Allegiance Bancshares (ABTX) 10-Q 1 Nov 19 2019 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 30, 2019
Cover [Abstract]
Entity Registrant Name	Allegiance Bancshares, Inc.
Entity Central Index Key	0001642081
Trading Symbol	ABTX
Security Exchange Name	NASDAQ
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Title of 12(b) Security	Common Stock, par value, $1.00 per share
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity File Number	001-37585
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	26-3564100
Entity Address, Address Line One	8847 West Sam Houston Parkway, N.
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77040
City Area Code	281
Local Phone Number	894-3200
Entity Common Stock, Shares Outstanding (in shares)		20,810,603
Document Quarterly Report	true
Document Transition Report	false

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
ASSETS
Cash and due from banks	$ 246,312	$ 118,771
Interest-bearing deposits at other financial institutions	54,307	150,176
Total cash and cash equivalents	300,619	268,947
Available for sale securities, at fair value	353,000	337,293
Loans held for investment	3,886,004	3,708,306
Less: allowance for loan losses	(29,808)	(26,331)
Loans, net	3,856,196	3,681,975
Accrued interest receivable	15,201	17,010
Premises and equipment, net	67,175	41,717
Other real estate owned	8,333	630
Federal Home Loan Bank stock	14,138	10,941
Bank owned life insurance	26,947	26,480
Goodwill	223,642	223,125
Core deposit intangibles, net	23,053	26,587
Other assets	17,536	20,544
TOTAL ASSETS	4,905,840	4,655,249
Deposits:
Noninterest-bearing	1,227,839	1,209,300
Interest-bearing
Demand	340,754	366,905
Money market and savings	1,114,233	879,840
Certificates and other time	1,214,659	1,206,491
Total interest-bearing deposits	2,669,646	2,453,236
Total deposits	3,897,485	3,662,536
Accrued interest payable	4,915	2,812
Borrowed funds	159,501	225,493
Subordinated debt	107,771	48,899
Other liabilities	29,860	12,525
Total liabilities	4,199,532	3,952,265
COMMITMENTS AND CONTINGENCIES (See Note 13)
SHAREHOLDERS’ EQUITY:
Preferred stock, $1 par value; 1,000,000 shares authorized; no shares issued or outstanding
Common stock, $1 par value; 80,000,000 shares authorized; 20,736,779 shares issued and outstanding at September 30, 2019 and 21,937,740 shares issued and outstanding at December 31, 2018	20,737	21,938
Capital surplus	529,688	571,803
Retained earnings	149,389	112,131
Accumulated other comprehensive income (loss)	6,494	(2,888)
Total shareholders’ equity	706,308	702,984
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 4,905,840	$ 4,655,249

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parentheticals) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Shares issued (in shares)	0	0
Shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	80,000,000	80,000,000
Common stock, shares issued (in shares)	20,736,779	21,937,740
Common stock, shares outstanding (in shares)	20,736,779	21,937,740

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
INTEREST INCOME:
Loans, including fees	$ 55,790	$ 32,988	$ 165,995	$ 94,951
Securities:
Taxable	2,090	636	4,909	1,881
Tax-exempt	483	1,447	2,465	4,357
Deposits in other financial institutions	302	265	1,391	731
Total interest income	58,665	35,336	174,760	101,920
INTEREST EXPENSE:
Demand, money market and savings deposits	4,975	1,248	13,216	3,111
Certificates and other time deposits	6,909	4,051	20,173	10,120
Borrowed funds	1,183	1,272	4,128	3,780
Subordinated debt	761	729	2,232	2,168
Total interest expense	13,828	7,300	39,749	19,179
NET INTEREST INCOME	44,837	28,036	135,011	82,741
Provision for loan losses	2,597	0	5,006	1,284
Net interest income after provision for loan losses	42,240	28,036	130,005	81,457
NONINTEREST INCOME:
Gain on sale of securities			846
Gain on sale of other real estate			71	1
Bank owned life insurance income	153	137	467	416
Rebate from correspondent bank	900	613	2,680	1,621
Other	1,289	826	4,421	2,270
Total noninterest income	2,889	1,928	10,023	5,379
NONINTEREST EXPENSE:
Salaries and employee benefits	20,221	12,965	59,320	38,537
Net occupancy and equipment	1,973	1,281	6,139	3,886
Depreciation	822	490	2,331	1,330
Data processing and software amortization	2,058	1,226	5,390	3,635
Professional fees	667	303	1,793	1,339
Regulatory assessments and FDIC insurance	(41)	505	1,489	1,533
Core deposit intangibles amortization	1,178	195	3,534	586
Communications	455	262	1,353	769
Advertising	449	351	1,770	1,021
Acquisition and merger-related expenses		196	1,326	821
Other	2,227	1,390	6,759	4,284
Total noninterest expense	30,009	19,164	91,204	57,741
INCOME BEFORE INCOME TAXES	15,120	10,800	48,824	29,095
Provision for income taxes	3,073	1,921	9,851	4,949
NET INCOME	$ 12,047	$ 8,879	$ 38,973	$ 24,146
EARNINGS PER SHARE:
Basic	$ 0.57	$ 0.66	$ 1.83	$ 1.81
Diluted	$ 0.57	$ 0.65	$ 1.81	$ 1.77
Deposit Account, Nonsufficient Funds Fee
NONINTEREST INCOME:
Revenue from contract with customer	$ 168	$ 175	$ 469	$ 565
Deposit Account, Service Charge Fee
NONINTEREST INCOME:
Revenue from contract with customer	$ 379	$ 177	$ 1,069	$ 506

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 12,047	$ 8,879	$ 38,973	$ 24,146
Unrealized gain (loss) on securities:
Change in unrealized holding gain (loss) on available for sale securities during the period	2,862	(2,265)	12,712	(8,106)
Reclassification of gain realized through the sale of securities			(846)
Total other comprehensive income (loss)	2,862	(2,265)	11,866	(8,106)
Deferred tax (expense) benefit related to other comprehensive income	(601)	476	(2,484)	1,774
Other comprehensive income (loss), net of tax	2,261	(1,789)	9,382	(6,332)
Comprehensive income	$ 14,308	$ 7,090	$ 48,355	$ 17,814

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2017	$ 306,865	$ 13,227	$ 218,408	$ 74,894	$ 336
Balance (in shares) at Dec. 31, 2017		13,226,826
Net income	24,146			24,146
Other comprehensive income (loss)	(6,332)				(6,332)
Reclassification of amounts within AOCI to retained earnings due to tax reform	(72)			(72)
Common stock issued in connection with the exercise of stock options and restricted stock awards	2,309	$ 170	2,139
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)		169,877
Stock based compensation expense	1,215		1,215
Balance at Sep. 30, 2018	328,131	$ 13,397	221,762	98,968	(5,996)
Balance (in shares) at Sep. 30, 2018		13,396,703
Balance at Jun. 30, 2018	319,888	$ 13,341	220,665	90,089	(4,207)
Balance (in shares) at Jun. 30, 2018		13,340,919
Net income	8,879			8,879
Other comprehensive income (loss)	(1,789)				(1,789)
Common stock issued in connection with the exercise of stock options and restricted stock awards	773	$ 56	717
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)		55,784
Stock based compensation expense	380		380
Balance at Sep. 30, 2018	328,131	$ 13,397	221,762	98,968	(5,996)
Balance (in shares) at Sep. 30, 2018		13,396,703
Balance at Dec. 31, 2018	702,984	$ 21,938	571,803	112,131	(2,888)
Balance (in shares) at Dec. 31, 2018		21,937,740
Cumulative effect of change in accounting principle related to ASU 2017-08 (Accounting Standards Update 2017-08) at Dec. 31, 2018	(1,715)			(1,715)
Total shareholders' equity at beginning of period, as adjusted at Dec. 31, 2018	701,269	$ 21,938	571,803	110,416	(2,888)
Net income	38,973			38,973
Other comprehensive income (loss)	9,382				9,382
Common stock issued in connection with the exercise of stock options and restricted stock awards	1,562	$ 160	1,402
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)		160,640
Repurchase of common stock	(47,155)	$ (1,361)	(45,794)
Repurchase of common stock (in shares)		(1,361,601)
Stock based compensation expense	2,277		2,277
Balance at Sep. 30, 2019	706,308	$ 20,737	529,688	149,389	6,494
Balance (in shares) at Sep. 30, 2019		20,736,779
Balance at Jun. 30, 2019	704,701	$ 21,147	541,979	137,342	4,233
Balance (in shares) at Jun. 30, 2019		21,147,179
Net income	12,047			12,047
Other comprehensive income (loss)	2,261				2,261
Common stock issued in connection with the exercise of stock options and restricted stock awards	496	$ 21	475
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)		20,590
Repurchase of common stock	(13,986)	$ (431)	(13,555)
Repurchase of common stock (in shares)		(430,990)
Stock based compensation expense	789		789
Balance at Sep. 30, 2019	$ 706,308	$ 20,737	$ 529,688	$ 149,389	$ 6,494
Balance (in shares) at Sep. 30, 2019		20,736,779

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 38,973	$ 24,146
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and core deposit intangibles amortization	5,865	1,916
Provision for loan losses	5,006	1,284
Net amortization of premium on investments	2,613	2,413
Excess tax benefit related to the exercise of stock options	(105)	(420)
Bank owned life insurance income	(467)	(416)
Net accretion of discount on loans	(7,112)	(207)
Net accretion of discount on subordinated debt	83	82
Net accretion of discount on certificates of deposit	(287)	(3)
Net gain on the sale or write down of premises, equipment and other real estate	(71)	(1)
Gain on sale of securities	846
Federal Home Loan Bank stock dividends	(332)	(268)
Stock based compensation expense	2,277	1,215
Net change in lease right-of-use assets	1,467
Decrease (increase) in accrued interest receivable and other assets	1,340	(2,846)
Increase in accrued interest payable and other liabilities	6,359	5,563
Net cash provided by operating activities	54,763	32,458
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities and principal paydowns of available for sale securities	2,245,919	2,014,951
Proceeds from sales of available for sale securities	149,366
Purchase of available for sale securities	(2,401,762)	(2,015,970)
Net change in total loans	(135,197)	(172,625)
Purchase of bank premises and equipment	(12,279)	(1,857)
Net (purchases) redemptions of Federal Home Loan Bank stock	(2,865)	1,279
Net cash paid for the LoweryBank branch acquisition	(32,867)
Net cash (used in) provided by investing activities	(189,685)	(174,222)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in noninterest-bearing deposits	4,659	106,595
Net increase in interest-bearing deposits	214,828	113,225
Paydowns on borrowed funds	(65,992)	(71,000)
Proceeds from subordinated notes issuance, net of offering expenses	58,692
Proceeds from the issuance of common stock, stock option exercises and the ESPP	1,562	2,309
Repurchase of common stock	(47,155)
Net cash provided by financing activities	166,594	151,129
NET CHANGE IN CASH AND CASH EQUIVALENTS	31,672	9,365
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	268,947	182,103
CASH AND CASH EQUIVALENTS, END OF PERIOD	300,619	191,468
SUPPLEMENTAL CASH FLOW INFORMATION:
Income taxes paid	8,000	4,700
Interest paid	37,645	$ 17,682
Operating lease cash flows	2,713
SUPPLEMENTAL NONCASH DISCLOSURE:
Lease right-of-use asset	13,277
Loans transferred to other real estate	$ 7,703

NATURE OF OPERATIONS AND SUMMAR

NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES	1. NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES Nature of Operations -Allegiance Bancshares, Inc. (“Allegiance”) and its wholly-owned subsidiary, Allegiance Bank, (the “Bank”, and together with Allegiance, collectively referred to as the “Company”) provide commercial and retail loans and commercial banking services. The Company derives substantially all of its revenues and income from the operation of the Bank. The Company is focused on delivering a wide variety of relationship-driven commercial banking products and community-oriented services tailored to meet the needs of small to medium-sized businesses, professionals and individual customers. The Company operated 27 full-service bank offices in the Houston region, which it defines as the Houston-The Woodlands-Sugar Land and Beaumont-Port Arthur metropolitan statistical areas, with 26 bank offices and one loan production office in the Houston metropolitan area and one bank office location in Beaumont, just outside of the Houston metropolitan area as of September 30, 2019. The Bank provides its customers with a variety of banking services including checking accounts, savings accounts and certificates of deposit, and its primary lending products are commercial, personal, automobile, mortgage and home improvement loans. The Bank also offers safe deposit boxes, automated teller machines, drive-through services and 24-hour depository facilities. Basis of Presentation -The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and in accordance with guidance provided by the Securities and Exchange Commission. Accordingly, the condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows of the Company on a consolidated basis, and all such adjustments are of a normal recurring nature. Transactions between the Company and the Bank have been eliminated. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018. Operating results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. Significant Accounting and Reporting Policies The Company’s significant accounting and reporting policies can be found in Note 1 of the Company’s annual financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018. New Accounting Standards Adoption of New Accounting Standards ASU 2016-02, “Leases (Topic 842)." ASU 2016-02 requires lessees to recognize a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 does not significantly change lease accounting requirements applicable to lessors; however, certain changes were made to align, where necessary, lessor accounting with the lessee accounting model and ASC Topic 606, “Revenue from Contracts with Customers.” ASU 2016-02 became effective for the Company on January 1, 2019. The Company adopted the standard through the required modified retrospective approach by applying the allowed transition method whereby comparative periods were not restated and a cumulative effect adjustment to the opening balance of retained earnings was recognized as of January 1, 2019. Topic 842 requires the recognition of a lease liability measured as the present value of unpaid lease payments for operating leases where the Company is the lessee, and a corresponding right-of-use (ROU) asset for the right to use the leased properties. The Company elected not to reassess whether contracts are or contain leases, lease classification or initial direct costs for existing leases, a set of practical expedients for transition provided by ASU 2016-12. Further, the Company elected the practical expedient to use hindsight in determining the lease term and assessing impairment. The election of the hindsight practical expedient resulted in longer lease terms for a limited number of strategic locations based on relevant factors as of the adoption date. The Company implemented a lease management system to assist in centralizing, maintaining and accounting for all leases to ensure the Company meets the ASU’s reporting and disclosure requirements. Prior comparable periods are presented in accordance with previous guidance under Accounting Standards Codification (ASC) 840, “Leases.” As of January 1, 2019, right-of-use assets and related lease liabilities totaled $15.3 million and $15.7 million, respectively. See Note 6 – Leases for further information regarding the Company’s leases on certain properties and equipment under operating leases. ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20) - Premium Amortization on Purchased Callable Debt Securities.” ASU 2017-08 shortens the amortization period for certain callable debt securities held at a premium to require such premiums to be amortized to the earliest call date unless applicable guidance related to certain pools of securities is applied to consider estimated prepayments. Under prior guidance, entities were generally required to amortize premiums on individual, non-pooled callable debt securities as a yield adjustment over the contractual life of the security. ASU 2017-08 does not change the accounting for callable debt securities held at a discount. ASU 2017-08 became effective for the Company on January 1, 2019. Upon adoption, the Company recognized a cumulative effect reduction in retained earnings totaling $1.7 million. Newly Issued But Not Yet Effective Accounting Standards ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” Among other things, ASU 2016-13 requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better form their credit loss estimates. Many of the loss estimation techniques applied today will still be permitted, although the inputs to those techniques will change to reflect the full amount of expected credit losses. In addition, ASU 2016-13 amends the accounting for credit losses on available for sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 is effective for the Company on January 1, 2020 and must be applied using the modified retrospective approach with limited exceptions. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. The Company has formed a cross functional team and, with the assistance of a third-party provider, is assessing the Company's data and system needs to evaluate the impact that adoption of this standard will have on the financial condition and results of operations of the Company. The Company expects the adoption of ASU 2016-13 to result in an increase in the allowance for loan losses as a result of changing from an “incurred loss” model, which encompasses allowances for current known and inherent losses within the portfolio, to an “expected loss” model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. ASU 2016-13 permits the use of estimation techniques that are practical and relevant to the Company’s circumstances, as long as they are applied consistently over time and reasonably estimate expected credit losses in accordance with the standard. The Company has developed its current expected credit loss estimation model and is working through its implementation plan which includes documentation of processes, internal controls and data sources; model development and documentation; and system configuration. The Company plans to implement the cohort method to estimate expected credit losses. This method will estimate credit losses over a forecast horizon and revert to long term historical loss experience. The cohort method also incorporates reasonable and supportable forecasts of economic conditions into the estimate which will require significant judgement. The Company will continue to perform and enhance parallel runs throughout 2019 as new processes, policies and controls are finalized. The impact of the standard will depend on the composition of the Company’s portfolio as well as economic conditions and forecasts at the time of adoption. ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” ASU 2017-04 eliminates Step 2 from the goodwill impairment test which required entities to compute the implied fair value of goodwill. Under ASU 2017-04, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-04 will be effective for the Company on January 1, 2020, with earlier adoption permitted and is not expected to have a significant impact on the Company's financial statements.

