BancFirst (BANF) 10-Q 31 Jul 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 28, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
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		15,916,719

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 183,753	$ 183,921
Interest-bearing deposits with banks	1,533,147	1,666,540
Federal funds sold		700
Securities (fair value: $451,435 and $469,871, respectively)	451,402	469,833
Loans held for sale	9,061	9,318
Loans (net of unearned interest)	4,578,393	4,400,232
Allowance for loan losses	(49,005)	(48,693)
Loans, net of allowance for loan losses	4,529,388	4,351,539
Premises and equipment, net	127,819	126,771
Other real estate owned	3,940	3,526
Intangible assets, net	12,203	13,330
Goodwill	54,042	54,042
Accrued interest receivable and other assets	141,834	139,432
Total assets	7,046,589	7,018,952
Deposits:
Noninterest-bearing	2,551,158	2,526,842
Interest-bearing	3,684,524	3,721,215
Total deposits	6,235,682	6,248,057
Short-term borrowings	1,000	500
Accrued interest payable and other liabilities	29,486	27,342
Junior subordinated debentures	31,959	31,959
Total liabilities	6,298,127	6,307,858
Stockholders' equity:
Common stock, $1.00 par, 40,000,000 shares authorized; shares issued and outstanding: 15,909,219 and 15,810,935, respectively	15,909	15,811
Capital surplus	121,349	117,541
Retained earnings	610,758	577,648
Accumulated other comprehensive income, net of income tax of $(281) and $(59), respectively	446	94
Total stockholders' equity	748,462	711,094
Total liabilities and stockholders' equity	7,046,589	7,018,952
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	Jun. 30, 2017	Dec. 31, 2016
Securities, fair value	$ 451,435	$ 469,871
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	15,909,219	15,810,935
Common stock, shares outstanding	15,909,219	15,810,935
Accumulated other comprehensive income, tax	$ (281)	$ (59)
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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
INTEREST INCOME
Loans, including fees	$ 54,763	$ 51,046	$ 108,398	$ 101,241
Securities:
Taxable	1,906	1,344	3,667	2,671
Tax-exempt	178	243	365	498
Federal funds sold	1		1
Interest-bearing deposits with banks	4,425	1,852	7,865	3,654
Total interest income	61,273	54,485	120,296	108,064
INTEREST EXPENSE
Deposits	4,300	3,092	8,025	6,172
Short-term borrowings	4	2	7	3
Junior subordinated debentures	530	523	1,057	1,045
Total interest expense	4,834	3,617	9,089	7,220
Net interest income	56,439	50,868	111,207	100,844
Provision for loan losses	1,841	2,804	1,913	6,907
Net interest income after provision for loan losses	54,598	48,064	109,294	93,937
NONINTEREST INCOME
Trust revenue	2,894	2,602	5,846	5,067
Service charges on deposits	16,448	15,485	32,226	30,195
Securities transactions (includes accumulated other comprehensive income reclassifications of $(142), $0, $(142) and $100, respectively)	(330)	(65)	(330)	35
Income from sales of loans	816	695	1,448	1,257
Insurance commissions	3,728	3,255	8,291	7,390
Cash management	2,799	2,732	5,553	5,050
(Loss)/gain on sale of other assets	(25)	55	(49)	59
Other	1,653	1,298	3,083	2,621
Total noninterest income	27,983	26,057	56,068	51,674
NONINTEREST EXPENSE
Salaries and employee benefits	31,547	30,008	62,201	59,365
Occupancy, net	2,992	3,071	5,966	5,898
Depreciation	2,392	2,567	4,812	5,097
Amortization of intangible assets	547	580	1,094	1,161
Data processing services	1,097	1,174	2,292	2,389
Net expense/(income) from other real estate owned	202	35	252	(1,106)
Marketing and business promotion	1,559	1,624	3,774	3,479
Deposit insurance	542	855	1,130	1,694
Other	8,075	7,806	17,020	16,034
Total noninterest expense	48,953	47,720	98,541	94,011
Income before taxes	33,628	26,401	66,821	51,600
Income tax expense	10,446	8,908	21,589	17,528
Net income	$ 23,182	$ 17,493	$ 45,232	$ 34,072
NET INCOME PER COMMON SHARE
Basic	$ 1.46	$ 1.12	$ 2.85	$ 2.19
Diluted	$ 1.42	$ 1.10	$ 2.78	$ 2.15
OTHER COMPREHENSIVE INCOME
Unrealized gains on securities, net of tax of $(280), $(345), $(167) and $(719), respectively	$ 443	$ 546	$ 265	$ 1,137
Reclassification adjustment for losses/(gains) included in net income, net of tax of $(55), $0, $(55) and $39, respectively	87		87	(61)
Other comprehensive gains, net of tax of $(335), $(345), $(222) and $(680), respectively	530	546	352	1,076
Comprehensive income	$ 23,712	$ 18,039	$ 45,584	$ 35,148

Consolidated Statements of Com5

Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Securities transactions accumulated other comprehensive income reclassifications	$ (142)	$ 0	$ (142)	$ 100
Unrealized gains on securities, tax	(280)	(345)	(167)	(719)
Reclassification adjustment for losses/(gains) included in net income, tax	(55)	0	(55)	39
Other comprehensive gains, tax	$ (335)	$ (345)	$ (222)	$ (680)

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, 2015		$ 15,597	$ 102,865	$ 535,521	$ 1,527
Shares issued, Value		63	1,867
Shares acquired and canceled, Value		(100)		(5,423)
Tax effect of stock options			43
Stock-based compensation arrangements			901
Net income	$ 34,072			34,072
Dividends on common stock				(11,179)
Net change	1,076				1,076
Balance at end of period at Jun. 30, 2016	676,830	15,560	105,676	552,991	2,603
Balance at beginning of period at Mar. 31, 2016		15,528	103,978	541,098	2,057
Shares issued, Value		32	996
Tax effect of stock options			252
Stock-based compensation arrangements			450
Net income	17,493			17,493
Dividends on common stock				(5,600)
Net change	546				546
Balance at end of period at Jun. 30, 2016	676,830	15,560	105,676	552,991	2,603
Balance at beginning of period at Dec. 31, 2016	711,094	15,811	117,541	577,648	94
Shares issued, Value		98	3,343
Stock-based compensation arrangements			465
Net income	45,232			45,232
Dividends on common stock				(12,122)
Net change	352				352
Balance at end of period at Jun. 30, 2017	748,462	15,909	121,349	610,758	446
Balance at beginning of period at Mar. 31, 2017		15,891	120,435	593,631	(84)
Shares issued, Value		18	671
Stock-based compensation arrangements			243
Net income	23,182			23,182
Dividends on common stock				(6,055)
Net change	530				530
Balance at end of period at Jun. 30, 2017	$ 748,462	$ 15,909	$ 121,349	$ 610,758	$ 446

Consolidated Statements of Sto7

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
RETAINED EARNINGS [Member]
Dividend on common stock	$ 0.38	$ 0.36	$ 0.76	$ 0.72

Consolidated Statements of Cash

Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 45,232	$ 34,072
Adjustments to reconcile to net cash provided by operating activities:
Provision for loan losses	1,913	6,907
Depreciation and amortization	5,906	6,258
Net amortization of securities premiums and discounts	(103)	184
Realized securities losses/(gains)	330	(35)
Gain on sales of loans	(1,448)	(1,257)
Cash receipts from the sale of loans originated for sale	97,146	86,121
Cash disbursements for loans originated for sale	(95,477)	(81,566)
Deferred income tax benefit	(723)	(1,917)
Loss/(gain) on other assets	62	(1,316)
Increase in interest receivable	(1,107)	(1,040)
Increase in interest payable	126	14
Amortization of stock-based compensation arrangements	465	901
Excess tax benefit from stock-based compensation arrangements	(1,784)
Other, net	3,234	(4,867)
Net cash provided by operating activities	53,772	42,459
INVESTING ACTIVITIES
Net decrease in federal funds sold	700
Purchases of held for investment securities	(220)	(215)
Purchases of available for sale securities	(42,006)	(8,553)
Proceeds from maturities, calls and paydowns of held for investment securities	644	690
Proceeds from maturities, calls and paydowns of available for sale securities	60,360	102,677
Proceeds from sales of available for sale securities		300
Net change in loans	(181,851)	(98,555)
Purchases of premises, equipment and computer software	(6,568)	(5,048)
Proceeds from the sale of other real estate owned and other assets	2,088	7,020
Net cash used in investing activities	(166,853)	(1,684)
FINANCING ACTIVITIES
Net change in deposits	(12,375)	(29,376)
Net increase in short-term borrowings	500	3,000
Issuance of common stock, net	3,441	1,973
Common stock acquired		(5,523)
Cash dividends paid	(12,046)	(11,204)
Net cash used in financing activities	(20,480)	(41,130)
Net decrease in cash, due from banks and interest-bearing deposits	(133,561)	(355)
Cash, due from banks and interest-bearing deposits at the beginning of the period	1,850,461	1,598,177
Cash, due from banks and interest-bearing deposits at the end of the period	1,716,900	1,597,822
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	8,963	7,207
Cash paid during the period for income taxes	20,450	17,900
Noncash investing and financing activities:
Unpaid common stock dividends declared	$ 6,045	$ 5,590

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2017
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, 2016. Basis of Presentation The accompanying unaudited interim consolidated financial statements include the accounts of BancFirst Corporation, Council Oak Partners, LLC, BancFirst Insurance Services, Inc., BancFirst Risk and Insurance Company, 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, 2016, 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, 2016, the date of the most recent annual report. 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 Standards Adopted During Current Period: In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2017-08, “Receivables – Nonrefundable Fees and Other Costs (Topic 310-20): Premium Amortization on Purchased Callable Debt Securities.” ASU 2017-08 shortens the amortization period for certain callable debt securities held at a premium. The Company opted for early adoption of ASU 2017-08, as was permitted, on January 1, 2017. ASU 2017-08 did not have a significant impact on the Company’s financial statements and no prior periods were adjusted. In October 2016, the FASB issued ASU No. 2016-17, “Consolidation (Topic 810): Interests Held Through Related Parties That Are Under Common Control.” ASU 2016-17 updates ASU No. 2015-02 to amend the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. ASU 2016-17 was adopted on January 1, 2017 and did not have a significant impact on the Company’s financial statements and no prior periods were adjusted. In March 2016, the FASB issued ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Under ASU 2016-09 all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. ASU 2016-09 also allows entities to make an entity-wide accounting policy election to account for forfeitures when they occur, which the Company has elected to do. 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 was adopted on January 1, 2017 and did not have a significant impact on the Company’s financial statements. In addition, ASU 2016-09 was applied prospectively and no prior periods were adjusted. The excess tax benefit for share-based payment awards that were exercised during the six months ended June 30, 2017 was approximately $1.8 million. 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. ASU 2014-15 was adopted on January 1, 2017. Adoption of ASU 2014-15 did not have a significant effect on the Company’s financial statements. Standards Not Yet Adopted: In May 2017, the FASB issued ASU No. 2017-09, “Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting.” The amendments in this update provide guidance about types of changes to the terms or conditions of share-based payment awards that would require an entity to apply modification accounting under ASC 718. ASU 2017-09 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. Early adoption is permitted with prospective applications. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” ASU 2017-04 removes the second step of goodwill testing. ASU 2017-04 will be effective on January 1, 2020 and is not expected to have a significant impact on the Company’s financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business.” ASU 2017-01 clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of a business. ASU 2017-01 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In October 2016, the FASB issued ASU No. 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” ASU 2016-16 provides guidance stating that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” ASU 2016-15 is intended to reduce the diversity in practice around how certain transactions are classified within the statement of cash flows. ASU 2016-15 will be effective on January 1, 2018. Early adoption is permitted with retrospective applications. The Company is currently evaluating the potential impact of ASU 2016-15 on its financial statements. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. ASU 2016-13 requires enhanced disclosures related to the significant estimates and judgements used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASU 2016-13 amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 will be effective on January 1, 2020. The Company is currently evaluating the potential impact of ASU 2016-13 on its financial statements. In 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 January of 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customer (Topic 606).” ASU 2014-09 implements a comprehensive new revenue recognition standard that will supersede substantially all existing revenue recognition guidance. The new standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in a manner that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, which comprises a significant portion of the Company’s revenue stream. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606).” ASU 2015-14 is an amendment to defer the effective date of ASU 2014-09. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. Adoption of ASU 2014-09 may require the Company to amend how it recognizes certain recurring revenue streams related to trust fees, which are recorded in non-interest expense; however, the Company does not expect the adoption of ASU 2014-09 to have a significant impact on the Company’s financial statements.

Recent Developments, Including

Recent Developments, Including Mergers and Acquisitions	6 Months Ended
	Jun. 30, 2017
Recent Developments Including Mergers And Acquisitions [Abstract]
Recent Developments, Including Mergers and Acquisitions	(2) RECENT DEVELOPMENTS, INCLUDING MERGERS AND ACQUISITIONS Effective June 1, 2017, the Company organized a new captive insurance company named BancFirst Risk and Insurance Company ("the Captive"). The Captive is a wholly-owned subsidiary of BancFirst Corporation and is regulated by the Oklahoma Insurance Department. It insures certain risks of the Company and has entered into reinsurance agreements with a risk-sharing pool.

