BancFirst (BANF) 10-K 7 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 31, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	BANF
Entity Registrant Name	BANCFIRST CORP /OK/
Entity Central Index Key	760,498
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		15,862,644
Entity Public Float			$ 476,810,720

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Cash and due from banks	$ 183,921	$ 203,364
Interest-bearing deposits with banks	1,666,540	1,394,813
Federal funds sold	700
Securities (fair value: $469,871 and $553,010, respectively)	469,833	552,949
Loans held for sale	9,318	13,725
Loans (net of unearned interest)	4,400,232	4,232,048
Allowance for loan losses	(48,693)	(41,666)
Loans, net of allowance for loan losses	4,351,539	4,190,382
Premises and equipment, net	126,771	126,813
Other real estate owned	3,526	7,984
Intangible assets, net	13,330	15,695
Goodwill	54,042	54,042
Accrued interest receivable and other assets	139,432	133,062
Total assets	7,018,952	6,692,829
Deposits:
Noninterest-bearing	2,526,842	2,409,769
Interest-bearing	3,721,215	3,563,589
Total deposits	6,248,057	5,973,358
Short-term borrowings	500	500
Accrued interest payable and other liabilities	27,342	31,502
Junior subordinated debentures	31,959	31,959
Total liabilities	6,307,858	6,037,319
Commitments and contingent liabilities (Note 19)
Stockholders' equity:
Common stock, $1.00 par, 20,000,000 shares authorized; shares issued and outstanding: 15,810,935 and 15,597,446, respectively	15,811	15,597
Capital surplus	117,541	102,865
Retained earnings	577,648	535,521
Accumulated other comprehensive income, net of income tax of $59 and $962, respectively	94	1,527
Total stockholders' equity	711,094	655,510
Total liabilities and stockholders' equity	7,018,952	6,692,829
Senior Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value
Cumulative Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Securities, fair value	$ 469,871	$ 553,010
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	15,810,935	15,597,446
Common stock, shares outstanding	15,810,935	15,597,446
Accumulated other comprehensive income, tax	$ 59	$ 962
Senior Preferred Stock [Member]
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Cumulative Preferred Stock [Member]
Preferred stock, par value	$ 5	$ 5
Preferred stock, shares authorized	900,000	900,000
Preferred stock, shares issued	0	0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INTEREST INCOME
Loans, including fees	$ 204,467	$ 190,292	$ 182,972
Securities:
Taxable	5,229	5,492	5,727
Tax-exempt	964	982	1,061
Federal funds sold	1	14	2
Interest-bearing deposits with banks	7,908	4,265	4,391
Total interest income	218,569	201,045	194,153
INTEREST EXPENSE
Deposits	12,638	10,251	10,795
Short-term borrowings	7	4	16
Long-term borrowings		32	25
Junior subordinated debentures	2,096	1,966	1,966
Total interest expense	14,741	12,253	12,802
Net interest income	203,828	188,792	181,351
Provision for loan losses	11,519	7,675	3,072
Net interest income after provision for loan losses	192,309	181,117	178,279
NONINTEREST INCOME
Trust revenue	10,630	9,091	9,180
Service charges on deposits	62,233	57,651	56,389
Securities transactions (includes accumulated other comprehensive income reclassifications of $15, $3,814 and $533, respectively)	(59)	9,269	1,641
Income from sales of loans	2,825	1,968	1,813
Insurance commissions	15,559	14,791	14,642
Cash management	10,616	7,510	6,741
Gain on sale of other assets	46	79	335
Other	5,182	5,449	5,672
Total noninterest income	107,032	105,808	96,413
NONINTEREST EXPENSE
Salaries and employee benefits	119,662	113,083	108,640
Occupancy, net	12,313	11,512	11,610
Depreciation	10,114	9,966	9,595
Amortization of intangible assets	2,269	1,935	1,754
Data processing services	4,796	4,579	4,689
Net (income) expense from other real estate owned	(747)	324	511
Marketing and business promotion	7,236	6,986	7,024
Deposit insurance	2,904	3,358	3,291
Other	32,857	33,972	36,407
Total noninterest expense	191,404	185,715	183,521
Income before taxes	107,937	101,210	91,171
Income tax expense	37,263	35,040	27,284
Net income	$ 70,674	$ 66,170	$ 63,887
NET INCOME PER COMMON SHARE
Basic	$ 4.53	$ 4.25	$ 4.14
Diluted	$ 4.44	$ 4.17	$ 4.04
OTHER COMPREHENSIVE INCOME
Reclassification adjustment for gains included in net income, net of tax of $6, $1,475 and $206, respectively	$ (9)	$ (2,339)	$ (327)
Unrealized (losses) gains on securities, net of tax of $897, $207 and $(747), respectively	(1,424)	(327)	613
Other comprehensive (loss) gain, net of tax of $903, $1,682 and $(541), respectively	(1,433)	(2,666)	286
Comprehensive income	$ 69,241	$ 63,504	$ 64,173

Consolidated Statements of Com5

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Securities transactions accumulated other comprehensive income reclassifications	$ 15	$ 3,814	$ 533
Unrealized gains (losses) on securities, tax	897	207	(747)
Reclassification adjustment for gains included in net income, tax	6	1,475	206
Other comprehensive gain (loss), tax	$ 903	$ 1,682	$ (541)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	COMMON STOCK [Member]	CAPITAL SURPLUS [Member]	RETAINED EARNINGS [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME [Member]
Balance at beginning of period at Dec. 31, 2013		$ 15,334	$ 88,803	$ 448,953	$ 3,907
Balance at beginning of period, Shares at Dec. 31, 2013		15,333,622
Shares issued, Value		$ 170	4,742
Shares issued, Shares		170,891
Net income	$ 63,887			63,887
Other comprehensive (loss) gain, net of tax of $903, $1,682 and $(541), respectively	286				286
Tax effect of stock options			1,620
Dividends on common stock				(20,064)
Stock-based compensation arrangements			1,676
Balance at end of period at Dec. 31, 2014	$ 609,314	$ 15,504	96,841	492,776	4,193
Balance at end of period, Shares at Dec. 31, 2014	15,504,513	15,504,513
Shares issued, Value		$ 121	3,116
Shares issued, Shares		121,380
Net income	$ 66,170			66,170
Other comprehensive (loss) gain, net of tax of $903, $1,682 and $(541), respectively	(2,666)				(2,666)
Tax effect of stock options			1,191
Dividends on common stock				(21,799)
Stock-based compensation arrangements			1,717
Shares acquired and canceled, Value		$ (28)		(1,626)
Shares acquired and canceled, Shares		(28,447)
Balance at end of period at Dec. 31, 2015	$ 655,510	$ 15,597	102,865	535,521	1,527
Balance at end of period, Shares at Dec. 31, 2015	15,597,446	15,597,446
Shares issued, Value		$ 314	9,519
Shares issued, Shares		313,489
Net income	$ 70,674			70,674
Other comprehensive (loss) gain, net of tax of $903, $1,682 and $(541), respectively	(1,433)				(1,433)
Tax effect of stock options			3,521
Dividends on common stock				(23,124)
Stock-based compensation arrangements			1,636
Shares acquired and canceled, Value		$ (100)		(5,423)
Shares acquired and canceled, Shares		(100,000)
Balance at end of period at Dec. 31, 2016	$ 711,094	$ 15,811	$ 117,541	$ 577,648	$ 94
Balance at end of period, Shares at Dec. 31, 2016	15,810,935	15,810,935

Consolidated Statements of Sto7

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
RETAINED EARNINGS [Member]
Dividend on common stock	$ 1.48	$ 1.40	$ 1.30

Consolidated Statements of Cash

Consolidated Statements of Cash Flow $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 70,674	$ 66,170	$ 63,887
Adjustments to reconcile to net cash provided by operating activities:
Provision for loan losses	11,519	7,675	3,072
Depreciation and amortization	12,383	11,901	11,349
Net amortization of securities premiums and discounts	128	1,020	910
Realized securities losses (gains)	59	(9,269)	(1,641)
Gain on sales of loans	(2,825)	(1,968)	(1,813)
Cash receipts from the sale of loans originated for sale	189,620	171,723	152,440
Cash disbursements for loans originated for sale	(182,425)	(174,047)	(153,592)
Deferred income tax benefit	(2,048)	(1,903)	(3,683)
Gain on other assets	(1,252)	(65)	(760)
Increase in interest receivable	(1,497)	(991)	(309)
Increase/(decrease) in interest payable	69	(105)	(333)
Amortization of stock-based compensation arrangements	1,636	1,717	1,676
Other, net	(5,500)	6,301	5,719
Net cash provided by operating activities	90,541	78,159	76,922
INVESTING ACTIVITIES
Net cash and due from banks (paid for) received from acquisitions		(4,007)	174,283
Net (increase)/decrease in federal funds sold	(700)	13,256	4,619
Purchases of held for investment securities	(838)	(1,771)	(708)
Purchases of available for sale securities	(224,655)	(91,136)	(224,217)
Proceeds from maturities, calls and paydowns of held for investment securities	5,260	2,103	4,101
Proceeds from maturities, calls and paydowns of available for sale securities	300,345	55,689	225,394
Proceeds from sales of available for sale securities	481	10,850	4,855
Net change in loans	(176,594)	(243,976)	(366,064)
Purchases of premises, equipment and computer software	(10,835)	(11,263)	(11,490)
Proceeds from the sale of other real estate owned and other assets	9,519	4,957	5,851
Net cash used in investing activities	(98,017)	(265,298)	(183,376)
FINANCING ACTIVITIES
Net change in deposits	274,699	(106,422)	183,371
Net change in short-term borrowings		(3,482)	(608)
Paydown of long-term borrowings			(6,938)
Issuance of common stock, net	13,354	4,428	6,532
Common stock acquired	(5,523)	(1,654)
Cash dividends paid	(22,770)	(21,449)	(19,543)
Net cash provided by (used in) financing activities	259,760	(128,579)	162,814
Net increase/(decrease) in cash, due from banks and interest-bearing deposits	252,284	(315,718)	56,360
Cash, due from banks and interest-bearing deposits at the beginning of the period	1,598,177	1,913,895	1,857,535
Cash, due from banks and interest-bearing deposits at the end of the period	1,850,461	1,598,177	1,913,895
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	14,673	12,255	13,135
Cash paid during the period for income taxes	32,700	33,531	26,178
Noncash investing and financing activities:
Unpaid common stock dividends declared	$ 5,969	$ 5,615	$ 5,265

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	(1) DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The accounting and reporting policies of BancFirst Corporation and its subsidiaries (the “Company”) conform to accounting principles generally accepted in the United States of America (U.S. GAAP) and general practice within the banking industry. A summary of the significant accounting policies follows. Nature of Operations BancFirst Corporation is an Oklahoma business corporation and a financial holding company under federal law. It conducts virtually all of its operating activities through its principal wholly-owned subsidiary, BancFirst (the “Bank” or “BancFirst”), a state-chartered bank headquartered in Oklahoma City, Oklahoma. The Bank provides a wide range of retail and commercial banking services, including: commercial, real estate, agricultural and consumer lending; depository and funds transfer services; collections; safe deposit boxes; cash management services; retail brokerage services; and other services tailored for both individual and corporate customers. The Bank also offers trust services and acts as executor, administrator, trustee, transfer agent and in various other fiduciary capacities. Through its Technology and Operations Center, the Bank provides item processing, research and other correspondent banking services to financial institutions and governmental units. The Company’s wholly-owned subsidiary, BancFirst Insurance Services, Inc., an independent insurance agency, offers a variety of commercial and personal insurance products. In addition, the Company’s wholly-owned subsidiary, Council Oak Partners, LLC, an Oklahoma limited liability company, engages in investing activities. Basis of Presentation The accompanying consolidated financial statements include the accounts of BancFirst Corporation, Council Oak Partners, LLC, BancFirst Insurance Services, Inc. and BancFirst and its subsidiaries. The principal operating subsidiaries of BancFirst are Council Oak Investment Corporation, Council Oak Real Estate Inc. and BancFirst Agency, Inc. All significant intercompany accounts and transactions have been eliminated. Assets held in a fiduciary or agency capacity are not assets of the Company and, accordingly, are not included in the consolidated financial statements. Certain amounts from 2015 and 2014 have been reclassified to conform to the 2016 presentation. These reclassifications were not material to the Company’s financial statements. Use of Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States inherently involves the use of estimates and assumptions that affect the amounts reported in the financial statements and the related disclosures. These estimates relate principally to the determination of the allowance for loan losses, income taxes, the fair value of financial instruments and the valuation of intangibles. Such estimates and assumptions may change over time and actual amounts realized may differ from those reported. Securities The Company does not engage in securities trading activities. Any sales of securities are for the purpose of executing the Company’s asset/liability management strategy, eliminating a perceived credit risk in a specific security or providing liquidity. Securities that are being held for indefinite periods of time, or that may be sold as part of the Company’s asset/liability management strategy, to provide liquidity or for other reasons, are classified as available for sale and are stated at estimated fair value. Unrealized gains or losses on securities available for sale are reported as a component of stockholders’ equity, net of income tax. Gains or losses from sales of securities are based upon the book values of the specific securities sold. Securities for which the Company has the intent and ability to hold to maturity are classified as held for investment and are stated at cost, adjusted for amortization of premiums and accretion of discounts computed under the interest method. The Company reviews its portfolio of securities for impairment at least quarterly. Impairment is considered to be other-than-temporary if it is likely that all amounts contractually due will not be received for debt securities and when there is no positive evidence indicating that an investment’s carrying amount is recoverable in the near term for equity securities. When impairment is considered other-than-temporary, the cost basis of the security is written down to fair value, with the impairment charge included in earnings. In evaluating whether the impairment is temporary or other-than-temporary, the Company considers, among other things, the time period the security has been in an unrealized loss position, and whether the Company has the intent and ability to hold a security for a period of time sufficient to allow for any anticipated recovery in fair value. Loans The lending function is governed by written policies and procedures, as determined by senior management and approved by the Board of Directors. The policies and procedures set the standards for lending in each major loan category by collateral type and use of loan proceeds. The objectives of these policies and procedures are to identify profitable markets, determine appropriate risk tolerance levels for each type of loan, establish limits for loan officer approval, set concentration limits, establish loan-to-value thresholds, set repayment terms and loan structure guidelines and adhere to documentation requirements. Interest rate risk is controlled by the use of variable rate provisions, approximately 50% of which have a rate floor, limits on fixing rates for longer periods and the use of prepayment penalties. One-to-four family residential real estate loans are made in accordance with underwriting policies and are fully documented. Credit worthiness is assessed based on significant credit characteristics including credit history and residential and employment stability. These loans include first liens, junior liens and home equity lines of credit. The composition of this portfolio is primarily first liens, which comprise more than 82% of the portfolio, with junior liens comprising less than 10%, and home equity lines of credit comprising less than 8%. The Company does not engage in any hybrid loan programs. In addition, the Company does not have any exposure to loans with negative amortization, interest rate carryover or discounting of the initial rates (teaser rates). Loans originated within the Company are stated at the principal amount outstanding, net of unearned interest, loan fees and allowance for loan losses. Interest on all performing loans is recognized, on a simple interest basis, based upon the principal amount outstanding. A loan is placed on nonaccrual status when, in the opinion of management, the future collectability of interest and/or principal is not probable. When interest accrual is discontinued, all unpaid accrued interest is reversed. Interest income is recognized on certain of these loans on a cash basis if the full collection of the remaining principal balance is reasonably expected. Otherwise, interest income is not recognized until the principal balance is fully collected. See Note (5) for loan disclosures. Acquired Loans Loans acquired through business combinations since December 2009 are required to be carried at fair value as of the date of the combination. Loans that would have a general allowance for loan losses or have specific evidence of deterioration of credit quality since origination are adjusted to fair value and any allowance for loan losses is eliminated. The difference between the fair value of loans which do not have specific evidence of deterioration of credit quality since origination and their principal balance is recognized in interest income on a level-yield method over the life of the loans. For loans which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments (as determined by the present value of expected future cash flows), the difference between the undiscounted cash flows expected at acquisition and the investment in the loan, or the “accretable yield,” is recognized in interest income on a level-yield method over the life of the loan. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as yield adjustments or as loss accruals or valuation allowances. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loan over its remaining life. Decreases in expected cash flows are recognized as impairments. Any probable loss due to subsequent credit deterioration of the loans since acquisition is provided for in the allowance for loan losses. Loans Held For Sale The Company originates mortgage loans to be sold. At the time of origination, the acquiring bank has already been determined and the terms of the loan, including the interest rate, have already been set by the acquiring bank allowing the Company to originate the loan at fair value. Mortgage loans are generally sold within 30 days of origination. Loans held for sale are carried at the lower of cost or market. Gains or losses recognized upon the sale of the loans are determined on a specific identification basis. The Company does not sell residential mortgage loans with recourse other than obligations under standard representations and warranties or for fraud. These obligations relate to loan performance for the life of the loan. The amount of loans repurchased since the inception of the program is not considered to be material, and therefore, no reserve has been required. Allowance for Loan Losses The allowance for loan losses is an estimate of probable credit losses related to specifically identified loans and for losses inherent in the portfolio that have been incurred as of the balance sheet date. The allowance for loan losses is increased by provisions charged to operating expense and is reduced by net loan charge-offs. The amount of the allowance for loan losses is based on past loan loss experience, evaluations of known impaired loans, levels of adversely graded loans, general economic conditions and other environmental factors. 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 aggregate for smaller-balance loans of a similar nature and on an individual loan basis for other loans. If a loan is impaired, a specific allowance is provided, 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 primarily 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. Appraisal Policy An updated appraisal of the collateral is obtained when a loan is first identified as a problem loan. Appraisals are reviewed annually and are updated as needed, or are updated more frequently if significant changes are believed to have occurred in the collateral or market conditions. Appraisals of other real estate owned are also reviewed and updated consistent with this policy. Nonaccrual Policy The Company does not accrue interest on (1) any loan upon which a default of principal or interest has existed for a period of 90 days or over unless the collateral margin or guarantor support are such that full collection of principal and interest are not in doubt, and an orderly plan for collection is in process; and (2) any other loan for which it is expected full collection of principal and interest is not probable. A nonaccrual loan may be restored to an accrual status when none of its principal and interest are past due and unpaid or otherwise becomes well secured and in the process of collection and when prospects for collection of future contractual payments are no longer in doubt. With the exception of a formal debt forgiveness agreement, no loan which has had principal charged-off shall be restored to accrual status unless the charged-off principal has been recovered. Charge-off Policy When a loan deteriorates to the point that the account officer or the Loan Committee concludes it no longer represents a viable asset, it will be charged off. Similarly, any portion of a loan that is deemed to no longer be a viable asset will be charged off. A loan will not be charged off unless such action has been approved by the branch President. Premises and Equipment Premises and equipment are stated at cost, less accumulated depreciation. Depreciation is charged to operating expense and is computed using the straight-line method over the estimated useful lives of the assets. Maintenance and repairs are charged to expense as incurred while improvements are capitalized. Premises and equipment is tested for impairment if events or changes in circumstances occur that indicate that the carrying amount of any premises and equipment may not be recoverable. Impairment losses are measured by comparing the fair values of the premises and equipment with their recorded amounts. Premises that are identified to be sold are transferred to other real estate owned at the lower of their carrying amounts or their fair values less estimated costs to sell. Any losses on premises identified to be sold are charged to operating expense. When premises and equipment are transferred to other real estate owned, sold, or otherwise retired, the cost and applicable accumulated depreciation are removed from the respective accounts and any resulting gains or losses are reported in the statement of comprehensive income. Other Real Estate Owned Other real estate owned consists of properties acquired through foreclosure proceedings or acceptance of a deed in lieu of foreclosure, and premises held for sale. These properties are carried at the lower of the book values of the related loans or fair values based upon appraisals, less estimated costs to sell. Losses arising at the time of reclassification of such properties from loans to other real estate owned are charged directly to the allowance for loan losses. Any losses on premises identified to be sold are charged to operating expense at the time of transfer from premises to other real estate owned. Losses from declines in value of the properties subsequent to classification as other real estate owned are charged to operating expense. During 2016, the Company had gains on the sale of other real estate owned totaling $1.2 million that is included in net expense (income) from other real estate owned in the consolidated statements of comprehensive income. Intangible Assets and Goodwill Core deposit intangibles are amortized on a straight-line basis over the estimated useful lives of seven to ten years and customer relationship intangibles are amortized on a straight-line basis over the estimated useful life of three to eighteen years. Mortgage servicing rights are amortized based on current prepayment assumptions. Goodwill is not amortized, but is evaluated at a reporting unit level at least annually for impairment, or more frequently if other indicators of impairment are present. At least annually in the fourth quarter, intangible assets, excluding mortgage servicing rights, are evaluated for possible impairment. Impairment losses are measured by comparing the fair values of the intangible assets with their recorded amounts. Any impairment losses are reported in the statement of comprehensive income. Mortgage servicing rights are adjusted to fair value semi-annually, if impaired. Derivatives The Company recognizes all of its derivative instruments as assets or liabilities in the balance sheet at fair value and recognizes the realized and unrealized change in fair value in the statement of comprehensive income. Income is derived from a fixed pricing spread when customer hedge contracts are immediately offset with counterparty contracts as compensation for administrative costs and credit risk and recognized in other noninterest income. Insurance Commissions and Fees Commission revenue is recognized at the later of the billing date or the effective date of the related insurance policies for those accounts billed by the Agency. Commission revenue, for accounts that are directly billed by the insurance company to the insured, is recognized when determinable by the Agency, which is generally when such commissions are received. The Agency also receives contingent commissions from insurance companies as additional incentive for achieving specified premium volume goals and/or loss experience parameters relating to the insurance placed by the Agency. Contingent commissions from insurance companies are recognized when determinable, which is generally when such commissions are received. Stock-based Compensation The Company recognizes stock-based compensation as compensation expense in the statement of comprehensive income based on the fair value of the Company’s stock options on the measurement date, which, for the Company, is the date of the grant. The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model and is based on certain assumptions including risk-free rate of return, dividend yield, stock price volatility and the expected term. The fair value of each option is expensed over its vesting period. Income Taxes The Company files a consolidated income tax return with its subsidiaries. Federal and state income tax expense or benefit has been allocated to subsidiaries on a separate return basis. Deferred taxes are recognized under the balance sheet method based upon the future tax consequences of temporary differences between the carrying amounts and tax basis of assets and liabilities, using the tax rates expected to apply to taxable income in the periods when the related temporary differences are expected to be realized. Realization of deferred tax assets is dependent upon the generation of a sufficient level of future taxable income and recoverable taxes paid in prior years. Although realization is not assured, management believes it is more likely than not that all of the deferred tax assets will be realized. Earnings Per Common Share Basic earnings per common share is computed by dividing net income, less any preferred dividends requirement, by the weighted average of common shares outstanding. Diluted earnings per common share reflects the potential dilution that could occur if options, convertible securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the Company. Comprehensive Income Comprehensive income includes all changes in stockholders’ equity during a period, except those resulting from transactions with stockholders. Besides net income, other components of the Company’s comprehensive income includes the after tax effect of changes in the net unrealized gain/loss on securities available for sale. Statement of Cash Flows For purposes of the statement of cash flows, the Company considers cash and due from banks and interest-bearing deposits with banks as cash equivalents. Recent Accounting Pronouncements In January 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2017-04, “Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” ASU 2017-04 removes the second step of goodwill testing. ASU 2017-04 will be effective on January 1, 2020 and is not expected to have a significant impact on the Company’s financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business.” ASU 2017-01 clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of a business. ASU 2017-01 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In October 2016, the FASB issued ASU No. 2016-17, “Consolidation (Topic 810): Interests Held Through Related Parties That Are Under Common Control.” ASU 2016-17 updates ASU No. 2015-02 to amend the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. ASU 2016-17 will be effective on January 1, 2017 and is not expected to have a significant impact on the Company’s financial statements. In October 2016, the FASB issued ASU No. 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” ASU 2016-16 provides guidance stating that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” ASU 2016-15 is intended to reduce the diversity in practice around how certain transactions are classified within the statement of cash flows. ASU 2016-15 will be effective on January 1, 2018. Early adoption is permitted with retrospective applications. The Company is currently evaluating the potential impact of ASU 2016-15 on its financial statements. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires a financial asset 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. ASU 2016-13 requires enhanced disclosures related to the significant estimates and judgements used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASU 2016-13 amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 will be effective on January 1, 2020. The Company is currently evaluating the potential impact of ASU 2016-13 on its financial statements. In March 2016, the FASB issued ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Under ASU 2016-09 all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. ASU 2016-09 also provides that an entity can make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest (current GAAP) or account for forfeitures when they occur. ASU 2016-09 changes the threshold to qualify for equity classification (rather than as a liability) to permit withholding up to the maximum statutory tax rates (rather than the minimum as was previously the case) in the applicable jurisdictions. ASU 2016-09 will be effective on January 1, 2017 and is not expected to have a significant impact on the Company’s financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases - (Topic 842).” ASU 2016-02 requires that lessees recognize on the balance sheet the assets and liabilities for the rights and obligations created by leases. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted. Adoption of ASU 2016-02 is not expected to have a significant impact on the Company’s financial statements. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments - Overall (Subtopic 825-10).” ASU 2016-01 require all 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 the fair value recognized through net income. In addition, the amendment will require 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. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. Early adoption is not permitted. Adoption of ASU 2016-01 is not expected to have a significant impact on the Company’s financial statements. In August 2014, the FASB issued ASU No. 2014-15, “Presentation of Financial Statements – Going Concern (Topic 205-40).” ASU 2014-15 provides guidance on management’s responsibility in evaluating whether there is substantial doubt about the Company’s ability to continue as a going concern and related footnote disclosures. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year from the date the financial statements are issued. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2016. Early adoption is permitted. Adoption of ASU 2014-15 is not expected to have a significant impact on the Company’s financial statements. In January of 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customer (Topic 606).” ASU 2014-09 implements a comprehensive new revenue recognition standard that will supersede substantially all existing revenue recognition guidance. The new standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in a manner that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, which comprises a significant portion of our revenue stream. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606).” ASU 2015-14 is an amendment to defer the effective date of ASU N. 2014-09. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted for the Company as of January 1, 2017. Adoption of ASU 2014-09 may require the Company to amend how it recognizes certain recurring revenue streams related to trust fees, which are recorded in non-interest expense; however, the Company does not expect the adoption of ASU 2014-09 to have a significant impact on the Company’s financial statements.

