Prosperity Bancshares (PB) 10-Q 7 Nov 16 2016 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 04, 2016
Document And Entity Information [Abstract]
Entity Registrant Name	PROSPERITY BANCSHARES INC
Entity Central Index Key	1,068,851
Trading Symbol	PB
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		69,483,828
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Cash and due from banks	$ 341,483	$ 562,544
Federal funds sold	630	1,418
Total cash and cash equivalents	342,113	563,962
Available for sale securities, at fair value	129,677	103,064
Held to maturity securities, at cost (fair value of $9,020,897 and $9,393,175, respectively)	8,858,344	9,399,363
Total securities	8,988,021	9,502,427
Loans held for sale	29,457	23,933
Loans held for investment	9,518,857	9,414,656
Total loans	9,548,314	9,438,589
Less: allowance for credit losses	(85,585)	(81,384)
Loans, net	9,462,729	9,357,205
Accrued interest receivable	48,469	51,924
Goodwill	1,900,349	1,868,827
Core deposit intangibles, net	48,010	49,417
Bank premises and equipment, net	270,386	267,996
Other real estate owned	16,280	2,963
Bank owned life insurance (BOLI)	248,149	235,429
Federal Home Loan Bank of Dallas stock	35,449	68,413
Other assets	44,089	68,653
TOTAL ASSETS	21,404,044	22,037,216
Deposits:
Noninterest-bearing	5,159,333	5,136,579
Interest-bearing	11,762,076	12,544,540
Total deposits	16,921,409	17,681,119
Other borrowings	425,916	491,399
Securities sold under repurchase agreements	318,449	315,253
Accrued interest payable	3,496	1,896
Other liabilities	139,962	84,639
Total liabilities	17,809,232	18,574,306
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS’ EQUITY:
Preferred stock, $1 par value; 20,000,000 shares authorized; none issued or outstanding
Common stock, $1 par value; 200,000,000 shares authorized; 69,477,578 shares issued and outstanding at September 30, 2016; 70,058,761 shares issued and 70,021,673 shares outstanding at December 31, 2015	69,477	70,059
Capital surplus	2,025,722	2,036,378
Retained earnings	1,498,111	1,355,040
Accumulated other comprehensive income—net unrealized gain on available for sale securities, net of tax of $808 and $1,098, respectively	1,502	2,040
Less: treasury stock, at cost, 37,088 shares		(607)
Total shareholders’ equity	3,594,812	3,462,910
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 21,404,044	$ 22,037,216

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Held to maturity securities, fair value	$ 9,020,897	$ 9,393,175
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	69,477,578	70,058,761
Common stock, shares outstanding (in shares)	69,477,578	70,021,673
Accumulated other comprehensive income-net unrealized gain on available for sale securities, tax	$ 808	$ 1,098
Treasury stock, shares (in shares)	0	37,088

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:
Loans, including fees	$ 116,247	$ 116,911	$ 359,066	$ 361,193
Securities	48,132	48,610	151,802	145,702
Federal funds sold	81	22	242	234
Total interest income	164,460	165,543	511,110	507,129
INTEREST EXPENSE:
Deposits	9,396	8,753	29,647	27,499
Other borrowings	752	473	1,944	967
Securities sold under repurchase agreements	248	209	694	620
Junior subordinated debentures			37	791
Total interest expense	10,396	9,435	32,322	29,877
NET INTEREST INCOME	154,064	156,108	478,788	477,252
PROVISION FOR CREDIT LOSSES	2,000	5,310	22,000	7,060
NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES	152,064	150,798	456,788	470,192
NONINTEREST INCOME:
Nonsufficient funds (NSF) fees	8,764	9,082	24,984	25,310
Credit card, debit card and ATM card income	5,903	5,955	17,659	17,596
Service charges on deposit accounts	4,698	4,438	13,898	12,806
Trust income	1,851	1,986	5,640	6,042
Mortgage income	2,143	1,770	5,386	4,431
Brokerage income	1,213	1,596	3,789	4,546
Net gain on sale of assets	37	173	1,389	1,822
Other	5,075	6,780	16,205	17,945
Total noninterest income	29,684	31,780	88,950	90,498
NONINTEREST EXPENSE:
Salaries and employee benefits	48,328	46,587	146,666	144,372
Net occupancy and equipment	5,997	6,088	17,362	17,864
Credit and debit card, data processing and software amortization	4,207	3,924	12,801	11,786
Regulatory assessments and FDIC insurance	3,434	3,366	10,311	11,973
Core deposit intangibles amortization	2,418	2,356	6,974	7,235
Depreciation	3,289	3,313	9,924	9,649
Communications	2,870	2,663	8,790	8,307
Other real estate expense	44	123	136	384
Other	8,889	8,010	26,275	24,057
Total noninterest expense	79,476	76,430	239,239	235,627
INCOME BEFORE INCOME TAXES	102,272	106,148	306,499	325,063
PROVISION FOR INCOME TAXES	33,621	35,550	100,826	108,892
NET INCOME	$ 68,651	$ 70,598	$ 205,673	$ 216,171
EARNINGS PER SHARE:
Basic	$ 0.99	$ 1.01	$ 2.95	$ 3.09
Diluted	$ 0.99	$ 1.01	$ 2.95	$ 3.09

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	$ 68,651	$ 70,598	$ 205,673	$ 216,171
Securities available for sale:
Change in unrealized gain during period	(186)	(867)	(828)	(1,949)
Total other comprehensive loss	(186)	(867)	(828)	(1,949)
Deferred taxes related to other comprehensive loss	65	303	290	682
Other comprehensive loss, net of tax	(121)	(564)	(538)	(1,267)
Comprehensive income	$ 68,530	$ 70,034	$ 205,135	$ 214,904

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]
BALANCE at Dec. 31, 2014	$ 3,244,826	$ 69,817	$ 2,025,235	$ 1,146,652	$ 3,729	$ (607)
BALANCE (in shares) at Dec. 31, 2014		69,816,653
Net income	216,171			216,171
Other comprehensive loss	(1,267)				(1,267)
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)		260,925
Common stock issued in connection with the exercise of stock options and restricted stock awards	223	$ 261	(38)
Stock based compensation expense	8,540		8,540
Cash dividends declared	(57,254)			(57,254)
BALANCE at Sep. 30, 2015	3,411,239	$ 70,078	2,033,737	1,305,569	2,462	(607)
BALANCE (in shares) at Sep. 30, 2015		70,077,578
BALANCE at Dec. 31, 2015	3,462,910	$ 70,059	2,036,378	1,355,040	2,040	(607)
BALANCE (in shares) at Dec. 31, 2015		70,058,761
Net income	205,673			205,673
Other comprehensive loss	(538)				(538)
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)		21,267
Common stock issued in connection with the exercise of stock options and restricted stock awards	667	$ 21	646
Common stock issued in connection with the acquisition of Tradition Bancshares, Inc. (in shares)		679,528
Common stock issued in connection with the acquisition of Tradition Bancshares, Inc.	32,522	$ 679	31,843
Treasury stock cancellation (in shares)		(37,088)
Treasury stock cancellation		$ (37)	(570)			607
Common stock repurchase (in shares)		(1,244,890)
Common stock repurchase	(51,057)	$ (1,245)	(49,812)
Stock based compensation expense	7,237		7,237
Cash dividends declared	(62,602)			(62,602)
BALANCE at Sep. 30, 2016	$ 3,594,812	$ 69,477	$ 2,025,722	$ 1,498,111	$ 1,502	$ 0
BALANCE (in shares) at Sep. 30, 2016		69,477,578

Consolidated Statements of Cha7

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Retained Earnings [Member]
Cash dividend declared, per share (in dollars per share)	$ 0.9000	$ 0.8175

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	$ 205,673	$ 216,171
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and core deposit intangibles amortization	16,898	16,884
Provision for credit losses	22,000	7,060
Net amortization of premium on investments	31,972	44,456
Loss (gain) on sale of other real estate	330	(86)
Gain on sale of assets	(1,389)	(1,822)
Net accretion of discount on loans	(31,418)	(44,283)
Net accretion of discount on deposits	(935)	(860)
Gain on sale of loans	(4,910)	(4,267)
Proceeds from sale of loans held for sale	205,137	185,319
Originations of loans held for sale	(208,095)	(185,014)
Stock based compensation expense	7,237	8,540
Decrease (increase) in accrued interest receivable and other assets	63,096	(1,388)
Increase in accrued interest payable and other liabilities	46,744	38,413
Net cash provided by operating activities	352,340	279,123
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities and principal paydowns of held to maturity securities	1,410,155	1,261,788
Purchase of held to maturity securities	(655,865)	(1,825,802)
Proceeds from maturities and principal paydowns of available for sale securities	8,123,458	4,642,623
Purchase of available for sale securities	(8,151,073)	(4,609,999)
Net decrease in loans held for investment	135,818	78,211
Purchase of bank premises and equipment	(3,933)	(7,959)
Proceeds from sale of bank premises, equipment and other real estate	7,206	9,948
Net cash provided by (used in) investing activities	856,803	(451,190)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net (decrease) increase in noninterest-bearing deposits	(287,225)	156,755
Net decrease in interest-bearing deposits	(961,271)	(909,116)
Net (repayments) proceeds from other short-term borrowings	(65,000)	780,000
Repayments of other long-term borrowings	(483)	(2,153)
Net increase (decrease) in securities sold under repurchase agreements	3,196	(5,485)
Redemption of junior subordinated debentures	(7,217)	(167,531)
Proceeds from stock option exercises	667	223
Repurchase of common stock	(51,057)
Payments of cash dividends	(62,602)	(57,254)
Net cash used in financing activities	(1,430,992)	(204,561)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(221,849)	(376,628)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	563,962	677,854
CASH AND CASH EQUIVALENTS, END OF PERIOD	342,113	301,226
NONCASH ACTIVITIES:
Acquisition of real estate through foreclosure of collateral	14,583	2,079
SUPPLEMENTAL INFORMATION:
Income taxes paid	83,275	73,274
Interest paid	30,722	$ 35,069
Tradition Bancshares Inc [Member]
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash used in the purchase of Tradition Bancshares, Inc.	(8,963)
NONCASH ACTIVITIES:
Stock issued in connection with the Tradition Bancshares, Inc. acquisition	$ 32,522

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	1. BASIS OF PRESENTATION The consolidated financial statements include the accounts of Prosperity Bancshares, Inc. ® ® The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for financial information and with the rules and regulations of the Securities and Exchange Commission. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the statements reflect all adjustments necessary for a fair presentation of the financial position, results of operations and cash flows of the Company on a consolidated basis, and all such adjustments are of a normal recurring nature. These financial statements and the notes thereto should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. Operating results for the nine-month period ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 or any other period.

Income Per Common Share

Income Per Common Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Income Per Common Share	2. INCOME PER COMMON SHARE Outstanding stock options issued by the Company represent the only dilutive effect reflected in diluted weighted average shares. The following table illustrates the computation of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount (Amounts in thousands, except per share data) Net income $ 68,651 $ 70,598 $ 205,673 $ 216,171 Basic: Weighted average shares outstanding 69,478 $ 0.99 70,041 $ 1.01 69,738 $ 2.95 70,037 $ 3.09 Diluted: Add incremental shares for: Effect of dilutive securities - options 6 12 7 17 Total 69,484 $ 0.99 70,053 $ 1.01 69,745 $ 2.95 70,054 $ 3.09 There were no stock options exercisable during the three and nine months ended September 30, 2016 or 2015 that would have had an anti-dilutive effect on the above computation.

New Accounting Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2016
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
New Accounting Standards	3. NEW ACCOUNTING STANDARDS Accounting Standards Updates (“ASU”) ASU 2016-15, ASU 2016-15 addresses certain cash receipts and cash payments with the objective of reducing the existing diversity in practice. ASU 2016-15 will be effective for the Company on January 1, 2018 and is not expected to have a significant impact on the Company's financial statements. ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326)—Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. Additionally, available for sale debt securities may realize value either through collection of contractual cash flows or through sale of the security at fair value. Therefore, the amendments limit the amount of the allowance for credit losses to the difference between amortized cost and fair value. ASU 2016-13 will be effective for the Company as of January 1, 2020. The Company is currently evaluating the potential impact of ASU 2016-13 on the Company’s financial statements. ASU 2016-12, “Revenue from Contracts with Customers (Topic 606)—Narrow-Scope Improvements and Practical Expedients.” ASU 2016-12 addresses narrow-scope improvements to the guidance on collectability, noncash consideration and completed contracts at transition. Additionally, the amendments in this update provide a practical expedient for contract modifications at transition and an accounting policy election related to the presentation of sales taxes and other similar taxes collected from customers. The amendments in this update affect the guidance in , which is effective January 1, 2018. The Company is in the process of evaluating the impact of this guidance and does not currently anticipate a significant impact on the Company’s financial statements. ASU 2016-10, “Revenue from Contracts with Customers (Topic 606)—Identifying Performance Obligations and Licensing.” ASU 2016-10 clarifies two aspects of ” (i) identifying performance obligations and (ii) the licensing implementation guidance. This ASU adds guidance on how to identify the promised goods or services in the contract and how to evaluate whether promised goods and services are distinct. Additionally, this update includes guidance on determining whether an entity’s promise to grant a license provides a customer with either a right to use the entity’s intellectual property (which is satisfied at a point in time) or a right to access the entity’s intellectual property (which is satisfied over time) and when to recognize revenue for a sales-based or use-based royalty promised in exchange for a license of intellectual property. The amendments in this update affect the guidance in ,” which is effective January 1, 2018. The Company is in the process of evaluating the impact of this guidance and does not currently anticipate a significant impact on the Company’s financial statements. ASU 2016-09, “Compensation - Stock Compensation (Topic 718) — Improvements to Employee Share-Based Payment Accounting.” ASU 2016-09 was issued as part of the FASB’s simplification initiative and affects all entities that issue share-based payment awards to their employees. This ASU covers accounting for income taxes, forfeitures and statutory tax withholding requirements, as well as classification in the statement of cash flows. ASU 2016-09 will be effective for the Company as of January 1, 2017. The Company is currently evaluating the potential impact of ASU 2016-09 on the Company’s financial statements. ASU 2016-08, “Revenue from Contracts with Customers (Topic 606)—Principal versus Agent Considerations (Reporting Revenue Gross versus Net).” ASU 2016-08 states that when another party is involved in providing goods or services to a customer, an entity is required to determine whether the nature of its promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for that good or service to be provided by the other party (that is, the entity is an agent). Additionally, when an principal entity satisfies a performance obligation, the entity recognizes revenue in the gross amount of consideration to which it expects to be entitled in exchange for the specified good or service transferred to the customer, but when an agent entity satisfies a performance obligation, the entity recognizes revenue in the amount of any fee or commission to which it expects to be entitled in exchange for arranging for the specified good or service to be provided by the other party. The amendments in this update affect the guidance in ,” which is effective January 1, 2018. The Company is in the process of evaluating the impact of this guidance and does not currently anticipate a significant impact on the Company’s financial statements. ASU 2016-02, "Leases (Topic 842)." ASU 2016-02 requires that lessees and lessors recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. ASU 2016-02 is effective for public companies for annual periods beginning January 1, 2019, including interim periods within those fiscal years. The Company is currently evaluating the potential impact of ASU 2016-02 on the Company’s financial statements. ASU 2016-01, “Financial Instruments—Overall (Subtopic 825-10) — Recognition and Measurement of Financial Assets and Financial Liabilities.” ASU 2016-01 addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 (i) requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (iii) eliminates the requirement to disclose the fair value of financial instruments measured at amortized cost for entities that are not public business entities; (iv) eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; (v) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (vi) requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; (vii) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements; and (viii) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. The amendments in this update affect all entities that hold financial assets or owe financial liabilities. ASU 2016-01 is effective for the Company beginning January 1, 2018, and is not expected to have a significant impact on the Company’s financial statements. ASU 2015-16, “Business Combinations (Topic 805) — Simplifying the Accounting for Measurement-Period Adjustments.” ASU 2015-16 requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The acquirer must record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. Additionally, the entity is required to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amounts had been recognized as of the acquisition date. ASU 2015-16 became effective for the Company on January 1, 2016 and did not have a significant impact on the Company’s financial statements. ASU 2015-01, “Income Statement - Extraordinary and Unusual Items (Subtopic 225-20) — Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items.” ASU 2015-01 eliminates from U.S. GAAP the concept of extraordinary items, which, among other things, required an entity to segregate extraordinary items considered to be unusual and infrequent from the results of ordinary operations and show the item separately in the income statement, net of tax, after income from continuing operations. ASU 2015-01 became effective for the Company on January 1, 2016 and did not have a significant impact on the Company’s financial statements. ASU 2014-12, “Compensation - Stock Compensation (Topic 718) — Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. ” ASU 2014-12 requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. The performance target should not be reflected in estimating the grant-date fair value of the award. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The requisite service period ends when the employee can cease rendering service and still be eligible to vest in the award if the performance target is achieved. ASU 2014-12 became effective for the Company on January 1, 2016 and did not have a significant impact on the Company’s financial statements. ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 supersedes the revenue recognition requirements in Revenue Recognition (Topic 605), and most industry-specific guidance throughout the Industry Topics of the Codification. Additionally, ASU 2014-09 supersedes some cost guidance included in Revenue Recognition—Construction-Type and Production-Type Contracts (Subtopic 605-35). In addition, the existing requirements for the recognition of a gain or loss on the transfer of nonfinancial assets that are not in a contract with a customer are amended to be consistent with the guidance on recognition and measurement. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. deferred the effective date for ASU 2014-09 by one year to January 1, 2018, with retrospective application to each prior reporting period presented. The Company is currently evaluating the requirements of ASU 2014-09, but it is not expected to have a significant impact on the Company’s financial statements.

