BancFirst (BANF) 10-K 11 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Jan. 29, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
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	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		15,532,079
Entity Public Float			$ 514,714,246

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and due from banks	$ 203,364	$ 203,545
Interest-bearing deposits with banks	1,394,813	1,710,350
Securities (fair value: $553,010 and $524,861, respectively)	552,949	524,783
Loans held for sale	13,725	9,433
Loans (net of unearned interest)	4,232,048	3,851,398
Allowance for loan losses	(41,666)	(40,889)
Loans, net of allowance for loan losses	4,190,382	3,810,509
Premises and equipment, net	126,813	121,341
Other real estate owned	7,984	7,859
Intangible assets, net	15,695	10,635
Goodwill	54,042	44,962
Accrued interest receivable and other assets	133,062	131,555
Total assets	6,692,829	6,574,972
Deposits:
Noninterest-bearing	2,409,769	2,411,066
Interest-bearing	3,563,589	3,493,638
Total deposits	5,973,358	5,904,704
Short-term borrowings	500	3,982
Accrued interest payable and other liabilities	31,502	30,168
Junior subordinated debentures	31,959	26,804
Total liabilities	$ 6,037,319	$ 5,965,658
Commitments and contingent liabilities (Note 19)
Stockholders' equity:
Common stock, $1.00 par, 20,000,000 shares authorized; shares issued and outstanding: 15,597,446 and 15,504,513, respectively	$ 15,597	$ 15,504
Capital surplus	102,865	96,841
Retained earnings	535,521	492,776
Accumulated other comprehensive income, net of income tax of $962 and $2,644, respectively	1,527	4,193
Total stockholders' equity	655,510	609,314
Total liabilities and stockholders' equity	$ 6,692,829	$ 6,574,972
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, 2015	Dec. 31, 2014
Securities, fair value	$ 553,010	$ 524,861
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	15,597,446	15,504,513
Common stock, shares outstanding	15,597,446	15,504,513
Accumulated other comprehensive income, tax	$ 962	$ 2,644
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, 2015	Dec. 31, 2014	Dec. 31, 2013
INTEREST INCOME
Loans, including fees	$ 190,292	$ 182,972	$ 167,051
Securities:
Taxable	5,492	5,727	4,947
Tax-exempt	982	1,061	1,222
Federal funds sold	14	2	2
Interest-bearing deposits with banks	4,265	4,391	4,064
Total interest income	201,045	194,153	177,286
INTEREST EXPENSE
Deposits	10,251	10,795	11,579
Short-term borrowings	4	16	6
Long-term borrowings	32	25	216
Junior subordinated debentures	1,966	1,966	1,966
Total interest expense	12,253	12,802	13,767
Net interest income	188,792	181,351	163,519
Provision for loan losses	7,675	3,072	1,258
Net interest income after provision for loan losses	181,117	178,279	162,261
NONINTEREST INCOME
Trust revenue	9,091	9,180	8,072
Service charges on deposits	57,651	56,389	52,450
Securities transactions (includes accumulated other comprehensive income reclassifications of $3,814, $533 and $137, respectively)	9,269	1,641	420
Income from sales of loans	1,968	1,813	2,306
Insurance commissions	14,791	14,642	14,094
Cash management	7,510	6,741	6,250
Gain on sale of other assets	79	335	293
Other	5,449	5,672	6,270
Total noninterest income	105,808	96,413	90,155
NONINTEREST EXPENSE
Salaries and employee benefits	113,083	108,640	102,165
Occupancy, net	11,512	11,610	10,635
Depreciation	9,966	9,595	9,412
Amortization of intangible assets	1,935	1,754	1,665
Data processing services	4,579	4,689	4,785
Net expense from other real estate owned	324	511	434
Marketing and business promotion	6,986	7,024	6,652
Deposit insurance	3,358	3,291	3,003
Other	33,972	36,407	32,823
Total noninterest expense	185,715	183,521	171,574
Income before taxes	101,210	91,171	80,842
Income tax expense	35,040	27,284	26,525
Net income	$ 66,170	$ 63,887	$ 54,317
NET INCOME PER COMMON SHARE
Basic	$ 4.25	$ 4.14	$ 3.56
Diluted	$ 4.17	$ 4.04	$ 3.49
OTHER COMPREHENSIVE INCOME
Unrealized gains (losses) on securities, net of tax of $207, $(747) and $1,249, respectively	$ (327)	$ 613	$ (2,321)
Reclassification adjustment for gains included in net income, net of tax of $1,475, $206 and $48, respectively	(2,339)	(327)	(89)
Other comprehensive gain (loss), net of tax of $1,682, $(541) and $1,297, respectively	(2,666)	286	(2,410)
Comprehensive income	$ 63,504	$ 64,173	$ 51,907

Consolidated Statements of Com5

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Securities transactions accumulated other comprehensive income reclassifications	$ 3,814	$ 533	$ 137
Unrealized gains (losses) on securities, tax	207	(747)	1,249
Reclassification adjustment for gains included in net income, tax	1,475	206	48
Other comprehensive gain (loss), tax	$ 1,682	$ (541)	$ 1,297

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, 2012		$ 15,242	$ 82,401	$ 415,607	$ 6,317
Balance at beginning of period, Shares at Dec. 31, 2012		15,242,308
Shares issued, Value		$ 158	3,590
Shares issued, Shares		157,155
Net income	$ 54,317			54,317
Net change	(2,410)				(2,410)
Tax effect of stock options			1,452
Dividends on common stock				(18,327)
Stock-based compensation arrangements			1,360
Shares acquired and canceled, Value		$ (66)		(2,644)
Shares acquired and canceled, Shares		(65,841)
Balance at end of period at Dec. 31, 2013	$ 556,997	$ 15,334	88,803	448,953	3,907
Balance at end of period, Shares at Dec. 31, 2013	15,333,622	15,333,622
Shares issued, Value		$ 170	4,742
Shares issued, Shares		170,891
Net income	$ 63,887			63,887
Net change	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
Net change	(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

Consolidated Statements of Sto7

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
RETAINED EARNINGS [Member]
Dividend on common stock	$ 1.40	$ 1.30	$ 1.20

Consolidated Statements of Cash

Consolidated Statements of Cash Flow $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 66,170	$ 63,887	$ 54,317
Adjustments to reconcile to net cash provided by operating activities:
Provision for loan losses	7,675	3,072	1,258
Depreciation and amortization	11,901	11,349	11,077
Net amortization of securities premiums and discounts	1,020	910	1,563
Realized securities gains	(9,269)	(1,641)	(420)
Gain on sales of loans	(1,968)	(1,813)	(2,306)
Cash receipts from the sale of loans originated for sale	171,723	152,440	200,946
Cash disbursements for loans originated for sale	(174,047)	(153,592)	(193,853)
Deferred income tax benefit	(1,903)	(3,683)	(483)
Gain on other assets	(65)	(760)	(790)
(Increase)/decrease in interest receivable	(991)	(309)	284
Decrease in interest payable	(105)	(333)	(375)
Amortization of stock-based compensation arrangements	1,717	1,676	1,360
Other, net	6,301	5,719	5,512
Net cash provided by operating activities	78,159	76,922	78,090
INVESTING ACTIVITIES
Net cash and due from banks (paid for) received from acquisitions	(4,007)	174,283
Net decrease in federal funds sold	13,256	4,619	700
Purchases of held for investment securities	(1,771)	(708)	(902)
Purchases of available for sale securities	(91,136)	(224,217)	(157,139)
Proceeds from maturities, calls and paydowns of held for investment securities	2,103	4,101	5,816
Proceeds from maturities, calls and paydowns of available for sale securities	55,689	225,394	181,769
Proceeds from sales of available for sale securities	10,850	4,855	521
Net change in loans	(243,976)	(366,064)	(153,336)
Purchases of premises, equipment and computer software	(11,263)	(11,490)	(13,896)
Proceeds from the sale of other assets	4,957	5,851	5,389
Net cash used in investing activities	(265,298)	(183,376)	(131,078)
FINANCING ACTIVITIES
Net change in deposits	(106,422)	183,371	(21,311)
Net (decrease)/increase in short-term borrowings	(3,482)	(608)	19
Paydown of long-term borrowings		(6,938)	(2,240)
Issuance of common stock, net	4,428	6,532	5,200
Common stock acquired	(1,654)		(2,710)
Cash dividends paid	(21,449)	(19,543)	(13,583)
Net cash (used in) provided by financing activities	(128,579)	162,814	(34,625)
Net (decrease)/increase in cash, due from banks and interest-bearing deposits	(315,718)	56,360	(87,613)
Cash, due from banks and interest-bearing deposits at the beginning of the period	1,913,895	1,857,535	1,945,148
Cash, due from banks and interest-bearing deposits at the end of the period	1,598,177	1,913,895	1,857,535
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	12,255	13,135	14,142
Cash paid during the period for income taxes	33,531	26,178	20,946
Noncash investing and financing activities:
Unpaid common stock dividends declared	$ 5,615	$ 5,265	$ 4,744

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
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 2014 and 2013 have been reclassified to conform to the 2015 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, the vast majority of which have a rate floor, limits on fixing rates for longer periods and strict adherence to the original amortization terms in a rising interest rate environment. 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 80% of the portfolio, with junior liens comprising less than 15%, and home equity lines of credit comprising less than 5%. 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. 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 liability 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 February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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 effect 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 effect on the Company’s financial statements. In February 2015, the FASB issued ASU No. 2015-02, “Consolidation (Topic 810) – Amendments to the Consolidation Analysis.” ASU 2015-02 implements changes to both the variable interest consolidation model and the voting interest consolidation model. ASU 2015-02 (i) eliminates certain criteria that must be met when determining when fees paid to a decision maker or service provider do not represent a variable interest, (ii) amends the criteria for determining whether a limited partnership is a variable interest entity and (iii) eliminates the presumption that a general partner controls a limited partnership in the voting model. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2015. Adoption of ASU 2015-02 is not expected to have a significant effect 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 effect on the Company’s financial statements. In January 2014, the FASB issued ASU No. 2014-04, “Receivables: Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure (Topic 310-40).” ASU 2014-04 clarifies that an in-substance repossession or foreclosure occurs upon either the creditor obtaining legal title to the residential real estate property or the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. The amendments were effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2014. Adoption of ASU 2014-04 did not have a significant effect on the Company’s financial statements. In January 2014, the FASB issued ASU No. 2014-01, “Accounting for Investments in Affordable Housing Projects (Topic 323).” ASU 2014-01 revises the necessary criteria that need to be met in order for an entity to account for investments in affordable housing projects net of the provision for income taxes. It also changes the method of recognition from an effective amortization approach to a proportional amortization approach. Additional disclosures were also set forth in this update. The amendments were effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2014. The amendments were required to be applied retrospectively to all periods presented. Early adoption was permitted and adoption of the standard was optional. Adoption of ASU 2014-01 did not have a material impact on the Company’s financial statements.

Recent Developments, Including

Recent Developments, Including Mergers and Acquisitions	12 Months Ended
	Dec. 31, 2015
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. In October 2015, the Company recorded a gain on sale of securities of $2.1 million, related to the redemption of warrants associated with a past loan transaction. In June 2015, Council Oak Partners, LLC, a wholly-owned subsidiary of the Company, recognized a pretax gain of approximately $5.2 million on one of its investments. In January 2015, Council Oak Investment Corporation, a wholly-owned subsidiary of BancFirst, recognized a pretax gain of approximately $1.7 million on one of its investments. 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, 2015
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, 2015 and 2014, 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, 2015 and 2014 is included in the following table: December 31, 2015 2014 (Dollars in thousands) Vault cash and funds on deposit with the Federal Reserve Bank $ 1,499,137 $ 1,804,028 Average required Reserves 40,093 44,711

