Hancock Whitney (HWC) 10-Q 7 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Aug. 03, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	HBHC
Entity Registrant Name	HANCOCK HOLDING CO
Entity Central Index Key	750,577
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		78,082,903

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
ASSETS
Cash and due from banks	$ 329,608	$ 356,455
Interest-bearing bank deposits	592,131	801,576
Federal funds sold	6,324	1,372
Securities available for sale, at fair value (amortized cost of $2,136,856 and $1,631,761)	2,151,134	1,660,165
Securities held to maturity (fair value of $2,310,103 and $2,186,340)	2,294,318	2,166,289
Loans held for sale	21,304	20,252
Loans	14,344,752	13,895,276
Less: allowance for loan losses	(131,087)	(128,762)
Loans, net	14,213,665	13,766,514
Property and equipment, net of accumulated depreciation of $198,595 and $193,527	383,686	398,384
Prepaid expenses	34,375	28,277
Other real estate, net	37,371	58,415
Accrued interest receivable	50,527	47,501
Goodwill	621,193	621,193
Other intangible assets, net	119,256	132,810
Life insurance contracts	431,895	426,617
FDIC loss share receivable	35,074	60,272
Deferred tax asset, net	78,203	74,335
Other assets	138,341	126,839
Total assets	21,538,405	20,747,266
Deposits:
Noninterest-bearing	6,180,814	5,945,208
Interest-bearing	11,120,974	10,627,623
Total deposits	17,301,788	16,572,831
Short-term borrowings	1,079,193	1,151,573
Long-term debt	507,341	374,371
Accrued interest payable	5,534	4,204
Other liabilities	214,509	171,885
Total liabilities	19,108,365	18,274,864
Stockholders' equity
Common stock - $3.33 par value per share; 350,000,000 shares authorized, 78,093,729 and 80,426,485 shares outstanding	260,052	267,820
Capital surplus	1,705,531	1,689,291
Treasury shares at cost - 8,721,782 and 7,053,028	(235,239)	(158,131)
Retained earnings	759,780	723,496
Accumulated other comprehensive loss, net	(60,084)	(50,074)
Total stockholders' equity	2,430,040	2,472,402
Total liabilities and stockholders' equity	$ 21,538,405	$ 20,747,266

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 2,136,856	$ 1,631,761
Held to maturity securities	2,310,103	2,186,340
Property and equipment, accumulated depreciation	$ 198,595	$ 193,527
Common stock, par value per share	$ 3.33	$ 3.33
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares outstanding	78,093,729	80,426,485
Treasury shares, shares	8,721,782	7,053,028

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Interest income:
Loans, including fees	$ 141,905	$ 151,603	$ 288,872	$ 302,585
Loans held for sale	222	152	318	347
Securities-taxable	21,674	21,069	42,464	43,777
Securities-tax exempt	845	965	1,725	1,992
Federal funds sold and other short term investments	274	212	628	440
Total interest income	164,920	174,001	334,007	349,141
Interest expense:
Deposits	7,621	5,251	14,747	10,603
Short-term borrowings	186	822	358	1,871
Long-term debt and other interest expense	5,322	3,150	8,953	6,327
Total interest expense	13,129	9,223	24,058	18,801
Net interest income	151,791	164,778	309,949	330,340
Provision for loan losses	6,608	6,691	12,762	14,654
Net interest income after provision for loan losses	145,183	158,087	297,187	315,686
Noninterest income:
Service charges on deposit accounts	17,908	19,269	35,223	37,981
Trust fees	11,795	11,499	22,995	21,737
Bank card and ATM fees	11,868	11,596	23,051	22,165
Investment and annuity fees	4,838	5,097	9,888	10,049
Secondary mortgage market operations	3,618	1,758	6,282	3,723
Insurance commissions and fees	2,595	1,888	4,349	5,632
Amortization of FDIC loss share receivable	(1,273)	(3,321)	(2,470)	(7,229)
Other income	9,525	8,612	17,769	19,039
Securities transactions gains, net			333
Total noninterest income	60,874	56,398	117,420	113,097
Noninterest expense:
Compensation expense	70,550	68,528	135,567	135,693
Employee benefits	12,870	12,588	28,504	26,855
Personnel expense	83,420	81,116	164,071	162,548
Net occupancy expense	11,804	10,869	22,981	22,135
Equipment expense	4,090	4,065	8,025	8,339
Data processing expense	14,012	12,887	27,568	25,306
Professional services expense	8,952	9,179	24,322	15,588
Amortization of intangibles	6,148	6,744	12,466	13,782
Telecommunications and postage	3,471	3,863	7,122	7,446
Deposit insurance and regulatory fees	4,213	2,743	7,808	5,710
Other real estate expense, net	501	84	957	1,861
Other expense	22,306	25,308	37,112	41,125
Total noninterest expense	158,917	156,858	312,432	303,840
Income before income taxes	47,140	57,627	102,175	124,943
Income taxes	12,311	17,665	27,187	35,866
Net income	$ 34,829	$ 39,962	$ 74,988	$ 89,077
Earnings per common share-basic	$ 0.44	$ 0.48	$ 0.93	$ 1.06
Earnings per common share-diluted	0.44	0.48	0.93	1.06
Dividends paid per share	$ 0.24	$ 0.24	$ 0.48	$ 0.48
Weighted average shares outstanding-basic	77,951	81,933	78,719	82,099
Weighted average shares outstanding-diluted	78,115	82,174	78,881	82,348

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 34,829	$ 39,962	$ 74,988	$ 89,077
Other comprehensive income:
Net change in unrealized (loss) gain	(18,370)	10,898	(12,957)	15,412
Reclassification adjustment for net losses (gains) realized and included in earnings	801	142	1,406	195
Valuation adjustment for employee benefit plans	(5,922)	2,006	(5,922)	2,006
Amortization of unrealized net gain on securities transferred to held to maturity	939	906	1,586	1,571
Other comprehensive income, before income taxes	(22,552)	13,952	(15,887)	19,184
Income tax (benefit) expense	(8,237)	5,254	(5,877)	7,096
Other comprehensive (losses) income net of income taxes	(14,315)	8,698	(10,010)	12,088
Comprehensive income	$ 20,514	$ 48,660	$ 64,978	$ 101,165

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]
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	89,077			89,077
Other comprehensive income	12,088				12,088
Comprehensive income	101,165			89,077	12,088
Cash dividends declared ($0.48 per common share)	(40,301)			(40,301)
Common stock activity, long-term incentive plan	6,649	$ 710	44,582			(38,643)
Common stock activity, long-term incentive plan, shares		213,359
Purchase of common stock under stock buyback program		$ (1,965)				1,965
Purchase of common stock under stock buyback program, shares		(590,222)
Balance at Jun. 30, 2014	2,492,582	$ 272,595	1,692,049	676,942	(23,291)	(125,713)
Balance, Shares at Jun. 30, 2014		81,860,299
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
Net income	74,988			74,988
Other comprehensive income	(10,010)				(10,010)
Comprehensive income	64,978			74,988	(10,010)
Cash dividends declared ($0.48 per common share)	(38,704)			(38,704)
Common stock activity, long-term incentive plan	6,634	$ 769	16,240			(10,375)
Common stock activity, long-term incentive plan, shares		230,851
Purchase of common stock under stock buyback program	(75,270)	$ (8,537)				(66,733)
Purchase of common stock under stock buyback program, shares		(2,563,607)
Balance at Jun. 30, 2015	$ 2,430,040	$ 260,052	$ 1,705,531	$ 759,780	$ (60,084)	$ (235,239)
Balance, Shares at Jun. 30, 2015		78,093,729

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash dividends declared, per common share	$ 0.48	$ 0.48
Retained Earnings [Member]
Cash dividends declared, per common share	$ 0.48	$ 0.48

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 74,988	$ 89,077
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,399	15,666
Provision for loan losses	12,762	14,654
(Gain) loss on other real estate owned	(374)	2,133
Deferred tax expense	10,838	21,495
Increase in cash surrender value of life insurance contracts	(5,336)	(4,601)
Loss (gain) on disposal of other assets	1,694	(265)
Net (increase) decrease in loans held for sale	(2,995)	338
Net amortization of securities premium/discount	9,741	8,543
Amortization of intangible assets	12,466	13,782
Amortization of FDIC indemnification asset	2,470	7,229
Stock-based compensation expense	6,353	7,120
Decrease in interest payable and other liabilities	(6,310)	(10,085)
Net payments from FDIC for loss share claims	14,153
Decrease in FDIC loss share receivable	5,147	8,730
(Increase) decrease in other assets	(16,925)	6,260
Other, net	(2,338)	4,010
Net cash provided by operating activities	130,733	184,086
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of securities	9,230	1,301
Proceeds from maturities of securities available for sale	562,162	145,812
Purchases of securities available for sale	(1,083,192)	(48,404)
Proceeds from maturities of securities held to maturity	187,864	266,657
Purchases of securities held to maturity	(266,759)	(1,031)
Net decrease (increase) in interest-bearing bank deposits	209,445	(172,106)
Net (increase) decrease in federal funds sold and short-term investments	(4,952)	258
Net increase in loans	(463,593)	(581,169)
Purchases of property and equipment	(13,896)	(10,881)
Proceeds from sales of property and equipment	12,168	6,946
Proceeds from sales of other real estate	31,953	29,688
Other, net	(8,656)	14,873
Net cash used in investing activities	(828,226)	(348,056)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in deposits	728,957	(115,289)
Net (decrease) increase in short-term borrowings	(72,380)	405,704
Repayments of long-term debt	(17,600)	(17,756)
Net proceeds from issuance of long-term debt	145,296	6,921
Dividends paid	(38,704)	(40,301)
Purchase of common stock under stock buyback program	(75,270)
Proceeds from exercise of stock options	347	860
Net cash provided by financing activities	670,646	240,139
NET (DECREASE) INCREASE IN CASH AND DUE FROM BANKS	(26,847)	76,169
CASH AND DUE FROM BANKS, BEGINNING	356,455	348,440
CASH AND DUE FROM BANKS, ENDING	329,608	424,609
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 10,390	$ 15,299

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	1. Basis of Presentation The consolidated financial statements include the accounts of Hancock Holding Company and all other entities in which it has a controlling interest (the “Company”). The financial statements include all adjustments that are, in the opinion of management, necessary to present fairly the Company’s financial condition, results of operations, changes in stockholders’ equity and cash flows for the interim periods presented. Some financial information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) have been condensed or omitted in this Form 10-Q pursuant to Securities and Exchange Commission rules and regulations. These financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. Financial information reported in these financial statements is not necessarily indicative of the Company’s financial condition, results of operations, or cash flows for any other interim or annual period. Use of Estimates The accounting principles the Company follows and the methods for applying these principles conform with GAAP and with those generally practiced within the banking industry. These accounting principles require management to make estimates and assumptions about future events that affect the amounts reported in the consolidated financial statements and the accompanying notes. Actual results could differ from those estimates. Critical Accounting Policies and Estimates There were no material changes or developments with respect to methodologies that the Company uses when applying what management believes are critical accounting policies and developing critical accounting estimates as disclosed in our Annual Report on Form 10-K for the year ended December 31, 2014.