Recent Developments, Including

Recent Developments, Including Mergers and Acquisitions	12 Months Ended
	Dec. 31, 2016
Recent Developments Including Mergers And Acquisitions [Abstract]
Recent Developments, Including Mergers and Acquisitions	(2) RECENT DEVELOPMENTS, INCLUDING MERGERS AND ACQUISITIONS On October 8, 2015, the Company completed its acquisition of CSB Bancshares Inc. and its subsidiary bank, Bank of Commerce, with locations in Yukon, Mustang and El Reno, Oklahoma. Bank of Commerce had approximately $196 million in total assets, $147 million in loans, $175 million in deposits and $22 million in equity capital. The acquisition was accounted for under the acquisition method and the Company acquired 100% of the voting interest. Bank of Commerce operated as a subsidiary of BancFirst Corporation until it was merged into BancFirst on November 13, 2015. As a result of the acquisition, the Company recorded a core deposit intangible of approximately $7.1 million and goodwill of approximately $9.4 million. The effect of this acquisition was included in the consolidated financial statements of the Company from the date of acquisition forward. The acquisition did not have a material effect on the Company’s consolidated financial statements. The acquisition of CSB Bancshares Inc. and its subsidiary bank, Bank of Commerce complements the Company’s community banking strategy by adding two communities to its banking network in Oklahoma. On January 24, 2014, BancFirst assumed all of the deposits and purchased certain assets of The Bank of Union, El Reno, Oklahoma (“The Bank of Union”). The Bank of Union was closed on that day by the Oklahoma State Banking Department. At the time of the closing, The Bank of Union had total deposits of approximately $302 million that were assumed by BancFirst. BancFirst initially purchased approximately $121 million of loans, the majority of which were classified as performing, $4.8 million of securities, and $10,000 of other real estate. Its bid included a discount for the loans purchased. BancFirst had bid on, but was generally not awarded, loans that were classified as nonperforming. As a result of the acquisition, the Company recorded a core deposit intangible of approximately $2.2 million and goodwill of $417,000. The effect of this acquisition was included in the consolidated financial statements of the Company from the date of acquisition forward. The acquisition did not have a material effect on the Company’s consolidated financial statements.

Cash, Due from Banks, Interest-

Cash, Due from Banks, Interest-Bearing Deposits and Federal Funds Sold	12 Months Ended
	Dec. 31, 2016
Cash And Cash Equivalents [Abstract]
Cash, Due from Banks, Interest-Bearing Deposits and Federal Funds Sold	(3) CASH, DUE FROM BANKS, INTEREST-BEARING DEPOSITS AND FEDERAL FUNDS SOLD The Company maintains accounts with the Federal Reserve Bank and various other financial institutions primarily for the purpose of holding excess liquidity and clearing cash items. It may also sell federal funds to certain of these institutions on an overnight basis. At December 31, 2016 and 2015, the Company had no significant concentrations of credit risk with other financial institutions. The Company maintained vault cash and funds on deposit with the Federal Reserve Bank, which is included in the table below. The Company is required, as a matter of law, to maintain a reserve balance in the form of vault cash or cash on deposit with the Federal Reserve Bank. The average amount of required reserves for each of the years ended December 31, 2016 and 2015 is included in the following table: December 31, 2016 2015 (Dollars in thousands) Vault cash and funds on deposit with the Federal Reserve Bank $ 1,754,956 $ 1,499,137 Average required Reserves 41,968 40,093

Securities

Securities	12 Months Ended
	Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]
Securities	(4) SECURITIES The following table summarizes securities held for investment and securities available for sale: December 31, 2016 2015 (Dollars in thousands) Held for investment, at cost (fair value: $4,403 and $8,850, respectively) $ 4,365 $ 8,789 Available for sale, at fair value 465,468 544,160 Total $ 469,833 $ 552,949 The following table summarizes the amortized cost and estimated fair values of securities held for investment: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (Dollars in thousands) December 31, 2016 Mortgage backed securities (1) $ 252 $ 17 $ — $ 269 States and political subdivisions 3,613 25 (4 ) 3,634 Other securities 500 — — 500 Total $ 4,365 $ 42 $ (4 ) $ 4,403 December 31, 2015 Mortgage backed securities (1) $ 347 $ 25 $ — $ 372 States and political subdivisions 7,942 36 — 7,978 Other securities 500 — — 500 Total $ 8,789 $ 61 $ — $ 8,850 The following table summarizes the amortized cost and estimated fair values of securities available for sale: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (Dollars in thousands) December 31, 2016 U.S. treasuries $ 268,763 $ 700 $ (920 ) $ 268,543 U.S. federal agencies 129,674 373 (405 ) 129,642 Mortgage backed securities (1) 19,949 290 (567 ) 19,672 States and political subdivisions 40,335 836 (129 ) 41,042 Other securities (2) 6,594 125 (150 ) 6,569 Total $ 465,315 $ 2,324 $ (2,171 ) $ 465,468 December 31, 2015 U.S. treasuries $ 328,965 $ 776 $ (45 ) $ 329,696 U.S. federal agencies 131,522 527 (153 ) 131,896 Mortgage backed securities (1) 21,973 425 (543 ) 21,855 States and political subdivisions 49,521 1,447 (48 ) 50,920 Other securities (2) 9,689 249 (145 ) 9,793 Total $ 541,670 $ 3,424 $ (934 ) $ 544,160 (1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies. (2) Primarily consists of equity securities. The maturities of securities held for investment and available for sale are summarized in the following table using contractual maturities. Actual maturities may differ from contractual maturities due to obligations that are called or prepaid. For purposes of the maturity table, mortgage-backed securities, which are not due at a single maturity date, have been presented at their contractual maturity. December 31, 2016 2015 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 1,561 $ 1,568 $ 5,168 $ 5,174 After one year but within five years 1,937 1,951 2,800 2,829 After five years but within ten years 707 723 795 319 After ten years 160 161 26 528 Total $ 4,365 $ 4,403 $ 8,789 $ 8,850 Available for Sale Contractual maturity of debt securities: Within one year $ 66,542 $ 66,662 $ 272,820 $ 272,779 After one year but within five years 320,150 319,839 178,617 180,145 After five years but within ten years 5,830 6,152 8,483 9,075 After ten years 66,199 66,246 75,522 75,853 Total debt securities 458,721 458,899 535,442 537,852 Other securities 6,594 6,569 6,228 6,308 Total $ 465,315 $ 465,468 $ 541,670 $ 544,160 The following is a detail of proceeds from sales and realized securities gains and losses, on available for sale securities: Year Ended December 31, 2016 2015 2014 (Dollars Proceeds $ 481 $ 10,850 $ 4,855 Gross gains realized 227 9,394 1,641 Gross losses realized 286 125 — Realized gains/losses are reported as securities transactions within the noninterest income section of the consolidated statement of comprehensive income. During 2015 the realized gains were from the following transactions: Council Oak Investment Corporation, a wholly-owned subsidiary of BancFirst, recognized a pretax gain of approximately $1.7 million from the sale of one of its equity investments, Council Oak Partners, LLC, a wholly-owned subsidiary of the Company, recognized a pretax gain of approximately $5.2 million from the sale of one of its equity investments and the Company recorded a gain of $2.1 million related to the redemption of warrants associated with a past loan transaction. The following table is a summary of the Company’s book value of securities that were pledged as collateral for public funds on deposit, repurchase agreements and for other purposes as required or permitted by law: Year Ended December 31, 2016 2015 (Dollars Book value of pledged securities $ 439,692 $ 493,540 The following table summarizes securities with unrealized losses, segregated by the duration of the unrealized loss, at December 31, 2016 and 2015 respectively: 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) December 31, 2016 Held for Investment Mortgage backed securities $ 7 $ — $ 9 $ — $ 16 $ — States and political subdivisions 476 4 — — 476 4 Total $ 483 $ 4 $ 9 $ — $ 492 $ 4 Available for Sale U.S. treasuries $ 103,705 $ 920 $ — $ — $ 103,705 $ 920 U.S. federal agencies 71,511 357 9,619 48 81,130 405 Mortgage backed securities 3 — 14,834 567 14,837 567 States and political subdivisions 15,289 62 779 67 16,068 129 Other securities — — 589 150 589 150 Total $ 190,508 $ 1,339 $ 25,821 $ 832 $ 216,329 $ 2,171 December 31, 2015 Held for Investment Mortgage backed securities $ 21 $ — $ — $ — $ 21 $ — States and political subdivisions — — — — — — Total $ 21 $ — $ — $ — $ 21 $ — Available for Sale U.S. treasuries $ 139,762 $ 45 $ — $ — $ 139,762 $ 45 U.S. federal agencies 46,948 118 5,969 35 52,917 153 Mortgage backed securities 59 — 14,844 543 14,903 543 States and political subdivisions 1,932 47 245 1 2,177 48 Other securities 304 142 105 3 409 145 Total $ 189,005 $ 352 $ 21,163 $ 582 $ 210,168 $ 934 Declines in the fair value of held for investment and available-for-sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses. In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer and (iii) the intent and ability of the Company to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value. Management has the ability and intent to hold the securities classified as held for investment until they mature, at which time the Company will receive full value for the securities. Furthermore, as of December 31, 2016 and 2015, the Company also had the ability and intent to hold the securities classified as available for sale for a period of time sufficient for 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 debt 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, and has no intent or requirement to sell before the recovery of the unrealized loss; therefore, the Company has not recognized any impairment in the Company’s consolidated statement of comprehensive income.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Loans and Allowance for Loan Losses	(5) LOANS AND ALLOWANCE FOR LOAN LOSSES The following is a schedule of loans outstanding by category: December 31, 2016 2015 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 828,260 18.82 % $ 795,803 18.80 % Oil & gas production and equipment 84,228 1.91 87,304 2.06 Agriculture 144,751 3.29 150,620 3.56 State and political subdivisions: Taxable 33,793 0.77 17,605 0.42 Tax-exempt 47,283 1.07 33,575 0.79 Real estate: Construction 420,884 9.57 403,664 9.54 Farmland 197,872 4.50 184,707 4.36 One to four family residences 846,360 19.24 821,251 19.41 Multifamily residential properties 57,806 1.31 65,477 1.55 Commercial 1,426,643 32.42 1,356,430 32.05 Consumer 279,704 6.36 283,636 6.70 Other (not classified above) 32,648 0.74 31,976 0.76 Total loans $ 4,400,232 100.00 % $ 4,232,048 100.00 % The Company’s commercial and industrial loan category includes a small percentage of loans to companies that provide ancillary services to the oil and gas industry, such as transportation, preparation contractors and equipment manufacturers. The balance of these loans at December 31, 2016 was approximately $56 million. The Company’s loans are mostly to customers within Oklahoma and over 65% of the loans are secured by real estate. Credit risk on loans is managed through limits on amounts loaned to individual borrowers, underwriting standards and loan monitoring procedures. The amounts and types of collateral obtained, if any, to secure loans are based upon the Company’s underwriting standards and management’s credit evaluation. Collateral varies, but may include real estate, equipment, accounts receivable, inventory, livestock and securities. The Company’s interest in collateral is secured through filing mortgages and liens, and in some cases, by possession of the collateral. There are inherent risks associated with the Company’s lending activities. These risks include, among other things, the impact of changes in interest rates and changes in the economic conditions in the markets where the Company operates. Increases in interest rates and/or weakening economic conditions could adversely impact the ability of borrowers to repay outstanding loans or the value of the collateral securing these loans. The Company is also subject to various laws and regulations that affect its lending activities. Failure to comply with applicable laws and regulations could subject the Company to regulatory enforcement action that could result in the assessment of significant civil money penalties against the Company. As a lender, the Company faces the risk that a significant number of its borrowers will fail to pay their loans when due. If borrower defaults cause losses in excess of the Company’s allowance for loan losses, it could have an adverse effect on the Company’s business, profitability, and financial condition. Loans secured by real estate, including farmland, multifamily, commercial, one-to-four family residential and construction and development loans, have been a large portion of the Company’s loan portfolio. The Company is subject to risk of future market fluctuations in property values relating to these loans. In addition, multi-family and commercial real estate (“CRE”) loans represent the majority of the Company’s real estate loans outstanding. A decline in tenant occupancy due to such factors or for other reasons could adversely impact the ability of the Company’s borrowers to repay their loans on a timely basis, which could have a negative impact on the Company’s financial condition and results of operation. The Company attempts to manage this risk through rigorous loan underwriting standards. During the ordinary course of business, the Company may foreclose on and take title to properties securing certain loans. In doing so, there is a risk that hazardous or toxic substances could be found on these properties. If hazardous or toxic substances are found, the Company may be liable for remediation costs, as well as for personal injury and property damage. Nonperforming and Restructured Assets The following is a summary of nonperforming and restructured assets: December 31, 2016 2015 (Dollars in thousands) Past due 90 days or more and still accruing $ 1,962 $ 1,841 Nonaccrual 31,798 30,096 Restructured 1,713 15,143 Total nonperforming and restructured loans 35,473 47,080 Other real estate owned and repossessed assets 3,866 8,214 Total nonperforming and restructured assets $ 39,339 $ 55,294 Had nonaccrual loans performed in accordance with their original contractual terms, the Company would have recognized additional interest income of approximately $2.0 million in 2016, $2.0 million in 2015 and $1.2 million in 2014. Restructured loans at December 31, 2015 consisted primarily of one relationship restructured in prior periods to defer certain principal payments. This relationship was re-evaluated by management and removed from restructured loans in 2016 due to sustained improvement in financial condition, performance and the commercially reasonable nature of its structure. The Company charges interest on principal balances outstanding during deferral periods. As a result, the current and future financial effects of the recorded balance of loans considered to be restructured were not considered to be material. Loans are segregated into classes based upon the nature of the collateral and the borrower. These classes are used to estimate the allowance for loan losses. The following table is a summary of amounts included in nonaccrual loans, segregated by class of loans. Residential real estate refers to one-to-four family real estate. December 31, 2016 2015 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 713 $ 261 Non-residential real estate other 5,688 3,957 Residential real estate permanent mortgage 1,116 656 Residential real estate all other 5,089 1,833 Commercial and financial: Non-consumer non-real estate 4,464 10,159 Consumer non-real estate 265 312 Other loans 8,370 9,381 Acquired loans 6,093 3,537 Total $ 31,798 $ 30,096 Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. The following table presents an age analysis of past due loans, segregated by class of loans: Age Analysis of Past Due Loans 30-59 Days Past Due 60-89 Days Past Due 90 Days and Greater Total Past Due Loans Current Loans Total Loans Accruing Loans 90 Days or More Past Due (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 2,255 $ 96 $ 150 $ 2,501 $ 569,130 $ 571,631 $ — Non-residential real estate other 611 16 418 1,045 1,122,351 1,123,396 — Residential real estate permanent mortgage 2,742 649 1,273 4,664 320,749 325,413 513 Residential real estate all other 2,559 531 1,416 4,506 743,723 748,229 369 Commercial and financial: Non-consumer non-real estate 1,269 1,628 741 3,638 1,047,547 1,051,185 608 Consumer non-real estate 2,046 760 419 3,225 280,652 283,877 274 Other loans 5,345 958 7,775 14,078 127,404 141,482 45 Acquired loans 825 310 408 1,543 153,476 155,019 153 Total $ 17,652 $ 4,948 $ 12,600 $ 35,200 $ 4,365,032 $ 4,400,232 $ 1,962 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 441 $ 179 $ 183 $ 803 $ 502,094 $ 502,897 $ — Non-residential real estate other 1,149 108 568 1,825 1,108,935 1,110,760 521 Residential real estate permanent mortgage 2,840 636 648 4,124 328,477 332,601 493 Residential real estate all other 2,842 609 824 4,275 672,414 676,689 193 Commercial and financial: Non-consumer non-real estate 2,278 161 187 2,626 982,136 984,762 152 Consumer non-real estate 2,237 772 349 3,358 265,511 268,869 278 Other loans 3,565 295 1,761 5,621 156,995 162,616 132 Acquired loans 1,052 71 918 2,041 190,813 192,854 72 Total $ 16,404 $ 2,831 $ 5,438 $ 24,673 $ 4,207,375 $ 4,232,048 $ 1,841 Impaired Loans Loans are considered impaired when, based on current information and events, it is probable the Company will be unable to collect the full amount of scheduled principal and interest payments in accordance with the original contractual terms of the loan agreement. If a loan is impaired, a specific valuation allowance may be allocated, if necessary, so that the loan is reported, net of allowance for loss, at the present value of future cash flows using the loan’s existing rate, or the fair value of collateral if repayment is expected solely from the collateral. The following table presents impaired loans, segregated by class of loans. No material amount of interest income was recognized on impaired loans subsequent to their classification as impaired. Impaired Loans Unpaid Principal Balance Recorded Investment with Allowance Related Allowance Average Recorded Investment (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 894 $ 806 $ 101 $ 825 Non-residential real estate other 7,742 5,688 574 5,854 Residential real estate permanent mortgage 1,878 1,683 124 1,612 Residential real estate all other 5,871 5,614 1,538 5,445 Commercial and financial: Non-consumer non-real estate 12,015 6,272 1,457 6,478 Consumer non-real estate 686 650 133 788 Other loans 9,799 8,415 1,870 8,062 Acquired loans 8,780 6,581 — 6,041 Total $ 47,665 $ 35,709 $ 5,797 $ 35,105 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 507 $ 383 $ 14 $ 446 Non-residential real estate other 21,068 19,052 357 19,655 Residential real estate permanent mortgage 1,401 1,209 81 1,125 Residential real estate all other 2,498 2,235 242 1,958 Commercial and financial: Non-consumer non-real estate 13,897 10,312 2,062 11,786 Consumer non-real estate 738 715 181 652 Other loans 10,722 9,513 331 10,335 Acquired loans 6,295 4,248 — 4,564 Total $ 57,126 $ 47,667 $ 3,268 $ 50,521 Credit Risk Monitoring and Loan Grading The Company considers various factors to monitor the credit risk in the loan portfolio including volume and severity of loan delinquencies, nonaccrual loans, internal grading of loans, historical loan loss experience and economic conditions. An internal risk grading system is used to indicate the credit risk of loans. The loan grades used by the Company are for internal risk identification purposes and do not directly correlate to regulatory classification categories or any financial reporting definitions. The general characteristics of the risk grades are as follows: Grade 1 – Acceptable - Loans graded 1 represent reasonable and satisfactory credit risk which requires normal attention and supervision. Capacity to repay through primary and/or secondary sources is not questioned. Grade 2 – Acceptable - Increased Attention - This category consists of loans that have credit characteristics deserving management’s close attention. These potential weaknesses could result in deterioration of the repayment prospects for the loan or the Bank’s credit position at some future date. Such credit characteristics include loans to highly leveraged borrowers in cyclical industries, adverse financial trends which could potentially weaken repayment capacity, loans that have fundamental structure deficiencies, loans lacking secondary sources of repayment where prudent, and loans with deficiencies in essential documentation, including financial information. Grade 3 – Loans with Problem Potential - This category consists of performing loans which are considered to exhibit problem potential. Loans in this category would generally include, but not be limited to, borrowers with a weakened financial condition or poor performance history, past dues, loans restructured to reduce payments to an amount that is below market standards and/or loans with severe documentation problems. In general, these loans have no identifiable loss potential in the near future, however; the possibility of a loss developing is heightened. Grade 4 - Problem Loans/Assets – Nonperforming - This category consists of nonperforming loans/assets which are considered to be problems. Nonperforming loans are described as being 90 days and over past due and still accruing, and loans that are nonaccrual. The government guaranteed portion of Small Business Administration (“SBA”) loans is excluded. Grade 5 - Loss Potential - This category consists of loans/assets which are considered to possess loss potential. While the loss may not occur in the current year, management expects that loans/assets in this category will ultimately result in a loss, unless substantial improvement occurs. Grade 6 - Charge Off - This category consists of loans that are considered uncollectible and other assets with little or no value. The following table presents internal loan grading by class of loans: Internal Loan Grading Grade 1 2 3 4 5 Total (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 464,504 $ 89,978 $ 16,220 $ 929 $ — $ 571,631 Non-residential real estate other 933,743 169,561 14,404 5,688 — 1,123,396 Residential real estate permanent mortgage 284,893 32,889 5,987 1,644 — 325,413 Residential real estate all other 614,338 119,018 9,382 5,491 — 748,229 Commercial and financial: Non-consumer non-real estate 856,318 170,865 19,101 4,901 — 1,051,185 Consumer non-real estate 263,442 17,154 2,640 641 — 283,877 Other loans 132,254 5,376 1,514 2,338 — 141,482 Acquired loans 92,946 42,668 12,888 6,517 — 155,019 Total $ 3,642,438 $ 647,509 $ 82,136 $ 28,149 $ — $ 4,400,232 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 417,529 $ 76,749 $ 8,304 $ 315 $ — $ 502,897 Non-residential real estate other 945,993 156,159 4,580 4,028 — 1,110,760 Residential real estate permanent mortgage 295,265 29,793 6,315 1,228 — 332,601 Residential real estate all other 554,007 111,879 9,109 1,694 — 676,689 Commercial and financial: Non-consumer non-real estate 821,394 140,384 12,687 10,297 — 984,762 Consumer non-real estate 251,994 14,433 1,779 662 1 268,869 Other loans 153,416 5,851 872 2,477 — 162,616 Acquired loans 165,305 12,566 11,049 3,858 76 192,854 Total $ 3,604,903 $ 547,814 $ 54,695 $ 24,559 $ 77 $ 4,232,048 Allowance for Loan Losses Methodology The allowance for loan losses (“ALL”) is determined by a calculation based on segmenting the loans into the following categories: (1) adversely graded loans [Grades 3, 4 and 5] that have a specific reserve allocation; (2) loans without a specific reserve segmented by loans secured by real estate other than one-to-four family residential property, loans secured by one-to-four family residential property, commercial, industrial and agricultural loans not secured by real estate, consumer purpose loans not secured by real estate, and loans over 60 days past due that are not otherwise Grade 3, 4, or 5; (3) Grade 2 loans; (4) Grade 1 loans and (5) loans held for sale which are excluded. The ALL is calculated as the sum of the following: (1) the total dollar amount of specific reserve allocations; (2) the dollar amount derived by multiplying each segment of adversely graded loans without a specific reserve allocation times its respective reserve factor; (3) the dollar amount derived by multiplying Grade 2 loans and Grade 1 loans (less certain exclusions) times the respective reserve factor; and (4) other adjustments as deemed appropriate and documented by the Senior Loan Committee or Board of Directors. The amount of the ALL is an estimate based upon factors which are subject to rapid change due to changing economic conditions and the economic prospects of borrowers. It is reasonably possible that a material change could occur in the estimated ALL in the near term. The following table details activity in the ALL by class of loans for the period presented. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. ALL Balance at beginning of period Charge- offs Recoveries Net charge-offs Provisions charged to operations Balance at end of period (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 4,661 $ (11 ) $ 3 $ (8 ) $ 949 $ 5,602 Non-residential real estate other 9,921 (9 ) 6 (3 ) 875 10,793 Residential real estate permanent mortgage 3,148 (208 ) 55 (153 ) 134 3,129 Residential real estate all other 6,725 (181 ) 21 (160 ) 2,057 8,622 Commercial and financial: Non-consumer non-real estate 11,754 (2,921 ) 122 (2,799 ) 3,466 12,421 Consumer non-real estate 2,642 (1,088 ) 159 (929 ) 1,091 2,804 Other loans 2,648 (388 ) 17 (371 ) 1,768 4,045 Acquired loans 167 (101 ) 32 (69 ) 1,179 1,277 Total $ 41,666 $ (4,907 ) $ 415 $ (4,492 ) $ 11,519 $ 48,693 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 4,406 $ (37 ) $ 1 $ (36 ) $ 291 $ 4,661 Non-residential real estate other 9,616 (708 ) 2 (706 ) 1,011 9,921 Residential real estate permanent mortgage 2,948 (222 ) 40 (182 ) 382 3,148 Residential real estate all other 6,269 (138 ) 17 (121 ) 577 6,725 Commercial and financial: Non-consumer non-real estate 12,771 (3,799 ) 199 (3,600 ) 2,583 11,754 Consumer non-real estate 2,404 (626 ) 124 (502 ) 740 2,642 Other loans 2,359 (1,109 ) 16 (1,093 ) 1,382 2,648 Acquired loans 116 (686 ) 28 (658 ) 709 167 Total $ 40,889 $ (7,325 ) $ 427 $ (6,898 ) $ 7,675 $ 41,666 The following table details the amount of ALL by class of loans for the period presented, on the basis of the impairment methodology used by the Company. ALL December 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Individually evaluated for impairment Collectively evaluated for impairment (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 716 $ 4,886 $ 323 $ 4,338 Non-residential real estate other 1,119 9,674 323 9,598 Residential real estate permanent mortgage 422 2,707 399 2,749 Residential real estate all other 2,160 6,462 839 5,886 Commercial and financial: Non-consumer non-real estate 3,317 9,104 3,365 8,389 Consumer non-real estate 478 2,326 445 2,197 Other loans 1,812 2,233 291 2,357 Acquired loans 495 782 — 167 Total $ 10,519 $ 38,174 $ 5,985 $ 35,681 The following table details the loans outstanding by class of loans for the period presented, on the basis of the impairment methodology used by the Company. Loans December 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 17,149 $ 554,482 $ — $ 8,619 $ 494,278 $ — Non-residential real estate other 20,092 1,103,304 — 8,608 1,102,152 — Residential real estate permanent mortgage 7,631 317,782 — 7,543 325,058 — Residential real estate all other 14,873 733,356 — 10,803 665,886 — Commercial and financial: Non-consumer non-real estate 24,002 1,027,183 — 22,983 961,779 — Consumer non-real estate 3,203 280,674 — 2,416 266,453 — Other loans 2,254 139,228 — 2,323 160,293 — Acquired loans 13,459 135,616 5,944 7,889 177,871 7,094 Total $ 102,663 $ 4,291,625 $ 5,944 $ 71,184 $ 4,153,770 $ 7,094 Transfers from Loans Transfers from loans to other real estate owned and repossessed assets are non-cash transactions, and are not included in the statements of cash flow. Transfers from loans to other real estate owned and repossessed assets during the periods presented are summarized as follows: Year ended December 31, 2016 2015 2014 (Dollars in thousands) Other real estate owned $ 2,553 $ 2,139 $ 3,573 Repossessed assets 1,402 1,098 1,209 Total $ 3,955 $ 3,237 $ 4,782 Related Party Loans The Company has made loans in the ordinary course of business to the executive officers and directors of the Company and to certain affiliates of these executive officers and directors. Management believes that all such loans were made on substantially the same terms as those prevailing at the time for comparable transactions with other persons and do not represent more than a normal risk of collectability or present other unfavorable features. A summary of these loans is as follows: Year Ended December 31, Balance Beginning of the Period Additions Collections/ Terminations Balance End of the Period (Dollars in thousands) 2016 $ 37,577 $ 16,133 $ (26,224 ) $ 27,486 2015 25,019 22,330 (9,772 ) 37,577 2014 27,134 22,521 (24,636 ) 25,019

Premises and Equipment, Net and

Premises and Equipment, Net and Other Assets	12 Months Ended
	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Premises and Equipment, Net and Other Assets	(6) PREMISES AND EQUIPMENT, NET AND OTHER ASSETS The following is a summary of premises and equipment by classification: December 31, Estimated Useful Lives 2016 2015 (Dollars in thousands) Land $ 32,441 $ 31,196 Buildings 10 to 40 years 138,901 135,694 Furniture, fixtures and equipment 3 to 15 years 64,293 63,436 Accumulated depreciation (108,864 ) (103,513 ) Premises and equipment, net $ 126,771 $ 126,813 Low Income Housing Tax Credit Investments We invest in affordable housing projects that qualify for the low income housing tax credit (LIHTC), which is designed to promote private development of low income housing. These investments generate a return primarily through realization of federal tax credits, and also through a tax deduction generated by operating losses of the investments. The investments are amortized through tax expense using the proportional amortization method as related tax credits are utilized. The Company is periodically required to provide additional contributions at the discretion of the project sponsors. Although in some cases the Company’s investment may exceed 50% of the equity interest in an entity, the Company does not consolidate these structures as variable interest entities due to the project sponsor’s ability to manage the projects, which is indicative of power in them. Total LIHTC investments were $15.2 million and $14.5 million at December 31, 2016 and 2015, respectively and are included in other assets on the balance sheet. The Company recognized tax credits and other tax benefits of $4.2 million, $4.0 million and $3.3 million in 2016, 2015 and 2014, respectively and amortization expense of $2.9 million, $2.6 million and $2.3 million in 2016, 2015 and 2014, respectively resulting from LIHTC investments. Additional contributions are made during the investment periods through the year 2032. Unfunded commitments to these investments as of December 31, 2016 totaled $13.5 million.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	(7) INTANGIBLE ASSETS AND GOODWILL The following is a summary of intangible assets: Gross Carrying Amount Accumulated Amortization Net Carrying Amount (Dollars in thousands) As of December 31, 2016 Core deposit intangibles $ 17,447 $ (6,611 ) $ 10,836 Customer relationship intangibles 5,699 (3,419 ) 2,280 Mortgage servicing intangibles 473 (259 ) 214 Total $ 23,619 $ (10,289 ) $ 13,330 As of December 31, 2015 Core deposit intangibles $ 20,333 $ (7,586 ) $ 12,747 Customer relationship intangibles 5,699 (3,061 ) 2,638 Mortgage servicing intangibles 538 (228 ) 310 Total $ 26,570 $ (10,875 ) $ 15,695 Mortgage servicing intangibles are amortized based on current prepayment assumptions and are adjusted to fair value semi-annually, if impaired. Fair value is estimated based on the present value of future cash flows over several interest rate scenarios, which are then discounted at risk-adjusted rates. The Company considers portfolio characteristics, contractually specified servicing fees, prepayment assumptions, delinquency rates, late charges, other ancillary revenue, costs to service and other economic factors. When available, fair value estimates and assumptions are compared to observable market data and the recent market activity and actual portfolio experience. Estimated amortization of intangible assets for the next five years, as of December 31, 2016, is as follows (dollars in thousands): Estimated Amortization 2017 $ 2,213 2018 2,213 2019 2,213 2020 2,101 2021 1,270 At December 31, 2016, the weighted-average remaining life of all intangible assets was approximately 6.7 years which consisted of customer relationship intangibles with a weighted-average life of 6.9 years, core deposit intangibles with a weighted-average life of 6.8 years and mortgage servicing intangibles with a weighted-average life of 2.0 years based on current prepayment assumptions. The following is a summary of goodwill by business segment: Other Executive, Metropolitan Community Financial Operations Banks Banks Services & Support Consolidated (Dollars in thousands) Year Ended December 31, 2016 Balance at beginning and end of period $ 8,078 $ 40,050 $ 5,464 $ 450 $ 54,042 Year Ended December 31, 2015 Balance at beginning of period $ 8,078 $ 30,970 $ 5,464 $ 450 $ 44,962 Acquisitions — 9,448 — — 9,448 Impairment — (368 ) — — (368 ) Balance at end of period $ 8,078 $ 40,050 $ 5,464 $ 450 $ 54,042 In June 2015, the Company recorded an impairment loss for goodwill of $368,000 after adopting a plan to close a small branch, which is included in other noninterest expense on the consolidated statement of comprehensive income.