Securities

Securities	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Securities	4. SECURITIES The amortized cost and fair value of investment securities were as follows: September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale States and political subdivisions $ 2,574 $ 6 $ — $ 2,580 Collateralized mortgage obligations 21,427 13 (307 ) 21,133 Mortgage-backed securities 90,777 2,566 (174 ) 93,169 Other securities 12,588 253 (46 ) 12,795 Total $ 127,366 $ 2,838 $ (527 ) $ 129,677 Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 33,479 $ 1,028 $ — $ 34,507 States and political subdivisions 389,555 8,801 (45 ) 398,311 Collateralized mortgage obligations 903 17 (4 ) 916 Mortgage-backed securities 8,434,307 154,373 (1,617 ) 8,587,063 Other securities 100 — — 100 Total $ 8,858,344 $ 164,219 $ (1,666 ) $ 9,020,897 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale States and political subdivisions $ 5,463 $ 22 $ — $ 5,485 Collateralized mortgage obligations 25,991 25 (100 ) 25,916 Mortgage-backed securities 55,884 3,098 (11 ) 58,971 Other securities 12,588 150 (46 ) 12,692 Total $ 99,926 $ 3,295 $ (157 ) $ 103,064 Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 47,598 $ 798 $ — $ 48,396 States and political subdivisions 363,505 7,080 (542 ) 370,043 Collateralized mortgage obligations 2,107 17 (2 ) 2,122 Mortgage-backed securities 8,986,153 68,868 (82,407 ) 8,972,614 Other securities — — — — Total $ 9,399,363 $ 76,763 $ (82,951 ) $ 9,393,175 Management evaluates securities for other-than-temporary impairment (“OTTI”) at least on a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. The investment securities portfolio is evaluated for OTTI by segregating the portfolio into two general segments and applying the appropriate OTTI analysis. Investment securities classified as available for sale or held to maturity are evaluated for OTTI under Financial Accounting Standards Board (“FASB”): Accounting Standards Codification (“ASC”) Topic 320, “ Investments-Debt and Equity Securities.” In determining OTTI, management considers many factors, including: (1) the length of time and the extent to which the fair value has been less than cost, (2) the financial condition and near-term prospects of the issuer, (3) whether the market decline was affected by macroeconomic conditions and (4) whether the entity has the intent to sell the debt security or more likely than not will be required to sell the debt security before its anticipated recovery. The assessment of whether an other-than-temporary decline exists involves a high degree of subjectivity and judgment and is based on the information available to management at a point in time. When OTTI occurs, the amount of the OTTI recognized in earnings depends on whether an entity intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss. If an entity intends to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the OTTI will be recognized in earnings equal to the entire difference between the investment’s amortized cost basis and its fair value at the balance sheet date. If an entity does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis less any current-period loss, the OTTI will be separated into the amount representing the credit-related portion of the impairment loss (“credit loss”) and the noncredit portion of the impairment loss (“noncredit portion”). The amount of the total OTTI related to the credit loss is determined based on the difference between the present value of cash flows expected to be collected and the amortized cost basis and such difference is recognized in earnings. The amount of the total OTTI related to the noncredit portion is recognized in other comprehensive income, net of applicable taxes. The previous amortized cost basis less the OTTI recognized in earnings will become the new amortized cost basis of the investment. As of September 30, 2016, management does not have the intent to sell any of its investment securities and believes that it is more likely than not that the Company will not have to sell any such securities before a recovery of cost. The unrealized losses are largely due to increases in market interest rates over the yields available at the time the underlying securities were purchased. The fair value is expected to recover as the securities approach their maturity date or repricing date or if market yields for such investments decline. Management does not believe any of the securities are impaired due to reasons of credit quality. Accordingly, as of September 30, 2016, management believes any impairment in the Company’s securities is temporary, and therefore no impairment loss has been realized in the Company’s consolidated statement of income. Securities with unrealized losses, segregated by length of time, that have been in a continuous loss position were as follows: September 30, 2016 Less than 12 Months More than 12 Months Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 18,791 $ (307 ) $ 25 $ — $ 18,816 $ (307 ) Mortgage-backed securities 48,836 (166 ) 2,231 (8 ) 51,067 (174 ) Other securities — — 1,691 (46 ) 1,691 (46 ) Total $ 67,627 $ (473 ) $ 3,947 $ (54 ) $ 71,574 $ (527 ) Held to Maturity States and political subdivisions $ 3,567 $ (8 ) $ 4,636 $ (37 ) $ 8,203 $ (45 ) Collateralized mortgage obligations 131 (4 ) 52 — 183 (4 ) Mortgage-backed securities 877,968 (1,067 ) 97,324 (550 ) 975,292 (1,617 ) Total $ 881,666 $ (1,079 ) $ 102,012 $ (587 ) $ 983,678 $ (1,666 ) December 31, 2015 Less than 12 Months More than 12 Months Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 14,331 $ (100 ) $ 1 $ — $ 14,332 $ (100 ) Mortgage-backed securities 793 (1 ) 2,465 (10 ) 3,258 (11 ) Other securities — — 1,691 (46 ) 1,691 (46 ) Total $ 15,124 $ (101 ) $ 4,157 $ (56 ) $ 19,281 $ (157 ) Held to Maturity States and political subdivisions $ 15,700 $ (82 ) $ 45,952 $ (460 ) $ 61,652 $ (542 ) Collateralized mortgage obligations 156 — 94 (2 ) 250 (2 ) Mortgage-backed securities 3,233,601 (36,016 ) 1,662,482 (46,391 ) 4,896,083 (82,407 ) Total $ 3,249,457 $ (36,098 ) $ 1,708,528 $ (46,853 ) $ 4,957,985 $ (82,951 ) At September 30, 2016 and December 31, 2015, there were 411 securities and 474 securities, respectively, in an unrealized loss position for more than 12 months. The amortized cost and fair value of investment securities at September 30, 2016, by contractual maturity, are shown below. Actual maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations at any time with or without call or prepayment penalties. Held to Maturity Available for Sale Amortized Cost Fair Value Amortized Cost Fair Value (Dollars in thousands) Due in one year or less $ 33,476 $ 33,633 $ 12,688 $ 12,895 Due after one year through five years 189,175 192,485 2,474 2,480 Due after five years through ten years 172,389 177,838 — — Due after ten years 28,094 28,962 — — Subtotal 423,134 432,918 15,162 15,375 Mortgage-backed securities and collateralized mortgage obligations 8,435,210 8,587,979 112,204 114,302 Total $ 8,858,344 $ 9,020,897 $ 127,366 $ 129,677 The Company recorded no gain or loss on sale of securities for the three and nine months ended September 30, 2016 and 2015. As of September 30, 2016, the Company did not own any non-agency collateralized mortgage obligations. At September 30, 2016 and December 31, 2015, the Company did not own securities of any one issuer (other than the U.S. government and its agencies) for which aggregate adjusted cost exceeded 10% of the consolidated shareholders’ equity at such respective dates. Securities with an amortized cost of $5.17 billion and $5.81 billion and a fair value of $5.25 billion and $5.79 billion at September 30, 2016 and December 31, 2015, respectively, were pledged to collateralize public deposits and for other purposes required or permitted by law.

