Franklin Financial Network (FSB) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	FSB
Entity Registrant Name	FRANKLIN FINANCIAL NETWORK INC.
Entity Central Index Key	1,407,067
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		14,373,890

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and due from financial institutions	$ 246,164	$ 251,543
Certificates of deposit at other financial institutions	2,855	2,855
Securities available for sale	1,186,420	999,881
Securities held to maturity (fair value 2018-$210,888 and 2017-$217,608)	213,381	214,856
Loans held for sale, at fair value	12,871	12,024
Loans	2,310,018	2,256,608
Allowance for loan losses	(21,738)	(21,247)
Net loans	2,288,280	2,235,361
Restricted equity securities, at cost	19,606	18,492
Premises and equipment, net	10,941	11,281
Accrued interest receivable	12,937	11,947
Bank owned life insurance	49,450	49,085
Deferred tax asset	13,807	10,007
Foreclosed assets	1,503	1,503
Servicing rights, net	3,602	3,620
Goodwill	9,124	9,124
Core deposit intangible, net	903	1,007
Other assets	11,819	10,940
Total assets	4,083,663	3,843,526
Deposits
Non-interest bearing	298,503	272,172
Interest bearing	3,056,650	2,895,056
Total deposits	3,355,153	3,167,228
Federal Home Loan Bank advances	317,000	272,000
Federal funds purchased and repurchase agreements	36,071	31,004
Subordinated notes, net	58,559	58,515
Accrued interest payable	2,775	2,769
Other liabilities	9,240	7,357
Total liabilities	3,778,798	3,538,873
Equity
Preferred stock, no par value: 1,000,000 shares authorized; no shares outstanding at March 31, 2018 and December 31, 2017
Common stock, no par value: 30,000,000 and 30,000,000 shares authorized at March 31, 2018 and December 31, 2017 , respectively; 13,258,142 and 13,237,128 issued at March 31, 2018 and December 31, 2017 , respectively	223,594	222,665
Retained earnings	98,723	88,671
Accumulated other comprehensive loss	(17,555)	(6,786)
Total shareholders' equity	304,762	304,550
Noncontrolling interest in consolidated subsidiary	103	103
Total equity	304,865	304,653
Total liabilities and equity	$ 4,083,663	$ 3,843,526

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Held-to-maturity securities, fair value	$ 210,888	$ 217,608
Preferred stock, no par value
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, no par value
Common stock shares authorized	30,000,000	30,000,000
Common stock shares issued	13,258,142	13,237,128

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest income and dividends
Loans, including fees	$ 28,793	$ 22,560
Securities:
Taxable	6,111	5,617
Tax-Exempt	1,915	2,020
Dividends on restricted equity securities	274	181
Federal funds sold and other	954	163
Total interest income	38,047	30,541
Interest expense
Deposits	10,643	5,246
Federal Home Loan Bank advances	1,110	508
Federal funds purchased and repurchase agreements	96	70
Subordinated notes and other borrowings	1,082	1,074
Total interest expense	12,931	6,898
Net interest income	25,116	23,643
Provision for loan losses	573	1,855
Net interest income after provision for loan losses	24,543	21,788
Noninterest income
Service charges on deposit accounts	42	30
Other service charges and fees	751	752
Net gains on sale of loans	1,439	2,334
Wealth management	704	593
Loan servicing fees, net	119	107
Net (loss) gain on sale of foreclosed assets	3	3
Other	398	189
Total noninterest income	3,456	4,008
Noninterest expense
Salaries and employee benefits	9,188	8,033
Occupancy and equipment	2,594	2,095
FDIC assessment expense	660	760
Marketing	280	267
Professional fees	869	1,035
Amortization of core deposit intangible	104	127
Other	1,793	1,959
Total noninterest expense	15,488	14,276
Income before income tax expense	12,511	11,520
Income tax expense	2,459	3,586
Net income	10,052	7,934
Net income available to common shareholders	$ 10,052	$ 7,934
Earnings per share:
Basic	$ 0.76	$ 0.61
Diluted	$ 0.73	$ 0.58

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 10,052	$ 7,934
Unrealized gains on securities:
Unrealized holding loss arising during the period	(14,577)	(641)
Reclassification adjustment for gains included in net income	0	0
Net unrealized losses	(14,577)	(641)
Tax effect	3,808	251
Total other comprehensive loss	(10,769)	(390)
Comprehensive income (loss)	$ (717)	$ 7,544

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2016	$ 270,361	$ 0	$ 218,354	$ 59,386	$ (7,482)	$ 103
Beginning balance, shares at Dec. 31, 2016			13,036,954
Exercise of common stock options	177		$ 177
Exercise of common stock options, number of shares			20,268
Exercise of common stock warrants	$ 132		$ 132
Exercise of common stock warrants, number of shares	11,011		11,011
Stock based compensation expense, net of restricted share forfeitures	$ 447		$ 447
Stock based compensation expense, net of restricted share forfeitures, shares			(180)
Stock issued in conjunction with 401(k) employer match, net of distributions	(151)		$ (151)
Stock issued in conjunction with 401(k) employer match, net of distributions, number of shares			(3,943)
Net income	7,934			7,934
Other comprehensive loss	(390)				(390)
Ending balance at Mar. 31, 2017	278,510		$ 218,959	67,320	(7,872)	103
Ending balance, shares at Mar. 31, 2017			13,064,110
Beginning balance at Dec. 31, 2017	304,653		$ 222,665	88,671	(6,786)	103
Beginning balance, shares at Dec. 31, 2017			13,237,128
Exercise of common stock options	220		$ 220
Exercise of common stock options, number of shares			21,348
Stock based compensation expense, net of restricted share forfeitures	759		$ 759
Stock based compensation expense, net of restricted share forfeitures, shares			(334)
Stock issued in conjunction with 401(k) employer match, net of distributions	(50)		$ (50)
Net income	10,052			10,052
Other comprehensive loss	(10,769)				(10,769)
Ending balance at Mar. 31, 2018	$ 304,865		$ 223,594	$ 98,723	$ (17,555)	$ 103
Ending balance, shares at Mar. 31, 2018			13,258,142

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income	$ 10,052	$ 7,934
Adjustments to reconcile net income to net cash from operating activities
Depreciation and amortization on premises and equipment	403	368
Accretion of purchase accounting adjustments	(252)	(381)
Net amortization of securities	1,904	2,452
Amortization of loan servicing right asset	214	213
Amortization of core deposit intangible	104	127
Amortization of debt issuance costs	44	44
Provision for loan losses	573	1,855
Deferred income tax benefit	10	(561)
Origination of loans held for sale	(83,226)	(65,213)
Proceeds from sale of loans held for sale	83,622	78,379
Net gain on sale of loans	(1,439)	(2,334)
Income from bank owned life insurance	(365)	(155)
Stock-based compensation	759	447
Deferred gain on sale of loans	(4)	(58)
Deferred gain on sale of foreclosed assets	(3)	(3)
Net change in:
Accrued interest receivable and other assets	(1,871)	(1,687)
Accrued interest payable and other liabilities	1,896	5,944
Net cash from operating activities	12,421	27,371
Available for sale securities:
Purchases	(224,712)	(363,298)
Maturities, prepayments and calls	22,129	42,167
Held to maturity securities:
Purchases	(1,676)	(1,996)
Maturities, prepayments and calls	2,714	4,335
Net change in loans	(53,240)	(177,360)
Purchase of restricted equity securities	(1,114)	(3,135)
Purchases of premises and equipment, net	(63)	(1,048)
Increase in certificates of deposits at other financial institutions		(980)
Net cash from investing activities	(255,962)	(501,315)
Cash flows from financing activities
Increase in deposits	187,925	425,394
Increase (Decrease) in federal funds purchased and repurchase agreements	5,067	(12,871)
Proceeds from Federal Home Loan Bank advances	95,000	230,000
Repayment of Federal Home Loan Bank advances	(50,000)	(145,000)
Proceeds from exercise of common stock warrants		132
Proceeds from exercise of common stock options	220	177
Divestment of common stock issued to 401(k) plan	(50)	(151)
Net cash from financing activities	238,162	497,681
Net change in cash and cash equivalents	(5,379)	23,737
Cash and cash equivalents at beginning of period	251,543	90,927
Cash and cash equivalents at end of period	246,164	114,664
Supplemental information:
Interest paid	12,925	6,829
Income taxes paid	$ 525	$ 530

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	NOTE 1—BASIS OF PRESENTATION The accompanying unaudited consolidated financial statements have been prepared in accordance with instructions to Form 10-Q S-X, 10-01. Form 10-K These consolidated financial statements include the accounts of Franklin Financial Network, Inc. (“FFN”), and its wholly-owned subsidiaries, Franklin Synergy Bank (“Franklin Synergy” or the “Bank”) and Franklin Synergy Risk Management, Inc. (collectively, the “Company”). Franklin Synergy Investments of Tennessee, Inc., Franklin Synergy Investments of Nevada, Inc., and Franklin Synergy Preferred Capital, Inc. are direct or indirect subsidiaries of the Bank and are included in these consolidated financial statements. Significant intercompany transactions and accounts are eliminated in consolidation. Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers 2014-09”), 2014-09 2014-09. 2014-09, 2014-09 The Company has identified the contract with a customer, identified the performance obligations in the contract, determined the transaction price, allocated the transaction price to the performance obligations in the contract, and recognized revenue when (or as) the Company satisfied a performance obligation. Significant revenue has not been recognized in the current reporting period that results from performance obligations satisfied in previous periods. The Company’s primary sources of revenue are derived from interest and dividends earned on loans, investment securities, and other financial instruments that are not impacted by the new standard. The Company has evaluated the nature of its contracts with customers and determined that further disaggregation of revenue from contracts with customers into more granular categories beyond what is presented in the Consolidated Statements of Income was not necessary. The Company generally fully satisfies its performance obligations on its contracts with customers as services are rendered and the transaction prices are typically fixed; charged either on a periodic basis or based on activity. Because performance obligations are satisfied as services are rendered and the transaction prices are fixed, there is little judgment involved in applying the new standard that significantly affects the determination of the amount and timing of revenue from contracts with customers. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities 2016-01”). 2016-01 non-recurring In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments zero-coupon In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business 2017-01”) 2017-01 In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Subtopic 718): Scope of Modification Accounting 2017-09 2017-09 2017-09 Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02 Leases Leases 2016-02 right-of-use 2016-02 right-of-use 2016-02 In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments available-for-sale 2016-13 In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ASU 2017-04 ASU 2017-04 In March 2017, the FASB issued ASU 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): ASU 2017-08 ASU 2017-08 Acquisition of Civic Bank & Trust Effective April 1, 2018, the Company acquired Civic Bank & Trust, which was located in Nashville, Tennessee. Effective with the acquisition, Dr. Anil Patel, who was the chairman of the Civic Bank & Trust board of directors, was added to the Company’s board of directors for a term expiring at the Company’s 2018 annual meeting of shareholders.

Securities

Securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	NOTE 2—SECURITIES The following table summarizes the amortized cost and fair value of the securities available for sale portfolio at March 31, 2018 and December 31, 2017 and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income. Amortized Gross Gross Fair March 31, 2018 U.S. Treasury securities $ 289,086 $ — $ (515 ) $ 288,571 U.S. government sponsored entities and agencies 20,103 — (209 ) 19,894 Mortgage-backed securities: residential 782,579 45 (19,496 ) 763,128 Mortgage-backed securities: commercial 5,123 — (112 ) 5,011 State and political subdivisions 113,295 404 (3,883 ) 109,816 Total $ 1,210,186 $ 449 $ (24,215 ) $ 1,186,420 Amortized Gross Gross Fair December 31, 2017 U.S. Treasury securities $ 229,119 $ — $ (210 ) $ 228,909 U.S. government sponsored entities and agencies 20,125 — (164 ) 19,961 Mortgage-backed securities: residential 641,225 102 (8,761 ) 632,566 Mortgage-backed securities: commercial 5,133 — (59 ) 5,074 State and political subdivisions 113,468 1,787 (1,884 ) 113,371 Total $ 1,009,070 $ 1,889 $ (11,078 ) $ 999,881 The amortized cost and fair value of the securities held to maturity portfolio at March 31, 2018 and December 31, 2017 and the corresponding amounts of gross unrecognized gains and losses were as follows: Amortized Gross Gross Fair March 31, 2018 Mortgage backed securities: residential $ 92,152 $ 111 $ (3,495 ) $ 88,768 State and political subdivisions 121,229 1,064 (173 ) 122,120 Total $ 213,381 $ 1,175 $ (3,668 ) $ 210,888 December 31, 2017 Mortgage backed securities: residential $ 93,366 $ 207 $ (1,796 ) $ 91,777 State and political subdivisions 121,490 4,379 (38 ) 125,831 Total $ 214,856 $ 4,586 $ (1,834 ) $ 217,608 The proceeds from sales and calls of securities available for sale and the associated gains and losses were as follows: Three Months Ended March 31, 2018 2017 Proceeds $ — $ — Gross gains — — Gross losses — — The amortized cost and fair value of the investment securities portfolio are shown by contractual maturity. Securities not due at a single maturity date, primarily mortgage-backed securities, are shown separately. March 31, 2018 Amortized Fair Available for sale One year or less $ 289,086 $ 288,571 Over one year through five years 20,103 19,894 Over five years through ten years 410 406 Over ten years 112,885 109,410 Mortgage-backed securities: residential 782,579 763,128 Mortgage-backed securities: commercial 5,123 5,011 Total $ 1,210,186 $ 1,186,420 Held to maturity One year or less $ 501 $ 511 Over one year through five years 1,106 1,121 Over five years through ten years 11,875 11,907 Over ten years 107,747 108,581 Mortgage-backed securities: residential 92,152 88,768 Total $ 213,381 $ 210,888 Securities pledged at March 31, 2018 and December 31, 2017 had a carrying amount of $1,168,275 and $975,518, respectively, and were pledged to secure public deposits and repurchase agreements. At March 31, 2018 and December 31, 2017, there were no holdings of securities of any one issuer, other than the U.S. government-sponsored entities and agencies, in an amount greater than 10% of shareholders’ equity. The following table summarizes the securities with unrealized and unrecognized losses at March 31, 2018 and December 31, 2017, aggregated by major security type and length of time in a continuous unrealized loss position: Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized March 31, 2018 Available for sale U.S. Treasury securities $ 288,571 $ (515 ) $ — $ — $ 288,571 $ (515 ) U.S. government sponsored entities and agencies — — 19,894 (209 ) 19,894 (209 ) Mortgage-backed securities: residential 436,263 (7,882 ) 295,862 (11,614 ) 732,125 (19,496 ) Mortgage-backed securities: commercial 5,011 (112 ) — — 5,011 (112 ) State and political subdivisions 11,409 (164 ) 60,804 (3,719 ) 72,213 (3,883 ) Total available for sale $ 741,254 $ (8,673 ) $ 376,560 $ (15,542 ) $ 1,117,814 $ (24,215 ) Less Than 12 Months 12 Months or Longer Total Fair Unrecognized Fair Unrecognized Fair Unrecognized Held to maturity Mortgage-backed securities: residential $ 13,636 $ (306 ) $ 68,768 $ (3,189 ) $ 82,404 $ (3,495 ) State and political subdivisions 22,825 (127 ) 1,137 (46 ) 23,962 (173 ) Total held to maturity $ 36,461 $ (433 ) $ 69,905 $ (3,235 ) $ 106,366 $ (3,668 ) Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2017 Available for sale U.S. Treasury securities $ 228,909 $ (210 ) $ — $ — $ 228,909 $ (210 ) U.S. government sponsored entities and agencies 19,961 (164 ) — — 19,961 (164 ) Mortgage-backed securities: residential 301,158 (2,447 ) 311,366 (6,314 ) 612,524 (8,761 ) Mortgage-backed securities: commercial 5,074 (59 ) — — 5,074 (59 ) State and political subdivisions 1,298 (2 ) 62,725 (1,882 ) 64,023 (1,884 ) Total available for sale $ 556,400 $ (2,882 ) $ 374,091 $ (8,196 ) $ 930,491 $ (11,078 ) Less Than 12 Months 12 Months or Longer Total Fair Unrecognized Fair Unrecognized Fair Unrecognized Held to maturity Mortgage-backed securities: residential $ 11,191 $ (69 ) $ 72,582 $ (1,727 ) $ 83,773 $ (1,796 ) State and political subdivisions 262 (2 ) 1,148 (36 ) 1,410 (38 ) Total held to maturity $ 11,453 $ (71 ) $ 73,730 $ (1,763 ) $ 85,183 $ (1,834 ) Unrealized losses on debt securities have not been recognized into income because the issuers’ bonds are of high credit quality (rated AA or higher), management does not intend to sell and it is likely that management will not be required to sell the securities prior to their anticipated recovery, and the decline in fair value is largely due to changes in interest rates and other market conditions. The fair value is expected to recover as the bonds approach maturity.

