging instruments:  Interest rate swaps (2) N/A $ 1,172,752 $ 16,855 $ 17,420 $ 979,391 $ 18,405 $ 18,362  Risk participation agreements N/A 109,556 34 108 84,732 50 105  Forward commitments to sell residential mortgage loans N/A 93,809 91 669 75,676 900 221  Interest rate-lock commitments on residential mortgage loans N/A 71,786 534 71 46,840 189 228  Foreign exchange forward contracts N/A 55,081 2,465 2,423 56,152 771 729  1,502,984 19,979 20,691 1,242,791 20,315 19,645  Total derivatives $ 2,740,984 $ 19,979 $ 29,438 $ 2,342,791 $ 20,315 $ 27,432  Less: netting adjustment (3) (2,780) (16,747) — —  Total derivative assets/liabilities $ 17,199 $ 12,691 $ 20,315 $ 27,432 (1) Derivative assets and liabilities are reported at fair value in other assets or other liabilities, respectively, in the consolidated balance sheets. (2) The notional amount represents both the customer accommodation agreements and offsetting agreements with unrelated financial institutions.  (3) Represents balance sheet netting of derivative assets and liabilities for variation margin collateral held or placed with the same central clearing counterparty. See offsetting assets and liabilities for further information.    Cash Flow Hedges of Interest Rate Risk The Company is party to various interest rate swap agreements designated and qualify ing as cash flow hedges of the Company’s forec asted variable cash flows for pools of variable rate loans. For each agreement, the Company receives interest at a fixed rate and pays at a variable rate. The notional amounts of the swap agreements at September 30, 2017 expire as follows: $250 million in 2019 ; $200 million in 2020 ; and $425 million in 2022 . During the terms of the swap agreements, the effective portion of changes in the fair value of the derivative instruments are recorded in Accumulated Other Comprehensive Income (“AOCI”) and subsequently reclassified into earnings in the periods that the hedged forecasted variabl e rate interest payments affect earnings . The impact on AOCI is reflected in Note 7- Shareholders’ Equity. There was virtually no ineffective portion of the change in fair value of the derivative s recognized directly in earnings during the three or nine months ended September 30, 2017 and 2016 .  Fair Value Hedges of Interest Rate Risk  During 2017, the Company entered into interest rate swap agreements that modify the Company’s exposure to interest rate risk by effectively converting a portion of the Company’s brokered certificates of deposit from fixed rates to variable rates. The maturities and call features of these interest rate swaps match the features of the hedged deposits. As interest rates fall, the decline in the value of the certificates of deposit is offset by the increase in the value of the interest rate swaps. Conversely, as interest rates rise, the value of the underlying hedged deposits increases, but the value of the interest rate swaps decrease s , resu lting in no impact on earnings. Interest expense is adjusted by the difference between the fixed and floating rates for the period the swaps are in effect. Hedge ineffectiveness on these transactions results in an increase or decrease in noninterest income. Derivatives Not Designated as Hedges Customer interest rate derivative program The Bank enters into interest rate derivative agreements, primarily rate swaps, with commercial banking customers to facilitate their risk management strategies. The Bank enters into offsetting agreements with unrelated financial institutions, thereby mitigating its net risk exposure resulting from such transactions. Because the interest rate derivatives associated with this program do not meet hedge accounting requirements, changes in the fair value of both the customer derivatives and the offsetting derivatives are recognized directly in earnings. Risk participation agreements The Bank also enters into risk participation agreements under which it may either assume or sell credit risk associated with a borrower’s performance under certain interest rate derivative contracts. In those instances where the Bank has assumed credit risk, it is not a direct counterparty to the derivative contract with the borrower and has entered into the risk participation agreement because it is a party to the related loan agreement with the borrower. In those instances in which the Bank has sold credit risk, it is the sole counterparty to the derivative contract with the borrower and has entered into the risk participation agreement because other banks participate in the related loan ag reement. The Bank manages its credit risk under risk participation agreements by monitoring the creditworthine ss of the borrower, based on the Bank’s normal credit review process. Mortgage banking derivatives The Bank also enters into certain deri vative agreements as part of its mortgage banking activities. These agreements include interest rate lock commitments on prospective residential mortgage loans and forward commitments to sell these loans to investors on a best efforts delivery basis. Customer foreign exchange forward contract derivatives The Bank enters into foreign exchange forward derivative agreements, primarily forward foreign currency contracts, with commercial ban king customers to facilitate their risk management strategies. The Bank manages its risk exposure from such transactions by entering into offsetting agreements with unrelated financial institutions. Because the foreign exchange forward contract derivatives associated with this program do not meet hedge accounting requirements, changes in the fair value of both the customer derivatives and the offsetting derivatives are recognized directly in earnings. Effect of Derivative Instruments on the Income Statement  Derivative instrument income consisting primarily of customer interest rate swap fees, net of fair value adjustments, is reflected in the income statement in other noninterest income, totaling $ 1.3 million and $ 4.4 million for the three and nine months ended September 30, 2017, respectively, and $ 1.3 million and $ 1.7 million for the three and nine months ended September 30, 2016, respectively. The impact to interest income from cash flow hedges was ($0.1) million and ($0.2) million for the three and nine months ended September 30, 2017, respectively and $0.7 million and $1. 7 million for the three and nine months ended September 30, 2016, respectively. For the three and nine months ended September 30, 2017, the fair value hedges entered into during the period reduced interest expense on deposits by $0. 2 million and $0.6 million, respectively, and had minimal impact on noninterest income due to ineffectiveness . Credit Risk-R elated Contingent Features Certain of the Bank’s derivative instruments contain provisions allowing the financial institution counterparty to terminate the contracts in ce rtain circumstances, such as a downgrade of the Bank’s credit ratings below specified levels, a default by the Bank on its indebtedness, or the failure of the Bank to maintain specified minimum regulatory capital ratios or its regulatory status as a well-capitalized institution. These derivative agreements also contain provisions regarding the posting of collateral by each party. As of September 30, 2017 , the aggregate fair value of derivative instruments with credit risk-related contingent features that were in a net liability position was $ 16.6 million . Offsetting Assets and Liabilities The Bank’s derivative instruments with certain counterparties contain legally enforceable netting provisions that allow for net settlement of multiple transactions to a single amount, which may be positive, negative, or zero. Agreements with certain bilateral counterparties require both parties to maintain collateral in the event that the fair values of derivative instruments exceed established exposure thresholds. For centrally cleared derivatives, the Company is subject to initial margin posting and daily variation margin exchange with the central clearinghouses. As noted above, effective January 3, 2017, the Company began to reflect its derivative assets and liabilities net of the central clearing party variation margin account in the Statement of Income. Offsetting information in regards to all derivative assets and liabilities , including accrued interest, subject to these master netting agreements at September 30, 2017 and Decemb er 31, 2016 is presented in the following tables.      (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Income  Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income Financial Instruments Cash Collateral Net Amount  As of September 30, 2017  Derivative Assets $ 5,271 $ (3,942) $ 1,329 $ 1,329 $ — $ —   Derivative Liabilities $ 21,889 $ (16,322) $ 5,567 $ 1,329 $ 7,318 $ (3,080)      (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Income  Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income Financial Instruments Cash Collateral Net Amount  As of December 31, 2016  Derivative Assets $ 4,788 $ — $ 4,788 $ 4,788 $ — $ —   Derivative Liabilities $ 26,846 $ — $ 26,846 $ 4,788 $ 19,095 $ 2,963  The Company has excess collateral compared to total exposure due to initial margin requirements for day-to-day rate volatility.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity [Abstract]
Stockholders' Equity	 7 . Stockholders’ Equity  The present ation of the components of stock holders’ equity was modified from prior filings to consolidate treasury stock into surplus in the C onsolidated B alance S heets an d Statements of Changes in Stock holders’ E quity in order to simplify the presentation. Additional information on treasury s tock is reflected in the common shares outstanding section below.   Common Shares Outstanding  Common shares outstanding excludes treasury sha res of 1.0 m illion and 1.3 million at September 30 , 2017 and December 31, 2016, respectively, with a first-in-first-out cost basi s of $17. 6 mill ion and $24.1 m illion at September 30, 2017 and December 31, 2016, respectively. Shares outstanding also exclude s unvested restricted share awards of 1. 7 m illion and 2.0 million at September 30, 2017 and December 31, 2016, respectively. A ccumulated Other Comprehensive Income (Loss) T he components of AOCI and changes in those components are presented in the following table.     Available HTM Securities  for Sale Transferred Employee Cash  (in thousands) Securities from AFS Benefit Plans Flow Hedges Total  Balance, December 31, 2015 $ 4,268 $ (16,795) $ (67,890) $ (178) $ (80,595)  Other comprehensive income (loss) before income taxes:  Net change in unrealized gain 38,835 — — 1,162 39,997  Reclassification of net (gain) loss realized and included in earnings (1,435) — 4,395 — 2,960  Valuation adjustment for employee benefit plans — — (6,347) — (6,347)  Amortization of unrealized net loss on securities transferred to HTM — 2,736 — — 2,736  Income tax expense (benefit) 13,701 1,029 (714) 424 14,440  Balance, September 30, 2016 $ 27,967 $ (15,088) $ (69,128) $ 560 $ (55,689)  Balance, December 31, 2016 $ (28,679) $ (14,392) $ (72,501) $ (4,960) $ (120,532)  Other comprehensive income (loss) before income taxes:  Net change in unrealized gain (loss) 21,026 — — (1,232) 19,794  Reclassification of net losses realized and included in earnings — — 4,144 335 4,479  Valuation adjustment for pension plan amendment (a) — — 17,315 — 17,315  Other valuation adjustments for employee benefit plan — — (9,185) — (9,185)  Amortization of unrealized net loss on securities transferred to HTM — 2,726 — — 2,726  Income tax expense (benefit) 7,649 1,012 4,416 (329) 12,748  Balance, September 30, 2017 $ (15,302) $ (12,678) $ (64,643) $ (5,528) $ (98,151)  (a) For further discussion of the pension plan amendment, see Note 11 – Retirement Plans. AOCI is reported as a component of stockholders’ equity. AOCI can include, among other items, unrealized holding gains and losses on securities available for sale (“AFS”), gains and losses associa ted with pension or other post- retirement benefits that are not recognized immediately as a component of net periodic benefit cost, and gains and losses on derivative instruments that are designated as, and qualify as, cash flow hedges. Net unrealized gains/losses on AFS securities reclassified as securities held to maturity (“HTM”) also continue to be reported as a component of AOCI and will be amortized over the estimated remaining life of the securities as an adjustment to interest income. Subject to certain thresholds, unrealized losses on employee benefit plans will be reclassified into income as pension and post-retirement costs are recognized over the remaining service period of plan participants. Accumulated gains/losses on the cash flow hedge of the variable rate loans describe d in Note 6 will be reclassified into income over the life of the hedge. Gains (losses) in AOCI are net of deferred income taxes. The following table shows the line items of the consolidated statements of income affected by amounts reclassified from AOCI .      Nine Months Ended  Amount reclassified from AOCI (a) September 30, Affected line item on  (in thousands) 2017 2016 the statement of income  Gain on sale of AFS securities $ — $ 1,435 Securities transactions  Tax effect — (502) Income taxes  Net of tax — 933 Net income  Amortization of unrealized net loss on securities transferred to HTM (2,726) (2,736) Interest income  Tax effect 1,012 1,029 Income taxes  Net of tax (1,714) (1,707) Net income  Amortization of defined benefit pension and post-retirement items (4,144) (4,395) Employee benefits expense (b)  Tax effect 1,491 1,538 Income taxes  Net of tax (2,653) (2,857) Net income  Amortization of loss on terminated cash flow hedges (335) — Interest income  Tax effect 123 — Income taxes  Net of tax (212) — Net income  Total reclassifications, net of tax $ (4,579) $ (3,631) Net income (a) Amounts in parenthesis indicate reduction in net income.  (b) These AOCI components are included in the computation of net periodic pension and post-retirement cost that is reported with employee benefits expense (see Note 11 – Retirement Plans for additional details).

Other Noninterest Income

Other Noninterest Income	9 Months Ended
	Sep. 30, 2017
Other Noninterest Income [Abstract]
Other Noninterest Income	8 . Other Noninterest Income Components of other no ninterest income are as follows:                                Three Months Ended Nine Months Ended  September 30, September 30,  (in thousands) 2017 2016 2017 2016  Income from bank-owned life insurance $ 3,097 $ 4,097 $ 8,632 $ 11,148  Credit related fees 2,521 2,685 8,297 7,309  Derivative income 1,339 1,347 4,484 1,741  Net gain on sale of assets 400 991 4,465 4,557  Safety deposit box income 424 424 1,264 1,315  Other miscellaneous 3,371 2,322 9,759 6,698  Total other noninterest income $ 11,152 $ 11,866 $ 36,901 $ 32,768 

Other Noninterest Expense

Other Noninterest Expense	9 Months Ended
	Sep. 30, 2017
Other Noninterest Expense [Abstract]
Other Noninterest Expense	9 . Other Noninterest Expense Components of other non interest expense are as follows:     Three Months Ended Nine Months Ended  September 30, September 30,  (in thousands) 2017 2016 2017 2016  Advertising $ 3,910 $ 2,859 $ 11,971 $ 7,909  Ad valorem and franchise taxes 3,387 2,268 9,942 6,911  Printing and supplies 1,421 1,134 3,929 3,310  Insurance expense 671 803 2,295 2,467  Travel expense 1,226 1,022 3,635 3,050  Entertainment and contributions 2,322 1,686 6,087 5,319  Tax credit investment amortization 1,212 861 3,637 4,437  Loss share termination — — 6,603 —  Other miscellaneous 7,611 11,746 19,958 22,158  Total other noninterest expense $ 21,760 $ 22,379 $ 68,057 $ 55,561 

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	10 . Earnings Per Share The Company calculates earnings per share using the two-class method. The two-class method allocates net income to each class of common stock and participating security according to common dividends declared and participation rights in undistributed earnings. Participating secur ities consist of unvested stock based payment awards that contain nonforfeitable rights to dividends or dividend equivalents. A summary of the information used in the computation of earnings per common share follows.     Three Months Ended Nine Months Ended  September 30, September 30,  (in thousands, except per share data) 2017 2016 2017 2016  Numerator:  Net income to common shareholders $ 58,902 $ 46,719 $ 160,183 $ 97,465  Net income allocated to participating securities - basic and diluted 1,244 1,101 3,566 2,334  Net income allocated to common shareholders - basic and diluted $ 57,658 $ 45,618 $ 156,617 $ 95,131  Denominator:  Weighted-average common shares - basic $ 84,749 $ 77,550 $ 84,577 $ 77,525  Dilutive potential common shares 231 127 241 128  Weighted-average common shares - diluted $ 84,980 $ 77,677 $ 84,818 $ 77,653  Earnings per common share:  Basic $ 0.68 $ 0.59 $ 1.85 $ 1.23  Diluted $ 0.68 $ 0.59 $ 1.85 $ 1.23  Potential common shares consist of employee and director stock options. These potential common shares do not enter into the calculation of diluted earnings per share if the impact would be anti-dilutive, i.e., increase earnings per share or redu ce a loss per share. Weighted average anti-dilutive potential common shares totaled 1 ,380 and 11,057 , respectively , for the three and nine months ended September 30, 2017. Weighted-average anti-dilutive potential common shares totaled 317,893 and 578, 863 , respectively, for the three and nine months ended September 30, 2016.

Retirement Plans

Retirement Plans	9 Months Ended
	Sep. 30, 2017
Retirement Plans [Abstract]
Retirement Plans	11 . Retirement Plans  During the second quarter of 2017, the Company amended both the Hancock Holding Company Pension Plan and Trust Agreement (“Pension Plan”), a qualified defined benefit plan, and the Hancock Holding Company 401(k) Savings Plan and Trust Agreement (“401(k) Plan”), a defined contribution plan. The Pension Plan was amended to exclude any individual hired or rehired by the Company after June 30, 2017 from eligibility to participate. The Pension Plan amendment further provides that the accrued benefits of each participant in the Pension Plan whose combined age plus years of service as of January 1, 2018 totals less than 55 will be frozen as of January 1, 2018 and will not thereafter increase. As a result of the plan amendments, pension assets and the benefit obligations were re-measured as of June 30, 2017. The impact of the amendment to the benefit obligation was a reduction of $17.3 million. As of June 30, 2017, pension assets totaled $537.6 million and the benefit obligation totaled $476.9 million. The 401(k) Plan was amended for participants whose benefits are frozen under the Pension Plan, to add an enhanced Company contribution beginning January 1, 2018, in the amount of 2% , 4% or 6% of such participant’s eligible compensation, based on the participant’s age and years of service with the Company. The 401(k) Plan’s amendment further provides that the Company will contribute to the benefit of those associates of the Company hired or rehired after June 30, 2017 and those associates of the Company never enrolled in the Pension Plan an additional basic contribution in an amount equal to 2% of the associate’s eligible compensation beginning January 1, 2018. Participants will vest in the new basic and enhanced Company contributions upon completion of three years of service.  The Company also has a nonqualified defined benefit plan covering certa in legacy Whitney employees that was frozen as of December 31, 2012 and no future benefits are accrued under this plan . The Company sponsors defined benefit postretirement plans for both legacy Hancock and legacy Whitney employees that provide health care and life insurance benefits. Benefits under the Hancock plan are not available to employees hired on or after January 1, 2000. Benefits under the Whitney plan are restricted to retirees who were already receiving benefits at the time of plan amendments in 2007 or active participants who were eligible to receive benefits as of December 31, 2007.  The following tables show the components of net periodic benefits cost included in expense for the plans for the periods indicated.      Other Post-  (in thousands) Pension Benefits retirement Benefits  Three months Ended September 30, 2017 2017 2016 2017 2016  Service cost $ 3,769 $ 3,611 $ 17 $ 45  Interest cost 4,056 4,022 155 204  Expected return on plan assets (9,652) (8,554) — —  Amortization of net loss and prior service costs 1,167 1,426 (128) 53  Net periodic benefit cost (reduction of cost) $ (660) $ 505 $ 44 $ 302   Nine months ended September 30, 2017  Service cost $ 11,612 $ 10,487 $ 112 $ 119  Interest cost 12,470 13,033 514 613  Expected return on plan assets (27,978) (25,999) — —  Amortization of net loss and prior service costs 4,368 4,320 (224) 75  Net periodic benefit cost $ 472 $ 1,841 $ 402 $ 807  No contribution to the pension plans is required in 2017 to meet minimum funding requirements, and the Company has no plans to make a contribution in the current year.

