Bank OZK 10-Q 8 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	OZRK
Entity Registrant Name	BANK OF THE OZARKS INC
Entity Central Index Key	1,038,205
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		121,147,658

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Cash and due from banks	$ 876,096	$ 89,122
Interest earning deposits	93,426	1,866
Cash and cash equivalents	969,522	90,988
Investment securities - available for sale (“AFS”)	1,341,894	602,348
Non-purchased loans and leases	8,759,766	6,528,634
Purchased loans	5,399,831	1,806,037
Total loans and leases	14,159,597	8,334,671
Allowance for loan and lease losses	(69,760)	(60,854)
Net loans and leases	14,089,837	8,273,817
Premises and equipment, net	503,188	296,238
Foreclosed assets	44,250	22,870
Accrued interest receivable	33,022	25,499
Bank owned life insurance (“BOLI”)	576,380	300,427
Intangible assets, net	722,153	152,340
Other, net	171,537	114,932
Total assets	18,451,783	9,879,459
LIABILITIES AND STOCKHOLDERS’ EQUITY
Demand non-interest bearing	2,562,913	1,515,482
Savings and interest bearing transaction	7,575,977	4,017,504
Time	4,984,914	2,438,482
Total deposits	15,123,804	7,971,468
Repurchase agreements with customers	70,640	65,800
Other borrowings	41,978	204,540
Subordinated notes	222,420
Subordinated debentures	118,102	117,685
Accrued interest payable and other liabilities	115,288	52,172
Total liabilities	15,692,232	8,411,665
Commitments and contingencies
Stockholders’ equity:
Preferred stock; $0.01 par value; 1,000,000 shares authorized; no shares outstanding at September 30, 2016 or December 31, 2015
Common stock; $0.01 par value; 300,000,000 and 125,000,000 shares authorized at September 30, 2016 and December 31, 2015, respectively; 121,134,158 and 90,612,388 shares issued at September 30, 2016 and December 31, 2015, respectively	1,211	906
Additional paid-in capital	1,894,864	755,995
Retained earnings	846,636	706,628
Accumulated other comprehensive income	13,635	7,959
Treasury stock, at cost, none at September 30, 2016 and 133,492 shares at December 31, 2015		(6,857)
Total stockholders’ equity before noncontrolling interest	2,756,346	1,464,631
Noncontrolling interest	3,205	3,163
Total stockholders’ equity	2,759,551	1,467,794
Total liabilities and stockholders’ equity	$ 18,451,783	$ 9,879,459

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	125,000,000
Common stock, shares issued	121,134,158	90,612,388
Treasury stock, Shares	0	133,492

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest income:
Non-purchased loans and leases	$ 109,365	$ 62,688	$ 294,410	$ 169,757
Purchased loans	77,208	33,255	132,942	101,877
Investment securities:
Taxable	3,102	3,253	7,815	9,968
Tax-exempt	4,549	4,280	11,708	13,405
Deposits with banks and federal funds sold	133	8	151	35
Total interest income	194,357	103,484	447,026	295,042
Interest expense:
Deposits	14,535	4,634	32,598	12,088
Repurchase agreements with customers	22	20	64	56
Other borrowings	286	1,459	880	4,605
Subordinated notes	3,259		3,542
Subordinated debentures	1,105	984	3,237	2,660
Total interest expense	19,207	7,097	40,321	19,409
Net interest income	175,150	96,387	406,705	275,633
Provision for loan and lease losses	(7,086)	(3,581)	(13,937)	(14,205)
Net interest income after provision for loan and lease losses	168,064	92,806	392,768	261,428
Non-interest income:
Service charges on deposit accounts	10,926	7,425	26,703	21,140
Mortgage lending income	2,616	1,825	5,957	5,104
Trust income	1,564	1,500	4,645	4,395
BOLI income	4,638	2,264	10,243	7,672
Other income from purchased loans, net	4,635	5,456	12,285	21,335
Gains on sales of other assets	594	1,905	2,619	7,290
Net gains on investment securities				2,619
Other	4,258	1,763	9,377	4,920
Total non-interest income	29,231	22,138	71,829	74,475
Non-interest expense:
Salaries and employee benefits	38,069	21,207	86,351	66,450
Net occupancy and equipment	11,669	8,076	28,587	22,711
Other operating expenses	29,043	16,145	62,457	50,175
Total non-interest expense	78,781	45,428	177,395	139,336
Income before taxes	118,514	69,516	287,202	196,567
Provision for income taxes	42,470	23,385	104,967	65,714
Net income	76,044	46,131	182,235	130,853
Earnings attributable to noncontrolling interest	(14)	(3)	(42)	(55)
Net income available to common stockholders	$ 76,030	$ 46,128	$ 182,193	$ 130,798
Basic earnings per common share	$ 0.66	$ 0.53	$ 1.84	$ 1.52
Diluted earnings per common share	0.66	0.52	1.84	1.51
Dividends declared per common share	$ 0.16	$ 0.14	$ 0.465	$ 0.405

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 76,044	$ 46,131	$ 182,235	$ 130,853
Other comprehensive income (loss):
Unrealized gains and losses on investment securities AFS	(2,262)	5,918	8,120	(1,274)
Tax effect of unrealized gains and losses on investment securities AFS	791	(2,265)	(2,444)	484
Reclassification of gains and losses on investment securities AFS included in net income				(2,619)
Tax effect of reclassification of gains and losses on investment securities AFS included in net income				998
Total other comprehensive income (loss)	(1,471)	3,653	5,676	(2,411)
Total comprehensive income	$ 74,573	$ 49,784	$ 187,911	$ 128,442

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Intervest Bancshares Corporation [Member]	Bank of Carolinas Corporation [Member]	C1 Financial, Inc. [Member]	Community & Southern Holdings, Inc. [Member]	Common Stock [Member]	Common Stock [Member]Intervest Bancshares Corporation [Member]	Common Stock [Member]Bank of Carolinas Corporation [Member]	Common Stock [Member]C1 Financial, Inc. [Member]	Common Stock [Member]Community & Southern Holdings, Inc. [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]Intervest Bancshares Corporation [Member]	Additional Paid-In Capital [Member]Bank of Carolinas Corporation [Member]	Additional Paid-In Capital [Member]C1 Financial, Inc. [Member]	Additional Paid-In Capital [Member]Community & Southern Holdings, Inc. [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Non-Controlling Interest [Member]
Balances at Dec. 31, 2014	$ 911,842					$ 799					$ 324,354					$ 571,454	$ 14,132	$ (2,349)	$ 3,452
Net income	130,853															130,853
Earnings attributable to noncontrolling interest																(55)			55
Total other comprehensive income (loss)	(2,411)																(2,411)
Common stock dividends paid	(34,280)															(34,280)
Dividend paid to non-controlling interest	(350)																		(350)
Issuance of common stock for exercise of stock options	1,286					1					1,285
Issuance of unvested restricted common stock						2					(2,351)							2,349
Excess tax benefit on exercise and forfeiture of stock options and restricted common stock	818										818
Stock-based compensation expense	6,214										6,214
Issuance of common stock for acquisition		$ 238,376	$ 65,326				$ 66	$ 15				$ 238,310	$ 65,311
Balances at Sep. 30, 2015	1,317,674					883					633,941					667,972	11,721		3,157
Balances at Dec. 31, 2015	1,467,794					906					755,995					706,628	7,959	(6,857)	3,163
Net income	182,235															182,235
Earnings attributable to noncontrolling interest																(42)			42
Total other comprehensive income (loss)	5,676																5,676
Common stock dividends paid	(42,185)															(42,185)
Issuance of common stock for exercise of stock options	1,255					1					1,254
Issuance of unvested restricted common stock						2					(6,859)							$ 6,857
Excess tax benefit on exercise and forfeiture of stock options and restricted common stock	962										962
Stock-based compensation expense	7,953										7,953
Issuance of common stock for acquisition				$ 348,315	$ 787,546				$ 93	$ 209				$ 348,222	$ 787,337
Balances at Sep. 30, 2016	$ 2,759,551					$ 1,211					$ 1,894,864					$ 846,636	$ 13,635		$ 3,205

Consolidated Statements of Sto7

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Common stock dividends paid	$ 0.465	$ 0.405
Issuance of common stock for exercise of stock options, shares	83,670	116,050
Issuance of unvested restricted common stock, shares	218,761	245,300
Forfeiture of unvested restricted common stock, shares	13,986	41,325
Issuance of common stock to non-employee directors, shares	12,415	7,657
Intervest Bancshares Corporation [Member]
Issuance of common stock for acquisitions		6,637,243
Common stock issuance costs		$ 100,000
Bank of Carolinas Corporation [Member]
Issuance of common stock for acquisitions		1,447,620
Common stock issuance costs		$ 64,000
Community & Southern Holdings, Inc. [Member]
Issuance of common stock for acquisitions	20,983,815
Common stock issuance costs	$ 395,000
C1 Financial, Inc. [Member]
Issuance of common stock for acquisitions	9,370,587
Common stock issuance costs	$ 82,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income	$ 182,235	$ 130,853
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	10,268	7,252
Amortization	6,402	4,934
Earnings attributable to noncontrolling interest	(42)	(55)
Provision for loan and lease losses	13,937	14,205
Provision for losses on foreclosed assets	2,117	2,980
Net amortization of investment securities AFS	3,446	41
Net gains on investment securities AFS	0	(2,619)
Originations of mortgage loans held for sale	(204,085)	(197,989)
Proceeds from sales of mortgage loans held for sale	191,923	196,756
Accretion of purchased loans	(40,734)	(41,217)
Gains on sales of other assets	(2,619)	(7,290)
Prepayment penalty on Federal Home Loan Bank of Dallas advances		2,480
Deferred income tax expense	4,102	6,940
Increase in cash surrender value of BOLI	(9,434)	(5,383)
BOLI death benefits in excess of cash surrender value	(809)	(2,289)
Stock-based compensation expense	7,953	6,214
Excess tax benefit on stock-based compensation	(962)	(818)
Changes in assets and liabilities:
Accrued interest receivable	4,833	(5,547)
Other assets, net	(5,429)	30,723
Accrued interest payable and other liabilities	(2,862)	(2,358)
Net cash provided by operating activities	160,240	137,813
Cash flows from investing activities:
Proceeds from sales of investment securities AFS	0	32,777
Proceeds from maturities/calls/paydowns of investment securities AFS	145,386	111,838
Purchases of investment securities AFS	(382,583)	(61,534)
Net increase of non-purchased loans and leases	(2,232,950)	(1,495,210)
Net payments received on purchased loans	751,073	565,154
Purchases of premises and equipment	(34,455)	(11,978)
Purchases of BOLI	(145,000)	(85,000)
Proceeds from BOLI death benefits	2,116	3,149
Proceeds from sales of other assets	22,678	48,514
Cash received from (invested in) unconsolidated investments and noncontrolling interest	345	(1,056)
Net cash received in merger and acquisition transactions	203,695	299,810
Net cash used by investing activities	(1,669,695)	(593,536)
Cash flows from financing activities:
Net increase in deposits	2,586,932	636,870
Net repayments of other borrowings	(386,130)	(31,475)
Net increase in repurchase agreements with customers	4,840	13,925
Proceeds from exercise of stock options	1,255	1,286
Proceeds from issuance of subordinated notes	222,315
Excess tax benefit on stock-based compensation	962	818
Cash dividends paid on common stock	(42,185)	(34,280)
Net cash provided by financing activities	2,387,989	587,144
Net increase in cash and cash equivalents	878,534	131,421
Cash and cash equivalents – beginning of period	90,988	150,203
Cash and cash equivalents – end of period	$ 969,522	$ 281,624

Organization and Principles of

Organization and Principles of Consolidation	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Principles of Consolidation	1. Organization and Principles of Consolidation Bank of the Ozarks, Inc. (the “Company”) is a financial holding company headquartered in Little Rock, Arkansas, which operates under the rules and regulations of the Board of Governors of the Federal Reserve System. The Company owns a wholly-owned state chartered bank subsidiary – Bank of the Ozarks (the “Bank”), eight 100%-owned finance subsidiary business trusts – Ozark Capital Statutory Trust II (“Ozark II”), Ozark Capital Statutory Trust III (“Ozark III”), Ozark Capital Statutory Trust IV (“Ozark IV”), Ozark Capital Statutory Trust V (“Ozark V”) (collectively, the “Ozark Trusts”), Intervest Statutory Trust II (“Intervest II”), Intervest Statutory Trust III (“Intervest III”), Intervest Statutory Trust IV (“Intervest IV”) and Intervest Statutory Trust V (“Intervest V”), (collectively, the “Intervest Trusts”; and together with Ozark Trusts, the “Trusts”) and, indirectly through the Bank, a subsidiary that holds the Company’s investment securities, a subsidiary engaged in the development of real estate, a subsidiary that owns private aircraft and various other entities that hold loans, foreclosed assets or tax credits or engage in other activities. The Company and Bank are subject to the regulation of certain federal and state agencies and undergo periodic examinations by those regulatory authorities. The consolidated financial statements include the accounts of the Company, the Bank, the investment subsidiary, the real estate subsidiary, the aircraft subsidiary and certain of those various other entities in accordance with accounting principles generally accepted in the United States (“GAAP”). Significant intercompany transactions and amounts have been eliminated in consolidation. At September 30, 2016, the Company had 255 offices, including 83 in Arkansas, 73 in Georgia, 44 in Florida, 24 in North Carolina, 22 in Texas, three in Alabama and two offices each in South Carolina, New York and California.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation	2. Basis of Presentation The accompanying consolidated financial statements have been prepared by the Company, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) in Article 10 of Regulation S-X and in accordance with the instructions to Form 10-Q and GAAP for interim financial information. Certain information, accounting policies and footnote disclosures normally included in complete financial statements prepared in accordance with GAAP have been condensed or omitted in accordance with such rules and regulations. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. In the opinion of management, all adjustments considered necessary, consisting of normal recurring items, have been included for a fair statement of the accompanying consolidated financial statements. Operating results for the three months and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the full year or future periods. As provided under GAAP, management has up to twelve months following the date of an acquisition to finalize the fair values of the acquired assets and assumed liabilities. Once management has finalized the fair values of acquired assets and assumed liabilities within this 12-month period, management considers such values to be the day 1 fair values (“Day 1 Fair Values”). Certain reclassifications of prior period amounts have been made to conform with the current period presentation. These reclassifications had no impact on previously reported net income.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Acquisitions	3. Acquisitions Community & Southern Holdings, Inc. On July 20, 2016, the Company completed its acquisition of Community & Southern Holdings, Inc. (“C&S”) and its wholly-owned bank subsidiary, Community & Southern Bank, in a transaction valued at approximately $800.3 million. Pursuant to the terms of the merger agreement, the Company issued 20,983,815 shares of its common stock (plus cash in lieu of fractional shares) to C&S stockholders and to holders of outstanding C&S stock options, restricted stock units, deferred stock units and warrants in satisfaction of all outstanding C&S equity awards (net of shares withheld for taxes). The acquisition of C&S provided the Company with 46 banking offices throughout Georgia and one banking office in Jacksonville, Florida. On September 23, 2016, the Company closed one of the acquired banking offices in Georgia. The following table provides a summary of the assets acquired and liabilities assumed as recorded by C&S, the estimates of the fair value adjustments necessary to adjust those acquired assets and assumed liabilities to estimated fair value and the estimates of the resultant fair values of those assets and liabilities as recorded by the Company. The fair value adjustments and the resultant fair values shown in the following table continue to be evaluated and may be subject to further adjustment. July 20, 2016 As Recorded by C&S Fair Value Adjustments (1) As Recorded by the Company (1) (Dollars in thousands) Assets acquired: Cash, due from banks and interest earning deposits $ 72,942 $ — $ 72,942 Investment securities 447,674 4,063 a 451,737 Loans 3,090,579 (61,649 ) b 3,028,930 Allowance for loan losses (42,395 ) 42,395 b — Premises and equipment 73,238 31,969 c 105,207 Foreclosed assets 6,274 (521 ) d 5,753 BOLI 86,596 (45 ) e 86,551 Goodwill 44,514 (44,514 ) f — Core deposit intangible asset 12,227 21,327 g 33,554 Deferred income taxes 23,298 (9,059 ) h 14,239 Accrued interest receivable and other assets 38,226 (2,003 ) i 36,223 Total assets acquired 3,853,173 (18,037 ) 3,835,136 Liabilities assumed: Deposits 3,256,372 11,813 j 3,268,185 Other borrowings 90,000 — 90,000 Accrued interest payable and other liabilities 22,991 (585 ) k 22,406 Total liabilities assumed 3,369,363 11,228 3,380,591 Net assets acquired $ 483,810 $ (29,265 ) 454,545 Consideration paid: Cash (12,336 ) Stock (787,942 ) Total consideration paid (800,278 ) Goodwill $ 345,733 (1) Management continues to evaluate and may revise, if necessary, one or more of the fair value adjustments in future periods. To the extent that any of these fair value adjustments are revised in future periods, the resultant fair values and the amount of goodwill may be subject to further adjustment. Explanation of preliminary fair value adjustments a- Adjustment reflects the fair value adjustment based on the pricing of the acquired held to maturity investment securities portfolio. b- Adjustment reflects the fair value adjustment based on the evaluation of the acquired loan portfolio and to eliminate the recorded allowance for loan losses. c- Adjustment reflects the fair value adjustment based on the evaluation of the premises and equipment acquired. d- Adjustment reflects the fair value adjustment based on the evaluation of the acquired foreclosed assets. e- Adjustment reflects the fair value adjustment based on the evaluation of BOLI acquired. f- Adjustment reflects the elimination of previously recorded goodwill. g- Adjustment reflects the fair value adjustment for the core deposit intangible asset recorded as a result of the acquisition net of the elimination of previously recorded core deposit intangible assets. h- This adjustment reflects the differences in the carrying values of acquired assets and assumed liabilities for financial reporting purposes and their basis for federal income tax purposes. i - Adjustment reflects the fair value adjustment based on the evaluation of accrued interest receivable and other assets. j- Adjustment reflects the fair value adjustment based on the evaluation of the acquired deposits. k- Adjustment reflects the amount needed to adjust other liabilities to estimated fair value and to record certain liabilities directly attributable to the C&S acquisition. Goodwill of $345.7 million, which is the excess of the merger consideration over the estimated fair value of net assets acquired, was recorded in the C&S acquisition and is the result of expected operational synergies, expansion of full service banking in Georgia and other factors. This goodwill is not expected to be deductible for tax purposes. Management continues to evaluate the fair value adjustments and the resultant fair values of acquired assets and assumed liabilities recorded in the C&S acquisition. To the extent that management revises any of the fair value adjustments, the amount of goodwill recorded in the C&S acquisition may be subject to further adjustment. The Company’s consolidated results of operations include the operating results of C&S beginning July 21, 2016 through the end of the reporting period. For both the three months and nine months ended September 30, 2016, C&S contributed approximately $37.0 million of net interest income and approximately $17.5 million of net income to the Company’s operating results. The following unaudited supplemental pro forma information is presented to show the estimated results assuming C&S was acquired as of the beginning of each period presented, adjusted for estimated costs savings. These unaudited pro forma results are not necessarily indicative of the operating results that the Company would have achieved had it completed the acquisition as of January 1, 2015 or 2016 and should not be considered as representative of future operating results. Nine Months Ended September 30, 2016 2015 (Dollars in thousands, except per share amounts) Net interest income – pro forma (unaudited) $ 493,602 $ 404,497 Net income – pro forma (unaudited) $ 222,029 $ 176,635 Diluted earnings per common share – pro forma (unaudited) $ 1.94 $ 1.64 C1 Financial, Inc. On July 21, 2016, the Company completed its acquisition of C1 Financial, Inc. (“C1”) and its wholly-owned bank subsidiary, C1 Bank, in a transaction valued at approximately $376.1 million. Pursuant to the terms of the merger agreement and immediately after the effective time of the C1 Merger and in accordance with the terms of the Brazilian standby purchase agreement dated December 21, 2015, the Company sold certain C1 Bank loans (“Brazilian Loans”) equal to the aggregate purchase price of the Brazilian Loans. As a result of the closing of the C1 Merger, the Company issued 9,370,587 shares of its common stock to C1 shareholders, net of the shares redeemed in exchange for the Brazilian Loans. The acquisition of C1 provided the Company with 33 banking offices throughout the west coast of Florida and in Miami-Dade and Orange counties. The following table provides a summary of the assets acquired and liabilities assumed as recorded by C1, the estimates of the fair value adjustments necessary to adjust those acquired assets and assumed liabilities to estimated fair value and the estimates of the resultant fair values of those assets and liabilities as recorded by the Company. The fair value adjustments and the resultant fair values shown in the following table continue to be evaluated and may be subject to further adjustment. July 21, 2016 As Recorded by C1 Fair Value Adjustments (1) As Recorded by the Company (1) (Dollars in thousands) Assets acquired: Cash, due from banks and interest earning deposits $ 143,592 $ — $ 143,592 Investment securities 7,618 (28 ) a 7,590 Loans 1,353,498 (40,456 ) b 1,313,042 Allowance for loan losses (7,307 ) 7,307 b — Premises and equipment 63,943 13,690 c 77,633 Foreclosed assets 21,704 (1,656 ) d 20,048 BOLI 36,280 — 36,280 Core deposit and other intangible assets 576 9,198 e 9,774 Deferred income taxes 1,608 8,288 f 9,896 Accrued interest receivable and other assets 12,182 (3,124 ) g 9,058 Total assets acquired 1,633,694 (6,781 ) 1,626,913 Liabilities assumed: Deposits 1,294,439 2,779 h 1,297,218 Other borrowings 131,010 2,558 i 133,568 Accrued interest payable and other liabilities 4,775 1,040 j 5,815 Total liabilities assumed 1,430,224 6,377 1,436,601 Net assets acquired $ 203,470 $ (13,158 ) 190,312 Consideration paid: Cash and shares redeemed for Brazilian Loans (27,694 ) Stock (348,397 ) Total consideration paid (376,091 ) Goodwill $ 185,779 (1) Management continues to evaluate and may revise, if necessary, one or more of the fair value adjustments in future periods. To the extent that any of these fair value adjustments are revised in future periods, the resultant fair values and the amount of goodwill may be subject to further adjustment. Explanation of preliminary fair value adjustments a- Adjustment reflects the fair value adjustment based on the pricing of the acquired investment securities portfolio. b- Adjustment reflects the fair value adjustment based on the evaluation of the acquired loan portfolio and to eliminate the recorded allowance for loan losses. c- Adjustment reflects the fair value adjustment based on the evaluation of the premises and equipment acquired. d- Adjustment reflects the fair value adjustment based on the evaluation of the acquired foreclosed assets. e- Adjustment reflects the fair value adjustment for the core deposit and other intangible assets recorded as a result of the acquisition. f- This adjustment reflects the differences in the carrying values of acquired assets and assumed liabilities for financial reporting purposes and their basis for federal income tax purposes. g- Adjustment reflects the fair value adjustment based on the evaluation of accrued interest receivable and other assets. h- Adjustment reflects the fair value adjustment based on the evaluation of the acquired deposits. i - Adjustment reflects the fair value adjustment of these assumed liabilities. j- Adjustment reflects the amount needed to adjust other liabilities to estimated fair value and to record certain liabilities directly attributable to the C1 acquisition. Goodwill of $185.8 million, which is the excess of the merger consideration over the estimated fair value of net assets acquired, was recorded in the C1 acquisition and is the result of expected operational synergies, expansion of full service banking throughout the west coast of Florida and in Miami-Dade and Orange counties, the acquisition of the former C1 labs innovation group and other factors. This goodwill is not expected to be deductible for tax purposes. Management continues to evaluate the fair value adjustments and the resultant fair values of acquired assets and assumed liabilities recorded in the C1 acquisition. To the extent that management revises any of the fair value adjustments, the amount of goodwill recorded in the C1 acquisition may be subject to further adjustment. The Company’s consolidated results of operations include the operating results of C1 beginning July 22, 2016 through the end of the reporting period. For both the three months and nine months ended September 30, 2016, C1 contributed approximately $16.2 million of net interest income and approximately $7.2 million of net income to the Company’s operating results. The following unaudited supplemental pro forma information is presented to show the estimated results assuming C1 was acquired as of the beginning of each period presented, adjusted for estimated costs savings. These unaudited pro forma results are not necessarily indicative of the operating results that the Company would have achieved had it completed the acquisition as of January 1, 2015 or 2016 and should not be considered as representative of future operating results. Nine Months Ended September 30, 2016 2015 (Dollars in thousands, except per share amounts) Net interest income – pro forma (unaudited) $ 448,903 $ 334,960 Net income – pro forma (unaudited) $ 198,814 $ 152,847 Diluted earnings per common share – pro forma (unaudited) $ 1.88 $ 1.42