Loans

Loans	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Loans	NOTE 3—LOANS Loans at March 31, 2018 and December 31, 2017 were as follows: March 31, December 31, Loans that are not PCI loans Construction and land development $ 523,660 $ 494,818 Commercial real estate: Nonfarm, nonresidential 673,497 628,554 Other 43,110 49,684 Residential real estate: Closed-end 1-4 430,467 407,695 Other 172,216 169,640 Commercial and industrial 462,954 502,006 Consumer and other 3,899 3,781 Loans before net deferred loan fees 2,309,803 2,256,178 Deferred loan fees, net (2,225 ) (1,963 ) Total loans that are not PCI loans 2,307,578 2,254,215 Total PCI loans 2,440 2,393 Allowance for loan losses (21,738 ) (21,247 ) Total loans, net of allowance for loan losses $ 2,288,280 $ 2,235,361 The following table presents the activity in the allowance for loan losses by portfolio segment for the three month periods ended March 31, 2018 and 2017: Construction Commercial Residential Commercial Consumer Total Three Months Ended March 31, 2018 Allowance for loan losses: Beginning balance $ 3,802 $ 5,981 $ 3,834 $ 7,587 $ 43 $ 21,247 Provision for loan losses 582 (106 ) (241 ) 328 10 573 Loans charged-off (39 ) — (7 ) (49 ) (11 ) (106 ) Recoveries — — 19 — 5 24 Total ending allowance balance $ 4,345 $ 5,875 $ 3,605 $ 7,866 $ 47 $ 21,738 Three Months Ended March 31, 2017 Allowance for loan losses: Beginning balance $ 3,776 $ 4,266 $ 2,398 $ 6,068 $ 45 $ 16,553 Provision for loan losses 61 393 262 1,117 22 1,855 Loans charged-off — — — (300 ) (23 ) (323 ) Recoveries — — 12 — 8 20 Total ending allowance balance $ 3,837 $ 4,659 $ 2,672 $ 6,885 $ 52 $ 18,105 The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method as of March 31, 2018 and December 31, 2017. For purposes of this disclosure, recorded investment in loans excludes accrued interest receivable and deferred loan fees, net due to immateriality. Construction Commercial Residential Commercial Consumer Total March 31, 2018 Allowance for loan losses: Ending allowance balance attributable to loans: Individually evaluated for impairment $ — $ — $ — $ 543 $ — $ 543 Collectively evaluated for impairment 4,345 5,875 3,605 7,317 47 21,189 Construction Commercial Residential Commercial Consumer Total Purchased credit-impaired loans — — — 6 — 6 Total ending allowance balance $ 4,345 $ 5,875 $ 3,605 $ 7,866 $ 47 $ 21,738 Loans: Individually evaluated for impairment $ 165 $ — $ 694 $ 2,466 $ — $ 3,325 Collectively evaluated for impairment 523,495 716,607 601,989 460,488 3,899 2,306,478 Purchased credit-impaired loans — 371 96 1,973 — 2,440 Total ending loans balance $ 523,660 $ 716,978 $ 602,779 $ 464,927 $ 3,899 $ 2,312,243 December 31, 2017 Allowance for loan losses: Ending allowance balance attributable to loans: Individually evaluated for impairment $ — $ — $ — $ 879 $ — $ 879 Collectively evaluated for impairment 3,802 5,981 3,834 6,708 43 20,368 Purchased credit-impaired loans — — — — — — Total ending allowance balance $ 3,802 $ 5,981 $ 3,834 $ 7,587 $ 43 $ 21,247 Loans: Individually evaluated for impairment $ 217 $ — $ 834 $ 3,090 $ — $ 4,141 Collectively evaluated for impairment 494,601 678,238 576,501 498,916 3,781 2,252,037 Purchased credit-impaired loans — 380 105 1,908 — 2,393 Total ending loans balance $ 494,818 $ 678,618 $ 577,440 $ 503,914 $ 3,781 $ 2,258,571 Loans collectively evaluated for impairment reported at March 31, 2018 include certain acquired loans. At March 31, 2018, these non-PCI non-PCI The following table presents information related to impaired loans by class of loans as of March 31, 2018 and December 31, 2017: Unpaid Recorded Allowance for March 31, 2018 With no allowance recorded: Construction and land development $ 203 $ 165 $ — Commercial real estate: Nonfarm, nonresidential — — — Residential real estate: Closed-end 1-4 581 581 — Other 113 113 — Commercial and industrial 92 92 — Consumer and other — — — Subtotal 989 951 — With an allowance recorded: Commercial and industrial 2,374 2,374 543 Subtotal 2,374 2,374 543 Total $ 3,363 $ 3,325 $ 543 December 31, 2017 With no allowance recorded: Construction and land development $ 217 $ 217 $ — Unpaid Recorded Allowance for Residential real estate: Closed-end 1-4 14 14 — Other 820 820 — Commercial and industrial 108 108 — Subtotal 1,159 1,159 — With an allowance recorded: Commercial and industrial 2,982 2,982 879 Subtotal 2,982 2,982 879 Total $ 4,141 $ 4,141 $ 879 The following table presents the average recorded investment of impaired loans by class of loans for the three months ended March 31, 2018 and 2017: Three Months Ended March 31, Average Recorded Investment 2018 2017 With no allowance recorded: Construction and land development $ 367 $ — Commercial real estate: Nonfarm, nonresidential — 4,128 Residential real estate: Closed-end 1-4 420 1,799 Other 372 120 Commercial and industrial 626 — Subtotal 1,785 6,047 With an allowance recorded: Commercial and industrial $ 1,785 $ 2,585 Subtotal 1,785 2,585 Total $ 3,570 $ 8,632 The impact on net interest income for these loans was not material to the Company’s results of operations for the three months ended March 31, 2018 and 2017. The following table presents the recorded investment in nonaccrual and loans past due over 90 days still on accrual by class of loans as of March 31, 2018 and December 31, 2017: Nonaccrual Loans Past Due March 31, 2018 Construction and land development $ 165 $ — Residential real estate: Closed-end 1-4 581 — Other 113 12 Commercial and industrial 2,466 166 Total $ 3,325 $ 178 December 31, 2017 Residential real estate: Closed-end 1-4 $ 257 $ 14 Other 114 — Commercial and industrial 2,466 191 Total $ 2,837 $ 205 Nonaccrual loans and loans past due 90 days still on accrual include both smaller balance homogeneous loans that are collectively evaluated for impairment and individually classified impaired loans. The following table presents the aging of the recorded investment in past due loans as of March 31, 2018 and December 31, 2017 by class of loans: 30-59 60-89 Greater Nonaccrual Total Loans PCI Total March 31, 2018 Construction and land development $ 473 $ — $ — $ 165 $ 638 $ 523,022 $ — $ 523,660 Commercial real estate: Nonfarm, nonresidential — — — — — 673,497 371 673,868 Other 5 — — — 5 43,105 — 43,110 Residential real estate: Closed-end 1-4 610 1,060 — 581 2,251 428,216 96 430,563 Other 116 — 12 113 241 171,975 — 172,216 Commercial and industrial 440 195 166 2,466 3,267 459,687 1,973 464,927 Consumer and other — 200 — — 200 3,699 — 3,899 $ 1,644 $ 1,455 $ 178 $ 3,325 $ 6,602 $ 2,303,201 $ 2,440 $ 2,312,243 December 31, 2017 Construction and land development $ 1,918 $ 136 $ — $ — $ 2,054 $ 492,764 $ — $ 494,818 Commercial real estate: Nonfarm, nonresidential — — — — — 628,554 380 628,934 Other — — — — — 49,681 — 49,684 Residential real estate: Closed-end 1-4 — — 14 257 271 407,424 105 407,800 Other 146 719 — 114 979 168,661 — 169,640 Commercial and industrial 532 27 191 2,466 3,216 498,790 1,908 503,914 Consumer and other — — — — — 3,781 — 3,781 $ 2,596 $ 882 $ 205 $ 2,837 $ 6,520 $ 2,249,658 $ 2,393 $ 2,258,571 Credit Quality Indicators: non-homogeneous Special Mention. Substandard. Loans not meeting the criteria above that are analyzed individually as part of the above described process are considered to be pass-rated loans. The following table includes PCI loans, which are included in the “Substandard” column. Based on the most recent analysis performed, the risk category of loans by class of loans is as follows as of March 31, 2018 and December 31, 2017: Pass Special Substandard Total March 31, 2018 Construction and land development $ 519,831 $ 3,664 $ 165 $ 523,660 Commercial real estate: Nonfarm, nonresidential 658,683 11,098 4,087 673,868 Other 42,730 — 380 43,110 Residential real estate: Closed-end 1-4 426,856 — 3,707 430,563 Other 170,467 — 1,749 172,216 Commercial and industrial 448,395 9,003 7,529 464,927 Consumer and other 3,896 3 — 3,899 $ 2,270,858 $ 23,768 $ 17,617 $ 2,312,243 Pass Special Substandard Total December 31, 2017 Construction and land development $ 494,601 $ — $ 217 $ 494,818 Commercial real estate: Nonfarm, nonresidential 609,458 12,602 6,874 628,934 Other 49,303 — 381 49,684 Residential real estate: 1-4 404,832 615 2,353 407,800 Other 167,886 — 1,754 169,640 Commercial and industrial 485,363 10,350 8,201 503,914 Consumer and other 3,777 4 — 3,781 $ 2,215,220 $ 23,571 $ 19,780 $ 2,258,571 Troubled Debt Restructurings As of March 31, 2018 and December 31, 2017, the Company’s loan portfolio contains one loan that has been modified in a troubled debt restructuring with a balance of $165 and $608, respectively. During the first quarter of 2018 one loan was added as a troubled debt restructuring with a balance of $165, and the loan that was previously reported as a troubled debt restructuring at December 31, 2017 was paid down by $575 by the borrower, and the remaining $33 was charged off.

Loan Servicing

Loan Servicing	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Loan Servicing	NOTE 4—LOAN SERVICING Loans serviced for others are not reported as assets. The principal balances of these loans at March 31, 2018 and December 31, 2017 are as follows: March 31, December 31, Loan portfolios serviced for: Federal Home Loan Mortgage Corporation $ 507,375 $ 507,233 Other 4,589 4,626 The components of net loan servicing fees for the three months ended March 31, 2018 and 2017 were as follows: Three Months Ended 2018 2017 Loan servicing fees, net: Loan servicing fees $ 333 $ 320 Amortization of loan servicing fees (214 ) (213 ) Change in impairment — — Total $ 119 $ 107 The fair value of servicing rights was estimated by management to be approximately $5,305 at March 31, 2018. Fair value for March 31, 2018 was determined using a weighted average discount rate of 10.5% and a weighted average prepayment speed of 9.4%. At December 31, 2017, the fair value of servicing rights was estimated by management to be approximately $5,089. Fair value for December 31, 2017 was determined using a weighted average discount rate of 10.5% and a weighted average prepayment speed of 9.9%.

