BancFirst (BANF) 10-Q 6 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 29, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Trading Symbol	BANF
Entity Registrant Name	BANCFIRST CORP /OK/
Entity Central Index Key	760,498
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		15,546,253

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
ASSETS
Cash and due from banks	$ 169,969	$ 203,364
Interest-bearing deposits with banks	1,498,356	1,394,813
Securities (fair value: $498,041 and $553,010, respectively)	497,986	552,949
Loans held for sale	7,626	13,725
Loans (net of unearned interest)	4,275,112	4,232,048
Allowance for loan losses	(44,571)	(41,666)
Loans, net of allowance for loan losses	4,230,541	4,190,382
Premises and equipment, net	127,093	126,813
Other real estate owned	3,963	7,984
Intangible assets, net	15,093	15,695
Goodwill	54,042	54,042
Accrued interest receivable and other assets	136,269	133,062
Total assets	6,740,938	6,692,829
Deposits:
Noninterest-bearing	2,413,700	2,409,769
Interest-bearing	3,597,172	3,563,589
Total deposits	6,010,872	5,973,358
Short-term borrowings	1,300	500
Accrued interest payable and other liabilities	34,146	31,502
Junior subordinated debentures	31,959	31,959
Total liabilities	6,078,277	6,037,319
Stockholders' equity:
Common stock, $1.00 par, 20,000,000 shares authorized; shares issued and outstanding: 15,527,804 and 15,597,446, respectively	15,528	15,597
Capital surplus	103,978	102,865
Retained earnings	541,098	535,521
Accumulated other comprehensive income, net of income tax of $1,297 and $962, respectively	2,057	1,527
Total stockholders' equity	662,661	655,510
Total liabilities and stockholders' equity	$ 6,740,938	$ 6,692,829
Senior Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value
Cumulative Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Securities, fair value	$ 498,041	$ 553,010
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	15,527,804	15,597,446
Common stock, shares outstanding	15,527,804	15,597,446
Accumulated other comprehensive income, tax	$ 1,297	$ 962
Senior Preferred Stock [Member]
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Cumulative Preferred Stock [Member]
Preferred stock, par value	$ 5	$ 5
Preferred stock, shares authorized	900,000	900,000
Preferred stock, shares issued	0	0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
INTEREST INCOME
Loans, including fees	$ 50,195	$ 45,949
Securities:
Taxable	1,327	1,399
Tax-exempt	255	246
Interest-bearing deposits with banks	1,802	1,062
Total interest income	53,579	48,656
INTEREST EXPENSE
Deposits	3,080	2,538
Short-term borrowings	1	1
Junior subordinated debentures	522	491
Total interest expense	3,603	3,030
Net interest income	49,976	45,626
Provision for loan losses	4,103	1,334
Net interest income after provision for loan losses	45,873	44,292
NONINTEREST INCOME
Trust revenue	2,465	2,342
Service charges on deposits	14,710	13,352
Securities transactions (includes accumulated other comprehensive income reclassifications of $100 and $606, respectively)	100	1,729
Income from sales of loans	562	440
Insurance commissions	4,135	4,068
Cash management	2,318	1,819
Gain on sale of other assets	4	40
Other	1,323	1,506
Total noninterest income	25,617	25,296
NONINTEREST EXPENSE
Salaries and employee benefits	29,357	27,513
Occupancy, net	2,827	2,835
Depreciation	2,530	2,464
Amortization of intangible assets	581	444
Data processing services	1,215	1,117
Net expense from other real estate owned	(1,141)	314
Marketing and business promotion	1,855	1,679
Deposit insurance	839	826
Other	8,228	7,731
Total noninterest expense	46,291	44,923
Income before taxes	25,199	24,665
Income tax expense	8,620	8,406
Net income	$ 16,579	$ 16,259
NET INCOME PER COMMON SHARE
Basic	$ 1.07	$ 1.05
Diluted	$ 1.05	$ 1.03
OTHER COMPREHENSIVE INCOME
Unrealized gains on securities, net of tax of $(374) and $(700), respectively	$ 591	$ 1,111
Reclassification adjustment for gains included in net income, net of tax of $39 and $234, respectively	(61)	(372)
Other comprehensive gains, net of tax of $(335) and $(466), respectively	530	739
Comprehensive income	$ 17,109	$ 16,998

Consolidated Statements of Com5

Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Securities transactions accumulated other comprehensive income reclassifications	$ 100	$ 606
Unrealized gains (losses) on securities, tax	(374)	(700)
Reclassification adjustment for gains included in net income, tax	39	234
Other comprehensive gain (loss), tax	$ (335)	$ (466)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - 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, 2014		$ 15,504	$ 96,841	$ 492,776	$ 4,193
Shares issued, Value		8	236
Net income	$ 16,259			16,259
Net change	739				739
Tax effect of stock options			(64)
Dividends on common stock				(5,277)
Stock-based compensation arrangements			464
Balance at end of period at Mar. 31, 2015	621,679	15,512	97,477	503,758	4,932
Balance at beginning of period at Dec. 31, 2015	655,510	15,597	102,865	535,521	1,527
Shares issued, Value		31	871
Net income	16,579			16,579
Net change	530				530
Tax effect of stock options			(209)
Dividends on common stock				(5,579)
Stock-based compensation arrangements			451
Shares acquired and canceled, Value		(100)		(5,423)
Balance at end of period at Mar. 31, 2016	$ 662,661	$ 15,528	$ 103,978	$ 541,098	$ 2,057

Consolidated Statements of Sto7

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
RETAINED EARNINGS [Member]
Dividend on common stock	$ 0.36	$ 0.34

Consolidated Statements of Cash

Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 16,579	$ 16,259
Adjustments to reconcile to net cash provided by operating activities:
Provision for loan losses	4,103	1,334
Depreciation and amortization	3,111	2,908
Net amortization of securities premiums and discounts	148	148
Realized securities gains	(100)	(1,729)
Gain on sales of loans	(562)	(440)
Cash receipts from the sale of loans originated for sale	40,271	36,163
Cash disbursements for loans originated for sale	(33,610)	(37,393)
Deferred income tax benefit	(829)	(586)
(Gain)/loss on other assets	(1,222)	207
Increase in interest receivable	(176)	(356)
Increase/(decrease) in interest payable	13	(20)
Amortization of stock-based compensation arrangements	451	464
Other, net	300	5,855
Net cash provided by operating activities	28,477	22,814
INVESTING ACTIVITIES
Net increase in federal funds sold		(1,000)
Purchases of available for sale securities		(30,740)
Proceeds from maturities, calls and paydowns of held for investment securities	410	311
Proceeds from maturities, calls and paydowns of available for sale securities	55,071	6,144
Proceeds from sales of available for sale securities	299	1,729
Net change in loans	(45,010)	3,613
Purchases of premises, equipment and computer software	(2,939)	(4,107)
Proceeds from the sale of other assets	5,971	1,955
Net cash provided by (used in) investing activities	13,802	(22,095)
FINANCING ACTIVITIES
Net change in deposits	37,514	(20,903)
Net increase/(decrease) in short-term borrowings	800	(1,939)
Issuance of common stock, net	693	180
Common stock acquired	(5,523)
Cash dividends paid	(5,615)	(5,271)
Net cash provided by (used in) financing activities	27,869	(27,933)
Net increase/(decrease) in cash, due from banks and interest-bearing deposits	70,148	(27,214)
Cash, due from banks and interest-bearing deposits at the beginning of the period	1,598,177	1,913,895
Cash, due from banks and interest-bearing deposits at the end of the period	1,668,325	1,886,681
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	3,591	3,050
Cash paid during the period for income taxes	1,050	600
Noncash investing and financing activities:
Unpaid common stock dividends declared	$ 5,579	$ 5,271

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	(1) DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The accounting and reporting policies of BancFirst Corporation and its subsidiaries (the “Company”) conform to accounting principles generally accepted in the United State of America (U.S. GAAP) and general practice within the banking industry. A summary of significant accounting policies can be found in Note (1) to the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. Basis of Presentation The accompanying unaudited interim 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 unaudited interim consolidated financial statements. The accompanying unaudited interim consolidated financial statements and notes are presented in accordance with the instructions for Form 10-Q. The information contained in the financial statements and footnotes included in BancFirst Corporation’s Annual Report on Form 10-K for the year ended December 31, 2015, should be referred to in connection with these unaudited interim consolidated financial statements. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period. The unaudited interim consolidated financial statements contained herein reflect all adjustments which are, in the opinion of management, necessary to provide a fair statement of the financial position and results of operations of the Company for the interim periods presented. All such adjustments are of a normal and recurring nature. There have been no significant changes in the accounting policies of the Company since December 31, 2015, the date of the most recent annual report. Reclassifications Certain items in prior financial statements have been reclassified to conform to the current presentation. Such reclassifications had no effect on previously reported cash flows, stockholders’ equity or comprehensive income. 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. Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Under ASU 2016-09 all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. ASU 2016-09 also provides that an entity can make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest (current GAAP) or account for forfeitures when they occur. ASU 2016-09 changes the threshold to qualify for equity classification (rather than as a liability) to permit withholding up to the maximum statutory tax rates (rather than the minimum as was previously the case) in the applicable jurisdictions. ASU 2016-09 will be effective on January 1, 2017 and is not expected to have a significant impact on the Company’s financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases - (Topic 842).” ASU 2016-02 requires that lessees recognize on the balance sheet the assets and liabilities for the rights and obligations created by leases. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted. Adoption of ASU 2016-02 is not expected to have a significant 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 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.

Recent Developments, Including

Recent Developments, Including Mergers and Acquisitions	3 Months Ended
	Mar. 31, 2016
Recent Developments Including Mergers And Acquisitions [Abstract]
Recent Developments, Including Mergers and Acquisitions	(2) RECENT DEVELOPMENTS, INCLUDING MERGERS AND ACQUISITIONS On October 8, 2015, the Company completed its acquisition of CSB Bancshares Inc. and its subsidiary bank, Bank of Commerce, with locations in Yukon, Mustang and El Reno, Oklahoma. Bank of Commerce had approximately $196 million in total assets, $147 million in loans, $175 million in deposits and $22 million in equity capital. The acquisition was accounted for under the acquisition method and the Company acquired 100% of the voting interest. Bank of Commerce operated as a subsidiary of BancFirst Corporation until it was merged into BancFirst on November 13, 2015. As a result of the acquisition, the Company recorded a core deposit intangible of approximately $7.1 million and goodwill of approximately $9.4 million. The effect of this acquisition was included in the consolidated financial statements of the Company from the date of acquisition forward. The acquisition did not have a material effect on the Company’s consolidated financial statements. The acquisition of CSB Bancshares Inc. and its subsidiary bank, Bank of Commerce will complement our community banking strategy by adding two communities to our banking network throughout Oklahoma. During the quarter ended March 31, 2016, the Company had gains on the sale of other real estate owned totaling $1.2 million that is included in net expense from other real estate owned on the consolidated statements of comprehensive income.