Securities

Securities	12 Months Ended
	Dec. 31, 2015
Investments Debt And Equity Securities [Abstract]
Securities	(4) SECURITIES The following table summarizes securities held for investment and securities available for sale: December 31, 2015 2014 (Dollars in thousands) Held for investment, at cost (fair value: $8,850 and $8,671, respectively) $ 8,789 $ 8,593 Available for sale, at fair value 544,160 516,190 Total $ 552,949 $ 524,783 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, 2015 Mortgage backed securities (1) $ 347 $ 25 $ — $ 372 States and political subdivisions 8,442 36 — 8,478 Total $ 8,789 $ 61 $ — $ 8,850 December 31, 2014 Mortgage backed securities (1) $ 471 $ 34 $ — $ 505 States and political subdivisions 8,122 44 — 8,166 Total $ 8,593 $ 78 $ — $ 8,671 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, 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 December 31, 2014 U.S. treasuries $ 248,767 $ 404 $ (178 ) $ 248,993 U.S. federal agencies 171,641 983 (175 ) 172,449 Mortgage backed securities (1) 26,441 602 (586 ) 26,457 States and political subdivisions 51,706 1,716 (49 ) 53,373 Other securities (2) 10,798 4,252 (132 ) 14,918 Total $ 509,353 $ 7,957 $ (1,120 ) $ 516,190 (1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies. (2) Primarily consists of equity securities. The unrealized gains decreased in 2015 primarily due to the reclassification of an unrealized gain on one investment of $3.3 million from other comprehensive income to a realized gain by Council Oak Partners, LLC, a wholly-owned subsidiary of the Company. The realized gain is reported as securities transactions within the noninterest income section of the consolidated statement of comprehensive income. 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, 2015 2014 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 5,168 $ 5,174 $ 1,451 $ 1,456 After one year but within five years 2,800 2,829 6,603 6,642 After five years but within ten years 795 319 380 396 After ten years 26 528 159 177 Total $ 8,789 $ 8,850 $ 8,593 $ 8,671 Available for Sale Contractual maturity of debt securities: Within one year $ 272,820 $ 272,779 $ 41,772 $ 41,870 After one year but within five years 178,617 180,145 350,975 352,044 After five years but within ten years 8,483 9,075 21,990 22,717 After ten years 75,522 75,853 87,252 88,132 Total debt securities 535,442 537,852 501,989 504,763 Equity securities 6,228 6,308 7,364 11,427 Total $ 541,670 $ 544,160 $ 509,353 $ 516,190 The following is a detail of proceeds from sales and realized securities gains and losses, on available for sale securities: Year Ended December 31, 2015 2014 2013 (Dollars Proceeds $ 10,850 $ 4,855 $ 521 Gross gains realized 9,394 1,641 456 Gross losses realized 125 — 36 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, 2015 2014 (Dollars Book value of pledged securities $ 493,540 $ 522,190 The following table summarizes securities with unrealized losses, segregated by the duration of the unrealized loss, at December 31, 2015 and 2014 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, 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 December 31, 2014 Held for Investment Mortgage backed securities $ — $ — $ — $ — $ — $ — States and political subdivisions — — — — — — Total $ — $ — $ — $ — $ — $ — Available for Sale U.S. treasuries $ 149,589 $ 178 $ — $ — $ 149,589 $ 178 U.S. federal agencies 40,551 113 13,653 62 54,204 175 Mortgage backed securities 17,041 585 26 1 17,067 586 States and political subdivisions 3,093 26 977 23 4,070 49 Other securities — — 300 132 300 132 Total $ 210,274 $ 902 $ 14,956 $ 218 $ 225,230 $ 1,120 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, 2015 and 2014, 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, 2015
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, 2015 2014 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 795,803 18.80 % $ 745,106 19.35 % Oil & gas production and equipment 87,304 2.06 104,940 2.72 Agriculture 150,620 3.56 132,830 3.45 State and political subdivisions: Taxable 17,605 0.42 20,431 0.53 Tax-exempt 33,575 0.79 20,952 0.54 Real estate: Construction 403,664 9.54 356,621 9.26 Farmland 184,707 4.36 149,507 3.88 One to four family residences 821,251 19.41 766,362 19.90 Multifamily residential properties 65,477 1.55 66,766 1.73 Commercial 1,356,430 32.05 1,191,477 30.94 Consumer 283,636 6.70 267,179 6.94 Other (not classified above) 31,976 0.76 29,227 0.76 Total loans $ 4,232,048 100.00 % $ 3,851,398 100.00 % 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, 2015 2014 (Dollars in thousands) Past due 90 days or more and still accruing $ 1,841 $ 1,135 Nonaccrual 30,096 16,410 Restructured 15,143 16,515 Total nonperforming and restructured loans 47,080 34,060 Other real estate owned and repossessed assets 8,214 8,079 Total nonperforming and restructured assets $ 55,294 $ 42,139 Nonaccrual loans, accruing loans past due 90 days or more, and restructured loans are shown in the table above. 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 2015, $1.2 million in 2014 and $1.5 million in 2013. Restructured loans consisted primarily of one relationship restructured to defer principal payments. The relationship was evaluated by management and determined to be well collateralized. Additionally, none of the concessions granted involved a principal reduction or a change from the current market rate of interest. The collateral value is monitored periodically to evaluate possible impairment. 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, 2015 2014 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 261 $ 296 Non-residential real estate other 3,957 5,126 Residential real estate permanent mortgage 656 681 Residential real estate all other 1,833 1,796 Commercial and financial: Non-consumer non-real estate 10,159 1,556 Consumer non-real estate 312 250 Other loans 9,381 1,659 Acquired loans 3,537 5,046 Total $ 30,096 $ 16,410 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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 635 $ — $ 269 $ 904 $ 482,731 $ 483,635 $ 70 Non-residential real estate other 377 317 825 1,519 952,484 954,003 — Residential real estate permanent mortgage 2,010 758 544 3,312 304,267 307,579 172 Residential real estate all other 1,820 194 1,488 3,502 633,586 637,088 387 Commercial and financial: Non-consumer non-real estate 841 71 793 1,705 965,002 966,707 24 Consumer non-real estate 1,914 711 330 2,955 244,810 247,765 215 Other loans 1,858 916 741 3,515 149,469 152,984 — Acquired loans 1,815 997 1,304 4,116 97,521 101,637 267 Total $ 11,270 $ 3,964 $ 6,294 $ 21,528 $ 3,829,870 $ 3,851,398 $ 1,135 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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 521 $ 448 $ 15 $ 453 Non-residential real estate other 23,154 21,164 1,364 21,522 Residential real estate permanent mortgage 1,095 880 85 1,042 Residential real estate all other 2,480 2,270 299 2,273 Commercial and financial: Non-consumer non-real estate 1,895 1,580 431 1,646 Consumer non-real estate 664 648 138 602 Other loans 2,101 1,659 228 1,512 Acquired loans 10,933 7,708 — 8,082 Total $ 42,843 $ 36,357 $ 2,560 $ 37,132 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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 402,706 $ 75,555 $ 5,008 $ 366 $ — $ 483,635 Non-residential real estate other 795,209 133,542 20,126 5,126 — 954,003 Residential real estate permanent mortgage 272,411 27,855 6,369 944 — 307,579 Residential real estate all other 529,555 99,214 6,146 2,173 — 637,088 Commercial and financial: Non-consumer non-real estate 821,094 117,457 26,550 1,606 — 966,707 Consumer non-real estate 233,424 12,229 1,548 564 — 247,765 Other loans 147,758 4,261 601 173 191 152,984 Acquired loans 46,465 36,951 12,651 5,206 364 101,637 Total $ 3,248,622 $ 507,064 $ 78,999 $ 16,158 $ 555 $ 3,851,398 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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 4,827 $ (42 ) $ 102 $ 60 $ (481 ) $ 4,406 Non-residential real estate other 11,026 (29 ) 49 20 (1,430 ) 9,616 Residential real estate permanent mortgage 2,825 (207 ) 78 (129 ) 252 2,948 Residential real estate all other 6,708 (171 ) 32 (139 ) (300 ) 6,269 Commercial and financial: Non-consumer non-real estate 8,977 (564 ) 70 (494 ) 4,288 12,771 Consumer non-real estate 2,556 (687 ) 203 (484 ) 332 2,404 Other loans 1,991 (351 ) 149 (202 ) 570 2,359 Acquired loans 124 (568 ) 719 151 (159 ) 116 Total $ 39,034 $ (2,619 ) $ 1,402 $ (1,217 ) $ 3,072 $ 40,889 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, 2015 December 31, 2014 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 $ 323 $ 4,338 $ 202 $ 4,204 Non-residential real estate other 323 9,598 1,518 8,098 Residential real estate permanent mortgage 399 2,749 407 2,541 Residential real estate all other 839 5,886 743 5,526 Commercial and financial: Non-consumer non-real estate 3,365 8,389 4,671 8,100 Consumer non-real estate 445 2,197 372 2,032 Other loans 291 2,357 214 2,145 Acquired loans — 167 — 116 Total $ 5,985 $ 35,681 $ 8,127 $ 32,762 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, 2015 December 31, 2014 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 $ 8,619 $ 494,278 $ — $ 5,374 $ 478,261 $ — Non-residential real estate other 8,608 1,102,152 — 25,251 928,752 — Residential real estate permanent mortgage 7,543 325,058 — 7,313 300,266 — Residential real estate all other 10,803 665,886 — 8,319 628,769 — Commercial and financial: Non-consumer non-real estate 22,983 961,779 — 28,156 938,551 — Consumer non-real estate 2,416 266,453 — 2,112 245,653 — Other loans 2,323 160,293 — 233 152,751 — Acquired loans — 177,871 14,983 — 83,416 18,221 Total $ 63,295 $ 4,153,770 $ 14,983 $ 76,758 $ 3,756,419 $ 18,221 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, 2015 2014 2013 (Dollars in thousands) Other real estate owned $ 2,139 $ 3,573 $ 1,710 Repossessed assets 1,098 1,209 1,171 Total $ 3,237 $ 4,782 $ 2,881 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 Period (Dollars in thousands) 2015 $ 25,019 $ 22,330 $ (9,772 ) $ 37,577 2014 27,134 22,521 (24,636 ) 25,019 2013 29,030 11,979 (13,875 ) 27,134

Premises and Equipment, Net

Premises and Equipment, Net	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Premises and Equipment, Net	(6) PREMISES AND EQUIPMENT, NET The following is a summary of premises and equipment by classification: December 31, Estimated Useful Lives 2015 2014 (Dollars in thousands) Land $ 31,196 $ 29,658 Buildings 10 to 40 years 135,694 127,250 Furniture, fixtures and equipment 3 to 15 years 63,436 64,734 Accumulated depreciation (103,513 ) (100,301 ) Premises and equipment, net $ 126,813 $ 121,341

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2015
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, 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 As of December 31, 2014 Core deposit intangibles $ 13,198 $ (6,013 ) $ 7,185 Customer relationship intangibles 5,699 (2,699 ) 3,000 Mortgage servicing intangibles 643 (193 ) 450 Total $ 19,540 $ (8,905 ) $ 10,635 Estimated amortization of intangible assets for the next five years, as of December 31, 2015, is as follows (dollars in thousands): Estimated Amortization 2016 $ 2,305 2017 2,223 2018 2,223 2019 2,223 2020 2,111 At December 31, 2015, the weighted-average remaining life of all intangible assets was approximately 7.6 years which consisted of customer relationship intangibles with a weighted-average life of 7.8 years, core deposit intangibles with a weighted-average life of 7.6 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, 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 Year Ended December 31, 2014 Balance at beginning of period $ 8,078 $ 30,553 $ 5,464 $ 450 $ 44,545 Acquisitions — 417 — — 417 Balance at end of period $ 8,078 $ 30,970 $ 5,464 $ 450 $ 44,962 In June 2015, the Company recorded an impairment loss of $368,000 after adopting a plan in the second quarter 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, 2015
Banking And Thrift [Abstract]
Time Deposits	(8) TIME DEPOSITS Time deposits include certificates of deposit and individual retirement accounts. At December 31, 2015, the scheduled maturities of all time deposits are as follows (Dollars in thousands): 2016 $ 465,972 2017 112,460 2018 61,014 2019 53,850 2020 35,859 Thereafter 443 Total $ 729,598 The following table is a summary of large time deposits for the periods presented: December 31, 2015 2014 (Dollars in thousands) Time deposits of $100,000 or more $ 342,916 $ 347,563 The aggregate amount of domestic certificates of deposit that meet or exceed the current FDIC insurance limit was $114.5 million at both December 31, 2015 and 2014.

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Short-Term Borrowings	(9) SHORT-TERM BORROWINGS The following is a summary of short-term borrowings: December 31, 2015 2014 (Dollars in thousands) Federal funds purchased $ 500 $ 1,000 Repurchase agreements — 2,982 Total $ 500 $ 3,982 Weighted average interest rate 0.15 % 0.18 % End of period interest rate 0.38 % 0.14 % Federal funds purchased represent borrowings of overnight funds from other financial institutions. The Company enters into sales of securities to certain of its customers with simultaneous agreements to repurchase. These agreements represent an overnight borrowing of funds.

Long-Term Borrowings

Long-Term Borrowings	12 Months Ended
	Dec. 31, 2015
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 $669.8 million, are pledged as collateral for the borrowings under the line of credit. As of December 31, 2015, the Company had the ability to draw up to $525.3 million on the FHLB line of credit based on FHLB stock holdings of $552,500 with no advances outstanding. In addition, the Company has a revolving line of credit with the ability to draw up to $10.0 million. 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, 2015
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, 2015
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, 2015 2014 2013 (Dollars in thousands) Current taxes: Federal $ 32,348 $ 28,258 $ 23,326 State 4,595 2,709 3,682 Deferred taxes (1,903 ) (3,683 ) (483 ) Total income taxes $ 35,040 $ 27,284 $ 26,525 Income tax expense applicable to securities transactions approximated $3.2 million, $574,000 and $147,000 for the years ended December 31, 2015, 2014 and 2013, 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, 2015 2014 2013 (Dollars in thousands) Tax expense at the federal statutory tax rate $ 35,424 $ 31,910 $ 28,295 Increase (decrease) in tax expense from: Tax-exempt income, net (663 ) (571 ) (621 ) Modified endowment life contracts (763 ) (755 ) (812 ) State tax expense, net of federal tax benefit 2,898 1,469 2,303 Federal tax credits (5,165 ) (6,479 ) (4,132 ) Other, net 3,309 1,710 1,492 Total tax expense $ 35,040 $ 27,284 $ 26,525 The net deferred tax asset consisted of the following and is reported in other assets: December 31, 2015 2014 (Dollars in thousands) Provision for loan losses $ 16,110 $ 15,814 Write-downs of other real estate owned 1,252 1,297 Deferred compensation 3,108 2,652 Stock-based compensation 3,201 3,190 Investments in partnership interests 3,651 1,966 Other 917 306 Gross deferred tax assets 28,239 25,225 Unrealized net gains on securities (962 ) (2,644 ) Premium on securities of banks acquired (563 ) (715 ) Intangibles (5,575 ) (2,917 ) Basis difference related to tax credits (2,689 ) (1,977 ) Depreciation (6,449 ) (5,504 ) Leveraged lease (1,671 ) (1,964 ) Other (606 ) (89 ) Gross deferred tax liabilities (18,515 ) (15,810 ) Net deferred tax asset $ 9,724 $ 9,415 The Company recognizes accrued interest and penalties related to unrecognized tax benefits, if applicable, in income tax expense. During the years ended December 31, 2015, 2014 and 2013, 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 2013 to 2015. 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, 2015
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 3,000,000 shares in May 2013. At December 31, 2015, 5,735 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, 2015 will become exercisable through the year 2022. 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 230,000 shares in May 2014. At December 31, 2015, 20,000 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, 2015 will become exercisable through the year 2018. 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, 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 Year Ended December 31, 2014 Outstanding at December 31, 2013 1,158,317 $ 34.45 Options granted 44,000 61.78 Options exercised (169,535 ) 28.73 Options canceled, forfeited, or expired (3,125 ) 36.73 Outstanding at December 31, 2014 1,029,657 36.55 8.59Yrs $ 27,638 Exercisable at December 31, 2014 492,557 29.84 5.15Yrs $ 16,525 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, 2015 2014 2013 (Dollars in thousands) Weighted average grant-date fair value per share of options granted $ 11.72 $ 12.27 $ 10.88 Total intrinsic value of options exercised 4,376 5,597 3,723 Cash received from options exercised 3,212 4,870 3,846 Tax benefit realized from options exercised 1,693 2,165 1,440 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, 2015 2014 2013 (Dollars in thousands) Stock-based compensation expense $ 1,717 $ 1,676 $ 1,360 Tax benefit 664 648 526 Stock-based compensation expense, net of tax $ 1,053 $ 1,028 $ 834 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, 2015 (Dollars in thousands) Unearned stock-based compensation expense $ 4,094 The following table shows the assumptions used for computing stock-based compensation expense under the fair value method: Year Ended December 31, 2015 2014 2013 Risk-free interest rate 1.83 to 2.26% 2.10 to 2.54% 1.95 to 3.15% Dividend yield 2.00 % 2.00 % 2.00 % Stock price volatility 18.23 to 21.08% 18.03 to 18.98% 18.35 to 20.21% 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 91,110 shares in May 2014. 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 622 and 1,356 during the years ended December 31, 2015 and 2014, respectively. A summary of the accumulated stock units is as follows: December 31, 2015 2014 Accumulated stock units 66,376 60,859 Average price $ 39.64 $ 37.41

