Allegiance Bancshares (ABTX) 10-Q 31 Jul 20 2020 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 28, 2020
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	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
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)		20,431,612
Document Quarterly Report	true
Document Transition Report	false

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
ASSETS
Cash and due from banks	$ 237,585	$ 213,347
Interest-bearing deposits at other financial institutions	28,815	132,901
Total cash and cash equivalents	266,400	346,248
Available for sale securities, at fair value	618,751	372,545
Loans held for investment	4,583,656	3,915,310
Less: allowance for loan losses	(47,642)	(29,438)
Loans, net	4,536,014	3,885,872
Accrued interest receivable	32,795	15,468
Premises and equipment, net	67,229	66,790
Other real estate owned	11,847	8,337
Federal Home Loan Bank stock	14,844	6,242
Bank owned life insurance	27,398	27,104
Goodwill	223,642	223,642
Core deposit intangibles, net	19,896	21,876
Other assets	18,065	18,530
TOTAL ASSETS	5,836,881	4,992,654
Deposits:
Noninterest-bearing	1,754,128	1,252,232
Interest-bearing
Demand	375,353	367,278
Money market and savings	1,270,437	1,258,008
Certificates and other time	1,300,793	1,190,583
Total interest-bearing deposits	2,946,583	2,815,869
Total deposits	4,700,711	4,068,101
Accrued interest payable	3,293	4,326
Borrowed funds	255,509	75,503
Subordinated debt	108,061	107,799
Other liabilities	33,164	27,060
Total liabilities	5,100,738	4,282,789
COMMITMENTS AND CONTINGENCIES (See Note 14)
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; 20,430,836 shares issued and outstanding at June 30, 2020 and 20,523,816 shares issued and outstanding at December 31, 2019	20,431	20,524
Capital surplus	515,045	521,066
Retained earnings	172,723	163,375
Accumulated other comprehensive income	27,944	4,900
Total shareholders’ equity	736,143	709,865
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 5,836,881	$ 4,992,654

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
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)	20,430,836	20,523,816
Common stock, shares outstanding (in shares)	20,430,836	20,523,816

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
INTEREST INCOME:
Loans, including fees	$ 56,421	$ 56,016	$ 111,045	$ 110,205
Securities:
Taxable	1,842	1,837	3,929	2,819
Tax-exempt	2,169	692	2,715	1,982
Deposits in other financial institutions	20	401	215	1,089
Total interest income	60,452	58,946	117,904	116,095
INTEREST EXPENSE:
Demand, money market and savings deposits	1,729	4,513	6,093	8,241
Certificates and other time deposits	5,845	7,008	11,929	13,264
Borrowed funds	562	1,118	1,068	2,945
Subordinated debt	1,469	736	2,942	1,471
Total interest expense	9,605	13,375	22,032	25,921
NET INTEREST INCOME	50,847	45,571	95,872	90,174
Provision for loan losses	10,669	1,407	21,659	2,409
Net interest income after provision for loan losses	40,178	44,164	74,213	87,765
NONINTEREST INCOME:
Gain on sale of securities	93	846	287	846
(Loss) gain on sale of other real estate and other repossessed assets	(306)	70	(375)	71
Bank owned life insurance income	143	155	294	314
Rebate from correspondent bank	89	884	582	1,780
Other	1,140	1,386	2,470	3,132
Total noninterest income	1,562	3,845	4,287	7,134
NONINTEREST EXPENSE:
Salaries and employee benefits	19,334	19,415	39,115	39,099
Net occupancy and equipment	1,926	2,114	3,833	4,166
Depreciation	885	756	1,751	1,509
Data processing and software amortization	1,934	1,709	3,760	3,332
Professional fees	800	527	1,373	1,126
Regulatory assessments and FDIC insurance	609	802	1,241	1,530
Core deposit intangibles amortization	990	1,178	1,980	2,356
Communications	390	468	807	898
Advertising	370	617	891	1,321
Acquisition and merger-related expenses		153		1,326
Other	2,541	2,341	7,429	4,532
Total noninterest expense	29,779	30,080	62,180	61,195
INCOME BEFORE INCOME TAXES	11,961	17,929	16,320	33,704
Provision for income taxes	2,054	3,681	2,897	6,778
NET INCOME	$ 9,907	$ 14,248	$ 13,423	$ 26,926
EARNINGS PER SHARE:
Basic	$ 0.49	$ 0.67	$ 0.66	$ 1.25
Diluted	0.48	$ 0.66	0.65	$ 1.24
DIVIDENDS PER SHARE:	$ 0.10		$ 0.20
Deposit Account, Nonsufficient Funds Fee
NONINTEREST INCOME:
Revenue from contract with customer	$ 60	$ 139	$ 229	$ 301
Deposit Account, Service Charge Fee
NONINTEREST INCOME:
Revenue from contract with customer	$ 343	$ 365	$ 800	$ 690

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 9,907	$ 14,248	$ 13,423	$ 26,926
Unrealized gain on securities:
Change in unrealized holding gain on available for sale securities during the period, net of tax	21,776	1,886	24,516	7,789
Reclassification of gain realized through the sale of securities, net of tax	(73)	(668)	(227)	(668)
Change in fair value of cash flow hedge, net of tax	(1,245)		(1,245)
Total other comprehensive income, net of tax	20,458	1,218	23,044	7,121
Comprehensive income	$ 30,365	$ 15,466	$ 36,467	$ 34,047

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, 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 (See Note 1) at Dec. 31, 2018	701,269	21,938	571,803	110,416	(2,888)
Net income	26,926			26,926
Other comprehensive income	7,121				7,121
Common stock issued in connection with the exercise of stock options and restricted stock awards	$ 1,066	139	927
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)	140,050
Repurchase of common stock	$ (33,169)	(930)	(32,239)
Repurchase of common stock (in shares)	(930,611)
Stock based compensation expense	$ 1,488		1,488
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
Balance at Mar. 31, 2019	$ 703,777	21,484	556,184	123,094	3,015
Balance (in shares) at Mar. 31, 2019	21,483,972
Net income	$ 14,248			14,248
Other comprehensive income	1,218				1,218
Common stock issued in connection with the exercise of stock options and restricted stock awards	$ 401	107	294
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)	107,403
Repurchase of common stock	$ (15,825)	(444)	(15,381)
Repurchase of common stock (in shares)	(444,196)
Stock based compensation expense	$ 882		882
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
Balance at Dec. 31, 2019	$ 709,865	20,524	521,066	163,375	4,900
Balance (in shares) at Dec. 31, 2019	20,523,816
Net income	$ 13,423			13,423
Other comprehensive income	23,044				23,044
Cash dividends declared	(4,075)			(4,075)
Common stock issued in connection with the exercise of stock options and restricted stock awards	$ 1,470	151	1,319
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)	151,354
Repurchase of common stock	$ (9,302)	(244)	(9,058)
Repurchase of common stock (in shares)	(244,334)
Stock based compensation expense	$ 1,718		1,718
Balance at Jun. 30, 2020	$ 736,143	20,431	515,045	172,723	27,944
Balance (in shares) at Jun. 30, 2020	20,430,836
Balance at Mar. 31, 2020	$ 706,593	20,355	513,894	164,858	7,486
Balance (in shares) at Mar. 31, 2020	20,355,120
Net income	$ 9,907			9,907
Other comprehensive income	20,458				20,458
Cash dividends declared	(2,042)			(2,042)
Common stock issued in connection with the exercise of stock options and restricted stock awards	$ 313	76	237
Common stock issued in connection with the exercise of stock options and restricted stock awards (in shares)	75,716
Stock based compensation expense	$ 914		914
Balance at Jun. 30, 2020	$ 736,143	$ 20,431	$ 515,045	$ 172,723	$ 27,944
Balance (in shares) at Jun. 30, 2020	20,430,836

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) (Parentheticals) - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Retained Earnings
Per share amount of cash dividends declared	$ 0.10	$ 0.10

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 13,423	$ 26,926
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and core deposit intangibles amortization	3,731	3,864
Provision for loan losses	21,659	2,409
Deferred income tax (benefit) expense	(4,663)	72
Net amortization of premium on investments	1,410	1,514
Excess tax benefit from stock based compensation	(62)	(36)
Bank owned life insurance income	(294)	(314)
Net accretion of discount on loans	(1,715)	(5,220)
Net amortization of discount on subordinated debt	56	55
Net accretion of discount on certificates of deposit	(213)	(287)
Loss (gain) on sale or write-downs of other real estate and other repossessed assets	2,589	(71)
Net gain on sale of securities	(287)	(846)
Federal Home Loan Bank stock dividends	(122)	(232)
Stock based compensation expense	1,718	1,488
Net change in operating leases	1,277	542
(Increase) decrease in accrued interest receivable and other assets	(16,862)	1,633
Increase in accrued interest payable and other liabilities	1,488	2,281
Net cash provided by operating activities	23,133	33,778
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities and principal paydowns of available for sale securities	1,929,713	1,488,427
Proceeds from sales of available for sale securities	30,790	149,366
Purchase of available for sale securities	(2,176,800)	(1,642,051)
Net change in total loans	(678,974)	(106,279)
Purchase of bank premises and equipment	(2,935)	(1,065)
Proceeds from sale of bank premises, equipment and other real estate	2,789
Net (purchases) redemptions of Federal Home Loan Bank stock	(8,480)	2,307
Net cash paid for the LoweryBank branch acquisition		(32,867)
Net cash used in investing activities	(903,897)	(142,162)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in noninterest-bearing deposits	501,896	(49,757)
Net increase in interest-bearing deposits	130,927	232,399
Net change in other borrowed funds	165,000	(78,495)
Net increase in borrowings under credit agreement	15,000
Dividends paid to common shareholders	(4,075)
Proceeds from the issuance of common stock, stock option exercises and the ESPP	1,470	1,066
Repurchase of common stock	(9,302)	(33,169)
Net cash provided by financing activities	800,916	72,044
NET CHANGE IN CASH AND CASH EQUIVALENTS	(79,848)	(36,340)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	346,248	268,947
CASH AND CASH EQUIVALENTS, END OF PERIOD	266,400	232,607
SUPPLEMENTAL CASH FLOW INFORMATION:
Income taxes paid		4,100
Interest paid	23,065	25,202
Cash paid for operating lease liabilities	1,603	1,860
SUPPLEMENTAL NONCASH DISCLOSURE:
Lease right-of-use asset obtained in exchange for lessee operating lease liabilities	532	15,266
Loans transferred to other real estate	3,510	$ 5,664
Other real estate transferred to loans	$ 1,615