Securities

Securities	3 Months Ended
	Mar. 31, 2016
Investments Debt And Equity Securities [Abstract]
Securities	(3) SECURITIES The following table summarizes securities held for investment and securities available for sale: March 31, 2016 December 31, 2015 (Dollars in thousands) Held for investment, at cost (fair value: $8,434 and $8,850, respectively) $ 8,379 $ 8,789 Available for sale, at fair value 489,607 544,160 Total $ 497,986 $ 552,949 The following table summarizes the amortized cost and estimated fair values of securities held for investment: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2016 (Dollars in thousands) Mortgage backed securities (1) $ 323 $ 25 $ — $ 348 States and political subdivisions 7,556 30 — 7,586 Other securities 500 — — 500 Total $ 8,379 $ 55 $ — $ 8,434 December 31, 2015 Mortgage backed securities (1) $ 347 $ 25 $ — $ 372 States and political subdivisions 7,942 36 — 7,978 Other securities 500 — — 500 Total $ 8,789 $ 61 $ — $ 8,850 The following table summarizes the amortized cost and estimated fair values of securities available for sale: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2016 (Dollars in thousands) U.S. treasuries $ 279,020 $ 1,695 $ — $ 280,715 U.S. federal agencies 128,391 539 (76 ) 128,854 Mortgage backed securities (1) 21,444 415 (550 ) 21,309 States and political subdivisions 47,904 1,473 (85 ) 49,292 Other securities (2) 9,494 125 (182 ) 9,437 Total $ 486,253 $ 4,247 $ (893 ) $ 489,607 December 31, 2015 U.S. treasuries $ 328,965 $ 776 $ (45 ) $ 329,696 U.S. federal agencies 131,522 527 (153 ) 131,896 Mortgage backed securities (1) 21,973 425 (543 ) 21,855 States and political subdivisions 49,521 1,447 (48 ) 50,920 Other securities (2) 9,689 249 (145 ) 9,793 Total $ 541,670 $ 3,424 $ (934 ) $ 544,160 (1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies. (2) Primarily consists of equity securities. Realized gains are reported as securities transactions within the noninterest income section of the consolidated statement of comprehensive income. 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. 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. March 31, 2016 December 31, 2015 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 4,983 $ 4,990 $ 5,168 $ 5,174 After one year but within five years 2,594 2,617 2,800 2,829 After five years but within ten years 778 802 795 319 After ten years 24 25 26 528 Total $ 8,379 $ 8,434 $ 8,789 $ 8,850 Available for Sale Contractual maturity of debt securities: Within one year $ 224,616 $ 224,814 $ 272,820 $ 272,779 After one year but within five years 175,071 177,377 178,617 180,145 After five years but within ten years 7,794 8,359 8,483 9,075 After ten years 72,746 73,052 75,522 75,853 Total debt securities 480,227 483,602 535,442 537,852 Equity securities 6,026 6,005 6,228 6,308 Total $ 486,253 $ 489,607 $ 541,670 $ 544,160 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: March 31, 2016 December 31, 2015 (Dollars Book value of pledged securities $ 458,893 $ 493,540

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
Loans and Allowance for Loan Losses	(4) LOANS AND ALLOWANCE FOR LOAN LOSSES The following is a schedule of loans outstanding by category: March 31, 2016 December 31, 2015 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 790,156 18.48 % $ 795,803 18.80 % Oil & gas production and equipment 86,524 2.02 87,304 2.06 Agriculture 149,442 3.50 150,620 3.56 State and political subdivisions: Taxable 17,628 0.41 17,605 0.42 Tax-exempt 36,177 0.85 33,575 0.79 Real estate: Construction 401,330 9.39 403,664 9.54 Farmland 189,934 4.44 184,707 4.36 One to four family residences 825,357 19.31 821,251 19.41 Multifamily residential properties 62,189 1.45 65,477 1.55 Commercial 1,406,204 32.89 1,356,430 32.05 Consumer 276,463 6.47 283,636 6.70 Other (not classified above) 33,708 0.79 31,976 0.76 Total loans $ 4,275,112 100.00 % $ 4,232,048 100.00 % 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. Accounting policies related to appraisals, nonaccruals and charge-offs are disclosed in Note (1) to the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. Nonperforming and Restructured Assets The following is a summary of nonperforming and restructured assets: March 31, December 31, 2016 2015 (Dollars in thousands) Past due 90 days or more and still accruing $ 1,099 $ 1,841 Nonaccrual 31,040 30,096 Restructured 533 15,143 Total nonperforming and restructured loans 32,672 47,080 Other real estate owned and repossessed assets 4,245 8,214 Total nonperforming and restructured assets $ 36,917 $ 55,294 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 $513,000 for the three months ended March 31, 2016 and approximately $310,000 for the three months ended March 31, 2015. Restructured loans consisted primarily of one relationship restructured in prior periods to defer certain principal payments. This relationship was re-evaluated and removed from restructured loans in 2016 due to sustained improvement in financial condition, performance and the commercially reasonable nature of its structure. The Company charges interest on principal balances outstanding during deferral periods. As a result, the current and future financial effects of the recorded balance of loans considered to be restructured were not considered to be material. Loans are segregated into classes based upon the nature of the collateral and the borrower. These classes are used to estimate the credit risk component in 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. March 31, 2016 December 31, 2015 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 372 $ 261 Non-residential real estate other 3,952 3,957 Residential real estate permanent mortgage 800 656 Residential real estate all other 4,548 1,833 Commercial and financial: Non-consumer non-real estate 8,283 10,159 Consumer non-real estate 301 312 Other loans 9,343 9,381 Acquired loans 3,441 3,537 Total $ 31,040 $ 30,096 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 March 31, 2016 Real estate: Non-residential real estate owner occupied $ 1,130 $ 17 $ 254 $ 1,401 $ 510,687 $ 512,088 $ — Non-residential real estate other 3,563 — 285 3,848 1,135,560 1,139,408 238 Residential real estate permanent mortgage 3,076 632 1,003 4,711 325,107 329,818 445 Residential real estate all other 5,652 339 775 6,766 693,107 699,873 113 Commercial and financial: Non-consumer non-real estate 2,825 130 487 3,442 975,485 978,927 92 Consumer non-real estate 1,862 676 344 2,882 261,565 264,447 168 Other loans 1,023 347 7,934 9,304 153,567 162,871 12 Acquired loans 1,252 419 615 2,286 185,394 187,680 31 Total $ 20,383 $ 2,560 $ 11,697 $ 34,640 $ 4,240,472 $ 4,275,112 $ 1,099 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 441 $ 179 $ 183 $ 803 $ 502,094 $ 502,897 $ — Non-residential real estate other 1,149 108 568 1,825 1,108,935 1,110,760 521 Residential real estate permanent mortgage 2,840 636 648 4,124 328,477 332,601 493 Residential real estate all other 2,842 609 824 4,275 672,414 676,689 193 Commercial and financial: Non-consumer non-real estate 2,278 161 187 2,626 982,136 984,762 152 Consumer non-real estate 2,237 772 349 3,358 265,511 268,869 278 Other loans 3,565 295 1,761 5,621 156,995 162,616 132 Acquired loans 1,052 71 918 2,041 190,813 192,854 72 Total $ 16,404 $ 2,831 $ 5,438 $ 24,673 $ 4,207,375 $ 4,232,048 $ 1,841 Impaired Loans Loans are considered impaired when, based on current information and events, it is probable the Company will be unable to collect the full amount of scheduled principal and interest payments in accordance with the original contractual terms of the loan agreement. If a loan is impaired, a specific valuation allowance may be allocated if necessary so that the loan is reported, net of allowance for loss, at the present value of future cash flows using the loan’s existing rate, or the fair value of collateral if repayment is expected solely from the collateral. The Company offers Small Business Administration (“SBA”) guaranteed loans through its Commercial Capital division to expand access to capital for creditworthy small businesses at reasonable terms. The SBA does not provide funds to the borrower, instead, the SBA guarantees a portion of the lender’s loan, which is conditional based on the lender following certain requirements established by the SBA. Typically, if the borrower defaults the SBA pays off the guaranteed portion of the remaining loan balance. However, if any of these requirements are not followed, the SBA can either deny a request for purchase of its guaranteed portion, or reduce the amount of its purchase by the amount of any loss. Because of the volume of SBA guaranteed loans, from time to time the Company may be in negotiation with the SBA regarding the amount of a guarantee that is collectable. If a request is denied, the Company could be required to record additional charge-offs of the previously guaranteed portion of the loan. As of the filing date, collectability on the guarantee for an SBA loan was uncertain; however, the amount of loss, if any, was not estimable. 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 March 31, 2016 Real estate: Non-residential real estate owner occupied $ 615 $ 487 $ 15 $ 418 Non-residential real estate other 6,207 4,190 157 15,123 Residential real estate permanent mortgage 1,498 1,305 86 1,276 Residential real estate all other 5,101 4,823 1,382 2,781 Commercial and financial: Non-consumer non-real estate 12,762 8,375 2,017 9,190 Consumer non-real estate 652 609 120 745 Other loans 10,705 9,355 459 9,892 Acquired loans 6,276 3,745 — 3,977 Total $ 43,816 $ 32,889 $ 4,236 $ 43,402 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 507 $ 383 $ 14 $ 446 Non-residential real estate other 21,068 19,052 357 19,655 Residential real estate permanent mortgage 1,401 1,209 81 1,125 Residential real estate all other 2,498 2,235 242 1,958 Commercial and financial: Non-consumer non-real estate 13,897 10,312 2,062 11,786 Consumer non-real estate 738 715 181 652 Other loans 10,722 9,513 331 10,335 Acquired loans 6,295 4,248 — 4,564 Total $ 57,126 $ 47,667 $ 3,268 $ 50,521 Credit Risk Monitoring and Loan Grading The Company considers various factors to monitor the credit risk in the loan portfolio including volume and severity of loan delinquencies, nonaccrual loans, internal grading of loans, historical loan loss experience and economic conditions. An internal risk grading system is used to indicate the credit risk of loans. The loan grades used by the Company are for internal risk identification purposes and do not directly correlate to regulatory classification categories or any financial reporting definitions. The general characteristics of the risk grades are disclosed in Note (5) to the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. 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 March 31, 2016 Real estate: Non-residential real estate owner occupied $ 423,003 $ 77,243 $ 11,470 $ 372 $ — $ 512,088 Non-residential real estate other 966,113 163,932 5,379 3,984 — 1,139,408 Residential real estate permanent mortgage 290,540 30,941 7,043 1,294 — 329,818 Residential real estate all other 574,683 112,736 7,649 4,805 — 699,873 Commercial and financial: Non-consumer non-real estate 809,004 136,143 25,513 8,267 — 978,927 Consumer non-real estate 247,419 14,419 2,099 510 — 264,447 Other loans 153,486 5,629 1,336 2,420 — 162,871 Acquired loans 159,016 13,924 10,991 3,674 75 187,680 Total $ 3,623,264 $ 554,967 $ 71,480 $ 25,326 $ 75 $ 4,275,112 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 417,529 $ 76,749 $ 8,304 $ 315 $ — $ 502,897 Non-residential real estate other 945,993 156,159 4,580 4,028 — 1,110,760 Residential real estate permanent mortgage 295,265 29,793 6,315 1,228 — 332,601 Residential real estate all other 554,007 111,879 9,109 1,694 — 676,689 Commercial and financial: Non-consumer non-real estate 821,394 140,384 12,687 10,297 — 984,762 Consumer non-real estate 251,994 14,433 1,779 662 1 268,869 Other loans 153,416 5,851 872 2,477 — 162,616 Acquired loans 165,305 12,566 11,049 3,858 76 192,854 Total $ 3,604,903 $ 547,814 $ 54,695 $ 24,559 $ 77 $ 4,232,048 Allowance for Loan Losses Methodology The allowance for loan losses (“ALL”) methodology is disclosed in Note (5) to the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. 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) Three Months Ended March 31, 2016 Real estate: Non-residential real estate owner occupied $ 4,661 $ (1 ) $ — $ (1 ) $ 172 $ 4,832 Non-residential real estate other 9,921 (1 ) 1 — 290 10,211 Residential real estate permanent mortgage 3,148 (50 ) 17 (33 ) 49 3,164 Residential real estate all other 6,725 (67 ) 4 (63 ) 1,327 7,989 Commercial and financial: Non-consumer non-real estate 11,754 (803 ) 11 (792 ) 1,851 12,813 Consumer non-real estate 2,642 (221 ) 38 (183 ) 94 2,553 Other loans 2,648 (133 ) 6 (127 ) 269 2,790 Acquired loans 167 (4 ) 5 1 51 219 Total $ 41,666 $ (1,280 ) $ 82 $ (1,198 ) $ 4,103 $ 44,571 ALL Balance at beginning of period Charge- offs Recoveries Net charge-offs Provisions charged to operations Balance at end of period (Dollars in thousands) Three Months Ended March 31, 2015 Real estate: Non-residential real estate owner occupied $ 4,406 $ (1 ) $ 1 $ — $ 55 $ 4,461 Non-residential real estate other 9,616 — — — 282 9,898 Residential real estate permanent mortgage 2,948 (40 ) 9 (31 ) 67 2,984 Residential real estate all other 6,269 (68 ) 5 (63 ) 372 6,578 Commercial and financial: Non-consumer non-real estate 12,771 (153 ) 31 (122 ) 419 13,068 Consumer non-real estate 2,404 (127 ) 15 (112 ) 35 2,327 Other loans 2,359 (213 ) 9 (204 ) 86 2,241 Acquired loans 116 (160 ) 26 (134 ) 18 — Total $ 40,889 $ (762 ) $ 96 $ (666 ) $ 1,334 $ 41,557 The following table details the amount of ALL by class of loans for the period presented, detailed on the basis of the impairment methodology used by the Company. ALL March 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Individually evaluated for impairment Collectively evaluated for impairment (Dollars in thousands) Real estate: Non-residential real estate owner occupied. $ 444 $ 4,388 $ 323 $ 4,338 Non-residential real estate other 351 9,860 323 9,598 Residential real estate permanent mortgage 438 2,726 399 2,749 Residential real estate all other 1,926 6,063 839 5,886 Commercial and financial: Non-consumer non-real estate 4,539 8,274 3,365 8,389 Consumer non-real estate 396 2,157 445 2,197 Other loans 413 2,377 291 2,357 Acquired loans — 219 — 167 Total $ 8,507 $ 36,064 $ 5,985 $ 35,681 The following table details the loans outstanding by class of loans for the period presented, on the basis of the impairment methodology used by the Company. Loans March 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 11,843 $ 500,245 $ — $ 8,619 $ 494,278 $ — Non-residential real estate other 9,363 1,130,045 — 8,608 1,102,152 — Residential real estate permanent mortgage 8,337 321,481 — 7,543 325,058 — Residential real estate all other 12,453 687,420 — 10,803 665,886 — Commercial and financial: Non-consumer non-real estate 33,780 945,147 — 22,983 961,779 — Consumer non-real estate 2,596 261,851 — 2,416 266,453 — Other loans 2,216 160,655 — 2,323 160,293 — Acquired loans — 172,940 14,740 — 177,871 14,983 Total $ 80,588 $ 4,179,784 $ 14,740 $ 63,295 $ 4,153,770 $ 14,983 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: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Other real estate owned $ 344 $ 260 Repossessed assets 404 220 Total $ 748 $ 480