Securities

Securities	6 Months Ended
	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Securities	2. Securities The amortized cost and fair value of securities classified as available for sale and held to maturity follow. Securities Available for Sale (in thousands) June 30, 2015 December 31, 2014 Amortized Gross Gross Fair Value Amortized Gross Gross Fair Value US Treasury and government agency securities $ 100,160 $ — $ 1,539 $ 98,621 $ 300,207 $ 372 $ 71 $ 300,508 Municipal obligations 12,723 177 25 12,875 13,995 186 5 14,176 Mortgage-backed securities 1,802,249 26,146 9,856 1,818,539 1,217,293 31,094 2,823 1,245,564 Collateralized mortgage obligations 215,713 546 1,471 214,788 88,093 — 1,229 86,864 Corporate debt securities 3,500 — — 3,500 3,500 — — 3,500 Equity securities 2,511 324 24 2,811 8,673 891 11 9,553 $ 2,136,856 $ 27,193 $ 12,915 $ 2,151,134 $ 1,631,761 $ 32,543 $ 4,139 $ 1,660,165 Securities Held to Maturity (in thousands) June 30, 2015 December 31, 2014 Amortized Gross Gross Fair Value Amortized Gross Unrealized Gross Fair Value US Treasury and government agency securities $ 200,000 $ 55 $ 770 199,285 $ — $ — $ — $ — Municipal obligations 186,528 3,074 1,834 187,768 180,615 3,416 1,144 182,887 Mortgage-backed securities 898,638 19,378 150 917,866 899,923 23,897 162 923,658 Collateralized mortgage obligations 1,009,152 5,192 9,160 1,005,184 1,085,751 5,590 11,546 1,079,795 $ 2,294,318 $ 27,699 $ 11,914 $ 2,310,103 $ 2,166,289 $ 32,903 $ 12,852 $ 2,186,340 The following table presents the amortized cost and fair value of debt securities at June 30, 2015 by contractual maturity. Actual maturities will differ from contractual maturities because of rights to call or repay obligations with or without penalties and scheduled and unscheduled principal payments on mortgage-backed securities and collateralized mortgage obligations. (in thousands) Amortized Fair Value Debt Securities Available for Sale Due in one year or less $ 140,435 $ 138,065 Due after one year through five years 84,499 85,910 Due after five years through ten years 262,769 270,342 Due after ten years 1,646,642 1,654,006 Total available for sale debt securities $ 2,134,345 $ 2,148,323 Amortized Fair Value Debt Securities Held to Maturity Due in one year or less $ 463,052 $ 462,421 Due after one year through five years 326,452 322,348 Due after five years through ten years 112,736 111,390 Due after ten years 1,392,078 1,413,944 Total held to maturity securities $ 2,294,318 $ 2,310,103 The Company held no securities classified as trading at June 30, 2015 or December 31, 2014. The details for securities classified as available for sale with unrealized losses for the periods indicated follow. June 30, 2015 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US Treasury and government agency securities $ 98,469 $ 1,538 $ 95 $ 1 $ 98,564 $ 1,539 Municipal obligations 2,975 25 — — 2,975 25 Mortgage-backed securities 678,428 6,944 117,793 2,912 796,221 9,856 Collateralized mortgage obligations 99,688 628 36,440 843 136,128 1,471 Equity securities 1,518 23 2 1 1,520 24 $ 881,078 $ 9,158 $ 154,330 $ 3,757 $ 1,035,408 $ 12,915 December 31, 2014 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US 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 Collateralized mortgage obligations — — 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 held to maturity with unrealized losses for the periods indicated follow. June 30, 2015 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US Treasury and government agency securities $ 149,230 $ 770 $ — $ — $ 149,230 $ 770 Municipal obligations 21,058 379 48,219 1,455 69,277 1,834 Mortgage-backed securities 169,049 150 — — 169,049 150 Collateralized mortgage obligations 134,704 391 456,865 8,769 591,569 9,160 $ 474,041 $ 1,690 $ 505,084 $ 10,224 $ 979,125 $ 11,914 December 31, 2014 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross Municipal obligations $ 4,316 $ 12 $ 58,105 $ 1,132 $ 62,421 $ 1,144 Mortgage-backed securities — — 95,522 162 95,522 162 Collateralized mortgage obligations 119,222 616 540,607 10,930 659,829 11,546 $ 123,538 $ 628 $ 694,234 $ 12,224 $ 817,772 $ 12,852 The unrealized losses relate to changes in market rates on fixed-rate debt securities since the respective purchase dates. In all cases, the indicated impairment would be recovered no later than the security’s maturity date or possibly earlier if the market price for the security increases with a reduction in the yield required by the market. None of the unrealized losses relate to the marketability of the securities or the issuer’s ability to meet contractual obligations. The Company believes it has adequate liquidity and, therefore, does not plan to and, more likely than not, will not be required to sell these securities before recovery of the indicated impairment. Accordingly, the unrealized losses on these securities have been determined to be temporary. 2. Securities The amortized cost and fair value of securities classified as available for sale and held to maturity follow. Securities Available for Sale (in thousands) June 30, 2015 December 31, 2014 Amortized Gross Gross Fair Value Amortized Gross Gross Fair Value US Treasury and government agency securities $ 100,160 $ — $ 1,539 $ 98,621 $ 300,207 $ 372 $ 71 $ 300,508 Municipal obligations 12,723 177 25 12,875 13,995 186 5 14,176 Mortgage-backed securities 1,802,249 26,146 9,856 1,818,539 1,217,293 31,094 2,823 1,245,564 Collateralized mortgage obligations 215,713 546 1,471 214,788 88,093 — 1,229 86,864 Corporate debt securities 3,500 — — 3,500 3,500 — — 3,500 Equity securities 2,511 324 24 2,811 8,673 891 11 9,553 $ 2,136,856 $ 27,193 $ 12,915 $ 2,151,134 $ 1,631,761 $ 32,543 $ 4,139 $ 1,660,165 Securities Held to Maturity (in thousands) June 30, 2015 December 31, 2014 Amortized Gross Gross Fair Value Amortized Gross Unrealized Gross Fair Value US Treasury and government agency securities $ 200,000 $ 55 $ 770 199,285 $ — $ — $ — $ — Municipal obligations 186,528 3,074 1,834 187,768 180,615 3,416 1,144 182,887 Mortgage-backed securities 898,638 19,378 150 917,866 899,923 23,897 162 923,658 Collateralized mortgage obligations 1,009,152 5,192 9,160 1,005,184 1,085,751 5,590 11,546 1,079,795 $ 2,294,318 $ 27,699 $ 11,914 $ 2,310,103 $ 2,166,289 $ 32,903 $ 12,852 $ 2,186,340 The following table presents the amortized cost and fair value of debt securities at June 30, 2015 by contractual maturity. Actual maturities will differ from contractual maturities because of rights to call or repay obligations with or without penalties and scheduled and unscheduled principal payments on mortgage-backed securities and collateralized mortgage obligations. (in thousands) Amortized Fair Value Debt Securities Available for Sale Due in one year or less $ 140,435 $ 138,065 Due after one year through five years 84,499 85,910 Due after five years through ten years 262,769 270,342 Due after ten years 1,646,642 1,654,006 Total available for sale debt securities $ 2,134,345 $ 2,148,323 Amortized Fair Value Debt Securities Held to Maturity Due in one year or less $ 463,052 $ 462,421 Due after one year through five years 326,452 322,348 Due after five years through ten years 112,736 111,390 Due after ten years 1,392,078 1,413,944 Total held to maturity securities $ 2,294,318 $ 2,310,103 The Company held no securities classified as trading at June 30, 2015 or December 31, 2014. The details for securities classified as available for sale with unrealized losses for the periods indicated follow: June 30, 2015 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US Treasury and government agency securities $ 98,469 $ 1,538 $ 95 $ 1 $ 98,564 $ 1,539 Municipal obligations 2,975 25 — — 2,975 25 Mortgage-backed securities 678,428 6,944 117,793 2,912 796,221 9,856 Collateralized mortgage obligations 99,688 628 36,440 843 136,128 1,471 Equity securities 1,518 23 2 1 1,520 24 $ 881,078 $ 9,158 $ 154,330 $ 3,757 $ 1,035,408 $ 12,915 December 31, 2014 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US 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 Collateralized mortgage obligations — — 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 held to maturity with unrealized losses for the periods indicated follow. June 30, 2015 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US Treasury and government agency securities $ 149,230 $ 770 $ — $ — $ 149,230 $ 770 Municipal obligations 21,058 379 48,219 1,455 69,277 1,834 Mortgage-backed securities 169,049 150 — — 169,049 150 Collateralized mortgage obligations 134,704 391 456,865 8,769 591,569 9,160 $ 474,041 $ 1,690 $ 505,084 $ 10,224 $ 979,125 $ 11,914 December 31, 2014 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross Municipal obligations $ 4,316 $ 12 $ 58,105 $ 1,132 $ 62,421 $ 1,144 Mortgage-backed securities — — 95,522 162 95,522 162 Collateralized mortgage obligations 119,222 616 540,607 10,930 659,829 11,546 $ 123,538 $ 628 $ 694,234 $ 12,224 $ 817,772 $ 12,852 The unrealized losses relate to changes in market rates on fixed-rate debt securities since the respective purchase dates. In all cases, the indicated impairment would be recovered no later than the security’s maturity date or possibly earlier if the market price for the security increases with a reduction in the yield required by the market. None of the unrealized losses relate to the marketability of the securities or the issuer’s ability to meet contractual obligations. The Company believes it has adequate liquidity and, therefore, does not plan to and, more likely than not, will not be required to sell these securities before recovery of the indicated impairment. Accordingly, the unrealized losses on these securities have been determined to be temporary.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2015
Receivables [Abstract]
Loans and Allowance for Loan Losses	3. Loans and Allowance for Loan Losses Loans, net of unearned income, consisted of the following. (in thousands) June 30, 2015 December 31, Originated loans: Commercial non-real estate $ 6,058,998 $ 5,917,728 Construction and land development 1,100,788 1,073,964 Commercial real estate 2,591,384 2,428,195 Residential mortgages 1,784,730 1,704,770 Consumer 1,854,591 1,685,542 Total originated loans $ 13,390,491 $ 12,810,199 Acquired loans: Commercial non-real estate $ 120,020 $ 120,137 Construction and land development 9,064 21,123 Commercial real estate 598,962 688,045 Residential mortgages 1,554 2,378 Consumer 24 985 Total acquired loans $ 729,624 $ 832,668 FDIC acquired loans: Commercial non-real estate $ 6,666 $ 6,195 Construction and land development 11,095 11,674 Commercial real estate 22,487 27,808 Residential mortgages 169,553 187,033 Consumer 14,836 19,699 Total FDIC acquired loans $ 224,637 $ 252,409 Total loans: Commercial non-real estate $ 6,185,684 $ 6,044,060 Construction and land development 1,120,947 1,106,761 Commercial real estate 3,212,833 3,144,048 Residential mortgages 1,955,837 1,894,181 Consumer 1,869,451 1,706,226 Total loans $ 14,344,752 $ 13,895,276 The following briefly describes the distinction among originated, acquired and FDIC acquired loans and certain significant accounting policies relevant to each category. Originated loans Loans reported as “originated” include both loans and leases 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 for 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 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 an increase in the loss share receivable’s amortization 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 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 an increase in the loss share receivable’s amortization 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. The following schedule shows activity in the loss share receivable for the six months ended June 30, 2015 and 2014. Six Months Ended (in thousands) June 30, June 30, Balance, January 1 $ 60,272 $ 113,834 Amortization (2,470 ) (7,229 ) Charge-offs, write-downs and other recoveries (4,667 ) (1,048 ) External expenses qualifying under loss share agreement 482 2,841 Changes due to changes in cash flow projections (2,536 ) (7,875 ) Settlement of disallowed loss claims (1,854 ) (10,268 ) Net payments from FDIC (14,153 ) — Ending balance $ 35,074 $ 90,255 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 schedule shows activity in the allowance for loan losses by portfolio segment for the six months ended June 30, 2015 and 2014 as well as the corresponding recorded investment in loans at the end of each period. (in thousands) Commercial non-real estate Construction Commercial Residential Consumer Total Six Months Ended June 30, 2015 Originated loans Allowance for loan losses: Beginning balance $ 50,258 $ 5,413 $ 16,544 $ 8,051 $ 17,435 $ 97,701 Charge-offs (2,215 ) (828 ) (525 ) (1,292 ) (6,729 ) (11,589 ) Recoveries 2,051 1,308 426 449 2,491 6,725 Net provision for loan losses 9,586 (982 ) 1,217 62 4,091 13,974 Ending balance $ 59,680 $ 4,911 $ 17,662 $ 7,270 $ 17,288 $ 106,811 Ending balance: Individually evaluated for impairment $ 2,903 $ 73 $ 2,203 $ 163 $ 6 $ 5,348 Collectively evaluated for impairment 56,777 4,838 15,459 7,107 17,282 101,463 Loans: Ending balance: $ 6,058,998 $ 1,100,788 $ 2,591,384 $ 1,784,730 $ 1,854,591 $ 13,390,491 Individually evaluated for impairment 32,379 4,360 31,840 1,369 116 70,064 Collectively evaluated for impairment 6,026,619 1,096,428 2,559,544 1,783,361 1,854,475 13,320,427 Acquired loans Allowance for loan losses: Beginning balance $ — $ — $ 477 $ — $ — $ 477 Charge-offs — — — — — — Recoveries — — — — — — Net provision for loan losses — — (263 ) — — (263 ) Ending balance $ — $ — $ 214 $ — $ — $ 214 Ending balance: Individually evaluated for impairment $ — $ — $ 214 $ — $ — $ 214 Amounts related to acquired-impaired loans — — — — — — Collectively evaluated for impairment — — — — — — Loans: Ending balance: $ 120,020 $ 9,064 $ 598,962 $ 1,554 $ 24 $ 729,624 Individually evaluated for impairment — — 2,543 — — 2,543 Acquired-impaired loans 7,001 8,370 17,851 1,554 24 34,800 Collectively evaluated for impairment 113,019 694 578,568 — — 692,281 (in thousands) Commercial non-real estate Construction Commercial Residential Consumer Total Six Months Ended June 30, 2015 FDIC acquired loans Allowance for loan losses: Beginning balance $ 911 $ 1,008 $ 4,061 $ 20,609 $ 3,995 $ 30,584 Charge-offs (1,099 ) (285 ) (2,368 ) (168 ) (140 ) (4,060 ) Recoveries 14 406 465 2 136 1,023 Net provision for loan losses 242 (211 ) (78 ) (682 ) (220 ) (949 ) Increase (decrease) in FDIC loss share receivable 575 (528 ) 532 (2,342 ) (773 ) (2,536 ) Ending balance $ 643 $ 390 $ 2,612 $ 17,419 $ 2,998 $ 24,062 Ending balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — Amounts related to acquired-impaired loans 643 390 2,612 17,419 2,998 24,062 Collectively evaluated for impairment — — — — — — Loans: Ending balance: $ 6,666 $ 11,095 $ 22,487 $ 169,553 $ 14,836 $ 224,637 Individually evaluated for impairment — — — — — — Acquired-impaired loans 6,666 11,095 22,487 169,553 14,836 224,637 Collectively evaluated for impairment — — — — — — Total loans Allowance for loan losses: Beginning balance $ 51,169 $ 6,421 $ 21,082 $ 28,660 $ 21,430 $ 128,762 Charge-offs (3,314 ) (1,113 ) (2,893 ) (1,460 ) (6,869 ) (15,649 ) Recoveries 2,065 1,714 891 451 2,627 7,748 Net provision for loan losses 9,828 (1,193 ) 876 (620 ) 3,871 12,762 Increase (decrease) in FDIC loss share receivable 575 (528 ) 532 (2,342 ) (773 ) (2,536 ) Ending balance $ 60,323 $ 5,301 $ 20,488 $ 24,689 $ 20,286 $ 131,087 Ending balance: Individually evaluated for impairment $ 2,903 $ 73 $ 2,417 $ 163 $ 6 $ 5,562 Amounts related to acquired-impaired loans 643 390 2,612 17,419 2,998 24,062 Collectively evaluated for impairment 56,777 4,838 15,459 7,107 17,282 101,463 Loans: Ending balance: $ 6,185,684 $ 1,120,947 $ 3,212,833 $ 1,955,837 $ 1,869,451 $ 14,344,752 Individually evaluated for impairment 32,379 4,360 34,383 1,369 116 72,607 Acquired-impaired loans 13,667 19,465 40,338 171,107 14,860 259,437 Collectively evaluated for impairment 6,139,638 1,097,122 3,138,112 1,783,361 1,854,475 14,012,708 Commercial non-real estate Construction Commercial Residential Consumer Total (In thousands) Six Months Ended June 30, 2014 Originated loans Allowance for loan losses: Beginning balance $ 33,091 $ 6,180 $ 20,649 $ 6,892 $ 12,073 $ 78,885 Charge-offs (3,658 ) (1,041 ) (1,373 ) (1,097 ) (7,622 ) (14,791 ) Recoveries 1,411 1,064 1,057 363 2,854 6,749 Net provision for loan losses 5,937 699 (5,060 ) 772 5,381 7,729 Ending balance $ 36,781 $ 6,902 $ 15,273 $ 6,930 $ 12,686 $ 78,572 Ending balance: Individually evaluated for impairment $ 640 $ 259 $ 116 $ 532 $ — $ 1,547 Collectively evaluated for impairment 36,141 6,643 15,157 6,398 12,686 77,025 Loans: Ending balance: $ 4,610,696 $ 903,610 $ 2,173,006 $ 1,469,977 $ 1,501,163 $ 10,658,452 Individually evaluated for impairment 6,765 6,702 11,198 2,532 — 27,197 Collectively evaluated for impairment 4,603,931 896,908 2,161,808 1,467,445 1,501,163 10,631,255 Acquired loans Allowance for loan losses: Beginning balance $ 1,603 $ 10 $ 34 $ — $ — $ 1,647 Charge-offs — — — — — — Recoveries — — — — — — Net provision for loan losses 6,135 210 630 14 311 7,300 Ending balance $ 7,738 $ 220 $ 664 $ 14 $ 311 $ 8,947 Ending balance: Individually evaluated for impairment $ 65 $ 24 $ 188 $ — $ — $ 277 Amounts related to acquired-impaired loans — — — — — — Collectively evaluated for impairment 7,673 196 476 14 311 8,670 Loans: Ending balance: $ 769,159 $ 119,847 $ 836,646 $ 111,724 $ 84,403 $ 1,921,779 Individually evaluated for impairment 1,957 739 2,280 — — 4,976 Acquired-impaired loans 17,410 18,976 27,993 4,547 1,057 69,983 Collectively evaluated for impairment 749,792 100,132 806,373 107,177 83,346 1,846,820 Commercial non-real estate Construction Commercial Residential Consumer Total (In thousands) Six Months Ended June 30, 2014 FDIC acquired loans Allowance for loan losses: Beginning balance $ 2,323 $ 2,655 $ 10,929 $ 27,989 $ 9,198 $ 53,094 Charge-offs (70 ) (624 ) (4,022 ) (730 ) (1,130 ) (6,576 ) Recoveries 451 896 1,371 19 148 2,885 Net provision for loan losses (57 ) (73 ) 30 (173 ) (102 ) (375 ) (Decrease) increase in FDIC loss share receivable (1,099 ) (1,302 ) 225 (3,442 ) (2,257 ) (7,875 ) Ending balance $ 1,548 $ 1,552 $ 8,533 $ 23,663 $ 5,857 $ 41,153 Ending balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — Amounts related to acquired-impaired loans 1,548 1,552 8,533 23,663 5,857 41,153 Collectively evaluated for impairment — — — — — — Loans: Ending balance: $ 13,836 $ 17,199 $ 46,611 $ 189,570 $ 36,609 $ 303,825 Individually evaluated for impairment — — — — — — Acquired-impaired loans 13,836 17,199 46,611 189,570 36,609 303,825 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 (3,728 ) (1,665 ) (5,395 ) (1,827 ) (8,752 ) (21,367 ) Recoveries 1,862 1,960 2,428 382 3,002 9,634 Net provision for loan losses 12,015 836 (4,400 ) 613 5,590 14,654 (Decrease) increase in FDIC loss share receivable (1,099 ) (1,302 ) 225 (3,442 ) (2,257 ) (7,875 ) Ending balance $ 46,067 $ 8,674 $ 24,470 $ 30,607 $ 18,854 $ 128,672 Ending balance: Individually evaluated for impairment $ 705 $ 283 $ 304 $ 532 $ — $ 1,824 Amounts related to acquired-impaired loans 1,548 1,552 8,533 23,663 5,857 41,153 Collectively evaluated for impairment 43,814 6,839 15,633 6,412 12,997 85,695 Loans: Ending balance: $ 5,393,691 $ 1,040,656 $ 3,056,263 $ 1,771,271 $ 1,622,175 $ 12,884,056 Individually evaluated for impairment 8,722 7,441 13,478 2,532 — 32,173 Acquired-impaired loans 31,246 36,175 74,604 194,117 37,666 373,808 Collectively evaluated for impairment 5,353,723 997,040 2,968,181 1,574,622 1,584,509 12,478,075 The following table shows the composition of nonaccrual loans by portfolio segment and class. Acquired-impaired and certain FDIC acquired 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) June 30, December 31, Originated loans: Commercial non-real estate $ 42,454 $ 15,511 Construction and land development 5,285 6,462 Commercial real estate 38,152 22,047 Residential mortgages 20,709 21,702 Consumer 4,855 5,574 Total originated loans $ 111,455 $ 71,296 Acquired loans: Commercial non-real estate $ — $ — Construction and land development — — Commercial real estate 5,401 6,139 Residential mortgages — — Consumer — — Total acquired loans $ 5,401 $ 6,139 FDIC acquired loans: Commercial non-real estate $ — $ — Construction and land development 1,156 1,103 Commercial real estate 433 433 Residential mortgages — 392 Consumer — 174 Total FDIC acquired loans $ 1,589 $ 2,102 Total loans: Commercial non-real estate $ 42,454 $ 15,511 Construction and land development 6,441 7,565 Commercial real estate 43,986 28,619 Residential mortgages 20,709 22,094 Consumer 4,855 5,748 Total loans $ 118,445 $ 79,537 The estimated amount of interest that would have been recorded on nonaccrual loans had the loans not been classified as nonaccrual in the six months ended June 30, 2015 was approximately $1.8 million. Interest actually received and recorded as income on nonaccrual loans during that period was approximately $0.6 million. Nonaccrual loans include loans modified in troubled debt restructurings (“TDRs”) of $4.9 million and $7.0 million at June 30, 2015 and December 31, 2014, respectively. Total TDRs, both accruing and nonaccruing, were $12.8 million as of June 30, 2015 and $16.0 million at December 31, 2014. The table below details TDRs that were modified during the six months ended June 30, 2015 and June 30, 2014 by portfolio segment. Six Months Ended (in thousands) June 30, 2015 June 30, 2014 Troubled Debt Restructurings: Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification Originated loans: Commercial non-real estate — $ — $ — — $ — $ — Construction and land development — — — — — — Commercial real estate 1 482 482 1 963 918 Residential mortgages 2 68 68 2 773 507 Consumer 1 20 20 — — — Total originated loans 4 $ 570 $ 570 3 $ 1,736 $ 1,425 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 — $ — $ — — $ — $ — Construction and land development — — — — — — Commercial real estate 1 482 482 1 963 918 Residential mortgages 2 68 68 2 773 507 Consumer 1 20 20 — — — Total loans 4 $ 570 $ 570 3 $ 1,736 $ 1,425 The table below details TDRs that subsequently defaulted within twelve months of modification. Six Months Ended (in thousands) June 30, 2015 June 30, 2014 Troubled Debt Restructurings: Number of Recorded Number of Recorded Originated loans: Commercial non-real estate — $ — 1 $ 909 Construction and land development — — — — Commercial real estate — — 2 1,025 Residential mortgages — — — — Consumer — — — — Total originated loans — $ — 3 $ 1,934 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 — — 2 1,025 Residential mortgages — — — — Consumer — — — — Total loans — $ — 3 $ 1,934 The tables below present loans that are individually evaluated for impairment disaggregated by class at June 30, 2015 and December 31, 2014. Loans individually evaluated for impairment include TDRs and loans that are determined to be impaired and have aggregate relationship balances of $1 million or more. June 30, 2015 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) Originated loans: With no related allowance recorded: Commercial non-real estate $ 12,192 $ 12,696 $ — $ 8,861 $ — Construction and land development 57 57 — 1,295 — Commercial real estate 12,001 14,005 — 10,376 20 Residential mortgages — — — 345 2 Consumer 98 98 — 66 — 24,348 26,856 — 20,943 22 With an allowance recorded: Commercial non-real estate $ 20,187 $ 20,949 $ 2,903 $ 8,116 3 Construction and land development 4,303 6,522 73 4,369 59 Commercial real estate 19,839 19,840 2,203 10,014 44 Residential mortgages 1,369 1,880 163 1,804 18 Consumer 18 18 6 15 3 45,716 49,209 5,348 24,318 127 Total: Commercial non-real estate 32,379 33,645 2,903 $ 16,977 3 Construction and land development 4,360 6,579 73 5,664 59 Commercial real estate 31,840 33,845 2,203 20,390 64 Residential mortgages 1,369 1,880 163 2,149 20 Consumer 116 116 6 81 3 Total originated loans $ 70,064 $ 76,065 $ 5,348 $ 45,261 $ 149 Acquired loans: With no related allowance recorded: Commercial non-real estate $ — $ — $ — $ — $ — Construction and land development — — — — — Commercial real estate — — — — — Residential mortgages — — — — — Consumer — — — — — — — — — — With an allowance recorded: Commercial non-real estate — — — $ — — Construction and land development — — — — — Commercial real estate 2,543 2,563 214 2,604 — Residential mortgages — — — — — Consumer — — — — — 2,543 2,563 214 2,604 — Total: Commercial non-real estate — — — $ — — Construction and land development — — — — — Commercial real estate 2,543 2,563 214 2,604 — Residential mortgages — — — — — Consumer — — — — — Total acquired loans $ 2,543 $ 2,563 $ 214 $ 2,604 $ — June 30, 2015 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) Total loans: With no related allowance recorded: Commercial non-real estate $ 12,192 $ 12,696 $ — $ 8,861 $ — Construction and land development 57 57 — 1,295 — Commercial real estate 12,001 14,005 — 10,376 20 Residential mortgages — — — 345 2 Consumer 98 98 — 66 — 24,348 26,856 — 20,943 22 With an allowance recorded: Commercial non-real estate 20,187 20,949 2,903 $ 8,116 3 Construction and land development 4,303 6,522 73 4,369 59 Commercial real estate 22,382 22,403 2,417 12,618 44 Residential mortgages 1,369 1,880 163 1,804 18 Consumer 18 18 6 15 3 48,259 51,772 5,562 26,922 127 Total: Commercial non-real estate 32,379 33,645 2,903 $ 16,977 3 Construction and land development 4,360 6,579 73 5,664 59 Commercial real estate 34,383 36,408 2,417 22,995 64 Residential mortgages 1,369 1,880 163 2,149 20 Consumer 116 116 6 81 3 Total loans $ 72,607 $ 78,628 $ 5,562 $ 47,866 $ 149 December 31, 2014 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) 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 December 31, 2014 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) 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 The tables below present the age analysis of past due loans at June 30, 2015 and December 31, 2014. FDIC acquired and acquired-impaired loans accounted for in pools with an accretable yield are considered to be current. June 30, 2015 30-59 days 60-89 days Greater than past due Total Current Total Loans Recorded (in thousands) Originated loans: Commercial non-real estate $ 5,215 $ 3,090 $ 10,250 $ 18,555 $ 6,040,443 $ 6,058,998 $ 826 Construction and land development 2,411 2,128 4,278 8,817 1,091,971 1,100,788 80 Commercial real estate 3,180 1,450 14,267 18,897 2,572,487 2,591,384 279 Residential mortgages 1,094 3,493 8,227 12,814 1,771,916 1,784,730 946 Consumer 10,414 3,286 3,228 16,928 1,837,663 1,854,591 1,347 Total $ 22,314 $ 13,447 $ 40,250 $ 76,011 $ 13,314,480 $ 13,390,491 $ 3,478 Acquired loans: Commercial non-real estate $ — $ — $ — $ — $ 120,020 $ 120,020 $ — Construction and land development — — — — 9,064 9,064 — Commercial real estate 1,954 138 2,032 4,124 594,838 598,962 — Residential mortgages — — — — 1,554 1,554 — Consumer — — — — 24 24 — Total $ 1,954 $ 138 $ 2,032 $ 4,124 $ 725,500 $ 729,624 $ — FDIC acquired loans: Commercial non-real estate $ — $ — $ — $ — $ 6,666 $ 6,666 $ — Construction and land development — — 1,156 1,156 9,939 11,095 — Commercial real estate — — 433 433 22,054 22,487 — Residential mortgages — — — — 169,553 169,553 — Consumer — — — — 14,836 14,836 — Total $ — $ — $ 1,589 $ 1,589 $ 223,048 $ 224,637 $ — Total loans: Commercial non-real estate $ 5,215 $ 3,090 $ 10,250 $ 18,555 $ 6,167,129 $ 6,185,684 $ 826 Construction and land development 2,411 2,128 5,434 9,973 1,110,974 1,120,947 80 Commercial real estate 5,134 1,588 16,732 23,454 3,189,379 3,212,833 279 Residential mortgages 1,094 3,493 8,227 12,814 1,943,023 1,955,837 946 Consumer 10,414 3,286 3,228 16,928 1,852,523 1,869,451 1,347 Total $ 24,268 $ 13,585 $ 43,871 $ 81,724 $ 14,263,028 $ 14,344,752 $ 3,478 December 31, 2014 30-59 days 60-89 days Greater than past due Total past due Current Total Loans Recorded (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 The following tables present the credit quality indicators of the Company’s various classes of loans at June 30, 2015 and December 31, 2014. Commercial Non-Real Estate Credit Exposure Credit Risk Profile by Internally Assigned Grade (in thousands) June 30, 2015 December 31, 2014 Originated Acquired FDIC acquired Total Originated Acquired FDIC acquired Total Grade: Pass $ 5,522,236 $ 113,200 $ 2,648 $ 5,638,084 $ 5,577,827 $ 111,847 $ 2,027 $ 5,691,701 Pass-Watch 142,837 101 988 143,926 174,742 715 1,120 176,577 Special Mention 209,716 282 — 209,998 52,962 350 — 53,312 Substandard 184,178 6,437 3,001 193,616 112,153 7,225 3,017 122,395 Doubtful 31 — 29 60 44 — 31 75 Total $ 6,058,998 $ 120,020 $ 6,666 $ 6,185,684 $ 5,917,728 $ 120,137 $ 6,195 $ 6,044,060 Construction Credit Exposure Credit Risk Profile by Internally Assigned Grade (in thousands) June 30, 2015 December 31, 2014 Originated Acquired FDIC acquired Total Originated Acquired FDIC acquired Total Grade: Pass $ 1,048,380 $ 1,743 $ 2,789 $ 1,052,912 $ 1,012,128 $ 14,377 $ 2,468 $ 1,028,973 Pass-Watch 7,471 2,275 519 10,265 21,516 432 532 22,480 Special Mention 4,920 — 313 5,233 7,097 129 319 7,545 Substandard 40,017 5,046 7,474 52,537 33,223 6,185 8,355 47,763 Total $ 1,100,788 $ 9,064 $ 11,095 $ 1,120,947 $ 1,073,964 $ 21,123 $ 11,674 $ 1,106,761 Commercial Real Estate Credit Exposure Credit Risk Profile by Internally Assigned Grade (in thousands) June 30, 2015 Dece

Securities Sold under Agreement

Securities Sold under Agreements to Repurchase	6 Months Ended
	Jun. 30, 2015
Banking and Thrift [Abstract]
Securities Sold under Agreements to Repurchase	4. Securities Sold under Agreements to Repurchase Included in short term borrowings at June 30, 2015 was $466.3 million of customer securities sold under agreements to repurchase (“repurchase agreements”) that mature daily and were secured by agency securities. The Company borrows funds on a secured basis by selling securities under agreements to repurchase, mainly in connection with treasury-management services offered to its deposit customers. As the Company maintains effective control over assets sold under agreements to repurchase, the securities continue to be carried on the consolidated statements of financial condition. Repurchase agreements mature daily and the Company acts as a borrower transferring assets to the counterparty. As such, the Company’s risk is very limited.