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 2013 (Dollars in thousands) 401(k) contributions $ 1,966 $ 1,870 $ 1,738 ESOP contributions 1,993 1,928 1,820 Total contributions $ 3,959 $ 3,798 $ 3,558

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity	(15) STOCKHOLDERS’ EQUITY As of December 31, 2015, 2014 and 2013 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, 2015 2015 2014 2013 Per 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 15,597,446 15,504,513 15,333,622 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, 2015, 2014 and 2013 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 under the SRP may be determined by management and approved by the Company’s Executive Committee. The following table is a summary of the shares under the program: Year Ended December 31, 2015 2014 2013 Number of shares repurchased 28,447 — 40,241 Average price of shares repurchased $ 58.19 $ — $ 40.88 Shares remaining to be repurchased 166,276 194,723 194,723 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, 2016, approximately $78.6 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, 2015, 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 Capitalized Under Adequacy Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of December 31, 2015: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 669,213 14.47 % $ 370,094 8.00 % N/A N/A BancFirst 607,604 13.15 % 369,607 8.00 % $ 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 N/A BancFirst 545,938 11.82 % 207,904 4.50 % $ 300,306 6.50 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 627,547 13.57 % $ 277,570 6.00 % N/A N/A BancFirst 565,938 12.25 % 277,205 6.00 % $ 369,607 8.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 627,547 9.49 % $ 264,333 4.00 % N/A N/A BancFirst 565,938 8.59 % 263,606 4.00 % $ 329,507 5.00 % As of December 31, 2014: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 616,862 14.75 % $ 334,531 8.00 % N/A N/A BancFirst 571,495 13.68 % 334,092 8.00 % $ 417,615 10.00 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 575,973 13.77 % $ 167,265 4.00 % N/A N/A BancFirst 530,606 12.71 % 167,046 4.00 % $ 250,569 6.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 575,973 8.83 % $ 197,249 3.00 % N/A N/A BancFirst 530,606 8.15 % 196,716 3.00 % $ 327,859 5.00 % As of December 31, 2015, 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 The Basel III Capital Rules were effective for the Company and BancFirst on January 1, 2015 (subject to a 4-year phase-in period). The Basel III Capital Rules, among other things, (i) introduce a new capital measure called “Common Equity Tier 1” (“CET1”), (ii) specify that Tier 1 capital consist of CET1 and “Additional Tier 1 capital” instruments meeting specified requirements, (iii) define CET1 narrowly by requiring that most deductions/adjustments to regulatory capital measures be made to CET1 and not to the other components of capital and (iv) expand the scope of the deductions/adjustments as compared to existing regulations. Implementation of the deductions and other adjustments to CET1 began on January 1, 2015 and will be phased-in over a 4-year period (beginning at 40% on January 1, 2015 and an additional 20% per year thereafter). Under the new rule, 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 will begin on January 1, 2016 at the 0.625% level and 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, 2015, 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, 2015
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, 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 Year Ended December 31, 2013 Basic Income available to common stockholders $ 54,317 15,268,843 $ 3.56 Effect of stock options — 279,979 Diluted Income available to common stockholders plus assumed exercises of stock options $ 54,317 15,548,822 $ 3.49 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, 2015 177,718 $ 58.47 December 31, 2014 69,405 55.87 December 31, 2013 118,603 42.79

Condensed Parent Company Financ

Condensed Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Parent Company Financial Statements	(17) CONDENSED PARENT COMPANY FINANCIAL STATEMENTS BALANCE SHEETS December 31, 2015 2014 (Dollars in thousands) ASSETS Cash $ 45,437 $ 36,700 Securities 103 103 Investments in subsidiaries 639,119 598,413 Goodwill 450 450 Dividends receivable 6,773 6,434 Other assets 1,688 983 Total assets $ 693,570 $ 643,083 LIABILITIES AND STOCKHOLDERS’ EQUITY Other liabilities $ 6,101 $ 6,965 Junior subordinated debentures 31,959 26,804 Stockholders’ equity 655,510 609,314 Total liabilities and stockholders’ equity $ 693,570 $ 643,083 STATEMENTS OF INCOME Year Ended December 31, 2015 2014 2013 (Dollars in thousands) OPERATING INCOME Dividends from subsidiaries $ 26,043 $ 24,851 $ 22,612 Interest on interest-bearing deposits 66 62 47 Other 2 14 92 Total operating income 26,111 24,927 22,751 OPERATING EXPENSE Interest 1,998 1,965 1,965 Other 628 667 661 Total operating expense 2,626 2,632 2,626 Income before taxes and equity in undistributed earnings of subsidiaries 23,485 22,295 20,125 Allocated income tax (expense)/benefit (796 ) 472 978 Income before equity in undistributed earnings of subsidiaries 22,689 22,767 21,103 Equity in undistributed earnings of subsidiaries 44,653 42,196 34,351 Amortization of stock-based compensation arrangements of subsidiaries (1,172 ) (1,076 ) (1,137 ) Net income $ 66,170 $ 63,887 $ 54,317 STATEMENTS OF CASH FLOW Year Ended December 31, 2015 2014 2013 (Dollars in thousands) CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 66,170 $ 63,887 $ 54,317 Adjustments to reconcile to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (44,653 ) (42,196 ) (34,351 ) Amortization of stock-based compensation arrangements 1,172 1,076 1,137 Other, net (343 ) (656 ) (2,116 ) Net cash provided by operating activities 22,346 22,111 18,987 INVESTING ACTIVITIES Net cash provided by acquisitions 5,066 — — Sales and maturities of held for investment and available for sale securities — 8 63 Net cash provided by investing activities 5,066 8 63 FINANCING ACTIVITIES Issuance of common stock 4,428 6,532 5,200 Common stock acquired (1,654 ) — (2,710 ) Cash dividends paid (21,449 ) (19,543 ) (13,583 ) Net cash used for financing activities (18,675 ) (13,011 ) (11,093 ) Net increase in cash 8,737 9,108 7,957 Cash and due from banks at the beginning of the period 36,700 27,592 19,635 Cash and due from banks at the end of the period $ 45,437 $ 36,700 $ 27,592 SUPPLEMENTAL DISCLOSURE Cash paid during the period for interest $ 1,998 $ 1,965 $ 1,965 Cash received during the period for income taxes, net $ 1,131 $ 1,822 $ 4,449

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
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, 2015
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, 2015 2014 (Dollars in thousands) Loan commitments $ 960,490 $ 937,221 Stand-by letters of credit 61,889 63,734 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, three 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, 2015, were as follows (Dollars in thousands): 2016 $ 1,050 2017 745 2018 226 2019 162 2020 40 Later years 594 Total $ 2,817 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: 2015 $ 1,360 2014 1,255 2013 1,175 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, 2015
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, foreclosed 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, 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 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 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 entire portfolio 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 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. Mortgage Servicing Intangibles The Company acquired mortgage servicing intangibles with the acquisition of 1 st The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2015 and 2014, 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, 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 Mortgage servicing intangibles — — 310 310 December 31, 2014 Securities available for sale: U.S. Treasury $ 248,993 $ — $ — $ 248,993 U.S. federal agencies — 172,449 — 172,449 Mortgage-backed securities — 9,425 17,032 26,457 States and political subdivisions — 53,373 — 53,373 Other securities — 3,491 11,427 14,918 Derivative assets — 6,124 — 6,124 Derivative liabilities — 4,756 — 4,756 Loans held for sale — 9,433 — 9,433 Mortgage servicing intangibles — — 450 450 The changes in Level 3 assets measured at estimated fair value on a recurring basis during the years ended December 31, 2015 and 2014 were as follows: Twelve Months Ended December 31, 2015 2014 (Dollars in thousands) Balance at the beginning of the year $ 28,909 $ 32,002 Purchases, issuances and settlements (1,718 ) (1,314 ) Sales (8,817 ) (3,433 ) Gains included in earnings 7,001 1,469 Total unrealized (losses) gains (3,941 ) 185 Balance at the end of the period $ 21,434 $ 28,909 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, 2015 and 2014, 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. Foreclosed 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 foreclosed 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 and the related gains or losses recognized during the year: Total Fair Value Level 3 Losses (Dollars in thousands) As of and for the Year-to-date Period Ended December 31, 2015 Impaired loans (less specific allowance) $ 44,399 $ — Foreclosed assets 230 — Other real estate owned 7,984 128 As of and for the Year-to-date Period Ended December 31, 2014 Impaired loans (less specific allowance) $ 33,797 $ — Foreclosed assets 220 — Other real estate owned 7,859 730 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 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, 2015 2014 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,598,177 $ 1,598,177 $ 1,913,895 $ 1,913,895 Securities held for investment 8,289 8,350 8,593 8,671 Level 3 inputs: Securities held for investment 500 500 — — Loans, net of allowance for loan losses 4,190,382 4,222,153 3,810,509 3,847,791 FINANCIAL LIABILITIES Level 2 inputs: Deposits 5,973,358 6,028,012 5,904,704 5,945,502 Short-term borrowings 500 500 3,982 3,982 Junior subordinated debentures 31,959 33,793 26,804 31,200 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,681 1,640 Letters of credit 464 478 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, 2015 or 2014. 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, 2015 or 2014.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 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 86 $ 604 312 $ 4,629 Derivative liabilities Barrels (86 ) (378 ) (312 ) (4,271 ) Natural Gas Derivative assets MMBTUs 3,920 1,342 2,010 1,495 Derivative liabilities MMBTUs (3,920 ) (611 ) (2,010 ) (485 ) Total Fair Value Included in Derivative assets Other assets 1,946 6,124 Derivative liabilities Other liabilities (989 ) (4,756 ) 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, 2015 2014 2013 (Dollars in thousands) Derivative income $ 341 $ 500 $ 521 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, 2015 2014 (Dollars in Credit exposure $ 37 $ 4,028 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, 2015
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, 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 December 31, 2013 Net interest income (expense) $ 56,346 $ 102,705 $ 6,239 $ (1,771 ) $ — $ 163,519 Provision for loan losses (154 ) 1,205 121 86 — 1,258 Noninterest income 12,881 48,418 25,659 59,298 (56,101 ) 90,155 Depreciation and amortization 2,178 7,011 521 1,367 — 11,077 Other expenses 31,396 84,011 21,604 23,818 (332 ) 160,497 Income before taxes $ 35,807 $ 58,896 $ 9,652 $ 32,256 $ (55,769 ) $ 80,842 Total assets $ 2,079,444 $ 3,764,429 $ 103,656 $ 703,294 $ (611,849 ) $ 6,038,974 Capital expenditures $ 5,534 $ 6,445 $ 219 $ 1,698 $ — $ 13,896 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, 2015
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, 2015 and 2014 is as follows: Quarter Fourth Third Second First (Dollars in thousands, except per share data) 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 2014 Net interest income $ 47,319 $ 46,514 $ 45,489 $ 42,029 Provision for loan losses 1,840 (3,115 ) 3,129 1,218 Securities transactions 822 284 85 450 Noninterest income 24,302 24,938 23,611 23,562 Noninterest expense 46,886 46,942 45,857 43,836 Net income 15,749 18,793 14,688 14,657 Net income per common share: Basic 1.02 1.22 0.94 0.96 Diluted 0.99 1.19 0.92 0.94

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Event	(24) SUBSEQUENT EVENT Subsequent to December 31, 2015, the Company repurchased 100,000 shares of its common stock at an average price of $55.23 under the Company’s stock repurchase program.

Description of Business and S33

Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
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 2014 and 2013 have been reclassified to conform to the 2015 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, the vast majority of which have a rate floor, limits on fixing rates for longer periods and strict adherence to the original amortization terms in a rising interest rate environment. 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 80% of the portfolio, with junior liens comprising less than 15%, and home equity lines of credit comprising less than 5%. 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.
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 liability 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 February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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 effect 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 effect on the Company’s financial statements. In February 2015, the FASB issued ASU No. 2015-02, “Consolidation (Topic 810) – Amendments to the Consolidation Analysis.” ASU 2015-02 implements changes to both the variable interest consolidation model and the voting interest consolidation model. ASU 2015-02 (i) eliminates certain criteria that must be met when determining when fees paid to a decision maker or service provider do not represent a variable interest, (ii) amends the criteria for determining whether a limited partnership is a variable interest entity and (iii) eliminates the presumption that a general partner controls a limited partnership in the voting model. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2015. Adoption of ASU 2015-02 is not expected to have a significant effect 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 effect on the Company’s financial statements. In January 2014, the FASB issued ASU No. 2014-04, “Receivables: Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure (Topic 310-40).” ASU 2014-04 clarifies that an in-substance repossession or foreclosure occurs upon either the creditor obtaining legal title to the residential real estate property or the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. The amendments were effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2014. Adoption of ASU 2014-04 did not have a significant effect on the Company’s financial statements. In January 2014, the FASB issued ASU No. 2014-01, “Accounting for Investments in Affordable Housing Projects (Topic 323).” ASU 2014-01 revises the necessary criteria that need to be met in order for an entity to account for investments in affordable housing projects net of the provision for income taxes. It also changes the method of recognition from an effective amortization approach to a proportional amortization approach. Additional disclosures were also set forth in this update. The amendments were effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2014. The amendments were required to be applied retrospectively to all periods presented. Early adoption was permitted and adoption of the standard was optional. Adoption of ASU 2014-01 did not have a material 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, 2015
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, 2015 and 2014 is included in the following table: December 31, 2015 2014 (Dollars in thousands) Vault cash and funds on deposit with the Federal Reserve Bank $ 1,499,137 $ 1,804,028 Average required Reserves 40,093 44,711