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
ACQUISITIONS	2. ACQUISITIONS Acquisitions are accounted for using the acquisition method of accounting. Accordingly, the assets and liabilities of an acquired entity are recorded at their fair value at the acquisition date. The excess of the purchase price over the estimated fair value of the net assets is recorded as goodwill. The results of operations for an acquisition have been included in the Company’s consolidated financial results beginning on the respective acquisition date. The measurement period for the Company to determine the fair values of acquired identifiable assets and assumed liabilities will end at the earlier of (1) twelve months from the date of the acquisition or (2) as soon as the Company receives the information it was seeking about facts and circumstances that existed as of the acquisition date or learns that more information is not obtainable. The following acquisitions were completed on the dates indicated below: 2018 Acquisition Acquisition of Post Oak Bancshares, Inc. —On October 1, 2018, the Company completed the acquisition of Post Oak Bancshares, Inc. (“Post Oak”) and its wholly-owned subsidiary Post Oak Bank, N.A. headquartered in Houston, Texas. Post Oak operated thirteen bank offices, twelve located throughout the greater Houston metropolitan area and one in Beaumont, just outside of the Houston metropolitan area. The Company acquired Post Oak to further expand its Houston, Texas area market. Goodwill resulted from a combination of expected operational synergies and an enhanced branching network. Goodwill is not expected to be deductible for tax purposes. Pursuant to the merger agreement, the Company issued 8,402,010 shares of Company common stock for all outstanding shares of Post Oak common stock and paid $21 thousand in cash for any fractional shares held by Post Oak shareholders. Additionally, all outstanding Post Oak options were assumed by Allegiance and converted using the 0.7017 exchange ratio to 299,352 options at a weighted average exercise price of $12.83 per option. Based on the $41.70 per share closing price of Allegiance common stock on September 28, 2018, the total transaction value was approximately $359.0 million. The acquisition was accounted for under the acquisition method of accounting in accordance with ASC Topic 805, Business Combinations. The Company recognized goodwill of $183.7 million which is calculated as the excess of both the consideration exchanged and liabilities assumed as compared to the fair value of identifiable assets acquired, none of which is expected to be deductible for tax purposes. The intangible assets recognized in the transaction are amortized utilizing an accelerated method over their ten year estimated useful lives. As of September 30, 2019, the Company finalized its valuation of all assets and liabilities acquired, resulting in no changes to preliminary acquisition accounting adjustments. A summary of the purchase price allocation is as follows (in thousands): Fair value of consideration paid: Common shares issued (8,402,010 shares) $ 350,364 Stock options issued (299,352) 8,639 Cash in lieu of fractional shares 21 Total consideration paid $ 359,024 Fair value of assets acquired: Cash and cash equivalents $ 230,416 Investment securities 42,779 Loans 1,164,281 Premises and equipment 21,988 Core deposit intangibles 25,128 Other assets 18,076 Total assets acquired $ 1,502,668 Fair value of liabilities assumed: Deposits $ 1,291,310 Other borrowed funds 30,000 Other liabilities 6,070 Total liabilities assumed 1,327,380 Fair value of net assets acquired $ 175,288 Goodwill resulting from acquisition $ 183,736 The fair value of net assets acquired includes fair value adjustments to certain acquired loans that were not considered impaired as of the acquisition date. The fair value adjustments were determined using discounted contractual cash flows. The following presents details of all loans acquired as of October 1, 2018: Contractual Balance Fair Value Discount (Dollars in thousands) Commercial and industrial $ 221,098 $ 217,204 $ (3,894 ) Real estate: Commercial real estate (including multi-family residential) 450,947 443,512 (7,435 ) Commercial real estate construction and land development 167,386 165,387 (1,999 ) 1-4 family residential (including home equity) 288,304 285,099 (3,205 ) Residential construction 23,812 23,812 - Consumer and other 29,684 29,267 (417 ) Total loans $ 1,181,231 $ 1,164,281 $ (16,950 ) In connection with the Post Oak acquisition, the Company acquired loans both with and without evidence of credit quality deterioration since origination. The acquired loans were initially recorded at fair value with no carryover of any allowance for loan losses. Acquired loans were segregated between those considered to be purchased credit impaired (“PCI”) loans and those without credit impairment at acquisition. The Company incurred approximately $1.3 million of pre-tax acquisition and merger-related expenses reflected on the Company’s income statement during the nine months ended September 30, 2019 related to the Post Oak acquisition. 2019 Acquisition Acquisition of LoweryBank Branch —On February 1, 2019, the Bank completed the acquisition of LoweryBank, the Sugar Land location of Huntington State Bank. The Bank paid $32.9 million in cash to acquire certain assets which included approximately $45.0 million in loans and assumed approximately $16.0 million in customer deposits. The Bank consolidated its existing Sugar Land bank office into this new bank office location, which was less than one mile away. The acquisition of LoweryBank was accounted for under the acquisition method of accounting in accordance with ASC Topic 805, Business Combinations. The Company recognized goodwill of $578 thousand which is calculated as the excess of both the consideration exchanged and liabilities assumed as compared to the fair value of identifiable assets acquired, which is expected to be deductible for tax purposes. Income and expense generated from acquired assets and liabilities assumed would not have a material impact, therefore, proforma numbers are not presented.

GOODWILL AND CORE DEPOSIT INTAN

GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS	9 Months Ended
	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS	3. GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS Changes in the carrying amount of the Company’s goodwill and core deposit intangible assets were as follows: Core Deposit Goodwill Intangibles (Dollars in thousands) Balance as of December 31, 2017 $ 39,389 $ 3,274 Amortization — (586 ) Balance as of September 30, 2018 39,389 2,688 Balance as of December 31, 2018 $ 223,125 $ 26,587 Acquisition of LoweryBank branch 578 — Measurement period adjustment (61 ) — Amortization — (3,534 ) Balance as of September 30, 2019 $ 223,642 $ 23,053 Goodwill is recorded on the acquisition date of an entity. During the measurement period, the Company may record subsequent adjustments to goodwill for provisional amounts recorded at the acquisition date. There was a $61 thousand measurement period adjustment recorded during the first quarter 2019 related to the Post Oak Bank acquisition. Management performs an evaluation annually, and more frequently if a triggering event occurs, of whether any impairment of the goodwill and other intangible assets has occurred. If any such impairment is determined, a write-down is recorded. As of September 30, 2019, there were no impairments recorded on goodwill and other intangible assets. The estimated aggregate future amortization expense for core deposit intangible assets remaining as of September 30, 2019 is as follows (dollars in thousands): Remaining 2019 $ 1,179 2020 3,922 2021 3,296 2022 3,003 2023 2,323 Thereafter 9,330 Total $ 23,053

SECURITIES

SECURITIES	9 Months Ended
	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
SECURITIES	4. SECURITIES The amortized cost and fair value of investment securities were as follows: September 30, 2019 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (Dollars in thousands) Available for Sale U.S. Government and agency securities $ 30,250 $ 332 $ (325 ) $ 30,257 Municipal securities 71,782 4,034 — 75,816 Agency mortgage-backed pass-through securities 97,374 1,779 (126 ) 99,027 Agency collateralized mortgage obligations 99,702 2,138 (166 ) 101,674 Corporate bonds and other 45,661 580 (15 ) 46,226 Total $ 344,769 $ 8,863 $ (632 ) $ 353,000 December 31, 2018 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (Dollars in thousands) Available for Sale U.S. Government and agency securities $ 8,570 $ 161 $ (46 ) $ 8,685 Municipal securities 219,068 1,258 (3,541 ) 216,785 Agency mortgage-backed pass-through securities 66,987 237 (1,029 ) 66,195 Corporate bonds and other 46,303 15 (690 ) 45,628 Total $ 340,928 $ 1,671 $ (5,306 ) $ 337,293 As of September 30, 2019, the Company’s management did not expect to sell any securities classified as available for sale with material unrealized losses, and the Company believes it is more likely than not it will not be required to sell any of these securities before their anticipated recovery, at which time the Company will receive full value for the securities. The fair value is expected to recover as the securities approach their maturity date or repricing date or if market yields for such investments decline. Management does not believe any of the securities are impaired due to reasons of credit quality. Accordingly, as of September 30, 2019, management believed the unrealized losses in the previous table are temporary and no other than temporary impairment loss has been realized in the Company’s consolidated statements of income. The amortized cost and fair value of investment securities at September 30, 2019, by contractual maturity, are shown below. Expected maturities may differ from contractual maturities if borrowers have the right to call or prepay obligations at any time with or without call or prepayment penalties. Amortized Fair Cost Value (Dollars in thousands) Due in one year or less $ 29,040 $ 29,136 Due after one year through five years 21,274 21,722 Due after five years through ten years 49,782 51,194 Due after ten years 47,597 50,247 Subtotal 147,693 152,299 Agency mortgage-backed pass through and collateralized mortgage obligation securities 197,076 200,701 Total $ 344,769 $ 353,000 Securities with unrealized losses segregated by length of time such securities have been in a continuous loss position are as follows: September 30, 2019 Less than 12 Months More than 12 Months Total Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in thousands) Available for Sale U.S. Government and agency securities $ 22,651 $ (324 ) $ 438 $ (1 ) $ 23,089 $ (325 ) Agency mortgage-backed pass-through securities 9,819 (62 ) 8,578 (64 ) 18,397 (126 ) Agency collateralized mortgage obligations 17,005 (166 ) — — 17,005 (166 ) Corporate bonds and other — — 1,505 (15 ) 1,505 (15 ) Total $ 49,475 $ (552 ) $ 10,521 $ (80 ) $ 59,996 $ (632 ) December 31, 2018 Less than 12 Months More than 12 Months Total Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in thousands) Available for Sale U.S. Government and agency securities $ 999 $ — $ 1,417 $ (46 ) $ 2,416 $ (46 ) Municipal securities 10,140 (29 ) 136,934 (3,512 ) 147,074 (3,541 ) Agency mortgage-backed pass-through securities 17,168 (209 ) 22,819 (820 ) 39,987 (1,029 ) Corporate bonds and other 13,634 (35 ) 29,014 (655 ) 42,648 (690 ) Total $ 41,941 $ (273 ) $ 190,184 $ (5,033 ) $ 232,125 $ (5,306 ) There were no securities sold during the three months ended September 30, 2019. The Company sold $149.4 million in securities and recorded gross gains of $1.4 million and gross losses of $576 thousand for a net gain of $846 thousand during the nine months ended September 30, 2019. There were no securities sold during the three months and nine months ended September 30, 2018. At September 30, 2019 and December 31, 2018, the Company did not own securities of any one issuer, other than the U.S government and its agencies, in an amount greater than 10% of consolidated shareholders’ equity at such respective dates. The carrying value of pledged securities was $25.2 million at September 30, 2019 and $28.9 million at December 31, 2018, respectively. The majority of the securities were pledged to collateralize public fund deposits.

LOANS AND ALLOWANCE FOR LOAN LO

LOANS AND ALLOWANCE FOR LOAN LOSSES	9 Months Ended
	Sep. 30, 2019
Loans And Allowance For Loan Losses [Abstract]
LOANS AND ALLOWANCE FOR LOAN LOSSES	5. LOANS AND ALLOWANCE FOR LOAN LOSSES The loan portfolio balances, net of unearned income and fees, consist of various types of loans primarily made to borrowers located within Texas and are classified by major type as follows: September 30, December 31, 2019 2018 (Dollars in thousands) Commercial and industrial $ 675,055 $ 702,037 Mortgage warehouse 36,594 48,274 Real estate: Commercial real estate (including multi-family residential) 1,859,721 1,650,912 Commercial real estate construction and land development 386,723 430,128 1-4 family residential (including home equity) 695,520 649,311 Residential construction 189,608 186,411 Consumer and other 42,783 41,233 Total loans 3,886,004 3,708,306 Allowance for loan losses (29,808 ) (26,331 ) Loans, net $ 3,856,196 $ 3,681,975 Acquired Loans PCI loans The Company has loans that were acquired and for which there was, at acquisition, evidence of deterioration of credit quality since origination and for which it was probable, at acquisition, that all contractually required payments would not be collected. The carrying amount of PCI loans included in the consolidated balance sheet and the related outstanding balance owed at September 30, 2019 are presented in the table below (dollars in thousands): As of September 30, 2019 As of December 31, 2018 Outstanding balance $ 20,206 $ 26,862 Less: Discount (2,991 ) (3,599 ) Recorded investment $ 17,215 $ 23,263 Acquired loans were recorded through acquisition accounting without an allowance. There was an allocation of $231 thousand established in the allowance for loan losses relating to PCI loans at September 30, 2019. Changes in the accretable yield for PCI loans for the three and nine months ended September 30, 2019 were as follows (dollars in thousands): Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Balance at beginning of period $ 2,195 $ 436 Measurement period adjustment - 2,674 Additions - - Reclassifications from nonaccretable 88 301 Accretion (379 ) (1,507 ) Balance at September 30, 2019 $ 1,904 $ 1,904 There were no PCI loans at September 30, 2018. Nonaccrual and Past Due Loans An aging analysis of the recorded investment in past due loans, segregated by class of loans, is as follows: September 30, 2019 Loans Past Due and Still Accruing 30-89 90 or More Total Past Nonaccrual Current Total Days Days Due Loans Loans Loans Loans (Dollars in thousands) Commercial and industrial $ 4,162 $ — $ 4,162 $ 8,033 $ 662,860 $ 675,055 Mortgage warehouse — — — — 36,594 36,594 Real estate: Commercial real estate (including multi-family residential) 9,203 — 9,203 15,356 1,835,162 1,859,721 Commercial real estate construction and land development 147 — 147 9,050 377,526 386,723 1-4 family residential (including home equity) 2,585 — 2,585 1,992 690,943 695,520 Residential construction 932 — 932 — 188,676 189,608 Consumer and other 93 — 93 184 42,506 42,783 Total loans $ 17,122 $ — $ 17,122 $ 34,615 $ 3,834,267 $ 3,886,004 December 31, 2018 Loans Past Due and Still Accruing 30-89 90 or More Total Past Nonaccrual Current Total Days Days Due Loans Loans Loans Loans (Dollars in thousands) Commercial and industrial $ 1,951 $ — $ 1,951 $ 10,861 $ 689,225 $ 702,037 Mortgage warehouse — — — — 48,274 48,274 Real estate: Commercial real estate (including multi-family residential) 3,502 — 3,502 17,776 1,629,634 1,650,912 Commercial real estate construction and land development 1,300 — 1,300 974 427,854 430,128 1-4 family residential (including home equity) 3,643 — 3,643 3,201 642,467 649,311 Residential construction — — — — 186,411 186,411 Consumer and other 91 — 91 141 41,001 41,233 Total loans $ 10,487 $ — $ 10,487 $ 32,953 $ 3,664,866 $ 3,708,306 Impaired Loans Impaired loans by class of loans are set forth in the following tables. As of September 30, 2019 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 3,568 $ 3,683 $ — Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 6,715 6,795 — Commercial real estate construction and land development 9,050 9,050 — 1-4 family residential (including home equity) 1,598 1,598 — Residential construction — — — Consumer and other 57 57 — Total 20,988 21,183 — With an allowance recorded: Commercial and industrial 8,450 8,845 4,354 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 11,749 11,749 2,236 Commercial real estate construction and land development 3,114 3,114 191 1-4 family residential (including home equity) — — — Residential construction — — — Consumer and other 32 32 28 Total 23,345 23,740 6,809 Total: Commercial and industrial 12,018 12,528 4,354 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 18,464 18,544 2,236 Commercial real estate construction and land development 12,164 12,164 191 1-4 family residential (including home equity) 1,598 1,598 — Residential construction — — — Consumer and other 89 89 28 $ 44,333 $ 44,923 $ 6,809 As of December 31, 2018 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 4,354 $ 4,771 $ — Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 11,322 11,322 — Commercial real estate construction and land development 1,326 1,326 — 1-4 family residential (including home equity) 2,742 2,741 — Residential construction — — — Consumer and other 3 3 — Total 19,747 20,163 — With an allowance recorded: Commercial and industrial 9,150 9,545 3,898 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 11,542 11,542 2,641 Commercial real estate construction and land development 3,114 3,114 190 1-4 family residential (including home equity) — — — Residential construction — — — Consumer and other — — — Total 23,806 24,201 6,729 Total: Commercial and industrial 13,504 14,316 3,898 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 22,864 22,864 2,641 Commercial real estate construction and land development 4,440 4,440 190 1-4 family residential (including home equity) 2,742 2,741 — Residential construction — — — Consumer and other 3 3 — $ 43,553 $ 44,364 $ 6,729 The following table presents average impaired loans and interest recognized on impaired loans for the three and nine months ended September 30, 2019 and 2018: Three Months Ended September 30, 2019 2018 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 12,268 $ 94 $ 12,979 $ 119 Mortgage warehouse — — — — Real estate: Commercial real estate (including multi-family residential) 18,762 86 18,242 181 Commercial real estate construction and land development 12,005 52 695 5 1-4 family residential (including home equity) 1,609 — 2,993 4 Residential construction — — — — Consumer and other 91 1 — — Total $ 44,735 $ 233 $ 34,909 $ 309 Nine Months Ended September 30, 2019 2018 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 12,265 $ 261 $ 13,370 $ 316 Mortgage warehouse — — — — Real estate: Commercial real estate (including multi-family residential) 19,453 279 18,409 497 Commercial real estate construction and land development 10,263 140 600 8 1-4 family residential (including home equity) 1,641 4 3,033 9 Residential construction — — — — Consumer and other 96 — — — Total $ 43,718 $ 684 $ 35,412 $ 830 Credit Quality Indicators The Company categorizes loans into risk categories based on relevant information about the ability of borrowers to service their debt, including factors such as: current financial information, historical payment experience, credit documentation, public information and current economic trends. The Company analyzes loans individually by classifying the loans by credit risk. As part of the ongoing monitoring of the credit quality of the Company’s loan portfolio and methodology for calculating the allowance for credit losses, management assigns and tracks risk ratings to be used as credit quality indicators. The following is a general description of the risk ratings used: Pass —Loans classified as pass are loans with low to average risk and not otherwise classified as watch, special mention, substandard or doubtful. In addition, the guaranteed portion of SBA loans are considered pass risk rated loans. Watch —Loans classified as watch loans may still be of high quality, but have an element of risk added to the credit such as declining payment history, deteriorating financial position of the borrower or a decrease in collateral value. Special Mention —Loans classified as special mention have a potential weakness that deserves management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or of the institution’s credit position at some future date. They are characterized by the distinct possibility that the institution will sustain some loss if the deficiencies are not corrected. Substandard —Loans classified as substandard have well-defined weaknesses on a continuing basis and are inadequately protected by the current net worth and paying capacity of the borrower, impaired or declining collateral values, or a continuing downturn in their industry which is reducing their profits to below zero and having a significantly negative impact on their cash flow. These classified loans are characterized by the distinct possibility that the institution will sustain some loss if the deficiencies are not corrected. Doubtful —Loans classified as doubtful have all the weaknesses inherent in those classified as substandard with the added characteristic that the weaknesses make collection or liquidation in full on the basis of currently existing facts, conditions and values highly questionable and improbable. Based on the most recent analysis performed, the risk category of loans by class of loan at September 30, 2019 is as follows: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 633,253 $ 9,167 $ 7,547 $ 25,008 $ 80 $ 675,055 Mortgage warehouse 36,594 — — — — 36,594 Real estate: Commercial real estate (including multi-family residential) 1,782,152 30,240 7,891 39,438 — 1,859,721 Commercial real estate construction and land development 372,601 1,296 1,350 11,476 — 386,723 1-4 family residential (including home equity) 663,642 15,720 7,214 8,944 — 695,520 Residential construction 184,410 2,867 2,331 — — 189,608 Consumer and other 42,203 7 335 238 — 42,783 Total loans $ 3,714,855 $ 59,297 $ 26,668 $ 85,104 $ 80 $ 3,886,004 The following table presents the risk category of loans by class of loan at December 31, 2018: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 656,783 $ 9,696 $ 13,874 $ 21,684 $ — $ 702,037 Mortgage warehouse 48,274 — — — — 48,274 Real estate: Commercial real estate (including multi-family residential) 1,570,243 29,702 7,101 43,866 — 1,650,912 Commercial real estate construction and land development 424,460 729 2,149 2,790 — 430,128 1-4 family residential (including home equity) 629,657 3,797 4,216 11,641 — 649,311 Residential construction 186,411 — — — — 186,411 Consumer and other 40,673 31 301 228 — 41,233 Total loans $ 3,556,501 $ 43,955 $ 27,641 $ 80,209 $ — $ 3,708,306 Allowance for Loan Losses The following table presents the activity in the allowance for loan losses by portfolio type for the three and nine months ended September 30, 2019 and 2018: Commercial and Mortgage warehouse Commercial real estate (including multi-family residential) Commercial real estate construction and land development 1-4 family residential (including home equity) Residential construction Consumer and other Total (Dollars in thousands) Allowance for loan losses: Three Months Ended Balance June 30, 2019 $ 8,255 $ — $ 12,940 $ 2,257 $ 3,376 $ 1,004 $ 108 $ 27,940 Provision for loan losses 1,322 — 613 (222 ) 608 247 29 2,597 Charge-offs (769 ) — — (44 ) — — — (813 ) Recoveries 84 — — — — — — 84 Net charge-offs (685 ) — — (44 ) — — — (729 ) Balance September 30, 2019 $ 8,892 $ — $ 13,553 $ 1,991 $ 3,984 $ 1,251 $ 137 $ 29,808 Nine Months Ended Balance December 31, 2018 $ 8,351 $ — $ 11,901 $ 2,724 $ 2,242 $ 1,040 $ 73 $ 26,331 Provision for loan losses 1,668 — 1,729 (689 ) 2,037 211 50 5,006 Charge-offs (1,357 ) — (80 ) (44 ) (295 ) — (8 ) (1,784 ) Recoveries 230 — 3 — — — 22 255 Net (charge-offs) recoveries (1,127 ) — (77 ) (44 ) (295 ) — 14 (1,529 ) Balance September 30, 2019 $ 8,892 $ — $ 13,553 $ 1,991 $ 3,984 $ 1,251 $ 137 $ 29,808 Allowance for loan losses: Three Months Ended Balance June 30, 2018 $ 9,154 $ — $ 9,203 $ 2,288 $ 2,189 $ 914 $ 83 $ 23,831 Provision for loan losses (621 ) — (2 ) 447 35 153 (12 ) — Charge-offs (235 ) — — — (25 ) — — (260 ) Recoveries 15 — — — — — — 15 Net charge-offs (220 ) — — — (25 ) — — (245 ) Balance September 30, 2018 $ 8,313 $ — $ 9,201 $ 2,735 $ 2,199 $ 1,067 $ 71 $ 23,586 Nine Months Ended Balance December 31, 2017 $ 7,694 $ — $ 10,253 $ 2,525 $ 2,140 $ 942 $ 95 $ 23,649 Provision for loan losses 2,002 — (1,113 ) 210 84 125 (24 ) 1,284 Charge-offs (2,123 ) — (41 ) — (25 ) — — (2,189 ) Recoveries 740 — 102 — — — — 842 Net (charge-offs) recoveries (1,383 ) — 61 — (25 ) — — (1,347 ) Balance September 30, 2018 $ 8,313 $ — $ 9,201 $ 2,735 $ 2,199 $ 1,067 $ 71 $ 23,586 The following table presents the balance of the allowance for loan losses by portfolio type based on the impairment method as of September 30, 2019 and December 31, 2018: Commercial and Mortgage warehouse Commercial real estate (including multi-family residential) Commercial real estate construction and land development 1-4 family residential (including home equity) Residential construction Consumer and other Total (Dollars in thousands) Allowance for loan losses related to: September 30, 2019 Individually evaluated for impairment $ 4,354 $ — $ 2,236 $ 191 $ — $ — $ 28 $ 6,809 Collectively evaluated for impairment 4,509 - 11,198 1,792 3,909 1,251 109 22,768 PCI 29 — 119 8 75 — — 231 Total allowance for loan losses $ 8,892 $ — $ 13,553 $ 1,991 $ 3,984 $ 1,251 $ 137 $ 29,808 December 31, 2018 Individually evaluated for impairment $ 3,898 $ — $ 2,641 $ 190 $ — $ — $ — $ 6,729 Collectively evaluated for impairment 4,453 — 9,260 2,534 2,242 1,040 73 19,602 Total allowance for loan losses $ 8,351 $ — $ 11,901 $ 2,724 $ 2,242 $ 1,040 $ 73 $ 26,331 The following table presents the recorded investment in loans held for investment by portfolio type based on the impairment method as of September 30, 2019 and December 31, 2018: Commercial and Mortgage warehouse Commercial real estate (including multi-family residential) Commercial real estate construction and land development 1-4 family residential (including home equity) Residential construction Consumer and other Total (Dollars in thousands) Recorded investment in loans: September 30, 2019 Individually evaluated for impairment $ 12,018 $ — $ 18,464 $ 12,164 $ 1,598 $ — $ 89 $ 44,333 Collectively evaluated for impairment 663,037 36,594 1,841,257 374,559 693,922 189,608 42,694 3,841,671 Total loans evaluated for impairment $ 675,055 $ 36,594 $ 1,859,721 $ 386,723 $ 695,520 $ 189,608 $ 42,783 $ 3,886,004 December 31, 2018 Individually evaluated for impairment $ 13,504 $ — $ 22,864 $ 4,440 $ 2,742 $ — $ 3 $ 43,553 Collectively evaluated for impairment 688,533 48,274 1,628,048 425,688 646,569 186,411 41,230 3,664,753 Total loans evaluated for impairment $ 702,037 $ 48,274 $ 1,650,912 $ 430,128 $ 649,311 $ 186,411 $ 41,233 $ 3,708,306 Troubled Debt Restructurings As of September 30, 2019 and December 31, 2018, the Company had a recorded investment in troubled debt restructurings of $27.5 million and $33.1 million, respectively. The Company allocated $4.5 million and $3.0 million of specific reserves for troubled debt restructurings at September 30, 2019 and December 31, 2018, respectively. The following tables present information regarding loans modified in a troubled debt restructuring during the three and nine months ended September 30, 2019 and 2018: Three Months Ended September 30, 2019 2018 Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment (Dollars in thousands) Troubled Debt Restructurings Commercial and industrial 4 $ 1,502 $ 1,502 1 $ 200 $ 200 Mortgage warehouse — — — — — — Real estate: Commercial real estate (including multi-family residential) — — — — — — Commercial real estate construction and land development — — — — — — 1-4 family residential (including home equity) — — — — — — Residential construction — — — — — — Consumer and other — — — — — — Total 4 $ 1,502 $ 1,502 1 $ 200 $ 200 Nine Months Ended September 30, 2019 2018 Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment (Dollars in thousands) Troubled Debt Restructurings Commercial and industrial 11 $ 2,069 $ 2,069 9 $ 1,797 $ 1,797 Mortgage warehouse — — — — — — Real estate: Commercial real estate (including multi-family residential) 1 303 303 — — — Commercial real estate construction and land development — — — — — — 1-4 family residential (including home equity) 1 396 396 — — — Residential construction — — — — — — Consumer and other 1 38 38 — — — Total 14 $ 2,806 $ 2,806 9 $ 1,797 $ 1,797 Troubled debt restructurings resulted in a $251 thousand charge-off during the three and nine months ended September 30, 2019. Troubled debt restructurings resulted in charge-offs of $55 thousand and $72 thousand during the three and nine months ended September 30, 2018, respectively. As of September 30, 2019, seven loans for a total of $4.7 million were modified under a troubled debt restructuring during the previous twelve-month period that subsequently defaulted during the nine months ended September 30, 2019. As of September 30, 2018, a $29 thousand loan was modified under a troubled debt restructurings during the previous twelve-month period that subsequently defaulted during the nine months ended September 30, 2018. Default is determined at 90 or more days past due. The modifications primarily related to extending the amortization periods of the loans. The Company did not grant principal reductions on any restructured loans. There were no commitments to lend additional amounts to troubled debt restructured loans for the three and nine months ended September 30, 2019 and 2018. During the nine months ended September 30, 2019, the Company added $2.8 million in new troubled debt restructurings, of which $2.7 million was still outstanding on September 30, 2019. During the nine months ended September 30, 2018, the Company added $1.8 million in new troubled debt restructurings, all of which were still outstanding on September 30, 2018.

