Hancock Whitney Corporation - 6 (HWC) 10-K 27 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 20, 2015	Jan. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	HBHC
Entity Registrant Name	HANCOCK HOLDING CO
Entity Central Index Key	750577
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding			80,436,669
Entity Public Float		$2.90

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets:
Cash and due from banks	$356,455	$348,440
Interest-bearing bank deposits	801,576	267,236
Federal funds sold	1,372	1,604
Securities available for sale, at fair value (amortized cost of $1,631,761 and $1,408,780)	1,660,165	1,421,772
Securities held to maturity (fair value of $2,186,340 and $2,576,584)	2,166,289	2,611,352
Loans held for sale	20,252	24,515
Loans	13,895,276	12,324,817
Less: allowance for loan losses	-128,762	-133,626
Loans, net	13,766,514	12,191,191
Property and equipment, net of accumulated depreciation of $193,527 and $172,798	398,384	432,346
Prepaid expense	28,277	65,220
Other real estate, net	58,415	76,668
Accrued interest receivable	47,501	42,977
Goodwill	621,193	625,675
Other intangible assets, net	132,810	159,773
Life insurance contracts	426,617	381,437
FDIC loss share receivable	60,272	113,834
Deferred tax asset, net	74,335	89,708
Other assets	126,839	155,503
Total assets	20,747,266	19,009,251
Deposits:
Noninterest-bearing demand	5,945,208	5,530,253
Interest-bearing savings, NOW, money market and time	10,627,623	9,830,263
Total deposits	16,572,831	15,360,516
Short-term borrowings	1,151,573	657,960
Long-term debt	374,371	385,826
Accrued interest payable	4,204	4,353
Other liabilities	171,885	175,527
Total liabilities	18,274,864	16,584,182
Stockholders' equity:
Common stock-$3.33 par value per share; 350,000,000 shares authorized, 80,426,485 and 82,237,162 outstanding, respectively	267,820	273,850
Capital surplus	1,689,291	1,647,467
Treasury shares at cost-7,053,028 and 5,160,509 shares, respectively	-158,131	-89,035
Retained earnings	723,496	628,166
Accumulated other comprehensive (loss), net	-50,074	-35,379
Total stockholders' equity	2,472,402	2,425,069
Total liabilities and stockholders' equity	$20,747,266	$19,009,251

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$1,631,761	$1,408,780
Held to maturity securities	2,186,340	2,576,584
Property and equipment, accumulated depreciation	$193,527	$172,798
Common stock, par value per share	$3.33	$3.33
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares outstanding	80,426,485	82,237,162
Treasury shares, shares	7,053,028	5,160,509

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest income:
Loans, including fees	$601,466	$629,882	$667,014
Loans held for sale	708	882	1,373
Securities-taxable	85,806	85,426	86,402
Securities-tax exempt	3,873	4,621	5,841
Federal funds sold and other short- term investments	960	1,399	1,919
Total interest income	692,813	722,210	762,549
Interest expense:
Deposits	23,223	24,175	32,741
Short-term borrowings	2,361	4,542	6,005
Long-term debt and other interest expense	12,535	12,762	12,936
Total interest expense	38,119	41,479	51,682
Net interest income	654,694	680,731	710,867
Provision for loan losses	33,840	32,734	54,192
Net interest income after provision for loan losses	620,854	647,997	656,675
Noninterest income:
Service charges on deposit accounts	77,006	79,000	78,246
Trust fees	44,826	38,186	32,736
Bank card and ATM fees	45,031	45,939	49,112
Investment and annuity fees	20,291	19,574	18,033
Secondary mortgage market operations	8,036	12,543	16,488
Insurance commissions and fees	9,473	15,804	15,692
(Amortization) accretion of loss share receivable	-12,102	-2,239	5,000
Other income	35,438	37,231	36,888
Securities gains, net		105	1,552
Total noninterest income	227,999	246,143	253,747
Noninterest expense:
Compensation expense	276,881	291,225	293,783
Employee benefits	51,415	65,257	72,401
Personnel expense	328,296	356,482	366,184
Net occupancy expense	43,596	48,854	54,467
Equipment expense	16,953	20,026	24,097
Data processing expense	51,369	48,367	49,935
Professional services expense	33,221	39,357	57,457
Amortization of intangibles	26,797	29,470	32,067
Telecommunications and postage	14,676	17,432	21,437
Deposit insurance and regulatory fees	11,872	14,914	14,902
Other real estate expense, net	2,758	8,036	12,250
Other expense	77,128	95,336	80,271
Total noninterest expense	606,666	678,274	713,067
Income before income taxes	242,187	215,866	197,355
Income taxes	66,465	52,510	45,613
Net income	$175,722	$163,356	$151,742
Basic earnings per common share	$2.10	$1.93	$1.77
Diluted earnings per common share	$2.10	$1.93	$1.75

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$175,722	$163,356	$151,742
Other comprehensive income before income taxes
Net change in unrealized (loss) gain	-26,311	-22,772	8,140
Reclassification adjustment for net losses realized and included in earnings	390	8,527	6,418
Accretion (amortization) of unrealized net gain (loss) on securities transferred to held to maturity	3,297	-6,371	-8,752
Other comprehensive (loss) income before income taxes	-22,624	-20,616	5,806
Income tax (benefit) expense	-7,929	-8,162	2,221
Other comprehensive (loss) income net of income taxes	-14,695	-12,454	3,585
Comprehensive income	$161,027	$150,902	$155,327

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]
In Thousands, except Share data
Balance at Dec. 31, 2011	$2,367,163	$282,069	$1,679,818	$476,970	($26,510)	($45,184)
Balance, Shares at Dec. 31, 2011		84,705,496
Net income	151,742			151,742
Other comprehensive income	3,585				3,585
Cash dividends declared ($0.96 per common share)	-82,690			-82,690
Common stock activity, long-term incentive plan	13,478	474	-11,301			24,305
Common stock activity, long-term incentive plan, shares		142,300
Balance at Dec. 31, 2012	2,453,278	282,543	1,668,517	546,022	-22,925	-20,879
Balance, Shares at Dec. 31, 2012		84,847,796
Net income	163,356			163,356
Other comprehensive income	-12,454				-12,454
Cash dividends declared ($0.96 per common share)	-81,212			-81,212
Common stock activity, long-term incentive plan	17,101	690	-21,050			37,461
Common stock activity, long-term incentive plan, shares		207,006
Purchase of common stock	-115,000	-9,383				-105,617
Purchase of common stock, shares		-2,817,640
Balance at Dec. 31, 2013	2,425,069	273,850	1,647,467	628,166	-35,379	-89,035
Balance, Shares at Dec. 31, 2013		82,237,162
Net income	175,722			175,722
Other comprehensive income	-14,695				-14,695
Cash dividends declared ($0.96 per common share)	-80,392			-80,392
Common stock activity, long-term incentive plan	14,316	1,029	41,824			-28,537
Common stock activity, long-term incentive plan, shares		309,087
Purchase of common stock	-47,618	-7,059				-40,559
Purchase of common stock, shares		-2,119,764
Balance at Dec. 31, 2014	$2,472,402	$267,820	$1,689,291	$723,496	($50,074)	($158,131)
Balance, Shares at Dec. 31, 2014		80,426,485

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash dividends declared, per common share	$0.96	$0.96	$0.96
Retained Earnings [Member]
Cash dividends declared, per common share	$0.96	$0.96	$0.96

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$175,722	$163,356	$151,742
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	30,310	32,063	32,856
Provision for loan losses	33,840	32,734	54,192
(Gain) loss on other real estate owned	-105	4,329	8,353
Deferred tax expense	23,537	40,920	32,465
Increase in cash surrender value of life insurance contracts	-11,774	-11,223	-12,807
Gain on sales of securities, net		-105	-1,552
Writedowns on closed branch transfers to other real estate owned	2,132	12,809	4,586
(Gain) loss on disposal of other assets	-1,282	235	51
Net decrease in loans held for sale	18,234	29,103	21,991
Net amortization of securities premium/discount	16,977	31,970	49,887
Amortization of intangible assets	26,798	29,635	32,067
Amortization (accretion) of FDIC loss share receivable	12,102	2,239	-5,000
Stock-based compensation expense	13,958	13,079	11,019
(Decrease) increase in interest payable and other liabilities	-15,235	29,553	-58,289
Net payments from FDIC	14,395	61,765	114,976
Decrease (increase) in FDIC loss share receivable	5,723	-9,117	-45,284
Decrease (increase) in other assets	11,082	-724	52,155
Other, net	-3,986	10,911	-376
Net cash provided by operating activities	352,428	473,532	443,032
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of securities available for sale	1,455	178	48,336
Proceeds from maturities of securities available for sale	283,982	592,147	1,081,193
Purchases of securities available for sale	-512,088	-1,074,744	-285,825
Proceeds from maturities of securities held to maturity	442,559	503,654	432,331
Purchases of securities held to maturity	-1,031	-481,513	-560,324
Net (increase) decrease in interest-bearing bank deposits	-534,340	1,231,749	-314,763
Net decrease (increase) in federal funds sold and short-term investments	232	-401	-1,006
Net increase in loans	-1,622,867	-834,933	-507,530
Purchase of life insurance contracts	-30,000
Purchases of property, equipment and intangible assets	-20,449	-32,029	-42,979
Proceeds from sales of property and equipment	12,235	1,698	6,270
Proceeds from sales of other real estate	59,752	92,662	120,083
Net cash paid for divestiture of branches	0	0	0
Other, net	10,101	-2,965	6,481
Net cash (used in) investing activities	-1,910,459	-4,497	-17,733
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in deposits	1,212,315	-383,672	30,609
Net increase (decrease) in short-term borrowings	493,613	18,827	-405,321
Repayments of long-term debt	-35,360	-35,278	-192,087
Issuance of long-term debt	21,000	24,515	232,720
Dividends paid	-80,392	-81,212	-82,690
Repurchase of common stock	-47,618	-115,000
Proceeds from exercise of stock options	2,488	2,734	2,014
Net cash provided by (used by) financing activities	1,566,046	-569,086	-414,755
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	8,015	-100,051	10,544
CASH AND DUE FROM BANKS, BEGINNING	348,440	448,491	437,947
CASH AND DUE FROM BANKS, ENDING	356,455	348,440	448,491
SUPPLEMENTAL INFORMATION
Income taxes paid (refunded)	24,114	24,052	-24,237
Interest paid	38,268	41,996	57,370
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	31,371	51,461	76,128
Transfers from available for sale securities to held to maturity securities		$1,039,979	$1,523,585

Summary_of_Significant_Account

Summary of Significant Accounting Policies and Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Recent Accounting Pronouncements	Note 1. Summary of Significant Accounting Policies and Recent Accounting Pronouncements
	DESCRIPTION OF BUSINESS
	Hancock Holding Company (which we refer to as Hancock or the Company) is a financial services company that provides a comprehensive network of full-service financial choices to the Gulf South region through its bank subsidiary, Whitney Bank, a Mississippi state bank. Whitney Bank operates under brands: “Hancock Bank” in Mississippi, Alabama and Florida and “Whitney Bank” in Louisiana and Texas. Hancock was organized in 1984 as a bank holding company registered under the Bank Holding Company Act of 1956, as amended. In 2002, the Company qualified as a financial holding company giving it broader powers. The corporate headquarters of the Company is in Gulfport, Mississippi. Prior to March 31, 2014, Hancock was the parent company of two wholly-owned bank subsidiaries, Hancock Bank and Whitney Bank. On March 31, 2014, Hancock consolidated the legal charters of its two subsidiary banks and renamed the consolidated entity Whitney Bank. Hancock Bank, Whitney Bank, and the recently consolidated Whitney Bank are referred to collectively as the “Bank” throughout this document.
	The Bank offers a broad range of traditional and online community banking services to commercial, small business and retail customers, providing a variety of transaction and savings deposit products, treasury management services, investment brokerage services, secured and unsecured loan products, (including revolving credit facilities), and letters of credit and similar financial guarantees. The Bank also provides trust and investment management services to retirement plans, corporations and individuals.
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the U.S. (U.S. GAAP) and those generally practiced within the banking industry. The following is a summary of the more significant accounting policies.
	Basis of Presentation
	The consolidated financial statements include the accounts of the Company and all other entities in which the Company has a controlling interest. Significant inter-company transactions and balances have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation.
	Use of Estimates
	The accounting principles the Company follows and the methods for applying these principles conform with U.S. GAAP and with general practices followed by the banking industry. These accounting principles and practices 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.
	Fair Value Accounting
	U.S. GAAP requires the use of fair values in determining the carrying values of certain assets and liabilities in the financial statements, as well as for specific disclosures about certain assets and liabilities.
	Accounting guidance established 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 (level 1) and the lowest priority to unobservable inputs such as a reporting entity’s own data or information or assumptions developed from this 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.
	Acquisition Accounting
	Acquisitions are accounted for under the purchase method of accounting. Purchased assets, including identifiable intangibles, and assumed liabilities are recorded at their respective acquisition date fair values. If the fair value of net assets purchased exceeds the consideration given, a bargain purchase gain is recognized. If the consideration given exceeds the fair value of the net assets received, goodwill is recognized. Fair values are subject to refinement for up to one year after the closing date of an acquisition as information relative to closing date fair values becomes available. Purchased loans acquired in a business combination are recorded at estimated fair value on their purchase date with no carryover of the related allowance for loan losses. See the Acquired Loans section below for accounting policy regarding loans acquired in a business combination.
	All identifiable intangible assets that are acquired in a business combination are recognized at fair value on the acquisition date. Identifiable intangible assets are recognized separately if they arise from contractual or other legal rights or if they are separable (i.e., capable of being sold, transferred, licensed, rented, or exchanged separately from the entity).
	Securities
	Securities are classified as trading, held to maturity or available for sale. Management determines the appropriate classification of debt and equity securities at the time of purchase and re-evaluates this classification periodically as conditions change that could require reclassification.
	Available for sale securities are stated at fair value. Unrealized holding gains and unrealized holding losses, other than those determined to be other than temporary, are reported net of tax in other comprehensive income and in accumulated other comprehensive income until realized.
	Securities that the Company both positively intends and has the ability to hold to maturity are classified as securities held to maturity and are carried at amortized cost. The intent and ability to hold are not considered satisfied when a security is available to be sold in response to changes in interest rates, prepayment rates, liquidity needs or other reasons as part of an overall asset/liability management strategy.
	Premiums and discounts on securities, both those held to maturity and those available for sale, are amortized and accreted to income as an adjustment to the securities’ yields using the effective interest method. Realized gains and losses on securities, including declines in value judged to be other than temporary, are reported net as a component of noninterest income. The cost of securities sold is specifically identified for use in calculating realized gains and losses.
	Loans
	Originated loans
	Loans reported as “originated” include both loans originated for investment and acquired-performing loans where the discount (premium) has been fully accreted (amortized). Originated loans are reported at the principal balance outstanding net of unearned income. Interest on loans and accretion of unearned income, including deferred loan fees, are computed in a manner that approximates a level yield on recorded principal. Interest on loans is recognized in income as earned.
	The accrual of interest on an originated loan is discontinued when, in management’s opinion, it is probable that the borrower will be unable to meet payment obligations as they become due, as well as when required by regulatory provisions. When accrual of interest is discontinued on a loan, all unpaid accrued interest is reversed and payments subsequently received are applied first to recover principal. Interest income is recognized for payments received after contractual principal has been satisfied. Loans are returned to accrual status when all the principal and interest contractually due are brought current and future payment performance is reasonably assured.
	Acquired loans
	Loans reported as “acquired” are those loans that were purchased in the 2011 Whitney Holding Corporation acquisition. These loans were recorded at estimated fair value at the acquisition date with no carryover of the related allowance for loan losses. The Whitney acquired loans were segregated between those considered to be performing (“acquired-performing”) and those with evidence of credit deterioration (“acquired-impaired”) based on such factors as past due status, nonaccrual status and credit risk ratings (rated substandard or worse). The acquired loans were further segregated into loan pools designed to facilitate the development of expected cash flows to be used in estimating fair value to facilitate purchase accounting. Acquired-performing loans are accounted for under ASC 310-20 and acquired-impaired loans are accounted for under ASC 310-30.
	Acquired-performing loans were segregated into pools based on common risk characteristics such as loan type, credit risk ratings, and contractual interest rate and repayment terms. The major loan types included commercial and industrial loans not secured by real estate, real estate construction and land development loans, commercial real estate loans, residential mortgage loans, and consumer loans, with further segregation within certain loan types as needed. Expected cash flows, both principal and interest, from each pool were estimated based on key assumptions covering such factors as prepayments, default rates, and severity of loss given a default. These assumptions were developed using both historical experience and the portfolio characteristics at acquisition as well as available market research. The fair value estimate for each acquired-performing pool was based on the estimate of expected cash flows from the pool discounted at prevailing market rates.
	The difference at the acquisition date between the fair value and the contractual amounts due of an acquired-performing loan pool (the “fair value discount”) is accreted into income over the estimated life of the pool. Acquired-performing loans are placed on nonaccrual status and reported as nonperforming or past due using the same criteria applied to the originated portfolio.
	The acquired-impaired loans were segregated into pools by identifying loans with common credit risk profiles and were based primarily on characteristics such as loan type and market area in which originated. The major loan types included commercial and industrial loans not secured by real estate, real estate construction and land development loans, commercial real estate loans, and residential mortgage loans, with further segregation within certain loan types as needed. The acquired-impaired loans were further disaggregated by geographic region in recognition of the differences in general economic conditions affecting borrowers in certain states. The fair value estimate for each pool of acquired-impaired loans was based on the estimate of expected cash flows from the pool discounted at prevailing market rates.
	The excess of estimated cash flows expected to be collected from an acquired-impaired loan pool over the pool’s carrying value is referred to as the accretable yield and is recognized in interest income using an effective yield method over the expected life of the loan pool. Each pool of acquired-impaired loans is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. Acquired-impaired loans in pools with an accretable yield and expected cash flows that are reasonably estimable are considered to be accruing and performing even though collection of contractual payments on loans within the pool may be in doubt, because the pool is the unit of accounting. Acquired-impaired loans are generally not subject to individual evaluation for impairment and are not reported with impaired loans or troubled debt restructurings even if they would otherwise qualify for such treatment.
	FDIC acquired loans and the related loss share receivable
	Loans reported as “FDIC acquired” are loans purchased in the 2009 acquisition of Peoples First Community Bank (Peoples First) that were covered by two loss share agreements between the FDIC and the Company. These loans are accounted for as acquired-impaired loans as described above in the section on acquired loans. The Company treated all loans for the Peoples First acquisition as impaired based on the significant amount of deteriorating and nonperforming loans comprised mainly of adjustable rate mortgages and home equity loans located in Florida. The loss share receivable is measured separately from the related covered loans as it is not contractually embedded in the loans and is not transferrable should the loans be sold. The fair value of the loss share receivable at acquisition was estimated by discounting expected reimbursements for losses from the loans covered by the loss share agreements, including appropriate consideration of possible true-up payments to the FDIC at the expiration of the agreements.
	The loss share receivable is reviewed and updated prospectively as loss estimates related to covered loan pools change. Increases in expected reimbursements under the loss sharing agreement will lead to an increase in the loss share receivable. A decrease in expected reimbursements is reflected first as a reversal of any previously recorded increase in the loss share receivable on the covered loan pool with the remainder reflected as a reduction in the loss share receivable’s accretion rate. Increases and decreases in the loss share receivable related to changes in loss estimates result in reductions in or additions to the provision for loan losses, which serves to offset the impact on the provision from impairments or impairment reversals recognized on the underlying covered loan pool. The excess (or shortfall) of expected claims as compared to the carrying value of the loss share receivable is accreted (amortized) into noninterest income over the shorter of the remaining life of the covered loan pool or the life of the loss share agreement. The impact on operations of a reduction in the loss share receivable’s accretion rate is associated with an increase in the accretable yield on the underlying loan pool. The loss share receivable is reduced as cash is received from the FDIC related to losses incurred on covered assets.
	Loans Held for Sale
	Residential mortgage loans originated for sale are classified as loans held for sale and carried at the lower of cost or market. Forward sales commitments on a best-efforts basis are entered into with third parties concurrently with rate lock commitments made to prospective borrowers. At times, management may decide to sell loans that were not originated for that purpose. Those loans are reclassified as held for sale when that decision is made and also carried at the lower of cost or market.
	Troubled Debt Restructurings
	Troubled debt restructurings (TDRs) occur when a borrower is experiencing, or is expected to experience, financial difficulties in the near-term and a modification in loan terms is granted that would otherwise not have been considered.
	Troubled debt restructurings can result in loans remaining on nonaccrual, moving to nonaccrual, or continuing to accrue, depending on the individual facts and circumstances of the borrower. All loans whose terms have been modified in a TDR, including both commercial and retail loans, are initially considered “impaired.” When measuring impairment on a TDR, the loan’s value is determined by either the present value of expected cash flows calculated using the loan’s effective interest rate before the restructuring, or the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. If the value as determined is less than the recorded investment in the loan, the difference is charged-off through the allowance for loan and lease losses. Modified acquired-impaired loans are not removed from their accounting pool and accounted for as a TDR even if those loans would otherwise be deemed TDRs.
	Allowance for Loan Losses
	Originated loans
	The ALLL is a valuation account available to absorb losses on loans. The ALLL is established and maintained at an amount sufficient to cover estimated credit losses inherent in the loan and lease portfolios of the Company as of the date of the determination. Credit losses arise not only from credit risk, but also from other risks inherent in the lending process including, but not limited to, collateral risk, operational risk, concentration risk, and economic risk. As such, all related risks of lending are considered when assessing the adequacy of the allowance for loan and lease losses. Quarterly, management estimates inherent losses in the portfolio based on a number of factors, including the Company’s past loan loss and delinquency experience, known and inherent risks in the portfolio, adverse situations that may affect the borrowers’ ability to repay, the estimated value of any underlying collateral and current economic conditions.
	The analysis and methodology for estimating the ALLL include two primary elements. A loss rate analysis which incorporates a historical loss rate as updated for current conditions is used for loans collectively evaluated for impairment, and a specific reserve analysis is used for loans individually evaluated for impairment. For the loss rate analysis, the Company segments loans into commercial non-real estate, construction and land development, commercial real estate, residential mortgage and consumer. Both quantitative and qualitative factors are applied at the detailed portfolio segments. Commercial loans (commercial non-real estate, construction and land development, and commercial real estate) are further subdivided by risk rating, while retail loans (residential mortgage and consumer) are further subdivided by delinquency. The Company uses loss emergence periods developed based on historical experience, which is currently eighteen-months for commercial loans and twelve-months for retail loans. Historical loss rates are calculated using a weighted average of the most recent three loss emergence periods. As circumstances dictate, management will make adjustments to the overall loss rate to reflect differences in current conditions as compared to those during the historical loss period. Conditions to be considered include problem loan trends, current business and economic conditions, credit concentrations, lending policies and procedures, lending staff, collateral values, loan profiles and volumes, loan review quality, and changes in competition and regulations.
	The Company considers a loan to be impaired when, based upon current information and events, it believes it is probable all amounts due according to the contractual terms of the loan agreement will not be collected. A loan is not considered impaired due to a delay in payment if all amounts due, including interest accrued at the contractual interest rate for the period of delay, is expected to be collected. Impaired loans include troubled debt restructurings, and performing and nonperforming loans. When a loan is determined to be impaired, the amount of impairment is recognized by creating a specific allowance for any shortfall between the loan’s value and its recorded investment. The loan’s value is measured by either the loan’s observable market price, the fair value of the collateral of the loan (less liquidation costs) if it is collateral dependent, or by the present value of expected future cash flows discounted at the loan’s effective interest rate. Any loans individually analyzed for impairment are not incorporated into the pool analysis to avoid double counting. The Company limits the specific reserve analysis to include all impaired commercial, commercial real estate and mortgage loans with balances of $1 million or greater and all loans classified as troubled debt restructurings.
	It is the policy of the Company to promptly charge off all commercial and residential mortgage loans, or portions of loans, when available information reasonably confirms that they are wholly or partially uncollectible. Prior to recognizing a loss, asset value is established based on an assessment of the value of the collateral securing the loan, the borrower’s and the guarantor’s ability and willingness to pay and the status of the account in bankruptcy court, if applicable. Consumer loans are generally charged down when the loan is 90 days past due for unsecured loans or 120 days past due for secured loans, unless the loan is clearly both well secured and in the process of collection. Loans are charged down to the fair value of the collateral, if any, less estimated selling costs. Loans are charged off against the allowance for loan losses with subsequent recoveries added back to the allowance.
	Acquired and FDIC acquired loans
	Allowance for acquired-performing loans is evaluated at each reporting date subsequent to acquisition. An allowance is determined for each loan pool using a methodology similar to that described above for originated loans and then compared to the remaining fair value discount for that pool. If the allowance is greater than the discount, the excess is recognized as an addition to the allowance through a provision for loan losses. If the allowance is less than the discount, no additional allowance is recognized.
	For acquired-impaired, including those acquired in the FDIC-assisted transaction, estimated cash flows expected to be collected are recast at each reporting date for each loan pool. These evaluations require the continued use and updating of key assumptions and estimates such as default rates, loss severity given default and prepayment speed assumptions, similar to those used for the initial fair value estimate. Management judgment must be applied in developing these assumptions. If the present value of expected cash flows for a pool is less than its carrying value, impairment is recognized by an increase in the allowance for loan losses and a charge to the provision for loan losses. If the present value of expected cash flows for a pool is greater than its carrying value, any previously established allowance for loan losses is reversed and any remaining difference increases the accretable yield which will be taken into interest income over the remaining life of the loan pool. Acquired-impaired loans are generally not subject to individual evaluation for impairment and are not reported with impaired loans or troubled debt restructurings, even if they would otherwise qualify for such treatment.
	Property and Equipment
	Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation is charged to expense over the estimated useful lives of the assets, which are up to 39 years for buildings and three to ten years for furniture and equipment. Amortization expense for software is generally charged over three years, or seven years for core systems. Leasehold improvements are amortized over the terms of the respective leases or the estimated useful lives of the improvements, whichever is shorter.
	Gains and losses related to retirement or disposition of property and equipment are recorded in other income under noninterest income on the consolidated statements of income. The Company continually evaluates whether events and circumstances have occurred that indicate that such long-lived assets have been impaired. Measurement of any impairment of such long-lived assets is based on those assets’ fair values.
	Other Real Estate
	Other real estate owned includes real property that has been acquired in satisfaction of loans and property no longer used in the Bank’s business. These assets are recorded at the estimated fair value less the estimated cost of disposition and carried at the lower of either cost or market. Fair value is based on independent appraisals and other relevant factors. Any initial reduction in the carrying amount of a loan to the fair value of the collateral received less selling costs is charged to the allowance for loan losses. Other real estate is revalued on an annual basis or more often if market conditions necessitate. Subsequent losses on the periodic revaluation of the property are charged to current earnings, as are revenues from and costs of operating and maintaining the properties and gains or losses recognized on their disposition. Improvements made to properties are capitalized if the expenditures are expected to be recovered upon the sale of the properties.
	Goodwill and Other Intangible Assets
	Goodwill, which represents the excess of cost over the fair value of the net assets of an acquired business, is not amortized but tested for impairment on an annual basis, or more often if events or circumstances indicate there may be impairment. Impairment is defined as the amount by which the implied fair value of the goodwill contained in any reporting unit is less than the goodwill’s carrying value. Impairment losses would be charged to operating expense. Management reviews goodwill for impairment by first comparing the estimated fair value of the reporting unit to its carrying value. If the reporting unit’s fair value is less than its carrying value, an estimate of the implied fair value of the unit’s goodwill is compared to its carrying value. The Company uses a present value technique to estimate fair value which incorporates assumptions that market participants would use in their estimates of fair value, such as assumptions about the economic environment, expected net interest margins, growth rates, and the interest rate at which cash flows are discounted.
	Other identifiable intangible assets with finite lives, such as core deposit intangibles and trade name, are initially recorded at fair value and are generally amortized over the periods benefited. These assets are evaluated for impairment similar to long-lived assets.
	Bank-Owned Life Insurance
	Bank-owned life insurance (BOLI) is long-term life insurance on the lives of certain current and past employees where the insurance policy benefits and ownership are retained by the employer. Its cash surrender value is an asset that the Company uses to partially offset the future cost of employee benefits. The cash value accumulation on BOLI is permanently tax deferred if the policy is held to the insured person’s death and certain other conditions are met.
	Derivative Instruments and Hedging Activities
	The Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. Changes in the fair value of derivatives to which hedge accounting does not apply are recognized immediately in earnings, otherwise it is included in other comprehensive income. Note 5 describes the derivative instruments currently used by the Company and discloses how these derivatives impact Hancock’s financial position and results of operations.
	Income Taxes
	Income taxes are accounted for using the asset and liability method. Current tax liabilities or assets are recognized for the estimated income taxes payable or refundable on tax returns to be filed with respect to the current year. Deferred tax assets and liabilities are based on temporary differences between the financial statement carrying amounts and the tax bases of the Company’s assets and liabilities. Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be realized or settled. Valuation allowances are established against deferred tax assets if, based on all available evidence, it is more likely than not that some or all of the assets will not be realized. The benefit of a position taken or expected to be taken in a tax return is recognized when it is more likely than not that the position will be sustained on its technical merits.
	The Company invests in projects that yield tax credits issued under the Qualified Zone Academy Bonds (QZAB), Qualified School Construction Bonds (QSCB), Federal and State New Market Tax Credit (NMTC), and Low-Income Housing Tax Credit (LIHTC) programs. Returns on these investments are generated through the receipt of federal and state tax credits. The tax credits are recorded as a reduction to the income tax provision in the year that they are earned. Tax credits from QZAB and QSCB bonds are generally earned over the life of the bonds in lieu of interest income. Credits on Federal NMTC investments are earned over the 7 year compliance period beginning with the year of investment. Credits on State NMTC investments are generally earned over a 3 to 5 year period depending upon the specific state program. Tax credits are earned over a 10 year period for Low-Income Housing investments beginning with the year in which rental activity begins. These tax credits, if not used in the tax return for the year when the credits are first available for use, can be carried forward for 20 years. For those investments where the return of the principal is not expected, the equity investment is amortized over the life of the tax compliance period as a component of noninterest expense.
	Retirement Benefits
The Company sponsors defined benefit pension plans and certain other defined benefit postretirement plans for eligible employees. The amounts reported in the consolidated financial statements with respect to these plans are based on actuarial valuations that incorporate various assumptions regarding future experience under the plans. Note 11 discusses the actuarial assumptions and provides information about the liabilities or assets recognized for the funded status of the Company’s obligations under these plans, the net benefit expense charged to current operations, and the amounts recognized as a component of other comprehensive income and accumulated other comprehensive income.
Share-Based Payment Arrangements
The grant date fair value of equity instruments awarded to employees and directors establishes the cost of the services received in exchange, and the cost associated with awards that are expected to vest is recognized over the requisite service period.
Revenue Recognition
The largest source of revenue for the Company is interest revenue. Interest revenue is recognized on an accrual basis driven by written contracts, such as loan agreements or securities contracts. Loan origination fees are amortized over the life of the loan. Other credit-related fees, including letter of credit fees, are recognized in noninterest income when earned. The Company recognizes commission revenue and brokerage, exchange and clearance fees on a trade-date basis. Other types of noninterest revenue such as service charges on deposits and trust revenues, are accrued and recognized into income as services are provided and the amount of fees earned can be reasonably determined.
Earnings Per Share
Hancock 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 the common dividends declared and participation rights in undistributed earnings. Participating securities currently consist of unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents.
Basic earnings per common share is computed by dividing income applicable to common shareholders by the weighted-average number of common shares outstanding for the applicable period. Shares outstanding are adjusted for restricted shares issued to employees under the long-term incentive compensation plan and for certain shares that will be issued under the directors’ compensation plan. Diluted earnings per common share is computed using the weighted-average number of common shares outstanding increased by the number of shares in which employees would vest under performance-based stock awards and stock unit awards based on expected performance factors and by the number of additional shares that would have been issued if potentially dilutive stock options were exercised, each as determined using the treasury stock method.
Statements of Cash Flows
The Company considers only cash on hand, cash items in process of collection and balances due from financial institutions as cash and cash equivalents for purposes of the consolidated statements of cash flows.
Reportable Segment Disclosures
Accounting standards require that information be reported about a company’s operating segments using a “management approach.” Reportable segments are identified in these standards as those revenue-producing components for which separate financial information is produced internally and which are subject to evaluation by the chief operating decision maker in deciding how to allocate resources to segments. On March 31, 2014, the Company combined its two state bank charters into one charter. Due to the charter change and consistent with its stated strategy that is focused on providing a consistent package of community banking products and services throughout a coherent market area, the Company has identified its overall banking operations as its only reportable segment. Because the overall banking operations comprise substantially all of the consolidated operations, no separate segment disclosures are presented.
Other
Assets held by the Bank in a fiduciary capacity are not assets of the Bank and are not included in the consolidated balance sheets.
RECENT ACCOUNTING PRONOUNCEMENTS
In August 2014, the FASB issued an Accounting Standard Update (ASU) to address the diversity in practice regarding the classification and measurement of foreclosed loans which were part of a government-sponsored loan guarantee program (e.g. HUD, FHA, VA). The ASU outlines certain criteria that, if met, the loan (residential or commercial) should be derecognized and a separate other receivable should be recorded upon foreclosure at the amount of the loan balance (principal and interest) expected to be recovered from the guarantor. This ASU is effective for annual reporting periods beginning after December 15, 2014, including interim periods within that reporting period. Early adoption is permitted, provided the entity has adopted ASU 2014-04. The guidance is not expected to have a material impact on the Company’s financial condition or results of operations.
In June 2014, the FASB issued an ASU regarding repurchase-to-maturity transactions, repurchase financings, and disclosures. Under the new standard, repurchase-to-maturity transactions will be reported as secured borrowings, and transferors will no longer apply the current “linked” accounting model to repurchase agreements executed contemporaneously with the initial transfer of the underlying financial asset with the same counterparty. Public business entities are generally required to apply the accounting changes and comply with the enhanced disclosure requirements for periods beginning after December 15, 2014 and interim periods beginning after March 15, 2015. A public business entity may not early adopt the standard’s provisions. 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 an ASU regarding revenue from contracts with customers 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. The standard will be effective for the Company for periods beginning after December 15, 2016. The Company is currently assessing this pronouncement and adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.
In January 2014, the FASB issued an ASU on reclassification of residential real estate collateralized consumer mortgage loans upon foreclosure. The new ASU clarifies when an in substance repossession or foreclosure occurs – that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized. The new ASU requires a creditor to reclassify a collateralized consumer mortgage loan to real estate property upon obtaining legal title to the real estate collateral, or the borrower voluntarily conveying all interest in the real estate property to the lender to satisfy the loan through a deed in lieu of foreclosure or similar legal agreement. The ASU is effective for interim and annual reporting periods beginning after December 15, 2014. The adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.
In January 2014, the FASB issued an ASU in order to provide guidance on accounting for investments in flow-through limited liability entities that manage or invest in affordable housing projects that qualify for low-income housing tax credit (“LIHTC”). Through the Company’s investments in these entities, the Company receives tax credits and/or tax deductions from operating losses, which are allowable on the Company’s filed income tax returns over the life of the project beginning with the first year the tax credits are earned. The ASU is effective beginning with the Company’s first quarter ending March 31, 2015, with early adoption permitted. If adopted, the provisions of ASU No. 2014-01 would be applied retrospectively to all financial statement periods presented. The Company does not anticipate that the potential accounting policy change to the proportional amortization method would be material to the financial condition, results of operations, or liquidity of the Company. The expanded disclosures required by this ASU will be incorporated in the Company’s future consolidated financial statements upon adoption.

Securities

Securities	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Securities	Note 2. Securities
	The amortized cost and fair value of securities classified as available for sale and held to maturity follow:
	Securities Available for Sale
		December 31, 2014								December 31, 2013
	in thousands	Amortized		Gross		Gross		Fair Value		Amortized		Gross		Gross		Fair Value
		Cost		Unrealized		Unrealized				Cost		Unrealized		Unrealized
				Gains		Losses						Gains		Losses
	U.S. Treasury and government agency securities	$	300,207	$	372	$	71	$	300,508	$	504	$	2	$	1	$	505
	Municipal obligations		13,995		186		5		14,176		35,809		177		25		35,961
	Mortgage-backed securities		1,217,293		31,094		2,823		1,245,564		1,262,633		24,402		10,077		1,276,958
	CMOs		88,093		—		1,229		86,864		96,369		—		2,244		94,125
	Corporate debt securities		3,500		—		—		3,500		3,500		—		—		3,500
	Equity securities		8,673		891		11		9,553		9,965		785		27		10,723
		$	1,631,761	$	32,543	$	4,139	$	1,660,165	$	1,408,780	$	25,366	$	12,374	$	1,421,772
	Securities Held to Maturity
		December 31, 2014								December 31, 2013
	in thousands	Amortized		Gross		Gross		Fair Value		Amortized		Gross		Gross		Fair Value
		Cost		Unrealized		Unrealized				Cost		Unrealized		Unrealized
				Gains		Losses						Gains		Losses
	U.S. Treasury and government agency securities	$	—	$	—	$	—	$	—	$	100,000	$	316	$	—	$	100,316
	Municipal obligations		180,615		3,416		1,144		182,887		193,189		919		6,436		187,672
	Mortgage-backed securities		899,923		23,897		162		923,658		1,003,327		296		4,671		998,952
	CMOs		1,085,751		5,590		11,546		1,079,795		1,314,836		1,062		26,254		1,289,644
		$	2,166,289	$	32,903	$	12,852	$	2,186,340	$	2,611,352	$	2,593	$	37,361	$	2,576,584
	During the third quarter of 2013, approximately $1.0 billion of securities available for sale were reclassified as securities held to maturity. Management determined that the reclassified securities were not needed for liquidity purposes and that the Company had the ability and intent to hold the securities to maturity. The reclassified securities consisted of mortgage-backed securities and collateral mortgage obligations (CMOs). The securities were transferred at fair value on the date of their reclassification, which became the cost basis for the securities held to maturity. The unrealized net holding loss on the available for sale securities on the date of transfer totaled approximately $56.8 million, and continued to be reported, net of tax, as a component of accumulated other comprehensive income. This net unrealized loss is being accreted to interest income over the remaining life of the securities as a yield adjustment. There were no gains or losses recognized as a result of this transfer.
	The following table presents the amortized cost and fair value of debt securities at December 31, 2014 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 CMOs.
	in thousands	Amortized		Fair
		Cost		Value
	Debt Securities Available for Sale
	Due in one year or less	$	303,284	$	303,589
	Due after one year through five years		154,189		154,534
	Due after five years through ten years		236,461		244,535
	Due after ten years		929,154		947,954
	Total available for sale debt securities	$	1,623,088	$	1,650,612
	in thousands	Amortized		Fair
		Cost		Value
	Debt Securities Held to Maturity
	Due in one year or less	$	169,617	$	170,786
	Due after one year through five years		453,352		446,039
	Due after five years through ten years		115,748		115,195
	Due after ten years		1,427,572		1,454,320
	Total held to maturity securities	$	2,166,289	$	2,186,340
	The Company held no securities classified as trading at December 31, 2014 or 2013.
	The details for securities classified as available for sale with unrealized losses as of December 31, 2014 follow:
	Available for sale
		Losses < 12 months				Losses 12 months or >				Total
	in thousands	Fair		Gross		Fair		Gross		Fair		Gross
		Value		Unrealized		Value		Unrealized		Value		Unrealized
				Losses				Losses				Losses
	U.S. Treasury and government agency securities	$	99,950	$	70	$	121	$	1	$	100,071	$	71
	Municipal obligations		2,995		5		—		—		2,995		5
	Mortgage-backed securities		38,955		163		125,641		2,660		164,596		2,823
	CMOs		—		—		86,864		1,229		86,864		1,229
	Equity securities		5,998		10		3		1		6,001		11
		$	147,898	$	248	$	212,629	$	3,891	$	360,527	$	4,139
	The details for securities classified as available for sale with unrealized losses as of December 31, 2013 follow:
	Available for sale
		Losses < 12 months				Losses 12 months or >				Total
	in thousands	Fair		Gross		Fair		Gross		Fair		Gross
		Value		Unrealized		Value		Unrealized		Value		Unrealized
				Losses				Losses				Losses
	U.S. Treasury and government agency securities	$	205	$	1	$	—	$	—	$	205	$	1
	Municipal obligations		7,975		25		—		—		7,975		25
	Mortgage-backed securities		376,350		7,164		49,061		2,913		425,411		10,077
CMOs		94,125		2,244		—		—		94,125		2,244
Equity securities		3,282		26		3		1		3,285		27
	$	481,937	$	9,460	$	49,064	$	2,914	$	531,001	$	12,374
The details for securities classified as held to maturity with unrealized losses as of December 31, 2014 follow:
Held to maturity
	Losses < 12 months				Losses 12 months or >				Total
in thousands	Fair		Gross		Fair		Gross		Fair		Gross
	Value		Unrealized		Value		Unrealized		Value		Unrealized
			Losses				Losses				Losses
Municipal obligations	$	4,316	$	12	$	58,105	$	1,132	$	62,421	$	1,144
Mortgage-backed securities		—		—		95,522		162		95,522		162
CMOs		119,222		616		540,607		10,930		659,829		11,546
	$	123,538	$	628	$	694,234	$	12,224	$	817,772	$	12,852
The details for securities classified as held to maturity with unrealized losses as of December 31, 2013 follow:
Held to maturity
	Losses < 12 months				Losses 12 months or >				Total
in thousands	Fair		Gross		Fair		Gross		Fair		Gross
	Value		Unrealized		Value		Unrealized		Value		Unrealized
			Losses				Losses				Losses
Municipal obligations	$	131,499	$	6,311	$	2,878	$	125	$	134,377	$	6,436
Mortgage-backed securities		950,288		4,671		—		—		950,288		4,671
CMOs		947,061		25,088		175,633		1,166		1,122,694		26,254
	$	2,028,848	$	36,070	$	178,511	$	1,291	$	2,207,359	$	37,361
The unrealized losses relate to changes in market rates on fixed-rate debt securities since the respective purchase date. In all cases, the indicated impairment would be recovered by the security’s maturity date or possibly earlier if the market price for the security increases with a reduction in the yield required by the market. None of the unrealized losses relate to the marketability of the securities or the issuer’s ability to meet contractual obligations. The Company 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 sales of securities available for sale were approximately $1.5 million in 2014, $0.2 million in 2013, and $48 million in 2012. Realized gross gains and losses, computed through specific identification, were insignificant.
Securities with carrying values totaling approximately $3.2 billion at December 31, 2014 and $3.1 billion at December 31, 2013 were pledged primarily to secure public deposits or sold under agreements to repurchase.