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 (Dollars in thousands) Held for investment, at cost (fair value: $8,850 and $8,671, respectively) $ 8,789 $ 8,593 Available for sale, at fair value 544,160 516,190 Total $ 552,949 $ 524,783
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, 2015 Mortgage backed securities (1) $ 347 $ 25 $ — $ 372 States and political subdivisions 8,442 36 — 8,478 Total $ 8,789 $ 61 $ — $ 8,850 December 31, 2014 Mortgage backed securities (1) $ 471 $ 34 $ — $ 505 States and political subdivisions 8,122 44 — 8,166 Total $ 8,593 $ 78 $ — $ 8,671
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, 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 December 31, 2014 U.S. treasuries $ 248,767 $ 404 $ (178 ) $ 248,993 U.S. federal agencies 171,641 983 (175 ) 172,449 Mortgage backed securities (1) 26,441 602 (586 ) 26,457 States and political subdivisions 51,706 1,716 (49 ) 53,373 Other securities (2) 10,798 4,252 (132 ) 14,918 Total $ 509,353 $ 7,957 $ (1,120 ) $ 516,190 (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, 2015 2014 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 5,168 $ 5,174 $ 1,451 $ 1,456 After one year but within five years 2,800 2,829 6,603 6,642 After five years but within ten years 795 319 380 396 After ten years 26 528 159 177 Total $ 8,789 $ 8,850 $ 8,593 $ 8,671 Available for Sale Contractual maturity of debt securities: Within one year $ 272,820 $ 272,779 $ 41,772 $ 41,870 After one year but within five years 178,617 180,145 350,975 352,044 After five years but within ten years 8,483 9,075 21,990 22,717 After ten years 75,522 75,853 87,252 88,132 Total debt securities 535,442 537,852 501,989 504,763 Equity securities 6,228 6,308 7,364 11,427 Total $ 541,670 $ 544,160 $ 509,353 $ 516,190
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, 2015 2014 2013 (Dollars Proceeds $ 10,850 $ 4,855 $ 521 Gross gains realized 9,394 1,641 456 Gross losses realized 125 — 36
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, 2015 2014 (Dollars Book value of pledged securities $ 493,540 $ 522,190
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, 2015 and 2014 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, 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 December 31, 2014 Held for Investment Mortgage backed securities $ — $ — $ — $ — $ — $ — States and political subdivisions — — — — — — Total $ — $ — $ — $ — $ — $ — Available for Sale U.S. treasuries $ 149,589 $ 178 $ — $ — $ 149,589 $ 178 U.S. federal agencies 40,551 113 13,653 62 54,204 175 Mortgage backed securities 17,041 585 26 1 17,067 586 States and political subdivisions 3,093 26 977 23 4,070 49 Other securities — — 300 132 300 132 Total $ 210,274 $ 902 $ 14,956 $ 218 $ 225,230 $ 1,120

Loans and Allowance for Loan 36

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Schedule of Loans Outstanding by Category	The following is a schedule of loans outstanding by category: December 31, 2015 2014 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 795,803 18.80 % $ 745,106 19.35 % Oil & gas production and equipment 87,304 2.06 104,940 2.72 Agriculture 150,620 3.56 132,830 3.45 State and political subdivisions: Taxable 17,605 0.42 20,431 0.53 Tax-exempt 33,575 0.79 20,952 0.54 Real estate: Construction 403,664 9.54 356,621 9.26 Farmland 184,707 4.36 149,507 3.88 One to four family residences 821,251 19.41 766,362 19.90 Multifamily residential properties 65,477 1.55 66,766 1.73 Commercial 1,356,430 32.05 1,191,477 30.94 Consumer 283,636 6.70 267,179 6.94 Other (not classified above) 31,976 0.76 29,227 0.76 Total loans $ 4,232,048 100.00 % $ 3,851,398 100.00 %
Summary of Nonperforming and Restructured Assets	The following is a summary of nonperforming and restructured assets: December 31, 2015 2014 (Dollars in thousands) Past due 90 days or more and still accruing $ 1,841 $ 1,135 Nonaccrual 30,096 16,410 Restructured 15,143 16,515 Total nonperforming and restructured loans 47,080 34,060 Other real estate owned and repossessed assets 8,214 8,079 Total nonperforming and restructured assets $ 55,294 $ 42,139
Summary of Amounts Included in Nonaccrual Loans Segregated by Class of Loans	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, 2015 2014 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 261 $ 296 Non-residential real estate other 3,957 5,126 Residential real estate permanent mortgage 656 681 Residential real estate all other 1,833 1,796 Commercial and financial: Non-consumer non-real estate 10,159 1,556 Consumer non-real estate 312 250 Other loans 9,381 1,659 Acquired loans 3,537 5,046 Total $ 30,096 $ 16,410
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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 635 $ — $ 269 $ 904 $ 482,731 $ 483,635 $ 70 Non-residential real estate other 377 317 825 1,519 952,484 954,003 — Residential real estate permanent mortgage 2,010 758 544 3,312 304,267 307,579 172 Residential real estate all other 1,820 194 1,488 3,502 633,586 637,088 387 Commercial and financial: Non-consumer non-real estate 841 71 793 1,705 965,002 966,707 24 Consumer non-real estate 1,914 711 330 2,955 244,810 247,765 215 Other loans 1,858 916 741 3,515 149,469 152,984 — Acquired loans 1,815 997 1,304 4,116 97,521 101,637 267 Total $ 11,270 $ 3,964 $ 6,294 $ 21,528 $ 3,829,870 $ 3,851,398 $ 1,135
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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 521 $ 448 $ 15 $ 453 Non-residential real estate other 23,154 21,164 1,364 21,522 Residential real estate permanent mortgage 1,095 880 85 1,042 Residential real estate all other 2,480 2,270 299 2,273 Commercial and financial: Non-consumer non-real estate 1,895 1,580 431 1,646 Consumer non-real estate 664 648 138 602 Other loans 2,101 1,659 228 1,512 Acquired loans 10,933 7,708 — 8,082 Total $ 42,843 $ 36,357 $ 2,560 $ 37,132
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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 402,706 $ 75,555 $ 5,008 $ 366 $ — $ 483,635 Non-residential real estate other 795,209 133,542 20,126 5,126 — 954,003 Residential real estate permanent mortgage 272,411 27,855 6,369 944 — 307,579 Residential real estate all other 529,555 99,214 6,146 2,173 — 637,088 Commercial and financial: Non-consumer non-real estate 821,094 117,457 26,550 1,606 — 966,707 Consumer non-real estate 233,424 12,229 1,548 564 — 247,765 Other loans 147,758 4,261 601 173 191 152,984 Acquired loans 46,465 36,951 12,651 5,206 364 101,637 Total $ 3,248,622 $ 507,064 $ 78,999 $ 16,158 $ 555 $ 3,851,398
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, 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 As of December 31, 2014 Real estate: Non-residential real estate owner occupied $ 4,827 $ (42 ) $ 102 $ 60 $ (481 ) $ 4,406 Non-residential real estate other 11,026 (29 ) 49 20 (1,430 ) 9,616 Residential real estate permanent mortgage 2,825 (207 ) 78 (129 ) 252 2,948 Residential real estate all other 6,708 (171 ) 32 (139 ) (300 ) 6,269 Commercial and financial: Non-consumer non-real estate 8,977 (564 ) 70 (494 ) 4,288 12,771 Consumer non-real estate 2,556 (687 ) 203 (484 ) 332 2,404 Other loans 1,991 (351 ) 149 (202 ) 570 2,359 Acquired loans 124 (568 ) 719 151 (159 ) 116 Total $ 39,034 $ (2,619 ) $ 1,402 $ (1,217 ) $ 3,072 $ 40,889
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, 2015 December 31, 2014 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 $ 323 $ 4,338 $ 202 $ 4,204 Non-residential real estate other 323 9,598 1,518 8,098 Residential real estate permanent mortgage 399 2,749 407 2,541 Residential real estate all other 839 5,886 743 5,526 Commercial and financial: Non-consumer non-real estate 3,365 8,389 4,671 8,100 Consumer non-real estate 445 2,197 372 2,032 Other loans 291 2,357 214 2,145 Acquired loans — 167 — 116 Total $ 5,985 $ 35,681 $ 8,127 $ 32,762
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, 2015 December 31, 2014 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 $ 8,619 $ 494,278 $ — $ 5,374 $ 478,261 $ — Non-residential real estate other 8,608 1,102,152 — 25,251 928,752 — Residential real estate permanent mortgage 7,543 325,058 — 7,313 300,266 — Residential real estate all other 10,803 665,886 — 8,319 628,769 — Commercial and financial: Non-consumer non-real estate 22,983 961,779 — 28,156 938,551 — Consumer non-real estate 2,416 266,453 — 2,112 245,653 — Other loans 2,323 160,293 — 233 152,751 — Acquired loans — 177,871 14,983 — 83,416 18,221 Total $ 63,295 $ 4,153,770 $ 14,983 $ 76,758 $ 3,756,419 $ 18,221
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, 2015 2014 2013 (Dollars in thousands) Other real estate owned $ 2,139 $ 3,573 $ 1,710 Repossessed assets 1,098 1,209 1,171 Total $ 3,237 $ 4,782 $ 2,881
Related Party Loans	A summary of these loans is as follows: Year Ended December 31, Balance Beginning of the Period Additions Collections/ Terminations Period (Dollars in thousands) 2015 $ 25,019 $ 22,330 $ (9,772 ) $ 37,577 2014 27,134 22,521 (24,636 ) 25,019 2013 29,030 11,979 (13,875 ) 27,134

Premises and Equipment, Net (Ta

Premises and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2015
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 2015 2014 (Dollars in thousands) Land $ 31,196 $ 29,658 Buildings 10 to 40 years 135,694 127,250 Furniture, fixtures and equipment 3 to 15 years 63,436 64,734 Accumulated depreciation (103,513 ) (100,301 ) Premises and equipment, net $ 126,813 $ 121,341

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2015
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, 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 As of December 31, 2014 Core deposit intangibles $ 13,198 $ (6,013 ) $ 7,185 Customer relationship intangibles 5,699 (2,699 ) 3,000 Mortgage servicing intangibles 643 (193 ) 450 Total $ 19,540 $ (8,905 ) $ 10,635
Estimated Amortization of Intangible Assets	Estimated amortization of intangible assets for the next five years, as of December 31, 2015, is as follows (dollars in thousands): Estimated Amortization 2016 $ 2,305 2017 2,223 2018 2,223 2019 2,223 2020 2,111
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, 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 Year Ended December 31, 2014 Balance at beginning of period $ 8,078 $ 30,553 $ 5,464 $ 450 $ 44,545 Acquisitions — 417 — — 417 Balance at end of period $ 8,078 $ 30,970 $ 5,464 $ 450 $ 44,962

Time Deposits (Tables)

Time Deposits (Tables)	12 Months Ended
	Dec. 31, 2015
Banking And Thrift [Abstract]
Schedule of Maturities of Time Deposits	At December 31, 2015, the scheduled maturities of all time deposits are as follows (Dollars in thousands): 2016 $ 465,972 2017 112,460 2018 61,014 2019 53,850 2020 35,859 Thereafter 443 Total $ 729,598
Summary of Large Time Deposits for Periods Presented	The following table is a summary of large time deposits for the periods presented: December 31, 2015 2014 (Dollars in thousands) Time deposits of $100,000 or more $ 342,916 $ 347,563 The aggregate amount of domestic certificates of deposit that meet or exceed the current FDIC insurance limit was $114.5 million at both December 31, 2015 and 2014.

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Summary of Short- Term Borrowings	The following is a summary of short-term borrowings: December 31, 2015 2014 (Dollars in thousands) Federal funds purchased $ 500 $ 1,000 Repurchase agreements — 2,982 Total $ 500 $ 3,982 Weighted average interest rate 0.15 % 0.18 % End of period interest rate 0.38 % 0.14 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 2013 (Dollars in thousands) Current taxes: Federal $ 32,348 $ 28,258 $ 23,326 State 4,595 2,709 3,682 Deferred taxes (1,903 ) (3,683 ) (483 ) Total income taxes $ 35,040 $ 27,284 $ 26,525
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, 2015 2014 2013 (Dollars in thousands) Tax expense at the federal statutory tax rate $ 35,424 $ 31,910 $ 28,295 Increase (decrease) in tax expense from: Tax-exempt income, net (663 ) (571 ) (621 ) Modified endowment life contracts (763 ) (755 ) (812 ) State tax expense, net of federal tax benefit 2,898 1,469 2,303 Federal tax credits (5,165 ) (6,479 ) (4,132 ) Other, net 3,309 1,710 1,492 Total tax expense $ 35,040 $ 27,284 $ 26,525
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, 2015 2014 (Dollars in thousands) Provision for loan losses $ 16,110 $ 15,814 Write-downs of other real estate owned 1,252 1,297 Deferred compensation 3,108 2,652 Stock-based compensation 3,201 3,190 Investments in partnership interests 3,651 1,966 Other 917 306 Gross deferred tax assets 28,239 25,225 Unrealized net gains on securities (962 ) (2,644 ) Premium on securities of banks acquired (563 ) (715 ) Intangibles (5,575 ) (2,917 ) Basis difference related to tax credits (2,689 ) (1,977 ) Depreciation (6,449 ) (5,504 ) Leveraged lease (1,671 ) (1,964 ) Other (606 ) (89 ) Gross deferred tax liabilities (18,515 ) (15,810 ) Net deferred tax asset $ 9,724 $ 9,415

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
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, 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 Year Ended December 31, 2014 Outstanding at December 31, 2013 1,158,317 $ 34.45 Options granted 44,000 61.78 Options exercised (169,535 ) 28.73 Options canceled, forfeited, or expired (3,125 ) 36.73 Outstanding at December 31, 2014 1,029,657 36.55 8.59Yrs $ 27,638 Exercisable at December 31, 2014 492,557 29.84 5.15Yrs $ 16,525
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, 2015 2014 2013 (Dollars in thousands) Weighted average grant-date fair value per share of options granted $ 11.72 $ 12.27 $ 10.88 Total intrinsic value of options exercised 4,376 5,597 3,723 Cash received from options exercised 3,212 4,870 3,846 Tax benefit realized from options exercised 1,693 2,165 1,440
Stock-based Employee Compensation Expense	The following table is a summary of the Company’s recorded stock-based compensation expense: Year Ended December 31, 2015 2014 2013 (Dollars in thousands) Stock-based compensation expense $ 1,717 $ 1,676 $ 1,360 Tax benefit 664 648 526 Stock-based compensation expense, net of tax $ 1,053 $ 1,028 $ 834
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, 2015 (Dollars in thousands) Unearned stock-based compensation expense $ 4,094
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, 2015 2014 2013 Risk-free interest rate 1.83 to 2.26% 2.10 to 2.54% 1.95 to 3.15% Dividend yield 2.00 % 2.00 % 2.00 % Stock price volatility 18.23 to 21.08% 18.03 to 18.98% 18.35 to 20.21% 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, 2015 2014 Accumulated stock units 66,376 60,859 Average price $ 39.64 $ 37.41

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 2013 (Dollars in thousands) 401(k) contributions $ 1,966 $ 1,870 $ 1,738 ESOP contributions 1,993 1,928 1,820 Total contributions $ 3,959 $ 3,798 $ 3,558