Earnings Per Common Share ("EPS

Earnings Per Common Share ("EPS")	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Common Share ("EPS")	4. Earnings Per Common Share (“EPS”) Basic EPS is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding. Diluted EPS is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding after consideration of the dilutive effect, if any, of outstanding common stock options using the treasury stock method. For the three months and nine months ended September 30, 2016, options to purchase 648,135 shares and 652,077 shares, respectively, of the Company’s common stock were excluded from the diluted EPS calculations, and for the three months and nine months ended September 30, 2015, options to purchase 4,000 shares and 519,270 shares, respectively, of the Company’s common stock were excluded from the diluted EPS calculations as inclusion of such options during such periods would have been anti-dilutive. The following table presents the computation of basic and diluted EPS for the periods indicated. Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 (In thousands, except per share amounts) Numerator: Distributed earnings allocated to common stockholders $ 14,521 $ 12,154 $ 42,185 $ 34,280 Undistributed earnings allocated to common stockholders 61,509 33,974 140,008 96,518 Net income available to common stockholders $ 76,030 $ 46,128 $ 182,193 $ 130,798 Denominator: Denominator for basic EPS – weighted-average common shares 114,745 87,683 98,779 86,070 Effect of dilutive securities – stock options 262 771 285 769 Denominator for diluted EPS – weighted-average common shares and assumed conversions 115,007 88,454 99,064 86,839 Basic EPS $ 0.66 $ 0.53 $ 1.84 $ 1.52 Diluted EPS $ 0.66 $ 0.52 $ 1.84 $ 1.51

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Investment Securities	5. Investment Securities At both September 30, 2016 and December 31, 2015, the Company classified all of its investment securities portfolio as AFS. Accordingly, investment securities are stated at estimated fair value in the consolidated financial statements with unrealized gains and losses, net of related income tax, reported as a separate component of stockholders’ equity and included in accumulated other comprehensive income. The following table presents the amortized cost and estimated fair value of investment securities AFS as of the dates indicated. The Company’s investment in the “CRA qualified investment fund” includes shares held in a mutual fund that qualifies under the Community Reinvestment Act of 1977 for community reinvestment purposes. The Company’s holdings of “other equity securities” include Federal Home Loan Bank of Dallas (“FHLB”) and First National Banker’s Bankshares, Inc. (“FNBB”) shares which do not have readily determinable fair values and are carried at cost. Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (Dollars in thousands) September 30, 2016: Obligations of state and political subdivisions $ 735,494 $ 16,325 $ (1,094 ) $ 750,725 U.S. Government agency securities 568,130 6,224 (418 ) 573,936 Corporate obligations 10,089 — (67 ) 10,022 CRA qualified investment fund 1,055 7 — 1,062 Other equity securities 6,149 — — 6,149 Total $ 1,320,917 $ 22,556 $ (1,579 ) $ 1,341,894 December 31, 2015: Obligations of state and political subdivisions $ 415,095 $ 12,321 $ (138 ) $ 427,278 U.S. Government agency securities 146,265 1,720 (1,035 ) 146,950 Corporate obligations 3,562 — — 3,562 CRA qualified investment fund 1,038 — (10 ) 1,028 Other equity securities 23,530 — — 23,530 Total $ 589,490 $ 14,041 $ (1,183 ) $ 602,348 The following table shows estimated fair value of investment securities AFS having gross unrealized losses and the amount of such unrealized losses, aggregated by investment category and length of time that individual investment securities have been in a continuous unrealized loss position, as of the dates indicated. Less than 12 Months 12 Months or More Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) September 30, 2016: Obligations of state and political subdivisions $ 128,359 $ 1,084 $ 4,747 $ 10 $ 133,106 $ 1,094 U.S. Government agency securities 91,380 412 161 6 91,541 418 Corporate obligations 7,022 67 — — 7,022 67 Total temporarily impaired securities $ 226,761 $ 1,563 $ 4,908 $ 16 $ 231,669 $ 1,579 December 31, 2015: Obligations of state and political subdivisions $ 18,018 $ 114 $ 6,167 $ 24 $ 24,185 $ 138 U.S. Government agency securities 72,671 930 4,381 105 77,052 1,035 CRA qualified investment fund 1,029 10 — — 1,029 10 Total temporarily impaired securities $ 91,718 $ 1,054 $ 10,548 $ 129 $ 102,266 $ 1,183 In evaluating the Company’s unrealized loss positions for other-than-temporary impairment of its investment securities portfolio, management considers the credit quality of the issuer, the nature and cause of the unrealized loss, the severity and duration of the impairments and other factors. At both September 30, 2016 and December 31, 2015, management determined the unrealized losses were the result of fluctuations in interest rates and did not reflect deteriorations of the credit quality of the investments. Accordingly, management considers these unrealized losses to be temporary in nature. The Company does not have the intent to sell these investment securities with unrealized losses and, more likely than not, will not be required to sell these investment securities before fair value recovers to amortized cost. The following table shows the amortized cost and estimated fair value of investment securities AFS by maturity or estimated date of repayment as of the date indicated. September 30, 2016 Maturity or Estimated Repayment Amortized Cost Estimated Fair Value (Dollars in thousands) One year or less $ 99,489 $ 100,484 After one year to five years 341,412 344,840 After five years to ten years 308,141 313,543 After ten years 571,875 583,027 Total $ 1,320,917 $ 1,341,894 For purposes of this maturity or repayment distribution, all investment securities AFS are shown based on their contractual maturity date or estimated date of repayment, except (i) FHLB and FNBB equity securities and the CRA qualified investment fund with no contractual maturity date are shown in the longest maturity category and (ii) U.S. Government agency securities and municipal housing authority securities backed by residential mortgages are allocated among various maturities or repayment categories based on an estimated repayment schedule utilizing Bloomberg median prepayment speeds or other estimates of prepayment speeds and interest rate levels at the measurement date. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. The following table is a summary of sales activities in the Company’s investment securities AFS for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Sales proceeds $ — $ — $ — $ 32,777 Gross realized gains — — — 2,620 Gross realized losses — — — (1 ) Net gains on investment securities $ — $ — $ — $ 2,619

Allowance for Loan and Lease Lo

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators	6. Allowance for Loan and Lease Losses (“ALLL”) and Credit Quality Indicators Allowance for Loan and Lease Losses The following table is a summary of activity within the ALLL for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Beginning balance $ 65,133 $ 56,749 $ 60,854 $ 52,918 Charge-offs of non-purchased loans and leases (1,791 ) (992 ) (4,356 ) (6,567 ) Recoveries of non-purchased loans and leases previously charged off 418 360 862 866 Net charge-offs – non-purchased loans and leases (1,373 ) (632 ) (3,494 ) (5,701 ) Chrage-offs of purchased loans (1,197 ) (829 ) (1,732 ) (2,945 ) Recoveries of purchased loans previously charged off 111 148 195 540 Net charge-offs – purchased loans (1,086 ) (681 ) (1,537 ) (2,405 ) Net charge-offs – total loans and leases (2,459 ) (1,313 ) (5,031 ) (8,106 ) Provision for loan and lease losses: Non-purchased loans and leases 5,600 2,900 12,000 11,800 Purchased loans 1,486 681 1,937 2,405 Total provision 7,086 3,581 13,937 14,205 Ending balance $ 69,760 $ 59,017 $ 69,760 $ 59,017 ALLL allocated to non-purchased loans and leases $ 68,160 $ 59,017 $ 68,160 $ 59,017 ALLL allocated to purchased loans 1,600 — 1,600 — Total ALLL $ 69,760 $ 59,017 $ 69,760 $ 59,017 The following tables are a summary of the Company’s ALLL for the periods indicated. Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Three months ended September 30, 2016: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 10,099 $ (94 ) $ 6 $ 312 $ 10,323 Non-farm/non-residential 19,118 (236 ) — 754 19,636 Construction/land development 17,496 (22 ) 2 2,582 20,058 Agricultural 3,755 — — (373 ) 3,382 Multifamily residential 3,661 — — (12 ) 3,649 Commercial and industrial 3,790 (45 ) 13 182 3,940 Consumer 712 (19 ) 1 870 1,564 Direct financing leases 4,092 (795 ) 4 842 4,143 Other 1,210 (580 ) 392 443 1,465 Total non-purchased loans and leases 63,933 (1,791 ) 418 5,600 68,160 Purchased loans 1,200 (1,197 ) 111 1,486 1,600 Total loans and leases $ 65,133 $ (2,988 ) $ 529 $ 7,086 $ 69,760 Nine months ended September 30, 2016: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 8,672 $ (350 ) $ 43 $ 1,958 $ 10,323 Non-farm/non-residential 16,796 (248 ) — 3,088 19,636 Construction/land development 18,176 (42 ) 53 1,871 20,058 Agricultural 3,388 (7 ) — 1 3,382 Multifamily residential 3,031 — 14 604 3,649 Commercial and industrial 2,574 (87 ) 52 1,401 3,940 Consumer 707 (87 ) 15 929 1,564 Direct financing leases 3,835 (2,263 ) 20 2,551 4,143 Other 2,475 (1,272 ) 665 (403 ) 1,465 Total non-purchased loans and leases 59,654 (4,356 ) 862 12,000 68,160 Purchased loans 1,200 (1,732 ) 195 1,937 1,600 Total loans and leases $ 60,854 $ (6,088 ) $ 1,057 $ 13,937 $ 69,760 Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Three months ended September 30, 2015: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 5,601 $ (121 ) $ 37 $ 92 $ 5,609 Non-farm/non-residential 18,232 (6 ) 1 (144 ) 18,083 Construction/land development 19,148 (38 ) 40 1,997 21,147 Agricultural 2,460 — — 12 2,472 Multifamily residential 2,886 (20 ) — 42 2,908 Commercial and industrial 3,249 (132 ) 149 (106 ) 3,160 Consumer 825 (11 ) 5 34 853 Direct financing leases 3,554 (222 ) 7 522 3,861 Other 794 (442 ) 121 451 924 Total non-purchased loans and leases 56,749 (992 ) 360 2,900 59,017 Purchased loans — (829 ) 148 681 — Total loans and leases $ 56,749 $ (1,821 ) $ 508 $ 3,581 $ 59,017 Nine months ended September 30, 2015: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 5,482 $ (742 ) $ 58 $ 811 $ 5,609 Non-farm/non-residential 17,190 (330 ) 18 1,205 18,083 Construction/land development 15,960 (809 ) 77 5,919 21,147 Agricultural 2,558 (13 ) — (73 ) 2,472 Multifamily residential 2,147 (228 ) — 989 2,908 Commercial and industrial 4,873 (2,672 ) 188 771 3,160 Consumer 818 (80 ) 47 68 853 Direct financing leases 2,989 (563 ) 20 1,415 3,861 Other 901 (1,130 ) 458 695 924 Total non-purchased loans and leases 52,918 (6,567 ) 866 11,800 59,017 Purchased loans — (2,945 ) 540 2,405 — Total loans and leases $ 52,918 $ (9,512 ) $ 1,406 $ 14,205 $ 59,017 The following table is a summary of the Company’s ALLL for non-purchased loans and leases and recorded investment in non-purchased loans and leases as of the dates indicated. ALLL for Non-Purchased Loans and Leases Non-Purchased Loans and Leases ALLL for Individually Evaluated Impaired Loans and Leases ALLL for All Other Loans and Leases Total ALLL (1) Individually Evaluated Impaired Loans and Leases All Other Loans and Leases Total Loans and Leases (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 32 $ 10,291 $ 10,323 $ 1,006 $ 429,538 $ 430,544 Non-farm/non-residential 4 19,632 19,636 1,562 2,393,280 2,394,842 Construction/land development 73 19,985 20,058 435 4,201,430 4,201,865 Agricultural 404 2,978 3,382 1,265 90,164 91,429 Multifamily residential — 3,649 3,649 — 518,702 518,702 Commercial and industrial 513 3,427 3,940 683 255,422 256,105 Consumer 3 1,561 1,564 23 114,968 114,991 Direct financing leases — 4,143 4,143 — 131,646 131,646 Other — 1,465 1,465 6 619,636 619,642 Total $ 1,029 $ 67,131 $ 68,160 $ 4,980 $ 8,754,786 $ 8,759,766 December 31, 2015: Real estate: Residential 1-4 family $ 297 $ 8,375 $ 8,672 $ 2,030 $ 348,224 $ 350,254 Non-farm/non-residential 31 16,765 16,796 940 2,009,926 2,010,866 Construction/land development 48 18,128 18,176 5,556 2,820,019 2,825,575 Agricultural 475 2,913 3,388 1,313 73,127 74,440 Multifamily residential — 3,031 3,031 83 440,745 440,828 Commercial and industrial 487 2,087 2,574 714 230,567 231,281 Consumer 2 705 707 24 27,721 27,745 Direct financing leases — 3,835 3,835 — 147,735 147,735 Other — 2,475 2,475 7 419,903 419,910 Total $ 1,340 $ 58,314 $ 59,654 $ 10,667 $ 6,517,967 $ 6,528,634 (1) Excludes $1.6 million and $1.2 million of ALLL allocated to the Company’s purchased loans at September 30, 2016 and December 31, 2015, respectively. The following table is a summary of impaired non-purchased loans and leases as of and for the three months and nine months ended September 30, 2016. Principal Balance Net Charge-offs to Date Principal Balance, Net of Charge-offs Specific ALLL Weighted Average Carrying Value – Three Months Ended September 30, 2016 Weighted Average Carrying Value – Nine Months Ended September 30, 2016 (Dollars in thousands) Impaired loans and leases for which there is a related ALLL: Real estate: Residential 1-4 family $ 348 $ (215 ) $ 133 $ 32 $ 568 $ 939 Non-farm/non-residential 928 (924 ) 4 4 89 71 Construction/land development 130 — 130 73 124 122 Agricultural 1,081 — 1,081 404 1,113 1,132 Commercial and industrial 838 (325 ) 513 513 510 511 Consumer 17 (4 ) 13 3 23 17 Total impaired loans and leases with a related ALLL 3,342 (1,468 ) 1,874 1,029 2,427 2,792 Impaired loans and leases for which there is not a related ALLL: Real estate: Residential 1-4 family 1,312 (439 ) 873 — 981 939 Non-farm/non-residential 2,021 (463 ) 1,558 — 1,209 1,042 Construction/land development 1,115 (810 ) 305 — 234 2,398 Agricultural 393 (209 ) 184 — 183 177 Multifamily residential 133 (133 ) — — — 41 Commercial and industrial 220 (50 ) 170 — 185 196 Consumer 15 (5 ) 10 — 10 11 Other 6 — 6 — 6 6 Total impaired loans and leases without a related ALLL 5,215 (2,109 ) 3,106 — 2,808 4,810 Total impaired non-purchased loans and leases $ 8,557 $ (3,577 ) $ 4,980 $ 1,029 $ 5,235 $ 7,602 The following table is a summary of impaired non-purchased loans and leases as of and for the year ended December 31, 2015. Principal Balance Net Charge-offs to Date Principal Balance, Net of Charge-offs Specific ALLL Weighted Average Carrying Value – Year Ended December 31, 2015 (Dollars in thousands) Impaired loans and leases for which there is a related ALLL: Real estate: Residential 1-4 family $ 2,914 $ (1,804 ) $ 1,110 $ 297 $ 1,279 Non-farm/non-residential 962 (907 ) 55 31 129 Construction/land development 121 — 121 48 896 Agricultural 1,153 — 1,153 475 479 Commercial and industrial 825 (322 ) 503 487 404 Consumer 26 (15 ) 11 2 16 Total impaired loans and leases with a related ALLL 6,001 (3,048 ) 2,953 1,340 3,203 Impaired loans and leases for which there is not a related ALLL: Real estate: Residential 1-4 family 1,306 (386 ) 920 — 955 Non-farm/non-residential 1,083 (198 ) 885 — 1,137 Construction/land development 7,873 (2,438 ) 5,435 — 8,255 Agricultural 362 (202 ) 160 — 261 Multifamily residential 216 (133 ) 83 — 155 Commercial and industrial 261 (50 ) 211 — 141 Consumer 18 (5 ) 13 — 14 Other 7 — 7 — 7 Total impaired loans and leases without a related ALLL 11,126 (3,412 ) 7,714 — 10,925 Total impaired non-purchased loans and leases $ 17,127 $ (6,460 ) $ 10,667 $ 1,340 $ 14,128 Management has determined that certain of the Company’s impaired non-purchased loans and leases do not require any specific allowance at September 30, 2016 or at December 31, 2015 because (i) management’s analysis of such individual loans and leases resulted in no impairment or (ii) all identified impairment on such loans and leases had previously been charged off. Interest income on impaired non-purchased loans and leases is recognized on a cash basis when and if actually collected. Total interest income recognized on impaired non-purchased loans and leases for the three and nine months ended September 30, 2016 and 2015 was not material. Credit Quality Indicators Non-Purchased Loans and Leases The following table is a summary of credit quality indicators for the Company’s non-purchased loans and leases as of the dates indicated. Satisfactory Moderate Watch Substandard Total (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family (1) $ 423,398 $ — $ 3,226 $ 3,920 $ 430,544 Non-farm/non-residential 2,069,077 272,746 47,063 5,956 2,394,842 Construction/land development 3,875,564 315,893 9,051 1,357 4,201,865 Agricultural 48,128 31,768 9,328 2,205 91,429 Multifamily residential 469,810 45,077 2,771 1,044 518,702 Commercial and industrial 161,387 87,302 6,305 1,111 256,105 Consumer (1) 114,617 — 120 254 114,991 Direct financing leases 130,560 56 234 796 131,646 Other (1) 613,799 5,610 222 11 619,642 Total $ 7,906,340 $ 758,452 $ 78,320 $ 16,654 $ 8,759,766 December 31, 2015: Real estate: Residential 1-4 family (1) $ 342,083 $ — $ 2,946 $ 5,225 $ 350,254 Non-farm/non-residential 1,692,632 235,999 73,788 8,447 2,010,866 Construction/land development 2,553,368 256,655 8,916 6,636 2,825,575 Agricultural 40,538 22,799 8,909 2,194 74,440 Multifamily residential 400,848 35,080 4,079 821 440,828 Commercial and industrial 179,797 47,802 1,854 1,828 231,281 Consumer (1) 27,219 — 276 250 27,745 Direct financing leases 146,934 201 190 410 147,735 Other (1) 415,686 4,027 182 15 419,910 Total $ 5,799,105 $ 602,563 $ 101,140 $ 25,826 $ 6,528,634 (1) The Company does not risk rate its residential 1-4 family loans, its consumer loans, and certain “other” loans. However, for purposes of the above table, the Company considers such loans to be (i) satisfactory – if they are performing and less than 30 days past due, (ii) watch – if they are performing and 30 to 89 days past due or (iii) substandard – if they are nonperforming or 90 days or more past due. The following categories of credit quality indicators are used by the Company. Satisfactory Moderate Watch Substandard The following table is an aging analysis of past due non-purchased loans and leases as of the dates indicated. 30-89 Days Past Due (1) 90 Days or More (2) Total Past Due Current (3) Total (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 3,330 $ 1,607 $ 4,937 $ 425,607 $ 430,544 Non-farm/non-residential 2,617 1,716 4,333 2,390,509 2,394,842 Construction/land development 2,403 204 2,607 4,199,258 4,201,865 Agricultural 150 228 378 91,051 91,429 Multifamily residential 779 — 779 517,923 518,702 Commercial and industrial 83 750 833 255,272 256,105 Consumer 125 53 178 114,813 114,991 Direct financing leases 418 659 1,077 130,569 131,646 Other 30 6 36 619,606 619,642 Total $ 9,935 $ 5,223 $ 15,158 $ 8,744,608 $ 8,759,766 December 31, 2015: Real estate: Residential 1-4 family $ 2,793 $ 1,507 $ 4,300 $ 345,954 $ 350,254 Non-farm/non-residential 1,881 777 2,658 2,008,208 2,010,866 Construction/land development 1,043 5,645 6,688 2,818,887 2,825,575 Agricultural 1,780 243 2,023 72,417 74,440 Multifamily residential — 83 83 440,745 440,828 Commercial and industrial 823 751 1,574 229,707 231,281 Consumer 248 33 281 27,464 27,745 Direct financing leases 517 321 838 146,897 147,735 Other 8 7 15 419,895 419,910 Total $ 9,093 $ 9,367 $ 18,460 $ 6,510,174 $ 6,528,634 (1) Includes $0.3 million and $1.9 million at September 30, 2016 and December 31, 2015, respectively, of loans and leases on nonaccrual status. (2) All loans and leases greater than 90 days past due were on nonaccrual status at September 30, 2016 and December 31, 2015. (3) Includes $1.8 million and $2.3 million of loans and leases on nonaccrual status at September 30, 2016 and December 31, 2015, respectively. Purchased Loans As of September 30, 2016, the Company had identified purchased loans where it had determined it was probable that the Company would be unable to collect all amounts according to the contractual terms thereof (for purchased loans without evidence of credit deterioration at date of acquisition) or the expected performance of such loans had deteriorated from its performance expectations established in conjunction with the determination of the Day 1 Fair Values or since its most recent review of such portfolio’s performance (for purchased loans with evidence of credit deterioration at date of acquisition). At September 30, 2016, the Company had $6.0 million of impaired purchased loans compared to $8.1 million at December 31, 2015. The following table is a summary of credit quality indicators for the Company’s purchased loans as of the dates indicated. Purchased Loans Without Evidence of Credit Deterioration at Acquisition Purchased Loans With Evidence of Credit Deterioration at Acquisition Total Purchased FV 33 FV 44 FV 55 FV 36 FV 77 FV 66 FV 88 Loans (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 111,115 $ 410,982 $ 168,343 $ 67,047 $ 235 $ 79,875 $ 1,918 $ 839,515 Non-farm/non-residential 319,635 1,573,456 422,873 3,556 578 133,188 3,108 2,456,394 Construction/land development 106,223 382,823 129,575 3,041 22 12,109 84 633,877 Agricultural 14,856 5,794 3,891 411 — 4,753 — 29,705 Multifamily residential 13,702 236,029 69,283 812 13 10,230 — 330,069 Commercial and industrial 19,865 178,415 14,326 2,687 23 4,917 67 220,300 Consumer 340,537 449,243 82,372 3,015 — 481 — 875,648 Other 5,815 1,908 138 75 — 6,387 — 14,323 Total $ 931,748 $ 3,238,650 $ 890,801 $ 80,644 $ 871 $ 251,940 $ 5,177 $ 5,399,831 December 31, 2015: Real estate: Residential 1-4 family $ 59,497 $ 117,498 $ 38,888 $ 85,684 $ 351 $ 82,862 $ 2,172 $ 386,952 Non-farm/non-residential 209,542 693,707 122,652 5,039 363 99,681 4,563 1,135,547 Construction/land development 13,121 12,511 7,137 4,771 22 10,224 37 47,823 Agricultural 4,825 7,963 1,456 797 — 4,877 — 19,918 Multifamily residential 20,347 86,588 27,818 896 13 3,835 — 139,497 Commercial and industrial 8,912 29,001 9,244 5,649 20 7,185 511 60,522 Consumer 726 205 185 6,106 2 263 — 7,487 Other 3,944 3,316 212 243 — 576 — 8,291 Total $ 320,914 $ 950,789 $ 207,592 $ 109,185 $ 771 $ 209,503 $ 7,283 $ 1,806,037 The following grades are used for purchased loans without evidence of credit deterioration at the date of acquisition. FV 33 FV 44 FV 55 FV 36 FV 77 The following grades are used for purchased loans with evidence of credit deterioration at the date of acquisition. FV 66 FV 88 The following table is an aging analysis of past due purchased loans as of the dates indicated. 30-89 Days Past Due 90 Days or More Total Past Due Current Total Purchased Loans (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 10,401 $ 9,857 $ 20,258 $ 819,257 $ 839,515 Non-farm/non-residential 8,542 19,569 28,111 2,428,283 2,456,394 Construction/land development 2,536 870 3,406 630,471 633,877 Agriculture 136 1,022 1,158 28,547 29,705 Multifamily residential 335 160 495 329,574 330,069 Commercial and industrial 1,129 1,373 2,502 217,798 220,300 Consumer 6,360 1,098 7,458 868,190 875,648 Other — — — 14,323 14,323 Total $ 29,439 $ 33,949 $ 63,388 $ 5,336,443 $ 5,399,831 Purchased loans without evidence of credit deterioration at date of acquisition $ 20,257 $ 8,336 $ 28,593 $ 5,114,121 $ 5,142,714 Purchased loans with evidence of credit deterioration at date of acquisition 9,182 25,613 34,795 222,322 257,117 Total $ 29,439 $ 33,949 $ 63,388 $ 5,336,443 $ 5,399,831 December 31, 2015: Real estate: Residential 1-4 family $ 9,042 $ 6,293 $ 15,335 $ 371,617 $ 386,952 Non-farm/non-residential 3,435 6,837 10,272 1,125,275 1,135,547 Construction/land development 919 1,255 2,174 45,649 47,823 Agriculture 106 356 462 19,456 19,918 Multifamily residential 299 — 299 139,198 139,497 Commercial and industrial 714 924 1,638 58,884 60,522 Consumer 101 41 142 7,345 7,487 Other 10 11 21 8,270 8,291 Total $ 14,626 $ 15,717 $ 30,343 $ 1,775,694 $ 1,806,037 Purchased loans without evidence of credit deterioration at date of acquisition $ 7,972 $ 2,743 $ 10,715 $ 1,578,536 $ 1,589,251 Purchased loans with evidence of credit deterioration at date of acquisition 6,654 12,974 19,628 197,158 216,786 Total $ 14,626 $ 15,717 $ 30,343 $ 1,775,694 $ 1,806,037 At September 30, 2016 and December 31, 2015, a portion of the Company’s purchased loans with evidence of credit deterioration at the date of acquisition were past due, including many that were 90 days or more past due. Such delinquencies were included in the Company’s performance expectations in determining the Day 1 Fair Values. Additionally, in accordance with GAAP, the Company continues to accrete into earnings income on such loans.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	7. Income Taxes The following table is a summary of the types of temporary differences between the tax basis of assets and liabilities and their financial reporting amounts that give rise to deferred income tax assets and liabilities and their approximate tax effects as of the dates indicated. September 30, December 31, 2016 2015 (Dollars in thousands) Deferred tax assets: Allowance for loan and lease losses $ 27,381 $ 22,802 Differences in amounts reflected in the financial statements and income tax basis for purchased loans 77,054 24,600 Differences in amounts reflected in the financial statements and income tax basis for deposits assumed in acquisitions 8,348 5,771 Stock-based compensation 7,237 4,199 Deferred compensation 2,318 2,035 Foreclosed assets 4,506 3,101 Deferred loan fees and costs, net — 10,579 Acquired net operating losses 29,585 27,862 Other, net 9,259 4,273 Total gross deferred tax assets 165,688 105,222 Less valuation allowance (474 ) (474 ) Net deferred tax asset 165,214 104,748 Deferred tax liabilities: Accelerated depreciation on premises and equipment 45,903 21,924 Investment securities AFS 12,431 5,650 Acquired intangible assets 11,301 1,448 Deferred loan fees and costs, net 1,846 — Total gross deferred tax liabilities 71,481 29,022 Net deferred tax assets $ 93,733 $ 75,726 Federal net operating losses were acquired in certain of the Company’s acquisitions. The federal net operating losses acquired totaled $80.9 million, of which $74.8 million remained to be utilized as of September 30, 2016 and will expire at various dates beginning in 2028 to 2034. State net operating losses were acquired in certain of the Company’s acquisitions. The state net operating losses acquired totaled $118.2 million, of which $106.4 million remained to be utilized as of September 30, 2016 and will expire at various dates beginning in 2022 to 2035. At September 30, 2016 and December 31, 2015, the Company had a deferred tax valuation allowance of $0.5 million to reflect its assessment that the realization of the benefits from the recovery of certain acquired net operating losses are expected to be subject to limitations under section 382 of the Internal Revenue Code. To the extent that additional information becomes available regarding the settlement or recovery of acquired net operating loss carryforwards or assets with built-in losses acquired in any of the Company’s previous acquisitions, management may be required to make adjustments to its deferred tax asset valuation allowance, which could affect goodwill or deferred income tax expense (benefit). Additionally, to the extent that management revises any of the fair value adjustments of acquired assets and assumed liabilities in the Company’s C&S or C1 acquisitions, such adjustments may result in adjustments to deferred tax assets and/or deferred tax liabilities.