Loans

Loans	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Loans	Note 3. Loans
	The Company generally makes loans in its market areas of south Mississippi, southern and central Alabama, south Louisiana, the Houston, Texas area and the northern, central and panhandle regions of Florida. The distinction between the originated, acquired and FDIC acquired loans presented here and certain significant accounting policies relevant to each category are discussed in detail in Note 1. Loans acquired in an FDIC-assisted transaction include non-single family loans covered by loss a share agreement that expired at December 31, 2014. As of December 31, 2014, $196.7 million of FDIC acquired loans remain covered by the single family loss share agreement, providing considerable protection against credit risk.
	Loans, net of unearned income, consisted of the following:
	(In thousands)		December 31,			December 31,
			2014			2013
	Originated loans: (a)
	Commercial non-real estate		$	5,917,728		$	4,113,837
	Construction and land development			1,073,964			752,381
	Commercial real estate			2,428,195			2,022,528
	Residential mortgages			1,704,770			1,196,256
	Consumer			1,685,542			1,409,130
	Total originated loans		$	12,810,199		$	9,494,132
	Acquired loans: (a)
	Commercial non-real estate		$	120,137		$	926,997
	Construction and land development			21,123			142,931
	Commercial real estate			688,045			967,148
	Residential mortgages			2,378			315,340
	Consumer			985			119,603
	Total acquired loans		$	832,668		$	2,472,019
	FDIC acquired loans:
	Commercial non-real estate		$	6,195		$	23,390
	Construction and land development			11,674			20,229
	Commercial real estate			27,808			53,165
	Residential mortgages			187,033			209,018
	Consumer			19,699			52,864
	Total FDIC acquired loans		$	252,409		$	358,666
	Total loans:
	Commercial non-real estate		$	6,044,060		$	5,064,224
	Construction and land development			1,106,761			915,541
	Commercial real estate			3,144,048			3,042,841
	Residential mortgages			1,894,181			1,720,614
	Consumer			1,706,226			1,581,597
	Total loans		$	13,895,276		$	12,324,817
		(a)	Originated loans at December 31, 2014 includes $1.2 billion of loans that were reported as acquired-performing at December 31, 2013, as the discount (premium) was fully accreted (amortized).
	The Bank makes loans in the normal course of business to directors and executive officers of the Company and the Bank and to their associates. Loans to such related parties are made on substantially the same terms, including interest rates and collateral requirements, as those prevailing at the time for comparable transactions with unrelated parties and do not involve more than normal risk of collectability when originated. Balances of loans to the Company’s directors, executive officers and their associates at December 31, 2014 and 2013 were approximately $16.2 million and $61.1 million, respectively. Related party loan activity for 2014 includes new loans of $12.9 million, repayments of $12.9 million, and a net balance reduction of ($44.9 million) related to changes in directors and executive officers and their associates.
	The following schedules show activity in the allowance for loan losses for 2014 and 2013 by portfolio segment and the corresponding recorded investment in loans as of December 31, 2014 and December 31, 2013.
			Commercial			Construction			Commercial			Residential			Consumer			Total
			non-real			and land			real estate			mortgages
			estate			development
	(In thousands)		Twelve Months Ended December 31, 2014
	Originated loans (a)
	Allowance for loan losses:
	Beginning balance		$	33,091		$	6,180		$	20,649		$	6,892		$	12,073		$	78,885
	Charge-offs			(6,813	)		(4,770	)		(3,579	)		(2,285	)		(14,055	)		(31,502	)
	Recoveries			3,047			4,000			1,678			644			5,014			14,383
	Net provision for loan losses			20,933			3			(2,204	)		2,800			14,403			35,935
	Ending balance		$	50,258		$	5,413		$	16,544		$	8,051		$	17,435		$	97,701
	Ending balance:
	Individually evaluated for impairment		$	14		$	19		$	11		$	330		$	3		$	377
	Collectively evaluated for impairment			50,244			5,394			16,533			7,721			17,432			97,324
	Loans:
	Ending balance:		$	5,917,728		$	1,073,964		$	2,428,195		$	1,704,770		$	1,685,542		$	12,810,199
	Individually evaluated for impairment			3,987			8,250			12,121			2,656			6			27,020
	Collectively evaluated for impairment			5,913,741			1,065,714			2,416,074			1,702,114			1,685,536			12,783,179
	Acquired loans (a)
	Allowance for loan losses:
	Beginning balance		$	1,603		$	10		$	34		$	—		$	—		$	1,647
	Charge-offs			—			—			—			—			—			—
	Recoveries			—			—			—			—			—			—
	Net provision for loan losses			(1,603	)		(10	)		443			—			—			(1,170	)
	Ending balance		$	—		$	—		$	477		$	—		$	—		$	477
	Ending balance:
	Individually evaluated for impairment		$	—		$	—		$	477		$	—		$	—		$	477
	Amounts related to acquired-impaired loans			—			—			—			—			—			—
Collectively evaluated for impairment			—			—			—			—			—			—
Loans:
Ending balance:		$	120,137		$	21,123		$	688,045		$	2,378		$	985		$	832,668
Individually evaluated for impairment			—			—			2,691			—			—			2,691
Acquired-impaired loans			8,446			19,681			29,777			2,378			985			61,267
Collectively evaluated for impairment			111,691			1,442			655,577			—			—			768,710
(a)	Originated loans at December 31, 2014 includes $1.2 billion of loans that were reported as acquired-performing at December 31, 2013, as the discount (premium) was fully accreted (amortized).
		Commercial			Construction			Commercial			Residential			Consumer			Total
		non-real			and land			real estate			mortgages
		estate			development
(In thousands)		Twelve Months Ended December 31, 2014
FDIC acquired loans
Allowance for loan losses:
Beginning balance		$	2,323		$	2,655		$	10,929		$	27,989		$	9,198		$	53,094
Charge-offs			(221	)		(148	)		(5,350	)		(1,008	)		(1,270	)		(7,997	)
Recoveries			485			3,138			1,441			1			431			5,496
Net provision for loan losses			(83	)		(208	)		(139	)		(299	)		(196	)		(925	)
Decrease in FDIC loss share receivable			(1,593	)		(4,429	)		(2,820	)		(6,074	)		(4,168	)		(19,084	)
Ending balance		$	911		$	1,008		$	4,061		$	20,609		$	3,995		$	30,584
Ending balance:
Individually evaluated for impairment		$	—		$	—		$	—		$	—		$	—		$	—
Amounts related to acquired-impaired loans			911			1,008			4,061			20,609			3,995			30,584
Collectively evaluated for impairment			—			—			—			—			—			—
Loans:
Ending balance:		$	6,195		$	11,674		$	27,808		$	187,033		$	19,699		$	252,409
Individually evaluated for impairment			—			—			—			—			—			—
Acquired-impaired loans			6,195			11,674			27,808			187,033			19,699			252,409
Collectively evaluated for impairment			—			—			—			—			—			—
Total loans
Allowance for loan losses:
Beginning balance		$	37,017		$	8,845		$	31,612		$	34,881		$	21,271		$	133,626
Charge-offs			(7,034	)		(4,918	)		(8,929	)		(3,293	)		(15,325	)		(39,499	)
Recoveries			3,532			7,138			3,119			645			5,445			19,879
Net provision for loan losses			19,247			(215	)		(1,900	)		2,501			14,207			33,840
Decrease in FDIC loss share receivable			(1,593	)		(4,429	)		(2,820	)		(6,074	)		(4,168	)		(19,084	)
Ending balance		$	51,169		$	6,421		$	21,082		$	28,660		$	21,430		$	128,762
Ending balance:
Individually evaluated for impairment		$	14		$	19		$	488		$	330		$	3		$	854
Amounts related to acquired-impaired loans			911			1,008			4,061			20,609			3,995			30,584
Collectively evaluated for impairment			50,244			5,394			16,533			7,721			17,432			97,324
Loans:
Ending balance:		$	6,044,060		$	1,106,761		$	3,144,048		$	1,894,181		$	1,706,226		$	13,895,276
Individually evaluated for impairment			3,987			8,250			14,812			2,656			6			29,711
Acquired-impaired loans			14,641			31,355			57,585			189,411			20,684			313,676
Collectively evaluated for impairment			6,025,432			1,067,156			3,071,651			1,702,114			1,685,536			13,551,889
		Commercial			Construction			Commercial			Residential			Consumer			Total
		non-real			and land			real estate			mortgages
		estate			development
(In thousands)		Year Ended December 31, 2013
Originated loans:
Allowance for loan losses:
Beginning balance		$	20,775		$	11,415		$	26,959		$	6,406		$	13,219		$	78,774
Charge-offs			(6,671	)		(10,312	)		(5,525	)		(2,297	)		(18,094	)		(42,899	)
Recoveries			5,790			1,676			3,359			1,936			5,829			18,590
Net provision for loan losses			13,197			3,401			(4,144	)		847			11,119			24,420
Ending balance		$	33,091		$	6,180		$	20,649		$	6,892		$	12,073		$	78,885
Ending balance:
Individually evaluated for impairment		$	477		$	22		$	268		$	1		$	—		$	768
Collectively evaluated for impairment			32,614			6,158			20,381			6,891			12,073			78,117
Loans:
Ending balance:		$	4,113,837		$	752,381		$	2,022,528		$	1,196,256		$	1,409,130		$	9,494,132
Individually evaluated for impairment			5,294			10,599			14,029			605			—			30,527
Collectively evaluated for impairment			4,108,543			741,782			2,008,499			1,195,651			1,409,130			9,463,605
Acquired loans:
Allowance for loan losses:
Beginning balance		$	788		$	—		$	—		$	—		$	—		$	788
Charge-offs			—			—			—			—			—			—
Recoveries			—			—			—			—			—			—
Net Provision for loan losses			815			10			34			—			—			859
Increase in FDIC loss share receivable			—			—			—			—			—			—
Ending balance		$	1,603		$	10		$	34		$	—		$	—		$	1,647
Ending balance:
Individually evaluated for impairment		$	—		$	—		$	—		$	—		$	—		$	—
Amounts related to acquired-impaired loans			—			—			—			—			—			—
Collectively evaluated for impairment			1,603			10			34			—			—			1,647
Loans:
Ending balance:		$	926,997		$	142,931		$	967,148		$	315,340		$	119,603		$	2,472,019
Individually evaluated for impairment			2,141			728			2,338			505			—			5,712
Acquired-impaired loans			19,094			17,335			26,058			5,494			94			68,075
Collectively evaluated for impairment			905,762			124,868			938,752			309,341			119,509			2,398,232
		Commercial			Construction			Commercial			Residential			Consumer			Total
		non-real			and land			real estate			mortgages
		estate			development
(In thousands)		Twelve Months Ended December 31, 2013
FDIC acquired loans:
Allowance for loan losses:
Beginning balance		$	2,162		$	5,623		$	9,433		$	30,471		$	8,920		$	56,609
Charge-offs			(1,071	)		(1,244	)		(4,414	)		(1,532	)		(1,250	)		(9,511	)
Recoveries			90			735			6,158			13			160			7,156
Net provision for loan losses			1,263			(1,566	)		(785	)		5,343			3,200			7,455
(Decrease) increase in FDIC loss share receivable			(121	)		(893	)		537			(6,306	)		(1,832	)		(8,615	)
Ending balance		$	2,323		$	2,655		$	10,929		$	27,989		$	9,198		$	53,094
Ending balance:
Individually evaluated for impairment		$	—		$	—		$	—		$	—		$	—		$	—
Amounts related to acquired-impaired loans			2,323			2,655			10,929			27,989			9,198			53,094
Collectively evaluated for impairment			—			—			—			—			—			—
Loans:
Ending balance:		$	23,390		$	20,229		$	53,165		$	209,018		$	52,864		$	358,666
Individually evaluated for impairment			—			—			—			—			—			—
Acquired-impaired loans			23,390			20,229			53,165			209,018			52,864			358,666
Collectively evaluated for impairment			—			—			—			—			—			—
Total loans:
Allowance for loan losses:
Beginning balance		$	23,725		$	17,038		$	36,392		$	36,877		$	22,139		$	136,171
Charge-offs			(7,742	)		(11,556	)		(9,939	)		(3,829	)		(19,344	)		(52,410	)
Recoveries			5,880			2,411			9,517			1,949			5,989			25,746
Net provision for loan losses			15,275			1,845			(4,895	)		6,190			14,319			32,734
(Decrease) increase in FDIC loss share receivable			(121	)		(893	)		537			(6,306	)		(1,832	)		(8,615	)
Ending balance		$	37,017		$	8,845		$	31,612		$	34,881		$	21,271		$	133,626
Ending balance:
Individually evaluated for impairment		$	477		$	22		$	268		$	1		$	—		$	768
Amounts related to acquired-impaired loans			2,323			2,655			10,929			27,989			9,198			53,094
Collectively evaluated for impairment			34,217			6,168			20,415			6,891			12,073			79,764
Loans:
Ending balance:		$	5,064,224		$	915,541		$	3,042,841		$	1,720,614		$	1,581,597		$	12,324,817
Individually evaluated for impairment			7,435			11,327			16,367			1,110			—			36,239
Acquired-impaired loans			42,484			37,564			79,223			214,512			52,958			426,741
Collectively evaluated for impairment			5,014,305			866,650			2,947,251			1,504,992			1,528,639			11,861,837
FDIC Loss Share Receivable
The receivable arising from the loss-sharing agreements (referred to as the “FDIC loss share receivable” on our consolidated statements of financial condition) is measured separately from the FDIC acquired loan portfolio because the agreements are not contractually part of the covered loans and are not transferable should the Company choose to dispose of the loans. The following schedule shows activity in the loss share receivable for 2014 and 2013:
(In thousands)		Years Ended December 31,
		2014			2013
Balance, January 1		$	113,834		$	177,844
(Amortization) accretion			(12,102	)		(2,239	)
Charge-offs, write-downs and other (recoveries) losses			(2,245	)		(1,619	)
External expenses qualifying under loss share agreement			4,532			9,117
Changes due to changes in cash flow projections			(19,084	)		(7,504	)
Settlement of disallowed claims			(10,268	)		—
Net payments from FDIC			(14,395	)		(61,765	)
Balance, December 31		$	60,272		$	113,834
Note 1 to the consolidated financial statements discusses the accounting for the loss share receivable. The loss share agreement covering the non-single family FDIC acquired portfolio expired in December 2014. The loss share agreement covering the single family portfolio expires in December 2019.
The following table shows the composition of nonaccrual loans by portfolio segment and class. Acquired-impaired and certain covered loans are considered to be performing due to the application of the accretion method and are excluded from the table. FDIC acquired loans accounted for using the cost recovery method do not have an accretable yield and are included below as nonaccrual loans. Acquired-performing loans that have subsequently been placed on nonaccrual status are also included below.
(In thousands)		December 31,			December 31,
		2014			2013
Originated loans:
Commercial non-real estate		$	15,511		$	10,148
Construction and land development			6,462			13,171
Commercial real estate			22,047			32,772
Residential mortgages			21,702			13,449
Consumer			5,574			4,802
Total originated loans		$	71,296		$	74,342
Acquired loans:
Commercial non-real estate		$	—		$	3,209
Construction and land development			—			1,990
Commercial real estate			6,139			6,525
Residential mortgages			—			8,262
Consumer			—			1,814
Total acquired loans		$	6,139		$	21,800
FDIC acquired loans:
Commercial non-real estate		$	—		$	2
Construction and land development			1,103			1,539
Commercial real estate			433			1,163
Residential mortgages			392			544
Consumer			174			296
Total FDIC acquired loans		$	2,102		$	3,544
Total loans:
Commercial non-real estate		$	15,511		$	13,359
Construction and land development			7,565			16,700
Commercial real estate			28,619			40,460
Residential mortgages			22,094			22,255
Consumer			5,748			6,912
Total loans		$	79,537		$	99,686
The estimated amount of interest that would have been recorded on nonaccrual loans had the loans not been classified as nonaccrual in 2014, 2013 and 2012, was $3.6 million, $5.4 million and $7.8 million, respectively. Interest actually received on nonaccrual loans during 2014, 2013 and 2012 was $1.5 million, $3.0 million and $2.6 million, respectively.
Nonaccrual loans include loans modified in troubled debt restructurings (TDRs) of $7.0 million and $15.7 million, respectively, at December 31, 2014 and 2013. Total TDRs, both accruing and nonaccruing, were $16.0 million at December 31, 2014 and $24.9 million at December 31, 2013. Modified acquired-impaired loans are not removed from their accounting pool and accounted for as TDRs, even if those loans would otherwise be deemed TDRs.
The table below details the TDRs that occurred during 2014 and 2013 by portfolio segment and TDRs that subsequently defaulted within twelve months of modification. All are individually evaluated for impairment.
($ in thousands)		2014									2013
		Number			Outstanding Recorded						Number			Outstanding Recorded
		of			Investment						of			Investment
		Contracts			Pre-			Post-			Contracts			Pre-			Post-
					Modification			Modification						Modification			Modification
Originated loans:
Commercial non-real estate			1		$	29		$	29			1		$	926		$	909
Construction and land development			—			—			—			—			—			—
Commercial real estate			3			4,488			4,446			4			1,332			1,157
Residential mortgages			7			1,961			1,090			1			456			330
Consumer			1			8			8			—			—			—
Total originated loans			12		$	6,486		$	5,573			6		$	2,714		$	2,396
Acquired loans:
Commercial non-real estate			—		$	—		$	—			—		$	—		$	—
Construction and land development			—			—			—			—			—			—
Commercial real estate			—			—			—			1			512			472
Residential mortgages			—			—			—			1			514			503
Consumer			—			—			—			—			—			—
Total acquired loans			—		$	—		$	—			2		$	1,026		$	975
FDIC acquired loans:
Commercial non-real estate			—		$	—		$	—			—		$	—		$	—
Construction and land development			—			—			—			—			—			—
Commercial real estate			—			—			—			—			—			—
Residential mortgages			—			—			—			—			—			—
Consumer			—			—			—			—			—			—
Total FDIC acquired loans			—		$	—		$	—			—		$	—		$	—
Total loans:
Commercial non-real estate			1		$	29		$	29			1		$	926		$	909
Construction and land development			—			—			—			—			—			—
Commercial real estate			3			4,488			4,446			5			1,844			1,629
Residential mortgages			7			1,961			1,090			2			970			833
Consumer			1			8			8			—			—			—
Total loans			12		$	6,486		$	5,573			8		$	3,740		$	3,371
Troubled Debt Restructurings That		2014						2013
Subsequently Defaulted:
($ in thousands)		Number of			Recorded			Number of			Recorded
		Contracts			Investment			Contracts			Investment
Originated loans:
Commercial non-real estate			1		$	909			—		$	—
Construction and land development			—			—			—			—
Commercial real estate			—			—			6			2,487
Residential mortgages			1			263			1			254
Consumer			—			—			—			—
Total originated loans			2		$	1,172			7		$	2,741
Acquired loans:
Commercial non-real estate			—		$	—			—		$	—
Construction and land development			—			—			—			—
Commercial real estate			—			—			—			—
Residential mortgages			—			—			—			—
Consumer			—			—			—			—
Total acquired loans			—		$	—			—		$	—
FDIC acquired loans:
Commercial non-real estate			—		$	—			—		$	—
Construction and land development			—			—			—			—
Commercial real estate			—			—			—			—
Residential mortgages			—			—			—			—
Consumer			—			—			—			—
Total FDIC acquired loans			—		$	—			—		$	—
Total loans:
Commercial non-real estate			1		$	909			—		$	—
Construction and land development			—			—			—			—
Commercial real estate			—			—			6			2,487
Residential mortgages			1			263			1			254
Consumer			—			—			—			—
Total loans			2		$	1,172			7		$	2,741
Those loans that are determined to be impaired and $1 million or greater and all TDRs are individually evaluated for impairment. The tables below present loans that are individually evaluated for impairment disaggregated by class at December 31, 2014 and 2013:
December 31, 2014		Recorded			Unpaid			Related			Average			Interest
		Investment			Principal			Allowance			Recorded			Income
(In thousands)					Balance						Investment			Recognized
Originated loans:
With no related allowance recorded:
Commercial non-real estate		$	3,003		$	3,646		$	—		$	1,209		$	51
Construction and land development			3,345			6,486			—			3,330			142
Commercial real estate			8,467			10,575			—			8,461			331
Residential mortgages			—			—			—			88			3
Consumer			—			—			—			—			—
			14,815			20,707			—			13,088			527
With an allowance recorded:
Commercial non-real estate			984			984			14			5,522			99
Construction and land development			4,905			4,906			19			6,660			137
Commercial real estate			3,654			3,654			11			7,500			109
Residential mortgages			2,656			3,311			330			2,204			50
Consumer			6			6			3			1			—
			12,205			12,861			377			21,887			395
Total:
Commercial non-real estate			3,987			4,630			14			6,732			150
Construction and land development			8,250			11,392			19			9,990			279
Commercial real estate			12,121			14,229			11			15,961			439
Residential mortgages			2,656			3,311			330			2,292			53
Consumer			6			6			3			1			—
Total originated loans		$	27,020		$	33,568		$	377		$	34,976		$	921
Acquired loans:
With no related allowance recorded:
Commercial non-real estate		$	—		$	—		$	—		$	357		$	—
Construction and land development			—			—			—			121			—
Commercial real estate			—			—			—			311			—
Residential mortgages			—			—			—			88			—
Consumer			—			—			—			—			—
			—			—			—			877			—
With an allowance recorded:
Commercial non-real estate			—			—			—			1,059			122
Construction and land development			—			—			—			1,037			56
Commercial real estate			2,691			2,720			477			1,357			75
Residential mortgages			—			—			—			—			—
Consumer			—			—			—			—			—
			2,691			2,720			477			3,453			253
Total:
Commercial non-real estate			—			—			—			1,416			122
Construction and land development			—			—			—			1,158			56
Commercial real estate			2,691			2,720			477			1,668			75
Residential mortgages			—			—			—			88			—
Consumer			—			—			—			—			—
Total acquired loans		$	2,691		$	2,720		$	477		$	4,330		$	253
Total loans:
With no related allowance recorded:
Commercial non-real estate		$	3,003		$	3,646		$	—		$	1,566		$	51
Construction and land development			3,345			6,486			—			3,451			142
Commercial real estate			8,467			10,575			—			8,772			331
Residential mortgages			—			—			—			176			3
Consumer			—			—			—			—			—
			14,815			20,707			—			13,965			527
With an allowance recorded:
Commercial non-real estate			984			984			14			6,581			221
Construction and land development			4,905			4,906			19			7,697			193
Commercial real estate			6,345			6,374			488			8,857			184
Residential mortgages			2,656			3,311			330			2,204			50
Consumer			6			6			3			1			—
			14,896			15,581			854			25,340			648
Total:
Commercial non-real estate			3,987			4,630			14			8,147			272
Construction and land development			8,250			11,392			19			11,148			335
Commercial real estate			14,812			16,949			488			17,629			515
Residential mortgages			2,656			3,311			330			2,380			53
Consumer			6			6			3			1			—
Total loans		$	29,711		$	36,288		$	854		$	39,305		$	1,175
December 31, 2013		Recorded			Unpaid			Related			Average			Interest
		Investment			Principal			Allowance			Recorded			Income
(in thousands)					Balance						Investment			Recognized
Originated loans:
With no related allowance recorded:
Commercial non-real estate		$	329		$	442		$	—		$	235		$	18
Construction and land development			4,101			5,131			—			2,780			82
Commercial real estate			5,321			7,458			—			15,886			374
Residential mortgages			—			—			—			262			—
Consumer			—			—			—			1,013			—
			9,751			13,031			—			20,176			474
With an allowance recorded:
Commercial non-real estate			4,965			5,303			477			8,936			180
Construction and land development			6,498			8,343			22			2,549			—
Commercial real estate			8,708			9,090			268			19,683			460
Residential mortgages			605			620			1			228			—
Consumer			—			—			—			1,025			—
			20,776			23,356			768			32,421			640
Total:
Commercial non-real estate			5,294			5,745			477			9,171			198
Construction and land development			10,599			13,474			22			5,329			82
Commercial real estate			14,029			16,548			268			35,569			834
Residential mortgages			605			620			1			490			—
Consumer			—			—			—			2,038			—
Total originated loans		$	30,527		$	36,387		$	768		$	52,597		$	1,114
Acquired loans:
With no related allowance recorded:
Commercial non-real estate		$	2,141		$	3,275		$	—		$	865		$	8
Construction and land development			728			1,142			—			296			3
Commercial real estate			2,338			2,634			—			1,339			49
Residential mortgages			505			507			—			407			—
Consumer			—			—			—			—			—
			5,712			7,558			—			2,907			60
With an allowance recorded:
Commercial non-real estate			—			—			—			2,747			63
Construction and land development			—			—			—			157			—
Commercial real estate			—			—			—			2,663			—
Residential mortgages			—			—			—			845			—
Consumer			—			—			—			—			—
			—			—			—			6,412			63
Total:
Commercial non-real estate			2,141			3,275			—			3,612			71
Construction and land development			728			1,142			—			453			3
Commercial real estate			2,338			2,634			—			4,002			49
Residential mortgages			505			507			—			1,252			—
Consumer			—			—			—			—			—
Total acquired loans		$	5,712		$	7,558		$	—		$	9,319		$	123
Total loans:
With no related allowance recorded:
Commercial non-real estate		$	2,470		$	3,717		$	—		$	1,100		$	26
Construction and land development			4,829			6,273			—			3,076			85
Commercial real estate			7,659			10,092			—			17,225			423
Residential mortgages			505			507			—			669			—
Consumer			—			—			—			1,013			—
			15,463			20,589			—			23,083			534
With an allowance recorded:
Commercial non-real estate			4,965			5,303			477			11,683			243
Construction and land development			6,498			8,343			22			2,706			—
Commercial real estate			8,708			9,090			268			22,346			460
Residential mortgages			605			620			1			1,073			—
Consumer			—			—			—			1,025			—
			20,776			23,356			768			38,833			703
Total:
Commercial non-real estate			7,435			9,020			477			12,783			269
Construction and land development			11,327			14,616			22			5,782			85
Commercial real estate			16,367			19,182			268			39,571			883
Residential mortgages			1,110			1,127			1			1,742			—
Consumer			—			—			—			2,038			—
Total loans		$	36,239		$	43,945		$	768		$	61,916		$	1,237
The following table presents the age analysis of past due loans at December 31, 2014 and December 31, 2013. FDIC acquired and acquired-impaired loans with an accretable yield are considered to be current in the following delinquency table:
December 31, 2014		30-59 days			60-89 days			Greater than			Total			Current			Total			Recorded
		past due			past due			90 days			past due						Loans			investment
								past due												> 90 days
																				and
																				accruing
(In thousands)
Originated loans:
Commercial non-real estate		$	4,380		$	1,742		$	8,560		$	14,682		$	5,903,046		$	5,917,728		$	630
Construction and land development			6,620			1,532			4,453			12,605			1,061,359			1,073,964			142
Commercial real estate			6,527			2,964			13,234			22,725			2,405,470			2,428,195			696
Residential mortgages			14,730			3,261			11,208			29,199			1,675,571			1,704,770			1,199
Consumer			8,422			2,450			4,365			15,237			1,670,305			1,685,542			1,897
Total		$	40,679		$	11,949		$	41,820		$	94,448		$	12,715,751		$	12,810,199		$	4,564
Acquired loans:
Commercial non-real estate		$	—		$	—		$	—		$	—		$	120,137		$	120,137		$	—
Construction and land development			111			—			—			111			21,012			21,123			—
Commercial real estate			3,861			282			1,591			5,734			682,311			688,045			261
Residential mortgages			—			—			—			—			2,378			2,378			—
Consumer			—			—			—			—			985			985			—
Total		$	3,972		$	282		$	1,591		$	5,845		$	826,823		$	832,668		$	261
FDIC acquired loans:
Commercial non-real estate		$	—		$	—		$	—		$	—		$	6,195		$	6,195		$	—
Construction and land development			—			—			1,103			1,103			10,571			11,674			—
Commercial real estate			—			—			433			433			27,375			27,808			—
Residential mortgages			—			272			—			272			186,761			187,033			—
Consumer			1			—			34			35			19,664			19,699			—
Total		$	1		$	272		$	1,570		$	1,843		$	250,566		$	252,409		$	—
Total loans:
Commercial non-real estate		$	4,380		$	1,742		$	8,560		$	14,682		$	6,029,378		$	6,044,060		$	630
Construction and land development			6,731			1,532			5,556			13,819			1,092,942			1,106,761			142
Commercial real estate			10,388			3,246			15,258			28,892			3,115,156			3,144,048			957
Residential mortgages			14,730			3,533			11,208			29,471			1,864,710			1,894,181			1,199
Consumer			8,423			2,450			4,399			15,272			1,690,954			1,706,226			1,897
Total		$	44,652		$	12,503		$	44,981		$	102,136		$	13,793,140		$	13,895,276		$	4,825
December 31, 2013		30-59 days			60-89 days			Greater than			Total			Current			Total			Recorded
		past due			past due			90 days			past due						Loans			investment
								past due												> 90 days
																				and
																				accruing
(In thousands)
Originated loans:
Commercial non-real estate		$	11,645		$	1,203		$	4,803		$	17,651		$	4,096,186		$	4,113,837		$	521
Construction and land development			5,877			1,264			5,970			13,111			739,270			752,381			—
Commercial real estate			8,178			5,744			14,620			28,542			1,993,986			2,022,528			420
Residential mortgages			12,410			3,870			3,540			19,820			1,176,436			1,196,256			—
Consumer			8,798			1,913			3,823			14,534			1,394,596			1,409,130			2,357
Total		$	46,908		$	13,994		$	32,756		$	93,658		$	9,400,474		$	9,494,132		$	3,298
Acquired loans:
Commercial non-real estate		$	1,982		$	2,332		$	1,467		$	5,781		$	921,216		$	926,997		$	541
Construction and land development			862			1,529			1,161			3,552			139,379			142,931			541
Commercial real estate			3,742			1,345			9,026			14,113			953,035			967,148			5,853
Residential mortgages			5,632			2,698			5,503			13,833			301,507			315,340			72
Consumer			1,029			120			1,013			2,162			117,441			119,603			82
Total		$	13,247		$	8,024		$	18,170		$	39,441		$	2,432,578		$	2,472,019		$	7,089
FDIC acquired loans:
Commercial non-real estate		$	—		$	—		$	—		$	—		$	23,390		$	23,390		$	—
Construction and land development			—			—			1,539			1,539			18,690			20,229			—
Commercial real estate			—			—			675			675			52,490			53,165			—
Residential mortgages			—			—			3			3			209,015			209,018			—
Consumer			—			—			—			—			52,864			52,864			—
Total		$	—		$	—		$	2,217		$	2,217		$	356,449		$	358,666		$	—
Total loans:
Commercial non-real estate		$	13,627		$	3,535		$	6,270		$	23,432		$	5,040,792		$	5,064,224		$	1,062
Construction and land development			6,739			2,793			8,670			18,202			897,339			915,541			541
Commercial real estate			11,920			7,089			24,321			43,330			2,999,511			3,042,841			6,273
Residential mortgages			18,042			6,568			9,046			33,656			1,686,958			1,720,614			72
Consumer			9,827			2,033			4,836			16,696			1,564,901			1,581,597			2,439
Total		$	60,155		$	22,018		$	53,143		$	135,316		$	12,189,501		$	12,324,817		$	10,387
The following table presents the credit quality indicators of the Company’s various classes of loans at December 31, 2014 and December 31, 2013.
Commercial Non-Real Estate Credit Exposure
Credit Risk Profile by Internally Assigned Grade
		December 31, 2014												December 31, 2013
(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
Grade:
Pass		$	5,577,827		$	111,847		$	2,027		$	5,691,701		$	3,990,318		$	846,135		$	10,477		$	4,846,930
Pass-Watch			174,742			715			1,120			176,577			46,734			44,105			9			90,848
Special Mention			52,962			350			—			53,312			41,812			19,914			2,897			64,623
Substandard			112,153			7,225			3,017			122,395			34,278			16,125			9,662			60,065
Doubtful			44			—			31			75			695			718			345			1,758
Total		$	5,917,728		$	120,137		$	6,195		$	6,044,060		$	4,113,837		$	926,997		$	23,390		$	5,064,224
Construction Credit Exposure
Credit Risk Profile Based on Payment Activity
		December 31, 2014												December 31, 2013
(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
Grade:
Pass		$	1,012,128		$	14,377		$	2,468		$	1,028,973		$	709,261		$	112,773		$	—		$	822,034
Pass-Watch			21,516			432			532			22,480			7,817			1,907			1,226			10,950
Special Mention			7,097			129			319			7,545			3,926			9,409			276			13,611
Substandard			33,223			6,185			8,355			47,763			31,377			18,842			11,499			61,718
Doubtful			—			—			—			—			—			—			7,228			7,228
Total		$	1,073,964		$	21,123		$	11,674		$	1,106,761		$	752,381		$	142,931		$	20,229		$	915,541
Commercial Real Estate Credit Exposure
Credit Risk Profile by Internally Assigned Grade
		December 31, 2014												December 31, 2013
(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
Grade:
Pass		$	2,241,391		$	641,966		$	4,139		$	2,887,496		$	1,864,116		$	896,578		$	1,678		$	2,762,372
Pass-Watch			61,589			11,142			4,547			77,278			49,578			9,530			10,266			69,374
Special Mention			21,543			8,113			1,319			30,975			15,785			19,798			1,999			37,582
Substandard			103,651			26,824			17,803			148,278			93,033			41,242			31,350			165,625
Doubtful			21			—			—			21			16			—			7,872			7,888
Total		$	2,428,195		$	688,045		$	27,808		$	3,144,048		$	2,022,528		$	967,148		$	53,165		$	3,042,841
Residential Mortgage Credit Exposure
Credit Risk Profile Based on Payment Activity and Accrual Status
		December 31, 2014												December 31, 2013
(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
Performing		$	1,681,868		$	2,378		$	186,641		$	1,870,887		$	1,182,266		$	307,006		$	208,473		$	1,697,742
Nonperforming			22,902			—			392			23,294			13,990			8,334			545			22,872
Total		$	1,704,770		$	2,378		$	187,033		$	1,894,181		$	1,196,256		$	315,340		$	209,018		$	1,720,614
Consumer Credit Exposure
Credit Risk Profile Based on Payment Activity and Accrual Status
		December 31, 2014												December 31, 2013
(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
Performing		$	1,678,069		$	985		$	19,525		$	1,698,579		$	1,401,688		$	117,707		$	52,554		$	1,571,949
Nonperforming			7,473			—			174			7,647			7,442			1,896			310			9,648
Total		$	1,685,542		$	985		$	19,699		$	1,706,226		$	1,409,130		$	119,603		$	52,864		$	1,581,597
Loan review uses a risk-focused continuous monitoring program that provides for an independent, objective and timely review of credit risk within the Company.
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 an 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 nor 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.
Changes in the carrying amount of acquired-impaired loans and accretable yield are presented in the following table for the years ended December 31, 2014 and 2013:
		December 31, 2014												December 31, 2013
		FDIC acquired						Acquired						FDIC acquired						Acquired
(In thousands)		Carrying			Accretable			Carrying			Accretable			Carrying			Accretable			Carrying			Accretable
		Amount			Yield			Amount			Yield			Amount			Yield			Amount			Yield
		of  Loans						of  Loans						of Loans						of  Loans
Balance at beginning of period		$	358,666		$	122,715		$	68,075		$	131,370		$	515,823		$	115,594		$	141,201		$	203,186
Payments received, net			(125,388	)		(1,071	)		(50,178	)		(32,855	)		(189,987	)		(1,298	)		(116,187	)		(47,330	)
Accretion			19,131			(19,131	)		43,379			(43,379	)		32,830			(32,830	)		43,061			(43,061	)
(Decrease)/increase in expected cash flows based on actual cash flow and changes in cash flow assumptions			—			(1,137	)		—			(203	)		—			(17,433	)		—			3,894
Net transfers from nonaccretable difference to accretable yield			—			11,412			—			19,735			—			58,682			—			14,681
Balance at end of period		$	252,409		$	112,788		$	61,276		$	74,668		$	358,666		$	122,715		$	68,075		$	131,370
Loans Held for Sale
Loans held for sale totaled $20.3 million and $24.5 million, respectively, at December 31, 2014 and 2013. Substantially all loans held for sale are residential mortgage loans originated on a best-efforts basis, whereby a commitment by a third party to purchase the loan has been received concurrent with the Bank’s commitment to the borrower to originate the loan.

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt	Note 4. Long-Term Debt
	Long-term debt consisted of the following:
		December 31,
	(in thousands)	2014		2013
	Subordinated notes payable	$	98,011	$	98,011
	Term note payable		149,600		184,800
	Other long-term debt		126,760		103,015
	Total long-term debt	$	374,371	$	385,826
	During the second quarter of 2012, the Company initiated a tender offer for up to $75 million of Whitney Bank’s subordinated debt. The 5.875% fixed-rate subordinated notes maturing in April 2017 had been issued by Whitney National Bank and were assumed by Hancock in the Whitney acquisition. During 2012, the Company repurchased approximately $52 million of these notes and incurred approximately $5.3 million in costs, including a premium of $5.1 million, which was included in noninterest expense. As of December 31, 2014, 40% of the balance of the subordinated notes qualifies as capital in the calculation of certain regulatory capital ratios. The qualifying amount will be further reduced by 20% in the second quarter of each year through maturity.
	On December 21, 2012, the Company entered into a three-year term loan agreement that provides for a $220 million term loan facility, all of which was borrowed on the closing date. The agreement also provides for up to $50 million in additional borrowings under the loan facility, subject to obtaining additional commitments from existing or new lenders and satisfaction of certain other conditions. Amounts borrowed under the loan facility bear interest at a variable rate based on LIBOR plus 1.875% per annum. The loan agreement requires quarterly principal payments of $8.8 million, and outstanding borrowings may be prepaid in whole or in part at any time prior to the December 21, 2015 maturity date without premium or penalty.
	The Company must satisfy certain financial covenants and is subject to other restrictions customary in financings of this nature, none of which is expected to adversely impact the operations of the Company. The financial covenants cover, among other things, the maintenance of minimum levels for regulatory capital ratios, consolidated net worth, consolidated return on assets, and holding company liquidity and dividend capacity, and specify a maximum ratio of consolidated nonperforming assets to consolidated total loans and other real estate, calculated without FDIC-covered assets. The Company was in compliance with all covenants as of December 31, 2014.
	Substantially all of the other long-term debt consists of borrowings associated with tax credit fund activities. These borrowings mature at various dates beginning in 2015 through 2052.

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Note 5. 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 our variable rate borrowing. The Bank has also entered 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 their net risk exposure resulting from such agreements. The Bank also enters into risk participation agreements under which they 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 amounts and fair values of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets as of December 31, 2014 and December 31, 2013.
													Fair Values (1)
					Notional Amounts								Assets								Liabilities
	(in thousands)		Type of		December 31,				December 31,				December 31,				December 31,				December 31,				December 31,
			Hedge		2014				2013				2014				2013				2014				2013
	Derivatives designated as hedging instruments:
	Interest rate swaps		Cash Flow		$	300,000			$	—			$	—			$	—			$	592			$	—
					$	300,000			$	—			$	—			$	—			$	592			$	—
	Derivatives not designated as hedging instruments:
	Interest rate swaps (2)		N/A		$	747,754			$	650,667			$	17,806			$	14,147			$	18,419			$	13,777
	Risk participation agreements		N/A			80,438				19,736				125				2				208				2
	Forward commitments to sell residential mortgage loans		N/A			52,238				45,910				80				326				250				115
	Interest rate-lock commitments on residential mortgage loans		N/A			33,068				25,956				111				56				44				107
	Foreign exchange forward contracts		N/A			89,432				21,299				1,310				1,048				1,347				1,005
					$	1,002,930			$	763,568			$	19,432			$	15,579			$	20,268			$	15,006
	-1	Derivative assets and liabilities are reported with 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.
	Cash Flow Hedges of Interest Rate Risk
	The Company is party to an interest rate swap agreement with a notional amount of $300 million under which the Company receives interest at a variable rate and pays at a fixed rate. The derivative instrument represented by this swap agreement was designated as and qualifies as a cash flow hedge of the Company’s forecasted variable cash flows for a pool of variable rate loans. The swap agreement expires in January 2017.
	During the term of the swap agreement, the effective portion of changes in the fair value of the derivative instrument is recorded in accumulated other comprehensive income (“AOCI”) and subsequently reclassified into earnings in the periods that the hedged forecasted variable-rate interest payments affects earnings. The impact on AOCI was insignificant during 2014. There was no ineffective portion of the change in fair value of the derivative recognized directly in earnings.
	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 have entered into the risk participation agreement because it is a party to the related loan agreement with the borrower. In those instances in which the Bank has sold credit risk, it is the sole counterparty to the derivative contract with the borrower and has entered into the risk participation agreement because other banks participate in the related loan agreement. The Bank manages their credit risk under risk participation agreements by monitoring the creditworthiness of the borrower, based on its normal credit review process.
	Mortgage banking derivatives
	The Bank also enters into certain derivative agreements as part of their 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 currency contracts, with commercial banking customers to facilitate their risk management strategies. The Bank manages its risk exposure from such transactions by entering into offsetting agreements with unrelated financial institutions. Because the foreign exchange forward contract derivatives associated with this program do not meet hedge accounting requirements, changes in the fair value of both the customer derivatives and the offsetting derivatives are recognized directly in earnings.
	Effect of Derivative Instruments on the Income Statement
	The effect of the Company’s derivative financial instruments on the income statement was immaterial for the years ended December 31, 2014, 2013 and 2012.
	Credit Risk-Related Contingent Features
	Certain of the Bank’s derivative instruments contain provisions allowing the financial institution counterparty to terminate the contracts in certain circumstances, such as the 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 December 31, 2014, the aggregate fair value of derivative instruments with credit-risk-related contingent features that were in a net liability position was $7.3 million, for which the Bank had posted collateral of $18.3 million.
	Offsetting Assets and Liabilities
	Offsetting information in regards to derivative assets and liabilities subject to master netting agreements at December 31, 2014 and December 31, 2013 is presented in the following tables:
	As of December 31, 2014
			Gross				Gross				Net
			Amounts				Amounts				Amounts				Gross Amounts Not Offset in the
			Recognized				Offset in				Presented				Statement of Financial Position
							the				in the
							Statement				Statement
							of Financial				of Financial
	(in thousands)						Position				Position				Financial				Cash Collateral				Net
															Instruments								Amount
	Derivative Assets		$	17,931			$	—			$	17,931			$	936			$	—			$	16,995
	Repurchase, securities borrowing, and similar arrangements			—				—				—				—				—				—
	Total		$	17,931			$	—			$	17,931			$	936			$	—			$	16,995
	Derivative Liabilities		$	18,627			$	—			$	18,627			$	936			$	17,343			$	348
	Reverse repurchase, securities lending, and similar arrangements			—				—				—				—				—				—
	Total		$	18,627			$	—			$	18,627			$	936			$	17,343			$	348
	As of December 31, 2013
			Gross				Gross				Net
			Amounts				Amounts				Amounts				Gross Amounts Not Offset in the
			Recognized				Offset in				Presented				Statement of Financial Position
							the				in the
							Statement				Statement
							of Financial				of Financial
	(in thousands)						Position				Position				Financial				Cash Collateral				Net
															Instruments								Amount
	Derivative Assets		$	14,149			$	—			$	14,149			$	3,462			$	—			$	10,687
Repurchase, securities borrowing, and similar arrangements			—				—				—				—				—				—
Total		$	14,149			$	—			$	14,149			$	3,462			$	—			$	10,687
Derivative Liabilities		$	13,779			$	—			$	13,779			$	3,462			$	7,406			$	2,911
Reverse repurchase, securities lending, and similar arrangements			—				—				—				—				—				—
Total		$	13,779			$	—			$	13,779			$	3,462			$	7,406			$	2,911

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment	Note 6. Property and Equipment
	Property and equipment consisted of the following:
		December 31,
	(in thousands)	2014			2013
	Land and land improvements	$	86,039		$	98,064
	Buildings and leasehold improvements		348,450			356,618
	Furniture, fixtures and equipment		90,244			90,948
	Software		57,305			51,924
	Assets under development		9,873			7,590
			591,911			605,144
	Accumulated depreciation and amortization		(193,527	)		(172,798	)
	Property and equipment, net	$	398,384		$	432,346
	Depreciation and amortization expense was $30.3 million, $32.1 million and $32.9 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Note 7. Goodwill and Other Intangible Assets
	Goodwill represents the excess of the consideration exchanged over the fair value of the net assets acquired in purchase business combinations. The Company tests goodwill for impairment annually and no impairment charges were identified in the most recent test performed in the fourth quarter of 2014 using data as of September 30, 2014. No goodwill impairment charges were recognized during 2014, 2013, or 2012. The following table provides a reconciliation of goodwill:
	(in thousands)
	Goodwill balance at December 31, 2012	$	628,877
	Reductions:
	Deferred tax purchase accounting adjustment made during 2013		(3,202	)
	Goodwill balance at December 31, 2013	$	625,675
	Reductions:
	Goodwill attributable to certain insurance business lines sold during 2014		(4,482	)
	Goodwill balance at December 31, 2014	$	621,193
	Identifiable intangible assets with finite lives are amortized over the periods benefited and are evaluated for impairment similar to other long-lived assets. In 2014, the Company eliminated the $0.2 million remaining carrying value of the insurance business acquired intangible in conjunction with the sale of certain insurance business lines. The carrying value of intangible assets subject to amortization was as follows:
		December 31, 2014
	(in thousands)	Purchase			Accumulated		Carrying
		Value			Amortization		Value
	Core deposit intangibles	$	198,002		$	85,254	$	112,748
	Credit card and trust relationships		22,400			10,366		12,034
	Non-compete agreements		400			400		—
	Trade name		11,722			9,334		2,388
	Merchant processing relationships		10,000			4,360		5,640
		$	242,524		$	109,714	$	132,810
		31-Dec-13
	(in thousands)	Purchase			Accumulated		Carrying
		Value			Amortization		Value
	Core deposit intangibles	$	198,002		$	65,357	$	132,645
	Credit card and trust relationships		22,400			7,800		14,600
	Value of insurance business acquired		2,431			2,232		199
	Non-compete agreements		400			300		100
	Trade name		11,722			6,729		4,993
	Merchant processing relationships		10,000			2,764		7,236
		$	244,955		$	85,182	$	159,773
		Years Ended December 31,
	(in thousands)	2014			2013		2012
	Aggregate amortization expense for:
	Core deposit intangibles	$	19,897		$	21,905	$	23,642
	Credit card and trust relationships		2,566			2,819		3,072
	Value of insurance business acquired		34			148		158
	Non-compete agreements		100			200		100
	Trade name		2,605			2,605		4,124
	Merchant processing relationships		1,595			1,793		971
		$	26,797		$	29,470	$	32,067
	The weighted-average remaining life of core deposit intangibles is 11 years. The weighted-average remaining life of other identifiable intangibles is 8 years.
	The following table shows estimated amortization expense of other intangible assets for the five succeeding years and thereafter, calculated based on current amortization schedules (in thousands):
	2015	$	24,333
	2016		19,962
	2017		17,975
	2018		15,981
	2019		13,447
	Thereafter		41,112
		$	132,810

Time_Deposits

Time Deposits	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Time Deposits	Note 8. Time Deposits
	The maturity of time deposits at December 31, 2014:
	(in thousands)	2014
	2015	$	1,660,864
	2016		425,377
	2017		125,880
	2018		19,566
	2019		23,759
	Thereafter		5,919
	Total time deposits	$	2,261,365
	Certificates of deposits of $250,000 or more totaled approximately $519 million at December 31, 2014 and $472 million at December 31, 2013. Other time deposits of $250,000 or more consisted primarily of balances in treasury-management deposit products for commercial and certain other larger deposit customers. Balances maintained in such products totaled $484 million and $363 million at December 31, 2014 and 2013, respectively. Most of these deposits mature on a daily basis.