Loans and Allowance for Credit

Loans and Allowance for Credit Losses	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Loans and Allowance for Credit Losses	5. LOANS AND ALLOWANCE FOR CREDIT LOSSES The loan portfolio consists of various types of loans and is categorized by major type as follows: September 30, 2016 December 31, 2015 (Dollars in thousands) Residential mortgage loans held for sale $ 29,457 $ 23,933 Commercial and industrial 1,542,059 1,692,246 Real estate: Construction, land development and other land loans 1,205,820 1,073,198 1-4 family residential (includes home equity) 2,677,995 2,616,732 Commercial real estate (includes multi-family residential) 3,158,569 3,131,083 Farmland 473,957 434,349 Agriculture 190,123 214,469 Consumer and other 270,334 252,579 Total loans held for investment 9,518,857 9,414,656 Total $ 9,548,314 $ 9,438,589 Concentrations of Credit. Most of the Company’s lending activity occurs within the states of Texas and Oklahoma. The majority of the Company’s loan portfolio consists of commercial real estate, 1-4 family residential loans and commercial and industrial loans. As of September 30, 2016 and December 31, 2015, there were no concentrations of loans related to any single industry in excess of 10% of total loans. Foreign Loans. The Company has U.S. dollar-denominated loans and commitments to borrowers in Mexico. The outstanding balance of these loans and the unfunded amounts available under these commitments were not significant at September 30, 2016 or December 31, 2015. Related Party Loans. As of September 30, 2016 and December 31, 2015, loans outstanding to directors, officers and their affiliates totaled $4.1 million. All transactions entered into between the Company and such related parties are done in the ordinary course of business and made on the same terms and conditions as similar transactions with unaffiliated persons. An analysis of activity with respect to these related party loans is as follows: September 30, 2016 December 31, 2015 (Dollars in thousands) Beginning balance on January 1 $ 4,063 $ 4,940 New loans 199 428 Repayments and reclassified related loans (184 ) (1,305 ) Ending balance $ 4,078 $ 4,063 Nonperforming Assets and Nonaccrual and Past Due Loans. The Company has several procedures in place to assist it in maintaining the overall quality of its loan portfolio. The Company has established underwriting guidelines to be followed by its officers, including requiring appraisals on loans collateralized by real estate. The Company also monitors its delinquency levels for any negative or adverse trends. Nevertheless, the Company’s loan portfolio could become subject to increasing pressures from deteriorating borrower credit due to general economic conditions. The Company generally places a loan on nonaccrual status and ceases accruing interest when the payment of principal or interest is delinquent for 90 days, or earlier in some cases, unless the loan is in the process of collection and the underlying collateral fully supports the carrying value of the loan. With respect to potential problem loans, an evaluation of the borrower’s overall financial condition is made to determine the need, if any, for possible writedowns or appropriate additions to the allowance for credit losses. An aging analysis of past due loans, segregated by category of loan, is presented below: September 30, 2016 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 4,699 $ 254 $ 4,953 $ 279 $ 1,200,588 $ 1,205,820 Agriculture and agriculture real estate (includes farmland) 591 — 591 248 663,241 664,080 1-4 family (includes home equity) (1) 2,667 — 2,667 3,311 2,701,474 2,707,452 Commercial real estate (includes multi-family residential) 5,068 145 5,213 12,984 3,140,372 3,158,569 Commercial and industrial 9,020 — 9,020 26,426 1,506,613 1,542,059 Consumer and other 2,153 — 2,153 203 267,978 270,334 Total $ 24,198 $ 399 $ 24,597 $ 43,451 $ 9,480,266 $ 9,548,314 December 31, 2015 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 4,097 $ — $ 4,097 $ 134 $ 1,068,967 $ 1,073,198 Agriculture and agriculture real estate (includes farmland) 946 — 946 208 647,664 648,818 1-4 family (includes home equity) (1) 4,748 220 4,968 1,894 2,633,803 2,640,665 Commercial real estate (includes multi-family residential) 12,922 — 12,922 15,535 3,102,626 3,131,083 Commercial and industrial 4,793 394 5,187 21,692 1,665,367 1,692,246 Consumer and other 1,274 — 1,274 248 251,057 252,579 Total $ 28,780 $ 614 $ 29,394 $ 39,711 $ 9,369,484 $ 9,438,589 (1) Includes $29.5 million and $23.9 million of residential mortgage loans held for sale at September 30, 2016 and December 31, 2015, respectively. The following table presents information regarding nonperforming assets as of the dates indicated: September 30, 2016 December 31, 2015 (Dollars in thousands) Nonaccrual loans (1) $ 43,451 $ 39,711 Accruing loans 90 or more days past due 399 614 Total nonperforming loans 43,850 40,325 Repossessed assets 36 171 Other real estate 16,280 2,963 Total nonperforming assets $ 60,166 $ 43,459 Nonperforming assets to total loans and other real estate 0.63 % 0.46 % (1) Includes troubled debt restructurings of $318 thousand and $681 thousand as of September 30, 2016 and December 31, 2015, respectively. The Company had $60.2 million in nonperforming assets at September 30, 2016 compared with $43.5 million at December 31, 2015. This increase was primarily due to two commercial real estate loans and two commercial and industrial loans. Nonperforming assets were 0.63% of total loans and other real estate at September 30, 2016 compared with 0.46% of total loans and other real estate at December 31, 2015. These low nonperforming assets to total loans and other real estate ratios are reflective of the Company’s conservative lending approach. If interest on nonaccrual loans had been accrued under the original loan terms, approximately $2.2 million and $2.8 million would have been recorded as income for the nine months ended September 30, 2016 and 2015, respectively. Acquired Loans. Acquired loans were preliminarily recorded at fair value based on a discounted cash flow valuation methodology that considers, among other things, interest rates, projected default rates, loss given default, and recovery rates (no allowance for credit losses was carried over from the acquisition completed during 2016). During the valuation process, the Company identified Purchased Credit-Impaired (“PCI”) and Non-PCI loans in the acquired loan portfolios. Loans acquired with evidence of credit quality deterioration at acquisition for which it was probable that the Company would not be able to collect all contractual amounts due were accounted for as PCI. PCI loan identification considers the following factors: payment history and past due status, debt service coverage, loan grading, collateral values and other factors that may indicate deterioration of credit quality since origination. Non-PCI loan identification considers the following factors: account types, remaining terms, annual interest rates or coupons, current market rates, interest types, past delinquencies, timing of principal and interest payments, loan to value ratios, loss exposures and remaining balances. Accretion of purchased discounts on PCI loans will be based on estimated future cash flows, regardless of contractual maturities. Accretion of purchased discounts on Non-PCI loans will be recognized on a level-yield basis based on contractual maturity of individual loans. PCI Loans. The carrying amount of PCI loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2016 and December 31, 2015. September 30, 2016 December 31, 2015 (Dollars in thousands) PCI loans: Outstanding balance $ 61,570 $ 79,802 Less: discount 28,155 39,976 Recorded investment $ 33,415 $ 39,826 Changes in the accretable yield for acquired PCI loans for the three and nine months ended September 30, 2016 and 2015 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Balance at beginning of period $ 12,015 $ 6,351 $ 5,664 $ 9,867 Additions — — 10,222 — Reclassifications from nonaccretable 1,378 3,940 8,809 12,572 Accretion (2,324 ) (3,974 ) (13,626 ) (16,122 ) Balance at September 30 $ 11,069 $ 6,317 $ 11,069 $ 6,317 Income recognition on PCI loans is subject to the Company’s ability to reasonably estimate both the timing and amount of future cash flows. PCI loans for which the Company is accruing interest income are not considered non-performing or impaired. The non-accretable difference represents contractual principal and interest the Company does not expect to collect. Non-PCI Loans. The carrying amount of Non-PCI loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2016 and December 31, 2015, including accrued but unpaid interest. September 30, 2016 December 31, 2015 (Dollars in thousands) Non-PCI loans: Outstanding balance $ 1,236,411 $ 1,430,501 Less: discount 39,360 54,734 Recorded investment $ 1,197,051 $ 1,375,767 Changes in the discount accretion for Non-PCI loans for the three and nine months ended September 30, 2016 and 2015 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Balance at beginning of period $ 44,672 $ 67,895 $ 54,734 $ 89,105 Additions — — 3,491 — Accretion charge-offs (16 ) (16 ) (1,073 ) (125 ) Accretion (5,296 ) (7,060 ) (17,792 ) (28,161 ) Balance at September 30 $ 39,360 $ 60,819 $ 39,360 $ 60,819 Impaired Loans. Loans are considered impaired when, based on current information and events, it is probable the Company will be unable to collect all amounts due in accordance with the original contractual terms of the loan agreement, including scheduled principal and interest payments. Impairment is evaluated in total for smaller-balance loans of a similar nature and on an individual loan basis for other loans. If a loan is impaired, a specific valuation allowance is allocated, if necessary, so that the loan is reported net, at the present value of estimated future cash flows using the loan’s existing rate or at the fair value of collateral if repayment is expected solely from the collateral. Interest payments on impaired loans are typically applied to principal unless collectability of the principal amount is reasonably assured, in which case interest is recognized on a cash basis. Impaired loans, or portions thereof, are charged off when deemed uncollectible. Impaired loans are set forth in the following tables. No interest income was recognized on impaired loans subsequent to their classification as impaired. The average recorded investment presented in the tables below is reported on a year-to-date basis. September 30, 2016 Recorded Investment Unpaid Contractual Principal Balance Related Allowance Average Recorded Investment (Dollars in thousands) With no related allowance recorded: Construction, land development and other land loans $ 177 $ 494 $ — $ 105 Agriculture and agriculture real estate (includes farmland) 10 15 — 15 1-4 family (includes home equity) 1,822 2,024 — 1,514 Commercial real estate (includes multi-family residential) 12,820 12,936 — 13,968 Commercial and industrial 10,663 10,957 — 6,009 Consumer and other 89 179 — 74 Total 25,581 26,605 — 21,685 With an allowance recorded: Construction, land development and other land loans — — — 4 Agriculture and agriculture real estate (includes farmland) 238 262 102 214 1-4 family (includes home equity) 459 482 140 419 Commercial real estate (includes multi-family residential) 69 69 13 166 Commercial and industrial 14,021 15,418 5,554 14,308 Consumer and other 74 107 46 128 Total 14,861 16,338 5,855 15,239 Total: Construction, land development and other land loans 177 494 — 109 Agriculture and agriculture real estate (includes farmland) 248 277 102 229 1-4 family (includes home equity) 2,281 2,506 140 1,933 Commercial real estate (includes multi-family residential) 12,889 13,005 13 14,134 Commercial and industrial 24,684 26,375 5,554 20,317 Consumer and other 163 286 46 202 $ 40,442 $ 42,943 $ 5,855 $ 36,924 December 31, 2015 Recorded Investment Unpaid Contractual Principal Balance Related Allowance Average Recorded Investment (Dollars in thousands) With no related allowance recorded: Construction, land development and other land loans $ 33 $ 346 $ — $ 142 Agriculture and agriculture real estate (includes farmland) 20 23 — 10 1-4 family (includes home equity) 1,206 1,365 — 1,458 Commercial real estate (includes multi-family residential) 15,115 15,398 — 10,104 Commercial and industrial 1,354 1,630 — 5,419 Consumer and other 58 131 — 4,101 Total 17,786 18,893 — 21,234 With an allowance recorded: Construction, land development and other land loans 7 11 2 141 Agriculture and agriculture real estate (includes farmland) 189 201 52 118 1-4 family (includes home equity) 379 386 93 902 Commercial real estate (includes multi-family residential) 262 1,857 262 162 Commercial and industrial 14,594 16,413 7,082 8,524 Consumer and other 181 220 44 208 Total 15,612 19,088 7,535 10,055 Total: Construction, land development and other land loans 40 357 2 283 Agriculture and agriculture real estate (includes farmland) 209 224 52 128 1-4 family (includes home equity) 1,585 1,751 93 2,360 Commercial real estate (includes multi-family residential) 15,377 17,255 262 10,266 Commercial and industrial 15,948 18,043 7,082 13,943 Consumer and other 239 351 44 4,309 $ 33,398 $ 37,981 $ 7,535 $ 31,289 Credit Quality Indicators. As part of the on-going monitoring of the credit quality of the Company’s loan portfolio and methodology for calculating the allowance for credit losses, management assigns and tracks loan grades to be used as credit quality indicators. The following is a general description of the loan grades used: Grade 1— Credits in this category have risk potential that is virtually nonexistent. These loans may be secured by insured certificates of deposit, insured savings accounts, U.S. Government securities and highly rated municipal bonds. Grade 2— Credits in this category are of the highest quality. These borrowers represent top rated companies and individuals with unquestionable financial standing with excellent global cash flow coverage, net worth, liquidity and collateral coverage. Grade 3— Credits in this category are not immune from risk but are well protected by the collateral and paying capacity of the borrower. These loans may exhibit a minor unfavorable credit factor, but the overall credit is sufficiently strong to minimize the possibility of loss. Grade 4— Credits in this category are considered to be of acceptable credit quality with moderately greater risk than Grade 3 and receiving closer monitoring. Loans in this category have sources of repayment that remain sufficient to preclude a larger than normal probability of default and secondary sources are likewise currently of sufficient quantity, quality, and liquidity to protect the Company against loss of principal and interest. These borrowers have specific risk factors, but the overall strength of the credit is acceptable based on other mitigating credit and/or collateral factors and can repay the debt in the normal course of business. Grade 5— Credits in this category constitute an undue and unwarranted credit risk; however, the factors do not rise to a level of substandard. These credits have potential weaknesses and/or declining trends that, if not corrected, could expose the Bank to risk at a future date. These loans are monitored on the Bank’s internally-generated watch list and evaluated on a quarterly basis. Grade 6— Credits in this category are considered “substandard” but “non-impaired” loans in accordance with regulatory guidelines. Loans in this category have well-defined weakness that, if not corrected, could make default of principal and interest possible. Loans in this category are still accruing interest and may be dependent upon secondary sources of repayment and/or collateral liquidation. Grade 7— Credits in this category are deemed “substandard” and “impaired” pursuant to regulatory guidelines. As such, the Bank has determined that it is probable that less than 100% of the contractual principal and interest will be collected. These loans are individually evaluated for a specific reserve and will typically have the accrual of interest stopped. Grade 8— Credits in this category include “doubtful” loans in accordance with regulatory guidance. Such loans are no longer accruing interest and factors indicate a loss is imminent. These loans are also deemed “impaired.” While a specific reserve may be in place while the loan and collateral is being evaluated, these loans are typically charged down to an amount the Bank estimates is collectible. Grade 9— Credits in this category are deemed a “loss” in accordance with regulatory guidelines and have been charged off or charged down. The Bank may continue collection efforts and may have partial recovery in the future. The following table presents risk grades and PCI loans by category of loan at September 30, 2016. Impaired loans include loans in risk grades 7, 8 and 9, as well as any PCI loan that has a specific reserve allocated to it. Construction, Land Development and Other Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Commercial Real Estate (includes Multi-Family Commercial and Industrial Consumer and Other Total (Dollars in thousands) Grade 1 $ — $ 14,055 $ — $ — $ 59,625 $ 40,858 $ 114,538 Grade 2 2,196 4,593 23,773 6,646 12,162 8,457 57,827 Grade 3 1,138,839 561,473 2,609,138 2,829,626 1,129,900 204,153 8,473,129 Grade 4 56,519 74,216 58,215 229,146 177,319 12,269 607,684 Grade 5 3,331 7,937 2,739 41,643 66,833 2,189 124,672 Grade 6 3,287 1,165 5,596 20,913 63,824 2,245 97,030 Grade 7 177 248 2,251 12,820 23,683 163 39,342 Grade 8 — — 30 69 578 — 677 Grade 9 — — — — — — — PCI Loans (2) 1,471 393 5,710 17,706 8,135 — 33,415 Total $ 1,205,820 $ 664,080 $ 2,707,452 $ 3,158,569 $ 1,542,059 $ 270,334 $ 9,548,314 (1) Includes $29.5 million of residential mortgage loans held for sale at September 30, 2016. (2) Of the total PCI loans, $3.2 million were classified as substandard at September 30, 2016, which includes $423 thousand with specific reserves of $224 thousand allocated to them. The following table presents risk grades and PCI loans by category of loan at December 31, 2015. Impaired loans include loans in risk grades 7, 8 and 9, as well as any PCI loan that has a specific reserve allocated to it. Construction, Land Development and Other Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Commercial Real Estate (includes Multi-Family Commercial and Industrial Consumer and Other Total (Dollars in thousands) Grade 1 $ — $ 12,733 $ — $ — $ 57,625 $ 44,389 $ 114,747 Grade 2 3,975 5,603 27,272 24,965 27,755 34,668 124,238 Grade 3 1,034,792 553,782 2,539,282 2,861,872 1,355,887 162,892 8,508,507 Grade 4 29,831 67,453 58,172 164,924 123,772 3,395 447,547 Grade 5 2,431 7,191 1,261 20,078 68,618 6,908 106,487 Grade 6 1,209 1,452 7,824 26,237 28,005 88 64,815 Grade 7 40 209 1,526 15,377 12,487 239 29,878 Grade 8 — — 59 — 2,485 — 2,544 Grade 9 — — — — — — — PCI Loans (2) 920 395 5,269 17,630 15,612 — 39,826 Total $ 1,073,198 $ 648,818 $ 2,640,665 $ 3,131,083 $ 1,692,246 $ 252,579 $ 9,438,589 (1) Includes $23.9 million of residential mortgage loans held for sale at December 31, 2015. (2) Of the total PCI loans, $7.3 million were classified as substandard at December 31, 2015, which includes $976 thousand with specific reserves of $836 thousand allocated to them. Allowance for Credit Losses. The allowance for credit losses is a valuation established through charges to earnings in the form of a provision for credit losses. Management has established an allowance for credit losses which it believes is adequate for estimated losses in the Company’s loan portfolio. The amount of the allowance for credit losses is affected by the following: (1) charge offs of loans that occur when loans are deemed uncollectible and decrease the allowance, (2) recoveries on loans previously charged off that increase the allowance and (3) provisions for credit losses charged to earnings that increase the allowance. Based on an evaluation of the loan portfolio and consideration of the factors listed below, management presents a quarterly review of the allowance for credit losses to the Bank’s Board of Directors, indicating any change in the allowance since the last review and any recommendations as to adjustments in the allowance. Although management believes it uses the best information available to make determinations with respect to the allowance for credit losses, future adjustments may be necessary if economic conditions or the borrower’s performance differ from the assumptions used in making the initial determinations. The Company’s allowance for credit losses consists of two components: a specific valuation allowance based on probable losses on specifically identified loans and a general valuation allowance based on historical loan loss experience, general economic conditions and other qualitative risk factors both internal and external to the Company. In setting the specific valuation allowance, the Company follows a loan review program to evaluate the credit risk in the total loan portfolio and assigns risk grades to each loan. Through this loan review process, the Company maintains an internal list of impaired loans which, along with the delinquency list of loans, helps management assess the overall quality of the loan portfolio and the adequacy of the allowance for credit losses. All loans that have been identified as impaired are reviewed on a quarterly basis in order to determine whether a specific reserve is required. For certain impaired loans, the Company allocates a specific loan loss reserve primarily based on the value of the collateral securing the impaired loan in accordance with ASC Topic 310-10, “ Receivables. In connection with this review of the loan portfolio, the Company considers risk elements attributable to particular loan types or categories in assessing the quality of individual loans. Some of the risk elements include: • for 1-4 family residential mortgage loans, the borrower’s ability to repay the loan, including a consideration of the debt to income ratio and employment and income stability, the loan to value ratio, and the age, condition and marketability of collateral; • for commercial real estate loans and multifamily residential loans, the debt service coverage ratio (income from the property in excess of operating expenses compared to loan payment requirements), operating results of the owner in the case of owner-occupied properties, the loan to value ratio, the age and condition of the collateral and the volatility of income, property value and future operating results typical of properties of that type; • for construction, land development and other land loans, the perceived feasibility of the project including the ability to sell developed lots or improvements constructed for resale or the ability to lease property constructed for lease, the quality and nature of contracts for presale or prelease, if any, experience and ability of the developer and loan to value ratio; • for commercial and industrial loans, the operating results of the commercial, industrial or professional enterprise, the borrower’s business, professional and financial ability and expertise, the specific risks and volatility of income and operating results typical for businesses in that category and the value, nature and marketability of collateral; • for agricultural real estate loans, the experience and financial capability of the borrower, projected debt service coverage of the operations of the borrower and loan to value ratio; and • for non-real estate agricultural loans, the operating results, experience and financial capability of the borrower, historical and expected market conditions and the value, nature and marketability of collateral. In determining the amount of the general valuation allowance, management considers factors such as historical loan loss experience, concentration risk of specific loan types, the volume, growth and composition of the Company’s loan portfolio, current economic conditions that may affect the borrower’s ability to pay and the value of collateral, the evaluation of the Company’s loan portfolio through its internal loan review process, general economic conditions and other qualitative risk factors both internal and external to the Company and other relevant factors in accordance with ASC Topic 450, “ Contingencies. In addition, for each category, the Company considers secondary sources of income and the financial strength and credit history of the borrower and any guarantors. At September 30, 2016, the allowance for credit losses totaled $85.6 million or 0.90% of total loans, including acquired loans with discounts. At December 31, 2015, the allowance for credit losses totaled $81.4 million or 0.86% of total loans, including acquired loans with discounts. The following table details activity in the allowance for credit losses by category of loan for the three and nine months ended September 30, 2016 and 2015. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Allowance for credit losses: Three Months Ended Balance June 30, 2016 $ 14,202 $ 4,129 $ 14,916 $ 12,672 $ 36,254 $ 1,653 $ 83,826 Provision for credit losses (78 ) (40 ) 167 (477 ) 1,753 675 2,000 Charge-offs — (1 ) (63 ) — (24 ) (946 ) (1,034 ) Recoveries 368 46 15 1 131 232 793 Net charge-offs 368 45 (48 ) 1 107 (714 ) (241 ) Balance September 30, 2016 $ 14,492 $ 4,134 $ 15,035 $ 12,196 $ 38,114 $ 1,614 $ 85,585 Nine Months Ended Balance December 31, 2015 $ 14,882 $ 3,845 $ 14,891 $ 12,996 $ 33,409 $ 1,361 $ 81,384 Provision for credit losses (969 ) 6,551 144 (545 ) 13,103 3,716 22,000 Charge-offs (7 ) (7,026 ) (114 ) (257 ) (10,641 ) (4,371 ) (22,416 ) Recoveries 586 764 114 2 2,243 908 4,617 Net charge-offs 579 (6,262 ) — (255 ) (8,398 ) (3,463 ) (17,799 ) Balance September 30, 2016 $ 14,492 $ 4,134 $ 15,035 $ 12,196 $ 38,114 $ 1,614 $ 85,585 Allowance for credit losses: Three Months Ended Balance June 30, 2015 $ 16,909 $ 3,771 $ 16,593 $ 13,002 $ 29,205 $ 1,492 $ 80,972 Provision for credit losses (1,506 ) (79 ) (1,386 ) (742 ) 8,507 516 5,310 Charge-offs (215 ) (3 ) (120 ) (54 ) (4,865 ) (933 ) (6,190 ) Recoveries 42 43 10 1 439 376 911 Net charge-offs (173 ) 40 (110 ) (53 ) (4,426 ) (557 ) (5,279 ) Balance September 30, 2015 $ 15,230 $ 3,732 $ 15,097 $ 12,207 $ 33,286 $ 1,451 $ 81,003 Nine Months Ended Balance December 31, 2014 $ 15,825 $ 3,722 $ 16,377 $ 12,744 $ 30,002 $ 2,092 $ 80,762 Provision for credit losses (279 ) (173 ) (1,072 ) (337 ) 8,186 735 7,060 Charge-offs (366 ) (3 ) (249 ) (233 ) (5,691 ) (2,406 ) (8,948 ) Recoveries 50 186 41 33 789 1,030 2,129 Net charge-offs (316 ) 183 (208 ) (200 ) (4,902 ) (1,376 ) (6,819 ) Balance September 30, 2015 $ 15,230 $ 3,732 $ 15,097 $ 12,207 $ 33,286 $ 1,451 $ 81,003 The following table details the amount of the allowance for credit losses allocated to each category of loan as of September 30, 2016, December 31, 2015 and September 30, 2015, on the basis of the impairment methodology used by the Company. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Allowance for credit losses related to: September 30, 2016 Individually evaluated for impairment $ — $ 102 $ 140 $ 13 $ 5,330 $ 46 $ 5,631 Collectively evaluated for impairment 14,492 4,032 14,895 12,183 32,560 1,568 79,730 PCI loans — — — — 224 — 224 Total allowance for credit losses $ 14,492 $ 4,134 $ 15,035 $ 12,196 $ 38,114 $ 1,614 $ 85,585 December 31, 2015 Individually evaluated for impairment $ 2 $ 52 $ 93 $ 262 $ 7,082 $ 44 $ 7,535 Collectively evaluated for impairment 14,880 3,793 14,798 12,734 25,491 1,317 73,013 PCI loans — — — — 836 — 836 Total allowance for credit losses $ 14,882 $ 3,845 $ 14,891 $ 12,996 $ 33,409 $ 1,361 $ 81,384 September 30, 2015 Individually evaluated for impairment $ 2 $ 123 $ 111 $ 292 $ 6,550 $ 43 $ 7,121 Collectively evaluated for impairment 15,228 3,609 14,986 11,915 26,474 1,408 73,620 PCI loans — — — — 262 — 262 Total allowance for credit losses $ 15,230 $ 3,732 $ 15,097 $ 12,207 $ 33,286 $ 1,451 $ 81,003 The following table details the recorded investment in loans as of September 30, 2016, December 31, 2015 and September 30, 2015, excluding $29.5 million, $23.9 million and $12.6 million, respectively, of residential mortgage loans held for sale, related to each balance in the allowance for credit losses by category of loan. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Recorded investment in loans: September 30, 2016 Individually evaluated for impairment $ 177 $ 248 $ 2,281 $ 12,889 $ 24,261 $ 163 $ 40,019 Collectively evaluated for impairment 1,204,172 663,439 2,670,004 3,127,974 1,509,663 270,171 9,445,423 PCI loans 1,471 393 5,710 17,706 8,135 — 33,415 Total loans evaluated for impairment $ 1,205,820 $ 664,080 $ 2,677,995 $ 3,158,569 $ 1,542,059 $ 270,334 $ 9,518,857 December 31, 2015 Individually evaluated for impairment $ 40 $ 209 $ 1,585 $ 15,377 $ 15,948 $ 239 $ 33,398 Collectively evaluated for impairment 1,072,238 648,214 2,609,878 3,098,076 1,660,686 252,340 9,341,432 PCI loans 920 395 5,269 17,630 15,612 — 39,826 Total loans evaluated for impairment $ 1,073,198 $ 648,818 $ 2,616,732 $ 3,131,083 $ 1,692,246 $ 252,579 $ 9,414,656 September 30, 2015 Individually evaluated for impairment $ 249 $ 348 $ 1,908 $ 15,623 $ 20,480 $ 264 $ 38,872 Collectively evaluated for impairment 1,071,693 617,739 2,576,497 2,959,065 1,612,067 275,033 9,112,094 PCI loans 1,043 476 5,616 18,038 16,285 — 41,458 Total loans evaluated for impairment $ 1,072,985 $ 618,563 $ 2,584,021 $ 2,992,726 $ 1,648,832 $ 275,297 $ 9,192,424 Troubled Debt Restructurings. The restructuring of a loan is considered a “troubled debt restructuring” if both (1) the borrower is experiencing financial difficulties and (2) the creditor has granted a concession. Concessions may include interest rate reductions or below market interest rates, principal forgiveness, restructuring amortization schedules and other actions intended to minimize potential losses. Under ASC topic 310-40 “ the Company evaluates all loan modifications to identify whether the restructuring constitutes a troubled debt restructuring. As of September 30, 2016 and 2015, the Company had $318 thousand and $607 thousand, respectively, in outstanding troubled debt restructurings. The following table presents information regarding the recorded investment of loans modified in a troubled debt restructuring during the nine months ended September 30, 2016 and 2015: Nine Months Ended September 30, 2016 2015 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment (Dollars in thousands) Troubled Debt Restructurings Construction, land development and other land loans — $ — $ — 1 $ 390 $ 307 Agriculture and agriculture real estate (includes farmland) 1 154 152 — — — 1-4 Family (includes home equity) — — — — — — Commercial real estate (includes multi-family resid