Subordinated Notes

Subordinated Notes	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Subordinated Notes	8 . Subordinated Notes On June 23, 2016, the Company completed an underwritten public offering of $225 million in aggregate principal amount of its 5.50% Fixed-to-Floating Rate Subordinated Notes due 2026 (the “Notes”) for net proceeds of $222.3 million. The Notes were issued pursuant to the Subordinated Indenture, dated as of June 23, 2016 (the “Base Indenture”), between the Company and U.S. Bank National Association, as trustee (the “Trustee”), as supplemented by the First Supplemental Indenture, dated as of June 23, 2016 (the “Supplemental Indenture”), between the Company and the Trustee. The Base Indenture, as amended and supplemented by the Supplemental Indenture, governs the terms of the Notes and provides that the Notes are unsecured, subordinated debt obligations of the Company and will mature on July 1, 2026. From and including the date of issuance to, but excluding July 1, 2021, the Notes will bear interest at an initial rate of 5.50% per annum. From and including July 1, 2021 to, but excluding the maturity date or earlier redemption, the Notes will bear interest at a floating rate equal to three-month London Interbank Offered Rate (“LIBOR”) as calculated on each applicable date of determination plus a spread of 442.5 basis points; provided, however, that in the event three-month LIBOR is less than zero, then three-month LIBOR shall be deemed to be zero. Debt issuance costs of $2.7 million are being amortized, using a level-yield methodology over the estimated holding period of seven years, as an increase in interest expense on the Notes. The Company may, beginning with the interest payment date of July 1, 2021, and on any interest payment date thereafter, redeem the Notes, in whole or in part, at a redemption price equal to 100% of the principal amount of the Notes to be redeemed plus accrued and unpaid interest to but excluding the date of redemption. The Company may also redeem the Notes at any time, including prior to July 1, 2021, at the Company’s option, in whole but not in part, if: (i) a change or prospective change in law occurs that could prevent the Company from deducting interest payable on the Notes for U.S. federal income tax purposes; (ii) a subsequent event occurs that could preclude the Notes from being recognized as Tier 2 capital for regulatory capital purposes; or (iii) the Company is required to register as an investment company under the Investment Company Act of 1940, as amended; in each case, at a redemption price equal to 100% of the principal amount of the Notes plus any accrued and unpaid interest to but excluding the redemption date.

Supplemental Data for Cash Flow

Supplemental Data for Cash Flows	9 Months Ended
	Sep. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Supplemental Data for Cash Flows	9 . Supplemental Data for Cash Flows The following table provides supplemental cash flow information for the periods indicated. Nine Months Ended September 30, 2016 2015 (Dollars in thousands) Cash paid during the period for: Interest $ 36,571 $ 20,438 Taxes 97,232 48,869 Supplemental schedule of non-cash investing and financing activities: Net change in unrealized gains/losses on investment securities AFS 8,120 (4,317 ) Loans transferred to foreclosed assets 17,093 14,493 Loans advanced for sales of foreclosed assets 271 — Unsettled AFS investment security purchases 38,349 2,640 Unsettled loan sales — 14,361 Common stock issued in merger and acquisition transactions, net of shares redeemed for Brazilian Loans 1,135,861 303,866

Guarantees and Commitments

Guarantees and Commitments	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Guarantees and Commitments	10. Guarantees and Commitments Outstanding standby letters of credit are contingent commitments issued by the Company generally to guarantee the performance of a customer in third party arrangements. The maximum amount of future payments the Company could be required to make under these guarantees at September 30, 2016 was $56.4 million. The Company holds collateral to support guarantees when deemed necessary. Collateralized commitments at September 30, 2016 totaled $55.5 million. At September 30, 2016, the Company had outstanding commitments totaling $8.66 billion to extend credit, consisting primarily of loans closed but not yet funded. The following table shows, as of the date indicated, the contractual maturities of such outstanding commitments. Contractual Maturities at September 30, 2016 Maturity Amount (Dollars in thousands) 2016 $ 122,873 2017 950,754 2018 2,503,466 2019 2,884,502 2020 1,957,622 Thereafter 241,587 Total $ 8,660,804 Additionally, the Company had commitments to extend credit under mortgage interest rate lock commitments totaling $32.4 million at September 30, 2016 and $15.7 million at December 31, 2015 that expire in one year or less and are not included in the above table.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation The Company has a nonqualified stock option plan for certain employees of the Company or any subsidiary. This plan provides for the granting of nonqualified options to purchase shares of common stock in the Company. No option may be granted under this plan for less than the fair market value of the common stock, defined by the plan as the average of the highest reported asked price and the lowest reported bid price, on the date of the grant. The benefits or amounts that may be received by or allocated to any particular officer or employee of the Company or any subsidiary under this plan will be determined in the sole discretion of the personnel and compensation committee of the Company’s board of directors. All employee options outstanding at September 30, 2016 were issued with a vesting date three years after issuance and an expiration date seven years after issuance. All shares issued in connection with options exercised under the employee nonqualified stock option plan were in the form of newly issued shares. In addition, the Company has a non-employee director stock plan (the “Director Plan”) that provides for awards of common stock to eligible non-employee directors. The Director Plan grants to each director who is not otherwise an employee of the Company, or any subsidiary, shares of common stock on the day of his or her election as director of the Company at each annual shareholders meeting, or any special meeting called for the purpose of electing a director or directors of the Company, and upon appointment for the first time as a director of the Company. The number of shares of common stock to be awarded is the equivalent of $35,000 worth of shares of common stock based on the average of the highest reported asked price and lowest reported bid price on the grant date. The common stock awarded under this plan is fully vested on the grant date. The aggregate number of shares of common stock which may be issued as awards under this plan will not exceed 50,000 shares, subject to certain adjustments. During the three months ended September 30, 2016 and 2015, no shares were issued and no stock-based compensation expense was recorded under the Director Plan. During the nine months ended September 30, 2016 and 2015, respectively, the Company issued 12,415 shares and 7,657 shares of common stock under the Director Plan. Stock-based compensation expense for shares of common stock issued under the Director Plan included in non-interest expense was $0.5 million for the nine months ended September 30, 2016 and $0.3 million for the nine months ended September 30, 2015. Prior to the adoption of the Director Plan, the Company had a nonqualified stock option plan for non-employee directors. No options were granted under this plan during the three months and nine months ended September 30, 2016 or 2015. All options previously granted under this plan were exercisable immediately and expire ten years after issuance. The following table summarizes stock option activity for the period indicated. Options Weighted- Average Exercise Price/Share Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Nine Months Ended September 30, 2016: Outstanding – December 31, 2015 2,034,476 $ 34.50 Granted 18,183 40.59 Exercised (83,670 ) 14.99 Forfeited (70,725 ) 39.61 Outstanding – September 30, 2016 1,898,264 35.22 5.0 $ 15,283 (1) Fully vested and exercisable – September 30, 2016 372,955 $ 14.90 3.4 $ 8,764 (1) Expected to vest in future periods 1,446,156 Fully vested and expected to vest – September 30, 2016 (2) 1,819,111 $ 34.70 4.9 $ 15,204 (1) (1) Based on closing price of $38.40 per share on September 30, 2016. (2) At September 30, 2016, the Company estimated that outstanding options to purchase 79,153 shares of its common stock would not vest and would be forfeited prior to their vesting date. Intrinsic value for stock options is defined as the amount by which the current market price of the underlying stock exceeds the exercise price. For those stock options where the exercise price exceeds the current market price of the underlying stock, the intrinsic value is zero. The total intrinsic value of options exercised during the three months ended September 30, 2016 and 2015 was $0.6 million and $0.5 million, respectively. The total intrinsic value of options exercised during the nine months ended September 30, 2016 and 2015 was $2.1 million and $3.3 million, respectively. Stock based compensation expense for stock options included in non-interest expense was $1.1 million and $0.6 million for the three months ended September 30, 2016 and 2015, respectively, and $3.0 million and $1.8 million for the nine months ended September 30, 2016 and 2015, respectively. Total unrecognized compensation cost related to non-vested stock option grants was $7.9 million at September 30, 2016 and is expected to be recognized over a weighted-average period of 1.9 years. The Company has a restricted stock and incentive plan whereby all officers and employees of the Company or any subsidiary are eligible to receive awards of restricted stock, restricted stock units or performance awards. The benefits or amounts that may be received by or allocated to any particular officer or employee of the Company or any subsidiary under this plan will be determined in the sole discretion of the Company’s board of directors or its personnel and compensation committee. Shares of common stock issued under the plan may be shares of original issuance or shares held in treasury that have been reacquired by the Company. The vesting period for all restricted stock awards granted under the plan shall be not less than three years from the date of grant, subject to limited exceptions. The following table summarizes non-vested restricted stock activity for the period indicated. Nine Months Ended September 30, 2016 Outstanding – December 31, 2015 435,475 Granted 218,761 Forfeited (13,986 ) Vested — Outstanding – September 30, 2016 640,250 Weighted-average grant date fair value $ 35.10 The fair value of the restricted stock awards is amortized to compensation expense over the vesting period and is based on the market price of the Company’s common stock at the date of grant multiplied by the number of shares granted that are expected to vest. Stock-based compensation expense for restricted stock included in non-interest expense was $1.8 million for the three months and $4.5 million for the nine months ended September 30, 2016, and was $1.4 million for the three months and $4.1 million for the nine months ended September 30, 2015. Unrecognized compensation expense for non-vested restricted stock awards was $11.1 million at September 30, 2016 and is expected to be recognized over a weighted-average period of 1.9 years.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	12. Fair Value Measurements The Company measures certain of its assets and liabilities on a fair value basis using various valuation techniques and assumptions, depending on the nature of the asset or liability. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Additionally, fair value is used either annually or on a non-recurring basis to evaluate certain assets and liabilities for impairment or for disclosure purposes. The Company had no liabilities that were accounted for at fair value at September 30, 2016 or December 31, 2015. The Company applies the following fair value hierarchy. Level 1 − Quoted prices for identical instruments in active markets. Level 2 − Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable. Level 3 − Instruments whose inputs are unobservable. The following table sets forth the Company’s assets, as of the dates indicated, that are accounted for at fair value. Level 1 Level 2 Level 3 Total (Dollars in thousands) September 30, 2016: Investment securities AFS (1) Obligations of state and political subdivisions $ — $ 732,969 $ 17,756 $ 750,725 U.S. Government agency securities — 573,936 — 573,936 Corporate obligations — 10,022 — 10,022 CRA qualified investment fund 1,062 — — 1,062 Total investment securities AFS 1,062 1,316,927 17,756 1,335,745 Impaired non-purchased loans and leases — — 3,951 3,951 Impaired purchased loans — — 6,048 6,048 Foreclosed assets — — 44,250 44,250 Total assets at fair value $ 1,062 $ 1,316,927 $ 72,005 $ 1,389,994 December 31, 2015: Investment securities AFS (1) Obligations of state and political subdivisions $ — $ 408,774 $ 18,504 $ 427,278 U.S. Government agency securities — 146,950 — 146,950 Corporate obligations — 3,562 — 3,562 CRA qualified investment fund 1,028 — — 1,028 Total investment securities AFS 1,028 559,286 18,504 578,818 Impaired non-purchased loans and leases — — 9,327 9,327 Impaired purchased loans — — 8,054 8,054 Foreclosed assets — — 22,870 22,870 Total assets at fair value $ 1,028 $ 559,286 $ 58,755 $ 619,069 (1) Does not include $6.1 million at September 30, 2016 and $23.5 million at December 31, 2015 of FHLB and FNBB equity securities that do not have readily determinable fair values and are carried at cost. The following table presents information related to Level 3 non-recurring fair value measurements as of the date indicated. Description Fair Value at September 30, 2016 Technique Unobservable Inputs (Dollars in thousands) Impaired non-purchased loans and leases $ 3,951 Third party appraisal (1) or discounted cash flows 1. Management discount based on underlying collateral characteristics and market conditions 2. Life of Loan Impaired purchased loans $ 6,048 Third party appraisal (1) and/or discounted cash flows 1. Management discount based on underlying collateral characteristics and market conditions 2. Life of Loan Foreclosed assets $ 44,250 Third party appraisal, (1) broker price opinions and/or discounted cash flows 1. Management discount based on underlying collateral characteristics and market conditions 2. Discount rate 3. Holding period (1) The Company utilizes valuation techniques consistent with the market, cost, and income approaches, or a combination thereof in determining fair value. The following methods and assumptions are used to estimate the fair value of the Company’s assets that are accounted for at fair value. Investment securities The Company has determined that certain of its investment securities had a limited to non-existent trading market at September 30, 2016. As a result, the Company considers these investments as Level 3 in the fair value hierarchy. Specifically, the fair values of certain obligations of state and political subdivisions consisting primarily of certain unrated private placement bonds (the “private placement bonds”) in the amount of $17.8 million at September 30, 2016 were calculated using Level 3 hierarchy inputs and assumptions as the trading market for such securities was determined to be “not active.” This determination was based on the limited number of trades or, in certain cases, the existence of no reported trades for the private placement bonds. The private placement bonds are generally prepayable at par value at the option of the issuer. As a result, management believes the private placement bonds should be individually valued at the lower of (i) the matrix pricing provided by the Company’s third party pricing services for comparable unrated municipal securities or (ii) par value. At September 30, 2016, the third parties’ pricing matrices valued the Company’s portfolio of private placement bonds at $17.8 million which was approximately the same as the aggregate par value of the private placement bonds. Accordingly, at September 30, 2016, the Company reported the private placement bonds at $17.8 million. Impaired non-purchased loans and leases Impaired purchased loans Foreclosed assets The following table presents additional information for the periods indicated about assets measured at fair value on a recurring basis and for which the Company has utilized Level 3 inputs to determine fair value. Investment Securities AFS (Dollars in Balance – December 31, 2015 $ 18,504 Total realized gains (losses) included in earnings — Total unrealized gains (losses) included in comprehensive income (47 ) Paydowns and maturities (701 ) Sales — Transfers in and/or out of Level 3 — Balance – September 30, 2016 $ 17,756 Balance – December 31, 2014 $ 19,401 Total realized gains (losses) included in earnings — Total unrealized gains (losses) included in comprehensive income (19 ) Paydowns and maturities (714 ) Sales — Transfers in and/or out of Level 3 — Balance – September 30, 2015 $ 18,668