ShortTerm_Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Short-Term Borrowings	Note 9. Short-Term Borrowings
	The following table presents information concerning short-term borrowings:
		December 31,
	(In thousands)	2014			2013
	Federal funds purchased:
	Amount outstanding at period-end	$	12,000		$	7,725
	Average amount outstanding during period		12,196			32,960
	Maximum amount at any month-end during period		12,000			37,320
	Weighted average interest at period-end		0.13	%		0.13	%
	Weighted average interest rate during period		0.25	%		0.22	%
	Securities sold under agreements to repurchase:
	Amount outstanding at period-end	$	624,573		$	650,235
	Average amount outstanding during period		688,704			763,259
	Maximum amount at any month-end during period		816,617			797,615
	Weighted average interest at period-end		0.03	%		0.64	%
	Weighted average interest rate during period		0.27	%		0.58	%
	FHLB borrowings:
	Amount outstanding at period-end	$	515,000		$	—
	Average amount outstanding during period		304,781			9,863
	Maximum amount at any month-end during period		565,000			—
	Weighted average interest at period-end		0.12	%		—
	Weighted average interest rate during period		0.15	%		0.18	%
	The Bank borrows funds on a secured basis by selling securities under agreements to repurchase, mainly in connection with treasury-management services offered to their deposit customers. Customer repurchase agreements generally mature daily. The Bank has the ability to exercise legal authority over the underlying securities. Federal funds purchased represent unsecured borrowings from other banks, generally on an overnight basis.
	The Bank has a line of credit with the Federal Home Loan Bank (FHLB) that is secured by a blanket pledge of certain mortgage loans. At December 31, 2014, the amount available under this line was approximately $2.8 billion, with the balance outstanding of $515 million. The Bank also has borrowing capacity at the Federal Reserve’s discount window of approximately $1.9 billion. No amounts were borrowed under this line at year-end 2014 or 2013.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stockholders' Equity	Note 10. Stockholders’ Equity
	Stock Repurchase Program
	On July 16, 2014, the Company’s board of directors approved a stock repurchase plan that authorized the repurchase of up to 5%, or approximately 4 million shares, of its currently outstanding common stock. The approved plan allows the Company to repurchase its common shares either in the open market in compliance with Rule 10b-18 promulgated under the Securities Exchange Act of 1934, as amended, or in privately negotiated transactions with non-affiliated sellers or as otherwise determined by the Company in one or more transactions, from time to time until December 31, 2015. Under this plan, we have purchased 1,529,542 shares of our common stock at an average price of $31.13 per share through December 31, 2014.
	The Company’s board of directors approved a stock repurchase program on April 30, 2013 that authorized the repurchase of up to 5% of the Company’s outstanding common stock. On May 8, 2013 Hancock entered into an accelerated share repurchase (ASR) transaction with Morgan Stanley & Co. LLC (Morgan Stanley). In the ASR transaction, the Company paid $115 million to Morgan Stanley and initially received from them approximately 2.8 million shares of Hancock common stock in 2013. On May 5, 2014, the final settlement of the ASR agreement occurred at which time the Company received an additional 0.6 million shares from Morgan Stanley. The number of shares delivered to the Company in this ASR transactions was based generally on the volume-weighted average price per share of the Hancock common stock during the term of the ASR agreement less a specified discount and on the amount paid at inception to Morgan Stanley, subject to certain adjustments in accordance with the terms of the ASR agreement. The 2013 program was superseded by the 2014 program.
	Accumulated Other Comprehensive Income (Loss)
	A rollforward of the components of accumulated other comprehensive income (loss) is included as follows:
	(in thousands)		Available			Held to			Employee			Loss on			Total
			for Sale			Maturity			Benefit			Effective
			Securities			Securities			Plans			Cash
						Transferred						Flow
						from AFS						Hedges
	Balance, December 31, 2011		$	60,478		$	—		$	(86,923	)	$	(65	)	$	(26,510	)
	Net change in unrealized gain (loss)			6,076			—			2,566			(502	)		8,140
	Transfer of net unrealized gain from AFS to HTM, net of cumulative tax effect			(24,598	)		24,598			—			—			—
	Reclassification adjustment for net losses realized and included in earnings			(1,441	)		—			7,548			311			6,418
	Amortization of unrealized net gain on securities transferred to held to maturity			—			(8,752	)		—			—			(8,752	)
	Income tax expense (benefit)			1,661			(3,244	)		3,879			(75	)		2,221
	Balance, December 31, 2012		$	38,854		$	19,090		$	(80,688	)	$	(181	)	$	(22,925	)
	Net change in unrealized gain (loss)			(105,270	)		—			82,502			(4	)		(22,772	)
	Transfer of net unrealized loss from AFS to HTM, net of cumulative tax effect			36,208			(36,208	)		—			—			—
	Reclassification adjustment for net losses realized and included in earnings			(105	)		—			8,331			301			8,527
	Amortization of unrealized net gain on securities transferred to held to maturity			—			(6,371	)		—			—			(6,371	)
	Income tax expense (benefit)			(38,576	)		(2,300	)		32,598			116			(8,162	)
	Balance, December 31, 2013		$	8,263		$	(21,189	)	$	(22,453	)	$	—		$	(35,379	)
	Net change in unrealized gain (loss)			15,413			—			(41,132	)		(592	)		(26,311	)
	Reclassification adjustment for net losses realized and included in earnings			—			—			390			—			390
	Amortization of unrealized net gain on securities transferred to held to maturity			—			3,297			—			—			3,297
	Income tax expense (benefit)			5,675			1,182			(14,569	)		(217	)		(7,929	)
	Balance, December 31, 2014		$	18,001		$	(19,074	)	$	(48,626	)	$	(375	)	$	(50,074	)
	Accumulated other comprehensive income (loss) (AOCI) is reported as a component of stockholders’ equity. AOCI includes unrealized gains and losses on available for sale (“AFS”) securities and unrealized gains/losses on AFS securities that were transferred to held to maturity securities in the first quarter of 2012 and the third quarter of 2013. Such amounts on the transferred securities will be amortized over the estimated remaining life of the security as an adjustment to yield, offsetting the related amortization of the net premium created in the transfer. 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 described in Note 5 will be reclassified into income over the life of the hedge. Gains and losses in AOCI are net of deferred income taxes.
	The following table shows the line items in the consolidated income statements affected by amounts reclassified from accumulated other comprehensive income:
	Twelve Months Ended December 31,
	Amount reclassified from AOCI (in thousands)		2014			2013			Increase (decrease) in affected line
									item in the income statement
	Gains and losses on sale of AFS securities		$	—		$	(105	)	Securities gains (losses)
	Tax effect			—			(37	)	Income taxes
	Net of tax			—			(68	)	Net income
	Amortization/accretion of unrealized net gain/loss on securities transferred to HTM		$	3,297		$	(6,371	)	Interest income
	Tax effect			1,154			(2,230	)	Income taxes
	Net of tax			2,143			(4,141	)	Net income
	Amortization of defined benefit pension and post-retirement items		$	390		$	8,331		(a) Employee benefits expense
	Tax effect			137			2,916		Income taxes
	Net of tax			253			5,415		Net income
	Gains and losses on cash flow hedges		$	—		$	301		Interest expense
	Tax effect			—			105		Income taxes
	Net of tax			—			196		Net income
	Total reclassifications, net of tax		$	2,396		$	1,402		Net income
	(a)	These accumulated other comprehensive income components are included in the computation of net periodic pension and post-retirement cost that is reported with employee benefits expense (see footnote 11 for additional details).
	Note: Tax effect calculated using 35% rate.
	Regulatory Capital
	Measures of regulatory capital are an important tool used by regulators to monitor the financial health of financial institutions. The primary quantitative measures used to gauge capital adequacy are the Tier 1 and total regulatory capital to risk-weighted assets (risk-based capital ratios) and the Tier 1 capital to average total assets (leverage ratio). Both the Company and the bank subsidiary are required to maintain minimum risk-based capital ratios of 8.0% total regulatory capital and 4.0% Tier 1 capital. The minimum leverage ratio is 3.0% for bank holding companies and banks that meet certain specified criteria, including having the highest supervisory rating. All others are required to maintain a leverage ratio of at least 4.0%.
	To evaluate capital adequacy, regulators compare an institution’s regulatory capital ratios with their agency guidelines, as well as with the guidelines established as part of the uniform regulatory framework for prompt corrective supervisory action toward financial institutions. The framework for prompt corrective action categorizes capital levels into one of five classifications rating from well-capitalized to critically under-capitalized. For an institution to be eligible to be classified as well capitalized its total risk-based capital ratios must be at least 10.0% for total capital and 6.0% for Tier 1 capital, and its leverage ratio must be at least 5.0%. In reaching an overall conclusion on capital adequacy or assigning a classification under the uniform framework, regulators also consider other subjective and quantitative measures of risk associated with an institution. The Bank was deemed to be well capitalized based upon the most recent notifications from their regulators. There are no conditions or events since those notifications that management believes would change the classifications. At December 31, 2014 and 2013, the Company and the Bank were in compliance with all of their respective minimum regulatory capital requirements.
	Following is a summary of the actual regulatory capital amounts and ratios for the Company and the Bank together with corresponding regulatory capital requirements at December 31, 2014 and 2013:
			Actual						Required for Minimum						To Be Well Capitalized
									Capital Adequacy						Under Prompt
															Corrective Action
															Provisions
	($ in thousands)		Amount			Ratio %			Amount			Ratio %			Amount			Ratio %
	At December 31, 2014
	Total capital (to risk weighted assets)
	Company		$	1,945,710			12.3		$	1,265,796			8			n/a			n/a
	Whitney Bank *			1,925,175			12.2			1,262,439			8		$	1,578,049			10
	Tier 1 capital (to risk weighted assets)
	Company		$	1,777,348			11.23		$	632,898			4			n/a			n/a
Whitney Bank *			1,756,813			11.13			631,220			4		$	946,829			6
Tier 1 leverage capital
Company		$	1,777,348			9.17		$	581,263			3			n/a			n/a
Whitney Bank *			1,756,813			9.13			577,493			3		$	962,488			5
At December 31, 2013
Total capital (to risk weighted assets)
Company		$	1,877,832			13.11		$	1,146,061			8			n/a			n/a
Hancock Bank			636,871			13.48			378,093			8		$	472,617			10
Whitney Bank			1,187,699			12.25			775,709			8			969,636			10
Tier 1 capital (to risk weighted assets)
Company		$	1,685,058			11.76		$	573,030			4			n/a			n/a
Hancock Bank			577,280			12.21			189,047			4		$	283,570			6
Whitney Bank			1,088,339			11.22			387,854			4			581,782			6
Tier 1 leverage capital
Company		$	1,685,058			9.34		$	541,066			3			n/a			n/a
Hancock Bank			577,280			9.01			192,137			3		$	320,228			5
Whitney Bank			1,088,339			9.02			361,878			3			603,129			5
*	(Consolidated charter effective 3/31/2014)
Regulatory Restrictions on Dividends
Regulatory policy statements provide that generally bank holding companies should pay dividends only out of current operating earnings and that the level of dividends must be consistent with current and expected capital requirements. Dividends received from its subsidiary banks have been the primary source of funds available to the Company for the payment of dividends to Hancock’s stockholders. Federal and state banking laws and regulations restrict the amount of dividends the Bank may distribute to Hancock without prior regulatory approval, as well as the amount of loans it may make to the Company. Dividends paid by Whitney Bank are subject to approval by the Commissioner of Banking and Consumer Finance of the State of Mississippi.

Retirement_Benefit_Plans

Retirement Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Retirement Benefit Plans	Note 11. Retirement Benefit Plans
	The Company offers a qualified defined benefit pension plan covering all eligible associates. Eligibility is based on minimum age and service-related requirements. The Company makes contributions to the qualified pension plans in amounts sufficient to meet funding requirements set forth in federal employee benefit and tax laws, plus such additional amounts as the Company may determine to be appropriate. Based on currently available information, Hancock plans to make a $10 million contribution to the pension plan during 2015.
	Certain legacy Whitney associates were also covered by an unfunded nonqualified defined benefit pension plan that provides retirement benefits to designated executive officers. Accrued benefits under the nonqualified plan covering certain legacy Whitney associates were frozen as of December 31, 2012 and no future benefits will be accrued under this plan. These benefits are calculated using the qualified plan’s formula, but without applying the restrictions imposed on qualified plans by certain provisions of the Internal Revenue Code. Benefits that become payable under the nonqualified plan supplement amounts paid from the qualified plan. The Whitney plan has been closed to new participants since 2008, and benefit accruals have been frozen for all participants other than those who met certain vesting, age and years of service criteria as of December 31, 2008.
	The Company also offers a defined contribution retirement benefit plan (401(k) plan) that covers substantially all associates who have been employed 60 days and meet certain other requirements and employment classification criteria. The Company matches 100% of the first 1% of compensation saved by a participant, and 50% of the next 5% of compensation saved. Newly eligible associates are automatically enrolled at an initial 3% savings rate unless the associate actively opts out of participation in the plan.
	The expense of the Company’s matching contributions to the 401(k) plan was $7.1 million in 2014, $7.0 million in 2013, and $6.1 million in 2012. The discretionary profit-sharing contribution under the legacy Whitney plan was $2.9 million for 2012.
	The Company also sponsors defined benefit postretirement plans for both legacy Hancock and legacy Whitney associates. The Hancock plans provide health care and life insurance benefits to retiring associates who participate in medical and/or group life insurance benefit plans for active associates at the time of retirement and have reached 55 years of age with ten years of service or age 65 with five years of service. The postretirement health care plan is contributory, with retiree contributions adjusted annually and subject to certain employer contribution maximums. Neither Hancock plan is available to associates hired on or after January 1, 2000.
	The legacy Whitney plans offer health care and life insurance benefit plans for retirees and their eligible dependents. Participant contributions are required under the health plan. Currently, these plans restrict eligibility for postretirement health benefits to retirees already receiving benefits as of the plan amendments in 2007 and to those active participants who were eligible to receive benefits as of December 31, 2007. Life insurance benefits are currently only available to associates who retired before December 31, 2007.
	The Company assumed certain trends in health care costs in the determination of the benefit obligations. At December 31, 2014, the plans assumed a 7.0% increase in the pre- and post-Medicare age health costs for 2015, declining over a period of five years to a 5.0% annual rate. At December 31, 2014, the RP 2014 Bottom Quartile mortality projection scale was used. Scale BB was used in 2013 and Scale AA was employed in 2012. Otherwise, the plan assumptions were substantially the same in 2013 all years.
	The following tables detail the changes in the benefit obligations and plan assets of the defined benefit for the years ended December 31, 2014 and 2013 as well as the funded status of the plans at each year end and the amounts recognized in the Company’s balance sheets. The Company uses a December 31 measurement date for all defined benefit pension plans and other postretirement benefit plans.
			2014			2013			2014			2013
	(in thousands)		Pension benefits						Other Post-
									retirement benefits
	Change in benefit obligation
	Benefit obligation:
	at beginning of year		$	412,608		$	437,104		$	31,592		$	37,831
	Service cost			12,920			16,118			126			215
	Interest cost			19,251			16,678			1,140			1,317
	Actuarial loss			29,738			(41,591	)		(3,467	)		(5,563	)
	Plan participants’ contributions			—			—			1,300			1,355
	Benefits paid			(17,606	)		(15,701	)		(2,323	)		(3,563	)
	Benefit obligation, end of year			456,911			412,608			28,368			31,592
	Change in plan assets
	Fair value of plan assets:
	at beginning of year			437,829			379,133			—			—
	Actual return on plan assets			17,826			63,695			—			—
	Employer contributions			1,123			11,123			1,023			2,208
	Plan participants’ contributions			—			—			1,300			1,355
	Benefit payments			(17,606	)		(15,701	)		(2,323	)		(3,563	)
	Expenses			(464	)		(421	)		—			—
	Fair value of plan assets, end of year			438,708			437,829			—			—
	Funded status at end of year—net (liability) asset		$	(18,203	)	$	25,221		$	(28,368	)	$	(31,592	)
	Amounts recognized in accumulated other comprehensive loss
	Unrecognized loss:
	at beginning of year		$	28,285		$	111,794		$	7,189		$	14,513
	Amount of (loss)/gain recognized during the year			(26	)		(6,570	)		(364	)		(1,761	)
	Net actuarial loss/(gain)			44,599			(76,939	)		(3,467	)		(5,563	)
	Unrecognized loss at end of year		$	72,858		$	28,285		$	3,358		$	7,189
	Projected benefit obligation			456,911			412,608			—			—
	Accumulated benefit obligation			426,073			379,607			—			—
	Fair value of plan assets			438,708			437,829			—			—
	The following table shows net periodic benefit cost included in expense and the changes in the amounts recognized in accumulated other comprehensive income during 2014 and 2013. Recognition of the net actuarial loss included in accumulated other comprehensive income is not required when the loss is less than ten percent of the projected benefit obligation or fair value of plan assets. Accordingly, Hancock will not recognize a material amount of the losses at December 31, 2014 as a component of net pension expense in 2015.
			Years Ended December 31,
			2014			2013			2012			2014			2013			2012
	($ in thousands)		Pension benefits									Other post-retirement benefits
	Net periodic benefit cost
	Service cost		$	12,920		$	16,118		$	12,989		$	126		$	215		$	192
	Interest cost			19,251			16,678			17,206			1,140			1,317			1,337
	Expected return on plan assets			(32,222	)		(27,928	)		(25,398	)		—			—			—
	Amortization of net loss/ prior service cost			26			6,570			6,582			364			1,761			918
	Recognized net amortization and deferral												—			—			—
	Net periodic benefit cost			(25	)		11,438			11,379			1,630			3,293			2,447
	Other changes in plan assets and benefit obligations recognized in other comprehensive income, before taxes
	Net (loss)/gain recognized during the year			(26	)		(6,570	)		(6,582	)		(364	)		(1,761	)		(966	)
	Net actuarial loss/(gain)			44,599			(76,939	)		(7,001	)		(3,467	)		(5,563	)		4,435
	Amortization of prior service cost			—			—			—			—			—			48
	Total recognized in other comprehensive income			44,573			(83,509	)		(13,583	)		(3,831	)		(7,324	)		3,517
	Total recognized in net periodic benefit cost and other comprehensive income		$	44,548		$	(72,071	)	$	(2,204	)	$	(2,201	)	$	(4,031	)	$	5,964
	Discount rate for benefit obligations			4.11	%		4.73	%		3.82	%		4.02	%		4.58	%		3.69	%
	Discount rate for net periodic benefit cost			4.73	%		3.82	%		4.32	%		4.58	%		3.69	%		4.18	%
	Expected long-term return on plan assets			7.5	%		7.5	%		7.5	%		n/a			n/a			n/a
	Rate of compensation increase			scaled	*		4	%		3.73	%		n/a			n/a			n/a
	*	Graded scale, declining from 7.00% at age 20 to 2.00% at age 60
	The long term rate of return on plan assets is determined by using the weighted-average of historical real returns for major asset classes based on target asset allocations. At December 31, 2014, the discount rate was calculated by matching expected future cash flows to the Wells Fargo Pension Discount Curve Liability Index. At December 31, 2013, this calculation used the Citigroup Pension Discount Curve Liability Index.
	The following shows expected plan benefit payments over the next ten years:
(in thousands)		Pension			Post-retirement			Total
2015		$	18,617		$	1,554		$	20,171
2016			19,744			1,503			21,247
2017			20,744			1,406			22,150
2018			21,863			1,397			23,260
2019			22,505			1,430			23,935
2020-2024			128,044			7,391			135,435
		$	231,517		$	14,681		$	246,198
The expected benefit payments are estimated based on the same assumptions used to measure the Company’s benefit obligations at December 31, 2014.
The following table illustrates the effect on the annual periodic postretirement benefit costs and postretirement benefit obligation of a 1% increase or 1% decrease in the assumed health care cost trend rates from the rates assumed at December 31, 2014:
(in thousands)		1% Decrease			Assumed			1% Increase
		in Rates			Rates			in Rates
Aggregated service and interest cost		$	1,115		$	1,266		$	1,451
Postretirement benefit obligation			25,046			28,366			32,412
The fair values of pension plan assets at December 31, 2014 and 2013, by asset category, are shown in the following tables:
Fair Value Measurements by Asset Category / Fund		Total			Quoted Prices in			Significant			Significant
					Active Markets			Observable			Unobservable
					for Identical			Inputs			Inputs
					Assets			(Level 2)			(Level 3)
					(Level 1)
(in thousands)
Fair Value Measurements at December 31, 2014
Cash and cash-equivalents:
Cash and equivalents		$	10,243		$	10,243		$	—		$	—
Total cash and cash-equivalents			10,243			10,243			—			—
Fixed income:
US government and agency securities			15,518			1,082			14,436			—
Municipal securities			33,980			—			33,980			—
Emerging market debt fund			19,505			—			—			19,505
Foreign bonds, notes and debentures			2,588			—			2,588			—
Hancock Horizon Core Bond Fund			51,529			—			51,529			—
Corporate debt			62,429			—			62,429			—
Total fixed income			185,549			1,082			164,962			19,505
Real Assets:
Real assets fund			24,151			24,151			—			—
Total cash and cash-equivalents			24,151			24,151			—			—
Equity:
Hancock Horizon Quantitative Long/Short Fund			5,603			5,603			—			—
Hancock Horizon Diversified International Fund			62,750			62,750			—			—
Hancock Horizon Burkenroad Small Cap Fund			9,296			9,296			—			—
Hancock Horizon Growth Fund			26,469			26,469			—			—
Hancock Horizon Value Fund			30,321			30,321			—			—
Equity securities			84,325			84,325			—			—
Mineral Interests			1			—			—			1
Total equity			218,765			218,764			—			1
Total		$	438,708		$	254,240		$	164,962		$	19,506
Fair Value Measurements by Asset Category / Fund		Total			Quoted Prices in			Significant			Significant
					Active Markets			Observable			Unobservable
					for Identical			Inputs			Inputs
					Assets (Level 1)			(Level 2)			(Level 3)
(in thousands)
Fair Value Measurements at December 31, 2013
Cash and cash-equivalents:
Cash and equivalents		$	5,683		$	5,683		$	—		$	—
Hancock Horizon Government Money Market Fund			9,531			9,531			—			—
Total cash and cash-equivalents			15,214			15,214			—			—
Fixed income:
US government and agency securities			21,485			4,383			17,102			—
Municipal securities			40,476			—			40,476			—
Hancock Horizon Core Bond Fund			59,674						59,674			—
Corporate debt			43,440			6,923			36,517			—
Total fixed income			165,075			11,306			153,769			—
Equity:
Hancock Horizon Quantitative Long/Short Fund			6,593			6,593			—			—
Hancock Horizon Diversified International Fund			26,072			26,072			—			—
Hancock Horizon Burkenroad Small Cap Fund			4,108			4,108			—			—
Hancock Horizon Growth Fund			27,847			27,847			—			—
Hancock Horizon Value Fund			34,216			34,216			—			—
Hancock Horizon Diversified Income Fund			8,758			8,758			—			—
Equity securities			149,946			149,946			—			—
Total Equity			257,540			257,540			—			—
TOTAL		$	437,829		$	284,060		$	153,769		$	—
The percentage allocations of the plan assets by asset category and corresponding target allocations at December 31, 2014 and 2013 follow:
		Plan Assets						Target Allocation at
		at December 31,						December 31,
		2014			2013			2014			2013
Asset category
Equity securities			50	%		59	%		30 - 60	%		30 - 70	%
Fixed income securities			42	%		38	%		25 - 65	%		25 - 65	%
Real Assets			6	%		0	%		0 - 10	%		0 - 10	%
Cash equivalents			2	%		3	%		0 - 5	%		0 - 5	%
			100	%		100	%
Plan assets are invested in long-term strategies and evaluated within the context of a long-term investment horizon. Plan assets will be diversified across multiple asset classes so as to minimize the risk of large losses. Short-term fluctuations in value will be considered secondary to long-term results. The Company employs a total return approach whereby a diversified mix of asset class investments are used to maximize the long-term return of plan assets for an acceptable level of risk. Risk tolerance is established through careful consideration of the plan liabilities, plan funded status and the Company’s financial condition. The investment performance of the plan is regularly monitored to ensure that appropriate risk levels are being taken and to evaluate returns versus a suitable market benchmark. The benefits investment committee meets periodically to review the policy, strategy, and performance of the plans.

ShareBased_Payment_Arrangement

Share-Based Payment Arrangements	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payment Arrangements	Note 12. Share-Based Payment Arrangements
	Hancock maintains incentive compensation plans that incorporate share-based payment arrangements for associates and directors. The current plan under which share-based awards may be granted, the 2014 Long Term Incentive Plan (the “2014 Plan”), was approved by the Company’s stockholders at the 2014 annual meeting as a successor to the Company’s 2005 Long-Term Incentive Plan (the “2005 Plan”). Certain share-based awards remain outstanding under the 2005 Plan and prior equity incentive compensation plans, but no future awards may be granted thereunder.
	The Compensation Committee of the Company’s Board of Directors administers the equity incentive plans, makes determinations with respect to participation by employees or directors and authorizes the share-based awards. Under the 2014 Plan, participants may be awarded stock options (including incentive stock options for associates), restricted shares, performance stock awards and stock appreciation rights, all on a stand-alone, combination or tandem basis. To date, the Committee has awarded stock options, tenure-based restricted shares and performance stock awards under the 2014 Plan and the prior equity incentive plans.
	Under the 2014 Plan, future awards may be granted for the issuance of an aggregate of 1,796,357 shares of the Company’s common stock, plus the number of any shares of the Company’s common stock for which awards under the 2005 Plan are cancelled, expired, forfeited or settled in cash. The 2014 Plan limits the number of shares for which awards may be granted to any participant during any calendar year to 100,000 shares. The Company may use authorized unissued shares or shares held in treasury to satisfy awards under the 2014 Plan.
	At December 31, 2014 there were 1.7 million shares available for future issuance under equity compensation plans (including 170,935 shares under the Company’s 2010 Employee Stock Ownership Plan).
	For the years ended December 31, 2014, 2013 and 2012 total share-based compensation recognized in income was $14.0 million, $13.1 million and $11.0 million, respectively. The total recognized tax benefit related to the share-based compensation was $4.9 million, $4.6 million and $3.9 million, respectively, for 2014, 2013 and 2012.
	A summary of option activity for 2014 is presented below:
	Options	Number of			Weighted-		Weighted-		Aggregate
		Shares			Average		Average		Intrinsic
					Exercise		Remaining		Value
					Price ($)		Contractual		$0
							Term
							(Years)
	Outstanding at January 1, 2014		1,332,656		$	38.85
	Granted		—			—
	Exercised		(81,842	)		30.4
	Cancelled/Forfeited		(197,974	)		36.06
	Expired		(113,447	)		63.41
	Outstanding at December 31, 2014		939,393		$	37.21		4.2	$	221
	Exercisable at December 31, 2014		781,529		$	38.62		3.7	$	107
	The number of shares subject to the outstanding options reflected above include shares to be issued upon the exercise of options that were assumed by the Company in the acquisition of Whitney Holding Corporation.
	The exercise price for stock options is set at the closing market price of the Company’s stock on the date immediately preceding the date of grant, except for the exercise price of certain options granted to major stockholders which is set at 110% of the market price. Option awards generally vest equally over five years of continuous service and have ten-year contractual terms.
	The total intrinsic value of options exercised during 2014, 2013 and 2012 was $0.4 million, $0.6 million, and $0.8 million, respectively.
	The weighted-average grant-date fair values of options awarded during 2012 were $8.43. There were no options granted in 2014 or 2013. The fair value of each option award was estimated as of the grant date using the Black-Scholes-Merton option-pricing model. The significant assumptions made in applying the option-pricing model are noted in the following table. Expected volatilities are based on implied volatilities from traded options on the Company’s stock, historical volatility of the Company’s stock and other factors. The expected term of options granted was derived from the output of the option valuation model and represents the period of time that options granted are expected to be outstanding.
		2012
	Expected volatility		38.64	%
	Expected dividends		3.23	%
	Expected term (in years)		6.58
	Risk-free rates		1.78	%
	There were no options granted in 2013.
	A summary of the status of the Company’s nonvested restricted and performance shares as of December 31, 2014 and changes during 2014 are presented below:
		Number of			Weighted-
		Shares			Average
					Grant-Date
					Fair Value  ($)
	Nonvested at January 1, 2014		1,981,820		$	31.75
	Granted		608,856			34.42
	Vested		(391,859	)		32.76
	Cancelled/Forfeited		(158,518	)		32.75
	Nonvested at December 31, 2014		2,040,299		$	32.27
	As of December 31, 2014, there was $32.8 million of total unrecognized compensation related to nonvested restricted shares expected to vest. This compensation is expected to be recognized in expense over a weighted-average period of 3.7 years. The total fair value of shares which vested during 2014 and 2013 was $12.8 million and $3.2 million, respectively.
	In 2014, Hancock granted 69,857 performance shares with an average fair value of $38.14 per share to key members of executive and senior management. The number of 2014 performance shares that ultimately vest, if any, at the end of the three-year required service period will be based on the relative rank of Hancock’s three-year total shareholder return (TSR) among the TSRs of a peer group of fifty regional banks. The maximum number of performance shares that could vest is 200% of the target award. The fair value of the awards at the grant date was determined using a Monte Carlo simulation method. Compensation expense for these performance shares will be recognized on a straight-line basis over the service period.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Note 13. Fair Value of Financial Instruments
	The Financial Accounting Standards Board (FASB) defines fair value as the exchange price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The FASB’s guidance also established 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 Measured on a Recurring Basis
	The following table presents for each of the fair-value hierarchy levels the Company’s financial assets and liabilities that are measured at fair value (in thousands) on a recurring basis in the consolidated balance sheets.
			December 31, 2014
	(in thousands)		Level 1		Level 2		Total
	Assets
	Available for sale debt securities:
	U.S. Treasury and government agency securities		$	—	$	300,508	$	300,508
	Municipal obligations			—		14,176		14,176
	Corporate debt securities			—		3,500		3,500
	Mortgage-backed securities			—		1,245,564		1,245,564
	Collateralized mortgage obligations			—		86,864		86,864
	Equity securities			9,553		—		9,553
	Total available for sale securities			9,553		1,650,612		1,660,165
	Derivative assets (1)			—		19,432		19,432
	Total recurring fair value measurements – assets		$	9,553	$	1,670,044	$	1,679,597
	Liabilities
	Derivative liabilities (1)		$	—	$	20,860	$	20,860
	Total recurring fair value measurements – liabilities		$	—	$	20,860	$	20,860
		-1	For further disaggregation of derivative assets and liabilities, see Note 5 – Derivatives
			31-Dec-13
	(in thousands)		Level 1		Level 2		Total
	Assets
	Available for sale debt securities:
	U.S. Treasury and government agency securities		$	505	$	—	$	505
	Municipal obligations			—		35,961		35,961
	Corporate debt securities			—		3,500		3,500
	Mortgage-backed securities			—		1,276,958		1,276,958
	Collateralized mortgage obligations			—		94,125		94,125
	Equity securities			10,723		—		10,723
	Total available for sale securities			11,228		1,410,544		1,421,772
	Derivative assets (1)			—		15,579		15,579
	Total recurring fair value measurements – assets		$	11,228	$	1,426,123	$	1,437,351
	Liabilities
	Derivative liabilities (1)		$	—	$	15,006	$	15,006
	Total recurring fair value measurements – liabilities		$	—	$	15,006	$	15,006
		-1	For further disaggregation of derivative assets and liabilities, see Note 5 – Derivatives
	Securities classified as level 1 within the valuation hierarchy include U.S. Treasury securities and certain other debt and equity securities. Level 2 classified securities include U.S. Treasury securities, obligations of 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 municipal bonds. The level 2 fair value measurements for investment securities are obtained quarterly from a third-party pricing service that uses industry-standard pricing models. Substantially all of the model inputs were observable in the marketplace or can be supported by observable data.
	The Company invests only in high quality securities of investment grade quality with a targeted duration, for the overall portfolio, generally between two to five. Company policies limit investments to securities having a rating of not less than “Baa” or its equivalent by a nationally recognized statistical rating agency. There were no transfers between valuation hierarchy levels during the periods shown.
	The fair value of derivative financial instruments, which are predominantly 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 subject to master netting arrangements consistent with how market participants would price the net risk exposure at the measurement date.
	The Company also has certain derivative instruments associated with the Bank’s mortgage-banking activities. These derivative instruments include interest rate lock commitments on prospective residential mortgage loans and forward commitments to sell these loans to investors on a best efforts delivery basis. The fair value of these derivative instruments is measured using observable market prices for similar instruments and is classified as a level 2 measurement.
	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 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 following table presents for each of the fair value hierarchy levels the Company’s financial assets that are measured at fair value on a nonrecurring basis:
			December 31, 2014
	(in thousands)		Level 1		Level 2		Level 3		Total
	Collateral dependent impaired loans		$	—	$	30,204	$	—	$	30,204
	Other real estate owned			—		—		29,715		29,715
	Total nonrecurring fair value measurements		$	—	$	30,204	$	29,715	$	59,919
			31-Dec-13
	(in thousands)		Level 1		Level 2		Level 3		Total
	Collateral dependent impaired loans		$	—	$	24,392	$	—	$	24,392
	Other real estate owned			—		—		34,105		34,105
	Total nonrecurring fair value measurements		$	—	$	24,392	$	34,105	$	58,497
	Accounting guidance from the FASB requires the disclosure of estimated fair value information about certain on-and off-balance sheet financial instruments, including those financial instruments that are not measured and reported at fair value on a recurring basis. The significant methods and assumptions used by the Company to estimate the fair value of financial instruments are discussed below.
	Cash, Short – Term Investments and Federal Funds Sold – for those 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. 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. For the remaining portfolio, fair values were generally estimated 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 with similar credit quality.
	Loans Held For Sale – these loans are recorded at fair value and carried at the lower of cost of market. The carrying amount is considered a reasonable estimate of fair value.
	Accrued Interest Receivable and Accrued Interest Payable – the carrying amounts are a reasonable estimate of fair values.
	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 amounts). The fair value of fixed-maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities.
	Federal Funds Purchased, Securities Sold under Agreements to Repurchase, 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.
The estimated fair values of the Company’s financial instruments were as follows:
		December 31, 2014						Total		Carrying
(in thousands)		Level 1		Level 2		Level 3		Fair Value		Amount
Financial assets:
Cash, interest-bearing bank deposits, and federal funds sold		$	1,159,403	$	—	$	—	$	1,159,403	$	1,159,403
Available for sale securities			9,553		1,650,612		—		1,660,165		1,660,165
Held to maturity securities			—		2,186,340		—		2,186,340		2,166,289
Loans, net			—		30,204		13,672,427		13,702,631		13,766,514
Loans held for sale			—		20,252		—		20,252		20,252
Accrued interest receivable			47,501		—		—		47,501		47,501
Derivative financial instruments			—		19,432		—		19,432		19,432
Financial liabilities:
Deposits		$	—	$	—	$	16,398,878	$	16,398,878	$	16,572,831
Federal funds purchased			12,000		—		—		12,000		12,000
Securities sold under agreements to repurchase			624,573		—		—		624,573		624,573
FHLB Borrowings			515,000		—		—		515,000		515,000
Long-term debt			—		346,379		—		346,379		374,371
Accrued interest payable			4,204		—		—		4,204		4,204
Derivative financial instruments			—		20,860		—		20,860		20,860
		31-Dec-13						Total		Carrying
(in thousands)		Level 1		Level 2		Level 3		Fair Value		Amount
Financial assets:
Cash, interest-bearing bank deposits, and federal funds sold		$	617,280	$	—	$	—	$	617,280	$	617,280
Available for sale securities			11,228		1,410,544		—		1,421,772		1,421,772
Held to maturity securities			—		2,576,584		—		2,576,584		2,611,352
Loans, net			—		24,392		12,023,330		12,047,722		12,191,191
Loans held for sale			—		24,515		—		24,515		24,515
Accrued interest receivable			42,977		—		—		42,977		42,977
Derivative financial instruments			—		15,579		—		15,579		15,579
Financial liabilities:
Deposits		$	—	$	—	$	15,352,024	$	15,352,024	$	15,360,516
Federal funds purchased			7,725		—		—		7,725		7,725
Securities sold under agreements to repurchase			650,235		—		—		650,235		650,235
Long-term debt			—		385,557		—		385,557		385,826
Accrued interest payable			4,353		—		—		4,353		4,353
Derivative financial instruments			—		15,006		—		15,006		15,006

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 14. Commitments and Contingencies
	Credit Related
	In the normal course of business, the Bank enters into financial instruments, such as commitments to extend credit and letters of credit, to meet the financing needs of their customers. Such instruments are not reflected in the accompanying consolidated financial statements until they are funded, although they expose the Bank to varying degrees of credit risk and interest rate risk in much the same way as funded loans.
	Commitments to extend credit include revolving commercial credit lines, nonrevolving loan commitments issued mainly to finance the acquisition and development or construction of real property or equipment, and credit card and personal credit lines. The availability of funds under commercial credit lines and loan commitments generally depends on whether the borrower continues to meet credit standards established in the underlying contract and has not violated other contractual conditions. Loan commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee by the borrower. Credit card and personal credit lines are generally subject to cancellation if the borrower’s credit quality deteriorates. A number of commercial and personal credit lines are used only partially or, in some cases, not at all before they expire, and the total commitment amounts do not necessarily represent future cash requirements of the Company.
	A substantial majority of the letters of credit are standby agreements that obligate the Bank to fulfill a customer’s financial commitments to a third party if the customer is unable to perform. The Bank issues standby letters of credit primarily to provide credit enhancement to their customers’ other commercial or public financing arrangements and to help them demonstrate financial capacity to vendors of essential goods and services.
	The contract amounts of these instruments reflect the Company’s exposure to credit risk. The Company undertakes the same credit evaluation in making loan commitments and assuming conditional obligations as it does for on-balance sheet instruments and may require collateral or other credit support. These off-balance sheet financial instruments are summarized below:
		December 31,
	(in thousands)	2014			2013
	Commitments to extend credit	$	5,700,546		$	5,234,929
	Letters of credit		414,408			422,284
	Legal Proceedings
	The Company is party to various legal proceedings arising in the ordinary course of business. Management does not believe that loss contingencies, if any, arising from pending litigation and regulatory matters will have a material adverse effect on the consolidated financial position or liquidity of the Company.
	Other Contingencies
	In connection with the 2011 Whitney acquisition, the Company recorded a $58.0 million liability for contingent payments to certain employees for arrangements that were in existence prior to acquisition. The following table presents the changes in the liability for 2014 and 2013.
	(in thousands)	2014			2013
	Balance, January 1	$	8,661		$	8,165
	Adjustments		(1,690	)		2,765
	Cash Payments		(6,971	)		(2,269	)
	Balance, December 31	$	—		$	8,661
	Lease Commitments
	The Company currently is obligated under a number of non-cancelable operating leases for buildings and equipment. Certain of these leases have escalation clauses and renewal options. Future minimum lease payments for non-cancelable operating leases with initial terms in excess of one year were as follows at December 31, 2014:
	(in thousands)	Operating
		Leases
	2015	$	11,766
	2016		11,856
	2017		11,064
	2018		9,782
	2019		7,917
	Thereafter		28,293
	Total minimum lease payments	$	80,678
	Rental expense approximated $11.4 million, $12.9 million and $14.3 million for the years ended December 31, 2014, 2013, and 2012, respectively.