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets	(5) INTANGIBLE ASSETS The following is a summary of intangible assets: Gross Carrying Amount Accumulated Amortization Net Carrying Amount (Dollars in thousands) As of March 31, 2016 Core deposit intangibles $ 18,659 $ (6,402 ) $ 12,257 Customer relationship intangibles 5,699 (3,151 ) 2,548 Mortgage servicing intangibles 525 (237 ) 288 Total $ 24,883 $ (9,790 ) $ 15,093 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 The following is a summary of goodwill by business segment: Other Executive, Metropolitan Community Financial Operations Banks Banks Services & Support Consolidated (Dollars in thousands) Three month ended March 31, 2016 Balance at beginning and end of period $ 8,078 $ 40,050 $ 5,464 $ 450 $ 54,042 Additional information for intangible assets can be found in Note (7) to the Company’s Annual Report on Form 10-K for the year ended December 31, 2015.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	(6) 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 March 31, 2016, 5,735 shares were available for future grants. The BancFirst ISOP will terminate on December 31, 2019. The options 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 March 31, 2016 will become exercisable through the year 2023. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant. In June 1999, the Company adopted the BancFirst Corporation Non-Employee Directors’ Stock Option Plan (the “BancFirst Directors’ Stock Option Plan”). Each non-employee director is granted an option for 10,000 shares. The Company amended the BancFirst Directors’ Stock Option Plan to increase the number of shares to be issued under the plan to 230,000 shares in May 2014. At March 31, 2016, 10,000 shares were available for future grants. The options 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 March 31, 2016 will become exercisable through the year 2020. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant. The Company currently uses newly issued stock to satisfy stock-based exercises, but reserves the right to use treasury stock 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) Three Months Ended March 31, 2016 Outstanding at December 31, 2015 1,018,149 $ 40.69 Options granted 15,000 55.15 Options exercised (29,600 ) 29.56 Options canceled, forfeited, or expired (5,000 ) 41.02 Outstanding at March 31, 2016 998,549 41.24 8.83 Yrs $ 15,767 Exercisable at March 31, 2016 486,874 33.47 5.55 Yrs $ 11,471 The following table has additional information regarding options granted and options exercised under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan: Three Months Ended March 31, 2016 2015 (Dollars in thousands except per share data) Weighted average grant-date fair value per share of options granted $ 11.47 $ 11.00 Total intrinsic value of options exercised 779 237 Cash received from options exercised 875 244 Tax benefit realized from options exercised 301 92 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: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Stock-based compensation expense $ 451 $ 464 Tax benefit 174 180 Stock-based compensation expense, net of tax $ 277 $ 284 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: March 31, 2016 (Dollars in thousands) Unearned stock-based compensation expense $ 3,834 The following table shows the assumptions used for computing stock-based compensation expense under the fair value method during the periods presented: Three Months Ended March 31, 2016 2015 Risk-free interest rate 1.91 to 2.02% 1.83 to 1.96% Dividend yield 2.00% 2.00% Stock price volatility 20.41 to 20.64% 18.23 to 18.50% Expected term 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 758 during the three months ended March 31, 2016. A summary of the accumulated stock units is as follows: March 31, December 31, 2016 2015 Accumulated stock units 67,558 66,376 Average price $ 40.17 $ 39.64

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Stockholders' Equity	(7) STOCKHOLDERS’ EQUITY 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 within the limitations of a Board approved share buyback program. The following table is a summary of the shares under the program: Three Months Ended March 31, 2016 2015 Number of shares repurchased 100,000 — Average price of shares repurchased $ 55.23 — Shares remaining to be repurchased 66,276 194,723 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 March 31, 2016, the Company and BancFirst met all capital adequacy requirements to which they are subject. The actual and required capital amounts and ratios are shown in the following table: Required To Be Well For Capital With Capitalized Under Adequacy Capital Conservation Prompt Corrective Actual Purposes Buffer Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of March 31, 2016: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 673,104 14.40% $ 373,849 8.00% $ 403,056 8.625% N/A N/A BancFirst 616,209 13.20% 373,346 8.00% 402,513 8.625% $ 466,682 10.00% Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 597,533 12.79% $ 210,290 4.50% $ 239,497 5.125% N/A N/A BancFirst 551,638 11.82% 210,007 4.50% 239,174 5.125% $ 303,343 6.50% Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 628,533 13.45% $ 280,387 6.00% $ 309,594 6.625% N/A N/A BancFirst 571,638 12.25% 280,009 6.00% 309,177 6.625% $ 373,346 8.00% Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 628,533 9.51% $ 264,328 4.00% N/A N/A N/A N/A BancFirst 571,638 8.68% 263,405 4.00% N/A N/A $ 329,256 5.00% As of March 31, 2016, the most recent notification from the Federal Reserve Bank of Kansas City and the FDIC categorized BancFirst as “well capitalized” under the regulatory framework from 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 notifications of BancFirst’s capital category that management believes would materially change its category under capital requirements existing as of the report date. Basel III Capital Rules Under the Basel III Capital Rules, in order to avoid limitations on capital distributions, including dividend payments and certain discretionary bonus payments to executive officers, a banking organization must hold a capital conservation buffer composed of CET1 capital above its minimum risk-based capital requirements. The implementation of the capital conservation buffer began on January 1, 2016 at the 0.625% level and will be phased in over a four-year period (increasing by that amount on each subsequent January 1, until it reaches 2.5% on January 1, 2019). Management believes that, as of March 31, 2016, the Company and BancFirst would meet all capital adequacy requirements under the Basel III Capital Rules on a fully phased-in basis as if such requirements were currently in effect.

Net Income Per Common Share

Net Income Per Common Share	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Net Income Per Common Share	(8) NET INCOME PER COMMON SHARE Basic and diluted net income per common share based on weighted-average shares outstanding are calculated as follows: Income (Numerator) Shares (Denominator) Per Share Amount (Dollars in thousands, except per share data) Three Months Ended March 31, 2016 Basic Income available to common stockholders $ 16,579 15,534,416 $ 1.07 Dilutive effect of stock options — 281,955 Diluted Income available to common stockholders plus assumed exercises of stock options $ 16,579 15,816,371 $ 1.05 Three Months Ended March 31, 2015 Basic Income available to common stockholders $ 16,259 15,507,346 $ 1.05 Dilutive effect of stock options — 331,202 Diluted Income available to common stockholders plus assumed exercises of stock options $ 16,259 15,838,548 $ 1.03 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 period because the options’ exercise prices were greater than the average market price of the common shares: Shares Average Exercise Three Months Ended March 31, 2016 236,451 $ 58.59 Three Months Ended March 31, 2015 128,667 57.68

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	(9) 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 ASC 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, goodwill and other intangible assets. Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis A description of the valuation methodologies and key inputs used to measure financial assets and financial liabilities at fair value on a recurring basis, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. These valuation methodologies were applied to the following categories of the Company’s financial assets and financial liabilities. Securities Available for Sale Securities classified as available for sale are reported at fair value. U.S. Treasuries are valued using Level 1 inputs. Other securities available for sale including U.S. federal agencies, registered mortgage backed securities and state and political subdivisions are valued using prices from an independent pricing service utilizing Level 2 data. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. The Company also invests in private label mortgage backed securities and equity securities classified as available for sale for which observable information is not readily available. These securities are reported at fair value utilizing Level 3 inputs. For these securities, management determines the fair value based on replacement cost, the income approach or information provided by outside consultants or lead investors. The Company reviews the prices for Level 1 and Level 2 securities supplied by the independent pricing service for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, the Company does not purchase investment portfolio securities that are esoteric or that have complicated structures. The Company’s 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 for pricing mentioned in the preceding paragraph adjusted for the specific issue. From time to time, the Company will validate, on a sample basis, prices supplied by the independent pricing service by comparison to prices obtained from third party sources. Derivatives Derivatives are reported at fair value utilizing Level 2 inputs. The Company obtains dealer and market quotations to value its oil and gas swaps and options. The Company utilizes dealer quotes and observable market data inputs to substantiate internal valuation models. Loans Held For Sale The Company originates mortgage loans to be sold. At the time of origination, the acquiring bank has already been determined and the terms of the loan, including interest rate, have already been set by the acquiring bank, allowing the Company to originate the loan at fair value. Mortgage loans are generally sold within 30 days of origination. Loans held for sale are valued using Level 2 inputs. Gains or losses recognized upon the sale of the loans are determined on a specific identification basis. The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of the periods presented, 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) March 31, 2016 Securities available for sale: U.S. Treasury $ 280,715 $ — $ — $ 280,715 U.S. federal agencies — 128,854 — 128,854 Mortgage-backed securities — 6,493 14,816 21,309 States and political subdivisions — 49,292 — 49,292 Other securities — 3,432 6,005 9,437 Derivative assets — 1,210 — 1,210 Derivative liabilities — 605 — 605 Loans held for sale — 7,626 — 7,626 December 31, 2015 Securities available for sale: U.S. Treasury $ 329,696 $ — $ — $ 329,696 U.S. federal agencies — 131,896 — 131,896 Mortgage-backed securities — 7,039 14,816 21,855 States and political subdivisions — 50,920 — 50,920 Other securities — 3,485 6,308 9,793 Derivative assets — 1,946 — 1,946 Derivative liabilities — 989 — 989 Loans held for sale — 13,725 — 13,725 The changes in Level 3 assets measured at estimated fair value on a recurring basis during the periods presented were as follows: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Balance at the beginning of the year $ 21,124 $ 28,459 Purchases, issuances and settlements (4 ) (744 ) Sales (299 ) (1,729 ) Gains included in earnings 100 1,729 Total unrealized (losses) gains (100 ) (589 ) Balance at the end of the period $ 20,821 $ 27,126 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 three months ended March 31, 2016 and 2015, the Company did not transfer any securities between levels in the fair value hierarchy. Financial Assets and Financial Liabilities Measured at Fair Value on a Nonrecurring Basis Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). These financial assets and financial liabilities are reported at fair value utilizing Level 3 inputs. Impaired loans are reported at the fair value of the underlying collateral if repayment is dependent on liquidation of the collateral. In no case does the fair value of an impaired loan exceed the fair value of the underlying collateral. The impaired loans are adjusted to fair value through a specific allocation of the allowance for loan losses or a direct charge-down of the loan. 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 losses recognized during the period: Total Fair Value Level 3 Losses (Dollars in thousands) As of and for the Year-to-date Period Ended March 31, 2016 Impaired loans (less specific allowance) $ 28,653 $ — Foreclosed assets 281 2 Other real estate owned 3,963 — 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 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: March 31, December 31, 2016 2015 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,668,325 $ 1,668,325 $ 1,598,177 $ 1,598,177 Securities held for investment 7,879 7,934 8,289 8,350 Level 3 inputs: Securities held for investment 500 500 500 500 Loans, net of allowance for loan losses 4,230,541 4,286,603 4,190,382 4,222,153 FINANCIAL LIABILITIES Level 2 inputs: Deposits 6,010,872 6,061,676 5,973,538 6,028,012 Short-term borrowings 1,300 1,300 500 500 Junior subordinated debentures 31,959 34,886 31,959 33,793 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,634 1,681 Letters of credit 443 464 Non-financial Assets and Non-financial Liabilities Measured at Fair Value The Company has no non-financial assets or non-financial liabilities measured at fair value on a recurring basis. Certain non-financial assets and non-financial liabilities measured at fair value on a nonrecurring basis include intangible assets (excluding mortgage service rights, which are valued semi-annually) and other non-financial long-lived assets measured at fair value and adjusted for impairment. These items are evaluated at least annually for impairment. 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 March 31, 2016 or December 31, 2015.