NATURE OF OPERATIONS AND SUMMAR

NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020. 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, 2019. Operating results for the three and six months ended June 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020. Impact of COVID-19 The coronavirus (COVID-19) pandemic has negatively impacted the global economy, disrupted global supply chains and increased unemployment levels. The resulting temporary closure of many businesses and the implementation of social distancing and sheltering-in-place policies has and may continue to impact many of the Company’s customers. While the full effects of the pandemic remain unknown, the Company is committed to supporting its customers, employees and communities during this difficult time. The Company has given hardship relief assistance to customers, including the consideration of various loan payment deferral and fee waiver options, and encourages customers to reach out for assistance to support their individual circumstances. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was signed by the President of the United States. Certain provisions within the CARES Act encourage financial institutions to practice prudent efforts to work with borrowers impacted by COVID-19. Under these provisions, modifications deemed to be COVID-19-related would not be considered a troubled debt restructuring (“TDR”) if the loan was not more than 30 days past due as of December 31, 2019 and the deferral was executed between March 1, 2020 and the earlier of 60 days after the date of termination of the COVID-19 national emergency or December 31, 2020. The banking regulators issued similar guidance, which also clarified that a COVID-19-related modification should not be considered a TDR if the borrower was current on payments at the time the underlying loan modification program was implemented and if the modification is considered to be short-term. For loans subject to the deferral program, each borrower is required to begin making their regularly scheduled loan payment at the end of the deferral period and the deferred amounts were generally moved to the end of the loan. Under these terms, as of June 30, 2020, the Company had processed first payment deferrals for 2,111 loans with an aggregate loan balance of $1.19 billion with associated accrued interest of $16.4 million. Additionally, upon request and after meeting certain conditions, borrowers could be granted a second payment deferral subsequent to the first deferral. The Company processed second payment deferrals for 129 loans with outstanding loan balances of $100.1 million with associated accrued interest of $1.4 million, through July 24, 2020, with substantially all considered performing at the time of deferrals. These deferrals were generally no more than 90 days in duration Additionally, the Bank is a lender for the Small Business Administration's (“SBA”) Paycheck Protection Program ("PPP") , a program under the CARES Act, and other SBA, Federal Reserve or United States Treasury programs that have been created in response to the pandemic and may be a lender for programs created in the future . These programs are new and their effects on the Company ’s business are uncertain. As of June 30 , 2020, the Company had funded over 5,800 PPP loans totaling in excess of $ million under the allocation a pproved by Congress . The Company identified several loan portfolio categories that it considered to be most “at-risk” from the COVID-19 pandemic, such as, oil and gas, hotel, and restaurants and bars with outstanding loan balances, excluding PPP loans, of $74.7 million, $134.0 million and $111.3 million at June 30, 2020, respectively. The Company’s exposure to the oil and gas industry is minimal as it does not participate in exploration and production or reserve-based lending; however, this industry is vital to the Houston region and the indirect effects could be significant. The Company considers these “at-risk” portfolios to be the most vulnerable to financial difficulties and risks from business disruptions caused by the pandemic spread mitigation efforts. Due to the uncertainty in the economy and potential impacts from unemployment as a result of COVID-19 and the volatility of crude oil prices, the impact could extend to the Company’s securities portfolio, income taxes, other real estate owned and goodwill and intangibles among other items, although the impact is dependent on future events which are highly uncertain and cannot be predicted at this time. Due to the COVID-19 pandemic, the Company initiated a re-evaluation of the accuracy of loan grades assigned to its commercial loan portfolio during the second quarter of 2020, the results of which are reflected in the financial statement disclosures for this quarter. Effects as a result of the pandemic may continue, potentially resulting in additional loans being identified. In a period of economic contraction, additional loan losses and lost interest income may occur, either in the industries previously noted or others to which the Company has exposure. The Company continues to accrue interest on loans modified under the new accounting standards. To the extent those borrowers are unable to resume normal contractual payments, the Company could experience additional losses of principal and interest. 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, 2019. Derivative Instruments — In accordance with ASC Topic 815, “Derivatives and Hedging”, derivative instruments are recorded on the accompanying consolidated balance sheet at their respective fair values. The accounting for changes in fair value (i.e., gains or losses) of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship. If the derivative instrument is not designated as a hedge, changes in the fair value of the derivative instrument are recognized in earnings in the period of change. The derivative is carried on the balance sheet in other liabilities. This derivative contract has been designated as a hedge and, as such, changes in the fair value of the derivative instrument are recorded in other comprehensive income. The Company prepared written hedge documentation for the derivative that is designated as a hedge. The written hedge documentation includes identification of, among other items, the risk management objective, hedging instrument, hedged item and methodologies for assessing and measuring hedge effectiveness and ineffectiveness, along with support for management's assertion that the hedge will be effective. For the designated hedging relationship, the Company performs retrospective and prospective effectiveness testing using quantitative methods where required by accounting standards. For the hedging relationship, effectiveness is tested through the matching of critical terms. Assessments of hedge effectiveness and measurements of hedge ineffectiveness are performed at least quarterly. The portion of the changes in the fair value of a derivative that is effective and that has been designated and qualifies as a cash flow hedge is initially recorded in accumulated other comprehensive income and will be reclassified to earnings in the same period that the hedged item impacts earnings; any ineffective portion is recorded in current period earnings. The derivative is carried at fair value based on the Company’s pricing model that utilizes observable market inputs and is reflected within Level 2 of the valuation hierarchy. New Accounting Standards Adoption of New Accounting Standards ASC 310-40, “Receivables – Troubled Debt Restructurings by Creditors,” (“ASC 310-40”), a restructuring of debt constitutes a troubled debt restructuring (“TDR”) if the creditor, for economic or legal reasons related to the debtor’s financial difficulties, grants a concession to the debtor that it would not otherwise consider. In response to COVID-19, new GAAP guidance was issued whereby, subject to certain restrictions, loan modifications may not be subject to classification as TDRs. Upon request and after meeting certain conditions, borrowers could be granted a second payment deferral subsequent to the first deferral. As of June 30, 2020, the Company granted first payment deferrals on 2,111 loans with an aggregate loan balance of $ 1.19 billion and second deferrals on loans with outstanding loan balance s of $ 39.9 million to qualified borrowers . ASU 2018-13, “Fair Value Measurement (Topic 820). – Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement.” ASU 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820. The amendments in ASU 2018-13 remove disclosures that no longer are considered cost beneficial, modify/clarify the specific requirements of certain disclosures and add disclosure requirements identified as relevant. ASU 2018-13 became effective for the Company on January 1, 2020 and did not have a significant impact on the Company’s financial statements. A SU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” 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 (“CECL”) 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, CECL amends the accounting for credit losses on available for sale debt securities and purchased financial assets with credit deterioration. CECL became effective for the Company on January 1, 2020 using the modified retrospective approach; however, the CARES Act, signed by the President of the United States on March 27, 2020 includes an option for entities to delay the implementation of ASU 2016-13 until the earlier of the termination date of the national emergency declaration by the President or December 31, 2020. The Company expects to adopt CECL as of January 1, 2020 after the deferral period ends. Due to the uncertainty of the impact of COVID-19 and the volatility of crude oil prices, which can be impactful to the Houston market, the Company has delayed its implementation of CECL and has calculated and recorded its provision for loan losses under the incurred loss model that existed prior to ASU 2016-13. The Company will continue to perform and enhance CECL model operations parallel with the incurred loss model throughout 2020, or until adoption. ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” to simplify various aspects of the current guidance to promote consistent application of the standard among reporting entities by moving certain exceptions to the general principles. The amendment is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. ASU 2019-12 will be become effective for the Company on January 1, 2021 and is not expected to have a significant impact on the Company’s financial statements.

ACQUISITIONS

ACQUISITIONS	6 Months Ended
	Jun. 30, 2020
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 acquisition s were completed on the date s 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. 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 $1.7 million and $1.3 million of pre-tax acquisition and merger-related expenses reflected on the Company’s income statement during the years ended December 31, 2018 and 2019, respectively, 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	6 Months Ended
	Jun. 30, 2020
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, 2018 $ 223,125 $ 26,587 Acquisition of LoweryBank branch 578 — Measurement period adjustment (61 ) — Amortization — (4,711 ) Balance as of December 31, 2019 223,642 21,876 Amortization — (1,980 ) Balance as of June 30, 2020 $ 223,642 $ 19,896 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. The Company performs its annual evaluation of goodwill impairment in the fourth quarter of each year and on an interim basis if events or changes in circumstances between annual tests suggest additional testing may be warranted to determine if goodwill might be impaired. As of June 30, 2020, the Company performed a qualitative analysis taking into account the effect that the COVID-19 pandemic continues to have on the economy and determined that goodwill was not impaired. The estimated aggregate future amortization expense for core deposit intangible assets remaining as of June 30, 2020 is as follows (dollars in thousands): Remaining 2020 $ 1,942 2021 3,296 2022 3,003 2023 2,323 2024 2,188 Thereafter 7,144 Total $ 19,896