Securities Sold Under Agreement

Securities Sold Under Agreement to Repurchase	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Securities Sold Under Agreement to Repurchase	NOTE 5—SECURITIES SOLD UNDER AGREEMENT TO REPURCHASE Our subsidiary bank enters into borrowing arrangements with our retail business customers and correspondent banks through agreements to repurchase (“securities sold under agreements to repurchase”) under which the bank pledges investment securities owned and under its control as collateral against these short-term borrowing arrangements. At maturity the securities underlying the agreements are returned to the Company. At March 31, 2018 and December 31, 2017, these short-term borrowings totaled $36,071 and $31,004, respectively, and were secured by securities with carrying amounts of $41,377 and $41,618, respectively. At March 31, 2018, all of the Company’s repurchase agreements had one-day The following table provides additional details as of March 31, 2018: As of March 31, 2018 Mortgage- State and Total Market value of securities pledged $ 919 $ 40,845 $ 41,764 Borrowings related to pledged amounts $ — $ 36,071 $ 36,071 Market value pledged as a % of borrowings — % 113 % 116 % The following table provides additional details as of December 31, 2017: As of December 31, 2017 Mortgage- State and Total Market value of securities pledged $ 1,004 $ 42,109 $ 43,113 Borrowings related to pledged amounts $ — $ 31,004 $ 31,004 Market value pledged as a % of borrowings — % 136 % 139 %

Share-Based Payments

Share-Based Payments	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Share-Based Payments	NOTE 6—SHARE-BASED PAYMENTS In connection with the Company’s 2010 private offering, 32,425 warrants were issued to shareholders, one warrant for every twenty shares of common stock purchased. Each warrant allowed the shareholders to purchase an additional share of common stock at $12.00 per share. The warrants were issued with an effective date of March 30, 2010 and were exercisable in whole or in part up to seven years following the date of issuance. The warrants were detachable from the common stock. There were 11,011 warrants exercised during the three months ended March 31, 2017. The warrants expired on March 30, 2017; therefore at March 31, 2018, there were no outstanding warrants associated with the 2010 offering. A summary of the stock warrant activity for the three months ended March 31, 2018 and 2017 follows: March 31, March 31, Stock warrants exercised: Intrinsic value of warrants exercised $ — $ 291 Cash received from warrants exercised — 132 The Company has two share based compensation plans as described below. Total compensation cost that has been charged against income for those plans was $759 and $447 for the three months ended March 31, 2018 and 2017, respectively. The total income tax benefit, which is shown on the Consolidated Statements of Income as a reduction of income tax expense, was $63 and $93 for the three months ended March 31, 2018 and 2017, respectively. Stock Options On April 12, 2018, the Compensation Committee of the Company’s Board of Directors (the “Committee”) approved the Amended and Restated 2017 Omnibus Equity Incentive Plan (the “Amended and Restated 2017 Plan”) in order to make the following amendments to the 2017 Plan in response to feedback the Company received from its shareholders: • reduce the number of shares of common stock available for issuance from 5,000,000 shares under the 2017 Plan to 3,500,000 shares under the Amended and Restated 2017 Plan; • revise the definition of Change in Control to include only actual changes in control (and removed triggering events that represented a potential change in control); • remove the Committee’s authority to accelerate vesting (other than in cases of termination of the participant’s employment); • remove certain provisions allowing recycling of shares and to clarify that (1) shares tendered in payment of an option, (2) shares delivered or withheld to satisfy tax withholding obligations and (3) shares covered by a stock-settled SAR or other awards that were not issued upon settlement of the award will not be available for issuance under the Amended and Restated 2017 Plan; and • remove the ability to grant reload options (automatic granting of new options at the time of exercise). Employee, organizer and director awards are generally granted with an exercise price equal to the market price of the Company’s common stock at the date of grant; those option awards have a vesting period of three to five years and have a ten-year non-qualified non-qualified. The fair value of each option award is estimated on the date of grant using a closed form option valuation (Black-Scholes) model that uses the assumptions noted in the table below. Expected stock price volatility is based on historical volatilities of a peer group. The Company uses historical data to estimate option exercise and post-vesting termination behavior. The expected term of options granted represents the period of time that options granted are expected to be outstanding, which takes into account that the options are not transferable. The risk-free interest rate for the expected term of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. The fair value of options granted was determined using the following weighted-average assumptions as of grant date. March 31, March 31, Risk-free interest rate 2.49 % 2.28 % Expected term 7.5 years 7.4 years Expected stock price volatility 32.48 % 34.20 % Dividend yield 0.00 % 0.04 % The weighted average fair value of options granted for the three months ended March 31, 2018 and 2017 were $14.77 and $17.25, respectively. A summary of the activity in the plans for the three months ended March 31, 2018 follows: Shares Weighted Weighted Aggregate Outstanding at beginning of year 1,507,168 $ 21.37 6.55 $ 19,180 Granted 28,125 36.40 Exercised (21,348 ) 10.32 Forfeited, expired, or cancelled (11,754 ) 29.37 Outstanding at period end 1,502,191 $ 21.75 6.41 $ 16,299 Vested or expected to vest 1,427,082 $ 21.75 6.41 $ 15,484 Exercisable at period end 760,955 $ 14.17 4.75 $ 14,022 For the three months 2018 2017 Stock options exercised: Intrinsic value of options exercised $ 511 $ 610 Cash received from options exercised 220 177 Tax benefit realized from option exercises 63 93 As of March 31, 2018, there was $5,708 of total unrecognized compensation cost related to non-vested Restricted Stock A summary of activity for non-vested Non-vested Shares Weighted- Non-vested 94,181 $ 25.42 Granted — — Vested — — Forfeited (334 ) 37.35 Non-vested 96,409 $ 25.38 Compensation expense associated with the restricted share awards is recognized on a straight-line basis over the time period that the restrictions associated with the awards lapse based on the total cost of the award at the grant date. As of March 31, 2018, there was $1,580 of total unrecognized compensation cost related to non-vested

Regulatory Capital Matters

Regulatory Capital Matters	3 Months Ended
	Mar. 31, 2018
Banking and Thrift [Abstract]
Regulatory Capital Matters	NOTE 7—REGULATORY CAPITAL MATTERS Banks and bank holding companies are subject to regulatory capital requirements administered by federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities, and certain off-balance-sheet The Basel III rules additionally provide for countercyclical capital requirements so that the required amount of capital increases in times of economic expansion and decreases in times of economic contraction, consistent with safety and soundness. Under the Basel III rules, banks must maintain a capital conservation buffer consisting of additional Common Equity Tier 1 Capital equal to 2.5% of risk-weighted assets above each of the required minimum capital levels in order to avoid limitations on paying dividends, engaging in share repurchases, and paying certain discretionary bonuses. This new capital conservation buffer requirement was phased in beginning January 2016 at 0.625% of risk-weighted assets and will increase each year until fully implemented at 2.5% in January 2019. The capital conservation buffer in effect for 2018 is 1.875%. Prompt corrective action regulations provide five classifications: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized, although these terms are not used to represent overall financial condition. If adequately capitalized, regulatory approval is required to accept brokered deposits. If undercapitalized, capital distributions are limited, as is asset growth and expansion, and capital restoration plans are required. At March 31, 2018, the most recent regulatory notifications categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. Management believes that, as of March 31, 2018, the Company and Bank met all capital adequacy requirements to which they are subject. There are no conditions or events since that notification that management believes have changed the institution’s category. Actual and required capital amounts and ratios are presented below as of March 31, 2018 and December 31, 2017 for the Company and Bank: Actual Required To Be Well Amount Ratio Amount Ratio Amount Ratio March 31, 2018 Company common equity Tier 1 capital to risk-weighted assets $ 310,218 11.45 % $ 121,874 4.50 % N/A N/A Company Total Capital to risk weighted assets $ 390,600 14.42 % $ 216,665 8.00 % N/A N/A Company Tier 1 (Core) Capital to risk weighted assets $ 310,218 11.45 % $ 162,499 6.00 % N/A N/A Company Tier 1 (Core) Capital to average assets $ 310,218 7.80 % $ 158,986 4.00 % N/A N/A Bank common equity Tier 1 capital to risk-weighted assets $ 365,295 13.49 % $ 121,874 4.50 % $ 176,040 6.50 % Bank Total Capital to risk weighted assets $ 387,126 14.29 % $ 216,665 8.00 % $ 270,831 10.00 % Bank Tier 1 (Core) Capital to risk weighted assets $ 365,295 13.49 % $ 162,499 6.00 % $ 216,665 8.00 % Bank Tier 1 (Core) Capital to average assets $ 365,295 9.19 % $ 158,857 4.00 % $ 198,572 5.00 % December 31, 2017 Company common equity Tier 1 capital to risk-weighted assets $ 299,229 11.37 % $ 118,479 4.50 % N/A N/A Company Total Capital to risk weighted assets $ 379,083 14.40 % $ 210,629 8.00 % N/A N/A Company Tier 1 (Core) Capital to risk weighted assets $ 299,229 11.37 % $ 157,972 6.00 % N/A N/A Company Tier 1 (Core) Capital to average assets $ 299,229 8.25 % $ 145,100 4.00 % N/A N/A Bank common equity Tier 1 capital to risk-weighted assets $ 353,512 13.43 % $ 118,489 4.50 % $ 171,151 6.50 % Bank Total Capital to risk weighted assets $ 374,851 14.24 % $ 210,647 8.00 % $ 263,309 10.00 % Bank Tier 1 (Core) Capital to risk weighted assets $ 353,512 13.43 % $ 157,985 6.00 % $ 210,647 8.00 % Bank Tier 1 (Core) Capital to average assets $ 353,512 9.75 % $ 145,003 4.00 % $ 181,253 5.00 % Note: Minimum ratios presented exclude the capital conservation buffer Dividend Restrictions

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value	NOTE 8—FAIR VALUE Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. There are three levels of inputs that may be used to measure fair values: Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active markets that the entity has the ability to access as of the measurement date. Level 2: Significant other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. Level 3: Significant unobservable inputs that reflect a reporting entity’s own assumptions about the assumptions that market participants would use in pricing an asset or liability. Securities Derivatives Impaired Loans Non-real Foreclosed Assets Appraisals for both collateral-dependent impaired loans and real estate owned are performed by certified general appraisers (for commercial properties) or certified residential appraisers (for residential properties) whose qualifications and licenses have been reviewed and verified by the Company. Once received, a member of the credit administration department reviews the assumptions and approaches utilized in the appraisal as well as the overall resulting fair value in comparison with independent data sources such as recent market data or industry-wide statistics. On an annual basis, the Company compares the actual selling price of collateral that has been sold to the most recent appraised value to determine what additional adjustment should be made to the appraisal value to arrive at fair value. Loans Held For Sale Assets and liabilities measured at fair value on a recurring basis, including financial assets and liabilities for which the Company has elected the fair value option, are summarized below: Fair Value Measurements at Quoted Prices Significant Significant Financial Assets Securities available for sale U.S. Treasury securities $ — $ 288,571 $ — U.S. government sponsored entities and agencies — 19,894 — Mortgage-backed securities-residential — 763,128 — Mortgage-backed securities-commercial — 5,011 — State and political subdivisions — 109,816 — Total securities available for sale $ — $ 1,186,420 $ — Loans held for sale $ — $ 12,871 $ — Mortgage banking derivatives $ — $ 382 $ — Financial Liabilities Mortgage banking derivatives $ — $ 45 $ — Fair Value Measurements at Quoted Prices Significant Significant Financial Assets Securities available for sale U.S. Treasury securities $ — $ 228,909 $ — U.S. government sponsored entities and agencies — 19,961 — Mortgage-backed securities-residential — 632,566 — Mortgage-backed securities-commercial — 5,074 — State and political subdivisions — 113,371 — Total securities available for sale $ — $ 999,881 $ — Loans held for sale $ — $ 12,024 $ — Mortgage banking derivatives $ — $ 175 $ — Financial Liabilities Mortgage banking derivatives $ — $ 35 $ — As of March 31, 2018, the unpaid principal balance of loans held for sale was $12,554 resulting in an unrealized gain of $317 included in gains on sale of loans. As of December 31, 2017, the unpaid principal balance of loans held for sale was $11,681, resulting in an unrealized gain of $343 included in gains on sale of loans. For the three months ended March 31, 2018 and 2017, the change in fair value related to loans held for sale, which is included in gain on sale of loans, was $(26) and $113, respectively. None of these loans were 90 days or more past due or on nonaccrual as of March 31, 2018 and December 31, 2017. There were no transfers between level 1 and 2 during 2018 or 2017. Assets measured at fair value on a non-recurring There was one collateral-dependent commercial and industrial impaired loans carried at fair value of $1,831 as of March 31, 2018 and December 31, 2017. For the three months ended March 31, 2018 and 2017, there was no additional provision for loan losses recorded related to impaired loans recorded at fair value of collateral. Foreclosed assets measured at fair value less costs to sell, had a net carrying amount of $1,503 as of March 31, 2018 and December 31, 2017. The foreclosed property was previously collateral for a commercial real estate loan. There were no properties at March 31, 2018 or 2017 that had required write-downs to fair value resulting in no write downs for the three months ended March 31, 2018 and 2017, respectively. The carrying amounts and estimated fair values of financial instruments at March 31, 2018 and December 31, 2017 are as follows: Carrying Fair Value Measurements at Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 246,164 $ 246,164 $ — $ — $ 246,164 Certificates of deposit held at other financial institutions 2,855 — 2,855 — 2,855 Securities available for sale 1,186,420 — 1,186,420 — 1,186,420 Securities held to maturity 213,381 — 210,888 — 210,888 Loans held for sale 12,871 — 12,871 — 12,871 Net loans 2,288,280 — — 2,295,275 2,295,275 Restricted equity securities 19,606 n/a n/a n/a n/a Servicing rights, net 3,602 — — 5,305 5,305 Mortgage banking derivative assets 382 — 382 — 382 Accrued interest receivable 12,937 182 6,400 6,355 12,937 Financial liabilities Deposits $ 3,355,153 $ 2,026,994 $ 1,284,426 $ — $ 3,311,420 Repurchase agreements 36,071 — 36,071 — 36,071 Federal Home Loan Bank advances 317,000 — 314,341 — 314,341 Subordinated notes, net 58,559 — — 62,259 62,259 Mortgage banking derivative liabilities 45 — 45 — 45 Accrued interest payable 2,775 93 2,332 350 2,775 Carrying Fair Value Measurements at Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 251,543 $ 251,543 $ — $ — $ 251,543 Certificates of deposit held at other financial institutions 2,855 — 2,855 — 2,855 Securities available for sale 999,881 — 999,881 — 999,881 Securities held to maturity 214,856 — 217,608 — 217,608 Loans held for sale 12,024 — 12,024 — 12,024 Net loans 2,235,361 — — 2,230,607 2,230,607 Restricted equity securities 18,492 n/a n/a n/a n/a Servicing rights, net 3,620 — — 5,089 5,089 Mortgage banking derivative assets 175 — 175 — 175 Accrued interest receivable 11,947 73 5,724 6,150 11,947 Financial liabilities Deposits $ 3,167,228 $ 1,911,928 $ 1,224,041 $ — $ 3,135,969 Federal funds purchased and repurchase agreements 31,004 — 31,004 — 31,004 Federal Home Loan Bank advances 272,000 — 270,311 — 270,311 Subordinated notes, net 58,515 — — 59,951 59,951 Mortgage banking derivative liabilities 35 — 35 — 35 Accrued interest payable 2,769 51 2,030 688 2,769 The methods and assumptions not previously described used to estimate fair values are described as follows: (a) Cash and Cash Equivalents: (b) Loans: (c) Restricted Equity Securities: (d) Mortgage Servicing Rights: (e) Deposits: non-interest (f) Federal Funds Purchased and Repurchase Agreements: (g) Federal Home Loan Bank Advances: (h) Subordinated Notes: (i) Accrued Interest Receivable/Payable: (j) Off-balance off-balance

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 9—EARNINGS PER SHARE The two-class two-class Three Months Ended March 31, 2018 2017 Basic Net income available to common shareholders $ 10,052 $ 7,934 Less: earnings allocated to participating securities (71 ) (65 ) Net income allocated to common shareholders $ 9,981 $ 7,869 Weighted average common shares outstanding including participating securities 13,249,728 13,049,012 Less: Participating securities (94,010 ) (106,323 ) Average shares 13,155,718 12,942,689 Basic earnings per common share $ 0.76 $ 0.61 Diluted Net income allocated to common shareholders $ 9,981 $ 7,869 Weighted average common shares outstanding for basic earnings per common share 13,155,718 12,942,689 Add: Dilutive effects of assumed exercises of stock options 516,666 708,694 Add: Dilutive effects of assumed exercises of stock warrants — 5,974 Average shares and dilutive potential common shares 13,672,384 13,657,357 Diluted earnings per common share $ 0.73 $ 0.58 For the three months ended March 31, 2018 and 2017, stock options for 411,279 and 108,000 shares of common stock were not considered in computing diluted earnings per common share because they were antidilutive.