Share-Based Payment Arrangement

Share-Based Payment Arrangements	9 Months Ended
	Sep. 30, 2017
Share-Based Payment Arrangements [Abstract]
Share-Based Payment Arrangements	12 . Share-Based Payment Arrangements Hancock maintains incentive compensation plans that provide for awards of share-based compensation to employees and directors. These plans have been approved by the Company’s shareholders. Detailed descriptions of these plans were included in Note 16 to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 . Effective January 1, 2017, the Company prospectively adopted accounting guidance intended to improve the accounting for employee share-based payments. The Company elected to account for forfeitures as they occur. The adoption of this guidance did not have a material impact on the Company’s financial condition or results of operations. A summary of option activity for the nine months ended September 30 , 201 7 is presented below:    Weighted  Average  Weighted Remaining  Average Contractual Aggregate  Number of Exercise Term Intrinsic  Options Shares Price (Years) Value ($000)  Outstanding at January 1, 2017 456,258 $ 35.91 — $ 3,734  Exercised/Released (335,758) 34.58 — 4,111  Cancelled/Forfeited (538) 32.09 — 6  Expired (16,675) 68.18 — —  Outstanding at September 30, 2017 103,287 $ 35.06 2.92 $ 1,383  Exercisable at September 30, 2017 103,287 $ 35.06 2.92 $ 1,383  The total intrins ic value of options exercised for the nine months ended September 30, 2017 was $4.1 million. There was minimal intrinsic value of options exercised for the nine months ended September 30, 2016 . The restricted and performance shares in the table below are subject to service requirements. A summary of the status of the Company’s nonvested restricted and performance shares as of September 30, 2017 and changes during the nine months ended September 30, 2017 , is presented in the following table.    Weighted  Average  Number of Grant Date  Shares Fair Value  Nonvested at January 1, 2017 2,152,119 $ 32.15  Granted 63,127 42.16  Vested (209,440) 30.23  Forfeited (54,493) 32.36  Nonvested at September 30, 2017 1,951,313 $ 32.67  As of September 30, 2017 , there was $ 40.1 million of total unrecognized compensation expense related to nonvested restricted and performance shares expected to vest. This compensation is expected to be recognized in expense over a weighted average period of 3 years . The total fair value of shares which vested during the nine months ended September 30, 2017 and 2016 was $10.1 million and $2. 2 million , respectively. During the nine months ended September 30, 2017 , the Company granted 23,489 performance shares subject to a total shareholder return (“TSR”) performance metric with a grant date fair value of $42.92 per share and 23,489 performance shares subject to a core earnings per share performance metric with a grant date fair value of $38.26 per share to key members of executive management. The number of performance shares subject to TSR that ultimately vest at the end of the three -year performance period, if any, will be based on the relative rank of the Company’s three-year TSR among the TSRs of a peer group of 44 regional banks. The fair value of the performance shares subject to TSR at the grant date was determined using a Monte Carlo simulation method. The number of performance shares subject to core earnings per share that ultimately vest will be based on the Company’s attainment of certain core earnings per share goals over the two -year performance period. The maximum number of performance shares that could vest is 200% of the target award. Compensation expense for these performance shares is recognized on a straight line basis over the three -year service period.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2017
Fair Value [Abstract]
Fair Value	13 . Fair Value The Financial Accounting Standards Board (“FASB”) defines fair value as the exchange price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market partici pants on the measurement date. The FASB’s guid ance also establishes a fair value hierarchy that prioritizes the inputs to these valuation techniques used to measure fair value, giving preference to quoted prices in active markets for identical assets or liabilities (“level 1”) and the lowest priority to unobservable inputs such as a reporting entity’s own data (“level 3”). Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in markets that are not active, observable inputs other than quoted prices, such as interest rates and yield curves, and inputs that are derived principally from or corroborated by observable market data by correlation or other means. Fair Value of Assets and Liabilities Measured on a Recurring Basis The following tables present for each of the fair value hierarchy levels the Company’s assets and liabilities that are measured at fair value on a recurring basis in the consolidated balance sheets.     September 30, 2017  (in thousands) Level 1 Level 2 Level 3 Total  Assets  Available for sale debt securities:  U.S. Treasury and government agency securities $ — $ 73,442 $ — $ 73,442  Municipal obligations — 242,678 — 242,678  Corporate debt securities — 3,500 — 3,500  Residential mortgage-backed securities — 1,793,426 — 1,793,426  Commercial mortgage-backed securities — 568,353 — 568,353  Collateralized mortgage obligations — 173,879 — 173,879  Total available for sale securities — 2,855,278 — 2,855,278  Derivative assets (1) — 17,199 — 17,199  Total recurring fair value measurements - assets $ — $ 2,872,477 $ — $ 2,872,477  Liabilities  Derivative liabilities (1) $ — $ 12,691 $ — $ 12,691  Total recurring fair value measurements - liabilities $ — $ 12,691 $ — $ 12,691  (1) For further disaggregation of derivative as sets and liabilities, see Note 6 - Derivatives .      December 31, 2016  (in thousands) Level 1 Level 2 Level 3 Total  Assets  Available for sale debt securities:  U.S. Treasury and government agency securities $ — $ 54,828 $ — $ 54,828  Municipal obligations — 242,155 — 242,155  Corporate debt securities — 3,500 — 3,500  Residential mortgage-backed securities — 1,611,355 — 1,611,355  Commercial mortgage-backed securities — 402,591 — 402,591  Collateralized mortgage obligations — 202,479 — 202,479  Total available for sale securities — 2,516,908 — 2,516,908  Derivative assets (1) — 20,315 — 20,315  Total recurring fair value measurements - assets $ — $ 2,537,223 $ — $ 2,537,223  Liabilities  Derivative liabilities (1) $ — $ 27,432 $ — $ 27,432  Total recurring fair value measurements - liabilities $ — $ 27,432 $ — $ 27,432  (1) For further disaggregation of derivative as sets and liabilities, see Note 6 - Derivatives . Securities classified as level 2 include obligations of U.S. Government agencies and U.S. Government-sponsored agencies, residential mortgage-backed securities and collateralized mortgage obligations that are issued or guaranteed by U.S. government agencies, and state and munic ipal bonds. The level 2 fair value measurements for investment securities are obtained quarterly from a third-party pricing service that uses industry-standard pricing models. Substantially all of the model inputs are observable in the marketplace or can be supported by observable data.   The Company invests only in securities of investment grade quality with a targeted duration, for the overall portfolio, generally between two and five years . Company policies generally limit investments to U.S. agency securities and municipal securities determined to be investment grade according to an internally generated score which generally includes a rating of not less than “Baa” or its equivalent by a nationally recognized statistical rating agency. The fair value of derivative financial instruments, which are predominantly customer interest rate swaps, is obtained from a third-party pricing service that uses an industry-standard discounted cash flow model that relies on inputs, LIBOR swap curves and Overnight Index swap rate curves, observable in the marketplace. To comply with the accounting guidance, credit valuation adjustments are incorporated in the fair values to appropriately reflect nonperformance risk for both the Company and the counterparties. Although the Company has determined that the majority of the inputs used to value the derivative instruments fall within level 2 of the fair value hierarchy, the credit value adjustments utilize level 3 inputs, such as estimates of current credit spreads. The Company has determined that the impact of the credit valuation adjustments is not significant to the overall valuation of these derivatives. As a result, the Company has classified its derivative valuations in their entirety in level 2 of the fair value hierarchy. The Company’s policy is to measure counterparty credit risk quarterly for all derivative instruments, including those subject to master netting arrangements consistent with how market participants would price the net risk exposure at the measurement date. The Company also has certain derivative instruments asso ciated with the Bank’s mortgage banking activities. These derivative instruments include interest rate lock commitments on prospective residential mortgage loans and forward commitments to sell these loans to investors on a best efforts delivery basis. The fair value of these derivative instruments is measured using observable market prices for similar instruments and is classified as a level 2 measurement. The Company’s policy is to recognize transfers between valuation hierarchy levels as of the end of a reporting period. There were no transfers between levels during the periods shown. Fair Value of Assets Measured on a Nonrecurring Basis Certain assets and liabilities are measured at fair value on a nonrecurring basis. Collateral-dependent impaired loans are level 2 assets measured at the fair value of the underlying collateral based on independent third-party appraisals that take into consideration market-based information such as recent sales activity for similar assets in the property’s market. Other real estate owned, including both foreclosed property and surplus banking property, are level 3 assets that are adjusted to fair value, less estimated selling costs, upon transfer to other real estate owned. Subsequently, other real estate owned is carried at the lower of carrying value or fair value less estimated selling costs. Fair values are determined by sales agreement or third-party appraisals as discounted for estimated selling costs, information from comparable sales, and marketability of the property. The fair value information presented below is not as of the period-end, rather it was as of the date the fair value adjustment was recorded during the twelve months for each of the dates presented below, and excludes nonrecurring fair value measurements of assets no longer on the balance sheet. The following tables present the Company’s financial assets that are measured at fair value on a nonrecurring basis for each of the fair value hierarchy levels.      September 30, 2017  (in thousands) Level 1 Level 2 Level 3 Total  Collateral-dependent impaired loans $ — $ 129,230 $ — $ 129,230  Other real estate owned — — 6,810 6,810  Total nonrecurring fair value measurements $ — $ 129,230 $ 6,810 $ 136,040      December 31, 2016  (in thousands) Level 1 Level 2 Level 3 Total  Collateral-dependent impaired loans $ — $ 169,888 $ — $ 169,888  Other real estate owned — — 13,968 13,968  Total nonrecurring fair value measurements $ — $ 169,888 $ 13,968 $ 183,856  Accounting guidance from the FASB requires the disclosure of estimated fair value information about certain on- and off-balance sheet financial instruments, including those financial instruments that are not measured and reported at fair value on a recurring basis. The significant methods and assumptions used by the Company to estimate the fair value of financial i nstruments are discussed below. Cash, Short ‑Term Investments and Federal Funds Sold – For these short ‑term instruments, the carrying amount is a reasonable estimate of fair value. Securities – The fair value measurement for securities available for sale was discussed earlier in the note. The same measurement techniques were applied to the valuation of securities held to maturity. Loans, Net – The fair value measurement for certain impaired loans was discussed earlier in the note. For the remaining portfolio, fair values were generally determined by discounting scheduled cash flows using discount rates determined with reference to current market rates at which loans with similar terms would be made to borrowers of similar credit quality. Loans Held for Sale – These loans are recorded at fair value and carried at the lower of cost or market. The carrying amount is considered a reasonable estimate of fair value. Deposits – The accounting guidance requires that the fair value of deposits with no stated maturity, such as noninterest-bearing demand deposits, interest-bearing checking and savings accounts, be assigned fair values equal to amounts payable upon demand (“carrying amou nts”). The fair value of fixed maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. Securities Sold under Agreements to Repurchase, Federal Funds Purchased, and FHLB Borrowings – For these short-term liabilities, the carrying amount is a reasonable estimate of fair value. Long-Term Debt – The fair value is estimated by discounting the future contractual cash flows using current market rates at which debt with similar terms could be obtained. Derivative Financial Instruments – The fair value measurement for derivative financial instruments was discussed earlier in the note. The following tables present the estimated fair values of the Company’s financial instruments by fair value hierarchy levels and the corresponding carrying amount at September 30, 2017 and December 31, 2016 .      September 30, 2017  Total Fair Carrying  (in thousands) Level 1 Level 2 Level 3 Value Amount  Financial assets:  Cash, interest-bearing bank deposits, and federal funds sold $ 445,500 $ — $ — $ 445,500 $ 445,500  Available for sale securities — 2,855,278 — 2,855,278 2,855,278  Held to maturity securities — 2,768,148 — 2,768,148 2,769,274  Loans, net — 129,230 18,300,747 18,429,977 18,563,163  Loans held for sale — 23,236 — 23,236 23,236  Derivative financial instruments — 17,199 — 17,199 17,199  Financial liabilities:  Deposits $ — $ — $ 21,523,649 $ 21,523,649 $ 21,533,859  Federal funds purchased 1,150 — — 1,150 1,150  Securities sold under agreements to repurchase 512,001 — — 512,001 512,001  FHLB short-term borrowings 1,224,000 — — 1,224,000 1,224,000  Long-term debt — 330,909 — 330,909 331,179  Derivative financial instruments — 12,691 — 12,691 12,691      December 31, 2016  Total Fair Carrying  (in thousands) Level 1 Level 2 Level 3 Value Amount  Financial assets:  Cash, interest-bearing bank deposits, and federal funds sold $ 450,866 $ — $ — $ 450,866 $ 450,866  Available for sale securities — 2,516,908 — 2,516,908 2,516,908  Held to maturity securities — 2,470,117 — 2,470,117 2,500,220  Loans, net — 169,888 16,326,961 16,496,849 16,522,733  Loans held for sale — 34,064 — 34,064 34,064  Derivative financial instruments — 20,315 — 20,315 20,315  Financial liabilities:  Deposits $ — $ — $ 19,430,939 $ 19,430,939 $ 19,424,266  Federal funds purchased 2,275 — — 2,275 2,275  Securities sold under agreements to repurchase 358,131 — — 358,131 358,131  FHLB short-term borrowings 865,000 — — 865,000 865,000  Long-term debt — 435,747 — 435,747 436,280  Derivative financial instruments — 27,432 — 27,432 27,432 