SECURITIES

SECURITIES	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
SECURITIES	4. SECURITIES The amortized cost and fair value of investment securities were as follows: June 30, 2020 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (Dollars in thousands) Available for Sale U.S. government and agency securities $ 27,308 $ 694 $ — $ 28,002 Municipal securities 317,769 28,268 — 346,037 Agency mortgage-backed pass-through securities 95,385 3,984 — 99,369 Agency collateralized mortgage obligations 97,618 3,994 (126 ) 101,486 Corporate bonds and other 43,712 217 (72 ) 43,857 Total $ 581,792 $ 37,157 $ (198 ) $ 618,751 December 31, 2019 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (Dollars in thousands) Available for Sale U.S. government and agency securities $ 29,420 $ 298 $ (243 ) $ 29,475 Municipal securities 84,200 3,453 (116 ) 87,537 Agency mortgage-backed pass-through securities 104,669 1,713 (214 ) 106,168 Agency collateralized mortgage obligations 106,351 1,199 (208 ) 107,342 Corporate bonds and other 41,691 346 (14 ) 42,023 Total $ 366,331 $ 7,009 $ (795 ) $ 372,545 As of June 30, 2020, 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 June 3 0 , 20 20 , management b elieved 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 June 30, 2020, 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 $ 11,002 $ 11,038 Due after one year through five years 8,503 9,009 Due after five years through ten years 83,999 87,239 Due after ten years 285,285 310,610 Subtotal 388,789 417,896 Agency mortgage-backed pass through and collateralized mortgage obligation securities 193,003 200,855 Total $ 581,792 $ 618,751 Securities with unrealized losses segregated by length of time such securities have been in a continuous loss position are as follows: June 30, 2020 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 Agency collateralized mortgage obligations $ 24,895 $ (85 ) $ 4,499 $ (41 ) $ 29,394 $ (126 ) Corporate bonds and other 4,427 (72 ) — — 4,427 (72 ) Total $ 29,322 $ (157 ) $ 4,499 $ (41 ) $ 33,821 $ (198 ) December 31, 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 $ 22,295 $ (239 ) $ 436 $ (4 ) $ 22,731 $ (243 ) Agency mortgage-backed pass-through securities 20,792 (155 ) 4,369 (59 ) 25,161 (214 ) Agency collateralized mortgage obligations 22,340 (208 ) — — 22,340 (208 ) Municipal securities 9,514 (116 ) — — 9,514 (116 ) Corporate bonds and other 5,492 (14 ) — — 5,492 (14 ) Total $ 80,433 $ (732 ) $ 4,805 $ (63 ) $ 85,238 $ (795 ) The Company sold $1.1 million and had calls of $5.5 million of securities recording gross gains of $93 thousand during the three months ended June 30, 2020 and sold $30.8 million and had calls of $5.5 million of securities recording gross gains of $391 thousand and gross losses of $104 thousand for a net gain of $287 thousand for the six months ended June 30, 2020. The Company sold $149.4 million of securities and recorded gross gains of $1.4 million and gross losses of $576 thousand for a net gain of $846 thousand during the three and six months ended June 30, 2019. At June 30, 2020 and December 31, 2019, 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 $22.4 million at June 30, 2020 and $24.3 million at December 31, 2019, 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	6 Months Ended
	Jun. 30, 2020
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: June 30, December 31, 2020 2019 (Dollars in thousands) Commercial and industrial $ 651,430 $ 689,360 Mortgage warehouse — 8,304 Paycheck Protection Program (PPP) 695,772 — Real estate: Commercial real estate (including multi-family residential) 1,956,116 1,873,782 Commercial real estate construction and land development 386,865 410,471 1-4 family residential (including home equity) 703,513 698,957 Residential construction 171,656 192,515 Consumer and other 18,304 41,921 Total loans 4,583,656 3,915,310 Allowance for loan losses (47,642 ) (29,438 ) Loans, net $ 4,536,014 $ 3,885,872 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 June 30, 2020 and December 31, 2019 are presented in the table below: As of June 30, 2020 As of December 31, 2019 (Dollars in thousands) Outstanding balance $ 15,687 $ 16,589 Less: Discount (2,211 ) (2,414 ) Less: Allowance (1,432 ) (259 ) Recorded investment $ 12,044 $ 13,916 Acquired loans were recorded through acquisition accounting without an allowance. There was an allocation of $1.4 million in the allowance for loan losses relating to PCI loans at June 30, 2020. Changes in the accretable yield for PCI loans for the three and six months ended June 30, 2020 and 2019 were deemed immaterial. Nonaccrual and Past Due Loans An aging analysis of the recorded investment, defined as the unpaid principal balance, in past due loans, segregated by class of loans, is as follows: June 30, 2020 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 $ 6,129 $ — $ 6,129 $ 12,578 $ 632,723 $ 651,430 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) — — — — 695,772 695,772 Real estate: Commercial real estate (including multi-family residential) 5,594 — 5,594 16,127 1,934,395 1,956,116 Commercial real estate construction and land development 2,310 — 2,310 53 384,502 386,865 1-4 family residential (including home equity) 1,825 — 1,825 3,434 698,254 703,513 Residential construction 191 — 191 898 170,567 171,656 Consumer and other 277 — 277 133 17,894 18,304 Total loans $ 16,326 $ — $ 16,326 $ 33,223 $ 4,534,107 $ 4,583,656 December 31, 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 $ 3,098 $ — $ 3,098 $ 8,388 $ 677,874 $ 689,360 Mortgage warehouse — — — — 8,304 8,304 Real estate: Commercial real estate (including multi-family residential) 4,421 — 4,421 6,741 1,862,620 1,873,782 Commercial real estate construction and land development 66 — 66 9,050 401,355 410,471 1-4 family residential (including home equity) 1,598 — 1,598 3,294 694,065 698,957 Residential construction 564 — 564 746 191,205 192,515 Consumer and other 254 — 254 152 41,515 41,921 Total loans $ 10,001 $ — $ 10,001 $ 28,371 $ 3,876,938 $ 3,915,310 Impaired Loans Impaired loans by class of loans are set forth in the following tables. As of June 30, 2020 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 5,986 $ 6,126 $ — Mortgage warehouse — — — Paycheck Protection Program (PPP) — — — Real estate: Commercial real estate (including multi-family residential) 20,833 20,914 — Commercial real estate construction and land development 53 53 — 1-4 family residential (including home equity) 1,353 1,353 — Residential construction — — — Consumer and other 27 27 — Total 28,252 28,473 — With an allowance recorded: Commercial and industrial 10,691 11,086 4,435 Mortgage warehouse — — — Paycheck Protection Program (PPP) — — — Real estate: Commercial real estate (including multi-family residential) 5,810 5,810 381 Commercial real estate construction and land development 3,367 3,367 221 1-4 family residential (including home equity) 1,156 1,262 78 Residential construction 898 898 53 Consumer and other 25 25 25 Total 21,947 22,448 5,193 Total: Commercial and industrial 16,677 17,212 4,435 Mortgage warehouse — — — Paycheck Protection Program (PPP) — — — Real estate: Commercial real estate (including multi-family residential) 26,643 26,724 381 Commercial real estate construction and land development 3,420 3,420 221 1-4 family residential (including home equity) 2,509 2,615 78 Residential construction 898 898 53 Consumer and other 52 52 25 $ 50,199 $ 50,921 $ 5,193 As of December 31, 2019 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 5,721 $ 6,136 $ — Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 19,478 19,558 — Commercial real estate construction and land development — — — 1-4 family residential (including home equity) 2,000 2,000 — Residential construction 208 208 — Consumer and other 38 38 — Total 27,445 27,940 — With an allowance recorded: Commercial and industrial 7,812 7,286 3,480 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 5,335 5,335 459 Commercial real estate construction and land development 12,142 12,142 2,085 1-4 family residential (including home equity) — — — Residential construction 537 537 66 Consumer and other 26 26 26 PCI 2,039 2,959 659 Total 27,891 28,285 6,775 Total: Commercial and industrial 13,533 13,422 3,480 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 24,813 24,893 459 Commercial real estate construction and land development 12,142 12,142 2,085 1-4 family residential (including home equity) 2,000 2,000 — Residential construction 745 745 66 Consumer and other 64 64 26 PCI 2,039 2,959 659 $ 55,336 $ 56,225 $ 6,775 The following table presents average impaired loans and interest recognized on impaired loans for the three and six months ended June 30, 2020 and 2019: Three Months Ended June 30, 2020 2019 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 16,997 $ 62 $ 12,280 $ 75 Mortgage warehouse — — — — Paycheck Protection Program (PPP) — — — — Real estate: Commercial real estate (including multi-family residential) 26,710 74 19,589 98 Commercial real estate construction and land development 3,436 50 4,661 57 1-4 family residential (including home equity) 2,529 3 1,293 — Residential construction 940 — — — Consumer and other 55 1 37 — Total $ 50,667 $ 190 $ 37,860 $ 230 Six Months Ended June 30, 2020 2019 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 17,302 $ 164 $ 12,575 $ 167 Mortgage warehouse — — — — Paycheck Protection Program (PPP) — — — — Real estate: Commercial real estate (including multi-family residential) 26,825 307 19,781 193 Commercial real estate construction and land development 3,289 97 4,664 88 1-4 family residential (including home equity) 2,547 6 1,310 4 Residential construction 822 — — — Consumer and other 56 1 38 — Total $ 50,841 $ 575 $ 38,368 $ 452 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 loan 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 their recorded investment at June 30, 2020 is as follows: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 582,937 $ 27,633 $ 11,877 $ 28,830 $ 153 $ 651,430 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) 695,772 — — — — 695,772 Real estate: Commercial real estate (including multi-family residential) 1,745,562 143,848 26,487 40,219 — 1,956,116 Commercial real estate construction and land development 368,788 15,488 — 2,589 — 386,865 1-4 family residential (including home equity) 662,551 27,384 5,668 7,910 — 703,513 Residential construction 168,087 2,671 — 898 — 171,656 Consumer and other 17,676 170 277 181 — 18,304 Total loans $ 4,241,373 $ 217,194 $ 44,309 $ 80,627 $ 153 $ 4,583,656 The following table presents the risk category of loans by class of loan at December 31, 2019: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 641,696 $ 14,170 $ 9,121 $ 24,295 $ 78 $ 689,360 Mortgage warehouse 8,304 — — — — 8,304 Real estate: Commercial real estate (including multi-family residential) 1,775,789 47,762 9,289 40,942 — 1,873,782 Commercial real estate construction and land development 388,151 9,583 639 12,098 — 410,471 1-4 family residential (including home equity) 669,288 15,798 5,844 8,027 — 698,957 Residential construction 189,209 2,560 — 746 — 192,515 Consumer and other 41,355 6 358 202 — 41,921 Total loans $ 3,713,792 $ 89,879 $ 25,251 $ 86,310 $ 78 $ 3,915,310 Allowance for Loan Losses The following table presents the activity in the allowance for loan losses by portfolio type for the three and six months ended June 30, 2020 and 2019: Commercial and Mortgage warehouse Paycheck Protection Program (PPP) 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 March 31, 2020 $ 10,164 $ — $ — $ 16,751 $ 2,989 $ 6,058 $ 1,431 $ 118 $ 37,511 Provision for loan losses 3,517 — — 4,131 982 1,609 372 58 10,669 Charge-offs (358 ) — — 7 (106 ) (125 ) — — (582 ) Recoveries 44 — — — — — — — 44 Net charge-offs (314 ) — — 7 (106 ) (125 ) — — (538 ) Balance June 30, 2020 $ 13,367 $ — $ — $ 20,889 $ 3,865 $ 7,542 $ 1,803 $ 176 $ 47,642 Six Months Ended Balance December 31, 2019 $ 8,818 $ — $ — $ 11,170 $ 4,421 $ 3,852 $ 1,057 $ 120 $ 29,438 Provision for loan losses 5,382 — — 9,856 1,714 3,905 746 56 21,659 Charge-offs (1,092 ) — — (137 ) (2,270 ) (215 ) — — (3,714 ) Recoveries 259 — — — — — — — 259 Net charge-offs (833 ) — — (137 ) (2,270 ) (215 ) — — (3,455 ) Balance June 30, 2020 $ 13,367 $ — $ — $ 20,889 $ 3,865 $ 7,542 $ 1,803 $ 176 $ 47,642 Allowance for loan losses: Three Months Ended Balance March 31, 2019 $ 8,999 $ — $ — $ 11,739 $ 2,289 $ 2,895 $ 1,124 $ 77 $ 27,123 Provision for loan losses (457 ) — — 1,201 (32 ) 776 (120 ) 39 1,407 Charge-offs (342 ) — — — — (295 ) — (8 ) (645 ) Recoveries 55 — — — — — — — 55 Net charge-offs (287 ) — — — — (295 ) — (8 ) (590 ) Balance June 30, 2019 $ 8,255 $ — $ — $ 12,940 $ 2,257 $ 3,376 $ 1,004 $ 108 $ 27,940 Six Months Ended Balance December 31, 2018 $ 8,351 $ — $ — $ 11,901 $ 2,724 $ 2,242 $ 1,040 $ 73 $ 26,331 Provision for loan losses 346 — — 1,116 (467 ) 1,429 (36 ) 21 2,409 Charge-offs (588 ) — — (80 ) — (295 ) — (8 ) (971 ) Recoveries 146 — — 3 — — — 22 171 Net charge-offs (442 ) — — (77 ) — (295 ) — 14 (800 ) Balance June 30, 2019 $ 8,255 $ — $ — $ 12,940 $ 2,257 $ 3,376 $ 1,004 $ 108 $ 27,940 The following table presents the balance of the allowance for loan losses by portfolio type based on the i mpairment method as of June 3 0 , 20 20 and December 31, 201 9 : Commercial and Mortgage warehouse Paycheck Protection Program (PPP) 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: June 30, 2020 Individually evaluated for impairment $ 4,435 $ — $ — $ 381 $ 221 $ 78 $ 53 $ 25 $ 5,193 Collectively evaluated for impairment 8,932 — — 20,508 3,644 7,464 1,750 151 42,449 Total allowance for loan losses $ 13,367 $ — $ — $ 20,889 $ 3,865 $ 7,542 $ 1,803 $ 176 $ 47,642 December 31, 2019 Individually evaluated for impairment $ 4,139 $ — $ — $ 459 $ 2,085 $ — $ 66 $ 26 $ 6,775 Collectively evaluated for impairment 4,679 — — 10,711 2,336 3,852 991 94 22,663 Total allowance for loan losses $ 8,818 $ — $ — $ 11,170 $ 4,421 $ 3,852 $ 1,057 $ 120 $ 29,438 The following table presents the recorded investment in loans held for investment by portfolio type based on the impairment method as of June 30, 2020 and December 31, 2019: Commercial and Mortgage warehouse Paycheck Protection Program (PPP) 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: June 30, 2020 Individually evaluated for impairment $ 16,677 $ — $ — $ 26,643 $ 3,420 $ 2,509 $ 898 $ 52 $ 50,199 Collectively evaluated for impairment 634,753 — 695,772 1,929,473 383,445 701,004 170,758 18,252 4,533,457 Total loans evaluated for impairment $ 651,430 $ — $ 695,772 $ 1,956,116 $ 386,865 $ 703,513 $ 171,656 $ 18,304 $ 4,583,656 December 31, 2019 Individually evaluated for impairment $ 15,572 $ — $ — $ 24,813 $ 12,142 $ 2,000 $ 745 $ 64 $ 55,336 Collectively evaluated for impairment 673,788 8,304 — 1,848,969 398,329 696,957 191,770 41,857 3,859,974 Total loans evaluated for impairment $ 689,360 $ 8,304 $ — $ 1,873,782 $ 410,471 $ 698,957 $ 192,515 $ 41,921 $ 3,915,310 Troubled Debt Restructurings As of June 30, 2020 and December 31, 2019, the Company had a recorded investment in troubled debt restructurings of $29.1 million and $28.9 million, respectively. The Company allocated $3.2 million of specific reserves for troubled debt restructurings at June 30, 2020 and December 31, 2019. The following table presents information regarding loans modified in a troubled debt restructuring during the three and six months ended June 30, 2020 and 2019: Three Months Ended June 30, 2020 2019 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 6 $ 899 $ 899 1 $ 56 $ 56 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) — — — — — — Real estate: Commercial real estate (including multi-family residential) — — — 1 303 303 Commercial real estate construction and land development 1 830 830 — — — 1-4 family residential (including home equity) 2 821 821 — — — Residential construction — — — — — — Consumer and other — — — — — — Total 9 $ 2,550 $ 2,550 2 $ 359 $ 359 Six Months Ended June 30, 2020 2019 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 $ 2,004 $ 2,004 7 $ 567 $ 567 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) — — — — — — Real estate: Commercial real estate (including multi-family residential) — — — 1 303 303 Commercial real estate construction and land development 1 830 830 — — — 1-4 family residential (including home equity) 3 940 940 1 396 396 Residential construction — — — — — — Consumer and other 1 30 30 1 38 38 Total 16 $ 3,804 $ 3,804 10 $ 1,304 $ 1,304 Troubled debt restructurings resulted in $632 thousand of charge-offs during the six months ended June 30, 2020 and no charge-offs during the six months ended June 30, 2019. There were no loans modified under a troubled debt restructuring during the previous twelve-month period that subsequently defaulted during the six months ended June 30, 2020. As of June 30, 2019, two loans for a total of $4.2 million loan were modified under a troubled debt restructuring during the previous twelve-month period that subsequently defaulted during the six months ended June 30, 2019. 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 six months ended June 30, 2020 and 2019. During the six months ended June 30, 2020, the Company added $3.8 million in new troubled debt restructurings, of which $2.9 million was still outstanding on June 30, 2020. During the six months ended June 30, 2019, the Company added $1.3 million in new troubled debt restructurings, of which $1.2 million was still outstanding on June 30, 2019. In working with customers adversely affected by the COVID-19 pandemic, the Company implemented a payment deferral program where customers meeting certain conditions were able to request payment deferrals that were not considered troubled debt restructurings. As of June 30, 2020, the Company executed 2,111 principal and interest deferrals on outstanding loan balances of $1.19 billion with associated accrued interest of $16.4 million. Additionally, upon request and after meeting certain conditions, borrowers could be granted a second payment deferral subsequent to the first deferral. The Company processed second payment deferrals for 129 loans with outstanding loan balances of $100.1 million through July 24, 2020 with associated accrued interest of $1.4 million. The deferrals were generally no more than 90 days in duration and were not considered troubled debt restructurings. While the modifications themselves did not trigger a downgrade, if the impact of COVID-19 continues, borrower operations do not improve or if other negative events occur, such modified loans could transition to potential problem loans or into problem loans. The following table presents information regarding principal and interest deferrals as of June 30, 2020 associated with loan modifications related to COVID-19: Loan Balance Deferred Loan Balance Percentage of Total Deferrals (Dollars in thousands) Commercial and industrial $ 651,430 $ 134,073 11.3 % Mortgage warehouse — — 0.0 % Paycheck Protection Program (PPP) 695,772 — 0.0 % Real estate: Commercial real estate (including multi-family residential) 1,956,116 793,115 66.8 % Commercial real estate construction and land development 386,865 101,456 8.5 % 1-4 family residential (including home equity) 703,513 139,565 11.8 % Residential construction 171,656 18,017 1.5 % Consumer and other 18,304 1,197 0.1 % Total loans $ 4,583,656 $ 1,187,423 100.0 %