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	(10) 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, the Company simultaneously enters into an offsetting contract with a counterparty to mitigate the exposure to fluctuations in oil and gas prices. 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: March 31, 2016 December 31, 2015 Oil and Natural Gas Swaps and Options Notional Units Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value (Notional amounts and dollars in thousands) Oil Derivative assets Barrels 98 $ 107 86 $ 604 Derivative liabilities Barrels (98 ) (5 ) (86 ) (378 ) Natural Gas Derivative assets MMBTUs 3,230 1,103 3,920 1,342 Derivative liabilities MMBTUs (3,230 ) (600 ) (3,920 ) (611 ) Total Fair Value Included in Derivative assets Other assets 1,210 1,946 Derivative liabilities Other liabilities (605 ) (989 ) The following table is a summary of the Company’s recognized income related to the activity, which was included in other noninterest income: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Derivative income $ 5 $ 155 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 is 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: March 31, 2016 December 31, 2015 (Dollars in Credit exposure $ — $ 37 Balance Sheet Offsetting Derivatives may be eligible for offset in the consolidated balance sheet and/or subject to master netting arrangements. The Company’s derivative transactions with upstream financial institution counterparties and bank customers are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements which include “right of set-off” provisions. In such cases there is generally a legally enforceable right to offset recognized amounts and there may be an intention to settle such amounts on a net basis. Nonetheless, the Company does not generally offset such financial instruments for financial reporting purposes.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Segment Information	(11) 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) Three Months Ended March 31, 2016 Net interest income (expense) $ 15,843 $ 33,122 $ 1,416 $ (405 ) $ — $ 49,976 Noninterest income 3,788 13,596 7,479 17,678 (16,924 ) 25,617 Income before taxes 9,348 19,094 3,114 10,500 (16,857 ) 25,199 Three Months Ended March 31, 2015 Net interest income (expense) $ 15,400 $ 29,055 $ 1,618 $ (447 ) $ — $ 45,626 Noninterest income 3,457 12,326 8,727 17,292 (16,506 ) 25,296 Income before taxes 9,889 16,407 5,007 9,804 (16,442 ) 24,665 Total Assets: March 31, 2016 $ 2,307,503 $ 4,401,449 $ 127,748 $ 628,843 $ (724,605 ) $ 6,740,938 December 31, 2015 2,277,870 4,379,205 128,697 624,428 (717,371 ) 6,692,829 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.

Description of Business and S20

Description of Business and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim 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 unaudited interim consolidated financial statements. The accompanying unaudited interim consolidated financial statements and notes are presented in accordance with the instructions for Form 10-Q. The information contained in the financial statements and footnotes included in BancFirst Corporation’s Annual Report on Form 10-K for the year ended December 31, 2015, should be referred to in connection with these unaudited interim consolidated financial statements. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period. The unaudited interim consolidated financial statements contained herein reflect all adjustments which are, in the opinion of management, necessary to provide a fair statement of the financial position and results of operations of the Company for the interim periods presented. All such adjustments are of a normal and recurring nature. There have been no significant changes in the accounting policies of the Company since December 31, 2015, the date of the most recent annual report.
Reclassifications	Reclassifications Certain items in prior financial statements have been reclassified to conform to the current presentation. Such reclassifications had no effect on previously reported cash flows, stockholders’ equity or comprehensive income.
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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Under ASU 2016-09 all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. ASU 2016-09 also provides that an entity can make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest (current GAAP) or account for forfeitures when they occur. ASU 2016-09 changes the threshold to qualify for equity classification (rather than as a liability) to permit withholding up to the maximum statutory tax rates (rather than the minimum as was previously the case) in the applicable jurisdictions. ASU 2016-09 will be effective on January 1, 2017 and is not expected to have a significant impact on the Company’s financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases - (Topic 842).” ASU 2016-02 requires that lessees recognize on the balance sheet the assets and liabilities for the rights and obligations created by leases. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted. Adoption of ASU 2016-02 is not expected to have a significant 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 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.

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2016
Investments Debt And Equity Securities [Abstract]
Summary of Securities Held for Investment and Securities Available for Sale	The following table summarizes securities held for investment and securities available for sale: March 31, 2016 December 31, 2015 (Dollars in thousands) Held for investment, at cost (fair value: $8,434 and $8,850, respectively) $ 8,379 $ 8,789 Available for sale, at fair value 489,607 544,160 Total $ 497,986 $ 552,949
Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment	The following table summarizes the amortized cost and estimated fair values of securities held for investment: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2016 (Dollars in thousands) Mortgage backed securities (1) $ 323 $ 25 $ — $ 348 States and political subdivisions 7,556 30 — 7,586 Other securities 500 — — 500 Total $ 8,379 $ 55 $ — $ 8,434 December 31, 2015 Mortgage backed securities (1) $ 347 $ 25 $ — $ 372 States and political subdivisions 7,942 36 — 7,978 Other securities 500 — — 500 Total $ 8,789 $ 61 $ — $ 8,850
Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale	The following table summarizes the amortized cost and estimated fair values of securities available for sale: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2016 (Dollars in thousands) U.S. treasuries $ 279,020 $ 1,695 $ — $ 280,715 U.S. federal agencies 128,391 539 (76 ) 128,854 Mortgage backed securities (1) 21,444 415 (550 ) 21,309 States and political subdivisions 47,904 1,473 (85 ) 49,292 Other securities (2) 9,494 125 (182 ) 9,437 Total $ 486,253 $ 4,247 $ (893 ) $ 489,607 December 31, 2015 U.S. treasuries $ 328,965 $ 776 $ (45 ) $ 329,696 U.S. federal agencies 131,522 527 (153 ) 131,896 Mortgage backed securities (1) 21,973 425 (543 ) 21,855 States and political subdivisions 49,521 1,447 (48 ) 50,920 Other securities (2) 9,689 249 (145 ) 9,793 Total $ 541,670 $ 3,424 $ (934 ) $ 544,160 (1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies. (2) Primarily consists of equity securities.
Maturity of Securities	The maturities of securities held for investment and available for sale are summarized in the following table using contractual maturities. Actual maturities may differ from contractual maturities due to obligations that are called or prepaid. For purposes of the maturity table, mortgage-backed securities, which are not due at a single maturity date, have been presented at their contractual maturity. March 31, 2016 December 31, 2015 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 4,983 $ 4,990 $ 5,168 $ 5,174 After one year but within five years 2,594 2,617 2,800 2,829 After five years but within ten years 778 802 795 319 After ten years 24 25 26 528 Total $ 8,379 $ 8,434 $ 8,789 $ 8,850 Available for Sale Contractual maturity of debt securities: Within one year $ 224,616 $ 224,814 $ 272,820 $ 272,779 After one year but within five years 175,071 177,377 178,617 180,145 After five years but within ten years 7,794 8,359 8,483 9,075 After ten years 72,746 73,052 75,522 75,853 Total debt securities 480,227 483,602 535,442 537,852 Equity securities 6,026 6,005 6,228 6,308 Total $ 486,253 $ 489,607 $ 541,670 $ 544,160
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: March 31, 2016 December 31, 2015 (Dollars Book value of pledged securities $ 458,893 $ 493,540