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2017
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	14. Recent Accounting Pronouncements  Accounting Standards Adopted in 2017  In March 2017, the FASB issued Accounting Standards Update (“ASU”) 2017-08, “Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities,” which amends the amortization period for certain purchased callable debt securities held at a premium. The amendments require the premium to be amortized to the earliest call date. The amendments do not, however, require an accounting change for securities held at a discount; instead, the discount continues to be amortized to maturity. The amendments in this ASU more closely align the amortization period of premiums and discounts to expectations incorporated in market pricing on the underlying securities. These amendments are effective for fiscal years, and for interim period s within those fiscal years, beginning after December 15, 2018. The Company early adopted this amendment in the second quarter of 2017 and, in accordance with the standards, the Company began amortizing the premium for certain purchased callable debt securities to the earliest call date. The adoption of this guidance did not have a material impact on the Company’s financial condition or results of operations.  In March 2016, the FASB issued ASU 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting,” to improve the accounting for employee share-based payments. Several aspects of the accounting for share-based payment award transactions are simplified, including income tax consequences; classification of awards as either equity or liabilities; and classification on the statement of cash flows. The amendments were effective for public business entities for annual periods beginning after December 15, 2016, and interim periods within those annual periods. The Company adopted the guidance effective January 1, 2017. In accordance with the standard, the Company elected to account for forfeitures of stock-based compensation as they occur and will reclassify dividends paid on forfeited shares to compensation expense from retained earnings. Classification of shares forfeited for taxes are reflected in the statement of cash flows as a financing rather than operating activity, with all historical periods restated. In addition, the Company began recognizing excess tax benefits and tax deficiencies during the period in income (rather than in equity) on a prospective basis. Adoption of this guidance did not have a material impact on the Company’s financial condition or results of operations; however, the prospective change in treatment of excess tax benefits resulted in a reduction in income tax expense of approximately $0.2 million and $2.0 million for the three and nine months periods ended September 30, 2017, respectively, and could result in volatility of future earnings, depending on changes in the Company’s stock price.  Issued but Not Yet Adopted Accounting Standards  In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities,” with the objective of improving financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. The update provides changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. The amendments in this update are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early application is permitted in any interim period after issuance of the update. All transition requirements and elections are to be applied to hedging relationships existing on the date of adoption, and the effect of the adoption should be reflected as of the beginning of the fiscal year of adoption. The Company is currently assessing all potential impacts of adoption of this update and is considering early adoption effective January 1, 2018. In May 2017, the FASB issued ASU 2017-09, “Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting,” which seeks to provide clarity, reduce diversity in practice, and reduce complexity when applying the guidance regarding a change to the terms of conditions of a share-based payment award. Specifically, an entity is to account for the effects of a modification, unless all of the following are satisfied: (1) the fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the modified award is the same as the fair value (or calculated value or intrinsic value, if such an alternative measurement is used) of the original award immediately before the original award is modified; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; and (3) the classification of the modified award as an equity instrument or as a liability instrument is the same as the classification of the original award immediately before the original award is modified. The amendments are effective for annual periods, and for interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period, for reporting periods for which financial statements have not yet been issued. The Company does not expect the adoption of this guidance to have a material impact on its financial condition or results of operations.  In March 2017, the FASB issued ASU 2017-07, “Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Costs,” to improve the presentation of net periodic pension cost and net periodic postretirement benefit cost. The amendments require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. The amendments also allow only the service cost component to be eligible for capitalization when applicable. These amendments are effective for public business entities for annual periods beginning after December 15, 2017, including interim periods within those annual periods. Disclosures of the nature of and reason for the change in accounting principle are required in the first interim and annual periods of adoption. The amendments should be applied retrospectively for the presentation of the service cost component and the other components of net periodic pension cost and net periodic postretirement benefit cost in the income statement and prospectively, on and after the effective date, for the capitalization of the service cost component of net periodic pension cost and net periodic postretirement benefit in assets. Refer to Note 11 – Retirement Plans – for detail on the components of net periodic pension and post-retirement benefit costs. Application of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.  In January 2017, the FASB issued ASU 2017-04, “Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which simplifies the manner in which an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Under the amendments in this ASU, an entity should (1) perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and (2) recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value, with the understanding that the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, ASU No. 2017-04 removes the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails such qualitative test, to perform Step 2 of the goodwill impairment test. This ASU is effective for public business entities that are SEC filers for fiscal years beginning after December 15, 2019, and for interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The ASU should be applied using a prospective method. Application of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.  In January 2017, the FASB issued ASU 2017-01, “Business Combinations (Topic 805) – Clarifying the Definition of a Business,” which addresses stakeholders’ concerns that the current definition of a business is applied too broadly and analyzing transactions under the current definition is difficult and costly. Under the amended guidance, a transaction is initially subject to a screening process to determine whether a “set” (i.e. an integrated set of assets and activities) qualifies as a business. Under the screen, if substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or in a group of similar identifiable assets, the set is deemed not to be a business. Further evaluation is required only if the transferred set does not meet the screen. Under the further evaluation, to be considered a business, a set must include, at a minimum, an input and a substantive process that, together, significantly contribute to the ability to create output. The amendment also narrows the definition of the term “output” so that it is consistent with the manner in which outputs are described in Topic 606, Revenue from Contracts with Customers. The amendments are effective for annual periods beginning after December 15, 2017, including interim periods within those periods. Early application is permitted under certain circumstances. The amendments should be applied prospectively on or after the effective date. Adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.  In October 2016, the FASB issued ASU No. 2016-16, “Income Taxes (Topic 740) – Intra-Entity Transfers of Assets Other than Inventory,” which addresses stakeholders’ concerns that the limited amount of authoritative guidance has led to diversity in practice and is a source of complexity in financial reporting and results in an unfaithful representation of the economics of an intra-entity asset transfer. The amendment eliminates the exception to the United States generally accepted accounting principle (“U.S. GAAP”) of comprehensive recognition of current and deferred income taxes that prohibits recognizing current and deferred income tax consequences for an intra-equity asset transfer (excluding the transfer of inventory) until the asset has been sold to an outside party. The amendments are effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual reporting periods. Early adoption is permitted, including adoption in an interim period. The amendments should be applied using a retrospective transition method to each period presented. Adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” to address diversity in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments provide guidance on eight specific cash flow issues, including debt prepayment or extinguishment costs, settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies (including bank-owned), life insurance policies, distributions received from equity method investees, beneficial interests in securitization transactions, and separately identifiable cash flows and application of the predominance principle. The amendments are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The amendments should be applied using a retrospective transition method to each period presented. Adoption of this guidance will not have a material impact on the Company’s financial condition or results of operations, and the Company does not expect a material impact to the presentation of its Statement of Cash Flows.  In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credits Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” to improve financial reporting by requiring timelier recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. The ASU, more commonly referred to as Current Expected Credit Losses, or CECL, requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better inform their credit loss estimates. Many of the loss estimation techniques currently applied will still be permitted, although the inputs to those techniques will change to reflect the full amount of expected credit losses. Organizations will continue to use judgment to determine which loss estimation method is appropriate for their circumstances. In addition, the ASU amends the accounting for credit losses on debt securities and purchased financial assets with credit deterioration. The ASU is effective for SEC filers for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with a cumulative-effect adjustment to retained earnings as of the beginning of the year of adoption. Early application is permitted for all organizations for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company has begun the process of implementation and currently is not planning to early adopt. The Company expects the guidance will result in an increase in the allowance for loan losses given the change from covering losses inherent in the portfolio to covering losses over the remaining expected life of the portfolio and the nonaccretable difference on purchased credit impaired loans moving to an allowance (offset by an increase in the carrying value of the related loans). The guidance will also result in the establishment of an allowance for credit loss on held to maturity debt securities. The amount of the increase in these allowances will be impacted by the portfolio composition and quality at the adoption date as well as economic conditions and forecasts at that time.  In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” that provides new lease accounting guidance. Under the guidance, lessees (with the exception of short-term leases) will be required to recognize a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. Lessor accounting is largely unchanged. Lessees will need to recognize almost all leases on their balance sheet as a right-of-use asset and a lease liability. Lessees will no longer be provided with a source of off-balance sheet financing. Public business entities are required to apply the amendments for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is currently assessing this pronouncement and the impact of adoption by reviewing its existing lease contracts and service contracts that may include embedded leases. The Company expects a gross-up of its Consolidated Balance Sheets as a result of recognizing lease liabilities and right of use assets; the extent of such is under evaluation. The Company does not expect material changes to its consolidated results of operations.  In January 2016, the FASB issued ASU 2016-01, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities,” that improves the recognition and measurement of financial instruments through targeted changes to existing GAAP. It requires equity investments (except those that are accounted for under the equity method of accounting or result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. It also requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company is currently assessing this pronouncement; however, the adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” affecting any entity that enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards. The core principle of this standard is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Most revenue associated with financial instruments, including interest and loan origination fees, is outside the scope of the guidance. Gains and losses on investment securities, derivatives, and sales of financial instruments are also excluded from the scope. Subsequent to issuance of the revenue recognition guidance, the FASB has issued several updates that deferred by one year the effective date for revenue recognition guidance; clarified its guidance for performing the principal-versus-agent analysis; clarified guidance for identifying performance obligations allowing entities to ignore immaterial promised goods and services in the context of a contract with a customer and other clarifying guidance and technical corrections. Entities can elect to adopt the guidance either on a full or modified retrospective basis. Full retrospective adoption will require a cumulative effect adjustment to retained earnings as of the beginning of the earliest comparative period presented. Modified retrospective adoption will require a cumulative effect adjustment to retained earnings as of the beginning of the reporting period in which the entity first applies the new guidance. The standard will be effective for the Company for annual reporting periods beginning after December 15, 2017. The Company will adopt this guidance on January 1, 2018 and plans to use the modified retrospective approach. The Company has inventoried its contracts with customers and has evaluated a material portion of those contracts for compliance with the standard. The Company has not yet identified any material changes to the timing of revenue recognition. Based on the analysis performed to date, adoption of this guidance is not expected to have a material impact on its financial condition or results of operations. The Company is continuing to evaluate disaggregation for select categories of revenue in the scope of the guidance. Upon adoption, the Company will provide qualitative disclosures of its performance obligations related to revenue recognition.

Basis of Presentation23

Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Basis of Presentation [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of Hancock Holding Company and all other entities in which it has a controlling interest (the “Company”). The financial statements include all adjustments that are, in the opinion of management, necessary to fairly state the Company’s financial condition, results of operations, changes in stockholders’ equity and cash flows for the interim periods presented. The Company has also evaluated all subsequent events for potential recognition and disclosure through the date of the filing of this Quarterly Report on Form 10-Q. Some financial information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) have been condensed or omitted in this Quarterly Report on Form 10-Q pursuant to Securities and Exchange Commission rules and regulations. These financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016. Financial information reported in these financial statements is not necessarily indicative of the Company’s financial condition, results of operations, or cash flows for any other interim or annual period. Certain prior period amounts have been reclassified to conform to the current period presentation. Select Stockholders’ Equity line items in the Consolidated Balance Sheets and Statements of Changes in Stockholders’ Equity have been modified to simplify the presentation as discussed in Note 7 – Stockholders’ Equity. Presentation of derivatives contracts cleared through a central clearing counterparty has been revised prospectively to reflect netting of variation margin as settlements to the derivative assets and liabilities rather than collateral, effective January 3, 2017, as discussed in Note 6 – Derivatives. These changes in presentation did not have a material impact on the Company’s financial condition or operating results.
Use of Estimates	Use of Estimates The accounting principles the Company follows and the methods for applying these principles conform to GAAP and general practices followed by the banking industry. These accounting principles require management to make estimates and assumptions about future events that affect the amounts reported in the consolidated financial statements and the accompanying notes. Actual results could differ from those estimates.
Critical Accounting Policies and Estimates	Critical Accounting Policies and Estimates  There were no material changes or developments during the reporting period with respect to methodologies that the Company uses when applying what management believes are critical accounting policies and developing critical accounting estimates as disclosed in its Annual Report on Form 10-K for the year ended December 31, 2016. Refer to Note 14 – Recent Accounting Pronouncements for a discussion of accounting standards adopted in 2017.

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2017
Acquisitions [Abstract]
Schedule of Fair Value of Net Assets Acquired	  FNBC I FNBC II  (in thousands) March 10, 2017 April 28, 2017 Total  ASSETS  Cash and due from banks $ 2,856 $ 157,932 $ 160,788  Interest-bearing time deposits with other banks — 382,622 382,622  Fed funds sold and other short-term investments — 148 148  Securities — 213,877 213,877  Total loans 1,211,523 165,577 1,377,100  Property and equipment 11,837 8,988 20,825  Accrued interest receivable 2,969 885 3,854  Identifiable intangible assets 3,900 21,400 25,300  Other assets 63 4,150 4,213  Total identifiable assets 1,233,148 955,579 2,188,727   LIABILITIES  Deposits 398,171 1,530,338 1,928,509  Short-term borrowings 510,749 85,886 596,635  Long-term debt 93,120 — 93,120  Other liabilities 1,607 3,079 4,686  Total liabilities 1,003,647 1,619,303 2,622,950  Net identifiable assets acquired (liabilities assumed) 229,501 (663,724) (434,223)   Consideration (Paid) Received (325,564) 641,577 316,013  Goodwill $ 96,063 $ 22,147 $ 118,210 
Schedule of Goodwill	  Goodwill balance at December 31, 2016 $ 621,193  Additions:  Initial goodwill recorded in FNBC I transaction 95,568  Measurement period adjustments - FNBC I transaction 495  Initial goodwill recorded in FNBC II transaction 23,009  Measurement period adjustments - FNBC II transaction (862)  Goodwill balance at September 30, 2017 $ 739,403 
Schedule of Merger-Related Expense	  (in thousands) Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017  Personnel expense $ 2,120 $ 3,662  Net occupancy and equipment expense 500 777  Professional services expense 2,854 9,681  Data processing expense 929 974  Other real estate - (1,511)  Advertising expense 358 1,389  Other expense 2,132 4,398  Total merger-related expenses $ 8,893 $ 19,370 

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2017
Gain (Loss) on Investments [Line Items]
Amortized Cost and Fair Value of Securities Available for Sale	   Securities Available for Sale  (in thousands) September 30, 2017 December 31, 2016  Gross Gross Gross Gross  Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair  Cost Gains Losses Value Cost Gains Losses Value  U.S. Treasury and government agency securities $ 75,019 $ 29 $ 1,606 $ 73,442 $ 56,751 $ — $ 1,923 $ 54,828  Municipal obligations 246,805 534 4,661 242,678 253,228 113 11,186 242,155  Residential mortgage-backed securities 1,795,397 9,701 11,672 1,793,426 1,620,191 10,592 19,428 1,611,355  Commercial mortgage-backed securities 584,503 569 16,719 568,353 425,750 — 23,159 402,591  Collateralized mortgage obligations 174,119 114 354 173,879 202,580 490 591 202,479  Corporate debt securities 3,500 — — 3,500 3,500 — — 3,500  $ 2,879,343 $ 10,947 $ 35,012 $ 2,855,278 $ 2,562,000 $ 11,195 $ 56,287 $ 2,516,908 
Amortized Cost and Fair Value of Securities Held to Maturity	   Securities Held to Maturity  (in thousands) September 30, 2017 December 31, 2016  Gross Gross Gross Gross  Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair  Cost Gains Losses Value Cost Gains Losses Value  U.S. Treasury and government agency securities $ 50,000 $ — $ 63 $ 49,937 $ 50,000 $ — $ 44 $ 49,956  Municipal obligations 725,484 7,677 7,396 725,765 648,093 2,147 20,175 630,065  Residential mortgage-backed securities 760,158 8,896 776 768,278 862,162 4,329 3,068 863,423  Commercial mortgage-backed securities 75,688 — 2,592 73,096 75,739 — 4,038 71,701  Collateralized mortgage obligations 1,157,944 2,476 9,348 1,151,072 864,226 1,420 10,674 854,972  $ 2,769,274 $ 19,049 $ 20,175 $ 2,768,148 $ 2,500,220 $ 7,896 $ 37,999 $ 2,470,117 
Available for Sale [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	 (in thousands) Amortized Fair Debt Securities Available for Sale Cost Value Due in one year or less $ 5,392 $ 5,425 Due after one year through five years 46,852 47,394 Due after five years through ten years 1,097,850 1,082,709 Due after ten years 1,729,249 1,719,750 Total available for sale debt securities $ 2,879,343 $ 2,855,278  
Securities with Unrealized Losses	   Available for Sale  September 30, 2017 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 52,866 1,606 $ — $ — $ 52,866 $ 1,606  Municipal obligations 145,441 2,286 66,640 2,375 212,081 4,661  Residential mortgage-backed securities 1,255,266 11,514 5,360 158 1,260,626 11,672  Commercial mortgage-backed securities 465,596 15,366 30,151 1,353 495,747 16,719  Collateralized mortgage obligations 66,149 201 5,565 153 71,714 354  $ 1,985,318 $ 30,973 $ 107,716 $ 4,039 $ 2,093,034 $ 35,012       Available for Sale  December 31, 2016 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 54,788 $ 1,923 $ — $ — $ 54,788 $ 1,923  Municipal obligations 228,588 11,186 — — 228,588 11,186  Residential mortgage-backed securities 1,087,644 19,359 3,738 69 1,091,382 19,428  Commercial mortgage-backed securities 402,591 23,159 — — 402,591 23,159  Collateralized mortgage obligations 83,701 591 — — 83,701 591  $ 1,857,312 $ 56,218 $ 3,738 $ 69 $ 1,861,050 $ 56,287 
Held to Maturity [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	 Amortized Fair Debt Securities Held to Maturity Cost Value Due in one year or less $ 10,081 $ 10,123 Due after one year through five years 108,164 108,726 Due after five years through ten years 837,353 833,465 Due after ten years 1,813,676 1,815,834 Total held to maturity debt securities $ 2,769,274 $ 2,768,148 
Securities with Unrealized Losses	   Held to maturity  September 30, 2017 Losses < 12 months Losses 12 months or > Total  Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 49,938 $ 63 $ — $ — $ 49,938 $ 63  Municipal obligations 275,874 2,975 98,976 4,421 374,850 7,396  Residential mortgage-backed securities 254,743 776 — — 254,743 776  Commercial mortgage-backed securities 73,096 2,592 — — 73,096 2,592  Collateralized mortgage obligations 559,859 3,852 232,697 5,496 792,556 9,348  $ 1,213,510 $ 10,258 $ 331,673 $ 9,917 $ 1,545,183 $ 20,175      Held to maturity  December 31, 2016 Losses < 12 months Losses 12 months or > Total   Gross Gross Gross  Fair Unrealized Fair Unrealized Fair Unrealized  (in thousands) Value Losses Value Losses Value Losses  U.S. Treasury and government agency securities $ 49,956 $ 44 $ — $ — $ 49,956 $ 44  Municipal obligations 494,470 19,706 11,750 469 506,220 20,175  Residential mortgage-backed securities 278,369 3,068 — — 278,369 3,068  Commercial mortgage-backed securities 71,701 4,038 — — 71,701 4,038  Collateralized mortgage obligations 618,739 7,296 115,375 3,378 734,114 10,674  $ 1,513,235 $ 34,152 $ 127,125 $ 3,847 $ 1,640,360 $ 37,999 