Other_Noninterest_Income_and_O

Other Noninterest Income and Other Noninterest Expense	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Other Noninterest Income and Other Noninterest Expense	Note 15. Other Noninterest Income and Other Noninterest Expense
	The components of other noninterest income and other noninterest expense are as follows:
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Other noninterest income:
	Income from bank-owned life insurance	$	10,314	$	11,223	$	11,163
	Credit-related fees		11,121		8,724		6,681
	Income from derivatives		1,645		4,675		3,600
	Gain on sales of assets		1,279		1,932		4,366
	Safety deposit box income		1,830		1,923		2,006
	Other miscellaneous income		9,249		8,754		9,072
	Total other noninterest income	$	35,438	$	37,231	$	36,888
	Other noninterest expense:
	Advertising	$	8,937	$	10,399	$	13,515
	Ad valorem and franchise taxes		10,492		9,727		8,321
	Printing and supplies		4,550		5,112		7,491
	Insurance expense		3,919		4,094		5,494
	Travel		4,066		4,716		5,758
	Entertainment and contributions		5,762		5,265		6,049
	Tax credit investment amortization		8,817		10,781		5,974
	Other miscellaneous expense		30,585		45,242		27,669
	Total other noninterest expense	$	77,128	$	95,336	$	80,271
	Other miscellaneous expense as shown in the table above includes nonoperating items totaling $9.6 million in 2014, $19.7 million in 2013 and $3.2 million in 2012. Details of the 2014 items are further discussed below:
	FDIC Settlement
	During the second quarter of 2014, the Company recorded a $10.3 million expense for the settlement of an assessment by the FDIC related to its targeted review of certain previously paid loss claim reimbursement amounts. The assessment demanded repayment of these amounts due to the FDIC’s disagreement with the manner in which certain assets were administered and losses were calculated. During the third quarter, the settlement was paid and the FDIC resumed payment of claims.
	Sale of Insurance Business
	In April 2014, the Company sold its property and casualty and group benefits insurance intermediary business. The lines of business being divested represent approximately half of the Company’s 2013 insurance commissions and fees. A gain of $9.4 million was recorded on the sale based on a $15.5 million sales price less the related tangible and intangible assets.
	Branch Closures
	During 2014, the Company recorded $4.6 million in write-downs related to the 2014 closure of 15 branch locations in Mississippi, Florida and Louisiana as part of its ongoing branch rationalization process.
	Reverse Repurchase Obligations Early Termination Fee
	During the second quarter of 2014, the Company recorded $3.5 million in fees related to the early termination of reverse repurchase obligations.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Note 16. Income Taxes
	Income tax expense included in net income consisted of the following components:
		Years Ended December 31,
	(in thousands)	2014			2013			2012
	Included in net income
	Current federal	$	41,441		$	14,797		$	11,195
	Current state		1,487			(3,207	)		1,953
	Total current provision		42,928			11,590			13,148
	Deferred federal		21,483			37,403			34,219
	Deferred state		2,054			3,517			(1,754	)
	Total deferred provision		23,537			40,920			32,465
	Total included in net income	$	66,465		$	52,510		$	45,613
	Included in shareholders’ equity
	Deferred tax related to retirement benefits		(14,681	)	$	32,749		$	3,788
	Deferred tax related to securities		6,857			(40,876	)		(1,583	)
	Deferred tax related to derivatives and hedging		(217	)		116			(75	)
	Total included in shareholders’ equity	$	(8,041	)	$	(8,011	)	$	2,130
	Temporary differences arise between the tax bases of assets or liabilities and their carrying amounts for financial reporting purposes. The expected tax effects when these differences are resolved are recorded currently as deferred tax assets or liabilities.
	Significant components of the Company’s deferred tax assets and liabilities were as follows:
		December 31,
	(in thousands)	2014			2013
	Deferred tax assets:
	Allowance for loan losses	$	57,667		$	64,389
	Employee compensation and benefits		50,361			31,293
	Loan purchase accounting adjustments		35,094			75,595
	Tax credit carryforward		35,553			41,083
	Securities		—			6,432
	State net operating loss		1,535			1,535
	Other		18,702			21,611
	Gross deferred tax assets		198,912			241,938
	Federal valuation allowance		—			—
	State valuation allowance		(1,529	)		(1,531	)
	Subtotal valuation allowance		(1,529	)		(1,531	)
	Net deferred tax assets		197,383			240,407
	Deferred tax liabilities:
	Fixed assets & intangibles		(88,062	)		(93,952	)
	Securities		(724	)		—
	Deferred gain on acquisition		—			(4,407	)
	FDIC indemnification asset		(18,769	)		(37,775	)
	Other		(15,493	)		(14,565	)
	Gross deferred tax liabilities		(123,048	)		(150,699	)
	Net deferred tax asset (liability)	$	74,335		$	89,708
	Reported income tax expense differed from amounts computed by applying the statutory income tax rate of 35% to earnings before income taxes because of the following factors:
		Years Ended December 31,
		2014						2013						2012
	($ in thousands)	Amount			%			Amount			%			Amount			%
	Taxes computed at statutory rate	$	84,766			35	%	$	75,553			35	%	$	69,074			35	%
	Increases (decreases) in taxes resulting from:
	State income taxes, net of federal income tax benefit		4,649			2	%		2,352			1	%		(78	)		0	%
	Tax-exempt interest		(6,301	)		-3	%		(6,487	)		-3	%		(7,127	)		-4	%
	Bank owned life insurance		(3,554	)		-1	%		(3,926	)		-2	%		(4,005	)		-2	%
	Tax credits		(16,577	)		-7	%		(15,743	)		-7	%		(13,661	)		-7	%
	Other, net		3,482			1	%		761			0	%		1,410			1	%
	Income tax expense	$	66,465			27	%	$	52,510			24	%	$	45,613			23	%
	As of December 31, 2014, the Company had approximately $36 million in federal tax credit carryforwards that originated in the tax years from 2008 through 2014 and that begin expiring in 2028. The Company had approximately $29 million in state net operating loss carryforwards that originated in the tax years 2002 through 2014 and that begin expiring in 2017. A valuation allowance has been established for the state net operating loss carryforwards. The impact of this valuation allowance is immaterial to the financial statements.
	The tax benefit of a position taken or expected to be taken in a tax return should be recognized when it is more likely than not that the position will be sustained on its technical merits. The liability for unrecognized tax benefits was immaterial at December 31, 2014 and 2013. The Company does not expect the liability for unrecognized tax benefits to change significantly during 2014. Hancock recognizes interest and penalties, if any, related to income tax matters in income tax expense, and the amounts recognized during 2014, 2013 and 2012 were insignificant.
	The Company invests in Federal NMTC projects related to tax credit allocations that have been awarded to its wholly-owned Community Development Entity (CDE) as well as projects that utilize credits awarded to unrelated CDEs. From 2008 through 2014, the Company’s CDE was awarded three allocations totaling $148 million. These awards are expected to generate tax credits totaling $57.7 million over their seven-year compliance periods.
	The Company intends to continue making investments in tax credit projects, though its ability to access new credits will depend upon, among other factors, federal and state tax policies and the level of competition for such credits. Based only on tax credit investments that have been made, the Company expects to realize tax credits over the next three years totaling $12.9 million, $10.1 million and $9.0 million for 2015, 2016 and 2017, respectively.
	The Company and its subsidiaries file a consolidated U.S. federal income tax return, as well as filing various state returns. Generally, the returns for years prior to 2011 are no longer subject to examination by taxing authorities.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share	Note 17. Earnings Per Share
	Hancock 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 securities consist of unvested share-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:
		Years Ended December 31,
	($ in thousands, except per share amounts)	2014		2013		2012
	Numerator:
	Net income to common shareholders	$	175,722	$	163,356	$	151,742
	Net income allocated to participating securities - basic and diluted		3,631		3,105		1,557
	Net income allocated to common shareholders - basic and diluted	$	172,091	$	160,251	$	150,185
	Denominator:
	Weighted-average common shares - basic		81,804		83,066		84,767
	Dilutive potential common shares		230		101		821
	Weighted average common shares - diluted		82,034		83,167		85,588
	Earnings per common share:
	Basic	$	2.1	$	1.93	$	1.77
	Diluted	$	2.1	$	1.93	$	1.75
	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 reduce a loss per share. Weighted-average anti-dilutive potential common shares totaled 621,327 for the twelve months ended December 31, 2014, 916,756 for the twelve months ended December 31, 2013, and 1,057,925 for the twelve months ended December 31, 2012.

Segment_Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Reporting	Note 18. Segment Reporting
	Accounting standards require that information be reported about a company’s operating segments using a “management approach.” Reportable segments are identified in these standards as those revenue-producing components for which separate financial information is produced internally and which are subject to evaluation by the chief operating decision maker in deciding how to allocate resources to segments. On March 31, 2014, the Company combined its two state bank charters into one charter. Due to the charter change and consistent with its stated strategy that is focused on providing a consistent package of community banking products and services across all markets, the Company has identified its overall banking operations as its only reportable segment. Because the overall banking operations comprise substantially all of the consolidated operations, no separate segment disclosures are presented.

Condensed_Parent_Company_Infor

Condensed Parent Company Information	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Parent Company Information	Note 19. Condensed Parent Company Information
	The following condensed financial statements reflect the accounts and transactions of Hancock Holding Company only:
	Condensed Balance Sheets
		December 31,
	(in thousands)	2014			2013
	Assets:
	Cash	$	44,771		$	66,338
	Securities available for sale		97,423			107,017
	Investment in bank subsidiaries		2,452,529			2,408,389
	Investment in non-bank subsidiaries		3,202			5,319
	Due from subsidiaries and other assets		24,896			24,091
		$	2,622,821		$	2,611,154
	Liabilities and Stockholders’ Equity:
	Long term debt	$	149,600		$	184,800
	Other liabilities		819			1,285
	Stockholders’ equity		2,472,402			2,425,069
		$	2,622,821		$	2,611,154
	Condensed Statements of Income
		Years Ended December 31,
	(in thousands)	2014			2013			2012
	Operating Income
	From subsidiaries
	Cash dividends received from bank subsidiaries	$	124,000		$	249,000		$	25,000
	Non-cash dividend from bank subsidiary in restructuring		—			—			225,000
	Dividends received from non-bank subsidiaries		—			2,990			150
	Equity in earnings of subsidiaries greater than (less than) dividends received		58,358			(82,203	)		(94,486	)
	Total operating income		182,358			169,787			155,664
	Other (expense) income, net		(10,035	)		(10,335	)		(6,673	)
	Income tax expense (benefit)		(3,399	)		(3,904	)		(2,751	)
	Net income	$	175,722		$	163,356		$	151,742
	Condensed Statements of Cash Flows
		Years Ended December 31,
	(in thousands)	2014			2013			2012
	Cash flows from operating activities—principally dividends received from subsidiaries	$	126,491		$	257,251		$	18,789
	Net cash provided by operating activities		126,491			257,251			18,789
	Cash flows from investing activities
	Contribution of capital to subsidiary		—			(870	)		(955	)
	Loans to nonbank subsidiaries, net of repayments		—			—			1,684
	Purchase of available for sale securities		—			—			(77,058	)
	Proceeds from principal paydowns of securities available for sale		12,664			18,685			47,305
	Other, net		—			(5,630	)		—
	Net cash used by investing activities		12,664			12,185			(29,024	)
	Cash flows from financing activities:
	Proceeds from issuance of long term debt		—			—			217,933
	Repayment of long term debt		(35,200	)		(35,200	)		(140,000	)
	Dividends paid to stockholders		(80,392	)		(81,673	)		(83,151	)
	Stock transactions, net		(45,130	)		(112,266	)		13,479
	Net cash provided by (used by) financing activities		(160,722	)		(229,139	)		8,261
	Net increase (decrease) in cash		(21,567	)		40,297			(1,974	)
	Cash, beginning of year		66,338			26,041			28,015
	Cash, end of year	$	44,771		$	66,338		$	26,041

Summary_of_Significant_Account1

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The consolidated financial statements include the accounts of the Company and all other entities in which the Company has a controlling interest. Significant inter-company transactions and balances have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation.
Use of Estimates	Use of Estimates
	The accounting principles the Company follows and the methods for applying these principles conform with U.S. GAAP and with general practices followed by the banking industry. These accounting principles and practices 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.
Fair Value Accounting	Fair Value Accounting
	U.S. GAAP requires the use of fair values in determining the carrying values of certain assets and liabilities in the financial statements, as well as for specific disclosures about certain assets and liabilities.
	Accounting guidance established 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 (level 1) and the lowest priority to unobservable inputs such as a reporting entity’s own data or information or assumptions developed from this 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.
Acquisition Accounting	Acquisition Accounting
	Acquisitions are accounted for under the purchase method of accounting. Purchased assets, including identifiable intangibles, and assumed liabilities are recorded at their respective acquisition date fair values. If the fair value of net assets purchased exceeds the consideration given, a bargain purchase gain is recognized. If the consideration given exceeds the fair value of the net assets received, goodwill is recognized. Fair values are subject to refinement for up to one year after the closing date of an acquisition as information relative to closing date fair values becomes available. Purchased loans acquired in a business combination are recorded at estimated fair value on their purchase date with no carryover of the related allowance for loan losses. See the Acquired Loans section below for accounting policy regarding loans acquired in a business combination.
	All identifiable intangible assets that are acquired in a business combination are recognized at fair value on the acquisition date. Identifiable intangible assets are recognized separately if they arise from contractual or other legal rights or if they are separable (i.e., capable of being sold, transferred, licensed, rented, or exchanged separately from the entity).
Securities	Securities
	Securities are classified as trading, held to maturity or available for sale. Management determines the appropriate classification of debt and equity securities at the time of purchase and re-evaluates this classification periodically as conditions change that could require reclassification.
	Available for sale securities are stated at fair value. Unrealized holding gains and unrealized holding losses, other than those determined to be other than temporary, are reported net of tax in other comprehensive income and in accumulated other comprehensive income until realized.
	Securities that the Company both positively intends and has the ability to hold to maturity are classified as securities held to maturity and are carried at amortized cost. The intent and ability to hold are not considered satisfied when a security is available to be sold in response to changes in interest rates, prepayment rates, liquidity needs or other reasons as part of an overall asset/liability management strategy.
	Premiums and discounts on securities, both those held to maturity and those available for sale, are amortized and accreted to income as an adjustment to the securities’ yields using the effective interest method. Realized gains and losses on securities, including declines in value judged to be other than temporary, are reported net as a component of noninterest income. The cost of securities sold is specifically identified for use in calculating realized gains and losses.
Loans	Loans
	Originated loans
	Loans reported as “originated” include both loans originated for investment and acquired-performing loans where the discount (premium) has been fully accreted (amortized). Originated loans are reported at the principal balance outstanding net of unearned income. Interest on loans and accretion of unearned income, including deferred loan fees, are computed in a manner that approximates a level yield on recorded principal. Interest on loans is recognized in income as earned.
	The accrual of interest on an originated loan is discontinued when, in management’s opinion, it is probable that the borrower will be unable to meet payment obligations as they become due, as well as when required by regulatory provisions. When accrual of interest is discontinued on a loan, all unpaid accrued interest is reversed and payments subsequently received are applied first to recover principal. Interest income is recognized for payments received after contractual principal has been satisfied. Loans are returned to accrual status when all the principal and interest contractually due are brought current and future payment performance is reasonably assured.
	Acquired loans
	Loans reported as “acquired” are those loans that were purchased in the 2011 Whitney Holding Corporation acquisition. These loans were recorded at estimated fair value at the acquisition date with no carryover of the related allowance for loan losses. The Whitney acquired loans were segregated between those considered to be performing (“acquired-performing”) and those with evidence of credit deterioration (“acquired-impaired”) based on such factors as past due status, nonaccrual status and credit risk ratings (rated substandard or worse). The acquired loans were further segregated into loan pools designed to facilitate the development of expected cash flows to be used in estimating fair value to facilitate purchase accounting. Acquired-performing loans are accounted for under ASC 310-20 and acquired-impaired loans are accounted for under ASC 310-30.
	Acquired-performing loans were segregated into pools based on common risk characteristics such as loan type, credit risk ratings, and contractual interest rate and repayment terms. The major loan types included commercial and industrial loans not secured by real estate, real estate construction and land development loans, commercial real estate loans, residential mortgage loans, and consumer loans, with further segregation within certain loan types as needed. Expected cash flows, both principal and interest, from each pool were estimated based on key assumptions covering such factors as prepayments, default rates, and severity of loss given a default. These assumptions were developed using both historical experience and the portfolio characteristics at acquisition as well as available market research. The fair value estimate for each acquired-performing pool was based on the estimate of expected cash flows from the pool discounted at prevailing market rates.
	The difference at the acquisition date between the fair value and the contractual amounts due of an acquired-performing loan pool (the “fair value discount”) is accreted into income over the estimated life of the pool. Acquired-performing loans are placed on nonaccrual status and reported as nonperforming or past due using the same criteria applied to the originated portfolio.
	The acquired-impaired loans were segregated into pools by identifying loans with common credit risk profiles and were based primarily on characteristics such as loan type and market area in which originated. The major loan types included commercial and industrial loans not secured by real estate, real estate construction and land development loans, commercial real estate loans, and residential mortgage loans, with further segregation within certain loan types as needed. The acquired-impaired loans were further disaggregated by geographic region in recognition of the differences in general economic conditions affecting borrowers in certain states. The fair value estimate for each pool of acquired-impaired loans was based on the estimate of expected cash flows from the pool discounted at prevailing market rates.
	The excess of estimated cash flows expected to be collected from an acquired-impaired loan pool over the pool’s carrying value is referred to as the accretable yield and is recognized in interest income using an effective yield method over the expected life of the loan pool. Each pool of acquired-impaired loans is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. Acquired-impaired loans in pools with an accretable yield and expected cash flows that are reasonably estimable are considered to be accruing and performing even though collection of contractual payments on loans within the pool may be in doubt, because the pool is the unit of accounting. Acquired-impaired loans are generally not subject to individual evaluation for impairment and are not reported with impaired loans or troubled debt restructurings even if they would otherwise qualify for such treatment.
	FDIC acquired loans and the related loss share receivable
	Loans reported as “FDIC acquired” are loans purchased in the 2009 acquisition of Peoples First Community Bank (Peoples First) that were covered by two loss share agreements between the FDIC and the Company. These loans are accounted for as acquired-impaired loans as described above in the section on acquired loans. The Company treated all loans for the Peoples First acquisition as impaired based on the significant amount of deteriorating and nonperforming loans comprised mainly of adjustable rate mortgages and home equity loans located in Florida. The loss share receivable is measured separately from the related covered loans as it is not contractually embedded in the loans and is not transferrable should the loans be sold. The fair value of the loss share receivable at acquisition was estimated by discounting expected reimbursements for losses from the loans covered by the loss share agreements, including appropriate consideration of possible true-up payments to the FDIC at the expiration of the agreements.
	The loss share receivable is reviewed and updated prospectively as loss estimates related to covered loan pools change. Increases in expected reimbursements under the loss sharing agreement will lead to an increase in the loss share receivable. A decrease in expected reimbursements is reflected first as a reversal of any previously recorded increase in the loss share receivable on the covered loan pool with the remainder reflected as a reduction in the loss share receivable’s accretion rate. Increases and decreases in the loss share receivable related to changes in loss estimates result in reductions in or additions to the provision for loan losses, which serves to offset the impact on the provision from impairments or impairment reversals recognized on the underlying covered loan pool. The excess (or shortfall) of expected claims as compared to the carrying value of the loss share receivable is accreted (amortized) into noninterest income over the shorter of the remaining life of the covered loan pool or the life of the loss share agreement. The impact on operations of a reduction in the loss share receivable’s accretion rate is associated with an increase in the accretable yield on the underlying loan pool. The loss share receivable is reduced as cash is received from the FDIC related to losses incurred on covered assets.
	Loans Held for Sale
	Residential mortgage loans originated for sale are classified as loans held for sale and carried at the lower of cost or market. Forward sales commitments on a best-efforts basis are entered into with third parties concurrently with rate lock commitments made to prospective borrowers. At times, management may decide to sell loans that were not originated for that purpose. Those loans are reclassified as held for sale when that decision is made and also carried at the lower of cost or market.
	Troubled Debt Restructurings
	Troubled debt restructurings (TDRs) occur when a borrower is experiencing, or is expected to experience, financial difficulties in the near-term and a modification in loan terms is granted that would otherwise not have been considered.
	Troubled debt restructurings can result in loans remaining on nonaccrual, moving to nonaccrual, or continuing to accrue, depending on the individual facts and circumstances of the borrower. All loans whose terms have been modified in a TDR, including both commercial and retail loans, are initially considered “impaired.” When measuring impairment on a TDR, the loan’s value is determined by either the present value of expected cash flows calculated using the loan’s effective interest rate before the restructuring, or the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. If the value as determined is less than the recorded investment in the loan, the difference is charged-off through the allowance for loan and lease losses. Modified acquired-impaired loans are not removed from their accounting pool and accounted for as a TDR even if those loans would otherwise be deemed TDRs.
Allowance for Loan Losses	Allowance for Loan Losses
	Originated loans
	The ALLL is a valuation account available to absorb losses on loans. The ALLL is established and maintained at an amount sufficient to cover estimated credit losses inherent in the loan and lease portfolios of the Company as of the date of the determination. Credit losses arise not only from credit risk, but also from other risks inherent in the lending process including, but not limited to, collateral risk, operational risk, concentration risk, and economic risk. As such, all related risks of lending are considered when assessing the adequacy of the allowance for loan and lease losses. Quarterly, management estimates inherent losses in the portfolio based on a number of factors, including the Company’s past loan loss and delinquency experience, known and inherent risks in the portfolio, adverse situations that may affect the borrowers’ ability to repay, the estimated value of any underlying collateral and current economic conditions.
	The analysis and methodology for estimating the ALLL include two primary elements. A loss rate analysis which incorporates a historical loss rate as updated for current conditions is used for loans collectively evaluated for impairment, and a specific reserve analysis is used for loans individually evaluated for impairment. For the loss rate analysis, the Company segments loans into commercial non-real estate, construction and land development, commercial real estate, residential mortgage and consumer. Both quantitative and qualitative factors are applied at the detailed portfolio segments. Commercial loans (commercial non-real estate, construction and land development, and commercial real estate) are further subdivided by risk rating, while retail loans (residential mortgage and consumer) are further subdivided by delinquency. The Company uses loss emergence periods developed based on historical experience, which is currently eighteen-months for commercial loans and twelve-months for retail loans. Historical loss rates are calculated using a weighted average of the most recent three loss emergence periods. As circumstances dictate, management will make adjustments to the overall loss rate to reflect differences in current conditions as compared to those during the historical loss period. Conditions to be considered include problem loan trends, current business and economic conditions, credit concentrations, lending policies and procedures, lending staff, collateral values, loan profiles and volumes, loan review quality, and changes in competition and regulations.
	The Company considers a loan to be impaired when, based upon current information and events, it believes it is probable all amounts due according to the contractual terms of the loan agreement will not be collected. A loan is not considered impaired due to a delay in payment if all amounts due, including interest accrued at the contractual interest rate for the period of delay, is expected to be collected. Impaired loans include troubled debt restructurings, and performing and nonperforming loans. When a loan is determined to be impaired, the amount of impairment is recognized by creating a specific allowance for any shortfall between the loan’s value and its recorded investment. The loan’s value is measured by either the loan’s observable market price, the fair value of the collateral of the loan (less liquidation costs) if it is collateral dependent, or by the present value of expected future cash flows discounted at the loan’s effective interest rate. Any loans individually analyzed for impairment are not incorporated into the pool analysis to avoid double counting. The Company limits the specific reserve analysis to include all impaired commercial, commercial real estate and mortgage loans with balances of $1 million or greater and all loans classified as troubled debt restructurings.
	It is the policy of the Company to promptly charge off all commercial and residential mortgage loans, or portions of loans, when available information reasonably confirms that they are wholly or partially uncollectible. Prior to recognizing a loss, asset value is established based on an assessment of the value of the collateral securing the loan, the borrower’s and the guarantor’s ability and willingness to pay and the status of the account in bankruptcy court, if applicable. Consumer loans are generally charged down when the loan is 90 days past due for unsecured loans or 120 days past due for secured loans, unless the loan is clearly both well secured and in the process of collection. Loans are charged down to the fair value of the collateral, if any, less estimated selling costs. Loans are charged off against the allowance for loan losses with subsequent recoveries added back to the allowance.
	Acquired and FDIC acquired loans
	Allowance for acquired-performing loans is evaluated at each reporting date subsequent to acquisition. An allowance is determined for each loan pool using a methodology similar to that described above for originated loans and then compared to the remaining fair value discount for that pool. If the allowance is greater than the discount, the excess is recognized as an addition to the allowance through a provision for loan losses. If the allowance is less than the discount, no additional allowance is recognized.
	For acquired-impaired, including those acquired in the FDIC-assisted transaction, estimated cash flows expected to be collected are recast at each reporting date for each loan pool. These evaluations require the continued use and updating of key assumptions and estimates such as default rates, loss severity given default and prepayment speed assumptions, similar to those used for the initial fair value estimate. Management judgment must be applied in developing these assumptions. If the present value of expected cash flows for a pool is less than its carrying value, impairment is recognized by an increase in the allowance for loan losses and a charge to the provision for loan losses. If the present value of expected cash flows for a pool is greater than its carrying value, any previously established allowance for loan losses is reversed and any remaining difference increases the accretable yield which will be taken into interest income over the remaining life of the loan pool. Acquired-impaired loans are generally not subject to individual evaluation for impairment and are not reported with impaired loans or troubled debt restructurings, even if they would otherwise qualify for such treatment.
Property and Equipment	Property and Equipment
	Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation is charged to expense over the estimated useful lives of the assets, which are up to 39 years for buildings and three to ten years for furniture and equipment. Amortization expense for software is generally charged over three years, or seven years for core systems. Leasehold improvements are amortized over the terms of the respective leases or the estimated useful lives of the improvements, whichever is shorter.
	Gains and losses related to retirement or disposition of property and equipment are recorded in other income under noninterest income on the consolidated statements of income. The Company continually evaluates whether events and circumstances have occurred that indicate that such long-lived assets have been impaired. Measurement of any impairment of such long-lived assets is based on those assets’ fair values.
Other Real Estate	Other Real Estate
	Other real estate owned includes real property that has been acquired in satisfaction of loans and property no longer used in the Bank’s business. These assets are recorded at the estimated fair value less the estimated cost of disposition and carried at the lower of either cost or market. Fair value is based on independent appraisals and other relevant factors. Any initial reduction in the carrying amount of a loan to the fair value of the collateral received less selling costs is charged to the allowance for loan losses. Other real estate is revalued on an annual basis or more often if market conditions necessitate. Subsequent losses on the periodic revaluation of the property are charged to current earnings, as are revenues from and costs of operating and maintaining the properties and gains or losses recognized on their disposition. Improvements made to properties are capitalized if the expenditures are expected to be recovered upon the sale of the properties.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets
	Goodwill, which represents the excess of cost over the fair value of the net assets of an acquired business, is not amortized but tested for impairment on an annual basis, or more often if events or circumstances indicate there may be impairment. Impairment is defined as the amount by which the implied fair value of the goodwill contained in any reporting unit is less than the goodwill’s carrying value. Impairment losses would be charged to operating expense. Management reviews goodwill for impairment by first comparing the estimated fair value of the reporting unit to its carrying value. If the reporting unit’s fair value is less than its carrying value, an estimate of the implied fair value of the unit’s goodwill is compared to its carrying value. The Company uses a present value technique to estimate fair value which incorporates assumptions that market participants would use in their estimates of fair value, such as assumptions about the economic environment, expected net interest margins, growth rates, and the interest rate at which cash flows are discounted.
	Other identifiable intangible assets with finite lives, such as core deposit intangibles and trade name, are initially recorded at fair value and are generally amortized over the periods benefited. These assets are evaluated for impairment similar to long-lived assets.
Bank-Owned Life Insurance	Bank-Owned Life Insurance
	Bank-owned life insurance (BOLI) is long-term life insurance on the lives of certain current and past employees where the insurance policy benefits and ownership are retained by the employer. Its cash surrender value is an asset that the Company uses to partially offset the future cost of employee benefits. The cash value accumulation on BOLI is permanently tax deferred if the policy is held to the insured person’s death and certain other conditions are met.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities
	The Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. Changes in the fair value of derivatives to which hedge accounting does not apply are recognized immediately in earnings, otherwise it is included in other comprehensive income. Note 5 describes the derivative instruments currently used by the Company and discloses how these derivatives impact Hancock’s financial position and results of operations.
Income Taxes	Income Taxes
	Income taxes are accounted for using the asset and liability method. Current tax liabilities or assets are recognized for the estimated income taxes payable or refundable on tax returns to be filed with respect to the current year. Deferred tax assets and liabilities are based on temporary differences between the financial statement carrying amounts and the tax bases of the Company’s assets and liabilities. Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be realized or settled. Valuation allowances are established against deferred tax assets if, based on all available evidence, it is more likely than not that some or all of the assets will not be realized. The benefit of a position taken or expected to be taken in a tax return is recognized when it is more likely than not that the position will be sustained on its technical merits.
	The Company invests in projects that yield tax credits issued under the Qualified Zone Academy Bonds (QZAB), Qualified School Construction Bonds (QSCB), Federal and State New Market Tax Credit (NMTC), and Low-Income Housing Tax Credit (LIHTC) programs. Returns on these investments are generated through the receipt of federal and state tax credits. The tax credits are recorded as a reduction to the income tax provision in the year that they are earned. Tax credits from QZAB and QSCB bonds are generally earned over the life of the bonds in lieu of interest income. Credits on Federal NMTC investments are earned over the 7 year compliance period beginning with the year of investment. Credits on State NMTC investments are generally earned over a 3 to 5 year period depending upon the specific state program. Tax credits are earned over a 10 year period for Low-Income Housing investments beginning with the year in which rental activity begins. These tax credits, if not used in the tax return for the year when the credits are first available for use, can be carried forward for 20 years. For those investments where the return of the principal is not expected, the equity investment is amortized over the life of the tax compliance period as a component of noninterest expense.
Retirement Benefits	Retirement Benefits
	The Company sponsors defined benefit pension plans and certain other defined benefit postretirement plans for eligible employees. The amounts reported in the consolidated financial statements with respect to these plans are based on actuarial valuations that incorporate various assumptions regarding future experience under the plans. Note 11 discusses the actuarial assumptions and provides information about the liabilities or assets recognized for the funded status of the Company’s obligations under these plans, the net benefit expense charged to current operations, and the amounts recognized as a component of other comprehensive income and accumulated other comprehensive income.
Share-Based Payment Arrangements	Share-Based Payment Arrangements
	The grant date fair value of equity instruments awarded to employees and directors establishes the cost of the services received in exchange, and the cost associated with awards that are expected to vest is recognized over the requisite service period.
Revenue Recognition	Revenue Recognition
	The largest source of revenue for the Company is interest revenue. Interest revenue is recognized on an accrual basis driven by written contracts, such as loan agreements or securities contracts. Loan origination fees are amortized over the life of the loan. Other credit-related fees, including letter of credit fees, are recognized in noninterest income when earned. The Company recognizes commission revenue and brokerage, exchange and clearance fees on a trade-date basis. Other types of noninterest revenue such as service charges on deposits and trust revenues, are accrued and recognized into income as services are provided and the amount of fees earned can be reasonably determined.
Earnings Per Share	Earnings Per Share
	Hancock 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 the common dividends declared and participation rights in undistributed earnings. Participating securities currently consist of unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents.
	Basic earnings per common share is computed by dividing income applicable to common shareholders by the weighted-average number of common shares outstanding for the applicable period. Shares outstanding are adjusted for restricted shares issued to employees under the long-term incentive compensation plan and for certain shares that will be issued under the directors’ compensation plan. Diluted earnings per common share is computed using the weighted-average number of common shares outstanding increased by the number of shares in which employees would vest under performance-based stock awards and stock unit awards based on expected performance factors and by the number of additional shares that would have been issued if potentially dilutive stock options were exercised, each as determined using the treasury stock method.
Statements of Cash Flows	Statements of Cash Flows
	The Company considers only cash on hand, cash items in process of collection and balances due from financial institutions as cash and cash equivalents for purposes of the consolidated statements of cash flows.
Reportable Segment Disclosures	Reportable Segment Disclosures
	Accounting standards require that information be reported about a company’s operating segments using a “management approach.” Reportable segments are identified in these standards as those revenue-producing components for which separate financial information is produced internally and which are subject to evaluation by the chief operating decision maker in deciding how to allocate resources to segments. On March 31, 2014, the Company combined its two state bank charters into one charter. Due to the charter change and consistent with its stated strategy that is focused on providing a consistent package of community banking products and services throughout a coherent market area, the Company has identified its overall banking operations as its only reportable segment. Because the overall banking operations comprise substantially all of the consolidated operations, no separate segment disclosures are presented.
Other	Other
	Assets held by the Bank in a fiduciary capacity are not assets of the Bank and are not included in the consolidated balance sheets.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS
	In August 2014, the FASB issued an Accounting Standard Update (ASU) to address the diversity in practice regarding the classification and measurement of foreclosed loans which were part of a government-sponsored loan guarantee program (e.g. HUD, FHA, VA). The ASU outlines certain criteria that, if met, the loan (residential or commercial) should be derecognized and a separate other receivable should be recorded upon foreclosure at the amount of the loan balance (principal and interest) expected to be recovered from the guarantor. This ASU is effective for annual reporting periods beginning after December 15, 2014, including interim periods within that reporting period. Early adoption is permitted, provided the entity has adopted ASU 2014-04. The guidance is not expected to have a material impact on the Company’s financial condition or results of operations.
	In June 2014, the FASB issued an ASU regarding repurchase-to-maturity transactions, repurchase financings, and disclosures. Under the new standard, repurchase-to-maturity transactions will be reported as secured borrowings, and transferors will no longer apply the current “linked” accounting model to repurchase agreements executed contemporaneously with the initial transfer of the underlying financial asset with the same counterparty. Public business entities are generally required to apply the accounting changes and comply with the enhanced disclosure requirements for periods beginning after December 15, 2014 and interim periods beginning after March 15, 2015. A public business entity may not early adopt the standard’s provisions. 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 an ASU regarding revenue from contracts with customers 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. The standard will be effective for the Company for periods beginning after December 15, 2016. The Company is currently assessing this pronouncement and adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.
	In January 2014, the FASB issued an ASU on reclassification of residential real estate collateralized consumer mortgage loans upon foreclosure. The new ASU clarifies when an in substance repossession or foreclosure occurs – that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized. The new ASU requires a creditor to reclassify a collateralized consumer mortgage loan to real estate property upon obtaining legal title to the real estate collateral, or the borrower voluntarily conveying all interest in the real estate property to the lender to satisfy the loan through a deed in lieu of foreclosure or similar legal agreement. The ASU is effective for interim and annual reporting periods beginning after December 15, 2014. The adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.
	In January 2014, the FASB issued an ASU in order to provide guidance on accounting for investments in flow-through limited liability entities that manage or invest in affordable housing projects that qualify for low-income housing tax credit (“LIHTC”). Through the Company’s investments in these entities, the Company receives tax credits and/or tax deductions from operating losses, which are allowable on the Company’s filed income tax returns over the life of the project beginning with the first year the tax credits are earned. The ASU is effective beginning with the Company’s first quarter ending March 31, 2015, with early adoption permitted. If adopted, the provisions of ASU No. 2014-01 would be applied retrospectively to all financial statement periods presented. The Company does not anticipate that the potential accounting policy change to the proportional amortization method would be material to the financial condition, results of operations, or liquidity of the Company. The expanded disclosures required by this ASU will be incorporated in the Company’s future consolidated financial statements upon adoption.