Loans and Allowance for Loan 22

Loans and Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
Schedule of Loans Outstanding by Category	The following is a schedule of loans outstanding by category: March 31, 2016 December 31, 2015 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 790,156 18.48 % $ 795,803 18.80 % Oil & gas production and equipment 86,524 2.02 87,304 2.06 Agriculture 149,442 3.50 150,620 3.56 State and political subdivisions: Taxable 17,628 0.41 17,605 0.42 Tax-exempt 36,177 0.85 33,575 0.79 Real estate: Construction 401,330 9.39 403,664 9.54 Farmland 189,934 4.44 184,707 4.36 One to four family residences 825,357 19.31 821,251 19.41 Multifamily residential properties 62,189 1.45 65,477 1.55 Commercial 1,406,204 32.89 1,356,430 32.05 Consumer 276,463 6.47 283,636 6.70 Other (not classified above) 33,708 0.79 31,976 0.76 Total loans $ 4,275,112 100.00 % $ 4,232,048 100.00 %
Summary of Nonperforming and Restructured Assets	The following is a summary of nonperforming and restructured assets: March 31, December 31, 2016 2015 (Dollars in thousands) Past due 90 days or more and still accruing $ 1,099 $ 1,841 Nonaccrual 31,040 30,096 Restructured 533 15,143 Total nonperforming and restructured loans 32,672 47,080 Other real estate owned and repossessed assets 4,245 8,214 Total nonperforming and restructured assets $ 36,917 $ 55,294
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. March 31, 2016 December 31, 2015 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 372 $ 261 Non-residential real estate other 3,952 3,957 Residential real estate permanent mortgage 800 656 Residential real estate all other 4,548 1,833 Commercial and financial: Non-consumer non-real estate 8,283 10,159 Consumer non-real estate 301 312 Other loans 9,343 9,381 Acquired loans 3,441 3,537 Total $ 31,040 $ 30,096
Age Analysis of Past Due Loans Segregated by Class of Loans	The following table presents an age analysis of past due loans, segregated by class of loans: Age Analysis of Past Due Loans 30-59 Days Past Due 60-89 Days Past Due 90 Days and Greater Total Past Due Loans Current Loans Total Loans Accruing Loans 90 Days or More Past Due (Dollars in thousands) As of March 31, 2016 Real estate: Non-residential real estate owner occupied $ 1,130 $ 17 $ 254 $ 1,401 $ 510,687 $ 512,088 $ — Non-residential real estate other 3,563 — 285 3,848 1,135,560 1,139,408 238 Residential real estate permanent mortgage 3,076 632 1,003 4,711 325,107 329,818 445 Residential real estate all other 5,652 339 775 6,766 693,107 699,873 113 Commercial and financial: Non-consumer non-real estate 2,825 130 487 3,442 975,485 978,927 92 Consumer non-real estate 1,862 676 344 2,882 261,565 264,447 168 Other loans 1,023 347 7,934 9,304 153,567 162,871 12 Acquired loans 1,252 419 615 2,286 185,394 187,680 31 Total $ 20,383 $ 2,560 $ 11,697 $ 34,640 $ 4,240,472 $ 4,275,112 $ 1,099 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 441 $ 179 $ 183 $ 803 $ 502,094 $ 502,897 $ — Non-residential real estate other 1,149 108 568 1,825 1,108,935 1,110,760 521 Residential real estate permanent mortgage 2,840 636 648 4,124 328,477 332,601 493 Residential real estate all other 2,842 609 824 4,275 672,414 676,689 193 Commercial and financial: Non-consumer non-real estate 2,278 161 187 2,626 982,136 984,762 152 Consumer non-real estate 2,237 772 349 3,358 265,511 268,869 278 Other loans 3,565 295 1,761 5,621 156,995 162,616 132 Acquired loans 1,052 71 918 2,041 190,813 192,854 72 Total $ 16,404 $ 2,831 $ 5,438 $ 24,673 $ 4,207,375 $ 4,232,048 $ 1,841
Impaired Loans Segregated by Class of Loans	The following table presents impaired loans, segregated by class of loans. No material amount of interest income was recognized on impaired loans subsequent to their classification as impaired. Impaired Loans Unpaid Principal Balance Recorded Investment with Allowance Related Allowance Average Recorded Investment (Dollars in thousands) As of March 31, 2016 Real estate: Non-residential real estate owner occupied $ 615 $ 487 $ 15 $ 418 Non-residential real estate other 6,207 4,190 157 15,123 Residential real estate permanent mortgage 1,498 1,305 86 1,276 Residential real estate all other 5,101 4,823 1,382 2,781 Commercial and financial: Non-consumer non-real estate 12,762 8,375 2,017 9,190 Consumer non-real estate 652 609 120 745 Other loans 10,705 9,355 459 9,892 Acquired loans 6,276 3,745 — 3,977 Total $ 43,816 $ 32,889 $ 4,236 $ 43,402 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 507 $ 383 $ 14 $ 446 Non-residential real estate other 21,068 19,052 357 19,655 Residential real estate permanent mortgage 1,401 1,209 81 1,125 Residential real estate all other 2,498 2,235 242 1,958 Commercial and financial: Non-consumer non-real estate 13,897 10,312 2,062 11,786 Consumer non-real estate 738 715 181 652 Other loans 10,722 9,513 331 10,335 Acquired loans 6,295 4,248 — 4,564 Total $ 57,126 $ 47,667 $ 3,268 $ 50,521
Internal Loan Grading by Class of Loans	The following table presents internal loan grading by class of loans: Internal Loan Grading Grade 1 2 3 4 5 Total (Dollars in thousands) As of March 31, 2016 Real estate: Non-residential real estate owner occupied $ 423,003 $ 77,243 $ 11,470 $ 372 $ — $ 512,088 Non-residential real estate other 966,113 163,932 5,379 3,984 — 1,139,408 Residential real estate permanent mortgage 290,540 30,941 7,043 1,294 — 329,818 Residential real estate all other 574,683 112,736 7,649 4,805 — 699,873 Commercial and financial: Non-consumer non-real estate 809,004 136,143 25,513 8,267 — 978,927 Consumer non-real estate 247,419 14,419 2,099 510 — 264,447 Other loans 153,486 5,629 1,336 2,420 — 162,871 Acquired loans 159,016 13,924 10,991 3,674 75 187,680 Total $ 3,623,264 $ 554,967 $ 71,480 $ 25,326 $ 75 $ 4,275,112 As of December 31, 2015 Real estate: Non-residential real estate owner occupied $ 417,529 $ 76,749 $ 8,304 $ 315 $ — $ 502,897 Non-residential real estate other 945,993 156,159 4,580 4,028 — 1,110,760 Residential real estate permanent mortgage 295,265 29,793 6,315 1,228 — 332,601 Residential real estate all other 554,007 111,879 9,109 1,694 — 676,689 Commercial and financial: Non-consumer non-real estate 821,394 140,384 12,687 10,297 — 984,762 Consumer non-real estate 251,994 14,433 1,779 662 1 268,869 Other loans 153,416 5,851 872 2,477 — 162,616 Acquired loans 165,305 12,566 11,049 3,858 76 192,854 Total $ 3,604,903 $ 547,814 $ 54,695 $ 24,559 $ 77 $ 4,232,048
Activity in ALL by Class of Loans	The following table details activity in the ALL by class of loans for the period presented. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. ALL Balance at beginning of period Charge- offs Recoveries Net charge-offs Provisions charged to operations Balance at end of period (Dollars in thousands) Three Months Ended March 31, 2016 Real estate: Non-residential real estate owner occupied $ 4,661 $ (1 ) $ — $ (1 ) $ 172 $ 4,832 Non-residential real estate other 9,921 (1 ) 1 — 290 10,211 Residential real estate permanent mortgage 3,148 (50 ) 17 (33 ) 49 3,164 Residential real estate all other 6,725 (67 ) 4 (63 ) 1,327 7,989 Commercial and financial: Non-consumer non-real estate 11,754 (803 ) 11 (792 ) 1,851 12,813 Consumer non-real estate 2,642 (221 ) 38 (183 ) 94 2,553 Other loans 2,648 (133 ) 6 (127 ) 269 2,790 Acquired loans 167 (4 ) 5 1 51 219 Total $ 41,666 $ (1,280 ) $ 82 $ (1,198 ) $ 4,103 $ 44,571 ALL Balance at beginning of period Charge- offs Recoveries Net charge-offs Provisions charged to operations Balance at end of period (Dollars in thousands) Three Months Ended March 31, 2015 Real estate: Non-residential real estate owner occupied $ 4,406 $ (1 ) $ 1 $ — $ 55 $ 4,461 Non-residential real estate other 9,616 — — — 282 9,898 Residential real estate permanent mortgage 2,948 (40 ) 9 (31 ) 67 2,984 Residential real estate all other 6,269 (68 ) 5 (63 ) 372 6,578 Commercial and financial: Non-consumer non-real estate 12,771 (153 ) 31 (122 ) 419 13,068 Consumer non-real estate 2,404 (127 ) 15 (112 ) 35 2,327 Other loans 2,359 (213 ) 9 (204 ) 86 2,241 Acquired loans 116 (160 ) 26 (134 ) 18 — Total $ 40,889 $ (762 ) $ 96 $ (666 ) $ 1,334 $ 41,557
Allowance for Loan Losses Outstanding by Impairment Methodology	The following table details the amount of ALL by class of loans for the period presented, detailed on the basis of the impairment methodology used by the Company. ALL March 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Individually evaluated for impairment Collectively evaluated for impairment (Dollars in thousands) Real estate: Non-residential real estate owner occupied. $ 444 $ 4,388 $ 323 $ 4,338 Non-residential real estate other 351 9,860 323 9,598 Residential real estate permanent mortgage 438 2,726 399 2,749 Residential real estate all other 1,926 6,063 839 5,886 Commercial and financial: Non-consumer non-real estate 4,539 8,274 3,365 8,389 Consumer non-real estate 396 2,157 445 2,197 Other loans 413 2,377 291 2,357 Acquired loans — 219 — 167 Total $ 8,507 $ 36,064 $ 5,985 $ 35,681
Loans Outstanding by Impairment Methodology	The following table details the loans outstanding by class of loans for the period presented, on the basis of the impairment methodology used by the Company. Loans March 31, 2016 December 31, 2015 Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality Individually evaluated for impairment Collectively evaluated for impairment Loans acquired with deteriorated credit quality (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 11,843 $ 500,245 $ — $ 8,619 $ 494,278 $ — Non-residential real estate other 9,363 1,130,045 — 8,608 1,102,152 — Residential real estate permanent mortgage 8,337 321,481 — 7,543 325,058 — Residential real estate all other 12,453 687,420 — 10,803 665,886 — Commercial and financial: Non-consumer non-real estate 33,780 945,147 — 22,983 961,779 — Consumer non-real estate 2,596 261,851 — 2,416 266,453 — Other loans 2,216 160,655 — 2,323 160,293 — Acquired loans — 172,940 14,740 — 177,871 14,983 Total $ 80,588 $ 4,179,784 $ 14,740 $ 63,295 $ 4,153,770 $ 14,983
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: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Other real estate owned $ 344 $ 260 Repossessed assets 404 220 Total $ 748 $ 480

Intangible Assets (Tables)

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	The following is a summary of intangible assets: Gross Carrying Amount Accumulated Amortization Net Carrying Amount (Dollars in thousands) As of March 31, 2016 Core deposit intangibles $ 18,659 $ (6,402 ) $ 12,257 Customer relationship intangibles 5,699 (3,151 ) 2,548 Mortgage servicing intangibles 525 (237 ) 288 Total $ 24,883 $ (9,790 ) $ 15,093 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
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) Three month ended March 31, 2016 Balance at beginning and end of period $ 8,078 $ 40,050 $ 5,464 $ 450 $ 54,042

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Activity Under Stock Option Plan	The following table is a summary of the activity under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan: Wgtd. Avg. Wgtd. Avg. Remaining Aggregate Exercise Contractual Intrinsic Options Price Term Value (Dollars in thousands, except option data) Three Months Ended March 31, 2016 Outstanding at December 31, 2015 1,018,149 $ 40.69 Options granted 15,000 55.15 Options exercised (29,600 ) 29.56 Options canceled, forfeited, or expired (5,000 ) 41.02 Outstanding at March 31, 2016 998,549 41.24 8.83 Yrs $ 15,767 Exercisable at March 31, 2016 486,874 33.47 5.55 Yrs $ 11,471
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: Three Months Ended March 31, 2016 2015 (Dollars in thousands except per share data) Weighted average grant-date fair value per share of options granted $ 11.47 $ 11.00 Total intrinsic value of options exercised 779 237 Cash received from options exercised 875 244 Tax benefit realized from options exercised 301 92
Stock-based Employee Compensation Expense	The following table is a summary of the Company’s recorded stock-based compensation expense: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Stock-based compensation expense $ 451 $ 464 Tax benefit 174 180 Stock-based compensation expense, net of tax $ 277 $ 284
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: March 31, 2016 (Dollars in thousands) Unearned stock-based compensation expense $ 3,834
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 during the periods presented: Three Months Ended March 31, 2016 2015 Risk-free interest rate 1.91 to 2.02% 1.83 to 1.96% Dividend yield 2.00% 2.00% Stock price volatility 20.41 to 20.64% 18.23 to 18.50% Expected term 10 Yrs 10 Yrs
Summary of Accumulated Stock Units	A summary of the accumulated stock units is as follows: March 31, December 31, 2016 2015 Accumulated stock units 67,558 66,376 Average price $ 40.17 $ 39.64

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Summary of Shares Repurchased Under Stock Purchase Program	The following table is a summary of the shares under the program: Three Months Ended March 31, 2016 2015 Number of shares repurchased 100,000 — Average price of shares repurchased $ 55.23 — Shares remaining to be repurchased 66,276 194,723
Required Capital Amounts and Company's Respective Ratios	The actual and required capital amounts and ratios are shown in the following table: Required To Be Well For Capital With Capitalized Under Adequacy Capital Conservation Prompt Corrective Actual Purposes Buffer Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of March 31, 2016: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 673,104 14.40% $ 373,849 8.00% $ 403,056 8.625% N/A N/A BancFirst 616,209 13.20% 373,346 8.00% 402,513 8.625% $ 466,682 10.00% Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 597,533 12.79% $ 210,290 4.50% $ 239,497 5.125% N/A N/A BancFirst 551,638 11.82% 210,007 4.50% 239,174 5.125% $ 303,343 6.50% Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 628,533 13.45% $ 280,387 6.00% $ 309,594 6.625% N/A N/A BancFirst 571,638 12.25% 280,009 6.00% 309,177 6.625% $ 373,346 8.00% Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 628,533 9.51% $ 264,328 4.00% N/A N/A N/A N/A BancFirst 571,638 8.68% 263,405 4.00% N/A N/A $ 329,256 5.00%