Loans and Allowance for Loan 26

Loans and Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Net of Unearned Income	   September 30, December 31,  (in thousands) 2017 2016  Commercial non-real estate $ 8,129,429 $ 7,613,917  Commercial real estate - owner occupied 2,076,014 1,906,821  Total commercial & industrial 10,205,443 9,520,738  Commercial real estate - income producing 2,511,808 2,013,890  Construction and land development 1,373,048 1,010,879  Residential mortgages 2,596,692 2,146,713  Consumer 2,099,294 2,059,931  Total loans $ 18,786,285 $ 16,752,151 
Allowance for Loan Losses by Portfolio Class	   Commercial Commercial  Commercial real estate- Total real estate- Construction  non-real owner commercial & income and land Residential  (in thousands) estate occupied industrial producing development mortgages Consumer Total  Nine Months Ended September 30, 2017  Allowance for loan losses:  Beginning balance $ 147,052 $ 11,083 $ 158,135 $ 13,509 $ 6,271 $ 25,361 $ 26,142 $ 229,418  Purchased credit impaired activity:  Charge-offs — — — — (77) (102) (153) (332)  Recoveries 5 110 115 — 49 23 72 259  Net provision for loan losses (27) (220) (247) (54) (124) 175 (192) (442)  Decrease in FDIC loss share receivable (47) — (47) — — (2,344) (135) (2,526)  Non-purchased credit impaired activity:  Charge-offs (35,247) (527) (35,774) (160) (593) (2,383) (22,691) (61,601)  Recoveries 6,437 337 6,774 655 1,001 316 5,176 13,922  Net provision for loan losses 15,922 2,776 18,698 540 54 3,988 21,144 44,424  Ending balance $ 134,095 $ 13,559 $ 147,654 $ 14,490 $ 6,581 $ 25,034 $ 29,363 $ 223,122  Ending balance:  Allowance:  Individually evaluated for impairment $ 20,880 $ 477 $ 21,357 $ 1,321 $ 1 $ 406 $ 405 $ 23,490  Amounts related to purchased credit impaired loans 417 784 1,201 199 254 12,795 863 15,312  Collectively evaluated for impairment 112,798 12,298 125,096 12,970 6,326 11,833 28,095 184,320  Total allowance $ 134,095 $ 13,559 $ 147,654 $ 14,490 $ 6,581 $ 25,034 $ 29,363 $ 223,122  Loans:  Individually evaluated for impairment $ 271,024 $ 6,351 $ 277,375 $ 14,295 $ 480 $ 8,942 $ 1,306 $ 302,397  Purchased credit impaired loans 20,186 13,021 33,207 5,353 6,670 123,244 7,637 176,111  Collectively evaluated for impairment 7,838,219 2,056,642 9,894,861 2,492,160 1,365,898 2,464,506 2,090,351 18,307,777  Total loans $ 8,129,429 $ 2,076,014 $ 10,205,443 $ 2,511,808 $ 1,373,048 $ 2,596,692 $ 2,099,294 $ 18,786,285        Commercial Commercial  Commercial real estate- Total real estate- Construction  non-real owner commercial & income and land Residential  (in thousands) estate occupied industrial producing development mortgages Consumer Total  Nine Months Ended September 30, 2016  Allowance for loan losses:  Beginning balance $ 109,428 $ 9,858 $ 119,286 $ 6,041 $ 5,642 $ 25,353 $ 24,857 $ 181,179  Purchased credit impaired activity:  Charge-offs — (28) (28) (1) (18) (91) (8) (146)  Recoveries 76 163 239 2 98 33 112 484  Net provision for loan losses 54 (140) (86) (436) (253) 1,685 (1,633) (723)  (Decrease) increase in FDIC loss share receivable (2) — (2) — — (3,341) 316 (3,027)  Non-purchased credit impaired activity:  Charge-offs (27,504) (1,660) (29,164) (191) (827) (908) (17,403) (48,493)  Recoveries 2,709 287 2,996 673 1,422 497 4,272 9,860  Net provision for loan losses 74,500 2,303 76,803 4,862 (216) 964 14,514 96,927  Ending balance $ 159,261 $ 10,783 $ 170,044 $ 10,950 $ 5,848 $ 24,192 $ 25,027 $ 236,061  Ending balance:  Allowance:  Individually evaluated for impairment $ 20,665 $ 223 $ 20,888 $ 57 $ 6 $ 94 $ 85 $ 21,130  Amounts related to purchased credit impaired loans 574 1,088 1,662 279 484 15,949 1,334 19,708  Collectively evaluated for impairment 138,022 9,472 147,494 10,614 5,358 8,149 23,608 195,223  Total allowance $ 159,261 $ 10,783 $ 170,044 $ 10,950 $ 5,848 $ 24,192 $ 25,027 $ 236,061  Loans:  Individually evaluated for impairment $ 235,039 $ 6,458 $ 241,497 $ 7,655 $ 2,062 $ 3,864 $ 1,485 $ 256,563  Purchased credit impaired loans 11,534 16,417 27,951 8,087 8,436 145,273 12,045 201,792  Collectively evaluated for impairment 6,887,355 1,878,950 8,766,305 1,974,567 936,094 1,888,025 2,047,475 15,612,466  Total loans $ 7,133,928 $ 1,901,825 $ 9,035,753 $ 1,990,309 $ 946,592 $ 2,037,162 $ 2,061,005 $ 16,070,821  
Composition of Nonaccrual Loans by Portfolio Class	   September 30, December 31,  (in thousands) 2017 2016  Commercial non-real estate $ 188,982 $ 249,037  Commercial real estate - owner occupied 14,305 14,413  Total commercial & industrial 203,287 263,450  Commercial real estate - income producing 14,360 13,954  Construction and land development 3,292 4,550  Residential mortgages 34,674 23,665  Consumer 14,063 12,351  Total loans $ 269,676 $ 317,970 
Troubled Debt Restructurings Modified by Portfolio Class	   Nine Months Ended  ($ in thousands) September 30, 2017 September 30, 2016  Pre-Modification Post-Modification Pre-Modification Post-Modification  Outstanding Outstanding Outstanding Outstanding  Number of Recorded Recorded Number of Recorded Recorded  Troubled Debt Restructurings: Contracts Investment Investment Contracts Investment Investment  Commercial non-real estate 50 $ 135,926 $ 135,926 17 $ 57,915 $ 57,915  Commercial real estate - owner occupied 4 3,734 3,734 — — —  Total commercial & industrial 54 139,660 139,660 17 57,915 57,915  Commercial real estate - income producing 5 5,684 5,684 — — —  Construction and land development — — — — — —  Residential mortgages 13 2,068 2,068 6 532 532  Consumer 1 40 42 — — —  Total loans 73 $ 147,452 $ 147,454 23 $ 58,447 $ 58,447 
Loans Individually Evaluated for Impairment Disaggregated by Portfolio Class	   September 30, 2017  Recorded investment Recorded investment Unpaid  (in thousands) without an allowance with an allowance principal balance Related allowance  Commercial non-real estate $ 92,583 $ 178,441 $ 276,879 $ 20,880  Commercial real estate - owner occupied 3,599 2,752 6,353 477  Total commercial & industrial 96,182 181,193 283,232 21,357  Commercial real estate - income producing 5,160 9,135 14,451 1,321  Construction and land development 464 16 1,445 1  Residential mortgages 6,311 2,630 11,961 406  Consumer 1 1,305 1,308 405  Total loans $ 108,118 $ 194,279 $ 312,397 $ 23,490    December 31, 2016  Recorded investment Recorded investment Unpaid  (in thousands) without an allowance with an allowance principal balance Related allowance  Commercial non-real estate $ 150,650 $ 120,612 $ 295,445 $ 28,187  Commercial real estate - owner occupied 4,261 2,007 6,646 246  Total commercial & industrial 154,911 122,619 302,091 28,433  Commercial real estate - income producing 10,447 4,929 15,708 466  Construction and land development 1,106 832 2,903 38  Residential mortgages 2,877 1,470 4,865 91  Consumer — 2,154 2,155 267  Total loans $ 169,341 $ 132,004 $ 327,722 $ 29,295 The tables below present the average balances and interest income for total impaired loans for the three and nine months ended September 30, 2017 and 2016. Interest income recognized represents interest on accruing loans modified in a TDR.      Three Months Ended  September 30, 2017 September 30, 2016  Average Interest Average Interest  recorded income recorded income  (in thousands) investment recognized investment recognized  Commercial non-real estate $ 260,640 $ 872 $ 233,913 $ 155  Commercial real estate - owner occupied 6,916 24 6,374 10  Total commercial & industrial 267,556 896 240,287 165  Commercial real estate - income producing 14,604 35 7,729 24  Construction and land development 663 1 1,655 —  Residential mortgages 6,204 7 2,466 3  Consumer 1,179 4 826 2  Total loans $ 290,206 $ 943 $ 252,963 $ 194      Nine Months Ended  September 30, 2017 September 30, 2016  Average Interest Average Interest  recorded income recorded income  (in thousands) investment recognized investment recognized  Commercial non-real estate $ 251,129 $ 1,806 $ 197,382 $ 1,002  Commercial real estate - owner occupied 5,895 46 6,015 39  Total commercial & industrial 257,024 1,852 203,397 1,041  Commercial real estate - income producing 14,449 112 8,624 67  Construction and land development 1,216 1 7,821 —  Residential mortgages 4,449 12 1,444 7  Consumer 1,644 9 348 4  Total loans $ 278,782 $ 1,986 $ 221,634 $ 1,119 
Age Analysis of Past Due Loans by Portfolio Class	   Recorded  Greater than investment  30-59 days 60-89 days 90 days Total Total > 90 days and  September 30, 2017 past due past due past due past due Current Loans still accruing  (in thousands)  Commercial non-real estate $ 31,634 $ 3,880 $ 104,334 $ 139,848 $ 7,989,581 $ 8,129,429 $ 24,400  Commercial real estate - owner occupied 18,579 303 8,950 27,832 2,048,182 2,076,014 767  Total commercial & industrial 50,213 4,183 113,284 167,680 10,037,763 10,205,443 25,167  Commercial real estate - income producing 1,540 3,731 5,676 10,947 2,500,861 2,511,808 2,907  Construction and land development 5,018 1,031 2,861 8,910 1,364,138 1,373,048 417  Residential mortgages 39,081 10,575 24,415 74,071 2,522,621 2,596,692 41  Consumer 15,574 7,426 7,710 30,710 2,068,584 2,099,294 318  Total $ 111,426 $ 26,946 $ 153,946 $ 292,318 $ 18,493,967 $ 18,786,285 $ 28,850      Recorded  Greater than investment  30-59 days 60-89 days 90 days Total Total > 90 days and  December 31, 2016 past due past due past due past due Current Loans still accruing  (in thousands)  Commercial non-real estate $ 19,722 $ 1,909 $ 68,505 $ 90,136 $ 7,523,781 $ 7,613,917 $ 384  Commercial real estate - owner occupied 3,008 581 6,310 9,899 1,896,922 1,906,821 52  Total commercial & industrial 22,730 2,490 74,815 100,035 9,420,703 9,520,738 436  Commercial real estate - income producing 838 50 5,026 5,914 2,007,976 2,013,890 216  Construction and land development 694 171 5,300 6,165 1,004,714 1,010,879 1,563  Residential mortgages 24,599 8,816 14,369 47,784 2,098,929 2,146,713 1  Consumer 18,621 7,441 9,147 35,209 2,024,722 2,059,931 823  Total $ 67,482 $ 18,968 $ 108,657 $ 195,107 $ 16,557,044 $ 16,752,151 $ 3,039 
Changes in Carrying Amount of Purchased Credit Impaired Loans and Related Accretable Yield	   September 30, 2017 December 31, 2016  Carrying Carrying  Amount Accretable Amount Accretable  (in thousands) of Loans Yield of Loans Yield  Balance at beginning of period $ 190,915 $ 113,686 $ 225,838 $ 129,488  Addition of cost recovery loans 23,431 — — —  Payments received, net (51,040) (6,651) (55,194) (11,024)  Accretion 12,805 (12,805) 20,271 (20,271)  Increase in expected cash flows based on actual cash flows and changes in cash flow assumptions — 4,149 — 5,358  Net transfers from nonaccretable difference to accretable yield — 8,095 — 10,135  Balance at end of period $ 176,111 $ 106,474 $ 190,915 $ 113,686 
Activity in Loss Share Receivable	   September 30, September 30,  (in thousands) 2017 2016  Beginning Balance $ 16,219 $ 29,868  Amortization (2,427) (4,678)  Charge-offs, write-downs and other recoveries (2,442) (5,569)  External expenses qualifying under loss share agreements 79 1,000  Adjustment due to changes in cash flow projections (2,526) (3,027)  Net payments to FDIC 934 436  Write-down for termination of loss share agreements (6,603) —  Cash received from FDIC for final settlement of agreements (3,234) —  Ending balance $ — $ 18,030 
Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit Quality Indicators by Segments and Portfolio Class	   September 30, 2017  (in thousands) Commercial non-real estate Commercial real estate - owner-occupied Total commercial & industrial Commercial real estate - income producing Construction and land development Total commercial  Grade:  Pass $ 6,941,591 $ 1,840,553 $ 8,782,144 $ 2,327,685 $ 1,278,648 $ 12,388,477  Pass-Watch 345,073 83,808 428,881 107,568 73,538 609,987  Special Mention 122,023 41,270 163,293 12,802 7,484 183,579  Substandard 717,436 110,383 827,819 63,744 13,378 904,941  Doubtful 3,306 — 3,306 9 — 3,315  Total $ 8,129,429 $ 2,076,014 $ 10,205,443 $ 2,511,808 $ 1,373,048 $ 14,090,299   December 31, 2016  (in thousands) Commercial non-real estate Commercial real estate - owner-occupied Total commercial & industrial Commercial real estate - income producing Construction and land development Total commercial  Grade:  Pass $ 6,364,348 $ 1,719,114 $ 8,083,462 $ 1,873,644 $ 968,505 $ 10,925,611  Pass-Watch 203,311 47,676 250,987 78,309 22,592 351,888  Special Mention 181,763 40,299 222,062 22,492 4,142 248,696  Substandard 846,793 99,732 946,525 39,434 15,640 1,001,599  Doubtful 17,702 — 17,702 11 — 17,713  Total $ 7,613,917 $ 1,906,821 $ 9,520,738 $ 2,013,890 $ 1,010,879 $ 12,545,507 
Residential Mortgage and Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit Quality Indicators by Segments and Portfolio Class	   September 30, 2017 December 31, 2016  (in thousands) Residential mortgage Consumer Total Residential mortgage Consumer Total  Performing $ 2,561,977 $ 2,084,913 $ 4,646,890 $ 2,123,048 $ 2,046,757 $ 4,169,805  Nonperforming 34,715 14,381 49,096 23,665 13,174 36,839  Total $ 2,596,692 $ 2,099,294 $ 4,695,986 $ 2,146,713 $ 2,059,931 $ 4,206,644 

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2017
Derivatives [Abstract]
Fair Values of Derivative Financial Instruments	    September 30, 2017 December 31, 2016  Derivative (1) Derivative (1)  (in thousands) Type of Hedge Notional or Contractual Amount Assets Liabilities Notional or Contractual Amount Assets Liabilities  Derivatives designated as hedging instruments:  Interest rate swaps Cash Flow $ 875,000 $ — $ 7,924 $ 1,100,000 $ — $ 7,787  Interest rate swaps Fair Value 363,000 — 823 — — —  $ 1,238,000 $ — $ 8,747 $ 1,100,000 $ — $ 7,787  Derivatives not designated as hedging instruments:  Interest rate swaps (2) N/A $ 1,172,752 $ 16,855 $ 17,420 $ 979,391 $ 18,405 $ 18,362  Risk participation agreements N/A 109,556 34 108 84,732 50 105  Forward commitments to sell residential mortgage loans N/A 93,809 91 669 75,676 900 221  Interest rate-lock commitments on residential mortgage loans N/A 71,786 534 71 46,840 189 228  Foreign exchange forward contracts N/A 55,081 2,465 2,423 56,152 771 729  1,502,984 19,979 20,691 1,242,791 20,315 19,645  Total derivatives $ 2,740,984 $ 19,979 $ 29,438 $ 2,342,791 $ 20,315 $ 27,432  Less: netting adjustment (3) (2,780) (16,747) — —  Total derivative assets/liabilities $ 17,199 $ 12,691 $ 20,315 $ 27,432 (1) Derivative assets and liabilities are reported at fair value in other assets or other liabilities, respectively, in the consolidated balance sheets. (2) The notional amount represents both the customer accommodation agreements and offsetting agreements with unrelated financial institutions.  (3) Represents balance sheet netting of derivative assets and liabilities for variation margin collateral held or placed with the same central clearing counterparty. See offsetting assets and liabilities for further information.   
Offsetting Derivative Assets and Liabilities Subject to Master Netting Arrangements	   (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Income  Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income Financial Instruments Cash Collateral Net Amount  As of September 30, 2017  Derivative Assets $ 5,271 $ (3,942) $ 1,329 $ 1,329 $ — $ —   Derivative Liabilities $ 21,889 $ (16,322) $ 5,567 $ 1,329 $ 7,318 $ (3,080)      (in thousands) Gross Amounts Net Amounts Gross Amounts Not Offset in the Statement of Income  Description Gross Amounts Recognized Offset in the Statement of Income Presented in the Statement of Income Financial Instruments Cash Collateral Net Amount  As of December 31, 2016  Derivative Assets $ 4,788 $ — $ 4,788 $ 4,788 $ — $ —   Derivative Liabilities $ 26,846 $ — $ 26,846 $ 4,788 $ 19,095 $ 2,963 

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity [Abstract]
Components of Accumulated Other Comprehensive Income (Loss)	   Available HTM Securities  for Sale Transferred Employee Cash  (in thousands) Securities from AFS Benefit Plans Flow Hedges Total  Balance, December 31, 2015 $ 4,268 $ (16,795) $ (67,890) $ (178) $ (80,595)  Other comprehensive income (loss) before income taxes:  Net change in unrealized gain 38,835 — — 1,162 39,997  Reclassification of net (gain) loss realized and included in earnings (1,435) — 4,395 — 2,960  Valuation adjustment for employee benefit plans — — (6,347) — (6,347)  Amortization of unrealized net loss on securities transferred to HTM — 2,736 — — 2,736  Income tax expense (benefit) 13,701 1,029 (714) 424 14,440  Balance, September 30, 2016 $ 27,967 $ (15,088) $ (69,128) $ 560 $ (55,689)  Balance, December 31, 2016 $ (28,679) $ (14,392) $ (72,501) $ (4,960) $ (120,532)  Other comprehensive income (loss) before income taxes:  Net change in unrealized gain (loss) 21,026 — — (1,232) 19,794  Reclassification of net losses realized and included in earnings — — 4,144 335 4,479  Valuation adjustment for pension plan amendment (a) — — 17,315 — 17,315  Other valuation adjustments for employee benefit plan — — (9,185) — (9,185)  Amortization of unrealized net loss on securities transferred to HTM — 2,726 — — 2,726  Income tax expense (benefit) 7,649 1,012 4,416 (329) 12,748  Balance, September 30, 2017 $ (15,302) $ (12,678) $ (64,643) $ (5,528) $ (98,151)  (a) For further discussion of the pension plan amendment, see Note 11 – Retirement Plans.
Line Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income	   Nine Months Ended  Amount reclassified from AOCI (a) September 30, Affected line item on  (in thousands) 2017 2016 the statement of income  Gain on sale of AFS securities $ — $ 1,435 Securities transactions  Tax effect — (502) Income taxes  Net of tax — 933 Net income  Amortization of unrealized net loss on securities transferred to HTM (2,726) (2,736) Interest income  Tax effect 1,012 1,029 Income taxes  Net of tax (1,714) (1,707) Net income  Amortization of defined benefit pension and post-retirement items (4,144) (4,395) Employee benefits expense (b)  Tax effect 1,491 1,538 Income taxes  Net of tax (2,653) (2,857) Net income  Amortization of loss on terminated cash flow hedges (335) — Interest income  Tax effect 123 — Income taxes  Net of tax (212) — Net income  Total reclassifications, net of tax $ (4,579) $ (3,631) Net income (a) Amounts in parenthesis indicate reduction in net income.  (b) These AOCI components are included in the computation of net periodic pension and post-retirement cost that is reported with employee benefits expense (see Note 11 – Retirement Plans for additional details).