LEASES

LEASES	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
LEASES	6. LEASES Lease payments over the expected term are discounted using the Company’s incremental borrowing rate for borrowings of similar terms. Generally, the Company cannot be reasonably certain about whether or not it will renew a lease until such time as the lease is within the last two years of the existing lease term. When the Company is reasonably certain that a renewal option will be exercised, it measures/remeasures the right-of-use asset and related lease liability using the lease payments specified for the renewal period or, if such amounts are unspecified, the Company generally assumes an increase (evaluated on a case-by-case basis in light of prevailing market conditions) in the lease payment over the final period of the existing lease term. There were no sale and leaseback transactions, leveraged leases or lease transactions with related parties during the nine months ended September 30, 2019. At September 30, 2019, the Company leased 14 branch locations and office space along with equipment. On the September 30, 2019 balance sheet, the right-of-use asset is classified within premises and equipment and the lease liability is included in other liabilities. All leases were classified as operating leases. Leases with an initial term of 12 months or less are not recorded on the balance sheet and the related lease expense is recognized on a straight-line basis over the lease term. During the third quarter 2019, Allegiance Bank purchased two previously leased properties for a total of $10.7 million. Operating lease costs classified as occupancy and equipment expense were $848 thousand and $2.7 million for the three and nine months ended September 30, 2019, respectively. Included in these amounts were short-term lease costs of $132 thousand and $506 thousand for the three and nine months ended September 30, 2019, respectively. Certain leases include options to renew, with renewal terms that can extend the lease term from one to five years. Lease assets and liabilities include related options that are reasonably certain of being exercised. The depreciable life of leased assets are limited by the expected lease term. Supplemental lease information at or for the nine months ended September 30, 2019 is as follows (dollars in thousands): Balance Sheet: Operating lease asset classified as premises and equipment $ 11,810 Operating lease liability classified as other liabilities 12,116 Income Statement: Operating lease cost classified as occupancy and equipment expense $ 2,733 Weighted average lease term, in years 5.70 Weighted average discount rate 3.19 % A maturity analysis of the Company’s lease liabilities at September 30, 2019 is as follows (dollars in thousands): Lease payments due: Within one year $ 2,885 After one but within two years 2,867 After two but within three years 2,608 After three but within four years 2,204 After four but within five years 1,596 After five years 3,293 Total lease payments $ 15,453 Discount on cash flows (3,337 ) Total lease liability $ 12,116

FAIR VALUE

FAIR VALUE	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE	7. FAIR VALUE The Company uses fair value measurements to record fair value adjustments to certain assets and to determine fair value disclosures. Fair value represents the exchange price that would be received from selling an asset or paid to transfer a liability, otherwise known as an “exit price,” in the principal or most advantageous market available to the entity in an orderly transaction between market participants on the measurement date. Fair Value Hierarchy 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. The Company groups financial assets and financial liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. These levels are: • Level 1—Quoted prices 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 management’s judgment and assumptions that market participants would use in pricing an asset or liability that are supported by little or no market activity. The carrying amounts and estimated fair values of financial instruments that are reported on the balance sheet are as follows: As of September 30, 2019 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 300,619 $ 300,619 $ — $ — $ 300,619 Available for sale securities 353,000 — 353,000 — 353,000 Loans held for investment, net of allowance 3,856,196 — — 3,888,672 3,888,672 Accrued interest receivable 15,201 9 1,560 13,632 15,201 Financial liabilities Deposits $ 3,897,485 $ — $ 3,902,191 $ — $ 3,902,191 Accrued interest payable 4,915 — 4,915 — 4,915 Borrowed funds 159,501 — 159,501 — 159,501 Subordinated debt 107,771 — 107,771 — 107,771 As of December 31, 2018 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 268,947 $ 268,947 $ — $ — $ 268,947 Available for sale securities 337,293 — 337,293 — 337,293 Loans held for investment, net of allowance 3,681,975 — — 3,674,241 3,674,241 Accrued interest receivable 17,010 65 3,498 13,447 17,010 Financial liabilities Deposits $ 3,662,536 $ — $ 3,653,244 $ — $ 3,653,244 Accrued interest payable 2,812 — 2,812 — 2,812 Borrowed funds 225,493 — 230,445 — 230,445 Subordinated debt 48,899 — 49,663 — 49,663 The following tables present fair values for assets measured at fair value on a recurring basis: September 30, 2019 Level 1 Level 2 Level 3 Total (Dollars in thousands) Available for sale securities: U.S. Government and agency securities $ — $ 30,257 $ — $ 30,257 Municipal securities — 75,816 — 75,816 Agency mortgage-backed pass-through securities — 99,027 — 99,027 Agency collateralized mortgage obligations — 101,674 101,674 Corporate bonds and other — 46,226 — 46,226 Total $ — $ 353,000 $ — $ 353,000 December 31, 2018 Level 1 Level 2 Level 3 Total (Dollars in thousands) Available for sale securities: U.S. Government and agency securities $ — $ 8,685 $ — $ 8,685 Municipal securities — 216,785 — 216,785 Agency mortgage-backed pass-through securities — 66,195 — 66,195 Corporate bonds and other — 45,628 — 45,628 Total $ — $ 337,293 $ — $ 337,293 There were no liabilities measured at fair value on a recurring basis as of September 30, 2019 or December 31, 2018. There were no transfers between levels during the nine months ended September 30, 2019 or 2018. The following table presents certain assets and liabilities measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis, but are subject to fair value adjustments in certain circumstances such as evidence of impairment. As of September 30, 2019 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 4,096 Commercial real estate (including multi- family residential) — — 9,513 Commercial real estate construction and land development — — 2,923 Consumer and other — — 4 Other real estate owned — — 8,333 $ — $ — $ 24,869 As of December 31, 2018 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 5,252 Commercial real estate (including multi- family residential) — — 8,901 Commercial real estate construction and land development — — 2,924 Other real estate owned — — 630 $ — $ — $ 17,707 Impaired Loans with Specific Allocation of Allowance During the nine months ended September 30, 2019 and the year ended December 31, 2018, certain impaired loans were reevaluated and reported at fair value through a specific allocation of the allowance for loan losses. At September 30, 2019, the total reported fair value of impaired loans of $16.5 million based on collateral valuations utilizing Level 3 valuation inputs had a carrying value of $23.3 million that was reduced by specific allowance allocations totaling $6.8 million. At December 31, 2018, the total reported fair value of impaired loans of $17.1 million based on collateral valuations utilizing Level 3 valuation inputs had a carrying value of $23.8 million that was reduced by specific allowance allocations totaling $6.7 million. Other Real Estate Owned At September 30, 2019, the $8.3 million balance of other real estate owned consisted of three foreclosed commercial real estate properties, one commercial tract of land, one residential vacant lot and one foreclosed residential rental property recorded as a result of obtaining the physical possession of the property. The Company had $630 thousand of other real estate owned at December 31, 2018.

DEPOSITS

DEPOSITS	9 Months Ended
	Sep. 30, 2019
Deposit Liabilities [Abstract]
DEPOSITS	8. DEPOSITS Time deposits that met or exceeded the Federal Deposit Insurance Corporation insurance limit of $250 thousand at September 30, 2019 and December 31, 2018 were $488.0 million and $509.3 million, respectively. Scheduled maturities of time deposits for the next five years are as follows (dollars in thousands): Within one year $ 244,325 After one but within two years 624,573 After two but within three years 145,761 After three but within four years 102,882 After four but within five years 97,118 Total $ 1,214,659 The Company had $276.3 million and $235.1 million of brokered deposits as of September 30, 2019 and December 31, 2018, respectively. There were no major concentrations of deposits with any one depositor at September 30, 2019 and December 31, 2018.

BORROWINGS AND BORROWING CAPACI

BORROWINGS AND BORROWING CAPACITY	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
BORROWINGS AND BORROWING CAPACITY	9. BORROWINGS AND BORROWING CAPACITY The Company has an available line of credit with the Federal Home Loan Bank (“FHLB”) of Dallas, which allows the Company to borrow on a collateralized basis. FHLB advances are used to manage liquidity as needed. The advances are secured by a blanket lien on certain loans. Maturing advances are replaced by drawing on available cash, making additional borrowings or through increased customer deposits. At September 30, 2019, the Company had a total borrowing capacity of $1.67 billion, of which $1.41 billion was available and $261.8 million was outstanding. FHLB advances of $125.0 million were outstanding at September 30, 2019, at a weighted average interest rate of 2.54%. Letters of credit were $136.8 million at September 30, 2019, of which $45.5 million will expire during the remaining months of 2019, $88.8 million will expire in 2020 and $2.5 million will expire in 2021. On December 28, 2018, the Company amended its revolving credit agreement to increase the maximum commitment to advance funds to $45.0 million which will reduce annually by $7.5 million beginning in December 2020 and on each December 22nd for the following years thereafter. The Company is required to repay any outstanding balance in excess of the then-current maximum commitment amount. The revised agreement will mature in December 2025 and is secured by 100% of the capital stock of the Bank. At September 30, 2019, the balance of the revolving credit agreement was $34.6 million. The credit agreement contains certain restrictive covenants. At September 30, 2019, the Company believes it was in compliance with all such debt covenants and had not been made aware of any noncompliance by the lender. The interest rate on the debt is the Prime Rate minus 25 basis points, or 4.75%, at September 30, 2019, and is paid quarterly.

SUBORDINATED DEBT

SUBORDINATED DEBT	9 Months Ended
	Sep. 30, 2019
Subordinated Borrowings [Abstract]
SUBORDINATED DEBT	10. SUBORDINATED DEBT Junior Subordinated Debentures On January 1, 2015, the Company acquired F&M Bancshares, Inc. and assumed Farmers & Merchants Capital Trust II and Farmers & Merchants Capital Trust III. Each of these trusts is a capital or statutory business trust organized for the sole purpose of issuing trust securities and investing the proceeds in the Company’s junior subordinated debentures. The preferred trust securities of each trust represent preferred beneficial interests in the assets of the respective trusts and are subject to mandatory redemption upon payment of the junior subordinated debentures held by the trust. The common securities of each trust are wholly owned by the Company. Each trust’s ability to pay amounts due on the trust preferred securities is solely dependent upon the Company making payment on the related junior subordinated debentures. The debentures, which are the only assets of each trust, are subordinate and junior in right of payment to all of the Company’s present and future senior indebtedness. The Company has fully and unconditionally guaranteed each trust’s obligations under the trust securities issued by such trust to the extent not paid or made by such trust, provided such trust has funds available for such obligations. Under the provisions of each issue of the debentures, the Company has the right to defer payment of interest on the debentures at any time, or from time to time, for periods not exceeding five years. If interest payments on either issue of the debentures are deferred, the distributions on the applicable trust preferred securities and common securities will also be deferred. The Company assumed the junior subordinated debentures with an aggregate original principal amount of $11.3 million and a current carrying value at September 30, 2019 of $9.5 million. At acquisition, the Company recorded a discount of $2.5 million on the debentures. The difference between the carrying value and contractual balance will be recognized as a yield adjustment over the remaining term for the debentures. At September 30, 2019, the Company had $11.3 million outstanding in junior subordinated debentures issued to the Company’s unconsolidated subsidiary trusts. The junior subordinated debentures are included in tier 1 capital under current regulatory guidelines and interpretations. A summary of pertinent information related to the Company’s issues of junior subordinated debentures outstanding at September 30, 2019 is set forth in the table below: Description Issuance Date Trust Preferred Securities Outstanding Interest Rate (1) Junior Subordinated Debt Owed to Trusts Maturity Date (2) (Dollars in thousands) Farmers & Merchants Capital Trust II November 13, 2003 $ 7,500 3 month LIBOR + 3.00% $ 7,732 November 8, 2033 Farmers & Merchants Capital Trust III June 30, 2005 3,500 3 month LIBOR + 1.80% 3,609 July 7, 2035 $ 11,341 (1) The 3-month LIBOR in effect as of September 30, 2019 was 2.1252%. (2) All debentures are currently callable. Subordinated Notes In December 2017, the Bank completed the issuance, through a private placement, of $40.0 million aggregate principal amount of Fixed-to-Floating Rate Subordinated Notes (the "Bank Notes") due December 15, 2027. The Bank Notes were issued at a price equal to 100% of the principal amount, resulting in net proceeds to the Bank of $39.4 million. The Bank Notes bear a fixed interest rate of 5.25% per annum until (but excluding) December 15, 2022, payable semi-annually in arrears. From December 15, 2022, the Bank Notes will bear a floating rate of interest equal to 3-Month LIBOR + 3.03% until the Bank Notes mature on December 15, 2027, or such earlier redemption date, payable quarterly in arrears. The Bank Notes will be redeemable by the Bank, in whole or in part, on or after December 15, 2022 or, in whole but not in part, upon the occurrence of certain specified tax events, capital events or investment company events. Any redemption will be at a redemption price equal to 100% of the principal amount of Bank Notes being redeemed, plus accrued and unpaid interest, and will be subject to, and require, prior regulatory approval. The Bank Notes are not subject to redemption at the option of the holders. In September 2019, the Company completed the issuance of $60.0 million aggregate principal amount of Fixed-to-Floating Rate Subordinated Notes (the "Company Notes") due October 1, 2029. The Company Notes were issued at a price equal to 100% of the principal amount, resulting in net proceeds to the Company of $58.7 million. The Company intends to use the net proceeds from the offering to support its growth and for general corporate purposes. The Company Notes bear a fixed interest rate of 4.70% per annum until (but excluding) October 1, 2024, payable semi-annually in arrears on April 1 and October 1, commencing on April 1, 2020. Thereafter, from October 1, 2024 through the maturity date, October 1, 2029, or earlier redemption date, the Company Notes will bear interest at a floating rate equal to the then-current three-month LIBOR, plus 313 basis points (3.13%) for each quarterly interest period (subject to certain provisions set forth under “Description of the Notes—Interest Rates and Interest Payment Dates” included in the Prospectus Supplement), payable quarterly in arrears on January 1, April 1, July 1 and October 1 of each year. Any redemption will be at a redemption price equal to 100% of the principal amount of Company Notes being redeemed, plus accrued and unpaid interest, and will be subject to, and require, prior regulatory approval. The Company Notes are not subject to redemption at the option of the holders.