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value	6. FAIR VALUE The Company uses fair value measurements to record fair value adjustments to certain assets and to determine fair value disclosures. Fair values represent the estimated price that would be received from selling an asset or paid to transfer a liability, otherwise known as an “exit price.” Securities available for sale are recorded at fair value on a recurring basis. Additionally, from time to time, the Company may be required to record other assets at fair value on a nonrecurring basis such as certain loans including residential mortgage loans held for sale, goodwill and other intangible assets and other real estate owned. These nonrecurring fair value adjustments typically involve application of lower-of-cost-or-market accounting or write downs of individual assets. ASC Topic 820 “ Fair Value Measurements and Disclosures Fair Value Hierarchy The Company groups financial assets and financial liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. These levels are: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Other significant observable inputs (including quoted prices in active markets for similar assets or liabilities) or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, the Company utilizes valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. The fair value disclosures below represent the Company’s estimates based on relevant market information and information about the financial instruments. Fair value estimates are based on judgments regarding current economic conditions, risk characteristics of the various instruments and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in the above methodologies and assumptions could significantly affect the estimates. The following tables present fair values for assets and liabilities measured at fair value on a recurring basis: As of September 30, 2016 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: States and political subdivisions $ — $ 2,580 $ — $ 2,580 Collateralized mortgage obligations — 21,133 — 21,133 Mortgage-backed securities — 93,169 — 93,169 Other securities 12,795 — — 12,795 Total $ 12,795 $ 116,882 $ — $ 129,677 As of December 31, 2015 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: States and political subdivisions $ — $ 5,485 $ — $ 5,485 Collateralized mortgage obligations — 25,916 — 25,916 Mortgage-backed securities — 58,971 — 58,971 Other securities 12,692 — — 12,692 Total $ 12,692 $ 90,372 $ — $ 103,064 Certain assets and liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). These instruments include other real estate owned, repossessed assets, held to maturity debt securities, loans held for sale and impaired loans, which are included as loans held for investment. For the three and nine months ended September 30, 2016, the Company had additions to other real estate owned of $727 thousand and $14.6 million, respectively, of which $727 thousand and $14.4 million were still outstanding as of September 30, 2016. For the three and nine months ended September 30, 2016, the Company had additions to impaired loans of $15.0 million and $38.9 million, respectively, of which $15.0 million and $31.5 million were still outstanding as of September 30, 2016. The remaining financial assets and liabilities measured at fair value on a non-recurring basis that were recorded in 2016 and remained outstanding at September 30, 2016 were not significant. The following table presents carrying and fair value information of financial instruments as of the dates indicated: As of September 30, 2016 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total Assets (Dollars in thousands) Cash and due from banks $ 341,483 $ 341,483 $ — $ — $ 341,483 Federal funds sold 630 630 — — 630 Held to maturity securities 8,858,344 — 9,020,897 — 9,020,897 Loans held for sale 29,457 — 29,457 — 29,457 Loans held for investment, net of allowance 9,433,272 — — 9,448,097 9,448,097 Other real estate owned 16,280 — 16,280 — 16,280 Liabilities Deposits: Noninterest-bearing $ 5,159,333 $ — $ 5,159,333 $ — $ 5,159,333 Interest-bearing 11,762,076 — 11,766,996 — 11,766,996 Other borrowings 425,916 — 426,455 — 426,455 Securities sold under repurchase agreements 318,449 — 318,452 — 318,452 As of December 31, 2015 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total Assets (Dollars in thousands) Cash and due from banks $ 562,544 $ 562,544 $ — $ — $ 562,544 Federal funds sold 1,418 1,418 — — 1,418 Held to maturity securities 9,399,363 — 9,393,175 — 9,393,175 Loans held for sale 23,933 — 23,933 — 23,933 Loans held for investment, net of allowance 9,333,272 — — 9,365,758 9,365,758 Other real estate owned 2,963 — 2,963 — 2,963 Liabilities Deposits: Noninterest-bearing $ 5,136,579 $ — $ 5,136,579 $ — $ 5,136,579 Interest-bearing 12,544,540 — 12,548,050 — 12,548,050 Other borrowings 491,399 — 492,061 — 492,061 Securities sold under repurchase agreements 315,253 — 315,241 — 315,241 The following is a description of the fair value estimates, methods and assumptions that are used by the Company in estimating the fair values of financial instruments. Cash and due from banks —For these short-term instruments, the carrying amount is a reasonable estimate of fair value. The Company classifies the estimated fair value of these instruments as Level 1. Federal funds sold —For these short-term instruments, the carrying amount is a reasonable estimate of fair value. The Company classifies the estimated fair value of these instruments as Level 1. Securities — Fair value measurements based upon quoted prices are considered Level 1 inputs. Level 1 securities consist of U.S. Treasury securities and certain equity securities which are included in the available for sale portfolio. For all other available for sale and held to maturity securities, if quoted prices are not available, fair values are measured using Level 2 inputs. For these securities, the Company generally obtains fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. The Company reviews the prices supplied by the independent pricing service, as well as their underlying pricing methodologies, for reasonableness. Securities available for sale are recorded at fair value on a recurring basis. Loans held for sale — Loans held for sale are carried at the lower of cost or estimated fair value. Fair value for consumer mortgages held for sale is based on commitments on hand from investors or prevailing market prices. As such, the Company classifies loans subjected to nonrecurring fair value adjustments as Level 2. Loans held for investment — The Company does not record loans at fair value on a recurring basis. As such, valuation techniques discussed herein for loans are primarily for estimating fair value disclosures. However, from time to time, the Company records nonrecurring fair value adjustments to impaired loans to reflect (1) partial write downs that are based on the observable market price or current appraised value of the collateral, or (2) the full charge off of the loan carrying value. Where appraisals are not available, estimated cash flows are discounted using a rate commensurate with the credit risk associated with those cash flows. Assumptions regarding credit risk, cash flows and discount rates are judgmentally determined using available market information and specific borrower information. The estimated fair value approximates carrying value for variable-rate loans that reprice frequently and with no significant change in credit risk. The fair value of fixed-rate loans and variable-rate loans which reprice on an infrequent basis is estimated by discounting future cash flows using the current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality. An overall valuation adjustment is made for specific credit risks as well as general portfolio credit risk. The Company classifies the estimated fair value of loans held for investment as Level 3. Other real estate owned — Other real estate owned is primarily foreclosed properties securing residential loans and commercial real estate. Foreclosed assets are adjusted to fair value less estimated costs to sell upon transfer of the loans to other real estate owned. Subsequently, these assets are carried at the lower of carrying value or fair value less estimated costs to sell. Other real estate carried at fair value based on an observable market price or a current appraised value is classified by the Company as Level 2. When management determines that the fair value of other real estate requires additional adjustments, either as a result of a non-current appraisal or when there is no observable market price, the Company classifies the other real estate as Level 3. Deposits —The fair value of demand deposits, savings accounts and certain money market deposits is the amount payable on demand at the reporting date. The fair value of fixed-maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. Deposits fair value measurements utilize Level 2 inputs. Other borrowings —Rates currently available to the Company for debt with similar terms and remaining maturities are used to estimate the fair value of other borrowings using a discounted cash flows methodology and are measured utilizing Level 2 inputs. Securities sold under repurchase agreements —The fair value of securities sold under repurchase agreements is the amount payable on demand at the reporting date and are measured utilizing Level 2 inputs. Off-balance sheet financial instruments —The fair value of commitments to extend credit and standby letters of credit is estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreement and the present creditworthiness of the counterparties. The Company has reviewed the unfunded portion of commitments to extend credit as well as standby and other letters of credit, and has determined that the fair value of such financial instruments is not material. The Company classifies the estimated fair value of credit-related financial instruments as Level 3. The fair value estimates presented herein are based on pertinent information available to management at September 30, 2016. Although management is not aware of any factors that would significantly affect the estimated fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since those dates and, therefore, current estimates of fair value may differ significantly from the amounts presented herein.

Goodwill and Core Deposit Intan

Goodwill and Core Deposit Intangibles	9 Months Ended
	Sep. 30, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Core Deposit Intangibles	7. GOODWILL AND CORE DEPOSIT INTANGIBLES Changes in the carrying amount of the Company’s goodwill and core deposit intangibles for the nine months ended September 30, 2016 and the year ended December 31, 2015 were as follows: Goodwill Core Deposit Intangibles (Dollars in thousands) Balance as of December 31, 2014 $ 1,874,191 $ 58,947 Less: Amortization — (9,530 ) Add: Measurement period adjustments (5,364 ) — Balance as of December 31, 2015 1,868,827 49,417 Less: Amortization — (6,974 ) Add: Acquisition of Tradition Bancshares, Inc. 31,522 5,567 Measurement period adjustments — — Balance as of September 30, 2016 $ 1,900,349 $ 48,010 Goodwill is recorded on the acquisition date of each entity. The Company may record subsequent adjustments to goodwill for amounts undeterminable at acquisition date, such as deferred taxes and real estate valuations, and therefore the goodwill amounts may change accordingly. The Company initially records the total premium paid on acquisitions as goodwill. After finalizing the valuation, core deposit intangibles are identified and reclassified from goodwill to core deposit intangibles on the balance sheet. This reclassification has no effect on total assets, liabilities, shareholders’ equity, net income or cash flows. Management performs an evaluation annually, and more frequently if a triggering event occurs, of whether any impairment of the goodwill and core deposit intangibles has occurred. If any such impairment is determined, a write-down is recorded. As of September 30, 2016, there was no impairment recorded on goodwill and core deposit intangibles. The measurement period for the Company to determine the fair value of acquired identifiable assets and assumed liabilities will be at the end of the earlier of (1) twelve months from the date of acquisition or (2) as soon as the Company receives the information it was seeking about facts and circumstances that existed as of the date of acquisition. Core deposit intangibles are being amortized on a non-pro rata basis over their estimated lives, which the Company believes is between 10 and 15 years. Amortization expense related to intangible assets totaled $2.4 million for the three months ended September 30, 2016 and 2015, and $7.0 million and $7.2 million for the nine months ended September 30, 2016 and 2015, respectively. The estimated aggregate future amortization expense for core deposit intangibles remaining as of September 30, 2016 is as follows (dollars in thousands): Remaining 2016 $ 2,226 2017 6,942 2018 5,959 2019 5,051 2020 4,483 Thereafter 23,349 Total $ 48,010

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	8. STOCK–BASED COMPENSATION At September 30, 2016, the Company had two stock-based employee compensation plans with awards outstanding. One of these plans adopted by the Company has expired and therefore no additional awards may be issued under that plan. During 2004, Bancshares’ Board of Directors established the Prosperity Bancshares, Inc. 2004 Stock Incentive Plan (the “2004 Plan”) which was approved by Bancshares’ shareholders and authorized the issuance of up to 1,250,000 shares of common stock upon the exercise of options granted under the 2004 Plan or upon the grant or exercise, as the case may be, of other awards granted under the 2004 Plan. The 2004 Plan provided for the granting of incentive and nonqualified stock options to employees and nonqualified stock options to directors who are not employees. The 2004 Plan also provided for the granting of shares of restricted stock, stock appreciation rights, phantom stock awards and performance awards on substantially similar terms. The 2004 Plan has expired and therefore no additional shares may be issued from the 2004 Plan. During 2012, Bancshares’ Board of Directors established the Prosperity Bancshares, Inc. 2012 Stock Incentive Plan (the “2012 Plan”), which was approved by Bancshares’ shareholders and authorized the issuance of up to 1,250,000 shares of common stock upon the exercise of options granted under the 2012 Plan or pursuant to the grant or exercise, as the case may be, of other awards granted under the 2012 Plan, including restricted stock, stock appreciation rights, phantom stock awards and performance awards. A total of 327,801 shares have been granted under the 2012 Plan as of September 30, 2016. The Company received $469 thousand and $667 thousand from the exercise of stock options during the three- and nine-month periods ended September 30, 2016, and $155 thousand and $223 thousand during the three- and nine-month periods ended September 30, 2015. There was no tax benefit realized from option exercises of the stock-based payment arrangements during the three- and nine-month periods ended September 30, 2016 and 2015. As of September 30, 2016, there was $19.4 million of total unrecognized compensation expense related to stock-based compensation arrangements. That cost is expected to be recognized over a weighted average period of 1.60 years.

Contractual Obligations and Off

Contractual Obligations and Off-Balance Sheet Items	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Contractual Obligations and Off-Balance Sheet Items	9. CONTRACTUAL OBLIGATIONS AND OFF-BALANCE SHEET ITEMS Contractual Obligations The following table summarizes the Company’s contractual obligations and other commitments to make future payments as of September 30, 2016 (other than deposit obligations and securities sold under repurchase agreements). The Company’s future cash payments associated with its contractual obligations pursuant to its FHLB notes payable and operating leases as of September 30, 2016 are summarized below. Payments for FHLB notes payable include interest of $760 thousand that will be paid over the future periods. Payments related to leases are based on actual payments specified in underlying contracts. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Federal Home Loan Bank notes payable $ 420,871 $ 4,916 $ 659 $ 230 $ 426,676 Operating leases 5,733 8,106 4,923 6,989 25,751 Total $ 426,604 $ 13,022 $ 5,582 $ 7,219 $ 452,427 Off-Balance Sheet Items In the normal course of business, the Company enters into various transactions, which, in accordance with GAAP, are not included in its consolidated balance sheets. The Company enters into these transactions to meet the financing needs of its customers. These transactions include commitments to extend credit and standby letters of credit, which involve, to varying degrees, elements of credit risk and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The Company’s commitments associated with outstanding standby letters of credit and commitments to extend credit expiring by periods as of September 30, 2016 are summarized below. Since commitments associated with letters of credit and commitments to extend credit may expire unused, the amounts shown do not necessarily reflect the actual future cash funding requirements. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Standby letters of credit $ 63,168 $ 7,227 $ 226 $ 20 $ 70,641 Commitments to extend credit 1,018,584 314,222 83,258 568,608 1,984,672 Total $ 1,081,752 $ 321,449 $ 83,484 $ 568,628 $ 2,055,313

Other Comprehensive (Loss) Inco

Other Comprehensive (Loss) Income	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Other Comprehensive (Loss) Income	10. OTHER COMPREHENSIVE (LOSS) INCOME The tax effects allocated to each component of other comprehensive loss were as follows: Three Months Ended September 30, 2016 2015 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive loss: Securities available for sale: Change in unrealized gain during period $ (186 ) $ 65 $ (121 ) $ (867 ) $ 303 $ (564 ) Total securities available for sale (186 ) 65 (121 ) (867 ) 303 (564 ) Total other comprehensive loss $ (186 ) $ 65 $ (121 ) $ (867 ) $ 303 $ (564 ) Nine Months Ended September 30, 2016 2015 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive loss: Securities available for sale: Change in unrealized gain during period $ (828 ) $ 290 $ (538 ) $ (1,949 ) $ 682 $ (1,267 ) Total securities available for sale (828 ) 290 (538 ) (1,949 ) 682 (1,267 ) Total other comprehensive loss $ (828 ) $ 290 $ (538 ) $ (1,949 ) $ 682 $ (1,267 ) Activity in accumulated other comprehensive income associated with securities available for sale, net of tax, was as follows: Securities Available for Sale Accumulated Other Comprehensive Income (Dollars in thousands) Balance at January 1, 2016 $ 2,040 $ 2,040 Other comprehensive loss (538 ) (538 ) Balance at September 30, 2016 $ 1,502 $ 1,502 Balance at January 1, 2015 $ 3,729 $ 3,729 Other comprehensive loss (1,267 ) (1,267 ) Balance at September 30, 2015 $ 2,462 $ 2,462

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Acquisitions	11. ACQUISITIONS Acquisition of Tradition Bancshares, Inc. — On January 1, 2016, the Company completed the acquisition of Tradition and its wholly-owned subsidiary Tradition Bank, headquartered in Houston, Texas. Tradition Bank operated 7 banking offices in the Houston, Texas area, including its main office in Bellaire, 3 banking centers in Katy and 1 banking center in The Woodlands. The acquisition was not considered significant to the Company’s financial statements and therefore pro forma financial data and related disclosures are not included. Under the terms of the definitive agreement, Bancshares issued 679,528 shares of its common stock plus $39.0 million in cash for all outstanding shares of Tradition capital stock, for total merger consideration of $71.5 million, based on Bancshares’ closing stock price of $47.86 on December 31, 2015. As of September 30, 2016, total goodwill related to the Tradition acquisition was $31.5 million, which does not include subsequent fair value adjustments that are still being finalized. Goodwill is calculated as the excess of both the consideration exchanged and liabilities assumed as compared to the fair value of identifiable assets acquired, none of which is expected to be deductible for tax purposes.

New Accounting Standards (Polic

New Accounting Standards (Policies)	9 Months Ended
	Sep. 30, 2016
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Accounting Standards Updates (“ASU”)	Accounting Standards Updates (“ASU”) ASU 2016-15, ASU 2016-15 addresses certain cash receipts and cash payments with the objective of reducing the existing diversity in practice. ASU 2016-15 will be effective for the Company on January 1, 2018 and is not expected to have a significant impact on the Company's financial statements. ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326)—Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. Additionally, available for sale debt securities may realize value either through collection of contractual cash flows or through sale of the security at fair value. Therefore, the amendments limit the amount of the allowance for credit losses to the difference between amortized cost and fair value. ASU 2016-13 will be effective for the Company as of January 1, 2020. The Company is currently evaluating the potential impact of ASU 2016-13 on the Company’s financial statements. ASU 2016-12, “Revenue from Contracts with Customers (Topic 606)—Narrow-Scope Improvements and Practical Expedients.” ASU 2016-12 addresses narrow-scope improvements to the guidance on collectability, noncash consideration and completed contracts at transition. Additionally, the amendments in this update provide a practical expedient for contract modifications at transition and an accounting policy election related to the presentation of sales taxes and other similar taxes collected from customers. The amendments in this update affect the guidance in , which is effective January 1, 2018. The Company is in the process of evaluating the impact of this guidance and does not currently anticipate a significant impact on the Company’s financial statements. ASU 2016-10, “Revenue from Contracts with Customers (Topic 606)—Identifying Performance Obligations and Licensing.” ASU 2016-10 clarifies two aspects of ” (i) identifying performance obligations and (ii) the licensing implementation guidance. This ASU adds guidance on how to identify the promised goods or services in the contract and how to evaluate whether promised goods and services are distinct. Additionally, this update includes guidance on determining whether an entity’s promise to grant a license provides a customer with either a right to use the entity’s intellectual property (which is satisfied at a point in time) or a right to access the entity’s intellectual property (which is satisfied over time) and when to recognize revenue for a sales-based or use-based royalty promised in exchange for a license of intellectual property. The amendments in this update affect the guidance in ,” which is effective January 1, 2018. The Company is in the process of evaluating the impact of this guidance and does not currently anticipate a significant impact on the Company’s financial statements. ASU 2016-09, “Compensation - Stock Compensation (Topic 718) — Improvements to Employee Share-Based Payment Accounting.” ASU 2016-09 was issued as part of the FASB’s simplification initiative and affects all entities that issue share-based payment awards to their employees. This ASU covers accounting for income taxes, forfeitures and statutory tax withholding requirements, as well as classification in the statement of cash flows. ASU 2016-09 will be effective for the Company as of January 1, 2017. The Company is currently evaluating the potential impact of ASU 2016-09 on the Company’s financial statements. ASU 2016-08, “Revenue from Contracts with Customers (Topic 606)—Principal versus Agent Considerations (Reporting Revenue Gross versus Net).” ASU 2016-08 states that when another party is involved in providing goods or services to a customer, an entity is required to determine whether the nature of its promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for that good or service to be provided by the other party (that is, the entity is an agent). Additionally, when an principal entity satisfies a performance obligation, the entity recognizes revenue in the gross amount of consideration to which it expects to be entitled in exchange for the specified good or service transferred to the customer, but when an agent entity satisfies a performance obligation, the entity recognizes revenue in the amount of any fee or commission to which it expects to be entitled in exchange for arranging for the specified good or service to be provided by the other party. The amendments in this update affect the guidance in ,” which is effective January 1, 2018. The Company is in the process of evaluating the impact of this guidance and does not currently anticipate a significant impact on the Company’s financial statements. ASU 2016-02, "Leases (Topic 842)." ASU 2016-02 requires that lessees and lessors recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. ASU 2016-02 is effective for public companies for annual periods beginning January 1, 2019, including interim periods within those fiscal years. The Company is currently evaluating the potential impact of ASU 2016-02 on the Company’s financial statements. ASU 2016-01, “Financial Instruments—Overall (Subtopic 825-10) — Recognition and Measurement of Financial Assets and Financial Liabilities.” ASU 2016-01 addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 (i) requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (iii) eliminates the requirement to disclose the fair value of financial instruments measured at amortized cost for entities that are not public business entities; (iv) eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; (v) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (vi) requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; (vii) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements; and (viii) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. The amendments in this update affect all entities that hold financial assets or owe financial liabilities. ASU 2016-01 is effective for the Company beginning January 1, 2018, and is not expected to have a significant impact on the Company’s financial statements. ASU 2015-16, “Business Combinations (Topic 805) — Simplifying the Accounting for Measurement-Period Adjustments.” ASU 2015-16 requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The acquirer must record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. Additionally, the entity is required to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amounts had been recognized as of the acquisition date. ASU 2015-16 became effective for the Company on January 1, 2016 and did not have a significant impact on the Company’s financial statements. ASU 2015-01, “Income Statement - Extraordinary and Unusual Items (Subtopic 225-20) — Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items.” ASU 2015-01 eliminates from U.S. GAAP the concept of extraordinary items, which, among other things, required an entity to segregate extraordinary items considered to be unusual and infrequent from the results of ordinary operations and show the item separately in the income statement, net of tax, after income from continuing operations. ASU 2015-01 became effective for the Company on January 1, 2016 and did not have a significant impact on the Company’s financial statements. ASU 2014-12, “Compensation - Stock Compensation (Topic 718) — Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. ” ASU 2014-12 requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. The performance target should not be reflected in estimating the grant-date fair value of the award. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The requisite service period ends when the employee can cease rendering service and still be eligible to vest in the award if the performance target is achieved. ASU 2014-12 became effective for the Company on January 1, 2016 and did not have a significant impact on the Company’s financial statements. ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 supersedes the revenue recognition requirements in Revenue Recognition (Topic 605), and most industry-specific guidance throughout the Industry Topics of the Codification. Additionally, ASU 2014-09 supersedes some cost guidance included in Revenue Recognition—Construction-Type and Production-Type Contracts (Subtopic 605-35). In addition, the existing requirements for the recognition of a gain or loss on the transfer of nonfinancial assets that are not in a contract with a customer are amended to be consistent with the guidance on recognition and measurement. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. deferred the effective date for ASU 2014-09 by one year to January 1, 2018, with retrospective application to each prior reporting period presented. The Company is currently evaluating the requirements of ASU 2014-09, but it is not expected to have a significant impact on the Company’s financial statements.