Time Deposits

Time Deposits	12 Months Ended
	Dec. 31, 2016
Banking And Thrift [Abstract]
Time Deposits	(8) TIME DEPOSITS Time deposits include certificates of deposit and individual retirement accounts. At December 31, 2016, the scheduled maturities of all time deposits are as follows (Dollars in thousands): 2017 $ 418,543 2018 124,568 2019 66,981 2020 37,823 2021 39,306 Thereafter 29 Total $ 687,250 The following table is a summary of large time deposits for the periods presented: December 31, 2016 2015 (Dollars in thousands) Time deposits of $100,000 or more $ 328,363 $ 342,916 The aggregate amount of domestic certificates of deposit that meet or exceed the current FDIC insurance limit was $122.2 million and $120.0 million at December 31, 2016 and 2015, respectively.

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Short-Term Borrowings	(9) SHORT-TERM BORROWINGS The following is a summary of short-term borrowings: December 31, 2016 2015 (Dollars in thousands) Federal funds purchased $ 500 $ 500 Weighted average interest rate 0.38 % 0.15 % End of period interest rate 0.63 % 0.38 % Federal funds purchased represent borrowings of overnight funds from other financial institutions.

Long-Term Borrowings

Long-Term Borrowings	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Long-Term Borrowings	(10) LONG-TERM BORROWINGS The Company has a line of credit from the Federal Home Loan Bank (“FHLB”) of Topeka, Kansas to use for liquidity or to match-fund certain long-term fixed rate loans. The Company’s assets, including residential first mortgages of $674.5 million, are pledged as collateral for the borrowings under the line of credit. As of December 31, 2016, the Company had the ability to draw up to $517.5 million on the FHLB line of credit based on FHLB stock holdings of $551,900 with no advances outstanding. In addition, the Company has a revolving line of credit with the ability to draw up to $10.0 million with no advances outstanding. This line of credit has a variable rate based on prime rate minus 25 basis points and matures in 2020.

Junior Subordinated Debentures

Junior Subordinated Debentures	12 Months Ended
	Dec. 31, 2016
Offsetting [Abstract]
Junior Subordinated Debentures	(11) JUNIOR SUBORDINATED DEBENTURES In January 2004, the Company established BFC Capital Trust II (“BFC II”), a trust formed under the Delaware Business Trust Act. The Company owns all of the common securities of BFC II. In February 2004, BFC II issued $25 million of aggregate liquidation amount of 7.20% Cumulative Trust Preferred Securities (the “Cumulative Trust Preferred Securities”) to other investors. In March 2004, BFC II issued an additional $1 million in Cumulative Trust Preferred Securities through the execution of an over-allotment option. The proceeds from the sale of the Cumulative Trust Preferred Securities and the common securities of BFC II were invested in $26.8 million of 7.20% Junior Subordinated Debentures of the Company. Interest payments on the $26.8 million of 7.20% Junior Subordinated Debentures are payable January 15, April 15, July 15 and October 15 of each year. Such interest payments may be deferred for up to twenty consecutive quarters. The stated maturity date of the $26.8 million of 7.20% Junior Subordinated Debentures is March 31, 2034, but they are subject to mandatory redemption pursuant to optional prepayment terms. The Cumulative Trust Preferred Securities represent an undivided interest in the $26.8 million of 7.20% Junior Subordinated Debentures and are guaranteed by the Company. During any deferral period or during any event of default, the Company may not declare or pay any dividends on any of its capital stock. The Cumulative Trust Preferred Securities were callable at par, in whole or in part, after March 31, 2009. On October 8, 2015, the Company acquired CSB Bancshares Statutory Trust I (CSB Trust I), a trust formed under the Delaware Business Trust Act, from the merger of CSB Bancshares Inc. CSB Trust I had issued $5.0 million aggregate liquidation amount of floating rate capital securities to other purchasers and $155,000 aggregate liquidation amount of common securities to CSB Bancshares Inc., which were assumed by the Company as a result of the merger. The proceeds from the sale of the securities of CSB Trust I were invested in $5.2 million of Floating Rate Junior Subordinated Deferrable Interest Debentures of CSB Bancshares Inc., which were assumed by the Company as a result of the merger. Interest payments on the $5.2 million of Floating Rate Junior Subordinated Deferrable Interest Debentures are payable March 15, June 15, September 15 and December 15 of each year. The interest rate on the $5.2 million of Floating Rate Junior Subordinated Deferrable Interest Debentures was set at three month LIBOR plus 182 basis points. The Floating Rate Junior Subordinated Deferrable Interest Debentures are due September 15, 2036.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	(12) INCOME TAXES The components of the Company’s income tax expense (benefit) are as follows: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Current taxes: Federal $ 34,003 $ 32,348 $ 28,258 State 5,308 4,595 2,709 Deferred taxes (2,048 ) (1,903 ) (3,683 ) Total income taxes $ 37,263 $ 35,040 $ 27,284 Income tax (benefit) expense applicable to securities transactions approximated $(21,000), $3.2 million and $574,000 for the years ended December 31, 2016, 2015 and 2014, respectively. A reconciliation of tax expense at the federal statutory tax rate applied to income before taxes is presented in the following table: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Tax expense at the federal statutory tax rate $ 37,778 $ 35,424 $ 31,910 Increase (decrease) in tax expense from: Tax-exempt income, net (756 ) (663 ) (571 ) Modified endowment life contracts (852 ) (763 ) (755 ) State tax expense, net of federal tax benefit 3,250 2,898 1,469 Utilization of tax credits: New markets tax credits (1,254 ) (1,195 ) (1,108 ) Low-income housing tax credits, net of amortization (1,424 ) (1,274 ) (1,209 ) Other tax credits (319 ) (248 ) (1,979 ) Other, net 840 861 (473 ) Total tax expense $ 37,263 $ 35,040 $ 27,284 The net deferred tax asset consisted of the following and is reported in other assets: December 31, 2016 2015 (Dollars in thousands) Provision for loan losses $ 18,748 $ 16,110 Write-downs of other real estate owned 769 1,252 Deferred compensation 3,197 3,108 Stock-based compensation 2,441 3,201 Investments in partnership interests 4,603 3,651 Other 666 917 Gross deferred tax assets 30,424 28,239 Unrealized net gains on securities (59 ) (962 ) Premium on securities of banks acquired (453 ) (563 ) Intangibles (5,365 ) (5,575 ) Basis difference related to tax credits (3,435 ) (2,689 ) Depreciation (6,758 ) (6,449 ) Leveraged lease (1,408 ) (1,671 ) Other (271 ) (606 ) Gross deferred tax liabilities (17,749 ) (18,515 ) Net deferred tax asset $ 12,675 $ 9,724 The Company recognizes accrued interest and penalties related to unrecognized tax benefits, if applicable, in income tax expense. During the years ended December 31, 2016, 2015 and 2014, the Company did not recognize or accrue any interest and penalties related to unrecognized tax benefits. Federal and various state income tax statutes dictate that tax returns filed in any of the previous three reporting periods remain open to examination which includes the years 2014 to 2016. The Company has no open examinations with either the Internal Revenue Service or any state agency. Management performs an analysis of the Company’s tax position annually and believes it is more likely than not that all of its tax positions will be utilized in future years.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	(13) STOCK-BASED COMPENSATION The Company adopted a nonqualified incentive stock option plan (the “BancFirst ISOP”) in May 1986. The Company amended the BancFirst ISOP to increase the number of shares to be issued under the plan to 3,200,000 shares in May 2016. At December 31, 2016, 215,735 shares were available for future grants. The BancFirst ISOP will terminate on December 31, 2019. The options vest and are exercisable beginning four years from the date of grant at the rate of 25% per year for four years. Options expire at the end of fifteen years from the date of grant. Options outstanding as of December 31, 2016 will become exercisable through the year 2023. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant. In June 1999, the Company adopted the BancFirst Corporation Non-Employee Directors’ Stock Option Plan (the “BancFirst Directors’ Stock Option Plan”). Each non-employee director is granted an option for 10,000 shares. The Company amended the BancFirst Directors’ Stock Option Plan to increase the number of shares to be issued under the plan to 260,000 shares in May 2016. At December 31, 2016, 40,000 shares were available for future grants. The options vest and are exercisable beginning one year from the date of grant at the rate of 25% per year for four years, and expire at the end of fifteen years from the date of grant. Options outstanding as of December 31, 2016 will become exercisable through the year 2020. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant. The Company currently uses newly issued shares for stock option exercises, but reserves the right to use shares purchased under the Company’s Stock Repurchase Program (the “SRP”) in the future. The following table is a summary of the activity under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan: Wgtd. Avg. Wgtd. Avg. Remaining Aggregate Exercise Contractual Intrinsic Options Price Term Value (Dollars in thousands, except option data) Year Ended December 31, 2016 Outstanding at December 31, 2015 1,018,149 $ 40.69 Options granted 30,000 58.08 Options exercised (310,699 ) 31.28 Options canceled, forfeited, or expired (30,000 ) 55.88 Outstanding at December 31, 2016 707,450 44.92 9.59Yrs $ 34,049 Exercisable at December 31, 2016 325,200 37.19 6.78Yrs $ 18,167 Year Ended December 31, 2015 Outstanding at December 31, 2014 1,029,657 $ 36.55 Options granted 133,000 59.37 Options exercised (120,758 ) 26.60 Options canceled, forfeited, or expired (23,750 ) 37.16 Outstanding at December 31, 2015 1,018,149 40.69 8.84Yrs $ 18,251 Exercisable at December 31, 2015 499,599 32.98 5.53Yrs $ 12,812 The following table has additional information regarding options granted and options exercised under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan: Year Ended December 31, 2016 2015 2014 (Dollars in thousands, except per share data) Weighted average grant-date fair value per share of options granted $ 11.92 $ 11.72 $ 12.27 Total intrinsic value of options exercised 12,230 4,376 5,597 Cash received from options exercised 9,720 3,212 4,870 Tax benefit realized from options exercised 4,731 1,693 2,165 The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model and is based on certain assumptions including risk-free rate of return, dividend yield, stock price volatility and the expected term. The fair value of each option is expensed over its vesting period. The following table is a summary of the Company’s recorded stock-based compensation expense: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Stock-based compensation expense $ 1,636 $ 1,717 $ 1,676 Tax benefit 633 664 648 Stock-based compensation expense, net of tax $ 1,003 $ 1,053 $ 1,028 The Company will continue to amortize the unearned stock-based compensation expense over the remaining vesting period of approximately seven years. The following table shows the unearned stock-based compensation expense: December 31, 2016 (Dollars in thousands) Unearned stock-based compensation expense $ 2,770 The following table shows the assumptions used for computing stock-based compensation expense under the fair value method: Year Ended December 31, 2016 2015 2014 Risk-free interest rate 1.46 to 2.02% 1.83 to 2.26% 2.10 to 2.54% Dividend yield 2.00 % 2.00 % 2.00 % Stock price volatility 20.41 to 21.78% 18.23 to 21.08% 18.03 to 18.98% Expected term 10 Yrs 10 Yrs 10 Yrs The risk-free interest rate is determined by reference to the spot zero-coupon rate for the U.S. Treasury security with a maturity similar to the expected term of the options. The dividend yield is the expected yield for the expected term. The stock price volatility is estimated from the recent historical volatility of the Company’s stock. The expected term is estimated from the historical option exercise experience. In May 1999, the Company adopted the BancFirst Corporation Directors’ Deferred Stock Compensation Plan (the “BancFirst Deferred Stock Compensation Plan”). The Company amended the BancFirst Deferred Stock Compensation Plan to increase the number of shares to be issued under the plan to 111,110 shares in May 2016. Under the plan, directors and members of the community advisory boards of the Company and its subsidiaries may defer up to 100% of their board fees. They are credited for each deferral with a number of stock units based on the current market price of the Company’s stock, which accumulate in an account until such time as the director or community board member terminates serving as a board member. Shares of common stock of the Company are then distributed to the terminating director or community board member based upon the number of stock units accumulated in his or her account. The number of shares of common stock distributed from the BancFirst Deferred Stock Compensation Plan was 2,790 and 622 during the years ended December 31, 2016 and 2015, respectively. A summary of the accumulated stock units is as follows: December 31, 2016 2015 Accumulated stock units 70,022 66,376 Average price $ 41.74 $ 39.64

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2016
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	(14) RETIREMENT PLANS In May 1986, the Company adopted the BancFirst Corporation Employee Stock Ownership (“ESOP”) and Thrift Plan (“401(k)”) effective January 1, 1985. The plan was separated into two individual plans effective January 1, 2009. The 401(k) and ESOP plans cover all eligible employees, as defined in the plans, of the Company and its subsidiaries. The 401(k) plan allows employees to defer up to the maximum legal limit of their compensation, of which the Company may match up to 3% of their compensation. In addition, the Company may make discretionary contributions based on employee contributions or eligible compensation to the ESOP plan, as determined by the Company’s Board of Directors. The aggregate amounts of contributions by the Company to the 401(k) and ESOP plans are shown in the following table: December 31, 2016 2015 2014 (Dollars in thousands) 401(k) contributions $ 2,074 $ 1,966 $ 1,870 ESOP contributions 2,352 1,993 1,928 Total contributions $ 4,426 $ 3,959 $ 3,798

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholders' Equity	(15) STOCKHOLDERS’ EQUITY As of December 31, 2016, 2015 and 2014 the Company’s authorized and outstanding preferred and common stock was as follows: No. of Shares Authorized at No. of Shares Outstanding at December 31, Class of Stock December 31, 2016 2016 2015 2014 Par Value Per Share Dividends Voting Rights Senior Preferred 10,000,000 — — — $ 1.00 As declared Voting 10% Cumulative Preferred 900,000 — — — 5.00 As declared Non-voting Common 20,000,000 15,810,935 15,597,446 15,504,513 1.00 As declared Voting The following is a description of the capital stock of the Company: (a) Senior Preferred Stock: No shares issued or outstanding. Shares may be issued with such voting, dividend, redemption, sinking fund, conversion, exchange, liquidation and other rights as shall be determined by the Company’s Board of Directors, without approval of the stockholders. The Senior Preferred Stock would have a preference over common stock as to payment of dividends, as to the right to distribution of assets upon redemption of such shares or upon liquidation of the Company. (b) 10% Cumulative Preferred Stock: Redeemable at the Company’s option at $5.00 per share plus accumulated dividends; non-voting; cumulative dividends at the rate of 10% payable semi-annually on January 15 and July 15; no shares issued or outstanding. (c) Common stock: At December 31, 2016, 2015 and 2014 the shares issued equaled shares outstanding. In November 1999, the Company adopted a Stock Repurchase Program (the “SRP”). The SRP may be used as a means to increase earnings per share and return on equity, to purchase treasury stock for the exercise of stock options or for distributions under the Deferred Stock Compensation Plan, to provide liquidity for optionees to dispose of stock from exercises of their stock options, and to provide liquidity for stockholders wishing to sell their stock. All shares repurchased under the SRP have been retired and not held as treasury stock. The timing, price and amount of stock repurchases may be determined by management within the limitations of the SRP. During the third quarter of 2016 the SRP was amended to increase the remaining shares to be repurchased to 150,000. The following table is a summary of the shares under the program: Year Ended December 31, 2016 2015 2014 Number of shares repurchased 100,000 28,447 — Average price of shares repurchased $ 55.23 $ 58.19 $ — Shares remaining to be repurchased 150,000 166,276 194,723 The Company’s ability to pay dividends is dependent upon dividend payments received from BancFirst. Banking regulations limit bank dividends based upon net earnings retained and minimum capital requirements. Dividends in excess of these requirements require regulatory approval. At January 1, 2017, approximately $83.3 million of the equity of BancFirst was available for dividend payments to the Company. During any deferral period or any event of default on the Junior Subordinated Debentures, the Company may not declare or pay any dividends on any of its capital stock. The Company and BancFirst are subject to risk-based capital guidelines issued by the Board of Governors of the Federal Reserve System and the Federal Deposit Insurance Corporation (“FDIC”). These guidelines are used to evaluate capital adequacy and involve both quantitative and qualitative evaluations of the Company’s and BancFirst’s assets, liabilities, and certain off-balance-sheet items calculated under regulatory practices. Failure to meet the minimum capital requirements can initiate certain mandatory or discretionary actions by the regulatory agencies that could have a direct material effect on the Company’s financial statements. Management believes that as of December 31, 2016, the Company and BancFirst met all capital adequacy requirements to which they are subject. The actual and required capital amounts and ratios are shown in the following table: Required To Be Well For Capital With Capitalized Under Adequacy Capital Conservation Prompt Corrective Actual Purposes Buffer Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of December 31, 2016: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 728,635 15.33 % $ 380,351 8.00% $ 410,066 8.625 % N/A N/A BancFirst 655,620 13.80 % 379,948 8.00% 409,631 8.625 % $ 474,934 10.00 % Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 648,942 13.65 % $ 213,947 4.50% $ 243,662 5.125 % N/A N/A BancFirst 586,927 12.36 % 213,720 4.50% 243,404 5.125 % $ 308,707 6.50 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 679,942 14.30 % $ 285,263 6.00% $ 314,978 6.625 % N/A N/A BancFirst 606,927 12.78 % 284,961 6.00% 314,644 6.625 % $ 379,948 8.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 679,942 9.94 % $ 273,510 4.00% N/A N/A N/A N/A BancFirst 606,927 8.89 % 273,152 4.00% N/A N/A $ 341,440 5.00 % As of December 31, 2015: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 669,213 14.47 % $ 370,094 8.00% N/A 8.625 % N/A N/A BancFirst 607,604 13.15 % 369,607 8.00% N/A 8.625 % $ 462,009 10.00 % Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 596,547 12.90 % $ 208,178 4.50% N/A 5.125 % N/A N/A BancFirst 545,938 11.82 % 207,904 4.50% N/A 5.125 % $ 300,306 6.50 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 627,547 13.57 % $ 277,570 6.00% N/A 6.625 % N/A N/A BancFirst 565,938 12.25 % 277,205 6.00% N/A 6.625 % $ 369,607 8.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 627,547 9.49 % $ 264,333 4.00% N/A N/A N/A N/A BancFirst 565,938 8.59 % 263,606 4.00% N/A N/A $ 329,507 5.00 % As of December 31, 2016, the most recent notification from the Federal Reserve Bank of Kansas City and the FDIC categorized BancFirst as “well capitalized” under the regulatory framework for prompt corrective action. The Company’s trust preferred securities have continued to be included in Tier 1 capital as the Company’s total assets do not exceed $15 billion. There are no conditions or events since the most recent notification of BancFirst’s capital category that management believes would materially change its category under capital requirements existing as of the report date. Basel III Capital Rules Under the Basel III Capital Rules, in order to avoid limitations on capital distributions, including dividend payments and certain discretionary bonus payments to executive officers, a banking organization must hold a capital conservation buffer composed of CET1 capital above its minimum risk-based capital requirements. The implementation of the capital conservation buffer began on January 1, 2016 at the 0.625% level and will be phased in over a four-year period (increasing by that amount on each subsequent January 1, until it reaches 2.5% on January 1, 2019). Management believes that, as of December 31, 2016, the Company and BancFirst would meet all capital adequacy requirements under the Basel III Capital Rules on a fully phased-in basis as if such requirements were currently in effect.