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Long-Term Debt	5. Long-Term Debt Long-term debt consisted of the following. June 30, December 31, (in thousands) 2015 2014 Subordinated notes payable, maturing June 2045 $ 150,000 $ — Subordinated notes payable, maturing April 2017 98,011 98,011 Term note payable, maturing December 2015 132,000 149,600 Other long-term debt 127,330 126,760 Total long-term debt $ 507,341 $ 374,371 On March 9, 2015, the Company completed the issuance of subordinated notes payable with an aggregate principal amount of $150 million. The notes mature on June 15, 2045 and accrue interest at a rate of 5.95% per annum. Quarterly interest payments began in June. Subject to prior approval by the Federal Reserve, the Company may redeem the notes in whole or in part on any interest payment date on or after June 15, 2020. This debt qualifies as Tier 2 capital in the calculation of certain regulatory capital ratios. The 5.875% fixed-rate subordinated notes maturing April 2017 had been issued by Whitney National Bank and were assumed by Hancock in the Whitney acquisition. As of June 30, 2015, 20% of the balance of these notes qualifies as capital in the calculation of certain regulatory capital ratios. The notes will no longer qualify as capital as of April 1, 2016. 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 and the Bank must satisfy certain financial covenants in the term loan agreement and are subject to other restrictions customary in financings of this nature, none of which are expected to adversely impact our operations. 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 acquired assets. The Company was in compliance with all covenants as of June 30, 2015 and December 31, 2014. Substantially all of the other long-term debt consists of borrowings associated with tax credit fund activities. Although these borrowings have indicated maturities through 2052, they are expected to be paid off at the end of their seven-year compliance period.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value	6. Fair Value The Financial Accounting Standards Board (“FASB”) defines fair value as the exchange price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market 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 and Liabilities Measured on a Recurring Basis The following tables present for each of the fair value hierarchy levels the Company’s assets and liabilities that are measured at fair value on a recurring basis in the consolidated balance sheets. June 30, 2015 (in thousands) Level 1 Level 2 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 98,621 $ 98,621 Municipal obligations — 12,875 12,875 Corporate debt securities — 3,500 3,500 Mortgage-backed securities — 1,818,539 1,818,539 Collateralized mortgage obligations — 214,788 214,788 Equity securities 2,811 — 2,811 Total available for sale securities 2,811 2,148,323 2,151,134 Derivative assets (1) — 24,096 24,096 Total recurring fair value measurements - assets $ 2,811 $ 2,172,419 $ 2,175,230 Liabilities Derivative liabilities (1) $ — $ 22,157 $ 22,157 Total recurring fair value measurements - liabilities $ — $ 22,157 $ 22,157 (1) For further disaggregation of derivative assets and liabilities, see Note 7 - Derivatives. 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 7 - 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 obligations of U.S. Government agencies and U.S. Government-sponsored agencies, residential mortgage-backed securities and collateralized mortgage obligations that are issued or guaranteed by U.S. government agencies, and state and 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 are 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 and five. Company policies generally limit investments to agency securities and municipal securities determined to be investment grade according to an internally generated score which generally includes a rating of not less than “Baa” or its equivalent by a nationally recognized statistical rating agency. There were no transfers between valuation hierarchy levels during the periods shown. The fair value of derivative financial instruments, which are predominantly customer interest rate swaps, is obtained from a third-party pricing service that uses an industry-standard discounted cash flow model that relies on inputs, LIBOR swap curves and Overnight Index swap rate curves, observable in the marketplace. To comply with the accounting guidance, credit valuation adjustments are incorporated in the fair values to appropriately reflect nonperformance risk for both the Company and the counterparties. Although the Company has determined that the majority of the inputs used to value the derivative instruments fall within level 2 of the fair value hierarchy, the credit value adjustments utilize level 3 inputs, such as estimates of current credit spreads. The Company has determined that the impact of the credit valuation adjustments is not significant to the overall valuation of these derivatives. As a result, the Company has classified its derivative valuations in their entirety in level 2 of the fair value hierarchy. The Company’s policy is to measure counterparty credit risk quarterly for all derivative instruments, including those subject to master netting arrangements consistent with how market participants would price the net risk exposure at the measurement date. The Company also has certain derivative instruments 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 independent third-party appraisals that take into consideration market-based information such as recent sales activity for similar assets in the property’s market. Other real estate owned, including both foreclosed property and surplus banking property, are level 3 assets that are adjusted to fair value, less estimated selling costs, upon transfer to other real estate owned. Subsequently, other real estate owned is carried at the lower of carrying value or fair value less estimated selling costs. Fair values are determined by sales agreement or third-party appraisals as discounted for estimated selling costs, information from comparable sales, and marketability of the property. The fair value information presented below is not as of the period-end, rather it was as of the date the fair value adjustment was recorded during the twelve months ended June 30, 2015, and excludes nonrecurring fair value measurements of assets no longer on the balance sheet. The following tables present the Company’s financial assets that are measured at fair value on a nonrecurring basis for each of the fair value hierarchy levels. June 30, 2015 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 60,165 $ — $ 60,165 Other real estate owned — — 21,289 21,289 Total nonrecurring fair value measurements $ — $ 60,165 $ 21,289 $ 81,484 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 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 short-term Securities Loans, Net Loans Held for Sale Deposits Securities Sold under Agreements to Repurchase, Federal Funds Purchased, and Federal Home Loan Bank (“FHLB”) Borrowings Long-Term Debt Derivative Financial Instruments The following tables present the estimated fair values of the Company’s financial instruments by fair value hierarchy levels and the corresponding carrying amount at June 30, 2015 and December 31, 2014. June 30, 2015 Total Carrying (in thousands) Level 1 Level 2 Level 3 Fair Value Amount Financial assets: Cash, interest-bearing bank deposits, and federal funds sold $ 928,063 $ — $ — $ 928,063 $ 928,063 Available for sale securities 2,811 2,148,323 — 2,151,134 2,151,134 Held to maturity securities — 2,310,103 — 2,310,103 2,294,318 Loans, net — 60,165 14,133,549 14,193,714 14,213,665 Loans held for sale — 21,304 — 21,304 21,304 Derivative financial instruments — 24,096 — 24,096 24,096 Financial liabilities: Deposits $ — $ — $ 17,282,802 $ 17,282,802 $ 17,301,788 Federal funds purchased 12,850 — — 12,850 12,850 Securities sold under agreements to repurchase 466,343 — — 466,343 466,343 FHLB borrowings 600,000 — — 600,000 600,000 Long-term debt — 511,424 — 511,424 507,341 Derivative financial instruments — 22,157 — 22,157 22,157 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 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 Derivative financial instruments — 20,860 — 20,860 20,860

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	7. 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 June 30, 2015 and December 31, 2014. Fair Values (1) Notional Amounts Assets Liabilities (in thousands) Type of June 30, December 31, June 30, December 31, June 30, December 31, Derivatives designated as hedging instruments: Interest rate swaps Cash Flow $ 500,000 $ 300,000 $ 413 $ — $ — $ 592 $ 500,000 $ 300,000 $ 413 $ — $ — $ 592 Derivatives not designated as hedging instruments: Interest rate swaps (2) N/A $ 731,843 $ 747,754 $ 17,916 $ 17,806 $ 18,170 $ 18,419 Risk participation agreements N/A 87,901 80,438 82 125 168 208 Forward commitments to sell residential mortgage loans N/A 67,942 52,238 2,069 80 215 250 Interest rate-lock commitments on residential mortgage loans N/A 46,184 33,068 143 111 157 44 Foreign exchange forward contracts N/A 68,361 89,432 3,473 1,310 3,447 1,347 $ 1,002,231 $ 1,002,930 $ 23,683 $ 19,432 $ 22,157 $ 20,268 (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 two interest rate swap agreements – one with a notional amount of $300 million and the second with a notional amount of $200 million. For both agreements, the Company receives interest at a fixed rate and pays at a variable rate. The derivative instrument represented by these swap agreements was designated as and qualifies as cash flow hedges of the Company’s forecasted variable cash flows for a pool of variable rate loans. The $300 million swap agreement expires in January, 2017 and the $200 million swap agreement expires in June, 2017. During the terms of the swap agreements, the effective portion of changes in the fair value of the derivative instruments are recorded in accumulated other comprehensive income (“AOCI”) and subsequently reclassified into earnings in the periods that the hedged forecasted variable-rate interest payments affects earnings. The impact on AOCI was insignificant in the second quarter and for the six months ended 2015. 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 has entered into the risk participation agreement because it is a party to the related loan agreement with the borrower. In those instances in which the Bank has sold credit risk, it is the sole counterparty to the derivative contract with the borrower and has entered into the risk participation agreement because other banks participate in the related loan 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 its mortgage banking activities. These agreements include interest rate lock commitments on prospective residential mortgage loans and forward commitments to sell these loans to investors on a best efforts delivery basis. Customer foreign exchange forward contract derivatives The Bank enters into foreign exchange forward derivative agreements, primarily forward currency contracts, with commercial banking customers to facilitate its 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 three-month and six-month 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 June 30, 2015, the aggregate fair value of derivative instruments with credit risk-related contingent features that were in a net liability position was $7.9 million, for which the Bank had posted collateral of $20.6 million. Offsetting Assets and Liabilities Offsetting information in regards to derivative assets and liabilities subject to master netting agreements at June 30, 2015 and December 31, 2014 is presented in the following tables. Gross Net Amounts Gross Amounts Not Offset in the Statement (in thousands) Gross the the Financial Cash Net Amount As of June 30, 2015 Derivative Assets $ 17,998 $ — $ 17,998 $ 474 $ — $ 17,524 Total $ 17,998 $ — $ 17,998 $ 474 $ — $ 17,524 Derivative Liabilities $ 18,338 $ — $ 18,338 $ 474 $ 20,121 $ (2,257 ) Total $ 18,338 $ — $ 18,338 $ 474 $ 20,121 $ (2,257 ) Gross Net Amounts Gross Amounts Not Offset in the Statement Description Gross Statement of Statement of Financial Cash Net Amount As of December 31, 2014 Derivative Assets $ 17,931 $ — $ 17,931 $ 936 $ — $ 16,995 Total $ 17,931 $ — $ 17,931 $ 936 $ — $ 16,995 Derivative Liabilities $ 18,627 $ — $ 18,627 $ 936 $ 17,343 $ 348 Total $ 18,627 $ — $ 18,627 $ 936 $ 17,343 $ 348

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Stock Repurchase Program In March 2015, the Company completed the stock repurchase program approved by the Company’s board of directors on July 16, 2014 which authorized the repurchase of up to 5%, or approximately 4.1 million shares, of its outstanding common stock. The approved plan allowed 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. Under this plan, the Company repurchased a total of 4.1 million shares of our common stock at an average price of $30.02 per share. Accumulated Other Comprehensive Income (Loss) AOCI is reported as a component of stockholders’ equity. AOCI can include, among other items, unrealized holding gains and losses on securities available for sale (“AFS”), gains and losses associated with pension or other post retirement benefits that are not recognized immediately as a component of net periodic benefit cost, and gains and losses on derivative instruments that are designated as, and qualify as, cash flow hedges. Net unrealized gains/losses on AFS securities reclassified as securities held to maturity (“HTM”) also continue to be reported as a component of AOCI and will be amortized over the estimated remaining life of the securities as an adjustment to interest income. The components of AOCI are reported net of related tax effects. The components of AOCI and changes in those components are presented in the following table. (in thousands) Available HTM Securities Employee Loss on Total Balance, December 31, 2013 $ 8,263 $ (21,189 ) $ (22,453 ) $ — $ (35,379 ) Other comprehensive income before income taxes: Net change in unrealized gain 15,412 — — — 15,412 Reclassification of net losses realized and included in earnings — — 195 — 195 Valuation adjustment for employee benefit plans — — 2,006 — 2,006 Amortization of unrealized net loss on securities transferred to HTM — 1,571 — — 1,571 Income tax expense 5,637 554 905 — 7,096 Balance, June 30, 2014 $ 18,038 $ (20,172 ) $ (21,157 ) $ — $ (23,291 ) Balance, December 31, 2014 $ 18,001 $ (19,074 ) $ (48,626 ) $ (375 ) $ (50,074 ) Other comprehensive income before income taxes: Net change in unrealized (loss) gain (13,962 ) — — 1,005 (12,957 ) Reclassification of net (gain) losses realized and included in earnings (165 ) — 1,571 — 1,406 Valuation adjustment for employee benefit plans — — (5,922 ) (5,922 ) Amortization of unrealized net loss on securities transferred to HTM — 1,586 — — 1,586 Income tax (benefit) expense (5,249 ) 580 (1,574 ) 366 (5,877 ) Balance, June 30, 2015 $ 9,123 $ (18,068 ) $ (51,403 ) $ 264 $ (60,084 ) The following table shows the line items in the consolidated income statements affected by amounts reclassified from accumulated other comprehensive income. Amount reclassified from AOCI (a) Six Months Ended Affected line item on (in thousands) 2015 2014 Gain on sale of AFS securities $ 165 $ — Securities gains (losses) Tax effect (58 ) — Income taxes Net of tax 107 — Net income Amortization of unrealized net loss on securities transferred to HTM $ (1,586 ) $ (1,571 ) Interest income Tax effect 580 554 Income taxes Net of tax (1,006 ) (1,017 ) Net income Amortization of defined benefit pension and post-retirement items (1,571 ) (195 ) Employee benefits expense (b) Tax effect 550 68 Income taxes Net of tax (1,021 ) (127 ) Net income Total reclassifications, net of tax $ (1,920 ) $ (1,144 ) Net income (a) Amounts in parenthesis indicate reduction in net income. (b) These accumulated other comprehensive income components are included in the computation of net periodic pension and post-retirement

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	9. 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 stock-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents. A summary of the information used in the computation of earnings per common share follows. Three Months Ended Six Months Ended (in thousands, except per share data) 2015 2014 2015 2014 Numerator: Net income to common shareholders $ 34,829 $ 39,962 $ 74,988 $ 89,077 Net income allocated to participating securities - basic and diluted 766 819 1,701 1,900 Net income allocated to common shareholders - basic and diluted $ 34,063 $ 39,143 $ 73,287 $ 87,177 Denominator: Weighted-average common shares - basic 77,951 81,933 78,719 82,099 Dilutive potential common shares 164 241 162 249 Weighted-average common shares - diluted 78,115 82,174 78,881 82,348 Earnings per common share: Basic $ 0.44 $ 0.48 $ 0.93 $ 1.06 Diluted $ 0.44 $ 0.48 $ 0.93 $ 1.06 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 574,037 and 843,544, respectively, for the three and six months ended June 30, 2015 and 660,778 and 675,108, respectively, for the three and six months ended June 30, 2014.

Share-Based Payment Arrangement

Share-Based Payment Arrangements	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payment Arrangements	10. Share-Based Payment Arrangements Hancock maintains incentive compensation plans that provide for awards of share-based compensation to employees and directors. These plans have been approved by the Company’s shareholders. Detailed descriptions of these plans were included in Note 12 to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. A summary of option activity for the six months ended June 30, 2014 is presented below. Options Number of Weighted Weighted Aggregate Outstanding at January 1, 2015 933,750 $ 37.03 Exercised (11,577 ) 29.94 Cancelled/Forfeited (51,110 ) 35.43 Expired (109,147 ) 34.15 Outstanding at June 30, 2015 761,916 $ 37.65 4.1 $ 480 Exercisable at June 30, 2015 643,454 $ 39.01 3.7 $ 284 The total intrinsic value of options exercised was $0.2 million for both the six months ended June 30, 2015 and 2014. The restricted and performance shares in the table below are subject to service requirements. A summary of the status of the Company’s nonvested restricted and performance shares as of June 30, 2015 and changes during the six months ended June 30, 2015, is presented in the following table. Number of Weighted Nonvested at January 1, 2015 2,040,299 $ 32.27 Granted 97,906 27.28 Vested (235,987 ) 31.96 Forfeited (123,621 ) 32.74 Nonvested at June 30, 2015 1,778,597 $ 32.01 As of June 30, 2015, there were $35.6 million of total unrecognized compensation expense related to nonvested restricted and performance shares expected to vest. This compensation is expected to be recognized in expense over a weighted average period of 3.3 years. The total fair value of shares which vested during the six months ended June 30, 2015 and 2014 was $7.5 million and $8.9 million, respectively. During the six months ended June 30, 2015, the Company granted 59,312 performance shares with a grant date fair value of $25.77 per share to key members of executive and senior management. The number of 2015 performance shares that ultimately vest at the end of the three-year required service period, if any, 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 performance awards at the grant date was determined using a Monte Carlo simulation method. Compensation expense for these performance shares is recognized on a straight-line basis over the service period.

Retirement Plans

Retirement Plans	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Retirement Plans	11. Retirement Plans The Company has a qualified defined benefit pension plan covering all eligible employees. Eligibility is based on minimum age-related and service-related requirements as well as job classification. Accrued benefits under a nonqualified plan covering certain legacy Whitney employees were frozen as of December 31, 2012 and no future benefits will be accrued under this plan. The Company also sponsors defined benefit postretirement plans for both legacy Hancock and legacy Whitney employees that provide health care and life insurance benefits. Benefits under the Hancock plan are not available to employees hired on or after January 1, 2000. Benefits under the Whitney plan are restricted to retirees who were already receiving benefits at the time of plan amendments in 2007 or active participants who were eligible to receive benefits as of December 31, 2007. The following tables show the components of net periodic benefits cost included in expense for the plans for the periods indicated. (in thousands) Pension benefits Other Post- Three Months Ended June 30, 2015 2014 2015 2014 Service cost $ 3,382 $ 3,035 $ 22 $ 26 Interest cost 4,672 4,817 174 232 Expected return on plan assets (8,206 ) (8,050 ) — — Amortization of net loss 842 5 (40 ) 25 Net periodic benefit cost $ 690 $ (193 ) $ 156 $ 283 Six Months Ended June 30, Service cost $ 6,745 $ 6,460 72 $ 63 Interest cost 9,291 9,626 543 570 Expected return on plan assets (16,419 ) (16,111 ) — — Amortization of net loss 1,486 13 85 182 Net periodic benefit cost $ 1,103 $ (12 ) $ 700 $ 815 Hancock contributed $10 million to the pension plan during the first quarter of 2015. Based on currently available information, the Company does not anticipate making any further contribution during the remainder of 2015. The Company also provides a defined contribution 401(k) retirement benefit plan. Under the plan, the Company matches 100% of the first 1% of compensation saved by a participant, and 50% of the next 5% of compensation saved.

Other Noninterest Income

Other Noninterest Income	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Other Noninterest Income	12. Other Noninterest Income Components of other noninterest income are as follows. Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2015 2014 2015 2014 Income from bank-owned life insurance $ 2,671 $ 2,357 $ 5,337 $ 4,671 Credit related fees 2,611 2,834 5,068 5,566 Income from derivatives 1,464 481 1,412 1,240 Net (loss) gain on sale of assets (62 ) (217 ) (55 ) 1,465 Safety deposit box income 429 443 915 956 Other miscellaneous 2,412 2,714 5,092 5,141 Total other noninterest income $ 9,525 $ 8,612 $ 17,769 $ 19,039

Other Noninterest Expense

Other Noninterest Expense	6 Months Ended
	Jun. 30, 2015
Text Block [Abstract]
Other Noninterest Expense	13. Other Noninterest Expense Components of other noninterest expense are as follows. Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2015 2014 2015 2014 Advertising $ 2,133 $ 2,179 $ 4,298 $ 3,938 Ad valorem and franchise taxes 2,736 2,638 5,451 5,299 Printing and supplies 1,158 949 2,375 2,278 Insurance expense 928 1,018 1,850 2,058 Travel expense 1,308 1,061 2,527 1,957 Entertainment and contributions 1,736 1,529 3,375 2,941 Tax credit investment amortization 2,096 2,198 4,191 4,370 Other miscellaneous 10,211 13,736 13,045 18,284 Total other noninterest expense $ 22,306 $ 25,308 $ 37,112 $ 41,125 Included in other miscellaneous expense in the table above were nonoperating expenses totaling $5.0 million in the second quarter of 2015 and $7.3 million in the second quarter of 2014. For the first half of 2015 and 2014, respectively, included in other expense were nonoperating expenses of $2.7 million and $7.3 million. In 2015, these nonoperating expenses primarily include the net impact from branch sales and closings and the resolution of FDIC denied claims. Other nonoperating expenses in 2014 included expenses related to the FDIC settlement, sale of certain insurance business lines, branch closures and fees related to the early termination of reverse purchase obligations.

New Accounting Pronouncements

New Accounting Pronouncements	6 Months Ended
	Jun. 30, 2015
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	14. New Accounting Pronouncements In May 2015, the FASB issued an Accounting Standard Update (“ASU”) to remove the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient and remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations. In April 2015, the FASB issued an ASU to provide guidance to customers about how to account for a cloud computing arrangement depending on whether or not it includes a software license. If a cloud computing arrangement includes a software license, then the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The guidance will not change GAAP for a customer’s accounting for service contracts. For public business entities, the amendments will be effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2015. Early adoption is permitted for all entities. The adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations. In April 2015, the FASB issued an ASU to simplify presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2015. Early adoption of the amendments in this update is permitted for financial statements that have not been previously issued. The adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations. In February 2015, the FASB issued an ASU to change the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. The amendments in this ASU (1) modify the evaluation of whether limited partnerships and similar legal entities are variable interest entities (VIEs) or voting interest entities; (2) eliminate the presumption that a general partner should consolidate a limited partnership; (3) affect the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships; and (4) provide a scope exception from consolidation guidance for reporting entities with interests in legal entities that are required to comply with or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. The amendments in this update are effective for public business entities for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, including adoption in an interim period. 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 2015, the FASB issued an ASU to address the elimination of the concept of extraordinary items. The standard is the first in the FASB’s simplification initiative that is aimed at reducing the cost and complexity of financial reporting while improving or maintaining the usefulness of information reported to investors. The amendments in this update are effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted but adoption must occur at the beginning of the year. The Company adopted this guidance in January 2015 and it did not have a material impact on the Company’s financial condition or results of operations. In August 2014, the FASB issued an 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. 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 was effective for annual reporting periods beginning after December 15, 2014, including interim periods within that reporting period. The Company adopted this guidance in January 2015 and it did not 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 Company adopted the accounting guidance in January 2015 and it did not have a material impact on the Company’s financial condition or results of operations. The new disclosure requirements are included in Note 4 – Securities Sold Under Agreements to Repurchase. 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 annual reporting periods beginning after December 15, 2017. 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 Company adopted this guidance in January 2015 and it did not have a material impact on the Company’s financial condition or results of operations. The new disclosure requirements are included at the end of Note 3 – Loans and Allowance for Loan Losses. 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 Company adopted this guidance in January 2015 and it did not have a material impact on the Company’s financial condition or results of operations.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	1. Basis of Presentation The consolidated financial statements include the accounts of Hancock Holding Company and all other entities in which it has a controlling interest (the “Company”). The financial statements include all adjustments that are, in the opinion of management, necessary to present fairly the Company’s financial condition, results of operations, changes in stockholders’ equity and cash flows for the interim periods presented. Some financial information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) have been condensed or omitted in this Form 10-Q pursuant to Securities and Exchange Commission rules and regulations. These financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. Financial information reported in these financial statements is not necessarily indicative of the Company’s financial condition, results of operations, or cash flows for any other interim or annual period.
Use of Estimates	Use of Estimates The accounting principles the Company follows and the methods for applying these principles conform with GAAP and with those generally practiced within the banking industry. These accounting principles require management to make estimates and assumptions about future events that affect the amounts reported in the consolidated financial statements and the accompanying notes. Actual results could differ from those estimates.