Securities_Tables

Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Amortized Cost and Fair Value of Available for Sale Securities	The amortized cost and fair value of securities classified as available for sale and held to maturity follow:
	Securities Available for Sale
		December 31, 2014								December 31, 2013
				Gross		Gross						Gross		Gross
		Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
	in thousands	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
	U.S. Treasury and government agency securities	$	300,207	$	372	$	71	$	300,508	$	504	$	2	$	1	$	505
	Municipal obligations		13,995		186		5		14,176		35,809		177		25		35,961
	Mortgage-backed securities		1,217,293		31,094		2,823		1,245,564		1,262,633		24,402		10,077		1,276,958
	CMOs		88,093		—		1,229		86,864		96,369		—		2,244		94,125
	Corporate debt securities		3,500		—		—		3,500		3,500		—		—		3,500
	Equity securities		8,673		891		11		9,553		9,965		785		27		10,723
		$	1,631,761	$	32,543	$	4,139	$	1,660,165	$	1,408,780	$	25,366	$	12,374	$	1,421,772
Amortized Cost and Fair Value of Held to Maturity Securities	Securities Held to Maturity
		31-Dec-14								31-Dec-13
				Gross		Gross						Gross		Gross
		Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
	in thousands	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
	U.S. Treasury and government agency securities	$	—	$	—	$	—	$	—	$	100,000	$	316	$	—	$	100,316
	Municipal obligations		180,615		3,416		1,144		182,887		193,189		919		6,436		187,672
	Mortgage-backed securities		899,923		23,897		162		923,658		1,003,327		296		4,671		998,952
	CMOs		1,085,751		5,590		11,546		1,079,795		1,314,836		1,062		26,254		1,289,644
		$	2,166,289	$	32,903	$	12,852	$	2,186,340	$	2,611,352	$	2,593	$	37,361	$	2,576,584
Available for Sale Securities Unrealized Losses	The details for securities classified as available for sale with unrealized losses as of December 31, 2014 follow:
	Available for sale
		Losses < 12 months				Losses 12 months or >				Total
	in thousands	Fair		Gross		Fair		Gross		Fair		Gross
		Value		Unrealized		Value		Unrealized		Value		Unrealized
				Losses				Losses				Losses
	U.S. Treasury and government agency securities	$	99,950	$	70	$	121	$	1	$	100,071	$	71
	Municipal obligations		2,995		5		—		—		2,995		5
	Mortgage-backed securities		38,955		163		125,641		2,660		164,596		2,823
	CMOs		—		—		86,864		1,229		86,864		1,229
	Equity securities		5,998		10		3		1		6,001		11
		$	147,898	$	248	$	212,629	$	3,891	$	360,527	$	4,139
	The details for securities classified as available for sale with unrealized losses as of December 31, 2013 follow:
	Available for sale
		Losses < 12 months				Losses 12 months or >				Total
	in thousands	Fair		Gross		Fair		Gross		Fair		Gross
		Value		Unrealized		Value		Unrealized		Value		Unrealized
				Losses				Losses				Losses
	U.S. Treasury and government agency securities	$	205	$	1	$	—	$	—	$	205	$	1
	Municipal obligations		7,975		25		—		—		7,975		25
	Mortgage-backed securities		376,350		7,164		49,061		2,913		425,411		10,077
	CMOs		94,125		2,244		—		—		94,125		2,244
	Equity securities		3,282		26		3		1		3,285		27
		$	481,937	$	9,460	$	49,064	$	2,914	$	531,001	$	12,374
Held to Maturity with Unrealized Losses	The details for securities classified as held to maturity with unrealized losses as of December 31, 2014 follow:
	Held to maturity
		Losses < 12 months				Losses 12 months or >				Total
	in thousands	Fair		Gross		Fair		Gross		Fair		Gross
		Value		Unrealized		Value		Unrealized		Value		Unrealized
				Losses				Losses				Losses
	Municipal obligations	$	4,316	$	12	$	58,105	$	1,132	$	62,421	$	1,144
	Mortgage-backed securities		—		—		95,522		162		95,522		162
	CMOs		119,222		616		540,607		10,930		659,829		11,546
		$	123,538	$	628	$	694,234	$	12,224	$	817,772	$	12,852
	The details for securities classified as held to maturity with unrealized losses as of December 31, 2013 follow:
	Held to maturity
		Losses < 12 months				Losses 12 months or >				Total
	in thousands	Fair		Gross		Fair		Gross		Fair		Gross
		Value		Unrealized		Value		Unrealized		Value		Unrealized
				Losses				Losses				Losses
	Municipal obligations	$	131,499	$	6,311	$	2,878	$	125	$	134,377	$	6,436
	Mortgage-backed securities		950,288		4,671		—		—		950,288		4,671
	CMOs		947,061		25,088		175,633		1,166		1,122,694		26,254
		$	2,028,848	$	36,070	$	178,511	$	1,291	$	2,207,359	$	37,361
Available for Sale Securities [Member]
Amortized Cost and Fair Value of Available for Sale Securities by Final Contractual Maturity	The following table presents the amortized cost and fair value of debt securities at December 31, 2014 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 CMOs.
		Amortized		Fair
	in thousands	Cost		Value
	Debt Securities Available for Sale
	Due in one year or less	$	303,284	$	303,589
	Due after one year through five years		154,189		154,534
	Due after five years through ten years		236,461		244,535
	Due after ten years		929,154		947,954
	Total available for sale debt securities	$	1,623,088	$	1,650,612
Held to Maturity Securities Transferred from AFS [Member]
Amortized Cost and Fair Value of Available for Sale Securities by Final Contractual Maturity
		Amortized		Fair
	in thousands	Cost		Value
	Debt Securities Held to Maturity
	Due in one year or less	$	169,617	$	170,786
	Due after one year through five years		453,352		446,039
	Due after five years through ten years		115,748		115,195
	Due after ten years		1,427,572		1,454,320
	Total held to maturity securities	$	2,166,289	$	2,186,340

Loans_Tables

Loans (Tables)	12 Months Ended
	Dec. 31, 2014
Loans, Net of Unearned Income	Loans, net of unearned income, consisted of the following:
	(In thousands)		December 31,			December 31,
			2014			2013
	Originated loans: (a)
	Commercial non-real estate		$	5,917,728		$	4,113,837
	Construction and land development			1,073,964			752,381
	Commercial real estate			2,428,195			2,022,528
	Residential mortgages			1,704,770			1,196,256
	Consumer			1,685,542			1,409,130
	Total originated loans		$	12,810,199		$	9,494,132
	Acquired loans: (a)
	Commercial non-real estate		$	120,137		$	926,997
	Construction and land development			21,123			142,931
	Commercial real estate			688,045			967,148
	Residential mortgages			2,378			315,340
	Consumer			985			119,603
	Total acquired loans		$	832,668		$	2,472,019
	FDIC acquired loans:
	Commercial non-real estate		$	6,195		$	23,390
	Construction and land development			11,674			20,229
	Commercial real estate			27,808			53,165
	Residential mortgages			187,033			209,018
	Consumer			19,699			52,864
	Total FDIC acquired loans		$	252,409		$	358,666
	Total loans:
	Commercial non-real estate		$	6,044,060		$	5,064,224
	Construction and land development			1,106,761			915,541
	Commercial real estate			3,144,048			3,042,841
	Residential mortgages			1,894,181			1,720,614
	Consumer			1,706,226			1,581,597
	Total loans		$	13,895,276		$	12,324,817
		(a)	Originated loans at December 31, 2014 includes $1.2 billion of loans that were reported as acquired-performing at December 31, 2013, as the discount (premium) was fully accreted (amortized).
Allowance for Loan Losses by Portfolio Segment and Related Recorded Investment in Loans	The following schedules show activity in the allowance for loan losses for 2014 and 2013 by portfolio segment and the corresponding recorded investment in loans as of December 31, 2014 and December 31, 2013.
						Construction
			Commercial			and land			Commercial			Residential
			non-real estate			development			real estate			mortgages			Consumer			Total
	(In thousands)		Twelve Months Ended December 31, 2014
	Originated loans (a)
	Allowance for loan losses:
	Beginning balance		$	33,091		$	6,180		$	20,649		$	6,892		$	12,073		$	78,885
	Charge-offs			(6,813	)		(4,770	)		(3,579	)		(2,285	)		(14,055	)		(31,502	)
	Recoveries			3,047			4,000			1,678			644			5,014			14,383
	Net provision for loan losses			20,933			3			(2,204	)		2,800			14,403			35,935
	Ending balance		$	50,258		$	5,413		$	16,544		$	8,051		$	17,435		$	97,701
	Ending balance:
	Individually evaluated for impairment		$	14		$	19		$	11		$	330		$	3		$	377
	Collectively evaluated for impairment			50,244			5,394			16,533			7,721			17,432			97,324
	Loans:
	Ending balance:		$	5,917,728		$	1,073,964		$	2,428,195		$	1,704,770		$	1,685,542		$	12,810,199
	Individually evaluated for impairment			3,987			8,250			12,121			2,656			6			27,020
	Collectively evaluated for impairment			5,913,741			1,065,714			2,416,074			1,702,114			1,685,536			12,783,179
	Acquired loans (a)
	Allowance for loan losses:
	Beginning balance		$	1,603		$	10		$	34		$	—		$	—		$	1,647
	Charge-offs			—			—			—			—			—			—
	Recoveries			—			—			—			—			—			—
	Net provision for loan losses			(1,603	)		(10	)		443			—			—			(1,170	)
	Ending balance		$	—		$	—		$	477		$	—		$	—		$	477
	Ending balance:
	Individually evaluated for impairment		$	—		$	—		$	477		$	—		$	—		$	477
	Amounts related to acquired-impaired loans			—			—			—			—			—			—
	Collectively evaluated for impairment			—			—			—			—			—			—
	Loans:
	Ending balance:		$	120,137		$	21,123		$	688,045		$	2,378		$	985		$	832,668
	Individually evaluated for impairment			—			—			2,691			—			—			2,691
	Acquired-impaired loans			8,446			19,681			29,777			2,378			985			61,267
	Collectively evaluated for impairment			111,691			1,442			655,577			—			—			768,710
						Construction
			Commercial			and land			Commercial			Residential
			non-real estate			development			real estate			mortgages			Consumer			Total
	(In thousands)		Twelve Months Ended December 31, 2014
	FDIC acquired loans
	Allowance for loan losses:
	Beginning balance		$	2,323		$	2,655		$	10,929		$	27,989		$	9,198		$	53,094
	Charge-offs			(221	)		(148	)		(5,350	)		(1,008	)		(1,270	)		(7,997	)
	Recoveries			485			3,138			1,441			1			431			5,496
	Net provision for loan losses			(83	)		(208	)		(139	)		(299	)		(196	)		(925	)
	Decrease in FDIC loss share receivable			(1,593	)		(4,429	)		(2,820	)		(6,074	)		(4,168	)		(19,084	)
	Ending balance		$	911		$	1,008		$	4,061		$	20,609		$	3,995		$	30,584
	Ending balance:
	Individually evaluated for impairment		$	—		$	—		$	—		$	—		$	—		$	—
	Amounts related to acquired-impaired loans			911			1,008			4,061			20,609			3,995			30,584
	Collectively evaluated for impairment			—			—			—			—			—			—
	Loans:
	Ending balance:		$	6,195		$	11,674		$	27,808		$	187,033		$	19,699		$	252,409
	Individually evaluated for impairment			—			—			—			—			—			—
	Acquired-impaired loans			6,195			11,674			27,808			187,033			19,699			252,409
	Collectively evaluated for impairment			—			—			—			—			—			—
	Total loans
	Allowance for loan losses:
	Beginning balance		$	37,017		$	8,845		$	31,612		$	34,881		$	21,271		$	133,626
	Charge-offs			(7,034	)		(4,918	)		(8,929	)		(3,293	)		(15,325	)		(39,499	)
	Recoveries			3,532			7,138			3,119			645			5,445			19,879
	Net provision for loan losses			19,247			(215	)		(1,900	)		2,501			14,207			33,840
	Decrease in FDIC loss share receivable			(1,593	)		(4,429	)		(2,820	)		(6,074	)		(4,168	)		(19,084	)
	Ending balance		$	51,169		$	6,421		$	21,082		$	28,660		$	21,430		$	128,762
Ending balance:
Individually evaluated for impairment		$	14		$	19		$	488		$	330		$	3		$	854
Amounts related to acquired-impaired loans			911			1,008			4,061			20,609			3,995			30,584
Collectively evaluated for impairment			50,244			5,394			16,533			7,721			17,432			97,324
Loans:
Ending balance:		$	6,044,060		$	1,106,761		$	3,144,048		$	1,894,181		$	1,706,226		$	13,895,276
Individually evaluated for impairment			3,987			8,250			14,812			2,656			6			29,711
Acquired-impaired loans			14,641			31,355			57,585			189,411			20,684			313,676
Collectively evaluated for impairment			6,025,432			1,067,156			3,071,651			1,702,114			1,685,536			13,551,889
(a)	Originated loans at December 31, 2014 includes $1.2 billion of loans that were previously reported as acquired-performing as the discount (premium) was fully accreted (amortized).
		Commercial			Construction
		non-real			and land			Commercial			Residential
		estate			development			real estate			mortgages			Consumer			Total
(In thousands)		Year Ended December 31, 2013
Originated loans:
Allowance for loan losses:
Beginning balance		$	20,775		$	11,415		$	26,959		$	6,406		$	13,219		$	78,774
Charge-offs			(6,671	)		(10,312	)		(5,525	)		(2,297	)		(18,094	)		(42,899	)
Recoveries			5,790			1,676			3,359			1,936			5,829			18,590
Net provision for loan losses			13,197			3,401			(4,144	)		847			11,119			24,420
Ending balance		$	33,091		$	6,180		$	20,649		$	6,892		$	12,073		$	78,885
Ending balance:
Individually evaluated for impairment		$	477		$	22		$	268		$	1		$	—		$	768
Collectively evaluated for impairment			32,614			6,158			20,381			6,891			12,073			78,117
Loans:
Ending balance:		$	4,113,837		$	752,381		$	2,022,528		$	1,196,256		$	1,409,130		$	9,494,132
Individually evaluated for impairment			5,294			10,599			14,029			605			—			30,527
Collectively evaluated for impairment			4,108,543			741,782			2,008,499			1,195,651			1,409,130			9,463,605
Acquired loans:
Allowance for loan losses:
Beginning balance		$	788		$	—		$	—		$	—		$	—		$	788
Charge-offs			—			—			—			—			—			—
Recoveries			—			—			—			—			—			—
Net Provision for loan losses			815			10			34			—			—			859
Increase in FDIC loss share receivable			—			—			—			—			—			—
Ending balance		$	1,603		$	10		$	34		$	—		$	—		$	1,647
Ending balance:
Individually evaluated for impairment		$	—		$	—		$	—		$	—		$	—		$	—
Amounts related to acquired-impaired loans			—			—			—			—			—			—
Collectively evaluated for impairment			1,603			10			34			—			—			1,647
Loans:
Ending balance:		$	926,997		$	142,931		$	967,148		$	315,340		$	119,603		$	2,472,019
Individually evaluated for impairment			2,141			728			2,338			505			—			5,712
Acquired-impaired loans			19,094			17,335			26,058			5,494			94			68,075
Collectively evaluated for impairment			905,762			124,868			938,752			309,341			119,509			2,398,232
		Commercial			Construction			Commercial			Residential			Consumer			Total
		non-real estate			and land			real estate			mortgages
					development
(In thousands)		Twelve Months Ended December 31, 2013
FDIC acquired loans:
Allowance for loan losses:
Beginning balance		$	2,162		$	5,623		$	9,433		$	30,471		$	8,920		$	56,609
Charge-offs			(1,071	)		(1,244	)		(4,414	)		(1,532	)		(1,250	)		(9,511	)
Recoveries			90			735			6,158			13			160			7,156
Net provision for loan losses			1,263			(1,566	)		(785	)		5,343			3,200			7,455
(Decrease) increase in FDIC loss share receivable			(121	)		(893	)		537			(6,306	)		(1,832	)		(8,615	)
Ending balance		$	2,323		$	2,655		$	10,929		$	27,989		$	9,198		$	53,094
Ending balance:
Individually evaluated for impairment		$	—		$	—		$	—		$	—		$	—		$	—
Amounts related to acquired-impaired loans			2,323			2,655			10,929			27,989			9,198			53,094
Collectively evaluated for impairment			—			—			—			—			—			—
Loans:
Ending balance:		$	23,390		$	20,229		$	53,165		$	209,018		$	52,864		$	358,666
Individually evaluated for impairment			—			—			—			—			—			—
Acquired-impaired loans			23,390			20,229			53,165			209,018			52,864			358,666
Collectively evaluated for impairment			—			—			—			—			—			—
Total loans:
Allowance for loan losses:
Beginning balance		$	23,725		$	17,038		$	36,392		$	36,877		$	22,139		$	136,171
Charge-offs			(7,742	)		(11,556	)		(9,939	)		(3,829	)		(19,344	)		(52,410	)
Recoveries			5,880			2,411			9,517			1,949			5,989			25,746
Net provision for loan losses			15,275			1,845			(4,895	)		6,190			14,319			32,734
(Decrease) increase in FDIC loss share receivable			(121	)		(893	)		537			(6,306	)		(1,832	)		(8,615	)
Ending balance		$	37,017		$	8,845		$	31,612		$	34,881		$	21,271		$	133,626
Ending balance:
Individually evaluated for impairment		$	477		$	22		$	268		$	1		$	—		$	768
Amounts related to acquired-impaired loans			2,323			2,655			10,929			27,989			9,198			53,094
Collectively evaluated for impairment			34,217			6,168			20,415			6,891			12,073			79,764
Loans:
Ending balance:		$	5,064,224		$	915,541		$	3,042,841		$	1,720,614		$	1,581,597		$	12,324,817
Individually evaluated for impairment			7,435			11,327			16,367			1,110			—			36,239
Acquired-impaired loans			42,484			37,564			79,223			214,512			52,958			426,741
Collectively evaluated for impairment			5,014,305			866,650			2,947,251			1,504,992			1,528,639			11,861,837
Schedule of Activity in Loss Share Receivable	The following schedule shows activity in the loss share receivable for 2014 and 2013:
	(In thousands)		Years Ended December 31,
			2014			2013
	Balance, January 1		$	113,834		$	177,844
	(Amortization) accretion			(12,102	)		(2,239	)
	Charge-offs, write-downs and other (recoveries) losses			(2,245	)		(1,619	)
	External expenses qualifying under loss share agreement			4,532			9,117
	Changes due to changes in cash flow projections			(19,084	)		(7,504	)
	Settlement of disallowed claims			(10,268	)		—
	Net payments from FDIC			(14,395	)		(61,765	)
	Balance, December 31		$	60,272		$	113,834
Summary of Composition of Non-Accrual Loans by Portfolio Segment	The following table shows the composition of non-accrual loans by portfolio segment and class. Acquired-impaired and certain covered loans are considered to be performing due to the application of the accretion method and are excluded from the table. FDIC acquired loans accounted for using the cost recovery method do not have an accretable yield and are included below as non-accrual loans. Acquired-performing loans that have subsequently been placed on non-accrual status are also included below.
	Nonaccrual Loans
			December 31,			December 31,
	(In thousands)		2014			2013
	Originated loans:
	Commercial non-real estate		$	15,511		$	10,148
	Construction and land development			6,462			13,171
	Commercial real estate			22,047			32,772
	Residential mortgages			21,702			13,449
	Consumer			5,574			4,802
	Total originated loans		$	71,296		$	74,342
	Acquired loans:
	Commercial non-real estate		$	—		$	3,209
	Construction and land development			—			1,990
	Commercial real estate			6,139			6,525
	Residential mortgages			—			8,262
	Consumer			—			1,814
	Total acquired loans		$	6,139		$	21,800
	FDIC acquired loans: (a)
	Commercial non-real estate		$	—		$	2
	Construction and land development			1,103			1,539
	Commercial real estate			433			1,163
	Residential mortgages			392			544
	Consumer			174			296
	Total FDIC acquired loans		$	2,102		$	3,544
	Total loans:
	Commercial non-real estate		$	15,511		$	13,359
	Construction and land development			7,565			16,700
	Commercial real estate			28,619			40,460
	Residential mortgages			22,094			22,255
	Consumer			5,748			6,912
	Total loans		$	79,537		$	99,686
Schedule of Troubled Debt Restructurings Occurred During Period by Portfolio Segment	The table below details the TDRs that occurred during 2014 and 2013 by portfolio segment and TDRs that subsequently defaulted within twelve months of modification. All are individually evaluated for impairment.
	($ in thousands)		2014									2013
			Number			Outstanding Recorded						Number			Outstanding Recorded
			of			Investment						of			Investment
			Contracts			Pre-			Post-			Contracts			Pre-			Post-
						Modification			Modification						Modification			Modification
	Originated loans:
	Commercial non-real estate			1		$	29		$	29			1		$	926		$	909
	Construction and land development			—			—			—			—			—			—
	Commercial real estate			3			4,488			4,446			4			1,332			1,157
	Residential mortgages			7			1,961			1,090			1			456			330
	Consumer			1			8			8			—			—			—
	Total originated loans			12		$	6,486		$	5,573			6		$	2,714		$	2,396
	Acquired loans:
	Commercial non-real estate			—		$	—		$	—			—		$	—		$	—
	Construction and land development			—			—			—			—			—			—
	Commercial real estate			—			—			—			1			512			472
	Residential mortgages			—			—			—			1			514			503
	Consumer			—			—			—			—			—			—
	Total acquired loans			—		$	—		$	—			2		$	1,026		$	975
	FDIC acquired loans:
	Commercial non-real estate			—		$	—		$	—			—		$	—		$	—
	Construction and land development			—			—			—			—			—			—
	Commercial real estate			—			—			—			—			—			—
	Residential mortgages			—			—			—			—			—			—
	Consumer			—			—			—			—			—			—
	Total FDIC acquired loans			—		$	—		$	—			—		$	—		$	—
	Total loans:
	Commercial non-real estate			1		$	29		$	29			1		$	926		$	909
	Construction and land development			—			—			—			—			—			—
	Commercial real estate			3			4,488			4,446			5			1,844			1,629
	Residential mortgages			7			1,961			1,090			2			970			833
	Consumer			1			8			8			—			—			—
	Total loans			12		$	6,486		$	5,573			8		$	3,740		$	3,371
Summary of Impaired Loans Disaggregated by Class	The tables below present loans that are individually evaluated for impairment disaggregated by class at December 31, 2014 and 2013:
	December 31, 2014		Recorded			Unpaid			Related			Average			Interest
			Investment			Principal			Allowance			Recorded			Income
	(In thousands)					Balance						Investment			Recognized
	Originated loans:
	With no related allowance recorded:
	Commercial non-real estate		$	3,003		$	3,646		$	—		$	1,209		$	51
	Construction and land development			3,345			6,486			—			3,330			142
	Commercial real estate			8,467			10,575			—			8,461			331
	Residential mortgages			—			—			—			88			3
	Consumer			—			—			—			—			—
				14,815			20,707			—			13,088			527
	With an allowance recorded:
	Commercial non-real estate			984			984			14			5,522			99
	Construction and land development			4,905			4,906			19			6,660			137
	Commercial real estate			3,654			3,654			11			7,500			109
	Residential mortgages			2,656			3,311			330			2,204			50
	Consumer			6			6			3			1			—
				12,205			12,861			377			21,887			395
	Total:
	Commercial non-real estate			3,987			4,630			14			6,732			150
	Construction and land development			8,250			11,392			19			9,990			279
	Commercial real estate			12,121			14,229			11			15,961			439
	Residential mortgages			2,656			3,311			330			2,292			53
	Consumer			6			6			3			1			—
	Total originated loans		$	27,020		$	33,568		$	377		$	34,976		$	921
	Acquired loans:
	With no related allowance recorded:
	Commercial non-real estate		$	—		$	—		$	—		$	357		$	—
	Construction and land development			—			—			—			121			—
	Commercial real estate			—			—			—			311			—
	Residential mortgages			—			—			—			88			—
	Consumer			—			—			—			—			—
				—			—			—			877			—
	With an allowance recorded:
	Commercial non-real estate			—			—			—			1,059			122
	Construction and land development			—			—			—			1,037			56
	Commercial real estate			2,691			2,720			477			1,357			75
	Residential mortgages			—			—			—			—			—
	Consumer			—			—			—			—			—
				2,691			2,720			477			3,453			253
	Total:
	Commercial non-real estate			—			—			—			1,416			122
	Construction and land development			—			—			—			1,158			56
	Commercial real estate			2,691			2,720			477			1,668			75
	Residential mortgages			—			—			—			88			—
	Consumer			—			—			—			—			—
	Total acquired loans		$	2,691		$	2,720		$	477		$	4,330		$	253
	Total loans:
	With no related allowance recorded:
	Commercial non-real estate		$	3,003		$	3,646		$	—		$	1,566		$	51
	Construction and land development			3,345			6,486			—			3,451			142
	Commercial real estate			8,467			10,575			—			8,772			331
	Residential mortgages			—			—			—			176			3
	Consumer			—			—			—			—			—
				14,815			20,707			—			13,965			527
	With an allowance recorded:
	Commercial non-real estate			984			984			14			6,581			221
	Construction and land development			4,905			4,906			19			7,697			193
	Commercial real estate			6,345			6,374			488			8,857			184
	Residential mortgages			2,656			3,311			330			2,204			50
	Consumer			6			6			3			1			—
				14,896			15,581			854			25,340			648
	Total:
Commercial non-real estate			3,987			4,630			14			8,147			272
Construction and land development			8,250			11,392			19			11,148			335
Commercial real estate			14,812			16,949			488			17,629			515
Residential mortgages			2,656			3,311			330			2,380			53
Consumer			6			6			3			1			—
Total loans		$	29,711		$	36,288		$	854		$	39,305		$	1,175
December 31, 2013		Recorded			Unpaid			Related			Average			Interest
		Investment			Principal			Allowance			Recorded			Income
(in thousands)					Balance						Investment			Recognized
Originated loans:
With no related allowance recorded:
Commercial non-real estate		$	329		$	442		$	—		$	235		$	18
Construction and land development			4,101			5,131			—			2,780			82
Commercial real estate			5,321			7,458			—			15,886			374
Residential mortgages			—			—			—			262			—
Consumer			—			—			—			1,013			—
			9,751			13,031			—			20,176			474
With an allowance recorded:
Commercial non-real estate			4,965			5,303			477			8,936			180
Construction and land development			6,498			8,343			22			2,549			—
Commercial real estate			8,708			9,090			268			19,683			460
Residential mortgages			605			620			1			228			—
Consumer			—			—			—			1,025			—
			20,776			23,356			768			32,421			640
Total:
Commercial non-real estate			5,294			5,745			477			9,171			198
Construction and land development			10,599			13,474			22			5,329			82
Commercial real estate			14,029			16,548			268			35,569			834
Residential mortgages			605			620			1			490			—
Consumer			—			—			—			2,038			—
Total originated loans		$	30,527		$	36,387		$	768		$	52,597		$	1,114
Acquired loans:
With no related allowance recorded:
Commercial non-real estate		$	2,141		$	3,275		$	—		$	865		$	8
Construction and land development			728			1,142			—			296			3
Commercial real estate			2,338			2,634			—			1,339			49
Residential mortgages			505			507			—			407			—
Consumer			—			—			—			—			—
			5,712			7,558			—			2,907			60
With an allowance recorded:
Commercial non-real estate			—			—			—			2,747			63
Construction and land development			—			—			—			157			—
Commercial real estate			—			—			—			2,663			—
Residential mortgages			—			—			—			845			—
Consumer			—			—			—			—			—
			—			—			—			6,412			63
Total:
Commercial non-real estate			2,141			3,275			—			3,612			71
Construction and land development			728			1,142			—			453			3
Commercial real estate			2,338			2,634			—			4,002			49
Residential mortgages			505			507			—			1,252			—
Consumer			—			—			—			—			—
Total acquired loans		$	5,712		$	7,558		$	—		$	9,319		$	123
Total loans:
With no related allowance recorded:
Commercial non-real estate		$	2,470		$	3,717		$	—		$	1,100		$	26
Construction and land development			4,829			6,273			—			3,076			85
Commercial real estate			7,659			10,092			—			17,225			423
Residential mortgages			505			507			—			669			—
Consumer			—			—			—			1,013			—
			15,463			20,589			—			23,083			534
With an allowance recorded:
Commercial non-real estate			4,965			5,303			477			11,683			243
Construction and land development			6,498			8,343			22			2,706			—
Commercial real estate			8,708			9,090			268			22,346			460
Residential mortgages			605			620			1			1,073			—
Consumer			—			—			—			1,025			—
			20,776			23,356			768			38,833			703
Total:
Commercial non-real estate			7,435			9,020			477			12,783			269
Construction and land development			11,327			14,616			22			5,782			85
Commercial real estate			16,367			19,182			268			39,571			883
Residential mortgages			1,110			1,127			1			1,742			—
Consumer			—			—			—			2,038			—
Total loans		$	36,239		$	43,945		$	768		$	61,916		$	1,237
Summary of Age Analysis of Past Due Loans	The following table presents the age analysis of past due loans at December 31, 2014 and December 31, 2013. FDIC acquired and acquired-impaired loans with an accretable yield are considered to be current in the following delinquency table:
	December 31, 2014		30-59 days			60-89 days			Greater than			Total			Current			Total			Recorded
			past due			past due			90 days			past due						Loans			investment
									past due												> 90 days
																					and
																					accruing
	(In thousands)
	Originated loans:
	Commercial non-real estate		$	4,380		$	1,742		$	8,560		$	14,682		$	5,903,046		$	5,917,728		$	630
	Construction and land development			6,620			1,532			4,453			12,605			1,061,359			1,073,964			142
	Commercial real estate			6,527			2,964			13,234			22,725			2,405,470			2,428,195			696
	Residential mortgages			14,730			3,261			11,208			29,199			1,675,571			1,704,770			1,199
	Consumer			8,422			2,450			4,365			15,237			1,670,305			1,685,542			1,897
	Total		$	40,679		$	11,949		$	41,820		$	94,448		$	12,715,751		$	12,810,199		$	4,564
	Acquired loans:
	Commercial non-real estate		$	—		$	—		$	—		$	—		$	120,137		$	120,137		$	—
	Construction and land development			111			—			—			111			21,012			21,123			—
	Commercial real estate			3,861			282			1,591			5,734			682,311			688,045			261
	Residential mortgages			—			—			—			—			2,378			2,378			—
	Consumer			—			—			—			—			985			985			—
	Total		$	3,972		$	282		$	1,591		$	5,845		$	826,823		$	832,668		$	261
	FDIC acquired loans:
	Commercial non-real estate		$	—		$	—		$	—		$	—		$	6,195		$	6,195		$	—
	Construction and land development			—			—			1,103			1,103			10,571			11,674			—
	Commercial real estate			—			—			433			433			27,375			27,808			—
	Residential mortgages			—			272			—			272			186,761			187,033			—
	Consumer			1			—			34			35			19,664			19,699			—
	Total		$	1		$	272		$	1,570		$	1,843		$	250,566		$	252,409		$	—
	Total loans:
	Commercial non-real estate		$	4,380		$	1,742		$	8,560		$	14,682		$	6,029,378		$	6,044,060		$	630
	Construction and land development			6,731			1,532			5,556			13,819			1,092,942			1,106,761			142
	Commercial real estate			10,388			3,246			15,258			28,892			3,115,156			3,144,048			957
	Residential mortgages			14,730			3,533			11,208			29,471			1,864,710			1,894,181			1,199
	Consumer			8,423			2,450			4,399			15,272			1,690,954			1,706,226			1,897
	Total		$	44,652		$	12,503		$	44,981		$	102,136		$	13,793,140		$	13,895,276		$	4,825
	December 31, 2013		30-59 days			60-89 days			Greater than			Total			Current			Total			Recorded
			past due			past due			90 days			past due						Loans			investment
									past due												> 90 days
																					and
																					accruing
	(In thousands)
	Originated loans:
	Commercial non-real estate		$	11,645		$	1,203		$	4,803		$	17,651		$	4,096,186		$	4,113,837		$	521
	Construction and land development			5,877			1,264			5,970			13,111			739,270			752,381			—
	Commercial real estate			8,178			5,744			14,620			28,542			1,993,986			2,022,528			420
	Residential mortgages			12,410			3,870			3,540			19,820			1,176,436			1,196,256			—
	Consumer			8,798			1,913			3,823			14,534			1,394,596			1,409,130			2,357
	Total		$	46,908		$	13,994		$	32,756		$	93,658		$	9,400,474		$	9,494,132		$	3,298
	Acquired loans:
	Commercial non-real estate		$	1,982		$	2,332		$	1,467		$	5,781		$	921,216		$	926,997		$	541
	Construction and land development			862			1,529			1,161			3,552			139,379			142,931			541
	Commercial real estate			3,742			1,345			9,026			14,113			953,035			967,148			5,853
	Residential mortgages			5,632			2,698			5,503			13,833			301,507			315,340			72
	Consumer			1,029			120			1,013			2,162			117,441			119,603			82
	Total		$	13,247		$	8,024		$	18,170		$	39,441		$	2,432,578		$	2,472,019		$	7,089
	FDIC acquired loans:
	Commercial non-real estate		$	—		$	—		$	—		$	—		$	23,390		$	23,390		$	—
	Construction and land development			—			—			1,539			1,539			18,690			20,229			—
	Commercial real estate			—			—			675			675			52,490			53,165			—
	Residential mortgages			—			—			3			3			209,015			209,018			—
	Consumer			—			—			—			—			52,864			52,864			—
	Total		$	—		$	—		$	2,217		$	2,217		$	356,449		$	358,666		$	—
	Total loans:
	Commercial non-real estate		$	13,627		$	3,535		$	6,270		$	23,432		$	5,040,792		$	5,064,224		$	1,062
Construction and land development			6,739			2,793			8,670			18,202			897,339			915,541			541
Commercial real estate			11,920			7,089			24,321			43,330			2,999,511			3,042,841			6,273
Residential mortgages			18,042			6,568			9,046			33,656			1,686,958			1,720,614			72
Consumer			9,827			2,033			4,836			16,696			1,564,901			1,581,597			2,439
Total		$	60,155		$	22,018		$	53,143		$	135,316		$	12,189,501		$	12,324,817		$	10,387
Changes in Carrying Amount of Acquired Loans and Accretable Yield for Loans Receivable	Changes in the carrying amount of acquired-impaired loans and accretable yield are presented in the following table for the years ended December 31, 2014 and 2013:
			December 31, 2014												December 31, 2013
			FDIC acquired						Acquired						FDIC acquired						Acquired
	(In thousands)		Carrying			Accretable			Carrying			Accretable			Carrying			Accretable			Carrying			Accretable
			Amount			Yield			Amount			Yield			Amount			Yield			Amount			Yield
			of  Loans						of  Loans						of Loans						of  Loans
	Balance at beginning of period		$	358,666		$	122,715		$	68,075		$	131,370		$	515,823		$	115,594		$	141,201		$	203,186
	Payments received, net			(125,388	)		(1,071	)		(50,178	)		(32,855	)		(189,987	)		(1,298	)		(116,187	)		(47,330	)
	Accretion			19,131			(19,131	)		43,379			(43,379	)		32,830			(32,830	)		43,061			(43,061	)
	(Decrease)/increase in expected cash flows based on actual cash flow and changes in cash flow assumptions			—			(1,137	)		—			(203	)		—			(17,433	)		—			3,894
	Net transfers from nonaccretable difference to accretable yield			—			11,412			—			19,735			—			58,682			—			14,681
	Balance at end of period		$	252,409		$	112,788		$	61,276		$	74,668		$	358,666		$	122,715		$	68,075		$	131,370
Commercial Non-Real Estate [Member]
Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile by Internally Assigned Grade	The following table presents the credit quality indicators of the Company’s various classes of loans at December 31, 2014 and December 31, 2013.
	Commercial Non-Real Estate Credit Exposure
	Credit Risk Profile by Internally Assigned Grade
			December 31, 2014												December 31, 2013
	(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
	Grade:
	Pass		$	5,577,827		$	111,847		$	2,027		$	5,691,701		$	3,990,318		$	846,135		$	10,477		$	4,846,930
	Pass-Watch			174,742			715			1,120			176,577			46,734			44,105			9			90,848
	Special Mention			52,962			350			—			53,312			41,812			19,914			2,897			64,623
	Substandard			112,153			7,225			3,017			122,395			34,278			16,125			9,662			60,065
	Doubtful			44			—			31			75			695			718			345			1,758
	Total		$	5,917,728		$	120,137		$	6,195		$	6,044,060		$	4,113,837		$	926,997		$	23,390		$	5,064,224
Construction and Land Development [Member]
Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile Based on Payment Activity	Construction Credit Exposure
	Credit Risk Profile Based on Payment Activity
			December 31, 2014												December 31, 2013
	(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
	Grade:
	Pass		$	1,012,128		$	14,377		$	2,468		$	1,028,973		$	709,261		$	112,773		$	—		$	822,034
	Pass-Watch			21,516			432			532			22,480			7,817			1,907			1,226			10,950
	Special Mention			7,097			129			319			7,545			3,926			9,409			276			13,611
	Substandard			33,223			6,185			8,355			47,763			31,377			18,842			11,499			61,718
	Doubtful			—			—			—			—			—			—			7,228			7,228
	Total		$	1,073,964		$	21,123		$	11,674		$	1,106,761		$	752,381		$	142,931		$	20,229		$	915,541
Commercial Real Estate [Member]
Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile by Internally Assigned Grade	Commercial Real Estate Credit Exposure
	Credit Risk Profile by Internally Assigned Grade
			December 31, 2014												December 31, 2013
	(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
	Grade:
	Pass		$	2,241,391		$	641,966		$	4,139		$	2,887,496		$	1,864,116		$	896,578		$	1,678		$	2,762,372
	Pass-Watch			61,589			11,142			4,547			77,278			49,578			9,530			10,266			69,374
	Special Mention			21,543			8,113			1,319			30,975			15,785			19,798			1,999			37,582
	Substandard			103,651			26,824			17,803			148,278			93,033			41,242			31,350			165,625
	Doubtful			21			—			—			21			16			—			7,872			7,888
	Total		$	2,428,195		$	688,045		$	27,808		$	3,144,048		$	2,022,528		$	967,148		$	53,165		$	3,042,841
Residential Mortgages [Member]
Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile Based on Payment Activity and Accrual Status	Residential Mortgage Credit Exposure
	Credit Risk Profile Based on Payment Activity and Accrual Status
			December 31, 2014												December 31, 2013
	(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
	Performing		$	1,681,868		$	2,378		$	186,641		$	1,870,887		$	1,182,266		$	307,006		$	208,473		$	1,697,742
	Nonperforming			22,902			—			392			23,294			13,990			8,334			545			22,872
	Total		$	1,704,770		$	2,378		$	187,033		$	1,894,181		$	1,196,256		$	315,340		$	209,018		$	1,720,614
Consumer [Member]
Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile Based on Payment Activity and Accrual Status	Consumer Credit Exposure
	Credit Risk Profile Based on Payment Activity and Accrual Status
			December 31, 2014												December 31, 2013
	(In thousands)		Originated			Acquired			FDIC acquired			Total			Originated			Acquired			FDIC acquired			Total
	Performing		$	1,678,069		$	985		$	19,525		$	1,698,579		$	1,401,688		$	117,707		$	52,554		$	1,571,949
	Nonperforming			7,473			—			174			7,647			7,442			1,896			310			9,648
	Total		$	1,685,542		$	985		$	19,699		$	1,706,226		$	1,409,130		$	119,603		$	52,864		$	1,581,597
Troubled Debt Restructurings That Subsequently Defaulted [Member]
Schedule of Troubled Debt Restructurings Occurred During Period by Portfolio Segment
	Troubled Debt Restructurings That
	Subsequently Defaulted:		2014						2013
			Number of			Recorded			Number of			Recorded
	($ in thousands)		Contract			Investment			Contract			Investment
	Originated loans:
	Commercial non-real estate			1		$	909			—		$	—
	Construction and land development			—			—			—			—
	Commercial real estate			—			—			6			2,487
	Residential mortgages			1			263			1			254
	Consumer			—			—			—			—
	Total originated loans			2		$	1,172			7		$	2,741
	Aquired loans:
	Commercial non-real estate			—		$	—			—		$	—
	Construction and land development			—			—			—			—
	Commercial real estate			—			—			—			—
	Residential mortgages			—			—			—			—
	Consumer			—			—			—			—
	Total acquired loans			—		$	—			—		$	—
	FDIC acquired loans:
	Commercial non-real estate			—		$	—			—		$	—
	Construction and land development			—			—			—			—
	Commercial real estate			—			—			—			—
	Residential mortgages			—			—			—			—
	Consumer			—			—			—			—
	Total FDIC acquired loans			—		$	—			—		$	—
	Total loans:
	Commercial non-real estate			1		$	909			—		$	—
	Construction and land development			—			—			—			—
	Commercial real estate			—			—			6			2,487
	Residential mortgages			1			263			1			254
	Consumer			—			—			—			—
	Total loans			2		$	1,172			7		$	2,741

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt	Long-term debt consisted of the following:
		December 31,
	(in thousands)	2014		2013
	Subordinated notes payable	$	98,011	$	98,011
	Term note payable		149,600		184,800
	Other long-term debt		126,760		103,015
	Total long-term debt	$	374,371	$	385,826

Derivatives_Tables

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values of Derivative Instruments on Balance Sheet	The table below presents the notional amounts and fair values of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets as of December 31, 2014 and December 31, 2013.
													Fair Values (1)
					Notional Amounts								Assets								Liabilities
	(in thousands)		Type of		December 31,				December 31,				December 31,				December 31,				December 31,				December 31,
			Hedge		2014				2013				2014				2013				2014				2013
	Derivatives designated as hedging instruments:
	Interest rate swaps		Cash Flow		$	300,000			$	—			$	—			$	—			$	592			$	—
					$	300,000			$	—			$	—			$	—			$	592			$	—
	Derivatives not designated as hedging instruments:
	Interest rate swaps (2)		N/A		$	747,754			$	650,667			$	17,806			$	14,147			$	18,419			$	13,777
	Risk participation agreements		N/A			80,438				19,736				125				2				208				2
	Forward commitments to sell residential mortgage loans		N/A			52,238				45,910				80				326				250				115
	Interest rate-lock commitments on residential mortgage loans		N/A			33,068				25,956				111				56				44				107
	Foreign exchange forward contracts		N/A			89,432				21,299				1,310				1,048				1,347				1,005
					$	1,002,930			$	763,568			$	19,432			$	15,579			$	20,268			$	15,006
	-1	Derivative assets and liabilities are reported with 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.
Offsetting Derivative Assets and Liabilities	Offsetting information in regards to derivative assets and liabilities subject to master netting agreements at December 31, 2014 and December 31, 2013 is presented in the following tables:
	As of December 31, 2014
							Gross				Net
							Amounts				Amounts
							Offset in				Presented				Gross Amounts Not Offset in the
							the				in the				Statement of Financial Position
			Gross				Statement				Statement
			Amounts				of Financial				of				Financial								Net
	Description		Recognized				Position				Financial				Instruments				Cash Collateral				Amount
	Derivative Assets		$	17,931			$	—			$	17,931			$	936			$	—			$	16,995
	Repurchase, securities borrowing, and similar arrangements			—				—				—				—				—				—
	Total		$	17,931			$	—			$	17,931			$	936			$	—			$	16,995
	Derivative Liabilities		$	18,627			$	—			$	18,627			$	936			$	17,343			$	348
	Reverse repurchase, securities lending, and similar arrangements			—				—				—				—				—				—
	Total		$	18,627			$	—			$	18,627			$	936			$	17,343			$	348
	As of December 31, 2013
							Gross				Net
							Amounts				Amounts
							Offset in				Presented				Gross Amounts Not Offset in the
							the				in the				Statement of Financial Position
			Gross				Statement				Statement
			Amounts				of Financial				of				Financial								Net
	Description		Recognized				Position				Financial				Instruments				Cash Collateral				Amount
	Derivative Assets		$	14,149			$	—			$	14,149			$	3,462			$	—			$	10,687
	Repurchase, securities borrowing, and similar arrangements			—				—				—				—				—				—
	Total		$	14,149			$	—			$	14,149			$	3,462			$	—			$	10,687
	Derivative Liabilities		$	13,779			$	—			$	13,779			$	3,462			$	7,406			$	2,911
	Reverse repurchase, securities lending, and similar arrangements			—				—				—				—				—				—
	Total		$	13,779			$	—			$	13,779			$	3,462			$	7,406			$	2,911

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and equipment consisted of the following:
		December 31,
	(in thousands)	2014			2013
	Land and land improvements	$	86,039		$	98,064
	Buildings and leasehold improvements		348,450			356,618
	Furniture, fixtures and equipment		90,244			90,948
	Software		57,305			51,924
	Assets under development		9,873			7,590
			591,911			605,144
	Accumulated depreciation and amortization		(193,527	)		(172,798	)
	Property and equipment, net	$	398,384		$	432,346

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Reconciliation of Goodwill and Other Indefinite Lived Intangibles	The following table provides a reconciliation of goodwill:
	(in thousands)
	Goodwill balance at December 31, 2012	$	628,877
	Reductions:
	Deferred tax purchase accounting adjustment made during 2013		(3,202	)
	Goodwill balance at December 31, 2013	$	625,675
	Reductions:
	Goodwill attributable to certain insurance business lines sold during 2014		(4,482	)
	Goodwill balance at December 31, 2014	$	621,193
Components of Other Intangible Assets and Related Amortization	The carrying value of intangible assets subject to amortization was as follows:
		December 31, 2014
		Purchase			Accumulated		Carrying
	(in thousands)	Value			Amortization		Value
	Core deposit intangibles	$	198,002		$	85,254	$	112,748
	Credit card and trust relationships		22,400			10,366		12,034
	Non-compete agreements		400			400		—
	Trade name		11,722			9,334		2,388
	Merchant processing relationships		10,000			4,360		5,640
		$	242,524		$	109,714	$	132,810
		31-Dec-13
		Purchase			Accumulated		Carrying
	(in thousands)	Value			Amortization		Value
	Core deposit intangibles	$	198,002		$	65,357	$	132,645
	Credit card and trust relationships		22,400			7,800		14,600
	Value of insurance business acquired		2,431			2,232		199
	Non-compete agreements		400			300		100
	Trade name		11,722			6,729		4,993
	Merchant processing relationships		10,000			2,764		7,236
		$	244,955		$	85,182	$	159,773
		Years Ended December 31,
	(in thousands)	2014			2013		2012
	Aggregate amortization expense for:
	Core deposit intangibles	$	19,897		$	21,905	$	23,642
	Credit card and trust relationships		2,566			2,819		3,072
	Value of insurance business acquired		34			148		158
	Non-compete agreements		100			200		100
	Trade name		2,605			2,605		4,124
	Merchant processing relationships		1,595			1,793		971
		$	26,797		$	29,470	$	32,067
Estimated Amortization Expense of Other Intangible Assets	The following table shows estimated amortization expense of other intangible assets for the five succeeding years and thereafter, calculated based on current amortization schedules (in thousands):
	2015	$	24,333
	2016		19,962
	2017		17,975
	2018		15,981
	2019		13,447
	Thereafter		41,112
		$	132,810

Time_Deposits_Tables

Time Deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Maturities of Time Deposits	The maturity of time deposits at December 31, 2014:
	(in thousands)	2014
	2015	$	1,660,864
	2016		425,377
	2017		125,880
	2018		19,566
	2019		23,759
	Thereafter		5,919
	Total time deposits	$	2,261,365

ShortTerm_Borrowings_Tables

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Short-Term Borrowings	The following table presents information concerning short-term borrowings:
		December 31,
	(In thousands)	2014			2013
	Federal funds purchased:
	Amount outstanding at period-end	$	12,000		$	7,725
	Average amount outstanding during period		12,196			32,960
	Maximum amount at any month-end during period		12,000			37,320
	Weighted average interest at period-end		0.13	%		0.13	%
	Weighted average interest rate during period		0.25	%		0.22	%
	Securities sold under agreements to repurchase:
	Amount outstanding at period-end	$	624,573		$	650,235
	Average amount outstanding during period		688,704			763,259
	Maximum amount at any month-end during period		816,617			797,615
	Weighted average interest at period-end		0.03	%		0.64	%
	Weighted average interest rate during period		0.27	%		0.58	%
	FHLB borrowings:
	Amount outstanding at period-end	$	515,000		$	—
	Average amount outstanding during period		304,781			9,863
	Maximum amount at any month-end during period		565,000			—
	Weighted average interest at period-end		0.12	%		—
	Weighted average interest rate during period		0.15	%		0.18	%