LEASES

LEASES	6 Months Ended
	Jun. 30, 2020
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 six months ended June 30, 2020 and 2019. At June 30, 2020, the Company had 14 leases consisting of branch locations and office space along with equipment. On the June 30, 2020 balance sheet, the right-of-use asset is classified within premises and equipment and the lease liability is included in other liabilities. The Company also owns certain office facilities which it leases to outside parties under operating lessor leases; however, such leases are not significant. 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. 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 the dates indicated is as follows: June 30, 2020 December 31, 2019 (Dollars in thousands) Balance Sheet: Operating lease right of use asset classified as premises and equipment $ 10,435 $ 11,180 Operating lease liability classified as other liabilities 10,711 11,477 Weighted average lease term, in years 5.21 5.53 Weighted average discount rate 3.11 % 3.19 % Lease costs for the dates indicated is as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (Dollars in thousands) Income Statement: Operating lease cost $ 763 $ 777 $ 1,584 $ 1,547 Short-term lease cost 36 183 50 374 Sublease income (12 ) (18 ) (30 ) (36 ) Total operating lease costs $ 787 $ 942 $ 1,604 $ 1,885 A maturity analysis of the Company’s lease liabilities is as follows: June 30, 2020 December 31, 2019 (Dollars in thousands) Lease payments due: Within one year $ 2,856 $ 2,867 After one but within two years 2,652 2,608 After two but within three years 1,864 2,204 After three but within four years 1,627 1,596 After four but within five years 817 1,131 After five years 1,830 2,162 Total lease payments 11,646 12,568 Discount on cash flows 935 1,091 Total lease liability $ 10,711 $ 11,477

FAIR VALUE

FAIR VALUE	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 266,400 $ 266,400 $ — $ — $ 266,400 Available for sale securities 618,751 — 618,751 — 618,751 Loans held for investment, net of allowance 4,536,014 — — 4,495,391 4,495,391 Accrued interest receivable 32,795 2 4,558 28,235 32,795 Financial liabilities Deposits $ 4,700,711 $ — $ 4,721,264 $ — $ 4,721,264 Accrued interest payable 3,293 — 3,293 — 3,293 Borrowed funds 255,509 — 257,442 — 257,442 Subordinated debt 108,061 — 102,928 — 102,928 Interest rate swap 1,575 — 1,575 — 1,575 As of December 31, 2019 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 346,248 $ 346,248 $ — $ — $ 346,248 Available for sale securities 372,545 — 372,545 — 372,545 Loans held for investment, net of allowance 3,885,872 — — 3,918,210 3,918,210 Accrued interest receivable 15,468 13 1,783 13,672 15,468 Financial liabilities Deposits $ 4,068,101 $ — $ 4,073,031 $ — $ 4,073,031 Accrued interest payable 4,326 — 4,326 — 4,326 Borrowed funds 75,503 — 83,302 — 83,302 Subordinated debt 107,799 — 109,607 — 109,607 The following tables present fair values for assets and liabilities measured at fair value on a recurring basis: June 30, 2020 Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial Assets Available for sale securities: U.S. government and agency securities $ — $ 28,002 $ — $ 28,002 Municipal securities — 346,037 — 346,037 Agency mortgage-backed pass-through securities — 99,369 — 99,369 Agency collateralized mortgage obligations — 101,486 — 101,486 Corporate bonds and other — 43,857 — 43,857 Total available for sale securities $ — $ 618,751 $ — $ 618,751 Financial liabilities Interest rate swap $ — $ 1,575 $ — $ 1,575 December 31, 2019 Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial Assets Available for sale securities: U.S. government and agency securities $ — $ 29,475 $ — $ 29,475 Municipal securities — 87,537 — 87,537 Agency mortgage-backed pass-through securities — 106,168 — 106,168 Agency collateralized mortgage obligations — 107,342 — 107,342 Corporate bonds and other — 42,023 — 42,023 Total available for sale securities $ — $ 372,545 $ — $ 372,545 There were no liabilities measured at fair value on a recurring basis as of December 31, 2019. There were no transfers between levels during the six months ended June 30, 2020 or 2019. The following table presents certain assets 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 June 30, 2020 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 6,256 Commercial real estate (including multi- family residential) — — 5,429 Commercial real estate construction and land development — — 3,146 1-4 family residential (including home equity) — — 1,078 Residential construction — — 845 Other real estate owned — — 11,847 $ — $ — $ 28,601 As of December 31, 2019 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 4,332 Commercial real estate (including multi- family residential) — — 4,876 Commercial real estate construction and land development — — 10,057 Residential construction — — 471 PCI — — 1,380 Other real estate owned — — 8,337 $ — $ — $ 29,453 Impaired Loans with Specific Allocation of Allowance A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect all amounts due pursuant to the contractual terms of the loan agreement. Impairment is measured by estimating the fair value of the loan based on the present value of expected cash flows, the market price of the loan or the underlying fair value of the loan’s collateral. For real estate loans, fair value of the impaired loan’s collateral is determined by third-party appraisals, which are then adjusted for the estimated selling and closing costs related to liquidation of the collateral. For this asset class, the actual valuation methods (income, sales comparable or cost) vary based on the status of the project or property. For example, land is generally based on the sales comparable method while construction is based on the income and/or sales comparable methods. The unobservable inputs may vary depending on the individual assets with no one of the three methods being the predominant approach. The Company re views the third- party appraisal for appropriateness and adjusts the value downward to consider selling and closing costs, which typically range from 5 % to 10 % of the appraised value. For non-real estate loans, fair value of the impaired loan’s collateral may be determined using an appraisal, net book value per the borrower’s financial statements or aging reports, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of the valuation and management’s expertise and knowledge of the customer and the customer's business. During the six months ended June 30, 2020 and the year ended December 31, 2019, certain impaired loans were reevaluated and reported at fair value through a specific allocation of the allowance for loan losses. At June 30, 2020, the total reported fair value of impaired loans of $16.8 million based on collateral valuations utilizing Level 3 valuation inputs had a recorded investment of $21.9 million that was reduced by specific allowance allocations totaling $5.2 million. At December 31, 2019, the total reported fair value of impaired loans of $21.1 million based on collateral valuations utilizing Level 3 valuation inputs had a recorded investment of $27.9 million that was reduced by specific allowance allocations totaling $6.8 million. Other Real Estate Owned Other real estate owned is comprised of real estate acquired in partial or full satisfaction of loans. Other real estate owned is recorded at its estimated fair value less estimated selling and closing costs at the date of transfer. Any excess of the related loan balance over the fair value less expected selling costs is charged to the allowance. Subsequent declines in fair value are reported as adjustments to the carrying amount and are recorded against earnings. The fair value of other real estate owned is determined using third-party appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace. For this asset class, the actual valuation methods (income, sales comparable or cost) vary based on the status of the project or property. For example, land is generally based on the sales comparable method while construction is based on the income and/or sales comparable methods. The unobservable inputs may vary depending on the individual assets with no one of the three methods being the predominant approach. The Company reviews the third party appraisal for appropriateness and adjusts the value downward to consider selling and closing costs, which typically range from 5% to 10% of the appraised value. At June 30, 2020, the $11.8 million balance of other real estate owned consisted of three foreclosed commercial real estate properties, one tract of vacant land, one foreclosed residential property and one rural homestead recorded as a result of obtaining the physical possession of the property. The Company had $8.3 million of other real estate owned at December 31, 2019 consisting primarily of foreclosed commercial real estate properties as a result of obtaining physical possession of the property.

DEPOSITS

DEPOSITS	6 Months Ended
	Jun. 30, 2020
Deposit Liabilities [Abstract]
DEPOSITS	8. DEPOSITS Time deposits that met or exceeded the Federal Deposit Insurance Corporation insurance limit of $250 thousand at June 30, 2020 and December 31, 2019 were $615.2 million and $485.8 million, respectively. Scheduled maturities of time deposits for the next five years are as follows (dollars in thousands): Within one year $ 862,957 After one but within two years 226,874 After two but within three years 112,381 After three but within four years 45,778 After four but within five years 52,803 Total $ 1,300,793 The Company had $385.9 million and $263.5 million of brokered deposits as of June 30, 2020 and December 31, 2019, respectively. There were no concentrations of deposits with any one depositor at June 30, 2020 and December 31, 2019.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	9. DERIVATIVE INSTRUMENTS During the second quarter of 2020, the Company entered into a financial derivative. Financial derivatives are reported at fair value in other assets or other liabilities. The accounting for changes in the fair value of a derivative depends on whether it has been designated and qualifies as part of a hedging relationship. Derivatives designated as cash flow hedges For derivative instruments that are designated and qualify as a cash flow hedge, the aggregate fair value of the derivative instrum ent is recorded in other assets or other liabilities with any gain or loss related to changes in fair value recorded in accumulated other comprehensive income, net of tax. The gain or loss is reclassified into earnings in the same period during which the hedged asset or liability affects earnings and is presented in the same income statement line item as the earnings effect of the hedged asset or liability. The Company uses forward cash flow hedges in an effort to manage future interest rate exposure on liabilities. The hedging strategy converts the LIBOR-based variable interest rate on liabilities to a fixed interest rate and is used in an effort to protect the Company from floating interest rate variability. A summary of the Company’s cash flow hedge relationship as of June 30, 2020 is as follows: Balance Sheet Location Weighted Average Maturity (In Years) Weighted Average Pay Rate Receive Rate Notional Amount Estimated Fair Value (Dollars in thousands) Liability derivatives Interest rate swap Other liabilities 4.78 0.64% 3 month LIBOR $ 100,000 $ (1,575 ) The effects of the Company’s cash flow hedge relationship on the statement of comprehensive income (loss) during the three and six months ended June 30, 2020 and 2019 were as follows, net of tax: Amount of Gain (Loss) Recognized in Other Comprehensive Income (Loss) Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (Dollars in thousands) Liability derivatives Interest rate swap $ (1,245 ) $ — $ (1,245 ) $ — The cash flow hedge was determined to be effective during the periods presented and as a result qualified for hedge accounting treatment. The hedge would no longer be considered effective if a portion of the hedge becomes ineffective, the item hedged is no longer in existence or the Company discontinues hedge accounting. The Company expects the hedge at June 30, 2020 to continue to be effective and qualify for hedge accounting during the remaining terms of the original hedging transactions. At June 30, 2020, the Company expected $131 thousand of the unrealized gain to be reclassified as a reduction of interest expense during the next twelve months. Gains/Losses totaling $103 thousand, net of tax, were reclassified from accumulated other comprehensive income into net income during the three and six months ended June 30, 2020.

BORROWINGS AND BORROWING CAPACI

BORROWINGS AND BORROWING CAPACITY	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
BORROWINGS AND BORROWING CAPACITY	10. 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 June 30, 2020, the Company had a total borrowing capacity of $1.75 billion, of which $1.23 billion was available and $515.5 million was outstanding. FHLB advances of $240.0 million were outstanding at June 30, 2020, at a weighted average interest rate of 0.86%. Letters of credit were $275.5 million at June 30, 2020, of which $42.9 million will expire during the remaining months of 2020, $179.4 million will expire in 2021 and $53.2 million will expire in 2022. 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 each year 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 June 30, 2020, the balance of the revolving credit agreement was $15.6 million. The credit agreement contains certain restrictive covenants. At June 30, 2020, the Company believes it was in compliance with all such debt covenants. The interest rate on the debt is the Prime Rate minus 25 basis points, or 3.00%, at June 30, 2020, and is paid quarterly.

SUBORDINATED DEBT

SUBORDINATED DEBT	6 Months Ended
	Jun. 30, 2020
Subordinated Borrowings [Abstract]
SUBORDINATED DEBT	11. 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 June 30, 2020 of $9.6 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 June 30, 2020, 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 June 30, 2020 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 June 30, 2020 was 0.31026%. (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 $58.6 million. The Company used 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	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	12. 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 six months ended June 30, 2020, income tax expense was $2.1 million and $2.9 million, respectively, compared with $3.7 million and $6.8 million, respectively, for the three and six months ended June 30, 2019. The effective income tax rate for the three and six months ended June 30, 2020 was 17.2% and 17.8%, respectively, compared to 20.5% and 20.1%, respectively, for the three and six months ended June 30, 2019. 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 six months ended June 30, 2020. The Company is no longer subject to examination by the U.S. Federal Tax Jurisdiction for the years prior to 2016.