Net Income Per Common Share

Net Income Per Common Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Net Income Per Common Share	(16) NET INCOME PER COMMON SHARE Basic and diluted net income per common share are calculated as follows: Income (Numerator) Shares (Denominator) Per Share Amount (Dollars in thousands, except per share data) Year Ended December 31, 2016 Basic Income available to common stockholders $ 70,674 15,615,170 $ 4.53 Effect of stock options — 296,092 Diluted Income available to common stockholders plus assumed exercises of stock options $ 70,674 15,911,262 $ 4.44 Year Ended December 31, 2015 Basic Income available to common stockholders $ 66,170 15,559,059 $ 4.25 Effect of stock options — 327,186 Diluted Income available to common stockholders plus assumed exercises of stock options $ 66,170 15,886,245 $ 4.17 Year Ended December 31, 2014 Basic Income available to common stockholders $ 63,887 15,430,773 $ 4.14 Effect of stock options — 363,630 Diluted Income available to common stockholders plus assumed exercises of stock options $ 63,887 15,794,403 $ 4.04 The following table shows the number and average exercise price of options that were excluded from the computation of diluted net income per common share for each year because the options’ exercise prices were greater than the average market price of the common shares. Shares Average Exercise December 31, 2016 147,219 $ 60.49 December 31, 2015 177,718 58.47 December 31, 2014 69,405 55.87

Condensed Parent Company Financ

Condensed Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Parent Company Financial Statements	(17) CONDENSED PARENT COMPANY FINANCIAL STATEMENTS BALANCE SHEETS December 31, 2016 2015 (Dollars in thousands) ASSETS Cash $ 57,537 $ 45,437 Securities 97 103 Investments in subsidiaries 681,861 639,119 Goodwill 450 450 Dividends receivable 6,998 6,773 Other assets 2,610 1,688 Total assets $ 749,553 $ 693,570 LIABILITIES AND STOCKHOLDERS’ EQUITY Other liabilities $ 6,500 $ 6,101 Junior subordinated debentures 31,959 31,959 Stockholders’ equity 711,094 655,510 Total liabilities and stockholders’ equity $ 749,553 $ 693,570 STATEMENTS OF INCOME Year Ended December 31, 2016 2015 2014 (Dollars in thousands) OPERATING INCOME Dividends from subsidiaries $ 28,175 $ 26,043 $ 24,851 Interest on interest-bearing deposits 160 66 62 Other 3 2 14 Total operating income 28,338 26,111 24,927 OPERATING EXPENSE Interest 2,096 1,998 1,965 Other 583 628 667 Total operating expense 2,679 2,626 2,632 Income before taxes and equity in undistributed earnings of subsidiaries 25,659 23,485 22,295 Allocated income tax benefit/(expense) 1,244 (796 ) 472 Income before equity in undistributed earnings of subsidiaries 26,903 22,689 22,767 Equity in undistributed earnings of subsidiaries 44,172 44,653 42,196 Amortization of stock-based compensation arrangements of subsidiaries (401 ) (1,172 ) (1,076 ) Net income $ 70,674 $ 66,170 $ 63,887 STATEMENTS OF CASH FLOW Year Ended December 31, 2016 2015 2014 (Dollars in thousands) CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 70,674 $ 66,170 $ 63,887 Adjustments to reconcile to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (44,172 ) (44,653 ) (42,196 ) Amortization of stock-based compensation arrangements 401 1,172 1,076 Other, net 136 (343 ) (656 ) Net cash provided by operating activities 27,039 22,346 22,111 INVESTING ACTIVITIES Net cash provided by acquisitions — 5,066 — Sales and maturities of held for investment and available for sale securities — — 8 Net cash provided by investing activities — 5,066 8 FINANCING ACTIVITIES Issuance of common stock 13,354 4,428 6,532 Common stock acquired (5,523 ) (1,654 ) — Cash dividends paid (22,770 ) (21,449 ) (19,543 ) Net cash used for financing activities (14,939 ) (18,675 ) (13,011 ) Net increase in cash 12,100 8,737 9,108 Cash and due from banks at the beginning of the period 45,437 36,700 27,592 Cash and due from banks at the end of the period $ 57,537 $ 45,437 $ 36,700 SUPPLEMENTAL DISCLOSURE Cash paid during the period for interest $ 2,096 $ 1,998 $ 1,965 Cash received during the period for income taxes, net $ 5,031 $ 1,131 $ 1,822

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	(18) RELATED PARTY TRANSACTIONS Refer to Note (5) for information regarding loan transactions with related parties.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	(19) COMMITMENTS AND CONTINGENT LIABILITIES The Company is a party to financial instruments with off balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include loan commitments and standby letters of credit which involve elements of credit and interest-rate risk to varying degrees. The Company’s exposure to credit loss in the event of nonperformance by the other party to the instrument is represented by the instrument’s contractual amount. To control this credit risk, the Company uses the same underwriting standards as it uses for loans recorded on the balance sheet. The amounts of financial instruments with off-balance-sheet risk are as follows: December 31, 2016 2015 (Dollars in thousands) Loan commitments $ 981,777 $ 960,490 Stand-by letters of credit 56,551 61,889 Loan commitments are agreements to lend to a customer, as long as there is no violation of any condition established in the contract. Stand-by letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. These instruments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the instruments are expected to expire without being drawn upon, the total amounts do not necessarily represent commitments that will be funded in the future. The Company leases two parcels of land on which it owns buildings, twenty ATM locations, two storage facilities, four parking lots and office space in thirteen buildings. These leases expire at various dates through 2064. The future minimum rental payments under these leases at December 31, 2016, were as follows (Dollars in thousands): 2017 $ 419 2018 421 2019 355 2020 205 2021 172 Later years 700 Total $ 2,272 Rental expense on all property and equipment rented, including those rented on a monthly or temporary basis were as follows (Dollars in thousands): Year Ending December 31: 2016 $ 1,524 2015 1,360 2014 1,255 The Company is a defendant in legal actions arising from normal business activities. Management believes that all legal actions against the Company are without merit or that the ultimate liability, if any, resulting from them will not materially affect the Company’s financial statements.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	(20) FAIR VALUE MEASUREMENTS Accounting standards define fair value as the price that would be received to sell an asset or the price paid to transfer a liability in the principal or most advantageous market available to the entity in an orderly transaction between market participants on the measurement date. FASB Accounting Standards Codification Topic 820 establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: • Level 1 Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2 Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset and liability, either directly or indirectly, for substantially the full term of the financial instrument. • 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. Level 3 assets and liabilities include financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. This category includes certain impaired loans, repossessed assets, other real estate owned, goodwill and other intangible assets. Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis A description of the valuation methodologies and key inputs used to measure financial assets and financial liabilities at fair value on a recurring basis, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. These valuation methodologies were applied to the following categories of the Company’s financial assets and financial liabilities. Securities Available for Sale Securities classified as available for sale are reported at fair value. U.S. Treasuries are valued using Level 1 inputs. Other securities available for sale including U.S. federal agencies, registered mortgage backed securities and state and political subdivisions are valued using prices from an independent pricing service utilizing Level 2 data. 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 also invests in private label mortgage backed securities and equity securities classified as available for sale for which observable information is not readily available. These securities are reported at fair value utilizing Level 3 inputs. For these securities, management determines the fair value based on replacement cost, the income approach or information provided by outside consultants or lead investors. The Company reviews the prices for Level 1 and Level 2 securities supplied by the independent pricing service for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, the Company does not purchase investment portfolio securities that are esoteric or that have complicated structures. The Company’s portfolio primarily consists of traditional investments including U.S. Treasury obligations, federal agency mortgage pass-through securities, general obligation municipal bonds and a small amount of municipal revenue bonds. Pricing for such instruments is fairly generic and is easily obtained. For in-state bond issues that have relatively low issue sizes and liquidity, the Company utilizes the same parameters for pricing mentioned in the preceding paragraph adjusted for the specific issue. From time to time, the Company will validate, on a sample basis, prices supplied by the independent pricing service by comparison to prices obtained from third party sources. Derivatives Derivatives are reported at fair value utilizing Level 2 inputs. The Company obtains dealer and market quotations to value its oil and gas swaps and options. The Company utilizes dealer quotes and observable market data inputs to substantiate internal valuation models. Loans Held For Sale The Company originates mortgage loans to be sold. At the time of origination, the acquiring bank has already been determined and the terms of the loan, including interest rate, have already been set by the acquiring bank allowing the Company to originate the loan at fair value. Mortgage loans are generally sold within 30 days of origination. Loans held for sale are valued using Level 2 inputs. Gains or losses recognized upon the sale of the loans are determined on a specific identification basis. The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2016 and 2015, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (Dollars in thousands) December 31, 2016 Securities available for sale: U.S. Treasury $ 268,543 $ — $ — $ 268,543 U.S. federal agencies — 129,642 — 129,642 Mortgage-backed securities — 4,856 14,816 19,672 States and political subdivisions — 41,042 — 41,042 Other securities — — 6,569 6,569 Derivative assets — 1,569 — 1,569 Derivative liabilities — 1,306 — 1,306 Loans held for sale — 9,318 — 9,318 December 31, 2015 Securities available for sale: U.S. Treasury $ 329,696 $ — $ — $ 329,696 U.S. federal agencies — 131,896 — 131,896 Mortgage-backed securities — 7,039 14,816 21,855 States and political subdivisions — 50,920 — 50,920 Other securities — 3,485 6,308 9,793 Derivative assets — 1,946 — 1,946 Derivative liabilities — 989 — 989 Loans held for sale — 13,725 — 13,725 The changes in Level 3 assets measured at estimated fair value on a recurring basis during the years ended December 31, 2016 and 2015 were as follows: Twelve Months Ended December 31, 2016 2015 (Dollars in thousands) Balance at the beginning of the year $ 21,124 $ 28,459 Purchases 1,096 609 Settlements (191 ) (2,327 ) Sales (429 ) (8,817 ) (Losses) gains included in earnings (111 ) 7,141 Total unrealized losses (104 ) (3,941 ) Balance at the end of the period $ 21,385 $ 21,124 The Company’s policy is to recognize transfers in and transfers out of Levels 1, 2 and 3 as of the end of the reporting period. During the years ended December 31, 2016 and 2015, the Company did not transfer any securities between levels in the fair value hierarchy. Financial Assets and Financial Liabilities Measured at Fair Value on a Nonrecurring Basis Certain financial assets and financial 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 financial assets and financial liabilities are reported at fair value utilizing Level 3 inputs. Impaired loans are reported at the fair value of the underlying collateral if repayment is dependent on liquidation of the collateral. In no case does the fair value of an impaired loan exceed the fair value of the underlying collateral. The impaired loans are adjusted to fair value through a specific allocation of the allowance for loan losses or a direct charge-down of the loan. Repossessed assets, upon initial recognition, are measured and adjusted to fair value through a charge-off to the allowance for possible loan losses based upon the fair value of the repossessed asset. Other real estate owned is revalued at fair value subsequent to initial recognition, with any losses recognized in net expense from other real estate owned. The following table summarizes assets measured at fair value on a nonrecurring basis. The fair value represents end of period values, which approximate fair value measurements that occurred on various measurement dates throughout the period. The related losses represent the amounts recognized during the period regardless of whether the asset is still held at period end: Total Fair Value Level 3 Losses (Dollars in thousands) As of and for the Year-to-date Period Ended December 31, 2016 Impaired loans (less specific allowance) $ 29,912 $ — Repossessed assets 340 3 Other real estate owned 1,480 231 As of and for the Year-to-date Period Ended December 31, 2015 Impaired loans (less specific allowance) $ 44,399 $ — Repossessed assets 230 — Other real estate owned 3,607 128 Estimated Fair Value of Financial Instruments The Company is required under current authoritative accounting guidance to disclose the estimated fair value of their financial instruments that are not recorded at fair value. For the Company, as for most financial institutions, substantially all of its assets and liabilities are considered financial instruments. A financial instrument is defined as cash, evidence of an ownership interest in an entity or a contract that creates a contractual obligation or right to deliver or receive cash or another financial instrument from a second entity. The following methods and assumptions were used to estimate the fair value of each class of financial instruments: Cash and Cash Equivalents Include: Cash and Due from Banks, Federal Funds Sold and Interest-Bearing Deposits The carrying amount of these short-term instruments is a reasonable estimate of fair value. Securities Held for Investment For securities held for investment, which are generally traded in secondary markets, fair values are based on quoted market prices or dealer quotes, if available. If a quoted market price is not available, fair value is estimated using quoted market prices for similar securities making adjustments for credit or liquidity if applicable. Loans For certain homogeneous categories of loans, such as some residential mortgages, fair values are estimated using the quoted market prices for securities backed by similar loans, adjusted for differences in loan characteristics. The fair values of other types of loans are estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. Deposits The fair values of transaction and savings accounts are the amounts payable on demand at the reporting date. The fair values of fixed-maturity certificates of deposit are estimated using the rates currently offered for deposits of similar remaining maturities. Short-term Borrowings The amounts payable on these short-term instruments are reasonable estimates of fair value. Junior Subordinated Debentures The fair values of junior subordinated debentures are estimated using the rates that would be charged for junior subordinated debentures of similar remaining maturities. Loan Commitments and Letters of Credit The fair values of commitments are estimated using the fees currently charged to enter into similar agreements, taking into account the terms of the agreements. The fair values of letters of credit are based on fees currently charged for similar agreements. The estimated fair values of the Company’s financial instruments that are reported at amortized cost in the Company’s consolidated balance sheets, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value, are as follows: December 31, 2016 2015 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,851,161 $ 1,851,161 $ 1,598,177 $ 1,598,177 Securities held for investment 3,722 3,760 8,289 8,350 Level 3 inputs: Securities held for investment 643 643 500 500 Loans, net of allowance for loan losses 4,351,539 4,367,363 4,190,382 4,222,153 FINANCIAL LIABILITIES Level 2 inputs: Deposits 6,248,057 6,313,622 5,973,358 6,028,012 Short-term borrowings 500 500 500 500 Junior subordinated debentures 31,959 34,339 31,959 33,793 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,718 1,681 Letters of credit 424 464 Non-financial Assets and Non-financial Liabilities Measured at Fair Value The Company has no non-financial assets or non-financial liabilities measured at fair value on a recurring basis. Certain non-financial assets and non-financial liabilities measured at fair value on a nonrecurring basis include intangible assets (excluding mortgage service rights, which are valued semi-annually) and other non-financial long-lived assets measured at fair value and adjusted for impairment. These items are evaluated at least annually for impairment, of which there were none as of December 31, 2016 or 2015. The overall levels of non-financial assets and non-financial liabilities measured at fair value on a nonrecurring basis were not considered to be significant to the Company at December 31, 2016 or 2015.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	(21) DERIVATIVE FINANCIAL INSTRUMENTS The Company enters into oil and gas swaps and options contracts to accommodate the business needs of its customers. Upon the origination of an oil or gas swap or option contract with a customer, to mitigate the exposure to fluctuations in oil and gas prices, the Company simultaneously enters into an offsetting contract with a counterparty. These derivatives are not designated as hedged instruments and are recorded on the Company’s consolidated balance sheet at fair value. The Company utilizes dealer quotations and observable market data inputs to substantiate internal valuation models. The notional amounts and estimated fair values of oil and gas derivative positions outstanding are presented in the following table: December 31, 2016 2015 Oil and Natural Gas Swaps and Options Notional Units Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value (Notional amounts and dollars in thousands) Oil Derivative assets Barrels 83 $ 576 86 $ 604 Derivative liabilities Barrels (83 ) (496 ) (86 ) (378 ) Natural Gas Derivative assets MMBTUs 1,900 993 3,920 1,342 Derivative liabilities MMBTUs (1,900 ) (810 ) (3,920 ) (611 ) Total Fair Value Included in Derivative assets Other assets 1,569 1,946 Derivative liabilities Other liabilities (1,306 ) (989 ) The following table is a summary of the Company’s recognized income related to the activity, which was included in other noninterest income: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Derivative income $ 32 $ 341 $ 500 The Company’s credit exposure on oil and gas swaps and options varies based on the current market prices of oil and natural gas. Other than credit risk, changes in the fair value of customer positions will be offset by equal and opposite changes in the counterparty positions. The net positive fair value of the contracts represents the profit derived from the activity and is unaffected by market price movements. The Company’s share of total profit is approximately 35%. Customer credit exposure is managed by strict position limits and is primarily offset by first liens on production while the remainder is offset by cash. Counterparty credit exposure is managed by selecting highly rated counterparties (rated A- or better by Standard and Poor’s) and monitoring market information. The following table is a summary of the Company’s net credit exposure relating to oil and gas swaps and options with bank counterparties: December 31, 2016 2015 (Dollars in Credit exposure $ — $ 37 Balance Sheet Offsetting Derivatives may be eligible for offset in the consolidated balance sheet and/or subject to master netting arrangements. The Company’s derivative transactions with upstream financial institution counterparties and bank customers are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements which include “right of set-off” provisions. In such cases there is generally a legally enforceable right to offset recognized amounts and there may be an intention to settle such amounts on a net basis. Nonetheless, the Company does not generally offset such financial instruments for financial reporting purposes.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Information	(22) SEGMENT INFORMATION The Company evaluates its performance with an internal profitability measurement system that measures the profitability of its business units on a pre-tax basis. The four principal business units are metropolitan banks, community banks, other financial services and executive, operations and support. Metropolitan and community banks offer traditional banking products such as commercial and retail lending, and a full line of deposit accounts. Metropolitan banks consist of banking locations in the metropolitan Oklahoma City and Tulsa areas. Community banks consist of banking locations in communities throughout Oklahoma. Other financial services are specialty product business units including guaranteed small business lending, residential mortgage lending, trust services, securities brokerage, electronic banking and insurance. The executive, operations and support groups represent executive management, operational support and corporate functions that are not allocated to the other business units. The results of operations and selected financial information for the four business units are as follows: Metropolitan Banks Community Banks Other Financial Services Executive, Operations & Support Eliminations Consolidated (Dollars in thousands) December 31, 2016 Net interest income (expense) $ 63,519 $ 135,508 $ 6,132 $ (1,331 ) $ — $ 203,828 Provision for loan losses 2,229 7,509 1,653 128 — 11,519 Noninterest income 16,372 57,745 29,711 75,415 (72,211 ) 107,032 Depreciation and amortization 2,341 8,281 510 1,251 — 12,383 Other expenses 34,130 96,627 22,216 26,375 (327 ) 179,021 Income before taxes $ 41,191 $ 80,836 $ 11,464 $ 46,330 $ (71,884 ) $ 107,937 Total assets $ 2,493,096 $ 4,412,174 $ 83,594 $ 803,810 $ (773,722 ) $ 7,018,952 Capital expenditures $ 1,525 $ 7,738 $ 125 $ 1,447 $ — $ 10,835 December 31, 2015 Net interest income (expense) $ 61,500 $ 122,404 $ 6,798 $ (1,910 ) $ — $ 188,792 Provision for loan losses 2,684 3,806 1,176 9 — 7,675 Noninterest income 16,552 52,598 33,629 72,806 (69,777 ) 105,808 Depreciation and amortization 2,273 7,894 514 1,220 — 11,901 Other expenses 32,942 91,655 22,308 27,221 (312 ) 173,814 Income before taxes $ 40,153 $ 71,647 $ 16,429 $ 42,446 $ (69,465 ) $ 101,210 Total assets $ 2,277,870 $ 4,379,205 $ 128,697 $ 624,428 $ (717,371 ) $ 6,692,829 Capital expenditures $ 3,743 $ 4,634 $ 121 $ 2,765 $ — $ 11,263 December 31, 2014 Net interest income (expense) $ 59,923 $ 116,935 $ 6,155 $ (1,662 ) $ — $ 181,351 Provision for loan losses 3,077 (488 ) 481 2 — 3,072 Noninterest income 13,752 51,415 28,079 69,442 (66,275 ) 96,413 Depreciation and amortization 2,216 7,277 522 1,334 — 11,349 Other expenses 32,300 89,888 22,304 27,998 (318 ) 172,172 Income before taxes $ 36,082 $ 71,673 $ 10,927 $ 38,446 $ (65,957 ) $ 91,171 Total assets $ 2,298,828 $ 4,113,783 $ 145,814 $ 679,194 $ (662,647 ) $ 6,574,972 Capital expenditures $ 1,948 $ 7,972 $ 121 $ 1,449 $ — $ 11,490 The financial information for each business unit is presented on the basis used internally by management to evaluate performance and allocate resources. The Company utilizes a transfer pricing system to allocate the benefit or cost of funds provided or used by the various business units. Certain services provided by the support group to other business units, such as item processing, are allocated at rates approximating the cost of providing the services. Eliminations are adjustments to consolidate the business units and companies. Capital expenditures are generally charged to the business unit using the asset.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	(23) SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) A summary of the unaudited quarterly results of operations for the years ended December 31, 2016 and 2015 is as follows: Quarter Fourth Third Second First (Dollars in thousands, except per share data) 2016 Net interest income $ 51,553 $ 51,431 $ 50,868 $ 49,976 Provision for loan losses 1,672 2,940 2,804 4,103 Securities transactions 52 (146 ) (65 ) 100 Noninterest income 27,431 27,927 26,057 25,617 Noninterest expense 48,189 49,204 47,720 46,291 Net income 18,620 17,982 17,493 16,579 Net income per common share: Basic 1.19 1.15 1.12 1.07 Diluted 1.16 1.13 1.10 1.05 2015 Net interest income $ 50,075 $ 46,876 $ 46,215 $ 45,626 Provision for loan losses 3,646 1,424 1,271 1,334 Securities transactions 2,148 — 5,392 1,729 Noninterest income 26,473 25,324 28,715 25,296 Noninterest expense 49,011 46,352 45,429 44,923 Net income 15,728 15,630 18,553 16,259 Net income per common share: Basic 1.00 1.01 1.19 1.05 Diluted 0.99 0.98 1.17 1.03

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Event

Description of Business and S33

Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations BancFirst Corporation is an Oklahoma business corporation and a financial holding company under federal law. It conducts virtually all of its operating activities through its principal wholly-owned subsidiary, BancFirst (the “Bank” or “BancFirst”), a state-chartered bank headquartered in Oklahoma City, Oklahoma. The Bank provides a wide range of retail and commercial banking services, including: commercial, real estate, agricultural and consumer lending; depository and funds transfer services; collections; safe deposit boxes; cash management services; retail brokerage services; and other services tailored for both individual and corporate customers. The Bank also offers trust services and acts as executor, administrator, trustee, transfer agent and in various other fiduciary capacities. Through its Technology and Operations Center, the Bank provides item processing, research and other correspondent banking services to financial institutions and governmental units. The Company’s wholly-owned subsidiary, BancFirst Insurance Services, Inc., an independent insurance agency, offers a variety of commercial and personal insurance products. In addition, the Company’s wholly-owned subsidiary, Council Oak Partners, LLC, an Oklahoma limited liability company, engages in investing activities.
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of BancFirst Corporation, Council Oak Partners, LLC, BancFirst Insurance Services, Inc. and BancFirst and its subsidiaries. The principal operating subsidiaries of BancFirst are Council Oak Investment Corporation, Council Oak Real Estate Inc. and BancFirst Agency, Inc. All significant intercompany accounts and transactions have been eliminated. Assets held in a fiduciary or agency capacity are not assets of the Company and, accordingly, are not included in the consolidated financial statements. Certain amounts from 2015 and 2014 have been reclassified to conform to the 2016 presentation. These reclassifications were not material to the Company’s financial statements.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States inherently involves the use of estimates and assumptions that affect the amounts reported in the financial statements and the related disclosures. These estimates relate principally to the determination of the allowance for loan losses, income taxes, the fair value of financial instruments and the valuation of intangibles. Such estimates and assumptions may change over time and actual amounts realized may differ from those reported.
Securities	Securities The Company does not engage in securities trading activities. Any sales of securities are for the purpose of executing the Company’s asset/liability management strategy, eliminating a perceived credit risk in a specific security or providing liquidity. Securities that are being held for indefinite periods of time, or that may be sold as part of the Company’s asset/liability management strategy, to provide liquidity or for other reasons, are classified as available for sale and are stated at estimated fair value. Unrealized gains or losses on securities available for sale are reported as a component of stockholders’ equity, net of income tax. Gains or losses from sales of securities are based upon the book values of the specific securities sold. Securities for which the Company has the intent and ability to hold to maturity are classified as held for investment and are stated at cost, adjusted for amortization of premiums and accretion of discounts computed under the interest method. The Company reviews its portfolio of securities for impairment at least quarterly. Impairment is considered to be other-than-temporary if it is likely that all amounts contractually due will not be received for debt securities and when there is no positive evidence indicating that an investment’s carrying amount is recoverable in the near term for equity securities. When impairment is considered other-than-temporary, the cost basis of the security is written down to fair value, with the impairment charge included in earnings. In evaluating whether the impairment is temporary or other-than-temporary, the Company considers, among other things, the time period the security has been in an unrealized loss position, and whether the Company has the intent and ability to hold a security for a period of time sufficient to allow for any anticipated recovery in fair value.
Loans	Loans The lending function is governed by written policies and procedures, as determined by senior management and approved by the Board of Directors. The policies and procedures set the standards for lending in each major loan category by collateral type and use of loan proceeds. The objectives of these policies and procedures are to identify profitable markets, determine appropriate risk tolerance levels for each type of loan, establish limits for loan officer approval, set concentration limits, establish loan-to-value thresholds, set repayment terms and loan structure guidelines and adhere to documentation requirements. Interest rate risk is controlled by the use of variable rate provisions, approximately 50% of which have a rate floor, limits on fixing rates for longer periods and the use of prepayment penalties. One-to-four family residential real estate loans are made in accordance with underwriting policies and are fully documented. Credit worthiness is assessed based on significant credit characteristics including credit history and residential and employment stability. These loans include first liens, junior liens and home equity lines of credit. The composition of this portfolio is primarily first liens, which comprise more than 82% of the portfolio, with junior liens comprising less than 10%, and home equity lines of credit comprising less than 8%. The Company does not engage in any hybrid loan programs. In addition, the Company does not have any exposure to loans with negative amortization, interest rate carryover or discounting of the initial rates (teaser rates). Loans originated within the Company are stated at the principal amount outstanding, net of unearned interest, loan fees and allowance for loan losses. Interest on all performing loans is recognized, on a simple interest basis, based upon the principal amount outstanding. A loan is placed on nonaccrual status when, in the opinion of management, the future collectability of interest and/or principal is not probable. When interest accrual is discontinued, all unpaid accrued interest is reversed. Interest income is recognized on certain of these loans on a cash basis if the full collection of the remaining principal balance is reasonably expected. Otherwise, interest income is not recognized until the principal balance is fully collected. See Note (5) for loan disclosures.
Acquired Loans	Acquired Loans Loans acquired through business combinations since December 2009 are required to be carried at fair value as of the date of the combination. Loans that would have a general allowance for loan losses or have specific evidence of deterioration of credit quality since origination are adjusted to fair value and any allowance for loan losses is eliminated. The difference between the fair value of loans which do not have specific evidence of deterioration of credit quality since origination and their principal balance is recognized in interest income on a level-yield method over the life of the loans. For loans which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments (as determined by the present value of expected future cash flows), the difference between the undiscounted cash flows expected at acquisition and the investment in the loan, or the “accretable yield,” is recognized in interest income on a level-yield method over the life of the loan. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as yield adjustments or as loss accruals or valuation allowances. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loan over its remaining life. Decreases in expected cash flows are recognized as impairments. Any probable loss due to subsequent credit deterioration of the loans since acquisition is provided for in the allowance for loan losses.
Loans Held For Sale	Loans Held For Sale The Company originates mortgage loans to be sold. At the time of origination, the acquiring bank has already been determined and the terms of the loan, including the interest rate, have already been set by the acquiring bank allowing the Company to originate the loan at fair value. Mortgage loans are generally sold within 30 days of origination. Loans held for sale are carried at the lower of cost or market. Gains or losses recognized upon the sale of the loans are determined on a specific identification basis. The Company does not sell residential mortgage loans with recourse other than obligations under standard representations and warranties or for fraud. These obligations relate to loan performance for the life of the loan. The amount of loans repurchased since the inception of the program is not considered to be material, and therefore, no reserve has been required.
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses is an estimate of probable credit losses related to specifically identified loans and for losses inherent in the portfolio that have been incurred as of the balance sheet date. The allowance for loan losses is increased by provisions charged to operating expense and is reduced by net loan charge-offs. The amount of the allowance for loan losses is based on past loan loss experience, evaluations of known impaired loans, levels of adversely graded loans, general economic conditions and other environmental factors. 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 aggregate for smaller-balance loans of a similar nature and on an individual loan basis for other loans. If a loan is impaired, a specific allowance is provided, 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 primarily 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.
Appraisal Policy	Appraisal Policy An updated appraisal of the collateral is obtained when a loan is first identified as a problem loan. Appraisals are reviewed annually and are updated as needed, or are updated more frequently if significant changes are believed to have occurred in the collateral or market conditions. Appraisals of other real estate owned are also reviewed and updated consistent with this policy.
Nonaccrual Policy	Nonaccrual Policy The Company does not accrue interest on (1) any loan upon which a default of principal or interest has existed for a period of 90 days or over unless the collateral margin or guarantor support are such that full collection of principal and interest are not in doubt, and an orderly plan for collection is in process; and (2) any other loan for which it is expected full collection of principal and interest is not probable. A nonaccrual loan may be restored to an accrual status when none of its principal and interest are past due and unpaid or otherwise becomes well secured and in the process of collection and when prospects for collection of future contractual payments are no longer in doubt. With the exception of a formal debt forgiveness agreement, no loan which has had principal charged-off shall be restored to accrual status unless the charged-off principal has been recovered.
Charge-off Policy	Charge-off Policy When a loan deteriorates to the point that the account officer or the Loan Committee concludes it no longer represents a viable asset, it will be charged off. Similarly, any portion of a loan that is deemed to no longer be a viable asset will be charged off. A loan will not be charged off unless such action has been approved by the branch President.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost, less accumulated depreciation. Depreciation is charged to operating expense and is computed using the straight-line method over the estimated useful lives of the assets. Maintenance and repairs are charged to expense as incurred while improvements are capitalized. Premises and equipment is tested for impairment if events or changes in circumstances occur that indicate that the carrying amount of any premises and equipment may not be recoverable. Impairment losses are measured by comparing the fair values of the premises and equipment with their recorded amounts. Premises that are identified to be sold are transferred to other real estate owned at the lower of their carrying amounts or their fair values less estimated costs to sell. Any losses on premises identified to be sold are charged to operating expense. When premises and equipment are transferred to other real estate owned, sold, or otherwise retired, the cost and applicable accumulated depreciation are removed from the respective accounts and any resulting gains or losses are reported in the statement of comprehensive income.
Other Real Estate Owned	Other Real Estate Owned Other real estate owned consists of properties acquired through foreclosure proceedings or acceptance of a deed in lieu of foreclosure, and premises held for sale. These properties are carried at the lower of the book values of the related loans or fair values based upon appraisals, less estimated costs to sell. Losses arising at the time of reclassification of such properties from loans to other real estate owned are charged directly to the allowance for loan losses. Any losses on premises identified to be sold are charged to operating expense at the time of transfer from premises to other real estate owned. Losses from declines in value of the properties subsequent to classification as other real estate owned are charged to operating expense. During 2016, the Company had gains on the sale of other real estate owned totaling $1.2 million that is included in net expense (income) from other real estate owned in the consolidated statements of comprehensive income.
Intangible Assets and Goodwill	Intangible Assets and Goodwill Core deposit intangibles are amortized on a straight-line basis over the estimated useful lives of seven to ten years and customer relationship intangibles are amortized on a straight-line basis over the estimated useful life of three to eighteen years. Mortgage servicing rights are amortized based on current prepayment assumptions. Goodwill is not amortized, but is evaluated at a reporting unit level at least annually for impairment, or more frequently if other indicators of impairment are present. At least annually in the fourth quarter, intangible assets, excluding mortgage servicing rights, are evaluated for possible impairment. Impairment losses are measured by comparing the fair values of the intangible assets with their recorded amounts. Any impairment losses are reported in the statement of comprehensive income. Mortgage servicing rights are adjusted to fair value semi-annually, if impaired.
Derivatives	Derivatives The Company recognizes all of its derivative instruments as assets or liabilities in the balance sheet at fair value and recognizes the realized and unrealized change in fair value in the statement of comprehensive income. Income is derived from a fixed pricing spread when customer hedge contracts are immediately offset with counterparty contracts as compensation for administrative costs and credit risk and recognized in other noninterest income.
Insurance Commissions and Fees	Insurance Commissions and Fees Commission revenue is recognized at the later of the billing date or the effective date of the related insurance policies for those accounts billed by the Agency. Commission revenue, for accounts that are directly billed by the insurance company to the insured, is recognized when determinable by the Agency, which is generally when such commissions are received. The Agency also receives contingent commissions from insurance companies as additional incentive for achieving specified premium volume goals and/or loss experience parameters relating to the insurance placed by the Agency. Contingent commissions from insurance companies are recognized when determinable, which is generally when such commissions are received.
Stock-based Compensation	Stock-based Compensation The Company recognizes stock-based compensation as compensation expense in the statement of comprehensive income based on the fair value of the Company’s stock options on the measurement date, which, for the Company, is the date of the grant. The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model and is based on certain assumptions including risk-free rate of return, dividend yield, stock price volatility and the expected term. The fair value of each option is expensed over its vesting period.
Income Taxes	Income Taxes The Company files a consolidated income tax return with its subsidiaries. Federal and state income tax expense or benefit has been allocated to subsidiaries on a separate return basis. Deferred taxes are recognized under the balance sheet method based upon the future tax consequences of temporary differences between the carrying amounts and tax basis of assets and liabilities, using the tax rates expected to apply to taxable income in the periods when the related temporary differences are expected to be realized. Realization of deferred tax assets is dependent upon the generation of a sufficient level of future taxable income and recoverable taxes paid in prior years. Although realization is not assured, management believes it is more likely than not that all of the deferred tax assets will be realized.
Earnings Per Common Share	Earnings Per Common Share Basic earnings per common share is computed by dividing net income, less any preferred dividends requirement, by the weighted average of common shares outstanding. Diluted earnings per common share reflects the potential dilution that could occur if options, convertible securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the Company.
Comprehensive Income	Comprehensive Income Comprehensive income includes all changes in stockholders’ equity during a period, except those resulting from transactions with stockholders. Besides net income, other components of the Company’s comprehensive income includes the after tax effect of changes in the net unrealized gain/loss on securities available for sale.
Statement of Cash Flows	Statement of Cash Flows For purposes of the statement of cash flows, the Company considers cash and due from banks and interest-bearing deposits with banks as cash equivalents.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In January 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2017-04, “Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” ASU 2017-04 removes the second step of goodwill testing. ASU 2017-04 will be effective on January 1, 2020 and is not expected to have a significant impact on the Company’s financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business.” ASU 2017-01 clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of a business. ASU 2017-01 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In October 2016, the FASB issued ASU No. 2016-17, “Consolidation (Topic 810): Interests Held Through Related Parties That Are Under Common Control.” ASU 2016-17 updates ASU No. 2015-02 to amend the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. ASU 2016-17 will be effective on January 1, 2017 and is not expected to have a significant impact on the Company’s financial statements. In October 2016, the FASB issued ASU No. 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” ASU 2016-16 provides guidance stating that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” ASU 2016-15 is intended to reduce the diversity in practice around how certain transactions are classified within the statement of cash flows. ASU 2016-15 will be effective on January 1, 2018. Early adoption is permitted with retrospective applications. The Company is currently evaluating the potential impact of ASU 2016-15 on its financial statements. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires a financial asset 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. ASU 2016-13 requires enhanced disclosures related to the significant estimates and judgements used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASU 2016-13 amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 will be effective on January 1, 2020. The Company is currently evaluating the potential impact of ASU 2016-13 on its financial statements. In March 2016, the FASB issued ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Under ASU 2016-09 all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. ASU 2016-09 also provides that an entity can make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest (current GAAP) or account for forfeitures when they occur. ASU 2016-09 changes the threshold to qualify for equity classification (rather than as a liability) to permit withholding up to the maximum statutory tax rates (rather than the minimum as was previously the case) in the applicable jurisdictions. ASU 2016-09 will be effective on January 1, 2017 and is not expected to have a significant impact on the Company’s financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases - (Topic 842).” ASU 2016-02 requires that lessees recognize on the balance sheet the assets and liabilities for the rights and obligations created by leases. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted. Adoption of ASU 2016-02 is not expected to have a significant impact on the Company’s financial statements. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments - Overall (Subtopic 825-10).” ASU 2016-01 require all 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 the fair value recognized through net income. In addition, the amendment will require 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. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. Early adoption is not permitted. Adoption of ASU 2016-01 is not expected to have a significant impact on the Company’s financial statements. In August 2014, the FASB issued ASU No. 2014-15, “Presentation of Financial Statements – Going Concern (Topic 205-40).” ASU 2014-15 provides guidance on management’s responsibility in evaluating whether there is substantial doubt about the Company’s ability to continue as a going concern and related footnote disclosures. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year from the date the financial statements are issued. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2016. Early adoption is permitted. Adoption of ASU 2014-15 is not expected to have a significant impact on the Company’s financial statements. In January of 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customer (Topic 606).” ASU 2014-09 implements a comprehensive new revenue recognition standard that will supersede substantially all existing revenue recognition guidance. The new standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in a manner that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, which comprises a significant portion of our revenue stream. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606).” ASU 2015-14 is an amendment to defer the effective date of ASU N. 2014-09. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted for the Company as of January 1, 2017. Adoption of ASU 2014-09 may require the Company to amend how it recognizes certain recurring revenue streams related to trust fees, which are recorded in non-interest expense; however, the Company does not expect the adoption of ASU 2014-09 to have a significant impact on the Company’s financial statements.