Securities

Securities	6 Months Ended
	Jun. 30, 2017
Investments Debt And Equity Securities [Abstract]
Securities	(3) SECURITIES The following table summarizes securities held for investment and securities available for sale: June 30, 2017 December 31, 2016 (Dollars in thousands) Held for investment, at cost (fair value: $3,975 and $4,403, respectively) $ 3,942 $ 4,365 Available for sale, at fair value 447,460 465,468 Total $ 451,402 $ 469,833 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 June 30, 2017 (Dollars in thousands) Mortgage backed securities (1) $ 217 $ 12 $ — $ 229 States and political subdivisions 3,225 22 (1 ) 3,246 Other securities 500 — — 500 Total $ 3,942 $ 34 $ (1 ) $ 3,975 December 31, 2016 Mortgage backed securities (1) $ 252 $ 17 $ — $ 269 States and political subdivisions 3,613 25 (4 ) 3,634 Other securities 500 — — 500 Total $ 4,365 $ 42 $ (4 ) $ 4,403 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 June 30, 2017 (Dollars in thousands) U.S. treasuries $ 284,791 $ 867 $ (271 ) $ 285,387 U.S. federal agencies 98,311 397 (310 ) 98,398 Mortgage backed securities (1) 19,052 246 (513 ) 18,785 States and political subdivisions 38,129 865 (59 ) 38,935 Other securities (2) 6,450 189 (684 ) 5,955 Total $ 446,733 $ 2,564 $ (1,837 ) $ 447,460 December 31, 2016 U.S. treasuries $ 268,763 $ 700 $ (920 ) $ 268,543 U.S. federal agencies 129,674 373 (405 ) 129,642 Mortgage backed securities (1) 19,949 290 (567 ) 19,672 States and political subdivisions 40,335 836 (129 ) 41,042 Other securities (2) 6,594 125 (150 ) 6,569 Total $ 465,315 $ 2,324 $ (2,171 ) $ 465,468 (1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies. (2) Primarily consists of equity securities. The maturities of securities held for investment and available for sale are summarized in the following table using contractual maturities. Actual maturities may differ from contractual maturities due to obligations that are called or prepaid. For purposes of the maturity table, mortgage-backed securities, which are not due at a single maturity date, have been presented at their contractual maturity. June 30, 2017 December 31, 2016 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 1,672 $ 1,683 $ 1,561 $ 1,568 After one year but within five years 1,593 1,603 1,937 1,951 After five years but within ten years 667 674 707 723 After ten years 10 15 160 161 Total $ 3,942 $ 3,975 $ 4,365 $ 4,403 Available for Sale Contractual maturity of debt securities: Within one year $ 66,022 $ 66,105 $ 66,542 $ 66,662 After one year but within five years 308,283 308,913 320,150 319,839 After five years but within ten years 5,849 6,184 5,830 6,152 After ten years 60,129 60,303 66,199 66,246 Total debt securities 440,283 441,505 458,721 458,899 Equity securities 6,450 5,955 6,594 6,569 Total $ 446,733 $ 447,460 $ 465,315 $ 465,468 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: June 30, 2017 December 31, 2016 (Dollars Book value of pledged securities $ 394,974 $ 439,692

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 December 31, 2016 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 927,616 20.26 % $ 828,260 18.82 % Oil & gas production and equipment 96,230 2.10 84,228 1.91 Agriculture 135,298 2.96 144,751 3.29 State and political subdivisions: Taxable 81,164 1.77 33,793 0.77 Tax-exempt 48,840 1.07 47,283 1.07 Real estate: Construction 412,367 9.01 420,884 9.57 Farmland 201,535 4.40 197,872 4.50 One to four family residences 859,980 18.78 846,360 19.24 Multifamily residential properties 46,995 1.03 57,806 1.31 Commercial 1,455,612 31.79 1,426,643 32.42 Consumer 280,345 6.12 279,704 6.36 Other (not classified above) 32,411 0.71 32,648 0.74 Total loans $ 4,578,393 100.00 % $ 4,400,232 100.00 % The Company’s commercial and industrial loan category includes a small percentage of loans to companies that provide ancillary services to the oil and gas industry, such as transportation, preparation contractors and equipment manufacturers. The balance of these loans was approximately $70 million at June 30, 2017 and approximately $56 million at December 31, 2016. 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 and related 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, 2016. Nonperforming and Restructured Assets The following is a summary of nonperforming and restructured assets: June 30, December 31, 2017 2016 (Dollars in thousands) Past due 90 days or more and still accruing $ 2,217 $ 1,962 Nonaccrual 19,607 31,798 Restructured 3,561 1,713 Total nonperforming and restructured loans 25,385 35,473 Other real estate owned and repossessed assets 4,211 3,866 Total nonperforming and restructured assets $ 29,596 $ 39,339 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 $886,000 for the six months ended June 30, 2017 and approximately $982,000 for the six months ended June 30, 2016. The Company charges interest on principal balances outstanding on restructured loans during deferral periods. 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. June 30, December 31, 2017 2016 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 641 $ 713 Non-residential real estate other 1,865 5,688 Residential real estate permanent mortgage 886 1,116 Residential real estate all other 4,829 5,089 Commercial and financial: Non-consumer non-real estate 3,542 4,464 Consumer non-real estate 271 265 Other loans 4,928 8,370 Acquired loans 2,645 6,093 Total $ 19,607 $ 31,798 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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 3,991 $ 145 $ 730 $ 4,866 $ 586,223 $ 591,089 $ 229 Non-residential real estate other 1,354 70 267 1,691 1,126,418 1,128,109 29 Residential real estate permanent mortgage 1,504 483 781 2,768 327,963 330,731 482 Residential real estate all other 4,872 294 1,011 6,177 751,940 758,117 287 Commercial and financial: Non-consumer non-real estate 4,133 671 1,771 6,575 1,201,751 1,208,326 564 Consumer non-real estate 1,562 505 554 2,621 281,536 284,157 388 Other loans 555 4,941 4,869 10,365 134,183 144,548 101 Acquired loans 728 113 416 1,257 132,059 133,316 137 Total $ 18,699 $ 7,222 $ 10,399 $ 36,320 $ 4,542,073 $ 4,578,393 $ 2,217 As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 2,255 $ 96 $ 150 $ 2,501 $ 569,130 $ 571,631 $ — Non-residential real estate other 611 16 418 1,045 1,122,351 1,123,396 — Residential real estate permanent mortgage 2,742 649 1,273 4,664 320,749 325,413 513 Residential real estate all other 2,559 531 1,416 4,506 743,723 748,229 369 Commercial and financial: Non-consumer non-real estate 1,269 1,628 741 3,638 1,047,547 1,051,185 608 Consumer non-real estate 2,046 760 419 3,225 280,652 283,877 274 Other loans 5,345 958 7,775 14,078 127,404 141,482 45 Acquired loans 825 310 408 1,543 153,476 155,019 153 Total $ 17,652 $ 4,948 $ 12,600 $ 35,200 $ 4,365,032 $ 4,400,232 $ 1,962 Impaired Loans Loans are considered impaired when, based on current information and events, it is probable the Company will be unable to collect the full amount of scheduled principal and interest payments in accordance with the original contractual terms of the loan agreement. If a loan is impaired, a specific valuation allowance may be allocated, if necessary, so that the loan is reported, net of allowance for loss, at the present value of future cash flows using the loan’s existing rate, or the fair value of collateral if repayment is expected solely from the collateral. The following table presents impaired loans, segregated by class of loans. During the six month period ended June 30, 2017, $2.3 million of interest income was recognized on impaired loans subsequent to their classification as impaired. During previous periods 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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 1,065 $ 958 $ 31 $ 1,060 Non-residential real estate other 1,967 1,894 184 2,057 Residential real estate permanent mortgage 1,623 1,418 104 1,483 Residential real estate all other 5,420 5,195 1,555 5,136 Commercial and financial: Non-consumer non-real estate 13,725 7,257 1,454 6,401 Consumer non-real estate 790 754 117 776 Other loans 6,471 5,030 689 5,523 Acquired loans 4,747 3,020 — 4,967 Total $ 35,808 $ 25,526 $ 4,134 $ 27,403 As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 894 $ 806 $ 101 $ 825 Non-residential real estate other 7,742 5,688 574 5,854 Residential real estate permanent mortgage 1,878 1,683 124 1,612 Residential real estate all other 5,871 5,614 1,538 5,445 Commercial and financial: Non-consumer non-real estate 12,015 6,272 1,457 6,478 Consumer non-real estate 686 650 133 788 Other loans 9,799 8,415 1,870 8,062 Acquired loans 8,780 6,581 — 6,041 Total $ 47,665 $ 35,709 $ 5,797 $ 35,105 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, 2016. 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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 474,155 $ 101,757 $ 14,536 $ 641 $ — $ 591,089 Non-residential real estate other 941,448 169,968 14,759 1,934 — 1,128,109 Residential real estate permanent mortgage 289,912 33,676 5,805 1,338 — 330,731 Residential real estate all other 607,861 134,189 10,918 5,149 — 758,117 Commercial and financial: Non-consumer non-real estate 947,575 234,258 22,652 3,841 — 1,208,326 Consumer non-real estate 263,875 17,473 2,093 716 — 284,157 Other loans 137,753 5,450 1,115 230 — 144,548 Acquired loans 76,955 34,875 18,390 3,096 — 133,316 Total $ 3,739,534 $ 731,646 $ 90,268 $ 16,945 $ — $ 4,578,393 As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 464,504 $ 89,978 $ 16,220 $ 929 $ — $ 571,631 Non-residential real estate other 933,743 169,561 14,404 5,688 — 1,123,396 Residential real estate permanent mortgage 284,893 32,889 5,987 1,644 — 325,413 Residential real estate all other 614,338 119,018 9,382 5,491 — 748,229 Commercial and financial: Non-consumer non-real estate 856,318 170,865 19,101 4,901 — 1,051,185 Consumer non-real estate 263,442 17,154 2,640 641 — 283,877 Other loans 132,254 5,376 1,514 2,338 — 141,482 Acquired loans 92,946 42,668 12,888 6,517 — 155,019 Total $ 3,642,438 $ 647,509 $ 82,136 $ 28,149 $ — $ 4,400,232 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, 2016. 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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 5,562 $ (40 ) $ 3 $ (37 ) $ 160 $ 5,685 Non-residential real estate other 10,788 (25 ) 1 (24 ) (284 ) 10,480 Residential real estate permanent mortgage 3,130 (36 ) 10 (26 ) 44 3,148 Residential real estate all other 8,659 (16 ) 6 (10 ) 263 8,912 Commercial and financial: Non-consumer non-real estate 12,810 (471 ) 61 (410 ) 1,243 13,643 Consumer non-real estate 2,725 (234 ) 32 (202 ) 183 2,706 Other loans 2,958 (56 ) 1 (55 ) 103 3,006 Acquired loans 1,289 (1 ) 8 7 129 1,425 Total $ 47,921 $ (879 ) $ 122 $ (757 ) $ 1,841 $ 49,005 Six Months Ended June 30, 2017 Real estate: Non-residential real estate owner occupied $ 5,602 $ (72 ) $ 4 $ (68 ) $ 151 $ 5,685 Non-residential real estate other 10,793 (26 ) 2 (24 ) (289 ) 10,480 Residential real estate permanent mortgage 3,129 (156 ) 11 (145 ) 164 3,148 Residential real estate all other 8,622 (73 ) 17 (56 ) 346 8,912 Commercial and financial: Non-consumer non-real estate 12,421 (677 ) 979 302 920 13,643 Consumer non-real estate 2,804 (468 ) 83 (385 ) 287 2,706 Other loans 4,045 (1,274 ) 5 (1,269 ) 230 3,006 Acquired loans 1,277 (14 ) 58 44 104 1,425 Total $ 48,693 $ (2,760 ) $ 1,159 $ (1,601 ) $ 1,913 $ 49,005 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 June 30, 2016 Real estate: Non-residential real estate owner occupied $ 4,832 $ (9 ) $ — $ (9 ) $ 73 $ 4,896 Non-residential real estate other 10,211 (3 ) 1 (2 ) 93 10,302 Residential real estate permanent mortgage 3,164 (49 ) 21 (28 ) 67 3,203 Residential real estate all other 7,989 (70 ) 7 (63 ) 367 8,293 Commercial and financial: Non-consumer non-real estate 12,813 (502 ) 35 (467 ) 1,095 13,441 Consumer non-real estate 2,553 (134 ) 38 (96 ) 292 2,749 Other loans 2,790 (149 ) 7 (142 ) 729 3,377 Acquired loans 219 (13 ) 11 (2 ) 88 305 Total $ 44,571 $ (929 ) $ 120 $ (809 ) $ 2,804 $ 46,566 Six Months Ended June 30, 2016 Real estate: Non-residential real estate owner occupied $ 4,661 $ (10 ) $ — $ (10 ) $ 245 $ 4,896 Non-residential real estate other 9,921 (4 ) 2 (2 ) 383 10,302 Residential real estate permanent mortgage 3,148 (99 ) 38 (61 ) 116 3,203 Residential real estate all other 6,725 (137 ) 11 (126 ) 1,694 8,293 Commercial and financial: Non-consumer non-real estate 11,754 (1,305 ) 46 (1,259 ) 2,946 13,441 Consumer non-real estate 2,642 (355 ) 76 (279 ) 386 2,749 Other loans 2,648 (282 ) 13 (269 ) 998 3,377 Acquired loans 167 (17 ) 16 (1 ) 139 305 Total $ 41,666 $ (2,209 ) $ 202 $ (2,007 ) $ 6,907 $ 46,566 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 June 30, 2017 December 31, 2016 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. $ 569 $ 5,116 $ 716 $ 4,886 Non-residential real estate other 739 9,741 1,119 9,674 Residential real estate permanent mortgage 391 2,757 422 2,707 Residential real estate all other 2,305 6,607 2,160 6,462 Commercial and financial: Non-consumer non-real estate 3,517 10,126 3,317 9,104 Consumer non-real estate 400 2,306 478 2,326 Other loans 656 2,350 1,812 2,233 Acquired loans 12 1,413 495 782 Total $ 8,589 $ 40,416 $ 10,519 $ 38,174 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 June 30, 2017 December 31, 2016 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 $ 15,177 $ 575,912 $ — $ 17,149 $ 554,482 $ — Non-residential real estate other 16,692 1,111,417 — 20,092 1,103,304 — Residential real estate permanent mortgage 7,144 323,587 — 7,631 317,782 — Residential real estate all other 16,067 742,050 — 14,873 733,356 — Commercial and financial: Non-consumer non-real estate 26,194 1,182,132 — 24,002 1,027,183 — Consumer non-real estate 2,809 281,348 — 3,203 280,674 — Other loans 572 143,976 — 2,254 139,228 — Acquired loans 15,834 111,830 5,652 13,459 135,616 5,944 Total $ 100,489 $ 4,472,252 $ 5,652 $ 102,663 $ 4,291,625 $ 5,944 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: Six Months Ended June 30, 2017 2016 (Dollars in thousands) Other real estate owned $ 1,513 $ 1,210 Repossessed assets 612 750 Total $ 2,125 $ 1,960 During the six months ended June 30, 2016, the Company had gains on the sale of other real estate owned totaling $1.3 million that is included in net expense from other real estate owned on the consolidated statements of comprehensive income.