STOCK BASED COMPENSATION

STOCK BASED COMPENSATION	6 Months Ended
	Jun. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
STOCK BASED COMPENSATION	13. STOCK BASED COMPENSATION At June 30, 2020, 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 $914 thousand and $1.7 million for the three and six months ended June 30, 2020, respectively, and $882 thousand and $1.5 million for the three and six months ended June 30, 2019, respectively. Stock Options Options to purchase a total of 1,309,231 shares of Company stock have been granted as of June 30, 2020. Options are exercisable for up to 10 years from the date of the grant and, dependent on the terms of the applicable award agreement generally vest 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 six months ended June 30, 2020 is set forth below: Weighted Weighted Average Average Aggregate Number of Exercise Remaining Intrinsic Options Price Contractual Term Value (In thousands) (In years) (In thousands) Options outstanding, January 1, 2020 616 $ 19.90 4.00 $ 10,904 Options granted — — Options exercised (86 ) 15.22 Options forfeited (2 ) 21.60 Options outstanding, June 30, 2020 528 $ 20.61 3.72 $ 2,521 Options vested and exercisable, June 30, 2020 498 $ 19.82 3.54 $ 2,775 As of June 30, 2020, there was $232 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 0.65 years. Restricted Stock Awards During the six months ended June 30, 2020, the Company issued 59,662 shares of restricted stock. The shares of restricted stock generally vest over a period of four years and are considered outstanding at the date of issuance. The Company accounts for shares of restricted stock 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 six months ended June 30, 2020 is as follows: Weighted Average Grant Number of Date Fair Shares Value (Shares in thousands) Nonvested share awards outstanding, January 1, 2020 167 $ 36.23 Share awards granted 60 22.47 Share awards vested (35 ) 33.62 Unvested share awards forfeited or cancelled (6 ) 38.69 Nonvested share awards outstanding, June 30, 2020 186 $ 32.23 As of June 30, 2020, there was $5.4 million of total unrecognized compensation cost related to the restricted stock awards which is expected to be recognized over a weighted-average period of 2.66 years. Performance Share Units (“PSUs”) PSUs are earned subject to certain performance goals being met after the two-year one-year

OFF-BALANCE SHEET ARRANGEMENTS,

OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES	14. 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: June 30, 2020 December 31, 2019 Fixed Variable Fixed Variable Rate Rate Rate Rate (Dollars in thousands) Commitments to extend credit $ 637,924 $ 504,261 $ 507,411 $ 531,470 Standby letters of credit 11,889 5,476 10,843 4,309 Total $ 649,813 $ 509,737 $ 518,254 $ 535,779 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 June 30, 2020, the funded fixed rate loan commitments had interest rates ranging from 1.95% to 8.25% with a weighted average maturity and rate of 2.74 years and 5.09%, respectively. As of December 31, 2019, the funded fixed rate loan commitments had interest rates ranging from 1.95% to 8.40% with a weighted average maturity and rate of 3.59 years and 5.32%, 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	6 Months Ended
	Jun. 30, 2020
Banking And Thrift [Abstract]
REGULATORY CAPITAL MATTERS	15. 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) were fully phased in on January 1, 2019 when the capital conservation buffer reached 2.5%. Management believes as of June 30, 2020 and December 31, 2019 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 as of June 30, 2020 and December 31, 2019: Actual Minimum Required for Capital Adequacy Purposes Minimum Required Plus Capital Conservation Buffer To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) ALLEGIANCE BANCSHARES, INC. (Consolidated) As of June 30, 2020 Total Capital (to risk weighted assets) $ 620,363 15.17 % $ 327,178 8.00 % $ 429,422 10.50 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 464,661 11.36 % 184,038 4.50 % 286,281 7.00 % N/A N/A Tier 1 Capital (to risk weighted assets) 474,242 11.60 % 245,384 6.00 % 347,627 8.50 % N/A N/A Tier 1 Capital (to average tangible assets) 474,242 8.83 % 214,867 4.00 % 214,867 4.00 % N/A N/A As of December 31, 2019 Total Capital (to risk weighted assets) $ 596,684 14.83 % $ 321,775 8.00 % $ 422,330 10.50 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 459,447 11.42 % 180,999 4.50 % 281,553 7.00 % N/A N/A Tier 1 Capital (to risk weighted assets) 468,972 11.66 % 241,331 6.00 % 341,886 8.50 % N/A N/A Tier 1 Capital (to average tangible assets) 468,972 10.02 % 187,146 4.00 % 187,146 4.00 % N/A N/A ALLEGIANCE BANK As of June 30, 2020 Total Capital (to risk weighted assets) $ 612,044 14.97 % $ 326,970 8.00 % $ 429,149 10.50 % $ 408,713 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 524,722 12.84 % 183,921 4.50 % 286,099 7.00 % 265,664 6.50 % Tier 1 Capital (to risk weighted assets) 524,722 12.84 % 245,228 6.00 % 347,406 8.50 % 326,970 8.00 % Tier 1 Capital (to average tangible assets) 524,722 9.77 % 214,758 4.00 % 214,758 4.00 % 268,447 5.00 % As of December 31, 2019 Total Capital (to risk weighted assets) $ 578,425 14.39 % $ 321,556 8.00 % $ 422,043 10.50 % $ 401,945 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 509,372 12.67 % 180,875 4.50 % 281,362 7.00 % 261,265 6.50 % Tier 1 Capital (to risk weighted assets) 509,372 12.67 % 241,167 6.00 % 341,654 8.50 % 321,556 8.00 % Tier 1 Capital (to average tangible assets) 509,372 10.89 % 187,018 4.00 % 187,018 4.00 % 233,773 5.00 %

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	16. 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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 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 $ 9,907 $ 14,248 $ 13,423 $ 26,926 Basic: Weighted average shares outstanding 20,414 $ 0.49 21,257 $ 0.67 20,413 $ 0.66 21,494 $ 1.25 Diluted: Add incremental shares for: Dilutive effect of stock option exercises 100 289 159 286 Total 20,514 $ 0.48 21,546 $ 0.66 20,572 $ 0.65 21,780 $ 1.24 Stock options for 71,990 and 41,875 shares were not considered in computing diluted earnings per common share as of June 30, 2020 and 2019, respectively, as they were antidilutive.

SUBSEQUENT EVENT

SUBSEQUENT EVENT	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
SUBSEQUENT EVENT	17 . On July 27, 2020, the Company opened its 28 th

NATURE OF OPERATIONS AND SUMM_2

NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2020
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, 2019. Operating results for the three and six months ended June 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020.
Impact of COVID-19	Impact of COVID-19 The coronavirus (COVID-19) pandemic has negatively impacted the global economy, disrupted global supply chains and increased unemployment levels. The resulting temporary closure of many businesses and the implementation of social distancing and sheltering-in-place policies has and may continue to impact many of the Company’s customers. While the full effects of the pandemic remain unknown, the Company is committed to supporting its customers, employees and communities during this difficult time. The Company has given hardship relief assistance to customers, including the consideration of various loan payment deferral and fee waiver options, and encourages customers to reach out for assistance to support their individual circumstances. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was signed by the President of the United States. Certain provisions within the CARES Act encourage financial institutions to practice prudent efforts to work with borrowers impacted by COVID-19. Under these provisions, modifications deemed to be COVID-19-related would not be considered a troubled debt restructuring (“TDR”) if the loan was not more than 30 days past due as of December 31, 2019 and the deferral was executed between March 1, 2020 and the earlier of 60 days after the date of termination of the COVID-19 national emergency or December 31, 2020. The banking regulators issued similar guidance, which also clarified that a COVID-19-related modification should not be considered a TDR if the borrower was current on payments at the time the underlying loan modification program was implemented and if the modification is considered to be short-term. For loans subject to the deferral program, each borrower is required to begin making their regularly scheduled loan payment at the end of the deferral period and the deferred amounts were generally moved to the end of the loan. Under these terms, as of June 30, 2020, the Company had processed first payment deferrals for 2,111 loans with an aggregate loan balance of $1.19 billion with associated accrued interest of $16.4 million. Additionally, upon request and after meeting certain conditions, borrowers could be granted a second payment deferral subsequent to the first deferral. The Company processed second payment deferrals for 129 loans with outstanding loan balances of $100.1 million with associated accrued interest of $1.4 million, through July 24, 2020, with substantially all considered performing at the time of deferrals. These deferrals were generally no more than 90 days in duration Additionally, the Bank is a lender for the Small Business Administration's (“SBA”) Paycheck Protection Program ("PPP") , a program under the CARES Act, and other SBA, Federal Reserve or United States Treasury programs that have been created in response to the pandemic and may be a lender for programs created in the future . These programs are new and their effects on the Company ’s business are uncertain. As of June 30 , 2020, the Company had funded over 5,800 PPP loans totaling in excess of $ million under the allocation a pproved by Congress . The Company identified several loan portfolio categories that it considered to be most “at-risk” from the COVID-19 pandemic, such as, oil and gas, hotel, and restaurants and bars with outstanding loan balances, excluding PPP loans, of $74.7 million, $134.0 million and $111.3 million at June 30, 2020, respectively. The Company’s exposure to the oil and gas industry is minimal as it does not participate in exploration and production or reserve-based lending; however, this industry is vital to the Houston region and the indirect effects could be significant. The Company considers these “at-risk” portfolios to be the most vulnerable to financial difficulties and risks from business disruptions caused by the pandemic spread mitigation efforts. Due to the uncertainty in the economy and potential impacts from unemployment as a result of COVID-19 and the volatility of crude oil prices, the impact could extend to the Company’s securities portfolio, income taxes, other real estate owned and goodwill and intangibles among other items, although the impact is dependent on future events which are highly uncertain and cannot be predicted at this time. Due to the COVID-19 pandemic, the Company initiated a re-evaluation of the accuracy of loan grades assigned to its commercial loan portfolio during the second quarter of 2020, the results of which are reflected in the financial statement disclosures for this quarter. Effects as a result of the pandemic may continue, potentially resulting in additional loans being identified. In a period of economic contraction, additional loan losses and lost interest income may occur, either in the industries previously noted or others to which the Company has exposure. The Company continues to accrue interest on loans modified under the new accounting standards. To the extent those borrowers are unable to resume normal contractual payments, the Company could experience additional losses of principal and interest.
Derivative Instruments	Derivative Instruments — In accordance with ASC Topic 815, “Derivatives and Hedging”, derivative instruments are recorded on the accompanying consolidated balance sheet at their respective fair values. The accounting for changes in fair value (i.e., gains or losses) of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship. If the derivative instrument is not designated as a hedge, changes in the fair value of the derivative instrument are recognized in earnings in the period of change. The derivative is carried on the balance sheet in other liabilities. This derivative contract has been designated as a hedge and, as such, changes in the fair value of the derivative instrument are recorded in other comprehensive income. The Company prepared written hedge documentation for the derivative that is designated as a hedge. The written hedge documentation includes identification of, among other items, the risk management objective, hedging instrument, hedged item and methodologies for assessing and measuring hedge effectiveness and ineffectiveness, along with support for management's assertion that the hedge will be effective. For the designated hedging relationship, the Company performs retrospective and prospective effectiveness testing using quantitative methods where required by accounting standards. For the hedging relationship, effectiveness is tested through the matching of critical terms. Assessments of hedge effectiveness and measurements of hedge ineffectiveness are performed at least quarterly. The portion of the changes in the fair value of a derivative that is effective and that has been designated and qualifies as a cash flow hedge is initially recorded in accumulated other comprehensive income and will be reclassified to earnings in the same period that the hedged item impacts earnings; any ineffective portion is recorded in current period earnings. The derivative is carried at fair value based on the Company’s pricing model that utilizes observable market inputs and is reflected within Level 2 of the valuation hierarchy.
New Accounting Standards	New Accounting Standards Adoption of New Accounting Standards ASC 310-40, “Receivables – Troubled Debt Restructurings by Creditors,” (“ASC 310-40”), a restructuring of debt constitutes a troubled debt restructuring (“TDR”) if the creditor, for economic or legal reasons related to the debtor’s financial difficulties, grants a concession to the debtor that it would not otherwise consider. In response to COVID-19, new GAAP guidance was issued whereby, subject to certain restrictions, loan modifications may not be subject to classification as TDRs. Upon request and after meeting certain conditions, borrowers could be granted a second payment deferral subsequent to the first deferral. As of June 30, 2020, the Company granted first payment deferrals on 2,111 loans with an aggregate loan balance of $ 1.19 billion and second deferrals on loans with outstanding loan balance s of $ 39.9 million to qualified borrowers . ASU 2018-13, “Fair Value Measurement (Topic 820). – Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement.” ASU 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820. The amendments in ASU 2018-13 remove disclosures that no longer are considered cost beneficial, modify/clarify the specific requirements of certain disclosures and add disclosure requirements identified as relevant. ASU 2018-13 became effective for the Company on January 1, 2020 and did not have a significant impact on the Company’s financial statements. A SU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” 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 (“CECL”) 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, CECL amends the accounting for credit losses on available for sale debt securities and purchased financial assets with credit deterioration. CECL became effective for the Company on January 1, 2020 using the modified retrospective approach; however, the CARES Act, signed by the President of the United States on March 27, 2020 includes an option for entities to delay the implementation of ASU 2016-13 until the earlier of the termination date of the national emergency declaration by the President or December 31, 2020. The Company expects to adopt CECL as of January 1, 2020 after the deferral period ends. Due to the uncertainty of the impact of COVID-19 and the volatility of crude oil prices, which can be impactful to the Houston market, the Company has delayed its implementation of CECL and has calculated and recorded its provision for loan losses under the incurred loss model that existed prior to ASU 2016-13. The Company will continue to perform and enhance CECL model operations parallel with the incurred loss model throughout 2020, or until adoption. ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” to simplify various aspects of the current guidance to promote consistent application of the standard among reporting entities by moving certain exceptions to the general principles. The amendment is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. ASU 2019-12 will be become effective for the Company on January 1, 2021 and is not expected to have a significant impact on the Company’s financial statements.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	6 Months Ended
	Jun. 30, 2020
Business Combinations [Abstract]
Schedule of Purchase Price Allocation	As of September 30, 2019, the Company finalized its valuation of all assets and liabilities acquired. 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)	6 Months Ended
	Jun. 30, 2020
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, 2018 $ 223,125 $ 26,587 Acquisition of LoweryBank branch 578 — Measurement period adjustment (61 ) — Amortization — (4,711 ) Balance as of December 31, 2019 223,642 21,876 Amortization — (1,980 ) Balance as of June 30, 2020 $ 223,642 $ 19,896
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated aggregate future amortization expense for core deposit intangible assets remaining as of June 30, 2020 is as follows (dollars in thousands): Remaining 2020 $ 1,942 2021 3,296 2022 3,003 2023 2,323 2024 2,188 Thereafter 7,144 Total $ 19,896

SECURITIES (Tables)