Other Noninterest Income (Table

Other Noninterest Income (Tables)	9 Months Ended
	Sep. 30, 2017
Other Noninterest Income [Abstract]
Components of Other Noninterest Income	   Three Months Ended Nine Months Ended  September 30, September 30,  (in thousands) 2017 2016 2017 2016  Income from bank-owned life insurance $ 3,097 $ 4,097 $ 8,632 $ 11,148  Credit related fees 2,521 2,685 8,297 7,309  Derivative income 1,339 1,347 4,484 1,741  Net gain on sale of assets 400 991 4,465 4,557  Safety deposit box income 424 424 1,264 1,315  Other miscellaneous 3,371 2,322 9,759 6,698  Total other noninterest income $ 11,152 $ 11,866 $ 36,901 $ 32,768 

Other Noninterest Expense (Tabl

Other Noninterest Expense (Tables)	9 Months Ended
	Sep. 30, 2017
Other Noninterest Expense [Abstract]
Components of Other Noninterest Expense	   Three Months Ended Nine Months Ended  September 30, September 30,  (in thousands) 2017 2016 2017 2016  Advertising $ 3,910 $ 2,859 $ 11,971 $ 7,909  Ad valorem and franchise taxes 3,387 2,268 9,942 6,911  Printing and supplies 1,421 1,134 3,929 3,310  Insurance expense 671 803 2,295 2,467  Travel expense 1,226 1,022 3,635 3,050  Entertainment and contributions 2,322 1,686 6,087 5,319  Tax credit investment amortization 1,212 861 3,637 4,437  Loss share termination — — 6,603 —  Other miscellaneous 7,611 11,746 19,958 22,158  Total other noninterest expense $ 21,760 $ 22,379 $ 68,057 $ 55,561 

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Computation of Earnings Per Common Share	   Three Months Ended Nine Months Ended  September 30, September 30,  (in thousands, except per share data) 2017 2016 2017 2016  Numerator:  Net income to common shareholders $ 58,902 $ 46,719 $ 160,183 $ 97,465  Net income allocated to participating securities - basic and diluted 1,244 1,101 3,566 2,334  Net income allocated to common shareholders - basic and diluted $ 57,658 $ 45,618 $ 156,617 $ 95,131  Denominator:  Weighted-average common shares - basic $ 84,749 $ 77,550 $ 84,577 $ 77,525  Dilutive potential common shares 231 127 241 128  Weighted-average common shares - diluted $ 84,980 $ 77,677 $ 84,818 $ 77,653  Earnings per common share:  Basic $ 0.68 $ 0.59 $ 1.85 $ 1.23  Diluted $ 0.68 $ 0.59 $ 1.85 $ 1.23 

Retirement Plans (Tables)

Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Retirement Plans [Abstract]
Components of Net Periodic Benefits Cost	   Other Post-  (in thousands) Pension Benefits retirement Benefits  Three months Ended September 30, 2017 2017 2016 2017 2016  Service cost $ 3,769 $ 3,611 $ 17 $ 45  Interest cost 4,056 4,022 155 204  Expected return on plan assets (9,652) (8,554) — —  Amortization of net loss and prior service costs 1,167 1,426 (128) 53  Net periodic benefit cost (reduction of cost) $ (660) $ 505 $ 44 $ 302   Nine months ended September 30, 2017  Service cost $ 11,612 $ 10,487 $ 112 $ 119  Interest cost 12,470 13,033 514 613  Expected return on plan assets (27,978) (25,999) — —  Amortization of net loss and prior service costs 4,368 4,320 (224) 75  Net periodic benefit cost $ 472 $ 1,841 $ 402 $ 807 

Share-Based Payment Arrangeme33

Share-Based Payment Arrangements (Tables)	9 Months Ended
	Sep. 30, 2017
Share-Based Payment Arrangements [Abstract]
Summary of Option Activity	   Weighted  Average  Weighted Remaining  Average Contractual Aggregate  Number of Exercise Term Intrinsic  Options Shares Price (Years) Value ($000)  Outstanding at January 1, 2017 456,258 $ 35.91 — $ 3,734  Exercised/Released (335,758) 34.58 — 4,111  Cancelled/Forfeited (538) 32.09 — 6  Expired (16,675) 68.18 — —  Outstanding at September 30, 2017 103,287 $ 35.06 2.92 $ 1,383  Exercisable at September 30, 2017 103,287 $ 35.06 2.92 $ 1,383 
Summary of Nonvested Restricted and Performance Shares	   Weighted  Average  Number of Grant Date  Shares Fair Value  Nonvested at January 1, 2017 2,152,119 $ 32.15  Granted 63,127 42.16  Vested (209,440) 30.23  Forfeited (54,493) 32.36  Nonvested at September 30, 2017 1,951,313 $ 32.67 

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	   September 30, 2017  (in thousands) Level 1 Level 2 Level 3 Total  Assets  Available for sale debt securities:  U.S. Treasury and government agency securities $ — $ 73,442 $ — $ 73,442  Municipal obligations — 242,678 — 242,678  Corporate debt securities — 3,500 — 3,500  Residential mortgage-backed securities — 1,793,426 — 1,793,426  Commercial mortgage-backed securities — 568,353 — 568,353  Collateralized mortgage obligations — 173,879 — 173,879  Total available for sale securities — 2,855,278 — 2,855,278  Derivative assets (1) — 17,199 — 17,199  Total recurring fair value measurements - assets $ — $ 2,872,477 $ — $ 2,872,477  Liabilities  Derivative liabilities (1) $ — $ 12,691 $ — $ 12,691  Total recurring fair value measurements - liabilities $ — $ 12,691 $ — $ 12,691  (1) For further disaggregation of derivative as sets and liabilities, see Note 6 - Derivatives .      December 31, 2016  (in thousands) Level 1 Level 2 Level 3 Total  Assets  Available for sale debt securities:  U.S. Treasury and government agency securities $ — $ 54,828 $ — $ 54,828  Municipal obligations — 242,155 — 242,155  Corporate debt securities — 3,500 — 3,500  Residential mortgage-backed securities — 1,611,355 — 1,611,355  Commercial mortgage-backed securities — 402,591 — 402,591  Collateralized mortgage obligations — 202,479 — 202,479  Total available for sale securities — 2,516,908 — 2,516,908  Derivative assets (1) — 20,315 — 20,315  Total recurring fair value measurements - assets $ — $ 2,537,223 $ — $ 2,537,223  Liabilities  Derivative liabilities (1) $ — $ 27,432 $ — $ 27,432  Total recurring fair value measurements - liabilities $ — $ 27,432 $ — $ 27,432  (1) For further disaggregation of derivative as sets and liabilities, see Note 6 - Derivatives .
Financial Assets Measured at Fair Value on Nonrecurring Basis	   September 30, 2017  (in thousands) Level 1 Level 2 Level 3 Total  Collateral-dependent impaired loans $ — $ 129,230 $ — $ 129,230  Other real estate owned — — 6,810 6,810  Total nonrecurring fair value measurements $ — $ 129,230 $ 6,810 $ 136,040      December 31, 2016  (in thousands) Level 1 Level 2 Level 3 Total  Collateral-dependent impaired loans $ — $ 169,888 $ — $ 169,888  Other real estate owned — — 13,968 13,968  Total nonrecurring fair value measurements $ — $ 169,888 $ 13,968 $ 183,856 
Estimated Fair Values of Financial Instruments	   September 30, 2017  Total Fair Carrying  (in thousands) Level 1 Level 2 Level 3 Value Amount  Financial assets:  Cash, interest-bearing bank deposits, and federal funds sold $ 445,500 $ — $ — $ 445,500 $ 445,500  Available for sale securities — 2,855,278 — 2,855,278 2,855,278  Held to maturity securities — 2,768,148 — 2,768,148 2,769,274  Loans, net — 129,230 18,300,747 18,429,977 18,563,163  Loans held for sale — 23,236 — 23,236 23,236  Derivative financial instruments — 17,199 — 17,199 17,199  Financial liabilities:  Deposits $ — $ — $ 21,523,649 $ 21,523,649 $ 21,533,859  Federal funds purchased 1,150 — — 1,150 1,150  Securities sold under agreements to repurchase 512,001 — — 512,001 512,001  FHLB short-term borrowings 1,224,000 — — 1,224,000 1,224,000  Long-term debt — 330,909 — 330,909 331,179  Derivative financial instruments — 12,691 — 12,691 12,691      December 31, 2016  Total Fair Carrying  (in thousands) Level 1 Level 2 Level 3 Value Amount  Financial assets:  Cash, interest-bearing bank deposits, and federal funds sold $ 450,866 $ — $ — $ 450,866 $ 450,866  Available for sale securities — 2,516,908 — 2,516,908 2,516,908  Held to maturity securities — 2,470,117 — 2,470,117 2,500,220  Loans, net — 169,888 16,326,961 16,496,849 16,522,733  Loans held for sale — 34,064 — 34,064 34,064  Derivative financial instruments — 20,315 — 20,315 20,315  Financial liabilities:  Deposits $ — $ — $ 19,430,939 $ 19,430,939 $ 19,424,266  Federal funds purchased 2,275 — — 2,275 2,275  Securities sold under agreements to repurchase 358,131 — — 358,131 358,131  FHLB short-term borrowings 865,000 — — 865,000 865,000  Long-term debt — 435,747 — 435,747 436,280  Derivative financial instruments — 27,432 — 27,432 27,432 

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details)	Apr. 28, 2017USD ($)entity	Mar. 10, 2017USD ($)entity	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Short-term borrowings			$ 1,737,151,000		$ 1,737,151,000		$ 1,225,406,000
Long-term borrowings			331,179,000		331,179,000		436,280,000
Goodwill			739,403,000		739,403,000		621,193,000
Revenue			202,857,000	$ 163,513,000	584,265,000	$ 491,318,000
Professional Fees			10,062,000	6,584,000	31,691,000	21,917,000
Other expense			21,760,000	22,379,000	68,057,000	55,561,000
Loan expected to be uncollectible			223,122,000	$ 236,061,000	223,122,000	$ 236,061,000	229,418,000	$ 181,179,000
Unpaid principal balance			312,397,000		312,397,000		327,722,000
Recorded investment with an allowance			194,279,000		194,279,000		132,004,000
Recorded investment without an allowance			108,118,000		108,118,000		$ 169,341,000
Whitney Bank [Member]
Business Acquisition [Line Items]
Number of branches | entity		9
Net of cash acquired		$ 323,000,000
Cash consideration		326,000,000
Cash acquired		3,000,000
Acquisition, Premium amount to pay		41,600,000
FNBC Transaction [Member]
Business Acquisition [Line Items]
Acquisition, debt assumed			93,120,000		93,120,000
Identifiable intangible assets			25,300,000		25,300,000
Goodwill			118,210,000		118,210,000
Fair value discount					41,000,000
Acquisition, debt assumed			4,686,000		4,686,000
Total Loans			1,377,100,000		1,377,100,000
Unpaid principal balance of the loans acquired			1,400,000,000		1,400,000,000
Liabilities assumed			2,622,950,000		2,622,950,000
Estimated uncollectible amount			31,700,000		31,700,000
Unpaid principal balance			39,900,000		39,900,000
Recorded investment with an allowance			23,400,000		23,400,000
Recorded investment without an allowance			16,500,000		$ 16,500,000
FNBC I [Member]
Business Acquisition [Line Items]
Acquisition, debt assumed		93,120,000
Identifiable intangible assets		3,900,000
Goodwill		96,063,000
Acquisition, debt assumed		1,607,000
Total Loans		1,211,523,000
Useful life					8 years
Liabilities assumed		1,003,647,000
FNBC I [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Liabilities assumed		$ 604,000,000
FNBC I [Member] | Variable-rate Term Notes [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Short-term borrowings			460,000,000		$ 460,000,000
FNBC I [Member] | Fixed-rate Term Notes [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Short-term borrowings			51,000,000		51,000,000
Long-term borrowings			93,100,000		93,100,000
FNBC I [Member] | $200 Debt Due 2025 [Member] | Variable-rate Term Notes [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Short-term borrowings			200,000,000		$ 200,000,000
Maturity year					2,025
FNBC I [Member] | $260 Debt Due 2026 [Member] | Variable-rate Term Notes [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Short-term borrowings			260,000,000		$ 260,000,000
Maturity year					2,026
FNBC I [Member] | $88 Debt Due 2018 [Member] | Fixed-rate Term Notes [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Maturity year					2,018
Long-term borrowings			88,000,000		$ 88,000,000
FNBC I [Member] | $3.2 Debt Due 2019 [Member] | Fixed-rate Term Notes [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Maturity year					2,019
Long-term borrowings			3,200,000		$ 3,200,000
FNBC I [Member] | $1.9 Debt Due 2023 [Member] | Fixed-rate Term Notes [Member] | FHLB Borrowings [Member]
Business Acquisition [Line Items]
Maturity year					2,023
Long-term borrowings			1,900,000		$ 1,900,000
FNBC II [Member]
Business Acquisition [Line Items]
Long-term borrowings			$ 0		$ 0
Identifiable intangible assets	$ 21,400,000
Goodwill	22,147,000
Acquisition, debt assumed	3,079,000
Total Loans	165,577,000
Useful life					11 years
Liabilities assumed	$ 1,619,303,000
FNBC II [Member] | Whitney Bank [Member]
Business Acquisition [Line Items]
Number of branches | entity	29
Cash received	$ 800,000,000
Cash acquired	158,000,000
Premium payment	35,000,000
Unpaid principal balance of the loans acquired, Net liabilities assumed	$ 642,000,000
FNBC II [Member] | Louisiana [Member] | Whitney Bank [Member]
Business Acquisition [Line Items]
Number of branches | entity	24
FNBC II [Member] | Florida [Member] | Whitney Bank [Member]
Business Acquisition [Line Items]
Number of branches | entity	5

Acquisitions (Schedule of Fair

Acquisitions (Schedule of Fair Value of Net Assets Acquired) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Apr. 28, 2017	Mar. 10, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 739,403			$ 621,193
FNBC Transaction [Member]
Business Acquisition [Line Items]
Cash and due from banks	160,788
Interest-bearing time deposits with other banks	382,622
Fed funds sold and other short-term investments	148
Securities	213,877
Total Loans	1,377,100
Property and equipment	20,825
Accrued interest receivable	3,854
Identifiable intangible assets	25,300
Other assets	4,213
Total identifiable assets	2,188,727
Deposits	1,928,509
Short-term borrowings	596,635
Long-term debt	93,120
Other liabilities	4,686
Total liabilities	2,622,950
Net identifiable assets acquired (liabilities assumed)	(434,223)
Consideration (Paid) Received	316,013
Goodwill	$ 118,210
FNBC I [Member]
Business Acquisition [Line Items]
Cash and due from banks			$ 2,856
Total Loans			1,211,523
Property and equipment			11,837
Accrued interest receivable			2,969
Identifiable intangible assets			3,900
Other assets			63
Total identifiable assets			1,233,148
Deposits			398,171
Short-term borrowings			510,749
Long-term debt			93,120
Other liabilities			1,607
Total liabilities			1,003,647
Net identifiable assets acquired (liabilities assumed)			229,501
Consideration (Paid) Received			(325,564)
Goodwill			$ 96,063
FNBC II [Member]
Business Acquisition [Line Items]
Cash and due from banks		$ 157,932
Interest-bearing time deposits with other banks		382,622
Fed funds sold and other short-term investments		148
Securities		213,877
Total Loans		165,577
Property and equipment		8,988
Accrued interest receivable		885
Identifiable intangible assets		21,400
Other assets		4,150
Total identifiable assets		955,579
Deposits		1,530,338
Short-term borrowings		85,886
Other liabilities		3,079
Total liabilities		1,619,303
Net identifiable assets acquired (liabilities assumed)		(663,724)
Consideration (Paid) Received		641,577
Goodwill		$ 22,147

Acquisitions (Schedule of Goodw

Acquisitions (Schedule of Goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Business Acquisition [Line Items]
Goodwill, Beginning Balance	$ 621,193
Goodwill, Ending Balance	739,403
FNBC Transaction [Member]
Business Acquisition [Line Items]
Goodwill, Ending Balance	118,210
FNBC I [Member]
Business Acquisition [Line Items]
Goodiwll, Initial good will recorded	95,568
Goodwill, Measurement period adjustments	495
FNBC II [Member]
Business Acquisition [Line Items]
Goodiwll, Initial good will recorded	23,009
Goodwill, Measurement period adjustments	$ (862)