Intangible Assets

Intangible Assets	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Core deposit intangibles $ 17,447 $ (7,531 ) $ 9,916 Customer relationship intangibles 5,699 (3,593 ) 2,106 Mortgage servicing intangibles 454 (273 ) 181 Total $ 23,600 $ (11,397 ) $ 12,203 As of December 31, 2016 Core deposit intangibles $ 17,447 $ (6,611 ) $ 10,836 Customer relationship intangibles 5,699 (3,419 ) 2,280 Mortgage servicing intangibles 473 (259 ) 214 Total $ 23,619 $ (10,289 ) $ 13,330 The following is a summary of goodwill by business segment: Other Executive, Metropolitan Community Financial Operations Banks Banks Services & Support Consolidated (Dollars in thousands) Six month ended June 30, 2017 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, 2016.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2017
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 3,200,000 shares in May 2016. At June 30, 2017, 190,735 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 June 30, 2017 will become exercisable through the year 2024. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant. In June 1999, the Company adopted the BancFirst Corporation Non-Employee Directors’ Stock Option Plan (the “BancFirst Directors’ Stock Option Plan”). Each non-employee director is granted an option for 10,000 shares. The Company amended the BancFirst Directors’ Stock Option Plan to increase the number of shares to be issued under the plan to 260,000 shares in May 2016. At June 30, 2017, 40,000 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 June 30, 2017 will become exercisable through the year 2020. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant. The Company currently uses newly issued shares for stock option exercises, but reserves the right to use shares purchased under the Company’s Stock Repurchase Program (the “SRP”) in the future. The following table is a summary of the activity under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan: Wgtd. Avg. Wgtd. Avg. Remaining Aggregate Exercise Contractual Intrinsic Options Price Term Value (Dollars in thousands, except option data) Six Months Ended June 30, 2017 Outstanding at December 31, 2016 707,450 $ 44.92 Options granted 25,000 91.39 Options exercised (93,325 ) 34.90 Outstanding at June 30, 2017 639,125 48.20 9.74 Yrs $ 30,933 Exercisable at June 30, 2017 277,250 38.77 6.85 Yrs $ 16,034 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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 (Dollars in thousands except per share data) Weighted average grant-date fair value per share of options granted $ 21.92 $ 11.29 $ 21.92 $ 11.40 Total intrinsic value of options exercised 1,032 891 5,645 1,670 Cash received from options exercised 647 1,001 3,257 1,876 Tax benefit realized from options exercised 399 345 2,183 646 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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 (Dollars in thousands) Stock-based compensation expense $ 282 $ 450 $ 465 $ 901 Tax benefit 109 174 180 348 Stock-based compensation expense, net of tax $ 173 $ 276 $ 285 $ 553 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: June 30, 2017 (Dollars in thousands) Unearned stock-based compensation expense $ 2,858 The following table shows the assumptions used for computing stock-based compensation expense under the fair value method on options granted during the periods presented: Six Months Ended June 30, 2017 2016 Risk-free interest rate 2.15 to 2.38% 1.46 to 2.02% Dividend yield 2.00% 2.00% Stock price volatility 22.57 to 23.13% 20.41 to 20.64% 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 111,110 shares in May 2016. Under the plan, directors and members of the community advisory boards of the Company and its subsidiaries may defer up to 100% of their board fees. They are credited for each deferral with a number of stock units based on the current market price of the Company’s stock, which accumulate in an account until such time as the director or community board member terminates serving as a board member. Shares of common stock of the Company are then distributed to the terminating director or community board member based upon the number of stock units accumulated in his or her account. There were 4,959 shares of common stock distributed from the BancFirst Deferred Stock Compensation Plan during the six months ended June 30, 2017. A summary of the accumulated stock units is as follows: June 30, December 31, 2017 2016 Accumulated stock units 67,226 70,022 Average price $ 43.69 $ 41.74

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2017
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 may be determined by management within the limitations of the SRP. During the third quarter of 2016 the SRP was amended to increase the remaining shares to be repurchased to 150,000. The following table is a summary of the shares under the program, all share repurchased in 2016 where purchased in the first three months of the year: Six Months Ended June 30, 2017 2016 Number of shares repurchased — 100,000 Average price of shares repurchased $ — $ 55.23 Shares remaining to be repurchased 150,000 66,276 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 June 30, 2017, 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 June 30, 2017: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 763,741 15.51% $ 394,051 8.00% $ 455,621 9.250% N/A N/A BancFirst 685,395 13.93% 393,644 8.00% 455,151 9.250% $ 492,055 10.00% Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 683,736 13.88% $ 221,653 4.50% $ 283,224 5.750% N/A N/A BancFirst 616,390 12.53% 221,425 4.50% 282,932 5.750% $ 319,836 6.50% Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 714,736 14.51% $ 295,538 6.00% $ 357,108 7.250% N/A N/A BancFirst 636,390 12.93% 295,233 6.00% 356,740 7.250% $ 393,644 8.00% Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 714,736 10.15% $ 281,701 4.00% N/A N/A N/A N/A BancFirst 636,390 9.05% 281,404 4.00% N/A N/A $ 351,755 5.00% As of June 30, 2017, 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 June 30, 2017, 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	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Basic Income available to common stockholders $ 23,182 15,903,805 $ 1.46 Dilutive effect of stock options — 357,883 Diluted Income available to common stockholders plus assumed exercises of stock options $ 23,182 16,261,688 $ 1.42 Three Months Ended June 30, 2016 Basic Income available to common stockholders $ 17,493 15,549,811 $ 1.12 Dilutive effect of stock options — 292,674 Diluted Income available to common stockholders plus assumed exercises of stock options $ 17,493 15,842,485 $ 1.10 Six Months Ended June 30, 2017 Basic Income available to common stockholders $ 45,232 15,884,414 $ 2.85 Dilutive effect of stock options — 365,581 Diluted Income available to common stockholders plus assumed exercises of stock options $ 45,232 16,249,995 $ 2.78 Six Months Ended June 30, 2016 Basic Income available to common stockholders $ 34,072 15,542,114 $ 2.19 Dilutive effect of stock options — 288,563 Diluted Income available to common stockholders plus assumed exercises of stock options $ 34,072 15,830,677 $ 2.15 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 June 30, 2017 19,505 $ 90.64 Three Months Ended June 30, 2016 241,945 58.52 Six Months Ended June 30, 2017 9,807 90.64 Six Months Ended June 30, 2016 239,198 58.55

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
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, repossessed assets, other real estate owned, goodwill and other intangible assets. Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis A description of the valuation methodologies and key inputs used to measure financial assets and financial liabilities at fair value on a recurring basis, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. These valuation methodologies were applied to the following categories of the Company’s financial assets and financial liabilities. Securities Available for Sale Securities classified as available for sale are reported at fair value. U.S. Treasuries are valued using Level 1 inputs. Other securities available for sale including U.S. federal agencies, registered mortgage backed securities and state and political subdivisions are valued using prices from an independent pricing service utilizing Level 2 data. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. The Company also invests in private label mortgage backed securities and equity securities classified as available for sale for which observable information is not readily available. These securities are reported at fair value utilizing Level 3 inputs. For these securities, management determines the fair value based on replacement cost, the income approach or information provided by outside consultants or lead investors. The Company reviews the prices for Level 1 and Level 2 securities supplied by the independent pricing service for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, the Company does not purchase investment portfolio securities that are esoteric or that have complicated structures. The Company’s portfolio primarily consists of traditional investments including U.S. Treasury obligations, federal agency mortgage pass-through securities, general obligation municipal bonds and a small amount of municipal revenue bonds. Pricing for such instruments is fairly generic and is easily obtained. For in-state bond issues that have relatively low issue sizes and liquidity, the Company utilizes the same parameters for pricing mentioned in the preceding paragraph adjusted for the specific issue. Periodically, the Company will validate 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) June 30, 2017 Securities available for sale: U.S. Treasury $ 285,387 $ — $ — $ 285,387 U.S. federal agencies — 98,398 — 98,398 Mortgage-backed securities — 5,767 13,018 18,785 States and political subdivisions — 38,935 — 38,935 Other securities — — 5,955 5,955 Derivative assets — 256 — 256 Derivative liabilities — 116 — 116 Loans held for sale — 9,061 — 9,061 December 31, 2016 Securities available for sale: U.S. Treasury $ 268,543 $ — $ — $ 268,543 U.S. federal agencies — 129,642 — 129,642 Mortgage-backed securities — 4,856 14,816 19,672 States and political subdivisions — 41,042 — 41,042 Other securities — — 6,569 6,569 Derivative assets — 1,569 — 1,569 Derivative liabilities — 1,306 — 1,306 Loans held for sale — 9,318 — 9,318 The changes in Level 3 assets measured at estimated fair value on a recurring basis during the periods presented were as follows: Six Months Ended June 30, Twelve Months Ended December 31, 2017 2016 (Dollars in thousands) Balance at the beginning of the year $ 21,385 $ 21,124 Purchases 293 1,096 Settlements (1,905 ) (191 ) Sales — (429 ) Losses included in earnings (330 ) (111 ) Total unrealized losses (470 ) (104 ) Balance at the end of the period $ 18,973 $ 21,385 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 six months ended June 30, 2017 and 2016, the Company did not transfer any securities between levels in the fair value hierarchy. Financial Assets and Financial Liabilities Measured at Fair Value on a Nonrecurring Basis Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). These financial assets and financial liabilities are reported at fair value utilizing Level 3 inputs. Impaired loans are reported at the fair value of the underlying collateral if repayment is dependent on liquidation of the collateral. In no case does the fair value of an impaired loan exceed the fair value of the underlying collateral. The impaired loans are adjusted to fair value through a specific allocation of the allowance for loan losses or a direct charge-down of the loan. Repossessed assets, upon initial recognition, are measured and adjusted to fair value through a charge-off to the allowance for possible loan losses based upon the fair value of the 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. The fair value represents end of period values, which approximate fair value measurements that occurred on various measurement dates throughout the period: Total Fair Value Level 3 (Dollars in thousands) As of and for the Year-to-date Period Ended June 30, 2017 Impaired loans (less specific allowance) $ 21,392 Repossessed assets 238 Other real estate owned 1,329 As of and for the Year-to-date Period Ended December 31, 2016 Impaired loans (less specific allowance) $ 29,912 Repossessed assets 340 Other real estate owned 1,480 Estimated Fair Value of Financial Instruments The Company is required under current authoritative accounting guidance to disclose the estimated fair value of their financial instruments that are not recorded at fair value. For the Company, as for most financial institutions, substantially all of its assets and liabilities are considered financial instruments. A financial instrument is defined as cash, evidence of an ownership interest in an entity or a contract that creates a contractual obligation or right to deliver or receive cash or another financial instrument from a second entity. The following methods and assumptions were used to estimate the fair value of each class of financial instruments: Cash and Cash Equivalents Include: Cash and Due from Banks, Federal Funds Sold and Interest-Bearing Deposits The carrying amount of these short-term instruments is a reasonable estimate of fair value. Securities Held for Investment For securities held for investment, which are generally traded in secondary markets, fair values are based on quoted market prices or dealer quotes, if available. If a quoted market price is not available, fair value is estimated using quoted market prices for similar securities making adjustments for credit or liquidity if applicable. Loans For certain homogeneous categories of loans, such as some residential mortgages, fair values are estimated using the quoted market prices for securities backed by similar loans, adjusted for differences in loan characteristics. The fair values of other types of loans are estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. Deposits The fair values of transaction and savings accounts are the amounts payable on demand at the reporting date. The fair values of fixed-maturity certificates of deposit are estimated using the rates currently offered for deposits of similar remaining maturities. Short-term Borrowings The amounts payable on these short-term instruments are reasonable estimates of fair value. Junior Subordinated Debentures The fair values of junior subordinated debentures are estimated using the rates that would be charged for junior subordinated debentures of similar remaining maturities. Loan Commitments and Letters of Credit The fair values of commitments are estimated using the fees currently charged to enter into similar agreements, taking into account the terms of the agreements. The fair values of letters of credit are based on fees currently charged for similar agreements. The estimated fair values of the Company’s financial instruments that are reported at amortized cost in the Company’s consolidated balance sheets, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value, are as follows: June 30, December 31, 2017 2016 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,716,900 $ 1,716,900 $ 1,851,161 $ 1,851,161 Securities held for investment 3,442 3,475 3,722 3,760 Level 3 inputs: Securities held for investment 500 500 643 643 Loans, net of allowance for loan losses 4,529,388 4,534,977 4,351,539 4,367,363 FINANCIAL LIABILITIES Level 2 inputs: Deposits 6,235,682 6,306,671 6,248,057 6,313,622 Short-term borrowings 1,000 1,000 500 500 Junior subordinated debentures 31,959 35,830 31,959 34,339 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,780 1,718 Letters of credit 443 424 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 June 30, 2017 or December 31, 2016.