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Summary of Authorized Outstanding Preferred and Common Stock	As of December 31, 2015, 2014 and 2013 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, 2015 2015 2014 2013 Per 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 15,597,446 15,504,513 15,333,622 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, 2015 2014 2013 Number of shares repurchased 28,447 — 40,241 Average price of shares repurchased $ 58.19 $ — $ 40.88 Shares remaining to be repurchased 166,276 194,723 194,723
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 Capitalized Under Adequacy Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of December 31, 2015: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 669,213 14.47 % $ 370,094 8.00 % N/A N/A BancFirst 607,604 13.15 % 369,607 8.00 % $ 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 N/A BancFirst 545,938 11.82 % 207,904 4.50 % $ 300,306 6.50 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 627,547 13.57 % $ 277,570 6.00 % N/A N/A BancFirst 565,938 12.25 % 277,205 6.00 % $ 369,607 8.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 627,547 9.49 % $ 264,333 4.00 % N/A N/A BancFirst 565,938 8.59 % 263,606 4.00 % $ 329,507 5.00 % As of December 31, 2014: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 616,862 14.75 % $ 334,531 8.00 % N/A N/A BancFirst 571,495 13.68 % 334,092 8.00 % $ 417,615 10.00 % Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 575,973 13.77 % $ 167,265 4.00 % N/A N/A BancFirst 530,606 12.71 % 167,046 4.00 % $ 250,569 6.00 % Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 575,973 8.83 % $ 197,249 3.00 % N/A N/A BancFirst 530,606 8.15 % 196,716 3.00 % $ 327,859 5.00 %

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2015
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, 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 Year Ended December 31, 2013 Basic Income available to common stockholders $ 54,317 15,268,843 $ 3.56 Effect of stock options — 279,979 Diluted Income available to common stockholders plus assumed exercises of stock options $ 54,317 15,548,822 $ 3.49
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, 2015 177,718 $ 58.47 December 31, 2014 69,405 55.87 December 31, 2013 118,603 42.79

Condensed Parent Company Fina46

Condensed Parent Company Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Summary of Balance Sheet of Parent Company	BALANCE SHEETS December 31, 2015 2014 (Dollars in thousands) ASSETS Cash $ 45,437 $ 36,700 Securities 103 103 Investments in subsidiaries 639,119 598,413 Goodwill 450 450 Dividends receivable 6,773 6,434 Other assets 1,688 983 Total assets $ 693,570 $ 643,083 LIABILITIES AND STOCKHOLDERS’ EQUITY Other liabilities $ 6,101 $ 6,965 Junior subordinated debentures 31,959 26,804 Stockholders’ equity 655,510 609,314 Total liabilities and stockholders’ equity $ 693,570 $ 643,083
Summary of Income Statement of Parent Company	STATEMENTS OF INCOME Year Ended December 31, 2015 2014 2013 (Dollars in thousands) OPERATING INCOME Dividends from subsidiaries $ 26,043 $ 24,851 $ 22,612 Interest on interest-bearing deposits 66 62 47 Other 2 14 92 Total operating income 26,111 24,927 22,751 OPERATING EXPENSE Interest 1,998 1,965 1,965 Other 628 667 661 Total operating expense 2,626 2,632 2,626 Income before taxes and equity in undistributed earnings of subsidiaries 23,485 22,295 20,125 Allocated income tax (expense)/benefit (796 ) 472 978 Income before equity in undistributed earnings of subsidiaries 22,689 22,767 21,103 Equity in undistributed earnings of subsidiaries 44,653 42,196 34,351 Amortization of stock-based compensation arrangements of subsidiaries (1,172 ) (1,076 ) (1,137 ) Net income $ 66,170 $ 63,887 $ 54,317
Summary of Cash Flow of Parent Company	STATEMENTS OF CASH FLOW Year Ended December 31, 2015 2014 2013 (Dollars in thousands) CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 66,170 $ 63,887 $ 54,317 Adjustments to reconcile to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (44,653 ) (42,196 ) (34,351 ) Amortization of stock-based compensation arrangements 1,172 1,076 1,137 Other, net (343 ) (656 ) (2,116 ) Net cash provided by operating activities 22,346 22,111 18,987 INVESTING ACTIVITIES Net cash provided by acquisitions 5,066 — — Sales and maturities of held for investment and available for sale securities — 8 63 Net cash provided by investing activities 5,066 8 63 FINANCING ACTIVITIES Issuance of common stock 4,428 6,532 5,200 Common stock acquired (1,654 ) — (2,710 ) Cash dividends paid (21,449 ) (19,543 ) (13,583 ) Net cash used for financing activities (18,675 ) (13,011 ) (11,093 ) Net increase in cash 8,737 9,108 7,957 Cash and due from banks at the beginning of the period 36,700 27,592 19,635 Cash and due from banks at the end of the period $ 45,437 $ 36,700 $ 27,592 SUPPLEMENTAL DISCLOSURE Cash paid during the period for interest $ 1,998 $ 1,965 $ 1,965 Cash received during the period for income taxes, net $ 1,131 $ 1,822 $ 4,449

Commitments and Contingent Li47

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 (Dollars in thousands) Loan commitments $ 960,490 $ 937,221 Stand-by letters of credit 61,889 63,734
Summary of Future Minimum Rental Payments Under Lease	The future minimum rental payments under these leases at December 31, 2015, were as follows (Dollars in thousands): 2016 $ 1,050 2017 745 2018 226 2019 162 2020 40 Later years 594 Total $ 2,817
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: 2015 $ 1,360 2014 1,255 2013 1,175

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 and 2014, 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, 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 Mortgage servicing intangibles — — 310 310 December 31, 2014 Securities available for sale: U.S. Treasury $ 248,993 $ — $ — $ 248,993 U.S. federal agencies — 172,449 — 172,449 Mortgage-backed securities — 9,425 17,032 26,457 States and political subdivisions — 53,373 — 53,373 Other securities — 3,491 11,427 14,918 Derivative assets — 6,124 — 6,124 Derivative liabilities — 4,756 — 4,756 Loans held for sale — 9,433 — 9,433 Mortgage servicing intangibles — — 450 450
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, 2015 and 2014 were as follows: Twelve Months Ended December 31, 2015 2014 (Dollars in thousands) Balance at the beginning of the year $ 28,909 $ 32,002 Purchases, issuances and settlements (1,718 ) (1,314 ) Sales (8,817 ) (3,433 ) Gains included in earnings 7,001 1,469 Total unrealized (losses) gains (3,941 ) 185 Balance at the end of the period $ 21,434 $ 28,909
Assets Measured at Fair Value on Nonrecurring Basis	The following table summarizes assets measured at fair value on a nonrecurring basis and the related gains or losses recognized during the year: Total Fair Value Level 3 Losses (Dollars in thousands) As of and for the Year-to-date Period Ended December 31, 2015 Impaired loans (less specific allowance) $ 44,399 $ — Foreclosed assets 230 — Other real estate owned 7,984 128 As of and for the Year-to-date Period Ended December 31, 2014 Impaired loans (less specific allowance) $ 33,797 $ — Foreclosed assets 220 — Other real estate owned 7,859 730
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, 2015 2014 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,598,177 $ 1,598,177 $ 1,913,895 $ 1,913,895 Securities held for investment 8,289 8,350 8,593 8,671 Level 3 inputs: Securities held for investment 500 500 — — Loans, net of allowance for loan losses 4,190,382 4,222,153 3,810,509 3,847,791 FINANCIAL LIABILITIES Level 2 inputs: Deposits 5,973,358 6,028,012 5,904,704 5,945,502 Short-term borrowings 500 500 3,982 3,982 Junior subordinated debentures 31,959 33,793 26,804 31,200 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,681 1,640 Letters of credit 464 478

Derivative Financial Instrume49

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 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 86 $ 604 312 $ 4,629 Derivative liabilities Barrels (86 ) (378 ) (312 ) (4,271 ) Natural Gas Derivative assets MMBTUs 3,920 1,342 2,010 1,495 Derivative liabilities MMBTUs (3,920 ) (611 ) (2,010 ) (485 ) Total Fair Value Included in Derivative assets Other assets 1,946 6,124 Derivative liabilities Other liabilities (989 ) (4,756 )
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, 2015 2014 2013 (Dollars in thousands) Derivative income $ 341 $ 500 $ 521
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, 2015 2014 (Dollars in Credit exposure $ 37 $ 4,028

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
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, 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 December 31, 2013 Net interest income (expense) $ 56,346 $ 102,705 $ 6,239 $ (1,771 ) $ — $ 163,519 Provision for loan losses (154 ) 1,205 121 86 — 1,258 Noninterest income 12,881 48,418 25,659 59,298 (56,101 ) 90,155 Depreciation and amortization 2,178 7,011 521 1,367 — 11,077 Other expenses 31,396 84,011 21,604 23,818 (332 ) 160,497 Income before taxes $ 35,807 $ 58,896 $ 9,652 $ 32,256 $ (55,769 ) $ 80,842 Total assets $ 2,079,444 $ 3,764,429 $ 103,656 $ 703,294 $ (611,849 ) $ 6,038,974 Capital expenditures $ 5,534 $ 6,445 $ 219 $ 1,698 $ — $ 13,896

Selected Quarterly Financial 51

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 and 2014 is as follows: Quarter Fourth Third Second First (Dollars in thousands, except per share data) 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 2014 Net interest income $ 47,319 $ 46,514 $ 45,489 $ 42,029 Provision for loan losses 1,840 (3,115 ) 3,129 1,218 Securities transactions 822 284 85 450 Noninterest income 24,302 24,938 23,611 23,562 Noninterest expense 46,886 46,942 45,857 43,836 Net income 15,749 18,793 14,688 14,657 Net income per common share: Basic 1.02 1.22 0.94 0.96 Diluted 0.99 1.19 0.92 0.94

Description of Business and S52

Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
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
Intangible assets, Estimated useful lives	7 years 7 months 6 days
Core Deposit Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	7 years 7 months 6 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	5.00%
First Liens [Member] | Minimum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	80.00%
Junior Liens [Member] | Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	15.00%

Recent Developments Including M

Recent Developments Including Mergers and Acquisitions - Additional Information (Detail) - USD ($)	1 Months Ended			3 Months Ended							12 Months Ended
	Oct. 31, 2015	Jun. 30, 2015	Jan. 31, 2015	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 08, 2015	Jan. 24, 2014
Business Combination Separately Recognized Transactions [Line Items]
Goodwill				$ 54,042,000			$ 44,962,000				$ 54,042,000	$ 44,962,000	$ 44,545,000
Gain on sale of securities	$ 2,100,000			$ 2,148,000	$ 5,392,000	$ 1,729,000	$ 822,000	$ 284,000	$ 85,000	$ 450,000	$ 9,269,000	$ 1,641,000	$ 420,000
Pretax gain on sale of investments		$ 5,200,000	$ 1,700,000
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, 2015	Dec. 31, 2014
Average Amount Of Required Reserves [Abstract]
Vault cash and funds on deposit with the Federal Reserve Bank	$ 1,499,137	$ 1,804,028
Average required Reserves	$ 40,093	$ 44,711

Securities - Summary of Securit

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Marketable Securities [Abstract]
Held for investment, at cost (fair value: $8,850 and $8,671, respectively)	$ 8,789	$ 8,593
Available for sale, at fair value	544,160	516,190
Total	$ 552,949	$ 524,783

Securities - Summary of Secur56

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Marketable Securities [Abstract]
Held for investment at fair value	$ 8,850	$ 8,671

Securities - Summary of Amortiz

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 8,789	$ 8,593
Gross Unrealized Gains	61	78
Estimated Fair Value	8,850	8,671
Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	347	471
Gross Unrealized Gains	25	34
Estimated Fair Value	372	505
States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	8,442	8,122
Gross Unrealized Gains	36	44
Estimated Fair Value	$ 8,478	$ 8,166

Securities - Summary of Amort58

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 541,670	$ 509,353
Gross Unrealized Gains	3,424	7,957
Gross Unrealized Losses	(934)	(1,120)
Estimated Fair Value	544,160	516,190
U.S. Treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	328,965	248,767
Gross Unrealized Gains	776	404
Gross Unrealized Losses	(45)	(178)
Estimated Fair Value	329,696	248,993
U.S. Federal Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	131,522	171,641
Gross Unrealized Gains	527	983
Gross Unrealized Losses	(153)	(175)
Estimated Fair Value	131,896	172,449
Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,973	26,441
Gross Unrealized Gains	425	602
Gross Unrealized Losses	(543)	(586)
Estimated Fair Value	21,855	26,457
States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,521	51,706
Gross Unrealized Gains	1,447	1,716
Gross Unrealized Losses	(48)	(49)
Estimated Fair Value	50,920	53,373
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	9,689	10,798
Gross Unrealized Gains	249	4,252
Gross Unrealized Losses	(145)	(132)
Estimated Fair Value	$ 9,793	$ 14,918

Securities - Additional Informa

Securities - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Investments Debt And Equity Securities [Abstract]
Realized gain on investment	$ 3.3

Securities - Maturity of Securi

Securities - Maturity of Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Held for Investment, Contractual maturity of debt securities, Amortized Cost
Amortized cost, Within one year	$ 5,168	$ 1,451
Amortized cost, After one year but within five years	2,800	6,603
Amortized cost, After five years but within ten years	795	380
Amortized cost, After ten years	26	159
Amortized Cost	8,789	8,593
Available for sale, Contractual maturity of debt securities, Amortized Cost
Amortized Cost, Within one year	272,820	41,772
Amortized Cost, After one year but within five years	178,617	350,975
Amortized Cost, After five years but within ten years	8,483	21,990
Amortized Cost, After ten years	75,522	87,252
Total debt securities	535,442	501,989
Amortized Cost, Equity securities	6,228	7,364
Amortized Cost	541,670	509,353
Held for Investment, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	5,174	1,456
Estimated Fair Value, After one year but within five years	2,829	6,642
Estimated Fair Value, After five years but within ten years	319	396
Estimated Fair Value, After ten years	528	177
Estimated Fair Value	8,850	8,671
Available for sale, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	272,779	41,870
Estimated Fair Value, After one year but within five years	180,145	352,044
Estimated Fair Value, After five years but within ten years	9,075	22,717
Estimated Fair Value, After ten years	75,853	88,132
Total debt securities	537,852	504,763
Estimated Fair Value, Equity securities	6,308	11,427
Estimated Fair Value, Total	$ 544,160	$ 516,190

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Available For Sale Securities Gross Realized Gain Loss [Abstract]
Proceeds	$ 10,850	$ 4,855	$ 521
Gross gains realized	9,394	$ 1,641	456
Gross losses realized	$ 125		$ 36

Securities - Company's Book Val

Securities - Company's Book Value of Pledged Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Pledged Financial Instruments Not Separately Reported Securities Pledged By Type Of Security [Abstract]
Book value of pledged securities	$ 493,540	$ 522,190