Securities (Tables)

Securities (Tables)	6 Months Ended
	Jun. 30, 2015
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 (in thousands) June 30, 2015 December 31, 2014 Amortized Gross Gross Fair Value Amortized Gross Gross Fair Value US Treasury and government agency securities $ 100,160 $ — $ 1,539 $ 98,621 $ 300,207 $ 372 $ 71 $ 300,508 Municipal obligations 12,723 177 25 12,875 13,995 186 5 14,176 Mortgage-backed securities 1,802,249 26,146 9,856 1,818,539 1,217,293 31,094 2,823 1,245,564 Collateralized mortgage obligations 215,713 546 1,471 214,788 88,093 — 1,229 86,864 Corporate debt securities 3,500 — — 3,500 3,500 — — 3,500 Equity securities 2,511 324 24 2,811 8,673 891 11 9,553 $ 2,136,856 $ 27,193 $ 12,915 $ 2,151,134 $ 1,631,761 $ 32,543 $ 4,139 $ 1,660,165
Amortized Cost and Fair Value of Held to Maturity Securities	Securities Held to Maturity (in thousands) June 30, 2015 December 31, 2014 Amortized Gross Gross Fair Value Amortized Gross Unrealized Gross Fair Value US Treasury and government agency securities $ 200,000 $ 55 $ 770 199,285 $ — $ — $ — $ — Municipal obligations 186,528 3,074 1,834 187,768 180,615 3,416 1,144 182,887 Mortgage-backed securities 898,638 19,378 150 917,866 899,923 23,897 162 923,658 Collateralized mortgage obligations 1,009,152 5,192 9,160 1,005,184 1,085,751 5,590 11,546 1,079,795 $ 2,294,318 $ 27,699 $ 11,914 $ 2,310,103 $ 2,166,289 $ 32,903 $ 12,852 $ 2,186,340
Available for Sale Securities Unrealized Losses	The details for securities classified as available for sale with unrealized losses for the periods indicated follow. June 30, 2015 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US Treasury and government agency securities $ 98,469 $ 1,538 $ 95 $ 1 $ 98,564 $ 1,539 Municipal obligations 2,975 25 — — 2,975 25 Mortgage-backed securities 678,428 6,944 117,793 2,912 796,221 9,856 Collateralized mortgage obligations 99,688 628 36,440 843 136,128 1,471 Equity securities 1,518 23 2 1 1,520 24 $ 881,078 $ 9,158 $ 154,330 $ 3,757 $ 1,035,408 $ 12,915 December 31, 2014 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US 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 Collateralized mortgage obligations — — 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
Held to Maturity with Unrealized Losses	The details for securities classified as held to maturity with unrealized losses for the periods indicated follow. June 30, 2015 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross US Treasury and government agency securities $ 149,230 $ 770 $ — $ — $ 149,230 $ 770 Municipal obligations 21,058 379 48,219 1,455 69,277 1,834 Mortgage-backed securities 169,049 150 — — 169,049 150 Collateralized mortgage obligations 134,704 391 456,865 8,769 591,569 9,160 $ 474,041 $ 1,690 $ 505,084 $ 10,224 $ 979,125 $ 11,914 December 31, 2014 Losses < 12 months Losses 12 months or > Total (in thousands) Fair Value Gross Fair Value Gross Fair Value Gross Municipal obligations $ 4,316 $ 12 $ 58,105 $ 1,132 $ 62,421 $ 1,144 Mortgage-backed securities — — 95,522 162 95,522 162 Collateralized mortgage obligations 119,222 616 540,607 10,930 659,829 11,546 $ 123,538 $ 628 $ 694,234 $ 12,224 $ 817,772 $ 12,852
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 June 30, 2015 by contractual maturity. Actual maturities will differ from contractual maturities because of rights to call or repay obligations with or without penalties and scheduled and unscheduled principal payments on mortgage-backed securities and collateralized mortgage obligations. (in thousands) Amortized Fair Value Debt Securities Available for Sale Due in one year or less $ 140,435 $ 138,065 Due after one year through five years 84,499 85,910 Due after five years through ten years 262,769 270,342 Due after ten years 1,646,642 1,654,006 Total available for sale debt securities $ 2,134,345 $ 2,148,323
Held to Maturity Securities Transferred from AFS [Member]
Amortized Cost and Fair Value of Available for Sale Securities by Final Contractual Maturity	Amortized Fair Value Debt Securities Held to Maturity Due in one year or less $ 463,052 $ 462,421 Due after one year through five years 326,452 322,348 Due after five years through ten years 112,736 111,390 Due after ten years 1,392,078 1,413,944 Total held to maturity securities $ 2,294,318 $ 2,310,103

Loans and Allowance for Loan 25

Loans and Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2015
Loans, Net of Unearned Income	Loans, net of unearned income, consisted of the following. (in thousands) June 30, 2015 December 31, Originated loans: Commercial non-real estate $ 6,058,998 $ 5,917,728 Construction and land development 1,100,788 1,073,964 Commercial real estate 2,591,384 2,428,195 Residential mortgages 1,784,730 1,704,770 Consumer 1,854,591 1,685,542 Total originated loans $ 13,390,491 $ 12,810,199 Acquired loans: Commercial non-real estate $ 120,020 $ 120,137 Construction and land development 9,064 21,123 Commercial real estate 598,962 688,045 Residential mortgages 1,554 2,378 Consumer 24 985 Total acquired loans $ 729,624 $ 832,668 FDIC acquired loans: Commercial non-real estate $ 6,666 $ 6,195 Construction and land development 11,095 11,674 Commercial real estate 22,487 27,808 Residential mortgages 169,553 187,033 Consumer 14,836 19,699 Total FDIC acquired loans $ 224,637 $ 252,409 Total loans: Commercial non-real estate $ 6,185,684 $ 6,044,060 Construction and land development 1,120,947 1,106,761 Commercial real estate 3,212,833 3,144,048 Residential mortgages 1,955,837 1,894,181 Consumer 1,869,451 1,706,226 Total loans $ 14,344,752 $ 13,895,276 Loans, net of unearned income, consisted of the following. (in thousands) June 30, 2015 December 31, Originated loans: Commercial non-real estate $ 6,058,998 $ 5,917,728 Construction and land development 1,100,788 1,073,964 Commercial real estate 2,591,384 2,428,195 Residential mortgages 1,784,730 1,704,770 Consumer 1,854,591 1,685,542 Total originated loans $ 13,390,491 $ 12,810,199 Acquired loans: Commercial non-real estate $ 120,020 $ 120,137 Construction and land development 9,064 21,123 Commercial real estate 598,962 688,045 Residential mortgages 1,554 2,378 Consumer 24 985 Total acquired loans $ 729,624 $ 832,668 FDIC acquired loans: Commercial non-real estate $ 6,666 $ 6,195 Construction and land development 11,095 11,674 Commercial real estate 22,487 27,808 Residential mortgages 169,553 187,033 Consumer 14,836 19,699 Total FDIC acquired loans $ 224,637 $ 252,409 Total loans: Commercial non-real estate $ 6,185,684 $ 6,044,060 Construction and land development 1,120,947 1,106,761 Commercial real estate 3,212,833 3,144,048 Residential mortgages 1,955,837 1,894,181 Consumer 1,869,451 1,706,226 Total loans $ 14,344,752 $ 13,895,276
Schedule of Activity in Loss Share Receivable	The following schedule shows activity in the loss share receivable for the six months ended June 30, 2015 and 2014. Six Months Ended (in thousands) June 30, June 30, Balance, January 1 $ 60,272 $ 113,834 Amortization (2,470 ) (7,229 ) Charge-offs, write-downs and other recoveries (4,667 ) (1,048 ) External expenses qualifying under loss share agreement 482 2,841 Changes due to changes in cash flow projections (2,536 ) (7,875 ) Settlement of disallowed loss claims (1,854 ) (10,268 ) Net payments from FDIC (14,153 ) — Ending balance $ 35,074 $ 90,255
Allowance for Loan Losses by Portfolio Segment and Related Recorded Investment in Loans	The following schedule shows activity in the allowance for loan losses by portfolio segment for the six months ended June 30, 2015 and 2014 as well as the corresponding recorded investment in loans at the end of each period. (in thousands) Commercial non-real estate Construction Commercial Residential Consumer Total Six Months Ended June 30, 2015 Originated loans Allowance for loan losses: Beginning balance $ 50,258 $ 5,413 $ 16,544 $ 8,051 $ 17,435 $ 97,701 Charge-offs (2,215 ) (828 ) (525 ) (1,292 ) (6,729 ) (11,589 ) Recoveries 2,051 1,308 426 449 2,491 6,725 Net provision for loan losses 9,586 (982 ) 1,217 62 4,091 13,974 Ending balance $ 59,680 $ 4,911 $ 17,662 $ 7,270 $ 17,288 $ 106,811 Ending balance: Individually evaluated for impairment $ 2,903 $ 73 $ 2,203 $ 163 $ 6 $ 5,348 Collectively evaluated for impairment 56,777 4,838 15,459 7,107 17,282 101,463 Loans: Ending balance: $ 6,058,998 $ 1,100,788 $ 2,591,384 $ 1,784,730 $ 1,854,591 $ 13,390,491 Individually evaluated for impairment 32,379 4,360 31,840 1,369 116 70,064 Collectively evaluated for impairment 6,026,619 1,096,428 2,559,544 1,783,361 1,854,475 13,320,427 Acquired loans Allowance for loan losses: Beginning balance $ — $ — $ 477 $ — $ — $ 477 Charge-offs — — — — — — Recoveries — — — — — — Net provision for loan losses — — (263 ) — — (263 ) Ending balance $ — $ — $ 214 $ — $ — $ 214 Ending balance: Individually evaluated for impairment $ — $ — $ 214 $ — $ — $ 214 Amounts related to acquired-impaired loans — — — — — — Collectively evaluated for impairment — — — — — — Loans: Ending balance: $ 120,020 $ 9,064 $ 598,962 $ 1,554 $ 24 $ 729,624 Individually evaluated for impairment — — 2,543 — — 2,543 Acquired-impaired loans 7,001 8,370 17,851 1,554 24 34,800 Collectively evaluated for impairment 113,019 694 578,568 — — 692,281 (in thousands) Commercial non-real estate Construction Commercial Residential Consumer Total Six Months Ended June 30, 2015 FDIC acquired loans Allowance for loan losses: Beginning balance $ 911 $ 1,008 $ 4,061 $ 20,609 $ 3,995 $ 30,584 Charge-offs (1,099 ) (285 ) (2,368 ) (168 ) (140 ) (4,060 ) Recoveries 14 406 465 2 136 1,023 Net provision for loan losses 242 (211 ) (78 ) (682 ) (220 ) (949 ) Increase (decrease) in FDIC loss share receivable 575 (528 ) 532 (2,342 ) (773 ) (2,536 ) Ending balance $ 643 $ 390 $ 2,612 $ 17,419 $ 2,998 $ 24,062 Ending balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — Amounts related to acquired-impaired loans 643 390 2,612 17,419 2,998 24,062 Collectively evaluated for impairment — — — — — — Loans: Ending balance: $ 6,666 $ 11,095 $ 22,487 $ 169,553 $ 14,836 $ 224,637 Individually evaluated for impairment — — — — — — Acquired-impaired loans 6,666 11,095 22,487 169,553 14,836 224,637 Collectively evaluated for impairment — — — — — — Total loans Allowance for loan losses: Beginning balance $ 51,169 $ 6,421 $ 21,082 $ 28,660 $ 21,430 $ 128,762 Charge-offs (3,314 ) (1,113 ) (2,893 ) (1,460 ) (6,869 ) (15,649 ) Recoveries 2,065 1,714 891 451 2,627 7,748 Net provision for loan losses 9,828 (1,193 ) 876 (620 ) 3,871 12,762 Increase (decrease) in FDIC loss share receivable 575 (528 ) 532 (2,342 ) (773 ) (2,536 ) Ending balance $ 60,323 $ 5,301 $ 20,488 $ 24,689 $ 20,286 $ 131,087 Ending balance: Individually evaluated for impairment $ 2,903 $ 73 $ 2,417 $ 163 $ 6 $ 5,562 Amounts related to acquired-impaired loans 643 390 2,612 17,419 2,998 24,062 Collectively evaluated for impairment 56,777 4,838 15,459 7,107 17,282 101,463 Loans: Ending balance: $ 6,185,684 $ 1,120,947 $ 3,212,833 $ 1,955,837 $ 1,869,451 $ 14,344,752 Individually evaluated for impairment 32,379 4,360 34,383 1,369 116 72,607 Acquired-impaired loans 13,667 19,465 40,338 171,107 14,860 259,437 Collectively evaluated for impairment 6,139,638 1,097,122 3,138,112 1,783,361 1,854,475 14,012,708 Commercial non-real estate Construction Commercial Residential Consumer Total (In thousands) Six Months Ended June 30, 2014 Originated loans Allowance for loan losses: Beginning balance $ 33,091 $ 6,180 $ 20,649 $ 6,892 $ 12,073 $ 78,885 Charge-offs (3,658 ) (1,041 ) (1,373 ) (1,097 ) (7,622 ) (14,791 ) Recoveries 1,411 1,064 1,057 363 2,854 6,749 Net provision for loan losses 5,937 699 (5,060 ) 772 5,381 7,729 Ending balance $ 36,781 $ 6,902 $ 15,273 $ 6,930 $ 12,686 $ 78,572 Ending balance: Individually evaluated for impairment $ 640 $ 259 $ 116 $ 532 $ — $ 1,547 Collectively evaluated for impairment 36,141 6,643 15,157 6,398 12,686 77,025 Loans: Ending balance: $ 4,610,696 $ 903,610 $ 2,173,006 $ 1,469,977 $ 1,501,163 $ 10,658,452 Individually evaluated for impairment 6,765 6,702 11,198 2,532 — 27,197 Collectively evaluated for impairment 4,603,931 896,908 2,161,808 1,467,445 1,501,163 10,631,255 Acquired loans Allowance for loan losses: Beginning balance $ 1,603 $ 10 $ 34 $ — $ — $ 1,647 Charge-offs — — — — — — Recoveries — — — — — — Net provision for loan losses 6,135 210 630 14 311 7,300 Ending balance $ 7,738 $ 220 $ 664 $ 14 $ 311 $ 8,947 Ending balance: Individually evaluated for impairment $ 65 $ 24 $ 188 $ — $ — $ 277 Amounts related to acquired-impaired loans — — — — — — Collectively evaluated for impairment 7,673 196 476 14 311 8,670 Loans: Ending balance: $ 769,159 $ 119,847 $ 836,646 $ 111,724 $ 84,403 $ 1,921,779 Individually evaluated for impairment 1,957 739 2,280 — — 4,976 Acquired-impaired loans 17,410 18,976 27,993 4,547 1,057 69,983 Collectively evaluated for impairment 749,792 100,132 806,373 107,177 83,346 1,846,820 Commercial non-real estate Construction Commercial Residential Consumer Total (In thousands) Six Months Ended June 30, 2014 FDIC acquired loans Allowance for loan losses: Beginning balance $ 2,323 $ 2,655 $ 10,929 $ 27,989 $ 9,198 $ 53,094 Charge-offs (70 ) (624 ) (4,022 ) (730 ) (1,130 ) (6,576 ) Recoveries 451 896 1,371 19 148 2,885 Net provision for loan losses (57 ) (73 ) 30 (173 ) (102 ) (375 ) (Decrease) increase in FDIC loss share receivable (1,099 ) (1,302 ) 225 (3,442 ) (2,257 ) (7,875 ) Ending balance $ 1,548 $ 1,552 $ 8,533 $ 23,663 $ 5,857 $ 41,153 Ending balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — Amounts related to acquired-impaired loans 1,548 1,552 8,533 23,663 5,857 41,153 Collectively evaluated for impairment — — — — — — Loans: Ending balance: $ 13,836 $ 17,199 $ 46,611 $ 189,570 $ 36,609 $ 303,825 Individually evaluated for impairment — — — — — — Acquired-impaired loans 13,836 17,199 46,611 189,570 36,609 303,825 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 (3,728 ) (1,665 ) (5,395 ) (1,827 ) (8,752 ) (21,367 ) Recoveries 1,862 1,960 2,428 382 3,002 9,634 Net provision for loan losses 12,015 836 (4,400 ) 613 5,590 14,654 (Decrease) increase in FDIC loss share receivable (1,099 ) (1,302 ) 225 (3,442 ) (2,257 ) (7,875 ) Ending balance $ 46,067 $ 8,674 $ 24,470 $ 30,607 $ 18,854 $ 128,672 Ending balance: Individually evaluated for impairment $ 705 $ 283 $ 304 $ 532 $ — $ 1,824 Amounts related to acquired-impaired loans 1,548 1,552 8,533 23,663 5,857 41,153 Collectively evaluated for impairment 43,814 6,839 15,633 6,412 12,997 85,695 Loans: Ending balance: $ 5,393,691 $ 1,040,656 $ 3,056,263 $ 1,771,271 $ 1,622,175 $ 12,884,056 Individually evaluated for impairment 8,722 7,441 13,478 2,532 — 32,173 Acquired-impaired loans 31,246 36,175 74,604 194,117 37,666 373,808 Collectively evaluated for impairment 5,353,723 997,040 2,968,181 1,574,622 1,584,509 12,478,075
Summary of Composition of Non-Accrual Loans by Portfolio Segment	The following table shows the composition of nonaccrual loans by portfolio segment and class. Acquired-impaired and certain FDIC acquired 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) June 30, December 31, Originated loans: Commercial non-real estate $ 42,454 $ 15,511 Construction and land development 5,285 6,462 Commercial real estate 38,152 22,047 Residential mortgages 20,709 21,702 Consumer 4,855 5,574 Total originated loans $ 111,455 $ 71,296 Acquired loans: Commercial non-real estate $ — $ — Construction and land development — — Commercial real estate 5,401 6,139 Residential mortgages — — Consumer — — Total acquired loans $ 5,401 $ 6,139 FDIC acquired loans: Commercial non-real estate $ — $ — Construction and land development 1,156 1,103 Commercial real estate 433 433 Residential mortgages — 392 Consumer — 174 Total FDIC acquired loans $ 1,589 $ 2,102 Total loans: Commercial non-real estate $ 42,454 $ 15,511 Construction and land development 6,441 7,565 Commercial real estate 43,986 28,619 Residential mortgages 20,709 22,094 Consumer 4,855 5,748 Total loans $ 118,445 $ 79,537
Schedule of Troubled Debt Restructurings Occurred During Period by Portfolio Segment	The table below details TDRs that were modified during the six months ended June 30, 2015 and June 30, 2014 by portfolio segment. Six Months Ended (in thousands) June 30, 2015 June 30, 2014 Troubled Debt Restructurings: Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification Originated loans: Commercial non-real estate — $ — $ — — $ — $ — Construction and land development — — — — — — Commercial real estate 1 482 482 1 963 918 Residential mortgages 2 68 68 2 773 507 Consumer 1 20 20 — — — Total originated loans 4 $ 570 $ 570 3 $ 1,736 $ 1,425 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 — $ — $ — — $ — $ — Construction and land development — — — — — — Commercial real estate 1 482 482 1 963 918 Residential mortgages 2 68 68 2 773 507 Consumer 1 20 20 — — — Total loans 4 $ 570 $ 570 3 $ 1,736 $ 1,425
Summary of Impaired Loans Disaggregated by Class	The tables below present loans that are individually evaluated for impairment disaggregated by class at June 30, 2015 and December 31, 2014. June 30, 2015 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) Originated loans: With no related allowance recorded: Commercial non-real estate $ 12,192 $ 12,696 $ — $ 8,861 $ — Construction and land development 57 57 — 1,295 — Commercial real estate 12,001 14,005 — 10,376 20 Residential mortgages — — — 345 2 Consumer 98 98 — 66 — 24,348 26,856 — 20,943 22 With an allowance recorded: Commercial non-real estate $ 20,187 $ 20,949 $ 2,903 $ 8,116 3 Construction and land development 4,303 6,522 73 4,369 59 Commercial real estate 19,839 19,840 2,203 10,014 44 Residential mortgages 1,369 1,880 163 1,804 18 Consumer 18 18 6 15 3 45,716 49,209 5,348 24,318 127 Total: Commercial non-real estate 32,379 33,645 2,903 $ 16,977 3 Construction and land development 4,360 6,579 73 5,664 59 Commercial real estate 31,840 33,845 2,203 20,390 64 Residential mortgages 1,369 1,880 163 2,149 20 Consumer 116 116 6 81 3 Total originated loans $ 70,064 $ 76,065 $ 5,348 $ 45,261 $ 149 Acquired loans: With no related allowance recorded: Commercial non-real estate $ — $ — $ — $ — $ — Construction and land development — — — — — Commercial real estate — — — — — Residential mortgages — — — — — Consumer — — — — — — — — — — With an allowance recorded: Commercial non-real estate — — — $ — — Construction and land development — — — — — Commercial real estate 2,543 2,563 214 2,604 — Residential mortgages — — — — — Consumer — — — — — 2,543 2,563 214 2,604 — Total: Commercial non-real estate — — — $ — — Construction and land development — — — — — Commercial real estate 2,543 2,563 214 2,604 — Residential mortgages — — — — — Consumer — — — — — Total acquired loans $ 2,543 $ 2,563 $ 214 $ 2,604 $ — June 30, 2015 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) Total loans: With no related allowance recorded: Commercial non-real estate $ 12,192 $ 12,696 $ — $ 8,861 $ — Construction and land development 57 57 — 1,295 — Commercial real estate 12,001 14,005 — 10,376 20 Residential mortgages — — — 345 2 Consumer 98 98 — 66 — 24,348 26,856 — 20,943 22 With an allowance recorded: Commercial non-real estate 20,187 20,949 2,903 $ 8,116 3 Construction and land development 4,303 6,522 73 4,369 59 Commercial real estate 22,382 22,403 2,417 12,618 44 Residential mortgages 1,369 1,880 163 1,804 18 Consumer 18 18 6 15 3 48,259 51,772 5,562 26,922 127 Total: Commercial non-real estate 32,379 33,645 2,903 $ 16,977 3 Construction and land development 4,360 6,579 73 5,664 59 Commercial real estate 34,383 36,408 2,417 22,995 64 Residential mortgages 1,369 1,880 163 2,149 20 Consumer 116 116 6 81 3 Total loans $ 72,607 $ 78,628 $ 5,562 $ 47,866 $ 149 December 31, 2014 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) 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 December 31, 2014 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized (in thousands) 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
Summary of Age Analysis of Past Due Loans	The tables below present the age analysis of past due loans at June 30, 2015 and December 31, 2014. June 30, 2015 30-59 days 60-89 days Greater than past due Total Current Total Loans Recorded (in thousands) Originated loans: Commercial non-real estate $ 5,215 $ 3,090 $ 10,250 $ 18,555 $ 6,040,443 $ 6,058,998 $ 826 Construction and land development 2,411 2,128 4,278 8,817 1,091,971 1,100,788 80 Commercial real estate 3,180 1,450 14,267 18,897 2,572,487 2,591,384 279 Residential mortgages 1,094 3,493 8,227 12,814 1,771,916 1,784,730 946 Consumer 10,414 3,286 3,228 16,928 1,837,663 1,854,591 1,347 Total $ 22,314 $ 13,447 $ 40,250 $ 76,011 $ 13,314,480 $ 13,390,491 $ 3,478 Acquired loans: Commercial non-real estate $ — $ — $ — $ — $ 120,020 $ 120,020 $ — Construction and land development — — — — 9,064 9,064 — Commercial real estate 1,954 138 2,032 4,124 594,838 598,962 — Residential mortgages — — — — 1,554 1,554 — Consumer — — — — 24 24 — Total $ 1,954 $ 138 $ 2,032 $ 4,124 $ 725,500 $ 729,624 $ — FDIC acquired loans: Commercial non-real estate $ — $ — $ — $ — $ 6,666 $ 6,666 $ — Construction and land development — — 1,156 1,156 9,939 11,095 — Commercial real estate — — 433 433 22,054 22,487 — Residential mortgages — — — — 169,553 169,553 — Consumer — — — — 14,836 14,836 — Total $ — $ — $ 1,589 $ 1,589 $ 223,048 $ 224,637 $ — Total loans: Commercial non-real estate $ 5,215 $ 3,090 $ 10,250 $ 18,555 $ 6,167,129 $ 6,185,684 $ 826 Construction and land development 2,411 2,128 5,434 9,973 1,110,974 1,120,947 80 Commercial real estate 5,134 1,588 16,732 23,454 3,189,379 3,212,833 279 Residential mortgages 1,094 3,493 8,227 12,814 1,943,023 1,955,837 946 Consumer 10,414 3,286 3,228 16,928 1,852,523 1,869,451 1,347 Total $ 24,268 $ 13,585 $ 43,871 $ 81,724 $ 14,263,028 $ 14,344,752 $ 3,478 December 31, 2014 30-59 days 60-89 days Greater than past due Total past due Current Total Loans Recorded (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
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 six months ended June 30, 2015 and the year ended December 31, 2014. (in thousands) June 30, 2015 December 31, 2014 FDIC acquired Acquired FDIC acquired Acquired Carrying Accretable Carrying Accretable Carrying Accretable Carrying Accretable Balance at beginning of period $ 252,409 $ 112,788 $ 61,276 $ 74,668 $ 358,666 $ 122,715 $ 68,075 $ 131,370 Payments received, net (34,649 ) (359 ) (35,640 ) (12,284 ) (125,388 ) (1,071 ) (50,178 ) (32,855 ) Accretion 6,877 (6,877 ) 9,163 (9,163 ) 19,131 (19,131 ) 43,379 (43,379 ) (Decrease) in expected cash flows based on actual cash flows and changes in cash flow assumptions — (3,918 ) — (219 ) — (1,137 ) — (203 ) Net transfers from nonaccretable difference to accretable yield — (2,878 ) — (2,104 ) — 11,412 — 19,735 Balance at end of period $ 224,637 $ 98,756 $ 34,799 $ 50,898 $ 252,409 $ 112,788 $ 61,276 $ 74,668
Commercial Non-Real Estate [Member]
Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile by Internally Assigned Grade	The following tables present the credit quality indicators of the Company’s various classes of loans at June 30, 2015 and December 31, 2014. Commercial Non-Real Estate Credit Exposure Credit Risk Profile by Internally Assigned Grade (in thousands) June 30, 2015 December 31, 2014 Originated Acquired FDIC acquired Total Originated Acquired FDIC acquired Total Grade: Pass $ 5,522,236 $ 113,200 $ 2,648 $ 5,638,084 $ 5,577,827 $ 111,847 $ 2,027 $ 5,691,701 Pass-Watch 142,837 101 988 143,926 174,742 715 1,120 176,577 Special Mention 209,716 282 — 209,998 52,962 350 — 53,312 Substandard 184,178 6,437 3,001 193,616 112,153 7,225 3,017 122,395 Doubtful 31 — 29 60 44 — 31 75 Total $ 6,058,998 $ 120,020 $ 6,666 $ 6,185,684 $ 5,917,728 $ 120,137 $ 6,195 $ 6,044,060
Construction and Land Development [Member]
Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile by Internally Assigned Grade	Construction Credit Exposure Credit Risk Profile by Internally Assigned Grade (in thousands) June 30, 2015 December 31, 2014 Originated Acquired FDIC acquired Total Originated Acquired FDIC acquired Total Grade: Pass $ 1,048,380 $ 1,743 $ 2,789 $ 1,052,912 $ 1,012,128 $ 14,377 $ 2,468 $ 1,028,973 Pass-Watch 7,471 2,275 519 10,265 21,516 432 532 22,480 Special Mention 4,920 — 313 5,233 7,097 129 319 7,545 Substandard 40,017 5,046 7,474 52,537 33,223 6,185 8,355 47,763 Total $ 1,100,788 $ 9,064 $ 11,095 $ 1,120,947 $ 1,073,964 $ 21,123 $ 11,674 $ 1,106,761
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 (in thousands) June 30, 2015 December 31, 2014 Originated Acquired FDIC acquired Total Originated Acquired FDIC acquired Total Grade: Pass $ 2,430,696 $ 565,820 $ 5,017 $ 3,001,533 $ 2,241,391 $ 641,966 $ 4,139 $ 2,887,496 Pass-Watch 33,185 10,974 2,807 46,966 61,589 11,142 4,547 77,278 Special Mention 25,974 5,798 1,609 33,381 21,543 8,113 1,319 30,975 Substandard 101,512 16,370 13,054 130,936 103,651 26,824 17,803 148,278 Doubtful 17 — — 17 21 — — 21 Total $ 2,591,384 $ 598,962 $ 22,487 $ 3,212,833 $ 2,428,195 $ 688,045 $ 27,808 $ 3,144,048
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 (in thousands) June 30, 2015 December 31, 2014 Originated Acquired FDIC acquired Total Originated Acquired FDIC acquired Total Performing $ 1,763,075 $ 1,554 $ 169,553 $ 1,934,182 $ 1,681,868 $ 2,378 $ 186,641 $ 1,870,887 Nonperforming 21,655 — — 21,655 22,902 — 392 23,294 Total $ 1,784,730 $ 1,554 $ 169,553 $ 1,955,837 $ 1,704,770 $ 2,378 $ 187,033 $ 1,894,181
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 (in thousands) June 30, 2015 December 31, 2014 Originated Acquired FDIC acquired Total Originated Acquired FDIC acquired Total Performing $ 1,848,389 $ 24 $ 14,836 $ 1,863,249 $ 1,678,069 $ 985 $ 19,525 $ 1,698,579 Nonperforming 6,202 — — 6,202 7,473 — 174 7,647 Total $ 1,854,591 $ 24 $ 14,836 $ 1,869,451 $ 1,685,542 $ 985 $ 19,699 $ 1,706,226
Troubled Debt Restructurings That Subsequently Defaulted [Member]
Schedule of Troubled Debt Restructurings Occurred During Period by Portfolio Segment	The table below details TDRs that subsequently defaulted within twelve months of modification. Six Months Ended (in thousands) June 30, 2015 June 30, 2014 Troubled Debt Restructurings: Number of Recorded Number of Recorded Originated loans: Commercial non-real estate — $ — 1 $ 909 Construction and land development — — — — Commercial real estate — — 2 1,025 Residential mortgages — — — — Consumer — — — — Total originated loans — $ — 3 $ 1,934 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 — — 2 1,025 Residential mortgages — — — — Consumer — — — — Total loans — $ — 3 $ 1,934