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 December 31, 2016 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 46 $ 108 83 $ 576 Derivative liabilities Barrels (46 ) (59 ) (83 ) (496 ) Natural Gas Derivative assets MMBTUs 830 148 1,900 993 Derivative liabilities MMBTUs (830 ) (57 ) (1,900 ) (810 ) Total Fair Value Included in Derivative assets Other assets 256 1,569 Derivative liabilities Other liabilities (116 ) (1,306 ) 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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 (Dollars in thousands) Derivative income $ — $ 6 $ 5 $ 11 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: June 30, 2017 December 31, 2016 (Dollars in Credit exposure $ 76 $ — 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	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Net interest income (expense) $ 17,832 $ 37,047 $ 1,698 $ (138 ) $ — $ 56,439 Noninterest income 3,945 13,660 7,456 25,644 (22,722 ) 27,983 Income before taxes 11,784 24,509 3,119 16,720 (22,504 ) 33,628 Three Months Ended June 30, 2016 Net interest income (expense) $ 15,699 $ 33,846 $ 1,591 $ (268 ) $ — $ 50,868 Noninterest income 4,098 14,408 6,646 18,798 (17,893 ) 26,057 Income before taxes 10,240 20,331 2,431 11,247 (17,848 ) 26,401 Six Months Ended June 30, 2017 Net interest income (expense) $ 36,352 $ 72,170 $ 3,193 $ (508 ) $ — $ 111,207 Noninterest income 7,767 26,937 15,766 50,116 (44,518 ) 56,068 Income before taxes 24,858 47,228 6,764 32,231 (44,260 ) 66,821 Six Months Ended June 30, 2016 Net interest income (expense) $ 31,542 $ 66,968 $ 3,007 $ (673 ) $ — $ 100,844 Noninterest income 7,886 28,004 14,125 36,476 (34,817 ) 51,674 Income before taxes 19,588 39,425 5,545 21,747 (34,705 ) 51,600 Total Assets: June 30, 2017 $ 2,506,852 $ 4,432,649 $ 97,894 $ 824,524 $ (815,330 ) $ 7,046,589 December 31, 2016 2,493,096 4,412,174 83,594 803,810 (773,722 ) 7,018,952 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.

Subsequent Event

Subsequent Event	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Event	(12) SUBSEQUENT EVENT Subsequent to June 30, 2017, the Company completed a two-for-one stock split of the Company’s outstanding shares of common stock. The stock is payable in the form of a dividend on or about July 31, 2017 to shareholders of record of the outstanding common stock as of the close of business record date of July 17, 2017. Stockholders will receive one additional share for each share held on that date. This represents the second stock split for the Company since going public.

Description of Business and S21

Description of Business and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
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., BancFirst Risk and Insurance Company, 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, 2016, 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, 2016, the date of the most recent annual report.
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 Standards Adopted During Current Period: In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2017-08, “Receivables – Nonrefundable Fees and Other Costs (Topic 310-20): Premium Amortization on Purchased Callable Debt Securities.” ASU 2017-08 shortens the amortization period for certain callable debt securities held at a premium. The Company opted for early adoption of ASU 2017-08, as was permitted, on January 1, 2017. ASU 2017-08 did not have a significant impact on the Company’s financial statements and no prior periods were adjusted. In October 2016, the FASB issued ASU No. 2016-17, “Consolidation (Topic 810): Interests Held Through Related Parties That Are Under Common Control.” ASU 2016-17 updates ASU No. 2015-02 to amend the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. ASU 2016-17 was adopted on January 1, 2017 and did not have a significant impact on the Company’s financial statements and no prior periods were adjusted. In March 2016, the FASB issued ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Under ASU 2016-09 all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. ASU 2016-09 also allows entities to make an entity-wide accounting policy election to account for forfeitures when they occur, which the Company has elected to do. 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 was adopted on January 1, 2017 and did not have a significant impact on the Company’s financial statements. In addition, ASU 2016-09 was applied prospectively and no prior periods were adjusted. The excess tax benefit for share-based payment awards that were exercised during the six months ended June 30, 2017 was approximately $1.8 million. 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. ASU 2014-15 was adopted on January 1, 2017. Adoption of ASU 2014-15 did not have a significant effect on the Company’s financial statements. Standards Not Yet Adopted: In May 2017, the FASB issued ASU No. 2017-09, “Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting.” The amendments in this update provide guidance about types of changes to the terms or conditions of share-based payment awards that would require an entity to apply modification accounting under ASC 718. ASU 2017-09 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. Early adoption is permitted with prospective applications. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” ASU 2017-04 removes the second step of goodwill testing. ASU 2017-04 will be effective on January 1, 2020 and is not expected to have a significant impact on the Company’s financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business.” ASU 2017-01 clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of a business. ASU 2017-01 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In October 2016, the FASB issued ASU No. 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” ASU 2016-16 provides guidance stating that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 will be effective on January 1, 2018 and is not expected to have a significant impact on the Company’s financial statements. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” ASU 2016-15 is intended to reduce the diversity in practice around how certain transactions are classified within the statement of cash flows. ASU 2016-15 will be effective on January 1, 2018. Early adoption is permitted with retrospective applications. The Company is currently evaluating the potential impact of ASU 2016-15 on its financial statements. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. ASU 2016-13 requires enhanced disclosures related to the significant estimates and judgements used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASU 2016-13 amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 will be effective on January 1, 2020. The Company is currently evaluating the potential impact of ASU 2016-13 on its financial statements. In 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 January of 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customer (Topic 606).” ASU 2014-09 implements a comprehensive new revenue recognition standard that will supersede substantially all existing revenue recognition guidance. The new standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in a manner that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, which comprises a significant portion of the Company’s revenue stream. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606).” ASU 2015-14 is an amendment to defer the effective date of ASU 2014-09. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. Adoption of ASU 2014-09 may require the Company to amend how it recognizes certain recurring revenue streams related to trust fees, which are recorded in non-interest expense; however, the Company does not expect the adoption of ASU 2014-09 to have a significant impact on the Company’s financial statements.

Securities (Tables)

Securities (Tables)	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 December 31, 2016 (Dollars in thousands) Held for investment, at cost (fair value: $3,975 and $4,403, respectively) $ 3,942 $ 4,365 Available for sale, at fair value 447,460 465,468 Total $ 451,402 $ 469,833
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 June 30, 2017 (Dollars in thousands) Mortgage backed securities (1) $ 217 $ 12 $ — $ 229 States and political subdivisions 3,225 22 (1 ) 3,246 Other securities 500 — — 500 Total $ 3,942 $ 34 $ (1 ) $ 3,975 December 31, 2016 Mortgage backed securities (1) $ 252 $ 17 $ — $ 269 States and political subdivisions 3,613 25 (4 ) 3,634 Other securities 500 — — 500 Total $ 4,365 $ 42 $ (4 ) $ 4,403
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 June 30, 2017 (Dollars in thousands) U.S. treasuries $ 284,791 $ 867 $ (271 ) $ 285,387 U.S. federal agencies 98,311 397 (310 ) 98,398 Mortgage backed securities (1) 19,052 246 (513 ) 18,785 States and political subdivisions 38,129 865 (59 ) 38,935 Other securities (2) 6,450 189 (684 ) 5,955 Total $ 446,733 $ 2,564 $ (1,837 ) $ 447,460 December 31, 2016 U.S. treasuries $ 268,763 $ 700 $ (920 ) $ 268,543 U.S. federal agencies 129,674 373 (405 ) 129,642 Mortgage backed securities (1) 19,949 290 (567 ) 19,672 States and political subdivisions 40,335 836 (129 ) 41,042 Other securities (2) 6,594 125 (150 ) 6,569 Total $ 465,315 $ 2,324 $ (2,171 ) $ 465,468 (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. June 30, 2017 December 31, 2016 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (Dollars in thousands) Held for Investment Contractual maturity of debt securities: Within one year $ 1,672 $ 1,683 $ 1,561 $ 1,568 After one year but within five years 1,593 1,603 1,937 1,951 After five years but within ten years 667 674 707 723 After ten years 10 15 160 161 Total $ 3,942 $ 3,975 $ 4,365 $ 4,403 Available for Sale Contractual maturity of debt securities: Within one year $ 66,022 $ 66,105 $ 66,542 $ 66,662 After one year but within five years 308,283 308,913 320,150 319,839 After five years but within ten years 5,849 6,184 5,830 6,152 After ten years 60,129 60,303 66,199 66,246 Total debt securities 440,283 441,505 458,721 458,899 Equity securities 6,450 5,955 6,594 6,569 Total $ 446,733 $ 447,460 $ 465,315 $ 465,468
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: June 30, 2017 December 31, 2016 (Dollars Book value of pledged securities $ 394,974 $ 439,692