Subordinated Debt Issuance

Subordinated Debt Issuance	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Subordinated Debt Issuance	NOTE 10—SUBORDINATED DEBT ISSUANCE The Company’s subordinated notes, net of issuance costs, totaled $58,559 and $58,515 at March 31, 2018 and at December 31, 2017, respectively. For regulatory capital purposes, the subordinated notes are treated as Tier 2 capital, subject to certain limitations, and are included in total regulatory capital when calculating the Company’s total capital to risk weighted assets ratio as indicated in Note 7 of these consolidated financial statements. The Company completed the issuance of $60,000 in principal amount of subordinated notes in two separate offerings. In March 2016, $40,000 of 6.875% fixed-to-floating fixed-to-floating The issuance costs related to the March 2016 Subordinated Notes amounted to $1,382 and are being amortized as interest expense over the ten-year ten-year The following table summarizes the terms of each subordinated note offering: March 2016 Subordinated Notes June 2016 Subordinated Notes Principal amount issued $40,000 $20,000 Maturity date March 30, 2026 July 1, 2026 Initial fixed interest rate 6.875% 7.00% Initial interest rate period 5 years 5 years First interest rate change date March 30, 2021 July 1, 2021 Interest payment frequency through year five* Semiannually Semiannually Interest payment frequency after five years* Quarterly Quarterly Interest repricing index and margin 3-month LIBOR plus 5.636% 3-month LIBOR plus 6.04% Repricing frequency after five years Quarterly Quarterly * Through March 31, 2018 all interest payments have been made in accordance with the terms of the agreements.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers 2014-09”), 2014-09 2014-09. 2014-09, 2014-09 The Company has identified the contract with a customer, identified the performance obligations in the contract, determined the transaction price, allocated the transaction price to the performance obligations in the contract, and recognized revenue when (or as) the Company satisfied a performance obligation. Significant revenue has not been recognized in the current reporting period that results from performance obligations satisfied in previous periods. The Company’s primary sources of revenue are derived from interest and dividends earned on loans, investment securities, and other financial instruments that are not impacted by the new standard. The Company has evaluated the nature of its contracts with customers and determined that further disaggregation of revenue from contracts with customers into more granular categories beyond what is presented in the Consolidated Statements of Income was not necessary. The Company generally fully satisfies its performance obligations on its contracts with customers as services are rendered and the transaction prices are typically fixed; charged either on a periodic basis or based on activity. Because performance obligations are satisfied as services are rendered and the transaction prices are fixed, there is little judgment involved in applying the new standard that significantly affects the determination of the amount and timing of revenue from contracts with customers. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities 2016-01”). 2016-01 non-recurring In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments zero-coupon In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business 2017-01”) 2017-01 In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Subtopic 718): Scope of Modification Accounting 2017-09 2017-09 2017-09
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02 Leases Leases 2016-02 right-of-use 2016-02 right-of-use 2016-02 In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments available-for-sale 2016-13 In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ASU 2017-04 ASU 2017-04 In March 2017, the FASB issued ASU 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): ASU 2017-08 ASU 2017-08
Acquisition of Civic Bank & Trust	Acquisition of Civic Bank & Trust Effective April 1, 2018, the Company acquired Civic Bank & Trust, which was located in Nashville, Tennessee. Effective with the acquisition, Dr. Anil Patel, who was the chairman of the Civic Bank & Trust board of directors, was added to the Company’s board of directors for a term expiring at the Company’s 2018 annual meeting of shareholders.

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost and Fair Value of Available for Sale Securities	The following table summarizes the amortized cost and fair value of the securities available for sale portfolio at March 31, 2018 and December 31, 2017 and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income. Amortized Gross Gross Fair March 31, 2018 U.S. Treasury securities $ 289,086 $ — $ (515 ) $ 288,571 U.S. government sponsored entities and agencies 20,103 — (209 ) 19,894 Mortgage-backed securities: residential 782,579 45 (19,496 ) 763,128 Mortgage-backed securities: commercial 5,123 — (112 ) 5,011 State and political subdivisions 113,295 404 (3,883 ) 109,816 Total $ 1,210,186 $ 449 $ (24,215 ) $ 1,186,420 Amortized Gross Gross Fair December 31, 2017 U.S. Treasury securities $ 229,119 $ — $ (210 ) $ 228,909 U.S. government sponsored entities and agencies 20,125 — (164 ) 19,961 Mortgage-backed securities: residential 641,225 102 (8,761 ) 632,566 Mortgage-backed securities: commercial 5,133 — (59 ) 5,074 State and political subdivisions 113,468 1,787 (1,884 ) 113,371 Total $ 1,009,070 $ 1,889 $ (11,078 ) $ 999,881
Schedule of Amortized Cost and Fair Value of Held to Maturity Securities Portfolio	The amortized cost and fair value of the securities held to maturity portfolio at March 31, 2018 and December 31, 2017 and the corresponding amounts of gross unrecognized gains and losses were as follows: Amortized Gross Gross Fair March 31, 2018 Mortgage backed securities: residential $ 92,152 $ 111 $ (3,495 ) $ 88,768 State and political subdivisions 121,229 1,064 (173 ) 122,120 Total $ 213,381 $ 1,175 $ (3,668 ) $ 210,888 December 31, 2017 Mortgage backed securities: residential $ 93,366 $ 207 $ (1,796 ) $ 91,777 State and political subdivisions 121,490 4,379 (38 ) 125,831 Total $ 214,856 $ 4,586 $ (1,834 ) $ 217,608
Summary of Proceeds from Sales and Calls of Securities Available for Sale and Associated Gains and Losses	The proceeds from sales and calls of securities available for sale and the associated gains and losses were as follows: Three Months Ended March 31, 2018 2017 Proceeds $ — $ — Gross gains — — Gross losses — —
Schedule of Amortized Cost and Fair Value of Investment Securities Portfolio by Contractual Maturity	The amortized cost and fair value of the investment securities portfolio are shown by contractual maturity. Securities not due at a single maturity date, primarily mortgage-backed securities, are shown separately. March 31, 2018 Amortized Fair Available for sale One year or less $ 289,086 $ 288,571 Over one year through five years 20,103 19,894 Over five years through ten years 410 406 Over ten years 112,885 109,410 Mortgage-backed securities: residential 782,579 763,128 Mortgage-backed securities: commercial 5,123 5,011 Total $ 1,210,186 $ 1,186,420 Held to maturity One year or less $ 501 $ 511 Over one year through five years 1,106 1,121 Over five years through ten years 11,875 11,907 Over ten years 107,747 108,581 Mortgage-backed securities: residential 92,152 88,768 Total $ 213,381 $ 210,888
Schedule of Unrealized Losses and Fair Value by Major Security Type	The following table summarizes the securities with unrealized and unrecognized losses at March 31, 2018 and December 31, 2017, aggregated by major security type and length of time in a continuous unrealized loss position: Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized March 31, 2018 Available for sale U.S. Treasury securities $ 288,571 $ (515 ) $ — $ — $ 288,571 $ (515 ) U.S. government sponsored entities and agencies — — 19,894 (209 ) 19,894 (209 ) Mortgage-backed securities: residential 436,263 (7,882 ) 295,862 (11,614 ) 732,125 (19,496 ) Mortgage-backed securities: commercial 5,011 (112 ) — — 5,011 (112 ) State and political subdivisions 11,409 (164 ) 60,804 (3,719 ) 72,213 (3,883 ) Total available for sale $ 741,254 $ (8,673 ) $ 376,560 $ (15,542 ) $ 1,117,814 $ (24,215 ) Less Than 12 Months 12 Months or Longer Total Fair Unrecognized Fair Unrecognized Fair Unrecognized Held to maturity Mortgage-backed securities: residential $ 13,636 $ (306 ) $ 68,768 $ (3,189 ) $ 82,404 $ (3,495 ) State and political subdivisions 22,825 (127 ) 1,137 (46 ) 23,962 (173 ) Total held to maturity $ 36,461 $ (433 ) $ 69,905 $ (3,235 ) $ 106,366 $ (3,668 ) Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2017 Available for sale U.S. Treasury securities $ 228,909 $ (210 ) $ — $ — $ 228,909 $ (210 ) U.S. government sponsored entities and agencies 19,961 (164 ) — — 19,961 (164 ) Mortgage-backed securities: residential 301,158 (2,447 ) 311,366 (6,314 ) 612,524 (8,761 ) Mortgage-backed securities: commercial 5,074 (59 ) — — 5,074 (59 ) State and political subdivisions 1,298 (2 ) 62,725 (1,882 ) 64,023 (1,884 ) Total available for sale $ 556,400 $ (2,882 ) $ 374,091 $ (8,196 ) $ 930,491 $ (11,078 ) Less Than 12 Months 12 Months or Longer Total Fair Unrecognized Fair Unrecognized Fair Unrecognized Held to maturity Mortgage-backed securities: residential $ 11,191 $ (69 ) $ 72,582 $ (1,727 ) $ 83,773 $ (1,796 ) State and political subdivisions 262 (2 ) 1,148 (36 ) 1,410 (38 ) Total held to maturity $ 11,453 $ (71 ) $ 73,730 $ (1,763 ) $ 85,183 $ (1,834 )