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Components of Accumulated Other Comprehensive Income (Loss)	A rollforward of the components of accumulated other comprehensive income (loss) is included as follows:
	(in thousands)		Available			Held to			Employee			Loss on			Total
			for Sale			Maturity			Benefit			Effective
			Securities			Securities			Plans			Cash
						Transferred						Flow
						from AFS						Hedges
	Balance, December 31, 2011		$	60,478		$	—		$	(86,923	)	$	(65	)	$	(26,510	)
	Net change in unrealized gain (loss)			6,076			—			2,566			(502	)		8,140
	Transfer of net unrealized gain from AFS to HTM, net of cumulative tax effect			(24,598	)		24,598			—			—			—
	Reclassification adjustment for net losses realized and included in earnings			(1,441	)		—			7,548			311			6,418
	Amortization of unrealized net gain on securities transferred to held to maturity			—			(8,752	)		—			—			(8,752	)
	Income tax expense (benefit)			1,661			(3,244	)		3,879			(75	)		2,221
	Balance, December 31, 2012		$	38,854		$	19,090		$	(80,688	)	$	(181	)	$	(22,925	)
	Net change in unrealized gain (loss)			(105,270	)		—			82,502			(4	)		(22,772	)
	Transfer of net unrealized loss from AFS to HTM, net of cumulative tax effect			36,208			(36,208	)		—			—			—
	Reclassification adjustment for net losses realized and included in earnings			(105	)		—			8,331			301			8,527
	Amortization of unrealized net gain on securities transferred to held to maturity			—			(6,371	)		—			—			(6,371	)
	Income tax expense (benefit)			(38,576	)		(2,300	)		32,598			116			(8,162	)
	Balance, December 31, 2013		$	8,263		$	(21,189	)	$	(22,453	)	$	—		$	(35,379	)
	Net change in unrealized gain (loss)			15,413			—			(41,132	)		(592	)		(26,311	)
	Reclassification adjustment for net losses realized and included in earnings			—			—			390			—			390
	Amortization of unrealized net gain on securities transferred to held to maturity			—			3,297			—			—			3,297
	Income tax expense (benefit)			5,675			1,182			(14,569	)		(217	)		(7,929	)
	Balance, December 31, 2014		$	18,001		$	(19,074	)	$	(48,626	)	$	(375	)	$	(50,074	)
Summary of Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income	The following table shows the line items in the consolidated income statements affected by amounts reclassified from accumulated other comprehensive income:
	Twelve Months Ended December 31,
	Amount reclassified from AOCI		2014			2013			Increase (decrease) in affected
	(in thousands)								line item in the income statement
	Gains and losses on sale of AFS securities		$	—		$	(105	)	Securities gains (losses)
	Tax effect			—			(37	)	Income taxes
	Net of tax			—			(68	)	Net income
	Amortization/accretion of unrealized net gain/loss on securities transferred to HTM		$	3,297		$	(6,371	)	Interest income
	Tax effect			1,154			(2,230	)	Income taxes
	Net of tax			2,143			(4,141	)	Net income
	Amortization of defined benefit pension and post-retirement items		$	390		$	8,331		(a) Employee benefits expense
	Tax effect			137			2,916		Income taxes
	Net of tax			253			5,415		Net income
	Gains and losses on cash flow hedges		$	—		$	301		Interest expense
	Tax effect			—			105		Income taxes
	Net of tax			—			196		Net income
	Total reclassifications, net of tax		$	2,396		$	1,402		Net income
	(a)	These accumulated other comprehensive income components are included in the computation of net periodic pension and post-retirement cost that is reported with employee benefits expense (see footnote 11 for additional details).
Schedule of Compliance with Regulatory Capital Requirements	Following is a summary of the actual regulatory capital amounts and ratios for the Company and the Bank together with corresponding regulatory capital requirements at December 31, 2014 and 2013:
			Actual						Required for Minimum						To Be Well Capitalized
									Capital Adequacy						Under Prompt
															Corrective Action
															Provisions
	($ in thousands)		Amount			Ratio %			Amount			Ratio %			Amount			Ratio %
	At December 31, 2014
	Total capital (to risk weighted assets)
	Company		$	1,945,710			12.3		$	1,265,796			8			n/a			n/a
	Whitney Bank *			1,925,175			12.2			1,262,439			8		$	1,578,049			10
	Tier 1 capital (to risk weighted assets)
	Company		$	1,777,348			11.23		$	632,898			4			n/a			n/a
	Whitney Bank *			1,756,813			11.13			631,220			4		$	946,829			6
	Tier 1 leverage capital
	Company		$	1,777,348			9.17		$	581,263			3			n/a			n/a
	Whitney Bank *			1,756,813			9.13			577,493			3		$	962,488			5
	At December 31, 2013
	Total capital (to risk weighted assets)
	Company		$	1,877,832			13.11		$	1,146,061			8			n/a			n/a
	Hancock Bank			636,871			13.48			378,093			8		$	472,617			10
	Whitney Bank			1,187,699			12.25			775,709			8			969,636			10
	Tier 1 capital (to risk weighted assets)
	Company		$	1,685,058			11.76		$	573,030			4			n/a			n/a
	Hancock Bank			577,280			12.21			189,047			4		$	283,570			6
	Whitney Bank			1,088,339			11.22			387,854			4			581,782			6
	Tier 1 leverage capital
	Company		$	1,685,058			9.34		$	541,066			3			n/a			n/a
	Hancock Bank			577,280			9.01			192,137			3		$	320,228			5
	Whitney Bank			1,088,339			9.02			361,878			3			603,129			5
	*	(Consolidated charter effective 3/31/2014)

Retirement_Benefit_Plans_Table

Retirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Components of Defined Benefit Obligation	The following tables detail the changes in the benefit obligations and plan assets of the defined benefit for the years ended December 31, 2014 and 2013 as well as the funded status of the plans at each year end and the amounts recognized in the Company’s balance sheets. The Company uses a December 31 measurement date for all defined benefit pension plans and other postretirement benefit plans.
			2014			2013			2014			2013
	(in thousands)		Pension benefits						Other Post-
									retirement benefits
	Change in benefit obligation
	Benefit obligation:
	at beginning of year		$	412,608		$	437,104		$	31,592		$	37,831
	Service cost			12,920			16,118			126			215
	Interest cost			19,251			16,678			1,140			1,317
	Actuarial loss			29,738			(41,591	)		(3,467	)		(5,563	)
	Plan participants’ contributions			—			—			1,300			1,355
	Benefits paid			(17,606	)		(15,701	)		(2,323	)		(3,563	)
	Benefit obligation, end of year			456,911			412,608			28,368			31,592
	Change in plan assets
	Fair value of plan assets:
	at beginning of year			437,829			379,133			—			—
	Actual return on plan assets			17,826			63,695			—			—
	Employer contributions			1,123			11,123			1,023			2,208
	Plan participants’ contributions			—			—			1,300			1,355
	Benefit payments			(17,606	)		(15,701	)		(2,323	)		(3,563	)
	Expenses			(464	)		(421	)		—			—
	Fair value of plan assets, end of year			438,708			437,829			—			—
	Funded status at end of year—net (liability) asset		$	(18,203	)	$	25,221		$	(28,368	)	$	(31,592	)
	Amounts recognized in accumulated other comprehensive loss
	Unrecognized loss:
	at beginning of year		$	28,285		$	111,794		$	7,189		$	14,513
	Amount of (loss)/gain recognized during the year			(26	)		(6,570	)		(364	)		(1,761	)
	Net actuarial loss/(gain)			44,599			(76,939	)		(3,467	)		(5,563	)
	Unrecognized loss at end of year		$	72,858		$	28,285		$	3,358		$	7,189
	Projected benefit obligation			456,911			412,608			—			—
	Accumulated benefit obligation			426,073			379,607			—			—
	Fair value of plan assets			438,708			437,829			—			—
Components of Net Periodic Benefit Cost	The following table shows net periodic benefit cost included in expense and the changes in the amounts recognized in accumulated other comprehensive income during 2014 and 2013.
			Years Ended December 31,
			2014			2013			2012			2014			2013			2012
	($ in thousands)		Pension benefits									Other post-retirement benefits
	Net periodic benefit cost
	Service cost		$	12,920		$	16,118		$	12,989		$	126		$	215		$	192
	Interest cost			19,251			16,678			17,206			1,140			1,317			1,337
	Expected return on plan assets			(32,222	)		(27,928	)		(25,398	)		—			—			—
	Amortization of net loss/ prior service cost			26			6,570			6,582			364			1,761			918
	Recognized net amortization and deferral												—			—			—
	Net periodic benefit cost			(25	)		11,438			11,379			1,630			3,293			2,447
	Other changes in plan assets and benefit obligations recognized in other comprehensive income, before taxes
	Net (loss)/gain recognized during the year			(26	)		(6,570	)		(6,582	)		(364	)		(1,761	)		(966	)
	Net actuarial loss/(gain)			44,599			(76,939	)		(7,001	)		(3,467	)		(5,563	)		4,435
	Amortization of prior service cost			—			—			—			—			—			48
	Total recognized in other comprehensive income			44,573			(83,509	)		(13,583	)		(3,831	)		(7,324	)		3,517
	Total recognized in net periodic benefit cost and other comprehensive income		$	44,548		$	(72,071	)	$	(2,204	)	$	(2,201	)	$	(4,031	)	$	5,964
	Discount rate for benefit obligations			4.11	%		4.73	%		3.82	%		4.02	%		4.58	%		3.69	%
	Discount rate for net periodic benefit cost			4.73	%		3.82	%		4.32	%		4.58	%		3.69	%		4.18	%
	Expected long-term return on plan assets			7.5	%		7.5	%		7.5	%		n/a			n/a			n/a
	Rate of compensation increase			scaled	*		4	%		3.73	%		n/a			n/a			n/a
	*	Graded scale, declining from 7.00% at age 20 to 2.00% at age 60
Expected Future Plan Benefit Payments	The following shows expected plan benefit payments over the next ten years:
	(in thousands)		Pension			Post-retirement			Total
	2015		$	18,617		$	1,554		$	20,171
	2016			19,744			1,503			21,247
	2017			20,744			1,406			22,150
	2018			21,863			1,397			23,260
	2019			22,505			1,430			23,935
	2020-2024			128,044			7,391			135,435
			$	231,517		$	14,681		$	246,198
Weighted Average Asset Allocations and Target Allocations	The percentage allocations of the plan assets by asset category and corresponding target allocations at December 31, 2014 and 2013 follow:
			Plan Assets						Target Allocation
			at December 31,						at December 31,
	Asset category		2014			2013			2014			2013
	Equity securities			50	%		59	%		30-60	%		30-70	%
	Fixed income securities			42	%		38	%		25-65	%		25-65	%
	Real Assets			6	%		0	%		0-10	%		0-10	%
	Cash equivalents			2	%		3	%		0-5	%		0-5	%
				100	%		100	%
Other Post-retirement Benefits [Member]
Assumed Health Care Cost Trend Rates	The following table illustrates the effect on the annual periodic postretirement benefit costs and postretirement benefit obligation of a 1% increase or 1% decrease in the assumed health care cost trend rates from the rates assumed at December 31, 2014:
	(in thousands)		1% Decrease			Assumed			1% Increase
			in Rates			Rates			in Rates
	Aggregated service and interest cost		$	1,115		$	1,266		$	1,451
	Postretirement benefit obligation			25,046			28,366			32,412
Pension Benefits [Member]
Fair Values Measurements of Pension Plan Assets	The fair values of pension plan assets at December 31, 2014 and 2013, by asset category, are shown in the following tables:
	Fair Value Measurements by Asset Category / Fund		Total			Quoted Prices in			Significant			Significant
						Active Markets			Observable			Unobservable
						for Identical			Inputs			Inputs
						Assets			(Level 2)			(Level 3)
						(Level 1)
	(in thousands)
	Fair Value Measurements at December 31, 2014
	Cash and cash-equivalents:
	Cash and equivalents		$	10,243		$	10,243		$	—		$	—
	Total cash and cash-equivalents			10,243			10,243			—			—
	Fixed income:
	US government and agency securities			15,518			1,082			14,436			—
	Municipal securities			33,980			—			33,980			—
	Emerging market debt fund			19,505			—			—			19,505
	Foreign bonds, notes and debentures			2,588			—			2,588			—
	Hancock Horizon Core Bond Fund			51,529			—			51,529			—
	Corporate debt			62,429			—			62,429			—
	Total fixed income			185,549			1,082			164,962			19,505
	Real Assets:
	Real assets fund			24,151			24,151			—			—
	Total cash and cash-equivalents			24,151			24,151			—			—
	Equity:
	Hancock Horizon Quantitative Long/Short Fund			5,603			5,603			—			—
	Hancock Horizon Diversified International Fund			62,750			62,750			—			—
	Hancock Horizon Burkenroad Small Cap Fund			9,296			9,296			—			—
	Hancock Horizon Growth Fund			26,469			26,469			—			—
	Hancock Horizon Value Fund			30,321			30,321			—			—
	Equity securities			84,325			84,325			—			—
	Mineral Interests			1			—			—			1
	Total equity			218,765			218,764			—			1
	Total		$	438,708		$	254,240		$	164,962		$	19,506
	Fair Value Measurements by Asset Category / Fund		Total			Quoted Prices in			Significant			Significant
						Active Markets			Observable			Unobservable
						for Identical			Inputs			Inputs
						Assets (Level 1)			(Level 2)			(Level 3)
	(in thousands)
	Fair Value Measurements at December 31, 2013
	Cash and cash-equivalents:
	Cash and equivalents		$	5,683		$	5,683		$	—		$	—
	Hancock Horizon Government Money Market Fund			9,531			9,531			—			—
	Total cash and cash-equivalents			15,214			15,214			—			—
	Fixed income:
	US government and agency securities			21,485			4,383			17,102			—
	Municipal securities			40,476			—			40,476			—
	Hancock Horizon Core Bond Fund			59,674						59,674			—
	Corporate debt			43,440			6,923			36,517			—
	Total fixed income			165,075			11,306			153,769			—
	Equity:
	Hancock Horizon Quantitative Long/Short Fund			6,593			6,593			—			—
	Hancock Horizon Diversified International Fund			26,072			26,072			—			—
	Hancock Horizon Burkenroad Small Cap Fund			4,108			4,108			—			—
	Hancock Horizon Growth Fund			27,847			27,847			—			—
	Hancock Horizon Value Fund			34,216			34,216			—			—
	Hancock Horizon Diversified Income Fund			8,758			8,758			—			—
	Equity securities			149,946			149,946			—			—
	Total Equity			257,540			257,540			—			—
	TOTAL		$	437,829		$	284,060		$	153,769		$	—

ShareBased_Payment_Arrangement1

Share-Based Payment Arrangements (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Option Activity Under Stock Option Plans	A summary of option activity for 2014 is presented below:
	Options	Number of			Weighted-		Weighted-		Aggregate
		Shares			Average		Average		Intrinsic
					Exercise		Remaining		Value ($000)
					Price ($)		Contractual
							Term
							(Years)
	Outstanding at January 1, 2014		1,332,656		$	38.85
	Granted		—			—
	Exercised		(81,842	)		30.4
	Cancelled/Forfeited		(197,974	)		36.06
	Expired		(113,447	)		63.41
	Outstanding at December 31, 2014		939,393		$	37.21		4.2	$	221
	Exercisable at December 31, 2014		781,529		$	38.62		3.7	$	107
Stock Options, Valuation Assumption	The significant assumptions made in applying the option-pricing model are noted in the following table. Expected volatilities are based on implied volatilities from traded options on the Company’s stock, historical volatility of the Company’s stock and other factors. The expected term of options granted was derived from the output of the option valuation model and represents the period of time that options granted are expected to be outstanding.
		2012
	Expected volatility		38.64	%
	Expected dividends		3.23	%
	Expected term (in years)		6.58
	Risk-free rates		1.78	%
Schedule of Nonvested Restricted and Performance Shares	A summary of the status of the Company’s nonvested restricted and performance shares as of December 31, 2014 and changes during 2014 are presented below:
		Number of			Weighted-
		Shares			Average
					Grant-Date
					Fair Value ($)
	Nonvested at January 1, 2014		1,981,820		$	31.75
	Granted		608,856			34.42
	Vested		(391,859	)		32.76
	Cancelled/Forfeited		(158,518	)		32.75
	Nonvested at December 31, 2014		2,040,299		$	32.27

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table presents for each of the fair-value hierarchy levels the Company’s financial assets and liabilities that are measured at fair value (in thousands) on a recurring basis in the consolidated balance sheets.
			December 31, 2014
	(in thousands)		Level 1		Level 2		Total
	Assets
	Available for sale debt securities:
	U.S. Treasury and government agency securities		$	—	$	300,508	$	300,508
	Municipal obligations			—		14,176		14,176
	Corporate debt securities			—		3,500		3,500
	Mortgage-backed securities			—		1,245,564		1,245,564
	Collateralized mortgage obligations			—		86,864		86,864
	Equity securities			9,553		—		9,553
	Total available for sale securities			9,553		1,650,612		1,660,165
	Derivative assets (1)			—		19,432		19,432
	Total recurring fair value measurements – assets		$	9,553	$	1,670,044	$	1,679,597
	Liabilities
	Derivative liabilities (1)		$	—	$	20,860	$	20,860
	Total recurring fair value measurements – liabilities		$	—	$	20,860	$	20,860
		-1	For further disaggregation of derivative assets and liabilities, see Note 5 – Derivatives
			31-Dec-13
	(in thousands)		Level 1		Level 2		Total
	Assets
	Available for sale debt securities:
	U.S. Treasury and government agency securities		$	505	$	—	$	505
	Municipal obligations			—		35,961		35,961
	Corporate debt securities			—		3,500		3,500
	Mortgage-backed securities			—		1,276,958		1,276,958
	Collateralized mortgage obligations			—		94,125		94,125
	Equity securities			10,723		—		10,723
	Total available for sale securities			11,228		1,410,544		1,421,772
	Derivative assets (1)			—		15,579		15,579
	Total recurring fair value measurements – assets		$	11,228	$	1,426,123	$	1,437,351
	Liabilities
	Derivative liabilities (1)		$	—	$	15,006	$	15,006
	Total recurring fair value measurements – liabilities		$	—	$	15,006	$	15,006
		-1	For further disaggregation of derivative assets and liabilities, see Note 5 – Derivatives
Schedule of Financial Assets Measured at Fair Value on Nonrecurring Basis	The following table presents for each of the fair value hierarchy levels the Company’s financial assets that are measured at fair value on a nonrecurring basis:
			December 31, 2014
	(in thousands)		Level 1		Level 2		Level 3		Total
	Collateral dependent impaired loans		$	—	$	30,204	$	—	$	30,204
	Other real estate owned			—		—		29,715		29,715
	Total nonrecurring fair value measurements		$	—	$	30,204	$	29,715	$	59,919
			31-Dec-13
	(in thousands)		Level 1		Level 2		Level 3		Total
	Collateral dependent impaired loans		$	—	$	24,392	$	—	$	24,392
	Other real estate owned			—		—		34,105		34,105
	Total nonrecurring fair value measurements		$	—	$	24,392	$	34,105	$	58,497
Schedule of Estimated Fair Values of Financial Instruments	The estimated fair values of the Company’s financial instruments were as follows:
			December 31, 2014						Total		Carrying
	(in thousands)		Level 1		Level 2		Level 3		Fair Value		Amount
	Financial assets:
	Cash, interest-bearing bank deposits, and federal funds sold		$	1,159,403	$	—	$	—	$	1,159,403	$	1,159,403
	Available for sale securities			9,553		1,650,612		—		1,660,165		1,660,165
	Held to maturity securities			—		2,186,340		—		2,186,340		2,166,289
	Loans, net			—		30,204		13,672,427		13,702,631		13,766,514
	Loans held for sale			—		20,252		—		20,252		20,252
	Accrued interest receivable			47,501		—		—		47,501		47,501
	Derivative financial instruments			—		19,432		—		19,432		19,432
	Financial liabilities:
	Deposits		$	—	$	—	$	16,398,878	$	16,398,878	$	16,572,831
	Federal funds purchased			12,000		—		—		12,000		12,000
	Securities sold under agreements to repurchase			624,573		—		—		624,573		624,573
	FHLB Borrowings			515,000		—		—		515,000		515,000
	Long-term debt			—		346,379		—		346,379		374,371
	Accrued interest payable			4,204		—		—		4,204		4,204
	Derivative financial instruments			—		20,860		—		20,860		20,860
			31-Dec-13						Total		Carrying
	(in thousands)		Level 1		Level 2		Level 3		Fair Value		Amount
	Financial assets:
	Cash, interest-bearing bank deposits, and federal funds sold		$	617,280	$	—	$	—	$	617,280	$	617,280
	Available for sale securities			11,228		1,410,544		—		1,421,772		1,421,772
	Held to maturity securities			—		2,576,584		—		2,576,584		2,611,352
	Loans, net			—		24,392		12,023,330		12,047,722		12,191,191
	Loans held for sale			—		24,515		—		24,515		24,515
	Accrued interest receivable			42,977		—		—		42,977		42,977
	Derivative financial instruments			—		15,579		—		15,579		15,579
	Financial liabilities:
	Deposits		$	—	$	—	$	15,352,024	$	15,352,024	$	15,360,516
	Federal funds purchased			7,725		—		—		7,725		7,725
	Securities sold under agreements to repurchase			650,235		—		—		650,235		650,235
	Long-term debt			—		385,557		—		385,557		385,826
	Accrued interest payable			4,353		—		—		4,353		4,353
	Derivative financial instruments			—		15,006		—		15,006		15,006

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Summary of Obligations	These off-balance sheet financial instruments are summarized below:
		December 31,
	(in thousands)	2014			2013
	Commitments to extend credit	$	5,700,546		$	5,234,929
	Letters of credit		414,408			422,284
Change in Liability	The following table presents the changes in the liability for 2014 and 2013.
	(in thousands)	2014			2013
	Balance, January 1	$	8,661		$	8,165
	Adjustments		(1,690	)		2,765
	Cash Payments		(6,971	)		(2,269	)
	Balance, December 31	$	—		$	8,661
Future Minimum Lease Payments for All Non-Cancelable Capital and Operating Leases	Future minimum lease payments for non-cancelable operating leases with initial terms in excess of one year were as follows at December 31, 2014:
		Operating
	(in thousands)	Leases
	2015	$	11,766
	2016		11,856
	2017		11,064
	2018		9,782
	2019		7,917
	Thereafter		28,293
	Total minimum lease payments	$	80,678

Other_Noninterest_Income_and_O1

Other Noninterest Income and Other Noninterest Expense (Tables)	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Components of Other Noninterest Income and Other Noninterest Expense	The components of other noninterest income and other noninterest expense are as follows:
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Other noninterest income:
	Income from bank-owned life insurance	$	10,314	$	11,223	$	11,163
	Credit-related fees		11,121		8,724		6,681
	Income from derivatives		1,645		4,675		3,600
	Gain on sales of assets		1,279		1,932		4,366
	Safety deposit box income		1,830		1,923		2,006
	Other miscellaneous income		9,249		8,754		9,072
	Total other noninterest income	$	35,438	$	37,231	$	36,888
	Other noninterest expense:
	Advertising	$	8,937	$	10,399	$	13,515
	Ad valorem and franchise taxes		10,492		9,727		8,321
	Printing and supplies		4,550		5,112		7,491
	Insurance expense		3,919		4,094		5,494
	Travel		4,066		4,716		5,758
	Entertainment and contributions		5,762		5,265		6,049
	Tax credit investment amortization		8,817		10,781		5,974
	Other miscellaneous expense		30,585		45,242		27,669
	Total other noninterest expense	$	77,128	$	95,336	$	80,271

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Components of Income Tax Expense	Income tax expense included in net income consisted of the following components:
		Years Ended December 31,
	(in thousands)	2014			2013			2012
	Included in net income
	Current federal	$	41,441		$	14,797		$	11,195
	Current state		1,487			(3,207	)		1,953
	Total current provision		42,928			11,590			13,148
	Deferred federal		21,483			37,403			34,219
	Deferred state		2,054			3,517			(1,754	)
	Total deferred provision		23,537			40,920			32,465
	Total included in net income	$	66,465		$	52,510		$	45,613
	Included in shareholders’ equity
	Deferred tax related to retirement benefits		(14,681	)	$	32,749		$	3,788
	Deferred tax related to securities		6,857			(40,876	)		(1,583	)
	Deferred tax related to derivatives and hedging		(217	)		116			(75	)
	Total included in shareholders’ equity	$	(8,041	)	$	(8,011	)	$	2,130
Components of the Company's Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and liabilities were as follows:
		December 31,
	(in thousands)	2014			2013
	Deferred tax assets:
	Allowance for loan losses	$	57,667		$	64,389
	Employee compensation and benefits		50,361			31,293
	Loan purchase accounting adjustments		35,094			75,595
	Tax credit carryforward		35,553			41,083
	Securities		—			6,432
	State net operating loss		1,535			1,535
	Other		18,702			21,611
	Gross deferred tax assets		198,912			241,938
	Federal valuation allowance		—			—
	State valuation allowance		(1,529	)		(1,531	)
	Subtotal valuation allowance		(1,529	)		(1,531	)
	Net deferred tax assets		197,383			240,407
	Deferred tax liabilities:
	Fixed assets & intangibles		(88,062	)		(93,952	)
	Securities		(724	)		—
	Deferred gain on acquisition		—			(4,407	)
	FDIC indemnification asset		(18,769	)		(37,775	)
	Other		(15,493	)		(14,565	)
	Gross deferred tax liabilities		(123,048	)		(150,699	)
	Net deferred tax asset (liability)	$	74,335		$	89,708
Schedule of Effective Income Tax Rate Reconciliation	Reported income tax expense differed from amounts computed by applying the statutory income tax rate of 35% to earnings before income taxes because of the following factors:
		Years Ended December 31,
		2014						2013						2012
	($ in thousands)	Amount			%			Amount			%			Amount			%
	Taxes computed at statutory rate	$	84,766			35	%	$	75,553			35	%	$	69,074			35	%
	Increases (decreases) in taxes resulting from:
	State income taxes, net of federal income tax benefit		4,649			2	%		2,352			1	%		(78	)		0	%
	Tax-exempt interest		(6,301	)		-3	%		(6,487	)		-3	%		(7,127	)		-4	%
	Bank owned life insurance		(3,554	)		-1	%		(3,926	)		-2	%		(4,005	)		-2	%
	Tax credits		(16,577	)		-7	%		(15,743	)		-7	%		(13,661	)		-7	%
	Other, net		3,482			1	%		761			0	%		1,410			1	%
	Income tax expense	$	66,465			27	%	$	52,510			24	%	$	45,613			23	%

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of Earnings Per Common Share	A summary of the information used in the computation of earnings per common share follows:
		Years Ended December 31,
	($ in thousands, except per share amounts)	2014		2013		2012
	Numerator:
	Net income to common shareholders	$	175,722	$	163,356	$	151,742
	Net income allocated to participating securities - basic and diluted		3,631		3,105		1,557
	Net income allocated to common shareholders - basic and diluted	$	172,091	$	160,251	$	150,185
	Denominator:
	Weighted-average common shares - basic		81,804		83,066		84,767
	Dilutive potential common shares		230		101		821
	Weighted average common shares - diluted		82,034		83,167		85,588
	Earnings per common share:
	Basic	$	2.1	$	1.93	$	1.77
	Diluted	$	2.1	$	1.93	$	1.75

Condensed_Parent_Company_Infor1

Condensed Parent Company Information (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets
		December 31,
	(in thousands)	2014			2013
	Assets:
	Cash	$	44,771		$	66,338
	Securities available for sale		97,423			107,017
	Investment in bank subsidiaries		2,452,529			2,408,389
	Investment in non-bank subsidiaries		3,202			5,319
	Due from subsidiaries and other assets		24,896			24,091
		$	2,622,821		$	2,611,154
	Liabilities and Stockholders’ Equity:
	Long term debt	$	149,600		$	184,800
	Other liabilities		819			1,285
	Stockholders’ equity		2,472,402			2,425,069
		$	2,622,821		$	2,611,154
Condensed Statements of Income	Condensed Statements of Income
		Years Ended December 31,
	(in thousands)	2014			2013			2012
	Operating Income
	From subsidiaries
	Cash dividends received from bank subsidiaries	$	124,000		$	249,000		$	25,000
	Non-cash dividend from bank subsidiary in restructuring		—			—			225,000
	Dividends received from non-bank subsidiaries		—			2,990			150
	Equity in earnings of subsidiaries greater than (less than) dividends received		58,358			(82,203	)		(94,486	)
	Total operating income		182,358			169,787			155,664
	Other (expense) income, net		(10,035	)		(10,335	)		(6,673	)
	Income tax expense (benefit)		(3,399	)		(3,904	)		(2,751	)
	Net income	$	175,722		$	163,356		$	151,742
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows
		Years Ended December 31,
	(in thousands)	2014			2013			2012
	Cash flows from operating activities—principally dividends received from subsidiaries	$	126,491		$	257,251		$	18,789
	Net cash provided by operating activities		126,491			257,251			18,789
	Cash flows from investing activities
	Contribution of capital to subsidiary		—			(870	)		(955	)
	Loans to nonbank subsidiaries, net of repayments		—			—			1,684
	Purchase of available for sale securities		—			—			(77,058	)
	Proceeds from principal paydowns of securities available for sale		12,664			18,685			47,305
	Other, net		—			(5,630	)		—
	Net cash used by investing activities		12,664			12,185			(29,024	)
	Cash flows from financing activities:
	Proceeds from issuance of long term debt		—			—			217,933
	Repayment of long term debt		(35,200	)		(35,200	)		(140,000	)
	Dividends paid to stockholders		(80,392	)		(81,673	)		(83,151	)
	Stock transactions, net		(45,130	)		(112,266	)		13,479
	Net cash provided by (used by) financing activities		(160,722	)		(229,139	)		8,261
	Net increase (decrease) in cash		(21,567	)		40,297			(1,974	)
	Cash, beginning of year		66,338			26,041			28,015
	Cash, end of year	$	44,771		$	66,338		$	26,041

Summary_of_Significant_Account2

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Subsidiary
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Number of wholly-owned subsidiaries merged	2
Maximum refinement period of fair values after closing date of an acquisition	1 year
Specific reserve balances to include all commercial, commercial real estate and substandard mortgage loans	1 million or greater
Tax Credit carry forward period	20 years
Federal NMTC Investment [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Period of tax credit earning	7 years
Low Income Housing Investments [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Period of tax credit earning	10 years
Commercial Loans [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Loss emergence period	18 months
Retail Loans [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Loss emergence period	12 months
Maximum [Member] | State NMTC Investment [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Period of tax credit earning	5 years
Minimum [Member] | State NMTC Investment [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Period of tax credit earning	3 years
Building [Member] | Maximum [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Estimated useful lives of the assets	39 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Estimated useful lives of the assets	10 years
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Estimated useful lives of the assets	3 years
Software [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Amortization expense charged off period	3 years

Securities_Amortized_Cost_and_

Securities - Amortized Cost and Fair Value of Available for Sale Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	$1,631,761	$1,408,780
Securities available for sale, Gross Unrealized Gains	32,543	25,366
Securities available for sale, Gross Unrealized Losses	4,139	12,374
Securities Available for Sale, Fair Value	1,660,165	1,421,772
U.S. Treasury and Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	300,207	504
Securities available for sale, Gross Unrealized Gains	372	2
Securities available for sale, Gross Unrealized Losses	71	1
Securities Available for Sale, Fair Value	300,508	505
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	13,995	35,809
Securities available for sale, Gross Unrealized Gains	186	177
Securities available for sale, Gross Unrealized Losses	5	25
Securities Available for Sale, Fair Value	14,176	35,961
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
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	8,673	9,965
Securities available for sale, Gross Unrealized Gains	891	785
Securities available for sale, Gross Unrealized Losses	11	27
Securities Available for Sale, Fair Value	9,553	10,723
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,217,293	1,262,633
Securities available for sale, Gross Unrealized Gains	31,094	24,402
Securities available for sale, Gross Unrealized Losses	2,823	10,077
Securities Available for Sale, Fair Value	1,245,564	1,276,958
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	88,093	96,369
Securities available for sale, Gross Unrealized Losses	1,229	2,244
Securities Available for Sale, Fair Value	$86,864	$94,125

Securities_Amortized_Cost_and_1

Securities - Amortized Cost and Fair Value of Held to Maturity Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	$2,166,289	$2,611,352
Securities Held to Maturity, Gross Unrealized Gains	32,903	2,593
Securities Held to Maturity, Gross Unrealized Losses	12,852	37,361
Securities Held to Maturity, Fair Value	2,186,340	2,576,584
U.S. Treasury and Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost		100,000
Securities Held to Maturity, Gross Unrealized Gains		316
Securities Held to Maturity, Fair Value		100,316
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	180,615	193,189
Securities Held to Maturity, Gross Unrealized Gains	3,416	919
Securities Held to Maturity, Gross Unrealized Losses	1,144	6,436
Securities Held to Maturity, Fair Value	182,887	187,672
Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	899,923	1,003,327
Securities Held to Maturity, Gross Unrealized Gains	23,897	296
Securities Held to Maturity, Gross Unrealized Losses	162	4,671
Securities Held to Maturity, Fair Value	923,658	998,952
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	1,085,751	1,314,836
Securities Held to Maturity, Gross Unrealized Gains	5,590	1,062
Securities Held to Maturity, Gross Unrealized Losses	11,546	26,254
Securities Held to Maturity, Fair Value	$1,079,795	$1,289,644

Securities_Additional_Informat

Securities - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortized Cost and Fair Value Debt Securities [Abstract]
Available for sale securities reclassified to held to maturity securities	$1,000,000,000
Unrealized net holding gain (loss) on the available for sale securities on the date of transfer	-56,800,000
Gains or losses recognized as a result of transfer	0
Proceeds from sales of securities available for sale		1,455,000	178,000	48,336,000
Securities pledged to secure public deposits and securities sold under agreements to repurchase		$3,200,000,000	$3,100,000,000

Securities_Amortized_Cost_and_2

Securities - Amortized Cost and Fair Value of Available for Sale Securities by Final Contractual Maturity (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity [Abstract]
Securities Available for Sale, Due in one year or less, Amortized Cost	$303,284
Securities Available for Sale, Due after one year through five years, Amortized Cost	154,189
Securities Available for Sale, Due after five years through ten years, Amortized Cost	236,461
Securities Available for Sale, Due after ten years, Amortized Cost	929,154
Total available for sale securities, Amortized Cost	1,623,088
Securities Available for Sale, Due in one year or less, Fair Value	303,589
Securities Available for Sale, Due after one year through five years, Fair Value	154,534
Securities Available for Sale, Due after five years through ten years, Fair Value	244,535
Securities Available for Sale, Due after ten years, Fair Value	947,954
Total available for sale securities, Fair Value	$1,650,612

Securities_Amortized_Cost_and_3

Securities - Amortized Cost and Fair Value of Held to Maturity Securities by Final Contractual Maturity (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity [Abstract]
Securities Held to Maturity, Due in one year or less, Amortized Cost	$169,617
Securities Held to Maturity, Due after one year through five years, Amortized Cost	453,352
Securities Held to Maturity, Due after five years through ten years, Amortized Cost	115,748
Securities Held to Maturity, Due after ten years, Amortized Cost	1,427,572
Securities Held to Maturity, Amortized Cost	2,166,289	2,611,352
Securities Held to Maturity, Due in one year or less, Fair Value	170,786
Securities Held to Maturity, Due after one year through five years, Fair Value	446,039
Securities Held to Maturity, Due after five years through ten years, Fair Value	115,195
Securities Held to Maturity, Due after ten years, Fair Value	1,454,320
Total Held to Maturity Securities, Fair Value	$2,186,340	$2,576,584

Securities_Available_for_Sale_

Securities - Available for Sale Securities Unrealized Losses (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Unrealized Loss And Fair Value Available For Sale Securities [Line Items]
Available for sale securities, Losses less than 12 months, Fair Value	$147,898	$481,937
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	248	9,460
Available for sale securities, Losses 12 months or longer, Fair value	212,629	49,064
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	3,891	2,914
Available for sale securities, Total, Fair value	360,527	531,001
Available for sale securities, Total, Gross Unrealized Losses	4,139	12,374
Equity Securities [Member]
Unrealized Loss And Fair Value Available For Sale Securities [Line Items]
Available for sale securities, Losses less than 12 months, Fair Value	5,998	3,282
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	10	26
Available for sale securities, Losses 12 months or longer, Fair value	3	3
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	1	1
Available for sale securities, Total, Fair value	6,001	3,285
Available for sale securities, Total, Gross Unrealized Losses	11	27
U.S. Treasury and Government Agency Securities [Member]
Unrealized Loss And Fair Value Available For Sale Securities [Line Items]
Available for sale securities, Losses less than 12 months, Fair Value	99,950	205
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	70	1
Available for sale securities, Losses 12 months or longer, Fair value	121
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	1
Available for sale securities, Total, Fair value	100,071	205
Available for sale securities, Total, Gross Unrealized Losses	71	1
Municipal Obligations [Member]
Unrealized Loss And Fair Value Available For Sale Securities [Line Items]
Available for sale securities, Losses less than 12 months, Fair Value	2,995	7,975
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	5	25
Available for sale securities, Total, Fair value	2,995	7,975
Available for sale securities, Total, Gross Unrealized Losses	5	25
Mortgage-Backed Securities [Member]
Unrealized Loss And Fair Value Available For Sale Securities [Line Items]
Available for sale securities, Losses less than 12 months, Fair Value	38,955	376,350
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	163	7,164
Available for sale securities, Losses 12 months or longer, Fair value	125,641	49,061
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	2,660	2,913
Available for sale securities, Total, Fair value	164,596	425,411
Available for sale securities, Total, Gross Unrealized Losses	2,823	10,077
Collateralized Mortgage Obligations [Member]
Unrealized Loss And Fair Value Available For Sale Securities [Line Items]
Available for sale securities, Losses less than 12 months, Fair Value		94,125
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses		2,244
Available for sale securities, Losses 12 months or longer, Fair value	86,864
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	1,229
Available for sale securities, Total, Fair value	86,864	94,125
Available for sale securities, Total, Gross Unrealized Losses	$1,229	$2,244

Securities_Held_to_Maturity_wi

Securities - Held to Maturity with Unrealized Losses (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	$123,538	$2,028,848
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	628	36,070
Held to maturity securities, Losses 12 months or longer, Fair value	694,234	178,511
Held to maturity securities, Losses 12 months or longer, Gross Unrealized Losses	12,224	1,291
Held to maturity securities, Total, Fair value	817,772	2,207,359
Held to maturity securities, Total, Gross Unrealized Losses	12,852	37,361
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	4,316	131,499
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	12	6,311
Held to maturity securities, Losses 12 months or longer, Fair value	58,105	2,878
Held to maturity securities, Losses 12 months or longer, Gross Unrealized Losses	1,132	125
Held to maturity securities, Total, Fair value	62,421	134,377
Held to maturity securities, Total, Gross Unrealized Losses	1,144	6,436
Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value		950,288
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses		4,671
Held to maturity securities, Losses 12 months or longer, Fair value	95,522
Held to maturity securities, Losses 12 months or longer, Gross Unrealized Losses	162
Held to maturity securities, Total, Fair value	95,522	950,288
Held to maturity securities, Total, Gross Unrealized Losses	162	4,671
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	119,222	947,061
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	616	25,088
Held to maturity securities, Losses 12 months or longer, Fair value	540,607	175,633
Held to maturity securities, Losses 12 months or longer, Gross Unrealized Losses	10,930	1,166
Held to maturity securities, Total, Fair value	659,829	1,122,694
Held to maturity securities, Total, Gross Unrealized Losses	$11,546	$26,254

Loans_Additional_Information_D

Loans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Single family loans in FDIC acquired loans covered by loss share agreement	$196,700,000
Balances of loans due from related parties	16,200,000	61,100,000
Changes in new loans	12,900,000
Repayments in affiliates loans	12,900,000
Net balance reduction in directors and affiliates loans	-44,900,000
Interest that would have been recorded on nonaccrual loans	3,600,000	5,400,000	7,800,000
Interest recovered on nonaccrual loans	1,500,000	3,000,000	2,600,000
Nonaccrual loans	79,537,000	99,686,000
Troubled debt restructuring	16,000,000	24,900,000
Minimum bank portfolio loan need to be reviewed	1,000,000
Loans held for sale	20,252,000	24,515,000
Troubled Debt Restructurings [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Nonaccrual loans	$7,000,000	$15,700,000
Performing [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Period for which payments of principal and interest are past due	Less than 90 days

Loans_Loans_Net_of_Unearned_In

Loans - Loans, Net of Unearned Income (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Loans Receivable [Line Items]
Total FDIC acquired loans	$252,409	$358,666
Total loans	13,895,276	12,324,817
Commercial Non-Real Estate [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	6,195	23,390
Total loans	6,044,060	5,064,224
Construction and Land Development [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	11,674	20,229
Total loans	1,106,761	915,541
Commercial Real Estate [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	27,808	53,165
Total loans	3,144,048	3,042,841
Residential Mortgages [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	187,033	209,018
Total loans	1,894,181	1,720,614
Consumer [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	19,699	52,864
Total loans	1,706,226	1,581,597
Originated Loans [Member]
Loans Receivable [Line Items]
Total loans	12,810,199	9,494,132
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial non-real estate	5,917,728	4,113,837
Originated Loans [Member] | Construction and Land Development [Member]
Loans Receivable [Line Items]
Total Construction and land development	1,073,964	752,381
Originated Loans [Member] | Commercial Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial real estate	2,428,195	2,022,528
Originated Loans [Member] | Residential Mortgages [Member]
Loans Receivable [Line Items]
Total Residential mortgages	1,704,770	1,196,256
Originated Loans [Member] | Consumer [Member]
Loans Receivable [Line Items]
Total Consumer	1,685,542	1,409,130
Acquired Loans [Member]
Loans Receivable [Line Items]
Total loans	832,668	2,472,019
Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial non-real estate	120,137	926,997
Acquired Loans [Member] | Construction and Land Development [Member]
Loans Receivable [Line Items]
Total Construction and land development	21,123	142,931
Acquired Loans [Member] | Commercial Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial real estate	688,045	967,148
Acquired Loans [Member] | Residential Mortgages [Member]
Loans Receivable [Line Items]
Total Residential mortgages	2,378	315,340
Acquired Loans [Member] | Consumer [Member]
Loans Receivable [Line Items]
Total Consumer	$985	$119,603

Loans_Loans_Net_of_Unearned_In1

Loans - Loans, Net of Unearned Income (Parenthetical) (Detail) (USD $)	Dec. 31, 2014
In Billions, unless otherwise specified
Receivables [Abstract]
Originated loans previously reported as acquired-performing	$1.20