Acquisitions (Schedule of Merge

Acquisitions (Schedule of Merger-Related Expense) (Details) - FNBC Transaction [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Personnel expense	$ 2,120	$ 3,662
Net occupancy and equipment expense	500	777
Professional services expense	2,854	9,681
Data processing expense	929	974
Other real estate		(1,511)
Advertising expense	358	1,389
Other expense	2,132	4,398
Total merger-related expenses	$ 8,893	$ 19,370

Securities (Narrative) (Details

Securities (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Securities [Abstract]
Securities classified as trading	$ 0		$ 0
Proceeds from sales of securities available for sale	213,877,000	$ 141,716,000
Realized gain	0	1,500,000
Realized loss	0	$ 0
Securities pledged as collateral	$ 3,600,000,000		$ 3,800,000,000

Securities (Amortized Cost and

Securities (Amortized Cost and Fair Value of Securities Available for Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Amortized Cost	$ 2,879,343	$ 2,562,000
Securities Available for Sale, Gross Unrealized Gains	10,947	11,195
Securities Available for Sale, Gross Unrealized Losses	35,012	56,287
Securities Available for Sale, Fair Value	2,855,278	2,516,908
U.S. Treasury And Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Amortized Cost	75,019	56,751
Securities Available for Sale, Gross Unrealized Gains	29
Securities Available for Sale, Gross Unrealized Losses	1,606	1,923
Securities Available for Sale, Fair Value	73,442	54,828
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Amortized Cost	246,805	253,228
Securities Available for Sale, Gross Unrealized Gains	534	113
Securities Available for Sale, Gross Unrealized Losses	4,661	11,186
Securities Available for Sale, Fair Value	242,678	242,155
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Amortized Cost	1,795,397	1,620,191
Securities Available for Sale, Gross Unrealized Gains	9,701	10,592
Securities Available for Sale, Gross Unrealized Losses	11,672	19,428
Securities Available for Sale, Fair Value	1,793,426	1,611,355
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Amortized Cost	584,503	425,750
Securities Available for Sale, Gross Unrealized Gains	569
Securities Available for Sale, Gross Unrealized Losses	16,719	23,159
Securities Available for Sale, Fair Value	568,353	402,591
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Amortized Cost	174,119	202,580
Securities Available for Sale, Gross Unrealized Gains	114	490
Securities Available for Sale, Gross Unrealized Losses	354	591
Securities Available for Sale, Fair Value	173,879	202,479
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available for Sale, Amortized Cost	3,500	3,500
Securities Available for Sale, Fair Value	$ 3,500	$ 3,500

Securities (Amortized Cost an41

Securities (Amortized Cost and Fair Value of Securities Held to Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	$ 2,769,274	$ 2,500,220
Securities Held to Maturity, Gross Unrealized Gains	19,049	7,896
Securities Held to Maturity, Gross Unrealized Losses	20,175	37,999
Securities Held to Maturity, Fair Value	2,768,148	2,470,117
U.S. Treasury And Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	50,000	50,000
Securities Held to Maturity, Gross Unrealized Losses	63	44
Securities Held to Maturity, Fair Value	49,937	49,956
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	725,484	648,093
Securities Held to Maturity, Gross Unrealized Gains	7,677	2,147
Securities Held to Maturity, Gross Unrealized Losses	7,396	20,175
Securities Held to Maturity, Fair Value	725,765	630,065
Residential Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	760,158	862,162
Securities Held to Maturity, Gross Unrealized Gains	8,896	4,329
Securities Held to Maturity, Gross Unrealized Losses	776	3,068
Securities Held to Maturity, Fair Value	768,278	863,423
Commercial Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	75,688	75,739
Securities Held to Maturity, Gross Unrealized Losses	2,592	4,038
Securities Held to Maturity, Fair Value	73,096	71,701
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	1,157,944	864,226
Securities Held to Maturity, Gross Unrealized Gains	2,476	1,420
Securities Held to Maturity, Gross Unrealized Losses	9,348	10,674
Securities Held to Maturity, Fair Value	$ 1,151,072	$ 854,972

Securities (Amortized Cost an42

Securities (Amortized Cost and Fair Value of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Securities [Abstract]
Debt Securities Available for Sale, Due in one year or less, Amortized Cost	$ 5,392
Debt Securities Available for Sale, Due after one year through five years, Amortized Cost	46,852
Debt Securities Available for Sale, Due after five years through ten years, Amortized Cost	1,097,850
Debt Securities Available for Sale, Due after ten years, Amortized Cost	1,729,249
Total available for sale debt securities, Amortized Cost	2,879,343
Debt Securities Available for Sale, Due in one year or less, Fair Value	5,425
Debt Securities Available for Sale, Due after one year through five years, Fair Value	47,394
Debt Securities Available for Sale, Due after five years through ten years, Fair Value	1,082,709
Debt Securities Available for Sale, Due after ten years, Fair Value	1,719,750
Total available for sale debt securities, Fair Value	2,855,278
Debt Securities Held to Maturity, Due in one year or less, Amortized Cost	10,081
Debt Securities Held to Maturity, Due after one year through five years, Amortized Cost	108,164
Debt Securities Held to Maturity, Due after five years through ten years, Amortized Cost	837,353
Debt Securities Held to Maturity, Due after ten years, Amortized Cost	1,813,676
Total held to maturity debt securities, Amortized Cost	2,769,274	$ 2,500,220
Debt Securities Held to Maturity, Due in one year or less, Fair Value	10,123
Debt Securities Held to Maturity, Due after one year through five years, Fair Value	108,726
Debt Securities Held to Maturity, Due after five years through ten years, Fair Value	833,465
Debt Securities Held to Maturity, Due after ten years, Fair Value	1,815,834
Total held to maturity debt securities, Fair Value	$ 2,768,148	$ 2,470,117

Securities (Securities Availabl

Securities (Securities Available for Sale with Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available for Sale, Losses less than 12 months, Fair Value	$ 1,985,318	$ 1,857,312
Available for Sale, Losses less than 12 months, Gross Unrealized Losses	30,973	56,218
Available for Sale, Losses 12 months or longer, Fair Value	107,716	3,738
Available for Sale, Losses 12 months or longer, Gross Unrealized Losses	4,039	69
Available for Sale, Total, Fair Value	2,093,034	1,861,050
Available for Sale, Total, Gross Unrealized Losses	35,012	56,287
U.S. Treasury And Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for Sale, Losses less than 12 months, Fair Value	52,866	54,788
Available for Sale, Losses less than 12 months, Gross Unrealized Losses	1,606	1,923
Available for Sale, Total, Fair Value	52,866	54,788
Available for Sale, Total, Gross Unrealized Losses	1,606	1,923
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for Sale, Losses less than 12 months, Fair Value	145,441	228,588
Available for Sale, Losses less than 12 months, Gross Unrealized Losses	2,286	11,186
Available for Sale, Losses 12 months or longer, Fair Value	66,640
Available for Sale, Losses 12 months or longer, Gross Unrealized Losses	2,375
Available for Sale, Total, Fair Value	212,081	228,588
Available for Sale, Total, Gross Unrealized Losses	4,661	11,186
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for Sale, Losses less than 12 months, Fair Value	1,255,266	1,087,644
Available for Sale, Losses less than 12 months, Gross Unrealized Losses	11,514	19,359
Available for Sale, Losses 12 months or longer, Fair Value	5,360	3,738
Available for Sale, Losses 12 months or longer, Gross Unrealized Losses	158	69
Available for Sale, Total, Fair Value	1,260,626	1,091,382
Available for Sale, Total, Gross Unrealized Losses	11,672	19,428
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for Sale, Losses less than 12 months, Fair Value	465,596	402,591
Available for Sale, Losses less than 12 months, Gross Unrealized Losses	15,366	23,159
Available for Sale, Losses 12 months or longer, Fair Value	30,151
Available for Sale, Losses 12 months or longer, Gross Unrealized Losses	1,353
Available for Sale, Total, Fair Value	495,747	402,591
Available for Sale, Total, Gross Unrealized Losses	16,719	23,159
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for Sale, Losses less than 12 months, Fair Value	66,149	83,701
Available for Sale, Losses less than 12 months, Gross Unrealized Losses	201	591
Available for Sale, Losses 12 months or longer, Fair Value	5,565
Available for Sale, Losses 12 months or longer, Gross Unrealized Losses	153
Available for Sale, Total, Fair Value	71,714	83,701
Available for Sale, Total, Gross Unrealized Losses	$ 354	$ 591

Securities (Securities Held to

Securities (Securities Held to Maturity with Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value	$ 1,213,510	$ 1,513,235
Held to maturity, Losses less than 12 months, Gross Unrealized Losses	10,258	34,152
Held to maturity, Losses 12 months or longer, Fair Value	331,673	127,125
Held to maturity, Losses 12 months or longer, Gross Unrealized Losses	9,917	3,847
Held to maturity, Total, Fair Value	1,545,183	1,640,360
Held to maturity, Total, Gross Unrealized Losses	20,175	37,999
U.S. Treasury And Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value	49,938	49,956
Held to maturity, Losses less than 12 months, Gross Unrealized Losses	63	44
Held to maturity, Total, Fair Value	49,938	49,956
Held to maturity, Total, Gross Unrealized Losses	63	44
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value	275,874	494,470
Held to maturity, Losses less than 12 months, Gross Unrealized Losses	2,975	19,706
Held to maturity, Losses 12 months or longer, Fair Value	98,976	11,750
Held to maturity, Losses 12 months or longer, Gross Unrealized Losses	4,421	469
Held to maturity, Total, Fair Value	374,850	506,220
Held to maturity, Total, Gross Unrealized Losses	7,396	20,175
Residential Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value	254,743	278,369
Held to maturity, Losses less than 12 months, Gross Unrealized Losses	776	3,068
Held to maturity, Total, Fair Value	254,743	278,369
Held to maturity, Total, Gross Unrealized Losses	776	3,068
Commercial Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value	73,096	71,701
Held to maturity, Losses less than 12 months, Gross Unrealized Losses	2,592	4,038
Held to maturity, Total, Fair Value	73,096	71,701
Held to maturity, Total, Gross Unrealized Losses	2,592	4,038
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair Value	559,859	618,739
Held to maturity, Losses less than 12 months, Gross Unrealized Losses	3,852	7,296
Held to maturity, Losses 12 months or longer, Fair Value	232,697	115,375
Held to maturity, Losses 12 months or longer, Gross Unrealized Losses	5,496	3,378
Held to maturity, Total, Fair Value	792,556	734,114
Held to maturity, Total, Gross Unrealized Losses	$ 9,348	$ 10,674

Loans and Allowance for Loan 45

Loans and Allowance for Loan Losses (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)contractagreement	Sep. 30, 2016USD ($)contract	Jun. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 269,676			$ 317,970
TDRs both accruing and nonaccruing	216,000			121,700
Post-Modification outstanding recorded investment	$ 147,454	$ 58,447
Number of TDRs subsequently defaulted | contract	0	0
TDRs and loans impaired with minimum aggregate relationship balances	$ 1,000
Loans receivable			$ 154,000
Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period for which payments of principal and interest are past due	less than 90 days
Troubled Debt Restructurings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 119,300			81,900
Troubled Debt Restructurings [Member] | Loans With Extended Amortization Terms Or Other Payment Concessions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extended terms and other payment concessions	96,100	$ 43,400
Troubled Debt Restructurings [Member] | Loans With Significant Covenant Waivers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Convenant waivers	50,100	14,700
Troubled Debt Restructurings [Member] | Loans With Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification outstanding recorded investment	$ 1,300
Other Modifications		$ 400
FDIC Loss Share Agreement [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loss share agreements | agreement	2
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 14,063			12,351
Post-Modification outstanding recorded investment	42
Real estate in process of foreclosure	8,000			10,100
Real estate acquired through foreclosure	$ 2,500			$ 3,100

Loans and Allowance for Loan 46

Loans and Allowance for Loan Losses (Loans, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 18,786,285	$ 16,752,151	$ 16,070,821
Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	14,090,299	12,545,507
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,596,692	2,146,713	2,037,162
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,099,294	2,059,931	2,061,005
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,511,808	2,013,890	1,990,309
Construction and Land Development [Member] | Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,373,048	1,010,879	946,592
Total Commercial & Industrial [Member] | Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	10,205,443	9,520,738	9,035,753
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	8,129,429	7,613,917	7,133,928
Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 2,076,014	$ 1,906,821	$ 1,901,825

Loans and Allowance for Loan 47

Loans and Allowance for Loan Losses (Allowance for Loan Losses by Portfolio Class) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			$ 229,418	$ 181,179
Allowance for loan losses: Net provision for loan losses	$ 13,040	$ 18,972	43,982	96,204
Allowance for loan losses: Decrease in FDIC loss share receivable			(2,526)	(3,027)
Allowance for loan losses: Ending balance	223,122	236,061	223,122	236,061
Allowance for loan losses: Individually evaluated for impairment	23,490	21,130	23,490	21,130
Allowance for loan losses: Amounts related to purchased credit impaired loans	15,312	19,708	15,312	19,708
Allowance for loan losses: Collectively evaluated for impairment	184,320	195,223	184,320	195,223
Loans: Individually evaluated for impairment	302,397	256,563	302,397	256,563
Loans: Purchased credit impaired loans	176,111	201,792	176,111	201,792	$ 190,915	$ 225,838
Loans: Collectively evaluated for impairment	18,307,777	15,612,466	18,307,777	15,612,466
Loans receivable	18,786,285	16,070,821	18,786,285	16,070,821	16,752,151
Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable	14,090,299		14,090,299		12,545,507
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			13,509	6,041
Allowance for loan losses: Ending balance	14,490	10,950	14,490	10,950
Allowance for loan losses: Individually evaluated for impairment	1,321	57	1,321	57
Allowance for loan losses: Amounts related to purchased credit impaired loans	199	279	199	279
Allowance for loan losses: Collectively evaluated for impairment	12,970	10,614	12,970	10,614
Loans: Individually evaluated for impairment	14,295	7,655	14,295	7,655
Loans: Purchased credit impaired loans	5,353	8,087	5,353	8,087
Loans: Collectively evaluated for impairment	2,492,160	1,974,567	2,492,160	1,974,567
Loans receivable	2,511,808	1,990,309	2,511,808	1,990,309	2,013,890
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			6,271	5,642
Allowance for loan losses: Ending balance	6,581	5,848	6,581	5,848
Allowance for loan losses: Individually evaluated for impairment	1	6	1	6
Allowance for loan losses: Amounts related to purchased credit impaired loans	254	484	254	484
Allowance for loan losses: Collectively evaluated for impairment	6,326	5,358	6,326	5,358
Loans: Individually evaluated for impairment	480	2,062	480	2,062
Loans: Purchased credit impaired loans	6,670	8,436	6,670	8,436
Loans: Collectively evaluated for impairment	1,365,898	936,094	1,365,898	936,094
Loans receivable	1,373,048	946,592	1,373,048	946,592	1,010,879
Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			25,361	25,353
Allowance for loan losses: Ending balance	25,034	24,192	25,034	24,192
Allowance for loan losses: Individually evaluated for impairment	406	94	406	94
Allowance for loan losses: Amounts related to purchased credit impaired loans	12,795	15,949	12,795	15,949
Allowance for loan losses: Collectively evaluated for impairment	11,833	8,149	11,833	8,149
Loans: Individually evaluated for impairment	8,942	3,864	8,942	3,864
Loans: Purchased credit impaired loans	123,244	145,273	123,244	145,273
Loans: Collectively evaluated for impairment	2,464,506	1,888,025	2,464,506	1,888,025
Loans receivable	2,596,692	2,037,162	2,596,692	2,037,162	2,146,713
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			26,142	24,857
Allowance for loan losses: Ending balance	29,363	25,027	29,363	25,027
Allowance for loan losses: Individually evaluated for impairment	405	85	405	85
Allowance for loan losses: Amounts related to purchased credit impaired loans	863	1,334	863	1,334
Allowance for loan losses: Collectively evaluated for impairment	28,095	23,608	28,095	23,608
Loans: Individually evaluated for impairment	1,306	1,485	1,306	1,485
Loans: Purchased credit impaired loans	7,637	12,045	7,637	12,045
Loans: Collectively evaluated for impairment	2,090,351	2,047,475	2,090,351	2,047,475
Loans receivable	2,099,294	2,061,005	2,099,294	2,061,005	2,059,931
Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(332)	(146)
Allowance for loan losses: Recoveries			259	484
Allowance for loan losses: Net provision for loan losses			(442)	(723)
Allowance for loan losses: Decrease in FDIC loss share receivable			(2,526)	(3,027)
Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs				(1)
Allowance for loan losses: Recoveries				2
Allowance for loan losses: Net provision for loan losses			(54)	(436)
Allowance for loan losses: Decrease in FDIC loss share receivable
Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(77)	(18)
Allowance for loan losses: Recoveries			49	98
Allowance for loan losses: Net provision for loan losses			(124)	(253)
Allowance for loan losses: Decrease in FDIC loss share receivable
Purchased Credit Impaired Loans [Member] | Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(102)	(91)
Allowance for loan losses: Recoveries			23	33
Allowance for loan losses: Net provision for loan losses			175	1,685
Allowance for loan losses: Decrease in FDIC loss share receivable			(2,344)	(3,341)
Purchased Credit Impaired Loans [Member] | Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(153)	(8)
Allowance for loan losses: Recoveries			72	112
Allowance for loan losses: Net provision for loan losses			(192)	(1,633)
Allowance for loan losses: Decrease in FDIC loss share receivable			(135)	316
Non-Purchased Credit Impaired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(61,601)	(48,493)
Allowance for loan losses: Recoveries			13,922	9,860
Allowance for loan losses: Net provision for loan losses			44,424	96,927
Non-Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(160)	(191)
Allowance for loan losses: Recoveries			655	673
Allowance for loan losses: Net provision for loan losses			540	4,862
Non-Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(593)	(827)
Allowance for loan losses: Recoveries			1,001	1,422
Allowance for loan losses: Net provision for loan losses			54	(216)
Non-Purchased Credit Impaired Loans [Member] | Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(2,383)	(908)
Allowance for loan losses: Recoveries			316	497
Allowance for loan losses: Net provision for loan losses			3,988	964
Non-Purchased Credit Impaired Loans [Member] | Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(22,691)	(17,403)
Allowance for loan losses: Recoveries			5,176	4,272
Allowance for loan losses: Net provision for loan losses			21,144	14,514
Total Commercial & Industrial [Member] | Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			158,135	119,286
Allowance for loan losses: Ending balance	147,654	170,044	147,654	170,044
Allowance for loan losses: Individually evaluated for impairment	21,357	20,888	21,357	20,888
Allowance for loan losses: Amounts related to purchased credit impaired loans	1,201	1,662	1,201	1,662
Allowance for loan losses: Collectively evaluated for impairment	125,096	147,494	125,096	147,494
Loans: Individually evaluated for impairment	277,375	241,497	277,375	241,497
Loans: Purchased credit impaired loans	33,207	27,951	33,207	27,951
Loans: Collectively evaluated for impairment	9,894,861	8,766,305	9,894,861	8,766,305
Loans receivable	10,205,443	9,035,753	10,205,443	9,035,753	9,520,738
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			147,052	109,428
Allowance for loan losses: Ending balance	134,095	159,261	134,095	159,261
Allowance for loan losses: Individually evaluated for impairment	20,880	20,665	20,880	20,665
Allowance for loan losses: Amounts related to purchased credit impaired loans	417	574	417	574
Allowance for loan losses: Collectively evaluated for impairment	112,798	138,022	112,798	138,022
Loans: Individually evaluated for impairment	271,024	235,039	271,024	235,039
Loans: Purchased credit impaired loans	20,186	11,534	20,186	11,534
Loans: Collectively evaluated for impairment	7,838,219	6,887,355	7,838,219	6,887,355
Loans receivable	8,129,429	7,133,928	8,129,429	7,133,928	7,613,917
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Beginning balance			11,083	9,858
Allowance for loan losses: Ending balance	13,559	10,783	13,559	10,783
Allowance for loan losses: Individually evaluated for impairment	477	223	477	223
Allowance for loan losses: Amounts related to purchased credit impaired loans	784	1,088	784	1,088
Allowance for loan losses: Collectively evaluated for impairment	12,298	9,472	12,298	9,472
Loans: Individually evaluated for impairment	6,351	6,458	6,351	6,458
Loans: Purchased credit impaired loans	13,021	16,417	13,021	16,417
Loans: Collectively evaluated for impairment	2,056,642	1,878,950	2,056,642	1,878,950
Loans receivable	$ 2,076,014	$ 1,901,825	2,076,014	1,901,825	$ 1,906,821
Total Commercial & Industrial [Member] | Purchased Credit Impaired Loans [Member] | Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs				(28)
Allowance for loan losses: Recoveries			115	239
Allowance for loan losses: Net provision for loan losses			(247)	(86)
Allowance for loan losses: Decrease in FDIC loss share receivable			(47)	(2)
Total Commercial & Industrial [Member] | Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs
Allowance for loan losses: Recoveries			5	76
Allowance for loan losses: Net provision for loan losses			(27)	54
Allowance for loan losses: Decrease in FDIC loss share receivable			(47)	(2)
Total Commercial & Industrial [Member] | Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs				(28)
Allowance for loan losses: Recoveries			110	163
Allowance for loan losses: Net provision for loan losses			(220)	(140)
Allowance for loan losses: Decrease in FDIC loss share receivable
Total Commercial & Industrial [Member] | Non-Purchased Credit Impaired Loans [Member] | Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(35,774)	(29,164)
Allowance for loan losses: Recoveries			6,774	2,996
Allowance for loan losses: Net provision for loan losses			18,698	76,803
Total Commercial & Industrial [Member] | Non-Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(35,247)	(27,504)
Allowance for loan losses: Recoveries			6,437	2,709
Allowance for loan losses: Net provision for loan losses			15,922	74,500
Total Commercial & Industrial [Member] | Non-Purchased Credit Impaired Loans [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Charge-offs			(527)	(1,660)
Allowance for loan losses: Recoveries			337	287
Allowance for loan losses: Net provision for loan losses			$ 2,776	$ 2,303