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Summary of Loans	Loans at March 31, 2018 and December 31, 2017 were as follows: March 31, December 31, Loans that are not PCI loans Construction and land development $ 523,660 $ 494,818 Commercial real estate: Nonfarm, nonresidential 673,497 628,554 Other 43,110 49,684 Residential real estate: Closed-end 1-4 430,467 407,695 Other 172,216 169,640 Commercial and industrial 462,954 502,006 Consumer and other 3,899 3,781 Loans before net deferred loan fees 2,309,803 2,256,178 Deferred loan fees, net (2,225 ) (1,963 ) Total loans that are not PCI loans 2,307,578 2,254,215 Total PCI loans 2,440 2,393 Allowance for loan losses (21,738 ) (21,247 ) Total loans, net of allowance for loan losses $ 2,288,280 $ 2,235,361
Activity in Allowance for Loan Losses by Portfolio Segment	The following table presents the activity in the allowance for loan losses by portfolio segment for the three month periods ended March 31, 2018 and 2017: Construction Commercial Residential Commercial Consumer Total Three Months Ended March 31, 2018 Allowance for loan losses: Beginning balance $ 3,802 $ 5,981 $ 3,834 $ 7,587 $ 43 $ 21,247 Provision for loan losses 582 (106 ) (241 ) 328 10 573 Loans charged-off (39 ) — (7 ) (49 ) (11 ) (106 ) Recoveries — — 19 — 5 24 Total ending allowance balance $ 4,345 $ 5,875 $ 3,605 $ 7,866 $ 47 $ 21,738 Three Months Ended March 31, 2017 Allowance for loan losses: Beginning balance $ 3,776 $ 4,266 $ 2,398 $ 6,068 $ 45 $ 16,553 Provision for loan losses 61 393 262 1,117 22 1,855 Loans charged-off — — — (300 ) (23 ) (323 ) Recoveries — — 12 — 8 20 Total ending allowance balance $ 3,837 $ 4,659 $ 2,672 $ 6,885 $ 52 $ 18,105
Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment and Based on Impairment Method	The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method as of March 31, 2018 and December 31, 2017. For purposes of this disclosure, recorded investment in loans excludes accrued interest receivable and deferred loan fees, net due to immateriality. Construction Commercial Residential Commercial Consumer Total March 31, 2018 Allowance for loan losses: Ending allowance balance attributable to loans: Individually evaluated for impairment $ — $ — $ — $ 543 $ — $ 543 Collectively evaluated for impairment 4,345 5,875 3,605 7,317 47 21,189 Construction Commercial Residential Commercial Consumer Total Purchased credit-impaired loans — — — 6 — 6 Total ending allowance balance $ 4,345 $ 5,875 $ 3,605 $ 7,866 $ 47 $ 21,738 Loans: Individually evaluated for impairment $ 165 $ — $ 694 $ 2,466 $ — $ 3,325 Collectively evaluated for impairment 523,495 716,607 601,989 460,488 3,899 2,306,478 Purchased credit-impaired loans — 371 96 1,973 — 2,440 Total ending loans balance $ 523,660 $ 716,978 $ 602,779 $ 464,927 $ 3,899 $ 2,312,243 December 31, 2017 Allowance for loan losses: Ending allowance balance attributable to loans: Individually evaluated for impairment $ — $ — $ — $ 879 $ — $ 879 Collectively evaluated for impairment 3,802 5,981 3,834 6,708 43 20,368 Purchased credit-impaired loans — — — — — — Total ending allowance balance $ 3,802 $ 5,981 $ 3,834 $ 7,587 $ 43 $ 21,247 Loans: Individually evaluated for impairment $ 217 $ — $ 834 $ 3,090 $ — $ 4,141 Collectively evaluated for impairment 494,601 678,238 576,501 498,916 3,781 2,252,037 Purchased credit-impaired loans — 380 105 1,908 — 2,393 Total ending loans balance $ 494,818 $ 678,618 $ 577,440 $ 503,914 $ 3,781 $ 2,258,571
Summary of Impaired Loans by Class of Loans	The following table presents information related to impaired loans by class of loans as of March 31, 2018 and December 31, 2017: Unpaid Recorded Allowance for March 31, 2018 With no allowance recorded: Construction and land development $ 203 $ 165 $ — Commercial real estate: Nonfarm, nonresidential — — — Residential real estate: Closed-end 1-4 581 581 — Other 113 113 — Commercial and industrial 92 92 — Consumer and other — — — Subtotal 989 951 — With an allowance recorded: Commercial and industrial 2,374 2,374 543 Subtotal 2,374 2,374 543 Total $ 3,363 $ 3,325 $ 543 December 31, 2017 With no allowance recorded: Construction and land development $ 217 $ 217 $ — Unpaid Recorded Allowance for Residential real estate: Closed-end 1-4 14 14 — Other 820 820 — Commercial and industrial 108 108 — Subtotal 1,159 1,159 — With an allowance recorded: Commercial and industrial 2,982 2,982 879 Subtotal 2,982 2,982 879 Total $ 4,141 $ 4,141 $ 879 The following table presents the average recorded investment of impaired loans by class of loans for the three months ended March 31, 2018 and 2017: Three Months Ended March 31, Average Recorded Investment 2018 2017 With no allowance recorded: Construction and land development $ 367 $ — Commercial real estate: Nonfarm, nonresidential — 4,128 Residential real estate: Closed-end 1-4 420 1,799 Other 372 120 Commercial and industrial 626 — Subtotal 1,785 6,047 With an allowance recorded: Commercial and industrial $ 1,785 $ 2,585 Subtotal 1,785 2,585 Total $ 3,570 $ 8,632
Schedule of Recorded Investment in Nonaccrual and Loans Past Due Over 90 Days on Accrual by Class of Loans	The following table presents the recorded investment in nonaccrual and loans past due over 90 days still on accrual by class of loans as of March 31, 2018 and December 31, 2017: Nonaccrual Loans Past Due March 31, 2018 Construction and land development $ 165 $ — Residential real estate: Closed-end 1-4 581 — Other 113 12 Commercial and industrial 2,466 166 Total $ 3,325 $ 178 December 31, 2017 Residential real estate: Closed-end 1-4 $ 257 $ 14 Other 114 — Commercial and industrial 2,466 191 Total $ 2,837 $ 205
Schedule of Aging of Recorded Investment in Past Due Loans by Class of Loans	The following table presents the aging of the recorded investment in past due loans as of March 31, 2018 and December 31, 2017 by class of loans: 30-59 60-89 Greater Nonaccrual Total Loans PCI Total March 31, 2018 Construction and land development $ 473 $ — $ — $ 165 $ 638 $ 523,022 $ — $ 523,660 Commercial real estate: Nonfarm, nonresidential — — — — — 673,497 371 673,868 Other 5 — — — 5 43,105 — 43,110 Residential real estate: Closed-end 1-4 610 1,060 — 581 2,251 428,216 96 430,563 Other 116 — 12 113 241 171,975 — 172,216 Commercial and industrial 440 195 166 2,466 3,267 459,687 1,973 464,927 Consumer and other — 200 — — 200 3,699 — 3,899 $ 1,644 $ 1,455 $ 178 $ 3,325 $ 6,602 $ 2,303,201 $ 2,440 $ 2,312,243 December 31, 2017 Construction and land development $ 1,918 $ 136 $ — $ — $ 2,054 $ 492,764 $ — $ 494,818 Commercial real estate: Nonfarm, nonresidential — — — — — 628,554 380 628,934 Other — — — — — 49,681 — 49,684 Residential real estate: Closed-end 1-4 — — 14 257 271 407,424 105 407,800 Other 146 719 — 114 979 168,661 — 169,640 Commercial and industrial 532 27 191 2,466 3,216 498,790 1,908 503,914 Consumer and other — — — — — 3,781 — 3,781 $ 2,596 $ 882 $ 205 $ 2,837 $ 6,520 $ 2,249,658 $ 2,393 $ 2,258,571
Summary of Risk Category of Loans by Class of Loans	Based on the most recent analysis performed, the risk category of loans by class of loans is as follows as of March 31, 2018 and December 31, 2017: Pass Special Substandard Total March 31, 2018 Construction and land development $ 519,831 $ 3,664 $ 165 $ 523,660 Commercial real estate: Nonfarm, nonresidential 658,683 11,098 4,087 673,868 Other 42,730 — 380 43,110 Residential real estate: Closed-end 1-4 426,856 — 3,707 430,563 Other 170,467 — 1,749 172,216 Commercial and industrial 448,395 9,003 7,529 464,927 Consumer and other 3,896 3 — 3,899 $ 2,270,858 $ 23,768 $ 17,617 $ 2,312,243 Pass Special Substandard Total December 31, 2017 Construction and land development $ 494,601 $ — $ 217 $ 494,818 Commercial real estate: Nonfarm, nonresidential 609,458 12,602 6,874 628,934 Other 49,303 — 381 49,684 Residential real estate: 1-4 404,832 615 2,353 407,800 Other 167,886 — 1,754 169,640 Commercial and industrial 485,363 10,350 8,201 503,914 Consumer and other 3,777 4 — 3,781 $ 2,215,220 $ 23,571 $ 19,780 $ 2,258,571

Loan Servicing (Tables)

Loan Servicing (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Schedule of Loans Serviced Not Reported as Assets	Loans serviced for others are not reported as assets. The principal balances of these loans at March 31, 2018 and December 31, 2017 are as follows: March 31, December 31, Loan portfolios serviced for: Federal Home Loan Mortgage Corporation $ 507,375 $ 507,233 Other 4,589 4,626
Components of Net Loan Servicing Fees	The components of net loan servicing fees for the three months ended March 31, 2018 and 2017 were as follows: Three Months Ended 2018 2017 Loan servicing fees, net: Loan servicing fees $ 333 $ 320 Amortization of loan servicing fees (214 ) (213 ) Change in impairment — — Total $ 119 $ 107

Securities Sold Under Agreeme22

Securities Sold Under Agreement to Repurchase (Tables)	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Additional Details of Securities Sold under Agreement to Repurchase	The following table provides additional details as of March 31, 2018: As of March 31, 2018 Mortgage- State and Total Market value of securities pledged $ 919 $ 40,845 $ 41,764 Borrowings related to pledged amounts $ — $ 36,071 $ 36,071 Market value pledged as a % of borrowings — % 113 % 116 % The following table provides additional details as of December 31, 2017: As of December 31, 2017 Mortgage- State and Total Market value of securities pledged $ 1,004 $ 42,109 $ 43,113 Borrowings related to pledged amounts $ — $ 31,004 $ 31,004 Market value pledged as a % of borrowings — % 136 % 139 %

Share-Based Payments (Tables)

Share-Based Payments (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Summary of Stock Warrant Activity	A summary of the stock warrant activity for the three months ended March 31, 2018 and 2017 follows: March 31, March 31, Stock warrants exercised: Intrinsic value of warrants exercised $ — $ 291 Cash received from warrants exercised — 132
Fair Value Assumptions of Stock Options	The fair value of options granted was determined using the following weighted-average assumptions as of grant date. March 31, March 31, Risk-free interest rate 2.49 % 2.28 % Expected term 7.5 years 7.4 years Expected stock price volatility 32.48 % 34.20 % Dividend yield 0.00 % 0.04 %
Summary of Company's Stock Option Activities	A summary of the activity in the plans for the three months ended March 31, 2018 follows: Shares Weighted Weighted Aggregate Outstanding at beginning of year 1,507,168 $ 21.37 6.55 $ 19,180 Granted 28,125 36.40 Exercised (21,348 ) 10.32 Forfeited, expired, or cancelled (11,754 ) 29.37 Outstanding at period end 1,502,191 $ 21.75 6.41 $ 16,299 Vested or expected to vest 1,427,082 $ 21.75 6.41 $ 15,484 Exercisable at period end 760,955 $ 14.17 4.75 $ 14,022
Summary of Stock Options Exercised	For the three months 2018 2017 Stock options exercised: Intrinsic value of options exercised $ 511 $ 610 Cash received from options exercised 220 177 Tax benefit realized from option exercises 63 93
Summary of Activity for Nonvested Restricted Share Awards	A summary of activity for non-vested Non-vested Shares Weighted- Non-vested 94,181 $ 25.42 Granted — — Vested — — Forfeited (334 ) 37.35 Non-vested 96,409 $ 25.38

Regulatory Capital Matters (Tab

Regulatory Capital Matters (Tables)	3 Months Ended
	Mar. 31, 2018
Banking and Thrift [Abstract]
Actual and Required Capital Amounts and Ratios	Actual and required capital amounts and ratios are presented below as of March 31, 2018 and December 31, 2017 for the Company and Bank: Actual Required To Be Well Amount Ratio Amount Ratio Amount Ratio March 31, 2018 Company common equity Tier 1 capital to risk-weighted assets $ 310,218 11.45 % $ 121,874 4.50 % N/A N/A Company Total Capital to risk weighted assets $ 390,600 14.42 % $ 216,665 8.00 % N/A N/A Company Tier 1 (Core) Capital to risk weighted assets $ 310,218 11.45 % $ 162,499 6.00 % N/A N/A Company Tier 1 (Core) Capital to average assets $ 310,218 7.80 % $ 158,986 4.00 % N/A N/A Bank common equity Tier 1 capital to risk-weighted assets $ 365,295 13.49 % $ 121,874 4.50 % $ 176,040 6.50 % Bank Total Capital to risk weighted assets $ 387,126 14.29 % $ 216,665 8.00 % $ 270,831 10.00 % Bank Tier 1 (Core) Capital to risk weighted assets $ 365,295 13.49 % $ 162,499 6.00 % $ 216,665 8.00 % Bank Tier 1 (Core) Capital to average assets $ 365,295 9.19 % $ 158,857 4.00 % $ 198,572 5.00 % December 31, 2017 Company common equity Tier 1 capital to risk-weighted assets $ 299,229 11.37 % $ 118,479 4.50 % N/A N/A Company Total Capital to risk weighted assets $ 379,083 14.40 % $ 210,629 8.00 % N/A N/A Company Tier 1 (Core) Capital to risk weighted assets $ 299,229 11.37 % $ 157,972 6.00 % N/A N/A Company Tier 1 (Core) Capital to average assets $ 299,229 8.25 % $ 145,100 4.00 % N/A N/A Bank common equity Tier 1 capital to risk-weighted assets $ 353,512 13.43 % $ 118,489 4.50 % $ 171,151 6.50 % Bank Total Capital to risk weighted assets $ 374,851 14.24 % $ 210,647 8.00 % $ 263,309 10.00 % Bank Tier 1 (Core) Capital to risk weighted assets $ 353,512 13.43 % $ 157,985 6.00 % $ 210,647 8.00 % Bank Tier 1 (Core) Capital to average assets $ 353,512 9.75 % $ 145,003 4.00 % $ 181,253 5.00 % Note: Minimum ratios presented exclude the capital conservation buffer

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis, including financial assets and liabilities for which the Company has elected the fair value option, are summarized below: Fair Value Measurements at Quoted Prices Significant Significant Financial Assets Securities available for sale U.S. Treasury securities $ — $ 288,571 $ — U.S. government sponsored entities and agencies — 19,894 — Mortgage-backed securities-residential — 763,128 — Mortgage-backed securities-commercial — 5,011 — State and political subdivisions — 109,816 — Total securities available for sale $ — $ 1,186,420 $ — Loans held for sale $ — $ 12,871 $ — Mortgage banking derivatives $ — $ 382 $ — Financial Liabilities Mortgage banking derivatives $ — $ 45 $ — Fair Value Measurements at Quoted Prices Significant Significant Financial Assets Securities available for sale U.S. Treasury securities $ — $ 228,909 $ — U.S. government sponsored entities and agencies — 19,961 — Mortgage-backed securities-residential — 632,566 — Mortgage-backed securities-commercial — 5,074 — State and political subdivisions — 113,371 — Total securities available for sale $ — $ 999,881 $ — Loans held for sale $ — $ 12,024 $ — Mortgage banking derivatives $ — $ 175 $ — Financial Liabilities Mortgage banking derivatives $ — $ 35 $ —
Carrying Amount and Estimated Fair Value of Financial Instruments	The carrying amounts and estimated fair values of financial instruments at March 31, 2018 and December 31, 2017 are as follows: Carrying Fair Value Measurements at Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 246,164 $ 246,164 $ — $ — $ 246,164 Certificates of deposit held at other financial institutions 2,855 — 2,855 — 2,855 Securities available for sale 1,186,420 — 1,186,420 — 1,186,420 Securities held to maturity 213,381 — 210,888 — 210,888 Loans held for sale 12,871 — 12,871 — 12,871 Net loans 2,288,280 — — 2,295,275 2,295,275 Restricted equity securities 19,606 n/a n/a n/a n/a Servicing rights, net 3,602 — — 5,305 5,305 Mortgage banking derivative assets 382 — 382 — 382 Accrued interest receivable 12,937 182 6,400 6,355 12,937 Financial liabilities Deposits $ 3,355,153 $ 2,026,994 $ 1,284,426 $ — $ 3,311,420 Repurchase agreements 36,071 — 36,071 — 36,071 Federal Home Loan Bank advances 317,000 — 314,341 — 314,341 Subordinated notes, net 58,559 — — 62,259 62,259 Mortgage banking derivative liabilities 45 — 45 — 45 Accrued interest payable 2,775 93 2,332 350 2,775 Carrying Fair Value Measurements at Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 251,543 $ 251,543 $ — $ — $ 251,543 Certificates of deposit held at other financial institutions 2,855 — 2,855 — 2,855 Securities available for sale 999,881 — 999,881 — 999,881 Securities held to maturity 214,856 — 217,608 — 217,608 Loans held for sale 12,024 — 12,024 — 12,024 Net loans 2,235,361 — — 2,230,607 2,230,607 Restricted equity securities 18,492 n/a n/a n/a n/a Servicing rights, net 3,620 — — 5,089 5,089 Mortgage banking derivative assets 175 — 175 — 175 Accrued interest receivable 11,947 73 5,724 6,150 11,947 Financial liabilities Deposits $ 3,167,228 $ 1,911,928 $ 1,224,041 $ — $ 3,135,969 Federal funds purchased and repurchase agreements 31,004 — 31,004 — 31,004 Federal Home Loan Bank advances 272,000 — 270,311 — 270,311 Subordinated notes, net 58,515 — — 59,951 59,951 Mortgage banking derivative liabilities 35 — 35 — 35 Accrued interest payable 2,769 51 2,030 688 2,769