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	11. INCOME TAXES The amount of the Company’s federal and state income tax expense is influenced by the amount of pre-tax income, the amount of tax-exempt income and the amount of other nondeductible items. For the three and nine months ended September 30, 2019, income tax expense was $3.1 million and $9.9 million, respectively, compared with $1.9 million and $4.9 million for the three and nine months ended September 30, 2018, respectively. The effective income tax rate for the three and nine months ended September 30, 2019 was 20.3% and 20.2%, respectively, compared to 17.8% and 17.0% for the three and nine months ended September 30, 2018, respectively. Interest and penalties related to tax positions are recognized in the period in which they begin accruing or when the entity claims the position that does not meet the minimum statutory thresholds. The Company does not have any uncertain tax positions and does not have any interest and penalties recorded in the income statement for the three and nine months ended September 30, 2019. The Company is no longer subject to examination by the U.S. Federal Tax Jurisdiction for the years prior to 2015.

STOCK BASED COMPENSATION

STOCK BASED COMPENSATION	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
STOCK BASED COMPENSATION	12. STOCK BASED COMPENSATION At September 30, 2019, the Company had two stock-based employee compensation plans with awards outstanding. In connection with the acquisition of Post Oak Bancshares, Inc. on October 1, 2018, the Company assumed the Post Oak Bancshares, Inc. Stock Option Plan, under which no additional awards will be issued. During 2019, the Company’s Board of Directors and shareholders approved the 2019 Amended and Restated Stock Awards and Incentive Plan (the “Plan”) covering certain awards of stock-based compensation to key employees and directors of the Company. Under the Plan, the Company is authorized to issue a maximum aggregate of 3,200,000 shares of stock, up to 1,800,000 of which may be issued through incentive stock options. The Company accounts for stock based employee compensation plans using the fair value-based method of accounting. The Company recognized total stock based compensation expense of $789 thousand and $2.3 million for the three and nine months ended September 30, 2019, respectively, and $380 thousand and $1.2 million for the three and nine months ended September 30, 2018, respectively. Stock Options Options to purchase a total of 1,309,231 shares of Company stock have been granted as of September 30, 2019. Options are exercisable for up to 10 years from the date of the grant and are generally fully vested four years after the date of grant. The fair value of stock options granted is estimated at the date of grant using the Black-Scholes option-pricing model. A summary of the activity in the stock option plans during the nine months ended September 30, 2019 is set forth below: Weighted Weighted Average Average Remaining Aggregate Number of Options Exercise Price Contractual Term Intrinsic Value (In thousands) (In years) (In thousands) Options outstanding, December 31, 2018 802 $ 18.88 4.61 $ 10,830 Options granted — — Options exercised (98 ) 15.89 Options forfeited (4 ) 27.85 Options outstanding, September 30, 2019 700 $ 19.25 3.98 $ 8,983 Options vested and exercisable, September 30, 2019 646 $ 18.28 3.71 $ 8,924 As of September 30, 2019, there was $509 thousand of total unrecognized compensation cost related to nonvested stock options granted under the Plan. The cost is expected to be recognized over a weighted-average period of 0.99 years. Restricted Stock Awards During the nine months ended September 30, 2019, the Company issued 84,522 shares of restricted stock. The forfeiture restrictions on restricted shares generally lapse over a period of four years, and the shares are considered outstanding at the date of issuance. The Company accounts for restricted stock grants by recording the fair value of the grant on the award date as compensation expense over the vesting period. A summary of the activity of the nonvested shares of restricted stock during the nine months ended September 30, 2019 is as follows: Weighted Average Grant Number of Date Fair Shares Value (Shares in thousands) Nonvested share awards outstanding, December 31, 2018 143 $ 37.48 Share awards granted 85 34.95 Share awards vested (17 ) 33.75 Unvested share awards forfeited or cancelled (19 ) 38.50 Nonvested share awards outstanding, September 30, 2019 192 $ 36.44 As of September 30, 2019, there was $6.7 million of total unrecognized compensation cost related to the restricted stock awards which is expected to be recognized over a weighted-average period of 3.22 years.

OFF-BALANCE SHEET ARRANGEMENTS,

OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES	13. OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES In the normal course of business, the Company enters into various transactions, which, in accordance with accounting principles generally accepted in the United States, are not included in the Company’s consolidated balance sheets. The Company enters into these transactions to meet the financing needs of its customers. These transactions include commitments to extend credit and standby letters of credit, which involve to varying degrees elements of credit risk and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The Company uses the same credit policies in making commitments and conditional obligations as it does for on balance sheet instruments. The contractual amounts of financial instruments with off-balance sheet risk are as follows: September 30, 2019 December 31, 2018 Fixed Variable Fixed Variable Rate Rate Rate Rate (Dollars in thousands) Commitments to extend credit $ 517,669 $ 556,833 $ 471,440 $ 530,546 Standby letters of credit 13,491 3,843 14,217 9,067 Total $ 531,160 $ 560,676 $ 485,657 $ 539,613 Commitments to extend credit include lines of credit as well as commitments to make new loans. Commitments to make loans are generally made for an approval period of 120 days or fewer. As of September 30, 2019, the funded fixed rate loan commitments had interest rates ranging from 1.95% to 8.70% with a weighted average maturity and rate of 3.24 years and 5.22%, respectively. As of December 31, 2018, the funded fixed rate loan commitments had interest rates ranging from 1.95% to 8.70% with a weighted average maturity and rate of 2.94 years and 5.26%, respectively. Litigation From time to time, the Company is subject to claims and litigation arising in the ordinary course of business. In the opinion of management, the Company is not party to any legal proceedings the resolution of which it believes would have a material adverse effect on the Company’s business, prospects, financial condition, liquidity, results of operation, cash flows or capital levels. However, one or more unfavorable outcomes in any claim or litigation against the Company could have a material adverse effect for the period in which such claim or litigation is resolved. In addition, regardless of their merits or their ultimate outcomes, such matters are costly, divert management’s attention and may materially adversely affect the Company’s reputation, even if resolved in its favor. The Company intends to defend itself vigorously against any future claims or litigation.

REGULATORY CAPITAL MATTERS

REGULATORY CAPITAL MATTERS	9 Months Ended
	Sep. 30, 2019
Banking And Thrift [Abstract]
REGULATORY CAPITAL MATTERS	14. REGULATORY CAPITAL MATTERS The Company and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies. Capital adequacy guidelines, and for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities and certain off balance sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators about components, risk weightings and other factors. Failure to meet minimum capital requirements can cause regulators to initiate actions that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. The final rules implementing Basel Committee on Banking Supervision's capital guideline for U.S. Banks (Basel III Rules) became effective for the Company on January 1, 2015 with full compliance with all of the requirements being phased in over a multi-year schedule, and were fully phased in on January 1, 2019. Starting in January 2016, the implementation of the capital conservation buffer was effective for the Company starting at the 0.625% level and increasing 0.625% each year thereafter, until it reached 2.5% on January 1, 2019. Management believes as of September 30, 2019 and December 31, 2018 the Company and the Bank met all capital adequacy requirements to which they were then subject. 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 less than well 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. The following is a summary of the Company’s and the Bank’s actual and required capital ratios at September 30, 2019 and December 31, 2018: To Be Categorized As Well Capitalized Under Actual For Capital Adequacy Purposes Minimum Required Plus Capital Conservation Buffer Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) ALLEGIANCE BANCSHARES, INC. (Consolidated) As of September 30, 2019 Total Capital (to risk weighted assets) $ 590,698 14.70 % $ 321,431 8.00 % $ 421,878 10.500 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 453,119 11.28 % 180,805 4.50 % 281,252 7.000 % N/A N/A Tier 1 Capital (to risk weighted assets) 462,616 11.51 % 241,073 6.00 % 341,520 8.500 % N/A N/A Tier 1 Capital (to average tangible assets) 462,616 10.06 % 184,030 4.00 % 184,030 4.000 % N/A N/A As of December 31, 2018 Total Capital (to risk weighted assets) $ 531,453 13.70 % $ 310,295 8.00 % $ 383,020 9.875 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 456,223 11.76 % 174,541 4.50 % 247,266 6.375 % N/A N/A Tier 1 Capital (to risk weighted assets) 465,637 12.01 % 232,721 6.00 % 305,446 7.875 % N/A N/A Tier 1 Capital (to average tangible assets) 465,637 10.61 % 175,621 4.00 % 175,621 4.000 % N/A N/A ALLEGIANCE BANK As of September 30, 2019 Total Capital (to risk weighted assets) $ 562,604 14.01 % $ 321,287 8.00 % $ 421,689 10.500 % $ 401,609 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 493,213 12.28 % 180,724 4.50 % 281,126 7.000 % 261,046 6.50 % Tier 1 Capital (to risk weighted assets) 493,213 12.28 % 240,965 6.00 % 341,368 8.500 % 321,287 8.00 % Tier 1 Capital (to average tangible assets) 493,213 10.73 % 183,922 4.00 % 183,922 4.000 % 229,903 5.00 % As of December 31, 2018 Total Capital (to risk weighted assets) $ 524,660 13.53 % $ 310,179 8.00 % $ 382,877 9.875 % $ 387,724 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 458,844 11.83 % 174,476 4.50 % 247,174 6.375 % 252,021 6.50 % Tier 1 Capital (to risk weighted assets) 458,844 11.83 % 232,634 6.00 % 305,333 7.875 % 310,179 8.00 % Tier 1 Capital (to average tangible assets) 458,844 10.45 % 175,552 4.00 % 175,552 4.000 % 219,440 5.00 %

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	15. EARNINGS PER COMMON SHARE Diluted earnings per common share is computed using the weighted-average number of common shares determined for the basic earnings per common share computation plus the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock using the treasury stock method. Outstanding stock options issued by the Company represent the only dilutive effect reflected in diluted weighted average shares. Restricted shares are considered outstanding at the date of grant, accounted for as participating securities and included in basic and diluted weighted average common shares outstanding. Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Per Share Per Share Per Share Per Share Amount Amount Amount Amount Amount Amount Amount Amount (Amounts in thousands, except per share data) Net income attributable to shareholders $ 12,047 $ 8,879 $ 38,973 $ 24,146 Basic: Weighted average shares outstanding 20,981 $ 0.57 13,371 $ 0.66 21,321 $ 1.83 13,320 $ 1.81 Diluted: Add incremental shares for: Dilutive effect of stock option exercises 275 266 270 285 Total 21,256 $ 0.57 13,637 $ 0.65 21,591 $ 1.81 13,605 $ 1.77 Stock options for 51,875 shares were not considered in computing diluted earnings per common share as of September 30, 2019 as they were antidilutive. There were no antidilutive shares as of September 30, 2018.

NATURE OF OPERATIONS AND SUMM_2

NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation -The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and in accordance with guidance provided by the Securities and Exchange Commission. Accordingly, the condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows of the Company on a consolidated basis, and all such adjustments are of a normal recurring nature. Transactions between the Company and the Bank have been eliminated. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018. Operating results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019.
New Accounting Standards	New Accounting Standards Adoption of New Accounting Standards ASU 2016-02, “Leases (Topic 842)." ASU 2016-02 requires lessees to recognize a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 does not significantly change lease accounting requirements applicable to lessors; however, certain changes were made to align, where necessary, lessor accounting with the lessee accounting model and ASC Topic 606, “Revenue from Contracts with Customers.” ASU 2016-02 became effective for the Company on January 1, 2019. The Company adopted the standard through the required modified retrospective approach by applying the allowed transition method whereby comparative periods were not restated and a cumulative effect adjustment to the opening balance of retained earnings was recognized as of January 1, 2019. Topic 842 requires the recognition of a lease liability measured as the present value of unpaid lease payments for operating leases where the Company is the lessee, and a corresponding right-of-use (ROU) asset for the right to use the leased properties. The Company elected not to reassess whether contracts are or contain leases, lease classification or initial direct costs for existing leases, a set of practical expedients for transition provided by ASU 2016-12. Further, the Company elected the practical expedient to use hindsight in determining the lease term and assessing impairment. The election of the hindsight practical expedient resulted in longer lease terms for a limited number of strategic locations based on relevant factors as of the adoption date. The Company implemented a lease management system to assist in centralizing, maintaining and accounting for all leases to ensure the Company meets the ASU’s reporting and disclosure requirements. Prior comparable periods are presented in accordance with previous guidance under Accounting Standards Codification (ASC) 840, “Leases.” As of January 1, 2019, right-of-use assets and related lease liabilities totaled $15.3 million and $15.7 million, respectively. See Note 6 – Leases for further information regarding the Company’s leases on certain properties and equipment under operating leases. ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20) - Premium Amortization on Purchased Callable Debt Securities.” ASU 2017-08 shortens the amortization period for certain callable debt securities held at a premium to require such premiums to be amortized to the earliest call date unless applicable guidance related to certain pools of securities is applied to consider estimated prepayments. Under prior guidance, entities were generally required to amortize premiums on individual, non-pooled callable debt securities as a yield adjustment over the contractual life of the security. ASU 2017-08 does not change the accounting for callable debt securities held at a discount. ASU 2017-08 became effective for the Company on January 1, 2019. Upon adoption, the Company recognized a cumulative effect reduction in retained earnings totaling $1.7 million. Newly Issued But Not Yet Effective Accounting Standards ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” Among other things, ASU 2016-13 requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better form their credit loss estimates. Many of the loss estimation techniques applied today will still be permitted, although the inputs to those techniques will change to reflect the full amount of expected credit losses. In addition, ASU 2016-13 amends the accounting for credit losses on available for sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 is effective for the Company on January 1, 2020 and must be applied using the modified retrospective approach with limited exceptions. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. The Company has formed a cross functional team and, with the assistance of a third-party provider, is assessing the Company's data and system needs to evaluate the impact that adoption of this standard will have on the financial condition and results of operations of the Company. The Company expects the adoption of ASU 2016-13 to result in an increase in the allowance for loan losses as a result of changing from an “incurred loss” model, which encompasses allowances for current known and inherent losses within the portfolio, to an “expected loss” model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. ASU 2016-13 permits the use of estimation techniques that are practical and relevant to the Company’s circumstances, as long as they are applied consistently over time and reasonably estimate expected credit losses in accordance with the standard. The Company has developed its current expected credit loss estimation model and is working through its implementation plan which includes documentation of processes, internal controls and data sources; model development and documentation; and system configuration. The Company plans to implement the cohort method to estimate expected credit losses. This method will estimate credit losses over a forecast horizon and revert to long term historical loss experience. The cohort method also incorporates reasonable and supportable forecasts of economic conditions into the estimate which will require significant judgement. The Company will continue to perform and enhance parallel runs throughout 2019 as new processes, policies and controls are finalized. The impact of the standard will depend on the composition of the Company’s portfolio as well as economic conditions and forecasts at the time of adoption. ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” ASU 2017-04 eliminates Step 2 from the goodwill impairment test which required entities to compute the implied fair value of goodwill. Under ASU 2017-04, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-04 will be effective for the Company on January 1, 2020, with earlier adoption permitted and is not expected to have a significant impact on the Company's financial statements.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Schedule of Purchase Price Allocation	As of September 30, 2019, the Company finalized its valuation of all assets and liabilities acquired, resulting in no changes to preliminary acquisition accounting adjustments. A summary of the purchase price allocation is as follows (in thousands): Fair value of consideration paid: Common shares issued (8,402,010 shares) $ 350,364 Stock options issued (299,352) 8,639 Cash in lieu of fractional shares 21 Total consideration paid $ 359,024 Fair value of assets acquired: Cash and cash equivalents $ 230,416 Investment securities 42,779 Loans 1,164,281 Premises and equipment 21,988 Core deposit intangibles 25,128 Other assets 18,076 Total assets acquired $ 1,502,668 Fair value of liabilities assumed: Deposits $ 1,291,310 Other borrowed funds 30,000 Other liabilities 6,070 Total liabilities assumed 1,327,380 Fair value of net assets acquired $ 175,288 Goodwill resulting from acquisition $ 183,736
Schedule of Details of Loans Acquired	The following presents details of all loans acquired as of October 1, 2018: Contractual Balance Fair Value Discount (Dollars in thousands) Commercial and industrial $ 221,098 $ 217,204 $ (3,894 ) Real estate: Commercial real estate (including multi-family residential) 450,947 443,512 (7,435 ) Commercial real estate construction and land development 167,386 165,387 (1,999 ) 1-4 family residential (including home equity) 288,304 285,099 (3,205 ) Residential construction 23,812 23,812 - Consumer and other 29,684 29,267 (417 ) Total loans $ 1,181,231 $ 1,164,281 $ (16,950 )

GOODWILL AND CORE DEPOSIT INT_2

GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill	Changes in the carrying amount of the Company’s goodwill and core deposit intangible assets were as follows: Core Deposit Goodwill Intangibles (Dollars in thousands) Balance as of December 31, 2017 $ 39,389 $ 3,274 Amortization — (586 ) Balance as of September 30, 2018 39,389 2,688 Balance as of December 31, 2018 $ 223,125 $ 26,587 Acquisition of LoweryBank branch 578 — Measurement period adjustment (61 ) — Amortization — (3,534 ) Balance as of September 30, 2019 $ 223,642 $ 23,053
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated aggregate future amortization expense for core deposit intangible assets remaining as of September 30, 2019 is as follows (dollars in thousands): Remaining 2019 $ 1,179 2020 3,922 2021 3,296 2022 3,003 2023 2,323 Thereafter 9,330 Total $ 23,053

SECURITIES (Tables)