Cash, Due from Banks, Interes34

Cash, Due from Banks, Interest-Bearing Deposits and Federal Funds Sold (Tables)	12 Months Ended
	Dec. 31, 2016
Cash And Cash Equivalents [Abstract]
Summary of Average Amount of Required Reserves	The average amount of required reserves for each of the years ended December 31, 2016 and 2015 is included in the following table: December 31, 2016 2015 (Dollars in thousands) Vault cash and funds on deposit with the Federal Reserve Bank $ 1,754,956 $ 1,499,137 Average required Reserves 41,968 40,093

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]
Summary of Securities Held for Investment and Securities Available for Sale	The following table summarizes securities held for investment and securities available for sale: December 31, 2016 2015 (Dollars in thousands) Held for investment, at cost (fair value: $4,403 and $8,850, respectively) $ 4,365 $ 8,789 Available for sale, at fair value 465,468 544,160 Total $ 469,833 $ 552,949
Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment	The following table summarizes the amortized cost and estimated fair values of securities held for investment: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (Dollars in thousands) December 31, 2016 Mortgage backed securities (1) $ 252 $ 17 $ — $ 269 States and political subdivisions 3,613 25 (4 ) 3,634 Other securities 500 — — 500 Total $ 4,365 $ 42 $ (4 ) $ 4,403 December 31, 2015 Mortgage backed securities (1) $ 347 $ 25 $ — $ 372 States and political subdivisions 7,942 36 — 7,978 Other securities 500 — — 500 Total $ 8,789 $ 61 $ — $ 8,850
Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale	The following table summarizes the amortized cost and estimated fair values of securities available for sale: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (Dollars in thousands) December 31, 2016 U.S. treasuries $ 268,763 $ 700 $ (920 ) $ 268,543 U.S. federal agencies 129,674 373 (405 ) 129,642 Mortgage backed securities (1) 19,949 290 (567 ) 19,672 States and political subdivisions 40,335 836 (129 ) 41,042 Other securities (2) 6,594 125 (150 ) 6,569 Total $ 465,315 $ 2,324 $ (2,171 ) $ 465,468 December 31, 2015 U.S. treasuries $ 328,965 $ 776 $ (45 ) $ 329,696 U.S. federal agencies 131,522 527 (153 ) 131,896 Mortgage backed securities (1) 21,973 425 (543 ) 21,855 States and political subdivisions 49,521 1,447 (48 ) 50,920 Other securities (2) 9,689 249 (145 ) 9,793 Total $ 541,670 $ 3,424 $ (934 ) $ 544,160 (1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies. (2) Primarily consists of equity securities.
Maturity of Securities	The maturities of securities held for investment and available for sale are summarized in the following table using contractual maturities. Actual maturities may differ from contractual maturities due to obligations that are called or prepaid. For purposes of the maturity table, mortgage-backed securities, which are not due at a single maturity date, have been presented at their contractual maturity. December 31, 2016 2015 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 1,561 $ 1,568 $ 5,168 $ 5,174 After one year but within five years 1,937 1,951 2,800 2,829 After five years but within ten years 707 723 795 319 After ten years 160 161 26 528 Total $ 4,365 $ 4,403 $ 8,789 $ 8,850 Available for Sale Contractual maturity of debt securities: Within one year $ 66,542 $ 66,662 $ 272,820 $ 272,779 After one year but within five years 320,150 319,839 178,617 180,145 After five years but within ten years 5,830 6,152 8,483 9,075 After ten years 66,199 66,246 75,522 75,853 Total debt securities 458,721 458,899 535,442 537,852 Other securities 6,594 6,569 6,228 6,308 Total $ 465,315 $ 465,468 $ 541,670 $ 544,160
Proceeds from Sales and Realized Securities Gains and Losses, on Available for Sale Securities	The following is a detail of proceeds from sales and realized securities gains and losses, on available for sale securities: Year Ended December 31, 2016 2015 2014 (Dollars Proceeds $ 481 $ 10,850 $ 4,855 Gross gains realized 227 9,394 1,641 Gross losses realized 286 125 —
Company's Book Value of Pledged Securities	The following table is a summary of the Company’s book value of securities that were pledged as collateral for public funds on deposit, repurchase agreements and for other purposes as required or permitted by law: Year Ended December 31, 2016 2015 (Dollars Book value of pledged securities $ 439,692 $ 493,540
Summary of Securities with Unrealized Losses, Segregated by Duration of Unrealized Loss	The following table summarizes securities with unrealized losses, segregated by the duration of the unrealized loss, at December 31, 2016 and 2015 respectively: 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) December 31, 2016 Held for Investment Mortgage backed securities $ 7 $ — $ 9 $ — $ 16 $ — States and political subdivisions 476 4 — — 476 4 Total $ 483 $ 4 $ 9 $ — $ 492 $ 4 Available for Sale U.S. treasuries $ 103,705 $ 920 $ — $ — $ 103,705 $ 920 U.S. federal agencies 71,511 357 9,619 48 81,130 405 Mortgage backed securities 3 — 14,834 567 14,837 567 States and political subdivisions 15,289 62 779 67 16,068 129 Other securities — — 589 150 589 150 Total $ 190,508 $ 1,339 $ 25,821 $ 832 $ 216,329 $ 2,171 December 31, 2015 Held for Investment Mortgage backed securities $ 21 $ — $ — $ — $ 21 $ — States and political subdivisions — — — — — — Total $ 21 $ — $ — $ — $ 21 $ — Available for Sale U.S. treasuries $ 139,762 $ 45 $ — $ — $ 139,762 $ 45 U.S. federal agencies 46,948 118 5,969 35 52,917 153 Mortgage backed securities 59 — 14,844 543 14,903 543 States and political subdivisions 1,932 47 245 1 2,177 48 Other securities 304 142 105 3 409 145 Total $ 189,005 $ 352 $ 21,163 $ 582 $ 210,168 $ 934

Loans and Allowance for Loan 36

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Schedule of Loans Outstanding by Category	The following is a schedule of loans outstanding by category: December 31, 2016 2015 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 828,260 18.82 % $ 795,803 18.80 % Oil & gas production and equipment 84,228 1.91 87,304 2.06 Agriculture 144,751 3.29 150,620 3.56 State and political subdivisions: Taxable 33,793 0.77 17,605 0.42 Tax-exempt 47,283 1.07 33,575 0.79 Real estate: Construction 420,884 9.57 403,664 9.54 Farmland 197,872 4.50 184,707 4.36 One to four family residences 846,360 19.24 821,251 19.41 Multifamily residential properties 57,806 1.31 65,477 1.55 Commercial 1,426,643 32.42 1,356,430 32.05 Consumer 279,704 6.36 283,636 6.70 Other (not classified above) 32,648 0.74 31,976 0.76 Total loans $ 4,400,232 100.00 % $ 4,232,048 100.00 %
Summary of Nonperforming and Restructured Assets	The following is a summary of nonperforming and restructured assets: December 31, 2016 2015 (Dollars in thousands) Past due 90 days or more and still accruing $ 1,962 $ 1,841 Nonaccrual 31,798 30,096 Restructured 1,713 15,143 Total nonperforming and restructured loans 35,473 47,080 Other real estate owned and repossessed assets 3,866 8,214 Total nonperforming and restructured assets $ 39,339 $ 55,294
Summary of Amounts Included in Nonaccrual Loans Segregated by Class of Loans	Loans are segregated into classes based upon the nature of the collateral and the borrower. These classes are used to estimate the allowance for loan losses. The following table is a summary of amounts included in nonaccrual loans, segregated by class of loans. Residential real estate refers to one-to-four family real estate. December 31, 2016 2015 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 713 $ 261 Non-residential real estate other 5,688 3,957 Residential real estate permanent mortgage 1,116 656 Residential real estate all other 5,089 1,833 Commercial and financial: Non-consumer non-real estate 4,464 10,159 Consumer non-real estate 265 312 Other loans 8,370 9,381 Acquired loans 6,093 3,537 Total $ 31,798 $ 30,096
Age Analysis of Past Due Loans Segregated by Class of Loans	The following table presents an age analysis of past due loans, segregated by class of loans: Age Analysis of Past Due Loans 30-59 Days Past Due 60-89 Days Past Due 90 Days and Greater Total Past Due Loans Current Loans Total Loans Accruing Loans 90 Days or More Past Due (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 2,255 $ 96 $ 150 $ 2,501 $ 569,130 $ 571,631 $ — Non-residential real estate other 611 16 418 1,045 1,122,351 1,123,396 — Residential real estate permanent mortgage 2,742 649 1,273 4,664 320,749 325,413 513 Residential real estate all other 2,559 531 1,416 4,506 743,723 748,229 369 Commercial and financial: Non-consumer non-real estate 1,269 1,628 741 3,638 1,047,547 1,051,185 608 Consumer non-real estate 2,046 760 419 3,225 280,652 283,877 274 Other loans 5,345 958 7,775 14,078 127,404 141,482 45 Acquired loans 825 310 408 1,543 153,476 155,019 153 Total $ 17,652 $ 4,948 $ 12,600 $ 35,200 $ 4,365,032 $ 4,400,232 $ 1,962 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 441 $ 179 $ 183 $ 803 $ 502,094 $ 502,897 $ — Non-residential real estate other 1,149 108 568 1,825 1,108,935 1,110,760 521 Residential real estate permanent mortgage 2,840 636 648 4,124 328,477 332,601 493 Residential real estate all other 2,842 609 824 4,275 672,414 676,689 193 Commercial and financial: Non-consumer non-real estate 2,278 161 187 2,626 982,136 984,762 152 Consumer non-real estate 2,237 772 349 3,358 265,511 268,869 278 Other loans 3,565 295 1,761 5,621 156,995 162,616 132 Acquired loans 1,052 71 918 2,041 190,813 192,854 72 Total $ 16,404 $ 2,831 $ 5,438 $ 24,673 $ 4,207,375 $ 4,232,048 $ 1,841
Impaired Loans Segregated by Class of Loans	The following table presents impaired loans, segregated by class of loans. No material amount of interest income was recognized on impaired loans subsequent to their classification as impaired. Impaired Loans Unpaid Principal Balance Recorded Investment with Allowance Related Allowance Average Recorded Investment (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 894 $ 806 $ 101 $ 825 Non-residential real estate other 7,742 5,688 574 5,854 Residential real estate permanent mortgage 1,878 1,683 124 1,612 Residential real estate all other 5,871 5,614 1,538 5,445 Commercial and financial: Non-consumer non-real estate 12,015 6,272 1,457 6,478 Consumer non-real estate 686 650 133 788 Other loans 9,799 8,415 1,870 8,062 Acquired loans 8,780 6,581 — 6,041 Total $ 47,665 $ 35,709 $ 5,797 $ 35,105 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 507 $ 383 $ 14 $ 446 Non-residential real estate other 21,068 19,052 357 19,655 Residential real estate permanent mortgage 1,401 1,209 81 1,125 Residential real estate all other 2,498 2,235 242 1,958 Commercial and financial: Non-consumer non-real estate 13,897 10,312 2,062 11,786 Consumer non-real estate 738 715 181 652 Other loans 10,722 9,513 331 10,335 Acquired loans 6,295 4,248 — 4,564 Total $ 57,126 $ 47,667 $ 3,268 $ 50,521
Internal Loan Grading by Class of Loans	The following table presents internal loan grading by class of loans: Internal Loan Grading Grade 1 2 3 4 5 Total (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 464,504 $ 89,978 $ 16,220 $ 929 $ — $ 571,631 Non-residential real estate other 933,743 169,561 14,404 5,688 — 1,123,396 Residential real estate permanent mortgage 284,893 32,889 5,987 1,644 — 325,413 Residential real estate all other 614,338 119,018 9,382 5,491 — 748,229 Commercial and financial: Non-consumer non-real estate 856,318 170,865 19,101 4,901 — 1,051,185 Consumer non-real estate 263,442 17,154 2,640 641 — 283,877 Other loans 132,254 5,376 1,514 2,338 — 141,482 Acquired loans 92,946 42,668 12,888 6,517 — 155,019 Total $ 3,642,438 $ 647,509 $ 82,136 $ 28,149 $ — $ 4,400,232 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 417,529 $ 76,749 $ 8,304 $ 315 $ — $ 502,897 Non-residential real estate other 945,993 156,159 4,580 4,028 — 1,110,760 Residential real estate permanent mortgage 295,265 29,793 6,315 1,228 — 332,601 Residential real estate all other 554,007 111,879 9,109 1,694 — 676,689 Commercial and financial: Non-consumer non-real estate 821,394 140,384 12,687 10,297 — 984,762 Consumer non-real estate 251,994 14,433 1,779 662 1 268,869 Other loans 153,416 5,851 872 2,477 — 162,616 Acquired loans 165,305 12,566 11,049 3,858 76 192,854 Total $ 3,604,903 $ 547,814 $ 54,695 $ 24,559 $ 77 $ 4,232,048
Activity in ALL by Class of Loans	The following table details activity in the ALL by class of loans for the period presented. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. ALL Balance at beginning of period Charge- offs Recoveries Net charge-offs Provisions charged to operations Balance at end of period (Dollars in thousands) As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 4,661 $ (11 ) $ 3 $ (8 ) $ 949 $ 5,602 Non-residential real estate other 9,921 (9 ) 6 (3 ) 875 10,793 Residential real estate permanent mortgage 3,148 (208 ) 55 (153 ) 134 3,129 Residential real estate all other 6,725 (181 ) 21 (160 ) 2,057 8,622 Commercial and financial: Non-consumer non-real estate 11,754 (2,921 ) 122 (2,799 ) 3,466 12,421 Consumer non-real estate 2,642 (1,088 ) 159 (929 ) 1,091 2,804 Other loans 2,648 (388 ) 17 (371 ) 1,768 4,045 Acquired loans 167 (101 ) 32 (69 ) 1,179 1,277 Total $ 41,666 $ (4,907 ) $ 415 $ (4,492 ) $ 11,519 $ 48,693 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 4,406 $ (37 ) $ 1 $ (36 ) $ 291 $ 4,661 Non-residential real estate other 9,616 (708 ) 2 (706 ) 1,011 9,921 Residential real estate permanent mortgage 2,948 (222 ) 40 (182 ) 382 3,148 Residential real estate all other 6,269 (138 ) 17 (121 ) 577 6,725 Commercial and financial: Non-consumer non-real estate 12,771 (3,799 ) 199 (3,600 ) 2,583 11,754 Consumer non-real estate 2,404 (626 ) 124 (502 ) 740 2,642 Other loans 2,359 (1,109 ) 16 (1,093 ) 1,382 2,648 Acquired loans 116 (686 ) 28 (658 ) 709 167 Total $ 40,889 $ (7,325 ) $ 427 $ (6,898 ) $ 7,675 $ 41,666
Allowance for Loan Losses Outstanding by Impairment Methodology	The following table details the amount of ALL by class of loans for the period presented, on the basis of the impairment methodology used by the Company. ALL December 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Individually evaluated for impairment Collectively evaluated for impairment (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 716 $ 4,886 $ 323 $ 4,338 Non-residential real estate other 1,119 9,674 323 9,598 Residential real estate permanent mortgage 422 2,707 399 2,749 Residential real estate all other 2,160 6,462 839 5,886 Commercial and financial: Non-consumer non-real estate 3,317 9,104 3,365 8,389 Consumer non-real estate 478 2,326 445 2,197 Other loans 1,812 2,233 291 2,357 Acquired loans 495 782 — 167 Total $ 10,519 $ 38,174 $ 5,985 $ 35,681
Loans Outstanding by Impairment Methodology	The following table details the loans outstanding by class of loans for the period presented, on the basis of the impairment methodology used by the Company. Loans December 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 17,149 $ 554,482 $ — $ 8,619 $ 494,278 $ — Non-residential real estate other 20,092 1,103,304 — 8,608 1,102,152 — Residential real estate permanent mortgage 7,631 317,782 — 7,543 325,058 — Residential real estate all other 14,873 733,356 — 10,803 665,886 — Commercial and financial: Non-consumer non-real estate 24,002 1,027,183 — 22,983 961,779 — Consumer non-real estate 3,203 280,674 — 2,416 266,453 — Other loans 2,254 139,228 — 2,323 160,293 — Acquired loans 13,459 135,616 5,944 7,889 177,871 7,094 Total $ 102,663 $ 4,291,625 $ 5,944 $ 71,184 $ 4,153,770 $ 7,094
Transfers from Loans to Other Real Estate Owned and Repossessed Assets	Transfers from loans to other real estate owned and repossessed assets during the periods presented are summarized as follows: Year ended December 31, 2016 2015 2014 (Dollars in thousands) Other real estate owned $ 2,553 $ 2,139 $ 3,573 Repossessed assets 1,402 1,098 1,209 Total $ 3,955 $ 3,237 $ 4,782
Related Party Loans	A summary of these loans is as follows: Year Ended December 31, Balance Beginning of the Period Additions Collections/ Terminations Balance End of the Period (Dollars in thousands) 2016 $ 37,577 $ 16,133 $ (26,224 ) $ 27,486 2015 25,019 22,330 (9,772 ) 37,577 2014 27,134 22,521 (24,636 ) 25,019

Premises and Equipment, Net a37

Premises and Equipment, Net and Other Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Summary of Premises and Equipment by Classification	The following is a summary of premises and equipment by classification: December 31, Estimated Useful Lives 2016 2015 (Dollars in thousands) Land $ 32,441 $ 31,196 Buildings 10 to 40 years 138,901 135,694 Furniture, fixtures and equipment 3 to 15 years 64,293 63,436 Accumulated depreciation (108,864 ) (103,513 ) Premises and equipment, net $ 126,771 $ 126,813

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	The following is a summary of intangible assets: Gross Carrying Amount Accumulated Amortization Net Carrying Amount (Dollars in thousands) As of December 31, 2016 Core deposit intangibles $ 17,447 $ (6,611 ) $ 10,836 Customer relationship intangibles 5,699 (3,419 ) 2,280 Mortgage servicing intangibles 473 (259 ) 214 Total $ 23,619 $ (10,289 ) $ 13,330 As of December 31, 2015 Core deposit intangibles $ 20,333 $ (7,586 ) $ 12,747 Customer relationship intangibles 5,699 (3,061 ) 2,638 Mortgage servicing intangibles 538 (228 ) 310 Total $ 26,570 $ (10,875 ) $ 15,695
Estimated Amortization of Intangible Assets	Estimated amortization of intangible assets for the next five years, as of December 31, 2016, is as follows (dollars in thousands): Estimated Amortization 2017 $ 2,213 2018 2,213 2019 2,213 2020 2,101 2021 1,270
Summary of Goodwill by Business Segment	The following is a summary of goodwill by business segment: Other Executive, Metropolitan Community Financial Operations Banks Banks Services & Support Consolidated (Dollars in thousands) Year Ended December 31, 2016 Balance at beginning and end of period $ 8,078 $ 40,050 $ 5,464 $ 450 $ 54,042 Year Ended December 31, 2015 Balance at beginning of period $ 8,078 $ 30,970 $ 5,464 $ 450 $ 44,962 Acquisitions — 9,448 — — 9,448 Impairment — (368 ) — — (368 ) Balance at end of period $ 8,078 $ 40,050 $ 5,464 $ 450 $ 54,042

Time Deposits (Tables)

Time Deposits (Tables)	12 Months Ended
	Dec. 31, 2016
Banking And Thrift [Abstract]
Schedule of Maturities of Time Deposits	At December 31, 2016, the scheduled maturities of all time deposits are as follows (Dollars in thousands): 2017 $ 418,543 2018 124,568 2019 66,981 2020 37,823 2021 39,306 Thereafter 29 Total $ 687,250
Summary of Large Time Deposits for Periods Presented	The following table is a summary of large time deposits for the periods presented: December 31, 2016 2015 (Dollars in thousands) Time deposits of $100,000 or more $ 328,363 $ 342,916 The aggregate amount of domestic certificates of deposit that meet or exceed the current FDIC insurance limit was $122.2 million and $120.0 million at December 31, 2016 and 2015, respectively.