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Computation of Earnings per Share	The factors used in the earnings per share computation follow: Three Months Ended March 31, 2018 2017 Basic Net income available to common shareholders $ 10,052 $ 7,934 Less: earnings allocated to participating securities (71 ) (65 ) Net income allocated to common shareholders $ 9,981 $ 7,869 Weighted average common shares outstanding including participating securities 13,249,728 13,049,012 Less: Participating securities (94,010 ) (106,323 ) Average shares 13,155,718 12,942,689 Basic earnings per common share $ 0.76 $ 0.61 Diluted Net income allocated to common shareholders $ 9,981 $ 7,869 Weighted average common shares outstanding for basic earnings per common share 13,155,718 12,942,689 Add: Dilutive effects of assumed exercises of stock options 516,666 708,694 Add: Dilutive effects of assumed exercises of stock warrants — 5,974 Average shares and dilutive potential common shares 13,672,384 13,657,357 Diluted earnings per common share $ 0.73 $ 0.58

Subordinated Debt Issuance (Tab

Subordinated Debt Issuance (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Summary of Terms of Each Subordinated Note offering	The following table summarizes the terms of each subordinated note offering: March 2016 Subordinated Notes June 2016 Subordinated Notes Principal amount issued $40,000 $20,000 Maturity date March 30, 2026 July 1, 2026 Initial fixed interest rate 6.875% 7.00% Initial interest rate period 5 years 5 years First interest rate change date March 30, 2021 July 1, 2021 Interest payment frequency through year five* Semiannually Semiannually Interest payment frequency after five years* Quarterly Quarterly Interest repricing index and margin 3-month LIBOR plus 5.636% 3-month LIBOR plus 6.04% Repricing frequency after five years Quarterly Quarterly * Through March 31, 2018 all interest payments have been made in accordance with the terms of the agreements.

Securities - Summary of Amortiz

Securities - Summary of Amortized Cost and Fair Value of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,210,186	$ 1,009,070
Gross Unrealized Gains	449	1,889
Gross Unrealized Losses	(24,215)	(11,078)
Fair Value	1,186,420	999,881
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	289,086	229,119
Gross Unrealized Losses	(515)	(210)
Fair Value	288,571	228,909
U.S. Government Sponsored Entities and Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	20,103	20,125
Gross Unrealized Losses	(209)	(164)
Fair Value	19,894	19,961
Mortgage-Backed Securities: Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	782,579	641,225
Gross Unrealized Gains	45	102
Gross Unrealized Losses	(19,496)	(8,761)
Fair Value	763,128	632,566
Mortgage-Backed Securities: Commercial [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,123	5,133
Gross Unrealized Losses	(112)	(59)
Fair Value	5,011	5,074
State and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	113,295	113,468
Gross Unrealized Gains	404	1,787
Gross Unrealized Losses	(3,883)	(1,884)
Fair Value	$ 109,816	$ 113,371

Securities - Schedule of Amorti

Securities - Schedule of Amortized Cost and Fair Value of Securities Held to Maturity Portfolio (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 213,381	$ 214,856
Gross Unrecognized Gains	1,175	4,586
Gross Unrecognized Losses	(3,668)	(1,834)
Fair Value	210,888	217,608
Mortgage-Backed Securities: Residential [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	92,152	93,366
Gross Unrecognized Gains	111	207
Gross Unrecognized Losses	(3,495)	(1,796)
Fair Value	88,768	91,777
State and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	121,229	121,490
Gross Unrecognized Gains	1,064	4,379
Gross Unrecognized Losses	(173)	(38)
Fair Value	$ 122,120	$ 125,831

Securities - Summary of Proceed

Securities - Summary of Proceeds from Sales and Calls of Securities Available for Sale and Associated Gains and Losses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Available-for-sale Securities [Abstract]
Proceeds	$ 0	$ 0
Gross gains	0	0
Gross losses	$ 0	$ 0

Securities - Schedule of Amor31

Securities - Schedule of Amortized Cost and Fair Value of Investment Securities Portfolio by Contractual Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Available for sale
Amortized Cost, One year or less	$ 289,086
Amortized Cost, Over one year through five years	20,103
Amortized Cost, Over five years through ten years	410
Amortized Cost, Over ten years	112,885
Amortized Cost, Total	1,210,186	$ 1,009,070
Held to maturity
Amortized Cost,One year or less	501
Amortized Cost, Over one year through five years	1,106
Amortized Cost, Over five years through ten years	11,875
Amortized Cost, Over ten years	107,747
Amortized Cost, Total	213,381	214,856
Available for sale
Fair Value, One year or less	288,571
Fair Value, Over one year through five years	19,894
Fair Value, Over five years through ten years	406
Fair Value, Over ten years	109,410
Fair Value, Total	1,186,420	999,881
Held to maturity
Fair Value, One year or less	511
Fair Value, Over one year through five years	1,121
Fair Value, Over five years through ten years	11,907
Fair Value, Over ten years	108,581
Fair Value, Total	210,888	217,608
Mortgage-Backed Securities: Residential [Member]
Available for sale
Amortized Cost, Mortgage-backed securities not due at a single maturity date	782,579
Amortized Cost, Total	782,579	641,225
Held to maturity
Amortized Cost, Mortgage-backed securities not due at a single maturity date	92,152
Amortized Cost, Total	92,152	93,366
Available for sale
Fair Value, Mortgage-backed securities not due at a single maturity date	763,128
Fair Value, Total	763,128	632,566
Held to maturity
Fair Value, Mortgage-backed securities not due at a single maturity date	88,768
Fair Value, Total	88,768	91,777
Mortgage-Backed Securities: Commercial [Member]
Available for sale
Amortized Cost, Mortgage-backed securities not due at a single maturity date	5,123
Amortized Cost, Total	5,123	5,133
Available for sale
Fair Value, Mortgage-backed securities not due at a single maturity date	5,011
Fair Value, Total	$ 5,011	$ 5,074

Securities - Additional Informa

Securities - Additional Information (Detail) $ in Thousands	Mar. 31, 2018USD ($)Securities	Dec. 31, 2017USD ($)Securities
Marketable Securities [Line Items]
Carrying value of pledged securities | $	$ 1,168,275	$ 975,518
Other than US Government Sponsored Entities and Agencies [Member]
Marketable Securities [Line Items]
Amount of holdings of securities of any one issuer | Securities	0	0

Securities - Schedule of Unreal

Securities - Schedule of Unrealized Losses and Fair Value by Major Security Type (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	$ 741,254	$ 556,400
Less Than 12 Months Available for sale Unrealized Losses	(8,673)	(2,882)
12 Months or Longer Available for sale Fair Value	376,560	374,091
12 Months or Longer Available for sale Unrealized Losses	(15,542)	(8,196)
Available for sale Fair Value, Total	1,117,814	930,491
Available for sale Unrealized Losses, Total	(24,215)	(11,078)
Less Than 12 Months Held to maturity Fair Value	36,461	11,453
Less Than 12 Months Held to maturity Unrealized Losses	(433)	(71)
12 Months or Longer Held to maturity Fair Value	69,905	73,730
12 Months or Longer Held to maturity Unrealized Losses	(3,235)	(1,763)
Held to maturity Fair Value, Total	106,366	85,183
Held to maturity Unrealized Losses, Total	(3,668)	(1,834)
U.S. Government Sponsored Entities and Agencies [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value		19,961
Less Than 12 Months Available for sale Unrealized Losses		(164)
12 Months or Longer Available for sale Fair Value	19,894
12 Months or Longer Available for sale Unrealized Losses	(209)
Available for sale Fair Value, Total	19,894	19,961
Available for sale Unrealized Losses, Total	(209)	(164)
Mortgage-Backed Securities: Residential [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	436,263	301,158
Less Than 12 Months Available for sale Unrealized Losses	(7,882)	(2,447)
12 Months or Longer Available for sale Fair Value	295,862	311,366
12 Months or Longer Available for sale Unrealized Losses	(11,614)	(6,314)
Available for sale Fair Value, Total	732,125	612,524
Available for sale Unrealized Losses, Total	(19,496)	(8,761)
Less Than 12 Months Held to maturity Fair Value	13,636	11,191
Less Than 12 Months Held to maturity Unrealized Losses	(306)	(69)
12 Months or Longer Held to maturity Fair Value	68,768	72,582
12 Months or Longer Held to maturity Unrealized Losses	(3,189)	(1,727)
Held to maturity Fair Value, Total	82,404	83,773
Held to maturity Unrealized Losses, Total	(3,495)	(1,796)
Mortgage-Backed Securities: Commercial [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	5,011	5,074
Less Than 12 Months Available for sale Unrealized Losses	(112)	(59)
Available for sale Fair Value, Total	5,011	5,074
Available for sale Unrealized Losses, Total	(112)	(59)
State and Political Subdivisions [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	11,409	1,298
Less Than 12 Months Available for sale Unrealized Losses	(164)	(2)
12 Months or Longer Available for sale Fair Value	60,804	62,725
12 Months or Longer Available for sale Unrealized Losses	(3,719)	(1,882)
Available for sale Fair Value, Total	72,213	64,023
Available for sale Unrealized Losses, Total	(3,883)	(1,884)
Less Than 12 Months Held to maturity Fair Value	22,825	262
Less Than 12 Months Held to maturity Unrealized Losses	(127)	(2)
12 Months or Longer Held to maturity Fair Value	1,137	1,148
12 Months or Longer Held to maturity Unrealized Losses	(46)	(36)
Held to maturity Fair Value, Total	23,962	1,410
Held to maturity Unrealized Losses, Total	(173)	(38)
U.S. Treasury Securities [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	288,571	228,909
Less Than 12 Months Available for sale Unrealized Losses	(515)	(210)
Available for sale Fair Value, Total	288,571	228,909
Available for sale Unrealized Losses, Total	$ (515)	$ (210)

Loans - Summary of Loans (Detai

Loans - Summary of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 2,309,803	$ 2,256,178
Deferred loan fees, net	(2,225)	(1,963)
Total loans that are not PCI loans	2,307,578	2,254,215
Total PCI loans	2,440	2,393
Allowance for loan losses	(21,738)	(21,247)	$ (18,105)	$ (16,553)
Net loans	2,288,280	2,235,361
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Construction and land development	523,660	494,818
Allowance for loan losses	(4,345)	(3,802)	(3,837)	(3,776)
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	462,954	502,006
Total PCI loans	1,973	1,908
Allowance for loan losses	(7,866)	(7,587)	(6,885)	(6,068)
Consumer and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Consumer and other	3,899	3,781
Allowance for loan losses	(47)	(43)	$ (52)	$ (45)
Commercial Real Estate Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonfarm, nonresidential	673,497	628,554
Commercial Real Estate, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other	43,110	49,684
Real Estate Residential Closed-end 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Closed-end 1-4 family	430,467	407,695
Residential Real Estate, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other	$ 172,216	$ 169,640

Loans - Activity in Allowance f

Loans - Activity in Allowance for Loan Losses by Portfolio Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 21,247	$ 16,553
Provision for loan losses	573	1,855
Loans charged-off	(106)	(323)
Recoveries	24	20
Total ending allowance balance	21,738	18,105
Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	3,802	3,776
Provision for loan losses	582	61
Loans charged-off	(39)
Total ending allowance balance	4,345	3,837
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	5,981	4,266
Provision for loan losses	(106)	393
Total ending allowance balance	5,875	4,659
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	3,834	2,398
Provision for loan losses	(241)	262
Loans charged-off	(7)
Recoveries	19	12
Total ending allowance balance	3,605	2,672
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	7,587	6,068
Provision for loan losses	328	1,117
Loans charged-off	(49)	(300)
Total ending allowance balance	7,866	6,885
Consumer and Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	43	45
Provision for loan losses	10	22
Loans charged-off	(11)	(23)
Recoveries	5	8
Total ending allowance balance	$ 47	$ 52

Loans - Allowance for Loan Loss

Loans - Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment and Based on Impairment Method (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Individually evaluated for impairment	$ 543	$ 879
Allowance for loan losses, Collectively evaluated for impairment	21,189	20,368
Allowance for loan losses, Purchased credit-impaired loans	6
Total ending allowance balance	21,738	21,247	$ 18,105	$ 16,553
Loans, Individually evaluated for impairment	3,325	4,141
Loans, Collectively evaluated for impairment	2,306,478	2,252,037
Loans, Purchased credit-impaired loans	2,440	2,393
Total ending loans balance	2,312,243	2,258,571
Construction and Land Development [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Collectively evaluated for impairment	4,345	3,802
Total ending allowance balance	4,345	3,802	3,837	3,776
Loans, Individually evaluated for impairment	165	217
Loans, Collectively evaluated for impairment	523,495	494,601
Total ending loans balance	523,660	494,818
Commercial Real Estate [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Collectively evaluated for impairment	5,875	5,981
Total ending allowance balance	5,875	5,981	4,659	4,266
Loans, Collectively evaluated for impairment	716,607	678,238
Loans, Purchased credit-impaired loans	371	380
Total ending loans balance	716,978	678,618
Residential Real Estate [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Collectively evaluated for impairment	3,605	3,834
Total ending allowance balance	3,605	3,834	2,672	2,398
Loans, Individually evaluated for impairment	694	834
Loans, Collectively evaluated for impairment	601,989	576,501
Loans, Purchased credit-impaired loans	96	105
Total ending loans balance	602,779	577,440
Commercial and Industrial [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Individually evaluated for impairment	543	879
Allowance for loan losses, Collectively evaluated for impairment	7,317	6,708
Allowance for loan losses, Purchased credit-impaired loans	6
Total ending allowance balance	7,866	7,587	6,885	6,068
Loans, Individually evaluated for impairment	2,466	3,090
Loans, Collectively evaluated for impairment	460,488	498,916
Loans, Purchased credit-impaired loans	1,973	1,908
Total ending loans balance	464,927	503,914
Consumer and Other [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Collectively evaluated for impairment	47	43
Total ending allowance balance	47	43	$ 52	$ 45
Loans, Collectively evaluated for impairment	3,899	3,781
Total ending loans balance	$ 3,899	$ 3,781