SECURITIES (Tables)	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Available-for-sale Securities	The amortized cost and fair value of investment securities were as follows: June 30, 2020 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (Dollars in thousands) Available for Sale U.S. government and agency securities $ 27,308 $ 694 $ — $ 28,002 Municipal securities 317,769 28,268 — 346,037 Agency mortgage-backed pass-through securities 95,385 3,984 — 99,369 Agency collateralized mortgage obligations 97,618 3,994 (126 ) 101,486 Corporate bonds and other 43,712 217 (72 ) 43,857 Total $ 581,792 $ 37,157 $ (198 ) $ 618,751 December 31, 2019 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (Dollars in thousands) Available for Sale U.S. government and agency securities $ 29,420 $ 298 $ (243 ) $ 29,475 Municipal securities 84,200 3,453 (116 ) 87,537 Agency mortgage-backed pass-through securities 104,669 1,713 (214 ) 106,168 Agency collateralized mortgage obligations 106,351 1,199 (208 ) 107,342 Corporate bonds and other 41,691 346 (14 ) 42,023 Total $ 366,331 $ 7,009 $ (795 ) $ 372,545
Investments Classified by Contractual Maturity Date	The amortized cost and fair value of investment securities at June 30, 2020, 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 $ 11,002 $ 11,038 Due after one year through five years 8,503 9,009 Due after five years through ten years 83,999 87,239 Due after ten years 285,285 310,610 Subtotal 388,789 417,896 Agency mortgage-backed pass through and collateralized mortgage obligation securities 193,003 200,855 Total $ 581,792 $ 618,751
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: June 30, 2020 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 Agency collateralized mortgage obligations $ 24,895 $ (85 ) $ 4,499 $ (41 ) $ 29,394 $ (126 ) Corporate bonds and other 4,427 (72 ) — — 4,427 (72 ) Total $ 29,322 $ (157 ) $ 4,499 $ (41 ) $ 33,821 $ (198 ) December 31, 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 $ 22,295 $ (239 ) $ 436 $ (4 ) $ 22,731 $ (243 ) Agency mortgage-backed pass-through securities 20,792 (155 ) 4,369 (59 ) 25,161 (214 ) Agency collateralized mortgage obligations 22,340 (208 ) — — 22,340 (208 ) Municipal securities 9,514 (116 ) — — 9,514 (116 ) Corporate bonds and other 5,492 (14 ) — — 5,492 (14 ) Total $ 80,433 $ (732 ) $ 4,805 $ (63 ) $ 85,238 $ (795 )

LOANS AND ALLOWANCE FOR LOAN _2

LOANS AND ALLOWANCE FOR LOAN LOSSES (Tables)	6 Months Ended
	Jun. 30, 2020
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: June 30, December 31, 2020 2019 (Dollars in thousands) Commercial and industrial $ 651,430 $ 689,360 Mortgage warehouse — 8,304 Paycheck Protection Program (PPP) 695,772 — Real estate: Commercial real estate (including multi-family residential) 1,956,116 1,873,782 Commercial real estate construction and land development 386,865 410,471 1-4 family residential (including home equity) 703,513 698,957 Residential construction 171,656 192,515 Consumer and other 18,304 41,921 Total loans 4,583,656 3,915,310 Allowance for loan losses (47,642 ) (29,438 ) Loans, net $ 4,536,014 $ 3,885,872
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 June 30, 2020 and December 31, 2019 are presented in the table below: As of June 30, 2020 As of December 31, 2019 (Dollars in thousands) Outstanding balance $ 15,687 $ 16,589 Less: Discount (2,211 ) (2,414 ) Less: Allowance (1,432 ) (259 ) Recorded investment $ 12,044 $ 13,916
Past Due Financing Receivables	An aging analysis of the recorded investment, defined as the unpaid principal balance, in past due loans, segregated by class of loans, is as follows: June 30, 2020 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 $ 6,129 $ — $ 6,129 $ 12,578 $ 632,723 $ 651,430 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) — — — — 695,772 695,772 Real estate: Commercial real estate (including multi-family residential) 5,594 — 5,594 16,127 1,934,395 1,956,116 Commercial real estate construction and land development 2,310 — 2,310 53 384,502 386,865 1-4 family residential (including home equity) 1,825 — 1,825 3,434 698,254 703,513 Residential construction 191 — 191 898 170,567 171,656 Consumer and other 277 — 277 133 17,894 18,304 Total loans $ 16,326 $ — $ 16,326 $ 33,223 $ 4,534,107 $ 4,583,656 December 31, 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 $ 3,098 $ — $ 3,098 $ 8,388 $ 677,874 $ 689,360 Mortgage warehouse — — — — 8,304 8,304 Real estate: Commercial real estate (including multi-family residential) 4,421 — 4,421 6,741 1,862,620 1,873,782 Commercial real estate construction and land development 66 — 66 9,050 401,355 410,471 1-4 family residential (including home equity) 1,598 — 1,598 3,294 694,065 698,957 Residential construction 564 — 564 746 191,205 192,515 Consumer and other 254 — 254 152 41,515 41,921 Total loans $ 10,001 $ — $ 10,001 $ 28,371 $ 3,876,938 $ 3,915,310
Impaired Financing Receivables	Impaired loans by class of loans are set forth in the following tables. As of June 30, 2020 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 5,986 $ 6,126 $ — Mortgage warehouse — — — Paycheck Protection Program (PPP) — — — Real estate: Commercial real estate (including multi-family residential) 20,833 20,914 — Commercial real estate construction and land development 53 53 — 1-4 family residential (including home equity) 1,353 1,353 — Residential construction — — — Consumer and other 27 27 — Total 28,252 28,473 — With an allowance recorded: Commercial and industrial 10,691 11,086 4,435 Mortgage warehouse — — — Paycheck Protection Program (PPP) — — — Real estate: Commercial real estate (including multi-family residential) 5,810 5,810 381 Commercial real estate construction and land development 3,367 3,367 221 1-4 family residential (including home equity) 1,156 1,262 78 Residential construction 898 898 53 Consumer and other 25 25 25 Total 21,947 22,448 5,193 Total: Commercial and industrial 16,677 17,212 4,435 Mortgage warehouse — — — Paycheck Protection Program (PPP) — — — Real estate: Commercial real estate (including multi-family residential) 26,643 26,724 381 Commercial real estate construction and land development 3,420 3,420 221 1-4 family residential (including home equity) 2,509 2,615 78 Residential construction 898 898 53 Consumer and other 52 52 25 $ 50,199 $ 50,921 $ 5,193 As of December 31, 2019 Unpaid Recorded Principal Related Investment Balance Allowance (Dollars in thousands) With no related allowance recorded: Commercial and industrial $ 5,721 $ 6,136 $ — Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 19,478 19,558 — Commercial real estate construction and land development — — — 1-4 family residential (including home equity) 2,000 2,000 — Residential construction 208 208 — Consumer and other 38 38 — Total 27,445 27,940 — With an allowance recorded: Commercial and industrial 7,812 7,286 3,480 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 5,335 5,335 459 Commercial real estate construction and land development 12,142 12,142 2,085 1-4 family residential (including home equity) — — — Residential construction 537 537 66 Consumer and other 26 26 26 PCI 2,039 2,959 659 Total 27,891 28,285 6,775 Total: Commercial and industrial 13,533 13,422 3,480 Mortgage warehouse — — — Real estate: Commercial real estate (including multi-family residential) 24,813 24,893 459 Commercial real estate construction and land development 12,142 12,142 2,085 1-4 family residential (including home equity) 2,000 2,000 — Residential construction 745 745 66 Consumer and other 64 64 26 PCI 2,039 2,959 659 $ 55,336 $ 56,225 $ 6,775 The following table presents average impaired loans and interest recognized on impaired loans for the three and six months ended June 30, 2020 and 2019: Three Months Ended June 30, 2020 2019 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 16,997 $ 62 $ 12,280 $ 75 Mortgage warehouse — — — — Paycheck Protection Program (PPP) — — — — Real estate: Commercial real estate (including multi-family residential) 26,710 74 19,589 98 Commercial real estate construction and land development 3,436 50 4,661 57 1-4 family residential (including home equity) 2,529 3 1,293 — Residential construction 940 — — — Consumer and other 55 1 37 — Total $ 50,667 $ 190 $ 37,860 $ 230 Six Months Ended June 30, 2020 2019 Average Interest Average Interest Recorded Income Recorded Income Investment Recognized Investment Recognized (Dollars in thousands) Commercial and industrial $ 17,302 $ 164 $ 12,575 $ 167 Mortgage warehouse — — — — Paycheck Protection Program (PPP) — — — — Real estate: Commercial real estate (including multi-family residential) 26,825 307 19,781 193 Commercial real estate construction and land development 3,289 97 4,664 88 1-4 family residential (including home equity) 2,547 6 1,310 4 Residential construction 822 — — — Consumer and other 56 1 38 — Total $ 50,841 $ 575 $ 38,368 $ 452
Financing Receivable Credit Quality Indicators	Based on the most recent analysis performed, the risk category of loans by class of loan at their recorded investment at June 30, 2020 is as follows: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 582,937 $ 27,633 $ 11,877 $ 28,830 $ 153 $ 651,430 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) 695,772 — — — — 695,772 Real estate: Commercial real estate (including multi-family residential) 1,745,562 143,848 26,487 40,219 — 1,956,116 Commercial real estate construction and land development 368,788 15,488 — 2,589 — 386,865 1-4 family residential (including home equity) 662,551 27,384 5,668 7,910 — 703,513 Residential construction 168,087 2,671 — 898 — 171,656 Consumer and other 17,676 170 277 181 — 18,304 Total loans $ 4,241,373 $ 217,194 $ 44,309 $ 80,627 $ 153 $ 4,583,656 The following table presents the risk category of loans by class of loan at December 31, 2019: Pass Watch Special Mention Substandard Doubtful Total (Dollars in thousands) Commercial and industrial $ 641,696 $ 14,170 $ 9,121 $ 24,295 $ 78 $ 689,360 Mortgage warehouse 8,304 — — — — 8,304 Real estate: Commercial real estate (including multi-family residential) 1,775,789 47,762 9,289 40,942 — 1,873,782 Commercial real estate construction and land development 388,151 9,583 639 12,098 — 410,471 1-4 family residential (including home equity) 669,288 15,798 5,844 8,027 — 698,957 Residential construction 189,209 2,560 — 746 — 192,515 Consumer and other 41,355 6 358 202 — 41,921 Total loans $ 3,713,792 $ 89,879 $ 25,251 $ 86,310 $ 78 $ 3,915,310
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 six months ended June 30, 2020 and 2019: Commercial and Mortgage warehouse Paycheck Protection Program (PPP) 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 March 31, 2020 $ 10,164 $ — $ — $ 16,751 $ 2,989 $ 6,058 $ 1,431 $ 118 $ 37,511 Provision for loan losses 3,517 — — 4,131 982 1,609 372 58 10,669 Charge-offs (358 ) — — 7 (106 ) (125 ) — — (582 ) Recoveries 44 — — — — — — — 44 Net charge-offs (314 ) — — 7 (106 ) (125 ) — — (538 ) Balance June 30, 2020 $ 13,367 $ — $ — $ 20,889 $ 3,865 $ 7,542 $ 1,803 $ 176 $ 47,642 Six Months Ended Balance December 31, 2019 $ 8,818 $ — $ — $ 11,170 $ 4,421 $ 3,852 $ 1,057 $ 120 $ 29,438 Provision for loan losses 5,382 — — 9,856 1,714 3,905 746 56 21,659 Charge-offs (1,092 ) — — (137 ) (2,270 ) (215 ) — — (3,714 ) Recoveries 259 — — — — — — — 259 Net charge-offs (833 ) — — (137 ) (2,270 ) (215 ) — — (3,455 ) Balance June 30, 2020 $ 13,367 $ — $ — $ 20,889 $ 3,865 $ 7,542 $ 1,803 $ 176 $ 47,642 Allowance for loan losses: Three Months Ended Balance March 31, 2019 $ 8,999 $ — $ — $ 11,739 $ 2,289 $ 2,895 $ 1,124 $ 77 $ 27,123 Provision for loan losses (457 ) — — 1,201 (32 ) 776 (120 ) 39 1,407 Charge-offs (342 ) — — — — (295 ) — (8 ) (645 ) Recoveries 55 — — — — — — — 55 Net charge-offs (287 ) — — — — (295 ) — (8 ) (590 ) Balance June 30, 2019 $ 8,255 $ — $ — $ 12,940 $ 2,257 $ 3,376 $ 1,004 $ 108 $ 27,940 Six Months Ended Balance December 31, 2018 $ 8,351 $ — $ — $ 11,901 $ 2,724 $ 2,242 $ 1,040 $ 73 $ 26,331 Provision for loan losses 346 — — 1,116 (467 ) 1,429 (36 ) 21 2,409 Charge-offs (588 ) — — (80 ) — (295 ) — (8 ) (971 ) Recoveries 146 — — 3 — — — 22 171 Net charge-offs (442 ) — — (77 ) — (295 ) — 14 (800 ) Balance June 30, 2019 $ 8,255 $ — $ — $ 12,940 $ 2,257 $ 3,376 $ 1,004 $ 108 $ 27,940 The following table presents the balance of the allowance for loan losses by portfolio type based on the i mpairment method as of June 3 0 , 20 20 and December 31, 201 9 : Commercial and Mortgage warehouse Paycheck Protection Program (PPP) 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: June 30, 2020 Individually evaluated for impairment $ 4,435 $ — $ — $ 381 $ 221 $ 78 $ 53 $ 25 $ 5,193 Collectively evaluated for impairment 8,932 — — 20,508 3,644 7,464 1,750 151 42,449 Total allowance for loan losses $ 13,367 $ — $ — $ 20,889 $ 3,865 $ 7,542 $ 1,803 $ 176 $ 47,642 December 31, 2019 Individually evaluated for impairment $ 4,139 $ — $ — $ 459 $ 2,085 $ — $ 66 $ 26 $ 6,775 Collectively evaluated for impairment 4,679 — — 10,711 2,336 3,852 991 94 22,663 Total allowance for loan losses $ 8,818 $ — $ — $ 11,170 $ 4,421 $ 3,852 $ 1,057 $ 120 $ 29,438 The following table presents the recorded investment in loans held for investment by portfolio type based on the impairment method as of June 30, 2020 and December 31, 2019: Commercial and Mortgage warehouse Paycheck Protection Program (PPP) 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: June 30, 2020 Individually evaluated for impairment $ 16,677 $ — $ — $ 26,643 $ 3,420 $ 2,509 $ 898 $ 52 $ 50,199 Collectively evaluated for impairment 634,753 — 695,772 1,929,473 383,445 701,004 170,758 18,252 4,533,457 Total loans evaluated for impairment $ 651,430 $ — $ 695,772 $ 1,956,116 $ 386,865 $ 703,513 $ 171,656 $ 18,304 $ 4,583,656 December 31, 2019 Individually evaluated for impairment $ 15,572 $ — $ — $ 24,813 $ 12,142 $ 2,000 $ 745 $ 64 $ 55,336 Collectively evaluated for impairment 673,788 8,304 — 1,848,969 398,329 696,957 191,770 41,857 3,859,974 Total loans evaluated for impairment $ 689,360 $ 8,304 $ — $ 1,873,782 $ 410,471 $ 698,957 $ 192,515 $ 41,921 $ 3,915,310
Troubled Debt Restructurings on Financing Receivables	The following table presents information regarding loans modified in a troubled debt restructuring during the three and six months ended June 30, 2020 and 2019: Three Months Ended June 30, 2020 2019 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 6 $ 899 $ 899 1 $ 56 $ 56 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) — — — — — — Real estate: Commercial real estate (including multi-family residential) — — — 1 303 303 Commercial real estate construction and land development 1 830 830 — — — 1-4 family residential (including home equity) 2 821 821 — — — Residential construction — — — — — — Consumer and other — — — — — — Total 9 $ 2,550 $ 2,550 2 $ 359 $ 359 Six Months Ended June 30, 2020 2019 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 $ 2,004 $ 2,004 7 $ 567 $ 567 Mortgage warehouse — — — — — — Paycheck Protection Program (PPP) — — — — — — Real estate: Commercial real estate (including multi-family residential) — — — 1 303 303 Commercial real estate construction and land development 1 830 830 — — — 1-4 family residential (including home equity) 3 940 940 1 396 396 Residential construction — — — — — — Consumer and other 1 30 30 1 38 38 Total 16 $ 3,804 $ 3,804 10 $ 1,304 $ 1,304
Schedule of Principal and Interest Deferrals Associated with Loan Modifications Related to COVID 19	The following table presents information regarding principal and interest deferrals as of June 30, 2020 associated with loan modifications related to COVID-19: Loan Balance Deferred Loan Balance Percentage of Total Deferrals (Dollars in thousands) Commercial and industrial $ 651,430 $ 134,073 11.3 % Mortgage warehouse — — 0.0 % Paycheck Protection Program (PPP) 695,772 — 0.0 % Real estate: Commercial real estate (including multi-family residential) 1,956,116 793,115 66.8 % Commercial real estate construction and land development 386,865 101,456 8.5 % 1-4 family residential (including home equity) 703,513 139,565 11.8 % Residential construction 171,656 18,017 1.5 % Consumer and other 18,304 1,197 0.1 % Total loans $ 4,583,656 $ 1,187,423 100.0 %