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	13. Fair Value of Financial Instruments The following methods and assumptions were used to estimate the fair value of financial instruments. Cash and due from banks Investment securities Loans and leases Deposit liabilities Repurchase agreements Other borrowed funds Subordinated notes and debentures Off-balance sheet instruments The fair values of certain of these instruments were calculated by discounting expected cash flows, which contain numerous uncertainties and involve significant judgments by management. Fair value is the estimated amount at which financial assets or liabilities could be exchanged in a current transaction between willing parties other than in a forced or liquidation sale. Because no market exists for certain of these financial instruments and because management does not intend to sell these financial instruments, the estimated fair values may differ materially from the values which the respective financial instruments could be sold individually or in the aggregate. The following table presents the carrying amounts and estimated fair values as of the dates indicated and the fair value hierarchy of the Company’s financial instruments. September 30, 2016 December 31, 2015 Fair Value Hierarchy Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value (Dollars in thousands) Financial assets: Cash and cash equivalents Level 1 $ 969,522 $ 969,522 $ 90,988 $ 90,988 Investment securities AFS Levels 2 and 3 1,341,894 1,341,894 602,348 602,348 Loans and leases, net of ALLL Level 3 14,089,837 14,004,121 8,273,817 8,165,123 Financial liabilities: Demand, savings and interest bearing transaction deposits Level 1 $ 10,138,890 $ 10,138,890 $ 5,532,986 $ 5,532,986 Time deposits Level 2 4,984,914 5,014,194 2,438,482 2,456,323 Repurchase agreements with customers Level 1 70,640 70,640 65,800 65,800 Other borrowings Level 2 41,978 43,101 204,540 205,918 Subordinated notes Level 2 222,420 223,072 — — Subordinated debentures Level 2 118,102 90,775 117,685 77,534

Repurchase Agreements With Cust

Repurchase Agreements With Customers	9 Months Ended
	Sep. 30, 2016
Brokers And Dealers [Abstract]
Repurchase Agreements With Customers	14. Repurchase Agreements With Customers At September 30, 2016 and December 31, 2015, securities sold under agreements to repurchase (“repurchase agreements”) totaled $70.6 million and $65.8 million, respectively. Securities utilized as collateral for repurchase agreements are primarily U.S. Government agency residential mortgage-backed securities and are maintained by the Company’s safekeeping agents. These securities are reviewed by the Company on a daily basis, and the Company may be required to provide additional collateral due to changes in the fair market value of these securities. The terms of the Company’s repurchase agreements are continuous but may be cancelled at any time by the Company or the customer.

Changes in and Reclassification

Changes in and Reclassifications From Accumulated Other Comprehensive Income ("AOCI")	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Changes in and Reclassifications From Accumulated Other Comprehensive Income ("AOCI")	15. Changes In and Reclassifications From Accumulated Other Comprehensive Income (“AOCI”) The following table presents changes in AOCI for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Beginning balance of AOCI – unrealized gains and losses on investment securities AFS $ 15,106 $ 8,068 $ 7,959 $ 14,132 Other comprehensive income (loss): Unrealized gains and losses on investment securities AFS (2,262 ) 5,918 8,120 (1,274 ) Tax effect of unrealized gains and losses on investment securities AFS 791 (2,265 ) (2,444 ) 484 Amounts reclassified from AOCI — — — (2,619 ) Tax effect of amounts reclassified from AOCI — — — 998 Total other comprehensive income (loss) (1,471 ) 3,653 5,676 (2,411 ) Ending balance of AOCI – unrealized gains and losses on investment securities AFS $ 13,635 $ 11,721 $ 13,635 $ 11,721 Amounts reclassified from AOCI are included in net gains on investment securities and the tax effect of amounts reclassified from AOCI are included in provision for income tax in the consolidated statements of income. The amounts reclassified from AOCI relate entirely to unrealized gains/losses on investment securities AFS that were sold during the periods indicated.

Other Operating Expenses

Other Operating Expenses	9 Months Ended
	Sep. 30, 2016
Other Income And Expenses [Abstract]
Other Operating Expenses	16. Other Operating Expenses The following table is a summary of other operating expenses for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Salaries and employee benefits $ 38,069 $ 21,207 $ 86,351 $ 66,450 Net occupancy and equipment 11,669 8,076 28,587 22,711 Other operating expenses: Professional and outside services 6,509 2,772 14,072 9,684 Postage and supplies 1,709 1,015 3,840 2,944 Advertising and public relations 1,941 575 4,543 1,744 Telecommunication services 1,883 1,583 5,339 4,547 Software and data processing 1,633 630 3,226 2,145 ATM expense 1,821 591 3,530 1,842 Travel and meals 2,778 922 5,850 2,538 FDIC insurance 1,725 1,020 4,125 2,670 FDIC and state assessments 392 330 1,071 971 Loan collection and repossession expense 1,524 1,322 3,244 4,075 Writedowns of foreclosed and other assets 859 553 2,119 2,980 Amortization of intangibles 2,596 1,697 5,879 4,934 FHLB prepayment penalty — — — 2,480 Other 3,673 3,135 5,619 6,621 Total non-interest expense $ 78,781 $ 45,428 $ 177,395 $ 139,336

Recent and Proposed Accounting

Recent and Proposed Accounting Pronouncements	9 Months Ended
	Sep. 30, 2016
Accounting Changes And Error Corrections [Abstract]
Recent and Proposed Accounting Pronouncements	17. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers.” In April 2015, FASB issued ASU 2015-03, “Interest – Imputation of Interest (Subtopic 835-30) – Simplifying the Presentation of Debt Issuance Costs.” In January 2016, FASB issued ASU 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities.” In February 2016, FASB issued ASU 2016-02, “Leases (Topic 842) In March 2016, FASB issued ASU 2016-09 “Improvements to Employee Share-Based Payment Accounting.” In June 2016, FASB issued ASU 2016-13 “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” In August 2016, the FASB issued ASU 2016-15 “ Statement of Cash Flows (Topic 230)

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2016
Community & Southern Holdings, Inc. [Member]
Summary of Assets Acquired and Liabilities Assumed in Acquisition	The following table provides a summary of the assets acquired and liabilities assumed as recorded by C&S, the estimates of the fair value adjustments necessary to adjust those acquired assets and assumed liabilities to estimated fair value and the estimates of the resultant fair values of those assets and liabilities as recorded by the Company. The fair value adjustments and the resultant fair values shown in the following table continue to be evaluated and may be subject to further adjustment. July 20, 2016 As Recorded by C&S Fair Value Adjustments (1) As Recorded by the Company (1) (Dollars in thousands) Assets acquired: Cash, due from banks and interest earning deposits $ 72,942 $ — $ 72,942 Investment securities 447,674 4,063 a 451,737 Loans 3,090,579 (61,649 ) b 3,028,930 Allowance for loan losses (42,395 ) 42,395 b — Premises and equipment 73,238 31,969 c 105,207 Foreclosed assets 6,274 (521 ) d 5,753 BOLI 86,596 (45 ) e 86,551 Goodwill 44,514 (44,514 ) f — Core deposit intangible asset 12,227 21,327 g 33,554 Deferred income taxes 23,298 (9,059 ) h 14,239 Accrued interest receivable and other assets 38,226 (2,003 ) i 36,223 Total assets acquired 3,853,173 (18,037 ) 3,835,136 Liabilities assumed: Deposits 3,256,372 11,813 j 3,268,185 Other borrowings 90,000 — 90,000 Accrued interest payable and other liabilities 22,991 (585 ) k 22,406 Total liabilities assumed 3,369,363 11,228 3,380,591 Net assets acquired $ 483,810 $ (29,265 ) 454,545 Consideration paid: Cash (12,336 ) Stock (787,942 ) Total consideration paid (800,278 ) Goodwill $ 345,733 (1) Management continues to evaluate and may revise, if necessary, one or more of the fair value adjustments in future periods. To the extent that any of these fair value adjustments are revised in future periods, the resultant fair values and the amount of goodwill may be subject to further adjustment. Explanation of preliminary fair value adjustments a- Adjustment reflects the fair value adjustment based on the pricing of the acquired held to maturity investment securities portfolio. b- Adjustment reflects the fair value adjustment based on the evaluation of the acquired loan portfolio and to eliminate the recorded allowance for loan losses. c- Adjustment reflects the fair value adjustment based on the evaluation of the premises and equipment acquired. d- Adjustment reflects the fair value adjustment based on the evaluation of the acquired foreclosed assets. e- Adjustment reflects the fair value adjustment based on the evaluation of BOLI acquired. f- Adjustment reflects the elimination of previously recorded goodwill. g- Adjustment reflects the fair value adjustment for the core deposit intangible asset recorded as a result of the acquisition net of the elimination of previously recorded core deposit intangible assets. h- This adjustment reflects the differences in the carrying values of acquired assets and assumed liabilities for financial reporting purposes and their basis for federal income tax purposes. i - Adjustment reflects the fair value adjustment based on the evaluation of accrued interest receivable and other assets. j- Adjustment reflects the fair value adjustment based on the evaluation of the acquired deposits. k- Adjustment reflects the amount needed to adjust other liabilities to estimated fair value and to record certain liabilities directly attributable to the C&S acquisition.
Summary of Supplemental Pro-forma Information	The following unaudited supplemental pro forma information is presented to show the estimated results assuming C&S was acquired as of the beginning of each period presented, adjusted for estimated costs savings. These unaudited pro forma results are not necessarily indicative of the operating results that the Company would have achieved had it completed the acquisition as of January 1, 2015 or 2016 and should not be considered as representative of future operating results. Nine Months Ended September 30, 2016 2015 (Dollars in thousands, except per share amounts) Net interest income – pro forma (unaudited) $ 493,602 $ 404,497 Net income – pro forma (unaudited) $ 222,029 $ 176,635 Diluted earnings per common share – pro forma (unaudited) $ 1.94 $ 1.64
C1 Financial, Inc. [Member]
Summary of Assets Acquired and Liabilities Assumed in Acquisition	The following table provides a summary of the assets acquired and liabilities assumed as recorded by C1, the estimates of the fair value adjustments necessary to adjust those acquired assets and assumed liabilities to estimated fair value and the estimates of the resultant fair values of those assets and liabilities as recorded by the Company. The fair value adjustments and the resultant fair values shown in the following table continue to be evaluated and may be subject to further adjustment. July 21, 2016 As Recorded by C1 Fair Value Adjustments (1) As Recorded by the Company (1) (Dollars in thousands) Assets acquired: Cash, due from banks and interest earning deposits $ 143,592 $ — $ 143,592 Investment securities 7,618 (28 ) a 7,590 Loans 1,353,498 (40,456 ) b 1,313,042 Allowance for loan losses (7,307 ) 7,307 b — Premises and equipment 63,943 13,690 c 77,633 Foreclosed assets 21,704 (1,656 ) d 20,048 BOLI 36,280 — 36,280 Core deposit and other intangible assets 576 9,198 e 9,774 Deferred income taxes 1,608 8,288 f 9,896 Accrued interest receivable and other assets 12,182 (3,124 ) g 9,058 Total assets acquired 1,633,694 (6,781 ) 1,626,913 Liabilities assumed: Deposits 1,294,439 2,779 h 1,297,218 Other borrowings 131,010 2,558 i 133,568 Accrued interest payable and other liabilities 4,775 1,040 j 5,815 Total liabilities assumed 1,430,224 6,377 1,436,601 Net assets acquired $ 203,470 $ (13,158 ) 190,312 Consideration paid: Cash and shares redeemed for Brazilian Loans (27,694 ) Stock (348,397 ) Total consideration paid (376,091 ) Goodwill $ 185,779 (1) Management continues to evaluate and may revise, if necessary, one or more of the fair value adjustments in future periods. To the extent that any of these fair value adjustments are revised in future periods, the resultant fair values and the amount of goodwill may be subject to further adjustment. Explanation of preliminary fair value adjustments a- Adjustment reflects the fair value adjustment based on the pricing of the acquired investment securities portfolio. b- Adjustment reflects the fair value adjustment based on the evaluation of the acquired loan portfolio and to eliminate the recorded allowance for loan losses. c- Adjustment reflects the fair value adjustment based on the evaluation of the premises and equipment acquired. d- Adjustment reflects the fair value adjustment based on the evaluation of the acquired foreclosed assets. e- Adjustment reflects the fair value adjustment for the core deposit and other intangible assets recorded as a result of the acquisition. f- This adjustment reflects the differences in the carrying values of acquired assets and assumed liabilities for financial reporting purposes and their basis for federal income tax purposes. g- Adjustment reflects the fair value adjustment based on the evaluation of accrued interest receivable and other assets. h- Adjustment reflects the fair value adjustment based on the evaluation of the acquired deposits. i - Adjustment reflects the fair value adjustment of these assumed liabilities. j- Adjustment reflects the amount needed to adjust other liabilities to estimated fair value and to record certain liabilities directly attributable to the C1 acquisition.
Summary of Supplemental Pro-forma Information	The following unaudited supplemental pro forma information is presented to show the estimated results assuming C1 was acquired as of the beginning of each period presented, adjusted for estimated costs savings. These unaudited pro forma results are not necessarily indicative of the operating results that the Company would have achieved had it completed the acquisition as of January 1, 2015 or 2016 and should not be considered as representative of future operating results. Nine Months Ended September 30, 2016 2015 (Dollars in thousands, except per share amounts) Net interest income – pro forma (unaudited) $ 448,903 $ 334,960 Net income – pro forma (unaudited) $ 198,814 $ 152,847 Diluted earnings per common share – pro forma (unaudited) $ 1.88 $ 1.42

Earnings Per Common Share ("E27

Earnings Per Common Share ("EPS") (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Schedule of Calculation of Numerator and Denominator in Basic and Diluted Earnings Per Share	The following table presents the computation of basic and diluted EPS for the periods indicated. Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 (In thousands, except per share amounts) Numerator: Distributed earnings allocated to common stockholders $ 14,521 $ 12,154 $ 42,185 $ 34,280 Undistributed earnings allocated to common stockholders 61,509 33,974 140,008 96,518 Net income available to common stockholders $ 76,030 $ 46,128 $ 182,193 $ 130,798 Denominator: Denominator for basic EPS – weighted-average common shares 114,745 87,683 98,779 86,070 Effect of dilutive securities – stock options 262 771 285 769 Denominator for diluted EPS – weighted-average common shares and assumed conversions 115,007 88,454 99,064 86,839 Basic EPS $ 0.66 $ 0.53 $ 1.84 $ 1.52 Diluted EPS $ 0.66 $ 0.52 $ 1.84 $ 1.51

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Summary of Amortized Cost and Estimated Fair Value of Investment Securities	The following table presents the amortized cost and estimated fair value of investment securities AFS as of the dates indicated. The Company’s investment in the “CRA qualified investment fund” includes shares held in a mutual fund that qualifies under the Community Reinvestment Act of 1977 for community reinvestment purposes. The Company’s holdings of “other equity securities” include Federal Home Loan Bank of Dallas (“FHLB”) and First National Banker’s Bankshares, Inc. (“FNBB”) shares which do not have readily determinable fair values and are carried at cost. Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (Dollars in thousands) September 30, 2016: Obligations of state and political subdivisions $ 735,494 $ 16,325 $ (1,094 ) $ 750,725 U.S. Government agency securities 568,130 6,224 (418 ) 573,936 Corporate obligations 10,089 — (67 ) 10,022 CRA qualified investment fund 1,055 7 — 1,062 Other equity securities 6,149 — — 6,149 Total $ 1,320,917 $ 22,556 $ (1,579 ) $ 1,341,894 December 31, 2015: Obligations of state and political subdivisions $ 415,095 $ 12,321 $ (138 ) $ 427,278 U.S. Government agency securities 146,265 1,720 (1,035 ) 146,950 Corporate obligations 3,562 — — 3,562 CRA qualified investment fund 1,038 — (10 ) 1,028 Other equity securities 23,530 — — 23,530 Total $ 589,490 $ 14,041 $ (1,183 ) $ 602,348
Gross Unrealized Losses and Estimated Fair Value of Investment Securities	The following table shows estimated fair value of investment securities AFS having gross unrealized losses and the amount of such unrealized losses, aggregated by investment category and length of time that individual investment securities have been in a continuous unrealized loss position, as of the dates indicated. Less than 12 Months 12 Months or More Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) September 30, 2016: Obligations of state and political subdivisions $ 128,359 $ 1,084 $ 4,747 $ 10 $ 133,106 $ 1,094 U.S. Government agency securities 91,380 412 161 6 91,541 418 Corporate obligations 7,022 67 — — 7,022 67 Total temporarily impaired securities $ 226,761 $ 1,563 $ 4,908 $ 16 $ 231,669 $ 1,579 December 31, 2015: Obligations of state and political subdivisions $ 18,018 $ 114 $ 6,167 $ 24 $ 24,185 $ 138 U.S. Government agency securities 72,671 930 4,381 105 77,052 1,035 CRA qualified investment fund 1,029 10 — — 1,029 10 Total temporarily impaired securities $ 91,718 $ 1,054 $ 10,548 $ 129 $ 102,266 $ 1,183
Amortized Cost and Estimated Fair Value of Investment Securities AFS by Maturity or Estimated Date of Repayment	The following table shows the amortized cost and estimated fair value of investment securities AFS by maturity or estimated date of repayment as of the date indicated. September 30, 2016 Maturity or Estimated Repayment Amortized Cost Estimated Fair Value (Dollars in thousands) One year or less $ 99,489 $ 100,484 After one year to five years 341,412 344,840 After five years to ten years 308,141 313,543 After ten years 571,875 583,027 Total $ 1,320,917 $ 1,341,894
Sales Activities of Company's Investment Securities AFS are Summarized	The following table is a summary of sales activities in the Company’s investment securities AFS for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Sales proceeds $ — $ — $ — $ 32,777 Gross realized gains — — — 2,620 Gross realized losses — — — (1 ) Net gains on investment securities $ — $ — $ — $ 2,619