Loans_Allowance_for_Loan_Losse

Loans - Allowance for Loan Losses by Portfolio Segment and Related Recorded Investment in Loans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	$133,626
Ending balance: FDIC acquired loans	252,409	358,666
Ending balance: Loans	13,895,276	12,324,817
Net provision for loan losses	33,840	32,734	54,192
(Decrease) increase in FDIC loss share receivable	-19,084	-7,504
Loans and Leases receivable, Allowance, Ending Balance	128,762	133,626
Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	133,626	136,171
Charge-offs	-39,499	-52,410
Recoveries	19,879	25,746
Net provision for loan losses	33,840	32,734
(Decrease) increase in FDIC loss share receivable	-19,084	-8,615
Loans and Leases receivable, Allowance, Ending Balance	128,762	133,626
Ending balance: Individually evaluated for impairment	854	768
Ending balance: Amounts related to acquired-impaired loans	30,584	53,094
Ending balance: Collectively evaluated for impairment	97,324	79,764
Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	13,895,276	12,324,817
Ending balance: Individually evaluated for impairment	29,711	36,239
Ending balance: Acquired-impaired loans	313,676	426,741
Ending balance: Collectively evaluated for impairment	13,551,889	11,861,837
Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	6,195	23,390
Ending balance: Loans	6,044,060	5,064,224
Commercial Non-Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	37,017	23,725
Charge-offs	-7,034	-7,742
Recoveries	3,532	5,880
Net provision for loan losses	19,247	15,275
(Decrease) increase in FDIC loss share receivable	-1,593	-121
Loans and Leases receivable, Allowance, Ending Balance	51,169	37,017
Ending balance: Individually evaluated for impairment	14	477
Ending balance: Amounts related to acquired-impaired loans	911	2,323
Ending balance: Collectively evaluated for impairment	50,244	34,217
Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	6,044,060	5,064,224
Ending balance: Individually evaluated for impairment	3,987	7,435
Ending balance: Acquired-impaired loans	14,641	42,484
Ending balance: Collectively evaluated for impairment	6,025,432	5,014,305
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	11,674	20,229
Ending balance: Loans	1,106,761	915,541
Construction and Land Development [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	8,845	17,038
Charge-offs	-4,918	-11,556
Recoveries	7,138	2,411
Net provision for loan losses	-215	1,845
(Decrease) increase in FDIC loss share receivable	-4,429	-893
Loans and Leases receivable, Allowance, Ending Balance	6,421	8,845
Ending balance: Individually evaluated for impairment	19	22
Ending balance: Amounts related to acquired-impaired loans	1,008	2,655
Ending balance: Collectively evaluated for impairment	5,394	6,168
Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,106,761	915,541
Ending balance: Individually evaluated for impairment	8,250	11,327
Ending balance: Acquired-impaired loans	31,355	37,564
Ending balance: Collectively evaluated for impairment	1,067,156	866,650
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	27,808	53,165
Ending balance: Loans	3,144,048	3,042,841
Commercial Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	31,612	36,392
Charge-offs	-8,929	-9,939
Recoveries	3,119	9,517
Net provision for loan losses	-1,900	-4,895
(Decrease) increase in FDIC loss share receivable	-2,820	537
Loans and Leases receivable, Allowance, Ending Balance	21,082	31,612
Ending balance: Individually evaluated for impairment	488	268
Ending balance: Amounts related to acquired-impaired loans	4,061	10,929
Ending balance: Collectively evaluated for impairment	16,533	20,415
Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	3,144,048	3,042,841
Ending balance: Individually evaluated for impairment	14,812	16,367
Ending balance: Acquired-impaired loans	57,585	79,223
Ending balance: Collectively evaluated for impairment	3,071,651	2,947,251
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	187,033	209,018
Ending balance: Loans	1,894,181	1,720,614
Residential Mortgages [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	34,881	36,877
Charge-offs	-3,293	-3,829
Recoveries	645	1,949
Net provision for loan losses	2,501	6,190
(Decrease) increase in FDIC loss share receivable	-6,074	-6,306
Loans and Leases receivable, Allowance, Ending Balance	28,660	34,881
Ending balance: Individually evaluated for impairment	330	1
Ending balance: Amounts related to acquired-impaired loans	20,609	27,989
Ending balance: Collectively evaluated for impairment	7,721	6,891
Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,894,181	1,720,614
Ending balance: Individually evaluated for impairment	2,656	1,110
Ending balance: Acquired-impaired loans	189,411	214,512
Ending balance: Collectively evaluated for impairment	1,702,114	1,504,992
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	19,699	52,864
Ending balance: Loans	1,706,226	1,581,597
Consumer [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	21,271	22,139
Charge-offs	-15,325	-19,344
Recoveries	5,445	5,989
Net provision for loan losses	14,207	14,319
(Decrease) increase in FDIC loss share receivable	-4,168	-1,832
Loans and Leases receivable, Allowance, Ending Balance	21,430	21,271
Ending balance: Individually evaluated for impairment	3
Ending balance: Amounts related to acquired-impaired loans	3,995	9,198
Ending balance: Collectively evaluated for impairment	17,432	12,073
Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,706,226	1,581,597
Ending balance: Individually evaluated for impairment	6
Ending balance: Acquired-impaired loans	20,684	52,958
Ending balance: Collectively evaluated for impairment	1,685,536	1,528,639
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	12,810,199	9,494,132
Originated Loans [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	78,885	78,774
Charge-offs	-31,502	-42,899
Recoveries	14,383	18,590
Net provision for loan losses	35,935	24,420
Loans and Leases receivable, Allowance, Ending Balance	97,701	78,885
Ending balance: Individually evaluated for impairment	377	768
Ending balance: Collectively evaluated for impairment	97,324	78,117
Originated Loans [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	12,810,199	9,494,132
Ending balance: Individually evaluated for impairment	27,020	30,527
Ending balance: Collectively evaluated for impairment	12,783,179	9,463,605
Originated Loans [Member] | Commercial Non-Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	33,091	20,775
Charge-offs	-6,813	-6,671
Recoveries	3,047	5,790
Net provision for loan losses	20,933	13,197
Loans and Leases receivable, Allowance, Ending Balance	50,258	33,091
Ending balance: Individually evaluated for impairment	14	477
Ending balance: Collectively evaluated for impairment	50,244	32,614
Originated Loans [Member] | Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	5,917,728	4,113,837
Ending balance: Individually evaluated for impairment	3,987	5,294
Ending balance: Collectively evaluated for impairment	5,913,741	4,108,543
Originated Loans [Member] | Construction and Land Development [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	6,180	11,415
Charge-offs	-4,770	-10,312
Recoveries	4,000	1,676
Net provision for loan losses	3	3,401
Loans and Leases receivable, Allowance, Ending Balance	5,413	6,180
Ending balance: Individually evaluated for impairment	19	22
Ending balance: Collectively evaluated for impairment	5,394	6,158
Originated Loans [Member] | Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,073,964	752,381
Ending balance: Individually evaluated for impairment	8,250	10,599
Ending balance: Collectively evaluated for impairment	1,065,714	741,782
Originated Loans [Member] | Commercial Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	20,649	26,959
Charge-offs	-3,579	-5,525
Recoveries	1,678	3,359
Net provision for loan losses	-2,204	-4,144
Loans and Leases receivable, Allowance, Ending Balance	16,544	20,649
Ending balance: Individually evaluated for impairment	11	268
Ending balance: Collectively evaluated for impairment	16,533	20,381
Originated Loans [Member] | Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	2,428,195	2,022,528
Ending balance: Individually evaluated for impairment	12,121	14,029
Ending balance: Collectively evaluated for impairment	2,416,074	2,008,499
Originated Loans [Member] | Residential Mortgages [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	6,892	6,406
Charge-offs	-2,285	-2,297
Recoveries	644	1,936
Net provision for loan losses	2,800	847
Loans and Leases receivable, Allowance, Ending Balance	8,051	6,892
Ending balance: Individually evaluated for impairment	330	1
Ending balance: Collectively evaluated for impairment	7,721	6,891
Originated Loans [Member] | Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,704,770	1,196,256
Ending balance: Individually evaluated for impairment	2,656	605
Ending balance: Collectively evaluated for impairment	1,702,114	1,195,651
Originated Loans [Member] | Consumer [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	12,073	13,219
Charge-offs	-14,055	-18,094
Recoveries	5,014	5,829
Net provision for loan losses	14,403	11,119
Loans and Leases receivable, Allowance, Ending Balance	17,435	12,073
Ending balance: Individually evaluated for impairment	3
Ending balance: Collectively evaluated for impairment	17,432	12,073
Originated Loans [Member] | Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,685,542	1,409,130
Ending balance: Individually evaluated for impairment	6
Ending balance: Collectively evaluated for impairment	1,685,536	1,409,130
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	832,668	2,472,019
Acquired Loans [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	1,647	788
Net provision for loan losses	-1,170	859
Loans and Leases receivable, Allowance, Ending Balance	477	1,647
Ending balance: Individually evaluated for impairment	477
Ending balance: Collectively evaluated for impairment		1,647
Acquired Loans [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	832,668	2,472,019
Ending balance: Individually evaluated for impairment	2,691	5,712
Ending balance: Acquired-impaired loans	61,267	68,075
Ending balance: Collectively evaluated for impairment	768,710	2,398,232
Acquired Loans [Member] | Commercial Non-Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	1,603	788
Net provision for loan losses	-1,603	815
Loans and Leases receivable, Allowance, Ending Balance		1,603
Ending balance: Collectively evaluated for impairment		1,603
Acquired Loans [Member] | Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	120,137	926,997
Ending balance: Individually evaluated for impairment		2,141
Ending balance: Acquired-impaired loans	8,446	19,094
Ending balance: Collectively evaluated for impairment	111,691	905,762
Acquired Loans [Member] | Construction and Land Development [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	10
Net provision for loan losses	-10	10
Loans and Leases receivable, Allowance, Ending Balance		10
Ending balance: Collectively evaluated for impairment		10
Acquired Loans [Member] | Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	21,123	142,931
Ending balance: Individually evaluated for impairment		728
Ending balance: Acquired-impaired loans	19,681	17,335
Ending balance: Collectively evaluated for impairment	1,442	124,868
Acquired Loans [Member] | Commercial Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	34
Net provision for loan losses	443	34
Loans and Leases receivable, Allowance, Ending Balance	477	34
Ending balance: Individually evaluated for impairment	477
Ending balance: Collectively evaluated for impairment		34
Acquired Loans [Member] | Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	688,045	967,148
Ending balance: Individually evaluated for impairment	2,691	2,338
Ending balance: Acquired-impaired loans	29,777	26,058
Ending balance: Collectively evaluated for impairment	655,577	938,752
Acquired Loans [Member] | Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	2,378	315,340
Ending balance: Individually evaluated for impairment		505
Ending balance: Acquired-impaired loans	2,378	5,494
Ending balance: Collectively evaluated for impairment		309,341
Acquired Loans [Member] | Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	985	119,603
Ending balance: Acquired-impaired loans	985	94
Ending balance: Collectively evaluated for impairment		119,509
FDIC Acquired Loans [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	53,094	56,609
Charge-offs	-7,997	-9,511
Recoveries	5,496	7,156
Net provision for loan losses	-925	7,455
(Decrease) increase in FDIC loss share receivable	-19,084	-8,615
Loans and Leases receivable, Allowance, Ending Balance	30,584	53,094
Ending balance: Amounts related to acquired-impaired loans	30,584	53,094
FDIC Acquired Loans [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	252,409	358,666
Ending balance: Acquired-impaired loans	252,409	358,666
FDIC Acquired Loans [Member] | Commercial Non-Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	2,323	2,162
Charge-offs	-221	-1,071
Recoveries	485	90
Net provision for loan losses	-83	1,263
(Decrease) increase in FDIC loss share receivable	-1,593	-121
Loans and Leases receivable, Allowance, Ending Balance	911	2,323
Ending balance: Amounts related to acquired-impaired loans	911	2,323
FDIC Acquired Loans [Member] | Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	6,195	23,390
Ending balance: Acquired-impaired loans	6,195	23,390
FDIC Acquired Loans [Member] | Construction and Land Development [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	2,655	5,623
Charge-offs	-148	-1,244
Recoveries	3,138	735
Net provision for loan losses	-208	-1,566
(Decrease) increase in FDIC loss share receivable	-4,429	-893
Loans and Leases receivable, Allowance, Ending Balance	1,008	2,655
Ending balance: Amounts related to acquired-impaired loans	1,008	2,655
FDIC Acquired Loans [Member] | Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	11,674	20,229
Ending balance: Acquired-impaired loans	11,674	20,229
FDIC Acquired Loans [Member] | Commercial Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	10,929	9,433
Charge-offs	-5,350	-4,414
Recoveries	1,441	6,158
Net provision for loan losses	-139	-785
(Decrease) increase in FDIC loss share receivable	-2,820	537
Loans and Leases receivable, Allowance, Ending Balance	4,061	10,929
Ending balance: Amounts related to acquired-impaired loans	4,061	10,929
FDIC Acquired Loans [Member] | Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	27,808	53,165
Ending balance: Acquired-impaired loans	27,808	53,165
FDIC Acquired Loans [Member] | Residential Mortgages [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	27,989	30,471
Charge-offs	-1,008	-1,532
Recoveries	1	13
Net provision for loan losses	-299	5,343
(Decrease) increase in FDIC loss share receivable	-6,074	-6,306
Loans and Leases receivable, Allowance, Ending Balance	20,609	27,989
Ending balance: Amounts related to acquired-impaired loans	20,609	27,989
FDIC Acquired Loans [Member] | Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	187,033	209,018
Ending balance: Acquired-impaired loans	187,033	209,018
FDIC Acquired Loans [Member] | Consumer [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance	9,198	8,920
Charge-offs	-1,270	-1,250
Recoveries	431	160
Net provision for loan losses	-196	3,200
(Decrease) increase in FDIC loss share receivable	-4,168	-1,832
Loans and Leases receivable, Allowance, Ending Balance	3,995	9,198
Ending balance: Amounts related to acquired-impaired loans	3,995	9,198
FDIC Acquired Loans [Member] | Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	19,699	52,864
Ending balance: Acquired-impaired loans	$19,699	$52,864

Loans_Allowance_for_Loan_Losse1

Loans - Allowance for Loan Losses by Portfolio Segment and Related Recorded Investment in Loans (Parenthetical) (Detail) (USD $)	Dec. 31, 2014
In Billions, unless otherwise specified
Receivables [Abstract]
Originated loans previously reported as acquired-performing	$1.20

Loans_Schedule_of_Activity_in_

Loans - Schedule of Activity in Loss Share Receivable (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Beginning balance	$113,834	$177,844
(Amortization) accretion	-12,102	-2,239	5,000
Charge-offs, write-downs and other (recoveries) losses	-2,245	-1,619
External expenses qualifying under loss share agreement	4,532	9,117
Changes due to changes in cash flow projections	-19,084	-7,504
Settlement of disallowed claims	-10,268
Net payments to (from) FDIC	-14,395	-61,765
Ending balance	$60,272	$113,834	$177,844

Loans_Summary_of_Composition_o

Loans - Summary of Composition of Non-Accrual Loans by Portfolio Segment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	$79,537	$99,686
Commercial Non-Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	15,511	13,359
Construction and Land Development [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	7,565	16,700
Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	28,619	40,460
Residential Mortgages [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	22,094	22,255
Consumer [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	5,748	6,912
Originated Loans [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	71,296	74,342
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	15,511	10,148
Originated Loans [Member] | Construction and Land Development [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	6,462	13,171
Originated Loans [Member] | Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	22,047	32,772
Originated Loans [Member] | Residential Mortgages [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	21,702	13,449
Originated Loans [Member] | Consumer [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	5,574	4,802
Acquired Loans [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	6,139	21,800
Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans		3,209
Acquired Loans [Member] | Construction and Land Development [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans		1,990
Acquired Loans [Member] | Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	6,139	6,525
Acquired Loans [Member] | Residential Mortgages [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans		8,262
Acquired Loans [Member] | Consumer [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans		1,814
FDIC Acquired Loans [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	2,102	3,544
FDIC Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans		2
FDIC Acquired Loans [Member] | Construction and Land Development [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	1,103	1,539
FDIC Acquired Loans [Member] | Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	433	1,163
FDIC Acquired Loans [Member] | Residential Mortgages [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	392	544
FDIC Acquired Loans [Member] | Consumer [Member]
Nonaccrual Loans By Portfolio [Line Items]
Non-accrual loans	$174	$296

Loans_Schedule_of_Troubled_Deb

Loans - Schedule of Troubled Debt Restructurings Occurred During Period by Portfolio Segment (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	Contract	Contract
Troubled Debt Restructurings [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	12	8
Pre-Modification Outstanding Recorded Investment	$6,486	$3,740
Post-Modification Outstanding Recorded Investment	5,573	3,371
Troubled Debt Restructurings [Member] | Commercial Non-Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1	1
Pre-Modification Outstanding Recorded Investment	29	926
Post-Modification Outstanding Recorded Investment	29	909
Troubled Debt Restructurings [Member] | Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	3	5
Pre-Modification Outstanding Recorded Investment	4,488	1,844
Post-Modification Outstanding Recorded Investment	4,446	1,629
Troubled Debt Restructurings [Member] | Residential Mortgages [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	7	2
Pre-Modification Outstanding Recorded Investment	1,961	970
Post-Modification Outstanding Recorded Investment	1,090	833
Troubled Debt Restructurings [Member] | Consumer [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1
Pre-Modification Outstanding Recorded Investment	8
Post-Modification Outstanding Recorded Investment	8
Troubled Debt Restructurings [Member] | Originated Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	12	6
Pre-Modification Outstanding Recorded Investment	6,486	2,714
Post-Modification Outstanding Recorded Investment	5,573	2,396
Troubled Debt Restructurings [Member] | Originated Loans [Member] | Commercial Non-Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1	1
Pre-Modification Outstanding Recorded Investment	29	926
Post-Modification Outstanding Recorded Investment	29	909
Troubled Debt Restructurings [Member] | Originated Loans [Member] | Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	3	4
Pre-Modification Outstanding Recorded Investment	4,488	1,332
Post-Modification Outstanding Recorded Investment	4,446	1,157
Troubled Debt Restructurings [Member] | Originated Loans [Member] | Residential Mortgages [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	7	1
Pre-Modification Outstanding Recorded Investment	1,961	456
Post-Modification Outstanding Recorded Investment	1,090	330
Troubled Debt Restructurings [Member] | Originated Loans [Member] | Consumer [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1
Pre-Modification Outstanding Recorded Investment	8
Post-Modification Outstanding Recorded Investment	8
Troubled Debt Restructurings [Member] | Acquired Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts		2
Pre-Modification Outstanding Recorded Investment		1,026
Post-Modification Outstanding Recorded Investment		975
Troubled Debt Restructurings [Member] | Acquired Loans [Member] | Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts		1
Pre-Modification Outstanding Recorded Investment		512
Post-Modification Outstanding Recorded Investment		472
Troubled Debt Restructurings [Member] | Acquired Loans [Member] | Residential Mortgages [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts		1
Pre-Modification Outstanding Recorded Investment		514
Post-Modification Outstanding Recorded Investment		503
Troubled Debt Restructurings That Subsequently Defaulted [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	2	7
Recorded Investment	1,172	2,741
Troubled Debt Restructurings That Subsequently Defaulted [Member] | Commercial Non-Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1
Recorded Investment	909
Troubled Debt Restructurings That Subsequently Defaulted [Member] | Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts		6
Recorded Investment		2,487
Troubled Debt Restructurings That Subsequently Defaulted [Member] | Residential Mortgages [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1	1
Recorded Investment	263	254
Troubled Debt Restructurings That Subsequently Defaulted [Member] | Originated Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	2	7
Recorded Investment	1,172	2,741
Troubled Debt Restructurings That Subsequently Defaulted [Member] | Originated Loans [Member] | Commercial Non-Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1
Recorded Investment	909
Troubled Debt Restructurings That Subsequently Defaulted [Member] | Originated Loans [Member] | Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts		6
Recorded Investment		2,487
Troubled Debt Restructurings That Subsequently Defaulted [Member] | Originated Loans [Member] | Residential Mortgages [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1	1
Recorded Investment	$263	$254

Loans_Summary_of_Impaired_Loan

Loans - Summary of Impaired Loans Disaggregated by Class (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	$14,815	$15,463
Recorded Investment, With a related allowance recorded	14,896	20,776
Recorded Investment, Total	29,711	36,239
Unpaid Principal Balance, With no related allowance recorded	20,707	20,589
Unpaid Principal Balance, With a related allowance recorded	15,581	23,356
Unpaid Principal Balance, Total	36,288	43,945
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	854	768
Related Allowance, Total	854	768
Average Recorded Investment, With no related allowance recorded	13,965	23,083
Average Recorded Investment, With a related allowance recorded	25,340	38,833
Average Recorded Investment, Total	39,305	61,916
Interest Income Recognized, With no related allowance recorded	527	534
Interest Income Recognized, With a related allowance recorded	648	703
Interest Income Recognized, Total	1,175	1,237
Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	3,003	2,470
Recorded Investment, With a related allowance recorded	984	4,965
Recorded Investment, Total	3,987	7,435
Unpaid Principal Balance, With no related allowance recorded	3,646	3,717
Unpaid Principal Balance, With a related allowance recorded	984	5,303
Unpaid Principal Balance, Total	4,630	9,020
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	14	477
Related Allowance, Total	14	477
Average Recorded Investment, With no related allowance recorded	1,566	1,100
Average Recorded Investment, With a related allowance recorded	6,581	11,683
Average Recorded Investment, Total	8,147	12,783
Interest Income Recognized, With no related allowance recorded	51	26
Interest Income Recognized, With a related allowance recorded	221	243
Interest Income Recognized, Total	272	269
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	3,345	4,829
Recorded Investment, With a related allowance recorded	4,905	6,498
Recorded Investment, Total	8,250	11,327
Unpaid Principal Balance, With no related allowance recorded	6,486	6,273
Unpaid Principal Balance, With a related allowance recorded	4,906	8,343
Unpaid Principal Balance, Total	11,392	14,616
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	19	22
Related Allowance, Total	19	22
Average Recorded Investment, With no related allowance recorded	3,451	3,076
Average Recorded Investment, With a related allowance recorded	7,697	2,706
Average Recorded Investment, Total	11,148	5,782
Interest Income Recognized, With no related allowance recorded	142	85
Interest Income Recognized, With a related allowance recorded	193
Interest Income Recognized, Total	335	85
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	8,467	7,659
Recorded Investment, With a related allowance recorded	6,345	8,708
Recorded Investment, Total	14,812	16,367
Unpaid Principal Balance, With no related allowance recorded	10,575	10,092
Unpaid Principal Balance, With a related allowance recorded	6,374	9,090
Unpaid Principal Balance, Total	16,949	19,182
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	488	268
Related Allowance, Total	488	268
Average Recorded Investment, With no related allowance recorded	8,772	17,225
Average Recorded Investment, With a related allowance recorded	8,857	22,346
Average Recorded Investment, Total	17,629	39,571
Interest Income Recognized, With no related allowance recorded	331	423
Interest Income Recognized, With a related allowance recorded	184	460
Interest Income Recognized, Total	515	883
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded		505
Recorded Investment, With a related allowance recorded	2,656	605
Recorded Investment, Total	2,656	1,110
Unpaid Principal Balance, With no related allowance recorded		507
Unpaid Principal Balance, With a related allowance recorded	3,311	620
Unpaid Principal Balance, Total	3,311	1,127
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	330	1
Related Allowance, Total	330	1
Average Recorded Investment, With no related allowance recorded	176	669
Average Recorded Investment, With a related allowance recorded	2,204	1,073
Average Recorded Investment, Total	2,380	1,742
Interest Income Recognized, With no related allowance recorded	3
Interest Income Recognized, With a related allowance recorded	50
Interest Income Recognized, Total	53
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With a related allowance recorded	6
Recorded Investment, Total	6
Unpaid Principal Balance, With a related allowance recorded	6
Unpaid Principal Balance, Total	6
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	3
Related Allowance, Total	3
Average Recorded Investment, With no related allowance recorded		1,013
Average Recorded Investment, With a related allowance recorded	1	1,025
Average Recorded Investment, Total	1	2,038
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	14,815	9,751
Recorded Investment, With a related allowance recorded	12,205	20,776
Recorded Investment, Total	27,020	30,527
Unpaid Principal Balance, With no related allowance recorded	20,707	13,031
Unpaid Principal Balance, With a related allowance recorded	12,861	23,356
Unpaid Principal Balance, Total	33,568	36,387
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	377	768
Related Allowance, Total	377	768
Average Recorded Investment, With no related allowance recorded	13,088	20,176
Average Recorded Investment, With a related allowance recorded	21,887	32,421
Average Recorded Investment, Total	34,976	52,597
Interest Income Recognized, With no related allowance recorded	527	474
Interest Income Recognized, With a related allowance recorded	395	640
Interest Income Recognized, Total	921	1,114
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	3,003	329
Recorded Investment, With a related allowance recorded	984	4,965
Recorded Investment, Total	3,987	5,294
Unpaid Principal Balance, With no related allowance recorded	3,646	442
Unpaid Principal Balance, With a related allowance recorded	984	5,303
Unpaid Principal Balance, Total	4,630	5,745
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	14	477
Related Allowance, Total	14	477
Average Recorded Investment, With no related allowance recorded	1,209	235
Average Recorded Investment, With a related allowance recorded	5,522	8,936
Average Recorded Investment, Total	6,732	9,171
Interest Income Recognized, With no related allowance recorded	51	18
Interest Income Recognized, With a related allowance recorded	99	180
Interest Income Recognized, Total	150	198
Originated Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	3,345	4,101
Recorded Investment, With a related allowance recorded	4,905	6,498
Recorded Investment, Total	8,250	10,599
Unpaid Principal Balance, With no related allowance recorded	6,486	5,131
Unpaid Principal Balance, With a related allowance recorded	4,906	8,343
Unpaid Principal Balance, Total	11,392	13,474
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	19	22
Related Allowance, Total	19	22
Average Recorded Investment, With no related allowance recorded	3,330	2,780
Average Recorded Investment, With a related allowance recorded	6,660	2,549
Average Recorded Investment, Total	9,990	5,329
Interest Income Recognized, With no related allowance recorded	142	82
Interest Income Recognized, With a related allowance recorded	137
Interest Income Recognized, Total	279	82
Originated Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	8,467	5,321
Recorded Investment, With a related allowance recorded	3,654	8,708
Recorded Investment, Total	12,121	14,029
Unpaid Principal Balance, With no related allowance recorded	10,575	7,458
Unpaid Principal Balance, With a related allowance recorded	3,654	9,090
Unpaid Principal Balance, Total	14,229	16,548
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	11	268
Related Allowance, Total	11	268
Average Recorded Investment, With no related allowance recorded	8,461	15,886
Average Recorded Investment, With a related allowance recorded	7,500	19,683
Average Recorded Investment, Total	15,961	35,569
Interest Income Recognized, With no related allowance recorded	331	374
Interest Income Recognized, With a related allowance recorded	109	460
Interest Income Recognized, Total	439	834
Originated Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With a related allowance recorded	2,656	605
Recorded Investment, Total	2,656	605
Unpaid Principal Balance, With a related allowance recorded	3,311	620
Unpaid Principal Balance, Total	3,311	620
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	330	1
Related Allowance, Total	330	1
Average Recorded Investment, With no related allowance recorded	88	262
Average Recorded Investment, With a related allowance recorded	2,204	228
Average Recorded Investment, Total	2,292	490
Interest Income Recognized, With no related allowance recorded	3
Interest Income Recognized, With a related allowance recorded	50
Interest Income Recognized, Total	53
Originated Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With a related allowance recorded	6
Recorded Investment, Total	6
Unpaid Principal Balance, With a related allowance recorded	6
Unpaid Principal Balance, Total	6
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	3
Related Allowance, Total	3
Average Recorded Investment, With no related allowance recorded		1,013
Average Recorded Investment, With a related allowance recorded	1	1,025
Average Recorded Investment, Total	1	2,038
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded		5,712
Recorded Investment, With a related allowance recorded	2,691
Recorded Investment, Total	2,691	5,712
Unpaid Principal Balance, With no related allowance recorded		7,558
Unpaid Principal Balance, With a related allowance recorded	2,720
Unpaid Principal Balance, Total	2,720	7,558
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	477
Related Allowance, Total	477
Average Recorded Investment, With no related allowance recorded	877	2,907
Average Recorded Investment, With a related allowance recorded	3,453	6,412
Average Recorded Investment, Total	4,330	9,319
Interest Income Recognized, With no related allowance recorded		60
Interest Income Recognized, With a related allowance recorded	253	63
Interest Income Recognized, Total	253	123
Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded		2,141
Recorded Investment, Total		2,141
Unpaid Principal Balance, With no related allowance recorded		3,275
Unpaid Principal Balance, Total		3,275
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	357	865
Average Recorded Investment, With a related allowance recorded	1,059	2,747
Average Recorded Investment, Total	1,416	3,612
Interest Income Recognized, With no related allowance recorded		8
Interest Income Recognized, With a related allowance recorded	122	63
Interest Income Recognized, Total	122	71
Acquired Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded		728
Recorded Investment, Total		728
Unpaid Principal Balance, With no related allowance recorded		1,142
Unpaid Principal Balance, Total		1,142
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	121	296
Average Recorded Investment, With a related allowance recorded	1,037	157
Average Recorded Investment, Total	1,158	453
Interest Income Recognized, With no related allowance recorded		3
Interest Income Recognized, With a related allowance recorded	56
Interest Income Recognized, Total	56	3
Acquired Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded		2,338
Recorded Investment, With a related allowance recorded	2,691
Recorded Investment, Total	2,691	2,338
Unpaid Principal Balance, With no related allowance recorded		2,634
Unpaid Principal Balance, With a related allowance recorded	2,720
Unpaid Principal Balance, Total	2,720	2,634
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	477
Related Allowance, Total	477
Average Recorded Investment, With no related allowance recorded	311	1,339
Average Recorded Investment, With a related allowance recorded	1,357	2,663
Average Recorded Investment, Total	1,668	4,002
Interest Income Recognized, With no related allowance recorded		49
Interest Income Recognized, With a related allowance recorded	75
Interest Income Recognized, Total	75	49
Acquired Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded		505
Recorded Investment, Total		505
Unpaid Principal Balance, With no related allowance recorded		507
Unpaid Principal Balance, Total		507
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	88	407
Average Recorded Investment, With a related allowance recorded		845
Average Recorded Investment, Total	88	1,252
Acquired Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance, With no related allowance recorded	$0	$0

Loans_Summary_of_Age_Analysis_

Loans - Summary of Age Analysis of Past Due Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	$252,409	$358,666
Total loans	13,895,276	12,324,817
30-59 days past due	44,652	60,155
60-89 days past due	12,503	22,018
Greater than 90 days past due	44,981	53,143
Total past due	102,136	135,316
Current	13,793,140	12,189,501
Recorded investment > 90 days and accruing	4,825	10,387
Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	6,195	23,390
Total loans	6,044,060	5,064,224
30-59 days past due	4,380	13,627
60-89 days past due	1,742	3,535
Greater than 90 days past due	8,560	6,270
Total past due	14,682	23,432
Current	6,029,378	5,040,792
Recorded investment > 90 days and accruing	630	1,062
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	11,674	20,229
Total loans	1,106,761	915,541
30-59 days past due	6,731	6,739
60-89 days past due	1,532	2,793
Greater than 90 days past due	5,556	8,670
Total past due	13,819	18,202
Current	1,092,942	897,339
Recorded investment > 90 days and accruing	142	541
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	27,808	53,165
Total loans	3,144,048	3,042,841
30-59 days past due	10,388	11,920
60-89 days past due	3,246	7,089
Greater than 90 days past due	15,258	24,321
Total past due	28,892	43,330
Current	3,115,156	2,999,511
Recorded investment > 90 days and accruing	957	6,273
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	187,033	209,018
Total loans	1,894,181	1,720,614
30-59 days past due	14,730	18,042
60-89 days past due	3,533	6,568
Greater than 90 days past due	11,208	9,046
Total past due	29,471	33,656
Current	1,864,710	1,686,958
Recorded investment > 90 days and accruing	1,199	72
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	19,699	52,864
Total loans	1,706,226	1,581,597
30-59 days past due	8,423	9,827
60-89 days past due	2,450	2,033
Greater than 90 days past due	4,399	4,836
Total past due	15,272	16,696
Current	1,690,954	1,564,901
Recorded investment > 90 days and accruing	1,897	2,439
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	12,810,199	9,494,132
30-59 days past due	40,679	46,908
60-89 days past due	11,949	13,994
Greater than 90 days past due	41,820	32,756
Total past due	94,448	93,658
Current	12,715,751	9,400,474
Recorded investment > 90 days and accruing	4,564	3,298
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial non-real estate	5,917,728	4,113,837
30-59 days past due	4,380	11,645
60-89 days past due	1,742	1,203
Greater than 90 days past due	8,560	4,803
Total past due	14,682	17,651
Current	5,903,046	4,096,186
Recorded investment > 90 days and accruing	630	521
Originated Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Construction and land development	1,073,964	752,381
30-59 days past due	6,620	5,877
60-89 days past due	1,532	1,264
Greater than 90 days past due	4,453	5,970
Total past due	12,605	13,111
Current	1,061,359	739,270
Recorded investment > 90 days and accruing	142
Originated Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial real estate	2,428,195	2,022,528
30-59 days past due	6,527	8,178
60-89 days past due	2,964	5,744
Greater than 90 days past due	13,234	14,620
Total past due	22,725	28,542
Current	2,405,470	1,993,986
Recorded investment > 90 days and accruing	696	420
Originated Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Residential mortgages	1,704,770	1,196,256
30-59 days past due	14,730	12,410
60-89 days past due	3,261	3,870
Greater than 90 days past due	11,208	3,540
Total past due	29,199	19,820
Current	1,675,571	1,176,436
Recorded investment > 90 days and accruing	1,199
Originated Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Consumer	1,685,542	1,409,130
30-59 days past due	8,422	8,798
60-89 days past due	2,450	1,913
Greater than 90 days past due	4,365	3,823
Total past due	15,237	14,534
Current	1,670,305	1,394,596
Recorded investment > 90 days and accruing	1,897	2,357
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	832,668	2,472,019
30-59 days past due	3,972	13,247
60-89 days past due	282	8,024
Greater than 90 days past due	1,591	18,170
Total past due	5,845	39,441
Current	826,823	2,432,578
Recorded investment > 90 days and accruing	261	7,089
Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial non-real estate	120,137	926,997
30-59 days past due		1,982
60-89 days past due		2,332
Greater than 90 days past due		1,467
Total past due		5,781
Current	120,137	921,216
Recorded investment > 90 days and accruing		541
Acquired Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Construction and land development	21,123	142,931
30-59 days past due	111	862
60-89 days past due		1,529
Greater than 90 days past due		1,161
Total past due	111	3,552
Current	21,012	139,379
Recorded investment > 90 days and accruing		541
Acquired Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial real estate	688,045	967,148
30-59 days past due	3,861	3,742
60-89 days past due	282	1,345
Greater than 90 days past due	1,591	9,026
Total past due	5,734	14,113
Current	682,311	953,035
Recorded investment > 90 days and accruing	261	5,853
Acquired Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Residential mortgages	2,378	315,340
30-59 days past due		5,632
60-89 days past due		2,698
Greater than 90 days past due		5,503
Total past due		13,833
Current	2,378	301,507
Recorded investment > 90 days and accruing		72
Acquired Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Consumer	985	119,603
30-59 days past due		1,029
60-89 days past due		120
Greater than 90 days past due		1,013
Total past due		2,162
Current	985	117,441
Recorded investment > 90 days and accruing		82
FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 days past due	1
60-89 days past due	272
Greater than 90 days past due	1,570	2,217
Total past due	1,843	2,217
Current	250,566	356,449
FDIC Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	6,195	23,390
FDIC Acquired Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Greater than 90 days past due	1,103	1,539
Total past due	1,103	1,539
Current	10,571	18,690
FDIC Acquired Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Greater than 90 days past due	433	675
Total past due	433	675
Current	27,375	52,490
FDIC Acquired Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
60-89 days past due	272
Greater than 90 days past due		3
Total past due	272	3
Current	186,761	209,015
FDIC Acquired Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 days past due	1
Greater than 90 days past due	34
Total past due	35
Current	$19,664	$52,864

Loans_Schedule_of_Credit_Quali

Loans - Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile by Internally Assigned Grade (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	$6,044,060	$5,064,224
Commercial Non Real Estate Credit Exposure [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,691,701	4,846,930
Commercial Non Real Estate Credit Exposure [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	176,577	90,848
Commercial Non Real Estate Credit Exposure [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	53,312	64,623
Commercial Non Real Estate Credit Exposure [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	122,395	60,065
Commercial Non Real Estate Credit Exposure [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	75	1,758
Commercial Non Real Estate Credit Exposure [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,917,728	4,113,837
Commercial Non Real Estate Credit Exposure [Member] | Originated Loans [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,577,827	3,990,318
Commercial Non Real Estate Credit Exposure [Member] | Originated Loans [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	174,742	46,734
Commercial Non Real Estate Credit Exposure [Member] | Originated Loans [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	52,962	41,812
Commercial Non Real Estate Credit Exposure [Member] | Originated Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	112,153	34,278
Commercial Non Real Estate Credit Exposure [Member] | Originated Loans [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	44	695
Commercial Non Real Estate Credit Exposure [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	120,137	926,997
Commercial Non Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	111,847	846,135
Commercial Non Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	715	44,105
Commercial Non Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	350	19,914
Commercial Non Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	7,225	16,125
Commercial Non Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade		718
Commercial Non Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	6,195	23,390
Commercial Non Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,027	10,477
Commercial Non Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	1,120	9
Commercial Non Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade		2,897
Commercial Non Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	3,017	9,662
Commercial Non Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	31	345
Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	3,144,048	3,042,841
Commercial Real Estate Credit Exposure [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,887,496	2,762,372
Commercial Real Estate Credit Exposure [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	77,278	69,374
Commercial Real Estate Credit Exposure [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	30,975	37,582
Commercial Real Estate Credit Exposure [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	148,278	165,625
Commercial Real Estate Credit Exposure [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	21	7,888
Commercial Real Estate Credit Exposure [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,428,195	2,022,528
Commercial Real Estate Credit Exposure [Member] | Originated Loans [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,241,391	1,864,116
Commercial Real Estate Credit Exposure [Member] | Originated Loans [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	61,589	49,578
Commercial Real Estate Credit Exposure [Member] | Originated Loans [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	21,543	15,785
Commercial Real Estate Credit Exposure [Member] | Originated Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	103,651	93,033
Commercial Real Estate Credit Exposure [Member] | Originated Loans [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	21	16
Commercial Real Estate Credit Exposure [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	688,045	967,148
Commercial Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	641,966	896,578
Commercial Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	11,142	9,530
Commercial Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	8,113	19,798
Commercial Real Estate Credit Exposure [Member] | Acquired Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	26,824	41,242
Commercial Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	27,808	53,165
Commercial Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	4,139	1,678
Commercial Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	4,547	10,266
Commercial Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	1,319	1,999
Commercial Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	17,803	31,350
Commercial Real Estate Credit Exposure [Member] | FDIC Acquired Loans [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade		$7,872

Loans_Schedule_of_Credit_Quali1

Loans - Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile Based on Payment Activity (Detail) (Construction Credit Exposure [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	$1,106,761	$915,541
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	1,073,964	752,381
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	21,123	142,931
FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	11,674	20,229
Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	1,028,973	822,034
Pass [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	1,012,128	709,261
Pass [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	14,377	112,773
Pass [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	2,468
Pass-Watch [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	22,480	10,950
Pass-Watch [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	21,516	7,817
Pass-Watch [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	432	1,907
Pass-Watch [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	532	1,226
Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	7,545	13,611
Special Mention [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	7,097	3,926
Special Mention [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	129	9,409
Special Mention [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	319	276
Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	47,763	61,718
Substandard [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	33,223	31,377
Substandard [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	6,185	18,842
Substandard [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity	8,355	11,499
Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity		7,228
Doubtful [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity		$7,228

Loans_Schedule_of_Credit_Quali2

Loans - Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile Based on Payment Activity and Accrual Status (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	$1,894,181	$1,720,614
Residential Mortgages [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,870,887	1,697,742
Residential Mortgages [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	23,294	22,872
Residential Mortgages [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,704,770	1,196,256
Residential Mortgages [Member] | Originated Loans [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,681,868	1,182,266
Residential Mortgages [Member] | Originated Loans [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	22,902	13,990
Residential Mortgages [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	2,378	315,340
Residential Mortgages [Member] | Acquired Loans [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	2,378	307,006
Residential Mortgages [Member] | Acquired Loans [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status		8,334
Residential Mortgages [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	187,033	209,018
Residential Mortgages [Member] | FDIC Acquired Loans [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	186,641	208,473
Residential Mortgages [Member] | FDIC Acquired Loans [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	392	545
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,706,226	1,581,597
Consumer [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,698,579	1,571,949
Consumer [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	7,647	9,648
Consumer [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,685,542	1,409,130
Consumer [Member] | Originated Loans [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,678,069	1,401,688
Consumer [Member] | Originated Loans [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	7,473	7,442
Consumer [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	985	119,603
Consumer [Member] | Acquired Loans [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	985	117,707
Consumer [Member] | Acquired Loans [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status		1,896
Consumer [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	19,699	52,864
Consumer [Member] | FDIC Acquired Loans [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	19,525	52,554
Consumer [Member] | FDIC Acquired Loans [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	$174	$310

Loans_Changes_in_Carrying_Amou

Loans - Changes in Carrying Amount of Acquired Loans and Accretable Yield for Loans Receivable (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
FDIC Acquired Loans [Member]
Financing Receivable, Impaired [Line Items]
Carrying Amount of Loans, Balance at beginning of period	$358,666	$515,823
Carrying Amount of Loans, Additions	0	0
Carrying Amount of Loans, Payments received, net	-125,388	-189,987
Carrying Amount of Loans, Accretion	19,131	32,830
Carrying Amount of Loans, Balance at end of period	252,409	358,666
Accretable Yield, Balance at beginning of period	122,715	115,594
Accretable Yield, Additions	0	0
Accretable Yield, Payments received, net	-1,071	-1,298
Accretable Yield, Accretion	-19,131	-32,830
Accretable Yield, Increase (Decrease) in expected cash flows based on actual cash flows and changes in cash flow assumptions	-1,137	-17,433
Net transfers from nonaccretable difference to accretable yield	11,412	58,682
Accretable Yield, Balance at end of period	112,788	122,715
Acquired Loans [Member]
Financing Receivable, Impaired [Line Items]
Carrying Amount of Loans, Balance at beginning of period	68,075	141,201
Carrying Amount of Loans, Additions	0	0
Carrying Amount of Loans, Payments received, net	-50,178	-116,187
Carrying Amount of Loans, Accretion	43,379	43,061
Carrying Amount of Loans, Balance at end of period	61,276	68,075
Accretable Yield, Balance at beginning of period	131,370	203,186
Accretable Yield, Additions	0	0
Accretable Yield, Payments received, net	-32,855	-47,330
Accretable Yield, Accretion	-43,379	-43,061
Accretable Yield, Increase (Decrease) in expected cash flows based on actual cash flows and changes in cash flow assumptions	-203	3,894
Net transfers from nonaccretable difference to accretable yield	19,735	14,681
Accretable Yield, Balance at end of period	$74,668	$131,370

LongTerm_Debt_LongTerm_Debt_De

Long-Term Debt - Long-Term Debt (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]
Subordinated notes payable	$98,011	$98,011
Term note payable	149,600	184,800	220,000
Other long-term debt	126,760	103,015
Total long-term debt	$374,371	$385,826

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2013	Jun. 30, 2012
Debt Disclosure [Abstract]
Subordinated notes interest rate	5.88%
Percentage of potential amount of reduction from capital	20.00%
Debt Offer initiated				$75,000,000
Repurchase of subordinated Debt		52,000,000
Debt cost incurred		5,300,000
Non Interest Expense Premium		5,100,000
Term note payable	149,600,000	220,000,000	184,800,000
Additional borrowings		50,000,000
Reference rate for loan variable rate	LIBOR
Percentage points added to reference rate		1.88%
Debt instrument term loan facility maturity date	21-Dec-15
Principal payment of term loan		$8,800,000
Borrowings maturity date, starting period	2015
Borrowings maturity date, ending period	2052

Derivatives_Fair_Values_of_Der

Derivatives - Fair Values of Derivative Instruments on Balance Sheet (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]
Derivative Fair Value Of Asset	$19,432	$15,579
Derivative Fair Value Of Liability	20,860	15,006
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	300,000
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	300,000	0
Derivative Fair Value Of Asset	0	0
Derivative Fair Value Of Liability	592	0
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	300,000	0
Derivative Fair Value Of Asset	0	0
Derivative Fair Value Of Liability	592	0
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,002,930	763,568
Derivative Fair Value Of Asset	19,432	15,579
Derivative Fair Value Of Liability	20,268	15,006
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	747,754	650,667
Derivative Fair Value Of Asset	17,806	14,147
Derivative Fair Value Of Liability	18,419	13,777
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	80,438	19,736
Derivative Fair Value Of Asset	125	2
Derivative Fair Value Of Liability	208	2
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	52,238	45,910
Derivative Fair Value Of Asset	80	326
Derivative Fair Value Of Liability	250	115
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	33,068	25,956
Derivative Fair Value Of Asset	111	56
Derivative Fair Value Of Liability	44	107
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	89,432	21,299
Derivative Fair Value Of Asset	1,310	1,048
Derivative Fair Value Of Liability	$1,347	$1,005

Derivatives_Additional_Informa

Derivatives - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Derivative [Line Items]
Variable rate term loan agreement maturity	Jan-17
Termination value of derivatives in a net liability position	$7,300,000
Collateral obligations for derivative counterparties	18,300,000
Interest Rate Swaps [Member]
Derivative [Line Items]
Notional amount of derivatives	$300,000,000

Derivatives_Offsetting_Derivat

Derivatives - Offsetting Derivative Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross Amounts Recognized	$18,627	$13,779
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial	18,627	13,779
Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments	936	3,462
Gross Amounts Not offset in the Statement of Financial Position - Cash Collateral	17,343	7,406
Net Amount	348	2,911
Gross Amounts Recognized	17,931	14,149
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial	17,931	14,149
Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments	936	3,462
Gross Amounts Not offset in the Statement of Financial Position - Cash Collateral	0	0
Net Amount	$16,995	$10,687

Property_and_Equipment_Propert

Property and Equipment - Property and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$591,911	$605,144
Accumulated depreciation and amortization	-193,527	-172,798
Property and equipment, net	398,384	432,346
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	86,039	98,064
Buildings and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	348,450	356,618
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	90,244	90,948
Software [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	57,305	51,924
Assets Under Development [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$9,873	$7,590

Property_and_Equipment_Additio

Property and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$30.30	$32.10	$32.90

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill And Other Intangible Assets [Line Items]
Goodwill impairment	$0	$0	$0	$0
Intangible assets written off related to the sale of business unit		$200,000
Core Deposit Intangibles [Member]
Goodwill And Other Intangible Assets [Line Items]
Weighted-average remaining life of intangible assets		11 years
Other Identifiable Intangibles [Member]
Goodwill And Other Intangible Assets [Line Items]
Weighted-average remaining life of intangible assets		8 years

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets - Reconciliation of Goodwill and Other Indefinite Lived Intangibles (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill beginning balance	$625,675	$628,877
Goodwill attributable to certain insurance business lines sold during 2014	-4,482
Deferred tax purchase accounting adjustment made during the period		-3,202
Goodwill ending balance	$621,193	$625,675

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets - Components of Other Intangible Assets and Related Amortization (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Purchase Value	$242,524	$244,955
Accumulated Amortization	109,714	85,182
Carrying Value	132,810	159,773
Aggregate amortization expense	26,797	29,470	32,067
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Purchase Value	198,002	198,002
Accumulated Amortization	85,254	65,357
Carrying Value	112,748	132,645
Aggregate amortization expense	19,897	21,905	23,642
Credit Card and Trust Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Purchase Value	22,400	22,400
Accumulated Amortization	10,366	7,800
Carrying Value	12,034	14,600
Aggregate amortization expense	2,566	2,819	3,072
Value of Insurance Business Acquired [Member]
Finite-Lived Intangible Assets [Line Items]
Purchase Value		2,431
Accumulated Amortization		2,232
Carrying Value		199
Aggregate amortization expense	34	148	158
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Purchase Value	400	400
Accumulated Amortization	400	300
Carrying Value		100
Aggregate amortization expense	100	200	100
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Purchase Value	11,722	11,722
Accumulated Amortization	9,334	6,729
Carrying Value	2,388	4,993
Aggregate amortization expense	2,605	2,605	4,124
Merchant Processing Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Purchase Value	10,000	10,000
Accumulated Amortization	4,360	2,764
Carrying Value	5,640	7,236
Aggregate amortization expense	$1,595	$1,793	$971

Goodwill_and_Other_Intangible_5

Goodwill and Other Intangible Assets - Estimated Amortization Expense of Other Intangible Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
2015	$24,333
2016	19,962
2017	17,975
2018	15,981
2019	13,447
Thereafter	41,112
Carrying Value	$132,810	$159,773

Deposits_Maturities_of_Time_De

Deposits - Maturities of Time Deposits (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Time Deposits [Abstract]
2015	$1,660,864
2016	425,377
2017	125,880
2018	19,566
2019	23,759
Thereafter	5,919
Total time deposits	$2,261,365

Deposits_Additional_Informatio

Deposits - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Time Deposits [Abstract]
Time deposits of $250,000 or more	$519	$472
Balances in deposits	$484	$363
Deposit maturity description	Most of these deposits mature on a daily basis.