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Long-Term Debt	Long-term debt consisted of the following. June 30, December 31, (in thousands) 2015 2014 Subordinated notes payable, maturing June 2045 $ 150,000 $ — Subordinated notes payable, maturing April 2017 98,011 98,011 Term note payable, maturing December 2015 132,000 149,600 Other long-term debt 127,330 126,760 Total long-term debt $ 507,341 $ 374,371

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables present for each of the fair value hierarchy levels the Company’s assets and liabilities that are measured at fair value on a recurring basis in the consolidated balance sheets. June 30, 2015 (in thousands) Level 1 Level 2 Total Assets Available for sale debt securities: U.S. Treasury and government agency securities $ — $ 98,621 $ 98,621 Municipal obligations — 12,875 12,875 Corporate debt securities — 3,500 3,500 Mortgage-backed securities — 1,818,539 1,818,539 Collateralized mortgage obligations — 214,788 214,788 Equity securities 2,811 — 2,811 Total available for sale securities 2,811 2,148,323 2,151,134 Derivative assets (1) — 24,096 24,096 Total recurring fair value measurements - assets $ 2,811 $ 2,172,419 $ 2,175,230 Liabilities Derivative liabilities (1) $ — $ 22,157 $ 22,157 Total recurring fair value measurements - liabilities $ — $ 22,157 $ 22,157 (1) For further disaggregation of derivative assets and liabilities, see Note 7 - Derivatives. 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 7 - Derivatives.
Schedule of Financial Assets Measured at Fair Value on Nonrecurring Basis	The following tables present the Company’s financial assets that are measured at fair value on a nonrecurring basis for each of the fair value hierarchy levels. June 30, 2015 (in thousands) Level 1 Level 2 Level 3 Total Collateral-dependent impaired loans $ — $ 60,165 $ — $ 60,165 Other real estate owned — — 21,289 21,289 Total nonrecurring fair value measurements $ — $ 60,165 $ 21,289 $ 81,484 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
Schedule of Estimated Fair Values of Financial Instruments	The following tables present the estimated fair values of the Company’s financial instruments by fair value hierarchy levels and the corresponding carrying amount at June 30, 2015 and December 31, 2014. June 30, 2015 Total Carrying (in thousands) Level 1 Level 2 Level 3 Fair Value Amount Financial assets: Cash, interest-bearing bank deposits, and federal funds sold $ 928,063 $ — $ — $ 928,063 $ 928,063 Available for sale securities 2,811 2,148,323 — 2,151,134 2,151,134 Held to maturity securities — 2,310,103 — 2,310,103 2,294,318 Loans, net — 60,165 14,133,549 14,193,714 14,213,665 Loans held for sale — 21,304 — 21,304 21,304 Derivative financial instruments — 24,096 — 24,096 24,096 Financial liabilities: Deposits $ — $ — $ 17,282,802 $ 17,282,802 $ 17,301,788 Federal funds purchased 12,850 — — 12,850 12,850 Securities sold under agreements to repurchase 466,343 — — 466,343 466,343 FHLB borrowings 600,000 — — 600,000 600,000 Long-term debt — 511,424 — 511,424 507,341 Derivative financial instruments — 22,157 — 22,157 22,157 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 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 Derivative financial instruments — 20,860 — 20,860 20,860

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2015
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 June 30, 2015 and December 31, 2014. Fair Values (1) Notional Amounts Assets Liabilities (in thousands) Type of June 30, December 31, June 30, December 31, June 30, December 31, Derivatives designated as hedging instruments: Interest rate swaps Cash Flow $ 500,000 $ 300,000 $ 413 $ — $ — $ 592 $ 500,000 $ 300,000 $ 413 $ — $ — $ 592 Derivatives not designated as hedging instruments: Interest rate swaps (2) N/A $ 731,843 $ 747,754 $ 17,916 $ 17,806 $ 18,170 $ 18,419 Risk participation agreements N/A 87,901 80,438 82 125 168 208 Forward commitments to sell residential mortgage loans N/A 67,942 52,238 2,069 80 215 250 Interest rate-lock commitments on residential mortgage loans N/A 46,184 33,068 143 111 157 44 Foreign exchange forward contracts N/A 68,361 89,432 3,473 1,310 3,447 1,347 $ 1,002,231 $ 1,002,930 $ 23,683 $ 19,432 $ 22,157 $ 20,268 (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 June 30, 2015 and December 31, 2014 is presented in the following tables. Gross Net Amounts Gross Amounts Not Offset in the Statement (in thousands) Gross the the Financial Cash Net Amount As of June 30, 2015 Derivative Assets $ 17,998 $ — $ 17,998 $ 474 $ — $ 17,524 Total $ 17,998 $ — $ 17,998 $ 474 $ — $ 17,524 Derivative Liabilities $ 18,338 $ — $ 18,338 $ 474 $ 20,121 $ (2,257 ) Total $ 18,338 $ — $ 18,338 $ 474 $ 20,121 $ (2,257 ) Gross Net Amounts Gross Amounts Not Offset in the Statement Description Gross Statement of Statement of Financial Cash Net Amount As of December 31, 2014 Derivative Assets $ 17,931 $ — $ 17,931 $ 936 $ — $ 16,995 Total $ 17,931 $ — $ 17,931 $ 936 $ — $ 16,995 Derivative Liabilities $ 18,627 $ — $ 18,627 $ 936 $ 17,343 $ 348 Total $ 18,627 $ — $ 18,627 $ 936 $ 17,343 $ 348

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Components of Accumulated Other Comprehensive Income (Loss)	The components of AOCI and changes in those components are presented in the following table. (in thousands) Available HTM Securities Employee Loss on Total Balance, December 31, 2013 $ 8,263 $ (21,189 ) $ (22,453 ) $ — $ (35,379 ) Other comprehensive income before income taxes: Net change in unrealized gain 15,412 — — — 15,412 Reclassification of net losses realized and included in earnings — — 195 — 195 Valuation adjustment for employee benefit plans — — 2,006 — 2,006 Amortization of unrealized net loss on securities transferred to HTM — 1,571 — — 1,571 Income tax expense 5,637 554 905 — 7,096 Balance, June 30, 2014 $ 18,038 $ (20,172 ) $ (21,157 ) $ — $ (23,291 ) Balance, December 31, 2014 $ 18,001 $ (19,074 ) $ (48,626 ) $ (375 ) $ (50,074 ) Other comprehensive income before income taxes: Net change in unrealized (loss) gain (13,962 ) — — 1,005 (12,957 ) Reclassification of net (gain) losses realized and included in earnings (165 ) — 1,571 — 1,406 Valuation adjustment for employee benefit plans — — (5,922 ) (5,922 ) Amortization of unrealized net loss on securities transferred to HTM — 1,586 — — 1,586 Income tax (benefit) expense (5,249 ) 580 (1,574 ) 366 (5,877 ) Balance, June 30, 2015 $ 9,123 $ (18,068 ) $ (51,403 ) $ 264 $ (60,084 )
Summary of Line 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. Amount reclassified from AOCI (a) Six Months Ended Affected line item on (in thousands) 2015 2014 Gain on sale of AFS securities $ 165 $ — Securities gains (losses) Tax effect (58 ) — Income taxes Net of tax 107 — Net income Amortization of unrealized net loss on securities transferred to HTM $ (1,586 ) $ (1,571 ) Interest income Tax effect 580 554 Income taxes Net of tax (1,006 ) (1,017 ) Net income Amortization of defined benefit pension and post-retirement items (1,571 ) (195 ) Employee benefits expense (b) Tax effect 550 68 Income taxes Net of tax (1,021 ) (127 ) Net income Total reclassifications, net of tax $ (1,920 ) $ (1,144 ) Net income (a) Amounts in parenthesis indicate reduction in net income. (b) These accumulated other comprehensive income components are included in the computation of net periodic pension and post-retirement

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2015
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. Three Months Ended Six Months Ended (in thousands, except per share data) 2015 2014 2015 2014 Numerator: Net income to common shareholders $ 34,829 $ 39,962 $ 74,988 $ 89,077 Net income allocated to participating securities - basic and diluted 766 819 1,701 1,900 Net income allocated to common shareholders - basic and diluted $ 34,063 $ 39,143 $ 73,287 $ 87,177 Denominator: Weighted-average common shares - basic 77,951 81,933 78,719 82,099 Dilutive potential common shares 164 241 162 249 Weighted-average common shares - diluted 78,115 82,174 78,881 82,348 Earnings per common share: Basic $ 0.44 $ 0.48 $ 0.93 $ 1.06 Diluted $ 0.44 $ 0.48 $ 0.93 $ 1.06

Share-Based Payment Arrangeme31

Share-Based Payment Arrangements (Tables)	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Option Activity Under Stock Option Plans	A summary of option activity for the six months ended June 30, 2014 is presented below. Options Number of Weighted Weighted Aggregate Outstanding at January 1, 2015 933,750 $ 37.03 Exercised (11,577 ) 29.94 Cancelled/Forfeited (51,110 ) 35.43 Expired (109,147 ) 34.15 Outstanding at June 30, 2015 761,916 $ 37.65 4.1 $ 480 Exercisable at June 30, 2015 643,454 $ 39.01 3.7 $ 284
Schedule of Nonvested Restricted and Performance Shares	A summary of the status of the Company’s nonvested restricted and performance shares as of June 30, 2015 and changes during the six months ended June 30, 2015, is presented in the following table. Number of Weighted Nonvested at January 1, 2015 2,040,299 $ 32.27 Granted 97,906 27.28 Vested (235,987 ) 31.96 Forfeited (123,621 ) 32.74 Nonvested at June 30, 2015 1,778,597 $ 32.01

Retirement Plans (Tables)

Retirement Plans (Tables)	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Components of Net Periodic Benefits Cost	The following tables show the components of net periodic benefits cost included in expense for the plans for the periods indicated. (in thousands) Pension benefits Other Post- Three Months Ended June 30, 2015 2014 2015 2014 Service cost $ 3,382 $ 3,035 $ 22 $ 26 Interest cost 4,672 4,817 174 232 Expected return on plan assets (8,206 ) (8,050 ) — — Amortization of net loss 842 5 (40 ) 25 Net periodic benefit cost $ 690 $ (193 ) $ 156 $ 283 Six Months Ended June 30, Service cost $ 6,745 $ 6,460 72 $ 63 Interest cost 9,291 9,626 543 570 Expected return on plan assets (16,419 ) (16,111 ) — — Amortization of net loss 1,486 13 85 182 Net periodic benefit cost $ 1,103 $ (12 ) $ 700 $ 815

Other Noninterest Income (Table

Other Noninterest Income (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Components of Other Noninterest Income	Components of other noninterest income are as follows. Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2015 2014 2015 2014 Income from bank-owned life insurance $ 2,671 $ 2,357 $ 5,337 $ 4,671 Credit related fees 2,611 2,834 5,068 5,566 Income from derivatives 1,464 481 1,412 1,240 Net (loss) gain on sale of assets (62 ) (217 ) (55 ) 1,465 Safety deposit box income 429 443 915 956 Other miscellaneous 2,412 2,714 5,092 5,141 Total other noninterest income $ 9,525 $ 8,612 $ 17,769 $ 19,039

Other Noninterest Expense (Tabl

Other Noninterest Expense (Tables)	6 Months Ended
	Jun. 30, 2015
Text Block [Abstract]
Components of Other Noninterest Expense	Components of other noninterest expense are as follows. Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2015 2014 2015 2014 Advertising $ 2,133 $ 2,179 $ 4,298 $ 3,938 Ad valorem and franchise taxes 2,736 2,638 5,451 5,299 Printing and supplies 1,158 949 2,375 2,278 Insurance expense 928 1,018 1,850 2,058 Travel expense 1,308 1,061 2,527 1,957 Entertainment and contributions 1,736 1,529 3,375 2,941 Tax credit investment amortization 2,096 2,198 4,191 4,370 Other miscellaneous 10,211 13,736 13,045 18,284 Total other noninterest expense $ 22,306 $ 25,308 $ 37,112 $ 41,125

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value of Available for Sale Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	$ 2,136,856	$ 1,631,761
Securities available for sale, Gross Unrealized Gains	27,193	32,543
Securities available for sale, Gross Unrealized Losses	12,915	4,139
Securities Available for Sale, Fair Value	2,151,134	1,660,165
U.S. Treasury and Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	100,160	300,207
Securities available for sale, Gross Unrealized Gains		372
Securities available for sale, Gross Unrealized Losses	1,539	71
Securities Available for Sale, Fair Value	98,621	300,508
Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	12,723	13,995
Securities available for sale, Gross Unrealized Gains	177	186
Securities available for sale, Gross Unrealized Losses	25	5
Securities Available for Sale, Fair Value	12,875	14,176
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	2,511	8,673
Securities available for sale, Gross Unrealized Gains	324	891
Securities available for sale, Gross Unrealized Losses	24	11
Securities Available for Sale, Fair Value	2,811	9,553
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,802,249	1,217,293
Securities available for sale, Gross Unrealized Gains	26,146	31,094
Securities available for sale, Gross Unrealized Losses	9,856	2,823
Securities Available for Sale, Fair Value	1,818,539	1,245,564
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	215,713	88,093
Securities available for sale, Gross Unrealized Gains	546
Securities available for sale, Gross Unrealized Losses	1,471	1,229
Securities Available for Sale, Fair Value	$ 214,788	$ 86,864

Securities - Amortized Cost a36

Securities - Amortized Cost and Fair Value of Held to Maturity Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	$ 2,294,318	$ 2,166,289
Securities Held to Maturity, Gross Unrealized Gains	27,699	32,903
Securities Held to Maturity, Gross Unrealized Losses	11,914	12,852
Securities Held to Maturity, Fair Value	2,310,103	2,186,340
U.S. Treasury and Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	200,000
Securities Held to Maturity, Gross Unrealized Gains	55
Securities Held to Maturity, Gross Unrealized Losses	770
Securities Held to Maturity, Fair Value	199,285
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	186,528	180,615
Securities Held to Maturity, Gross Unrealized Gains	3,074	3,416
Securities Held to Maturity, Gross Unrealized Losses	1,834	1,144
Securities Held to Maturity, Fair Value	187,768	182,887
Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	898,638	899,923
Securities Held to Maturity, Gross Unrealized Gains	19,378	23,897
Securities Held to Maturity, Gross Unrealized Losses	150	162
Securities Held to Maturity, Fair Value	917,866	923,658
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities Held to Maturity, Amortized Cost	1,009,152	1,085,751
Securities Held to Maturity, Gross Unrealized Gains	5,192	5,590
Securities Held to Maturity, Gross Unrealized Losses	9,160	11,546
Securities Held to Maturity, Fair Value	$ 1,005,184	$ 1,079,795

Securities - Amortized Cost a37

Securities - Amortized Cost and Fair Value of Available for Sale Securities by Final Contractual Maturity (Detail) $ in Thousands	Jun. 30, 2015USD ($)
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	$ 140,435
Securities Available for Sale, Due after one year through five years, Amortized Cost	84,499
Securities Available for Sale, Due after five years through ten years, Amortized Cost	262,769
Securities Available for Sale, Due after ten years, Amortized Cost	1,646,642
Total available for sale securities, Amortized Cost	2,134,345
Securities Available for Sale, Due in one year or less, Fair Value	138,065
Securities Available for Sale, Due after one year through five years, Fair Value	85,910
Securities Available for Sale, Due after five years through ten years, Fair Value	270,342
Securities Available for Sale, Due after ten years, Fair Value	1,654,006
Available for sale debt securities	$ 2,148,323

Securities - Amortized Cost a38

Securities - Amortized Cost and Fair Value of Held to Maturity Securities by Final Contractual Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
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	$ 463,052
Securities Held to Maturity, Due after one year through five years, Amortized Cost	326,452
Securities Held to Maturity, Due after five years through ten years, Amortized Cost	112,736
Securities Held to Maturity, Due after ten years, Amortized Cost	1,392,078
Securities Held to Maturity, Amortized Cost	2,294,318	$ 2,166,289
Securities Held to Maturity, Due in one year or less, Fair Value	462,421
Securities Held to Maturity, Due after one year through five years, Fair Value	322,348
Securities Held to Maturity, Due after five years through ten years, Fair Value	111,390
Securities Held to Maturity, Due after ten years, Fair Value	1,413,944
Total Held to Maturity Securities, Fair Value	$ 2,310,103	$ 2,186,340