Allowance for Loan and Lease 29

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators (Tables)	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Schedule of Activity Within Allowance for Loan and Lease Losses	The following table is a summary of activity within the ALLL for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Beginning balance $ 65,133 $ 56,749 $ 60,854 $ 52,918 Charge-offs of non-purchased loans and leases (1,791 ) (992 ) (4,356 ) (6,567 ) Recoveries of non-purchased loans and leases previously charged off 418 360 862 866 Net charge-offs – non-purchased loans and leases (1,373 ) (632 ) (3,494 ) (5,701 ) Chrage-offs of purchased loans (1,197 ) (829 ) (1,732 ) (2,945 ) Recoveries of purchased loans previously charged off 111 148 195 540 Net charge-offs – purchased loans (1,086 ) (681 ) (1,537 ) (2,405 ) Net charge-offs – total loans and leases (2,459 ) (1,313 ) (5,031 ) (8,106 ) Provision for loan and lease losses: Non-purchased loans and leases 5,600 2,900 12,000 11,800 Purchased loans 1,486 681 1,937 2,405 Total provision 7,086 3,581 13,937 14,205 Ending balance $ 69,760 $ 59,017 $ 69,760 $ 59,017 ALLL allocated to non-purchased loans and leases $ 68,160 $ 59,017 $ 68,160 $ 59,017 ALLL allocated to purchased loans 1,600 — 1,600 — Total ALLL $ 69,760 $ 59,017 $ 69,760 $ 59,017
Summary of Company's Allowance for Loan and Lease Losses	The following tables are a summary of the Company’s ALLL for the periods indicated. Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Three months ended September 30, 2016: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 10,099 $ (94 ) $ 6 $ 312 $ 10,323 Non-farm/non-residential 19,118 (236 ) — 754 19,636 Construction/land development 17,496 (22 ) 2 2,582 20,058 Agricultural 3,755 — — (373 ) 3,382 Multifamily residential 3,661 — — (12 ) 3,649 Commercial and industrial 3,790 (45 ) 13 182 3,940 Consumer 712 (19 ) 1 870 1,564 Direct financing leases 4,092 (795 ) 4 842 4,143 Other 1,210 (580 ) 392 443 1,465 Total non-purchased loans and leases 63,933 (1,791 ) 418 5,600 68,160 Purchased loans 1,200 (1,197 ) 111 1,486 1,600 Total loans and leases $ 65,133 $ (2,988 ) $ 529 $ 7,086 $ 69,760 Nine months ended September 30, 2016: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 8,672 $ (350 ) $ 43 $ 1,958 $ 10,323 Non-farm/non-residential 16,796 (248 ) — 3,088 19,636 Construction/land development 18,176 (42 ) 53 1,871 20,058 Agricultural 3,388 (7 ) — 1 3,382 Multifamily residential 3,031 — 14 604 3,649 Commercial and industrial 2,574 (87 ) 52 1,401 3,940 Consumer 707 (87 ) 15 929 1,564 Direct financing leases 3,835 (2,263 ) 20 2,551 4,143 Other 2,475 (1,272 ) 665 (403 ) 1,465 Total non-purchased loans and leases 59,654 (4,356 ) 862 12,000 68,160 Purchased loans 1,200 (1,732 ) 195 1,937 1,600 Total loans and leases $ 60,854 $ (6,088 ) $ 1,057 $ 13,937 $ 69,760 Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Three months ended September 30, 2015: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 5,601 $ (121 ) $ 37 $ 92 $ 5,609 Non-farm/non-residential 18,232 (6 ) 1 (144 ) 18,083 Construction/land development 19,148 (38 ) 40 1,997 21,147 Agricultural 2,460 — — 12 2,472 Multifamily residential 2,886 (20 ) — 42 2,908 Commercial and industrial 3,249 (132 ) 149 (106 ) 3,160 Consumer 825 (11 ) 5 34 853 Direct financing leases 3,554 (222 ) 7 522 3,861 Other 794 (442 ) 121 451 924 Total non-purchased loans and leases 56,749 (992 ) 360 2,900 59,017 Purchased loans — (829 ) 148 681 — Total loans and leases $ 56,749 $ (1,821 ) $ 508 $ 3,581 $ 59,017 Nine months ended September 30, 2015: Non-purchased loans and leases: Real estate: Residential 1-4 family $ 5,482 $ (742 ) $ 58 $ 811 $ 5,609 Non-farm/non-residential 17,190 (330 ) 18 1,205 18,083 Construction/land development 15,960 (809 ) 77 5,919 21,147 Agricultural 2,558 (13 ) — (73 ) 2,472 Multifamily residential 2,147 (228 ) — 989 2,908 Commercial and industrial 4,873 (2,672 ) 188 771 3,160 Consumer 818 (80 ) 47 68 853 Direct financing leases 2,989 (563 ) 20 1,415 3,861 Other 901 (1,130 ) 458 695 924 Total non-purchased loans and leases 52,918 (6,567 ) 866 11,800 59,017 Purchased loans — (2,945 ) 540 2,405 — Total loans and leases $ 52,918 $ (9,512 ) $ 1,406 $ 14,205 $ 59,017
Summary of Allowance for Loan and Lease Losses and Recorded Investment in Non-Purchased Loans and Leases	The following table is a summary of the Company’s ALLL for non-purchased loans and leases and recorded investment in non-purchased loans and leases as of the dates indicated. ALLL for Non-Purchased Loans and Leases Non-Purchased Loans and Leases ALLL for Individually Evaluated Impaired Loans and Leases ALLL for All Other Loans and Leases Total ALLL (1) Individually Evaluated Impaired Loans and Leases All Other Loans and Leases Total Loans and Leases (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 32 $ 10,291 $ 10,323 $ 1,006 $ 429,538 $ 430,544 Non-farm/non-residential 4 19,632 19,636 1,562 2,393,280 2,394,842 Construction/land development 73 19,985 20,058 435 4,201,430 4,201,865 Agricultural 404 2,978 3,382 1,265 90,164 91,429 Multifamily residential — 3,649 3,649 — 518,702 518,702 Commercial and industrial 513 3,427 3,940 683 255,422 256,105 Consumer 3 1,561 1,564 23 114,968 114,991 Direct financing leases — 4,143 4,143 — 131,646 131,646 Other — 1,465 1,465 6 619,636 619,642 Total $ 1,029 $ 67,131 $ 68,160 $ 4,980 $ 8,754,786 $ 8,759,766 December 31, 2015: Real estate: Residential 1-4 family $ 297 $ 8,375 $ 8,672 $ 2,030 $ 348,224 $ 350,254 Non-farm/non-residential 31 16,765 16,796 940 2,009,926 2,010,866 Construction/land development 48 18,128 18,176 5,556 2,820,019 2,825,575 Agricultural 475 2,913 3,388 1,313 73,127 74,440 Multifamily residential — 3,031 3,031 83 440,745 440,828 Commercial and industrial 487 2,087 2,574 714 230,567 231,281 Consumer 2 705 707 24 27,721 27,745 Direct financing leases — 3,835 3,835 — 147,735 147,735 Other — 2,475 2,475 7 419,903 419,910 Total $ 1,340 $ 58,314 $ 59,654 $ 10,667 $ 6,517,967 $ 6,528,634 (1) Excludes $1.6 million and $1.2 million of ALLL allocated to the Company’s purchased loans at September 30, 2016 and December 31, 2015, respectively.
Schedule of Impaired Non-purchased Loans and Leases, FDIC Loss Share Agreements	The following table is a summary of impaired non-purchased loans and leases as of and for the three months and nine months ended September 30, 2016. Principal Balance Net Charge-offs to Date Principal Balance, Net of Charge-offs Specific ALLL Weighted Average Carrying Value – Three Months Ended September 30, 2016 Weighted Average Carrying Value – Nine Months Ended September 30, 2016 (Dollars in thousands) Impaired loans and leases for which there is a related ALLL: Real estate: Residential 1-4 family $ 348 $ (215 ) $ 133 $ 32 $ 568 $ 939 Non-farm/non-residential 928 (924 ) 4 4 89 71 Construction/land development 130 — 130 73 124 122 Agricultural 1,081 — 1,081 404 1,113 1,132 Commercial and industrial 838 (325 ) 513 513 510 511 Consumer 17 (4 ) 13 3 23 17 Total impaired loans and leases with a related ALLL 3,342 (1,468 ) 1,874 1,029 2,427 2,792 Impaired loans and leases for which there is not a related ALLL: Real estate: Residential 1-4 family 1,312 (439 ) 873 — 981 939 Non-farm/non-residential 2,021 (463 ) 1,558 — 1,209 1,042 Construction/land development 1,115 (810 ) 305 — 234 2,398 Agricultural 393 (209 ) 184 — 183 177 Multifamily residential 133 (133 ) — — — 41 Commercial and industrial 220 (50 ) 170 — 185 196 Consumer 15 (5 ) 10 — 10 11 Other 6 — 6 — 6 6 Total impaired loans and leases without a related ALLL 5,215 (2,109 ) 3,106 — 2,808 4,810 Total impaired non-purchased loans and leases $ 8,557 $ (3,577 ) $ 4,980 $ 1,029 $ 5,235 $ 7,602 The following table is a summary of impaired non-purchased loans and leases as of and for the year ended December 31, 2015. Principal Balance Net Charge-offs to Date Principal Balance, Net of Charge-offs Specific ALLL Weighted Average Carrying Value – Year Ended December 31, 2015 (Dollars in thousands) Impaired loans and leases for which there is a related ALLL: Real estate: Residential 1-4 family $ 2,914 $ (1,804 ) $ 1,110 $ 297 $ 1,279 Non-farm/non-residential 962 (907 ) 55 31 129 Construction/land development 121 — 121 48 896 Agricultural 1,153 — 1,153 475 479 Commercial and industrial 825 (322 ) 503 487 404 Consumer 26 (15 ) 11 2 16 Total impaired loans and leases with a related ALLL 6,001 (3,048 ) 2,953 1,340 3,203 Impaired loans and leases for which there is not a related ALLL: Real estate: Residential 1-4 family 1,306 (386 ) 920 — 955 Non-farm/non-residential 1,083 (198 ) 885 — 1,137 Construction/land development 7,873 (2,438 ) 5,435 — 8,255 Agricultural 362 (202 ) 160 — 261 Multifamily residential 216 (133 ) 83 — 155 Commercial and industrial 261 (50 ) 211 — 141 Consumer 18 (5 ) 13 — 14 Other 7 — 7 — 7 Total impaired loans and leases without a related ALLL 11,126 (3,412 ) 7,714 — 10,925 Total impaired non-purchased loans and leases $ 17,127 $ (6,460 ) $ 10,667 $ 1,340 $ 14,128
Summary of Credit Quality Indicators for Loans and Leases, Including Purchased and Non-Purchased Loans and Leases	The following table is a summary of credit quality indicators for the Company’s non-purchased loans and leases as of the dates indicated. Satisfactory Moderate Watch Substandard Total (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family (1) $ 423,398 $ — $ 3,226 $ 3,920 $ 430,544 Non-farm/non-residential 2,069,077 272,746 47,063 5,956 2,394,842 Construction/land development 3,875,564 315,893 9,051 1,357 4,201,865 Agricultural 48,128 31,768 9,328 2,205 91,429 Multifamily residential 469,810 45,077 2,771 1,044 518,702 Commercial and industrial 161,387 87,302 6,305 1,111 256,105 Consumer (1) 114,617 — 120 254 114,991 Direct financing leases 130,560 56 234 796 131,646 Other (1) 613,799 5,610 222 11 619,642 Total $ 7,906,340 $ 758,452 $ 78,320 $ 16,654 $ 8,759,766 December 31, 2015: Real estate: Residential 1-4 family (1) $ 342,083 $ — $ 2,946 $ 5,225 $ 350,254 Non-farm/non-residential 1,692,632 235,999 73,788 8,447 2,010,866 Construction/land development 2,553,368 256,655 8,916 6,636 2,825,575 Agricultural 40,538 22,799 8,909 2,194 74,440 Multifamily residential 400,848 35,080 4,079 821 440,828 Commercial and industrial 179,797 47,802 1,854 1,828 231,281 Consumer (1) 27,219 — 276 250 27,745 Direct financing leases 146,934 201 190 410 147,735 Other (1) 415,686 4,027 182 15 419,910 Total $ 5,799,105 $ 602,563 $ 101,140 $ 25,826 $ 6,528,634 (1) The Company does not risk rate its residential 1-4 family loans, its consumer loans, and certain “other” loans. However, for purposes of the above table, the Company considers such loans to be (i) satisfactory – if they are performing and less than 30 days past due, (ii) watch – if they are performing and 30 to 89 days past due or (iii) substandard – if they are nonperforming or 90 days or more past due. The following table is a summary of credit quality indicators for the Company’s purchased loans as of the dates indicated. Purchased Loans Without Evidence of Credit Deterioration at Acquisition Purchased Loans With Evidence of Credit Deterioration at Acquisition Total Purchased FV 33 FV 44 FV 55 FV 36 FV 77 FV 66 FV 88 Loans (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 111,115 $ 410,982 $ 168,343 $ 67,047 $ 235 $ 79,875 $ 1,918 $ 839,515 Non-farm/non-residential 319,635 1,573,456 422,873 3,556 578 133,188 3,108 2,456,394 Construction/land development 106,223 382,823 129,575 3,041 22 12,109 84 633,877 Agricultural 14,856 5,794 3,891 411 — 4,753 — 29,705 Multifamily residential 13,702 236,029 69,283 812 13 10,230 — 330,069 Commercial and industrial 19,865 178,415 14,326 2,687 23 4,917 67 220,300 Consumer 340,537 449,243 82,372 3,015 — 481 — 875,648 Other 5,815 1,908 138 75 — 6,387 — 14,323 Total $ 931,748 $ 3,238,650 $ 890,801 $ 80,644 $ 871 $ 251,940 $ 5,177 $ 5,399,831 December 31, 2015: Real estate: Residential 1-4 family $ 59,497 $ 117,498 $ 38,888 $ 85,684 $ 351 $ 82,862 $ 2,172 $ 386,952 Non-farm/non-residential 209,542 693,707 122,652 5,039 363 99,681 4,563 1,135,547 Construction/land development 13,121 12,511 7,137 4,771 22 10,224 37 47,823 Agricultural 4,825 7,963 1,456 797 — 4,877 — 19,918 Multifamily residential 20,347 86,588 27,818 896 13 3,835 — 139,497 Commercial and industrial 8,912 29,001 9,244 5,649 20 7,185 511 60,522 Consumer 726 205 185 6,106 2 263 — 7,487 Other 3,944 3,316 212 243 — 576 — 8,291 Total $ 320,914 $ 950,789 $ 207,592 $ 109,185 $ 771 $ 209,503 $ 7,283 $ 1,806,037
Schedule of Aging Analysis Past Due Loans and Leases, Loans Purchased and Non-Purchased by FDIC Loss Share Agreements	The following table is an aging analysis of past due non-purchased loans and leases as of the dates indicated. 30-89 Days Past Due (1) 90 Days or More (2) Total Past Due Current (3) Total (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 3,330 $ 1,607 $ 4,937 $ 425,607 $ 430,544 Non-farm/non-residential 2,617 1,716 4,333 2,390,509 2,394,842 Construction/land development 2,403 204 2,607 4,199,258 4,201,865 Agricultural 150 228 378 91,051 91,429 Multifamily residential 779 — 779 517,923 518,702 Commercial and industrial 83 750 833 255,272 256,105 Consumer 125 53 178 114,813 114,991 Direct financing leases 418 659 1,077 130,569 131,646 Other 30 6 36 619,606 619,642 Total $ 9,935 $ 5,223 $ 15,158 $ 8,744,608 $ 8,759,766 December 31, 2015: Real estate: Residential 1-4 family $ 2,793 $ 1,507 $ 4,300 $ 345,954 $ 350,254 Non-farm/non-residential 1,881 777 2,658 2,008,208 2,010,866 Construction/land development 1,043 5,645 6,688 2,818,887 2,825,575 Agricultural 1,780 243 2,023 72,417 74,440 Multifamily residential — 83 83 440,745 440,828 Commercial and industrial 823 751 1,574 229,707 231,281 Consumer 248 33 281 27,464 27,745 Direct financing leases 517 321 838 146,897 147,735 Other 8 7 15 419,895 419,910 Total $ 9,093 $ 9,367 $ 18,460 $ 6,510,174 $ 6,528,634 (1) Includes $0.3 million and $1.9 million at September 30, 2016 and December 31, 2015, respectively, of loans and leases on nonaccrual status. (2) All loans and leases greater than 90 days past due were on nonaccrual status at September 30, 2016 and December 31, 2015. (3) Includes $1.8 million and $2.3 million of loans and leases on nonaccrual status at September 30, 2016 and December 31, 2015, respectively. The following table is an aging analysis of past due purchased loans as of the dates indicated. 30-89 Days Past Due 90 Days or More Total Past Due Current Total Purchased Loans (Dollars in thousands) September 30, 2016: Real estate: Residential 1-4 family $ 10,401 $ 9,857 $ 20,258 $ 819,257 $ 839,515 Non-farm/non-residential 8,542 19,569 28,111 2,428,283 2,456,394 Construction/land development 2,536 870 3,406 630,471 633,877 Agriculture 136 1,022 1,158 28,547 29,705 Multifamily residential 335 160 495 329,574 330,069 Commercial and industrial 1,129 1,373 2,502 217,798 220,300 Consumer 6,360 1,098 7,458 868,190 875,648 Other — — — 14,323 14,323 Total $ 29,439 $ 33,949 $ 63,388 $ 5,336,443 $ 5,399,831 Purchased loans without evidence of credit deterioration at date of acquisition $ 20,257 $ 8,336 $ 28,593 $ 5,114,121 $ 5,142,714 Purchased loans with evidence of credit deterioration at date of acquisition 9,182 25,613 34,795 222,322 257,117 Total $ 29,439 $ 33,949 $ 63,388 $ 5,336,443 $ 5,399,831 December 31, 2015: Real estate: Residential 1-4 family $ 9,042 $ 6,293 $ 15,335 $ 371,617 $ 386,952 Non-farm/non-residential 3,435 6,837 10,272 1,125,275 1,135,547 Construction/land development 919 1,255 2,174 45,649 47,823 Agriculture 106 356 462 19,456 19,918 Multifamily residential 299 — 299 139,198 139,497 Commercial and industrial 714 924 1,638 58,884 60,522 Consumer 101 41 142 7,345 7,487 Other 10 11 21 8,270 8,291 Total $ 14,626 $ 15,717 $ 30,343 $ 1,775,694 $ 1,806,037 Purchased loans without evidence of credit deterioration at date of acquisition $ 7,972 $ 2,743 $ 10,715 $ 1,578,536 $ 1,589,251 Purchased loans with evidence of credit deterioration at date of acquisition 6,654 12,974 19,628 197,158 216,786 Total $ 14,626 $ 15,717 $ 30,343 $ 1,775,694 $ 1,806,037

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Types of Temporary Differences Between Tax Basis of Assets and Liabilities	The following table is a summary of the types of temporary differences between the tax basis of assets and liabilities and their financial reporting amounts that give rise to deferred income tax assets and liabilities and their approximate tax effects as of the dates indicated. September 30, December 31, 2016 2015 (Dollars in thousands) Deferred tax assets: Allowance for loan and lease losses $ 27,381 $ 22,802 Differences in amounts reflected in the financial statements and income tax basis for purchased loans 77,054 24,600 Differences in amounts reflected in the financial statements and income tax basis for deposits assumed in acquisitions 8,348 5,771 Stock-based compensation 7,237 4,199 Deferred compensation 2,318 2,035 Foreclosed assets 4,506 3,101 Deferred loan fees and costs, net — 10,579 Acquired net operating losses 29,585 27,862 Other, net 9,259 4,273 Total gross deferred tax assets 165,688 105,222 Less valuation allowance (474 ) (474 ) Net deferred tax asset 165,214 104,748 Deferred tax liabilities: Accelerated depreciation on premises and equipment 45,903 21,924 Investment securities AFS 12,431 5,650 Acquired intangible assets 11,301 1,448 Deferred loan fees and costs, net 1,846 — Total gross deferred tax liabilities 71,481 29,022 Net deferred tax assets $ 93,733 $ 75,726

Supplemental Data for Cash Fl31

Supplemental Data for Cash Flows (Tables)	9 Months Ended
	Sep. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Schedule of Supplemental Cash Flow Information	The following table provides supplemental cash flow information for the periods indicated. Nine Months Ended September 30, 2016 2015 (Dollars in thousands) Cash paid during the period for: Interest $ 36,571 $ 20,438 Taxes 97,232 48,869 Supplemental schedule of non-cash investing and financing activities: Net change in unrealized gains/losses on investment securities AFS 8,120 (4,317 ) Loans transferred to foreclosed assets 17,093 14,493 Loans advanced for sales of foreclosed assets 271 — Unsettled AFS investment security purchases 38,349 2,640 Unsettled loan sales — 14,361 Common stock issued in merger and acquisition transactions, net of shares redeemed for Brazilian Loans 1,135,861 303,866

Guarantees and Commitments (Tab

Guarantees and Commitments (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Contractual Maturities	At September 30, 2016, the Company had outstanding commitments totaling $8.66 billion to extend credit, consisting primarily of loans closed but not yet funded. The following table shows, as of the date indicated, the contractual maturities of such outstanding commitments. Contractual Maturities at September 30, 2016 Maturity Amount (Dollars in thousands) 2016 $ 122,873 2017 950,754 2018 2,503,466 2019 2,884,502 2020 1,957,622 Thereafter 241,587 Total $ 8,660,804

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following table summarizes stock option activity for the period indicated. Options Weighted- Average Exercise Price/Share Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Nine Months Ended September 30, 2016: Outstanding – December 31, 2015 2,034,476 $ 34.50 Granted 18,183 40.59 Exercised (83,670 ) 14.99 Forfeited (70,725 ) 39.61 Outstanding – September 30, 2016 1,898,264 35.22 5.0 $ 15,283 (1) Fully vested and exercisable – September 30, 2016 372,955 $ 14.90 3.4 $ 8,764 (1) Expected to vest in future periods 1,446,156 Fully vested and expected to vest – September 30, 2016 (2) 1,819,111 $ 34.70 4.9 $ 15,204 (1) (1) Based on closing price of $38.40 per share on September 30, 2016. (2) At September 30, 2016, the Company estimated that outstanding options to purchase 79,153 shares of its common stock would not vest and would be forfeited prior to their vesting date.
Summary of Non-Vested Restricted Stock Activity	The following table summarizes non-vested restricted stock activity for the period indicated. Nine Months Ended September 30, 2016 Outstanding – December 31, 2015 435,475 Granted 218,761 Forfeited (13,986 ) Vested — Outstanding – September 30, 2016 640,250 Weighted-average grant date fair value $ 35.10

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Assets and Liabilities at Fair Value	The following table sets forth the Company’s assets, as of the dates indicated, that are accounted for at fair value. Level 1 Level 2 Level 3 Total (Dollars in thousands) September 30, 2016: Investment securities AFS (1) Obligations of state and political subdivisions $ — $ 732,969 $ 17,756 $ 750,725 U.S. Government agency securities — 573,936 — 573,936 Corporate obligations — 10,022 — 10,022 CRA qualified investment fund 1,062 — — 1,062 Total investment securities AFS 1,062 1,316,927 17,756 1,335,745 Impaired non-purchased loans and leases — — 3,951 3,951 Impaired purchased loans — — 6,048 6,048 Foreclosed assets — — 44,250 44,250 Total assets at fair value $ 1,062 $ 1,316,927 $ 72,005 $ 1,389,994 December 31, 2015: Investment securities AFS (1) Obligations of state and political subdivisions $ — $ 408,774 $ 18,504 $ 427,278 U.S. Government agency securities — 146,950 — 146,950 Corporate obligations — 3,562 — 3,562 CRA qualified investment fund 1,028 — — 1,028 Total investment securities AFS 1,028 559,286 18,504 578,818 Impaired non-purchased loans and leases — — 9,327 9,327 Impaired purchased loans — — 8,054 8,054 Foreclosed assets — — 22,870 22,870 Total assets at fair value $ 1,028 $ 559,286 $ 58,755 $ 619,069 (1) Does not include $6.1 million at September 30, 2016 and $23.5 million at December 31, 2015 of FHLB and FNBB equity securities that do not have readily determinable fair values and are carried at cost.
Schedule of Information Related to Level 3 Non-Recurring Fair Value Measurements	The following table presents information related to Level 3 non-recurring fair value measurements as of the date indicated. Description Fair Value at September 30, 2016 Technique Unobservable Inputs (Dollars in thousands) Impaired non-purchased loans and leases $ 3,951 Third party appraisal (1) or discounted cash flows 1. Management discount based on underlying collateral characteristics and market conditions 2. Life of Loan Impaired purchased loans $ 6,048 Third party appraisal (1) and/or discounted cash flows 1. Management discount based on underlying collateral characteristics and market conditions 2. Life of Loan Foreclosed assets $ 44,250 Third party appraisal, (1) broker price opinions and/or discounted cash flows 1. Management discount based on underlying collateral characteristics and market conditions 2. Discount rate 3. Holding period (1) The Company utilizes valuation techniques consistent with the market, cost, and income approaches, or a combination thereof in determining fair value.
Assets Measured at Fair Value on Recurring Basis Utilizing Level 3 Inputs	The following table presents additional information for the periods indicated about assets measured at fair value on a recurring basis and for which the Company has utilized Level 3 inputs to determine fair value. Investment Securities AFS (Dollars in Balance – December 31, 2015 $ 18,504 Total realized gains (losses) included in earnings — Total unrealized gains (losses) included in comprehensive income (47 ) Paydowns and maturities (701 ) Sales — Transfers in and/or out of Level 3 — Balance – September 30, 2016 $ 17,756 Balance – December 31, 2014 $ 19,401 Total realized gains (losses) included in earnings — Total unrealized gains (losses) included in comprehensive income (19 ) Paydowns and maturities (714 ) Sales — Transfers in and/or out of Level 3 — Balance – September 30, 2015 $ 18,668