ShortTerm_Borrowings_ShortTerm

Short-Term Borrowings - Short-Term Borrowings (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Amount outstanding at period-end	$12,000	$7,725
Average amount outstanding during period	12,196	32,960
Maximum amount at any month-end during period	12,000	37,320
Weighted average interest at period-end	0.13%	0.13%
Weighted average interest rate during period	0.25%	0.22%
Securities Sold Under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Amount outstanding at period-end	624,573	650,235
Average amount outstanding during period	688,704	763,259
Maximum amount at any month-end during period	816,617	797,615
Weighted average interest at period-end	0.03%	0.64%
Weighted average interest rate during period	0.27%	0.58%
FHLB Borrowings [Member]
Short-term Debt [Line Items]
Amount outstanding at period-end	515,000
Average amount outstanding during period	304,781	9,863
Maximum amount at any month-end during period	$565,000
Weighted average interest at period-end	0.12%
Weighted average interest rate during period	0.15%	0.18%

ShortTerm_Borrowings_Additiona

Short-Term Borrowings - Additional Information (Detail) (FHLB Borrowings [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
FHLB Borrowings [Member]
Short-term Debt [Line Items]
Approved line of credit	$2,800,000,000
Amount outstanding at period-end	515,000,000
Borrowing capacity	1,900,000,000
Balance outstanding	$0	$0

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended				12 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 16, 2014	5-May-14	8-May-13	Apr. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 16, 2014	8-May-13
Stockholders Equity [Line Items]
Shares authorized for repurchase	5.00%			5.00%
Number of shares authorized for repurchase	4,000,000							4,000,000
Shares repurchased	1,529,542
Shares repurchased, price per share	$31.13
Accelerated share repurchase transaction, paid			$115						$115
Received from accelerated share repurchase stock settlement		600,000	2,800,000
Effective tax rate					35.00%	35.00%	35.00%
Hancock [Member]
Stockholders Equity [Line Items]
Minimum risk-based capital ratio					8.00%	8.00%
Minimum Tier 1 capital ratio					4.00%	4.00%
Minimum Tier 1 leverage capital ratio					3.00%	3.00%
Well capitalized Tier 1 leverage capital ratio					5.00%
Well capitalized total risk based capital ratio					10.00%
Well capitalized Tier 1 risk-based capital ratio					6.00%
All Other [Member]
Stockholders Equity [Line Items]
Well capitalized Tier 1 leverage capital ratio					4.00%

Stockholders_Equity_Components

Stockholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance	($35,379)	($22,925)	($26,510)
Net change in unrealized gain (loss)	-26,311	-22,772	8,140
Reclassification adjustment for net losses realized and included in earnings	390	8,527	6,418
Amortization of unrealized net gain on securities transferred to held-to-maturity	3,297	-6,371	-8,752
Income tax expense (benefit)	-7,929	-8,162	2,221
Accumulated other comprehensive income (loss), Ending balance	-50,074	-35,379	-22,925
Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance	8,263	38,854	60,478
Net change in unrealized gain (loss)	15,413	-105,270	6,076
Transfer of net unrealized gain (loss) from AFS to HTM, net of cumulative tax effect		36,208	-24,598
Reclassification adjustment for net losses realized and included in earnings		-105	-1,441
Income tax expense (benefit)	5,675	-38,576	1,661
Accumulated other comprehensive income (loss), Ending balance	18,001	8,263	38,854
Held to Maturity Securities Transferred from AFS [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance	-21,189	19,090
Transfer of net unrealized gain (loss) from AFS to HTM, net of cumulative tax effect		-36,208	24,598
Amortization of unrealized net gain on securities transferred to held-to-maturity	3,297	-6,371	-8,752
Income tax expense (benefit)	1,182	-2,300	-3,244
Accumulated other comprehensive income (loss), Ending balance	-19,074	-21,189	19,090
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance	-22,453	-80,688	-86,923
Net change in unrealized gain (loss)	-41,132	82,502	2,566
Reclassification adjustment for net losses realized and included in earnings	390	8,331	7,548
Income tax expense (benefit)	-14,569	32,598	3,879
Accumulated other comprehensive income (loss), Ending balance	-48,626	-22,453	-80,688
Loss on Effective Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance		-181	-65
Net change in unrealized gain (loss)	-592	-4	-502
Reclassification adjustment for net losses realized and included in earnings	0	301	311
Income tax expense (benefit)	-217	116	-75
Accumulated other comprehensive income (loss), Ending balance	($375)		($181)

Stockholders_Equity_Summary_of

Stockholders' Equity - Summary of Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	($38,119)	($41,479)	($51,682)
Tax effect	66,465	52,510	45,613
Amount reclassified from accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	2,396	1,402
Amount reclassified from accumulated other comprehensive income [Member] | Gains and losses on sale of AFS securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains and losses on sale of AFS securities		-105
Tax effect		-37
Net of tax		-68
Amount reclassified from accumulated other comprehensive income [Member] | Unrealized Gains And Losses On Securities Available For Sale Transferred To Held To Maturity [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization/accretion of unrealized net gain/loss on securities transferred to HTM	3,297	-6,371
Tax effect	1,154	-2,230
Net of tax	2,143	-4,141
Amount reclassified from accumulated other comprehensive income [Member] | Amortization of defined benefit pension and post-retirement items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items	390	8,331
Tax effect	137	2,916
Net of tax	253	5,415
Amount reclassified from accumulated other comprehensive income [Member] | Gains and losses on cash flow hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense		301
Tax effect		105
Net of tax		$196

Stockholders_Equity_Schedule_o

Stockholders' Equity - Schedule of Compliance with Regulatory Capital Requirements (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Hancock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk weighted assets), Actual, Amount	$1,945,710	$1,877,832
Tier 1 capital (to risk weighted assets), Actual, Amount	1,777,348	1,685,058
Tier 1 leverage capital Actual, Amount	1,777,348	1,685,058
Total capital (to risk weighted assets), Actual, Ratio %	12.30%	13.11%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	11.23%	11.76%
Tier 1 leverage capital, Actual, Ratio %	9.17%	9.34%
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,265,796	1,146,061
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	632,898	573,030
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	581,263	541,066
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	8.00%	8.00%
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	4.00%	4.00%
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Ratio %	3.00%	3.00%
Total capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	10.00%
Tier 1 capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	6.00%
Tier 1 leverage capital, To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	5.00%
Hancock Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk weighted assets), Actual, Amount		636,871
Tier 1 capital (to risk weighted assets), Actual, Amount		577,280
Tier 1 leverage capital Actual, Amount		577,280
Total capital (to risk weighted assets), Actual, Ratio %		13.48%
Tier 1 capital (to risk weighted assets), Actual, Ratio %		12.21%
Tier 1 leverage capital, Actual, Ratio %		9.01%
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount		378,093
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount		189,047
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount		192,137
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %		8.00%
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %		4.00%
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Ratio %		3.00%
Total capital (to risk weighted assets), To Be Well Capitalized Under Prompt Correct Action Provisions, Amount		472,617
Tier 1 capital (to risk weighted assets), To Be Well Capitalized Under Prompt Correct Action Provisions, Amount		283,570
Tier 1 leverage capital, To Be Well Capitalized Under Prompt Correct Action Provisions, Amount		320,228
Total capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		10.00%
Tier 1 capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		6.00%
Tier 1 leverage capital, To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %		5.00%
Whitney Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk weighted assets), Actual, Amount	1,925,175	1,187,699
Tier 1 capital (to risk weighted assets), Actual, Amount	1,756,813	1,088,339
Tier 1 leverage capital Actual, Amount	1,756,813	1,088,339
Total capital (to risk weighted assets), Actual, Ratio %	12.20%	12.25%
Tier 1 capital (to risk weighted assets), Actual, Ratio %	11.13%	11.22%
Tier 1 leverage capital, Actual, Ratio %	9.13%	9.02%
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	1,262,439	775,709
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Amount	631,220	387,854
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Amount	577,493	361,878
Total capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	8.00%	8.00%
Tier 1 capital (to risk weighted assets), Required for Minimum Capital Adequacy, Ratio %	4.00%	4.00%
Tier 1 leverage capital, Required for Minimum Capital Adequacy, Ratio %	3.00%	3.00%
Total capital (to risk weighted assets), To Be Well Capitalized Under Prompt Correct Action Provisions, Amount	1,578,049	969,636
Tier 1 capital (to risk weighted assets), To Be Well Capitalized Under Prompt Correct Action Provisions, Amount	946,829	581,782
Tier 1 leverage capital, To Be Well Capitalized Under Prompt Correct Action Provisions, Amount	$962,488	$603,129
Total capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	10.00%	10.00%
Tier 1 capital (to risk weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	6.00%	6.00%
Tier 1 leverage capital, To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio %	5.00%	5.00%

Retirement_Benefit_Plans_Addit

Retirement Benefit Plans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Period of employment required to cover employee stock purchase plan	60 days
Percentage of compensation saved by participant for which employer contributes hundred percent	100.00%
Employer matching contribution for first one percent of compensation saved	1.00%
Percentage of compensation saved by participant for which employer contributes fifty percent	50.00%
Employer matching contribution for next five percent of compensation saved	5.00%
Initial saving rate for employees not participating in plan	3.00%
Hancock Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Year of service who have reached 55 years of age	10 years
Year of service who have reached 65 years of age	5 years
Minimum age for increase in per capita cost of health care benefit	55 years
Increase (decrease) in pre- and post-medicare age health costs rate	7.00%
Decrease in ultimate rate over a period of time	5.00%
Whitney 401K Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discretionary profit-sharing contribution by employer			$2,900,000
Minimum age for increase in per capita cost of health care benefit	65 years
Hancock 401k Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	$7,100,000	$7,000,000	$6,100,000

Retirement_Benefit_Plans_Compo

Retirement Benefit Plans - Components of Defined Benefit Obligation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, end of year	$438,708	$437,829
Fair value of plan assets	438,708	437,829
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation: at beginning of year	412,608	437,104
Service cost	12,920	16,118	12,989
Interest cost	19,251	16,678	17,206
Actuarial loss	29,738	-41,591
Benefits paid	-17,606	-15,701
Benefit obligation, end of year	456,911	412,608	437,104
Fair value of plan assets: at beginning of year	437,829	379,133
Actual return on plan assets	17,826	63,695
Employer contributions	1,123	11,123
Benefit payments	-17,606	-15,701
Expenses	-464	-421
Fair value of plan assets, end of year	438,708	437,829	379,133
Funded status at end of year-net (liability) asset	-18,203	25,221
Unrecognized loss: at beginning of year	28,285	111,794
Amount of (loss)/gain recognized during the year	-26	-6,570	-6,582
Net actuarial loss/(gain)	44,599	-76,939
Unrecognized loss at end of year	72,858	28,285	111,794
Projected benefit obligation	456,911	412,608	437,104
Accumulated benefit obligation	426,073	379,607
Fair value of plan assets	438,708	437,829	379,133
Other Post-retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation: at beginning of year	31,592	37,831
Service cost	126	215	192
Interest cost	1,140	1,317	1,337
Actuarial loss	-3,467	-5,563
Plan participants' contributions	1,300	1,355
Benefits paid	-2,323	-3,563
Benefit obligation, end of year	28,368	31,592	37,831
Employer contributions	1,023	2,208
Plan participants' contributions	1,300	1,355
Benefit payments	-2,323	-3,563
Funded status at end of year-net (liability) asset	-28,368	-31,592
Unrecognized loss: at beginning of year	7,189	14,513
Amount of (loss)/gain recognized during the year	-364	-1,761	-966
Net actuarial loss/(gain)	-3,467	-5,563
Unrecognized loss at end of year	3,358	7,189	14,513
Projected benefit obligation	$28,368	$31,592	$37,831

Retirement_Benefit_Plans_Compo1

Retirement Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Service cost	$12,920	$16,118	$12,989
Interest cost	19,251	16,678	17,206
Expected return on plan assets	-32,222	-27,928	-25,398
Amortization of net loss/ prior service cost	26	6,570	6,582
Recognized net amortization and deferral	0	0	0
Net periodic benefit cost	-25	11,438	11,379
Net (loss)/gain recognized during the year	-26	-6,570	-6,582
Net actuarial loss/(gain)	44,599	-76,939	-7,001
Total recognized in other comprehensive income	44,573	-83,509	-13,583
Total recognized in net periodic benefit cost and other comprehensive income	44,548	-72,071	-2,204
Discount rate for benefit obligations	4.11%	4.73%	3.82%
Discount rate for net periodic benefit cost	4.73%	3.82%	4.32%
Expected long-term return on plan assets	7.50%	7.50%	7.50%
Rate of compensation increase		4.00%	3.73%
Other Post-retirement Benefits [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Service cost	126	215	192
Interest cost	1,140	1,317	1,337
Amortization of net loss/ prior service cost	364	1,761	918
Recognized net amortization and deferral	0	0	0
Net periodic benefit cost	1,630	3,293	2,447
Net (loss)/gain recognized during the year	-364	-1,761	-966
Net actuarial loss/(gain)	-3,467	-5,563	4,435
Amortization of prior service cost			48
Total recognized in other comprehensive income	-3,831	-7,324	3,517
Total recognized in net periodic benefit cost and other comprehensive income	($2,201)	($4,031)	$5,964
Discount rate for benefit obligations	4.02%	4.58%	3.69%
Discount rate for net periodic benefit cost	4.58%	3.69%	4.18%

Retirement_Benefit_Plans_Compo2

Retirement Benefit Plans - Components of Net Periodic Benefit Cost (Parenthetical) (Detail) (Pension Benefits [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Rate of compensation increase	4.00%	3.73%
Age Twenty [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Rate of compensation increase			7.00%
Age Sixty [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Rate of compensation increase			2.00%

Retirement_Benefit_Plans_Expec

Retirement Benefit Plans - Expected Future Plan Benefit Payments (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Expected Future Pension Benefit Payment [Line Items]
2015	$20,171
2016	21,247
2017	22,150
2018	23,260
2019	23,935
2020-2024	135,435
Total	246,198
Pension Benefits [Member]
Schedule of Expected Future Pension Benefit Payment [Line Items]
2015	18,617
2016	19,744
2017	20,744
2018	21,863
2019	22,505
2020-2024	128,044
Total	231,517
Post-retirement [Member]
Schedule of Expected Future Pension Benefit Payment [Line Items]
2015	1,554
2016	1,503
2017	1,406
2018	1,397
2019	1,430
2020-2024	7,391
Total	$14,681

Retirement_Benefit_Plans_Assum

Retirement Benefit Plans - Assumed Health Care Cost Trend Rates (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Schedule Of Sale Of Subsidiary [Abstract]
Aggregated service and interest cost, 1% Decrease in Rates	$1,115
Postretirement benefit obligation, 1% Decrease in Rates	25,046
Aggregated service and interest cost, Assumed Rates	1,266
Postretirement benefit obligation, Assumed Rates	28,366
Aggregated service and interest cost, 1% Increase in Rates	1,451
Postretirement benefit obligation, 1% Increase in Rates	$32,412

RetirementBenefit_Plans_Fair_V

RetirementBenefit Plans - Fair Values Measurements of Pension Plan Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	$438,708	$437,829
Cash and equivalents [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	10,243	5,683
Total cash and cash-equivalents [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	10,243	15,214
U.S. government and agency securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	15,518	21,485
Municipal Securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	33,980	40,476
Emerging Market Debt Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	19,505
Foreign Bonds Notes And Debentures [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	2,588
Hancock Horizon Core Bond Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	51,529
Corporate Debt Securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	62,429	43,440
Total fixed income [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	185,549	165,075
Real Assets Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	24,151
Hancock Horizon Quantitative Long/ Short Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	5,603	6,593
Hancock Horizon Diversified International Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	62,750	26,072
Hancock Horizon Burkenroad Small Cap Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	9,296	4,108
Hancock Horizon Growth Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	26,469	27,847
Hancock Horizon Value Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	30,321	34,216
Equity Securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	84,325	149,946
Mineral Interests [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	1
Total Equity [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	218,765	257,540
Hancock Horizon Government Money Market Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets		9,531
Hancock Horizon Core Bond Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets		59,674
Hancock Horizon Diversified Income Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets		8,758
Level 1 [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	254,240	284,060
Level 1 [Member] | Cash and equivalents [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	10,243	5,683
Level 1 [Member] | Total cash and cash-equivalents [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	10,243	15,214
Level 1 [Member] | U.S. government and agency securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	1,082	4,383
Level 1 [Member] | Corporate Debt Securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets		6,923
Level 1 [Member] | Total fixed income [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	1,082	11,306
Level 1 [Member] | Real Assets Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	24,151
Level 1 [Member] | Hancock Horizon Quantitative Long/ Short Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	5,603	6,593
Level 1 [Member] | Hancock Horizon Diversified International Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	62,750	26,072
Level 1 [Member] | Hancock Horizon Burkenroad Small Cap Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	9,296	4,108
Level 1 [Member] | Hancock Horizon Growth Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	26,469	27,847
Level 1 [Member] | Hancock Horizon Value Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	30,321	34,216
Level 1 [Member] | Equity Securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	84,325	149,946
Level 1 [Member] | Total Equity [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	218,764	257,540
Level 1 [Member] | Hancock Horizon Government Money Market Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets		9,531
Level 1 [Member] | Hancock Horizon Diversified Income Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets		8,758
Level 2 [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	164,962	153,769
Level 2 [Member] | U.S. government and agency securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	14,436	17,102
Level 2 [Member] | Municipal Securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	33,980	40,476
Level 2 [Member] | Foreign Bonds Notes And Debentures [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	2,588
Level 2 [Member] | Hancock Horizon Core Bond Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	51,529
Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	62,429	36,517
Level 2 [Member] | Total fixed income [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	164,962	153,769
Level 2 [Member] | Hancock Horizon Core Bond Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets		59,674
Level 3 [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	19,506
Level 3 [Member] | Emerging Market Debt Fund [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	19,505
Level 3 [Member] | Total fixed income [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	19,505
Level 3 [Member] | Mineral Interests [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	1
Level 3 [Member] | Total Equity [Member]
Fair Value Of Pension Plan Assets [Line Items]
Fair value of pension plan assets	$1

Retirement_Benefit_Plans_Weigh

Retirement Benefit Plans - Weighted Average Asset Allocations and Target Allocations (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Assets Target Allocations [Line Items]
Plan Assets	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Plan Assets	50.00%	59.00%
Target Allocation, minimum	30.00%	30.00%
Target Allocation, maximum	60.00%	70.00%
Fixed Income Securities [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Plan Assets	42.00%	38.00%
Target Allocation, minimum	25.00%	25.00%
Target Allocation, maximum	65.00%	65.00%
Real Assets Fund [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Plan Assets	6.00%	0.00%
Target Allocation, minimum	0.00%	0.00%
Target Allocation, maximum	10.00%	10.00%
Cash Equivalents [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Plan Assets	2.00%	3.00%
Target Allocation, minimum	0.00%	0.00%
Target Allocation, maximum	5.00%	5.00%

ShareBased_Payment_Arrangement2

Share-Based Payment Arrangements - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Bank
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares can be granted under long term incentive plan	0	0
Recognized stock-based compensation	$14	$13.10	$11
Recognized tax benefit related to the share-based compensation	4.9	4.6	3.9
Percentage where a option price is equal to market price	110.00%
Term of option award vest, contractual term	10 Year
Term of option award vest for continuous service	5 years
Intrinsic value of options exercised	0.4	0.6	0.8
Weighted-average grant-date fair values of options granted			$8.43
Unrecognized compensation cost	32.8
Weighted-average period in years	3 years 8 months 12 days
Total fair value of shares vested	$12.80	$3.20
Shareholder return period	3 years
Number of peer group of regional banks	50
Performance Share Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted to key members of executives and senior management	69,857
Weighted average fair value of shares granted	$38.14
Percentage of maximum number of shares earned of target award	200.00%
2014 Long Term Incentive Plan [Member] | Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares can be granted under long term incentive Plan	1,796,357
Shares available for future issuance under equity compensation plans	1,700,000
Number of shares can be granted under long term incentive plan	100,000
2010 Employee Stock Ownership Plan [Member] | Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance under equity compensation plans	170,935

ShareBased_Payment_Arrangement3

Share-Based Payment Arrangements - Schedule of Option Activity Under Stock Option Plans (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Outstanding at Beginning	1,332,656
Number of Shares, Granted	0	0
Number of Shares, Exercised	-81,842
Number of Shares, Cancelled/Forfeited	-197,974
Number of Shares, Expired	-113,447
Number of Shares, Outstanding at Ending	939,393	1,332,656
Number of Shares, Exercisable at Ending	781,529
Weighted- Average Exercise Price, Outstanding at Beginning	$38.85
Weighted- Average Exercise Price, Granted	$0
Weighted- Average Exercise Price, Exercised	$30.40
Weighted- Average Exercise Price, Cancelled/Forfeited	$36.06
Weighted- Average Exercise Price, Expired	$63.41
Weighted- Average Exercise Price, Outstanding at Ending	$37.21	$38.85
Weighted- Average Exercise Price, Exercisable at Ending	$38.62
Weighted-Average Remaining Contractual Term, Outstanding at Ending Balance (in years)	4 years 2 months 12 days
Weighted-Average Remaining Contractual Term, Exercisable at Ending Balance (in years)	3 years 8 months 12 days
Aggregate Intrinsic Value, Outstanding at Ending	$221
Aggregate Intrinsic Value, Exercisable at Ending	$107

ShareBased_Payment_Arrangement4

Share-Based Payment Arrangements - Stock Options, Valuation Assumption (Detail)	12 Months Ended
	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected volatility	38.64%
Expected dividends	3.23%
Expected term (in years)	6 years 6 months 29 days
Risk-free rates	1.78%

ShareBased_Payment_Arrangement5

Share-Based Payment Arrangements - Schedule of Nonvested Restricted and Performance Shares (Detail) (Restricted Stock and Performance Shares [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Restricted Stock and Performance Shares [Member]
Nonvested Share Activity [Line Items]
Number of Shares, Nonvested at Beginning	1,981,820
Number of Shares, Granted	608,856
Number of Shares, Vested	-391,859
Number of Shares, Cancelled/Forfeited	-158,518
Number of Shares, Nonvested at Ending	2,040,299
Weighted-Average Grant-Date Fair Value, Nonvested at Beginning	$31.75
Weighted-Average Grant-Date Fair Value, Granted	$34.42
Weighted-Average Grant-Date Fair Value, Vested	$32.76
Weighted-Average Grant-Date Fair Value, Cancelled/Forfeited	$32.75
Weighted-Average Grant-Date Fair Value, Nonvested at Ending	$32.27

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	$1,660,165	$1,421,772
Derivative assets	19,432	15,579
Total recurring fair value measurements-assets	1,679,597	1,437,351
Derivative liabilities	20,860	15,006
Total recurring fair value measurements-liabilities	20,860	15,006
Municipal Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	14,176	35,961
U.S. Treasury and Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	300,508	505
Corporate Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	3,500	3,500
Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	1,245,564	1,276,958
Collateralized Mortgage Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	86,864	94,125
Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	9,553	10,723
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	9,553	11,228
Total recurring fair value measurements-assets	9,553	11,228
Level 1 [Member] | U.S. Treasury and Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities		505
Level 1 [Member] | Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	9,553	10,723
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	1,650,612	1,410,544
Derivative assets	19,432	15,579
Total recurring fair value measurements-assets	1,670,044	1,426,123
Derivative liabilities	20,860	15,006
Total recurring fair value measurements-liabilities	20,860	15,006
Level 2 [Member] | Municipal Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	14,176	35,961
Level 2 [Member] | U.S. Treasury and Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	300,508
Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	3,500	3,500
Level 2 [Member] | Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	1,245,564	1,276,958
Level 2 [Member] | Collateralized Mortgage Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	$86,864	$94,125

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Period of Investment	2 years
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Period of Investment	5 years

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments - Schedule of Financial Assets Measured at Fair Value on Nonrecurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Collateral dependent impaired loans	$30,204	$24,392
Other real estate owned	29,715	34,105
Total nonrecurring fair value measurements	59,919	58,497
Level 2 [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Collateral dependent impaired loans	30,204	24,392
Total nonrecurring fair value measurements	30,204	24,392
Level 3 [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Other real estate owned	29,715	34,105
Total nonrecurring fair value measurements	$29,715	$34,105

Fair_Value_of_Financial_Instru5

Fair Value of Financial Instruments - Schedule of Estimated Fair Values of Financial Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Available for sale securities	$1,660,165	$1,421,772
Held to maturity securities	2,166,289	2,611,352
Loans, net	13,766,514	12,191,191
Loans held for sale	20,252	24,515
Derivative financial instruments	19,432	15,579
Deposits	16,572,831	15,360,516
Long-term debt	374,371	385,826
Derivative financial instruments	20,860	15,006
Level 1 [Member]
Cash, interest-bearing bank deposits, and federal funds sold	1,159,403	617,280
Available for sale securities	9,553	11,228
Accrued interest receivable	47,501	42,977
Federal funds purchased	12,000	7,725
Securities sold under agreements to repurchase	624,573	650,235
FHLB Borrowings	515,000
Accrued interest payable	4,204	4,353
Level 2 [Member]
Available for sale securities	1,650,612	1,410,544
Held to maturity securities	2,186,340	2,576,584
Loans, net	30,204	24,392
Loans held for sale	20,252	24,515
Derivative financial instruments	19,432	15,579
Long-term debt	346,379	385,557
Derivative financial instruments	20,860	15,006
Level 3 [Member]
Loans, net	13,672,427	12,023,330
Deposits	16,398,878	15,352,024
Total Fair Value [Member]
Cash, interest-bearing bank deposits, and federal funds sold	1,159,403	617,280
Available for sale securities	1,660,165	1,421,772
Held to maturity securities	2,186,340	2,576,584
Loans, net	13,702,631	12,047,722
Loans held for sale	20,252	24,515
Accrued interest receivable	47,501	42,977
Derivative financial instruments	19,432	15,579
Deposits	16,398,878	15,352,024
Federal funds purchased	12,000	7,725
Securities sold under agreements to repurchase	624,573	650,235
FHLB Borrowings	515,000
Long-term debt	346,379	385,557
Accrued interest payable	4,204	4,353
Derivative financial instruments	20,860	15,006
Carrying Amount [Member]
Cash, interest-bearing bank deposits, and federal funds sold	1,159,403	617,280
Available for sale securities	1,660,165	1,421,772
Held to maturity securities	2,166,289	2,611,352
Loans, net	13,766,514	12,191,191
Loans held for sale	20,252	24,515
Accrued interest receivable	47,501	42,977
Derivative financial instruments	19,432	15,579
Deposits	16,572,831	15,360,516
Federal funds purchased	12,000	7,725
Securities sold under agreements to repurchase	624,573	650,235
FHLB Borrowings	515,000
Long-term debt	374,371	385,826
Accrued interest payable	4,204	4,353
Derivative financial instruments	$20,860	$15,006

Commitments_and_Contingencies_1

Commitments and Contingencies - Summary of Obligations (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Commitments to extend credit	$5,700,546	$5,234,929
Letters of credit [Member]
Loss Contingencies [Line Items]
Letters of credit	$414,408	$422,284

Commitments_and_Contingencies_2

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments And Contingencies [Line Items]
Rental expense	$11.40	$12.90	$14.30
Whitney [Member]
Commitments And Contingencies [Line Items]
Contingent liabilities payments to employees	$58

Commitments_and_Contingencies_3

Commitments and Contingencies - Changes in Liability (Detail) (Whitney [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Whitney [Member]
Business Acquisition, Contingent Consideration [Line Items]
Balance	$8,661	$8,165
Adjustments	-1,690	2,765
Cash Payments	-6,971	-2,269
Balance		$8,661

Commitments_and_Contingencies_4

Commitments and Contingencies - Future Minimum Lease Payments for All Non-Cancelable Capital and Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2015	$11,766
2016	11,856
2017	11,064
2018	9,782
2019	7,917
Thereafter	28,293
Total minimum lease payments	$80,678

Other_Noninterest_Income_and_O2

Other Noninterest Income and Other Noninterest Expense - Components of Other Noninterest Income and Other Noninterest Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other noninterest income:
Income from bank-owned life insurance	$10,314	$11,223	$11,163
Credit-related fees	11,121	8,724	6,681
Income from derivatives	1,645	4,675	3,600
Gain on sales of assets	1,279	1,932	4,366
Safety deposit box income	1,830	1,923	2,006
Other miscellaneous income	9,249	8,754	9,072
Total other noninterest income	35,438	37,231	36,888
Other noninterest expense:
Advertising	8,937	10,399	13,515
Ad valorem and franchise taxes	10,492	9,727	8,321
Printing and supplies	4,550	5,112	7,491
Insurance expense	3,919	4,094	5,494
Travel	4,066	4,716	5,758
Entertainment and contributions	5,762	5,265	6,049
Tax credit investment amortization	8,817	10,781	5,974
Other miscellaneous expense	30,585	45,242	27,669
Total other noninterest expense	$77,128	$95,336	$80,271

Other_Noninterest_Income_and_O3

Other Noninterest Income and Other Noninterest Expense - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Nonoperating expense [Line Items]
Other miscellaneous expenses		$30,585,000	$45,242,000	$27,669,000
Expense related to the settlement of the assessment with the FDIC	10,300,000
Gain on Sale of Insurance Business		9,400,000
Sales price of divested business		15,500,000
Early termination fee of reverse repurchase obligations	3,500,000
Other Miscellaneous Expense [Member]
Nonoperating expense [Line Items]
Other miscellaneous expenses		9,600,000	19,700,000	3,200,000
Branch Closures [Member]
Nonoperating expense [Line Items]
Expense related to closure of branches		$4,600,000
Number of branch locations		15

Income_Taxes_Components_of_Inc

Income Taxes - Components of Income Tax Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Included in net income
Current federal	$41,441	$14,797	$11,195
Current state	1,487	-3,207	1,953
Total current provision	42,928	11,590	13,148
Deferred federal	21,483	37,403	34,219
Deferred state	2,054	3,517	-1,754
Total deferred provision	23,537	40,920	32,465
Income tax expense	66,465	52,510	45,613
Included in shareholders' equity
Deferred tax related to retirement benefits	-14,681	32,749	3,788
Deferred tax related to securities	6,857	-40,876	-1,583
Deferred tax related to derivatives and hedging	-217	116	-75
Total included in shareholders' equity	($8,041)	($8,011)	$2,130

Income_Taxes_Components_of_Com

Income Taxes - Components of Company's Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Allowance for loan losses	$57,667	$64,389
Employee compensation and benefits	50,361	31,293
Loan purchase accounting adjustments	35,094	75,595
Tax credit carryforward	35,553	41,083
Securities		6,432
State net operating loss	1,535	1,535
Other	18,702	21,611
Gross deferred tax assets	198,912	241,938
Federal valuation allowance
State valuation allowance	-1,529	-1,531
Subtotal valuation allowance	-1,529	-1,531
Net deferred tax assets	197,383	240,407
Deferred tax liabilities:
Fixed assets & intangibles	-88,062	-93,952
Securities	-724
Deferred gain on acquisition		-4,407
FDIC indemnification asset	-18,769	-37,775
Other	-15,493	-14,565
Gross deferred tax liabilities	-123,048	-150,699
Net deferred tax asset (liability)	$74,335	$89,708

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax [Line Items]
Tax computed at statutory rate	35.00%	35.00%	35.00%
Federal tax credit carryforwards	$35,553,000	$41,083,000
Investment tax credit	57,700,000
Tax credit compliance period	7 years
Investment tax credit for 2015	12,900,000
Investment tax credit for 2016	10,100,000
Investment tax credit for 2017	9,000,000
From 2008 Through 2014 Tax Years [Member]
Income Tax [Line Items]
CDE award allocation total	148,000,000
From 2008 Through 2014 Tax Years [Member] | Federal [Member]
Income Tax [Line Items]
Federal tax credit carryforwards	36,000,000
Tax credit carry forwards, Expiration dates	Begin expiring in 2028
2002 Through 2014 Tax Years [Member] | State [Member]
Income Tax [Line Items]
State net operating loss carryforwards	$29,000,000
Operating loss carry forwards, Expiration dates	Begin expiring in 2017

Income_Taxes_Schedule_of_Effec

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Taxes computed at statutory rate, amount	$84,766	$75,553	$69,074
State income taxes, net of federal income tax benefit, amount	4,649	2,352	-78
Tax-exempt interest, amount	-6,301	-6,487	-7,127
Bank owned life insurance, amount	-3,554	-3,926	-4,005
Tax credits, amount	-16,577	-15,743	-13,661
Other, net, amount	3,482	761	1,410
Income tax expense	$66,465	$52,510	$45,613
Taxes computed at statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal income tax benefit	2.00%	1.00%	0.00%
Tax-exempt interest	-3.00%	-3.00%	-4.00%
Bank owned life insurance	-1.00%	-2.00%	-2.00%
Tax credits	-7.00%	-7.00%	-7.00%
Other, net	1.00%	0.00%	1.00%
Income tax expense	27.00%	24.00%	23.00%

Earnings_Per_Share_Computation

Earnings Per Share - Computation of Earnings Per Common Share (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator:
Net income to common shareholders	$175,722	$163,356	$151,742
Net income allocated to participating securities - basic and diluted	3,631	3,105	1,557
Net income allocated to common shareholders - basic and diluted	$172,091	$160,251	$150,185
Denominator:
Weighted-average common shares - basic	81,804	83,066	84,767
Dilutive potential common shares	230	101	821
Weighted average common shares - diluted	82,034	83,167	85,588
Earnings per common share:
Basic	$2.10	$1.93	$1.77
Diluted	$2.10	$1.93	$1.75

Earnings_Per_Share_Additional_

Earnings Per Share - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Weighted-average anti-dilutive potential common shares	621,327	916,756	1,057,925

Condensed_Parent_Company_Infor2

Condensed Parent Company Information - Condensed Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Assets:
Securities available for sale	$1,660,165	$1,421,772
Total assets	20,747,266	19,009,251
Liabilities and Stockholders' Equity:
Long term debt	374,371	385,826
Other liabilities	171,885	175,527
Stockholders' equity	2,472,402	2,425,069	2,453,278	2,367,163
Total liabilities and stockholders' equity	20,747,266	19,009,251
Hancock [Member]
Assets:
Cash	44,771	66,338
Securities available for sale	97,423	107,017
Investment in bank subsidiaries	2,452,529	2,408,389
Investment in non-bank subsidiaries	3,202	5,319
Due from subsidiaries and other assets	24,896	24,091
Total assets	2,622,821	2,611,154
Liabilities and Stockholders' Equity:
Long term debt	149,600	184,800
Other liabilities	819	1,285
Stockholders' equity	2,472,402	2,425,069
Total liabilities and stockholders' equity	$2,622,821	$2,611,154

Condensed_Parent_Company_Infor3

Condensed Parent Company Information - Condensed Statements of Income (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Income From subsidiaries
Income tax expense (benefit)	$66,465	$52,510	$45,613
Net income	175,722	163,356	151,742
Hancock [Member]
Operating Income From subsidiaries
Cash dividends received from bank subsidiaries	124,000	249,000	25,000
Non-cash dividend from bank subsidiary in restructuring			225,000
Dividends received from non-bank subsidiaries		2,990	150
Equity in earnings of subsidiaries greater than (less than) dividends received	58,358	-82,203	-94,486
Total operating income	182,358	169,787	155,664
Other (expense) income, net	-10,035	-10,335	-6,673
Income tax expense (benefit)	-3,399	-3,904	-2,751
Net income	$175,722	$163,356	$151,742

Condensed_Parent_Company_Infor4

Condensed Parent Company Information - Condensed Statements of Cash Flows (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	$352,428	$473,532	$443,032
Cash flows from investing activities
Purchase of available for sale securities	-512,088	-1,074,744	-285,825
Proceeds from principal paydowns of securities available for sale	1,455	178	48,336
Other, net	-3,986	10,911	-376
Net cash (used in) investing activities	-1,910,459	-4,497	-17,733
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of long term debt	21,000	24,515	232,720
Repayment of long term debt	-35,360	-35,278	-192,087
Dividends paid to stockholders	-80,392	-81,212	-82,690
Net cash provided by (used by) financing activities	1,566,046	-569,086	-414,755
Net increase (decrease) in cash	8,015	-100,051	10,544
CASH AND DUE FROM BANKS, BEGINNING	348,440	448,491	437,947
CASH AND DUE FROM BANKS, ENDING	356,455	348,440	448,491
Hancock [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities - principally dividends received from subsidiaries	126,491	257,251	18,789
Net cash provided by operating activities	126,491	257,251	18,789
Cash flows from investing activities
Contribution of capital to subsidiary		-870	-955
Loans to nonbank subsidiaries, net of repayments			1,684
Purchase of available for sale securities			-77,058
Proceeds from principal paydowns of securities available for sale	12,664	18,685	47,305
Other, net		-5,630
Net cash (used in) investing activities	12,664	12,185	-29,024
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of long term debt			217,933
Repayment of long term debt	-35,200	-35,200	-140,000
Dividends paid to stockholders	-80,392	-81,673	-83,151
Stock transactions, net	-45,130	-112,266	13,479
Net cash provided by (used by) financing activities	-160,722	-229,139	8,261
Net increase (decrease) in cash	-21,567	40,297	-1,974
CASH AND DUE FROM BANKS, BEGINNING	66,338	26,041	28,015
CASH AND DUE FROM BANKS, ENDING	$44,771	$66,338	$26,041