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Basic and Diluted Net Income Per Common Share Based on Weighted-average Shares Outstanding	Basic and diluted net income per common share based on weighted-average shares outstanding are calculated as follows: Income (Numerator) Shares (Denominator) Per Share Amount (Dollars in thousands, except per share data) Three Months Ended March 31, 2016 Basic Income available to common stockholders $ 16,579 15,534,416 $ 1.07 Dilutive effect of stock options — 281,955 Diluted Income available to common stockholders plus assumed exercises of stock options $ 16,579 15,816,371 $ 1.05 Three Months Ended March 31, 2015 Basic Income available to common stockholders $ 16,259 15,507,346 $ 1.05 Dilutive effect of stock options — 331,202 Diluted Income available to common stockholders plus assumed exercises of stock options $ 16,259 15,838,548 $ 1.03
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 period because the options’ exercise prices were greater than the average market price of the common shares: Shares Average Exercise Three Months Ended March 31, 2016 236,451 $ 58.59 Three Months Ended March 31, 2015 128,667 57.68

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities Measured on Recurring Basis	The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of the periods presented, 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) March 31, 2016 Securities available for sale: U.S. Treasury $ 280,715 $ — $ — $ 280,715 U.S. federal agencies — 128,854 — 128,854 Mortgage-backed securities — 6,493 14,816 21,309 States and political subdivisions — 49,292 — 49,292 Other securities — 3,432 6,005 9,437 Derivative assets — 1,210 — 1,210 Derivative liabilities — 605 — 605 Loans held for sale — 7,626 — 7,626 December 31, 2015 Securities available for sale: U.S. Treasury $ 329,696 $ — $ — $ 329,696 U.S. federal agencies — 131,896 — 131,896 Mortgage-backed securities — 7,039 14,816 21,855 States and political subdivisions — 50,920 — 50,920 Other securities — 3,485 6,308 9,793 Derivative assets — 1,946 — 1,946 Derivative liabilities — 989 — 989 Loans held for sale — 13,725 — 13,725
Changes in Level 3 Assets Measured at Estimated Fair Value on Recurring Basis	The changes in Level 3 assets measured at estimated fair value on a recurring basis during the periods presented were as follows: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Balance at the beginning of the year $ 21,124 $ 28,459 Purchases, issuances and settlements (4 ) (744 ) Sales (299 ) (1,729 ) Gains included in earnings 100 1,729 Total unrealized (losses) gains (100 ) (589 ) Balance at the end of the period $ 20,821 $ 27,126
Assets Measured at Fair Value on Nonrecurring Basis	The following table summarizes assets measured at fair value on a nonrecurring basis and the related losses recognized during the period: Total Fair Value Level 3 Losses (Dollars in thousands) As of and for the Year-to-date Period Ended March 31, 2016 Impaired loans (less specific allowance) $ 28,653 $ — Foreclosed assets 281 2 Other real estate owned 3,963 — 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
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: March 31, December 31, 2016 2015 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,668,325 $ 1,668,325 $ 1,598,177 $ 1,598,177 Securities held for investment 7,879 7,934 8,289 8,350 Level 3 inputs: Securities held for investment 500 500 500 500 Loans, net of allowance for loan losses 4,230,541 4,286,603 4,190,382 4,222,153 FINANCIAL LIABILITIES Level 2 inputs: Deposits 6,010,872 6,061,676 5,973,538 6,028,012 Short-term borrowings 1,300 1,300 500 500 Junior subordinated debentures 31,959 34,886 31,959 33,793 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,634 1,681 Letters of credit 443 464

Derivative Financial Instrume28

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Notional Amounts and Estimated Fair Values of Outstanding Derivative Positions	The Company utilizes dealer quotations and observable market data inputs to substantiate internal valuation models. The notional amounts and estimated fair values of oil and gas derivative positions outstanding are presented in the following table: March 31, 2016 December 31, 2015 Oil and Natural Gas Swaps and Options Notional Units Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value (Notional amounts and dollars in thousands) Oil Derivative assets Barrels 98 $ 107 86 $ 604 Derivative liabilities Barrels (98 ) (5 ) (86 ) (378 ) Natural Gas Derivative assets MMBTUs 3,230 1,103 3,920 1,342 Derivative liabilities MMBTUs (3,230 ) (600 ) (3,920 ) (611 ) Total Fair Value Included in Derivative assets Other assets 1,210 1,946 Derivative liabilities Other liabilities (605 ) (989 )
Recognized Derivative Income Included in Other Noninterest Income	The following table is a summary of the Company’s recognized income related to the activity, which was included in other noninterest income: Three Months Ended March 31, 2016 2015 (Dollars in thousands) Derivative income $ 5 $ 155
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: March 31, 2016 December 31, 2015 (Dollars in Credit exposure $ — $ 37

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Results of Operations and Selected Financial Information	The results of operations and selected financial information for the four business units are as follows: Metropolitan Banks Community Banks Other Financial Services Executive, Operations & Support Eliminations Consolidated (Dollars in thousands) Three Months Ended March 31, 2016 Net interest income (expense) $ 15,843 $ 33,122 $ 1,416 $ (405 ) $ — $ 49,976 Noninterest income 3,788 13,596 7,479 17,678 (16,924 ) 25,617 Income before taxes 9,348 19,094 3,114 10,500 (16,857 ) 25,199 Three Months Ended March 31, 2015 Net interest income (expense) $ 15,400 $ 29,055 $ 1,618 $ (447 ) $ — $ 45,626 Noninterest income 3,457 12,326 8,727 17,292 (16,506 ) 25,296 Income before taxes 9,889 16,407 5,007 9,804 (16,442 ) 24,665 Total Assets: March 31, 2016 $ 2,307,503 $ 4,401,449 $ 127,748 $ 628,843 $ (724,605 ) $ 6,740,938 December 31, 2015 2,277,870 4,379,205 128,697 624,428 (717,371 ) 6,692,829

Recent Developments Including M

Recent Developments Including Mergers and Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Oct. 08, 2015
Business Combination Separately Recognized Transactions [Line Items]
Goodwill	$ 54,042	$ 54,042
Gains on sale of other real estate owned	$ 1,200
Bank of Commerce [Member]
Business Combination Separately Recognized Transactions [Line Items]
Total assets acquired			$ 196,000
Loans			147,000
Deposits			175,000
Equity capital			$ 22,000
Percentage of voting interests acquired			100.00%
Intangibles assets, net			$ 7,100
Goodwill			$ 9,400

Securities - Summary of Securit

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Marketable Securities [Abstract]
Held for investment, at cost (fair value: $8,434 and $8,850, respectively)	$ 8,379	$ 8,789
Available for sale, at fair value	489,607	544,160
Total	$ 497,986	$ 552,949

Securities - Summary of Secur32

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Parenthetical) (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Marketable Securities [Abstract]
Held for investment at fair value	$ 8,434	$ 8,850

Securities - Summary of Amortiz

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 8,379	$ 8,789
Gross Unrealized Gains	55	61
Estimated Fair Value	8,434	8,850
Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	323	347
Gross Unrealized Gains	25	25
Estimated Fair Value	348	372
States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	7,556	7,942
Gross Unrealized Gains	30	36
Estimated Fair Value	7,586	7,978
Other Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	500	500
Estimated Fair Value	$ 500	$ 500

Securities - Summary of Amort34

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 486,253	$ 541,670
Gross Unrealized Gains	4,247	3,424
Gross Unrealized Losses	(893)	(934)
Estimated Fair Value	489,607	544,160
U.S. Treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	279,020	328,965
Gross Unrealized Gains	1,695	776
Gross Unrealized Losses		(45)
Estimated Fair Value	280,715	329,696
U.S. Federal Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	128,391	131,522
Gross Unrealized Gains	539	527
Gross Unrealized Losses	(76)	(153)
Estimated Fair Value	128,854	131,896
Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,444	21,973
Gross Unrealized Gains	415	425
Gross Unrealized Losses	(550)	(543)
Estimated Fair Value	21,309	21,855
States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	47,904	49,521
Gross Unrealized Gains	1,473	1,447
Gross Unrealized Losses	(85)	(48)
Estimated Fair Value	49,292	50,920
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	9,494	9,689
Gross Unrealized Gains	125	249
Gross Unrealized Losses	(182)	(145)
Estimated Fair Value	$ 9,437	$ 9,793

Securities - Additional Informa

Securities - Additional Information (Detail) $ in Millions	1 Months Ended
	Jan. 31, 2015USD ($)
Investments Debt And Equity Securities [Abstract]
Pretax gain on sale of investments	$ 1.7

Securities - Maturity of Securi

Securities - Maturity of Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Held for Investment, Contractual maturity of debt securities, Amortized Cost
Amortized cost, Within one year	$ 4,983	$ 5,168
Amortized cost, After one year but within five years	2,594	2,800
Amortized cost, After five years but within ten years	778	795
Amortized cost, After ten years	24	26
Amortized Cost	8,379	8,789
Available for sale, Contractual maturity of debt securities, Amortized Cost
Amortized Cost, Within one year	224,616	272,820
Amortized Cost, After one year but within five years	175,071	178,617
Amortized Cost, After five years but within ten years	7,794	8,483
Amortized Cost, After ten years	72,746	75,522
Total debt securities	480,227	535,442
Amortized Cost, Equity securities	6,026	6,228
Amortized Cost	486,253	541,670
Held for Investment, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	4,990	5,174
Estimated Fair Value, After one year but within five years	2,617	2,829
Estimated Fair Value, After five years but within ten years	802	319
Estimated Fair Value, After ten years	25	528
Estimated Fair Value	8,434	8,850
Available for sale, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	224,814	272,779
Estimated Fair Value, After one year but within five years	177,377	180,145
Estimated Fair Value, After five years but within ten years	8,359	9,075
Estimated Fair Value, After ten years	73,052	75,853
Total debt securities	483,602	537,852
Estimated Fair Value, Equity securities	6,005	6,308
Estimated Fair Value, Total	$ 489,607	$ 544,160

Securities - Company's Book Val

Securities - Company's Book Value of Pledged Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Pledged Financial Instruments Not Separately Reported Securities Pledged By Type Of Security [Abstract]
Book value of pledged securities	$ 458,893	$ 493,540

Loans and Allowance for Loan 38

Loans and Allowance for Loan Losses - Schedule of Loans Outstanding by Category (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 4,275,112	$ 4,232,048
Percent	100.00%	100.00%
Taxable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 17,628	$ 17,605
Percent	0.41%	0.42%
Tax-exempt [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 36,177	$ 33,575
Percent	0.85%	0.79%
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 790,156	$ 795,803
Percent	18.48%	18.80%
Oil & Gas Production And Equipment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 86,524	$ 87,304
Percent	2.02%	2.06%
Agriculture [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 149,442	$ 150,620
Percent	3.50%	3.56%
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 401,330	$ 403,664
Percent	9.39%	9.54%
Farmland [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 189,934	$ 184,707
Percent	4.44%	4.36%
One to Four Family Residences [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 825,357	$ 821,251
Percent	19.31%	19.41%
Multifamily Residential Properties [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 62,189	$ 65,477
Percent	1.45%	1.55%
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 1,406,204	$ 1,356,430
Percent	32.89%	32.05%
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 276,463	$ 283,636
Percent	6.47%	6.70%
Other (Not Classified Above) [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 33,708	$ 31,976
Percent	0.79%	0.76%

Loans and Allowance for Loan 39

Loans and Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016USD ($)SecurityLoan	Mar. 31, 2015USD ($)
Receivables [Abstract]
Percentage of loans secured by real estate	65.00%
Interest income recognized | $	$ 513,000	$ 310,000
Troubled debt restructuring principal deferral | SecurityLoan	1

Loans and Allowance for Loan 40

Loans and Allowance for Loan Losses - Summary of Nonperforming and Restructured Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Summary Of Nonperforming And Restructured Assets [Abstract]
Past due 90 days or more and still accruing	$ 1,099	$ 1,841
Nonaccrual	31,040	30,096
Restructured	533	15,143
Total nonperforming and restructured loans	32,672	47,080
Other real estate owned and repossessed assets	4,245	8,214
Total nonperforming and restructured assets	$ 36,917	$ 55,294