Loans and Allowance for Loan 23

Loans and Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Schedule of Loans Outstanding by Category	The following is a schedule of loans outstanding by category: June 30, 2017 December 31, 2016 Amount Percent Amount Percent (Dollars in thousands) Commercial and financial: Commercial and industrial $ 927,616 20.26 % $ 828,260 18.82 % Oil & gas production and equipment 96,230 2.10 84,228 1.91 Agriculture 135,298 2.96 144,751 3.29 State and political subdivisions: Taxable 81,164 1.77 33,793 0.77 Tax-exempt 48,840 1.07 47,283 1.07 Real estate: Construction 412,367 9.01 420,884 9.57 Farmland 201,535 4.40 197,872 4.50 One to four family residences 859,980 18.78 846,360 19.24 Multifamily residential properties 46,995 1.03 57,806 1.31 Commercial 1,455,612 31.79 1,426,643 32.42 Consumer 280,345 6.12 279,704 6.36 Other (not classified above) 32,411 0.71 32,648 0.74 Total loans $ 4,578,393 100.00 % $ 4,400,232 100.00 %
Summary of Nonperforming and Restructured Assets	The following is a summary of nonperforming and restructured assets: June 30, December 31, 2017 2016 (Dollars in thousands) Past due 90 days or more and still accruing $ 2,217 $ 1,962 Nonaccrual 19,607 31,798 Restructured 3,561 1,713 Total nonperforming and restructured loans 25,385 35,473 Other real estate owned and repossessed assets 4,211 3,866 Total nonperforming and restructured assets $ 29,596 $ 39,339
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. June 30, December 31, 2017 2016 (Dollars in thousands) Real estate: Non-residential real estate owner occupied $ 641 $ 713 Non-residential real estate other 1,865 5,688 Residential real estate permanent mortgage 886 1,116 Residential real estate all other 4,829 5,089 Commercial and financial: Non-consumer non-real estate 3,542 4,464 Consumer non-real estate 271 265 Other loans 4,928 8,370 Acquired loans 2,645 6,093 Total $ 19,607 $ 31,798
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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 3,991 $ 145 $ 730 $ 4,866 $ 586,223 $ 591,089 $ 229 Non-residential real estate other 1,354 70 267 1,691 1,126,418 1,128,109 29 Residential real estate permanent mortgage 1,504 483 781 2,768 327,963 330,731 482 Residential real estate all other 4,872 294 1,011 6,177 751,940 758,117 287 Commercial and financial: Non-consumer non-real estate 4,133 671 1,771 6,575 1,201,751 1,208,326 564 Consumer non-real estate 1,562 505 554 2,621 281,536 284,157 388 Other loans 555 4,941 4,869 10,365 134,183 144,548 101 Acquired loans 728 113 416 1,257 132,059 133,316 137 Total $ 18,699 $ 7,222 $ 10,399 $ 36,320 $ 4,542,073 $ 4,578,393 $ 2,217 As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 2,255 $ 96 $ 150 $ 2,501 $ 569,130 $ 571,631 $ — Non-residential real estate other 611 16 418 1,045 1,122,351 1,123,396 — Residential real estate permanent mortgage 2,742 649 1,273 4,664 320,749 325,413 513 Residential real estate all other 2,559 531 1,416 4,506 743,723 748,229 369 Commercial and financial: Non-consumer non-real estate 1,269 1,628 741 3,638 1,047,547 1,051,185 608 Consumer non-real estate 2,046 760 419 3,225 280,652 283,877 274 Other loans 5,345 958 7,775 14,078 127,404 141,482 45 Acquired loans 825 310 408 1,543 153,476 155,019 153 Total $ 17,652 $ 4,948 $ 12,600 $ 35,200 $ 4,365,032 $ 4,400,232 $ 1,962
Impaired Loans Segregated by Class of Loans	The following table presents impaired loans, segregated by class of loans. During the six month period ended June 30, 2017, $2.3 million of interest income was recognized on impaired loans subsequent to their classification as impaired. During previous periods 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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 1,065 $ 958 $ 31 $ 1,060 Non-residential real estate other 1,967 1,894 184 2,057 Residential real estate permanent mortgage 1,623 1,418 104 1,483 Residential real estate all other 5,420 5,195 1,555 5,136 Commercial and financial: Non-consumer non-real estate 13,725 7,257 1,454 6,401 Consumer non-real estate 790 754 117 776 Other loans 6,471 5,030 689 5,523 Acquired loans 4,747 3,020 — 4,967 Total $ 35,808 $ 25,526 $ 4,134 $ 27,403 As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 894 $ 806 $ 101 $ 825 Non-residential real estate other 7,742 5,688 574 5,854 Residential real estate permanent mortgage 1,878 1,683 124 1,612 Residential real estate all other 5,871 5,614 1,538 5,445 Commercial and financial: Non-consumer non-real estate 12,015 6,272 1,457 6,478 Consumer non-real estate 686 650 133 788 Other loans 9,799 8,415 1,870 8,062 Acquired loans 8,780 6,581 — 6,041 Total $ 47,665 $ 35,709 $ 5,797 $ 35,105
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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 474,155 $ 101,757 $ 14,536 $ 641 $ — $ 591,089 Non-residential real estate other 941,448 169,968 14,759 1,934 — 1,128,109 Residential real estate permanent mortgage 289,912 33,676 5,805 1,338 — 330,731 Residential real estate all other 607,861 134,189 10,918 5,149 — 758,117 Commercial and financial: Non-consumer non-real estate 947,575 234,258 22,652 3,841 — 1,208,326 Consumer non-real estate 263,875 17,473 2,093 716 — 284,157 Other loans 137,753 5,450 1,115 230 — 144,548 Acquired loans 76,955 34,875 18,390 3,096 — 133,316 Total $ 3,739,534 $ 731,646 $ 90,268 $ 16,945 $ — $ 4,578,393 As of December 31, 2016 Real estate: Non-residential real estate owner occupied $ 464,504 $ 89,978 $ 16,220 $ 929 $ — $ 571,631 Non-residential real estate other 933,743 169,561 14,404 5,688 — 1,123,396 Residential real estate permanent mortgage 284,893 32,889 5,987 1,644 — 325,413 Residential real estate all other 614,338 119,018 9,382 5,491 — 748,229 Commercial and financial: Non-consumer non-real estate 856,318 170,865 19,101 4,901 — 1,051,185 Consumer non-real estate 263,442 17,154 2,640 641 — 283,877 Other loans 132,254 5,376 1,514 2,338 — 141,482 Acquired loans 92,946 42,668 12,888 6,517 — 155,019 Total $ 3,642,438 $ 647,509 $ 82,136 $ 28,149 $ — $ 4,400,232
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 June 30, 2017 Real estate: Non-residential real estate owner occupied $ 5,562 $ (40 ) $ 3 $ (37 ) $ 160 $ 5,685 Non-residential real estate other 10,788 (25 ) 1 (24 ) (284 ) 10,480 Residential real estate permanent mortgage 3,130 (36 ) 10 (26 ) 44 3,148 Residential real estate all other 8,659 (16 ) 6 (10 ) 263 8,912 Commercial and financial: Non-consumer non-real estate 12,810 (471 ) 61 (410 ) 1,243 13,643 Consumer non-real estate 2,725 (234 ) 32 (202 ) 183 2,706 Other loans 2,958 (56 ) 1 (55 ) 103 3,006 Acquired loans 1,289 (1 ) 8 7 129 1,425 Total $ 47,921 $ (879 ) $ 122 $ (757 ) $ 1,841 $ 49,005 Six Months Ended June 30, 2017 Real estate: Non-residential real estate owner occupied $ 5,602 $ (72 ) $ 4 $ (68 ) $ 151 $ 5,685 Non-residential real estate other 10,793 (26 ) 2 (24 ) (289 ) 10,480 Residential real estate permanent mortgage 3,129 (156 ) 11 (145 ) 164 3,148 Residential real estate all other 8,622 (73 ) 17 (56 ) 346 8,912 Commercial and financial: Non-consumer non-real estate 12,421 (677 ) 979 302 920 13,643 Consumer non-real estate 2,804 (468 ) 83 (385 ) 287 2,706 Other loans 4,045 (1,274 ) 5 (1,269 ) 230 3,006 Acquired loans 1,277 (14 ) 58 44 104 1,425 Total $ 48,693 $ (2,760 ) $ 1,159 $ (1,601 ) $ 1,913 $ 49,005 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 June 30, 2016 Real estate: Non-residential real estate owner occupied $ 4,832 $ (9 ) $ — $ (9 ) $ 73 $ 4,896 Non-residential real estate other 10,211 (3 ) 1 (2 ) 93 10,302 Residential real estate permanent mortgage 3,164 (49 ) 21 (28 ) 67 3,203 Residential real estate all other 7,989 (70 ) 7 (63 ) 367 8,293 Commercial and financial: Non-consumer non-real estate 12,813 (502 ) 35 (467 ) 1,095 13,441 Consumer non-real estate 2,553 (134 ) 38 (96 ) 292 2,749 Other loans 2,790 (149 ) 7 (142 ) 729 3,377 Acquired loans 219 (13 ) 11 (2 ) 88 305 Total $ 44,571 $ (929 ) $ 120 $ (809 ) $ 2,804 $ 46,566 Six Months Ended June 30, 2016 Real estate: Non-residential real estate owner occupied $ 4,661 $ (10 ) $ — $ (10 ) $ 245 $ 4,896 Non-residential real estate other 9,921 (4 ) 2 (2 ) 383 10,302 Residential real estate permanent mortgage 3,148 (99 ) 38 (61 ) 116 3,203 Residential real estate all other 6,725 (137 ) 11 (126 ) 1,694 8,293 Commercial and financial: Non-consumer non-real estate 11,754 (1,305 ) 46 (1,259 ) 2,946 13,441 Consumer non-real estate 2,642 (355 ) 76 (279 ) 386 2,749 Other loans 2,648 (282 ) 13 (269 ) 998 3,377 Acquired loans 167 (17 ) 16 (1 ) 139 305 Total $ 41,666 $ (2,209 ) $ 202 $ (2,007 ) $ 6,907 $ 46,566
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 June 30, 2017 December 31, 2016 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. $ 569 $ 5,116 $ 716 $ 4,886 Non-residential real estate other 739 9,741 1,119 9,674 Residential real estate permanent mortgage 391 2,757 422 2,707 Residential real estate all other 2,305 6,607 2,160 6,462 Commercial and financial: Non-consumer non-real estate 3,517 10,126 3,317 9,104 Consumer non-real estate 400 2,306 478 2,326 Other loans 656 2,350 1,812 2,233 Acquired loans 12 1,413 495 782 Total $ 8,589 $ 40,416 $ 10,519 $ 38,174
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 June 30, 2017 December 31, 2016 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 $ 15,177 $ 575,912 $ — $ 17,149 $ 554,482 $ — Non-residential real estate other 16,692 1,111,417 — 20,092 1,103,304 — Residential real estate permanent mortgage 7,144 323,587 — 7,631 317,782 — Residential real estate all other 16,067 742,050 — 14,873 733,356 — Commercial and financial: Non-consumer non-real estate 26,194 1,182,132 — 24,002 1,027,183 — Consumer non-real estate 2,809 281,348 — 3,203 280,674 — Other loans 572 143,976 — 2,254 139,228 — Acquired loans 15,834 111,830 5,652 13,459 135,616 5,944 Total $ 100,489 $ 4,472,252 $ 5,652 $ 102,663 $ 4,291,625 $ 5,944
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: Six Months Ended June 30, 2017 2016 (Dollars in thousands) Other real estate owned $ 1,513 $ 1,210 Repossessed assets 612 750 Total $ 2,125 $ 1,960

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Core deposit intangibles $ 17,447 $ (7,531 ) $ 9,916 Customer relationship intangibles 5,699 (3,593 ) 2,106 Mortgage servicing intangibles 454 (273 ) 181 Total $ 23,600 $ (11,397 ) $ 12,203 As of December 31, 2016 Core deposit intangibles $ 17,447 $ (6,611 ) $ 10,836 Customer relationship intangibles 5,699 (3,419 ) 2,280 Mortgage servicing intangibles 473 (259 ) 214 Total $ 23,619 $ (10,289 ) $ 13,330
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) Six month ended June 30, 2017 Balance at beginning and end of period $ 8,078 $ 40,050 $ 5,464 $ 450 $ 54,042

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
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) Six Months Ended June 30, 2017 Outstanding at December 31, 2016 707,450 $ 44.92 Options granted 25,000 91.39 Options exercised (93,325 ) 34.90 Outstanding at June 30, 2017 639,125 48.20 9.74 Yrs $ 30,933 Exercisable at June 30, 2017 277,250 38.77 6.85 Yrs $ 16,034
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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 (Dollars in thousands except per share data) Weighted average grant-date fair value per share of options granted $ 21.92 $ 11.29 $ 21.92 $ 11.40 Total intrinsic value of options exercised 1,032 891 5,645 1,670 Cash received from options exercised 647 1,001 3,257 1,876 Tax benefit realized from options exercised 399 345 2,183 646
Stock-based Employee Compensation Expense	The following table is a summary of the Company’s recorded stock-based compensation expense: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (Dollars in thousands) Stock-based compensation expense $ 282 $ 450 $ 465 $ 901 Tax benefit 109 174 180 348 Stock-based compensation expense, net of tax $ 173 $ 276 $ 285 $ 553
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: June 30, 2017 (Dollars in thousands) Unearned stock-based compensation expense $ 2,858
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 on options granted during the periods presented: Six Months Ended June 30, 2017 2016 Risk-free interest rate 2.15 to 2.38% 1.46 to 2.02% Dividend yield 2.00% 2.00% Stock price volatility 22.57 to 23.13% 20.41 to 20.64% Expected term 10 Yrs 10 Yrs
Summary of Accumulated Stock Units	A summary of the accumulated stock units is as follows: June 30, December 31, 2017 2016 Accumulated stock units 67,226 70,022 Average price $ 43.69 $ 41.74

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Summary of Shares Repurchased Under Stock Purchase Program	The following table is a summary of the shares under the program, all share repurchased in 2016 where purchased in the first three months of the year: Six Months Ended June 30, 2017 2016 Number of shares repurchased — 100,000 Average price of shares repurchased $ — $ 55.23 Shares remaining to be repurchased 150,000 66,276
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 June 30, 2017: Total Capital (to Risk Weighted Assets)- BancFirst Corporation $ 763,741 15.51% $ 394,051 8.00% $ 455,621 9.250% N/A N/A BancFirst 685,395 13.93% 393,644 8.00% 455,151 9.250% $ 492,055 10.00% Common Equity Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 683,736 13.88% $ 221,653 4.50% $ 283,224 5.750% N/A N/A BancFirst 616,390 12.53% 221,425 4.50% 282,932 5.750% $ 319,836 6.50% Tier 1 Capital (to Risk Weighted Assets)- BancFirst Corporation $ 714,736 14.51% $ 295,538 6.00% $ 357,108 7.250% N/A N/A BancFirst 636,390 12.93% 295,233 6.00% 356,740 7.250% $ 393,644 8.00% Tier 1 Capital (to Total Assets)- BancFirst Corporation $ 714,736 10.15% $ 281,701 4.00% N/A N/A N/A N/A BancFirst 636,390 9.05% 281,404 4.00% N/A N/A $ 351,755 5.00%