Loans - Additional Information

Loans - Additional Information (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable carrying amount	$ 2,312,243	$ 2,258,571
Unpaid principal amount	3,363	4,141
Allowance for loan losses	$ 21,738	$ 21,247	$ 18,105	$ 16,553
Number of loans modified as troubled debt restructuring	1	1
Loans modified as troubled debt restructuring, Amount	$ 165	$ 608
Loans modified as troubled debt restructuring, Amount paid out	575
Loans modified as troubled debt restructuring, Amount charged off	33
Non PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable carrying amount	50,759	50,341
Unpaid principal amount	52,121	51,767
Estimated credit discount	1,362	1,426
Allowance for loan losses	$ 10	$ 10

Loans - Summary of Impaired Loa

Loans - Summary of Impaired Loans by Class of Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	$ 989		$ 1,159
Unpaid Principal Balance	3,363		4,141
Recorded Investment, With no allowance recorded	951		1,159
Recorded Investment	3,325		4,141
Unpaid Principal Balance, With an allowance recorded	2,374		2,982
Recorded Investment, With an allowance recorded	2,374		2,982
Allowance for Loan Losses Allocated	543		879
Average Recorded Investment, With no allowance recorded	1,785	$ 6,047
Average Recorded Investment, With an allowance recorded	1,785	2,585
Average Recorded Investment	3,570	8,632
Commercial Real Estate Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment, With no allowance recorded		4,128
Real Estate Residential Closed-end 1-4 Family [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	581		14
Recorded Investment, With no allowance recorded	581		14
Average Recorded Investment, With no allowance recorded	420	1,799
Residential Real Estate, Other [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	113		820
Recorded Investment, With no allowance recorded	113		820
Average Recorded Investment, With no allowance recorded	372	120
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	92		108
Recorded Investment, With no allowance recorded	92		108
Unpaid Principal Balance, With an allowance recorded	2,374		2,982
Recorded Investment, With an allowance recorded	2,374		2,982
Allowance for Loan Losses Allocated	543		879
Average Recorded Investment, With no allowance recorded	626
Average Recorded Investment, With an allowance recorded	1,785	$ 2,585
Construction and Land Development [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	203		217
Recorded Investment, With no allowance recorded	165		$ 217
Average Recorded Investment, With no allowance recorded	$ 367

Loans - Schedule of Recorded In

Loans - Schedule of Recorded Investment in Nonaccrual and Loans Past Due Over 90 Days on Accrual by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Nonaccrual	$ 3,325	$ 2,837
Recorded Investment, Loans Past Due Over 90 Days	178	205
Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Nonaccrual	165
Real Estate Residential Closed-end 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Nonaccrual	581	257
Recorded Investment, Loans Past Due Over 90 Days		14
Commercial and Industrial Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Nonaccrual	2,466	2,466
Recorded Investment, Loans Past Due Over 90 Days	166	191
Residential Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Nonaccrual	113	$ 114
Recorded Investment, Loans Past Due Over 90 Days	$ 12

Loans - Schedule of Aging of Re

Loans - Schedule of Aging of Recorded Investment in Past Due Loans by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Nonaccrual	$ 3,325	$ 2,837
Aging of Recorded Investment, Total Past Due	6,602	6,520
Aging of Recorded Investment, Loans Not Past Due	2,303,201	2,249,658
Aging of Recorded Investment, Total	2,312,243	2,258,571
Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Nonaccrual	165
Aging of Recorded Investment, Total Past Due	638	2,054
Aging of Recorded Investment, Loans Not Past Due	523,022	492,764
Aging of Recorded Investment, Total	523,660	494,818
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Nonaccrual	2,466	2,466
Aging of Recorded Investment, Total Past Due	3,267	3,216
Aging of Recorded Investment, Loans Not Past Due	459,687	498,790
Aging of Recorded Investment, Total	464,927	503,914
Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	200
Aging of Recorded Investment, Loans Not Past Due	3,699	3,781
Aging of Recorded Investment, Total	3,899	3,781
PCI Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	2,440	2,393
PCI Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	1,973	1,908
Commercial Real Estate Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Loans Not Past Due	673,497	628,554
Aging of Recorded Investment, Total	673,868	628,934
Commercial Real Estate Financing Receivable [Member] | PCI Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	371	380
Commercial Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	5
Aging of Recorded Investment, Loans Not Past Due	43,105	49,681
Aging of Recorded Investment, Total	43,110	49,684
Real Estate Residential Closed-end 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Nonaccrual	581	257
Aging of Recorded Investment, Total Past Due	2,251	271
Aging of Recorded Investment, Loans Not Past Due	428,216	407,424
Aging of Recorded Investment, Total	430,563	407,800
Real Estate Residential Closed-end 1-4 Family [Member] | PCI Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	96	105
Residential Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Nonaccrual	113	114
Aging of Recorded Investment, Total Past Due	241	979
Aging of Recorded Investment, Loans Not Past Due	171,975	168,661
Aging of Recorded Investment, Total	172,216	169,640
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	1,644	2,596
30 to 59 Days Past Due [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	473	1,918
30 to 59 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	440	532
30 to 59 Days Past Due [Member] | Commercial Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	5
30 to 59 Days Past Due [Member] | Real Estate Residential Closed-end 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	610
30 to 59 Days Past Due [Member] | Residential Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	116	146
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	1,455	882
60 to 89 Days Past Due [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due		136
60 to 89 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	195	27
60 to 89 Days Past Due [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	200
60 to 89 Days Past Due [Member] | Real Estate Residential Closed-end 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	1,060
60 to 89 Days Past Due [Member] | Residential Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due		719
Greater Than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	178	205
Greater Than 90 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	166	191
Greater Than 90 Days Past Due [Member] | Real Estate Residential Closed-end 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due		$ 14
Greater Than 90 Days Past Due [Member] | Residential Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Total Past Due	$ 12

Loans - Summary of Risk Categor

Loans - Summary of Risk Category of Loans by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Risk Category Of Loans [Line Items]
Total Loans	$ 2,312,243	$ 2,258,571
Construction and Land Development [Member]
Risk Category Of Loans [Line Items]
Total Loans	523,660	494,818
Commercial and Industrial [Member]
Risk Category Of Loans [Line Items]
Total Loans	464,927	503,914
Consumer and Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	3,899	3,781
Commercial Real Estate Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	673,868	628,934
Commercial Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	43,110	49,684
Real Estate Residential Closed-end 1-4 Family [Member]
Risk Category Of Loans [Line Items]
Total Loans	430,563	407,800
Residential Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	172,216	169,640
Pass [Member]
Risk Category Of Loans [Line Items]
Total Loans	2,270,858	2,215,220
Pass [Member] | Construction and Land Development [Member]
Risk Category Of Loans [Line Items]
Total Loans	519,831	494,601
Pass [Member] | Commercial and Industrial [Member]
Risk Category Of Loans [Line Items]
Total Loans	448,395	485,363
Pass [Member] | Consumer and Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	3,896	3,777
Pass [Member] | Commercial Real Estate Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	658,683	609,458
Pass [Member] | Commercial Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	42,730	49,303
Pass [Member] | Real Estate Residential Closed-end 1-4 Family [Member]
Risk Category Of Loans [Line Items]
Total Loans	426,856	404,832
Pass [Member] | Residential Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	170,467	167,886
Special Mention [Member]
Risk Category Of Loans [Line Items]
Total Loans	23,768	23,571
Special Mention [Member] | Construction and Land Development [Member]
Risk Category Of Loans [Line Items]
Total Loans	3,664
Special Mention [Member] | Commercial and Industrial [Member]
Risk Category Of Loans [Line Items]
Total Loans	9,003	10,350
Special Mention [Member] | Consumer and Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	3	4
Special Mention [Member] | Commercial Real Estate Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	11,098	12,602
Special Mention [Member] | Real Estate Residential Closed-end 1-4 Family [Member]
Risk Category Of Loans [Line Items]
Total Loans		615
Substandard [Member]
Risk Category Of Loans [Line Items]
Total Loans	17,617	19,780
Substandard [Member] | Construction and Land Development [Member]
Risk Category Of Loans [Line Items]
Total Loans	165	217
Substandard [Member] | Commercial and Industrial [Member]
Risk Category Of Loans [Line Items]
Total Loans	7,529	8,201
Substandard [Member] | Commercial Real Estate Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	4,087	6,874
Substandard [Member] | Commercial Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	380	381
Substandard [Member] | Real Estate Residential Closed-end 1-4 Family [Member]
Risk Category Of Loans [Line Items]
Total Loans	3,707	2,353
Substandard [Member] | Residential Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	$ 1,749	$ 1,754

Loan Servicing - Schedule of Lo

Loan Servicing - Schedule of Loans Serviced Not Reported as Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Federal Home Loan Mortgage Corporation [Member]
Loans Servicing For Institutional Investors [Line Items]
Loans serviced for others	$ 507,375	$ 507,233
Other Serviced Loans [Member]
Loans Servicing For Institutional Investors [Line Items]
Loans serviced for others	$ 4,589	$ 4,626

Loan Servicing - Components of

Loan Servicing - Components of Net Loan Servicing Fees (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Transfers and Servicing [Abstract]
Loan servicing fees	$ 333	$ 320
Amortization of loan servicing fees	(214)	(213)
Change in impairment	0	0
Total	$ 119	$ 107

Loan Servicing - Additional Inf

Loan Servicing - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Transfers and Servicing [Abstract]
Fair value of servicing rights	$ 5,305	$ 5,089
Weighted average discount rate	10.50%	10.50%
Weighted average prepayment speed	9.40%	9.90%

Securities Sold Under Agreeme45

Securities Sold Under Agreement to Repurchase - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Total short-term borrowings	$ 36,071	$ 31,004
Carrying value of securities used to secure borrowings	$ 41,377	$ 41,618

Securities Sold Under Agreeme46

Securities Sold Under Agreement to Repurchase - Additional Details of Securities Sold under Agreement to Repurchase (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets Sold under Agreements to Repurchase [Line Items]
Market value of securities pledged	$ 41,764	$ 43,113
Borrowings related to pledged amounts	$ 36,071	$ 31,004
Market value pledged as a % of borrowings	116.00%	139.00%
Mortgage-Backed Securities: Residential [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Market value of securities pledged	$ 919	$ 1,004
State and Political Subdivisions [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Market value of securities pledged	40,845	42,109
Borrowings related to pledged amounts	$ 36,071	$ 31,004
Market value pledged as a % of borrowings	113.00%	136.00%

Share-Based Payments - Addition

Share-Based Payments - Additional Information (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)Plans$ / sharesshares	Mar. 31, 2017USD ($)$ / sharesshares	Apr. 12, 2018shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants exercised		11,011
Number of share-based compensation plans | Plans	2
Compensation cost charged against income | $	$ 759	$ 447
Excess tax benefit related to vesting of restricted stock and exercise of stock options | $	$ 63	$ 93
2010 Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant shares issued	32,425
Warrant exercise price per share | $ / shares	$ 12
Shares issuable upon exercise of warrants to purchase common stock	20
Warrants exercisable period	7 years
Warrant expiration date	Mar. 30, 2017
Warrants outstanding	0
2017 Omnibus Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	5,000,000
Number of shares authorized for issuance	4,709,454
Amended and Restated 2017 Plan [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized			3,500,000
Stock Option [Member] | 2007 Omnibus Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	4,000,000
Options contractual term	10 years
Weighted average fair value of options | $ / shares	$ 14.77	$ 17.25
Unrecognized compensation cost, nonvested stock options | $	$ 5,708
Unrecognized compensation cost, period of recognition	1 year 7 months 6 days
Stock Option [Member] | 2007 Omnibus Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	3 years
Stock Option [Member] | 2007 Omnibus Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	5 years
Restricted Stock [Member] | 2007 Omnibus Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, nonvested stock options | $	$ 1,580
Unrecognized compensation cost, period of recognition	3 years 1 month 6 days
Shares, Vested	0	0
Restricted Stock [Member] | 2007 Omnibus Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	3 years
Restricted Stock [Member] | 2007 Omnibus Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	5 years

Share-Based Payments - Summary

Share-Based Payments - Summary of Stock Warrant Activity (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Intrinsic value of warrants exercised	$ 291
Cash received from warrants exercised	$ 132

Share-Based Payments - Fair Val

Share-Based Payments - Fair Value Assumptions of Stock Options (Detail)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	2.49%	2.28%
Expected term	7 years 6 months	7 years 4 months 24 days
Expected stock price volatility	32.48%	34.20%
Dividend yield	0.00%	0.04%

Share-Based Payments - Summar50

Share-Based Payments - Summary of Company's Stock Option Activities (Detail) - 2007 Omnibus Equity Incentive Plan [Member] - Stock Option [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding, Beginning Balance	1,507,168
Shares, Granted	28,125
Shares, Exercised	(21,348)
Shares, Forfeited, expired, or canceled	(11,754)
Shares, Outstanding, Ending Balance	1,502,191	1,507,168
Shares, Vested or expected to vest	1,427,082
Shares, Exercisable at period end	760,955
Weighted Average Exercise Price, Outstanding, Beginning Balance	$ 21.37
Weighted Average Exercise Price, Granted	36.40
Weighted Average Exercise Price, Exercised	10.32
Weighted Average Exercise Price, Forfeited, expired, or cancelled	29.37
Weighted Average Exercise Price, Outstanding, Ending Balance	21.75	$ 21.37
Weighted Average Exercise Price, Vested or expected to vest	21.75
Weighted Average Exercise Price, Exercisable at period end	$ 14.17
Weighted Average Remaining Contractual Term, Outstanding at beginning of year	6 years 4 months 28 days	6 years 6 months 18 days
Weighted Average Remaining Contractual Term, Vested or expected to vest	6 years 4 months 28 days
Weighted Average Remaining Contractual Term, Exercisable at period end	4 years 9 months
Aggregate Intrinsic Value, Outstanding at beginning of year	$ 16,299	$ 19,180
Aggregate Intrinsic Value, Vested or expected to vest	15,484
Aggregate Intrinsic Value, Exercisable at period end	$ 14,022