SECURITIES (Tables)	9 Months Ended
	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Available-for-sale Securities	The amortized cost and fair value of investment securities were as follows: September 30, 2019 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (Dollars in thousands) Available for Sale U.S. Government and agency securities $ 30,250 $ 332 $ (325 ) $ 30,257 Municipal securities 71,782 4,034 — 75,816 Agency mortgage-backed pass-through securities 97,374 1,779 (126 ) 99,027 Agency collateralized mortgage obligations 99,702 2,138 (166 ) 101,674 Corporate bonds and other 45,661 580 (15 ) 46,226 Total $ 344,769 $ 8,863 $ (632 ) $ 353,000
Investments Classified by Contractual Maturity Date	The amortized cost and fair value of investment securities at September 30, 2019, by contractual maturity, are shown below. Expected maturities may differ from contractual maturities if borrowers have the right to call or prepay obligations at any time with or without call or prepayment penalties. Amortized Fair Cost Value (Dollars in thousands) Due in one year or less $ 29,040 $ 29,136 Due after one year through five years 21,274 21,722 Due after five years through ten years 49,782 51,194 Due after ten years 47,597 50,247 Subtotal 147,693 152,299 Agency mortgage-backed pass through and collateralized mortgage obligation securities 197,076 200,701 Total $ 344,769 $ 353,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	Securities with unrealized losses segregated by length of time such securities have been in a continuous loss position are as follows: September 30, 2019 Less than 12 Months More than 12 Months Total Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in thousands) Available for Sale U.S. Government and agency securities $ 22,651 $ (324 ) $ 438 $ (1 ) $ 23,089 $ (325 ) Agency mortgage-backed pass-through securities 9,819 (62 ) 8,578 (64 ) 18,397 (126 ) Agency collateralized mortgage obligations 17,005 (166 ) — — 17,005 (166 ) Corporate bonds and other — — 1,505 (15 ) 1,505 (15 ) Total $ 49,475 $ (552 ) $ 10,521 $ (80 ) $ 59,996 $ (632 ) December 31, 2018 Less than 12 Months More than 12 Months Total Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in thousands) Available for Sale U.S. Government and agency securities $ 999 $ — $ 1,417 $ (46 ) $ 2,416 $ (46 ) Municipal securities 10,140 (29 ) 136,934 (3,512 ) 147,074 (3,541 ) Agency mortgage-backed pass-through securities 17,168 (209 ) 22,819 (820 ) 39,987 (1,029 ) Corporate bonds and other 13,634 (35 ) 29,014 (655 ) 42,648 (690 ) Total $ 41,941 $ (273 ) $ 190,184 $ (5,033 ) $ 232,125 $ (5,306 )

LOANS AND ALLOWANCE FOR LOAN _2

LOANS AND ALLOWANCE FOR LOAN LOSSES (Tables)	9 Months Ended
	Sep. 30, 2019
Loans And Allowance For Loan Losses [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The loan portfolio balances, net of unearned income and fees, consist of various types of loans primarily made to borrowers located within Texas and are classified by major type as follows: September 30, December 31, 2019 2018 (Dollars in thousands) Commercial and industrial $ 675,055 $ 702,037 Mortgage warehouse 36,594 48,274 Real estate: Commercial real estate (including multi-family residential) 1,859,721 1,650,912 Commercial real estate construction and land development 386,723 430,128 1-4 family residential (including home equity) 695,520 649,311 Residential construction 189,608 186,411 Consumer and other 42,783 41,233 Total loans 3,886,004 3,708,306 Allowance for loan losses (29,808 ) (26,331 ) Loans, net $ 3,856,196 $ 3,681,975
Carrying Amount of PCI Loans	The Company has loans that were acquired and for which there was, at acquisition, evidence of deterioration of credit quality since origination and for which it was probable, at acquisition, that all contractually required payments would not be collected. The carrying amount of PCI loans included in the consolidated balance sheet and the related outstanding balance owed at September 30, 2019 are presented in the table below (dollars in thousands): As of September 30, 2019 As of December 31, 2018 Outstanding balance $ 20,206 $ 26,862 Less: Discount (2,991 ) (3,599 ) Recorded investment $ 17,215 $ 23,263
Changes in Accretable Yield for PCI Loans	Changes in the accretable yield for PCI loans for the three and nine months ended September 30, 2019 were as follows (dollars in thousands): Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Balance at beginning of period $ 2,195 $ 436 Measurement period adjustment - 2,674 Additions - - Reclassifications from nonaccretable 88 301 Accretion (379 ) (1,507 ) Balance at September 30, 2019 $ 1,904 $ 1,904
Past Due Financing Receivables	An aging analysis of the recorded investment in past due loans, segregated by class of loans, is as follows: September 30, 2019 Loans Past Due and Still Accruing 30-89 90 or More Total Past Nonaccrual Current Total Days Days Due Loans Loans Loans Loans (Dollars in thousands) Commercial and industrial $ 4,162 $ — $ 4,162 $ 8,033 $ 662,860 $ 675,055 Mortgage warehouse — — — — 36,594 36,594 Real estate: Commercial real estate (including multi-family residential) 9,203 — 9,203 15,356 1,835,162 1,859,721 Commercial real estate construction and land development 147 — 147 9,050 377,526 386,723 1-4 family residential (including home equity) 2,585 — 2,585 1,992 690,943 695,520 Residential construction 932 — 932 — 188,676 189,608 Consumer and other 93 — 93 184 42,506 42,783 Total loans $ 17,122 $ — $ 17,122 $ 34,615 $ 3,834,267 $ 3,886,004 December 31, 2018 Loans Past Due and Still Accruing 30-89 90 or More Total Past Nonaccrual Current Total Days Days Due Loans Loans Loans Loans (Dollars in thousands) Commercial and industrial $ 1,951 $ — $ 1,951 $ 10,861 $ 689,225 $ 702,037 Mortgage warehouse — — — — 48,274 48,274 Real estate: Commercial real estate (including multi-family residential) 3,502 — 3,502 17,776 1,629,634 1,650,912 Commercial real estate construction and land development 1,300 — 1,300 974 427,854 430,128 1-4 family residential (including home equity) 3,643 — 3,643 3,201 642,467 649,311 Residential construction — — — — 186,411 186,411 Consumer and other 91 — 91 141 41,001 41,233 Total loans $ 10,487 $ — $ 10,487 $ 32,953 $ 3,664,866 $ 3,708,306
Impaired Financing Receivables	Impaired loans by class of loans are set forth in the following tables. As of September 30, 2019 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 3,568 $ 3,683 $ — Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 6,715 6,795 — Commercial real estate construction and land development 9,050 9,050 — 1-4 family residential (including home equity) 1,598 1,598 — Residential construction — — — Consumer and other 57 57 — Total 20,988 21,183 — With an allowance recorded: Commercial and industrial 8,450 8,845 4,354 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 11,749 11,749 2,236 Commercial real estate construction and land development 3,114 3,114 191 1-4 family residential (including home equity) — — — Residential construction — — — Consumer and other 32 32 28 Total 23,345 23,740 6,809 Total: Commercial and industrial 12,018 12,528 4,354 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 18,464 18,544 2,236 Commercial real estate construction and land development 12,164 12,164 191 1-4 family residential (including home equity) 1,598 1,598 — Residential construction — — — Consumer and other 89 89 28 $ 44,333 $ 44,923 $ 6,809 As of December 31, 2018 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 4,354 $ 4,771 $ — Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 11,322 11,322 — Commercial real estate construction and land development 1,326 1,326 — 1-4 family residential (including home equity) 2,742 2,741 — Residential construction — — — Consumer and other 3 3 — Total 19,747 20,163 — With an allowance recorded: Commercial and industrial 9,150 9,545 3,898 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 11,542 11,542 2,641 Commercial real estate construction and land development 3,114 3,114 190 1-4 family residential (including home equity) — — — Residential construction — — — Consumer and other — — — Total 23,806 24,201 6,729 Total: Commercial and industrial 13,504 14,316 3,898 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 22,864 22,864 2,641 Commercial real estate construction and land development 4,440 4,440 190 1-4 family residential (including home equity) 2,742 2,741 — Residential construction — — — Consumer and other 3 3 — $ 43,553 $ 44,364 $ 6,729 The following table presents average impaired loans and interest recognized on impaired loans for the three and nine months ended September 30, 2019 and 2018: Three Months Ended September 30, 2019 2018 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 12,268 $ 94 $ 12,979 $ 119 Mortgage warehouse — — — — Real estate: Commercial real estate (including multi-family residential) 18,762 86 18,242 181 Commercial real estate construction and land development 12,005 52 695 5 1-4 family residential (including home equity) 1,609 — 2,993 4 Residential construction — — — — Consumer and other 91 1 — — Total $ 44,735 $ 233 $ 34,909 $ 309 Nine Months Ended September 30, 2019 2018 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 12,265 $ 261 $ 13,370 $ 316 Mortgage warehouse — — — — Real estate: Commercial real estate (including multi-family residential) 19,453 279 18,409 497 Commercial real estate construction and land development 10,263 140 600 8 1-4 family residential (including home equity) 1,641 4 3,033 9 Residential construction — — — — Consumer and other 96 — — — Total $ 43,718 $ 684 $ 35,412 $ 830
Financing Receivable Credit Quality Indicators	Based on the most recent analysis performed, the risk category of loans by class of loan at September 30, 2019 is as follows: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 633,253 $ 9,167 $ 7,547 $ 25,008 $ 80 $ 675,055 Mortgage warehouse 36,594 — — — — 36,594 Real estate: Commercial real estate (including multi-family residential) 1,782,152 30,240 7,891 39,438 — 1,859,721 Commercial real estate construction and land development 372,601 1,296 1,350 11,476 — 386,723 1-4 family residential (including home equity) 663,642 15,720 7,214 8,944 — 695,520 Residential construction 184,410 2,867 2,331 — — 189,608 Consumer and other 42,203 7 335 238 — 42,783 Total loans $ 3,714,855 $ 59,297 $ 26,668 $ 85,104 $ 80 $ 3,886,004 The following table presents the risk category of loans by class of loan at December 31, 2018: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 656,783 $ 9,696 $ 13,874 $ 21,684 $ — $ 702,037 Mortgage warehouse 48,274 — — — — 48,274 Real estate: Commercial real estate (including multi-family residential) 1,570,243 29,702 7,101 43,866 — 1,650,912 Commercial real estate construction and land development 424,460 729 2,149 2,790 — 430,128 1-4 family residential (including home equity) 629,657 3,797 4,216 11,641 — 649,311 Residential construction 186,411 — — — — 186,411 Consumer and other 40,673 31 301 228 — 41,233 Total loans $ 3,556,501 $ 43,955 $ 27,641 $ 80,209 $ — $ 3,708,306
Allowance for Credit Losses on Financing Receivables	The following table presents the activity in the allowance for loan losses by portfolio type for the three and nine months ended September 30, 2019 and 2018: Commercial and Mortgage warehouse Commercial real estate (including multi-family residential) Commercial real estate construction and land development 1-4 family residential (including home equity) Residential construction Consumer and other Total (Dollars in thousands) Allowance for loan losses: Three Months Ended Balance June 30, 2019 $ 8,255 $ — $ 12,940 $ 2,257 $ 3,376 $ 1,004 $ 108 $ 27,940 Provision for loan losses 1,322 — 613 (222 ) 608 247 29 2,597 Charge-offs (769 ) — — (44 ) — — — (813 ) Recoveries 84 — — — — — — 84 Net charge-offs (685 ) — — (44 ) — — — (729 ) Balance September 30, 2019 $ 8,892 $ — $ 13,553 $ 1,991 $ 3,984 $ 1,251 $ 137 $ 29,808 Nine Months Ended Balance December 31, 2018 $ 8,351 $ — $ 11,901 $ 2,724 $ 2,242 $ 1,040 $ 73 $ 26,331 Provision for loan losses 1,668 — 1,729 (689 ) 2,037 211 50 5,006 Charge-offs (1,357 ) — (80 ) (44 ) (295 ) — (8 ) (1,784 ) Recoveries 230 — 3 — — — 22 255 Net (charge-offs) recoveries (1,127 ) — (77 ) (44 ) (295 ) — 14 (1,529 ) Balance September 30, 2019 $ 8,892 $ — $ 13,553 $ 1,991 $ 3,984 $ 1,251 $ 137 $ 29,808 Allowance for loan losses: Three Months Ended Balance June 30, 2018 $ 9,154 $ — $ 9,203 $ 2,288 $ 2,189 $ 914 $ 83 $ 23,831 Provision for loan losses (621 ) — (2 ) 447 35 153 (12 ) — Charge-offs (235 ) — — — (25 ) — — (260 ) Recoveries 15 — — — — — — 15 Net charge-offs (220 ) — — — (25 ) — — (245 ) Balance September 30, 2018 $ 8,313 $ — $ 9,201 $ 2,735 $ 2,199 $ 1,067 $ 71 $ 23,586 Nine Months Ended Balance December 31, 2017 $ 7,694 $ — $ 10,253 $ 2,525 $ 2,140 $ 942 $ 95 $ 23,649 Provision for loan losses 2,002 — (1,113 ) 210 84 125 (24 ) 1,284 Charge-offs (2,123 ) — (41 ) — (25 ) — — (2,189 ) Recoveries 740 — 102 — — — — 842 Net (charge-offs) recoveries (1,383 ) — 61 — (25 ) — — (1,347 ) Balance September 30, 2018 $ 8,313 $ — $ 9,201 $ 2,735 $ 2,199 $ 1,067 $ 71 $ 23,586 The following table presents the balance of the allowance for loan losses by portfolio type based on the impairment method as of September 30, 2019 and December 31, 2018: Commercial and Mortgage warehouse Commercial real estate (including multi-family residential) Commercial real estate construction and land development 1-4 family residential (including home equity) Residential construction Consumer and other Total (Dollars in thousands) Allowance for loan losses related to: September 30, 2019 Individually evaluated for impairment $ 4,354 $ — $ 2,236 $ 191 $ — $ — $ 28 $ 6,809 Collectively evaluated for impairment 4,509 - 11,198 1,792 3,909 1,251 109 22,768 PCI 29 — 119 8 75 — — 231 Total allowance for loan losses $ 8,892 $ — $ 13,553 $ 1,991 $ 3,984 $ 1,251 $ 137 $ 29,808 December 31, 2018 Individually evaluated for impairment $ 3,898 $ — $ 2,641 $ 190 $ — $ — $ — $ 6,729 Collectively evaluated for impairment 4,453 — 9,260 2,534 2,242 1,040 73 19,602 Total allowance for loan losses $ 8,351 $ — $ 11,901 $ 2,724 $ 2,242 $ 1,040 $ 73 $ 26,331 The following table presents the recorded investment in loans held for investment by portfolio type based on the impairment method as of September 30, 2019 and December 31, 2018: Commercial and Mortgage warehouse Commercial real estate (including multi-family residential) Commercial real estate construction and land development 1-4 family residential (including home equity) Residential construction Consumer and other Total (Dollars in thousands) Recorded investment in loans: September 30, 2019 Individually evaluated for impairment $ 12,018 $ — $ 18,464 $ 12,164 $ 1,598 $ — $ 89 $ 44,333 Collectively evaluated for impairment 663,037 36,594 1,841,257 374,559 693,922 189,608 42,694 3,841,671 Total loans evaluated for impairment $ 675,055 $ 36,594 $ 1,859,721 $ 386,723 $ 695,520 $ 189,608 $ 42,783 $ 3,886,004 December 31, 2018 Individually evaluated for impairment $ 13,504 $ — $ 22,864 $ 4,440 $ 2,742 $ — $ 3 $ 43,553 Collectively evaluated for impairment 688,533 48,274 1,628,048 425,688 646,569 186,411 41,230 3,664,753 Total loans evaluated for impairment $ 702,037 $ 48,274 $ 1,650,912 $ 430,128 $ 649,311 $ 186,411 $ 41,233 $ 3,708,306
Troubled Debt Restructurings on Financing Receivables	The following tables present information regarding loans modified in a troubled debt restructuring during the three and nine months ended September 30, 2019 and 2018: Three Months Ended September 30, 2019 2018 Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment (Dollars in thousands) Troubled Debt Restructurings Commercial and industrial 4 $ 1,502 $ 1,502 1 $ 200 $ 200 Mortgage warehouse — — — — — — Real estate: Commercial real estate (including multi-family residential) — — — — — — Commercial real estate construction and land development — — — — — — 1-4 family residential (including home equity) — — — — — — Residential construction — — — — — — Consumer and other — — — — — — Total 4 $ 1,502 $ 1,502 1 $ 200 $ 200 Nine Months Ended September 30, 2019 2018 Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment Number of Contracts Pre-Modification of Outstanding Recorded Investment Post Modification of Outstanding Recorded Investment (Dollars in thousands) Troubled Debt Restructurings Commercial and industrial 11 $ 2,069 $ 2,069 9 $ 1,797 $ 1,797 Mortgage warehouse — — — — — — Real estate: Commercial real estate (including multi-family residential) 1 303 303 — — — Commercial real estate construction and land development — — — — — — 1-4 family residential (including home equity) 1 396 396 — — — Residential construction — — — — — — Consumer and other 1 38 38 — — — Total 14 $ 2,806 $ 2,806 9 $ 1,797 $ 1,797

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Supplemental Lease Information	Supplemental lease information at or for the nine months ended September 30, 2019 is as follows (dollars in thousands): Balance Sheet: Operating lease asset classified as premises and equipment $ 11,810 Operating lease liability classified as other liabilities 12,116 Income Statement: Operating lease cost classified as occupancy and equipment expense $ 2,733 Weighted average lease term, in years 5.70 Weighted average discount rate 3.19 %
Maturity Analysis of Lease Liabilities	A maturity analysis of the Company’s lease liabilities at September 30, 2019 is as follows (dollars in thousands): Lease payments due: Within one year $ 2,885 After one but within two years 2,867 After two but within three years 2,608 After three but within four years 2,204 After four but within five years 1,596 After five years 3,293 Total lease payments $ 15,453 Discount on cash flows (3,337 ) Total lease liability $ 12,116

FAIR VALUE (Tables)

FAIR VALUE (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	The carrying amounts and estimated fair values of financial instruments that are reported on the balance sheet are as follows: As of September 30, 2019 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 300,619 $ 300,619 $ — $ — $ 300,619 Available for sale securities 353,000 — 353,000 — 353,000 Loans held for investment, net of allowance 3,856,196 — — 3,888,672 3,888,672 Accrued interest receivable 15,201 9 1,560 13,632 15,201 Financial liabilities Deposits $ 3,897,485 $ — $ 3,902,191 $ — $ 3,902,191 Accrued interest payable 4,915 — 4,915 — 4,915 Borrowed funds 159,501 — 159,501 — 159,501 Subordinated debt 107,771 — 107,771 — 107,771 As of December 31, 2018 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 268,947 $ 268,947 $ — $ — $ 268,947 Available for sale securities 337,293 — 337,293 — 337,293 Loans held for investment, net of allowance 3,681,975 — — 3,674,241 3,674,241 Accrued interest receivable 17,010 65 3,498 13,447 17,010 Financial liabilities Deposits $ 3,662,536 $ — $ 3,653,244 $ — $ 3,653,244 Accrued interest payable 2,812 — 2,812 — 2,812 Borrowed funds 225,493 — 230,445 — 230,445 Subordinated debt 48,899 — 49,663 — 49,663
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables present fair values for assets measured at fair value on a recurring basis: September 30, 2019 Level 1 Level 2 Level 3 Total (Dollars in thousands) Available for sale securities: U.S. Government and agency securities $ — $ 30,257 $ — $ 30,257 Municipal securities — 75,816 — 75,816 Agency mortgage-backed pass-through securities — 99,027 — 99,027 Agency collateralized mortgage obligations — 101,674 101,674 Corporate bonds and other — 46,226 — 46,226 Total $ — $ 353,000 $ — $ 353,000 December 31, 2018 Level 1 Level 2 Level 3 Total (Dollars in thousands) Available for sale securities: U.S. Government and agency securities $ — $ 8,685 $ — $ 8,685 Municipal securities — 216,785 — 216,785 Agency mortgage-backed pass-through securities — 66,195 — 66,195 Corporate bonds and other — 45,628 — 45,628 Total $ — $ 337,293 $ — $ 337,293
Fair Value Measurements, Nonrecurring	The following table presents certain assets and liabilities measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis, but are subject to fair value adjustments in certain circumstances such as evidence of impairment. As of September 30, 2019 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 4,096 Commercial real estate (including multi- family residential) — — 9,513 Commercial real estate construction and land development — — 2,923 Consumer and other — — 4 Other real estate owned — — 8,333 $ — $ — $ 24,869 As of December 31, 2018 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 5,252 Commercial real estate (including multi- family residential) — — 8,901 Commercial real estate construction and land development — — 2,924 Other real estate owned — — 630 $ — $ — $ 17,707

DEPOSITS (Tables)

DEPOSITS (Tables)	9 Months Ended
	Sep. 30, 2019
Deposit Liabilities [Abstract]
Schedule of Maturities of Time Deposits	Scheduled maturities of time deposits for the next five years are as follows (dollars in thousands): Within one year $ 244,325 After one but within two years 624,573 After two but within three years 145,761 After three but within four years 102,882 After four but within five years 97,118 Total $ 1,214,659

SUBORDINATED DEBT (Tables)

SUBORDINATED DEBT (Tables)	9 Months Ended
	Sep. 30, 2019
Subordinated Borrowings [Abstract]
Schedule of Subordinated Borrowing	A summary of pertinent information related to the Company’s issues of junior subordinated debentures outstanding at September 30, 2019 is set forth in the table below: Description Issuance Date Trust Preferred Securities Outstanding Interest Rate (1) Junior Subordinated Debt Owed to Trusts Maturity Date (2) (Dollars in thousands) Farmers & Merchants Capital Trust II November 13, 2003 $ 7,500 3 month LIBOR + 3.00% $ 7,732 November 8, 2033 Farmers & Merchants Capital Trust III June 30, 2005 3,500 3 month LIBOR + 1.80% 3,609 July 7, 2035 $ 11,341 (1) The 3-month LIBOR in effect as of September 30, 2019 was 2.1252%. (2) All debentures are currently callable.