Loans and Allowance for Loan 41

Loans and Allowance for Loan Losses - Summary of Amounts Included in Nonaccrual Loans Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	$ 31,040	$ 30,096
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	372	261
Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	3,952	3,957
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	800	656
Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	4,548	1,833
Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	8,283	10,159
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	301	312
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	9,343	9,381
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	$ 3,441	$ 3,537

Loans and Allowance for Loan 42

Loans and Allowance for Loan Losses - Age Analysis of Past Due Loans Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 34,640	$ 24,673
Current Loans	4,240,472	4,207,375
Total Loans	4,275,112	4,232,048
Accruing Loans 90 Days or More Past Due	1,099	1,841
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	20,383	16,404
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,560	2,831
90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	11,697	5,438
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,401	803
Current Loans	510,687	502,094
Total Loans	512,088	502,897
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	1,130	441
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	17	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	254	183
Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	3,848	1,825
Current Loans	1,135,560	1,108,935
Total Loans	1,139,408	1,110,760
Accruing Loans 90 Days or More Past Due	238	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	3,563	1,149
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
Non-residential Real Estate Other [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	285	568
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,711	4,124
Current Loans	325,107	328,477
Total Loans	329,818	332,601
Accruing Loans 90 Days or More Past Due	445	493
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	3,076	2,840
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	632	636
Residential Real Estate Permanent Mortgage [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,003	648
Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	6,766	4,275
Current Loans	693,107	672,414
Total Loans	699,873	676,689
Accruing Loans 90 Days or More Past Due	113	193
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	5,652	2,842
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	339	609
Residential Real Estate All Other [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	775	824
Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	3,442	2,626
Current Loans	975,485	982,136
Total Loans	978,927	984,762
Accruing Loans 90 Days or More Past Due	92	152
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	2,825	2,278
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	130	161
Non-consumer Non-real Estate [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	487	187
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,882	3,358
Current Loans	261,565	265,511
Total Loans	264,447	268,869
Accruing Loans 90 Days or More Past Due	168	278
Consumer Non-real Estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,862	2,237
Consumer Non-real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	676	772
Consumer Non-real Estate [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	344	349
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	9,304	5,621
Current Loans	153,567	156,995
Total Loans	162,871	162,616
Accruing Loans 90 Days or More Past Due	12	132
Other Loans [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,023	3,565
Other Loans [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	347	295
Other Loans [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	7,934	1,761
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,286	2,041
Current Loans	185,394	190,813
Total Loans	187,680	192,854
Accruing Loans 90 Days or More Past Due	31	72
Acquired Loans [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,252	1,052
Acquired Loans [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	419	71
Acquired Loans [Member] | 90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 615	$ 918

Loans and Allowance for Loan 43

Loans and Allowance for Loan Losses - Impaired Loans Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 43,816	$ 57,126
Recorded Investment with Allowance	32,889	47,667
Related Allowance	4,236	3,268
Average Recorded Investment	43,402	50,521
Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	615	507
Recorded Investment with Allowance	487	383
Related Allowance	15	14
Average Recorded Investment	418	446
Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	6,207	21,068
Recorded Investment with Allowance	4,190	19,052
Related Allowance	157	357
Average Recorded Investment	15,123	19,655
Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,498	1,401
Recorded Investment with Allowance	1,305	1,209
Related Allowance	86	81
Average Recorded Investment	1,276	1,125
Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	5,101	2,498
Recorded Investment with Allowance	4,823	2,235
Related Allowance	1,382	242
Average Recorded Investment	2,781	1,958
Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	12,762	13,897
Recorded Investment with Allowance	8,375	10,312
Related Allowance	2,017	2,062
Average Recorded Investment	9,190	11,786
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	652	738
Recorded Investment with Allowance	609	715
Related Allowance	120	181
Average Recorded Investment	745	652
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	10,705	10,722
Recorded Investment with Allowance	9,355	9,513
Related Allowance	459	331
Average Recorded Investment	9,892	10,335
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	6,276	6,295
Recorded Investment with Allowance	3,745	4,248
Average Recorded Investment	$ 3,977	$ 4,564

Loans and Allowance for Loan 44

Loans and Allowance for Loan Losses - Internal Loan Grading by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 4,275,112	$ 4,232,048
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	512,088	502,897
Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,139,408	1,110,760
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	329,818	332,601
Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	699,873	676,689
Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	978,927	984,762
Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	264,447	268,869
Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	162,871	162,616
Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	187,680	192,854
Grade 1 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,623,264	3,604,903
Grade 1 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	423,003	417,529
Grade 1 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	966,113	945,993
Grade 1 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	290,540	295,265
Grade 1 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	574,683	554,007
Grade 1 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	809,004	821,394
Grade 1 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	247,419	251,994
Grade 1 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	153,486	153,416
Grade 1 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	159,016	165,305
Grade 2 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	554,967	547,814
Grade 2 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	77,243	76,749
Grade 2 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	163,932	156,159
Grade 2 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	30,941	29,793
Grade 2 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	112,736	111,879
Grade 2 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	136,143	140,384
Grade 2 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	14,419	14,433
Grade 2 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	5,629	5,851
Grade 2 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	13,924	12,566
Grade 3 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	71,480	54,695
Grade 3 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	11,470	8,304
Grade 3 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	5,379	4,580
Grade 3 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	7,043	6,315
Grade 3 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	7,649	9,109
Grade 3 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	25,513	12,687
Grade 3 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,099	1,779
Grade 3 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,336	872
Grade 3 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	10,991	11,049
Grade 4 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	25,326	24,559
Grade 4 [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	372	315
Grade 4 [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,984	4,028
Grade 4 [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,294	1,228
Grade 4 [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	4,805	1,694
Grade 4 [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	8,267	10,297
Grade 4 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	510	662
Grade 4 [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,420	2,477
Grade 4 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,674	3,858
Grade 5 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	75	77
Grade 5 [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans		1
Grade 5 [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 75	$ 76

Loans and Allowance for Loan 45

Loans and Allowance for Loan Losses - Activity in All by Class of Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 41,666	$ 40,889
Charge- offs	(1,280)	(762)
Recoveries	82	96
Net charge- offs	(1,198)	(666)
Provisions charged to operations	4,103	1,334
Balance at end of period	44,571	41,557
Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	4,661	4,406
Charge- offs	(1)	(1)
Recoveries		1
Net charge- offs	(1)
Provisions charged to operations	172	55
Balance at end of period	4,832	4,461
Non-residential Real Estate Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	9,921	9,616
Charge- offs	(1)
Recoveries	1
Provisions charged to operations	290	282
Balance at end of period	10,211	9,898
Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	3,148	2,948
Charge- offs	(50)	(40)
Recoveries	17	9
Net charge- offs	(33)	(31)
Provisions charged to operations	49	67
Balance at end of period	3,164	2,984
Residential Real Estate All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	6,725	6,269
Charge- offs	(67)	(68)
Recoveries	4	5
Net charge- offs	(63)	(63)
Provisions charged to operations	1,327	372
Balance at end of period	7,989	6,578
Non-consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	11,754	12,771
Charge- offs	(803)	(153)
Recoveries	11	31
Net charge- offs	(792)	(122)
Provisions charged to operations	1,851	419
Balance at end of period	12,813	13,068
Consumer Non-real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	2,642	2,404
Charge- offs	(221)	(127)
Recoveries	38	15
Net charge- offs	(183)	(112)
Provisions charged to operations	94	35
Balance at end of period	2,553	2,327
Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	2,648	2,359
Charge- offs	(133)	(213)
Recoveries	6	9
Net charge- offs	(127)	(204)
Provisions charged to operations	269	86
Balance at end of period	2,790	2,241
Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	167	116
Charge- offs	(4)	(160)
Recoveries	5	26
Net charge- offs	1	(134)
Provisions charged to operations	51	$ 18
Balance at end of period	$ 219

Loans and Allowance for Loan 46

Loans and Allowance for Loan Losses - Allowance for Loan Losses Outstanding by Impairment Methodology (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 8,507	$ 5,985
Collectively evaluated for impairment	36,064	35,681
Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	444	323
Collectively evaluated for impairment	4,388	4,338
Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	351	323
Collectively evaluated for impairment	9,860	9,598
Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	438	399
Collectively evaluated for impairment	2,726	2,749
Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	1,926	839
Collectively evaluated for impairment	6,063	5,886
Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	4,539	3,365
Collectively evaluated for impairment	8,274	8,389
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	396	445
Collectively evaluated for impairment	2,157	2,197
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	413	291
Collectively evaluated for impairment	2,377	2,357
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collectively evaluated for impairment	$ 219	$ 167

Loans and Allowance for Loan 47

Loans and Allowance for Loan Losses - Loans Outstanding by Impairment Methodology (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 80,588	$ 63,295
Collectively evaluated for impairment	4,179,784	4,153,770
Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	14,740	14,983
Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	11,843	8,619
Collectively evaluated for impairment	500,245	494,278
Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	9,363	8,608
Collectively evaluated for impairment	1,130,045	1,102,152
Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	8,337	7,543
Collectively evaluated for impairment	321,481	325,058
Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	12,453	10,803
Collectively evaluated for impairment	687,420	665,886
Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	33,780	22,983
Collectively evaluated for impairment	945,147	961,779
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,596	2,416
Collectively evaluated for impairment	261,851	266,453
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,216	2,323
Collectively evaluated for impairment	160,655	160,293
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collectively evaluated for impairment	172,940	177,871
Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	$ 14,740	$ 14,983

Loans and Allowance for Loan 48

Loans and Allowance for Loan Losses - Transfers from Loans to Other Real Estate Owned and Repossessed Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Financing Receivable Allowance For Credit Loss Additional Information Transfer From Loans To Other Real Estate Owned And Repossessed Assets [Abstract]
Other real estate owned	$ 344	$ 260
Repossessed assets	404	220
Total	$ 748	$ 480

Intangible Assets - Summary of

Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 24,883	$ 26,570
Accumulated Amortization	(9,790)	(10,875)
Net Carrying Amount	15,093	15,695
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	18,659	20,333
Accumulated Amortization	(6,402)	(7,586)
Net Carrying Amount	12,257	12,747
Customer Relationship Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,699	5,699
Accumulated Amortization	(3,151)	(3,061)
Net Carrying Amount	2,548	2,638
Mortgage Servicing Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	525	538
Accumulated Amortization	(237)	(228)
Net Carrying Amount	$ 288	$ 310

Intangible Assets - Summary o50

Intangible Assets - Summary of Goodwill by Business Segment (Detail) $ in Thousands	Mar. 31, 2016USD ($)
Goodwill [Line Items]
Balance at December 31, 2015	$ 54,042
Balance at March 31, 2016	54,042
Metropolitan Banks [Member]
Goodwill [Line Items]
Balance at December 31, 2015	8,078
Balance at March 31, 2016	8,078
Community Banks [Member]
Goodwill [Line Items]
Balance at December 31, 2015	40,050
Balance at March 31, 2016	40,050
Other Financial Services [Member]
Goodwill [Line Items]
Balance at December 31, 2015	5,464
Balance at March 31, 2016	5,464
Executive, Operations & Support [Member]
Goodwill [Line Items]
Balance at December 31, 2015	450
Balance at March 31, 2016	$ 450

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - shares	3 Months Ended
	Mar. 31, 2016	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
Vesting period in years, start	4 years
Share based compensation options exercisable period	2,023
Options vest and exercisable Description	The options 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	10,000
Option exercisable rate	25.00%
Option exercisable period	1 year
Options expire period	15 years
Share based compensation options exercisable period	2,020
Options vest and exercisable Description	The options are exercisable beginning one year from the date of grant at the rate of 25% per year for four years
Vesting period in years	4 years
Number of options granted for non-employee director	10,000
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	758