LEASES (Tables)

LEASES (Tables)	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Supplemental Lease Information	Supplemental lease information at the dates indicated is as follows: June 30, 2020 December 31, 2019 (Dollars in thousands) Balance Sheet: Operating lease right of use asset classified as premises and equipment $ 10,435 $ 11,180 Operating lease liability classified as other liabilities 10,711 11,477 Weighted average lease term, in years 5.21 5.53 Weighted average discount rate 3.11 % 3.19 %
Summary of Lease Costs	Lease costs for the dates indicated is as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (Dollars in thousands) Income Statement: Operating lease cost $ 763 $ 777 $ 1,584 $ 1,547 Short-term lease cost 36 183 50 374 Sublease income (12 ) (18 ) (30 ) (36 ) Total operating lease costs $ 787 $ 942 $ 1,604 $ 1,885
Maturity Analysis of Lease Liabilities	A maturity analysis of the Company’s lease liabilities is as follows: June 30, 2020 December 31, 2019 (Dollars in thousands) Lease payments due: Within one year $ 2,856 $ 2,867 After one but within two years 2,652 2,608 After two but within three years 1,864 2,204 After three but within four years 1,627 1,596 After four but within five years 817 1,131 After five years 1,830 2,162 Total lease payments 11,646 12,568 Discount on cash flows 935 1,091 Total lease liability $ 10,711 $ 11,477

FAIR VALUE (Tables)

FAIR VALUE (Tables)	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 266,400 $ 266,400 $ — $ — $ 266,400 Available for sale securities 618,751 — 618,751 — 618,751 Loans held for investment, net of allowance 4,536,014 — — 4,495,391 4,495,391 Accrued interest receivable 32,795 2 4,558 28,235 32,795 Financial liabilities Deposits $ 4,700,711 $ — $ 4,721,264 $ — $ 4,721,264 Accrued interest payable 3,293 — 3,293 — 3,293 Borrowed funds 255,509 — 257,442 — 257,442 Subordinated debt 108,061 — 102,928 — 102,928 Interest rate swap 1,575 — 1,575 — 1,575 As of December 31, 2019 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial assets Cash and cash equivalents $ 346,248 $ 346,248 $ — $ — $ 346,248 Available for sale securities 372,545 — 372,545 — 372,545 Loans held for investment, net of allowance 3,885,872 — — 3,918,210 3,918,210 Accrued interest receivable 15,468 13 1,783 13,672 15,468 Financial liabilities Deposits $ 4,068,101 $ — $ 4,073,031 $ — $ 4,073,031 Accrued interest payable 4,326 — 4,326 — 4,326 Borrowed funds 75,503 — 83,302 — 83,302 Subordinated debt 107,799 — 109,607 — 109,607
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables present fair values for assets and liabilities measured at fair value on a recurring basis: June 30, 2020 Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial Assets Available for sale securities: U.S. government and agency securities $ — $ 28,002 $ — $ 28,002 Municipal securities — 346,037 — 346,037 Agency mortgage-backed pass-through securities — 99,369 — 99,369 Agency collateralized mortgage obligations — 101,486 — 101,486 Corporate bonds and other — 43,857 — 43,857 Total available for sale securities $ — $ 618,751 $ — $ 618,751 Financial liabilities Interest rate swap $ — $ 1,575 $ — $ 1,575 December 31, 2019 Level 1 Level 2 Level 3 Total (Dollars in thousands) Financial Assets Available for sale securities: U.S. government and agency securities $ — $ 29,475 $ — $ 29,475 Municipal securities — 87,537 — 87,537 Agency mortgage-backed pass-through securities — 106,168 — 106,168 Agency collateralized mortgage obligations — 107,342 — 107,342 Corporate bonds and other — 42,023 — 42,023 Total available for sale securities $ — $ 372,545 $ — $ 372,545
Fair Value Measurements, Nonrecurring	The following table presents certain assets 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 June 30, 2020 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 6,256 Commercial real estate (including multi- family residential) — — 5,429 Commercial real estate construction and land development — — 3,146 1-4 family residential (including home equity) — — 1,078 Residential construction — — 845 Other real estate owned — — 11,847 $ — $ — $ 28,601 As of December 31, 2019 Level 1 Level 2 Level 3 (Dollars in thousands) Impaired loans: Commercial and industrial $ — $ — $ 4,332 Commercial real estate (including multi- family residential) — — 4,876 Commercial real estate construction and land development — — 10,057 Residential construction — — 471 PCI — — 1,380 Other real estate owned — — 8,337 $ — $ — $ 29,453

DEPOSITS (Tables)

DEPOSITS (Tables)	6 Months Ended
	Jun. 30, 2020
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 $ 862,957 After one but within two years 226,874 After two but within three years 112,381 After three but within four years 45,778 After four but within five years 52,803 Total $ 1,300,793

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Summary of Cash Flow Hedge Relationships	A summary of the Company’s cash flow hedge relationship as of June 30, 2020 is as follows: Balance Sheet Location Weighted Average Maturity (In Years) Weighted Average Pay Rate Receive Rate Notional Amount Estimated Fair Value (Dollars in thousands) Liability derivatives Interest rate swap Other liabilities 4.78 0.64% 3 month LIBOR $ 100,000 $ (1,575 )
Effect of Cash Flow Hedge Relationship on Statement of Comprehensive Income (Loss)	The effects of the Company’s cash flow hedge relationship on the statement of comprehensive income (loss) during the three and six months ended June 30, 2020 and 2019 were as follows, net of tax: Amount of Gain (Loss) Recognized in Other Comprehensive Income (Loss) Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (Dollars in thousands) Liability derivatives Interest rate swap $ (1,245 ) $ — $ (1,245 ) $ —

SUBORDINATED DEBT (Tables)

SUBORDINATED DEBT (Tables)	6 Months Ended
	Jun. 30, 2020
Subordinated Borrowings [Abstract]
Schedule of Subordinated Borrowing	A summary of pertinent information related to the Company’s issues of junior subordinated debentures outstanding at June 30, 2020 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 June 30, 2020 was 0.31026%. (2) All debentures are currently callable.

STOCK BASED COMPENSATION (Table

STOCK BASED COMPENSATION (Tables)	6 Months Ended
	Jun. 30, 2020
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 six months ended June 30, 2020 is set forth below: Weighted Weighted Average Average Aggregate Number of Exercise Remaining Intrinsic Options Price Contractual Term Value (In thousands) (In years) (In thousands) Options outstanding, January 1, 2020 616 $ 19.90 4.00 $ 10,904 Options granted — — Options exercised (86 ) 15.22 Options forfeited (2 ) 21.60 Options outstanding, June 30, 2020 528 $ 20.61 3.72 $ 2,521 Options vested and exercisable, June 30, 2020 498 $ 19.82 3.54 $ 2,775
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of the activity of the nonvested shares of restricted stock during the six months ended June 30, 2020 is as follows: Weighted Average Grant Number of Date Fair Shares Value (Shares in thousands) Nonvested share awards outstanding, January 1, 2020 167 $ 36.23 Share awards granted 60 22.47 Share awards vested (35 ) 33.62 Unvested share awards forfeited or cancelled (6 ) 38.69 Nonvested share awards outstanding, June 30, 2020 186 $ 32.23

OFF-BALANCE SHEET ARRANGEMENT_2

OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES (Tables)	6 Months Ended
	Jun. 30, 2020
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: June 30, 2020 December 31, 2019 Fixed Variable Fixed Variable Rate Rate Rate Rate (Dollars in thousands) Commitments to extend credit $ 637,924 $ 504,261 $ 507,411 $ 531,470 Standby letters of credit 11,889 5,476 10,843 4,309 Total $ 649,813 $ 509,737 $ 518,254 $ 535,779

REGULATORY CAPITAL MATTERS (Tab

REGULATORY CAPITAL MATTERS (Tables)	6 Months Ended
	Jun. 30, 2020
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 as of June 30, 2020 and December 31, 2019: Actual Minimum Required for Capital Adequacy Purposes Minimum Required Plus Capital Conservation Buffer To Be Categorized As Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) ALLEGIANCE BANCSHARES, INC. (Consolidated) As of June 30, 2020 Total Capital (to risk weighted assets) $ 620,363 15.17 % $ 327,178 8.00 % $ 429,422 10.50 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 464,661 11.36 % 184,038 4.50 % 286,281 7.00 % N/A N/A Tier 1 Capital (to risk weighted assets) 474,242 11.60 % 245,384 6.00 % 347,627 8.50 % N/A N/A Tier 1 Capital (to average tangible assets) 474,242 8.83 % 214,867 4.00 % 214,867 4.00 % N/A N/A As of December 31, 2019 Total Capital (to risk weighted assets) $ 596,684 14.83 % $ 321,775 8.00 % $ 422,330 10.50 % N/A N/A Common Equity Tier 1 Capital (to risk weighted assets) 459,447 11.42 % 180,999 4.50 % 281,553 7.00 % N/A N/A Tier 1 Capital (to risk weighted assets) 468,972 11.66 % 241,331 6.00 % 341,886 8.50 % N/A N/A Tier 1 Capital (to average tangible assets) 468,972 10.02 % 187,146 4.00 % 187,146 4.00 % N/A N/A ALLEGIANCE BANK As of June 30, 2020 Total Capital (to risk weighted assets) $ 612,044 14.97 % $ 326,970 8.00 % $ 429,149 10.50 % $ 408,713 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 524,722 12.84 % 183,921 4.50 % 286,099 7.00 % 265,664 6.50 % Tier 1 Capital (to risk weighted assets) 524,722 12.84 % 245,228 6.00 % 347,406 8.50 % 326,970 8.00 % Tier 1 Capital (to average tangible assets) 524,722 9.77 % 214,758 4.00 % 214,758 4.00 % 268,447 5.00 % As of December 31, 2019 Total Capital (to risk weighted assets) $ 578,425 14.39 % $ 321,556 8.00 % $ 422,043 10.50 % $ 401,945 10.00 % Common Equity Tier 1 Capital (to risk weighted assets) 509,372 12.67 % 180,875 4.50 % 281,362 7.00 % 261,265 6.50 % Tier 1 Capital (to risk weighted assets) 509,372 12.67 % 241,167 6.00 % 341,654 8.50 % 321,556 8.00 % Tier 1 Capital (to average tangible assets) 509,372 10.89 % 187,018 4.00 % 187,018 4.00 % 233,773 5.00 %