Fair Value of Financial Instr35

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Estimated Fair Values of Financial Instruments	The following table presents the carrying amounts and estimated fair values as of the dates indicated and the fair value hierarchy of the Company’s financial instruments. September 30, 2016 December 31, 2015 Fair Value Hierarchy Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value (Dollars in thousands) Financial assets: Cash and cash equivalents Level 1 $ 969,522 $ 969,522 $ 90,988 $ 90,988 Investment securities AFS Levels 2 and 3 1,341,894 1,341,894 602,348 602,348 Loans and leases, net of ALLL Level 3 14,089,837 14,004,121 8,273,817 8,165,123 Financial liabilities: Demand, savings and interest bearing transaction deposits Level 1 $ 10,138,890 $ 10,138,890 $ 5,532,986 $ 5,532,986 Time deposits Level 2 4,984,914 5,014,194 2,438,482 2,456,323 Repurchase agreements with customers Level 1 70,640 70,640 65,800 65,800 Other borrowings Level 2 41,978 43,101 204,540 205,918 Subordinated notes Level 2 222,420 223,072 — — Subordinated debentures Level 2 118,102 90,775 117,685 77,534

Changes in and Reclassificati36

Changes in and Reclassifications From Accumulated Other Comprehensive Income ("AOCI") (Tables)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income	The following table presents changes in AOCI for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Beginning balance of AOCI – unrealized gains and losses on investment securities AFS $ 15,106 $ 8,068 $ 7,959 $ 14,132 Other comprehensive income (loss): Unrealized gains and losses on investment securities AFS (2,262 ) 5,918 8,120 (1,274 ) Tax effect of unrealized gains and losses on investment securities AFS 791 (2,265 ) (2,444 ) 484 Amounts reclassified from AOCI — — — (2,619 ) Tax effect of amounts reclassified from AOCI — — — 998 Total other comprehensive income (loss) (1,471 ) 3,653 5,676 (2,411 ) Ending balance of AOCI – unrealized gains and losses on investment securities AFS $ 13,635 $ 11,721 $ 13,635 $ 11,721

Other Operating Expenses (Table

Other Operating Expenses (Tables)	9 Months Ended
	Sep. 30, 2016
Other Income And Expenses [Abstract]
Summary of Other Operating Expenses	The following table is a summary of other operating expenses for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Salaries and employee benefits $ 38,069 $ 21,207 $ 86,351 $ 66,450 Net occupancy and equipment 11,669 8,076 28,587 22,711 Other operating expenses: Professional and outside services 6,509 2,772 14,072 9,684 Postage and supplies 1,709 1,015 3,840 2,944 Advertising and public relations 1,941 575 4,543 1,744 Telecommunication services 1,883 1,583 5,339 4,547 Software and data processing 1,633 630 3,226 2,145 ATM expense 1,821 591 3,530 1,842 Travel and meals 2,778 922 5,850 2,538 FDIC insurance 1,725 1,020 4,125 2,670 FDIC and state assessments 392 330 1,071 971 Loan collection and repossession expense 1,524 1,322 3,244 4,075 Writedowns of foreclosed and other assets 859 553 2,119 2,980 Amortization of intangibles 2,596 1,697 5,879 4,934 FHLB prepayment penalty — — — 2,480 Other 3,673 3,135 5,619 6,621 Total non-interest expense $ 78,781 $ 45,428 $ 177,395 $ 139,336

Organization and Principles o38

Organization and Principles of Consolidation - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016TrustOffice
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Ownership interest owned finance subsidiary business trusts	100.00%
Number of finance subsidiary trusts | Trust	8
Number of offices	255
Arkansas [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	83
Georgia [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	73
Florida [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	44
North Carolina [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	24
Texas [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	22
Alabama [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	3
South Carolina [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	2
New York [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	2
California [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of offices	2

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) $ in Thousands	Sep. 23, 2016Office	Jul. 21, 2016USD ($)Officeshares	Jul. 20, 2016USD ($)Officeshares	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)
Business Acquisition [Line Items]
Net interest income				$ 175,150	$ 96,387	$ 406,705	$ 275,633
Net income				76,030	$ 46,128	$ 182,193	$ 130,798
Community & Southern Holdings, Inc. [Member]
Business Acquisition [Line Items]
Acquisition completion date						Jul. 20, 2016
Total outstanding transaction value			$ 800,300
Number of common stock issued | shares			20,983,815
Goodwill			$ 345,700
Net interest income				37,000		$ 37,000
Net income				17,500		$ 17,500
Community & Southern Holdings, Inc. [Member] | Georgia [Member]
Business Acquisition [Line Items]
Number of bank offices | Office			46
Number Of Retail Banking Offices Closed | Office	1
Community & Southern Holdings, Inc. [Member] | Florida [Member]
Business Acquisition [Line Items]
Number of bank offices | Office			1
C1 Financial, Inc. [Member]
Business Acquisition [Line Items]
Acquisition completion date						Jul. 21, 2016
Total outstanding transaction value		$ 376,100
Number of common stock issued | shares		9,370,587
Goodwill		$ 185,800
Net interest income				16,200		$ 16,200
Net income				$ 7,200		$ 7,200
Purchase agreement date		Dec. 21, 2015
C1 Financial, Inc. [Member] | Florida [Member]
Business Acquisition [Line Items]
Number of bank offices | Office		33

Acquisitions - Summary of Asset

Acquisitions - Summary of Assets Acquired and Liabilities Assumed in Acquisition (Detail) - USD ($) $ in Thousands		Jul. 21, 2016	Jul. 20, 2016	Sep. 30, 2016
Community & Southern Holdings, Inc. [Member]
Business Combination Separately Recognized Transactions [Line Items]
Cash, due from banks and interest earning deposits			$ 72,942
Investment securities			447,674
Loans			3,090,579
Allowance for loan losses			(42,395)
Premises and equipment			73,238
Foreclosed assets			6,274
BOLI			86,596
Goodwill			44,514
Core deposit intangible asset			12,227
Deferred income taxes			23,298
Accrued interest receivable and other assets			38,226
Total assets acquired			3,853,173
Deposits			3,256,372
Other borrowings			90,000
Accrued interest payable and other liabilities			22,991
Total liabilities assumed			3,369,363
Net assets acquired			483,810
Stock				$ (787,546)
Total consideration paid			(800,300)
Goodwill			345,700
Preliminary Fair Value Adjustments Community & Southern Holdings, Inc. [Member]
Business Combination Separately Recognized Transactions [Line Items]
Investment securities	[1],[2]		4,063
Loans	[2],[3]		(61,649)
Allowance for loan losses	[2],[3]		42,395
Premises and equipment	[2],[4]		31,969
Foreclosed assets	[2],[5]		(521)
BOLI	[2],[6]		(45)
Goodwill	[2],[7]		(44,514)
Core deposit intangible asset	[2],[8]		21,327
Deferred income taxes	[2],[9]		(9,059)
Accrued interest receivable and other assets	[2],[10]		(2,003)
Total assets acquired	[2]		(18,037)
Deposits	[2],[11]		11,813
Accrued interest payable and other liabilities	[2],[12]		(585)
Total liabilities assumed	[2]		11,228
Net assets acquired	[2]		(29,265)
As Recorded by the Company [Member]
Business Combination Separately Recognized Transactions [Line Items]
Cash, due from banks and interest earning deposits	[2]	$ 143,592	72,942
Investment securities	[2]	7,590	451,737
Loans	[2]	1,313,042	3,028,930
Premises and equipment	[2]	77,633	105,207
Foreclosed assets	[2]	20,048	5,753
BOLI	[2]	36,280	86,551
Core deposit intangible asset	[2]	9,774	33,554
Deferred income taxes	[2]	9,896	14,239
Accrued interest receivable and other assets	[2]	9,058	36,223
Total assets acquired	[2]	1,626,913	3,835,136
Deposits	[2]	1,297,218	3,268,185
Other borrowings	[2]	133,568	90,000
Accrued interest payable and other liabilities	[2]	5,815	22,406
Total liabilities assumed	[2]	1,436,601	3,380,591
Net assets acquired	[2]	190,312	454,545
Cash	[2]		(12,336)
Stock	[2]	(348,397)	(787,942)
Total consideration paid	[2]	(376,091)	(800,278)
Goodwill	[2]	185,779	$ 345,733
As Recorded by the Company [Member] | Brazilian Loans [Member]
Business Combination Separately Recognized Transactions [Line Items]
Cash and shares redeemed for Brazilian Loans	[2]	(27,694)
C1 Financial, Inc. [Member]
Business Combination Separately Recognized Transactions [Line Items]
Cash, due from banks and interest earning deposits		143,592
Investment securities		7,618
Loans		1,353,498
Allowance for loan losses		(7,307)
Premises and equipment		63,943
Foreclosed assets		21,704
BOLI		36,280
Core deposit intangible asset		576
Deferred income taxes		1,608
Accrued interest receivable and other assets		12,182
Total assets acquired		1,633,694
Deposits		1,294,439
Other borrowings		131,010
Accrued interest payable and other liabilities		4,775
Total liabilities assumed		1,430,224
Net assets acquired		203,470
Stock				$ (348,315)
Total consideration paid		(376,100)
Goodwill		185,800
Preliminary Fair Value Adjustments C1 Financial, Inc. [Member]
Business Combination Separately Recognized Transactions [Line Items]
Investment securities	[2],[13]	(28)
Loans	[2],[3]	(40,456)
Allowance for loan losses	[2],[3]	7,307
Premises and equipment	[2],[4]	13,690
Foreclosed assets	[2],[5]	(1,656)
Core deposit intangible asset	[2],[14]	9,198
Deferred income taxes	[2],[15]	8,288
Accrued interest receivable and other assets	[2],[10]	(3,124)
Total assets acquired	[2]	(6,781)
Deposits	[2],[11]	2,779
Other borrowings	[2],[16]	2,558
Accrued interest payable and other liabilities	[2],[17]	1,040
Total liabilities assumed	[2]	6,377
Net assets acquired	[2]	$ (13,158)
[1]	Adjustment reflects the fair value adjustment based on the pricing of the acquired held to maturity investment securities portfolio.
[2]	Management continues to evaluate and may revise, if necessary, one or more of the fair value adjustments in future periods. To the extent that any of these fair value adjustments are revised in future periods, the resultant fair values and the amount of goodwill may be subject to further adjustment.
[3]	Adjustment reflects the fair value adjustment based on the evaluation of the acquired loan portfolio and to eliminate the recorded allowance for loan losses.
[4]	Adjustment reflects the fair value adjustment based on the evaluation of the premises and equipment acquired.
[5]	Adjustment reflects the fair value adjustment based on the evaluation of the acquired foreclosed assets.
[6]	Adjustment reflects the fair value adjustment based on the evaluation of BOLI acquired.
[7]	Adjustment reflects the elimination of previously recorded goodwill.
[8]	Adjustment reflects the fair value adjustment for the core deposit intangible asset recorded as a result of the acquisition net of the elimination of previously recorded core deposit intangible assets.
[9]	This adjustment reflects the differences in the carrying values of acquired assets and assumed liabilities for financial reporting purposes and their basis for federal income tax purposes.
[10]	Adjustment reflects the fair value adjustment based on the evaluation of accrued interest receivable and other assets.
[11]	Adjustment reflects the fair value adjustment based on the evaluation of the acquired deposits.
[12]	Adjustment reflects the amount needed to adjust other liabilities to estimated fair value and to record certain liabilities directly attributable to the C&S acquisition.
[13]	Adjustment reflects the fair value adjustment based on the pricing of the acquired investment securities portfolio.
[14]	Adjustment reflects the fair value adjustment for the core deposit and other intangible assets recorded as a result of the acquisition.
[15]	This adjustment reflects the differences in the carrying values of acquired assets and assumed liabilities for financial reporting purposes and their basis for federal income tax purposes.
[16]	Adjustment reflects the fair value adjustment of these assumed liabilities.
[17]	Adjustment reflects the amount needed to adjust other liabilities to estimated fair value and to record certain liabilities directly attributable to the C1 acquisition.

Acquisitions - Summary of Suppl

Acquisitions - Summary of Supplemental Pro-forma Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Community & Southern Holdings, Inc. [Member]
Pro-forma Information [Line Items]
Net interest income – pro forma (unaudited)	$ 493,602	$ 404,497
Net income – pro forma (unaudited)	$ 222,029	$ 176,635
Diluted earnings per common share – pro forma (unaudited)	$ 1.94	$ 1.64
C1 Financial, Inc. [Member]
Pro-forma Information [Line Items]
Net interest income – pro forma (unaudited)	$ 448,903	$ 334,960
Net income – pro forma (unaudited)	$ 198,814	$ 152,847
Diluted earnings per common share – pro forma (unaudited)	$ 1.88	$ 1.42

Earnings Per Common Share ("E42

Earnings Per Common Share ("EPS") - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Options to purchase shares of the Company's common stock	648,135	4,000	652,077	519,270

Earnings Per Common Share ("E43

Earnings Per Common Share ("EPS") - Schedule of Calculation of Numerator and Denominator in Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Distributed earnings allocated to common stockholders	$ 14,521	$ 12,154	$ 42,185	$ 34,280
Undistributed earnings allocated to common stockholders	61,509	33,974	140,008	96,518
Net income available to common stockholders	$ 76,030	$ 46,128	$ 182,193	$ 130,798
Denominator for basic EPS – weighted-average common shares	114,745	87,683	98,779	86,070
Effect of dilutive securities – stock options	262	771	285	769
Denominator for diluted EPS – weighted-average common shares and assumed conversions	115,007	88,454	99,064	86,839
Basic EPS	$ 0.66	$ 0.53	$ 1.84	$ 1.52
Diluted EPS	$ 0.66	$ 0.52	$ 1.84	$ 1.51

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Investment Securities (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		$ 1,320,917	$ 589,490
Gross Unrealized Gains		22,556	14,041
Gross Unrealized Losses		(1,579)	(1,183)
Estimated Fair Value		1,341,894	602,348
Obligations of State and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		735,494	415,095
Gross Unrealized Gains		16,325	12,321
Gross Unrealized Losses		(1,094)	(138)
Estimated Fair Value	[1]	750,725	427,278
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		568,130	146,265
Gross Unrealized Gains		6,224	1,720
Gross Unrealized Losses		(418)	(1,035)
Estimated Fair Value	[1]	573,936	146,950
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		10,089	3,562
Gross Unrealized Losses		(67)
Estimated Fair Value	[1]	10,022	3,562
CRA Qualified Investment Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,055	1,038
Gross Unrealized Gains		7
Gross Unrealized Losses			(10)
Estimated Fair Value	[1]	1,062	1,028
Other Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		6,149	23,530
Estimated Fair Value		$ 6,149	$ 23,530
[1]	Does not include $6.1 million at September 30, 2016 and $23.5 million at December 31, 2015 of FHLB and FNBB equity securities that do not have readily determinable fair values and are carried at cost.

Investment Securities - Gross U

Investment Securities - Gross Unrealized Losses and Estimated Fair Value of Investment Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Total temporarily impaired investment securities, Estimated Fair Value, Less than 12 Months	$ 226,761	$ 91,718
Total temporarily impaired investment securities, Unrealized Losses, Less than 12 Months	1,563	1,054
Total temporarily impaired investment securities, Estimated Fair Value, 12 Months or More	4,908	10,548
Total temporarily impaired investment securities, Unrealized Losses, 12 Months or More	16	129
Total temporarily impaired securities, Estimated Fair Value, Total	231,669	102,266
Total temporarily impaired securities, Unrealized Losses, Total	1,579	1,183
Obligations of State and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Total temporarily impaired investment securities, Estimated Fair Value, Less than 12 Months	128,359	18,018
Total temporarily impaired investment securities, Unrealized Losses, Less than 12 Months	1,084	114
Total temporarily impaired investment securities, Estimated Fair Value, 12 Months or More	4,747	6,167
Total temporarily impaired investment securities, Unrealized Losses, 12 Months or More	10	24
Total temporarily impaired securities, Estimated Fair Value, Total	133,106	24,185
Total temporarily impaired securities, Unrealized Losses, Total	1,094	138
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total temporarily impaired investment securities, Estimated Fair Value, Less than 12 Months	91,380	72,671
Total temporarily impaired investment securities, Unrealized Losses, Less than 12 Months	412	930
Total temporarily impaired investment securities, Estimated Fair Value, 12 Months or More	161	4,381
Total temporarily impaired investment securities, Unrealized Losses, 12 Months or More	6	105
Total temporarily impaired securities, Estimated Fair Value, Total	91,541	77,052
Total temporarily impaired securities, Unrealized Losses, Total	418	1,035
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Total temporarily impaired investment securities, Estimated Fair Value, Less than 12 Months	7,022
Total temporarily impaired investment securities, Unrealized Losses, Less than 12 Months	67
Total temporarily impaired securities, Estimated Fair Value, Total	7,022
Total temporarily impaired securities, Unrealized Losses, Total	$ 67
CRA Qualified Investment Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Total temporarily impaired investment securities, Estimated Fair Value, Less than 12 Months		1,029
Total temporarily impaired investment securities, Unrealized Losses, Less than 12 Months		10
Total temporarily impaired securities, Estimated Fair Value, Total		1,029
Total temporarily impaired securities, Unrealized Losses, Total		$ 10

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Estimated Fair Value of Investment Securities AFS by Maturity or Estimated Date of Repayment (Detail) $ in Thousands	Sep. 30, 2016USD ($)
Investments Debt And Equity Securities [Abstract]
Amortized Cost, One year or less	$ 99,489
Amortized Cost, After one year to five years	341,412
Amortized Cost, After five years to ten years	308,141
Amortized Cost, After ten years	571,875
Total, Amortized Cost	1,320,917
Estimated Fair Value, One year or less	100,484
Estimated Fair Value, After one year to five years	344,840
Estimated Fair Value, After five years to ten years	313,543
Estimated Fair Value, After ten years	583,027
Total, Estimated Fair Value	$ 1,341,894

Investment Securities - Sales A

Investment Securities - Sales Activities of Company's Investment Securities AFS are Summarized (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments Debt And Equity Securities [Abstract]
Sales proceeds	$ 0	$ 0	$ 0	$ 32,777
Gross realized gains	0	0	0	2,620
Gross realized losses	0	0	0	(1)
Net gains on investment securities	$ 0	$ 0	$ 0	$ 2,619

Allowance for Loan and Lease 48

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Activity Within Allowance for Loan and Lease Losses (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015	Dec. 31, 2015	[1]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 65,133		$ 56,749	$ 60,854		$ 52,918
Net charge-offs	(2,459)		(1,313)	(5,031)		(8,106)
Total provision	7,086		3,581	13,937		14,205
Ending balance	69,760		59,017	69,760		59,017
ALLL allocated to non-purchased loans and leases	68,160	[1]	59,017	68,160	[1]	59,017	$ 59,654
ALLL allocated to purchased loans	1,600			1,600
Total ALLL	69,760		59,017	69,760		59,017
Non-Purchased Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	63,933		56,749	59,654		52,918
Charge-offs of loans and leases	(1,791)		(992)	(4,356)		(6,567)
Recoveries of loans and leases charged off	418		360	862		866
Net charge-offs	(1,373)		(632)	(3,494)		(5,701)
Total provision	5,600		2,900	12,000		11,800
Ending balance	68,160		59,017	68,160		59,017
Purchased Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Charge-offs of loans and leases	(1,197)		(829)	(1,732)		(2,945)
Recoveries of loans and leases charged off	111		148	195		540
Net charge-offs	(1,086)		(681)	(1,537)		(2,405)
Total provision	$ 1,486		$ 681	$ 1,937		$ 2,405
[1]	Excludes $1.6 million and $1.2 million of ALLL allocated to the Company’s purchased loans at September 30, 2016 and December 31, 2015