Share-Based Payments - Summar51

Share-Based Payments - Summary of Stock Options Exercised (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock options exercised:
Cash received from options exercised	$ 220	$ 177
2007 Omnibus Equity Incentive Plan [Member] | Stock Option [Member]
Stock options exercised:
Intrinsic value of options exercised	511	610
Cash received from options exercised	220	177
Tax benefit realized from option exercises	$ 63	$ 93

Share-Based Payments - Summar52

Share-Based Payments - Summary of Activity for Nonvested Restricted Share Awards (Detail) - Restricted Stock [Member] - 2007 Omnibus Equity Incentive Plan [Member] - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Non-vested, Beginning Balance	94,181
Shares, Granted	0
Shares, Vested	0	0
Shares, Forfeited	(334)
Shares, Non-vested, Ending Balance	96,409
Weighted-Average Grant-Date Fair Value, Non-vested, Beginning Balance	$ 25.42
Weighted-Average Grant-Date Fair Value, Granted	0
Weighted-Average Grant-Date Fair Value, Vested	0
Weighted-Average Grant-Date Fair Value, Forfeited	37.35
Weighted-Average Grant-Date Fair Value, Non-vested, Ending Balance	$ 25.38

Regulatory Capital Matters - Ad

Regulatory Capital Matters - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018
Banking and Thrift [Abstract]
Capital conservation buffer	2.50%
Capital conservation buffer ratio to be phased in at beginning	0.625%
Capital conservation buffer phase in year	2,016
Capital conservation buffer period final year	2,019
Capital conservation buffer ratio during period	1.875%

Regulatory Capital Matters - Ac

Regulatory Capital Matters - Actual and Required Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity Tier 1 capital to risk-weighted assets, Actual Amount	$ 310,218	$ 299,229
Total Capital to risk-weighted assets, Actual Amount	390,600	379,083
Tier 1 (Core) Capital to risk weighted assets, Actual Amount	310,218	299,229
Tier 1 (Core) Capital to average assets, Actual Amount	$ 310,218	$ 299,229
Common equity Tier 1 capital to risk-weighted assets	11.45%	11.37%
Total Capital to risk weighted assets, Actual Ratio	14.42%	14.40%
Tier 1 (Core) Capital to risk weighted assets, Actual Ratio	11.45%	11.37%
Tier 1 (Core) Capital to average assets, Actual Ratio	7.80%	8.25%
Common equity Tier 1 capital to risk-weighted assets	$ 121,874	$ 118,479
Total Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	216,665	210,629
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	162,499	157,972
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Amount	$ 158,986	$ 145,100
Common equity Tier 1 capital to risk-weighted assets	4.50%	4.50%
Total Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	6.00%	6.00%
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Ratio	4.00%	4.00%
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity Tier 1 capital to risk-weighted assets, Actual Amount	$ 365,295	$ 353,512
Total Capital to risk-weighted assets, Actual Amount	387,126	374,851
Tier 1 (Core) Capital to risk weighted assets, Actual Amount	365,295	353,512
Tier 1 (Core) Capital to average assets, Actual Amount	$ 365,295	$ 353,512
Common equity Tier 1 capital to risk-weighted assets	13.49%	13.43%
Total Capital to risk weighted assets, Actual Ratio	14.29%	14.24%
Tier 1 (Core) Capital to risk weighted assets, Actual Ratio	13.49%	13.43%
Tier 1 (Core) Capital to average assets, Actual Ratio	9.19%	9.75%
Common equity Tier 1 capital to risk-weighted assets	$ 121,874	$ 118,489
Total Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	216,665	210,647
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	162,499	157,985
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Amount	$ 158,857	$ 145,003
Common equity Tier 1 capital to risk-weighted assets	4.50%	4.50%
Total Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	6.00%	6.00%
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Ratio	4.00%	4.00%
Common equity Tier 1 capital to risk-weighted assets	$ 176,040	$ 171,151
Total Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Amount	270,831	263,309
Tier 1 (Core) Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Amount	216,665	210,647
Tier 1 (Core) Capital to average assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Amount	$ 198,572	$ 181,253
Common equity Tier 1 capital to risk-weighted assets	6.50%	6.50%
Total Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	10.00%	10.00%
Tier 1 (Core) Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	8.00%	8.00%
Tier 1 (Core) Capital to average assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	5.00%	5.00%

Fair Value - Additional informa

Fair Value - Additional information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fair Value Measurements Of Financial Instruments [Line Items]
Fair value measurements, valuation techniques	For securities where quoted prices are not available, fair values are calculated based on market prices of similar securities (Level 2), using matrix pricing. Matrix pricing is a mathematical technique commonly used to price debt securities that are not actively traded, values debt securities without relying exclusively on quoted prices for the specific securities but rather by relying on the securities' relationship to other benchmark quoted securities (Level 2 inputs).
Change in fair value related to loans held for sale	$ 1,439,000	$ 2,334,000
Additional provision for loan losses	573,000	1,855,000
Carrying amount of impaired loans with specific allocations	3,325,000		$ 4,141,000
Foreclosed assets	1,503,000		1,503,000
Write-down value during period	0	0
Loans Held for Sale [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Unpaid principal balance of loans held for sale	12,554,000		11,681,000
Change in fair value related to loans held for sale	317,000		343,000
Change in fair value of loans held for sale	(26,000)	113,000
Changes Measurement [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Additional provision for loan losses	0	$ 0
Fair Value [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Carrying amount of impaired loans with specific allocations	$ 1,831,000		$ 1,831,000
Maximum [Member] | Loans Held for Sale [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Term of loan	90 days		90 days

Fair Value - Assets and Liabili

Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 1,186,420	$ 999,881
Loans held for sale	12,871	12,024
U.S. Government Sponsored Entities and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	19,894	19,961
Mortgage-Backed Securities: Residential [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	763,128	632,566
Mortgage-Backed Securities: Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	5,011	5,074
State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	109,816	113,371
U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	288,571	228,909
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,186,420	999,881
Loans held for sale	12,871	12,024
Mortgage banking derivatives	382	175
Mortgage banking derivatives	45	35
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Sponsored Entities and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	19,894	19,961
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities: Residential [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	763,128	632,566
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities: Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	5,011	5,074
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	109,816	113,371
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 288,571	$ 228,909

Fair Value - Carrying Amount an

Fair Value - Carrying Amount and Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Carrying Amount	$ 246,164	$ 251,543	$ 114,664	$ 90,927
Certificates of deposit held at other financial institutions	2,855	2,855
Securities available for sale	1,186,420	999,881
Securities held to maturity, Carrying Amount	213,381	214,856
Securities held to maturity, Fair Value	210,888	217,608
Loans held for sale, Fair Value	12,871	12,024
Net loans, Carrying Amount	2,288,280	2,235,361
Servicing rights, net, Carrying Amount	3,602	3,620
Servicing rights, net, Fair Value	5,305	5,089
Accrued interest receivable	12,937	11,947
Deposits, Carrying Amount	3,355,153	3,167,228
Federal funds purchased and repurchase agreements, Carrying Amount	36,071	31,004
Federal Home Loan Bank advances, Carrying Amount	317,000	272,000
Subordinated notes, net	58,559	58,515
Accrued interest payable	2,775	2,769
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Fair Value	246,164	251,543
Certificates of deposit held at other financial institutions, Fair Value	2,855	2,855
Securities available for sale	1,186,420	999,881
Securities held to maturity, Fair Value	210,888	217,608
Loans held for sale, Fair Value	12,871	12,024
Net loans, Fair Value	2,295,275	2,230,607
Restricted equity securities, Fair Value	0	0
Servicing rights, net, Fair Value	5,305	5,089
Mortgage banking derivative assets	382	175
Accrued interest receivable	12,937	11,947
Deposits, Fair Value	3,311,420	3,135,969
Federal funds purchased and repurchase agreements, Fair Value	36,071	31,004
Federal Home Loan Bank advances, Fair Value	314,341	270,311
Subordinated notes, net	62,259	59,951
Mortgage banking derivative liabilities	45	35
Accrued interest payable	2,775	2,769
Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Fair Value	246,164	251,543
Restricted equity securities, Fair Value	0	0
Accrued interest receivable	182	73
Deposits, Fair Value	2,026,994	1,911,928
Accrued interest payable	93	51
Fair Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Certificates of deposit held at other financial institutions, Fair Value	2,855	2,855
Securities available for sale	1,186,420	999,881
Securities held to maturity, Fair Value	210,888	217,608
Loans held for sale, Fair Value	12,871	12,024
Restricted equity securities, Fair Value	0	0
Mortgage banking derivative assets	382	175
Accrued interest receivable	6,400	5,724
Deposits, Fair Value	1,284,426	1,224,041
Federal funds purchased and repurchase agreements, Fair Value	36,071	31,004
Federal Home Loan Bank advances, Fair Value	314,341	270,311
Mortgage banking derivative liabilities	45	35
Accrued interest payable	2,332	2,030
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net loans, Fair Value	2,295,275	2,230,607
Restricted equity securities, Fair Value	0	0
Servicing rights, net, Fair Value	5,305	5,089
Accrued interest receivable	6,355	6,150
Subordinated notes, net	62,259	59,951
Accrued interest payable	350	688
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Carrying Amount	246,164	251,543
Certificates of deposit held at other financial institutions	2,855	2,855
Securities available for sale	1,186,420	999,881
Securities held to maturity, Carrying Amount	213,381	214,856
Loans held for sale, Carrying Amount	12,871	12,024
Net loans, Carrying Amount	2,288,280	2,235,361
Restricted equity securities, Carrying Amount	19,606	18,492
Servicing rights, net, Carrying Amount	3,602	3,620
Mortgage banking derivative assets	382	175
Accrued interest receivable	12,937	11,947
Deposits, Carrying Amount	3,355,153	3,167,228
Federal funds purchased and repurchase agreements, Carrying Amount	36,071	31,004
Federal Home Loan Bank advances, Carrying Amount	317,000	272,000
Subordinated notes, net	58,559	58,515
Mortgage banking derivative liabilities	45	35
Accrued interest payable	$ 2,775	$ 2,769

Earnings Per Share - Computatio

Earnings Per Share - Computation of Earnings per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basic
Net income available to common shareholders	$ 10,052	$ 7,934
Less: earnings allocated to participating securities	(71)	(65)
Net income allocated to common shareholders	$ 9,981	$ 7,869
Weighted average common shares outstanding including participating securities	13,249,728	13,049,012
Less: Participating securities	(94,010)	(106,323)
Average shares	13,155,718	12,942,689
Basic earnings per common share	$ 0.76	$ 0.61
Diluted
Net income allocated to common shareholders	$ 9,981	$ 7,869
Weighted average common shares outstanding for basic earnings per common share	13,155,718	12,942,689
Add: Dilutive effects of assumed exercises of stock options	516,666	708,694
Add: Dilutive effects of assumed exercises of stock warrants		5,974
Average shares and dilutive potential common shares	13,672,384	13,657,357
Diluted earnings per common share	$ 0.73	$ 0.58

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Stock options to purchase shares of the Company's common stock	411,279	108,000

Subordinated Debt Issuance - Ad

Subordinated Debt Issuance - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Jun. 30, 2016	Mar. 31, 2016
Debt Instrument [Line Items]
Subordinated notes, net of issuance costs	$ 58,559,000		$ 58,515,000
Amortization of debt issuance costs	44,000	$ 44,000
Subordinated Debt [Member]
Debt Instrument [Line Items]
Notes, Aggregate principal amount	60,000,000
Amortization of debt issuance costs	45,000	$ 45,000
Subordinated Debt [Member] | March 2016 Subordinated Notes [Member]
Debt Instrument [Line Items]
Notes, Aggregate principal amount					$ 40,000,000
Notes, Interest rate					6.875%
Notes, Issuance cost	$ 1,382,000
Term of notes	10 years
Subordinated Debt [Member] | June 2016 Subordinated Notes [Member]
Debt Instrument [Line Items]
Notes, Aggregate principal amount				$ 20,000,000
Notes, Interest rate				7.00%
Notes, Issuance cost	$ 404,000
Term of notes	10 years

Subordinated Debt Issuance - Su

Subordinated Debt Issuance - Summary of Terms of Each Subordinated Note offering (Detail) - Subordinated Debt [Member] - USD ($)	1 Months Ended		3 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2018
Debt Instrument [Line Items]
Principal amount issued			$ 60,000,000
March 2016 Subordinated Notes [Member]
Debt Instrument [Line Items]
Principal amount issued		$ 40,000,000
Maturity date		Mar. 30, 2026
Initial fixed interest rate		6.875%
Initial interest rate period			10 years
First interest rate change date		Mar. 30, 2021
Interest payment frequency through year five		Semiannually
Interest payment frequency after five years		Quarterly
March 2016 Subordinated Notes [Member] | Initial Term [Member]
Debt Instrument [Line Items]
Initial interest rate period		5 years
June 2016 Subordinated Notes [Member]
Debt Instrument [Line Items]
Principal amount issued	$ 20,000,000
Maturity date	Jul. 1, 2026
Initial fixed interest rate	7.00%
Initial interest rate period			10 years
First interest rate change date	Jul. 1, 2021
Interest payment frequency through year five	Semiannually
Interest payment frequency after five years	Quarterly
June 2016 Subordinated Notes [Member] | Initial Term [Member]
Debt Instrument [Line Items]
Initial interest rate period	5 years
LIBOR [Member] | March 2016 Subordinated Notes [Member]
Debt Instrument [Line Items]
Interest repricing index and margin		3-month LIBOR plus 5.636%
Interest payment frequency through year five		Quarterly
LIBOR [Member] | June 2016 Subordinated Notes [Member]
Debt Instrument [Line Items]
Interest repricing index and margin	3-month LIBOR plus 6.04%
Interest payment frequency through year five	Quarterly