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Basic Income available to common stockholders $ 23,182 15,903,805 $ 1.46 Dilutive effect of stock options — 357,883 Diluted Income available to common stockholders plus assumed exercises of stock options $ 23,182 16,261,688 $ 1.42 Three Months Ended June 30, 2016 Basic Income available to common stockholders $ 17,493 15,549,811 $ 1.12 Dilutive effect of stock options — 292,674 Diluted Income available to common stockholders plus assumed exercises of stock options $ 17,493 15,842,485 $ 1.10 Six Months Ended June 30, 2017 Basic Income available to common stockholders $ 45,232 15,884,414 $ 2.85 Dilutive effect of stock options — 365,581 Diluted Income available to common stockholders plus assumed exercises of stock options $ 45,232 16,249,995 $ 2.78 Six Months Ended June 30, 2016 Basic Income available to common stockholders $ 34,072 15,542,114 $ 2.19 Dilutive effect of stock options — 288,563 Diluted Income available to common stockholders plus assumed exercises of stock options $ 34,072 15,830,677 $ 2.15
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 June 30, 2017 19,505 $ 90.64 Three Months Ended June 30, 2016 241,945 58.52 Six Months Ended June 30, 2017 9,807 90.64 Six Months Ended June 30, 2016 239,198 58.55

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
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) June 30, 2017 Securities available for sale: U.S. Treasury $ 285,387 $ — $ — $ 285,387 U.S. federal agencies — 98,398 — 98,398 Mortgage-backed securities — 5,767 13,018 18,785 States and political subdivisions — 38,935 — 38,935 Other securities — — 5,955 5,955 Derivative assets — 256 — 256 Derivative liabilities — 116 — 116 Loans held for sale — 9,061 — 9,061 December 31, 2016 Securities available for sale: U.S. Treasury $ 268,543 $ — $ — $ 268,543 U.S. federal agencies — 129,642 — 129,642 Mortgage-backed securities — 4,856 14,816 19,672 States and political subdivisions — 41,042 — 41,042 Other securities — — 6,569 6,569 Derivative assets — 1,569 — 1,569 Derivative liabilities — 1,306 — 1,306 Loans held for sale — 9,318 — 9,318
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: Six Months Ended June 30, Twelve Months Ended December 31, 2017 2016 (Dollars in thousands) Balance at the beginning of the year $ 21,385 $ 21,124 Purchases 293 1,096 Settlements (1,905 ) (191 ) Sales — (429 ) Losses included in earnings (330 ) (111 ) Total unrealized losses (470 ) (104 ) Balance at the end of the period $ 18,973 $ 21,385
Assets Measured at Fair Value on Nonrecurring Basis	The following table summarizes assets measured at fair value on a nonrecurring basis. The fair value represents end of period values, which approximate fair value measurements that occurred on various measurement dates throughout the period: Total Fair Value Level 3 (Dollars in thousands) As of and for the Year-to-date Period Ended June 30, 2017 Impaired loans (less specific allowance) $ 21,392 Repossessed assets 238 Other real estate owned 1,329 As of and for the Year-to-date Period Ended December 31, 2016 Impaired loans (less specific allowance) $ 29,912 Repossessed assets 340 Other real estate owned 1,480
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: June 30, December 31, 2017 2016 Carrying Amount Fair Value Carrying Amount Fair Value (Dollars in thousands) FINANCIAL ASSETS Level 2 inputs: Cash and cash equivalents $ 1,716,900 $ 1,716,900 $ 1,851,161 $ 1,851,161 Securities held for investment 3,442 3,475 3,722 3,760 Level 3 inputs: Securities held for investment 500 500 643 643 Loans, net of allowance for loan losses 4,529,388 4,534,977 4,351,539 4,367,363 FINANCIAL LIABILITIES Level 2 inputs: Deposits 6,235,682 6,306,671 6,248,057 6,313,622 Short-term borrowings 1,000 1,000 500 500 Junior subordinated debentures 31,959 35,830 31,959 34,339 OFF-BALANCE SHEET FINANCIAL INSTRUMENTS Loan commitments 1,780 1,718 Letters of credit 443 424

Derivative Financial Instrume29

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 December 31, 2016 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 46 $ 108 83 $ 576 Derivative liabilities Barrels (46 ) (59 ) (83 ) (496 ) Natural Gas Derivative assets MMBTUs 830 148 1,900 993 Derivative liabilities MMBTUs (830 ) (57 ) (1,900 ) (810 ) Total Fair Value Included in Derivative assets Other assets 256 1,569 Derivative liabilities Other liabilities (116 ) (1,306 )
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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 (Dollars in thousands) Derivative income $ — $ 6 $ 5 $ 11
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: June 30, 2017 December 31, 2016 (Dollars in Credit exposure $ 76 $ —

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Net interest income (expense) $ 17,832 $ 37,047 $ 1,698 $ (138 ) $ — $ 56,439 Noninterest income 3,945 13,660 7,456 25,644 (22,722 ) 27,983 Income before taxes 11,784 24,509 3,119 16,720 (22,504 ) 33,628 Three Months Ended June 30, 2016 Net interest income (expense) $ 15,699 $ 33,846 $ 1,591 $ (268 ) $ — $ 50,868 Noninterest income 4,098 14,408 6,646 18,798 (17,893 ) 26,057 Income before taxes 10,240 20,331 2,431 11,247 (17,848 ) 26,401 Six Months Ended June 30, 2017 Net interest income (expense) $ 36,352 $ 72,170 $ 3,193 $ (508 ) $ — $ 111,207 Noninterest income 7,767 26,937 15,766 50,116 (44,518 ) 56,068 Income before taxes 24,858 47,228 6,764 32,231 (44,260 ) 66,821 Six Months Ended June 30, 2016 Net interest income (expense) $ 31,542 $ 66,968 $ 3,007 $ (673 ) $ — $ 100,844 Noninterest income 7,886 28,004 14,125 36,476 (34,817 ) 51,674 Income before taxes 19,588 39,425 5,545 21,747 (34,705 ) 51,600 Total Assets: June 30, 2017 $ 2,506,852 $ 4,432,649 $ 97,894 $ 824,524 $ (815,330 ) $ 7,046,589 December 31, 2016 2,493,096 4,412,174 83,594 803,810 (773,722 ) 7,018,952

Description of Business and S31

Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Excess tax benefit from share-based compensation	$ 1,784
Accounting Standards Update 2016-09 [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Excess tax benefit from share-based compensation	$ 1,800

Securities - Summary of Securit

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Marketable Securities [Abstract]
Held for investment, at cost (fair value: $3,975 and $4,403, respectively)	$ 3,942	$ 4,365
Available for sale, at fair value	447,460	465,468
Total	$ 451,402	$ 469,833

Securities - Summary of Secur33

Securities - Summary of Securities Held for Investment and Securities Available for Sale (Parenthetical) (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Marketable Securities [Abstract]
Held for investment at fair value	$ 3,975	$ 4,403

Securities - Summary of Amortiz

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 3,942	$ 4,365
Gross Unrealized Gains	34	42
Gross Unrealized Losses	(1)	(4)
Estimated Fair Value	3,975	4,403
Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	217	252
Gross Unrealized Gains	12	17
Estimated Fair Value	229	269
States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	3,225	3,613
Gross Unrealized Gains	22	25
Gross Unrealized Losses	(1)	(4)
Estimated Fair Value	3,246	3,634
Other Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	500	500
Estimated Fair Value	$ 500	$ 500

Securities - Summary of Amort35

Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 446,733	$ 465,315
Gross Unrealized Gains	2,564	2,324
Gross Unrealized Losses	(1,837)	(2,171)
Estimated Fair Value	447,460	465,468
U.S. Treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	284,791	268,763
Gross Unrealized Gains	867	700
Gross Unrealized Losses	(271)	(920)
Estimated Fair Value	285,387	268,543
U.S. Federal Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	98,311	129,674
Gross Unrealized Gains	397	373
Gross Unrealized Losses	(310)	(405)
Estimated Fair Value	98,398	129,642
Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	19,052	19,949
Gross Unrealized Gains	246	290
Gross Unrealized Losses	(513)	(567)
Estimated Fair Value	18,785	19,672
States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	38,129	40,335
Gross Unrealized Gains	865	836
Gross Unrealized Losses	(59)	(129)
Estimated Fair Value	38,935	41,042
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,450	6,594
Gross Unrealized Gains	189	125
Gross Unrealized Losses	(684)	(150)
Estimated Fair Value	$ 5,955	$ 6,569

Securities - Maturity of Securi

Securities - Maturity of Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Held for Investment, Contractual maturity of debt securities, Amortized Cost
Amortized cost, Within one year	$ 1,672	$ 1,561
Amortized cost, After one year but within five years	1,593	1,937
Amortized cost, After five years but within ten years	667	707
Amortized cost, After ten years	10	160
Amortized Cost	3,942	4,365
Available for sale, Contractual maturity of debt securities, Amortized Cost
Amortized Cost, Within one year	66,022	66,542
Amortized Cost, After one year but within five years	308,283	320,150
Amortized Cost, After five years but within ten years	5,849	5,830
Amortized Cost, After ten years	60,129	66,199
Total debt securities	440,283	458,721
Amortized Cost, Equity securities	6,450	6,594
Amortized Cost	446,733	465,315
Held for Investment, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	1,683	1,568
Estimated Fair Value, After one year but within five years	1,603	1,951
Estimated Fair Value, After five years but within ten years	674	723
Estimated Fair Value, After ten years	15	161
Estimated Fair Value	3,975	4,403
Available for sale, Contractual maturity of debt securities, Estimated Fair Value
Estimated Fair Value, Within one year	66,105	66,662
Estimated Fair Value, After one year but within five years	308,913	319,839
Estimated Fair Value, After five years but within ten years	6,184	6,152
Estimated Fair Value, After ten years	60,303	66,246
Total debt securities	441,505	458,899
Estimated Fair Value, Equity securities	5,955	6,569
Estimated Fair Value, Total	$ 447,460	$ 465,468

Securities - Company's Book Val

Securities - Company's Book Value of Pledged Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Pledged Financial Instruments Not Separately Reported Securities Pledged By Type Of Security [Abstract]
Book value of pledged securities	$ 394,974	$ 439,692

Loans and Allowance for Loan 38

Loans and Allowance for Loan Losses - Schedule of Loans Outstanding by Category (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 4,578,393	$ 4,400,232
Percent	100.00%	100.00%
Taxable [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 81,164	$ 33,793
Percent	1.77%	0.77%
Tax-exempt [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 48,840	$ 47,283
Percent	1.07%	1.07%
Commercial and Financial [Member] | Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 927,616	$ 828,260
Percent	20.26%	18.82%
Commercial and Financial [Member] | Oil & Gas Production And Equipment [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 96,230	$ 84,228
Percent	2.10%	1.91%
Commercial and Financial [Member] | Agriculture [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 135,298	$ 144,751
Percent	2.96%	3.29%
Real Estate [Member] | Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 412,367	$ 420,884
Percent	9.01%	9.57%
Real Estate [Member] | Farmland [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 201,535	$ 197,872
Percent	4.40%	4.50%
Real Estate [Member] | One to Four Family Residences [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 859,980	$ 846,360
Percent	18.78%	19.24%
Real Estate [Member] | Multifamily Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 46,995	$ 57,806
Percent	1.03%	1.31%
Real Estate [Member] | Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 1,455,612	$ 1,426,643
Percent	31.79%	32.42%
Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 280,345	$ 279,704
Percent	6.12%	6.36%
Other (Not Classified Above) [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 32,411	$ 32,648
Percent	0.71%	0.74%

Loans and Allowance for Loan 39

Loans and Allowance for Loan Losses - Additional Information (Detail) - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 4,578,393,000		$ 4,400,232,000
Percentage of loans secured by real estate	65.00%
Interest income that would have been recognized	$ 886,000	$ 982,000
Interest income recognized on impaired loans	2,300,000		0
Gains on sales of other real estate owned		$ 1,300,000
Commercial and Industrial [Member] | Ancillary Services [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 70,000,000		$ 56,000,000

Loans and Allowance for Loan 40

Loans and Allowance for Loan Losses - Summary of Nonperforming and Restructured Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Summary Of Nonperforming And Restructured Assets [Abstract]
Past due 90 days or more and still accruing	$ 2,217	$ 1,962
Nonaccrual	19,607	31,798
Restructured	3,561	1,713
Total nonperforming and restructured loans	25,385	35,473
Other real estate owned and repossessed assets	4,211	3,866
Total nonperforming and restructured assets	$ 29,596	$ 39,339