Securities - Summary of Secur63

Securities - Summary of Securities with Unrealized Losses, Segregated by Duration of Unrealized Loss (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 189,005	$ 210,274
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	352	902
Available-for-sale Securities, 12 Months or Longer, Fair Value	21,163	14,956
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	582	218
Available-for-sale Securities, Fair Value, Total	210,168	225,230
Available-for-sale Securities, Unrealized Losses, Total	934	1,120
Held for Investment
Held-to-maturity Securities, Less than 12 Months, Fair Value	21
Held-to-maturity Securities, Fair Value, Total	21
U.S. Treasuries [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	139,762	149,589
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	45	178
Available-for-sale Securities, Fair Value, Total	139,762	149,589
Available-for-sale Securities, Unrealized Losses, Total	45	178
U.S. Federal Agencies [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	46,948	40,551
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	118	113
Available-for-sale Securities, 12 Months or Longer, Fair Value	5,969	13,653
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	35	62
Available-for-sale Securities, Fair Value, Total	52,917	54,204
Available-for-sale Securities, Unrealized Losses, Total	153	175
Mortgage Backed Securities [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	59	17,041
Available-for-sale Securities, Less than 12 Months, Unrealized Losses		585
Available-for-sale Securities, 12 Months or Longer, Fair Value	14,844	26
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	543	1
Available-for-sale Securities, Fair Value, Total	14,903	17,067
Available-for-sale Securities, Unrealized Losses, Total	543	586
Held for Investment
Held-to-maturity Securities, Less than 12 Months, Fair Value	21
Held-to-maturity Securities, Fair Value, Total	21
States and Political Subdivisions [Member]
Available for Sale
Available-for-sale Securities, Less than 12 Months, Fair Value	1,932	3,093
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	47	26
Available-for-sale Securities, 12 Months or Longer, Fair Value	245	977
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	1	23
Available-for-sale Securities, Fair Value, Total	2,177	4,070
Available-for-sale Securities, Unrealized Losses, Total	48	49
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	105	300
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	3	132
Available-for-sale Securities, Fair Value, Total	409	300
Available-for-sale Securities, Unrealized Losses, Total	$ 145	$ 132

Loans and Allowance for Loan 64

Loans and Allowance for Loan Losses - Schedule of Loans Outstanding by Category (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 4,232,048	$ 3,851,398
Percent	100.00%	100.00%
Taxable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 17,605	$ 20,431
Percent	0.42%	0.53%
Tax-exempt [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 33,575	$ 20,952
Percent	0.79%	0.54%
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 795,803	$ 745,106
Percent	18.80%	19.35%
Oil & Gas Production And Equipment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 87,304	$ 104,940
Percent	2.06%	2.72%
Agriculture [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 150,620	$ 132,830
Percent	3.56%	3.45%
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 403,664	$ 356,621
Percent	9.54%	9.26%
Farmland [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 184,707	$ 149,507
Percent	4.36%	3.88%
One to Four Family Residences [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 821,251	$ 766,362
Percent	19.41%	19.90%
Multifamily Residential Properties [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 65,477	$ 66,766
Percent	1.55%	1.73%
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 1,356,430	$ 1,191,477
Percent	32.05%	30.94%
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 283,636	$ 267,179
Percent	6.70%	6.94%
Other (Not Classified Above) [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 31,976	$ 29,227
Percent	0.76%	0.76%

Loans and Allowance for Loan 65

Loans and Allowance for Loan Losses - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)SecurityLoan	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Receivables [Abstract]
Percentage of loans secured by real estate	65.00%
Interest income recognized | $	$ 2	$ 1.2	$ 1.5
Troubled debt restructuring principal deferral | SecurityLoan	1

Loans and Allowance for Loan 66

Loans and Allowance for Loan Losses - Summary of Nonperforming and Restructured Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Summary Of Nonperforming And Restructured Assets [Abstract]
Past due 90 days or more and still accruing	$ 1,841	$ 1,135
Nonaccrual	30,096	16,410
Restructured	15,143	16,515
Total nonperforming and restructured loans	47,080	34,060
Other real estate owned and repossessed assets	8,214	8,079
Total nonperforming and restructured assets	$ 55,294	$ 42,139

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, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	$ 30,096	$ 16,410
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	261	296
Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	3,957	5,126
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	656	681
Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	1,833	1,796
Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	10,159	1,556
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	312	250
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	9,381	1,659
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	$ 3,537	$ 5,046

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, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 24,673	$ 21,528
Current Loans	4,207,375	3,829,870
Total Loans	4,232,048	3,851,398
Accruing Loans 90 Days or More Past Due	1,841	1,135
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	16,404	11,270
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,831	3,964
90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	5,438	6,294
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	803	904
Current Loans	502,094	482,731
Total Loans	502,897	483,635
Accruing Loans 90 Days or More Past Due		70
Non-residential Real Estate Owner Occupied [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	441	635
Non-residential Real Estate Owner Occupied [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	179
Non-residential Real Estate Owner Occupied [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	183	269
Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,825	1,519
Current Loans	1,108,935	952,484
Total Loans	1,110,760	954,003
Accruing Loans 90 Days or More Past Due	521
Non-residential Real Estate Other [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,149	377
Non-residential Real Estate Other [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	108	317
Non-residential Real Estate Other [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	568	825
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,124	3,312
Current Loans	328,477	304,267
Total Loans	332,601	307,579
Accruing Loans 90 Days or More Past Due	493	172
Residential Real Estate Permanent Mortgage [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,840	2,010
Residential Real Estate Permanent Mortgage [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	636	758
Residential Real Estate Permanent Mortgage [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	648	544
Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,275	3,502
Current Loans	672,414	633,586
Total Loans	676,689	637,088
Accruing Loans 90 Days or More Past Due	193	387
Residential Real Estate All Other [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,842	1,820
Residential Real Estate All Other [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	609	194
Residential Real Estate All Other [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	824	1,488
Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,626	1,705
Current Loans	982,136	965,002
Total Loans	984,762	966,707
Accruing Loans 90 Days or More Past Due	152	24
Non-consumer Non-real Estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,278	841
Non-consumer Non-real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	161	71
Non-consumer Non-real Estate [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	187	793
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	3,358	2,955
Current Loans	265,511	244,810
Total Loans	268,869	247,765
Accruing Loans 90 Days or More Past Due	278	215
Consumer Non-real Estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,237	1,914
Consumer Non-real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	772	711
Consumer Non-real Estate [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	349	330
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	5,621	3,515
Current Loans	156,995	149,469
Total Loans	162,616	152,984
Accruing Loans 90 Days or More Past Due	132
Other Loans [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	3,565	1,858
Other Loans [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	295	916
Other Loans [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,761	741
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,041	4,116
Current Loans	190,813	97,521
Total Loans	192,854	101,637
Accruing Loans 90 Days or More Past Due	72	267
Acquired Loans [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,052	1,815
Acquired Loans [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	71	997
Acquired Loans [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 918	$ 1,304

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, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 57,126	$ 42,843
Recorded Investment with Allowance	47,667	36,357
Related Allowance	3,268	2,560
Average Recorded Investment	50,521	37,132
Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	507	521
Recorded Investment with Allowance	383	448
Related Allowance	14	15
Average Recorded Investment	446	453
Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	21,068	23,154
Recorded Investment with Allowance	19,052	21,164
Related Allowance	357	1,364
Average Recorded Investment	19,655	21,522
Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,401	1,095
Recorded Investment with Allowance	1,209	880
Related Allowance	81	85
Average Recorded Investment	1,125	1,042
Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	2,498	2,480
Recorded Investment with Allowance	2,235	2,270
Related Allowance	242	299
Average Recorded Investment	1,958	2,273
Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	13,897	1,895
Recorded Investment with Allowance	10,312	1,580
Related Allowance	2,062	431
Average Recorded Investment	11,786	1,646
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	738	664
Recorded Investment with Allowance	715	648
Related Allowance	181	138
Average Recorded Investment	652	602
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	10,722	2,101
Recorded Investment with Allowance	9,513	1,659
Related Allowance	331	228
Average Recorded Investment	10,335	1,512
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	6,295	10,933
Recorded Investment with Allowance	4,248	7,708
Average Recorded Investment	$ 4,564	$ 8,082

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, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 4,232,048	$ 3,851,398
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	502,897	483,635
Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,110,760	954,003
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	332,601	307,579
Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	676,689	637,088
Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	984,762	966,707
Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	268,869	247,765
Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	162,616	152,984
Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	192,854	101,637
Grade 1 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,604,903	3,248,622
Grade 1 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	417,529	402,706
Grade 1 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	945,993	795,209
Grade 1 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	295,265	272,411
Grade 1 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	554,007	529,555
Grade 1 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	821,394	821,094
Grade 1 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	251,994	233,424
Grade 1 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	153,416	147,758
Grade 1 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	165,305	46,465
Grade 2 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	547,814	507,064
Grade 2 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	76,749	75,555
Grade 2 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	156,159	133,542
Grade 2 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	29,793	27,855
Grade 2 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	111,879	99,214
Grade 2 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	140,384	117,457
Grade 2 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	14,433	12,229
Grade 2 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	5,851	4,261
Grade 2 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	12,566	36,951
Grade 3 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	54,695	78,999
Grade 3 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	8,304	5,008
Grade 3 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	4,580	20,126
Grade 3 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	6,315	6,369
Grade 3 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	9,109	6,146
Grade 3 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	12,687	26,550
Grade 3 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,779	1,548
Grade 3 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	872	601
Grade 3 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	11,049	12,651
Grade 4 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	24,559	16,158
Grade 4 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	315	366
Grade 4 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	4,028	5,126
Grade 4 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,228	944
Grade 4 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,694	2,173
Grade 4 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	10,297	1,606
Grade 4 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	662	564
Grade 4 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,477	173
Grade 4 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,858	5,206
Grade 5 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	77	555
Grade 5 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1
Grade 5 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans		191
Grade 5 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 76	$ 364

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, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				$ 40,889				$ 39,034	$ 40,889	$ 39,034
Charge- offs									(7,325)	(2,619)
Recoveries									427	1,402
Net charge- offs									(6,898)	(1,217)
Provisions charged to operations	$ 3,646	$ 1,424	$ 1,271	1,334	$ 1,840	$ (3,115)	$ 3,129	1,218	7,675	3,072	$ 1,258
Balance at end of period	41,666				40,889				41,666	40,889	39,034
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				4,406				4,827	4,406	4,827
Charge- offs									(37)	(42)
Recoveries									1	102
Net charge- offs									(36)	60
Provisions charged to operations									291	(481)
Balance at end of period	4,661				4,406				4,661	4,406	4,827
Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				9,616				11,026	9,616	11,026
Charge- offs									(708)	(29)
Recoveries									2	49
Net charge- offs									(706)	20
Provisions charged to operations									1,011	(1,430)
Balance at end of period	9,921				9,616				9,921	9,616	11,026
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				2,948				2,825	2,948	2,825
Charge- offs									(222)	(207)
Recoveries									40	78
Net charge- offs									(182)	(129)
Provisions charged to operations									382	252
Balance at end of period	3,148				2,948				3,148	2,948	2,825
Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				6,269				6,708	6,269	6,708
Charge- offs									(138)	(171)
Recoveries									17	32
Net charge- offs									(121)	(139)
Provisions charged to operations									577	(300)
Balance at end of period	6,725				6,269				6,725	6,269	6,708
Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				12,771				8,977	12,771	8,977
Charge- offs									(3,799)	(564)
Recoveries									199	70
Net charge- offs									(3,600)	(494)
Provisions charged to operations									2,583	4,288
Balance at end of period	11,754				12,771				11,754	12,771	8,977
Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				2,404				2,556	2,404	2,556
Charge- offs									(626)	(687)
Recoveries									124	203
Net charge- offs									(502)	(484)
Provisions charged to operations									740	332
Balance at end of period	2,642				2,404				2,642	2,404	2,556
Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				2,359				1,991	2,359	1,991
Charge- offs									(1,109)	(351)
Recoveries									16	149
Net charge- offs									(1,093)	(202)
Provisions charged to operations									1,382	570
Balance at end of period	2,648				2,359				2,648	2,359	1,991
Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period				$ 116				$ 124	116	124
Charge- offs									(686)	(568)
Recoveries									28	719
Net charge- offs									(658)	151
Provisions charged to operations									709	(159)
Balance at end of period	$ 167				$ 116				$ 167	$ 116	$ 124

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, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 5,985	$ 8,127
Collectively evaluated for impairment	35,681	32,762
Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	323	202
Collectively evaluated for impairment	4,338	4,204
Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	323	1,518
Collectively evaluated for impairment	9,598	8,098
Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	399	407
Collectively evaluated for impairment	2,749	2,541
Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	839	743
Collectively evaluated for impairment	5,886	5,526
Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	3,365	4,671
Collectively evaluated for impairment	8,389	8,100
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	445	372
Collectively evaluated for impairment	2,197	2,032
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	291	214
Collectively evaluated for impairment	2,357	2,145
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collectively evaluated for impairment	$ 167	$ 116

Loans and Allowance for Loan 73

Loans and Allowance for Loan Losses - Loans Outstanding by Impairment Methodology (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 63,295	$ 76,758
Collectively evaluated for impairment	4,153,770	3,756,419
Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	14,983	18,221
Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	8,619	5,374
Collectively evaluated for impairment	494,278	478,261
Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	8,608	25,251
Collectively evaluated for impairment	1,102,152	928,752
Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	7,543	7,313
Collectively evaluated for impairment	325,058	300,266
Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	10,803	8,319
Collectively evaluated for impairment	665,886	628,769
Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	22,983	28,156
Collectively evaluated for impairment	961,779	938,551
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,416	2,112
Collectively evaluated for impairment	266,453	245,653
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,323	233
Collectively evaluated for impairment	160,293	152,751
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collectively evaluated for impairment	177,871	83,416
Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	$ 14,983	$ 18,221

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable Allowance For Credit Loss Additional Information Transfer From Loans To Other Real Estate Owned And Repossessed Assets [Abstract]
Other real estate owned	$ 2,139	$ 3,573	$ 1,710
Repossessed assets	1,098	1,209	1,171
Total	$ 3,237	$ 4,782	$ 2,881

Loans and Allowance for Loan 75

Loans and Allowance for Loan Losses - Related Party Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Balance Beginning of the Period	$ 25,019	$ 27,134	$ 29,030
Additions	22,330	22,521	11,979
Collections/ Terminations	(9,772)	(24,636)	(13,875)
Balance End of the Period	$ 37,577	$ 25,019	$ 27,134

Premises and Equipment, Net - S

Premises and Equipment, Net - Summary of premises and equipment by classification (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Accumulated depreciation	$ (103,513)	$ (100,301)
Premises and equipment, net	126,813	121,341
Building [Member]
Property Plant And Equipment [Line Items]
Premises and Equipment, gross	$ 135,694	127,250
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	$ 63,436	64,734
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	$ 31,196	$ 29,658