Securities - Available for Sale

Securities - Available for Sale Securities Unrealized Losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Unrealized Loss And Fair Value Available For Sale Securities [Line Items]
Available for sale securities, Losses less than 12 months, Fair Value	$ 881,078	$ 147,898
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	9,158	248
Available for sale securities, Losses 12 months or longer, Fair value	154,330	212,629
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	3,757	3,891
Available for sale securities, Total, Fair value	1,035,408	360,527
Available for sale securities, Total, Gross Unrealized Losses	12,915	4,139
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	1,518	5,998
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	23	10
Available for sale securities, Losses 12 months or longer, Fair value	2	3
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	1	1
Available for sale securities, Total, Fair value	1,520	6,001
Available for sale securities, Total, Gross Unrealized Losses	24	11
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	98,469	99,950
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	1,538	70
Available for sale securities, Losses 12 months or longer, Fair value	95	121
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	1	1
Available for sale securities, Total, Fair value	98,564	100,071
Available for sale securities, Total, Gross Unrealized Losses	1,539	71
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	2,975	2,995
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	25	5
Available for sale securities, Total, Fair value	2,975	2,995
Available for sale securities, Total, Gross Unrealized Losses	25	5
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	678,428	38,955
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	6,944	163
Available for sale securities, Losses 12 months or longer, Fair value	117,793	125,641
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	2,912	2,660
Available for sale securities, Total, Fair value	796,221	164,596
Available for sale securities, Total, Gross Unrealized Losses	9,856	2,823
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	99,688
Available for sale securities, Losses Less than 12 months, Gross Unrealized Losses	628
Available for sale securities, Losses 12 months or longer, Fair value	36,440	86,864
Available for sale securities, Losses 12 months or longer, Gross Unrealized Losses	843	1,229
Available for sale securities, Total, Fair value	136,128	86,864
Available for sale securities, Total, Gross Unrealized Losses	$ 1,471	$ 1,229

Securities - Held to Maturity w

Securities - Held to Maturity with Unrealized Losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	$ 474,041	$ 123,538
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	1,690	628
Held to maturity securities, Losses 12 months or longer, Fair value	505,084	694,234
Held to maturity securities, Losses 12 months or longer, Gross Unrealized Losses	10,224	12,224
Held to maturity securities, Total, Fair value	979,125	817,772
Held to maturity securities, Total, Gross Unrealized Losses	11,914	12,852
Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	169,049
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	150
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	169,049	95,522
Held to maturity securities, Total, Gross Unrealized Losses	150	162
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	134,704	119,222
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	391	616
Held to maturity securities, Losses 12 months or longer, Fair value	456,865	540,607
Held to maturity securities, Losses 12 months or longer, Gross Unrealized Losses	8,769	10,930
Held to maturity securities, Total, Fair value	591,569	659,829
Held to maturity securities, Total, Gross Unrealized Losses	9,160	11,546
U.S. Treasury and Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	149,230
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	770
Held to maturity securities, Total, Fair value	149,230
Held to maturity securities, Total, Gross Unrealized Losses	770
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity securities, Losses less than 12 months, Fair Value	21,058	4,316
Held to maturity securities, Losses Less than 12 months, Gross Unrealized Losses	379	12
Held to maturity securities, Losses 12 months or longer, Fair value	48,219	58,105
Held to maturity securities, Losses 12 months or longer, Gross Unrealized Losses	1,455	1,132
Held to maturity securities, Total, Fair value	69,277	62,421
Held to maturity securities, Total, Gross Unrealized Losses	$ 1,834	$ 1,144

Securities - Additional Informa

Securities - Additional Information (Detail) - USD ($) $ in Billions	Jun. 30, 2015	Dec. 31, 2014
Amortized Cost and Fair Value Debt Securities [Abstract]
Securities pledged to secure public deposits and securities sold under agreements to repurchase	$ 3.2	$ 3.2

Loans and Allowance for Loan 42

Loans and Allowance for Loan Losses - Loans, Net of Unearned Income (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Loans Receivable [Line Items]
Total FDIC acquired loans	$ 224,637	$ 252,409
Total loans	14,344,752	13,895,276
Commercial Non-Real Estate [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	6,666	6,195
Total loans	6,185,684	6,044,060
Construction and Land Development [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	11,095	11,674
Total loans	1,120,947	1,106,761
Commercial Real Estate [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	22,487	27,808
Total loans	3,212,833	3,144,048
Residential Mortgages [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	169,553	187,033
Total loans	1,955,837	1,894,181
Consumer [Member]
Loans Receivable [Line Items]
Total FDIC acquired loans	14,836	19,699
Total loans	1,869,451	1,706,226
Originated Loans [Member]
Loans Receivable [Line Items]
Total loans	13,390,491	12,810,199
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial non-real estate	6,058,998	5,917,728
Originated Loans [Member] | Construction and Land Development [Member]
Loans Receivable [Line Items]
Total Construction and land development	1,100,788	1,073,964
Originated Loans [Member] | Commercial Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial real estate	2,591,384	2,428,195
Originated Loans [Member] | Residential Mortgages [Member]
Loans Receivable [Line Items]
Total Residential mortgages	1,784,730	1,704,770
Originated Loans [Member] | Consumer [Member]
Loans Receivable [Line Items]
Total Consumer	1,854,591	1,685,542
Acquired Loans [Member]
Loans Receivable [Line Items]
Total loans	729,624	832,668
Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial non-real estate	120,020	120,137
Acquired Loans [Member] | Construction and Land Development [Member]
Loans Receivable [Line Items]
Total Construction and land development	9,064	21,123
Acquired Loans [Member] | Commercial Real Estate [Member]
Loans Receivable [Line Items]
Total Commercial real estate	598,962	688,045
Acquired Loans [Member] | Residential Mortgages [Member]
Loans Receivable [Line Items]
Total Residential mortgages	1,554	2,378
Acquired Loans [Member] | Consumer [Member]
Loans Receivable [Line Items]
Total Consumer	$ 24	$ 985

Loans and Allowance for Loan 43

Loans and Allowance for Loan Losses - Schedule of Activity in Loss Share Receivable (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Receivables [Abstract]
Beginning balance			$ 60,272	$ 113,834
Amortization	$ (1,273)	$ (3,321)	(2,470)	(7,229)
Charge-offs, write-downs and other recoveries			(4,667)	(1,048)
External expenses qualifying under loss share agreement			482	2,841
Changes due to changes in cash flow projections			(2,536)	(7,875)
Settlement of disallowed loss claims			(1,854)	(10,268)
Net payments from FDIC			(14,153)
Ending balance	$ 35,074	$ 90,255	$ 35,074	$ 90,255

Loans and Allowance for Loan 44

Loans and Allowance for Loan Losses - Allowance for Loan Losses by Portfolio Segment and Related Recorded Investment in Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance			$ 128,762
Ending balance: FDIC acquired loans	$ 224,637		224,637		$ 252,409
Ending balance: Loans	14,344,752		14,344,752		13,895,276
Net provision for loan losses	(6,608)	$ (6,691)	(12,762)	$ (14,654)
Increase (decrease) in FDIC loss share receivable			(2,536)	(7,875)
Loans and Leases receivable, Allowance, Ending Balance	131,087		131,087
Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance			128,762	133,626
Charge-offs			(15,649)	(21,367)
Recoveries			7,748	9,634
Net provision for loan losses			12,762	14,654
Increase (decrease) in FDIC loss share receivable			(2,536)	(7,875)
Loans and Leases receivable, Allowance, Ending Balance	131,087	128,672	131,087	128,672
Ending balance: Individually evaluated for impairment	5,562	1,824	5,562	1,824
Ending balance: Amounts related to acquired-impaired loans	24,062	41,153	24,062	41,153
Ending balance: Collectively evaluated for impairment	101,463	85,695	101,463	85,695
Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	14,344,752	12,884,056	14,344,752	12,884,056
Ending balance: Individually evaluated for impairment	72,607	32,173	72,607	32,173
Ending balance: Acquired-impaired loans	259,437	373,808	259,437	373,808
Ending balance: Collectively evaluated for impairment	14,012,708	12,478,075	14,012,708	12,478,075
Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	6,666		6,666		6,195
Ending balance: Loans	6,185,684		6,185,684		6,044,060
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			51,169	37,017
Charge-offs			(3,314)	(3,728)
Recoveries			2,065	1,862
Net provision for loan losses			9,828	12,015
Increase (decrease) in FDIC loss share receivable			575	(1,099)
Loans and Leases receivable, Allowance, Ending Balance	60,323	46,067	60,323	46,067
Ending balance: Individually evaluated for impairment	2,903	705	2,903	705
Ending balance: Amounts related to acquired-impaired loans	643	1,548	643	1,548
Ending balance: Collectively evaluated for impairment	56,777	43,814	56,777	43,814
Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	6,185,684	5,393,691	6,185,684	5,393,691
Ending balance: Individually evaluated for impairment	32,379	8,722	32,379	8,722
Ending balance: Acquired-impaired loans	13,667	31,246	13,667	31,246
Ending balance: Collectively evaluated for impairment	6,139,638	5,353,723	6,139,638	5,353,723
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	11,095		11,095		11,674
Ending balance: Loans	1,120,947		1,120,947		1,106,761
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			6,421	8,845
Charge-offs			(1,113)	(1,665)
Recoveries			1,714	1,960
Net provision for loan losses			(1,193)	836
Increase (decrease) in FDIC loss share receivable			(528)	(1,302)
Loans and Leases receivable, Allowance, Ending Balance	5,301	8,674	5,301	8,674
Ending balance: Individually evaluated for impairment	73	283	73	283
Ending balance: Amounts related to acquired-impaired loans	390	1,552	390	1,552
Ending balance: Collectively evaluated for impairment	4,838	6,839	4,838	6,839
Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,120,947	1,040,656	1,120,947	1,040,656
Ending balance: Individually evaluated for impairment	4,360	7,441	4,360	7,441
Ending balance: Acquired-impaired loans	19,465	36,175	19,465	36,175
Ending balance: Collectively evaluated for impairment	1,097,122	997,040	1,097,122	997,040
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	22,487		22,487		27,808
Ending balance: Loans	3,212,833		3,212,833		3,144,048
Commercial Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance			21,082	31,612
Charge-offs			(2,893)	(5,395)
Recoveries			891	2,428
Net provision for loan losses			876	(4,400)
Increase (decrease) in FDIC loss share receivable			532	225
Loans and Leases receivable, Allowance, Ending Balance	20,488	24,470	20,488	24,470
Ending balance: Individually evaluated for impairment	2,417	304	2,417	304
Ending balance: Amounts related to acquired-impaired loans	2,612	8,533	2,612	8,533
Ending balance: Collectively evaluated for impairment	15,459	15,633	15,459	15,633
Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	3,212,833	3,056,263	3,212,833	3,056,263
Ending balance: Individually evaluated for impairment	34,383	13,478	34,383	13,478
Ending balance: Acquired-impaired loans	40,338	74,604	40,338	74,604
Ending balance: Collectively evaluated for impairment	3,138,112	2,968,181	3,138,112	2,968,181
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	169,553		169,553		187,033
Ending balance: Loans	1,955,837		1,955,837		1,894,181
Residential Mortgages [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance			28,660	34,881
Charge-offs			(1,460)	(1,827)
Recoveries			451	382
Net provision for loan losses			(620)	613
Increase (decrease) in FDIC loss share receivable			(2,342)	(3,442)
Loans and Leases receivable, Allowance, Ending Balance	24,689	30,607	24,689	30,607
Ending balance: Individually evaluated for impairment	163	532	163	532
Ending balance: Amounts related to acquired-impaired loans	17,419	23,663	17,419	23,663
Ending balance: Collectively evaluated for impairment	7,107	6,412	7,107	6,412
Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,955,837	1,771,271	1,955,837	1,771,271
Ending balance: Individually evaluated for impairment	1,369	2,532	1,369	2,532
Ending balance: Acquired-impaired loans	171,107	194,117	171,107	194,117
Ending balance: Collectively evaluated for impairment	1,783,361	1,574,622	1,783,361	1,574,622
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	14,836		14,836		19,699
Ending balance: Loans	1,869,451		1,869,451		1,706,226
Consumer [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance			21,430	21,271
Charge-offs			(6,869)	(8,752)
Recoveries			2,627	3,002
Net provision for loan losses			3,871	5,590
Increase (decrease) in FDIC loss share receivable			(773)	(2,257)
Loans and Leases receivable, Allowance, Ending Balance	20,286	18,854	20,286	18,854
Ending balance: Individually evaluated for impairment	6		6
Ending balance: Amounts related to acquired-impaired loans	2,998	5,857	2,998	5,857
Ending balance: Collectively evaluated for impairment	17,282	12,997	17,282	12,997
Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,869,451	1,622,175	1,869,451	1,622,175
Ending balance: Individually evaluated for impairment	116		116
Ending balance: Acquired-impaired loans	14,860	37,666	14,860	37,666
Ending balance: Collectively evaluated for impairment	1,854,475	1,584,509	1,854,475	1,584,509
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	13,390,491		13,390,491		12,810,199
Originated Loans [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			97,701	78,885
Charge-offs			(11,589)	(14,791)
Recoveries			6,725	6,749
Net provision for loan losses			13,974	7,729
Allowance for loan losses, Ending Balance	106,811	78,572	106,811	78,572
Ending balance: Individually evaluated for impairment	5,348	1,547	5,348	1,547
Ending balance: Collectively evaluated for impairment	101,463	77,025	101,463	77,025
Originated Loans [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	13,390,491	10,658,452	13,390,491	10,658,452
Ending balance: Individually evaluated for impairment	70,064	27,197	70,064	27,197
Ending balance: Collectively evaluated for impairment	13,320,427	10,631,255	13,320,427	10,631,255
Originated Loans [Member] | Commercial Non-Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			50,258	33,091
Charge-offs			(2,215)	(3,658)
Recoveries			2,051	1,411
Net provision for loan losses			9,586	5,937
Allowance for loan losses, Ending Balance	59,680	36,781	59,680	36,781
Ending balance: Individually evaluated for impairment	2,903	640	2,903	640
Ending balance: Collectively evaluated for impairment	56,777	36,141	56,777	36,141
Originated Loans [Member] | Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	6,058,998	4,610,696	6,058,998	4,610,696
Ending balance: Individually evaluated for impairment	32,379	6,765	32,379	6,765
Ending balance: Collectively evaluated for impairment	6,026,619	4,603,931	6,026,619	4,603,931
Originated Loans [Member] | Construction and Land Development [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			5,413	6,180
Charge-offs			(828)	(1,041)
Recoveries			1,308	1,064
Net provision for loan losses			(982)	699
Allowance for loan losses, Ending Balance	4,911	6,902	4,911	6,902
Ending balance: Individually evaluated for impairment	73	259	73	259
Ending balance: Collectively evaluated for impairment	4,838	6,643	4,838	6,643
Originated Loans [Member] | Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,100,788	903,610	1,100,788	903,610
Ending balance: Individually evaluated for impairment	4,360	6,702	4,360	6,702
Ending balance: Collectively evaluated for impairment	1,096,428	896,908	1,096,428	896,908
Originated Loans [Member] | Commercial Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			16,544	20,649
Charge-offs			(525)	(1,373)
Recoveries			426	1,057
Net provision for loan losses			1,217	(5,060)
Allowance for loan losses, Ending Balance	17,662	15,273	17,662	15,273
Ending balance: Individually evaluated for impairment	2,203	116	2,203	116
Ending balance: Collectively evaluated for impairment	15,459	15,157	15,459	15,157
Originated Loans [Member] | Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	2,591,384	2,173,006	2,591,384	2,173,006
Ending balance: Individually evaluated for impairment	31,840	11,198	31,840	11,198
Ending balance: Collectively evaluated for impairment	2,559,544	2,161,808	2,559,544	2,161,808
Originated Loans [Member] | Residential Mortgages [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			8,051	6,892
Charge-offs			(1,292)	(1,097)
Recoveries			449	363
Net provision for loan losses			62	772
Allowance for loan losses, Ending Balance	7,270	6,930	7,270	6,930
Ending balance: Individually evaluated for impairment	163	532	163	532
Ending balance: Collectively evaluated for impairment	7,107	6,398	7,107	6,398
Originated Loans [Member] | Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,784,730	1,469,977	1,784,730	1,469,977
Ending balance: Individually evaluated for impairment	1,369	2,532	1,369	2,532
Ending balance: Collectively evaluated for impairment	1,783,361	1,467,445	1,783,361	1,467,445
Originated Loans [Member] | Consumer [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			17,435	12,073
Charge-offs			(6,729)	(7,622)
Recoveries			2,491	2,854
Net provision for loan losses			4,091	5,381
Allowance for loan losses, Ending Balance	17,288	12,686	17,288	12,686
Ending balance: Individually evaluated for impairment	6		6
Ending balance: Collectively evaluated for impairment	17,282	12,686	17,282	12,686
Originated Loans [Member] | Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,854,591	1,501,163	1,854,591	1,501,163
Ending balance: Individually evaluated for impairment	116		116
Ending balance: Collectively evaluated for impairment	1,854,475	1,501,163	1,854,475	1,501,163
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	729,624		729,624		$ 832,668
Acquired Loans [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			477	1,647
Net provision for loan losses			(263)	7,300
Allowance for loan losses, Ending Balance	214	8,947	214	8,947
Ending balance: Individually evaluated for impairment	214	277	214	277
Ending balance: Collectively evaluated for impairment		8,670		8,670
Acquired Loans [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	729,624	1,921,779	729,624	1,921,779
Ending balance: Individually evaluated for impairment	2,543	4,976	2,543	4,976
Ending balance: Acquired-impaired loans	34,800	69,983	34,800	69,983
Ending balance: Collectively evaluated for impairment	692,281	1,846,820	692,281	1,846,820
Acquired Loans [Member] | Commercial Non-Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance				1,603
Net provision for loan losses				6,135
Allowance for loan losses, Ending Balance		7,738		7,738
Ending balance: Individually evaluated for impairment		65		65
Ending balance: Collectively evaluated for impairment		7,673		7,673
Acquired Loans [Member] | Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	120,020	769,159	120,020	769,159
Ending balance: Individually evaluated for impairment		1,957		1,957
Ending balance: Acquired-impaired loans	7,001	17,410	7,001	17,410
Ending balance: Collectively evaluated for impairment	113,019	749,792	113,019	749,792
Acquired Loans [Member] | Construction and Land Development [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance				10
Net provision for loan losses				210
Allowance for loan losses, Ending Balance		220		220
Ending balance: Individually evaluated for impairment		24		24
Ending balance: Collectively evaluated for impairment		196		196
Acquired Loans [Member] | Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	9,064	119,847	9,064	119,847
Ending balance: Individually evaluated for impairment		739		739
Ending balance: Acquired-impaired loans	8,370	18,976	8,370	18,976
Ending balance: Collectively evaluated for impairment	694	100,132	694	100,132
Acquired Loans [Member] | Commercial Real Estate [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, Beginning Balance			477	34
Net provision for loan losses			(263)	630
Allowance for loan losses, Ending Balance	214	664	214	664
Ending balance: Individually evaluated for impairment	214	188	214	188
Ending balance: Collectively evaluated for impairment		476		476
Acquired Loans [Member] | Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	598,962	836,646	598,962	836,646
Ending balance: Individually evaluated for impairment	2,543	2,280	2,543	2,280
Ending balance: Acquired-impaired loans	17,851	27,993	17,851	27,993
Ending balance: Collectively evaluated for impairment	578,568	806,373	578,568	806,373
Acquired Loans [Member] | Residential Mortgages [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net provision for loan losses				14
Allowance for loan losses, Ending Balance		14		14
Ending balance: Collectively evaluated for impairment		14		14
Acquired Loans [Member] | Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	1,554	111,724	1,554	111,724
Ending balance: Acquired-impaired loans	1,554	4,547	1,554	4,547
Ending balance: Collectively evaluated for impairment		107,177		107,177
Acquired Loans [Member] | Consumer [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net provision for loan losses				311
Allowance for loan losses, Ending Balance		311		311
Ending balance: Collectively evaluated for impairment		311		311
Acquired Loans [Member] | Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: Loans	24	84,403	24	84,403
Ending balance: Acquired-impaired loans	24	1,057	24	1,057
Ending balance: Collectively evaluated for impairment		83,346		83,346
FDIC Acquired Loans [Member] | Allowance for Loan Losses [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases receivable, Allowance, Beginning Balance			30,584	53,094
Charge-offs			(4,060)	(6,576)
Recoveries			1,023	2,885
Net provision for loan losses			(949)	(375)
Increase (decrease) in FDIC loss share receivable			(2,536)	(7,875)
Loans and Leases receivable, Allowance, Ending Balance	24,062	41,153	24,062	41,153
Ending balance: Amounts related to acquired-impaired loans	24,062	41,153	24,062	41,153
FDIC Acquired Loans [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	224,637	303,825	224,637	303,825
Ending balance: Acquired-impaired loans	224,637	303,825	224,637	303,825
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			911	2,323
Charge-offs			(1,099)	(70)
Recoveries			14	451
Net provision for loan losses			242	(57)
Increase (decrease) in FDIC loss share receivable			575	(1,099)
Loans and Leases receivable, Allowance, Ending Balance	643	1,548	643	1,548
Ending balance: Amounts related to acquired-impaired loans	643	1,548	643	1,548
FDIC Acquired Loans [Member] | Commercial Non-Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	6,666	13,836	6,666	13,836
Ending balance: Acquired-impaired loans	6,666	13,836	6,666	13,836
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			1,008	2,655
Charge-offs			(285)	(624)
Recoveries			406	896
Net provision for loan losses			(211)	(73)
Increase (decrease) in FDIC loss share receivable			(528)	(1,302)
Loans and Leases receivable, Allowance, Ending Balance	390	1,552	390	1,552
Ending balance: Amounts related to acquired-impaired loans	390	1,552	390	1,552
FDIC Acquired Loans [Member] | Construction and Land Development [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	11,095	17,199	11,095	17,199
Ending balance: Acquired-impaired loans	11,095	17,199	11,095	17,199
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			4,061	10,929
Charge-offs			(2,368)	(4,022)
Recoveries			465	1,371
Net provision for loan losses			(78)	30
Increase (decrease) in FDIC loss share receivable			532	225
Loans and Leases receivable, Allowance, Ending Balance	2,612	8,533	2,612	8,533
Ending balance: Amounts related to acquired-impaired loans	2,612	8,533	2,612	8,533
FDIC Acquired Loans [Member] | Commercial Real Estate [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	22,487	46,611	22,487	46,611
Ending balance: Acquired-impaired loans	22,487	46,611	22,487	46,611
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			20,609	27,989
Charge-offs			(168)	(730)
Recoveries			2	19
Net provision for loan losses			(682)	(173)
Increase (decrease) in FDIC loss share receivable			(2,342)	(3,442)
Loans and Leases receivable, Allowance, Ending Balance	17,419	23,663	17,419	23,663
Ending balance: Amounts related to acquired-impaired loans	17,419	23,663	17,419	23,663
FDIC Acquired Loans [Member] | Residential Mortgages [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	169,553	189,570	169,553	189,570
Ending balance: Acquired-impaired loans	169,553	189,570	169,553	189,570
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			3,995	9,198
Charge-offs			(140)	(1,130)
Recoveries			136	148
Net provision for loan losses			(220)	(102)
Increase (decrease) in FDIC loss share receivable			(773)	(2,257)
Loans and Leases receivable, Allowance, Ending Balance	2,998	5,857	2,998	5,857
Ending balance: Amounts related to acquired-impaired loans	2,998	5,857	2,998	5,857
FDIC Acquired Loans [Member] | Consumer [Member] | Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ending balance: FDIC acquired loans	14,836	36,609	14,836	36,609
Ending balance: Acquired-impaired loans	$ 14,836	$ 36,609	$ 14,836	$ 36,609