Loans and Allowance for Loan 48

Loans and Allowance for Loan Losses (Composition of Nonaccrual Loans by Portfolio Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 269,676	$ 317,970
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	14,360	13,954
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,292	4,550
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	34,674	23,665
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	14,063	12,351
Total Commercial & Industrial [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	203,287	263,450
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	188,982	249,037
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 14,305	$ 14,413

Loans and Allowance for Loan 49

Loans and Allowance for Loan Losses (Troubled Debt Restructurings Modified by Portfolio Class) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)contract	Sep. 30, 2016USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	73	23
Pre-Modification Outstanding Recorded Investment	$ 147,452	$ 58,447
Post-Modification Outstanding Recorded Investment	$ 147,454	$ 58,447
Total Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	54	17
Pre-Modification Outstanding Recorded Investment	$ 139,660	$ 57,915
Post-Modification Outstanding Recorded Investment	$ 139,660	$ 57,915
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	5
Pre-Modification Outstanding Recorded Investment	$ 5,684
Post-Modification Outstanding Recorded Investment	$ 5,684
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract
Pre-Modification Outstanding Recorded Investment
Post-Modification Outstanding Recorded Investment
Residential Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	13	6
Pre-Modification Outstanding Recorded Investment	$ 2,068	$ 532
Post-Modification Outstanding Recorded Investment	$ 2,068	$ 532
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1
Pre-Modification Outstanding Recorded Investment	$ 40
Post-Modification Outstanding Recorded Investment	$ 42
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	50	17
Pre-Modification Outstanding Recorded Investment	$ 135,926	$ 57,915
Post-Modification Outstanding Recorded Investment	$ 135,926	$ 57,915
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	4
Pre-Modification Outstanding Recorded Investment	$ 3,734
Post-Modification Outstanding Recorded Investment	$ 3,734

Loans and Allowance for Loan 50

Loans and Allowance for Loan Losses (Loans Individually Evaluated for Impairment Disaggregated by Portfolio Class) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	$ 108,118		$ 108,118		$ 169,341
Recorded investment with an allowance	194,279		194,279		132,004
Unpaid principal balance	312,397		312,397		327,722
Related allowance	23,490		23,490		29,295
Average recorded investment	290,206	$ 252,963	278,782	$ 221,634
Interest income recognized	943	194	1,986	1,119
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	5,160		5,160		10,447
Recorded investment with an allowance	9,135		9,135		4,929
Unpaid principal balance	14,451		14,451		15,708
Related allowance	1,321		1,321		466
Average recorded investment	14,604	7,729	14,449	8,624
Interest income recognized	35	24	112	67
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	464		464		1,106
Recorded investment with an allowance	16		16		832
Unpaid principal balance	1,445		1,445		2,903
Related allowance	1		1		38
Average recorded investment	663	1,655	1,216	7,821
Interest income recognized	1		1
Residential Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	6,311		6,311		2,877
Recorded investment with an allowance	2,630		2,630		1,470
Unpaid principal balance	11,961		11,961		4,865
Related allowance	406		406		91
Average recorded investment	6,204	2,466	4,449	1,444
Interest income recognized	7	3	12	7
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	1		1
Recorded investment with an allowance	1,305		1,305		2,154
Unpaid principal balance	1,308		1,308		2,155
Related allowance	405		405		267
Average recorded investment	1,179	826	1,644	348
Interest income recognized	4	2	9	4
Total Commercial & Industrial [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment			257,024	203,397
Interest income recognized			1,852	1,041
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment			251,129	197,382
Interest income recognized			1,806	1,002
Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment			5,895	6,015
Interest income recognized			46	$ 39
Total Commercial & Industrial [Member] | Total Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	96,182		96,182		154,911
Recorded investment with an allowance	181,193		181,193		122,619
Unpaid principal balance	283,232		283,232		302,091
Related allowance	21,357		21,357		28,433
Average recorded investment	267,556	240,287
Interest income recognized	896	165
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	92,583		92,583		150,650
Recorded investment with an allowance	178,441		178,441		120,612
Unpaid principal balance	276,879		276,879		295,445
Related allowance	20,880		20,880		28,187
Average recorded investment	260,640	233,913
Interest income recognized	872	155
Total Commercial & Industrial [Member] | Total Commercial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment without an allowance	3,599		3,599		4,261
Recorded investment with an allowance	2,752		2,752		2,007
Unpaid principal balance	6,353		6,353		6,646
Related allowance	477		$ 477		$ 246
Average recorded investment	6,916	6,374
Interest income recognized	$ 24	$ 10

Loans and Allowance for Loan 51

Loans and Allowance for Loan Losses (Age Analysis of Past Due Loans by Portfolio Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 292,318	$ 195,107
Current	18,493,967	16,557,044
Total loans	18,786,285	16,752,151	$ 16,070,821
Recorded investment > 90 days and still accruing	28,850	3,039
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	111,426	67,482
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	26,946	18,968
Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	153,946	108,657
Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	14,090,299	12,545,507
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	10,947	5,914
Current	2,500,861	2,007,976
Total loans	2,511,808	2,013,890	1,990,309
Recorded investment > 90 days and still accruing	2,907	216
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,540	838
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	3,731	50
Total Commercial [Member] | Commercial Real Estate - Income Producing [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	5,676	5,026
Total Commercial [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	8,910	6,165
Current	1,364,138	1,004,714
Total loans	1,373,048	1,010,879	946,592
Recorded investment > 90 days and still accruing	417	1,563
Total Commercial [Member] | Construction and Land Development [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	5,018	694
Total Commercial [Member] | Construction and Land Development [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,031	171
Total Commercial [Member] | Construction and Land Development [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2,861	5,300
Total Commercial [Member] | Total Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	167,680	100,035
Current	10,037,763	9,420,703
Total loans	10,205,443	9,520,738	9,035,753
Recorded investment > 90 days and still accruing	25,167	436
Total Commercial [Member] | Total Commercial & Industrial [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	50,213	22,730
Total Commercial [Member] | Total Commercial & Industrial [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	4,183	2,490
Total Commercial [Member] | Total Commercial & Industrial [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	113,284	74,815
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	139,848	90,136
Current	7,989,581	7,523,781
Total loans	8,129,429	7,613,917	7,133,928
Recorded investment > 90 days and still accruing	24,400	384
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	31,634	19,722
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	3,880	1,909
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	104,334	68,505
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	27,832	9,899
Current	2,048,182	1,896,922
Total loans	2,076,014	1,906,821	1,901,825
Recorded investment > 90 days and still accruing	767	52
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	18,579	3,008
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	303	581
Total Commercial [Member] | Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	8,950	6,310
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	74,071	47,784
Current	2,522,621	2,098,929
Total loans	2,596,692	2,146,713	2,037,162
Recorded investment > 90 days and still accruing	41	1
Residential Mortgages [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	39,081	24,599
Residential Mortgages [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	10,575	8,816
Residential Mortgages [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	24,415	14,369
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	30,710	35,209
Current	2,068,584	2,024,722
Total loans	2,099,294	2,059,931	$ 2,061,005
Recorded investment > 90 days and still accruing	318	823
Consumer [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	15,574	18,621
Consumer [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	7,426	7,441
Consumer [Member] | Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 7,710	$ 9,147

Loans and Allowance for Loan 52

Loans and Allowance for Loan Losses (Credit Quality Indicators by Segments and Portfolio Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 18,786,285	$ 16,752,151	$ 16,070,821
Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,090,299	12,545,507
Total Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,388,477	10,925,611
Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	609,987	351,888
Total Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	183,579	248,696
Total Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	904,941	1,001,599
Total Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,315	17,713
Residential Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,596,692	2,146,713	2,037,162
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,099,294	2,059,931	2,061,005
Residential Mortgage and Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,695,986	4,206,644
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,511,808	2,013,890	1,990,309
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,327,685	1,873,644
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	107,568	78,309
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,802	22,492
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	63,744	39,434
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9	11
Construction and Land Development [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,373,048	1,010,879	946,592
Construction and Land Development [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,278,648	968,505
Construction and Land Development [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	73,538	22,592
Construction and Land Development [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,484	4,142
Construction and Land Development [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,378	15,640
Total Commercial & Industrial [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	10,205,443	9,520,738	9,035,753
Total Commercial & Industrial [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,782,144	8,083,462
Total Commercial & Industrial [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	428,881	250,987
Total Commercial & Industrial [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	163,293	222,062
Total Commercial & Industrial [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	827,819	946,525
Total Commercial & Industrial [Member] | Total Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,306	17,702
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,129,429	7,613,917	7,133,928
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,941,591	6,364,348
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	345,073	203,311
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	122,023	181,763
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	717,436	846,793
Total Commercial & Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,306	17,702
Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,076,014	1,906,821	$ 1,901,825
Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,840,553	1,719,114
Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	83,808	47,676
Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	41,270	40,299
Total Commercial & Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	110,383	99,732
Performing [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,561,977	2,123,048
Performing [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,084,913	2,046,757
Performing [Member] | Residential Mortgage and Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,646,890	4,169,805
Nonperforming [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	34,715	23,665
Nonperforming [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,381	13,174
Nonperforming [Member] | Residential Mortgage and Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 49,096	$ 36,839

Loans and Allowance for Loan 53

Loans and Allowance for Loan Losses (Changes in Carrying Amount of Purchased Credit Impaired Loans and Related Accretable Yield) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Loans and Allowance for Loan Losses [Abstract]
Carrying Amount of Loans, Balance at beginning of period	$ 190,915	$ 225,838
Carrying Amount of Loans, Addition of cost recovery loans	23,431
Carrying Amount of Loans, Payments received, net	(51,040)	(55,194)
Carrying Amount of Loans, Accretion	12,805	20,271
Carrying Amount of Loans, Balance at end of period	176,111	190,915
Accretable Yield, Balance at beginning of period	113,686	129,488
Accretable Yield, Addition of cost recovery loans
Accretable Yield, Payments received, net	(6,651)	(11,024)
Accretable Yield, Accretion	(12,805)	(20,271)
Accretable Yield, Increase in expected cash flows based on actual cash flow and changes in cash flow assumptions	4,149	5,358
Accretable Yield, Net transfers from nonaccretable difference to accretable yield	8,095	10,135
Accretable Yield, Balance at end of period	$ 106,474	$ 113,686

Loans and Allowance for Loan 54

Loans and Allowance for Loan Losses (Activity in Loss Share Receivable) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Loans and Allowance for Loan Losses [Abstract]
Beginning balance		$ 16,219	$ 29,868
Amortization	$ (1,539)	(2,427)	(4,678)
Charge-offs, write-downs and other recoveries		(2,442)	(5,569)
External expenses qualifying under loss share agreement		79	1,000
Adjustment due to changes in cash flow projections		(2,526)	(3,027)
Net payments to FDIC		934	436
Write-down for termination of loss share agreement		6,603
Cash received from FDIC for final settlement of agreements		(3,234)
Ending balance	$ 18,030		$ 18,030

Securities Sold under Agreeme55

Securities Sold under Agreements to Repurchase (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Securities Sold under Agreements to Repurchase [Abstract]
Securities sold under agreements to repurchase	$ 512	$ 358.1

Derivatives (Narrative) (Detail

Derivatives (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Notional amount of derivatives	$ 2,740,984		$ 2,740,984		$ 2,342,791
Ineffective portion of change in derivative fair value	0	$ 0	0	$ 0
Derivative income reflected in the income statement	1,300	1,300	4,400	1,700
Impact to interest income from cash flow hedges	(100)	700	(200)	1,700
Aggregate fair value of derivatives in a net liability position	16,600		16,600
Deposits	21,789	$ 12,590	52,972	$ 36,926
Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional amount of derivatives	1,238,000		1,238,000		1,100,000
Interest Rate Swaps [Member]
Derivative [Line Items]
Deposits	200		600
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member]
Derivative [Line Items]
Notional amount of derivatives	875,000		875,000		$ 1,100,000
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Date One [Member] | Swap Agreement 3, Expires 2019 [Member]
Derivative [Line Items]
Notional amount of derivatives	250,000		$ 250,000
Derivative maturity expiration year			2,019
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Date Two [Member] | Swap Agreement 4, Expires 2020 [Member]
Derivative [Line Items]
Notional amount of derivatives	200,000		$ 200,000
Derivative maturity expiration year			2,020
Interest Rate Swaps [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Date Three [Member] | Swap Agreement 5, Expires 2022 [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 425,000		$ 425,000
Derivative maturity expiration year			2,022

Derivatives (Fair Values of Der

Derivatives (Fair Values of Derivative Financial Instruments) (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		$ 2,740,984	$ 2,342,791
Fair Values, Assets		1,329	4,788
Fair Values, Liabilities		5,567	26,846
Less: Netting Adjustment, Assets	[1],[2]	(2,780)
Less: Netting Adjustment, Liabilities	[1],[2]	(16,747)
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		1,238,000	1,100,000
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		1,502,984	1,242,791
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount	[3]	1,172,752	979,391
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		109,556	84,732
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		93,809	75,676
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		71,786	46,840
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		55,081	56,152
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Assets	[1]	19,979	20,315
Total derivative assets/liabilities	[1]	17,199	20,315
Other Assets [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Assets	[1]	19,979	20,315
Other Assets [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Assets	[1],[3]	16,855	18,405
Other Assets [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Assets	[1]	34	50
Other Assets [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Assets	[1]	91	900
Other Assets [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Assets	[1]	534	189
Other Assets [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Assets	[1]	2,465	771
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	29,438	27,432
Total derivative assets/liabilities	[1]	12,691	27,432
Other Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	8,747	7,787
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	20,691	19,645
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1],[3]	17,420	18,362
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	108	105
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	669	221
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	71	228
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	2,423	729
Cash Flow Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		875,000	1,100,000
Cash Flow Hedge [Member] | Other Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair Values, Liabilities	[1]	7,924	$ 7,787
Fair Value Hedging [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional or Contractual Amount		363,000
Fair Values, Liabilities	[1]	$ 823
[1]	Derivative assets and liabilities are reported at fair value in other assets or other liabilities, respectively, in the consolidated balance sheets.
[2]	Represents balance sheet netting of derivative assets and liabilities for variation margin collateral held or placed with the same central clearing counterparty. See offsetting assets and liabilities for further information.
[3]	The notional amount represents both the customer accommodation agreements and offsetting agreements with unrelated financial institutions.