Intangible Assets and Goodwil77

Intangible Assets and Goodwill - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,570	$ 19,540
Accumulated Amortization	(10,875)	(8,905)
Net Carrying Amount	15,695	10,635
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	20,333	13,198
Accumulated Amortization	(7,586)	(6,013)
Net Carrying Amount	12,747	7,185
Customer Relationship Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,699	5,699
Accumulated Amortization	(3,061)	(2,699)
Net Carrying Amount	2,638	3,000
Mortgage Servicing Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	538	643
Accumulated Amortization	(228)	(193)
Net Carrying Amount	$ 310	$ 450

Intangible Assets and Goodwil78

Intangible Assets and Goodwill - Estimated Amortization of Intangible Assets (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2,016	$ 2,305
2,017	2,223
2,018	2,223
2,019	2,223
2,020	$ 2,111

Intangible Assets and Goodwil79

Intangible Assets and Goodwill - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		7 years 7 months 6 days
Impairment loss		$ 368
Community Banks [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment loss		$ 368
Community Banks [Member] | Other Noninterest Expense [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment loss	$ 368
Customer Related Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		7 years 9 months 18 days
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		7 years 7 months 6 days
Mortgage Servicing Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average life		2 years

Intangible Assets and Goodwil80

Intangible Assets and Goodwill - Summary of Goodwill by Business Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Line Items]
Balance at December 31, 2014	$ 44,962	$ 44,545
Acquisitions	9,448	417
Impairment	(368)
Balance at December 31, 2015	54,042	44,962
Metropolitan Banks [Member]
Goodwill [Line Items]
Balance at December 31, 2014	8,078	8,078
Balance at December 31, 2015	8,078	8,078
Community Banks [Member]
Goodwill [Line Items]
Balance at December 31, 2014	30,970	30,553
Acquisitions	9,448	417
Impairment	(368)
Balance at December 31, 2015	40,050	30,970
Other Financial Services [Member]
Goodwill [Line Items]
Balance at December 31, 2014	5,464	5,464
Balance at December 31, 2015	5,464	5,464
Executive, Operations & Support [Member]
Goodwill [Line Items]
Balance at December 31, 2014	450	450
Balance at December 31, 2015	$ 450	$ 450

Time Deposits - Summary of Sche

Time Deposits - Summary of Scheduled Maturities of all Time Deposits (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Investments Schedule [Abstract]
2,016	$ 465,972
2,017	112,460
2,018	61,014
2,019	53,850
2,020	35,859
Thereafter	443
Total	$ 729,598

Time Deposits - Summary of Larg

Time Deposits - Summary of Large time Deposits for Periods Presented (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Investments Schedule [Abstract]
Time deposits of $100,000 or more	$ 342,916	$ 347,563

Time Deposits - Additional Info

Time Deposits - Additional Information (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Investments Schedule [Abstract]
Deposits not covered by deposit insurance	$ 114,500,000	$ 114,500,000

Short-Term Borrowings - Summary

Short-Term Borrowings - Summary of Short-Term Borrowings (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Short-term Debt [Line Items]
Total	$ 500	$ 3,982
Weighted average interest rate	0.15%	0.18%
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Total	$ 500	$ 1,000
Repurchase Agreements [Member]
Short-term Debt [Line Items]
Total		$ 2,982
Short-term Debt [Member]
Short-term Debt [Line Items]
End of period interest rate	0.38%	0.14%

Long-Term Borrowings - Addition

Long-Term Borrowings - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Maximum drawing capacity	$ 525,300,000
FHLB stock holdings	552,500
Advances outstanding	0
Residential Mortgage [Member]
Debt Instrument [Line Items]
Line of credit assets pledged as collateral	669,800,000
Revolving Line of Credit Member]
Debt Instrument [Line Items]
Maximum drawing capacity	$ 10,000,000
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, 2015	Dec. 31, 2014	Dec. 31, 2013
Junior Subordinated Debentures [Line Items]
Junior subordinated notes assumed				$ 31,959,000	$ 26,804,000
Issuance of common securities				$ 4,428,000	$ 6,532,000	$ 5,200,000
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]
Issuance of capital securities	$ 5,000,000
Issuance 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, 2015	Dec. 31, 2014	Dec. 31, 2013
Current taxes:
Federal	$ 32,348	$ 28,258	$ 23,326
State	4,595	2,709	3,682
Deferred taxes	(1,903)	(3,683)	(483)
Total income taxes	$ 35,040	$ 27,284	$ 26,525

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Securities transactions income tax expense	$ 3,200,000	$ 574,000	$ 147,000
Recognition of interest and penalties related to unrecognized tax benefits	$ 0	$ 0	$ 0
Earliest Tax Year [Member]
Income Taxes [Line Items]
Year under examination	2,013
Latest Tax Year [Member]
Income Taxes [Line Items]
Year under examination	2,015

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax expense at the federal statutory tax rate	$ 35,424	$ 31,910	$ 28,295
Increase (decrease) in tax expense from:
Tax-exempt income, net	(663)	(571)	(621)
Modified endowment life contracts	(763)	(755)	(812)
State tax expense, net of federal tax benefit	2,898	1,469	2,303
Federal tax credits	(5,165)	(6,479)	(4,132)
Other, net	3,309	1,710	1,492
Total income taxes	$ 35,040	$ 27,284	$ 26,525

Income Taxes - Summary of Net D

Income Taxes - Summary of Net Deferred Tax Asset Reported in Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Provision for loan losses	$ 16,110	$ 15,814
Write-downs of other real estate owned	1,252	1,297
Deferred compensation	3,108	2,652
Stock-based compensation	3,201	3,190
Investments in partnership interests	3,651	1,966
Other	917	306
Gross deferred tax assets	28,239	25,225
Unrealized net gains on securities	(962)	(2,644)
Premium on securities of banks acquired	(563)	(715)
Intangibles	(5,575)	(2,917)
Basis difference related to tax credits	(2,689)	(1,977)
Depreciation	(6,449)	(5,504)
Leveraged lease	(1,671)	(1,964)
Other	(606)	(89)
Gross deferred tax liabilities	(18,515)	(15,810)
Net deferred tax asset	$ 9,724	$ 9,415

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	May. 31, 2014	May. 31, 2013
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				3,000,000
Shares for future grants	5,735
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	2,022
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			230,000
Shares for future grants	20,000
Option exercisable rate	25.00%
Option exercisable period	1 year
Options expire period	15 years
Share based compensation options exercisable period	2,018
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			91,110
Number of shares of common stock distributed	622	1,356

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, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding at beginning period - Options	1,029,657	1,158,317
Options granted	133,000	44,000
Options exercised	(120,758)	(169,535)
Options canceled, forfeited or expired - Options	(23,750)	(3,125)
Outstanding at ending period - Options	1,018,149	1,029,657
Exercisable at ending period - Options	499,599	492,557
Outstanding at beginning period - Wgtd. Avg. Exercise Price	$ 36.55	$ 34.45
Options granted - Wgtd. Avg. Exercise Price	59.37	61.78
Options exercised - Wgtd. Avg. Exercise Price	26.60	28.73
Options cancelled, forfeited, or expired - Wgtd. Avg. Exercise Price	37.16	36.73
Outstanding at ending period - Wgtd. Avg. Exercise Price	40.69	36.55
Exercisable at ending period - Wgtd. Avg. Exercise Price	$ 32.98	$ 29.84
Outstanding at ending period - Wgtd. Avg. Remaining Contractual Term, years	8 years 10 months 2 days	8 years 7 months 2 days
Exercisable at ending period - Wgtd. Avg. Remaining Contractual Term, years	5 years 6 months 11 days	5 years 1 month 24 days
Outstanding at ending period - Aggregate Intrinsic Value	$ 18,251	$ 27,638
Exercisable at ending period - Aggregate Intrinsic Value	$ 12,812	$ 16,525

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award Options Additional Disclosures [Abstract]
Weighted average grant-date fair value per share of options granted	$ 11.72	$ 12.27	$ 10.88
Total intrinsic value of options exercised	$ 4,376	$ 5,597	$ 3,723
Cash received from options exercised	3,212	4,870	3,846
Tax benefit realized from options exercised	$ 1,693	$ 2,165	$ 1,440

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Employee Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Labor And Related Expense [Abstract]
Stock-based compensation expense	$ 1,717	$ 1,676	$ 1,360
Tax benefit	664	648	526
Stock-based compensation expense, net of tax	$ 1,053	$ 1,028	$ 834

Stock-Based Compensation - Unea

Stock-Based Compensation - Unearned Stock-based Compensation Expense (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Remaining Fair Value Of Stock Options [Abstract]
Unearned stock-based compensation expense	$ 4,094

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used for Computing Stock-Based Compensation Expense (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Risk-free interest rate, minimum	1.83%	2.10%	1.95%
Risk-free interest rate, maximum	2.26%	2.54%	3.15%
Dividend yield	2.00%	2.00%	2.00%
Stock price volatility, minimum	18.23%	18.03%	18.35%
Stock price volatility, maximum	21.08%	18.98%	20.21%
Expected term	10 years	10 years	10 years

Stock - Based Compensation - Su

Stock - Based Compensation - Summary of Accumulated Stock Units (Detail) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Accumulated stock units	66,376	60,859
Average price	$ 39.64	$ 37.41

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Plans
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, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Contribution Plan Disclosure [Line Items]
Total contributions	$ 3,959	$ 3,798	$ 3,558
401(k) contributions [Member]
Defined Contribution Plan Disclosure [Line Items]
Aggregate amounts of contributions	1,966	1,870	1,738
ESOP contributions [Member]
Defined Contribution Plan Disclosure [Line Items]
Aggregate amounts of contributions	$ 1,993	$ 1,928	$ 1,820

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Authorized Outstanding Preferred and Common Stock (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares outstanding	15,597,446	15,504,513	15,333,622
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, 2015	Jan. 01, 2016	Dec. 31, 2014
2015 [Member]
Stockholders Equity [Line Items]
Implementation of the deductions and other adjustments to CET1, phase-in period	4 years
Implementation of the deductions and other adjustments to CET1, Percentage	40.00%
After 2015 [Member]
Stockholders Equity [Line Items]
Implementation of the deductions and other adjustments to CET1, Additional Percentage	20.00%
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		$ 78,600,000
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 - Summa102

Stockholders' Equity - Summary of Shares Repurchased Under Stock Purchase Program (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2014
Summary Of Shares Repurchased Under Stock Purchase Program [Abstract]
Number of shares repurchased	28,447	40,241
Average price of shares repurchased	$ 58.19	$ 40.88
Shares remaining to be repurchased	166,276	194,723	194,723

Stockholders' Equity - Required

Stockholders' Equity - Required Capital Amounts and Company's Respective Ratios (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 669,213	$ 616,862
Total Capital To Risk Weighted Assets Actual Ratio	14.47%	14.75%
Capital Required For Capital Adequacy Amount	$ 370,094	$ 334,531
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%	8.00%
Common Equity Tier 1 Risk Based Capital Amount	$ 596,547
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.90%
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 208,178
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	4.50%
Tier 1 Risk Based Capital Amount	$ 627,547	$ 575,973
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	13.57%	13.77%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 277,570	$ 167,265
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	6.00%	4.00%
Tier 1 Capital Amount	$ 627,547	$ 575,973
Tier 1 Capital To Average Assets Ratio	9.49%	8.83%
Tier 1 Capital Required For Capital Adequacy Amount	$ 264,333	$ 197,249
Tier 1 Capital Required For Capital Adequacy To Average Assets Ratio	4.00%	3.00%
BancFirst [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 607,604	$ 571,495
Total Capital To Risk Weighted Assets Actual Ratio	13.15%	13.68%
Capital Required For Capital Adequacy Amount	$ 369,607	$ 334,092
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%	8.00%
Capital Required To Be Well Capitalized Amount	$ 462,009	$ 417,615
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	10.00%	10.00%
Common Equity Tier 1 Risk Based Capital Amount	$ 545,938
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	11.82%
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 207,904
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	4.50%
Common Equity Tier 1 Risk Based Capital Required To Be well Capitalized Amount	$ 300,306
Common Equity Tier 1 Risk Based Capital Required To Be well Capitalized Amount	6.50%
Tier 1 Risk Based Capital Amount	$ 565,938	$ 530,606
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.25%	12.71%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 277,205	$ 167,046
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	6.00%	4.00%
Tier 1 Risk Based Capital Required To Be well Capitalized Amount	$ 369,607	$ 250,569
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	8.00%	6.00%
Tier 1 Capital Amount	$ 565,938	$ 530,606
Tier 1 Capital To Average Assets Ratio	8.59%	8.15%
Tier 1 Capital Required For Capital Adequacy Amount	$ 263,606	$ 196,716
Tier 1 Capital Required For Capital Adequacy To Average Assets Ratio	4.00%	3.00%
Tier 1 Capital Required To Be Well Capitalized Amount	$ 329,507	$ 327,859
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, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share Reconciliation [Abstract]
Income available to common stockholders									$ 66,170	$ 63,887	$ 54,317
Income available to common stockholders plus assumed exercises of stock options									$ 66,170	$ 63,887	$ 54,317
Income available to common stockholders - Shares									15,559,059	15,430,773	15,268,843
Effect of stock options - Shares									327,186	363,630	279,979
Income available to common stockholders plus assumed exercises of stock options - Shares									15,886,245	15,794,403	15,548,822
Income available to common stockholders - Per Share Amount	$ 1	$ 1.01	$ 1.19	$ 1.05	$ 1.02	$ 1.22	$ 0.94	$ 0.96	$ 4.25	$ 4.14	$ 3.56
Income available to common stockholders plus assumed exercises of stock options - Per Share Amount	$ 0.99	$ 0.98	$ 1.17	$ 1.03	$ 0.99	$ 1.19	$ 0.92	$ 0.94	$ 4.17	$ 4.04	$ 3.49

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Abstract]
Shares	177,718	69,405	118,603
Average Exercise Price	$ 58.47	$ 55.87	$ 42.79

Condensed Parent Company Fin106

Condensed Parent Company Financial Statements - Summary of Balance Sheet of Parent Company (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Cash	$ 203,364	$ 203,545
Securities	552,949	524,783
Goodwill	54,042	44,962	$ 44,545
Total assets	6,692,829	6,574,972	6,038,974
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	31,502	30,168
Junior subordinated debentures	31,959	26,804
Stockholders’ equity	655,510	609,314	$ 556,997
Total liabilities and stockholders' equity	6,692,829	6,574,972
Parent Company [Member]
ASSETS
Cash	45,437	36,700
Securities	103	103
Investments in subsidiaries	639,119	598,413
Goodwill	450	450
Dividends receivable	6,773	6,434
Other assets	1,688	983
Total assets	693,570	643,083
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	6,101	6,965
Junior subordinated debentures	31,959	26,804
Stockholders’ equity	655,510	609,314
Total liabilities and stockholders' equity	$ 693,570	$ 643,083