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Summary of Short- Term Borrowings	The following is a summary of short-term borrowings: December 31, 2016 2015 (Dollars in thousands) Federal funds purchased $ 500 $ 500 Weighted average interest rate 0.38 % 0.15 % End of period interest rate 0.63 % 0.38 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Components of the Company's Income Tax Expense (Benefit)	The components of the Company’s income tax expense (benefit) are as follows: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Current taxes: Federal $ 34,003 $ 32,348 $ 28,258 State 5,308 4,595 2,709 Deferred taxes (2,048 ) (1,903 ) (3,683 ) Total income taxes $ 37,263 $ 35,040 $ 27,284
Reconciliation of Tax Expense at the Federal Statutory Tax Rate	A reconciliation of tax expense at the federal statutory tax rate applied to income before taxes is presented in the following table: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Tax expense at the federal statutory tax rate $ 37,778 $ 35,424 $ 31,910 Increase (decrease) in tax expense from: Tax-exempt income, net (756 ) (663 ) (571 ) Modified endowment life contracts (852 ) (763 ) (755 ) State tax expense, net of federal tax benefit 3,250 2,898 1,469 Utilization of tax credits: New markets tax credits (1,254 ) (1,195 ) (1,108 ) Low-income housing tax credits, net of amortization (1,424 ) (1,274 ) (1,209 ) Other tax credits (319 ) (248 ) (1,979 ) Other, net 840 861 (473 ) Total tax expense $ 37,263 $ 35,040 $ 27,284
Summary of Net Deferred Tax Asset Reported in Other Assets	The net deferred tax asset consisted of the following and is reported in other assets: December 31, 2016 2015 (Dollars in thousands) Provision for loan losses $ 18,748 $ 16,110 Write-downs of other real estate owned 769 1,252 Deferred compensation 3,197 3,108 Stock-based compensation 2,441 3,201 Investments in partnership interests 4,603 3,651 Other 666 917 Gross deferred tax assets 30,424 28,239 Unrealized net gains on securities (59 ) (962 ) Premium on securities of banks acquired (453 ) (563 ) Intangibles (5,365 ) (5,575 ) Basis difference related to tax credits (3,435 ) (2,689 ) Depreciation (6,758 ) (6,449 ) Leveraged lease (1,408 ) (1,671 ) Other (271 ) (606 ) Gross deferred tax liabilities (17,749 ) (18,515 ) Net deferred tax asset $ 12,675 $ 9,724

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Activity Under Stock Option Plan	The following table is a summary of the activity under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan: Wgtd. Avg. Wgtd. Avg. Remaining Aggregate Exercise Contractual Intrinsic Options Price Term Value (Dollars in thousands, except option data) Year Ended December 31, 2016 Outstanding at December 31, 2015 1,018,149 $ 40.69 Options granted 30,000 58.08 Options exercised (310,699 ) 31.28 Options canceled, forfeited, or expired (30,000 ) 55.88 Outstanding at December 31, 2016 707,450 44.92 9.59Yrs $ 34,049 Exercisable at December 31, 2016 325,200 37.19 6.78Yrs $ 18,167 Year Ended December 31, 2015 Outstanding at December 31, 2014 1,029,657 $ 36.55 Options granted 133,000 59.37 Options exercised (120,758 ) 26.60 Options canceled, forfeited, or expired (23,750 ) 37.16 Outstanding at December 31, 2015 1,018,149 40.69 8.84Yrs $ 18,251 Exercisable at December 31, 2015 499,599 32.98 5.53Yrs $ 12,812
Options Granted and Options Exercised Under Stock Option Plan	The following table has additional information regarding options granted and options exercised under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan: Year Ended December 31, 2016 2015 2014 (Dollars in thousands, except per share data) Weighted average grant-date fair value per share of options granted $ 11.92 $ 11.72 $ 12.27 Total intrinsic value of options exercised 12,230 4,376 5,597 Cash received from options exercised 9,720 3,212 4,870 Tax benefit realized from options exercised 4,731 1,693 2,165
Stock-based Employee Compensation Expense	The following table is a summary of the Company’s recorded stock-based compensation expense: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Stock-based compensation expense $ 1,636 $ 1,717 $ 1,676 Tax benefit 633 664 648 Stock-based compensation expense, net of tax $ 1,003 $ 1,053 $ 1,028
Unearned Stock-based Compensation Expense	The Company will continue to amortize the unearned stock-based compensation expense over the remaining vesting period of approximately seven years. The following table shows the unearned stock-based compensation expense: December 31, 2016 (Dollars in thousands) Unearned stock-based compensation expense $ 2,770
Assumptions Used for Computing Stock-Based Compensation Expense	The following table shows the assumptions used for computing stock-based compensation expense under the fair value method: Year Ended December 31, 2016 2015 2014 Risk-free interest rate 1.46 to 2.02% 1.83 to 2.26% 2.10 to 2.54% Dividend yield 2.00 % 2.00 % 2.00 % Stock price volatility 20.41 to 21.78% 18.23 to 21.08% 18.03 to 18.98% Expected term 10 Yrs 10 Yrs 10 Yrs
Summary of Accumulated Stock Units	A summary of the accumulated stock units is as follows: December 31, 2016 2015 Accumulated stock units 70,022 66,376 Average price $ 41.74 $ 39.64

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Compensation And Retirement Disclosure [Abstract]
Aggregate Amounts of Contributions to the 401(k) and ESOP Plans	The aggregate amounts of contributions by the Company to the 401(k) and ESOP plans are shown in the following table: December 31, 2016 2015 2014 (Dollars in thousands) 401(k) contributions $ 2,074 $ 1,966 $ 1,870 ESOP contributions 2,352 1,993 1,928 Total contributions $ 4,426 $ 3,959 $ 3,798

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Summary of Authorized Outstanding Preferred and Common Stock	As of December 31, 2016, 2015 and 2014 the Company’s authorized and outstanding preferred and common stock was as follows: No. of Shares Authorized at No. of Shares Outstanding at December 31, Class of Stock December 31, 2016 2016 2015 2014 Par Value Per Share Dividends Voting Rights Senior Preferred 10,000,000 — — — $ 1.00 As declared Voting 10% Cumulative Preferred 900,000 — — — 5.00 As declared Non-voting Common 20,000,000 15,810,935 15,597,446 15,504,513 1.00 As declared Voting
Summary of Shares Repurchased Under Stock Purchase Program	The following table is a summary of the shares under the program: Year Ended December 31, 2016 2015 2014 Number of shares repurchased 100,000 28,447 — Average price of shares repurchased $ 55.23 $ 58.19 $ — Shares remaining to be repurchased 150,000 166,276 194,723
Required Capital Amounts and Company's Respective Ratios	The actual and required capital amounts and ratios are shown in the following table: Required To Be Well For Capital With Capitalized Under Adequacy Capital Conservation Prompt Corrective Actual Purposes Buffer Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of December 31, 2016: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 728,635 15.33 % $ 380,351 8.00% $ 410,066 8.625 % N/A N/A BancFirst 655,620 13.80 % 379,948 8.00% 409,631 8.625 % $ 474,934 10.00 % Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 648,942 13.65 % $ 213,947 4.50% $ 243,662 5.125 % N/A N/A BancFirst 586,927 12.36 % 213,720 4.50% 243,404 5.125 % $ 308,707 6.50 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 679,942 14.30 % $ 285,263 6.00% $ 314,978 6.625 % N/A N/A BancFirst 606,927 12.78 % 284,961 6.00% 314,644 6.625 % $ 379,948 8.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 679,942 9.94 % $ 273,510 4.00% N/A N/A N/A N/A BancFirst 606,927 8.89 % 273,152 4.00% N/A N/A $ 341,440 5.00 % As of December 31, 2015: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 669,213 14.47 % $ 370,094 8.00% N/A 8.625 % N/A N/A BancFirst 607,604 13.15 % 369,607 8.00% N/A 8.625 % $ 462,009 10.00 % Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 596,547 12.90 % $ 208,178 4.50% N/A 5.125 % N/A N/A BancFirst 545,938 11.82 % 207,904 4.50% N/A 5.125 % $ 300,306 6.50 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 627,547 13.57 % $ 277,570 6.00% N/A 6.625 % N/A N/A BancFirst 565,938 12.25 % 277,205 6.00% N/A 6.625 % $ 369,607 8.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 627,547 9.49 % $ 264,333 4.00% N/A N/A N/A N/A BancFirst 565,938 8.59 % 263,606 4.00% N/A N/A $ 329,507 5.00 %

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Basic and Diluted Net Income Per Common Share	Basic and diluted net income per common share are calculated as follows: Income (Numerator) Shares (Denominator) Per Share Amount (Dollars in thousands, except per share data) Year Ended December 31, 2016 Basic Income available to common stockholders $ 70,674 15,615,170 $ 4.53 Effect of stock options — 296,092 Diluted Income available to common stockholders plus assumed exercises of stock options $ 70,674 15,911,262 $ 4.44 Year Ended December 31, 2015 Basic Income available to common stockholders $ 66,170 15,559,059 $ 4.25 Effect of stock options — 327,186 Diluted Income available to common stockholders plus assumed exercises of stock options $ 66,170 15,886,245 $ 4.17 Year Ended December 31, 2014 Basic Income available to common stockholders $ 63,887 15,430,773 $ 4.14 Effect of stock options — 363,630 Diluted Income available to common stockholders plus assumed exercises of stock options $ 63,887 15,794,403 $ 4.04
Average Exercise Price of Options Excluded from Computation of Diluted Net Income Per Common Share	The following table shows the number and average exercise price of options that were excluded from the computation of diluted net income per common share for each year because the options’ exercise prices were greater than the average market price of the common shares. Shares Average Exercise December 31, 2016 147,219 $ 60.49 December 31, 2015 177,718 58.47 December 31, 2014 69,405 55.87

Condensed Parent Company Fina46

Condensed Parent Company Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Summary of Balance Sheet of Parent Company	BALANCE SHEETS December 31, 2016 2015 (Dollars in thousands) ASSETS Cash $ 57,537 $ 45,437 Securities 97 103 Investments in subsidiaries 681,861 639,119 Goodwill 450 450 Dividends receivable 6,998 6,773 Other assets 2,610 1,688 Total assets $ 749,553 $ 693,570 LIABILITIES AND STOCKHOLDERS’ EQUITY Other liabilities $ 6,500 $ 6,101 Junior subordinated debentures 31,959 31,959 Stockholders’ equity 711,094 655,510 Total liabilities and stockholders’ equity $ 749,553 $ 693,570
Summary of Income Statement of Parent Company	STATEMENTS OF INCOME Year Ended December 31, 2016 2015 2014 (Dollars in thousands) OPERATING INCOME Dividends from subsidiaries $ 28,175 $ 26,043 $ 24,851 Interest on interest-bearing deposits 160 66 62 Other 3 2 14 Total operating income 28,338 26,111 24,927 OPERATING EXPENSE Interest 2,096 1,998 1,965 Other 583 628 667 Total operating expense 2,679 2,626 2,632 Income before taxes and equity in undistributed earnings of subsidiaries 25,659 23,485 22,295 Allocated income tax benefit/(expense) 1,244 (796 ) 472 Income before equity in undistributed earnings of subsidiaries 26,903 22,689 22,767 Equity in undistributed earnings of subsidiaries 44,172 44,653 42,196 Amortization of stock-based compensation arrangements of subsidiaries (401 ) (1,172 ) (1,076 ) Net income $ 70,674 $ 66,170 $ 63,887
Summary of Cash Flow of Parent Company	STATEMENTS OF CASH FLOW Year Ended December 31, 2016 2015 2014 (Dollars in thousands) CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 70,674 $ 66,170 $ 63,887 Adjustments to reconcile to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (44,172 ) (44,653 ) (42,196 ) Amortization of stock-based compensation arrangements 401 1,172 1,076 Other, net 136 (343 ) (656 ) Net cash provided by operating activities 27,039 22,346 22,111 INVESTING ACTIVITIES Net cash provided by acquisitions — 5,066 — Sales and maturities of held for investment and available for sale securities — — 8 Net cash provided by investing activities — 5,066 8 FINANCING ACTIVITIES Issuance of common stock 13,354 4,428 6,532 Common stock acquired (5,523 ) (1,654 ) — Cash dividends paid (22,770 ) (21,449 ) (19,543 ) Net cash used for financing activities (14,939 ) (18,675 ) (13,011 ) Net increase in cash 12,100 8,737 9,108 Cash and due from banks at the beginning of the period 45,437 36,700 27,592 Cash and due from banks at the end of the period $ 57,537 $ 45,437 $ 36,700 SUPPLEMENTAL DISCLOSURE Cash paid during the period for interest $ 2,096 $ 1,998 $ 1,965 Cash received during the period for income taxes, net $ 5,031 $ 1,131 $ 1,822

Commitments and Contingent Li47

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Summary of Financial Instruments with Off-Balance-Sheet Risks	The amounts of financial instruments with off-balance-sheet risk are as follows: December 31, 2016 2015 (Dollars in thousands) Loan commitments $ 981,777 $ 960,490 Stand-by letters of credit 56,551 61,889
Summary of Future Minimum Rental Payments Under Lease	The future minimum rental payments under these leases at December 31, 2016, were as follows (Dollars in thousands): 2017 $ 419 2018 421 2019 355 2020 205 2021 172 Later years 700 Total $ 2,272
Summary of Rental Expense	Rental expense on all property and equipment rented, including those rented on a monthly or temporary basis were as follows (Dollars in thousands): Year Ending December 31: 2016 $ 1,524 2015 1,360 2014 1,255

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities Measured on Recurring Basis	The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2016 and 2015, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (Dollars in thousands) December 31, 2016 Securities available for sale: U.S. Treasury $ 268,543 $ — $ — $ 268,543 U.S. federal agencies — 129,642 — 129,642 Mortgage-backed securities — 4,856 14,816 19,672 States and political subdivisions — 41,042 — 41,042 Other securities — — 6,569 6,569 Derivative assets — 1,569 — 1,569 Derivative liabilities — 1,306 — 1,306 Loans held for sale — 9,318 — 9,318 December 31, 2015 Securities available for sale: U.S. Treasury $ 329,696 $ — $ — $ 329,696 U.S. federal agencies — 131,896 — 131,896 Mortgage-backed securities — 7,039 14,816 21,855 States and political subdivisions — 50,920 — 50,920 Other securities — 3,485 6,308 9,793 Derivative assets — 1,946 — 1,946 Derivative liabilities — 989 — 989 Loans held for sale — 13,725 — 13,725
Changes in Level 3 Assets Measured at Estimated Fair Value on Recurring Basis	The changes in Level 3 assets measured at estimated fair value on a recurring basis during the years ended December 31, 2016 and 2015 were as follows: Twelve Months Ended December 31, 2016 2015 (Dollars in thousands) Balance at the beginning of the year $ 21,124 $ 28,459 Purchases 1,096 609 Settlements (191 ) (2,327 ) Sales (429 ) (8,817 ) (Losses) gains included in earnings (111 ) 7,141 Total unrealized losses (104 ) (3,941 ) Balance at the end of the period $ 21,385 $ 21,124
Assets Measured at Fair Value on Nonrecurring Basis	The following table summarizes assets measured at fair value on a nonrecurring basis. The fair value represents end of period values, which approximate fair value measurements that occurred on various measurement dates throughout the period. The related losses represent the amounts recognized during the period regardless of whether the asset is still held at period end: Total Fair Value Level 3 Losses (Dollars in thousands) As of and for the Year-to-date Period Ended December 31, 2016 Impaired loans (less specific allowance) $ 29,912 $ — Repossessed assets 340 3 Other real estate owned 1,480 231 As of and for the Year-to-date Period Ended December 31, 2015 Impaired loans (less specific allowance) $ 44,399 $ — Repossessed assets 230 — Other real estate owned 3,607 128
Estimated Fair Values of Financial Instruments	The estimated fair values of the Company’s financial instruments that are reported at amortized cost in the Company’s consolidated balance sheets, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value, are as follows: December 31, 2016 2015 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,851,161 $ 1,851,161 $ 1,598,177 $ 1,598,177 Securities held for investment 3,722 3,760 8,289 8,350 Level 3 inputs: Securities held for investment 643 643 500 500 Loans, net of allowance for loan losses 4,351,539 4,367,363 4,190,382 4,222,153 FINANCIAL LIABILITIES Level 2 inputs: Deposits 6,248,057 6,313,622 5,973,358 6,028,012 Short-term borrowings 500 500 500 500 Junior subordinated debentures 31,959 34,339 31,959 33,793 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,718 1,681 Letters of credit 424 464

Derivative Financial Instrume49

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Notional Amounts and Estimated Fair Values of Outstanding Derivative Positions	The Company utilizes dealer quotations and observable market data inputs to substantiate internal valuation models. The notional amounts and estimated fair values of oil and gas derivative positions outstanding are presented in the following table: December 31, 2016 2015 Oil and Natural Gas Swaps and Options Notional Units Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value (Notional amounts and dollars in thousands) Oil Derivative assets Barrels 83 $ 576 86 $ 604 Derivative liabilities Barrels (83 ) (496 ) (86 ) (378 ) Natural Gas Derivative assets MMBTUs 1,900 993 3,920 1,342 Derivative liabilities MMBTUs (1,900 ) (810 ) (3,920 ) (611 ) Total Fair Value Included in Derivative assets Other assets 1,569 1,946 Derivative liabilities Other liabilities (1,306 ) (989 )
Recognized Derivative Income Included in Other Noninterest Income	The following table is a summary of the Company’s recognized income related to the activity, which was included in other noninterest income: Year Ended December 31, 2016 2015 2014 (Dollars in thousands) Derivative income $ 32 $ 341 $ 500
Summary of Company's Net Credit Exposure Relating to Oil and Gas Swaps and Options with Bank Counterparties	The following table is a summary of the Company’s net credit exposure relating to oil and gas swaps and options with bank counterparties: December 31, 2016 2015 (Dollars in Credit exposure $ — $ 37

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Results of Operations and Selected Financial Information	The results of operations and selected financial information for the four business units are as follows: Metropolitan Banks Community Banks Other Financial Services Executive, Operations & Support Eliminations Consolidated (Dollars in thousands) December 31, 2016 Net interest income (expense) $ 63,519 $ 135,508 $ 6,132 $ (1,331 ) $ — $ 203,828 Provision for loan losses 2,229 7,509 1,653 128 — 11,519 Noninterest income 16,372 57,745 29,711 75,415 (72,211 ) 107,032 Depreciation and amortization 2,341 8,281 510 1,251 — 12,383 Other expenses 34,130 96,627 22,216 26,375 (327 ) 179,021 Income before taxes $ 41,191 $ 80,836 $ 11,464 $ 46,330 $ (71,884 ) $ 107,937 Total assets $ 2,493,096 $ 4,412,174 $ 83,594 $ 803,810 $ (773,722 ) $ 7,018,952 Capital expenditures $ 1,525 $ 7,738 $ 125 $ 1,447 $ — $ 10,835 December 31, 2015 Net interest income (expense) $ 61,500 $ 122,404 $ 6,798 $ (1,910 ) $ — $ 188,792 Provision for loan losses 2,684 3,806 1,176 9 — 7,675 Noninterest income 16,552 52,598 33,629 72,806 (69,777 ) 105,808 Depreciation and amortization 2,273 7,894 514 1,220 — 11,901 Other expenses 32,942 91,655 22,308 27,221 (312 ) 173,814 Income before taxes $ 40,153 $ 71,647 $ 16,429 $ 42,446 $ (69,465 ) $ 101,210 Total assets $ 2,277,870 $ 4,379,205 $ 128,697 $ 624,428 $ (717,371 ) $ 6,692,829 Capital expenditures $ 3,743 $ 4,634 $ 121 $ 2,765 $ — $ 11,263 December 31, 2014 Net interest income (expense) $ 59,923 $ 116,935 $ 6,155 $ (1,662 ) $ — $ 181,351 Provision for loan losses 3,077 (488 ) 481 2 — 3,072 Noninterest income 13,752 51,415 28,079 69,442 (66,275 ) 96,413 Depreciation and amortization 2,216 7,277 522 1,334 — 11,349 Other expenses 32,300 89,888 22,304 27,998 (318 ) 172,172 Income before taxes $ 36,082 $ 71,673 $ 10,927 $ 38,446 $ (65,957 ) $ 91,171 Total assets $ 2,298,828 $ 4,113,783 $ 145,814 $ 679,194 $ (662,647 ) $ 6,574,972 Capital expenditures $ 1,948 $ 7,972 $ 121 $ 1,449 $ — $ 11,490

Selected Quarterly Financial 51

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Summary of the Unaudited Quarterly Results of Operations	A summary of the unaudited quarterly results of operations for the years ended December 31, 2016 and 2015 is as follows: Quarter Fourth Third Second First (Dollars in thousands, except per share data) 2016 Net interest income $ 51,553 $ 51,431 $ 50,868 $ 49,976 Provision for loan losses 1,672 2,940 2,804 4,103 Securities transactions 52 (146 ) (65 ) 100 Noninterest income 27,431 27,927 26,057 25,617 Noninterest expense 48,189 49,204 47,720 46,291 Net income 18,620 17,982 17,493 16,579 Net income per common share: Basic 1.19 1.15 1.12 1.07 Diluted 1.16 1.13 1.10 1.05 2015 Net interest income $ 50,075 $ 46,876 $ 46,215 $ 45,626 Provision for loan losses 3,646 1,424 1,271 1,334 Securities transactions 2,148 — 5,392 1,729 Noninterest income 26,473 25,324 28,715 25,296 Noninterest expense 49,011 46,352 45,429 44,923 Net income 15,728 15,630 18,553 16,259 Net income per common share: Basic 1.00 1.01 1.19 1.05 Diluted 0.99 0.98 1.17 1.03

Description of Business and S52

Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of interest rate risk with rate floor	50.00%
Days from origination after which mortgage loan are sold	30 days
Loan upon which a default of principal or interest has existed for a period	90 days
Gains on sale of other real estate owned	$ 1.2
Intangible assets, Estimated useful lives	6 years 8 months 12 days
Core Deposit Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	6 years 9 months 18 days
Minimum [Member] | Core Deposit Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	7 years
Minimum [Member] | Customer Relationship Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	3 years
Maximum [Member] | Core Deposit Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	10 years
Maximum [Member] | Customer Relationship Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	18 years
Home Equity Lines of Credit [Member] | Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	8.00%
First Liens [Member] | Minimum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	82.00%
Junior Liens [Member] | Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	10.00%

Recent Developments Including M

Recent Developments Including Mergers and Acquisitions - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016USD ($)Community	Dec. 31, 2015USD ($)	Oct. 08, 2015USD ($)	Dec. 31, 2014USD ($)	Jan. 24, 2014USD ($)
Business Combination Separately Recognized Transactions [Line Items]
Goodwill	$ 54,042,000	$ 54,042,000		$ 44,962,000
Number of additional banking communities | Community	2
Bank of Commerce [Member]
Business Combination Separately Recognized Transactions [Line Items]
Total assets acquired			$ 196,000,000
Loans			147,000,000
Deposits			175,000,000
Equity capital			$ 22,000,000
Percentage of voting interests acquired			100.00%
Intangibles assets, net			$ 7,100,000
Goodwill			$ 9,400,000
The Bank of Union [Member] | BancFirst [Member]
Business Combination Separately Recognized Transactions [Line Items]
Loans					$ 121,000,000
Deposits					302,000,000
Equity capital					4,800,000
Intangibles assets, net					2,200,000
Goodwill					417,000
Other real estate					$ 10,000

Cash Due from Banks Interest-Be

Cash Due from Banks Interest-Bearing Deposits and Federal Funds Sold - Summary of Average Amount of Required Reserves (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Average Amount Of Required Reserves [Abstract]
Vault cash and funds on deposit with the Federal Reserve Bank	$ 1,754,956	$ 1,499,137
Average required Reserves	$ 41,968	$ 40,093

Securities - Summary of Securit

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Marketable Securities [Abstract]
Held for investment, at cost (fair value: $4,403 and $8,850, respectively)	$ 4,365	$ 8,789
Available for sale, at fair value	465,468	544,160
Total	$ 469,833	$ 552,949

Securities - Summary of Secur56

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Marketable Securities [Abstract]
Held for investment at fair value	$ 4,403	$ 8,850

Securities - Summary of Amortiz

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 4,365	$ 8,789
Gross Unrealized Gains	42	61
Gross Unrealized Losses	(4)
Estimated Fair Value	4,403	8,850
Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	252	347
Gross Unrealized Gains	17	25
Estimated Fair Value	269	372
States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	3,613	7,942
Gross Unrealized Gains	25	36
Gross Unrealized Losses	(4)
Estimated Fair Value	3,634	7,978
Other Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	500	500
Estimated Fair Value	$ 500	$ 500

Securities - Summary of Amort58

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 465,315	$ 541,670
Gross Unrealized Gains	2,324	3,424
Gross Unrealized Losses	(2,171)	(934)
Estimated Fair Value	465,468	544,160
U.S. Treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	268,763	328,965
Gross Unrealized Gains	700	776
Gross Unrealized Losses	(920)	(45)
Estimated Fair Value	268,543	329,696
U.S. Federal Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	129,674	131,522
Gross Unrealized Gains	373	527
Gross Unrealized Losses	(405)	(153)
Estimated Fair Value	129,642	131,896
Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	19,949	21,973
Gross Unrealized Gains	290	425
Gross Unrealized Losses	(567)	(543)
Estimated Fair Value	19,672	21,855
States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	40,335	49,521
Gross Unrealized Gains	836	1,447
Gross Unrealized Losses	(129)	(48)
Estimated Fair Value	41,042	50,920
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,594	9,689
Gross Unrealized Gains	125	249
Gross Unrealized Losses	(150)	(145)
Estimated Fair Value	$ 6,569	$ 9,793

Securities - Maturity of Securi

Securities - Maturity of Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Held for Investment, Contractual maturity of debt securities, Amortized Cost
Amortized cost, Within one year	$ 1,561	$ 5,168
Amortized cost, After one year but within five years	1,937	2,800
Amortized cost, After five years but within ten years	707	795
Amortized cost, After ten years	160	26
Amortized Cost	4,365	8,789
Available for sale, Contractual maturity of debt securities, Amortized Cost
Amortized Cost, Within one year	66,542	272,820
Amortized Cost, After one year but within five years	320,150	178,617
Amortized Cost, After five years but within ten years	5,830	8,483
Amortized Cost, After ten years	66,199	75,522
Total debt securities	458,721	535,442
Amortized Cost, Other securities	6,594	6,228
Amortized Cost	465,315	541,670
Held for Investment, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	1,568	5,174
Estimated Fair Value, After one year but within five years	1,951	2,829
Estimated Fair Value, After five years but within ten years	723	319
Estimated Fair Value, After ten years	161	528
Estimated Fair Value	4,403	8,850
Available for sale, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	66,662	272,779
Estimated Fair Value, After one year but within five years	319,839	180,145
Estimated Fair Value, After five years but within ten years	6,152	9,075
Estimated Fair Value, After ten years	66,246	75,853
Total debt securities	458,899	537,852
Estimated Fair Value, Other securities	6,569	6,308
Estimated Fair Value, Total	$ 465,468	$ 544,160