STOCK BASED COMPENSATION (Table

STOCK BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	A summary of the activity in the stock option plans during the nine months ended September 30, 2019 is set forth below: Weighted Weighted Average Average Remaining Aggregate Number of Options Exercise Price Contractual Term Intrinsic Value (In thousands) (In years) (In thousands) Options outstanding, December 31, 2018 802 $ 18.88 4.61 $ 10,830 Options granted — — Options exercised (98 ) 15.89 Options forfeited (4 ) 27.85 Options outstanding, September 30, 2019 700 $ 19.25 3.98 $ 8,983 Options vested and exercisable, September 30, 2019 646 $ 18.28 3.71 $ 8,924
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of the activity of the nonvested shares of restricted stock during the nine months ended September 30, 2019 is as follows: Weighted Average Grant Number of Date Fair Shares Value (Shares in thousands) Nonvested share awards outstanding, December 31, 2018 143 $ 37.48 Share awards granted 85 34.95 Share awards vested (17 ) 33.75 Unvested share awards forfeited or cancelled (19 ) 38.50 Nonvested share awards outstanding, September 30, 2019 192 $ 36.44

OFF-BALANCE SHEET ARRANGEMENT_2

OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Schedule of Fair Value, Off-balance Sheet Risks	The contractual amounts of financial instruments with off-balance sheet risk are as follows: September 30, 2019 December 31, 2018 Fixed Variable Fixed Variable Rate Rate Rate Rate (Dollars in thousands) Commitments to extend credit $ 517,669 $ 556,833 $ 471,440 $ 530,546 Standby letters of credit 13,491 3,843 14,217 9,067 Total $ 531,160 $ 560,676 $ 485,657 $ 539,613

REGULATORY CAPITAL MATTERS (Tab

REGULATORY CAPITAL MATTERS (Tables)	9 Months Ended
	Sep. 30, 2019
Banking And Thrift [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The following is a summary of the Company’s and the Bank’s actual and required capital ratios at September 30, 2019 and December 31, 2018: To Be Categorized As Well Capitalized Under Actual For Capital Adequacy Purposes Minimum Required Plus Capital Conservation Buffer Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) ALLEGIANCE BANCSHARES, INC. (Consolidated) As of September 30, 2019 Total Capital (to risk weighted assets) $ 590,698 14.70 % $ 321,431 8.00 % $ 421,878 10.500 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 453,119 11.28 % 180,805 4.50 % 281,252 7.000 % N/A N/A Tier 1 Capital (to risk weighted assets) 462,616 11.51 % 241,073 6.00 % 341,520 8.500 % N/A N/A Tier 1 Capital (to average tangible assets) 462,616 10.06 % 184,030 4.00 % 184,030 4.000 % N/A N/A As of December 31, 2018 Total Capital (to risk weighted assets) $ 531,453 13.70 % $ 310,295 8.00 % $ 383,020 9.875 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 456,223 11.76 % 174,541 4.50 % 247,266 6.375 % N/A N/A Tier 1 Capital (to risk weighted assets) 465,637 12.01 % 232,721 6.00 % 305,446 7.875 % N/A N/A Tier 1 Capital (to average tangible assets) 465,637 10.61 % 175,621 4.00 % 175,621 4.000 % N/A N/A ALLEGIANCE BANK As of September 30, 2019 Total Capital (to risk weighted assets) $ 562,604 14.01 % $ 321,287 8.00 % $ 421,689 10.500 % $ 401,609 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 493,213 12.28 % 180,724 4.50 % 281,126 7.000 % 261,046 6.50 % Tier 1 Capital (to risk weighted assets) 493,213 12.28 % 240,965 6.00 % 341,368 8.500 % 321,287 8.00 % Tier 1 Capital (to average tangible assets) 493,213 10.73 % 183,922 4.00 % 183,922 4.000 % 229,903 5.00 % As of December 31, 2018 Total Capital (to risk weighted assets) $ 524,660 13.53 % $ 310,179 8.00 % $ 382,877 9.875 % $ 387,724 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 458,844 11.83 % 174,476 4.50 % 247,174 6.375 % 252,021 6.50 % Tier 1 Capital (to risk weighted assets) 458,844 11.83 % 232,634 6.00 % 305,333 7.875 % 310,179 8.00 % Tier 1 Capital (to average tangible assets) 458,844 10.45 % 175,552 4.00 % 175,552 4.000 % 219,440 5.00 %

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Restricted shares are considered outstanding at the date of grant, accounted for as participating securities and included in basic and diluted weighted average common shares outstanding. Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Per Share Per Share Per Share Per Share Amount Amount Amount Amount Amount Amount Amount Amount (Amounts in thousands, except per share data) Net income attributable to shareholders $ 12,047 $ 8,879 $ 38,973 $ 24,146 Basic: Weighted average shares outstanding 20,981 $ 0.57 13,371 $ 0.66 21,321 $ 1.83 13,320 $ 1.81 Diluted: Add incremental shares for: Dilutive effect of stock option exercises 275 266 270 285 Total 21,256 $ 0.57 13,637 $ 0.65 21,591 $ 1.81 13,605 $ 1.77

NATURE OF OPERATIONS AND SUMM_3

NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES (Details) $ in Thousands	Sep. 30, 2019USD ($)officeBank	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
New Accounting Pronouncement Early Adoption [Line Items]
Number of offices in which entity operates | office	27
Number of banks in which entity operates | Bank	26
Right-of-use assets	$ 11,810
Lease liabilities	12,116
ASU 2016-02
New Accounting Pronouncement Early Adoption [Line Items]
Right-of-use assets		$ 15,300
Lease liabilities		$ 15,700
ASU 2017-08
New Accounting Pronouncement Early Adoption [Line Items]
Cumulative effect of adopting new accounting principle in period of adoption			$ 1,715
ASU 2017-08 | Retained Earnings
New Accounting Pronouncement Early Adoption [Line Items]
Cumulative effect of adopting new accounting principle in period of adoption	$ 1,700		$ 1,715
Houston
New Accounting Pronouncement Early Adoption [Line Items]
Number of loan production offices in which entity operates | office	1
Beaumont
New Accounting Pronouncement Early Adoption [Line Items]
Number of loan production offices in which entity operates | office	1

ACQUISITIONS - Narrative (Detai

ACQUISITIONS - Narrative (Details) $ / shares in Units, $ in Thousands	Feb. 01, 2019USD ($)	Oct. 01, 2018USD ($)branch$ / sharesshares	Sep. 30, 2019USD ($)$ / sharesshares	Sep. 28, 2018USD ($)$ / shares
Business Acquisition [Line Items]
Options exercised | $ / shares			$ 15.89
Post Oak Bancshares, Inc.
Business Acquisition [Line Items]
Effective date of acquisition		Oct. 1, 2018
Number of branches | branch		13
Number of shares issued in acquisition | shares		8,402,010	8,402,010
Cash paid for acquisition		$ 21
Number of shares per common share or option to purchase common shares		0.7017
Option issued in acquisition to purchase common shares | shares		299,352	299,352
Options exercised | $ / shares		$ 12.83
Business acquisition, share price | $ / shares				$ 41.70
Business acquisition, equity transaction value				$ 359,000
Goodwill, acquired during period		$ 183,700
Pre-tax acquisition and merger-related expenses			$ 1,300
Business acquisition, loans			1,164,281
Post Oak Bancshares, Inc. | Minimum
Business Acquisition [Line Items]
Intangibles, useful life		10 years
Post Oak Bancshares, Inc. | Houston, Texas
Business Acquisition [Line Items]
Number of branches | branch		12
Post Oak Bancshares, Inc. | Beaumont, TX
Business Acquisition [Line Items]
Number of branches | branch		1
Lowery Bank
Business Acquisition [Line Items]
Effective date of acquisition	Feb. 1, 2019
Goodwill, acquired during period	$ 578		$ 578
Business acquisition, customer deposits balances	16,000
Business acquisition, loans	45,000
Lowery Bank | Minimum
Business Acquisition [Line Items]
Cash paid for acquisition	$ 32,900

ACQUISITIONS - Allocation of th

ACQUISITIONS - Allocation of the Purchase Price to Assets and Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill resulting from acquisition	$ 223,642	$ 223,125	$ 39,389	$ 39,389
Post Oak Bancshares, Inc.
Business Acquisition [Line Items]
Stock options issued (299,352)	8,639
Cash in lieu of fractional shares	21
Total consideration paid	359,024
Cash and cash equivalents	230,416
Investment securities	42,779
Loans	1,164,281
Premises and equipment	21,988
Core deposit intangibles	25,128
Other assets	18,076
Total assets acquired	1,502,668
Deposits	1,291,310
Other borrowed funds	30,000
Other liabilities	6,070
Total liabilities assumed	1,327,380
Fair value of net assets acquired	175,288
Goodwill resulting from acquisition	183,736
Post Oak Bancshares, Inc. | Common Stock
Business Acquisition [Line Items]
Common shares issued (8,402,010 shares)	$ 350,364

ACQUISITIONS - Allocation of _2

ACQUISITIONS - Allocation of the Purchase Price to Assets and Liabilities - Narrative (Details) - Post Oak Bancshares, Inc. - shares	Oct. 01, 2018	Sep. 30, 2019
Business Acquisition [Line Items]
Number of shares issued in acquisition	8,402,010	8,402,010
Option issued in acquisition to purchase common shares	299,352	299,352

ACQUISITIONS - Details of Loans

ACQUISITIONS - Details of Loans Acquired (Details) $ in Thousands	Oct. 01, 2018USD ($)
Business Acquisition [Line Items]
Discount	$ (16,950)
Contractual Balance
Business Acquisition [Line Items]
Acquired loans receivable	1,181,231
Fair Value
Business Acquisition [Line Items]
Acquired loans receivable	1,164,281
Commercial and industrial
Business Acquisition [Line Items]
Discount	(3,894)
Commercial and industrial | Contractual Balance
Business Acquisition [Line Items]
Acquired loans receivable	221,098
Commercial and industrial | Fair Value
Business Acquisition [Line Items]
Acquired loans receivable	217,204
Real estate | Commercial real estate (including multi-family residential)
Business Acquisition [Line Items]
Discount	(7,435)
Real estate | Commercial real estate (including multi-family residential) | Contractual Balance
Business Acquisition [Line Items]
Acquired loans receivable	450,947
Real estate | Commercial real estate (including multi-family residential) | Fair Value
Business Acquisition [Line Items]
Acquired loans receivable	443,512
Real estate | Commercial real estate construction and land development
Business Acquisition [Line Items]
Discount	(1,999)
Real estate | Commercial real estate construction and land development | Contractual Balance
Business Acquisition [Line Items]
Acquired loans receivable	167,386
Real estate | Commercial real estate construction and land development | Fair Value
Business Acquisition [Line Items]
Acquired loans receivable	165,387
Real estate | 1-4 family residential (including home equity)
Business Acquisition [Line Items]
Discount	(3,205)
Real estate | 1-4 family residential (including home equity) | Contractual Balance
Business Acquisition [Line Items]
Acquired loans receivable	288,304
Real estate | 1-4 family residential (including home equity) | Fair Value
Business Acquisition [Line Items]
Acquired loans receivable	285,099
Real estate | Residential construction | Contractual Balance
Business Acquisition [Line Items]
Acquired loans receivable	23,812
Real estate | Residential construction | Fair Value
Business Acquisition [Line Items]
Acquired loans receivable	23,812
Consumer and other
Business Acquisition [Line Items]
Discount	(417)
Consumer and other | Contractual Balance
Business Acquisition [Line Items]
Acquired loans receivable	29,684
Consumer and other | Fair Value
Business Acquisition [Line Items]
Acquired loans receivable	$ 29,267

GOODWILL AND CORE DEPOSIT INT_3

GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS - Changes in Carrying Amount of Goodwill and Intangibles (Details) - USD ($) $ in Thousands	Feb. 01, 2019	Oct. 01, 2018	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill
Balance, beginning		$ 39,389		$ 223,125		$ 223,125	$ 39,389
Balance, ending			$ 223,642		$ 39,389	223,642	39,389
Core Deposit Intangible Assets
Balance, beginning				26,587		26,587
Amortization			(1,178)		(195)	(3,534)	(586)
Balance, ending			23,053			23,053
Core Deposit Intangible Assets
Core Deposit Intangible Assets
Balance, beginning		2,688		26,587		26,587	3,274
Amortization						(3,534)	(586)
Balance, ending			23,053		$ 2,688	23,053	$ 2,688
Lowery Bank
Goodwill
Goodwill, acquired during period	$ 578					578
Post Oak Bancshares, Inc.
Goodwill
Goodwill, acquired during period		$ 183,700
Measurement period adjustment				$ (61)		(61)
Balance, ending			$ 183,736			$ 183,736

GOODWILL AND CORE DEPOSIT INT_4

GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
	Mar. 31, 2019	Sep. 30, 2019
Post Oak Bancshares, Inc.
Finite Lived Intangible Assets [Line Items]
Measurement period adjustment	$ (61,000)	$ (61,000)
Acquisition of F&M
Finite Lived Intangible Assets [Line Items]
Goodwill impairment		$ 0

GOODWILL AND CORE DEPOSIT INT_5

GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS - Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Remaining 2019	$ 1,179
2020	3,922
2021	3,296
2022	3,003
2023	2,323
Thereafter	9,330
Total	$ 23,053	$ 26,587

SECURITIES - Amortized Cost and

SECURITIES - Amortized Cost and Fair Value of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 344,769	$ 340,928
Gross Unrealized Gains	8,863	1,671
Gross Unrealized Losses	(632)	(5,306)
Fair Value	353,000	337,293
U.S. Government and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	30,250	8,570
Gross Unrealized Gains	332	161
Gross Unrealized Losses	(325)	(46)
Fair Value	30,257	8,685
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	71,782	219,068
Gross Unrealized Gains	4,034	1,258
Gross Unrealized Losses		(3,541)
Fair Value	75,816	216,785
Agency mortgage-backed pass-through securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	97,374	66,987
Gross Unrealized Gains	1,779	237
Gross Unrealized Losses	(126)	(1,029)
Fair Value	99,027	66,195
Agency collateralized mortgage obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	99,702
Gross Unrealized Gains	2,138
Gross Unrealized Losses	(166)
Fair Value	101,674
Corporate bonds and other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	45,661	46,303
Gross Unrealized Gains	580	15
Gross Unrealized Losses	(15)	(690)
Fair Value	$ 46,226	$ 45,628

SECURITIES - Amortized Cost a_2

SECURITIES - Amortized Cost and Fair Value of Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Amortized Cost
Due in one year or less	$ 29,040
Due after one year through five years	21,274
Due after five years through ten years	49,782
Due after ten years	47,597
Subtotal	147,693
Agency mortgage-backed pass through and collateralized mortgage obligation securities	197,076
Amortized Cost	344,769	$ 340,928
Fair Value
Due in one year or less	29,136
Due after one year through five years	21,722
Due after five years through ten years	51,194
Due after ten years	50,247
Subtotal	152,299
Agency mortgage-backed pass through and collateralized mortgage obligation securities	200,701
Total	$ 353,000	$ 337,293

SECURITIES - Securities in a Co

SECURITIES - Securities in a Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value	$ 49,475	$ 41,941
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(552)	(273)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value	10,521	190,184
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses	(80)	(5,033)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	59,996	232,125
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	(632)	(5,306)
U.S. Government and agency securities
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value	22,651	999
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(324)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value	438	1,417
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses	(1)	(46)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	23,089	2,416
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	(325)	(46)
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value		10,140
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(29)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value		136,934
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses		(3,512)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value		147,074
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses		(3,541)
Agency mortgage-backed pass-through securities
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value	9,819	17,168
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(62)	(209)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value	8,578	22,819
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses	(64)	(820)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	18,397	39,987
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	(126)	(1,029)
Agency collateralized mortgage obligations
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value	17,005
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(166)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	17,005
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	(166)
Corporate bonds and other
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value		13,634
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(35)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value	1,505	29,014
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses	(15)	(655)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	1,505	42,648
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	$ (15)	$ (690)

SECURITIES - Narrative (Details

SECURITIES - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Investments Debt And Equity Securities [Abstract]
Gross realized gains			$ 1,400
Gross realized losses			576,000
Net realized gain			846,000
Proceeds from sales of available for sale securities	$ 0	$ 0	149,400,000	$ 0
Security owned and pledged as collateral	$ 25,200,000		$ 25,200,000		$ 28,900,000

LOANS AND ALLOWANCE FOR LOAN _3

LOANS AND ALLOWANCE FOR LOAN LOSSES - Loan Portfolio (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 3,886,004		$ 3,708,306
Allowance for loan losses	(29,808)	$ (27,940)	(26,331)	$ (23,586)	$ (23,831)	$ (23,649)
Loans, net	3,856,196		3,681,975
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	675,055		702,037
Allowance for loan losses	(8,892)	(8,255)	(8,351)	(8,313)	(9,154)	(7,694)
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	36,594		48,274
Allowance for loan losses	0	0	0	0	0	0
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	1,859,721		1,650,912
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	386,723		430,128
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	695,520		649,311
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	189,608		186,411
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	42,783		41,233
Allowance for loan losses	$ (137)	$ (108)	$ (73)	$ (71)	$ (83)	$ (95)

LOANS AND ALLOWANCE FOR LOAN _4

LOANS AND ALLOWANCE FOR LOAN LOSSES - Carrying Amount of PCI Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Accounts Notes And Loans Receivable [Line Items]
Outstanding balance	$ 44,923	$ 44,364
Recorded investment	44,333	43,553
PCI Loans
Accounts Notes And Loans Receivable [Line Items]
Outstanding balance	20,206	26,862	$ 0
Less: Discount	(2,991)	(3,599)
Recorded investment	$ 17,215	$ 23,263