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	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	$ 19,607	$ 31,798
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	641	713
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	1,865	5,688
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	886	1,116
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	4,829	5,089
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	3,542	4,464
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	271	265
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	4,928	8,370
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans, Total	$ 2,645	$ 6,093

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	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 36,320	$ 35,200
Current Loans	4,542,073	4,365,032
Total Loans	4,578,393	4,400,232
Accruing Loans 90 Days or More Past Due	2,217	1,962
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,866	2,501
Current Loans	586,223	569,130
Total Loans	591,089	571,631
Accruing Loans 90 Days or More Past Due	229
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,691	1,045
Current Loans	1,126,418	1,122,351
Total Loans	1,128,109	1,123,396
Accruing Loans 90 Days or More Past Due	29
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,768	4,664
Current Loans	327,963	320,749
Total Loans	330,731	325,413
Accruing Loans 90 Days or More Past Due	482	513
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	6,177	4,506
Current Loans	751,940	743,723
Total Loans	758,117	748,229
Accruing Loans 90 Days or More Past Due	287	369
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	6,575	3,638
Current Loans	1,201,751	1,047,547
Total Loans	1,208,326	1,051,185
Accruing Loans 90 Days or More Past Due	564	608
Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	2,621	3,225
Current Loans	281,536	280,652
Total Loans	284,157	283,877
Accruing Loans 90 Days or More Past Due	388	274
Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	10,365	14,078
Current Loans	134,183	127,404
Total Loans	144,548	141,482
Accruing Loans 90 Days or More Past Due	101	45
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,257	1,543
Current Loans	132,059	153,476
Total Loans	133,316	155,019
Accruing Loans 90 Days or More Past Due	137	153
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	18,699	17,652
30 to 59 Days Past Due [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	3,991	2,255
30 to 59 Days Past Due [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,354	611
30 to 59 Days Past Due [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,504	2,742
30 to 59 Days Past Due [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,872	2,559
30 to 59 Days Past Due [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,133	1,269
30 to 59 Days Past Due [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,562	2,046
30 to 59 Days Past Due [Member] | Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	555	5,345
30 to 59 Days Past Due [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	728	825
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	7,222	4,948
60 to 89 Days Past Due [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	145	96
60 to 89 Days Past Due [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	70	16
60 to 89 Days Past Due [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	483	649
60 to 89 Days Past Due [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	294	531
60 to 89 Days Past Due [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	671	1,628
60 to 89 Days Past Due [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	505	760
60 to 89 Days Past Due [Member] | Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,941	958
60 to 89 Days Past Due [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	113	310
90 Days and Greater [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	10,399	12,600
90 Days and Greater [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	730	150
90 Days and Greater [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	267	418
90 Days and Greater [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	781	1,273
90 Days and Greater [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,011	1,416
90 Days and Greater [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	1,771	741
90 Days and Greater [Member] | Consumer Non-real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	554	419
90 Days and Greater [Member] | Other Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	4,869	7,775
90 Days and Greater [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due Loans	$ 416	$ 408

Loans and Allowance for Loan 43

Loans and Allowance for Loan Losses - Impaired Loans Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 35,808	$ 47,665
Recorded Investment with Allowance	25,526	35,709
Related Allowance	4,134	5,797
Average Recorded Investment	27,403	35,105
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,065	894
Recorded Investment with Allowance	958	806
Related Allowance	31	101
Average Recorded Investment	1,060	825
Real Estate [Member] | Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,967	7,742
Recorded Investment with Allowance	1,894	5,688
Related Allowance	184	574
Average Recorded Investment	2,057	5,854
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,623	1,878
Recorded Investment with Allowance	1,418	1,683
Related Allowance	104	124
Average Recorded Investment	1,483	1,612
Real Estate [Member] | Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	5,420	5,871
Recorded Investment with Allowance	5,195	5,614
Related Allowance	1,555	1,538
Average Recorded Investment	5,136	5,445
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	13,725	12,015
Recorded Investment with Allowance	7,257	6,272
Related Allowance	1,454	1,457
Average Recorded Investment	6,401	6,478
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	790	686
Recorded Investment with Allowance	754	650
Related Allowance	117	133
Average Recorded Investment	776	788
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	6,471	9,799
Recorded Investment with Allowance	5,030	8,415
Related Allowance	689	1,870
Average Recorded Investment	5,523	8,062
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	4,747	8,780
Recorded Investment with Allowance	3,020	6,581
Average Recorded Investment	$ 4,967	$ 6,041

Loans and Allowance for Loan 44

Loans and Allowance for Loan Losses - Internal Loan Grading by Class of Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 4,578,393	$ 4,400,232
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	591,089	571,631
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,128,109	1,123,396
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	330,731	325,413
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	758,117	748,229
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,208,326	1,051,185
Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	284,157	283,877
Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	144,548	141,482
Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	133,316	155,019
Grade 1 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,739,534	3,642,438
Grade 1 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	474,155	464,504
Grade 1 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	941,448	933,743
Grade 1 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	289,912	284,893
Grade 1 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	607,861	614,338
Grade 1 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	947,575	856,318
Grade 1 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	263,875	263,442
Grade 1 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	137,753	132,254
Grade 1 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	76,955	92,946
Grade 2 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	731,646	647,509
Grade 2 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	101,757	89,978
Grade 2 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	169,968	169,561
Grade 2 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	33,676	32,889
Grade 2 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	134,189	119,018
Grade 2 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	234,258	170,865
Grade 2 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	17,473	17,154
Grade 2 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,450	5,376
Grade 2 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	34,875	42,668
Grade 3 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	90,268	82,136
Grade 3 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	14,536	16,220
Grade 3 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	14,759	14,404
Grade 3 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,805	5,987
Grade 3 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	10,918	9,382
Grade 3 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	22,652	19,101
Grade 3 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,093	2,640
Grade 3 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,115	1,514
Grade 3 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	18,390	12,888
Grade 4 [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	16,945	28,149
Grade 4 [Member] | Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	641	929
Grade 4 [Member] | Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,934	5,688
Grade 4 [Member] | Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,338	1,644
Grade 4 [Member] | Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,149	5,491
Grade 4 [Member] | Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,841	4,901
Grade 4 [Member] | Consumer Non-real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	716	641
Grade 4 [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	230	2,338
Grade 4 [Member] | Acquired Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 3,096	$ 6,517

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	$ 47,921	$ 44,571	$ 48,693	$ 41,666
Charge- offs	(879)	(929)	(2,760)	(2,209)
Recoveries	122	120	1,159	202
Net charge- offs	(757)	(809)	(1,601)	(2,007)
Provisions charged to operations	1,841	2,804	1,913	6,907
Balance at end of period	49,005	46,566	49,005	46,566
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	5,562	4,832	5,602	4,661
Charge- offs	(40)	(9)	(72)	(10)
Recoveries	3		4
Net charge- offs	(37)	(9)	(68)	(10)
Provisions charged to operations	160	73	151	245
Balance at end of period	5,685	4,896	5,685	4,896
Real Estate [Member] | Non-residential Real Estate Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	10,788	10,211	10,793	9,921
Charge- offs	(25)	(3)	(26)	(4)
Recoveries	1	1	2	2
Net charge- offs	(24)	(2)	(24)	(2)
Provisions charged to operations	(284)	93	(289)	383
Balance at end of period	10,480	10,302	10,480	10,302
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	3,130	3,164	3,129	3,148
Charge- offs	(36)	(49)	(156)	(99)
Recoveries	10	21	11	38
Net charge- offs	(26)	(28)	(145)	(61)
Provisions charged to operations	44	67	164	116
Balance at end of period	3,148	3,203	3,148	3,203
Real Estate [Member] | Residential Real Estate All Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	8,659	7,989	8,622	6,725
Charge- offs	(16)	(70)	(73)	(137)
Recoveries	6	7	17	11
Net charge- offs	(10)	(63)	(56)	(126)
Provisions charged to operations	263	367	346	1,694
Balance at end of period	8,912	8,293	8,912	8,293
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	12,810	12,813	12,421	11,754
Charge- offs	(471)	(502)	(677)	(1,305)
Recoveries	61	35	979	46
Net charge- offs	(410)	(467)	302	(1,259)
Provisions charged to operations	1,243	1,095	920	2,946
Balance at end of period	13,643	13,441	13,643	13,441
Consumer Non-real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	2,725	2,553	2,804	2,642
Charge- offs	(234)	(134)	(468)	(355)
Recoveries	32	38	83	76
Net charge- offs	(202)	(96)	(385)	(279)
Provisions charged to operations	183	292	287	386
Balance at end of period	2,706	2,749	2,706	2,749
Other Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	2,958	2,790	4,045	2,648
Charge- offs	(56)	(149)	(1,274)	(282)
Recoveries	1	7	5	13
Net charge- offs	(55)	(142)	(1,269)	(269)
Provisions charged to operations	103	729	230	998
Balance at end of period	3,006	3,377	3,006	3,377
Acquired Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of period	1,289	219	1,277	167
Charge- offs	(1)	(13)	(14)	(17)
Recoveries	8	11	58	16
Net charge- offs	7	(2)	44	(1)
Provisions charged to operations	129	88	104	139
Balance at end of period	$ 1,425	$ 305	$ 1,425	$ 305

Loans and Allowance for Loan 46

Loans and Allowance for Loan Losses - Allowance for Loan Losses Outstanding by Impairment Methodology (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 8,589	$ 10,519
Collectively evaluated for impairment	40,416	38,174
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	569	716
Collectively evaluated for impairment	5,116	4,886
Real Estate [Member] | Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	739	1,119
Collectively evaluated for impairment	9,741	9,674
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	391	422
Collectively evaluated for impairment	2,757	2,707
Real Estate [Member] | Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,305	2,160
Collectively evaluated for impairment	6,607	6,462
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	3,517	3,317
Collectively evaluated for impairment	10,126	9,104
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	400	478
Collectively evaluated for impairment	2,306	2,326
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	656	1,812
Collectively evaluated for impairment	2,350	2,233
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	12	495
Collectively evaluated for impairment	$ 1,413	$ 782

Loans and Allowance for Loan 47

Loans and Allowance for Loan Losses - Loans Outstanding by Impairment Methodology (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 100,489	$ 102,663
Collectively evaluated for impairment	4,472,252	4,291,625
Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	5,652	5,944
Real Estate [Member] | Non-residential Real Estate Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	15,177	17,149
Collectively evaluated for impairment	575,912	554,482
Real Estate [Member] | Non-residential Real Estate Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	16,692	20,092
Collectively evaluated for impairment	1,111,417	1,103,304
Real Estate [Member] | Residential Real Estate Permanent Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	7,144	7,631
Collectively evaluated for impairment	323,587	317,782
Real Estate [Member] | Residential Real Estate All Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	16,067	14,873
Collectively evaluated for impairment	742,050	733,356
Commercial and Financial [Member] | Non-consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	26,194	24,002
Collectively evaluated for impairment	1,182,132	1,027,183
Consumer Non-real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,809	3,203
Collectively evaluated for impairment	281,348	280,674
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	572	2,254
Collectively evaluated for impairment	143,976	139,228
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	15,834	13,459
Collectively evaluated for impairment	111,830	135,616
Acquired Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	$ 5,652	$ 5,944

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	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable Allowance For Credit Loss Additional Information Transfer From Loans To Other Real Estate Owned And Repossessed Assets [Abstract]
Other real estate owned	$ 1,513	$ 1,210
Repossessed assets	612	750
Total	$ 2,125	$ 1,960

Intangible Assets - Summary of

Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 23,600	$ 23,619
Accumulated Amortization	(11,397)	(10,289)
Net Carrying Amount	12,203	13,330
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	17,447	17,447
Accumulated Amortization	(7,531)	(6,611)
Net Carrying Amount	9,916	10,836
Customer Relationship Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,699	5,699
Accumulated Amortization	(3,593)	(3,419)
Net Carrying Amount	2,106	2,280
Mortgage Servicing Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	454	473
Accumulated Amortization	(273)	(259)
Net Carrying Amount	$ 181	$ 214

Intangible Assets - Summary o50

Intangible Assets - Summary of Goodwill by Business Segment (Detail) $ in Thousands	Jun. 30, 2017USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 54,042
Balance at end of period	54,042
Metropolitan Banks [Member]
Goodwill [Line Items]
Balance at beginning of period	8,078
Balance at end of period	8,078
Community Banks [Member]
Goodwill [Line Items]
Balance at beginning of period	40,050
Balance at end of period	40,050
Other Financial Services [Member]
Goodwill [Line Items]
Balance at beginning of period	5,464
Balance at end of period	5,464
Executive, Operations & Support [Member]
Goodwill [Line Items]
Balance at beginning of period	450
Balance at end of period	$ 450