Condensed Parent Company Fin107

Condensed Parent Company Financial Statements- Summary of Income Statement of Parent Company (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
OPERATING INCOME
Interest on interest-bearing deposits									$ 4,265	$ 4,391	$ 4,064
OPERATING EXPENSE
Other									33,972	36,407	32,823
Allocated income tax (expense)/benefit									(35,040)	(27,284)	(26,525)
Amortization of stock-based compensation arrangements of subsidiaries									(1,717)	(1,676)	(1,360)
Net income	$ 15,728	$ 15,630	$ 18,553	$ 16,259	$ 15,749	$ 18,793	$ 14,688	$ 14,657	66,170	63,887	54,317
Parent Company [Member]
OPERATING INCOME
Dividends from subsidiaries									(26,043)	(24,851)	(22,612)
Interest on interest-bearing deposits									66	62	47
Other									2	14	92
Total operating income									26,111	24,927	22,751
OPERATING EXPENSE
Interest									1,998	1,965	1,965
Other									628	667	661
Total operating expense									2,626	2,632	2,626
Income before taxes									23,485	22,295	20,125
Allocated income tax (expense)/benefit									(796)	472	978
Income before equity in undistributed earnings of subsidiaries									22,689	22,767	21,103
Equity in undistributed earnings of subsidiaries									44,653	42,196	34,351
Amortization of stock-based compensation arrangements of subsidiaries									(1,172)	(1,076)	(1,137)
Net income									$ 66,170	$ 63,887	$ 54,317

Condensed Parent Company Fin108

Condensed Parent Company Financial Statements - Summary of Cash Flow of Parent Company (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 15,728	$ 15,630	$ 18,553	$ 16,259	$ 15,749	$ 18,793	$ 14,688	$ 14,657	$ 66,170	$ 63,887	$ 54,317
Adjustments to reconcile to net cash provided by operating activities:
Amortization of stock-based compensation arrangements									1,717	1,676	1,360
Other, net									6,301	5,719	5,512
Net cash provided by operating activities									78,159	76,922	78,090
INVESTING ACTIVITIES
Net cash and due from banks (paid for) received from acquisitions									(4,007)	174,283
Net cash used in investing activities									(265,298)	(183,376)	(131,078)
FINANCING ACTIVITIES
Issuance of common stock, net									4,428	6,532	5,200
Common stock acquired									(1,654)		(2,710)
Cash dividends paid									(21,449)	(19,543)	(13,583)
Net cash (used in) provided by financing activities									(128,579)	162,814	(34,625)
Net (decrease)/increase in cash, due from banks and interest-bearing deposits									(315,718)	56,360	(87,613)
Cash, due from banks and interest-bearing deposits at the beginning of the period				1,913,895				1,857,535	1,913,895	1,857,535	1,945,148
Cash, due from banks and interest-bearing deposits at the end of the period	1,598,177				1,913,895				1,598,177	1,913,895	1,857,535
SUPPLEMENTAL DISCLOSURE
Cash paid during the period for interest									12,255	13,135	14,142
Cash received during the period for income taxes, net									33,531	26,178	20,946
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income									66,170	63,887	54,317
Adjustments to reconcile to net cash provided by operating activities:
Equity in undistributed earnings of subsidiaries									(44,653)	(42,196)	(34,351)
Amortization of stock-based compensation arrangements									1,172	1,076	1,137
Other, net									(343)	(656)	(2,116)
Net cash provided by operating activities									22,346	22,111	18,987
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	63
Net cash used in investing activities									5,066	8	63
FINANCING ACTIVITIES
Issuance of common stock, net									4,428	6,532	5,200
Common stock acquired									(1,654)		(2,710)
Cash dividends paid									(21,449)	(19,543)	(13,583)
Net cash (used in) provided by financing activities									(18,675)	(13,011)	(11,093)
Net (decrease)/increase in cash, due from banks and interest-bearing deposits									8,737	9,108	7,957
Cash, due from banks and interest-bearing deposits at the beginning of the period				$ 36,700				$ 27,592	36,700	27,592	19,635
Cash, due from banks and interest-bearing deposits at the end of the period	$ 45,437				$ 36,700				45,437	36,700	27,592
SUPPLEMENTAL DISCLOSURE
Cash paid during the period for interest									1,998	1,965	1,965
Cash received during the period for income taxes, net									$ 1,131	$ 1,822	$ 4,449

Commitments and Contingent L109

Commitments and Contingent Liabilities - Summary of Financial Instruments with Off-Balance-Sheet Risks (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract]
Loan commitments	$ 960,490	$ 937,221
Stand-by letters of credit	$ 61,889	$ 63,734

Commitments and Contingent L110

Commitments and Contingent Liabilities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015BuildingsLand_ParcelATMStorageSpacesParkingSpaces
Commitments And Contingencies Disclosure [Abstract]
Number of buildings | Buildings	13
Parcels of land | Land_Parcel	2
Number of ATM locations | ATM	20
Number of storage facilities | StorageSpaces	2
Number of parking lots | ParkingSpaces	3
Lease expiry period maximum	2,064

Commitments and Contingent L111

Commitments and Contingent Liabilities - Summary of Future Minimum Rental Payments Under Lease (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2,016	$ 1,050
2,017	745
2,018	226
2,019	162
2,020	40
Later years	594
Total	$ 2,817

Commitments and Contingent L112

Commitments and Contingent Liabilities - Summary of Rental Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Leases Rent Expense [Abstract]
Rent expense on all property and equipment rented	$ 1,360	$ 1,255	$ 1,175

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
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, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 544,160	$ 516,190
Derivative assets	1,946	6,124
Derivative liabilities	989	4,756
Loans held for sale	13,725	9,433
Mortgage servicing intangibles	310	450
U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	329,696	248,993
U.S. Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	131,896	172,449
Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	21,855	26,457
States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	50,920	53,373
Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	9,793	14,918
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	329,696	248,993
Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,946	6,124
Derivative liabilities	989	4,756
Loans held for sale	13,725	9,433
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	131,896	172,449
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	7,039	9,425
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	50,920	53,373
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	3,491
Level 3 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing intangibles	310	450
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	17,032
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	$ 6,308	$ 11,427

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, 2015	Dec. 31, 2014
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward
Balance at the beginning of the year	$ 28,909	$ 32,002
Purchases, issuances and settlements	(1,718)	(1,314)
Sales	(8,817)	(3,433)
Gains included in earnings	7,001	1,469
Total unrealized (losses) gains	(3,941)	185
Balance at the end of the period	$ 21,434	$ 28,909

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Impaired Loans (Less Specific Allowance) [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	$ 44,399	$ 33,797
Foreclosed Assets [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	230	220
Other Real Estate Owned [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Losses	128	730
Other Real Estate Owned [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	$ 7,984	$ 7,859

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
FINANCIAL ASSETS
Securities held for investment	$ 8,789	$ 8,593
Loans, net of allowance for loan losses	4,190,382	3,810,509
FINANCIAL LIABILITIES
Deposits	5,973,358	5,904,704
Short-term borrowings	500	3,982
Junior subordinated debentures	31,959	26,804
Carrying Amount [Member] | Level 2 Inputs [Member]
FINANCIAL ASSETS
Cash and cash equivalents	1,598,177	1,913,895
Securities held for investment	8,289	8,593
FINANCIAL LIABILITIES
Deposits	5,973,358	5,904,704
Short-term borrowings	500	3,982
Junior subordinated debentures	31,959	26,804
Carrying Amount [Member] | Level 3 Inputs [Member]
FINANCIAL ASSETS
Securities held for investment	500
Loans, net of allowance for loan losses	4,190,382	3,810,509
Fair Value [Member]
OFF-BALANCE SHEET FINANCIAL INSTRUMENTS
Loan commitments	1,681	1,640
Letters of credit	464	478
Fair Value [Member] | Level 2 Inputs [Member]
FINANCIAL ASSETS
Cash and cash equivalents	1,598,177	1,913,895
Securities held for investment	8,350	8,671
FINANCIAL LIABILITIES
Deposits	6,028,012	5,945,502
Short-term borrowings	500	3,982
Junior subordinated debentures	33,793	31,200
Fair Value [Member] | Level 3 Inputs [Member]
FINANCIAL ASSETS
Securities held for investment	500
Loans, net of allowance for loan losses	$ 4,222,153	$ 3,847,791

Derivative Financial Instrum118

Derivative Financial Instruments - Notional Amounts and Estimated Fair Values of Outstanding Derivative Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	$ 1,946	$ 6,124
Derivative liabilities, Estimated Fair Value	(989)	(4,756)
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	1,946	6,124
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Estimated Fair Value	$ (989)	(4,756)
Oil [Member]
Derivatives, Fair Value [Line Items]
Notional Units	Barrels
Derivative assets, Notional Amount	$ 86	312
Derivative assets, Estimated Fair Value	604	4,629
Derivative liabilities, Notional Amount	(86)	(312)
Derivative liabilities, Estimated Fair Value	$ (378)	(4,271)
Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Notional Units	MMBTUs
Derivative assets, Notional Amount	$ 3,920	2,010
Derivative assets, Estimated Fair Value	1,342	1,495
Derivative liabilities, Notional Amount	(3,920)	(2,010)
Derivative liabilities, Estimated Fair Value	$ (611)	$ (485)

Derivative Financial Instrum119

Derivative Financial Instruments - Recognized Derivative Income Included in Other Noninterest Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Gain Loss On Derivative Net [Abstract]
Derivative income	$ 341	$ 500	$ 521

Derivative Financial Instrum120

Derivative Financial Instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Company’s share of total profit	35.00%

Derivative Financial Instrum121

Derivative Financial Instruments - Summary of Company's Net Credit Exposure Relating to Oil and Gas Swaps and Options with Bank Counterparties (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Credit Risk Derivatives At Fair Value Net [Abstract]
Credit exposure	$ 37	$ 4,028

Segment Information - Additiona

Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Business_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, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 50,075	$ 46,876	$ 46,215	$ 45,626	$ 47,319	$ 46,514	$ 45,489	$ 42,029	$ 188,792	$ 181,351	$ 163,519
Provision for loan losses	3,646	1,424	1,271	1,334	1,840	(3,115)	3,129	1,218	7,675	3,072	1,258
Noninterest income	26,473	$ 25,324	$ 28,715	$ 25,296	24,302	$ 24,938	$ 23,611	$ 23,562	105,808	96,413	90,155
Depreciation and amortization									11,901	11,349	11,077
Other expenses									173,814	172,172	160,497
Income before taxes									101,210	91,171	80,842
Total assets	6,692,829				6,574,972				6,692,829	6,574,972	6,038,974
Capital expenditures									11,263	11,490	13,896
Operating Segments [Member] | Metropolitan Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									61,500	59,923	56,346
Provision for loan losses									2,684	3,077	(154)
Noninterest income									16,552	13,752	12,881
Depreciation and amortization									2,273	2,216	2,178
Other expenses									32,942	32,300	31,396
Income before taxes									40,153	36,082	35,807
Total assets	2,277,870				2,298,828				2,277,870	2,298,828	2,079,444
Capital expenditures									3,743	1,948	5,534
Operating Segments [Member] | Community Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									122,404	116,935	102,705
Provision for loan losses									3,806	(488)	1,205
Noninterest income									52,598	51,415	48,418
Depreciation and amortization									7,894	7,277	7,011
Other expenses									91,655	89,888	84,011
Income before taxes									71,647	71,673	58,896
Total assets	4,379,205				4,113,783				4,379,205	4,113,783	3,764,429
Capital expenditures									4,634	7,972	6,445
Operating Segments [Member] | Other Financial Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									6,798	6,155	6,239
Provision for loan losses									1,176	481	121
Noninterest income									33,629	28,079	25,659
Depreciation and amortization									514	522	521
Other expenses									22,308	22,304	21,604
Income before taxes									16,429	10,927	9,652
Total assets	128,697				145,814				128,697	145,814	103,656
Capital expenditures									121	121	219
Operating Segments [Member] | Executive, Operations & Support [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									(1,910)	(1,662)	(1,771)
Provision for loan losses									9	2	86
Noninterest income									72,806	69,442	59,298
Depreciation and amortization									1,220	1,334	1,367
Other expenses									27,221	27,998	23,818
Income before taxes									42,446	38,446	32,256
Total assets	624,428				679,194				624,428	679,194	703,294
Capital expenditures									2,765	1,449	1,698
Eliminations [Member]
Segment Reporting Information [Line Items]
Noninterest income									(69,777)	(66,275)	(56,101)
Other expenses									(312)	(318)	(332)
Income before taxes									(69,465)	(65,957)	(55,769)
Total assets	$ (717,371)				$ (662,647)				$ (717,371)	$ (662,647)	$ (611,849)

Selected Quarterly Financial124

Selected Quarterly Financial Data (Unaudited) - Summary of the Unaudited Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Oct. 31, 2015	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Net interest income		$ 50,075	$ 46,876	$ 46,215	$ 45,626	$ 47,319	$ 46,514	$ 45,489	$ 42,029	$ 188,792	$ 181,351	$ 163,519
Provision for loan losses		3,646	1,424	1,271	1,334	1,840	(3,115)	3,129	1,218	7,675	3,072	1,258
Securities transactions	$ 2,100	2,148		5,392	1,729	822	284	85	450	9,269	1,641	420
Noninterest income		26,473	25,324	28,715	25,296	24,302	24,938	23,611	23,562	105,808	96,413	90,155
Noninterest expense		49,011	46,352	45,429	44,923	46,886	46,942	45,857	43,836	185,715	183,521	171,574
Net income		$ 15,728	$ 15,630	$ 18,553	$ 16,259	$ 15,749	$ 18,793	$ 14,688	$ 14,657	$ 66,170	$ 63,887	$ 54,317
Net income per common share:
Basic		$ 1	$ 1.01	$ 1.19	$ 1.05	$ 1.02	$ 1.22	$ 0.94	$ 0.96	$ 4.25	$ 4.14	$ 3.56
Diluted		$ 0.99	$ 0.98	$ 1.17	$ 1.03	$ 0.99	$ 1.19	$ 0.92	$ 0.94	$ 4.17	$ 4.04	$ 3.49

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - $ / shares	Mar. 11, 2016	Dec. 31, 2015	Dec. 31, 2013
Subsequent Event [Line Items]
Number of shares repurchased		28,447	40,241
Average price of shares repurchased		$ 58.19	$ 40.88
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of shares repurchased	100,000
Average price of shares repurchased	$ 55.23