LOANS AND ALLOWANCE FOR LOAN _5

LOANS AND ALLOWANCE FOR LOAN LOSSES - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)contract	Sep. 30, 2018USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Accounts Notes And Loans Receivable [Line Items]
Allowance for loan losses	$ 29,808,000	$ 23,586,000	$ 29,808,000	$ 23,586,000	$ 27,940,000	$ 26,331,000	$ 23,831,000	$ 23,649,000
Outstanding balance	44,923,000		44,923,000			44,364,000
Recorded investment	27,500,000		27,500,000			33,100,000
Change in method of calculating impairment	4,500,000		4,500,000			3,000,000
Troubled debt restructuring, write-down	251,000	55,000	251	72,000
Troubled debt restructuring, addition			4,700,000	29,000
Modification of outstanding recorded investment	1,502,000	200,000	$ 2,806,000	1,797,000
Number of defaults on loan that were modified as troubled debt restructurings during the preceding 12 months | contract			7
Troubled debt added during quarter
Accounts Notes And Loans Receivable [Line Items]
Recorded investment	2,700,000	1,800,000	$ 2,700,000	1,800,000
PCI Loans
Accounts Notes And Loans Receivable [Line Items]
Allowance for loan losses	231,000		231,000
Outstanding balance	$ 20,206,000	$ 0	$ 20,206,000	$ 0		$ 26,862,000

LOANS AND ALLOWANCE FOR LOAN _6

LOANS AND ALLOWANCE FOR LOAN LOSSES - Changes in Accretable Yield for PCI Loans (Details) - PCI Loans - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Accounts Notes And Loans Receivable [Line Items]
Balance at beginning of period	$ 2,195	$ 436
Measurement period adjustment		2,674
Reclassifications from nonaccretable	88	301
Accretion	(379)	(1,507)
Balance at September 30, 2019	$ 1,904	$ 1,904

LOANS AND ALLOWANCE FOR LOAN _7

LOANS AND ALLOWANCE FOR LOAN LOSSES - Aging Analysis of the Recorded Investment in Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	$ 17,122	$ 10,487
Nonaccrual Loans	34,615	32,953
Current Loans	3,834,267	3,664,866
Total loans evaluated for impairment	3,886,004	3,708,306
Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	17,122	10,487
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	4,162	1,951
Nonaccrual Loans	8,033	10,861
Current Loans	662,860	689,225
Total loans evaluated for impairment	675,055	702,037
Commercial and industrial | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	4,162	1,951
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Current Loans	36,594	48,274
Total loans evaluated for impairment	36,594	48,274
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	9,203	3,502
Nonaccrual Loans	15,356	17,776
Current Loans	1,835,162	1,629,634
Total loans evaluated for impairment	1,859,721	1,650,912
Real estate | Commercial real estate (including multi-family residential) | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	9,203	3,502
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	147	1,300
Nonaccrual Loans	9,050	974
Current Loans	377,526	427,854
Total loans evaluated for impairment	386,723	430,128
Real estate | Commercial real estate construction and land development | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	147	1,300
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	2,585	3,643
Nonaccrual Loans	1,992	3,201
Current Loans	690,943	642,467
Total loans evaluated for impairment	695,520	649,311
Real estate | 1-4 family residential (including home equity) | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	2,585	3,643
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	932
Current Loans	188,676	186,411
Total loans evaluated for impairment	189,608	186,411
Real estate | Residential construction | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	932
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	93	91
Nonaccrual Loans	184	141
Current Loans	42,506	41,001
Total loans evaluated for impairment	42,783	41,233
Consumer and other | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	$ 93	$ 91

LOANS AND ALLOWANCE FOR LOAN _8

LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired Loans by Loan Class (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
With no related allowance recorded:
Recorded investment with no related allowance recorded	$ 20,988	$ 19,747
Unpaid principal balance with no related allowance recorded	21,183	20,163
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	23,345	23,806
Impaired financing receivable, with related allowance, unpaid principal balance	23,740	24,201
Related Allowance	6,809	6,729
Total:
Recorded Investment	44,333	43,553
Unpaid Principal Balance	44,923	44,364
Related Allowance	6,809	6,729
Commercial and industrial
With no related allowance recorded:
Recorded investment with no related allowance recorded	3,568	4,354
Unpaid principal balance with no related allowance recorded	3,683	4,771
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	8,450	9,150
Impaired financing receivable, with related allowance, unpaid principal balance	8,845	9,545
Related Allowance	4,354	3,898
Total:
Recorded Investment	12,018	13,504
Unpaid Principal Balance	12,528	14,316
Related Allowance	4,354	3,898
Mortgage warehouse
With no related allowance recorded:
Recorded investment with no related allowance recorded	0	0
Unpaid principal balance with no related allowance recorded	0	0
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	0	0
Impaired financing receivable, with related allowance, unpaid principal balance	0	0
Related Allowance	0	0
Total:
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Real estate | Commercial real estate (including multi-family residential)
With no related allowance recorded:
Recorded investment with no related allowance recorded	6,715	11,322
Unpaid principal balance with no related allowance recorded	6,795	11,322
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	11,749	11,542
Impaired financing receivable, with related allowance, unpaid principal balance	11,749	11,542
Related Allowance	2,236	2,641
Total:
Recorded Investment	18,464	22,864
Unpaid Principal Balance	18,544	22,864
Related Allowance	2,236	2,641
Real estate | Commercial real estate construction and land development
With no related allowance recorded:
Recorded investment with no related allowance recorded	9,050	1,326
Unpaid principal balance with no related allowance recorded	9,050	1,326
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	3,114	3,114
Impaired financing receivable, with related allowance, unpaid principal balance	3,114	3,114
Related Allowance	191	190
Total:
Recorded Investment	12,164	4,440
Unpaid Principal Balance	12,164	4,440
Related Allowance	191	190
Real estate | 1-4 family residential (including home equity)
With no related allowance recorded:
Recorded investment with no related allowance recorded	1,598	2,742
Unpaid principal balance with no related allowance recorded	1,598	2,741
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	0	0
Impaired financing receivable, with related allowance, unpaid principal balance	0	0
Related Allowance	0	0
Total:
Recorded Investment	1,598	2,742
Unpaid Principal Balance	1,598	2,741
Related Allowance	0	0
Real estate | Residential construction
With no related allowance recorded:
Recorded investment with no related allowance recorded	0	0
Unpaid principal balance with no related allowance recorded	0	0
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	0	0
Impaired financing receivable, with related allowance, unpaid principal balance	0	0
Related Allowance	0	0
Total:
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Consumer and other
With no related allowance recorded:
Recorded investment with no related allowance recorded	57	3
Unpaid principal balance with no related allowance recorded	57	3
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	32	0
Impaired financing receivable, with related allowance, unpaid principal balance	32	0
Related Allowance	28	0
Total:
Recorded Investment	89	3
Unpaid Principal Balance	89	3
Related Allowance	$ 28	$ 0

LOANS AND ALLOWANCE FOR LOAN _9

LOANS AND ALLOWANCE FOR LOAN LOSSES - Average Impaired Loans and Interest Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	$ 44,735	$ 34,909	$ 43,718	$ 35,412
Interest Income Recognized	233	309	684	830
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	12,268	12,979	12,265	13,370
Interest Income Recognized	94	119	261	316
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	0	0	0	0
Interest Income Recognized	0	0	0	0
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	18,762	18,242	19,453	18,409
Interest Income Recognized	86	181	279	497
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	12,005	695	10,263	600
Interest Income Recognized	52	5	140	8
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	1,609	2,993	1,641	3,033
Interest Income Recognized	0	4	4	9
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	0	0	0	0
Interest Income Recognized	0	0	0	0
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	91	0	96	0
Interest Income Recognized	$ 1	$ 0	$ 0	$ 0

LOANS AND ALLOWANCE FOR LOAN_10

LOANS AND ALLOWANCE FOR LOAN LOSSES - Risk Category of Loans by Class (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 3,886,004	$ 3,708,306
Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	3,714,855	3,556,501
Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	59,297	43,955
Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	26,668	27,641
Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	85,104	80,209
Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	80	0
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	675,055	702,037
Commercial and industrial | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	633,253	656,783
Commercial and industrial | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	9,167	9,696
Commercial and industrial | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	7,547	13,874
Commercial and industrial | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	25,008	21,684
Commercial and industrial | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	80	0
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	36,594	48,274
Mortgage warehouse | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	36,594	48,274
Mortgage warehouse | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Mortgage warehouse | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Mortgage warehouse | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Mortgage warehouse | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	1,859,721	1,650,912
Real estate | Commercial real estate (including multi-family residential) | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	1,782,152	1,570,243
Real estate | Commercial real estate (including multi-family residential) | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	30,240	29,702
Real estate | Commercial real estate (including multi-family residential) | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	7,891	7,101
Real estate | Commercial real estate (including multi-family residential) | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	39,438	43,866
Real estate | Commercial real estate (including multi-family residential) | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	386,723	430,128
Real estate | Commercial real estate construction and land development | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	372,601	424,460
Real estate | Commercial real estate construction and land development | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	1,296	729
Real estate | Commercial real estate construction and land development | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	1,350	2,149
Real estate | Commercial real estate construction and land development | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	11,476	2,790
Real estate | Commercial real estate construction and land development | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	695,520	649,311
Real estate | 1-4 family residential (including home equity) | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	663,642	629,657
Real estate | 1-4 family residential (including home equity) | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	15,720	3,797
Real estate | 1-4 family residential (including home equity) | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	7,214	4,216
Real estate | 1-4 family residential (including home equity) | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	8,944	11,641
Real estate | 1-4 family residential (including home equity) | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	189,608	186,411
Real estate | Residential construction | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	184,410	186,411
Real estate | Residential construction | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	2,867	0
Real estate | Residential construction | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	2,331	0
Real estate | Residential construction | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Real estate | Residential construction | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	42,783	41,233
Consumer and other | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	42,203	40,673
Consumer and other | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	7	31
Consumer and other | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	335	301
Consumer and other | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	238	228
Consumer and other | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 0	$ 0

LOANS AND ALLOWANCE FOR LOAN_11

LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Allowance for loan losses:
Balance, beginning of period	$ 27,940	$ 23,831	$ 26,331	$ 23,649
Provision for loan losses	2,597	0	5,006	1,284
Charge-offs	(813)	(260)	(1,784)	(2,189)
Recoveries	84	15	255	842
Net recoveries (charge-offs)	(729)	(245)	(1,529)	(1,347)
Balance, end of period	29,808	23,586	29,808	23,586
Allowance for loan losses related to:
Individually evaluated for impairment					$ 6,809	$ 6,729
Collectively evaluated for impairment					22,768	19,602
Total allowance for loan losses	29,808	23,831	29,808	23,586	29,808	26,331
Recorded investment in loans:
Individually evaluated for impairment					44,333	43,553
Collectively evaluated for impairment					3,841,671	3,664,753
Total loans evaluated for impairment					3,886,004	3,708,306
PCI
Allowance for loan losses:
Balance, end of period	231		231
Allowance for loan losses related to:
Total allowance for loan losses	231		231		231
Commercial and industrial
Allowance for loan losses:
Balance, beginning of period	8,255	9,154	8,351	7,694
Provision for loan losses	1,322	(621)	1,668	2,002
Charge-offs	(769)	(235)	(1,357)	(2,123)
Recoveries	84	15	230	740
Net recoveries (charge-offs)	(685)	(220)	(1,127)	(1,383)
Balance, end of period	8,892	8,313	8,892	8,313
Allowance for loan losses related to:
Individually evaluated for impairment					4,354	3,898
Collectively evaluated for impairment					4,509	4,453
Total allowance for loan losses	8,255	9,154	8,892	8,313	8,892	8,351
Recorded investment in loans:
Individually evaluated for impairment					12,018	13,504
Collectively evaluated for impairment					663,037	688,533
Total loans evaluated for impairment					675,055	702,037
Commercial and industrial | PCI
Allowance for loan losses:
Balance, end of period	29		29
Allowance for loan losses related to:
Total allowance for loan losses	29		29		29
Mortgage warehouse
Allowance for loan losses:
Balance, beginning of period	0	0	0	0
Provision for loan losses	0	0	0	0
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net recoveries (charge-offs)	0	0	0	0
Balance, end of period	0	0	0	0
Allowance for loan losses related to:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					0	0
Total allowance for loan losses	0	0	0	0	0	0
Recorded investment in loans:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					36,594	48,274
Total loans evaluated for impairment					36,594	48,274
Mortgage warehouse | PCI
Allowance for loan losses:
Balance, end of period	0		0
Allowance for loan losses related to:
Total allowance for loan losses	0		0		0
Commercial Real Estate Portfolio Segment | Commercial real estate (including multi-family residential)
Allowance for loan losses:
Balance, beginning of period	12,940	9,203	11,901	10,253
Provision for loan losses	613	(2)	1,729	(1,113)
Charge-offs	0	0	(80)	(41)
Recoveries	0	0	3	102
Net recoveries (charge-offs)	0	0	(77)	61
Balance, end of period	13,553	9,201	13,553	9,201
Allowance for loan losses related to:
Individually evaluated for impairment					2,236	2,641
Collectively evaluated for impairment					11,198	9,260
Total allowance for loan losses	12,940	9,203	13,553	9,201	13,553	11,901
Recorded investment in loans:
Individually evaluated for impairment					18,464	22,864
Collectively evaluated for impairment					1,841,257	1,628,048
Total loans evaluated for impairment					1,859,721	1,650,912
Commercial Real Estate Portfolio Segment | Commercial real estate (including multi-family residential) | PCI
Allowance for loan losses:
Balance, end of period	119		119
Allowance for loan losses related to:
Total allowance for loan losses	119		119		119
Commercial Real Estate Portfolio Segment | Commercial real estate construction and land development
Allowance for loan losses:
Balance, beginning of period	2,257	2,288	2,724	2,525
Provision for loan losses	(222)	447	(689)	210
Charge-offs	(44)	0	(44)	0
Recoveries	0	0	0	0
Net recoveries (charge-offs)	(44)	0	(44)	0
Balance, end of period	1,991	2,735	1,991	2,735
Allowance for loan losses related to:
Individually evaluated for impairment					191	190
Collectively evaluated for impairment					1,792	2,534
Total allowance for loan losses	2,257	2,288	1,991	2,735	1,991	2,724
Recorded investment in loans:
Individually evaluated for impairment					12,164	4,440
Collectively evaluated for impairment					374,559	425,688
Total loans evaluated for impairment					386,723	430,128
Commercial Real Estate Portfolio Segment | Commercial real estate construction and land development | PCI
Allowance for loan losses:
Balance, end of period	8		8
Allowance for loan losses related to:
Total allowance for loan losses	8		8		8
Commercial Real Estate Portfolio Segment | 1-4 family residential (including home equity)
Allowance for loan losses:
Balance, beginning of period	3,376	2,189	2,242	2,140
Provision for loan losses	608	35	2,037	84
Charge-offs	0	(25)	(295)	(25)
Recoveries	0	0	0	0
Net recoveries (charge-offs)	0	(25)	(295)	(25)
Balance, end of period	3,984	2,199	3,984	2,199
Allowance for loan losses related to:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					3,909	2,242
Total allowance for loan losses	3,376	2,189	3,984	2,199	3,984	2,242
Recorded investment in loans:
Individually evaluated for impairment					1,598	2,742
Collectively evaluated for impairment					693,922	646,569
Total loans evaluated for impairment					695,520	649,311
Commercial Real Estate Portfolio Segment | 1-4 family residential (including home equity) | PCI
Allowance for loan losses:
Balance, end of period	75		75
Allowance for loan losses related to:
Total allowance for loan losses	75		75		75
Commercial Real Estate Portfolio Segment | Residential construction
Allowance for loan losses:
Balance, beginning of period	1,004	914	1,040	942
Provision for loan losses	247	153	211	125
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net recoveries (charge-offs)	0	0	0	0
Balance, end of period	1,251	1,067	1,251	1,067
Allowance for loan losses related to:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					1,251	1,040
Total allowance for loan losses	1,004	914	1,251	1,067	1,251	1,040
Recorded investment in loans:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					189,608	186,411
Total loans evaluated for impairment					189,608	186,411
Commercial Real Estate Portfolio Segment | Residential construction | PCI
Allowance for loan losses:
Balance, end of period	0		0
Allowance for loan losses related to:
Total allowance for loan losses	0		0		0
Consumer and other
Allowance for loan losses:
Balance, beginning of period	108	83	73	95
Provision for loan losses	29	(12)	50	(24)
Charge-offs	0	0	(8)	0
Recoveries	0	0	22	0
Net recoveries (charge-offs)	0	0	14	0
Balance, end of period	137	71	137	71
Allowance for loan losses related to:
Individually evaluated for impairment					28	0
Collectively evaluated for impairment					109	73
Total allowance for loan losses	108	$ 83	137	$ 71	137	73
Recorded investment in loans:
Individually evaluated for impairment					89	3
Collectively evaluated for impairment					42,694	41,230
Total loans evaluated for impairment					42,783	$ 41,233
Consumer and other | PCI
Allowance for loan losses:
Balance, end of period	0		0
Allowance for loan losses related to:
Total allowance for loan losses	$ 0		$ 0		$ 0

LOANS AND ALLOWANCE FOR LOAN_12

LOANS AND ALLOWANCE FOR LOAN LOSSES - Loans Modified in a Troubled Debt Restructuring (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)contract	Sep. 30, 2018USD ($)contract	Sep. 30, 2019USD ($)contract	Sep. 30, 2018USD ($)contract
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	4	1	14	9
Pre- Modification of Outstanding Recorded Investment	$ 1,502	$ 200	$ 2,806	$ 1,797
Post- Modification of Outstanding Recorded Investment	$ 1,502	$ 200	$ 2,806	$ 1,797
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	4	1	11	9
Pre- Modification of Outstanding Recorded Investment	$ 1,502	$ 200	$ 2,069	$ 1,797
Post- Modification of Outstanding Recorded Investment	$ 1,502	$ 200	$ 2,069	$ 1,797
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	0	0	0	0
Pre- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	0	0	1	0
Pre- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 303	$ 0
Post- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 303	$ 0
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	0	0	0	0
Pre- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	0	0	1	0
Pre- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 396	$ 0
Post- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 396	$ 0
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	0	0	0	0
Pre- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	0	0	1	0
Pre- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 38	$ 0
Post- Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 38	$ 0

LEASES - Narrative (Details)

LEASES - Narrative (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)Property	Sep. 30, 2019USD ($)BranchLocationandOfficeSpaceProperty
Lessee Lease Description [Line Items]
Number of leased branch locations and office space along with equipment | BranchLocationandOfficeSpace		14
Short-term lease costs	$ 132	$ 506
Operating lease, existence of option to extend		true
Allegiance Bank
Lessee Lease Description [Line Items]
Operating lease, cost	$ 10,700
Number of leased properties | Property	2	2
Occupancy and Equipment Expenses
Lessee Lease Description [Line Items]
Operating lease, cost	$ 848	$ 2,733
Minimum
Lessee Lease Description [Line Items]
Operating lease renewal term	1 year	1 year
Maximum
Lessee Lease Description [Line Items]
Operating lease renewal term	5 years	5 years