Allowance for Loan and Lease 49

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Company's Allowance for Loan and Lease Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	$ 65,133	$ 56,749	$ 60,854	$ 52,918
Charge-offs	(2,988)	(1,821)	(6,088)	(9,512)
Recoveries	529	508	1,057	1,406
Provision	7,086	3,581	13,937	14,205
Ending balance	69,760	59,017	69,760	59,017
Purchased Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	1,200		1,200
Charge-offs	(1,197)	(829)	(1,732)	(2,945)
Recoveries	111	148	195	540
Provision	1,486	681	1,937	2,405
Ending balance	1,600		1,600
Non-Purchased Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	63,933	56,749	59,654	52,918
Charge-offs	(1,791)	(992)	(4,356)	(6,567)
Recoveries	418	360	862	866
Provision	5,600	2,900	12,000	11,800
Ending balance	68,160	59,017	68,160	59,017
Non-Purchased Loans [Member] | Real Estate [Member] | Residential 1-4 Family [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	10,099	5,601	8,672	5,482
Charge-offs	(94)	(121)	(350)	(742)
Recoveries	6	37	43	58
Provision	312	92	1,958	811
Ending balance	10,323	5,609	10,323	5,609
Non-Purchased Loans [Member] | Real Estate [Member] | Non-Farm/Non-Residential [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	19,118	18,232	16,796	17,190
Charge-offs	(236)	(6)	(248)	(330)
Recoveries		1		18
Provision	754	(144)	3,088	1,205
Ending balance	19,636	18,083	19,636	18,083
Non-Purchased Loans [Member] | Real Estate [Member] | Construction/Land Development [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	17,496	19,148	18,176	15,960
Charge-offs	(22)	(38)	(42)	(809)
Recoveries	2	40	53	77
Provision	2,582	1,997	1,871	5,919
Ending balance	20,058	21,147	20,058	21,147
Non-Purchased Loans [Member] | Real Estate [Member] | Agricultural [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	3,755	2,460	3,388	2,558
Charge-offs			(7)	(13)
Provision	(373)	12	1	(73)
Ending balance	3,382	2,472	3,382	2,472
Non-Purchased Loans [Member] | Real Estate [Member] | Multifamily Residential [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	3,661	2,886	3,031	2,147
Charge-offs		(20)		(228)
Recoveries			14
Provision	(12)	42	604	989
Ending balance	3,649	2,908	3,649	2,908
Non-Purchased Loans [Member] | Commercial and Industrial [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	3,790	3,249	2,574	4,873
Charge-offs	(45)	(132)	(87)	(2,672)
Recoveries	13	149	52	188
Provision	182	(106)	1,401	771
Ending balance	3,940	3,160	3,940	3,160
Non-Purchased Loans [Member] | Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	712	825	707	818
Charge-offs	(19)	(11)	(87)	(80)
Recoveries	1	5	15	47
Provision	870	34	929	68
Ending balance	1,564	853	1,564	853
Non-Purchased Loans [Member] | Direct Financing Leases [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	4,092	3,554	3,835	2,989
Charge-offs	(795)	(222)	(2,263)	(563)
Recoveries	4	7	20	20
Provision	842	522	2,551	1,415
Ending balance	4,143	3,861	4,143	3,861
Non-Purchased Loans [Member] | Other [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	1,210	794	2,475	901
Charge-offs	(580)	(442)	(1,272)	(1,130)
Recoveries	392	121	665	458
Provision	443	451	(403)	695
Ending balance	$ 1,465	$ 924	$ 1,465	$ 924

Allowance for Loan and Lease 50

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Allowance for Loan and Lease Losses and Recorded Investment in Non-Purchased Loans and Leases (Detail) - USD ($) $ in Thousands		Sep. 30, 2016		Jun. 30, 2016	Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for Individually Evaluated Impaired Loans and Leases		$ 1,029			$ 1,340
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		69,760		$ 65,133	60,854		$ 59,017	$ 56,749	$ 52,918
Non-Purchased Loans and Leases - Total ALLL		68,160	[1]		59,654	[1]	$ 59,017
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		4,980			10,667
Non-Purchased Loans and Leases - All Other Loans and Leases		8,754,786			6,517,967
Total non-purchased loans and leases		8,759,766			6,528,634
ALLL for All Other Loans and Leases [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		67,131			58,314
Real Estate [Member] | Residential 1-4 Family [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for Individually Evaluated Impaired Loans and Leases		32			297
Non-Purchased Loans and Leases - Total ALLL	[1]	10,323			8,672
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		1,006			2,030
Non-Purchased Loans and Leases - All Other Loans and Leases		429,538			348,224
Total non-purchased loans and leases		430,544			350,254
Real Estate [Member] | Non-Farm/Non-Residential [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for Individually Evaluated Impaired Loans and Leases		4			31
Non-Purchased Loans and Leases - Total ALLL	[1]	19,636			16,796
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		1,562			940
Non-Purchased Loans and Leases - All Other Loans and Leases		2,393,280			2,009,926
Total non-purchased loans and leases		2,394,842			2,010,866
Real Estate [Member] | Construction/Land Development [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for Individually Evaluated Impaired Loans and Leases		73			48
Non-Purchased Loans and Leases - Total ALLL	[1]	20,058			18,176
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		435			5,556
Non-Purchased Loans and Leases - All Other Loans and Leases		4,201,430			2,820,019
Total non-purchased loans and leases		4,201,865			2,825,575
Real Estate [Member] | Agricultural [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for Individually Evaluated Impaired Loans and Leases		404			475
Non-Purchased Loans and Leases - Total ALLL	[1]	3,382			3,388
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		1,265			1,313
Non-Purchased Loans and Leases - All Other Loans and Leases		90,164			73,127
Total non-purchased loans and leases		91,429			74,440
Real Estate [Member] | Multifamily Residential [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - Total ALLL	[1]	3,649			3,031
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases					83
Non-Purchased Loans and Leases - All Other Loans and Leases		518,702			440,745
Total non-purchased loans and leases		518,702			440,828
Real Estate [Member] | ALLL for All Other Loans and Leases [Member] | Residential 1-4 Family [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		10,291			8,375
Real Estate [Member] | ALLL for All Other Loans and Leases [Member] | Non-Farm/Non-Residential [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		19,632			16,765
Real Estate [Member] | ALLL for All Other Loans and Leases [Member] | Construction/Land Development [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		19,985			18,128
Real Estate [Member] | ALLL for All Other Loans and Leases [Member] | Agricultural [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		2,978			2,913
Real Estate [Member] | ALLL for All Other Loans and Leases [Member] | Multifamily Residential [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		3,649			3,031
Commercial and Industrial [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for Individually Evaluated Impaired Loans and Leases		513			487
Non-Purchased Loans and Leases - Total ALLL	[1]	3,940			2,574
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		683			714
Non-Purchased Loans and Leases - All Other Loans and Leases		255,422			230,567
Total non-purchased loans and leases		256,105			231,281
Commercial and Industrial [Member] | ALLL for All Other Loans and Leases [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		3,427			2,087
Consumer [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for Individually Evaluated Impaired Loans and Leases		3			2
Non-Purchased Loans and Leases - Total ALLL	[1]	1,564			707
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		23			24
Non-Purchased Loans and Leases - All Other Loans and Leases		114,968			27,721
Total non-purchased loans and leases		114,991			27,745
Consumer [Member] | ALLL for All Other Loans and Leases [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		1,561			705
Direct Financing Leases [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - Total ALLL	[1]	4,143			3,835
Non-Purchased Loans and Leases - All Other Loans and Leases		131,646			147,735
Total non-purchased loans and leases		131,646			147,735
Direct Financing Leases [Member] | ALLL for All Other Loans and Leases [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		4,143			3,835
Other [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - Total ALLL	[1]	1,465			2,475
Non-Purchased Loans and Leases - Individually Evaluated Impaired Loans and Leases		6			7
Non-Purchased Loans and Leases - All Other Loans and Leases		619,636			419,903
Total non-purchased loans and leases		619,642			419,910
Other [Member] | ALLL for All Other Loans and Leases [Member]
Allowance For Loan And Lease Losses [Line Items]
Non-Purchased Loans and Leases - ALLL for All Other Loans and Leases		$ 1,465			$ 2,475
[1]	Excludes $1.6 million and $1.2 million of ALLL allocated to the Company’s purchased loans at September 30, 2016 and December 31, 2015

Allowance for Loan and Lease 51

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Allowance for Loan and Lease Losses and Recorded Investment in Non-Purchased Loans and Leases (Parenthetical) (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Receivables [Abstract]
Allowance for purchased loan portfolio	$ 1.6	$ 1.2

Allowance for Loan and Lease 52

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Impaired Non-purchased Loans and Leases, FDIC Loss Share Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Principal Balance, with Related Allowance	$ 3,342	$ 3,342	$ 6,001
Net Charge-offs to Date, with Related Allowance	(1,468)	(1,468)	(3,048)
Principal Balance, with Related Allowance, Net of Charge-offs	1,874	1,874	2,953
Specific Allowance	1,029	1,029	1,340
Weighted Average Carrying Value, with Related Allowance	2,427	2,792	3,203
Principal Balance, with no Related Allowance	5,215	5,215	11,126
Net Charge-offs to Date, with no Related Allowance	(2,109)	(2,109)	(3,412)
Principal Balance, with no Related Allowance, Net of Charge-offs	3,106	3,106	7,714
Weighted Average Carrying Value, with no Related Allowance	2,808	4,810	10,925
Principal Balance	8,557	8,557	17,127
Net Charge-offs to Date	(3,577)	(3,577)	(6,460)
Principal Balance, Net of Charge-offs	4,980	4,980	10,667
Weighted Average Carrying Value	5,235	7,602	14,128
Real Estate [Member] | Residential 1-4 Family [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with Related Allowance	348	348	2,914
Net Charge-offs to Date, with Related Allowance	(215)	(215)	(1,804)
Principal Balance, with Related Allowance, Net of Charge-offs	133	133	1,110
Specific Allowance	32	32	297
Weighted Average Carrying Value, with Related Allowance	568	939	1,279
Principal Balance, with no Related Allowance	1,312	1,312	1,306
Net Charge-offs to Date, with no Related Allowance	(439)	(439)	(386)
Principal Balance, with no Related Allowance, Net of Charge-offs	873	873	920
Weighted Average Carrying Value, with no Related Allowance	981	939	955
Real Estate [Member] | Non-Farm/Non-Residential [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with Related Allowance	928	928	962
Net Charge-offs to Date, with Related Allowance	(924)	(924)	(907)
Principal Balance, with Related Allowance, Net of Charge-offs	4	4	55
Specific Allowance	4	4	31
Weighted Average Carrying Value, with Related Allowance	89	71	129
Principal Balance, with no Related Allowance	2,021	2,021	1,083
Net Charge-offs to Date, with no Related Allowance	(463)	(463)	(198)
Principal Balance, with no Related Allowance, Net of Charge-offs	1,558	1,558	885
Weighted Average Carrying Value, with no Related Allowance	1,209	1,042	1,137
Real Estate [Member] | Construction/Land Development [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with Related Allowance	130	130	121
Principal Balance, with Related Allowance, Net of Charge-offs	130	130	121
Specific Allowance	73	73	48
Weighted Average Carrying Value, with Related Allowance	124	122	896
Principal Balance, with no Related Allowance	1,115	1,115	7,873
Net Charge-offs to Date, with no Related Allowance	(810)	(810)	(2,438)
Principal Balance, with no Related Allowance, Net of Charge-offs	305	305	5,435
Weighted Average Carrying Value, with no Related Allowance	234	2,398	8,255
Real Estate [Member] | Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with Related Allowance	1,081	1,081	1,153
Principal Balance, with Related Allowance, Net of Charge-offs	1,081	1,081	1,153
Specific Allowance	404	404	475
Weighted Average Carrying Value, with Related Allowance	1,113	1,132	479
Principal Balance, with no Related Allowance	393	393	362
Net Charge-offs to Date, with no Related Allowance	(209)	(209)	(202)
Principal Balance, with no Related Allowance, Net of Charge-offs	184	184	160
Weighted Average Carrying Value, with no Related Allowance	183	177	261
Real Estate [Member] | Multifamily Residential [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with no Related Allowance	133	133	216
Net Charge-offs to Date, with no Related Allowance	(133)	(133)	(133)
Principal Balance, with no Related Allowance, Net of Charge-offs			83
Weighted Average Carrying Value, with no Related Allowance		41	155
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with Related Allowance	838	838	825
Net Charge-offs to Date, with Related Allowance	(325)	(325)	(322)
Principal Balance, with Related Allowance, Net of Charge-offs	513	513	503
Specific Allowance	513	513	487
Weighted Average Carrying Value, with Related Allowance	510	511	404
Principal Balance, with no Related Allowance	220	220	261
Net Charge-offs to Date, with no Related Allowance	(50)	(50)	(50)
Principal Balance, with no Related Allowance, Net of Charge-offs	170	170	211
Weighted Average Carrying Value, with no Related Allowance	185	196	141
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with Related Allowance	17	17	26
Net Charge-offs to Date, with Related Allowance	(4)	(4)	(15)
Principal Balance, with Related Allowance, Net of Charge-offs	13	13	11
Specific Allowance	3	3	2
Weighted Average Carrying Value, with Related Allowance	23	17	16
Principal Balance, with no Related Allowance	15	15	18
Net Charge-offs to Date, with no Related Allowance	(5)	(5)	(5)
Principal Balance, with no Related Allowance, Net of Charge-offs	10	10	13
Weighted Average Carrying Value, with no Related Allowance	10	11	14
Other [Member]
Financing Receivable, Impaired [Line Items]
Principal Balance, with no Related Allowance	6	6	7
Principal Balance, with no Related Allowance, Net of Charge-offs	6	6	7
Weighted Average Carrying Value, with no Related Allowance	$ 6	$ 6	$ 7

Allowance for Loan and Lease 53

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Credit Quality Indicators for Loans and Leases, Non-Purchased Loans and Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Loans And Leases [Line Items]
Total non-purchased loans and leases	$ 8,759,766	$ 6,528,634
Satisfactory [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	7,906,340	5,799,105
Moderate [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	758,452	602,563
Watch [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	78,320	101,140
Substandard [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	16,654	25,826
Real Estate [Member] | Residential 1-4 Family [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	430,544	350,254
Real Estate [Member] | Non-Farm/Non-Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	2,394,842	2,010,866
Real Estate [Member] | Construction/Land Development [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	4,201,865	2,825,575
Real Estate [Member] | Agricultural [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	91,429	74,440
Real Estate [Member] | Multifamily Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	518,702	440,828
Real Estate [Member] | Satisfactory [Member] | Residential 1-4 Family [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	423,398	342,083
Real Estate [Member] | Satisfactory [Member] | Non-Farm/Non-Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	2,069,077	1,692,632
Real Estate [Member] | Satisfactory [Member] | Construction/Land Development [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	3,875,564	2,553,368
Real Estate [Member] | Satisfactory [Member] | Agricultural [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	48,128	40,538
Real Estate [Member] | Satisfactory [Member] | Multifamily Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	469,810	400,848
Real Estate [Member] | Moderate [Member] | Non-Farm/Non-Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	272,746	235,999
Real Estate [Member] | Moderate [Member] | Construction/Land Development [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	315,893	256,655
Real Estate [Member] | Moderate [Member] | Agricultural [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	31,768	22,799
Real Estate [Member] | Moderate [Member] | Multifamily Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	45,077	35,080
Real Estate [Member] | Watch [Member] | Residential 1-4 Family [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	3,226	2,946
Real Estate [Member] | Watch [Member] | Non-Farm/Non-Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	47,063	73,788
Real Estate [Member] | Watch [Member] | Construction/Land Development [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	9,051	8,916
Real Estate [Member] | Watch [Member] | Agricultural [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	9,328	8,909
Real Estate [Member] | Watch [Member] | Multifamily Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	2,771	4,079
Real Estate [Member] | Substandard [Member] | Residential 1-4 Family [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	3,920	5,225
Real Estate [Member] | Substandard [Member] | Non-Farm/Non-Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	5,956	8,447
Real Estate [Member] | Substandard [Member] | Construction/Land Development [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	1,357	6,636
Real Estate [Member] | Substandard [Member] | Agricultural [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	2,205	2,194
Real Estate [Member] | Substandard [Member] | Multifamily Residential [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	1,044	821
Commercial and Industrial [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	256,105	231,281
Commercial and Industrial [Member] | Satisfactory [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	161,387	179,797
Commercial and Industrial [Member] | Moderate [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	87,302	47,802
Commercial and Industrial [Member] | Watch [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	6,305	1,854
Commercial and Industrial [Member] | Substandard [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	1,111	1,828
Consumer [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	114,991	27,745
Consumer [Member] | Satisfactory [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	114,617	27,219
Consumer [Member] | Watch [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	120	276
Consumer [Member] | Substandard [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	254	250
Direct Financing Leases [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	131,646	147,735
Direct Financing Leases [Member] | Satisfactory [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	130,560	146,934
Direct Financing Leases [Member] | Moderate [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	56	201
Direct Financing Leases [Member] | Watch [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	234	190
Direct Financing Leases [Member] | Substandard [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	796	410
Other [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	619,642	419,910
Other [Member] | Satisfactory [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	613,799	415,686
Other [Member] | Moderate [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	5,610	4,027
Other [Member] | Watch [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	222	182
Other [Member] | Substandard [Member]
Loans And Leases [Line Items]
Total non-purchased loans and leases	$ 11	$ 15

Allowance for Loan and Lease 54

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Aging Analysis Past Due Loans and Leases, Non-Purchased by FDIC Loss Share Agreements (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		$ 8,759,766	$ 6,528,634
Real Estate [Member] | Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		430,544	350,254
Real Estate [Member] | Non-Farm/Non-Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		2,394,842	2,010,866
Real Estate [Member] | Construction/Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		4,201,865	2,825,575
Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		91,429	74,440
Real Estate [Member] | Multifamily Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		518,702	440,828
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		256,105	231,281
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		114,991	27,745
Direct Financing Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		131,646	147,735
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total non-purchased loans and leases		619,642	419,910
Non-Purchased Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		15,158	18,460
Current	[1]	8,744,608	6,510,174
Total non-purchased loans and leases		8,759,766	6,528,634
Non-Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	9,935	9,093
Non-Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	5,223	9,367
Non-Purchased Loans [Member] | Real Estate [Member] | Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		4,937	4,300
Current	[1]	425,607	345,954
Total non-purchased loans and leases		430,544	350,254
Non-Purchased Loans [Member] | Real Estate [Member] | Residential 1-4 Family [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	3,330	2,793
Non-Purchased Loans [Member] | Real Estate [Member] | Residential 1-4 Family [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	1,607	1,507
Non-Purchased Loans [Member] | Real Estate [Member] | Non-Farm/Non-Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		4,333	2,658
Current	[1]	2,390,509	2,008,208
Total non-purchased loans and leases		2,394,842	2,010,866
Non-Purchased Loans [Member] | Real Estate [Member] | Non-Farm/Non-Residential [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	2,617	1,881
Non-Purchased Loans [Member] | Real Estate [Member] | Non-Farm/Non-Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	1,716	777
Non-Purchased Loans [Member] | Real Estate [Member] | Construction/Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,607	6,688
Current	[1]	4,199,258	2,818,887
Total non-purchased loans and leases		4,201,865	2,825,575
Non-Purchased Loans [Member] | Real Estate [Member] | Construction/Land Development [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	2,403	1,043
Non-Purchased Loans [Member] | Real Estate [Member] | Construction/Land Development [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	204	5,645
Non-Purchased Loans [Member] | Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		378	2,023
Current	[1]	91,051	72,417
Total non-purchased loans and leases		91,429	74,440
Non-Purchased Loans [Member] | Real Estate [Member] | Agricultural [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	150	1,780
Non-Purchased Loans [Member] | Real Estate [Member] | Agricultural [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	228	243
Non-Purchased Loans [Member] | Real Estate [Member] | Multifamily Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		779	83
Current	[1]	517,923	440,745
Total non-purchased loans and leases		518,702	440,828
Non-Purchased Loans [Member] | Real Estate [Member] | Multifamily Residential [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	779
Non-Purchased Loans [Member] | Real Estate [Member] | Multifamily Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]		83
Non-Purchased Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		833	1,574
Current	[1]	255,272	229,707
Total non-purchased loans and leases		256,105	231,281
Non-Purchased Loans [Member] | Commercial and Industrial [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	83	823
Non-Purchased Loans [Member] | Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	750	751
Non-Purchased Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		178	281
Current	[1]	114,813	27,464
Total non-purchased loans and leases		114,991	27,745
Non-Purchased Loans [Member] | Consumer [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	125	248
Non-Purchased Loans [Member] | Consumer [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	53	33
Non-Purchased Loans [Member] | Direct Financing Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,077	838
Current	[1]	130,569	146,897
Total non-purchased loans and leases		131,646	147,735
Non-Purchased Loans [Member] | Direct Financing Leases [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	418	517
Non-Purchased Loans [Member] | Direct Financing Leases [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	659	321
Non-Purchased Loans [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		36	15
Current	[1]	619,606	419,895
Total non-purchased loans and leases		619,642	419,910
Non-Purchased Loans [Member] | Other [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[2]	30	8
Non-Purchased Loans [Member] | Other [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[3]	$ 6	$ 7
[1]	Includes $1.8 million and $2.3 million of loans and leases on nonaccrual status at September 30, 2016 and December 31, 2015, respectively.
[2]	Includes $0.3 million and $1.9 million at September 30, 2016 and December 31, 2015, respectively, of loans and leases on nonaccrual status.
[3]	All loans and leases greater than 90 days past due were on nonaccrual status at September 30, 2016 and December 31, 2015.