Income Per Common Share (Tables

Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table illustrates the computation of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount (Amounts in thousands, except per share data) Net income $ 68,651 $ 70,598 $ 205,673 $ 216,171 Basic: Weighted average shares outstanding 69,478 $ 0.99 70,041 $ 1.01 69,738 $ 2.95 70,037 $ 3.09 Diluted: Add incremental shares for: Effect of dilutive securities - options 6 12 7 17 Total 69,484 $ 0.99 70,053 $ 1.01 69,745 $ 2.95 70,054 $ 3.09

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Schedule of Amortized Cost and Fair Value of Investment Securities	The amortized cost and fair value of investment securities were as follows: September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale States and political subdivisions $ 2,574 $ 6 $ — $ 2,580 Collateralized mortgage obligations 21,427 13 (307 ) 21,133 Mortgage-backed securities 90,777 2,566 (174 ) 93,169 Other securities 12,588 253 (46 ) 12,795 Total $ 127,366 $ 2,838 $ (527 ) $ 129,677 Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 33,479 $ 1,028 $ — $ 34,507 States and political subdivisions 389,555 8,801 (45 ) 398,311 Collateralized mortgage obligations 903 17 (4 ) 916 Mortgage-backed securities 8,434,307 154,373 (1,617 ) 8,587,063 Other securities 100 — — 100 Total $ 8,858,344 $ 164,219 $ (1,666 ) $ 9,020,897 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale States and political subdivisions $ 5,463 $ 22 $ — $ 5,485 Collateralized mortgage obligations 25,991 25 (100 ) 25,916 Mortgage-backed securities 55,884 3,098 (11 ) 58,971 Other securities 12,588 150 (46 ) 12,692 Total $ 99,926 $ 3,295 $ (157 ) $ 103,064 Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 47,598 $ 798 $ — $ 48,396 States and political subdivisions 363,505 7,080 (542 ) 370,043 Collateralized mortgage obligations 2,107 17 (2 ) 2,122 Mortgage-backed securities 8,986,153 68,868 (82,407 ) 8,972,614 Other securities — — — — Total $ 9,399,363 $ 76,763 $ (82,951 ) $ 9,393,175
Securities in Continuous Loss Position	Securities with unrealized losses, segregated by length of time, that have been in a continuous loss position were as follows: September 30, 2016 Less than 12 Months More than 12 Months Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 18,791 $ (307 ) $ 25 $ — $ 18,816 $ (307 ) Mortgage-backed securities 48,836 (166 ) 2,231 (8 ) 51,067 (174 ) Other securities — — 1,691 (46 ) 1,691 (46 ) Total $ 67,627 $ (473 ) $ 3,947 $ (54 ) $ 71,574 $ (527 ) Held to Maturity States and political subdivisions $ 3,567 $ (8 ) $ 4,636 $ (37 ) $ 8,203 $ (45 ) Collateralized mortgage obligations 131 (4 ) 52 — 183 (4 ) Mortgage-backed securities 877,968 (1,067 ) 97,324 (550 ) 975,292 (1,617 ) Total $ 881,666 $ (1,079 ) $ 102,012 $ (587 ) $ 983,678 $ (1,666 ) December 31, 2015 Less than 12 Months More than 12 Months Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 14,331 $ (100 ) $ 1 $ — $ 14,332 $ (100 ) Mortgage-backed securities 793 (1 ) 2,465 (10 ) 3,258 (11 ) Other securities — — 1,691 (46 ) 1,691 (46 ) Total $ 15,124 $ (101 ) $ 4,157 $ (56 ) $ 19,281 $ (157 ) Held to Maturity States and political subdivisions $ 15,700 $ (82 ) $ 45,952 $ (460 ) $ 61,652 $ (542 ) Collateralized mortgage obligations 156 — 94 (2 ) 250 (2 ) Mortgage-backed securities 3,233,601 (36,016 ) 1,662,482 (46,391 ) 4,896,083 (82,407 ) Total $ 3,249,457 $ (36,098 ) $ 1,708,528 $ (46,853 ) $ 4,957,985 $ (82,951 )
Investment Securities by Contractual Maturity	The amortized cost and fair value of investment securities at September 30, 2016, by contractual maturity, are shown below. Actual maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations at any time with or without call or prepayment penalties. Held to Maturity Available for Sale Amortized Cost Fair Value Amortized Cost Fair Value (Dollars in thousands) Due in one year or less $ 33,476 $ 33,633 $ 12,688 $ 12,895 Due after one year through five years 189,175 192,485 2,474 2,480 Due after five years through ten years 172,389 177,838 — — Due after ten years 28,094 28,962 — — Subtotal 423,134 432,918 15,162 15,375 Mortgage-backed securities and collateralized mortgage obligations 8,435,210 8,587,979 112,204 114,302 Total $ 8,858,344 $ 9,020,897 $ 127,366 $ 129,677

Loans and Allowance for Credi23

Loans and Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Types of Loans in Loan Portfolio	The loan portfolio consists of various types of loans and is categorized by major type as follows: September 30, 2016 December 31, 2015 (Dollars in thousands) Residential mortgage loans held for sale $ 29,457 $ 23,933 Commercial and industrial 1,542,059 1,692,246 Real estate: Construction, land development and other land loans 1,205,820 1,073,198 1-4 family residential (includes home equity) 2,677,995 2,616,732 Commercial real estate (includes multi-family residential) 3,158,569 3,131,083 Farmland 473,957 434,349 Agriculture 190,123 214,469 Consumer and other 270,334 252,579 Total loans held for investment 9,518,857 9,414,656 Total $ 9,548,314 $ 9,438,589
Related Party Loans	An analysis of activity with respect to these related party loans is as follows: September 30, 2016 December 31, 2015 (Dollars in thousands) Beginning balance on January 1 $ 4,063 $ 4,940 New loans 199 428 Repayments and reclassified related loans (184 ) (1,305 ) Ending balance $ 4,078 $ 4,063
Aging Analysis of Past Due Loans	An aging analysis of past due loans, segregated by category of loan, is presented below: September 30, 2016 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 4,699 $ 254 $ 4,953 $ 279 $ 1,200,588 $ 1,205,820 Agriculture and agriculture real estate (includes farmland) 591 — 591 248 663,241 664,080 1-4 family (includes home equity) (1) 2,667 — 2,667 3,311 2,701,474 2,707,452 Commercial real estate (includes multi-family residential) 5,068 145 5,213 12,984 3,140,372 3,158,569 Commercial and industrial 9,020 — 9,020 26,426 1,506,613 1,542,059 Consumer and other 2,153 — 2,153 203 267,978 270,334 Total $ 24,198 $ 399 $ 24,597 $ 43,451 $ 9,480,266 $ 9,548,314 December 31, 2015 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 4,097 $ — $ 4,097 $ 134 $ 1,068,967 $ 1,073,198 Agriculture and agriculture real estate (includes farmland) 946 — 946 208 647,664 648,818 1-4 family (includes home equity) (1) 4,748 220 4,968 1,894 2,633,803 2,640,665 Commercial real estate (includes multi-family residential) 12,922 — 12,922 15,535 3,102,626 3,131,083 Commercial and industrial 4,793 394 5,187 21,692 1,665,367 1,692,246 Consumer and other 1,274 — 1,274 248 251,057 252,579 Total $ 28,780 $ 614 $ 29,394 $ 39,711 $ 9,369,484 $ 9,438,589 (1) Includes $29.5 million and $23.9 million of residential mortgage loans held for sale at September 30, 2016 and December 31, 2015, respectively.
Non-performing Assets	The following table presents information regarding nonperforming assets as of the dates indicated: September 30, 2016 December 31, 2015 (Dollars in thousands) Nonaccrual loans (1) $ 43,451 $ 39,711 Accruing loans 90 or more days past due 399 614 Total nonperforming loans 43,850 40,325 Repossessed assets 36 171 Other real estate 16,280 2,963 Total nonperforming assets $ 60,166 $ 43,459 Nonperforming assets to total loans and other real estate 0.63 % 0.46 % (1) Includes troubled debt restructurings of $318 thousand and $681 thousand as of September 30, 2016 and December 31, 2015, respectively.
Carrying Amount of PCI Loans and Related Outstanding Balance	The carrying amount of PCI loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2016 and December 31, 2015. September 30, 2016 December 31, 2015 (Dollars in thousands) PCI loans: Outstanding balance $ 61,570 $ 79,802 Less: discount 28,155 39,976 Recorded investment $ 33,415 $ 39,826
Changes in Accretable Yield for Acquired PCI Loans	Changes in the accretable yield for acquired PCI loans for the three and nine months ended September 30, 2016 and 2015 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Balance at beginning of period $ 12,015 $ 6,351 $ 5,664 $ 9,867 Additions — — 10,222 — Reclassifications from nonaccretable 1,378 3,940 8,809 12,572 Accretion (2,324 ) (3,974 ) (13,626 ) (16,122 ) Balance at September 30 $ 11,069 $ 6,317 $ 11,069 $ 6,317
Carrying Amount of Non-PCI Loans and Related Outstanding Balance	The carrying amount of Non-PCI loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2016 and December 31, 2015, including accrued but unpaid interest. September 30, 2016 December 31, 2015 (Dollars in thousands) Non-PCI loans: Outstanding balance $ 1,236,411 $ 1,430,501 Less: discount 39,360 54,734 Recorded investment $ 1,197,051 $ 1,375,767
Changes in Discount Accretion for Non-PCI Loans	Changes in the discount accretion for Non-PCI loans for the three and nine months ended September 30, 2016 and 2015 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Balance at beginning of period $ 44,672 $ 67,895 $ 54,734 $ 89,105 Additions — — 3,491 — Accretion charge-offs (16 ) (16 ) (1,073 ) (125 ) Accretion (5,296 ) (7,060 ) (17,792 ) (28,161 ) Balance at September 30 $ 39,360 $ 60,819 $ 39,360 $ 60,819
Summary of Impaired Loans	Impaired loans are set forth in the following tables. No interest income was recognized on impaired loans subsequent to their classification as impaired. The average recorded investment presented in the tables below is reported on a year-to-date basis. September 30, 2016 Recorded Investment Unpaid Contractual Principal Balance Related Allowance Average Recorded Investment (Dollars in thousands) With no related allowance recorded: Construction, land development and other land loans $ 177 $ 494 $ — $ 105 Agriculture and agriculture real estate (includes farmland) 10 15 — 15 1-4 family (includes home equity) 1,822 2,024 — 1,514 Commercial real estate (includes multi-family residential) 12,820 12,936 — 13,968 Commercial and industrial 10,663 10,957 — 6,009 Consumer and other 89 179 — 74 Total 25,581 26,605 — 21,685 With an allowance recorded: Construction, land development and other land loans — — — 4 Agriculture and agriculture real estate (includes farmland) 238 262 102 214 1-4 family (includes home equity) 459 482 140 419 Commercial real estate (includes multi-family residential) 69 69 13 166 Commercial and industrial 14,021 15,418 5,554 14,308 Consumer and other 74 107 46 128 Total 14,861 16,338 5,855 15,239 Total: Construction, land development and other land loans 177 494 — 109 Agriculture and agriculture real estate (includes farmland) 248 277 102 229 1-4 family (includes home equity) 2,281 2,506 140 1,933 Commercial real estate (includes multi-family residential) 12,889 13,005 13 14,134 Commercial and industrial 24,684 26,375 5,554 20,317 Consumer and other 163 286 46 202 $ 40,442 $ 42,943 $ 5,855 $ 36,924 December 31, 2015 Recorded Investment Unpaid Contractual Principal Balance Related Allowance Average Recorded Investment (Dollars in thousands) With no related allowance recorded: Construction, land development and other land loans $ 33 $ 346 $ — $ 142 Agriculture and agriculture real estate (includes farmland) 20 23 — 10 1-4 family (includes home equity) 1,206 1,365 — 1,458 Commercial real estate (includes multi-family residential) 15,115 15,398 — 10,104 Commercial and industrial 1,354 1,630 — 5,419 Consumer and other 58 131 — 4,101 Total 17,786 18,893 — 21,234 With an allowance recorded: Construction, land development and other land loans 7 11 2 141 Agriculture and agriculture real estate (includes farmland) 189 201 52 118 1-4 family (includes home equity) 379 386 93 902 Commercial real estate (includes multi-family residential) 262 1,857 262 162 Commercial and industrial 14,594 16,413 7,082 8,524 Consumer and other 181 220 44 208 Total 15,612 19,088 7,535 10,055 Total: Construction, land development and other land loans 40 357 2 283 Agriculture and agriculture real estate (includes farmland) 209 224 52 128 1-4 family (includes home equity) 1,585 1,751 93 2,360 Commercial real estate (includes multi-family residential) 15,377 17,255 262 10,266 Commercial and industrial 15,948 18,043 7,082 13,943 Consumer and other 239 351 44 4,309 $ 33,398 $ 37,981 $ 7,535 $ 31,289
Risk Grades and PCI Loans by Category of Loan	The following table presents risk grades and PCI loans by category of loan at September 30, 2016. Impaired loans include loans in risk grades 7, 8 and 9, as well as any PCI loan that has a specific reserve allocated to it. Construction, Land Development and Other Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Commercial Real Estate (includes Multi-Family Commercial and Industrial Consumer and Other Total (Dollars in thousands) Grade 1 $ — $ 14,055 $ — $ — $ 59,625 $ 40,858 $ 114,538 Grade 2 2,196 4,593 23,773 6,646 12,162 8,457 57,827 Grade 3 1,138,839 561,473 2,609,138 2,829,626 1,129,900 204,153 8,473,129 Grade 4 56,519 74,216 58,215 229,146 177,319 12,269 607,684 Grade 5 3,331 7,937 2,739 41,643 66,833 2,189 124,672 Grade 6 3,287 1,165 5,596 20,913 63,824 2,245 97,030 Grade 7 177 248 2,251 12,820 23,683 163 39,342 Grade 8 — — 30 69 578 — 677 Grade 9 — — — — — — — PCI Loans (2) 1,471 393 5,710 17,706 8,135 — 33,415 Total $ 1,205,820 $ 664,080 $ 2,707,452 $ 3,158,569 $ 1,542,059 $ 270,334 $ 9,548,314 (1) Includes $29.5 million of residential mortgage loans held for sale at September 30, 2016. (2) Of the total PCI loans, $3.2 million were classified as substandard at September 30, 2016, which includes $423 thousand with specific reserves of $224 thousand allocated to them. The following table presents risk grades and PCI loans by category of loan at December 31, 2015. Impaired loans include loans in risk grades 7, 8 and 9, as well as any PCI loan that has a specific reserve allocated to it. Construction, Land Development and Other Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Commercial Real Estate (includes Multi-Family Commercial and Industrial Consumer and Other Total (Dollars in thousands) Grade 1 $ — $ 12,733 $ — $ — $ 57,625 $ 44,389 $ 114,747 Grade 2 3,975 5,603 27,272 24,965 27,755 34,668 124,238 Grade 3 1,034,792 553,782 2,539,282 2,861,872 1,355,887 162,892 8,508,507 Grade 4 29,831 67,453 58,172 164,924 123,772 3,395 447,547 Grade 5 2,431 7,191 1,261 20,078 68,618 6,908 106,487 Grade 6 1,209 1,452 7,824 26,237 28,005 88 64,815 Grade 7 40 209 1,526 15,377 12,487 239 29,878 Grade 8 — — 59 — 2,485 — 2,544 Grade 9 — — — — — — — PCI Loans (2) 920 395 5,269 17,630 15,612 — 39,826 Total $ 1,073,198 $ 648,818 $ 2,640,665 $ 3,131,083 $ 1,692,246 $ 252,579 $ 9,438,589 (1) Includes $23.9 million of residential mortgage loans held for sale at December 31, 2015. (2) Of the total PCI loans, $7.3 million were classified as substandard at December 31, 2015, which includes $976 thousand with specific reserves of $836 thousand allocated to them.
Allowance for Credit Losses by Category of Loan	The following table details activity in the allowance for credit losses by category of loan for the three and nine months ended September 30, 2016 and 2015. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Allowance for credit losses: Three Months Ended Balance June 30, 2016 $ 14,202 $ 4,129 $ 14,916 $ 12,672 $ 36,254 $ 1,653 $ 83,826 Provision for credit losses (78 ) (40 ) 167 (477 ) 1,753 675 2,000 Charge-offs — (1 ) (63 ) — (24 ) (946 ) (1,034 ) Recoveries 368 46 15 1 131 232 793 Net charge-offs 368 45 (48 ) 1 107 (714 ) (241 ) Balance September 30, 2016 $ 14,492 $ 4,134 $ 15,035 $ 12,196 $ 38,114 $ 1,614 $ 85,585 Nine Months Ended Balance December 31, 2015 $ 14,882 $ 3,845 $ 14,891 $ 12,996 $ 33,409 $ 1,361 $ 81,384 Provision for credit losses (969 ) 6,551 144 (545 ) 13,103 3,716 22,000 Charge-offs (7 ) (7,026 ) (114 ) (257 ) (10,641 ) (4,371 ) (22,416 ) Recoveries 586 764 114 2 2,243 908 4,617 Net charge-offs 579 (6,262 ) — (255 ) (8,398 ) (3,463 ) (17,799 ) Balance September 30, 2016 $ 14,492 $ 4,134 $ 15,035 $ 12,196 $ 38,114 $ 1,614 $ 85,585 Allowance for credit losses: Three Months Ended Balance June 30, 2015 $ 16,909 $ 3,771 $ 16,593 $ 13,002 $ 29,205 $ 1,492 $ 80,972 Provision for credit losses (1,506 ) (79 ) (1,386 ) (742 ) 8,507 516 5,310 Charge-offs (215 ) (3 ) (120 ) (54 ) (4,865 ) (933 ) (6,190 ) Recoveries 42 43 10 1 439 376 911 Net charge-offs (173 ) 40 (110 ) (53 ) (4,426 ) (557 ) (5,279 ) Balance September 30, 2015 $ 15,230 $ 3,732 $ 15,097 $ 12,207 $ 33,286 $ 1,451 $ 81,003 Nine Months Ended Balance December 31, 2014 $ 15,825 $ 3,722 $ 16,377 $ 12,744 $ 30,002 $ 2,092 $ 80,762 Provision for credit losses (279 ) (173 ) (1,072 ) (337 ) 8,186 735 7,060 Charge-offs (366 ) (3 ) (249 ) (233 ) (5,691 ) (2,406 ) (8,948 ) Recoveries 50 186 41 33 789 1,030 2,129 Net charge-offs (316 ) 183 (208 ) (200 ) (4,902 ) (1,376 ) (6,819 ) Balance September 30, 2015 $ 15,230 $ 3,732 $ 15,097 $ 12,207 $ 33,286 $ 1,451 $ 81,003 The following table details the amount of the allowance for credit losses allocated to each category of loan as of September 30, 2016, December 31, 2015 and September 30, 2015, on the basis of the impairment methodology used by the Company. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Allowance for credit losses related to: September 30, 2016 Individually evaluated for impairment $ — $ 102 $ 140 $ 13 $ 5,330 $ 46 $ 5,631 Collectively evaluated for impairment 14,492 4,032 14,895 12,183 32,560 1,568 79,730 PCI loans — — — — 224 — 224 Total allowance for credit losses $ 14,492 $ 4,134 $ 15,035 $ 12,196 $ 38,114 $ 1,614 $ 85,585 December 31, 2015 Individually evaluated for impairment $ 2 $ 52 $ 93 $ 262 $ 7,082 $ 44 $ 7,535 Collectively evaluated for impairment 14,880 3,793 14,798 12,734 25,491 1,317 73,013 PCI loans — — — — 836 — 836 Total allowance for credit losses $ 14,882 $ 3,845 $ 14,891 $ 12,996 $ 33,409 $ 1,361 $ 81,384 September 30, 2015 Individually evaluated for impairment $ 2 $ 123 $ 111 $ 292 $ 6,550 $ 43 $ 7,121 Collectively evaluated for impairment 15,228 3,609 14,986 11,915 26,474 1,408 73,620 PCI loans — — — — 262 — 262 Total allowance for credit losses $ 15,230 $ 3,732 $ 15,097 $ 12,207 $ 33,286 $ 1,451 $ 81,003 The following table details the recorded investment in loans as of September 30, 2016, December 31, 2015 and September 30, 2015, excluding $29.5 million, $23.9 million and $12.6 million, respectively, of residential mortgage loans held for sale, related to each balance in the allowance for credit losses by category of loan. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Recorded investment in loans: September 30, 2016 Individually evaluated for impairment $ 177 $ 248 $ 2,281 $ 12,889 $ 24,261 $ 163 $ 40,019 Collectively evaluated for impairment 1,204,172 663,439 2,670,004 3,127,974 1,509,663 270,171 9,445,423 PCI loans 1,471 393 5,710 17,706 8,135 — 33,415 Total loans evaluated for impairment $ 1,205,820 $ 664,080 $ 2,677,995 $ 3,158,569 $ 1,542,059 $ 270,334 $ 9,518,857 December 31, 2015 Individually evaluated for impairment $ 40 $ 209 $ 1,585 $ 15,377 $ 15,948 $ 239 $ 33,398 Collectively evaluated for impairment 1,072,238 648,214 2,609,878 3,098,076 1,660,686 252,340 9,341,432 PCI loans 920 395 5,269 17,630 15,612 — 39,826 Total loans evaluated for impairment $ 1,073,198 $ 648,818 $ 2,616,732 $ 3,131,083 $ 1,692,246 $ 252,579 $ 9,414,656 September 30, 2015 Individually evaluated for impairment $ 249 $ 348 $ 1,908 $ 15,623 $ 20,480 $ 264 $ 38,872 Collectively evaluated for impairment 1,071,693 617,739 2,576,497 2,959,065 1,612,067 275,033 9,112,094 PCI loans 1,043 476 5,616 18,038 16,285 — 41,458 Total loans evaluated for impairment $ 1,072,985 $ 618,563 $ 2,584,021 $ 2,992,726 $ 1,648,832 $ 275,297 $ 9,192,424
Troubled Debt Restructurings	The following table presents information regarding the recorded investment of loans modified in a troubled debt restructuring during the nine months ended September 30, 2016 and 2015: Nine Months Ended September 30, 2016 2015 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment (Dollars in thousands) Troubled Debt Restructurings Construction, land development and other land loans — $ — $ — 1 $ 390 $ 307 Agriculture and agriculture real estate (includes farmland) 1 154 152 — — — 1-4 Family (includes home equity) — — — — — — Commercial real estate (includes multi-family residential) — — — — — — Commercial and industrial — — — — — — Consumer and other — — — 1 10 9 Total 1 $ 154 $ 152 2 $ 400 $ 316