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Activity Under Stock Option Plan (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding at beginning period - Options | shares	1,018,149
Options granted | shares	15,000
Options exercised | shares	(29,600)
Options canceled, forfeited or expired - Options | shares	(5,000)
Outstanding at ending period - Options | shares	998,549
Exercisable at ending period - Options | shares	486,874
Outstanding at beginning period - Wgtd. Avg. Exercise Price | $ / shares	$ 40.69
Options granted - Wgtd. Avg. Exercise Price | $ / shares	55.15
Options exercised - Wgtd. Avg. Exercise Price | $ / shares	29.56
Options cancelled, forfeited, or expired - Wgtd. Avg. Exercise Price | $ / shares	41.02
Outstanding at ending period - Wgtd. Avg. Exercise Price | $ / shares	41.24
Exercisable at ending period - Wgtd. Avg. Exercise Price | $ / shares	$ 33.47
Outstanding at ending period - Wgtd. Avg. Remaining Contractual Term, years	8 years 9 months 29 days
Exercisable at ending period - Wgtd. Avg. Remaining Contractual Term, years	5 years 6 months 18 days
Outstanding at ending period - Aggregate Intrinsic Value | $	$ 15,767
Exercisable at ending period - Aggregate Intrinsic Value | $	$ 11,471

Stock-Based Compensation - Opti

Stock-Based Compensation - Options Granted and Options Exercised Under Stock Option Plan (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award Options Additional Disclosures [Abstract]
Weighted average grant-date fair value per share of options granted	$ 11.47	$ 11
Total intrinsic value of options exercised	$ 779	$ 237
Cash received from options exercised	875	244
Tax benefit realized from options exercised	$ 301	$ 92

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Employee Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Labor And Related Expense [Abstract]
Stock-based compensation expense	$ 451	$ 464
Tax benefit	174	180
Stock-based compensation expense, net of tax	$ 277	$ 284

Stock-Based Compensation - Unea

Stock-Based Compensation - Unearned Stock-based Compensation Expense (Detail) $ in Thousands	Mar. 31, 2016USD ($)
Remaining Fair Value Of Stock Options [Abstract]
Unearned stock-based compensation expense	$ 3,834

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used for Computing Stock-Based Compensation Expense (Detail)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Risk-free interest rate, minimum	1.91%	1.83%
Risk-free interest rate, maximum	2.02%	1.96%
Dividend yield	2.00%	2.00%
Stock price volatility, minimum	20.41%	18.23%
Stock price volatility, maximum	20.64%	18.50%
Expected term	10 years	10 years

Stock - Based Compensation - Su

Stock - Based Compensation - Summary of Accumulated Stock Units (Detail) - $ / shares	Mar. 31, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Accumulated stock units	67,558	66,376
Average price	$ 40.17	$ 39.64

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Shares Repurchased Under Stock Purchase Program (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Summary Of Shares Repurchased Under Stock Purchase Program [Abstract]
Number of shares repurchased	100,000
Average price of shares repurchased	$ 55.23
Shares remaining to be repurchased	66,276	194,723

Stockholders' Equity - Required

Stockholders' Equity - Required Capital Amounts and Company's Respective Ratios (Detail) $ in Thousands	Mar. 31, 2016USD ($)
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 673,104
Total Capital To Risk Weighted Assets Actual Ratio	14.40%
Capital Required For Capital Adequacy Amount	$ 373,849
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%
Capital With Capital Conservation Buffer Amount	$ 403,056
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	8.625%
Common Equity Tier 1 Risk Based Capital Amount	$ 597,533
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.79%
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 210,290
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 With Capital Conservation Buffer Amount	$ 239,497
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	5.125%
Tier 1 Risk Based Capital Amount	$ 628,533
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	13.45%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 280,387
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	6.00%
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 309,594
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	6.625%
Tier 1 Capital Amount	$ 628,533
Tier 1 Capital To Average Assets Ratio	9.51%
Tier 1 Capital Required For Capital Adequacy Amount	$ 264,328
Tier 1 Capital Required For Capital Adequacy To Average Assets Ratio	4.00%
BancFirst [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 616,209
Total Capital To Risk Weighted Assets Actual Ratio	13.20%
Capital Required For Capital Adequacy Amount	$ 373,346
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%
Capital With Capital Conservation Buffer Amount	$ 402,513
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	8.625%
Capital Required To Be Well Capitalized Amount	$ 466,682
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	10.00%
Common Equity Tier 1 Risk Based Capital Amount	$ 551,638
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	$ 210,007
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 With Capital Conservation Buffer Amount	$ 239,174
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	5.125%
Common Equity Tier 1 Risk Based Capital Required To Be well Capitalized Amount	$ 303,343
Common Equity Tier 1 Risk Based Capital Required To Be well Capitalized Amount	6.50%
Tier 1 Risk Based Capital Amount	$ 571,638
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.25%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 280,009
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	6.00%
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 309,177
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	6.625%
Tier 1 Risk Based Capital Required To Be well Capitalized Amount	$ 373,346
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	8.00%
Tier 1 Capital Amount	$ 571,638
Tier 1 Capital To Average Assets Ratio	8.68%
Tier 1 Capital Required For Capital Adequacy Amount	$ 263,405
Tier 1 Capital Required For Capital Adequacy To Average Assets Ratio	4.00%
Tier 1 Capital Required To Be Well Capitalized Amount	$ 329,256
Tier 1 Capital Required To Be Well Capitalized To Average assets Ratio	5.00%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016USD ($)
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

Net Income Per Common Share - B

Net Income Per Common Share - Basic and Diluted Net Income Per Common Share Based on Weighted-average Shares Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share Reconciliation [Abstract]
Income available to common stockholders	$ 16,579	$ 16,259
Income available to common stockholders plus assumed exercises of stock options	$ 16,579	$ 16,259
Income available to common stockholders - Shares	15,534,416	15,507,346
Dilutive effect of stock options - Shares	281,955	331,202
Income available to common stockholders plus assumed exercises of stock options - Shares	15,816,371	15,838,548
Income available to common stockholders - Per Share Amount	$ 1.07	$ 1.05
Income available to common stockholders plus assumed exercises of stock options - Per Share Amount	$ 1.05	$ 1.03

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	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Abstract]
Shares	236,451	128,667
Average Exercise Price	$ 58.59	$ 57.68

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Debt Instrument Fair Value Disclosure [Abstract]
Days from origination after which mortgage loan are sold	30 days
Transfer of securities between levels of fair value hierarchy	$ 0	$ 0
Amount of non-financial assets (liabilities)	0		$ 0
Non-financial assets or liabilities for which no impairment was provided	$ 0		$ 0

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 489,607	$ 544,160
Derivative assets	1,210	1,946
Derivative liabilities	605	989
Loans held for sale	7,626	13,725
Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,210	1,946
Derivative liabilities	605	989
Loans held for sale	7,626	13,725
U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	280,715	329,696
U.S. Treasuries [Member] | Level 1 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	280,715	329,696
U.S. Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	128,854	131,896
U.S. Federal Agencies [Member] | Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	128,854	131,896
Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	21,309	21,855
Mortgage Backed Securities [Member] | Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	6,493	7,039
Mortgage Backed Securities [Member] | Level 3 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	14,816	14,816
States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	49,292	50,920
States and Political Subdivisions [Member] | Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	49,292	50,920
Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	9,437	9,793
Other Securities [Member] | Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	3,432	3,485
Other Securities [Member] | Level 3 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 6,005	$ 6,308

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 Assets Measured at Estimated Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward
Balance at the beginning of the year	$ 21,124	$ 28,459
Purchases, issuances and settlements	(4)	(744)
Sales	(299)	(1,729)
Gains included in earnings	100	1,729
Total unrealized (losses) gains	(100)	(589)
Balance at the end of the period	$ 20,821	$ 27,126

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Impaired Loans (Less Specific Allowance) [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	$ 28,653	$ 44,399
Foreclosed Assets [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Losses	2
Foreclosed Assets [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	281	230
Other Real Estate Owned [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Losses		128
Other Real Estate Owned [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	$ 3,963	$ 7,984

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
FINANCIAL ASSETS
Securities held for investment	$ 8,379	$ 8,789
Loans, net of allowance for loan losses	4,230,541	4,190,382
FINANCIAL LIABILITIES
Deposits	6,010,872	5,973,358
Short-term borrowings	1,300	500
Junior subordinated debentures	31,959	31,959
Carrying Amount [Member] | Level 2 Inputs [Member]
FINANCIAL ASSETS
Cash and cash equivalents	1,668,325	1,598,177
Securities held for investment	7,879	8,289
FINANCIAL LIABILITIES
Deposits	6,010,872	5,973,538
Short-term borrowings	1,300	500
Junior subordinated debentures	31,959	31,959
Carrying Amount [Member] | Level 3 Inputs [Member]
FINANCIAL ASSETS
Securities held for investment	500	500
Loans, net of allowance for loan losses	4,230,541	4,190,382
Fair Value [Member]
OFF-BALANCE SHEET FINANCIAL INSTRUMENTS
Loan commitments	1,634	1,681
Letters of credit	443	464
Fair Value [Member] | Level 2 Inputs [Member]
FINANCIAL ASSETS
Cash and cash equivalents	1,668,325	1,598,177
Securities held for investment	7,934	8,350
FINANCIAL LIABILITIES
Deposits	6,061,676	6,028,012
Short-term borrowings	1,300	500
Junior subordinated debentures	34,886	33,793
Fair Value [Member] | Level 3 Inputs [Member]
FINANCIAL ASSETS
Securities held for investment	500	500
Loans, net of allowance for loan losses	$ 4,286,603	$ 4,222,153

Derivative Financial Instrume68

Derivative Financial Instruments - Notional Amounts and Estimated Fair Values of Outstanding Derivative Positions (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	$ 1,210	$ 1,946
Derivative liabilities, Estimated Fair Value	(605)	(989)
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	1,210	1,946
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Estimated Fair Value	$ (605)	(989)
Oil [Member]
Derivatives, Fair Value [Line Items]
Notional Units	Barrels
Derivative assets, Notional Amount	$ 98	86
Derivative assets, Estimated Fair Value	107	604
Derivative liabilities, Notional Amount	(98)	(86)
Derivative liabilities, Estimated Fair Value	$ (5)	(378)
Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Notional Units	MMBTUs
Derivative assets, Notional Amount	$ 3,230	3,920
Derivative assets, Estimated Fair Value	1,103	1,342
Derivative liabilities, Notional Amount	(3,230)	(3,920)
Derivative liabilities, Estimated Fair Value	$ (600)	$ (611)

Derivative Financial Instrume69

Derivative Financial Instruments - Recognized Derivative Income Included in Other Noninterest Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative Gain Loss On Derivative Net [Abstract]
Derivative income	$ 5	$ 155

Derivative Financial Instrume70

Derivative Financial Instruments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Company’s share of total profit	35.00%

Derivative Financial Instrume71

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

Segment Information - Additiona

Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016Business_Unit
Segment Reporting [Abstract]
Number of principal business units	4

Segment Information - Results o

Segment Information - Results of Operations and Selected Financial Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 49,976	$ 45,626
Noninterest income	25,617	25,296
Income before taxes	25,199	24,665
Total Assets	6,740,938		$ 6,692,829
Operating Segments [Member] | Metropolitan Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	15,843	15,400
Noninterest income	3,788	3,457
Income before taxes	9,348	9,889
Total Assets	2,307,503		2,277,870
Operating Segments [Member] | Community Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	33,122	29,055
Noninterest income	13,596	12,326
Income before taxes	19,094	16,407
Total Assets	4,401,449		4,379,205
Operating Segments [Member] | Other Financial Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	1,416	1,618
Noninterest income	7,479	8,727
Income before taxes	3,114	5,007
Total Assets	127,748		128,697
Operating Segments [Member] | Executive, Operations & Support [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	(405)	(447)
Noninterest income	17,678	17,292
Income before taxes	10,500	9,804
Total Assets	628,843		624,428
Eliminations [Member]
Segment Reporting Information [Line Items]
Noninterest income	(16,924)	(16,506)
Income before taxes	(16,857)	$ (16,442)
Total Assets	$ (724,605)		$ (717,371)