Loans and Allowance for Loan 45

Loans and Allowance for Loan Losses - Summary of Composition of Non-Accrual Loans by Portfolio Segment (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	$ 118,445	$ 79,537
Commercial Non-Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	42,454	15,511
Construction and Land Development [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	6,441	7,565
Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	43,986	28,619
Residential Mortgages [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	20,709	22,094
Consumer [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	4,855	5,748
Originated Loans [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	111,455	71,296
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	42,454	15,511
Originated Loans [Member] | Construction and Land Development [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	5,285	6,462
Originated Loans [Member] | Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	38,152	22,047
Originated Loans [Member] | Residential Mortgages [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	20,709	21,702
Originated Loans [Member] | Consumer [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	4,855	5,574
Acquired Loans [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	5,401	6,139
Acquired Loans [Member] | Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	5,401	6,139
FDIC Acquired Loans [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	1,589	2,102
FDIC Acquired Loans [Member] | Construction and Land Development [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	1,156	1,103
FDIC Acquired Loans [Member] | Commercial Real Estate [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans	$ 433	433
FDIC Acquired Loans [Member] | Residential Mortgages [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans		392
FDIC Acquired Loans [Member] | Consumer [Member]
Nonaccrual Loans By Portfolio [Line Items]
Nonaccrual loans		$ 174

Loans and Allowance for Loan 46

Loans and Allowance for Loan Losses - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Interest that would have been recorded on nonaccrual loans	$ 1,800,000
Interest recorded on nonaccrual loans	600,000
Nonaccrual loans	118,445,000	$ 79,537,000
Troubled debt restructuring both accruing and nonaccruing	12,800,000	16,000,000
Minimum bank portfolio loan need to be reviewed	1,000,000
Real estate acquired through foreclosure	37,371,000	58,415,000
Consumer [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Nonaccrual loans	4,855,000	5,748,000
Mortgage loan in process of foreclosure	7,000,000	13,700,000
Real estate acquired through foreclosure	$ 9,900,000	12,700,000
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
Troubled Debt Restructurings [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Nonaccrual loans	$ 4,900,000	7,000,000
FDIC Acquired Loans [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Nonaccrual loans	1,589,000	2,102,000
FDIC Acquired Loans [Member] | Consumer [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Nonaccrual loans		174,000
Mortgage loan in process of foreclosure	6,200,000	8,100,000
Real estate acquired through foreclosure	$ 4,200,000	$ 8,200,000

Loans and Allowance for Loan 47

Loans and Allowance for Loan Losses - Schedule of Troubled Debt Restructurings Occurred During Period by Portfolio Segment (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2015USD ($)Contract	Jun. 30, 2014USD ($)Contract
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	4	3
Pre-Modification Outstanding Recorded Investment	$ 570	$ 1,736
Post-Modification Outstanding Recorded Investment	$ 570	$ 1,425
Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	1	1
Pre-Modification Outstanding Recorded Investment	$ 482	$ 963
Post-Modification Outstanding Recorded Investment	$ 482	$ 918
Residential Mortgages [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	2	2
Pre-Modification Outstanding Recorded Investment	$ 68	$ 773
Post-Modification Outstanding Recorded Investment	$ 68	$ 507
Consumer [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	1
Pre-Modification Outstanding Recorded Investment	$ 20
Post-Modification Outstanding Recorded Investment	$ 20
Originated Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	4	3
Pre-Modification Outstanding Recorded Investment	$ 570	$ 1,736
Post-Modification Outstanding Recorded Investment	$ 570	$ 1,425
Originated Loans [Member] | Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	1	1
Pre-Modification Outstanding Recorded Investment	$ 482	$ 963
Post-Modification Outstanding Recorded Investment	$ 482	$ 918
Originated Loans [Member] | Residential Mortgages [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	2	2
Pre-Modification Outstanding Recorded Investment	$ 68	$ 773
Post-Modification Outstanding Recorded Investment	$ 68	$ 507
Originated Loans [Member] | Consumer [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts | Contract	1
Pre-Modification Outstanding Recorded Investment	$ 20
Post-Modification Outstanding Recorded Investment	$ 20

Loans and Allowance for Loan 48

Loans and Allowance for Loan Losses - Schedule of Troubled Debt Restructurings Occurred During Period by Portfolio Segment - Troubled Debt Restructurings That Subsequently Defaulted (Detail) - 6 months ended Jun. 30, 2014 $ in Thousands	USD ($)Contract
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	3
Recorded Investment | $	$ 1,934
Commercial Non-Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1
Recorded Investment | $	$ 909
Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	2
Recorded Investment | $	$ 1,025
Originated Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	3
Recorded Investment | $	$ 1,934
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	1
Recorded Investment | $	$ 909
Originated Loans [Member] | Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Number of Contracts	2
Recorded Investment | $	$ 1,025

Loans and Allowance for Loan 49

Loans and Allowance for Loan Losses - Summary of Impaired Loans Disaggregated by Class (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	$ 24,348	$ 14,815
Recorded Investment, With a related allowance recorded	48,259	14,896
Recorded Investment, Total	72,607	29,711
Unpaid Principal Balance, With no related allowance recorded	26,856	20,707
Unpaid Principal Balance, With a related allowance recorded	51,772	15,581
Unpaid Principal Balance, Total	78,628	36,288
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	5,562	854
Related Allowance, Total	5,562	854
Average Recorded Investment, With no related allowance recorded	20,943	13,965
Average Recorded Investment, With a related allowance recorded	26,922	25,340
Average Recorded Investment, Total	47,866	39,305
Interest Income Recognized, With no related allowance recorded	22	527
Interest Income Recognized, With a related allowance recorded	127	648
Interest Income Recognized, Total	149	1,175
Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	12,192	3,003
Recorded Investment, With a related allowance recorded	20,187	984
Recorded Investment, Total	32,379	3,987
Unpaid Principal Balance, With no related allowance recorded	12,696	3,646
Unpaid Principal Balance, With a related allowance recorded	20,949	984
Unpaid Principal Balance, Total	33,645	4,630
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	2,903	14
Related Allowance, Total	2,903	14
Average Recorded Investment, With no related allowance recorded	8,861	1,566
Average Recorded Investment, With a related allowance recorded	8,116	6,581
Average Recorded Investment, Total	16,977	8,147
Interest Income Recognized, With no related allowance recorded		51
Interest Income Recognized, With a related allowance recorded	3	221
Interest Income Recognized, Total	3	272
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	57	3,345
Recorded Investment, With a related allowance recorded	4,303	4,905
Recorded Investment, Total	4,360	8,250
Unpaid Principal Balance, With no related allowance recorded	57	6,486
Unpaid Principal Balance, With a related allowance recorded	6,522	4,906
Unpaid Principal Balance, Total	6,579	11,392
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	73	19
Related Allowance, Total	73	19
Average Recorded Investment, With no related allowance recorded	1,295	3,451
Average Recorded Investment, With a related allowance recorded	4,369	7,697
Average Recorded Investment, Total	5,664	11,148
Interest Income Recognized, With no related allowance recorded		142
Interest Income Recognized, With a related allowance recorded	59	193
Interest Income Recognized, Total	59	335
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	12,001	8,467
Recorded Investment, With a related allowance recorded	22,382	6,345
Recorded Investment, Total	34,383	14,812
Unpaid Principal Balance, With no related allowance recorded	14,005	10,575
Unpaid Principal Balance, With a related allowance recorded	22,403	6,374
Unpaid Principal Balance, Total	36,408	16,949
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	2,417	488
Related Allowance, Total	2,417	488
Average Recorded Investment, With no related allowance recorded	10,376	8,772
Average Recorded Investment, With a related allowance recorded	12,618	8,857
Average Recorded Investment, Total	22,995	17,629
Interest Income Recognized, With no related allowance recorded	20	331
Interest Income Recognized, With a related allowance recorded	44	184
Interest Income Recognized, Total	64	515
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With a related allowance recorded	1,369	2,656
Recorded Investment, Total	1,369	2,656
Unpaid Principal Balance, With a related allowance recorded	1,880	3,311
Unpaid Principal Balance, Total	1,880	3,311
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	163	330
Related Allowance, Total	163	330
Average Recorded Investment, With no related allowance recorded	345	176
Average Recorded Investment, With a related allowance recorded	1,804	2,204
Average Recorded Investment, Total	2,149	2,380
Interest Income Recognized, With no related allowance recorded	2	3
Interest Income Recognized, With a related allowance recorded	18	50
Interest Income Recognized, Total	20	53
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	98
Recorded Investment, With a related allowance recorded	18	6
Recorded Investment, Total	116	6
Unpaid Principal Balance, With no related allowance recorded	98
Unpaid Principal Balance, With a related allowance recorded	18	6
Unpaid Principal Balance, Total	116	6
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	6	3
Related Allowance, Total	6	3
Average Recorded Investment, With no related allowance recorded	66
Average Recorded Investment, With a related allowance recorded	15	1
Average Recorded Investment, Total	81	1
Interest Income Recognized, With a related allowance recorded	3
Interest Income Recognized, Total	3
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	24,348	14,815
Recorded Investment, With a related allowance recorded	45,716	12,205
Recorded Investment, Total	70,064	27,020
Unpaid Principal Balance, With no related allowance recorded	26,856	20,707
Unpaid Principal Balance, With a related allowance recorded	49,209	12,861
Unpaid Principal Balance, Total	76,065	33,568
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	5,348	377
Related Allowance, Total	5,348	377
Average Recorded Investment, With no related allowance recorded	20,943	13,088
Average Recorded Investment, With a related allowance recorded	24,318	21,887
Average Recorded Investment, Total	45,261	34,976
Interest Income Recognized, With no related allowance recorded	22	527
Interest Income Recognized, With a related allowance recorded	127	395
Interest Income Recognized, Total	149	921
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	12,192	3,003
Recorded Investment, With a related allowance recorded	20,187	984
Recorded Investment, Total	32,379	3,987
Unpaid Principal Balance, With no related allowance recorded	12,696	3,646
Unpaid Principal Balance, With a related allowance recorded	20,949	984
Unpaid Principal Balance, Total	33,645	4,630
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	2,903	14
Related Allowance, Total	2,903	14
Average Recorded Investment, With no related allowance recorded	8,861	1,209
Average Recorded Investment, With a related allowance recorded	8,116	5,522
Average Recorded Investment, Total	16,977	6,732
Interest Income Recognized, With no related allowance recorded		51
Interest Income Recognized, With a related allowance recorded	3	99
Interest Income Recognized, Total	3	150
Originated Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	57	3,345
Recorded Investment, With a related allowance recorded	4,303	4,905
Recorded Investment, Total	4,360	8,250
Unpaid Principal Balance, With no related allowance recorded	57	6,486
Unpaid Principal Balance, With a related allowance recorded	6,522	4,906
Unpaid Principal Balance, Total	6,579	11,392
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	73	19
Related Allowance, Total	73	19
Average Recorded Investment, With no related allowance recorded	1,295	3,330
Average Recorded Investment, With a related allowance recorded	4,369	6,660
Average Recorded Investment, Total	5,664	9,990
Interest Income Recognized, With no related allowance recorded		142
Interest Income Recognized, With a related allowance recorded	59	137
Interest Income Recognized, Total	59	279
Originated Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	12,001	8,467
Recorded Investment, With a related allowance recorded	19,839	3,654
Recorded Investment, Total	31,840	12,121
Unpaid Principal Balance, With no related allowance recorded	14,005	10,575
Unpaid Principal Balance, With a related allowance recorded	19,840	3,654
Unpaid Principal Balance, Total	33,845	14,229
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	2,203	11
Related Allowance, Total	2,203	11
Average Recorded Investment, With no related allowance recorded	10,376	8,461
Average Recorded Investment, With a related allowance recorded	10,014	7,500
Average Recorded Investment, Total	20,390	15,961
Interest Income Recognized, With no related allowance recorded	20	331
Interest Income Recognized, With a related allowance recorded	44	109
Interest Income Recognized, Total	64	439
Originated Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With a related allowance recorded	1,369	2,656
Recorded Investment, Total	1,369	2,656
Unpaid Principal Balance, With a related allowance recorded	1,880	3,311
Unpaid Principal Balance, Total	1,880	3,311
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	163	330
Related Allowance, Total	163	330
Average Recorded Investment, With no related allowance recorded	345	88
Average Recorded Investment, With a related allowance recorded	1,804	2,204
Average Recorded Investment, Total	2,149	2,292
Interest Income Recognized, With no related allowance recorded	2	3
Interest Income Recognized, With a related allowance recorded	18	50
Interest Income Recognized, Total	20	53
Originated Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With no related allowance recorded	98
Recorded Investment, With a related allowance recorded	18	6
Recorded Investment, Total	116	6
Unpaid Principal Balance, With no related allowance recorded	98
Unpaid Principal Balance, With a related allowance recorded	18	6
Unpaid Principal Balance, Total	116	6
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	6	3
Related Allowance, Total	6	3
Average Recorded Investment, With no related allowance recorded	66
Average Recorded Investment, With a related allowance recorded	15	1
Average Recorded Investment, Total	81	1
Interest Income Recognized, With a related allowance recorded	3
Interest Income Recognized, Total	3
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With a related allowance recorded	2,543	2,691
Recorded Investment, Total	2,543	2,691
Unpaid Principal Balance, With a related allowance recorded	2,563	2,720
Unpaid Principal Balance, Total	2,563	2,720
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	214	477
Related Allowance, Total	214	477
Average Recorded Investment, With no related allowance recorded		877
Average Recorded Investment, With a related allowance recorded	2,604	3,453
Average Recorded Investment, Total	2,604	4,330
Interest Income Recognized, With a related allowance recorded		253
Interest Income Recognized, Total		253
Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded		357
Average Recorded Investment, With a related allowance recorded		1,059
Average Recorded Investment, Total		1,416
Interest Income Recognized, With a related allowance recorded		122
Interest Income Recognized, Total		122
Acquired Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded		121
Average Recorded Investment, With a related allowance recorded		1,037
Average Recorded Investment, Total		1,158
Interest Income Recognized, With a related allowance recorded		56
Interest Income Recognized, Total		56
Acquired Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment, With a related allowance recorded	2,543	2,691
Recorded Investment, Total	2,543	2,691
Unpaid Principal Balance, With a related allowance recorded	2,563	2,720
Unpaid Principal Balance, Total	2,563	2,720
Related Allowance, With no related allowance recorded	0	0
Related Allowance, With a related allowance recorded	214	477
Related Allowance, Total	214	477
Average Recorded Investment, With no related allowance recorded		311
Average Recorded Investment, With a related allowance recorded	2,604	1,357
Average Recorded Investment, Total	2,604	1,668
Interest Income Recognized, With a related allowance recorded		75
Interest Income Recognized, Total		75
Acquired Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded		88
Average Recorded Investment, Total		88
Acquired Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance, With no related allowance recorded	$ 0	$ 0

Loans and Allowance for Loan 50

Loans and Allowance for Loan Losses - Summary of Age Analysis of Past Due Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	$ 224,637	$ 252,409
Total loans	14,344,752	13,895,276
30-59 days past due	24,268	44,652
60-89 days past due	13,585	12,503
Greater than 90 days past due	43,871	44,981
Total past due	81,724	102,136
Current	14,263,028	13,793,140
Recorded investment > 90 days and accruing	3,478	4,825
Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	6,666	6,195
Total loans	6,185,684	6,044,060
30-59 days past due	5,215	4,380
60-89 days past due	3,090	1,742
Greater than 90 days past due	10,250	8,560
Total past due	18,555	14,682
Current	6,167,129	6,029,378
Recorded investment > 90 days and accruing	826	630
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	11,095	11,674
Total loans	1,120,947	1,106,761
30-59 days past due	2,411	6,731
60-89 days past due	2,128	1,532
Greater than 90 days past due	5,434	5,556
Total past due	9,973	13,819
Current	1,110,974	1,092,942
Recorded investment > 90 days and accruing	80	142
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	22,487	27,808
Total loans	3,212,833	3,144,048
30-59 days past due	5,134	10,388
60-89 days past due	1,588	3,246
Greater than 90 days past due	16,732	15,258
Total past due	23,454	28,892
Current	3,189,379	3,115,156
Recorded investment > 90 days and accruing	279	957
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	169,553	187,033
Total loans	1,955,837	1,894,181
30-59 days past due	1,094	14,730
60-89 days past due	3,493	3,533
Greater than 90 days past due	8,227	11,208
Total past due	12,814	29,471
Current	1,943,023	1,864,710
Recorded investment > 90 days and accruing	946	1,199
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total FDIC acquired loans	14,836	19,699
Total loans	1,869,451	1,706,226
30-59 days past due	10,414	8,423
60-89 days past due	3,286	2,450
Greater than 90 days past due	3,228	4,399
Total past due	16,928	15,272
Current	1,852,523	1,690,954
Recorded investment > 90 days and accruing	1,347	1,897
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	13,390,491	12,810,199
30-59 days past due	22,314	40,679
60-89 days past due	13,447	11,949
Greater than 90 days past due	40,250	41,820
Total past due	76,011	94,448
Current	13,314,480	12,715,751
Recorded investment > 90 days and accruing	3,478	4,564
Originated Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial non-real estate	6,058,998	5,917,728
30-59 days past due	5,215	4,380
60-89 days past due	3,090	1,742
Greater than 90 days past due	10,250	8,560
Total past due	18,555	14,682
Current	6,040,443	5,903,046
Recorded investment > 90 days and accruing	826	630
Originated Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Construction and land development	1,100,788	1,073,964
30-59 days past due	2,411	6,620
60-89 days past due	2,128	1,532
Greater than 90 days past due	4,278	4,453
Total past due	8,817	12,605
Current	1,091,971	1,061,359
Recorded investment > 90 days and accruing	80	142
Originated Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial real estate	2,591,384	2,428,195
30-59 days past due	3,180	6,527
60-89 days past due	1,450	2,964
Greater than 90 days past due	14,267	13,234
Total past due	18,897	22,725
Current	2,572,487	2,405,470
Recorded investment > 90 days and accruing	279	696
Originated Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Residential mortgages	1,784,730	1,704,770
30-59 days past due	1,094	14,730
60-89 days past due	3,493	3,261
Greater than 90 days past due	8,227	11,208
Total past due	12,814	29,199
Current	1,771,916	1,675,571
Recorded investment > 90 days and accruing	946	1,199
Originated Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Consumer	1,854,591	1,685,542
30-59 days past due	10,414	8,422
60-89 days past due	3,286	2,450
Greater than 90 days past due	3,228	4,365
Total past due	16,928	15,237
Current	1,837,663	1,670,305
Recorded investment > 90 days and accruing	1,347	1,897
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	729,624	832,668
30-59 days past due	1,954	3,972
60-89 days past due	138	282
Greater than 90 days past due	2,032	1,591
Total past due	4,124	5,845
Current	725,500	826,823
Recorded investment > 90 days and accruing		261
Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial non-real estate	120,020	120,137
Current	120,020	120,137
Acquired Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Construction and land development	9,064	21,123
30-59 days past due		111
Total past due		111
Current	9,064	21,012
Acquired Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial real estate	598,962	688,045
30-59 days past due	1,954	3,861
60-89 days past due	138	282
Greater than 90 days past due	2,032	1,591
Total past due	4,124	5,734
Current	594,838	682,311
Recorded investment > 90 days and accruing		261
Acquired Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Residential mortgages	1,554	2,378
Current	1,554	2,378
Acquired Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Consumer	24	985
Current	24	985
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	1,589	1,570
Total past due	1,589	1,843
Current	223,048	250,566
FDIC Acquired Loans [Member] | Commercial Non-Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	6,666	6,195
FDIC Acquired Loans [Member] | Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Greater than 90 days past due	1,156	1,103
Total past due	1,156	1,103
Current	9,939	10,571
FDIC Acquired Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Greater than 90 days past due	433	433
Total past due	433	433
Current	22,054	27,375
FDIC Acquired Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
60-89 days past due		272
Total past due		272
Current	169,553	186,761
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	$ 14,836	$ 19,664

Loans and Allowance for Loan 51

Loans and Allowance for Loan Losses - Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile by Internally Assigned Grade (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	$ 1,120,947	$ 1,106,761
Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	6,185,684	6,044,060
Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	3,212,833	3,144,048
Originated Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	1,100,788	1,073,964
Originated Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	6,058,998	5,917,728
Originated Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,591,384	2,428,195
Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	9,064	21,123
Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	120,020	120,137
Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	598,962	688,045
FDIC Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	11,095	11,674
FDIC Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	6,666	6,195
FDIC Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	22,487	27,808
Pass [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	1,052,912	1,028,973
Pass [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,638,084	5,691,701
Pass [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	3,001,533	2,887,496
Pass [Member] | Originated Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	1,048,380	1,012,128
Pass [Member] | Originated Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,522,236	5,577,827
Pass [Member] | Originated Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,430,696	2,241,391
Pass [Member] | Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	1,743	14,377
Pass [Member] | Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	113,200	111,847
Pass [Member] | Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	565,820	641,966
Pass [Member] | FDIC Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,789	2,468
Pass [Member] | FDIC Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,648	2,027
Pass [Member] | FDIC Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,017	4,139
Pass-Watch [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	10,265	22,480
Pass-Watch [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	143,926	176,577
Pass-Watch [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	46,966	77,278
Pass-Watch [Member] | Originated Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	7,471	21,516
Pass-Watch [Member] | Originated Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	142,837	174,742
Pass-Watch [Member] | Originated Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	33,185	61,589
Pass-Watch [Member] | Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,275	432
Pass-Watch [Member] | Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	101	715
Pass-Watch [Member] | Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	10,974	11,142
Pass-Watch [Member] | FDIC Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	519	532
Pass-Watch [Member] | FDIC Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	988	1,120
Pass-Watch [Member] | FDIC Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	2,807	4,547
Special Mention [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,233	7,545
Special Mention [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	209,998	53,312
Special Mention [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	33,381	30,975
Special Mention [Member] | Originated Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	4,920	7,097
Special Mention [Member] | Originated Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	209,716	52,962
Special Mention [Member] | Originated Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	25,974	21,543
Special Mention [Member] | Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade		129
Special Mention [Member] | Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	282	350
Special Mention [Member] | Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,798	8,113
Special Mention [Member] | FDIC Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	313	319
Special Mention [Member] | FDIC Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	1,609	1,319
Substandard [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	52,537	47,763
Substandard [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	193,616	122,395
Substandard [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	130,936	148,278
Substandard [Member] | Originated Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	40,017	33,223
Substandard [Member] | Originated Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	184,178	112,153
Substandard [Member] | Originated Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	101,512	103,651
Substandard [Member] | Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	5,046	6,185
Substandard [Member] | Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	6,437	7,225
Substandard [Member] | Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	16,370	26,824
Substandard [Member] | FDIC Acquired Loans [Member] | Construction Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	7,474	8,355
Substandard [Member] | FDIC Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	3,001	3,017
Substandard [Member] | FDIC Acquired Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	13,054	17,803
Doubtful [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	60	75
Doubtful [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	17	21
Doubtful [Member] | Originated Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	31	44
Doubtful [Member] | Originated Loans [Member] | Commercial Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	17	21
Doubtful [Member] | FDIC Acquired Loans [Member] | Commercial Non Real Estate Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile by internally assigned grade	$ 29	$ 31