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Assets and Liabilities Measured on Recurring Basis	The following tables present fair values for assets and liabilities measured at fair value on a recurring basis: As of September 30, 2016 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: States and political subdivisions $ — $ 2,580 $ — $ 2,580 Collateralized mortgage obligations — 21,133 — 21,133 Mortgage-backed securities — 93,169 — 93,169 Other securities 12,795 — — 12,795 Total $ 12,795 $ 116,882 $ — $ 129,677 As of December 31, 2015 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: States and political subdivisions $ — $ 5,485 $ — $ 5,485 Collateralized mortgage obligations — 25,916 — 25,916 Mortgage-backed securities — 58,971 — 58,971 Other securities 12,692 — — 12,692 Total $ 12,692 $ 90,372 $ — $ 103,064
Financial Instruments Fair Value	The following table presents carrying and fair value information of financial instruments as of the dates indicated: As of September 30, 2016 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total Assets (Dollars in thousands) Cash and due from banks $ 341,483 $ 341,483 $ — $ — $ 341,483 Federal funds sold 630 630 — — 630 Held to maturity securities 8,858,344 — 9,020,897 — 9,020,897 Loans held for sale 29,457 — 29,457 — 29,457 Loans held for investment, net of allowance 9,433,272 — — 9,448,097 9,448,097 Other real estate owned 16,280 — 16,280 — 16,280 Liabilities Deposits: Noninterest-bearing $ 5,159,333 $ — $ 5,159,333 $ — $ 5,159,333 Interest-bearing 11,762,076 — 11,766,996 — 11,766,996 Other borrowings 425,916 — 426,455 — 426,455 Securities sold under repurchase agreements 318,449 — 318,452 — 318,452 As of December 31, 2015 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total Assets (Dollars in thousands) Cash and due from banks $ 562,544 $ 562,544 $ — $ — $ 562,544 Federal funds sold 1,418 1,418 — — 1,418 Held to maturity securities 9,399,363 — 9,393,175 — 9,393,175 Loans held for sale 23,933 — 23,933 — 23,933 Loans held for investment, net of allowance 9,333,272 — — 9,365,758 9,365,758 Other real estate owned 2,963 — 2,963 — 2,963 Liabilities Deposits: Noninterest-bearing $ 5,136,579 $ — $ 5,136,579 $ — $ 5,136,579 Interest-bearing 12,544,540 — 12,548,050 — 12,548,050 Other borrowings 491,399 — 492,061 — 492,061 Securities sold under repurchase agreements 315,253 — 315,241 — 315,241

Goodwill and Core Deposit Int25

Goodwill and Core Deposit Intangibles (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Core Deposit Intangibles	Changes in the carrying amount of the Company’s goodwill and core deposit intangibles for the nine months ended September 30, 2016 and the year ended December 31, 2015 were as follows: Goodwill Core Deposit Intangibles (Dollars in thousands) Balance as of December 31, 2014 $ 1,874,191 $ 58,947 Less: Amortization — (9,530 ) Add: Measurement period adjustments (5,364 ) — Balance as of December 31, 2015 1,868,827 49,417 Less: Amortization — (6,974 ) Add: Acquisition of Tradition Bancshares, Inc. 31,522 5,567 Measurement period adjustments — — Balance as of September 30, 2016 $ 1,900,349 $ 48,010
Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles	The estimated aggregate future amortization expense for core deposit intangibles remaining as of September 30, 2016 is as follows (dollars in thousands): Remaining 2016 $ 2,226 2017 6,942 2018 5,959 2019 5,051 2020 4,483 Thereafter 23,349 Total $ 48,010

Contractual Obligations and O26

Contractual Obligations and Off-Balance Sheet Items (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Schedule of Contractual Obligations and Other Commitments	The following table summarizes the Company’s contractual obligations and other commitments to make future payments as of September 30, 2016 (other than deposit obligations and securities sold under repurchase agreements). The Company’s future cash payments associated with its contractual obligations pursuant to its FHLB notes payable and operating leases as of September 30, 2016 are summarized below. Payments for FHLB notes payable include interest of $760 thousand that will be paid over the future periods. Payments related to leases are based on actual payments specified in underlying contracts. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Federal Home Loan Bank notes payable $ 420,871 $ 4,916 $ 659 $ 230 $ 426,676 Operating leases 5,733 8,106 4,923 6,989 25,751 Total $ 426,604 $ 13,022 $ 5,582 $ 7,219 $ 452,427
Schedule of Letters of Credit and Commitments	The Company’s commitments associated with outstanding standby letters of credit and commitments to extend credit expiring by periods as of September 30, 2016 are summarized below. Since commitments associated with letters of credit and commitments to extend credit may expire unused, the amounts shown do not necessarily reflect the actual future cash funding requirements. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Standby letters of credit $ 63,168 $ 7,227 $ 226 $ 20 $ 70,641 Commitments to extend credit 1,018,584 314,222 83,258 568,608 1,984,672 Total $ 1,081,752 $ 321,449 $ 83,484 $ 568,628 $ 2,055,313

Other Comprehensive (Loss) In27

Other Comprehensive (Loss) Income (Tables)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Tax Effects Allocated to Each Component of Other Comprehensive Loss	The tax effects allocated to each component of other comprehensive loss were as follows: Three Months Ended September 30, 2016 2015 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive loss: Securities available for sale: Change in unrealized gain during period $ (186 ) $ 65 $ (121 ) $ (867 ) $ 303 $ (564 ) Total securities available for sale (186 ) 65 (121 ) (867 ) 303 (564 ) Total other comprehensive loss $ (186 ) $ 65 $ (121 ) $ (867 ) $ 303 $ (564 ) Nine Months Ended September 30, 2016 2015 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive loss: Securities available for sale: Change in unrealized gain during period $ (828 ) $ 290 $ (538 ) $ (1,949 ) $ 682 $ (1,267 ) Total securities available for sale (828 ) 290 (538 ) (1,949 ) 682 (1,267 ) Total other comprehensive loss $ (828 ) $ 290 $ (538 ) $ (1,949 ) $ 682 $ (1,267 )
Activity in Accumulated Other Comprehensive Income Associated with Securities Available for Sale, Net of Tax	Activity in accumulated other comprehensive income associated with securities available for sale, net of tax, was as follows: Securities Available for Sale Accumulated Other Comprehensive Income (Dollars in thousands) Balance at January 1, 2016 $ 2,040 $ 2,040 Other comprehensive loss (538 ) (538 ) Balance at September 30, 2016 $ 1,502 $ 1,502 Balance at January 1, 2015 $ 3,729 $ 3,729 Other comprehensive loss (1,267 ) (1,267 ) Balance at September 30, 2015 $ 2,462 $ 2,462

Income Per Common Share - Compu

Income Per Common Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income	$ 68,651	$ 70,598	$ 205,673	$ 216,171
Weighted average shares outstanding (in shares)	69,478,000	70,041,000	69,738,000	70,037,000
Weighted average shares outstanding (in dollars per share)	$ 0.99	$ 1.01	$ 2.95	$ 3.09
Effect of dilutive securities - options (in shares)	6	12	7	17
Total (in shares)	69,484,000	70,053,000	69,745,000	70,054,000
Total (in dollars per share)	$ 0.99	$ 1.01	$ 2.95	$ 3.09

Income Per Common Share (Detail

Income Per Common Share (Details Textual) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Employee Stock Option [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0	0	0

Securities - Schedule of Amorti

Securities - Schedule of Amortized Cost and Fair Value of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	$ 127,366	$ 99,926
Available for Sale, Gross Unrealized Gains	2,838	3,295
Available for Sale, Gross Unrealized Losses	(527)	(157)
Available for Sale Securities	129,677	103,064
Held to Maturity, amortized cost, total	8,858,344	9,399,363
Held to Maturity, Gross Unrealized Gains	164,219	76,763
Held to Maturity, Gross Unrealized Losses	(1,666)	(82,951)
Held to Maturity securities	9,020,897	9,393,175
US States and Political Subdivisions Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	2,574	5,463
Available for Sale, Gross Unrealized Gains	6	22
Available for Sale Securities	2,580	5,485
Held to Maturity, amortized cost, total	389,555	363,505
Held to Maturity, Gross Unrealized Gains	8,801	7,080
Held to Maturity, Gross Unrealized Losses	(45)	(542)
Held to Maturity securities	398,311	370,043
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	21,427	25,991
Available for Sale, Gross Unrealized Gains	13	25
Available for Sale, Gross Unrealized Losses	(307)	(100)
Available for Sale Securities	21,133	25,916
Held to Maturity, amortized cost, total	903	2,107
Held to Maturity, Gross Unrealized Gains	17	17
Held to Maturity, Gross Unrealized Losses	(4)	(2)
Held to Maturity securities	916	2,122
Collateralized Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	90,777	55,884
Available for Sale, Gross Unrealized Gains	2,566	3,098
Available for Sale, Gross Unrealized Losses	(174)	(11)
Available for Sale Securities	93,169	58,971
Held to Maturity, amortized cost, total	8,434,307	8,986,153
Held to Maturity, Gross Unrealized Gains	154,373	68,868
Held to Maturity, Gross Unrealized Losses	(1,617)	(82,407)
Held to Maturity securities	8,587,063	8,972,614
Other Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	12,588	12,588
Available for Sale, Gross Unrealized Gains	253	150
Available for Sale, Gross Unrealized Losses	(46)	(46)
Available for Sale Securities	12,795	12,692
Held to Maturity, amortized cost, total	100
Held to Maturity securities	100
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, amortized cost, total	33,479	47,598
Held to Maturity, Gross Unrealized Gains	1,028	798
Held to Maturity securities	$ 34,507	$ 48,396

Securities - Additional Informa

Securities - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016USD ($)Security	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)SegmentSecurity	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)Security
Schedule Of Held To Maturity Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	$ 127,366		$ 127,366		$ 99,926
Available for Sale Securities	$ 129,677		$ 129,677		$ 103,064
Securities Concentration Risk [Member] | Stockholders' Equity, Total [Member]
Schedule Of Held To Maturity Securities [Line Items]
Concentration Risk, Percentage			10.00%		10.00%
Collateralized Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Number of Investment Securities Segments | Segment			2
Other than Temporary Impairment Losses, Investments			$ 0
Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions Greater Than or Equal to One Year | Security	411		411		474
Gain (Loss) on Sale of Securities, Net	$ 0	$ 0	$ 0	$ 0
Available for Sale Securities, Amortized Cost Basis	5,170,000		5,170,000		$ 5,810,000
Available for Sale Securities	$ 5,250,000		$ 5,250,000		$ 5,790,000

Securities - Securities in Cont

Securities - Securities in Continuous Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	$ 67,627	$ 15,124
Available for Sale, Unrealized Losses, Less than 12 Months	(473)	(101)
Available for Sale, Estimated Fair Value, More than 12 Months	3,947	4,157
Available for Sale, Unrealized Losses, More than 12 Months	(54)	(56)
Available for Sale, Estimated Fair Value, Total	71,574	19,281
Available for Sale, Unrealized Losses, Total	(527)	(157)
Held to Maturity, Estimated Fair Value, Less than 12 Months	881,666	3,249,457
Held to Maturity, Unrealized Losses, Less than 12 Months	(1,079)	(36,098)
Held to Maturity, Estimated Fair Value, More than 12 Months	102,012	1,708,528
Held to Maturity, Unrealized Losses, More than 12 Months	(587)	(46,853)
Held to Maturity, Estimated Fair Value, Total	983,678	4,957,985
Held to Maturity, Unrealized Losses, Total	(1,666)	(82,951)
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	18,791	14,331
Available for Sale, Unrealized Losses, Less than 12 Months	(307)	(100)
Available for Sale, Estimated Fair Value, More than 12 Months	25	1
Available for Sale, Estimated Fair Value, Total	18,816	14,332
Available for Sale, Unrealized Losses, Total	(307)	(100)
Held to Maturity, Estimated Fair Value, Less than 12 Months	131	156
Held to Maturity, Unrealized Losses, Less than 12 Months	(4)
Held to Maturity, Estimated Fair Value, More than 12 Months	52	94
Held to Maturity, Unrealized Losses, More than 12 Months		(2)
Held to Maturity, Estimated Fair Value, Total	183	250
Held to Maturity, Unrealized Losses, Total	(4)	(2)
Collateralized Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	48,836	793
Available for Sale, Unrealized Losses, Less than 12 Months	(166)	(1)
Available for Sale, Estimated Fair Value, More than 12 Months	2,231	2,465
Available for Sale, Unrealized Losses, More than 12 Months	(8)	(10)
Available for Sale, Estimated Fair Value, Total	51,067	3,258
Available for Sale, Unrealized Losses, Total	(174)	(11)
Held to Maturity, Estimated Fair Value, Less than 12 Months	877,968	3,233,601
Held to Maturity, Unrealized Losses, Less than 12 Months	(1,067)	(36,016)
Held to Maturity, Estimated Fair Value, More than 12 Months	97,324	1,662,482
Held to Maturity, Unrealized Losses, More than 12 Months	(550)	(46,391)
Held to Maturity, Estimated Fair Value, Total	975,292	4,896,083
Held to Maturity, Unrealized Losses, Total	(1,617)	(82,407)
Other Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, More than 12 Months	1,691	1,691
Available for Sale, Unrealized Losses, More than 12 Months	(46)	(46)
Available for Sale, Estimated Fair Value, Total	1,691	1,691
Available for Sale, Unrealized Losses, Total	(46)	(46)
US States and Political Subdivisions Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, Less than 12 Months	3,567	15,700
Held to Maturity, Unrealized Losses, Less than 12 Months	(8)	(82)
Held to Maturity, Estimated Fair Value, More than 12 Months	4,636	45,952
Held to Maturity, Unrealized Losses, More than 12 Months	(37)	(460)
Held to Maturity, Estimated Fair Value, Total	8,203	61,652
Held to Maturity, Unrealized Losses, Total	$ (45)	$ (542)

Securities - Investment Securit

Securities - Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Investments Debt And Equity Securities [Abstract]
Held to Maturity, amortized cost, due in one year or less	$ 33,476
Held to Maturity, amortized cost, due after one year through five years	189,175
Held to Maturity, amortized cost, due after five years through ten years	172,389
Held to Maturity, amortized cost, due after ten years	28,094
Held to Maturity, amortized cost, subtotal	423,134
Held to Maturity, amortized cost, mortgage-backed securities and collateralized mortgage obligations	8,435,210
Held to Maturity, amortized cost, total	8,858,344	$ 9,399,363
Held to Maturity, fair value, due in one year or less	33,633
Held to Maturity, fair value, due after one year through five years	192,485
Held to Maturity, fair value, due after five years through ten years	177,838
Held to Maturity, fair value, due after ten years	28,962
Held to Maturity, fair value, subtotal	432,918
Held to Maturity, fair value, mortgage-backed securities and collateralized mortgage obligations	8,587,979
Held to Maturity, fair value, total	9,020,897	$ 9,393,175
Available for Sale, amortized cost, due in one year or less	12,688
Available for Sale, amortized cost, due after one year through five years	2,474
Available for Sale, amortized cost, due after five years through ten years	0
Available for Sale, amortized cost, due after ten years	0
Available for Sale, amortized cost, subtotal	15,162
Available for Sale, amortized cost, mortgage-backed securities and collateralized mortgage obligations	112,204
Available for Sale, amortized cost, total	127,366
Available for Sale, fair value, due in one year or less	12,895
Available for Sale, fair value, due after one year through five years	2,480
Available for Sale, fair value, due after five years through ten years	0
Available for Sale, fair value, due after ten years	0
Available for Sale, fair value, subtotal	15,375
Available for Sale, fair value, mortgage-backed securities and collateralized mortgage obligations	114,302
Available for Sale securities, at fair value	$ 129,677

Loans and Allowance for Credi34

Loans and Allowance for Credit Losses - Types of Loans in Loan Portfolio (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage		$ 29,457		$ 23,933
Total loans held for investment		9,518,857		9,414,656		$ 9,192,424
Total		9,548,314		9,438,589
Residential Portfolio Segment [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage		29,457		23,933
Commercial and Industrial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans held for investment		1,542,059		1,692,246		1,648,832
Total		1,542,059		1,692,246
Construction, Land Development and Other Land Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans held for investment		1,205,820		1,073,198		1,072,985
Total		1,205,820		1,073,198
1-4 Family Residential (Includes Home Equity) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage		29,500		23,900		12,600
Total loans held for investment		2,677,995		2,616,732		2,584,021
Total	[2]	2,707,452	[1]	2,640,665	[3]
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans held for investment		3,158,569		3,131,083		2,992,726
Total		3,158,569		3,131,083
Farmland [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans held for investment		473,957		434,349
Agriculture [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans held for investment		190,123		214,469
Consumer and Other [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans held for investment		270,334		252,579		$ 275,297
Total		$ 270,334		$ 252,579
[1]	(1)Includes $29.5 million of residential mortgage loans held for sale at September 30, 2016.
[2]	Includes $29.5 million and $23.9 million of residential mortgage loans held for sale at September 30, 2016 and December 31, 2015, respectively.
[3]	(1)Includes $23.9 million of residential mortgage loans held for sale at December 31, 2015.