Derivatives (Offsetting Derivat

Derivatives (Offsetting Derivative Assets and Liabilities Subject to Master Netting Arrangements) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivatives [Abstract]
Gross Amounts Recognized, Derivative Assets	$ 5,271	$ 4,788
Gross Amounts Offset in the Statement of Income, Derivative Assets	(3,942)
Net Amounts Presented in the Statement of Income, Derivative Assets	1,329	4,788
Gross Amounts Not Offset in the Statement of Income - Financial Instruments, Derivative Assets	1,329	4,788
Gross Amounts Not offset in the Statement of Income -Cash Collateral, Derivative Assets
Net Amounts Presented in the Statement of Income, Derivative Assets
Gross Amounts Recognized, Derivative Liabilities	21,889	26,846
Gross Amounts Offset in the Statement of Income, Derivative Liabilities	(16,322)
Net Amounts Presented in the Statement of Income, Derivative Liabilities	5,567	26,846
Gross Amounts Not Offset in the Statement of Income - Financial Instruments, Derivative Liabilities	1,329	4,788
Gross Amounts Not offset in the Statement of Income -Cash Collateral, Derivative Liabilities	7,318	19,095
Net Amounts Presented in the Statement of Income, Derivative Liabilities		$ 2,963
Net Amount, Derivative Liabilities	$ (3,080)

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Treasury stock shares	1	1.3
Treasury stock, Carry basis	$ 17.6	$ 24.1
Restricted Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares nonvested	1.7	2

Stockholders' Equity (Component

Stockholders' Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				$ (120,532)	$ (80,595)
Net change in unrealized gain (loss)		$ 5,949	$ (5,604)	19,794	39,997
Reclassification of net (gain) loss realized and included in earnings		1,374	1,158	4,479	2,960
Valuation adjustment for pension plan amendment	[1]			17,315
Valuation adjustment for employee benefit plans		1,597	(6,347)	(9,185)	(6,347)
Amortization of unrealized net loss on securities transferred to HTM		977	1,108	2,726	2,736
Income tax expense (benefit)		3,609	(3,537)	12,748	14,440
Ending Balance		(98,151)	(55,689)	(98,151)	(55,689)
Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(28,679)	4,268
Net change in unrealized gain (loss)				21,026	38,835
Reclassification of net (gain) loss realized and included in earnings					(1,435)
Income tax expense (benefit)				7,649	13,701
Ending Balance		(15,302)	27,967	(15,302)	27,967
HTM Securities Transferred from AFS [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(14,392)	(16,795)
Amortization of unrealized net loss on securities transferred to HTM				2,726	2,736
Income tax expense (benefit)				1,012	1,029
Ending Balance		(12,678)	(15,088)	(12,678)	(15,088)
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(72,501)	(67,890)
Reclassification of net (gain) loss realized and included in earnings				4,144	4,395
Valuation adjustment for pension plan amendment	[1]			17,315
Valuation adjustment for employee benefit plans				(9,185)	(6,347)
Income tax expense (benefit)				4,416	(714)
Ending Balance		(64,643)	(69,128)	(64,643)	(69,128)
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				(4,960)	(178)
Net change in unrealized gain (loss)				(1,232)	1,162
Reclassification of net (gain) loss realized and included in earnings				335
Income tax expense (benefit)				(329)	424
Ending Balance		$ (5,528)	$ 560	(5,528)	560
Amount Reclassified from Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Valuation adjustment for pension plan amendment	[2],[3]			$ (4,144)	$ (4,395)
[1]	For further discussion of the pension plan amendment, see Note 11 - Retirement Plans.
[2]	Amounts in parenthesis indicate reduction in net income.
[3]	These AOCI components are included in the computation of net periodic pension and post-retirement cost that is reported with employee benefits expense (see Note 11 - Retirement Plans for additional details).

Stockholders' Equity (Line Item

Stockholders' Equity (Line Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items	[1]	$ 17,315
Employee Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items	[1]	17,315
Amount Reclassified from Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications, net of tax	[2]	(4,579)	$ (3,631)
Amount Reclassified from Accumulated Other Comprehensive Income [Member] | Available for Sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of AFS securities	[2]		1,435
Tax effect	[2]		(502)
Net of tax	[2]		933
Amount Reclassified from Accumulated Other Comprehensive Income [Member] | HTM Securities Transferred from AFS [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of unrealized net loss on securities transferred to HTM	[2]	(2,726)	(2,736)
Tax effect	[2]	1,012	1,029
Net of tax	[2]	(1,714)	(1,707)
Amount Reclassified from Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items	[2],[3]	(4,144)	(4,395)
Tax effect	[2]	1,491	1,538
Net of tax	[2]	(2,653)	$ (2,857)
Amount Reclassified from Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of loss on terminated cash flash hedges	[2]	(335)
Tax effect	[2]	123
Net of tax	[2]	$ (212)
[1]	For further discussion of the pension plan amendment, see Note 11 - Retirement Plans.
[2]	Amounts in parenthesis indicate reduction in net income.
[3]	These AOCI components are included in the computation of net periodic pension and post-retirement cost that is reported with employee benefits expense (see Note 11 - Retirement Plans for additional details).

Other Noninterest Income (Detai

Other Noninterest Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Noninterest Income [Abstract]
Income from bank-owned life insurance	$ 3,097	$ 4,097	$ 8,632	$ 11,148
Credit related fees	2,521	2,685	8,297	7,309
Derivative income	1,339	1,347	4,484	1,741
Net gain on sale of assets	400	991	4,465	4,557
Safety deposit box income	424	424	1,264	1,315
Other miscellaneous	3,371	2,322	9,759	6,698
Total other noninterest income	$ 11,152	$ 11,866	$ 36,901	$ 32,768

Other Noninterest Expense (Deta

Other Noninterest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Noninterest Expense [Abstract]
Advertising	$ 3,910	$ 2,859	$ 11,971	$ 7,909
Ad valorem and franchise taxes	3,387	2,268	9,942	6,911
Printing and supplies	1,421	1,134	3,929	3,310
Insurance expense	671	803	2,295	2,467
Travel expense	1,226	1,022	3,635	3,050
Entertainment and contributions	2,322	1,686	6,087	5,319
Tax credit investment amortization	1,212	861	3,637	4,437
Loss share termination			6,603
Other miscellaneous	7,611	11,746	19,958	22,158
Total other noninterest expense	$ 21,760	$ 22,379	$ 68,057	$ 55,561

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Weighted-average anti-dilutive potential common shares	1,380	317,893	11,057	578,863

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income to common shareholders	$ 58,902	$ 46,719	$ 160,183	$ 97,465
Net income allocated to participating securities - basic and diluted	1,244	1,101	3,566	2,334
Net income allocated to common shareholders - basic and diluted	$ 57,658	$ 45,618	$ 156,617	$ 95,131
Weighted-average common shares - basic	84,749	77,550	84,577	77,525
Dilutive potential common shares	231	127	241	128
Weighted-average common shares - diluted	84,980	77,677	84,818	77,653
Earnings per common share: Basic	$ 0.68	$ 0.59	$ 1.85	$ 1.23
Earnings per common share: Diluted	$ 0.68	$ 0.59	$ 1.85	$ 1.23

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details)	3 Months Ended	9 Months Ended
	Jun. 30, 2017USD ($)	Sep. 30, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Contributed to pension plan		$ 0
Estimated contribution in the current year		$ 0
Amended Hancock Pension Plan And 401K Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension assets	$ 537,600,000
Benefit obligation	476,900,000
Benefit obligation decreased	$ (17,300,000)
Amended Hancock 401K Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Period of employment for eligibility		3 years
Additional matching percentage	2
2% Of Contribution [Member] | Amended Hancock 401K Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage	2.00%
4% Of Contribution [Member] | Amended Hancock 401K Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage	4.00%
6% Of Contribution [Member] | Amended Hancock 401K Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching percentage	6.00%

Retirement Plans (Components of

Retirement Plans (Components of Net Periodic Benefits Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,769	$ 3,611	$ 11,612	$ 10,487
Interest cost	4,056	4,022	12,470	13,033
Expected return on plan assets	(9,652)	(8,554)	(27,978)	(25,999)
Amortization of net loss and prior service costs	1,167	1,426	4,368	4,320
Net periodic benefit cost (reduction of cost)	(660)	505	472	1,841
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	17	45	112	119
Interest cost	155	204	514	613
Amortization of net loss and prior service costs	(128)	53	(224)	75
Net periodic benefit cost (reduction of cost)	$ 44	$ 302	$ 402	$ 807

Share-Based Payment Arrangeme68

Share-Based Payment Arrangements (Narrative) (Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)entity$ / sharesshares	Sep. 30, 2016USD ($)
Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised | $	$ 4.1
Restricted and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense | $	$ 40.1
Weighted-average period	3 years
Total fair value of shares vested | $	$ 10.1	$ 2.2
Shares granted | shares	63,127
Grant date fair value per share | $ / shares	$ 42.16
Executive Management [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	3 years
Executive Management [Member] | Performance Shares [Member] | Total Shareholder Return [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted | shares	23,489
Grant date fair value per share | $ / shares	$ 42.92
Vesting performance period	3 years
Number of peer group regional banks | entity	44
Executive Management [Member] | Performance Shares [Member] | Core Earnings Per Share [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted | shares	23,489
Grant date fair value per share | $ / shares	$ 38.26
Vesting performance period	2 years
Executive Management [Member] | Tranche One [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of maximum number of shares vested	200.00%

Share-Based Payment Arrangeme69

Share-Based Payment Arrangements (Summary of Option Activity) (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate Intrinsic Value, Outstanding at Beginning | $	$ 3,734
Aggregate Intrinsic Value, Exercised/Released | $	4,111
Aggregate Intrinsic Value, Cancelled/Forfeited | $	$ 6
Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding at Beginning | shares	456,258
Number of Shares, Exercised/Released | shares	(335,758)
Number of Shares, Cancelled/Forfeited | shares	(538)
Number of Shares, Expired | shares	(16,675)
Number of Shares, Outstanding at Ending | shares	103,287
Number of Shares, Exercisable at Ending | shares	103,287
Weighted Average Exercise Price, Outstanding at Beginning | $ / shares	$ 35.91
Weighted Average Exercise Price, Exercised/Released | $ / shares	34.58
Weighted Average Exercise Price, Cancelled/Forfeited | $ / shares	32.09
Weighted Average Exercise Price, Expired | $ / shares	68.18
Weighted Average Exercise Price, Outstanding at Ending | $ / shares	35.06
Weighted Average Exercise Price, Exercisable at Ending | $ / shares	$ 35.06
Weighted Average Remaining Contractual Term (Years), Outstanding at Ending	2 years 11 months 1 day
Weighted Average Remaining Contractual Term (Years), Exercisable at Ending	2 years 11 months 1 day
Aggregate Intrinsic Value, Outstanding at Ending | $	$ 1,383
Aggregate Intrinsic Value, Exercisable at Ending | $	$ 1,383

Share-Based Payment Arrangeme70

Share-Based Payment Arrangements (Summary of Nonvested Restricted and Performance Shares) (Details) - Restricted and Performance Shares [Member]	9 Months Ended
	Sep. 30, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Nonvested at Beginning | shares	2,152,119
Number of Shares, Granted | shares	63,127
Number of Shares, Vested | shares	(209,440)
Number of Shares, Forfeited | shares	(54,493)
Number of Shares, Nonvested at Ending | shares	1,951,313
Weighted Average Grant Date Fair Value, Nonvested at Beginning | $ / shares	$ 32.15
Weighted Average Grant Date Fair Value, Granted | $ / shares	42.16
Weighted Average Grant Date Fair Value, Vested | $ / shares	30.23
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	32.36
Weighted Average Grant Date Fair Value, Nonvested at Ending | $ / shares	$ 32.67

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - Recurring [Member]	9 Months Ended
	Sep. 30, 2017USD ($)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Transfers of assets and liabilities between level 1, 2, 3	$ 0
Investment Securities [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Targeted duration	2 years
Investment Securities [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Targeted duration	5 years

Fair Value (Financial Assets an

Fair Value (Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		$ 2,855,278	$ 2,516,908
Derivative assets		1,329	4,788
Derivative liabilities		5,567	26,846
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		2,855,278	2,516,908
Derivative assets	[1]	17,199	20,315
Total recurring fair value measurements - assets		2,872,477	2,537,223
Derivative liabilities	[1]	12,691	27,432
Total recurring fair value measurements - liabilities		12,691	27,432
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		2,855,278	2,516,908
Derivative assets	[1]	17,199	20,315
Total recurring fair value measurements - assets		2,872,477	2,537,223
Derivative liabilities	[1]	12,691	27,432
Total recurring fair value measurements - liabilities		12,691	27,432
Recurring [Member] | U.S. Treasury And Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		73,442	54,828
Recurring [Member] | U.S. Treasury And Government Agency Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		73,442	54,828
Recurring [Member] | Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		242,678	242,155
Recurring [Member] | Municipal Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		242,678	242,155
Recurring [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		3,500	3,500
Recurring [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		3,500	3,500
Recurring [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		1,793,426	1,611,355
Recurring [Member] | Residential Mortgage-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		1,793,426	1,611,355
Recurring [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		568,353	402,591
Recurring [Member] | Commercial Mortgage-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		568,353	402,591
Recurring [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		173,879	202,479
Recurring [Member] | Collateralized Mortgage Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		$ 173,879	$ 202,479
[1]	For further disaggregation of derivative assets and liabilities, see Note 6 - Derivatives.

Fair Value (Financial Assets Me

Fair Value (Financial Assets Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral-dependent impaired loans	$ 129,230	$ 169,888
Other real estate owned	6,810	13,968
Total nonrecurring fair value measurements	136,040	183,856
Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral-dependent impaired loans
Other real estate owned
Total nonrecurring fair value measurements
Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral-dependent impaired loans	129,230	169,888
Total nonrecurring fair value measurements	129,230	169,888
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	6,810	13,968
Total nonrecurring fair value measurements	$ 6,810	$ 13,968

Fair Value (Estimated Fair Valu

Fair Value (Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	$ 2,855,278	$ 2,516,908
Held to maturity securities	2,769,274	2,500,220
Loans, net	18,786,285	16,752,151	$ 16,070,821
Derivative financial instruments	1,329	4,788
Derivative financial instruments	5,567	26,846
Total Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	445,500	450,866
Available for sale debt securities	2,855,278	2,516,908
Held to maturity securities	2,768,148	2,470,117
Loans, net	18,429,977	16,496,849
Loans held for sale	23,236	34,064
Derivative financial instruments	17,199	20,315
Deposits	21,523,649	19,430,939
Federal funds purchased	1,150	2,275
Securities sold under agreements to repurchase	512,001	358,131
FHLB short-term borrowings	1,224,000	865,000
Long-term debt	330,909	435,747
Derivative financial instruments	12,691	27,432
Total Fair Value [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	445,500	450,866
Federal funds purchased	1,150	2,275
Securities sold under agreements to repurchase	512,001	358,131
FHLB short-term borrowings	1,224,000	865,000
Total Fair Value [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	2,855,278	2,516,908
Held to maturity securities	2,768,148	2,470,117
Loans, net	129,230	169,888
Loans held for sale	23,236	34,064
Derivative financial instruments	17,199	20,315
Long-term debt	330,909	435,747
Derivative financial instruments	12,691	27,432
Total Fair Value [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	18,300,747	16,326,961
Deposits	21,523,649	19,430,939
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	445,500	450,866
Available for sale debt securities	2,855,278	2,516,908
Held to maturity securities	2,769,274	2,500,220
Loans, net	18,563,163	16,522,733
Loans held for sale	23,236	34,064
Derivative financial instruments	17,199	20,315
Deposits	21,533,859	19,424,266
Federal funds purchased	1,150	2,275
Securities sold under agreements to repurchase	512,001	358,131
FHLB short-term borrowings	1,224,000	865,000
Long-term debt	331,179	436,280
Derivative financial instruments	$ 12,691	$ 27,432

Recent Accounting Pronounceme75

Recent Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Recent Accounting Pronouncements [Abstract]
Possible income tax expense reduction	$ 0.2	$ 2