Loans and Allowance for Loan 52

Loans and Allowance for Loan Losses - Schedule of Credit Quality Indicators of Various Classes of Loans - Credit Risk Profile Based on Payment Activity and Accrual Status (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	$ 1,955,837	$ 1,894,181
Residential Mortgages [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,934,182	1,870,887
Residential Mortgages [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	21,655	23,294
Residential Mortgages [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,784,730	1,704,770
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	1,763,075	1,681,868
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	21,655	22,902
Residential Mortgages [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,554	2,378
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	1,554	2,378
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	169,553	187,033
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	169,553	186,641
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
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,869,451	1,706,226
Consumer [Member] | Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,863,249	1,698,579
Consumer [Member] | Nonperforming [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	6,202	7,647
Consumer [Member] | Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	1,854,591	1,685,542
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	1,848,389	1,678,069
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	6,202	7,473
Consumer [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	24	985
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	24	985
Consumer [Member] | FDIC Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit risk profile based on payment activity and accrual status	14,836	19,699
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	$ 14,836	19,525
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

Loans and Allowance for Loan 53

Loans and Allowance for Loan Losses - Changes in Carrying Amount of Acquired Loans and Accretable Yield for Loans Receivable (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
FDIC Acquired Loans [Member]
Financing Receivable, Impaired [Line Items]
Carrying Amount of Loans, Balance at beginning of period	$ 252,409	$ 358,666
Carrying Amount of Loans, Payments received, net	(34,649)	(125,388)
Carrying Amount of Loans, Accretion	6,877	19,131
Carrying Amount of Loans, Balance at end of period	224,637	252,409
Accretable Yield, Balance at beginning of period	112,788	122,715
Accretable Yield, Payments received, net	(359)	(1,071)
Accretable Yield, Accretion	(6,877)	(19,131)
Accretable Yield, Decrease in expected cash flows based on actual cash flows and changes in cash flow assumptions	(3,918)	(1,137)
Net transfers from nonaccretable difference to accretable yield	(2,878)	11,412
Accretable Yield, Balance at end of period	98,756	112,788
Acquired Loans [Member]
Financing Receivable, Impaired [Line Items]
Carrying Amount of Loans, Balance at beginning of period	61,276	68,075
Carrying Amount of Loans, Payments received, net	(35,640)	(50,178)
Carrying Amount of Loans, Accretion	9,163	43,379
Carrying Amount of Loans, Balance at end of period	34,799	61,276
Accretable Yield, Balance at beginning of period	74,668	131,370
Accretable Yield, Payments received, net	(12,284)	(32,855)
Accretable Yield, Accretion	(9,163)	(43,379)
Accretable Yield, Decrease in expected cash flows based on actual cash flows and changes in cash flow assumptions	(219)	(203)
Net transfers from nonaccretable difference to accretable yield	(2,104)	19,735
Accretable Yield, Balance at end of period	$ 50,898	$ 74,668

Securities Sold under Agreeme54

Securities Sold under Agreements to Repurchase - Additional Information (Detail) $ in Millions	Jun. 30, 2015USD ($)
Banking and Thrift [Abstract]
Securities sold under agreements to repurchase	$ 466.3

Long-Term Debt - Long-Term Debt

Long-Term Debt - Long-Term Debt (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 09, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Other long-term debt	$ 127,330		$ 126,760
Total long-term debt	507,341		374,371
Term Note Payable Maturing December 2015 [Member]
Debt Instrument [Line Items]
Term note payable	132,000		149,600
Subordinated Debt [Member] | Subordinated Notes Payable Maturing June 2045 [Member]
Debt Instrument [Line Items]
Subordinated notes payable	150,000	$ 150,000
Subordinated Debt [Member] | Subordinated Notes Payable Maturing April 2017 [Member]
Debt Instrument [Line Items]
Subordinated notes payable	$ 98,011		$ 98,011

Long-Term Debt - Long-Term De56

Long-Term Debt - Long-Term Debt (Parenthetical) (Detail) - Subordinated Debt [Member]	6 Months Ended
	Jun. 30, 2015
Subordinated Notes Payable Maturing June 2045 [Member]
Debt Instrument [Line Items]
Subordinated notes payable maturity date	Jun. 15, 2045
Subordinated Notes Payable Maturing April 2017 [Member]
Debt Instrument [Line Items]
Subordinated notes payable maturity date	Apr. 1, 2017

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 09, 2015	Dec. 21, 2012	Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Other long term debt maturity date, ending period			2,052
Expected compliance period			7 years
Subordinated Debt [Member]
Debt Instrument [Line Items]
Subordinated notes interest rate			5.875%
Qualified percentage of subordinated notes in regulatory capital			20.00%
Subordinated Notes Payable Maturing June 2045 [Member] | Subordinated Debt [Member]
Debt Instrument [Line Items]
Sale of aggregate principal amount of subordinated notes	$ 150,000		$ 150,000
Subordinated notes payable maturity date			Jun. 15, 2045
Subordinated notes interest rate	5.95%
Subordinated Notes Payable Maturing April 2017 [Member] | Subordinated Debt [Member]
Debt Instrument [Line Items]
Sale of aggregate principal amount of subordinated notes			$ 98,011	$ 98,011
Subordinated notes payable maturity date			Apr. 1, 2017
Three Year Term Loan [Member]
Debt Instrument [Line Items]
Term note payable		$ 220,000
Term loan agreement period		3 years
Additional borrowings		$ 50,000
Reference rate for loan variable rate			LIBOR
Percentage points added to reference rate		1.875%
Debt instrument term loan facility maturity date			December 21, 2015
Principal payment of term loan		$ 8,800

Fair Value - Schedule of Financ

Fair Value - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	$ 2,148,323
Available for sale equity securities	2,811	$ 9,553
Available for sale securities	2,151,134	1,660,165
Derivative assets	24,096	19,432
Total recurring fair value measurements-assets	2,175,230	1,679,597
Derivative liabilities	22,157	20,860
Total recurring fair value measurements-liabilities	22,157	20,860
Municipal Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	12,875	14,176
Available for sale securities	12,875	14,176
U.S. Treasury and Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	98,621	300,508
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	1,818,539	1,245,564
Collateralized Mortgage Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	214,788	86,864
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale equity securities	2,811	9,553
Available for sale securities	2,811	9,553
Total recurring fair value measurements-assets	2,811	9,553
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale securities	2,148,323	1,650,612
Derivative assets	24,096	19,432
Total recurring fair value measurements-assets	2,172,419	1,670,044
Derivative liabilities	22,157	20,860
Total recurring fair value measurements-liabilities	22,157	20,860
Level 2 [Member] | Municipal Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	12,875	14,176
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	98,621	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	1,818,539	1,245,564
Level 2 [Member] | Collateralized Mortgage Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale debt securities	$ 214,788	$ 86,864

Fair Value - Additional Informa

Fair Value - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2015
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 - Schedule of Fina60

Fair Value - Schedule of Financial Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Collateral-dependent impaired loans	$ 60,165	$ 30,204
Other real estate owned	21,289	29,715
Total nonrecurring fair value measurements	81,454	59,919
Level 2 [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Collateral-dependent impaired loans	60,165	30,204
Total nonrecurring fair value measurements	60,165	30,204
Level 3 [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Other real estate owned	21,289	29,715
Total nonrecurring fair value measurements	$ 21,289	$ 29,715

Fair Value - Schedule of Estima

Fair Value - Schedule of Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Available for sale securities	$ 2,151,134	$ 1,660,165
Held to maturity securities	2,294,318	2,166,289
Loans, net	14,213,665	13,766,514
Loans held for sale	21,304	20,252
Derivative financial instruments	24,096	19,432
Deposits	17,301,788	16,572,831
Securities sold under agreements to repurchase	466,300
Long-term debt	507,341	374,371
Derivative financial instruments	22,157	20,860
Level 1 [Member]
Cash, interest-bearing bank deposits, and federal funds sold	928,063	1,159,403
Available for sale securities	2,811	9,553
Federal funds purchased	12,850	12,000
Securities sold under agreements to repurchase	466,343	624,573
FHLB borrowings	600,000	515,000
Level 2 [Member]
Available for sale securities	2,148,323	1,650,612
Held to maturity securities	2,310,103	2,186,340
Loans, net	60,165	30,204
Loans held for sale	21,304	20,252
Derivative financial instruments	24,096	19,432
Long-term debt	511,424	346,379
Derivative financial instruments	22,157	20,860
Level 3 [Member]
Loans, net	14,133,549	13,672,427
Deposits	17,282,802	16,398,878
Total Fair Value [Member]
Cash, interest-bearing bank deposits, and federal funds sold	928,063	1,159,403
Available for sale securities	2,151,134	1,660,165
Held to maturity securities	2,310,103	2,186,340
Loans, net	14,193,714	13,702,631
Loans held for sale	21,304	20,252
Derivative financial instruments	24,096	19,432
Deposits	17,282,802	16,398,878
Federal funds purchased	12,850	12,000
Securities sold under agreements to repurchase	466,343	624,573
FHLB borrowings	600,000	515,000
Long-term debt	511,424	346,379
Derivative financial instruments	22,157	20,860
Carrying Amount [Member]
Cash, interest-bearing bank deposits, and federal funds sold	928,063	1,159,403
Available for sale securities	2,151,134	1,660,165
Held to maturity securities	2,294,318	2,166,289
Loans, net	14,213,665	13,766,514
Loans held for sale	21,304	20,252
Derivative financial instruments	24,096	19,432
Deposits	17,301,788	16,572,831
Federal funds purchased	12,850	12,000
Securities sold under agreements to repurchase	466,343	624,573
FHLB borrowings	600,000	515,000
Long-term debt	507,341	374,371
Derivative financial instruments	$ 22,157	$ 20,860

Derivatives - Fair Values of De

Derivatives - Fair Values of Derivative Instruments on Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Fair Value Of Asset	$ 24,096	$ 19,432
Derivative Fair Value Of Liability	22,157	20,860
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	500,000	300,000
Derivative Fair Value Of Asset	413
Derivative Fair Value Of Liability		592
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	500,000	300,000
Derivative Fair Value Of Asset	413
Derivative Fair Value Of Liability		592
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,002,231	1,002,930
Derivative Fair Value Of Asset	23,683	19,432
Derivative Fair Value Of Liability	22,157	20,268
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	731,843	747,754
Derivative Fair Value Of Asset	17,916	17,806
Derivative Fair Value Of Liability	18,170	18,419
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	87,901	80,438
Derivative Fair Value Of Asset	82	125
Derivative Fair Value Of Liability	168	208
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	67,942	52,238
Derivative Fair Value Of Asset	2,069	80
Derivative Fair Value Of Liability	215	250
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	46,184	33,068
Derivative Fair Value Of Asset	143	111
Derivative Fair Value Of Liability	157	44
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	68,361	89,432
Derivative Fair Value Of Asset	3,473	1,310
Derivative Fair Value Of Liability	$ 3,447	$ 1,347

Derivatives - Additional Inform

Derivatives - Additional Information (Detail) - Jun. 30, 2015 $ in Millions	USD ($)Agreement
Derivative [Line Items]
Termination value of derivatives in a net liability position	$ 7.9
Collateral obligations for derivative counterparties	$ 20.6
Interest Rate Swaps [Member]
Derivative [Line Items]
Number of interest rate swap agreements | Agreement	2
Interest Rate Swaps [Member] | $300 Million Swap Agreement [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 300
Variable rate term loan agreement maturity	January 2,017
Interest Rate Swaps [Member] | $200 Million Swap Agreement [Member]
Derivative [Line Items]
Notional amount of derivatives	$ 200
Variable rate term loan agreement maturity	June 2,017

Derivatives - Offsetting Deriva

Derivatives - Offsetting Derivative Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross Amounts Recognized, Derivative Liabilities	$ 18,338	$ 18,627
Gross Amounts Offset in the Statement of Financial Position, Derivative Liabilities	0	0
Net Amounts Presented in the Statement of Financial Position, Derivative Liabilities	18,338	18,627
Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments, Derivative Liabilities	474	936
Gross Amounts Not offset in the Statement of Financial Position -Cash Collateral, Derivative Liabilities	20,121	17,343
Net Amount, Derivative Liabilities	(2,257)	348
Gross Amounts Recognized, Derivative Assets	17,998	17,931
Gross Amounts Offset in the Statement of Financial Position, Derivative Assets	0	0
Net Amounts Presented in the Statement of Financial Position, Derivative Assets	17,998	17,931
Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments, Derivative Assets	474	936
Gross Amounts Not offset in the Statement of Financial Position -Cash Collateral, Derivative Assets	0	0
Net Amount, Derivative Assets	$ 17,524	$ 16,995

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - Jul. 16, 2014 - $ / shares	Total
Stockholders' Equity Note [Abstract]
Shares authorized for repurchase	5.00%
Number of shares authorized for repurchase	4,100,000
Repurchased common stock shares	4,100,000
Shares repurchased, price per share	$ 30.02

Stockholders' Equity - Componen

Stockholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance			$ (50,074)	$ (35,379)
Net change in unrealized (loss) gain	$ (18,370)	$ 10,898	(12,957)	15,412
Reclassification of net (gain) losses realized and included in earnings			1,406	195
Valuation adjustment for employee benefit plans	(5,922)	2,006	(5,922)	2,006
Amortization of unrealized net loss on securities transferred to HTM	939	906	1,586	1,571
Income tax (benefit) expense	(8,237)	5,254	(5,877)	7,096
Accumulated other comprehensive income (loss), Ending balance	(60,084)	(23,291)	(60,084)	(23,291)
Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance			18,001	8,263
Net change in unrealized (loss) gain			(13,962)	15,412
Reclassification of net (gain) losses realized and included in earnings			(165)
Income tax (benefit) expense			(5,249)	5,637
Accumulated other comprehensive income (loss), Ending balance	9,123	18,038	9,123	18,038
Held to Maturity Securities Transferred from AFS [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance			(19,074)	(21,189)
Amortization of unrealized net loss on securities transferred to HTM			1,586	1,571
Income tax (benefit) expense			580	554
Accumulated other comprehensive income (loss), Ending balance	(18,068)	(20,172)	(18,068)	(20,172)
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance			(48,626)	(22,453)
Reclassification of net (gain) losses realized and included in earnings			1,571	195
Valuation adjustment for employee benefit plans			(5,922)	2,006
Income tax (benefit) expense			(1,574)	905
Accumulated other comprehensive income (loss), Ending balance	(51,403)	$ (21,157)	(51,403)	$ (21,157)
Gains and Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), Beginning balance			(375)
Net change in unrealized (loss) gain			1,005
Income tax (benefit) expense			366
Accumulated other comprehensive income (loss), Ending balance	$ 264		$ 264

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Line Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax effect	$ (12,311)	$ (17,665)	$ (27,187)	$ (35,866)
Amount Reclassified from Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax			(1,920)	(1,144)
Amount Reclassified from Accumulated Other Comprehensive Income [Member] | Available for Sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of AFS securities			165
Tax effect			(58)
Net of tax			107
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 of unrealized net loss on securities transferred to HTM			(1,586)	(1,571)
Tax effect			580	554
Net of tax			(1,006)	(1,017)
Amount Reclassified from Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and post-retirement items			(1,571)	(195)
Tax effect			550	68
Net of tax			$ (1,021)	$ (127)

Earnings Per Share - Computatio

Earnings Per Share - Computation of Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Numerator:
Net income to common shareholders	$ 34,829	$ 39,962	$ 74,988	$ 89,077
Net income allocated to participating securities - basic and diluted	766	819	1,701	1,900
Net income allocated to common shareholders - basic and diluted	$ 34,063	$ 39,143	$ 73,287	$ 87,177
Denominator:
Weighted-average common shares - basic	77,951	81,933	78,719	82,099
Dilutive potential common shares	164	241	162	249
Weighted-average common shares - diluted	78,115	82,174	78,881	82,348
Earnings per common share:
Basic	$ 0.44	$ 0.48	$ 0.93	$ 1.06
Diluted	$ 0.44	$ 0.48	$ 0.93	$ 1.06

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Weighted-average anti-dilutive potential common shares	574,037	660,778	843,544	675,108

Share-Based Payment Arrangeme70

Share-Based Payment Arrangements - Schedule of Option Activity Under Stock Option Plans (Detail) - Jun. 30, 2015 - USD ($) $ / shares in Units, $ in Thousands	Total
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Outstanding at Beginning	933,750
Number of Shares, Exercised	(11,577)
Number of Shares, Cancelled/Forfeited	(51,110)
Number of Shares, Expired	(109,147)
Number of Shares, Outstanding at Ending	761,916
Number of Shares, Exercisable at Ending	643,454
Weighted- Average Exercise Price, Outstanding at Beginning	$ 37.03
Weighted- Average Exercise Price, Exercised	29.94
Weighted- Average Exercise Price, Cancelled/Forfeited	35.43
Weighted- Average Exercise Price, Expired	34.15
Weighted- Average Exercise Price, Outstanding at Ending	37.65
Weighted- Average Exercise Price, Exercisable at Ending	$ 39.01
Weighted-Average Remaining Contractual Term, Outstanding at Ending Balance (in years)	4 years 1 month 6 days
Weighted-Average Remaining Contractual Term, Exercisable at Ending Balance (in years)	3 years 8 months 12 days
Aggregate Intrinsic Value, Outstanding at Ending	$ 480
Aggregate Intrinsic Value, Exercisable at Ending	$ 284

Share-Based Payment Arrangeme71

Share-Based Payment Arrangements - Additional Information (Detail) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2015USD ($)Bank$ / sharesshares	Jun. 30, 2014USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised	$ 0.2	$ 0.2
Unrecognized compensation cost	$ 35.6
Weighted-average period in years	3 years 3 months 18 days
Total fair value of shares vested	$ 7.5	$ 8.9
Shareholder return period
Number of peer group of regional banks | Bank	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 | shares	59,312
Weighted average fair value of shares granted | $ / shares	$ 25.77
Percentage of maximum number of shares earned of target award	200.00%

Share-Based Payment Arrangeme72

Share-Based Payment Arrangements - Schedule of Nonvested Restricted and Performance Shares (Detail) - 6 months ended Jun. 30, 2015 - Restricted Stock and Performance Shares [Member] - $ / shares	Total
Nonvested Share Activity [Line Items]
Number of Shares, Nonvested at Beginning	2,040,299
Number of Shares, Granted	97,906
Number of Shares, Vested	(235,987)
Number of Shares, Forfeited	(123,621)
Number of Shares, Nonvested at Ending	1,778,597
Weighted-Average Grant-Date Fair Value, Nonvested at Beginning	$ 32.27
Weighted-Average Grant-Date Fair Value, Granted	27.28
Weighted-Average Grant-Date Fair Value, Vested	31.96
Weighted-Average Grant-Date Fair Value, Cancelled/Forfeited	32.74
Weighted-Average Grant-Date Fair Value, Nonvested at Ending	$ 32.01

Retirement Plans - Components o

Retirement Plans - Components of Net Periodic Benefits Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension Benefits [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Service cost	$ 3,382	$ 3,035	$ 6,745	$ 6,460
Interest cost	4,672	4,817	9,291	9,626
Expected return on plan assets	(8,206)	(8,050)	(16,419)	(16,111)
Amortization of net loss	842	5	1,486	13
Net periodic benefit cost	690	(193)	1,103	(12)
Other Post-retirement Benefits [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Service cost	22	26	72	63
Interest cost	174	232	543	570
Amortization of net loss	(40)	25	85	182
Net periodic benefit cost	$ 156	$ 283	$ 700	$ 815

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2015	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Contributed to pension plan	$ 10
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%

Other Noninterest Income - Comp

Other Noninterest Income - Components of Other Noninterest Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Noninterest Income [Abstract]
Income from bank-owned life insurance	$ 2,671	$ 2,357	$ 5,337	$ 4,671
Credit related fees	2,611	2,834	5,068	5,566
Income from derivatives	1,464	481	1,412	1,240
Net (loss) gain on sale of assets	(62)	(217)	(55)	1,465
Safety deposit box income	429	443	915	956
Other miscellaneous	2,412	2,714	5,092	5,141
Total other noninterest income	$ 9,525	$ 8,612	$ 17,769	$ 19,039

Other Noninterest Expense - Com

Other Noninterest Expense - Components of Other Noninterest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Noninterest Expense [Abstract]
Advertising	$ 2,133	$ 2,179	$ 4,298	$ 3,938
Ad valorem and franchise taxes	2,736	2,638	5,451	5,299
Printing and supplies	1,158	949	2,375	2,278
Insurance expense	928	1,018	1,850	2,058
Travel expense	1,308	1,061	2,527	1,957
Entertainment and contributions	1,736	1,529	3,375	2,941
Tax credit investment amortization	2,096	2,198	4,191	4,370
Other miscellaneous	10,211	13,736	13,045	18,284
Total other noninterest expense	$ 22,306	$ 25,308	$ 37,112	$ 41,125

Other Noninterest Expense - Add

Other Noninterest Expense - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Nonoperating expense [Line Items]
Other miscellaneous expenses	$ 10,211	$ 13,736	$ 13,045	$ 18,284
Other Miscellaneous Expense [Member]
Nonoperating expense [Line Items]
Other miscellaneous expenses	$ 5,000	$ 7,300	$ 2,700	$ 7,300