Allowance for Loan and Lease 55

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Aging Analysis Past Due Loans and Leases, Non-Purchased by FDIC Loss Share Agreements (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Non Accrual Loans Current [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases on nonaccrual status	$ 1.8	$ 2.3
Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases on nonaccrual status	$ 0.3	$ 1.9

Allowance for Loan and Lease 56

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Receivables [Abstract]
Impaired purchased loans	$ 6,048	$ 8,054

Allowance for Loan and Lease 57

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Credit Quality Indicators for Loans Purchased (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Loans And Leases [Line Items]
Total purchased Loans	$ 5,399,831	$ 1,806,037
Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	931,748	320,914
Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	3,238,650	950,789
Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	890,801	207,592
Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	80,644	109,185
Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 77 [Member]
Loans And Leases [Line Items]
Total purchased Loans	871	771
Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	251,940	209,503
Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | FV 88 [Member]
Loans And Leases [Line Items]
Total purchased Loans	5,177	7,283
Real Estate [Member] | Residential 1-4 Family [Member]
Loans And Leases [Line Items]
Total purchased Loans	839,515	386,952
Real Estate [Member] | Non-Farm/Non-Residential [Member]
Loans And Leases [Line Items]
Total purchased Loans	2,456,394	1,135,547
Real Estate [Member] | Construction/Land Development [Member]
Loans And Leases [Line Items]
Total purchased Loans	633,877	47,823
Real Estate [Member] | Agricultural [Member]
Loans And Leases [Line Items]
Total purchased Loans	29,705	19,918
Real Estate [Member] | Multifamily Residential [Member]
Loans And Leases [Line Items]
Total purchased Loans	330,069	139,497
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Residential 1-4 Family [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	111,115	59,497
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Residential 1-4 Family [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	410,982	117,498
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Residential 1-4 Family [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	168,343	38,888
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Residential 1-4 Family [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	67,047	85,684
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Residential 1-4 Family [Member] | FV 77 [Member]
Loans And Leases [Line Items]
Total purchased Loans	235	351
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Non-Farm/Non-Residential [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	319,635	209,542
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Non-Farm/Non-Residential [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	1,573,456	693,707
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Non-Farm/Non-Residential [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	422,873	122,652
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Non-Farm/Non-Residential [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	3,556	5,039
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Non-Farm/Non-Residential [Member] | FV 77 [Member]
Loans And Leases [Line Items]
Total purchased Loans	578	363
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Construction/Land Development [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	106,223	13,121
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Construction/Land Development [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	382,823	12,511
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Construction/Land Development [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	129,575	7,137
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Construction/Land Development [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	3,041	4,771
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Construction/Land Development [Member] | FV 77 [Member]
Loans And Leases [Line Items]
Total purchased Loans	22	22
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Agricultural [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	14,856	4,825
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Agricultural [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	5,794	7,963
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Agricultural [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	3,891	1,456
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Agricultural [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	411	797
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Multifamily Residential [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	13,702	20,347
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Multifamily Residential [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	236,029	86,588
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Multifamily Residential [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	69,283	27,818
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Multifamily Residential [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	812	896
Real Estate [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Multifamily Residential [Member] | FV 77 [Member]
Loans And Leases [Line Items]
Total purchased Loans	13	13
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Residential 1-4 Family [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	79,875	82,862
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Residential 1-4 Family [Member] | FV 88 [Member]
Loans And Leases [Line Items]
Total purchased Loans	1,918	2,172
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Non-Farm/Non-Residential [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	133,188	99,681
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Non-Farm/Non-Residential [Member] | FV 88 [Member]
Loans And Leases [Line Items]
Total purchased Loans	3,108	4,563
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Construction/Land Development [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	12,109	10,224
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Construction/Land Development [Member] | FV 88 [Member]
Loans And Leases [Line Items]
Total purchased Loans	84	37
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Agricultural [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	4,753	4,877
Real Estate [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Multifamily Residential [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	10,230	3,835
Commercial and Industrial [Member]
Loans And Leases [Line Items]
Total purchased Loans	220,300	60,522
Commercial and Industrial [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	19,865	8,912
Commercial and Industrial [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	178,415	29,001
Commercial and Industrial [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	14,326	9,244
Commercial and Industrial [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	2,687	5,649
Commercial and Industrial [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 77 [Member]
Loans And Leases [Line Items]
Total purchased Loans	23	20
Commercial and Industrial [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	4,917	7,185
Commercial and Industrial [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | FV 88 [Member]
Loans And Leases [Line Items]
Total purchased Loans	67	511
Consumer [Member]
Loans And Leases [Line Items]
Total purchased Loans	875,648	7,487
Consumer [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	340,537	726
Consumer [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	449,243	205
Consumer [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	82,372	185
Consumer [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	3,015	6,106
Consumer [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 77 [Member]
Loans And Leases [Line Items]
Total purchased Loans		2
Consumer [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	481	263
Other [Member]
Loans And Leases [Line Items]
Total purchased Loans	14,323	8,291
Other [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 33 [Member]
Loans And Leases [Line Items]
Total purchased Loans	5,815	3,944
Other [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 44 [Member]
Loans And Leases [Line Items]
Total purchased Loans	1,908	3,316
Other [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 55 [Member]
Loans And Leases [Line Items]
Total purchased Loans	138	212
Other [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | FV 36 [Member]
Loans And Leases [Line Items]
Total purchased Loans	75	243
Other [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | FV 66 [Member]
Loans And Leases [Line Items]
Total purchased Loans	$ 6,387	$ 576

Allowance for Loan and Lease 58

Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Aging Analysis of Past Due Loans Purchased by FDIC Loss Share Agreements (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	$ 5,399,831	$ 1,806,037
Real Estate [Member] | Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	839,515	386,952
Real Estate [Member] | Non-Farm/Non-Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	2,456,394	1,135,547
Real Estate [Member] | Construction/Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	633,877	47,823
Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	29,705	19,918
Real Estate [Member] | Multifamily Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	330,069	139,497
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	220,300	60,522
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	875,648	7,487
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total purchased loans	14,323	8,291
Purchased Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	63,388	30,343
Current	5,336,443	1,775,694
Total purchased loans	5,399,831	1,806,037
Purchased Loans [Member] | Real Estate [Member] | Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	20,258	15,335
Current	819,257	371,617
Total purchased loans	839,515	386,952
Purchased Loans [Member] | Real Estate [Member] | Non-Farm/Non-Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	28,111	10,272
Current	2,428,283	1,125,275
Total purchased loans	2,456,394	1,135,547
Purchased Loans [Member] | Real Estate [Member] | Construction/Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,406	2,174
Current	630,471	45,649
Total purchased loans	633,877	47,823
Purchased Loans [Member] | Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,158	462
Current	28,547	19,456
Total purchased loans	29,705	19,918
Purchased Loans [Member] | Real Estate [Member] | Multifamily Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	495	299
Current	329,574	139,198
Total purchased loans	330,069	139,497
Purchased Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,502	1,638
Current	217,798	58,884
Total purchased loans	220,300	60,522
Purchased Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7,458	142
Current	868,190	7,345
Total purchased loans	875,648	7,487
Purchased Loans [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		21
Current	14,323	8,270
Total purchased loans	14,323	8,291
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	29,439	14,626
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Real Estate [Member] | Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	10,401	9,042
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Real Estate [Member] | Non-Farm/Non-Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,542	3,435
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Real Estate [Member] | Construction/Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,536	919
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	136	106
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Real Estate [Member] | Multifamily Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	335	299
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,129	714
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,360	101
Purchased Loans [Member] | Financing Receivables, 30-89 Days Past Due [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		10
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	33,949	15,717
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate [Member] | Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	9,857	6,293
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate [Member] | Non-Farm/Non-Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	19,569	6,837
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate [Member] | Construction/Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	870	1,255
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,022	356
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate [Member] | Multifamily Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	160
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,373	924
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,098	41
Purchased Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		11
Purchased Loans [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	28,593	10,715
Current	5,114,121	1,578,536
Total purchased loans	5,142,714	1,589,251
Purchased Loans [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	20,257	7,972
Purchased Loans [Member] | Purchased Loans Without Evidence of Credit Deterioration at Date of Acquisition [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,336	2,743
Purchased Loans [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	34,795	19,628
Current	222,322	197,158
Total purchased loans	257,117	216,786
Purchased Loans [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	9,182	6,654
Purchased Loans [Member] | Purchased Loans with Evidence of Credit Deterioration of Acquisition [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 25,613	$ 12,974

Income Taxes - Types of Tempora

Income Taxes - Types of Temporary Differences Between Tax Basis of Assets and Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Allowance for loan and lease losses	$ 27,381	$ 22,802
Differences in amounts reflected in the financial statements and income tax basis for purchased loans	77,054	24,600
Differences in amounts reflected in the financial statements and income tax basis for deposits assumed in acquisitions	8,348	5,771
Stock-based compensation	7,237	4,199
Deferred compensation	2,318	2,035
Foreclosed assets	4,506	3,101
Deferred loan fees and costs, net		10,579
Acquired net operating losses	29,585	27,862
Other, net	9,259	4,273
Total gross deferred tax assets	165,688	105,222
Less valuation allowance	(474)	(474)
Net deferred tax asset	165,214	104,748
Accelerated depreciation on premises and equipment	45,903	21,924
Investment securities AFS	12,431	5,650
Acquired intangible assets	11,301	1,448
Deferred loan fees and costs, net	1,846
Total gross deferred tax liabilities	71,481	29,022
Net deferred tax assets	$ 93,733	$ 75,726

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Schedule Of Income Taxes [Line Items]
Deferred tax valuation allowance	$ 474,000	$ 474,000
Federal [Member]
Schedule Of Income Taxes [Line Items]
Net operating losses carryforwards	80,900,000
Operating loss carryforwards subject to expiration	$ 74,800,000
Federal [Member] | Expiration Year 2028 [Member]
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards expiration year	2,028
Federal [Member] | Expiration Year 2034 [Member]
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards expiration year	2,034
State [Member]
Schedule Of Income Taxes [Line Items]
Net operating losses carryforwards	$ 118,200
Operating loss carryforwards subject to expiration	$ 106,400
State [Member] | Expiration Year 2022 [Member]
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards expiration year	2,022
State [Member] | Expiration Year 2035 [Member]
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards expiration year	2,035

Subordinated Notes - Additional

Subordinated Notes - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 23, 2016	Sep. 30, 2016
Debt Disclosure [Abstract]
Aggregate principal amount of subordinated notes	$ 225,000	$ 222,420
Fixed to floating rate	5.50%
Proceeds from sale of securities	$ 222,300
Maturity date	Jul. 1, 2026
Initial interest rate	5.50%
Interest rate, adjustable quarterly		The Notes will bear interest at a floating rate equal to three-month London Interbank Offered Rate ("LIBOR") as calculated on each applicable date of determination plus a spread of 442.5 basis points; provided, however, that in the event three-month LIBOR is less than zero, then three-month LIBOR shall be deemed to be zero.
Basis spread points	4.425%
Debt issuance costs	$ 2,700
Debt issue costs, amortization period	7 years
Redemption price percentage	100.00%
Interest payment date	Jul. 1, 2021

Supplemental Data for Cash Fl62

Supplemental Data for Cash Flows - Schedule of Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Supplemental Cash Flow Elements [Line Items]
Interest	$ 36,571	$ 20,438
Taxes	97,232	48,869
Net change in unrealized gains/losses on investment securities AFS	8,120	(4,317)
Loans transferred to foreclosed assets	17,093	14,493
Loans advanced for sales of foreclosed assets	271
Unsettled AFS investment security purchases	38,349	2,640
Unsettled loan sales		14,361
Brazilian Loans [Member]
Supplemental Cash Flow Elements [Line Items]
Common stock issued in merger and acquisition transactions, net of shares redeemed for Brazilian Loans	$ 1,135,861	$ 303,866

Guarantees and Commitments - Ad

Guarantees and Commitments - Additional Information (Detail) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Guarantees And Commitments [Line Items]
Outstanding commitments to extend credit, consisting of loans closed, not yet funded	$ 8,660,000,000
Additional outstanding commitments to extend credit, under mortgage interest rate lock commitments	32,400,000	$ 15,700,000
Standby Letters of Credit [Member]
Guarantees And Commitments [Line Items]
Maximum amount of future payments required to make under guarantees	56,400,000
Collateralized commitments	$ 55,500,000

Guarantees and Commitments - Co

Guarantees and Commitments - Contractual Maturities (Detail) $ in Thousands	Sep. 30, 2016USD ($)
Contractual Obligation Fiscal Year Maturity [Abstract]
2,016	$ 122,873
2,017	950,754
2,018	2,503,466
2,019	2,884,502
2,020	1,957,622
Thereafter	241,587
Total	$ 8,660,804

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available to non-employee directors through the non qualified stock option plan for non-employee directors, other than annual meeting			18,183
Share-based compensation arrangement by share-based payment award options exercisable intrinsic value per share			$ 0
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense for stock options included in non-interest expense	$ 1,100,000	$ 600,000	$ 3,000,000	$ 1,800,000
Total intrinsic value of options exercised during the period	600,000	500,000	2,100,000	3,300,000
Total unrecognized compensation expenses	7,900,000		$ 7,900,000
Unrecognized compensation cost, weighted-average period, years			1 year 10 months 24 days
Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense for stock options included in non-interest expense	1,800,000	$ 1,400,000	$ 4,500,000	$ 4,100,000
Total unrecognized compensation expenses	$ 11,100,000		$ 11,100,000
Unrecognized compensation cost, weighted-average period, years			1 year 10 months 24 days
Maximum [Member] | Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award issued with a vesting period, years			3 years
Nonqualified Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award issued with a vesting period, years			3 years
Employee options expire after issuance, years			7 years
Expiration period of options issued to non-employee director			10 years
Nonqualified Stock Option Plan [Member] | Non Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available to non-employee directors through the non qualified stock option plan for non-employee directors, other than annual meeting	0	0	0	0
Non-Employee Directors Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of non-employee directors stock awards on the date of grant			$ 35,000
Number of common stock shares issued	0	0	12,415	7,657
Stock-based compensation expense for stock options included in non-interest expense	$ 0	$ 0	$ 500,000	$ 300,000
Non-Employee Directors Stock Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares issued as awards	50,000		50,000

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares		Sep. 30, 2015shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding – December 31, 2015, Options	2,034,476
Granted, Options	18,183
Exercised, Options	(83,670)		(116,050)
Forfeited, Options	(70,725)
Outstanding – September 30, 2016, Options	1,898,264
Fully vested and exercisable – September 30, 2016, Options	372,955
Expected to vest in future periods, Options	1,446,156
Fully vested and expected to vest – September 30, 2016, Options	1,819,111	[1]
Outstanding - January 1, 2016, Weighted-Average Exercise Price/Share | $ / shares	$ 34.50
Granted, Weighted-Average Exercise Price/Share | $ / shares	40.59
Exercised, Weighted-Average Exercise Price/Share | $ / shares	14.99
Forfeited, Weighted-Average Exercise Price/Share | $ / shares	39.61
Outstanding - September 30, 2016, Weighted-Average Exercise Price/Share | $ / shares	35.22
Fully vested and exercisable - September 30, 2016, Weighted-Average Exercise Price/Share | $ / shares	14.90
Fully vested and expected to vest - September 30, 2016, Weighted-Average Exercise Price/Share | $ / shares	$ 34.70	[1]
Outstanding - September 30, 2016, Weighted-Average Remaining Contractual Life (in years)	5 years
Fully vested and exercisable - September 30, 2016, Weighted-Average Remaining Contractual Life (in years)	3 years 4 months 24 days
Fully vested and expected to vest - September 30, 2016, Weighted-Average Remaining Contractual Life (in years)	4 years 10 months 24 days
Outstanding – September 30, 2016, Aggregate Intrinsic value | $	$ 15,283	[2]
Fully vested and exercisable – September 30, 2016, Aggregate Intrinsic value | $	8,764	[2]
Fully vested and expected to vest – September 30, 2016, Aggregate Intrinsic value | $	$ 15,204	[2]
[1]	At September 30, 2016, the Company estimated that outstanding options to purchase 79,153 shares of its common stock would not vest and would be forfeited prior to their vesting date.
[2]	Based on closing price of $38.40 per share on September 30, 2016.

Stock-Based Compensation - Su67

Stock-Based Compensation - Summary of Stock Option Activity (Parenthetical) (Detail)	Sep. 30, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated number of common shares that could be forfeited before the vesting date | shares	79,153
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, closing price, per share | $ / shares	$ 38.40

Stock-Based Compensation - Su68

Stock-Based Compensation - Summary of Non-Vested Restricted Stock Activity (Detail) - $ / shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments Restricted Stock [Abstract]
Outstanding – December 31, 2015	435,475
Granted	218,761
Forfeited	(13,986)	(41,325)
Outstanding – September 30, 2016	640,250
Weighted-average grant date fair value	$ 35.10

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities at fair value	$ 0	$ 0
Fair value of private placement bonds	17,800,000
Third party pricing for private placement bonds	17,800,000
Lower of the matrix price or par value of private placement bonds	17,800,000
Impaired financing receivable recorded investment reduction to estimated fair value	4,600,000
Estimated fair value of impaired loans and leases	4,000,000
Partial charge-offs to reduce carrying value of impaired loans and leases to estimated fair value	3,600,000
Specific loan and lease allocations to reduce carrying value of impaired loans and leases to estimated fair value	1,000,000
Impaired purchased loans	$ 6,000,000
Estimated cost percentage of repossessed personal properties and real estate, minimum	8.00%
Estimated cost percentage of repossessed personal properties and real estate, maximum	10.00%
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate used to determine net present value of purchased foreclosed assets	8.00%
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate used to determine net present value of purchased foreclosed assets	9.50%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities at Fair Value (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS		$ 1,341,894	$ 602,348
Total investment securities AFS	[1]	1,335,745	578,818
Impaired non-purchased loans and leases		3,951	9,327
Impaired purchased loans		6,048	8,054
Foreclosed assets		44,250	22,870
Total assets at fair value		1,389,994	619,069
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investment securities AFS	[1]	1,062	1,028
Total assets at fair value		1,062	1,028
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investment securities AFS	[1]	1,316,927	559,286
Total assets at fair value		1,316,927	559,286
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investment securities AFS	[1]	17,756	18,504
Impaired non-purchased loans and leases		3,951	9,327
Impaired purchased loans		6,048	8,054
Foreclosed assets		44,250	22,870
Total assets at fair value		72,005	58,755
Obligations of State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	750,725	427,278
Obligations of State and Political Subdivisions [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	732,969	408,774
Obligations of State and Political Subdivisions [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	17,756	18,504
U.S. Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	573,936	146,950
U.S. Government Agency Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	573,936	146,950
Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	10,022	3,562
Corporate Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	10,022	3,562
CRA Qualified Investment Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	1,062	1,028
CRA Qualified Investment Fund [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS	[1]	$ 1,062	$ 1,028
[1]	Does not include $6.1 million at September 30, 2016 and $23.5 million at December 31, 2015 of FHLB and FNBB equity securities that do not have readily determinable fair values and are carried at cost.

Fair Value Measurements - Ass71

Fair Value Measurements - Assets and Liabilities at Fair Value (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
FHLB and FNBB Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments carried at cost	$ 6.1	$ 23.5

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Information Related to Level 3 Non-Recurring Fair Value Measurements (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value Measurements Disclosure [Line Items]
Impaired non-purchased loans and leases	$ 3,951	$ 9,327
Impaired purchased loans	6,048	8,054
Foreclosed assets	44,250	22,870
Level 3 [Member]
Fair Value Measurements Disclosure [Line Items]
Impaired non-purchased loans and leases	3,951	9,327
Impaired purchased loans	6,048	8,054
Foreclosed assets	$ 44,250	$ 22,870

Fair Value Measurements - Ass73

Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis Utilizing Level 3 Inputs (Detail) - Investment Securities AFS [Member] - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning Balance, Asset	$ 18,504	$ 19,401
Total unrealized gains (losses) included in comprehensive income	(47)	(19)
Paydowns and maturities	(701)	(714)
Ending Balance, Asset	$ 17,756	$ 18,668

Fair Value of Financial Instr74

Fair Value of Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Investments in bank stock	$ 6.1	$ 23.5

Fair Value of Financial Instr75

Fair Value of Financial Instruments - Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 23, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities AFS	$ 1,341,894		$ 602,348
Time deposits	4,984,914		2,438,482
Repurchase agreements with customers	70,640		65,800
Other borrowings	41,978		204,540
Subordinated notes	222,420	$ 225,000
Subordinated debentures	118,102		117,685
Level 1 [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	969,522		90,988
Demand, savings and interest bearing transaction deposits	10,138,890		5,532,986
Repurchase agreements with customers	70,640		65,800
Level 1 [Member] | Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	969,522		90,988
Demand, savings and interest bearing transaction deposits	10,138,890		5,532,986
Repurchase agreements with customers	70,640		65,800
Level 2 and 3 [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities AFS	1,341,894		602,348
Level 2 and 3 [Member] | Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities AFS	1,341,894		602,348
Level 3 [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases, net of ALLL	14,089,837		8,273,817
Level 3 [Member] | Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases, net of ALLL	14,004,121		8,165,123
Level 2 [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	4,984,914		2,438,482
Other borrowings	41,978		204,540
Subordinated notes	222,420
Subordinated debentures	118,102		117,685
Level 2 [Member] | Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	5,014,194		2,456,323
Other borrowings	43,101		205,918
Subordinated notes	223,072
Subordinated debentures	$ 90,775		$ 77,534

Repurchase Agreements With Cu76

Repurchase Agreements With Customers - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Disclosure Of Repurchase Agreements [Abstract]
Repurchase agreements with customers	$ 70,640	$ 65,800

Changes in and Reclassificati77

Changes in and Reclassifications from Accumulated Other Comprehensive Income ("AOCI") - Changes in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance of AOCI - unrealized gains and losses on investment securities AFS			$ 7,959
Unrealized gains and losses on investment securities AFS	$ (2,262)	$ 5,918	8,120	$ (1,274)
Tax effect of unrealized gains and losses on investment securities AFS	791	(2,265)	(2,444)	484
Amounts reclassified from AOCI				(2,619)
Tax effect of amounts reclassified from AOCI				998
Total other comprehensive income (loss)	(1,471)	3,653	5,676	(2,411)
Ending balance of AOCI - unrealized gains and losses on investment securities AFS	13,635		13,635
Unrealized gains and losses on investment securities AFS [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance of AOCI - unrealized gains and losses on investment securities AFS	15,106	8,068	7,959	14,132
Unrealized gains and losses on investment securities AFS	(2,262)	5,918	8,120	(1,274)
Tax effect of unrealized gains and losses on investment securities AFS	791	(2,265)	(2,444)	484
Amounts reclassified from AOCI				(2,619)
Tax effect of amounts reclassified from AOCI				998
Total other comprehensive income (loss)	(1,471)	3,653	5,676	(2,411)
Ending balance of AOCI - unrealized gains and losses on investment securities AFS	$ 13,635	$ 11,721	$ 13,635	$ 11,721

Other Operating Expenses - Summ

Other Operating Expenses - Summary of Other Operating Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other Income And Expenses [Abstract]
Salaries and employee benefits	$ 38,069	$ 21,207	$ 86,351	$ 66,450
Net occupancy and equipment	11,669	8,076	28,587	22,711
Other operating expenses:
Professional and outside services	6,509	2,772	14,072	9,684
Postage and supplies	1,709	1,015	3,840	2,944
Advertising and public relations	1,941	575	4,543	1,744
Telecommunication services	1,883	1,583	5,339	4,547
Software and data processing	1,633	630	3,226	2,145
ATM expense	1,821	591	3,530	1,842
Travel and meals	2,778	922	5,850	2,538
FDIC insurance	1,725	1,020	4,125	2,670
FDIC and state assessments	392	330	1,071	971
Loan collection and repossession expense	1,524	1,322	3,244	4,075
Writedowns of foreclosed and other assets	859	553	2,119	2,980
Amortization of intangibles	2,596	1,697	5,879	4,934
FHLB prepayment penalty				2,480
Other	3,673	3,135	5,619	6,621
Total non-interest expense	$ 78,781	$ 45,428	$ 177,395	$ 139,336