LEASES - Supplemental Lease Inf

LEASES - Supplemental Lease Information (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Balance Sheet:
Operating lease asset classified as premises and equipment	$ 11,810	$ 11,810
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Operating lease liability classified as other liabilities	$ 12,116	$ 12,116
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities	us-gaap:OtherLiabilities
Income Statement:
Weighted average lease term, in years	5 years 8 months 12 days	5 years 8 months 12 days
Weighted average discount rate	3.19%	3.19%
Occupancy and Equipment Expenses
Income Statement:
Operating lease cost classified as occupancy and equipment expense	$ 848	$ 2,733

LEASES - Maturity Analysis of L

LEASES - Maturity Analysis of Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Lease payments due:
Within one year	$ 2,885
After one but within two years	2,867
After two but within three years	2,608
After three but within four years	2,204
After four but within five years	1,596
After five years	3,293
Total lease payments	15,453
Total lease payments	15,453
Discount on cash flows	(3,337)
Total lease liability	$ 12,116

FAIR VALUE - Carrying Amounts a

FAIR VALUE - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 353,000	$ 337,293
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	300,619	268,947
Available for sale securities	353,000	337,293
Loans held for investment, net of allowance	3,856,196	3,681,975
Accrued interest receivable	15,201	17,010
Deposits	3,897,485	3,662,536
Accrued interest payable	4,915	2,812
Borrowed funds	159,501	225,493
Subordinated debt	107,771	48,899
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	300,619	268,947
Available for sale securities	353,000	337,293
Loans held for investment, net of allowance	3,888,672	3,674,241
Accrued interest receivable	15,201	17,010
Deposits	3,902,191	3,653,244
Accrued interest payable	4,915	2,812
Borrowed funds	159,501	230,445
Subordinated debt	107,771	49,663
Estimated Fair Value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	300,619	268,947
Available for sale securities	0	0
Loans held for investment, net of allowance	0	0
Accrued interest receivable	9	65
Deposits	0	0
Accrued interest payable	0	0
Borrowed funds	0	0
Subordinated debt	0	0
Estimated Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Available for sale securities	353,000	337,293
Loans held for investment, net of allowance	0	0
Accrued interest receivable	1,560	3,498
Deposits	3,902,191	3,653,244
Accrued interest payable	4,915	2,812
Borrowed funds	159,501	230,445
Subordinated debt	107,771	49,663
Estimated Fair Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Available for sale securities	0	0
Loans held for investment, net of allowance	3,888,672	3,674,241
Accrued interest receivable	13,632	13,447
Deposits	0	0
Accrued interest payable	0	0
Borrowed funds	0	0
Subordinated debt	$ 0	$ 0

FAIR VALUE - Fair Values for As

FAIR VALUE - Fair Values for Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 353,000	$ 337,293
U.S. Government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	30,257	8,685
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	75,816	216,785
Agency mortgage-backed pass-through securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	99,027	66,195
Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	101,674
Corporate bonds and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	46,226	45,628
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	353,000	337,293
Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	353,000	337,293
Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | U.S. Government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	30,257	8,685
Recurring Basis | U.S. Government and agency securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | U.S. Government and agency securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	30,257	8,685
Recurring Basis | U.S. Government and agency securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	75,816	216,785
Recurring Basis | Municipal securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | Municipal securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	75,816	216,785
Recurring Basis | Municipal securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | Agency mortgage-backed pass-through securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	99,027	66,195
Recurring Basis | Agency mortgage-backed pass-through securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | Agency mortgage-backed pass-through securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	99,027	66,195
Recurring Basis | Agency mortgage-backed pass-through securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	101,674
Recurring Basis | Agency collateralized mortgage obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0
Recurring Basis | Agency collateralized mortgage obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	101,674
Recurring Basis | Agency collateralized mortgage obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0
Recurring Basis | Corporate bonds and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	46,226	45,628
Recurring Basis | Corporate bonds and other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring Basis | Corporate bonds and other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	46,226	45,628
Recurring Basis | Corporate bonds and other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 0	$ 0

FAIR VALUE - Narrative (Details

FAIR VALUE - Narrative (Details)	Sep. 30, 2019USD ($)Property	Dec. 31, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired financing receivable, with related allowance, recorded investment	$ 23,345,000	$ 23,806,000
Impaired financing receivable, with related allowance, unpaid principal balance	23,740,000	24,201,000
Related allowance	6,809,000	6,729,000
Other real estate owned	$ 8,333,000	630,000
Foreclosed Commercial Real Estate Property
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of properties | Property	3
Commercial Tract of Land
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of properties | Property	1
Foreclosed Residential Rental Property
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of properties | Property	1
Residential Vacant Lot
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of properties | Property	1
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired financing receivable, with related allowance, recorded investment	$ 16,500,000	17,100,000
Impaired financing receivable, with related allowance, unpaid principal balance	23,300,000	23,800,000
Related allowance	6,800,000	6,700,000
Other real estate owned	8,300,000	630,000
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	$ 0	$ 0

FAIR VALUE - Assets and Liabili

FAIR VALUE - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Nonrecurring Basis - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	$ 0	$ 0
Assets and liabilities are measured at fair value, nonrecurring basis	0	0
Level 1 | Commercial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0	0
Level 1 | Commercial real estate (including multi-family residential)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0	0
Level 1 | Consumer and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0
Level 1 | Commercial real estate construction and land development
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	0	0
Assets and liabilities are measured at fair value, nonrecurring basis	0	0
Level 2 | Commercial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0	0
Level 2 | Commercial real estate (including multi-family residential)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0	0
Level 2 | Consumer and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0
Level 2 | Commercial real estate construction and land development
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	8,333	630
Assets and liabilities are measured at fair value, nonrecurring basis	24,869	17,707
Level 3 | Commercial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	4,096	5,252
Level 3 | Commercial real estate (including multi-family residential)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	9,513	8,901
Level 3 | Consumer and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	4
Level 3 | Commercial real estate construction and land development
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	$ 2,923	$ 2,924

DEPOSITS - Narrative (Details)

DEPOSITS - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Deposit Liabilities [Abstract]
Time deposits, at or above FDIC insurance limit	$ 250
Time deposits 250,000 or more	488,000	$ 509,300
Brokered deposits	$ 276,300	$ 235,100

DEPOSITS - Time Deposits by Mat

DEPOSITS - Time Deposits by Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Deposit Liabilities [Abstract]
Within one year	$ 244,325
After one but within two years	624,573
After two but within three years	145,761
After three but within four years	102,882
After four but within five years	97,118
Total	$ 1,214,659	$ 1,206,491

BORROWINGS AND BORROWING CAPA_2

BORROWINGS AND BORROWING CAPACITY - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 28, 2018
Revolving Credit Agreement
Debt Instrument [Line Items]
Outstanding amount	$ 34,600,000
Amended Revolving Credit Agreement
Debt Instrument [Line Items]
Debt instrument maturity, month and year	2025-12
Percentage of debt secured by capital stock	100.00%
Borrowing Agreement | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.25%
Interest rate, effective percentage	4.75%
Credit Facility With Another Financial Institution | Amended Revolving Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 45,000,000
Annual reduction in borrowing capacity		$ 7,500,000
Federal Home Loan Bank of Dallas
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,670,000,000
Remaining borrowing capacity	1,410,000,000
Outstanding amount	261,800,000
Letters of credit, outstanding amount	136,800,000
Federal Home Loan Bank of Dallas | Expire in Remaining Month of 2019
Debt Instrument [Line Items]
Letters of credit, outstanding amount	45,500,000
Federal Home Loan Bank of Dallas | Expire in 2021
Debt Instrument [Line Items]
Letters of credit, outstanding amount	2,500,000
Federal Home Loan Bank of Dallas | Expire in 2020
Debt Instrument [Line Items]
Letters of credit, outstanding amount	88,800,000
Federal Home Loan Bank of Dallas | Short-term Debt
Debt Instrument [Line Items]
Federal Home Loan Bank, advances	$ 125,000,000
Federal Home Loan Bank of Dallas | Short-term Debt | Weighted Average
Debt Instrument [Line Items]
Federal Home Loan Bank, advances, interest rate	2.54%

SUBORDINATED DEBT - Narrative (

SUBORDINATED DEBT - Narrative (Details) - USD ($)	1 Months Ended		9 Months Ended
	Sep. 30, 2019	Dec. 31, 2017	Sep. 30, 2019	Jan. 01, 2015
Subordinated Borrowing [Line Items]
Junior subordinated debt owed to trusts	$ 11,341,000		$ 11,341,000
Subordinated Notes | Fixed-to-Floating Rate Subordinated Notes
Subordinated Borrowing [Line Items]
Debt instrument, face amount	$ 60,000,000	$ 40,000,000	$ 60,000,000
Issuance price, percentage	100.00%	100.00%	100.00%
Proceeds from issuance of debt	$ 58,700,000	$ 39,400,000
Stated percentage	4.70%	5.25%	4.70%
Redemption price, percentage	100.00%	100.00%
Subordinated Notes | Fixed-to-Floating Rate Subordinated Notes | 3 month LIBOR
Subordinated Borrowing [Line Items]
Basis spread on variable rate	3.13%	3.03%
F&M Bancshares. Inc. | Junior Subordinated Debt
Subordinated Borrowing [Line Items]
Debentures, period over which company may defer interest payments			5 years
Debt instrument, face amount	$ 11,300,000		$ 11,300,000
Borrowed funds	$ 9,500,000		$ 9,500,000
Debt instrument, unamortized discount				$ 2,500,000

SUBORDINATED DEBT - Summary of

SUBORDINATED DEBT - Summary of Pertinent Information Related to Junior Subordinated Debentures (Details)	9 Months Ended
	Sep. 30, 2019USD ($)
Subordinated Borrowing [Line Items]
Junior Subordinated Debt Owed to Trusts	$ 11,341,000
Junior Subordinated Debt | 3 month LIBOR
Subordinated Borrowing [Line Items]
Interest rate, period end	2.1252%
Junior Subordinated Debt | Farmers & Merchants Capital Trust II
Subordinated Borrowing [Line Items]
Issuance Date	Nov. 13, 2003
Trust Preferred Securities Outstanding	$ 7,500,000
Junior Subordinated Debt Owed to Trusts	$ 7,732,000
Maturity Date	Nov. 8, 2033	[1]
Junior Subordinated Debt | Farmers & Merchants Capital Trust II | 3 month LIBOR
Subordinated Borrowing [Line Items]
Basis spread on variable rate	3.00%	[2]
Junior Subordinated Debt | Farmers & Merchants Capital Trust III
Subordinated Borrowing [Line Items]
Issuance Date	Jun. 30, 2005
Trust Preferred Securities Outstanding	$ 3,500,000
Junior Subordinated Debt Owed to Trusts	$ 3,609,000
Maturity Date	Jul. 7, 2035	[1]
Junior Subordinated Debt | Farmers & Merchants Capital Trust III | 3 month LIBOR
Subordinated Borrowing [Line Items]
Basis spread on variable rate	1.80%	[2]
[1]	All debentures are currently callable.
[2]	The 3-month LIBOR in effect as of September 30, 2019 was 2.1252%.

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income tax expense	$ 3,073,000	$ 1,921,000	$ 9,851,000	$ 4,949,000
Effective income tax rate reconciliation, percent	20.30%	17.80%	20.20%	17.00%
Unrecognized tax benefits, income tax penalties and interest expense	$ 0		$ 0

STOCK BASED COMPENSATION - Narr

STOCK BASED COMPENSATION - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	3,200,000		3,200,000
Share-based compensation expense	$ 789	$ 380	$ 2,300	$ 1,200
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	1,800,000		1,800,000
Option, cumulative options granted since inception (in shares)	1,309,231		1,309,231
Expiration period			10 years
Award vesting period			4 years
Unrecognized compensation cost	$ 509		$ 509
Weighted average period over which unrecognized compensation			11 months 26 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Unrecognized compensation cost	$ 6,700		$ 6,700
Weighted average period over which unrecognized compensation			3 years 2 months 19 days
Equity instruments other than options, grants in period (in shares)			84,522

STOCK BASED COMPENSATION - Stoc

STOCK BASED COMPENSATION - Stock Option Plans Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Number of Options
Options outstanding, beginning balance (in shares)	802
Options exercised (in shares)	(98)
Options forfeited (in shares)	(4)
Options outstanding, ending balance (in shares)	700	802
Number of options vested and exercisable (in shares)	646
Weighted Average Exercise Price
Options outstanding, beginning balance (in dollars per share)	$ 18.88
Options exercised (in dollars per share)	15.89
Options forfeited (in dollars per share)	27.85
Options outstanding, ending balance (in dollars per share)	19.25	$ 18.88
Weighted Average Exercise Price, Options vested and exercisable (in dollars per share)	$ 18.28
Weighted Average Remaining Contractual Term, Options outstanding	3 years 11 months 23 days	4 years 7 months 9 days
Weighted Average Remaining Contractual Term, Options vested and exercisable	3 years 8 months 15 days
Aggregate Intrinsic Value, Options outstanding	$ 8,983	$ 10,830
Aggregate Intrinsic Value, Options vested and exercisable	$ 8,924

STOCK BASED COMPENSATION - Summ

STOCK BASED COMPENSATION - Summary of Restricted Stock Activity (Details) - Restricted Stock shares in Thousands	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Number of Shares
Nonvested share awards outstanding, beginning balance (in shares) | shares	143
Share awards granted (in shares) | shares	85
Share awards vested (in shares) | shares	(17)
Unvested share awards forfeited or cancelled (in shares) | shares	(19)
Nonvested share awards outstanding, ending balance (in shares) | shares	192
Weighted Average Grant Date Fair Value
Nonvested share awards outstanding, beginning balance (in dollars per share) | $ / shares	$ 37.48
Share awards granted (in dollars per share) | $ / shares	34.95
Share awards vested (in dollars per share) | $ / shares	33.75
Unvested share awards forfeited or cancelled (in dollars per share) | $ / shares	38.50
Nonvested share awards outstanding, ending balance | $ / shares	$ 36.44

OFF-BALANCE SHEET ARRANGEMENT_3

OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES - Contractual Amounts of Financial Instruments With Off-balance Sheet Risk (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	$ 531,160	$ 485,657
Variable Rate	560,676	539,613
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	517,669	471,440
Variable Rate	556,833	530,546
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	13,491	14,217
Variable Rate	$ 3,843	$ 9,067

OFF-BALANCE SHEET ARRANGEMENT_4

OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES - Narrative (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to make loans, period	120 days
Off-balance-sheet fixed rate loan commitments, weighted average maturity	3 years 2 months 26 days	2 years 11 months 8 days
Minimum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet fixed rate loan commitments, interest rate	1.95%	1.95%
Maximum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet fixed rate loan commitments, interest rate	8.70%	8.70%
Weighted Average
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet fixed rate loan commitments, interest rate	5.22%	5.26%

REGULATORY CAPITAL MATTERS - Na

REGULATORY CAPITAL MATTERS - Narrative (Details)	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2016
Banking And Thrift [Abstract]
Capital conservation buffer, phase in amount			0.625%
Capital conservation buffer, increase per year	0.625%
Capital conservation buffer		2.50%

REGULATORY CAPITAL MATTERS - Ac

REGULATORY CAPITAL MATTERS - Actual and Required Capital (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Total Capital
Capital	$ 590,698	$ 531,453
Capital to Risk Weighted Assets	14.70%	13.70%
Capital Required for Capital Adequacy	$ 321,431	$ 310,295
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Plus Capital Conservation Buffer	$ 421,878	$ 383,020
Plus Capital Conservation Buffer to Risk Weighted Assets	10.50%	9.875%
Common Equity Tier 1 Capital
Common Equity Tier 1 Risk Based Capital	$ 453,119	$ 456,223
Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	11.28%	11.76%
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy	$ 180,805	$ 174,541
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Plus Common Equity Tier 1 Risk Based Capital	$ 281,252	$ 247,266
Plus Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	7.00%	6.375%
Tier 1 Capital
Tier 1 Risk Based Capital	$ 462,616	$ 465,637
Tier 1 Risk Based Capital to Risk Weighted Assets	11.51%	12.01%
Tier 1 Risk Based Capital Required for Capital Adequacy	$ 241,073	$ 232,721
Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Plus Tier 1 Risk Based Capital	$ 341,520	$ 305,446
Plus Tier 1 Risk Based Capital to Risk Weighted Assets	8.50%	7.875%
Tier 1 Capital
Tier 1 Leverage Capital	$ 462,616	$ 465,637
Tier 1 Leverage Capital to Average Assets	10.06%	10.61%
Tier 1 Leverage Capital Required for Capital Adequacy	$ 184,030	$ 175,621
Tier 1 Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Plus Tier 1 Leverage Capital	$ 184,030	$ 175,621
Plus Tier 1 Leverage Capital to Average Assets	4.00%	4.00%
Allegiance Bank
Total Capital
Capital	$ 562,604	$ 524,660
Capital to Risk Weighted Assets	14.01%	13.53%
Capital Required for Capital Adequacy	$ 321,287	$ 310,179
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Plus Capital Conservation Buffer	$ 421,689	$ 382,877
Plus Capital Conservation Buffer to Risk Weighted Assets	10.50%	9.875%
Capital Required to be Well Capitalized	$ 401,609	$ 387,724
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Common Equity Tier 1 Capital
Common Equity Tier 1 Risk Based Capital	$ 493,213	$ 458,844
Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	12.28%	11.83%
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy	$ 180,724	$ 174,476
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Plus Common Equity Tier 1 Risk Based Capital	$ 281,126	$ 247,174
Plus Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	7.00%	6.375%
Common Equity Tier 1 Risk Based Capital Required to be Well Capitalized	$ 261,046	$ 252,021
Common Equity Tier 1 Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Tier 1 Capital
Tier 1 Risk Based Capital	$ 493,213	$ 458,844
Tier 1 Risk Based Capital to Risk Weighted Assets	12.28%	11.83%
Tier 1 Risk Based Capital Required for Capital Adequacy	$ 240,965	$ 232,634
Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Plus Tier 1 Risk Based Capital	$ 341,368	$ 305,333
Plus Tier 1 Risk Based Capital to Risk Weighted Assets	8.50%	7.875%
Tier 1 Risk Based Capital Required to be Well Capitalized	$ 321,287	$ 310,179
Tier 1 Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	8.00%
Tier 1 Capital
Tier 1 Leverage Capital	$ 493,213	$ 458,844
Tier 1 Leverage Capital to Average Assets	10.73%	10.45%
Tier 1 Leverage Capital Required for Capital Adequacy	$ 183,922	$ 175,552
Tier 1 Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Plus Tier 1 Leverage Capital	$ 183,922	$ 175,552
Plus Tier 1 Leverage Capital to Average Assets	4.00%	4.00%
Tier 1 Leverage Capital Required to be Well Capitalized	$ 229,903	$ 219,440
Tier 1 Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%

EARNINGS PER COMMON SHARE - Sum

EARNINGS PER COMMON SHARE - Summary of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income attributable to shareholders	$ 12,047	$ 8,879	$ 38,973	$ 24,146
Basic:
Weighted average shares outstanding (in shares)	20,981	13,371	21,321	13,320
Weighted average shares outstanding (in dollars per share)	$ 0.57	$ 0.66	$ 1.83	$ 1.81
Diluted:
Dilutive effect of stock option exercises (in shares)	275	266	270	285
Total (in shares)	21,256	13,637	21,591	13,605
Total (in dollars per share)	$ 0.57	$ 0.65	$ 1.81	$ 1.77

EARNINGS PER COMMON SHARE - Nar

EARNINGS PER COMMON SHARE - Narrative (Details) - shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	51,875	0