Securities - Proceeds from Sale

Securities - Proceeds from Sales and Realized Securities Gains and Losses, on Available for Sale Securities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Available For Sale Securities Gross Realized Gain Loss [Abstract]
Proceeds	$ 481	$ 10,850	$ 4,855
Gross gains realized	227	9,394	$ 1,641
Gross losses realized	$ 286	$ 125

Securities - Additional Informa

Securities - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended							12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Gain on sale of securities	$ 52	$ (146)	$ (65)	$ 100	$ 2,148	$ 5,392	$ 1,729	$ (59)	$ 9,269	$ 1,641
Council Oak Investment Corporation [Member]
Schedule of Available-for-sale Securities [Line Items]
Pretax gain on sale of equity investments									1,700
Council Oak Partners [Member]
Schedule of Available-for-sale Securities [Line Items]
Pretax gain on sale of equity investments									5,200
Gain on sale of securities									$ 2,100

Securities - Company's Book Val

Securities - Company's Book Value of Pledged Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Pledged Financial Instruments Not Separately Reported Securities Pledged By Type Of Security [Abstract]
Book value of pledged securities	$ 439,692	$ 493,540

Securities - Summary of Secur63

Securities - Summary of Securities with Unrealized Losses, Segregated by Duration of Unrealized Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 190,508	$ 189,005
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	1,339	352
Available-for-sale Securities, 12 Months or Longer, Fair Value	25,821	21,163
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	832	582
Available-for-sale Securities, Fair Value, Total	216,329	210,168
Available-for-sale Securities, Unrealized Losses, Total	2,171	934
Held for Investment
Held-to-maturity Securities, Less than 12 Months, Fair Value	483	21
Held-to-maturity Securities, Less than 12 Months, Unrealized Losses	4
Held-to-maturity Securities, 12 Months or Longer, Fair Value	9
Held-to-maturity Securities, Fair Value, Total	492	21
Held-to-maturity Securities, Unrealized Losses, Total	4
U.S. Treasuries [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	103,705	139,762
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	920	45
Available-for-sale Securities, Fair Value, Total	103,705	139,762
Available-for-sale Securities, Unrealized Losses, Total	920	45
U.S. Federal Agencies [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	71,511	46,948
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	357	118
Available-for-sale Securities, 12 Months or Longer, Fair Value	9,619	5,969
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	48	35
Available-for-sale Securities, Fair Value, Total	81,130	52,917
Available-for-sale Securities, Unrealized Losses, Total	405	153
Mortgage Backed Securities [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	3	59
Available-for-sale Securities, 12 Months or Longer, Fair Value	14,834	14,844
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	567	543
Available-for-sale Securities, Fair Value, Total	14,837	14,903
Available-for-sale Securities, Unrealized Losses, Total	567	543
Held for Investment
Held-to-maturity Securities, Less than 12 Months, Fair Value	7	21
Held-to-maturity Securities, 12 Months or Longer, Fair Value	9
Held-to-maturity Securities, Fair Value, Total	16	21
States and Political Subdivisions [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	15,289	1,932
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	62	47
Available-for-sale Securities, 12 Months or Longer, Fair Value	779	245
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	67	1
Available-for-sale Securities, Fair Value, Total	16,068	2,177
Available-for-sale Securities, Unrealized Losses, Total	129	48
Held for Investment
Held-to-maturity Securities, Less than 12 Months, Fair Value	476
Held-to-maturity Securities, Less than 12 Months, Unrealized Losses	4
Held-to-maturity Securities, Fair Value, Total	476
Held-to-maturity Securities, Unrealized Losses, Total	4
Other Securities [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value		304
Available-for-sale Securities, Less than 12 Months, Unrealized Losses		142
Available-for-sale Securities, 12 Months or Longer, Fair Value	589	105
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	150	3
Available-for-sale Securities, Fair Value, Total	589	409
Available-for-sale Securities, Unrealized Losses, Total	$ 150	$ 145

Loans and Allowance for Loan 64

Loans and Allowance for Loan Losses - Schedule of Loans Outstanding by Category (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 4,400,232	$ 4,232,048
Percent	100.00%	100.00%
Taxable [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 33,793	$ 17,605
Percent	0.77%	0.42%
Tax-exempt [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 47,283	$ 33,575
Percent	1.07%	0.79%
Commercial and Financial [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 828,260	$ 795,803
Percent	18.82%	18.80%
Commercial and Financial [Member] | Oil & Gas Production And Equipment [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 84,228	$ 87,304
Percent	1.91%	2.06%
Commercial and Financial [Member] | Agriculture [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 144,751	$ 150,620
Percent	3.29%	3.56%
Real Estate [Member] | Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 420,884	$ 403,664
Percent	9.57%	9.54%
Real Estate [Member] | Farmland [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 197,872	$ 184,707
Percent	4.50%	4.36%
Real Estate [Member] | One to Four Family Residences [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 846,360	$ 821,251
Percent	19.24%	19.41%
Real Estate [Member] | Multifamily Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 57,806	$ 65,477
Percent	1.31%	1.55%
Real Estate [Member] | Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 1,426,643	$ 1,356,430
Percent	32.42%	32.05%
Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 279,704	$ 283,636
Percent	6.36%	6.70%
Other (Not Classified Above) [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 32,648	$ 31,976
Percent	0.74%	0.76%

Loans and Allowance for Loan 65

Loans and Allowance for Loan Losses - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)SecurityLoan	Dec. 31, 2014USD ($)
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 4,400,232	$ 4,232,048
Percentage of loans secured by real estate	65.00%
Interest income that would have been recognized	$ 2,000	$ 2,000	$ 1,200
Troubled debt restructuring principal deferral | SecurityLoan		1
Commercial and Industrial [Member] | Ancillary Services [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 56,000

Loans and Allowance for Loan 66

Loans and Allowance for Loan Losses - Summary of Nonperforming and Restructured Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Summary Of Nonperforming And Restructured Assets [Abstract]
Past due 90 days or more and still accruing	$ 1,962	$ 1,841
Nonaccrual	31,798	30,096
Restructured	1,713	15,143
Total nonperforming and restructured loans	35,473	47,080
Other real estate owned and repossessed assets	3,866	8,214
Total nonperforming and restructured assets	$ 39,339	$ 55,294

Loans and Allowance for Loan 67

Loans and Allowance for Loan Losses - Summary of Amounts Included in Nonaccrual Loans Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	$ 31,798	$ 30,096
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	713	261
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	5,688	3,957
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	1,116	656
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	5,089	1,833
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	4,464	10,159
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	265	312
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	8,370	9,381
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	$ 6,093	$ 3,537

Loans and Allowance for Loan 68

Loans and Allowance for Loan Losses - Age Analysis of Past Due Loans Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 35,200	$ 24,673
Current Loans	4,365,032	4,207,375
Total Loans	4,400,232	4,232,048
Accruing Loans 90 Days or More Past Due	1,962	1,841
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	17,652	16,404
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,948	2,831
90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	12,600	5,438
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,501	803
Current Loans	569,130	502,094
Total Loans	571,631	502,897
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,045	1,825
Current Loans	1,122,351	1,108,935
Total Loans	1,123,396	1,110,760
Accruing Loans 90 Days or More Past Due		521
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,664	4,124
Current Loans	320,749	328,477
Total Loans	325,413	332,601
Accruing Loans 90 Days or More Past Due	513	493
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,506	4,275
Current Loans	743,723	672,414
Total Loans	748,229	676,689
Accruing Loans 90 Days or More Past Due	369	193
Real Estate [Member] | 30 to 59 Days Past Due [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,255	441
Real Estate [Member] | 30 to 59 Days Past Due [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	611	1,149
Real Estate [Member] | 30 to 59 Days Past Due [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,742	2,840
Real Estate [Member] | 30 to 59 Days Past Due [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,559	2,842
Real Estate [Member] | 60 to 89 Days Past Due [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	96	179
Real Estate [Member] | 60 to 89 Days Past Due [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	16	108
Real Estate [Member] | 60 to 89 Days Past Due [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	649	636
Real Estate [Member] | 60 to 89 Days Past Due [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	531	609
Real Estate [Member] | 90 Days and Greater [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	150	183
Real Estate [Member] | 90 Days and Greater [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	418	568
Real Estate [Member] | 90 Days and Greater [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,273	648
Real Estate [Member] | 90 Days and Greater [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,416	824
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	3,638	2,626
Current Loans	1,047,547	982,136
Total Loans	1,051,185	984,762
Accruing Loans 90 Days or More Past Due	608	152
Commercial and Financial [Member] | 30 to 59 Days Past Due [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,269	2,278
Commercial and Financial [Member] | 60 to 89 Days Past Due [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,628	161
Commercial and Financial [Member] | 90 Days and Greater [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	741	187
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	3,225	3,358
Current Loans	280,652	265,511
Total Loans	283,877	268,869
Accruing Loans 90 Days or More Past Due	274	278
Consumer Non-real Estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,046	2,237
Consumer Non-real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	760	772
Consumer Non-real Estate [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	419	349
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	14,078	5,621
Current Loans	127,404	156,995
Total Loans	141,482	162,616
Accruing Loans 90 Days or More Past Due	45	132
Other Loans [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	5,345	3,565
Other Loans [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	958	295
Other Loans [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	7,775	1,761
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,543	2,041
Current Loans	153,476	190,813
Total Loans	155,019	192,854
Accruing Loans 90 Days or More Past Due	153	72
Acquired Loans [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	825	1,052
Acquired Loans [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	310	71
Acquired Loans [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 408	$ 918

Loans and Allowance for Loan 69

Loans and Allowance for Loan Losses - Impaired Loans Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 47,665	$ 57,126
Recorded Investment with Allowance	35,709	47,667
Related Allowance	5,797	3,268
Average Recorded Investment	35,105	50,521
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	894	507
Recorded Investment with Allowance	806	383
Related Allowance	101	14
Average Recorded Investment	825	446
Real Estate [Member] | Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	7,742	21,068
Recorded Investment with Allowance	5,688	19,052
Related Allowance	574	357
Average Recorded Investment	5,854	19,655
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,878	1,401
Recorded Investment with Allowance	1,683	1,209
Related Allowance	124	81
Average Recorded Investment	1,612	1,125
Real Estate [Member] | Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	5,871	2,498
Recorded Investment with Allowance	5,614	2,235
Related Allowance	1,538	242
Average Recorded Investment	5,445	1,958
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	12,015	13,897
Recorded Investment with Allowance	6,272	10,312
Related Allowance	1,457	2,062
Average Recorded Investment	6,478	11,786
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	686	738
Recorded Investment with Allowance	650	715
Related Allowance	133	181
Average Recorded Investment	788	652
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	9,799	10,722
Recorded Investment with Allowance	8,415	9,513
Related Allowance	1,870	331
Average Recorded Investment	8,062	10,335
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	8,780	6,295
Recorded Investment with Allowance	6,581	4,248
Average Recorded Investment	$ 6,041	$ 4,564

Loans and Allowance for Loan 70

Loans and Allowance for Loan Losses - Internal Loan Grading by Class of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 4,400,232	$ 4,232,048
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	571,631	502,897
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,123,396	1,110,760
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	325,413	332,601
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	748,229	676,689
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,051,185	984,762
Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	283,877	268,869
Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	141,482	162,616
Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	155,019	192,854
Grade 1 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,642,438	3,604,903
Grade 1 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	464,504	417,529
Grade 1 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	933,743	945,993
Grade 1 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	284,893	295,265
Grade 1 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	614,338	554,007
Grade 1 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	856,318	821,394
Grade 1 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	263,442	251,994
Grade 1 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	132,254	153,416
Grade 1 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	92,946	165,305
Grade 2 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	647,509	547,814
Grade 2 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	89,978	76,749
Grade 2 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	169,561	156,159
Grade 2 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	32,889	29,793
Grade 2 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	119,018	111,879
Grade 2 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	170,865	140,384
Grade 2 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	17,154	14,433
Grade 2 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,376	5,851
Grade 2 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	42,668	12,566
Grade 3 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	82,136	54,695
Grade 3 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	16,220	8,304
Grade 3 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	14,404	4,580
Grade 3 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,987	6,315
Grade 3 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,382	9,109
Grade 3 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	19,101	12,687
Grade 3 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,640	1,779
Grade 3 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,514	872
Grade 3 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	12,888	11,049
Grade 4 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	28,149	24,559
Grade 4 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	929	315
Grade 4 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,688	4,028
Grade 4 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,644	1,228
Grade 4 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,491	1,694
Grade 4 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,901	10,297
Grade 4 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	641	662
Grade 4 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,338	2,477
Grade 4 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 6,517	3,858
Grade 5 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		77
Grade 5 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		1
Grade 5 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		$ 76

Loans and Allowance for Loan 71

Loans and Allowance for Loan Losses - Activity in ALL by Class of Loans (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				$ 41,666				$ 40,889	$ 41,666	$ 40,889
Charge- offs									(4,907)	(7,325)
Recoveries									415	427
Net charge- offs									(4,492)	(6,898)
Provisions charged to operations	$ 1,672	$ 2,940	$ 2,804	4,103	$ 3,646	$ 1,424	$ 1,271	1,334	11,519	7,675	$ 3,072
Balance at end of period	48,693				41,666				48,693	41,666	40,889
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				4,661				4,406	4,661	4,406
Charge- offs									(11)	(37)
Recoveries									3	1
Net charge- offs									(8)	(36)
Provisions charged to operations									949	291
Balance at end of period	5,602				4,661				5,602	4,661	4,406
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				9,921				9,616	9,921	9,616
Charge- offs									(9)	(708)
Recoveries									6	2
Net charge- offs									(3)	(706)
Provisions charged to operations									875	1,011
Balance at end of period	10,793				9,921				10,793	9,921	9,616
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				3,148				2,948	3,148	2,948
Charge- offs									(208)	(222)
Recoveries									55	40
Net charge- offs									(153)	(182)
Provisions charged to operations									134	382
Balance at end of period	3,129				3,148				3,129	3,148	2,948
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				6,725				6,269	6,725	6,269
Charge- offs									(181)	(138)
Recoveries									21	17
Net charge- offs									(160)	(121)
Provisions charged to operations									2,057	577
Balance at end of period	8,622				6,725				8,622	6,725	6,269
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				11,754				12,771	11,754	12,771
Charge- offs									(2,921)	(3,799)
Recoveries									122	199
Net charge- offs									(2,799)	(3,600)
Provisions charged to operations									3,466	2,583
Balance at end of period	12,421				11,754				12,421	11,754	12,771
Consumer Non-real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				2,642				2,404	2,642	2,404
Charge- offs									(1,088)	(626)
Recoveries									159	124
Net charge- offs									(929)	(502)
Provisions charged to operations									1,091	740
Balance at end of period	2,804				2,642				2,804	2,642	2,404
Other Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				2,648				2,359	2,648	2,359
Charge- offs									(388)	(1,109)
Recoveries									17	16
Net charge- offs									(371)	(1,093)
Provisions charged to operations									1,768	1,382
Balance at end of period	4,045				2,648				4,045	2,648	2,359
Acquired Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period				$ 167				$ 116	167	116
Charge- offs									(101)	(686)
Recoveries									32	28
Net charge- offs									(69)	(658)
Provisions charged to operations									1,179	709
Balance at end of period	$ 1,277				$ 167				$ 1,277	$ 167	$ 116

Loans and Allowance for Loan 72

Loans and Allowance for Loan Losses - Allowance for Loan Losses Outstanding by Impairment Methodology (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 10,519	$ 5,985
Collectively evaluated for impairment	38,174	35,681
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	716	323
Collectively evaluated for impairment	4,886	4,338
Real Estate [Member] | Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	1,119	323
Collectively evaluated for impairment	9,674	9,598
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	422	399
Collectively evaluated for impairment	2,707	2,749
Real Estate [Member] | Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,160	839
Collectively evaluated for impairment	6,462	5,886
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	3,317	3,365
Collectively evaluated for impairment	9,104	8,389
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	478	445
Collectively evaluated for impairment	2,326	2,197
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	1,812	291
Collectively evaluated for impairment	2,233	2,357
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	495
Collectively evaluated for impairment	$ 782	$ 167

Loans and Allowance for Loan 73

Loans and Allowance for Loan Losses - Loans Outstanding by Impairment Methodology (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 102,663	$ 71,184
Collectively evaluated for impairment	4,291,625	4,153,770
Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	5,944	7,094
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	17,149	8,619
Collectively evaluated for impairment	554,482	494,278
Real Estate [Member] | Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	20,092	8,608
Collectively evaluated for impairment	1,103,304	1,102,152
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	7,631	7,543
Collectively evaluated for impairment	317,782	325,058
Real Estate [Member] | Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	14,873	10,803
Collectively evaluated for impairment	733,356	665,886
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	24,002	22,983
Collectively evaluated for impairment	1,027,183	961,779
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	3,203	2,416
Collectively evaluated for impairment	280,674	266,453
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,254	2,323
Collectively evaluated for impairment	139,228	160,293
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	13,459	7,889
Collectively evaluated for impairment	135,616	177,871
Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	$ 5,944	$ 7,094

Loans and Allowance for Loan 74

Loans and Allowance for Loan Losses - Transfers from Loans to Other Real Estate Owned and Repossessed Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable Allowance For Credit Loss Additional Information Transfer From Loans To Other Real Estate Owned And Repossessed Assets [Abstract]
Other real estate owned	$ 2,553	$ 2,139	$ 3,573
Repossessed assets	1,402	1,098	1,209
Total	$ 3,955	$ 3,237	$ 4,782

Loans and Allowance for Loan 75

Loans and Allowance for Loan Losses - Related Party Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Balance Beginning of the Period	$ 37,577	$ 25,019	$ 27,134
Additions	16,133	22,330	22,521
Collections/ Terminations	(26,224)	(9,772)	(24,636)
Balance End of the Period	$ 27,486	$ 37,577	$ 25,019

Premises and Equipment, Net a76

Premises and Equipment, Net and Other Assets - Summary of premises and equipment by classification (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Accumulated depreciation	$ (108,864)	$ (103,513)
Premises and equipment, net	126,771	126,813
Building [Member]
Property Plant And Equipment [Line Items]
Premises and Equipment, gross	$ 138,901	135,694
Building [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Lives	10 years
Building [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Lives	40 years
Furniture Fixtures And Equipment [Member]
Property Plant And Equipment [Line Items]
Premises and Equipment, gross	$ 64,293	63,436
Furniture Fixtures And Equipment [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Lives	3 years
Furniture Fixtures And Equipment [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Lives	15 years
Land [Member]
Property Plant And Equipment [Line Items]
Premises and Equipment, gross	$ 32,441	$ 31,196

Premises and Equipment, Net a77

Premises and Equipment, Net and Other Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Percentage of equity investment	50.00%
Low income housing tax credit investments	$ 15.2	$ 14.5
Tax credits and other tax benefits recognized from LIHTC investments	4.2	4	$ 3.3
Amortization expense resulting from LIHTC investments	2.9	$ 2.6	$ 2.3
Unfunded commitment on investments	$ 13.5

Intangible Assets and Goodwil78

Intangible Assets and Goodwill - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 23,619	$ 26,570
Accumulated Amortization	(10,289)	(10,875)
Net Carrying Amount	13,330	15,695
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	17,447	20,333
Accumulated Amortization	(6,611)	(7,586)
Net Carrying Amount	10,836	12,747
Customer Relationship Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,699	5,699
Accumulated Amortization	(3,419)	(3,061)
Net Carrying Amount	2,280	2,638
Mortgage Servicing Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	473	538
Accumulated Amortization	(259)	(228)
Net Carrying Amount	$ 214	$ 310

Intangible Assets and Goodwil79

Intangible Assets and Goodwill - Estimated Amortization of Intangible Assets (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2,017	$ 2,213
2,018	2,213
2,019	2,213
2,020	2,101
2,021	$ 1,270

Intangible Assets and Goodwil80

Intangible Assets and Goodwill - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		6 years 8 months 12 days
Goodwill impairment loss		$ 0	$ 368
Community Banks [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment loss		$ 0	$ 368
Community Banks [Member] | Other Noninterest Expense [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment loss	$ 368
Customer Related Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		6 years 10 months 24 days
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		6 years 9 months 18 days
Mortgage Servicing Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		2 years

Intangible Assets and Goodwil81

Intangible Assets and Goodwill - Summary of Goodwill by Business Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Balance at beginning of period	$ 54,042	$ 44,962
Acquisitions	0	9,448
Impairment	0	(368)
Balance at end of period	54,042	54,042
Metropolitan Banks [Member]
Goodwill [Line Items]
Balance at beginning of period	8,078	8,078
Balance at end of period	8,078	8,078
Community Banks [Member]
Goodwill [Line Items]
Balance at beginning of period	40,050	30,970
Acquisitions	0	9,448
Impairment	0	(368)
Balance at end of period	40,050	40,050
Other Financial Services [Member]
Goodwill [Line Items]
Balance at beginning of period	5,464	5,464
Balance at end of period	5,464	5,464
Executive, Operations & Support [Member]
Goodwill [Line Items]
Balance at beginning of period	450	450
Balance at end of period	$ 450	$ 450

Time Deposits - Summary of Sche

Time Deposits - Summary of Scheduled Maturities of all Time Deposits (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Investments Schedule [Abstract]
2,017	$ 418,543
2,018	124,568
2,019	66,981
2,020	37,823
2,021	39,306
Thereafter	29
Total	$ 687,250

Time Deposits - Summary of Larg

Time Deposits - Summary of Large time Deposits for Periods Presented (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments Schedule [Abstract]
Time deposits of $100,000 or more	$ 328,363	$ 342,916

Time Deposits - Additional Info

Time Deposits - Additional Information (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Investments Schedule [Abstract]
Deposits not covered by deposit insurance	$ 122,200,000	$ 120,000,000

Short-Term Borrowings - Summary

Short-Term Borrowings - Summary of Short-Term Borrowings (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Total	$ 500	$ 500
Weighted average interest rate	0.38%	0.15%
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Total	$ 500	$ 500
Short-term Debt [Member]
Short-term Debt [Line Items]
End of period interest rate	0.63%	0.38%

Long-Term Borrowings - Addition

Long-Term Borrowings - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Maximum drawing capacity	$ 517,500,000
FHLB stock holdings	551,900
Advances outstanding	0
Residential Mortgage [Member]
Debt Instrument [Line Items]
Line of credit assets pledged as collateral	674,500,000
Revolving Line of Credit Member]
Debt Instrument [Line Items]
Maximum drawing capacity	10,000,000
Advances outstanding	$ 0
Description of variable interest rate	prime rate minus 25 basis points
Line of credit maturity year	2,020

Junior Subordinated Debentures

Junior Subordinated Debentures - Additional Information (Detail) - USD ($)	Oct. 08, 2015	Mar. 31, 2004	Feb. 29, 2004	Dec. 31, 2016	Dec. 31, 2015
Junior Subordinated Debentures [Line Items]
Junior subordinated notes assumed				$ 31,959,000	$ 31,959,000
BancFirst Capital Trust Two [Member] | Subordinated Debentures Subject to Mandatory Redemption [Member]
Junior Subordinated Debentures [Line Items]
Interest rate of securities				7.20%
Frequency of payment				Payable January 15, April 15, July 15 and October 15 of each year
Junior subordinated notes assumed				$ 26,800,000
Debt instrument maturity date				Mar. 31, 2034
BancFirst Capital Trust Two [Member] | Cumulative Preferred Stock [Member]
Junior Subordinated Debentures [Line Items]
Issue of securities		$ 1,000,000	$ 25,000,000
Cumulative trust preferred securities interest rate				7.20%
CSB Bancshares Statutory Trust I [Member]
Junior Subordinated Debentures [Line Items]
Business combination, acquisition of capital securities	$ 5,000,000
Business combination, acquisition of common securities	155,000
CSB Bancshares Statutory Trust I [Member] | Subordinated Deferrable Interest Debentures [Member]
Junior Subordinated Debentures [Line Items]
Frequency of payment				Payable March 15, June 15, September 15 and December 15 of each year
Junior subordinated notes assumed	$ 5,200,000
Debt instrument maturity date	Sep. 15, 2036
CSB Bancshares Statutory Trust I [Member] | Subordinated Deferrable Interest Debentures [Member] | LIBOR [Member]
Junior Subordinated Debentures [Line Items]
Debt instrument, Basis point rate	1.82%

Income Taxes - Components of th

Income Taxes - Components of the Company's Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current taxes:
Federal	$ 34,003	$ 32,348	$ 28,258
State	5,308	4,595	2,709
Deferred taxes	(2,048)	(1,903)	(3,683)
Total income taxes	$ 37,263	$ 35,040	$ 27,284

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Securities transactions income tax (benefit) expense	$ (21,000)	$ 3,200,000	$ 574,000
Recognition of interest and penalties related to unrecognized tax benefits	$ 0	$ 0	$ 0
Earliest Tax Year [Member]
Income Taxes [Line Items]
Year under examination	2,014
Latest Tax Year [Member]
Income Taxes [Line Items]
Year under examination	2,016

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Tax Expense at the Federal Statutory Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Tax expense at the federal statutory tax rate	$ 37,778	$ 35,424	$ 31,910
Increase (decrease) in tax expense from:
Tax-exempt income, net	(756)	(663)	(571)
Modified endowment life contracts	(852)	(763)	(755)
State tax expense, net of federal tax benefit	3,250	2,898	1,469
Utilization of tax credits:
New markets tax credits	(1,254)	(1,195)	(1,108)
Low-income housing tax credits, net of amortization	(1,424)	(1,274)	(1,209)
Other tax credits	(319)	(248)	(1,979)
Other, net	840	861	(473)
Total income taxes	$ 37,263	$ 35,040	$ 27,284

Income Taxes - Summary of Net D

Income Taxes - Summary of Net Deferred Tax Asset Reported in Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Provision for loan losses	$ 18,748	$ 16,110
Write-downs of other real estate owned	769	1,252
Deferred compensation	3,197	3,108
Stock-based compensation	2,441	3,201
Investments in partnership interests	4,603	3,651
Other	666	917
Gross deferred tax assets	30,424	28,239
Unrealized net gains on securities	(59)	(962)
Premium on securities of banks acquired	(453)	(563)
Intangibles	(5,365)	(5,575)
Basis difference related to tax credits	(3,435)	(2,689)
Depreciation	(6,758)	(6,449)
Leveraged lease	(1,408)	(1,671)
Other	(271)	(606)
Gross deferred tax liabilities	(17,749)	(18,515)
Net deferred tax asset	$ 12,675	$ 9,724