Loans and Allowance for Credi35

Loans and Allowance for Credit Losses - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)contract	Sep. 30, 2015USD ($)contract	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 9,518,857	$ 9,192,424	$ 9,414,656
Financing Receivable Ratio of Non-performing Loans to All Loans and Other Real Estate	0.63%		0.46%
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	$ 2,200	$ 2,800
Nonaccrual loans	$ 43,451		$ 39,711
Troubled debt restructurings, number of loans | contract	1	2
Troubled debt restructurings, pre-modification outstanding recorded investment	$ 154	$ 400
Troubled Debt Restructuring [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	318	$ 607
Nonperforming Financial Instruments [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 60,166		43,459
Substandard [Member]
Accounts Notes And Loans Receivable [Line Items]
Percentage of Loans Related to Single Industry on Loans	10.00%
Loans and Leases Receivable, Related Parties	$ 4,078		4,063	$ 4,940
Minimum Period for Ceases Accruing Interest	90 days
Financing Receivable, Allowance for Credit Losses	$ 85,600		$ 81,400
Allowance for Credit Losses as Percentage of Loans	0.90%		86.00%
Loan to be Considered as Payment Default in Period	90 days
Troubled debt restructurings, number of loans | contract	1	2
Troubled debt restructurings, pre-modification outstanding recorded investment	$ 154	$ 400
Financing Receivable, Modifications, Recorded Investment	$ 152	$ 316

Loans and Allowance for Credi36

Loans and Allowance for Credit Losses - Related Party Loans (Details) - Substandard [Member] - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Beginning balance on January 1	$ 4,063	$ 4,940
New loans	199	428
Repayments and reclassified related loans	(184)	(1,305)
Ending balance	$ 4,078	$ 4,063

Loans and Allowance for Credi37

Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		$ 24,597		$ 29,394
Nonaccrual loans		43,451		39,711
Current loans		9,480,266		9,369,484
Total loans		9,548,314		9,438,589
Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		24,198		28,780
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		399		614
Construction, Land Development and Other Land Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		4,953		4,097
Nonaccrual loans		279		134
Current loans		1,200,588		1,068,967
Total loans		1,205,820		1,073,198
Construction, Land Development and Other Land Loans [Member] | Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		4,699		4,097
Construction, Land Development and Other Land Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		254		0
Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		591		946
Nonaccrual loans		248		208
Current loans		663,241		647,664
Total loans		664,080		648,818
Agriculture and Agriculture Real Estate (Includes Farmland) [Member] | Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		591		946
Agriculture and Agriculture Real Estate (Includes Farmland) [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		0		0
1-4 Family Residential (Includes Home Equity) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing	[1]	2,667		4,968
Nonaccrual loans	[1]	3,311		1,894
Current loans	[1]	2,701,474		2,633,803
Total loans	[1]	2,707,452	[2]	2,640,665	[3]
1-4 Family Residential (Includes Home Equity) [Member] | Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing	[1]	2,667		4,748
1-4 Family Residential (Includes Home Equity) [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing	[1]	0		220
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		5,213		12,922
Nonaccrual loans		12,984		15,535
Current loans		3,140,372		3,102,626
Total loans		3,158,569		3,131,083
Commercial Real Estate (Includes Multi-Family Residential) [Member] | Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		5,068		12,922
Commercial Real Estate (Includes Multi-Family Residential) [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		145		0
Commercial and Industrial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		9,020		5,187
Nonaccrual loans		26,426		21,692
Current loans		1,506,613		1,665,367
Total loans		1,542,059		1,692,246
Commercial and Industrial [Member] | Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		9,020		4,793
Commercial and Industrial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		0		394
Consumer and Other [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		2,153		1,274
Nonaccrual loans		203		248
Current loans		267,978		251,057
Total loans		270,334		252,579
Consumer and Other [Member] | Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		2,153		1,274
Consumer and Other [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		$ 0		$ 0
[1]	Includes $29.5 million and $23.9 million of residential mortgage loans held for sale at September 30, 2016 and December 31, 2015, respectively.
[2]	(1)Includes $29.5 million of residential mortgage loans held for sale at September 30, 2016.
[3]	(1)Includes $23.9 million of residential mortgage loans held for sale at December 31, 2015.

Loans and Allowance for Credi38

Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Details) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	$ 29,457	$ 23,933
Residential Mortgage Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	$ 29,500	$ 23,900

Loans and Allowance for Credi39

Loans and Allowance for Credit Losses - Nonperforming Assets (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 9,518,857	$ 9,414,656	$ 9,192,424
Nonperforming assets to total loans and other real estate		0.63%	0.46%
Nonperforming Financial Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 43,850	$ 40,325
Nonperforming Financial Loans [Member] | Finance Receivable Nonaccrual Status [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	[1]	43,451	39,711
Nonperforming Financial Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		399	614
Nonperforming Financial Instruments [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		60,166	43,459
Nonperforming Financial Instruments [Member] | Repossessed Assets [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		36	171
Nonperforming Financial Instruments [Member] | Other Real Assets [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 16,280	$ 2,963
[1]	Includes troubled debt restructurings of $318 thousand and $681 thousand as of September 30, 2016 and December 31, 2015, respectively.

Loans and Allowance for Credi40

Loans and Allowance for Credit Losses - Nonperforming Assets (Details) (Parentheticals) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 9,518,857	$ 9,414,656	$ 9,192,424
Nonperforming Financial Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		43,850	40,325
Nonperforming Financial Loans [Member] | Finance Receivable Nonaccrual Status [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	[1]	43,451	39,711
Troubled Debt Restructuring [Member] | Nonperforming Financial Loans [Member] | Finance Receivable Nonaccrual Status [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 318	$ 681
[1]	Includes troubled debt restructurings of $318 thousand and $681 thousand as of September 30, 2016 and December 31, 2015, respectively.

Loans and Allowance for Credi41

Loans and Allowance for Credit Losses - Carrying Amount of PCI Loans and Related Outstanding Balance (Details) - Receivables Acquired with Deteriorated Credit Quality [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Outstanding balance	$ 61,570	$ 79,802
Less: discount	28,155	39,976
Recorded investment	$ 33,415	$ 39,826

Loans and Allowance for Credi42

Loans and Allowance for Credit Losses - Changes in Accretable Yield for Acquired PCI Loans (Details) - Receivables Acquired with Deteriorated Credit Quality [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable Impaired [Line Items]
Balance	$ 12,015	$ 6,351	$ 5,664	$ 9,867
Additions			10,222
Reclassifications from nonaccretable	1,378	3,940	8,809	12,572
Accretion	(2,324)	(3,974)	(13,626)	(16,122)
Balance	$ 11,069	$ 6,317	$ 11,069	$ 6,317

Loans and Allowance for Credi43

Loans and Allowance for Credit Losses - Carrying Amount of Non-PCI Loans and Related Outstanding Balance (Details) - Non PCI Loans [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Outstanding balance	$ 1,236,411	$ 1,430,501
Less: discount	39,360	54,734
Recorded investment	$ 1,197,051	$ 1,375,767

Loans and Allowance for Credi44

Loans and Allowance for Credit Losses - Changes in Discount Accretion for Non-PCI Loans (Details) - Non PCI Loans [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable Impaired [Line Items]
Balance	$ 44,672	$ 67,895	$ 54,734	$ 89,105
Additions			3,491
Accretion charge-offs	(16)	(16)	(1,073)	(125)
Accretion	(5,296)	(7,060)	(17,792)	(28,161)
Balance	$ 39,360	$ 60,819	$ 39,360	$ 60,819

Loans and Allowance for Credi45

Loans and Allowance for Credit Losses - Impaired Loans (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance, recorded investment	$ 25,581	$ 17,786
Impaired loans with no related allowance, unpaid principal balance	26,605	18,893
Impaired loans with no related allowance, average recorded investment	21,685	21,234
Impaired loans with related allowance, recorded investment	14,861	15,612
Impaired loans with related allowance, unpaid principal balance	16,338	19,088
Impaired loans with related allowance, related allowance	5,855	7,535
Impaired loans with related allowance, average recorded investment	15,239	10,055
Impaired loans, recorded investment	40,442	33,398
Impaired loans, unpaid principal balance	42,943	37,981
Impaired loans, average recorded investment	36,924	31,289
Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance, recorded investment	177	33
Impaired loans with no related allowance, unpaid principal balance	494	346
Impaired loans with no related allowance, average recorded investment	105	142
Impaired loans with related allowance, recorded investment		7
Impaired loans with related allowance, unpaid principal balance		11
Impaired loans with related allowance, related allowance		2
Impaired loans with related allowance, average recorded investment	4	141
Impaired loans, recorded investment	177	40
Impaired loans, unpaid principal balance	494	357
Impaired loans, average recorded investment	109	283
Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance, recorded investment	10	20
Impaired loans with no related allowance, unpaid principal balance	15	23
Impaired loans with no related allowance, average recorded investment	15	10
Impaired loans with related allowance, recorded investment	238	189
Impaired loans with related allowance, unpaid principal balance	262	201
Impaired loans with related allowance, related allowance	102	52
Impaired loans with related allowance, average recorded investment	214	118
Impaired loans, recorded investment	248	209
Impaired loans, unpaid principal balance	277	224
Impaired loans, average recorded investment	229	128
1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance, recorded investment	1,822	1,206
Impaired loans with no related allowance, unpaid principal balance	2,024	1,365
Impaired loans with no related allowance, average recorded investment	1,514	1,458
Impaired loans with related allowance, recorded investment	459	379
Impaired loans with related allowance, unpaid principal balance	482	386
Impaired loans with related allowance, related allowance	140	93
Impaired loans with related allowance, average recorded investment	419	902
Impaired loans, recorded investment	2,281	1,585
Impaired loans, unpaid principal balance	2,506	1,751
Impaired loans, average recorded investment	1,933	2,360
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance, recorded investment	12,820	15,115
Impaired loans with no related allowance, unpaid principal balance	12,936	15,398
Impaired loans with no related allowance, average recorded investment	13,968	10,104
Impaired loans with related allowance, recorded investment	69	262
Impaired loans with related allowance, unpaid principal balance	69	1,857
Impaired loans with related allowance, related allowance	13	262
Impaired loans with related allowance, average recorded investment	166	162
Impaired loans, recorded investment	12,889	15,377
Impaired loans, unpaid principal balance	13,005	17,255
Impaired loans, average recorded investment	14,134	10,266
Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance, recorded investment	10,663	1,354
Impaired loans with no related allowance, unpaid principal balance	10,957	1,630
Impaired loans with no related allowance, average recorded investment	6,009	5,419
Impaired loans with related allowance, recorded investment	14,021	14,594
Impaired loans with related allowance, unpaid principal balance	15,418	16,413
Impaired loans with related allowance, related allowance	5,554	7,082
Impaired loans with related allowance, average recorded investment	14,308	8,524
Impaired loans, recorded investment	24,684	15,948
Impaired loans, unpaid principal balance	26,375	18,043
Impaired loans, average recorded investment	20,317	13,943
Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance, recorded investment	89	58
Impaired loans with no related allowance, unpaid principal balance	179	131
Impaired loans with no related allowance, average recorded investment	74	4,101
Impaired loans with related allowance, recorded investment	74	181
Impaired loans with related allowance, unpaid principal balance	107	220
Impaired loans with related allowance, related allowance	46	44
Impaired loans with related allowance, average recorded investment	128	208
Impaired loans, recorded investment	163	239
Impaired loans, unpaid principal balance	286	351
Impaired loans, average recorded investment	$ 202	$ 4,309

Loans and Allowance for Credi46

Loans and Allowance for Credit Losses - Risk Grades and PCI Loans by Category of Loan (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Loans		$ 9,548,314		$ 9,438,589
Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		1,205,820		1,073,198
Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		664,080		648,818
1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans	[2]	2,707,452	[1]	2,640,665	[3]
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		3,158,569		3,131,083
Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		1,542,059		1,692,246
Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		270,334		252,579
Grade 1 [Member]
Financing Receivable Impaired [Line Items]
Loans		114,538		114,747
Grade 1 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 1 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		14,055		12,733
Grade 1 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		0	[1]	0	[3]
Grade 1 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 1 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		59,625		57,625
Grade 1 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		40,858		44,389
Grade 2 [Member]
Financing Receivable Impaired [Line Items]
Loans		57,827		124,238
Grade 2 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		2,196		3,975
Grade 2 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		4,593		5,603
Grade 2 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		23,773	[1]	27,272	[3]
Grade 2 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		6,646		24,965
Grade 2 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		12,162		27,755
Grade 2 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		8,457		34,668
Grade 3 [Member]
Financing Receivable Impaired [Line Items]
Loans		8,473,129		8,508,507
Grade 3 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		1,138,839		1,034,792
Grade 3 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		561,473		553,782
Grade 3 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		2,609,138	[1]	2,539,282	[3]
Grade 3 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		2,829,626		2,861,872
Grade 3 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		1,129,900		1,355,887
Grade 3 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		204,153		162,892
Grade 4 [Member]
Financing Receivable Impaired [Line Items]
Loans		607,684		447,547
Grade 4 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		56,519		29,831
Grade 4 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		74,216		67,453
Grade 4 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		58,215	[1]	58,172	[3]
Grade 4 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		229,146		164,924
Grade 4 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		177,319		123,772
Grade 4 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		12,269		3,395
Grade 5 [Member]
Financing Receivable Impaired [Line Items]
Loans		124,672		106,487
Grade 5 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		3,331		2,431
Grade 5 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		7,937		7,191
Grade 5 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		2,739	[1]	1,261	[3]
Grade 5 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		41,643		20,078
Grade 5 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		66,833		68,618
Grade 5 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		2,189		6,908
Grade 6 [Member]
Financing Receivable Impaired [Line Items]
Loans		97,030		64,815
Grade 6 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		3,287		1,209
Grade 6 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		1,165		1,452
Grade 6 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		5,596	[1]	7,824	[3]
Grade 6 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		20,913		26,237
Grade 6 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		63,824		28,005
Grade 6 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		2,245		88
Grade 7 [Member]
Financing Receivable Impaired [Line Items]
Loans		39,342		29,878
Grade 7 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		177		40
Grade 7 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		248		209
Grade 7 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		2,251	[1]	1,526	[3]
Grade 7 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		12,820		15,377
Grade 7 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		23,683		12,487
Grade 7 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		163		239
Grade 8 [Member]
Financing Receivable Impaired [Line Items]
Loans		677		2,544
Grade 8 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 8 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 8 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		30	[1]	59	[3]
Grade 8 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		69		0
Grade 8 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		578		2,485
Grade 8 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 9 [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 9 [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 9 [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 9 [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		0	[1]	0	[3]
Grade 9 [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 9 [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
Grade 9 [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		0		0
PCI Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		33,415	[4]	39,826	[5]
PCI Loans [Member] | Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
Loans		1,471	[4]	920	[5]
PCI Loans [Member] | Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Impaired [Line Items]
Loans		393	[4]	395	[5]
PCI Loans [Member] | 1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans		5,710	[1],[4]	5,269	[3],[5]
PCI Loans [Member] | Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Loans		17,706	[4]	17,630	[5]
PCI Loans [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Loans		8,135	[4]	15,612	[5]
PCI Loans [Member] | Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
Loans		$ 0	[4]	$ 0	[5]
[1]	(1)Includes $29.5 million of residential mortgage loans held for sale at September 30, 2016.
[2]	Includes $29.5 million and $23.9 million of residential mortgage loans held for sale at September 30, 2016 and December 31, 2015, respectively.
[3]	(1)Includes $23.9 million of residential mortgage loans held for sale at December 31, 2015.
[4]	(2)Of the total PCI loans, $3.2 million were classified as substandard at September 30, 2016, which includes $423 thousand with specific reserves of $224 thousand allocated to them.
[5]	(2)Of the total PCI loans, $7.3 million were classified as substandard at December 31, 2015, which includes $976 thousand with specific reserves of $836 thousand allocated to them.