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - shares	6 Months Ended
	Jun. 30, 2017	May 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Deferred board fees percentage for stock units accumulation	100.00%
Nonqualified Incentive Stock Option Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period in years	7 years
Nonqualified Incentive Stock Option Plan [Member] | Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares to be issued under incentive stock option plan		3,200,000
Shares for future grants	190,735
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	2,024
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		260,000
Shares for future grants	40,000
Option exercisable rate	25.00%
Option exercisable period	1 year
Options expire period	15 years
Share based compensation options exercisable period	2,020
Options vest and exercisable Description	The options 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		111,110
Number of shares of common stock distributed	4,959

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Activity Under Stock Option Plan (Detail) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding at beginning period - Options | shares	707,450
Options granted | shares	25,000
Options exercised | shares	(93,325)
Outstanding at ending period - Options | shares	639,125
Exercisable at ending period - Options | shares	277,250
Outstanding at beginning period - Wgtd. Avg. Exercise Price | $ / shares	$ 44.92
Options granted - Wgtd. Avg. Exercise Price | $ / shares	91.39
Options exercised - Wgtd. Avg. Exercise Price | $ / shares	34.90
Outstanding at ending period - Wgtd. Avg. Exercise Price | $ / shares	48.20
Exercisable at ending period - Wgtd. Avg. Exercise Price | $ / shares	$ 38.77
Outstanding at ending period - Wgtd. Avg. Remaining Contractual Term, years	9 years 8 months 26 days
Exercisable at ending period - Wgtd. Avg. Remaining Contractual Term, years	6 years 10 months 6 days
Outstanding at ending period - Aggregate Intrinsic Value | $	$ 30,933
Exercisable at ending period - Aggregate Intrinsic Value | $	$ 16,034

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award Options Additional Disclosures [Abstract]
Weighted average grant-date fair value per share of options granted	$ 21.92	$ 11.29	$ 21.92	$ 11.40
Total intrinsic value of options exercised	$ 1,032	$ 891	$ 5,645	$ 1,670
Cash received from options exercised	647	1,001	3,257	1,876
Tax benefit realized from options exercised	$ 399	$ 345	$ 2,183	$ 646

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Employee Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Labor And Related Expense [Abstract]
Stock-based compensation expense	$ 282	$ 450	$ 465	$ 901
Tax benefit	109	174	180	348
Stock-based compensation expense, net of tax	$ 173	$ 276	$ 285	$ 553

Stock-Based Compensation - Unea

Stock-Based Compensation - Unearned Stock-based Compensation Expense (Detail) $ in Thousands	Jun. 30, 2017USD ($)
Remaining Fair Value Of Stock Options [Abstract]
Unearned stock-based compensation expense	$ 2,858

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used for Computing Stock-Based Compensation Expense (Detail)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Risk-free interest rate, minimum	2.15%	1.46%
Risk-free interest rate, maximum	2.38%	2.02%
Dividend yield	2.00%	2.00%
Stock price volatility, minimum	22.57%	20.41%
Stock price volatility, maximum	23.13%	20.64%
Expected term	10 years	10 years

Stock - Based Compensation - Su

Stock - Based Compensation - Summary of Accumulated Stock Units (Detail) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Accumulated stock units	67,226	70,022
Average price	$ 43.69	$ 41.74

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Shares Repurchased Under Stock Purchase Program (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2017
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	150,000

Stockholders' Equity - Required

Stockholders' Equity - Required Capital Amounts and Company's Respective Ratios (Detail) $ in Thousands	Jun. 30, 2017USD ($)
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 763,741
Total Capital To Risk Weighted Assets Actual Ratio	15.51%
Capital Required For Capital Adequacy Amount	$ 394,051
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%
Capital With Capital Conservation Buffer Amount	$ 455,621
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	9.25%
Common Equity Tier 1 Risk Based Capital Amount	$ 683,736
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	13.88%
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 221,653
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	$ 283,224
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	5.75%
Tier 1 Risk Based Capital Amount	$ 714,736
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	14.51%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 295,538
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	$ 357,108
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	7.25%
Tier 1 Capital Amount	$ 714,736
Tier 1 Capital To Average Assets Ratio	10.15%
Tier 1 Capital Required For Capital Adequacy Amount	$ 281,701
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	$ 685,395
Total Capital To Risk Weighted Assets Actual Ratio	13.93%
Capital Required For Capital Adequacy Amount	$ 393,644
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	8.00%
Capital With Capital Conservation Buffer Amount	$ 455,151
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	9.25%
Capital Required To Be Well Capitalized Amount	$ 492,055
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	10.00%
Common Equity Tier 1 Risk Based Capital Amount	$ 616,390
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.53%
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 221,425
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	$ 282,932
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	5.75%
Common Equity Tier 1 Risk Based Capital Required To Be well Capitalized Amount	$ 319,836
Common Equity Tier 1 Risk Based Capital Required To Be well Capitalized Amount	6.50%
Tier 1 Risk Based Capital Amount	$ 636,390
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	12.93%
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 295,233
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	$ 356,740
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	7.25%
Tier 1 Risk Based Capital Required To Be well Capitalized Amount	$ 393,644
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	8.00%
Tier 1 Capital Amount	$ 636,390
Tier 1 Capital To Average Assets Ratio	9.05%
Tier 1 Capital Required For Capital Adequacy Amount	$ 281,404
Tier 1 Capital Required For Capital Adequacy To Average Assets Ratio	4.00%
Tier 1 Capital Required To Be Well Capitalized Amount	$ 351,755
Tier 1 Capital Required To Be Well Capitalized To Average assets Ratio	5.00%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017USD ($)
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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share Reconciliation [Abstract]
Income available to common stockholders	$ 23,182	$ 17,493	$ 45,232	$ 34,072
Income available to common stockholders plus assumed exercises of stock options	$ 23,182	$ 17,493	$ 45,232	$ 34,072
Income available to common stockholders - Shares	15,903,805	15,549,811	15,884,414	15,542,114
Dilutive effect of stock options - Shares	357,883	292,674	365,581	288,563
Income available to common stockholders plus assumed exercises of stock options - Shares	16,261,688	15,842,485	16,249,995	15,830,677
Income available to common stockholders - Per Share Amount	$ 1.46	$ 1.12	$ 2.85	$ 2.19
Income available to common stockholders plus assumed exercises of stock options - Per Share Amount	$ 1.42	$ 1.10	$ 2.78	$ 2.15

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Abstract]
Shares	19,505	241,945	9,807	239,198
Average Exercise Price	$ 90.64	$ 58.52	$ 90.64	$ 58.55

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
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	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 447,460	$ 465,468
Derivative assets	256	1,569
Derivative liabilities	116	1,306
Loans held for sale	9,061	9,318
U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	285,387	268,543
U.S. Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	98,398	129,642
Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	18,785	19,672
States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	38,935	41,042
Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	5,955	6,569
Level 1 Inputs [Member] | U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	285,387	268,543
Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	256	1,569
Derivative liabilities	116	1,306
Loans held for sale	9,061	9,318
Level 2 Inputs [Member] | U.S. Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	98,398	129,642
Level 2 Inputs [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	5,767	4,856
Level 2 Inputs [Member] | States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	38,935	41,042
Level 3 Inputs [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	13,018	14,816
Level 3 Inputs [Member] | Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, at fair value	$ 5,955	$ 6,569

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 Assets Measured at Estimated Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward
Balance at the beginning of the year	$ 21,385	$ 21,124
Purchases	293	1,096
Settlements	(1,905)	(191)
Sales		(429)
Losses included in earnings	(330)	(111)
Total unrealized losses	(470)	(104)
Balance at the end of the period	$ 18,973	$ 21,385

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value on Nonrecurring Basis (Detail) - Level 3 [Member] - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Impaired Loans (Less Specific Allowance) [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	$ 21,392	$ 29,912
Repossessed Assets [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	238	340
Other Real Estate Owned [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Fair Value	$ 1,329	$ 1,480

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
FINANCIAL ASSETS
Cash and cash equivalents, Carrying Amount	$ 1,716,900	$ 1,850,461	$ 1,597,822	$ 1,598,177
Securities held for investment, Carrying Amount	3,942	4,365
Loans, net of allowance for loan losses, Carrying Amount	4,529,388	4,351,539
Securities held for investment, Fair Value	3,975	4,403
FINANCIAL LIABILITIES
Deposits, Carrying Amount	6,235,682	6,248,057
Short-term borrowings, Carrying Amount	1,000	500
Junior subordinated debentures, Carrying Amount	31,959	31,959
OFF-BALANCE SHEET FINANCIAL INSTRUMENTS
Loan commitments, Fair Value	1,780	1,718
Letters of credit, Fair Value	443	424
Level 2 Inputs [Member]
FINANCIAL ASSETS
Cash and cash equivalents, Carrying Amount	1,716,900	1,851,161
Securities held for investment, Carrying Amount	3,442	3,722
Cash and cash equivalents, Fair Value	1,716,900	1,851,161
Securities held for investment, Fair Value	3,475	3,760
FINANCIAL LIABILITIES
Deposits, Carrying Amount	6,235,682	6,248,057
Short-term borrowings, Carrying Amount	1,000	500
Junior subordinated debentures, Carrying Amount	31,959	31,959
Deposits, Fair Value	6,306,671	6,313,622
Short-term borrowings, Fair Value	1,000	500
Junior subordinated debentures, Fair Value	35,830	34,339
Level 3 Inputs [Member]
FINANCIAL ASSETS
Securities held for investment, Carrying Amount	500	643
Loans, net of allowance for loan losses, Carrying Amount	4,529,388	4,351,539
Securities held for investment, Fair Value	500	643
Loans, net of allowance for loan losses, Fair Value	$ 4,534,977	$ 4,367,363

Derivative Financial Instrume68

Derivative Financial Instruments - Notional Amounts and Estimated Fair Values of Outstanding Derivative Positions (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	$ 256	$ 1,569
Derivative liabilities, Estimated Fair Value	(116)	(1,306)
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Estimated Fair Value	256	1,569
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Estimated Fair Value	$ (116)	(1,306)
Oil [Member]
Derivatives, Fair Value [Line Items]
Notional Units	Barrels
Derivative assets, Notional Amount	$ 46	83
Derivative assets, Estimated Fair Value	108	576
Derivative liabilities, Notional Amount	(46)	(83)
Derivative liabilities, Estimated Fair Value	$ (59)	(496)
Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Notional Units	MMBTUs
Derivative assets, Notional Amount	$ 830	1,900
Derivative assets, Estimated Fair Value	148	993
Derivative liabilities, Notional Amount	(830)	(1,900)
Derivative liabilities, Estimated Fair Value	$ (57)	$ (810)

Derivative Financial Instrume69

Derivative Financial Instruments - Recognized Derivative Income Included in Other Noninterest Income (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative Gain Loss On Derivative Net [Abstract]
Derivative income	$ 6	$ 5	$ 11

Derivative Financial Instrume70

Derivative Financial Instruments - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017
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	Jun. 30, 2017USD ($)
Credit Risk Derivatives At Fair Value Net [Abstract]
Credit exposure	$ 76

Segment Information - Additiona

Segment Information - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017Business_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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 56,439	$ 50,868	$ 111,207	$ 100,844
Noninterest income	27,983	26,057	56,068	51,674
Income before taxes	33,628	26,401	66,821	51,600
Total Assets	7,046,589		7,046,589		$ 7,018,952
Operating Segments [Member] | Metropolitan Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	17,832	15,699	36,352	31,542
Noninterest income	3,945	4,098	7,767	7,886
Income before taxes	11,784	10,240	24,858	19,588
Total Assets	2,506,852		2,506,852		2,493,096
Operating Segments [Member] | Community Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	37,047	33,846	72,170	66,968
Noninterest income	13,660	14,408	26,937	28,004
Income before taxes	24,509	20,331	47,228	39,425
Total Assets	4,432,649		4,432,649		4,412,174
Operating Segments [Member] | Other Financial Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	1,698	1,591	3,193	3,007
Noninterest income	7,456	6,646	15,766	14,125
Income before taxes	3,119	2,431	6,764	5,545
Total Assets	97,894		97,894		83,594
Operating Segments [Member] | Executive, Operations & Support [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	(138)	(268)	(508)	(673)
Noninterest income	25,644	18,798	50,116	36,476
Income before taxes	16,720	11,247	32,231	21,747
Total Assets	824,524		824,524		803,810
Eliminations [Member]
Segment Reporting Information [Line Items]
Noninterest income	(22,722)	(17,893)	(44,518)	(34,817)
Income before taxes	(22,504)	$ (17,848)	(44,260)	$ (34,705)
Total Assets	$ (815,330)		$ (815,330)		$ (773,722)

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Common Stock [Member]	Aug. 04, 2017shares	Jun. 30, 2017
Subsequent Event [Line Items]
Stock split description		Subsequent to June 30, 2017, the Company completed a two-for-one stock split of the Company’s outstanding shares of common stock.
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock split conversion ratio	2
Stock payable in form of dividend, payable date	Jul. 31, 2017
Stock payable in form of dividend, record date	Jul. 17, 2017
Additional shares to receive by stockholders for each share held	1