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	May 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Deferred board fees percentage for stock units accumulation	100.00%
Nonqualified Incentive Stock Option Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period in years	7 years
Nonqualified Incentive Stock Option Plan [Member] | Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares to be issued under incentive stock option plan			3,200,000
Shares for future grants	215,735
Stock option plan termination date	Dec. 31, 2019
Option exercisable rate	25.00%
Option exercisable period	4 years
Options expire period	15 years
Share based compensation options exercisable period	2,023
Vesting period in years, start	4 years
Options vest and exercisable Description	The options vest and are exercisable beginning four years from the date of grant at the rate of 25% per year for four years. Options expire at the end of fifteen years from the date of grant
Nonqualified Incentive Stock Option Plan [Member] | Stock Option [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock price percentage to fair value at grant date	100.00%
Non-Employee Directors Stock Option Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares to be issued under incentive stock option plan			260,000
Shares for future grants	40,000
Option exercisable rate	25.00%
Option exercisable period	1 year
Options expire period	15 years
Share based compensation options exercisable period	2,020
Options vest and exercisable Description	The options vest and are exercisable beginning one year from the date of grant at the rate of 25% per year for four years
Number of options granted for non-employee director	10,000
Vesting period in years	4 years
Non-Employee Directors Stock Option Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock price percentage to fair value at grant date	100.00%
Banc First Deferred Stock Compensation Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance under deferred compensation plan			111,110
Number of shares of common stock distributed	2,790	622

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Activity Under Stock Option Plan (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding at beginning period - Options	1,018,149	1,029,657
Options granted	30,000	133,000
Options exercised	(310,699)	(120,758)
Options canceled, forfeited or expired - Options	(30,000)	(23,750)
Outstanding at ending period - Options	707,450	1,018,149
Exercisable at ending period - Options	325,200	499,599
Outstanding at beginning period - Wgtd. Avg. Exercise Price	$ 40.69	$ 36.55
Options granted - Wgtd. Avg. Exercise Price	58.08	59.37
Options exercised - Wgtd. Avg. Exercise Price	31.28	26.60
Options cancelled, forfeited, or expired - Wgtd. Avg. Exercise Price	55.88	37.16
Outstanding at ending period - Wgtd. Avg. Exercise Price	44.92	40.69
Exercisable at ending period - Wgtd. Avg. Exercise Price	$ 37.19	$ 32.98
Outstanding at ending period - Wgtd. Avg. Remaining Contractual Term, years	9 years 7 months 2 days	8 years 10 months 2 days
Exercisable at ending period - Wgtd. Avg. Remaining Contractual Term, years	6 years 9 months 11 days	5 years 6 months 11 days
Outstanding at ending period - Aggregate Intrinsic Value	$ 34,049	$ 18,251
Exercisable at ending period - Aggregate Intrinsic Value	$ 18,167	$ 12,812

Stock-Based Compensation - Opti

Stock-Based Compensation - Options Granted and Options Exercised Under Stock Option Plan (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award Options Additional Disclosures [Abstract]
Weighted average grant-date fair value per share of options granted	$ 11.92	$ 11.72	$ 12.27
Total intrinsic value of options exercised	$ 12,230	$ 4,376	$ 5,597
Cash received from options exercised	9,720	3,212	4,870
Tax benefit realized from options exercised	$ 4,731	$ 1,693	$ 2,165

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Employee Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Labor And Related Expense [Abstract]
Stock-based compensation expense	$ 1,636	$ 1,717	$ 1,676
Tax benefit	633	664	648
Stock-based compensation expense, net of tax	$ 1,003	$ 1,053	$ 1,028

Stock-Based Compensation - Unea

Stock-Based Compensation - Unearned Stock-based Compensation Expense (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Remaining Fair Value Of Stock Options [Abstract]
Unearned stock-based compensation expense	$ 2,770

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used for Computing Stock-Based Compensation Expense (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Risk-free interest rate, minimum	1.46%	1.83%	2.10%
Risk-free interest rate, maximum	2.02%	2.26%	2.54%
Dividend yield	2.00%	2.00%	2.00%
Stock price volatility, minimum	20.41%	18.35%	18.03%
Stock price volatility, maximum	21.78%	21.08%	18.98%
Expected term	10 years	10 years	10 years

Stock - Based Compensation - Su

Stock - Based Compensation - Summary of Accumulated Stock Units (Detail) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Accumulated stock units	70,022	66,376
Average price	$ 41.74	$ 39.64

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Number of retirement plans	2
Maximum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Maximum legal limit of employer contribution to plan	3.00%

Retirement Plans - Aggregate Am

Retirement Plans - Aggregate Amounts of Contributions to the 401(k) and ESOP Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Contribution Plan Disclosure [Line Items]
Total contributions	$ 4,426	$ 3,959	$ 3,798
401(k) contributions [Member]
Defined Contribution Plan Disclosure [Line Items]
Aggregate amounts of contributions	2,074	1,966	1,870
ESOP contributions [Member]
Defined Contribution Plan Disclosure [Line Items]
Aggregate amounts of contributions	$ 2,352	$ 1,993	$ 1,928

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Authorized Outstanding Preferred and Common Stock (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares outstanding	15,810,935	15,597,446	15,504,513
Common stock, par value	$ 1	$ 1
Common stock dividend payment terms	As declared
Common stock, voting rights	Voting
Senior Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0
Preferred stock, par value	$ 1	$ 1
Preferred stock, dividend payment terms	As declared
Preferred stock, voting rights	Voting
Cumulative Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	900,000	900,000
Preferred stock, shares outstanding	0
Preferred stock, par value	$ 5	$ 5
Preferred stock, dividend payment terms	As declared
Preferred stock, voting rights	Non-voting

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 01, 2017	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Stockholders Equity [Line Items]
Increase remaining shares to be purchased	150,000		150,000	166,276	194,723
2016 [Member]
Stockholders Equity [Line Items]
Implementation of the capital conservation buffer, Percentage	0.625%
Capital conservation buffer implementation phase-in period	4 years
2019 [Member]
Stockholders Equity [Line Items]
Capital Conservation Buffer Maximum Level	2.50%
Maximum [Member]
Stockholders Equity [Line Items]
Quantitative limit for trust preferred securities to be included in tier 1 capital	$ 15,000,000,000
Subsequent Event [Member]
Stockholders Equity [Line Items]
Available equity of BancFirst for dividend payments to the company		$ 83,300,000
Senior Preferred Stock [Member]
Stockholders Equity [Line Items]
Preferred stock, shares issued	0			0
Preferred stock, shares outstanding	0
Cumulative Preferred Stock [Member]
Stockholders Equity [Line Items]
Preferred stock, shares issued	0			0
Preferred stock, shares outstanding	0
Dividend payable at redemption, per share	$ 5
Cumulative preferred stock dividend rate	10.00%

Stockholders' Equity - Summa103

Stockholders' Equity - Summary of Shares Repurchased Under Stock Purchase Program (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2016	Dec. 31, 2014
Summary Of Shares Repurchased Under Stock Purchase Program [Abstract]
Number of shares repurchased	100,000	28,447
Average price of shares repurchased	$ 55.23	$ 58.19
Shares remaining to be repurchased	150,000	166,276	150,000	194,723

Stockholders' Equity - Required

Stockholders' Equity - Required Capital Amounts and Company's Respective Ratios (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 728,635	$ 669,213
Total Capital To Risk Weighted Assets Actual Ratio	15.33%	14.47%
Capital Required For Capital Adequacy Amount	$ 380,351	$ 370,094
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%	8.00%
Capital With Capital Conservation Buffer Amount	$ 410,066
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	8.625%	8.625%
Common Equity Tier 1 Risk Based Capital Amount	$ 648,942	$ 596,547
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	13.65%	12.90%
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 213,947	$ 208,178
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	4.50%	4.50%
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 243,662
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	5.125%	5.125%
Tier 1 Risk Based Capital Amount	$ 679,942	$ 627,547
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	14.30%	13.57%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 285,263	$ 277,570
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	6.00%	6.00%
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 314,978
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	6.625%	6.625%
Tier 1 Capital Amount	$ 679,942	$ 627,547
Tier 1 Capital To Average Assets Ratio	9.94%	9.49%
Tier 1 Capital Required For Capital Adequacy Amount	$ 273,510	$ 264,333
Tier 1 Capital Required For Capital Adequacy To Average Assets Ratio	4.00%	4.00%
BancFirst [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 655,620	$ 607,604
Total Capital To Risk Weighted Assets Actual Ratio	13.80%	13.15%
Capital Required For Capital Adequacy Amount	$ 379,948	$ 369,607
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%	8.00%
Capital With Capital Conservation Buffer Amount	$ 409,631
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	8.625%	8.625%
Capital Required To Be Well Capitalized Amount	$ 474,934	$ 462,009
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	10.00%	10.00%
Common Equity Tier 1 Risk Based Capital Amount	$ 586,927	$ 545,938
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.36%	11.82%
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 213,720	$ 207,904
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	4.50%	4.50%
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 243,404
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	5.125%	5.125%
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 308,707	$ 300,306
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	6.50%	6.50%
Tier 1 Risk Based Capital Amount	$ 606,927	$ 565,938
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.78%	12.25%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 284,961	$ 277,205
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	6.00%	6.00%
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 314,644
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	6.625%	6.625%
Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 379,948	$ 369,607
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	8.00%	8.00%
Tier 1 Capital Amount	$ 606,927	$ 565,938
Tier 1 Capital To Average Assets Ratio	8.89%	8.59%
Tier 1 Capital Required For Capital Adequacy Amount	$ 273,152	$ 263,606
Tier 1 Capital Required For Capital Adequacy To Average Assets Ratio	4.00%	4.00%
Tier 1 Capital Required To Be Well Capitalized Amount	$ 341,440	$ 329,507
Tier 1 Capital Required To Be Well Capitalized To Average Assets Ratio	5.00%	5.00%

Net Income Per Common Share - B

Net Income Per Common Share - Basic and Diluted Net Income Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share Reconciliation [Abstract]
Income available to common stockholders									$ 70,674	$ 66,170	$ 63,887
Income available to common stockholders plus assumed exercises of stock options									$ 70,674	$ 66,170	$ 63,887
Income available to common stockholders - Shares									15,615,170	15,559,059	15,430,773
Effect of stock options - Shares									296,092	327,186	363,630
Income available to common stockholders plus assumed exercises of stock options - Shares									15,911,262	15,886,245	15,794,403
Income available to common stockholders - Per Share Amount	$ 1.19	$ 1.15	$ 1.12	$ 1.07	$ 1	$ 1.01	$ 1.19	$ 1.05	$ 4.53	$ 4.25	$ 4.14
Income available to common stockholders plus assumed exercises of stock options - Per Share Amount	$ 1.16	$ 1.13	$ 1.10	$ 1.05	$ 0.99	$ 0.98	$ 1.17	$ 1.03	$ 4.44	$ 4.17	$ 4.04

Net Income Per Common Share - A

Net Income Per Common Share - Average Exercise Prices of Options Excluded from Computation of Diluted Net Income Per Common Share (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Abstract]
Shares	147,219	177,718	69,405
Average Exercise Price	$ 60.49	$ 58.47	$ 55.87

Condensed Parent Company Fin107

Condensed Parent Company Financial Statements - Summary of Balance Sheet of Parent Company (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash	$ 183,921	$ 203,364
Securities	469,833	552,949
Goodwill	54,042	54,042	$ 44,962
Total assets	7,018,952	6,692,829	6,574,972
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	27,342	31,502
Junior subordinated debentures	31,959	31,959
Stockholders’ equity	711,094	655,510	$ 609,314
Total liabilities and stockholders' equity	7,018,952	6,692,829
Parent Company [Member]
ASSETS
Cash	57,537	45,437
Securities	97	103
Investments in subsidiaries	681,861	639,119
Goodwill	450	450
Dividends receivable	6,998	6,773
Other assets	2,610	1,688
Total assets	749,553	693,570
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	6,500	6,101
Junior subordinated debentures	31,959	31,959
Stockholders’ equity	711,094	655,510
Total liabilities and stockholders' equity	$ 749,553	$ 693,570

Condensed Parent Company Fin108

Condensed Parent Company Financial Statements- Summary of Income Statement of Parent Company (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING INCOME
Interest on interest-bearing deposits									$ 7,908	$ 4,265	$ 4,391
OPERATING EXPENSE
Other									32,857	33,972	36,407
Allocated income tax benefit/(expense)									(37,263)	(35,040)	(27,284)
Amortization of stock-based compensation arrangements of subsidiaries									(1,636)	(1,717)	(1,676)
Net income	$ 18,620	$ 17,982	$ 17,493	$ 16,579	$ 15,728	$ 15,630	$ 18,553	$ 16,259	70,674	66,170	63,887
Parent Company [Member]
OPERATING INCOME
Dividends from subsidiaries									28,175	26,043	24,851
Interest on interest-bearing deposits									160	66	62
Other									3	2	14
Total operating income									28,338	26,111	24,927
OPERATING EXPENSE
Interest									2,096	1,998	1,965
Other									583	628	667
Total operating expense									2,679	2,626	2,632
Income before taxes									25,659	23,485	22,295
Allocated income tax benefit/(expense)									1,244	(796)	472
Income before equity in undistributed earnings of subsidiaries									26,903	22,689	22,767
Equity in undistributed earnings of subsidiaries									44,172	44,653	42,196
Amortization of stock-based compensation arrangements of subsidiaries									(401)	(1,172)	(1,076)
Net income									$ 70,674	$ 66,170	$ 63,887

Condensed Parent Company Fin109

Condensed Parent Company Financial Statements - Summary of Cash Flow of Parent Company (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 18,620	$ 17,982	$ 17,493	$ 16,579	$ 15,728	$ 15,630	$ 18,553	$ 16,259	$ 70,674	$ 66,170	$ 63,887
Adjustments to reconcile to net cash provided by operating activities:
Amortization of stock-based compensation arrangements									1,636	1,717	1,676
Other, net									(5,500)	6,301	5,719
Net cash provided by operating activities									90,541	78,159	76,922
INVESTING ACTIVITIES
Net cash and due from banks (paid for) received from acquisitions										(4,007)	174,283
Net cash used in investing activities									(98,017)	(265,298)	(183,376)
FINANCING ACTIVITIES
Issuance of common stock, net									13,354	4,428	6,532
Common stock acquired									(5,523)	(1,654)
Cash dividends paid									(22,770)	(21,449)	(19,543)
Net cash provided by (used in) financing activities									259,760	(128,579)	162,814
Net increase in cash									252,284	(315,718)	56,360
Cash, due from banks and interest-bearing deposits at the beginning of the period				1,598,177				1,913,895	1,598,177	1,913,895	1,857,535
Cash, due from banks and interest-bearing deposits at the end of the period	1,850,461				1,598,177				1,850,461	1,598,177	1,913,895
SUPPLEMENTAL DISCLOSURE
Cash paid during the period for interest									14,673	12,255	13,135
Cash received during the period for income taxes, net									32,700	33,531	26,178
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income									70,674	66,170	63,887
Adjustments to reconcile to net cash provided by operating activities:
Equity in undistributed earnings of subsidiaries									(44,172)	(44,653)	(42,196)
Amortization of stock-based compensation arrangements									401	1,172	1,076
Other, net									136	(343)	(656)
Net cash provided by operating activities									27,039	22,346	22,111
INVESTING ACTIVITIES
Net cash and due from banks (paid for) received from acquisitions										5,066
Sales and maturities of held for investment and available for sale securities											8
Net cash used in investing activities										5,066	8
FINANCING ACTIVITIES
Issuance of common stock, net									13,354	4,428	6,532
Common stock acquired									(5,523)	(1,654)
Cash dividends paid									(22,770)	(21,449)	(19,543)
Net cash provided by (used in) financing activities									(14,939)	(18,675)	(13,011)
Net increase in cash									12,100	8,737	9,108
Cash, due from banks and interest-bearing deposits at the beginning of the period				$ 45,437				$ 36,700	45,437	36,700	27,592
Cash, due from banks and interest-bearing deposits at the end of the period	$ 57,537				$ 45,437				57,537	45,437	36,700
SUPPLEMENTAL DISCLOSURE
Cash paid during the period for interest									2,096	1,998	1,965
Cash received during the period for income taxes, net									$ 5,031	$ 1,131	$ 1,822

Commitments and Contingent L110

Commitments and Contingent Liabilities - Summary of Financial Instruments with Off-Balance-Sheet Risks (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Loan commitments	$ 981,777	$ 960,490
Stand-by letters of credit	$ 56,551	$ 61,889

Commitments and Contingent L111

Commitments and Contingent Liabilities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016StorageSpacesLand_ParcelATMParkingSpacesBuildings
Commitments And Contingencies Disclosure [Abstract]
Parcels of land | Land_Parcel	2
Number of ATM locations | ATM	20
Number of storage facilities | StorageSpaces	2
Number of parking lots | ParkingSpaces	4
Number of buildings | Buildings	13
Lease expiry period maximum	2,064

Commitments and Contingent L112

Commitments and Contingent Liabilities - Summary of Future Minimum Rental Payments Under Lease (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2,017	$ 419
2,018	421
2,019	355
2,020	205
2,021	172
Later years	700
Total	$ 2,272

Commitments and Contingent L113

Commitments and Contingent Liabilities - Summary of Rental Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Leases Rent Expense [Abstract]
Rent expense on all property and equipment rented	$ 1,524	$ 1,360	$ 1,255

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument Fair Value Disclosure [Abstract]
Days from origination after which mortgage loan are sold	30 days
Transfer of securities between levels of fair value hierarchy	$ 0	$ 0
Amount of non-financial assets (liabilities)	0	0
Non-financial assets or liabilities for which no impairment was provided	$ 0	$ 0

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 465,468	$ 544,160
Derivative assets	1,569	1,946
Derivative liabilities	1,306	989
Loans held for sale	9,318	13,725
U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	268,543	329,696
U.S. Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	129,642	131,896
Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	19,672	21,855
States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	41,042	50,920
Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	6,569	9,793
Level 1 Inputs [Member] | U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	268,543	329,696
Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,569	1,946
Derivative liabilities	1,306	989
Loans held for sale	9,318	13,725
Level 2 Inputs [Member] | U.S. Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	129,642	131,896
Level 2 Inputs [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	4,856	7,039
Level 2 Inputs [Member] | States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	41,042	50,920
Level 2 Inputs [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value		3,485
Level 3 Inputs [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	14,816	14,816
Level 3 Inputs [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 6,569	$ 6,308

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 Assets Measured at Estimated Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward
Balance at the beginning of the year	$ 21,124	$ 28,459
Purchases	1,096	609
Settlements	(191)	(2,327)
Sales	(429)	(8,817)
(Losses) gains included in earnings	(111)	7,141
Total unrealized losses	(104)	(3,941)
Balance at the end of the period	$ 21,385	$ 21,124

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Repossessed Assets [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Losses	$ 3
Other Real Estate Owned [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Losses	231	$ 128
Level 3 [Member] | Impaired Loans (Less Specific Allowance) [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	29,912	44,399
Level 3 [Member] | Repossessed Assets [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	340	230
Level 3 [Member] | Other Real Estate Owned [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	$ 1,480	$ 3,607

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
FINANCIAL ASSETS
Cash and cash equivalents, Carrying Amount	$ 1,850,461	$ 1,598,177	$ 1,913,895	$ 1,857,535
Securities held for investment, Carrying Amount	4,365	8,789
Loans, net of allowance for loan losses, Carrying Amount	4,351,539	4,190,382
Securities held for investment, Fair Value	4,403	8,850
FINANCIAL LIABILITIES
Deposits, Carrying Amount	6,248,057	5,973,358
Short-term borrowings, Carrying Amount	500	500
Junior subordinated debentures, Carrying Amount	31,959	31,959
OFF-BALANCE SHEET FINANCIAL INSTRUMENTS
Loan commitments, Fair Value	1,718	1,681
Letters of credit, Fair Value	424	464
Level 2 Inputs [Member]
FINANCIAL ASSETS
Cash and cash equivalents, Carrying Amount	1,851,161	1,598,177
Securities held for investment, Carrying Amount	3,722	8,289
Cash and cash equivalents, Fair Value	1,851,161	1,598,177
Securities held for investment, Fair Value	3,760	8,350
FINANCIAL LIABILITIES
Deposits, Carrying Amount	6,248,057	5,973,358
Short-term borrowings, Carrying Amount	500	500
Junior subordinated debentures, Carrying Amount	31,959	31,959
Deposits, Fair Value	6,313,622	6,028,012
Short-term borrowings, Fair Value	500	500
Junior subordinated debentures, Fair Value	34,339	33,793
Level 3 Inputs [Member]
FINANCIAL ASSETS
Securities held for investment, Carrying Amount	643	500
Loans, net of allowance for loan losses, Carrying Amount	4,351,539	4,190,382
Securities held for investment, Fair Value	643	500
Loans, net of allowance for loan losses, Fair Value	$ 4,367,363	$ 4,222,153

Derivative Financial Instrum119

Derivative Financial Instruments - Notional Amounts and Estimated Fair Values of Outstanding Derivative Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	$ 1,569	$ 1,946
Derivative liabilities, Estimated Fair Value	(1,306)	(989)
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	1,569	1,946
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Estimated Fair Value	$ (1,306)	(989)
Oil [Member]
Derivatives, Fair Value [Line Items]
Notional Units	Barrels
Derivative assets, Notional Amount	$ 83	86
Derivative assets, Estimated Fair Value	576	604
Derivative liabilities, Notional Amount	(83)	(86)
Derivative liabilities, Estimated Fair Value	$ (496)	(378)
Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Notional Units	MMBTUs
Derivative assets, Notional Amount	$ 1,900	3,920
Derivative assets, Estimated Fair Value	993	1,342
Derivative liabilities, Notional Amount	(1,900)	(3,920)
Derivative liabilities, Estimated Fair Value	$ (810)	$ (611)

Derivative Financial Instrum120

Derivative Financial Instruments - Recognized Derivative Income Included in Other Noninterest Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Gain Loss On Derivative Net [Abstract]
Derivative income	$ 32	$ 341	$ 500

Derivative Financial Instrum121

Derivative Financial Instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Company’s share of total profit	35.00%

Derivative Financial Instrum122

Derivative Financial Instruments - Summary of Company's Net Credit Exposure Relating to Oil and Gas Swaps and Options with Bank Counterparties (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Credit Risk Derivatives At Fair Value Net [Abstract]
Credit exposure	$ 37

Segment Information - Additiona

Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016Business_Unit
Segment Reporting [Abstract]
Number of principal business units	4

Segment Information - Results o

Segment Information - Results of Operations and Selected Financial Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 51,553	$ 51,431	$ 50,868	$ 49,976	$ 50,075	$ 46,876	$ 46,215	$ 45,626	$ 203,828	$ 188,792	$ 181,351
Provision for loan losses	1,672	2,940	2,804	4,103	3,646	1,424	1,271	1,334	11,519	7,675	3,072
Noninterest income	27,431	$ 27,927	$ 26,057	$ 25,617	26,473	$ 25,324	$ 28,715	$ 25,296	107,032	105,808	96,413
Depreciation and amortization									12,383	11,901	11,349
Other expenses									179,021	173,814	172,172
Income before taxes									107,937	101,210	91,171
Total assets	7,018,952				6,692,829				7,018,952	6,692,829	6,574,972
Capital expenditures									10,835	11,263	11,490
Operating Segments [Member] | Metropolitan Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									63,519	61,500	59,923
Provision for loan losses									2,229	2,684	3,077
Noninterest income									16,372	16,552	13,752
Depreciation and amortization									2,341	2,273	2,216
Other expenses									34,130	32,942	32,300
Income before taxes									41,191	40,153	36,082
Total assets	2,493,096				2,277,870				2,493,096	2,277,870	2,298,828
Capital expenditures									1,525	3,743	1,948
Operating Segments [Member] | Community Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									135,508	122,404	116,935
Provision for loan losses									7,509	3,806	(488)
Noninterest income									57,745	52,598	51,415
Depreciation and amortization									8,281	7,894	7,277
Other expenses									96,627	91,655	89,888
Income before taxes									80,836	71,647	71,673
Total assets	4,412,174				4,379,205				4,412,174	4,379,205	4,113,783
Capital expenditures									7,738	4,634	7,972
Operating Segments [Member] | Other Financial Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									6,132	6,798	6,155
Provision for loan losses									1,653	1,176	481
Noninterest income									29,711	33,629	28,079
Depreciation and amortization									510	514	522
Other expenses									22,216	22,308	22,304
Income before taxes									11,464	16,429	10,927
Total assets	83,594				128,697				83,594	128,697	145,814
Capital expenditures									125	121	121
Operating Segments [Member] | Executive, Operations & Support [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									(1,331)	(1,910)	(1,662)
Provision for loan losses									128	9	2
Noninterest income									75,415	72,806	69,442
Depreciation and amortization									1,251	1,220	1,334
Other expenses									26,375	27,221	27,998
Income before taxes									46,330	42,446	38,446
Total assets	803,810				624,428				803,810	624,428	679,194
Capital expenditures									1,447	2,765	1,449
Eliminations [Member]
Segment Reporting Information [Line Items]
Noninterest income									(72,211)	(69,777)	(66,275)
Other expenses									(327)	(312)	(318)
Income before taxes									(71,884)	(69,465)	(65,957)
Total assets	$ (773,722)				$ (717,371)				$ (773,722)	$ (717,371)	$ (662,647)

Selected Quarterly Financial125

Selected Quarterly Financial Data (Unaudited) - Summary of the Unaudited Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net interest income	$ 51,553	$ 51,431	$ 50,868	$ 49,976	$ 50,075	$ 46,876	$ 46,215	$ 45,626	$ 203,828	$ 188,792	$ 181,351
Provision for loan losses	1,672	2,940	2,804	4,103	3,646	1,424	1,271	1,334	11,519	7,675	3,072
Securities transactions	52	(146)	(65)	100	2,148		5,392	1,729	(59)	9,269	1,641
Noninterest income	27,431	27,927	26,057	25,617	26,473	25,324	28,715	25,296	107,032	105,808	96,413
Noninterest expense	48,189	49,204	47,720	46,291	49,011	46,352	45,429	44,923	191,404	185,715	183,521
Net income	$ 18,620	$ 17,982	$ 17,493	$ 16,579	$ 15,728	$ 15,630	$ 18,553	$ 16,259	$ 70,674	$ 66,170	$ 63,887
Net income per common share:
Basic	$ 1.19	$ 1.15	$ 1.12	$ 1.07	$ 1	$ 1.01	$ 1.19	$ 1.05	$ 4.53	$ 4.25	$ 4.14
Diluted	$ 1.16	$ 1.13	$ 1.10	$ 1.05	$ 0.99	$ 0.98	$ 1.17	$ 1.03	$ 4.44	$ 4.17	$ 4.04