Loans and Allowance for Credi47

Loans and Allowance for Credit Losses - Risk Grades and Impaired Loans by Class of Loan (Details) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Financing Receivable Impaired [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	$ 29,457	$ 23,933
Substandard [Member]
Financing Receivable Impaired [Line Items]
Loans Receivable, Fair Value Disclosure	3,200	7,300
Allocated Specific Reserves	224	836
1-4 Family Residential (Includes Home Equity) [Member]
Financing Receivable Impaired [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	$ 29,500	23,900	$ 12,600
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage		$ 23,900

Loans and Allowance for Credi48

Loans and Allowance for Credit Losses - Allowance for Credit Losses by Category of Loan (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Allowance for credit losses:
Allowance for credit losses, beginning balance	$ 83,826	$ 80,972	$ 81,384	$ 80,762
Provision for credit losses	2,000	5,310	22,000	7,060
Charge-offs	(1,034)	(6,190)	(22,416)	(8,948)
Recoveries	793	911	4,617	2,129
Net charge-offs	(241)	(5,279)	(17,799)	(6,819)
Allowance for credit losses, ending balance	85,585	81,003	85,585	81,003
Allowance for credit losses related to:
Allowance for credit losses, individually evaluated for impairment					$ 5,631	$ 7,535	$ 7,121
Allowance for credit losses, collectively evaluated for impairment					79,730	73,013	73,620
Allowance for credit losses, PCI loans					224	836	262
Total allowance for credit losses	85,585	80,972	85,585	81,003	85,585	81,384	81,003
Recorded investment in loans:
Loans, individually evaluated for impairment					40,019	33,398	38,872
Loans, collectively evaluated for impairment					9,445,423	9,341,432	9,112,094
PCI loans					33,415	39,826	41,458
Total loans evaluated for impairment					9,518,857	9,414,656	9,192,424
Construction, Land Development and Other Land Loans [Member]
Allowance for credit losses:
Allowance for credit losses, beginning balance	14,202	16,909	14,882	15,825
Provision for credit losses	(78)	(1,506)	(969)	(279)
Charge-offs		(215)	(7)	(366)
Recoveries	368	42	586	50
Net charge-offs	368	(173)	579	(316)
Allowance for credit losses, ending balance	14,492	15,230	14,492	15,230
Allowance for credit losses related to:
Allowance for credit losses, individually evaluated for impairment						2	2
Allowance for credit losses, collectively evaluated for impairment					14,492	14,880	15,228
Total allowance for credit losses	14,202	16,909	14,492	15,230	14,492	14,882	15,230
Recorded investment in loans:
Loans, individually evaluated for impairment					177	40	249
Loans, collectively evaluated for impairment					1,204,172	1,072,238	1,071,693
PCI loans					1,471	920	1,043
Total loans evaluated for impairment					1,205,820	1,073,198	1,072,985
Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Allowance for credit losses:
Allowance for credit losses, beginning balance	4,129	3,771	3,845	3,722
Provision for credit losses	(40)	(79)	6,551	(173)
Charge-offs	(1)	(3)	(7,026)	(3)
Recoveries	46	43	764	186
Net charge-offs	45	40	(6,262)	183
Allowance for credit losses, ending balance	4,134	3,732	4,134	3,732
Allowance for credit losses related to:
Allowance for credit losses, individually evaluated for impairment					102	52	123
Allowance for credit losses, collectively evaluated for impairment					4,032	3,793	3,609
Total allowance for credit losses	4,129	3,771	4,134	3,732	4,134	3,845	3,732
Recorded investment in loans:
Loans, individually evaluated for impairment					248	209	348
Loans, collectively evaluated for impairment					663,439	648,214	617,739
PCI loans					393	395	476
Total loans evaluated for impairment					664,080	648,818	618,563
1-4 Family Residential (Includes Home Equity) [Member]
Allowance for credit losses:
Allowance for credit losses, beginning balance	14,916	16,593	14,891	16,377
Provision for credit losses	167	(1,386)	144	(1,072)
Charge-offs	(63)	(120)	(114)	(249)
Recoveries	15	10	114	41
Net charge-offs	(48)	(110)		(208)
Allowance for credit losses, ending balance	15,035	15,097	15,035	15,097
Allowance for credit losses related to:
Allowance for credit losses, individually evaluated for impairment					140	93	111
Allowance for credit losses, collectively evaluated for impairment					14,895	14,798	14,986
Total allowance for credit losses	14,916	16,593	15,035	15,097	15,035	14,891	15,097
Recorded investment in loans:
Loans, individually evaluated for impairment					2,281	1,585	1,908
Loans, collectively evaluated for impairment					2,670,004	2,609,878	2,576,497
PCI loans					5,710	5,269	5,616
Total loans evaluated for impairment					2,677,995	2,616,732	2,584,021
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Allowance for credit losses:
Allowance for credit losses, beginning balance	12,672	13,002	12,996	12,744
Provision for credit losses	(477)	(742)	(545)	(337)
Charge-offs		(54)	(257)	(233)
Recoveries	1	1	2	33
Net charge-offs	1	(53)	(255)	(200)
Allowance for credit losses, ending balance	12,196	12,207	12,196	12,207
Allowance for credit losses related to:
Allowance for credit losses, individually evaluated for impairment					13	262	292
Allowance for credit losses, collectively evaluated for impairment					12,183	12,734	11,915
Total allowance for credit losses	12,672	13,002	12,196	12,207	12,196	12,996	12,207
Recorded investment in loans:
Loans, individually evaluated for impairment					12,889	15,377	15,623
Loans, collectively evaluated for impairment					3,127,974	3,098,076	2,959,065
PCI loans					17,706	17,630	18,038
Total loans evaluated for impairment					3,158,569	3,131,083	2,992,726
Commercial and Industrial [Member]
Allowance for credit losses:
Allowance for credit losses, beginning balance	36,254	29,205	33,409	30,002
Provision for credit losses	1,753	8,507	13,103	8,186
Charge-offs	(24)	(4,865)	(10,641)	(5,691)
Recoveries	131	439	2,243	789
Net charge-offs	107	(4,426)	(8,398)	(4,902)
Allowance for credit losses, ending balance	38,114	33,286	38,114	33,286
Allowance for credit losses related to:
Allowance for credit losses, individually evaluated for impairment					5,330	7,082	6,550
Allowance for credit losses, collectively evaluated for impairment					32,560	25,491	26,474
Allowance for credit losses, PCI loans					224	836	262
Total allowance for credit losses	36,254	29,205	38,114	33,286	38,114	33,409	33,286
Recorded investment in loans:
Loans, individually evaluated for impairment					24,261	15,948	20,480
Loans, collectively evaluated for impairment					1,509,663	1,660,686	1,612,067
PCI loans					8,135	15,612	16,285
Total loans evaluated for impairment					1,542,059	1,692,246	1,648,832
Consumer and Other [Member]
Allowance for credit losses:
Allowance for credit losses, beginning balance	1,653	1,492	1,361	2,092
Provision for credit losses	675	516	3,716	735
Charge-offs	(946)	(933)	(4,371)	(2,406)
Recoveries	232	376	908	1,030
Net charge-offs	(714)	(557)	(3,463)	(1,376)
Allowance for credit losses, ending balance	1,614	1,451	1,614	1,451
Allowance for credit losses related to:
Allowance for credit losses, individually evaluated for impairment					46	44	43
Allowance for credit losses, collectively evaluated for impairment					1,568	1,317	1,408
Total allowance for credit losses	$ 1,653	$ 1,492	$ 1,614	$ 1,451	1,614	1,361	1,451
Recorded investment in loans:
Loans, individually evaluated for impairment					163	239	264
Loans, collectively evaluated for impairment					270,171	252,340	275,033
Total loans evaluated for impairment					$ 270,334	$ 252,579	$ 275,297

Loans and Allowance for Credi49

Loans and Allowance for Credit Losses - Allowance for Credit Losses by Category of Loan (Details) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	$ 29,457	$ 23,933
1-4 Family Residential (Includes Home Equity) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	$ 29,500	$ 23,900	$ 12,600

Loans and Allowance for Credi50

Loans and Allowance for Credit Losses - Troubled Debt Restructurings (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)contract	Sep. 30, 2015USD ($)contract
Financing Receivable Modifications [Line Items]
Troubled debt restructurings, number of loans | contract	1	2
Troubled debt restructurings, pre-modification outstanding recorded investment	$ 154	$ 400
Troubled debt restructurings, post-modification outstanding recorded investment	$ 152	$ 316
Construction, Land Development and Other Land Loans [Member]
Financing Receivable Modifications [Line Items]
Troubled debt restructurings, number of loans | contract		1
Troubled debt restructurings, pre-modification outstanding recorded investment		$ 390
Troubled debt restructurings, post-modification outstanding recorded investment		$ 307
Agriculture and Agriculture Real Estate (Includes Farmland) [Member]
Financing Receivable Modifications [Line Items]
Troubled debt restructurings, number of loans | contract	1
Troubled debt restructurings, pre-modification outstanding recorded investment	$ 154
Troubled debt restructurings, post-modification outstanding recorded investment	$ 152
Consumer and Other [Member]
Financing Receivable Modifications [Line Items]
Troubled debt restructurings, number of loans | contract		1
Troubled debt restructurings, pre-modification outstanding recorded investment		$ 10
Troubled debt restructurings, post-modification outstanding recorded investment		$ 9

Fair Value - Fair Value Assets

Fair Value - Fair Value Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available for sale securities:
Available for sale securities, at fair value	$ 129,677	$ 103,064
Fair Value, Measurements, Recurring [Member]
Available for sale securities:
Available for sale securities, at fair value	129,677	103,064
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Available for sale securities:
Available for sale securities, at fair value	12,795	12,692
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Available for sale securities:
Available for sale securities, at fair value	116,882	90,372
Fair Value, Measurements, Recurring [Member] | States and Political Subdivisions [Member]
Available for sale securities:
Available for sale securities, at fair value	2,580	5,485
Fair Value, Measurements, Recurring [Member] | States and Political Subdivisions [Member] | Level 2 [Member]
Available for sale securities:
Available for sale securities, at fair value	2,580	5,485
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member]
Available for sale securities:
Available for sale securities, at fair value	21,133	25,916
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member] | Level 2 [Member]
Available for sale securities:
Available for sale securities, at fair value	21,133	25,916
Fair Value, Measurements, Recurring [Member] | Mortgage-backed Securities [Member]
Available for sale securities:
Available for sale securities, at fair value	93,169	58,971
Fair Value, Measurements, Recurring [Member] | Mortgage-backed Securities [Member] | Level 2 [Member]
Available for sale securities:
Available for sale securities, at fair value	93,169	58,971
Fair Value, Measurements, Recurring [Member] | Other Securities [Member]
Available for sale securities:
Available for sale securities, at fair value	12,795	12,692
Fair Value, Measurements, Recurring [Member] | Other Securities [Member] | Level 1 [Member]
Available for sale securities:
Available for sale securities, at fair value	$ 12,795	$ 12,692

Fair Value (Details Textual)

Fair Value (Details Textual) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Other real estate, additions	$ 727	$ 14,600
Real estate owned outstanding	727	14,400
Additions to impaired loans	15,000	38,900
Impaired loans outstanding	$ 15,000	$ 31,500

Fair Value - Financial Instrume

Fair Value - Financial Instruments Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets
Cash and due from banks	$ 341,483	$ 562,544
Federal funds sold	630	1,418
Held to Maturity securities	9,020,897	9,393,175
Loans held for sale	29,457	23,933
Other real estate owned	16,280	2,963
Liabilities
Noninterest-bearing	5,159,333	5,136,579
Interest-bearing	11,762,076	12,544,540
Other borrowings	425,916	491,399
Securities sold under repurchase agreements	318,449	315,253
Carrying Amount [Member]
Assets
Cash and due from banks	341,483	562,544
Federal funds sold	630	1,418
Held to Maturity securities	8,858,344	9,399,363
Loans held for sale	29,457	23,933
Loans held for investment, net of allowance	9,433,272	9,333,272
Other real estate owned	16,280	2,963
Liabilities
Noninterest-bearing	5,159,333	5,136,579
Interest-bearing	11,762,076	12,544,540
Other borrowings	425,916	491,399
Securities sold under repurchase agreements	318,449	315,253
Estimated Fair Value [Member]
Assets
Cash and due from banks	341,483	562,544
Federal funds sold	630	1,418
Held to Maturity securities	9,020,897	9,393,175
Loans held for sale	29,457	23,933
Loans held for investment, net of allowance	9,448,097	9,365,758
Other real estate owned	16,280	2,963
Liabilities
Noninterest-bearing	5,159,333	5,136,579
Interest-bearing	11,766,996	12,548,050
Other borrowings	426,455	492,061
Securities sold under repurchase agreements	318,452	315,241
Estimated Fair Value [Member] | Level 1 [Member]
Assets
Cash and due from banks	341,483	562,544
Federal funds sold	630	1,418
Estimated Fair Value [Member] | Level 2 [Member]
Assets
Held to Maturity securities	9,020,897	9,393,175
Loans held for sale	29,457	23,933
Other real estate owned	16,280	2,963
Liabilities
Noninterest-bearing	5,159,333	5,136,579
Interest-bearing	11,766,996	12,548,050
Other borrowings	426,455	492,061
Securities sold under repurchase agreements	318,452	315,241
Estimated Fair Value [Member] | Level 3 [Member]
Assets
Loans held for investment, net of allowance	$ 9,448,097	$ 9,365,758

Goodwill and Core Deposit Int54

Goodwill and Core Deposit Intangibles - Goodwill and Core Deposit Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Schedule Of Intangible Assets And Goodwill [Line Items]
Goodwill, Beginning balance			$ 1,868,827	$ 1,874,191	$ 1,874,191
Goodwill, Acquisition of Tradition Bancshares, Inc.			31,522
Goodwill, Measurement period adjustments					(5,364)
Goodwill, Ending balance	$ 1,900,349		1,900,349		1,868,827
Core Deposit Intangibles, Beginning balance			49,417
Core Deposit Intangibles, Amortization	(2,418)	$ (2,356)	(6,974)	(7,235)
Core Deposit Intangibles, Ending balance	48,010		48,010		49,417
Core Deposit Intangibles [Member]
Schedule Of Intangible Assets And Goodwill [Line Items]
Core Deposit Intangibles, Beginning balance			49,417	58,947	58,947
Core Deposit Intangibles, Amortization	(2,418)	$ (2,356)	(6,974)	$ (7,235)	(9,530)
Core Deposit Intangibles, Ending balance	$ 48,010		48,010		$ 49,417
Core Deposit Intangibles, Acquisition of Tradition Bancshares, Inc.			$ 5,567

Goodwill and Core Deposit Int55

Goodwill and Core Deposit Intangibles - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Schedule Of Intangible Assets And Goodwill [Line Items]
Amortization expense related to intangible assets	$ 2,418,000	$ 2,356,000	$ 6,974,000	$ 7,235,000
Core Deposit Intangibles [Member]
Schedule Of Intangible Assets And Goodwill [Line Items]
Impairment recorded on goodwill and core deposit intangibles			0
Amortization expense related to intangible assets	$ 2,418,000	$ 2,356,000	$ 6,974,000	$ 7,235,000	$ 9,530,000
Core Deposit Intangibles [Member] | Minimum [Member]
Schedule Of Intangible Assets And Goodwill [Line Items]
Finite-lived intangible assets, useful life			10 years
Core Deposit Intangibles [Member] | Maximum [Member]
Schedule Of Intangible Assets And Goodwill [Line Items]
Finite-lived intangible assets, useful life			15 years

Goodwill and Core Deposit Int56

Goodwill and Core Deposit Intangibles - Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Remaining 2,016	$ 2,226
2,017	6,942
2,018	5,959
2,019	5,051
2,020	4,483
Thereafter	23,349
Total	$ 48,010	$ 49,417

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)Planshares	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)Planshares	Sep. 30, 2015USD ($)	Dec. 31, 2012shares	Dec. 31, 2004shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Stock-Based Employee Compensation Plans | Plan	2		2
Number of Stock-Based Employee Compensation Plans Expired | Plan	1		1
Proceeds from stock option exercises | $	$ 469	$ 155	$ 667	$ 223
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options | $	0	$ 0	0	$ 0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 19,400		$ 19,400
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			1 year 7 months 6 days
2004 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized						1,250,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	0		0
2012 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized					1,250,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			327,801

Contractual Obligations and O58

Contractual Obligations and Off-Balance Sheet Items - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
To be Paid Over Future Periods [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
Interest Expense, Federal Home Loan Bank and Federal Reserve Bank Advances, Long-term	$ 760

Contractual Obligations and O59

Contractual Obligations and Off-Balance Sheet Items - Contractual Obligations and Other Commitments (Details) $ in Thousands	Sep. 30, 2016USD ($)
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	$ 426,604
More than 1 year but less than 3 years	13,022
3 years or more but less than 5 years	5,582
5 years or more	7,219
Total	452,427
Federal Home Loan Bank Advances [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	420,871
More than 1 year but less than 3 years	4,916
3 years or more but less than 5 years	659
5 years or more	230
Total	426,676
Operating Leases [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	5,733
More than 1 year but less than 3 years	8,106
3 years or more but less than 5 years	4,923
5 years or more	6,989
Total	$ 25,751

Contractual Obligations and O60

Contractual Obligations and Off-Balance Sheet Items - Letters of Credit and Commitments (Details) $ in Thousands	Sep. 30, 2016USD ($)
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	$ 426,604
More than 1 year but less than 3 years	13,022
3 years or more but less than 5 years	5,582
5 years or more	7,219
Total	452,427
Guarantee Obligations [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	1,081,752
More than 1 year but less than 3 years	321,449
3 years or more but less than 5 years	83,484
5 years or more	568,628
Total	2,055,313
Guarantee Obligations [Member] | Financial Guarantee [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	1,018,584
More than 1 year but less than 3 years	314,222
3 years or more but less than 5 years	83,258
5 years or more	568,608
Total	1,984,672
Guarantee Obligations [Member] | Standby Letters of Credit [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	63,168
More than 1 year but less than 3 years	7,227
3 years or more but less than 5 years	226
5 years or more	20
Total	$ 70,641

Other Comprehensive (Loss) In61

Other Comprehensive (Loss) Income - Tax Effects Allocated to Each Component of Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity [Abstract]
Change in unrealized gain during period, before tax	$ (186)	$ (867)	$ (828)	$ (1,949)
Change in unrealized gain during period, tax	65	303	290	682
Change in unrealized gain during period, net of tax	(121)	(564)	(538)	(1,267)
Total securities available for sale, before tax	(186)	(867)	(828)	(1,949)
Total securities available for sale, tax	65	303	290	682
Total securities available for sale, net of tax	(121)	(564)	(538)	(1,267)
Total other comprehensive loss	(186)	(867)	(828)	(1,949)
Total other comprehensive loss, tax	65	303	290	682
Other comprehensive loss, net of tax	$ (121)	$ (564)	$ (538)	$ (1,267)

Other Comprehensive (Loss) In62

Other Comprehensive (Loss) Income - Activity in Accumulated Other Comprehensive Income Associated with Securities Available for Sale, Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Beginning balance, accumulated other comprehensive income			$ 2,040	$ 3,729
Other comprehensive loss	$ (121)	$ (564)	(538)	(1,267)
Ending balance, accumulated other comprehensive income	1,502	2,462	1,502	2,462
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Beginning balance, accumulated other comprehensive income			2,040	3,729
Other comprehensive loss			(538)	(1,267)
Ending balance, accumulated other comprehensive income	$ 1,502	$ 2,462	$ 1,502	$ 2,462

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) $ / shares in Units, $ in Thousands	Jan. 02, 2016USD ($)Officeshares	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2014USD ($)
Business Acquisition [Line Items]
Goodwill		$ 1,900,349	$ 1,868,827	$ 1,874,191
Tradition Bancshares Inc [Member]
Business Acquisition [Line Items]
Business acquisition, equity interest issued or issuable, number of Shares | shares	679,528
Payments to acquire businesses, gross	$ 39,000
Business combination, consideration transferred	$ 71,500
Business acquisition, share price | $ / shares			$ 47.86
Goodwill		$ 31,500
Tradition Bancshares Inc [Member] | Houston [Member]
Business Acquisition [Line Items]
Number of operating banking offices | Office	7
Tradition Bancshares Inc [Member] | Katy [Member]
Business Acquisition [Line Items]
Number of operating banking offices | Office	3
Tradition Bancshares Inc [Member] | The Woodlands [Member]
Business Acquisition [Line Items]
Number of operating banking offices | Office	1