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	6 Months Ended
	Jun. 30, 2020
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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 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 $ 9,907 $ 14,248 $ 13,423 $ 26,926 Basic: Weighted average shares outstanding 20,414 $ 0.49 21,257 $ 0.67 20,413 $ 0.66 21,494 $ 1.25 Diluted: Add incremental shares for: Dilutive effect of stock option exercises 100 289 159 286 Total 20,514 $ 0.48 21,546 $ 0.66 20,572 $ 0.65 21,780 $ 1.24

NATURE OF OPERATIONS AND SUMM_3

NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)officeBankLoan	Jul. 24, 2020USD ($)Loan	Dec. 31, 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
Outstanding loan balances deferrals due to CARES Act	$ 1,187,423
Accrued interest receivable	$ 32,795		$ 15,468
Number of approved loans | Loan	5,800
Amount of loan under approved allocation	$ 695,800
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
Second Deferrals
New Accounting Pronouncement Early Adoption [Line Items]
Number of loans deferral due to CARES Act | Loan	47
Outstanding loan balances deferrals due to CARES Act	$ 39,900
COVID-19 | Oil and Gas
New Accounting Pronouncement Early Adoption [Line Items]
Outstanding loan balances, excluding PPP loans deferrals due to CARES Act	74,700
COVID-19 | Hotel and Restaurants
New Accounting Pronouncement Early Adoption [Line Items]
Outstanding loan balances, excluding PPP loans deferrals due to CARES Act	134,000
COVID-19 | Bars
New Accounting Pronouncement Early Adoption [Line Items]
Outstanding loan balances, excluding PPP loans deferrals due to CARES Act	$ 111,300
COVID-19 | First Payment Deferrals
New Accounting Pronouncement Early Adoption [Line Items]
Number of loans deferral due to CARES Act | Loan	2,111
Outstanding loan balances deferrals due to CARES Act	$ 1,190,000
Accrued interest receivable	$ 16,400
Subsequent Event | COVID-19 | Second Deferrals
New Accounting Pronouncement Early Adoption [Line Items]
Number of loans deferral due to CARES Act | Loan		129
Outstanding loan balances deferrals due to CARES Act		$ 100,100
Accrued interest receivable		$ 1,400
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	Jun. 30, 2020$ / shares	Sep. 30, 2019USD ($)shares	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 28, 2018USD ($)$ / shares
Business Acquisition [Line Items]
Options exercised | $ / shares			$ 15.22
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	$ 1,700
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	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill resulting from acquisition		$ 223,642	$ 223,642	$ 223,125
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	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Goodwill
Balance, beginning				$ 223,642	$ 223,125	$ 223,125
Measurement period adjustment						(61)
Balance, ending		$ 223,642		223,642		223,642
Core Deposit Intangible Assets
Balance, beginning				21,876
Amortization		(990)	$ (1,178)	(1,980)	(2,356)
Balance, ending		19,896		19,896		21,876
Core Deposit Intangible Assets
Core Deposit Intangible Assets
Balance, beginning				21,876	$ 26,587	26,587
Amortization				(1,980)		(4,711)
Balance, ending		$ 19,896		$ 19,896		21,876
Lowery Bank
Goodwill
Goodwill, acquired during period	$ 578					$ 578

GOODWILL AND CORE DEPOSIT INT_4

GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Jun. 30, 2020
Finite Lived Intangible Assets [Line Items]
Measurement period adjustment		$ (61,000)
Post Oak Bancshares, Inc.
Finite Lived Intangible Assets [Line Items]
Measurement period adjustment	$ (61,000)
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	Jun. 30, 2020	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Remaining 2020	$ 1,942
2021	3,296
2022	3,003
2023	2,323
2024	2,188
Thereafter	7,144
Total	$ 19,896	$ 21,876

SECURITIES - Amortized Cost and

SECURITIES - Amortized Cost and Fair Value of Investment Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 581,792	$ 366,331
Gross Unrealized Gains	37,157	7,009
Gross Unrealized Losses	(198)	(795)
Fair Value	618,751	372,545
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	27,308	29,420
Gross Unrealized Gains	694	298
Gross Unrealized Losses		(243)
Fair Value	28,002	29,475
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	317,769	84,200
Gross Unrealized Gains	28,268	3,453
Gross Unrealized Losses		(116)
Fair Value	346,037	87,537
Agency mortgage-backed pass-through securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	95,385	104,669
Gross Unrealized Gains	3,984	1,713
Gross Unrealized Losses		(214)
Fair Value	99,369	106,168
Agency collateralized mortgage obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	97,618	106,351
Gross Unrealized Gains	3,994	1,199
Gross Unrealized Losses	(126)	(208)
Fair Value	101,486	107,342
Corporate bonds and other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	43,712	41,691
Gross Unrealized Gains	217	346
Gross Unrealized Losses	(72)	(14)
Fair Value	$ 43,857	$ 42,023

SECURITIES - Amortized Cost a_2

SECURITIES - Amortized Cost and Fair Value of Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized Cost
Due in one year or less	$ 11,002
Due after one year through five years	8,503
Due after five years through ten years	83,999
Due after ten years	285,285
Subtotal	388,789
Agency mortgage-backed pass through and collateralized mortgage obligation securities	193,003
Amortized Cost	581,792	$ 366,331
Fair Value
Due in one year or less	11,038
Due after one year through five years	9,009
Due after five years through ten years	87,239
Due after ten years	310,610
Subtotal	417,896
Agency mortgage-backed pass through and collateralized mortgage obligation securities	200,855
Total	$ 618,751	$ 372,545

SECURITIES - Securities in a Co

SECURITIES - Securities in a Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value	$ 29,322	$ 80,433
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(157)	(732)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value	4,499	4,805
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses	(41)	(63)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	33,821	85,238
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	(198)	(795)
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		22,295
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(239)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value		436
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses		(4)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value		22,731
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses		(243)
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Securities in a Continuous Unrealized Loss Position, Less than 12 months, Estimated Fair Value		9,514
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(116)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value		9,514
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses		(116)
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	24,895	22,340
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(85)	(208)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value	4,499
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses	(41)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	29,394	22,340
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	(126)	(208)
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	4,427	5,492
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(72)	(14)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value	4,427	5,492
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses	$ (72)	(14)
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		20,792
Securities in a Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(155)
Securities in a Continuous Unrealized Loss Position, More than 12 Months, Estimated Fair Value		4,369
Securities in a Continuous Unrealized Loss Position, More than 12 Months Unrealized Losses		(59)
Securities in a Continuous Unrealized Loss Position, Total Estimated Fair Value		25,161
Securities in a Continuous Unrealized Loss Position, Total Unrealized Losses		$ (214)

SECURITIES - Narrative (Details

SECURITIES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Gross realized gains	$ 93	$ 1,400	$ 391	$ 1,400
Gross realized losses		576	104	576
Net realized gain (loss)		846	287	846
Proceeds from sales of available for sale securities	1,100	$ 149,400	30,800	$ 149,400
Calls of available for sale securities	5,500		5,500
Security owned and pledged as collateral	$ 22,400		$ 22,400		$ 24,300

LOANS AND ALLOWANCE FOR LOAN _3

LOANS AND ALLOWANCE FOR LOAN LOSSES - Loan Portfolio (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 4,583,656		$ 3,915,310
Allowance for loan losses	(47,642)	$ (37,511)	(29,438)	$ (27,940)	$ (27,123)	$ (26,331)
Loans, net	4,536,014		3,885,872
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	651,430		689,360
Allowance for loan losses	(13,367)	(10,164)	(8,818)	(8,255)	(8,999)	(8,351)
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0		8,304
Allowance for loan losses	0	0	0	0	0	0
Paycheck Protection Program (PPP)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	695,772		0
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	1,956,116		1,873,782
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	386,865		410,471
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	703,513		698,957
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	171,656		192,515
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	18,304		41,921
Allowance for loan losses	$ (176)	$ (118)	$ (120)	$ (108)	$ (77)	$ (73)

LOANS AND ALLOWANCE FOR LOAN _4

LOANS AND ALLOWANCE FOR LOAN LOSSES - Carrying Amount of PCI Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Recorded investment	$ 4,583,656	$ 3,915,310
PCI Loans
Accounts Notes And Loans Receivable [Line Items]
Outstanding balance	15,687	16,589
Less: Discount	(2,211)	(2,414)
Less: Allowance	(1,432)	(259)
Recorded investment	$ 12,044	$ 13,916

LOANS AND ALLOWANCE FOR LOAN _5

LOANS AND ALLOWANCE FOR LOAN LOSSES - Narrative (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)Loan	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)Loan	Jun. 30, 2019USD ($)contract	Jul. 24, 2020USD ($)Loan	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Accounts Notes And Loans Receivable [Line Items]
Allowance for loan losses	$ 47,642,000	$ 27,940,000	$ 47,642,000	$ 27,940,000		$ 37,511,000	$ 29,438,000	$ 27,123,000	$ 26,331,000
Recorded investment	29,100,000		29,100,000				28,900,000
Change in method of calculating impairment	3,200,000		3,200,000				3,200,000
Troubled debt restructuring, write-down			632,000	0
Troubled debt restructuring, addition			0	4,200,000
Modification of outstanding recorded investment	2,550,000	359,000	3,804,000	$ 1,304,000
Number of defaults on loan that were modified as troubled debt restructuring during the preceding 12 months | contract				2
Outstanding loan balances deferrals due to CARES Act	1,187,423,000		1,187,423,000
Accrued interest receivable	$ 32,795,000		$ 32,795,000				$ 15,468,000
Second Deferrals
Accounts Notes And Loans Receivable [Line Items]
Number of loans deferral due to CARES Act | Loan	47		47
Outstanding loan balances deferrals due to CARES Act	$ 39,900,000		$ 39,900,000
COVID-19 | First Payment Deferrals
Accounts Notes And Loans Receivable [Line Items]
Number of loans deferral due to CARES Act | Loan	2,111		2,111
Outstanding loan balances deferrals due to CARES Act	$ 1,190,000,000		$ 1,190,000,000
Accrued interest receivable	16,400,000		16,400,000
COVID-19 | Second Deferrals | Subsequent Event
Accounts Notes And Loans Receivable [Line Items]
Number of loans deferral due to CARES Act | Loan					129
Outstanding loan balances deferrals due to CARES Act					$ 100,100,000
Accrued interest receivable					$ 1,400,000
Troubled debt added during quarter
Accounts Notes And Loans Receivable [Line Items]
Recorded investment	2,900,000	$ 1,200,000	2,900,000	$ 1,200,000
PCI Loans
Accounts Notes And Loans Receivable [Line Items]
Allowance for loan losses	$ 1,400,000		$ 1,400,000

LOANS AND ALLOWANCE FOR LOAN _6

LOANS AND ALLOWANCE FOR LOAN LOSSES - Aging Analysis of the Recorded Investment in Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	$ 16,326	$ 10,001
Nonaccrual Loans	33,223	28,371
Current Loans	4,534,107	3,876,938
Total loans evaluated for impairment	4,583,656	3,915,310
Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	16,326	10,001
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	6,129	3,098
Nonaccrual Loans	12,578	8,388
Current Loans	632,723	677,874
Total loans evaluated for impairment	651,430	689,360
Commercial and industrial | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	6,129	3,098
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Current Loans		8,304
Total loans evaluated for impairment	0	8,304
Paycheck Protection Program (PPP)
Accounts Notes And Loans Receivable [Line Items]
Current Loans	695,772
Total loans evaluated for impairment	695,772	0
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	5,594	4,421
Nonaccrual Loans	16,127	6,741
Current Loans	1,934,395	1,862,620
Total loans evaluated for impairment	1,956,116	1,873,782
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	5,594	4,421
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	2,310	66
Nonaccrual Loans	53	9,050
Current Loans	384,502	401,355
Total loans evaluated for impairment	386,865	410,471
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	2,310	66
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	1,825	1,598
Nonaccrual Loans	3,434	3,294
Current Loans	698,254	694,065
Total loans evaluated for impairment	703,513	698,957
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	1,825	1,598
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	191	564
Nonaccrual Loans	898	746
Current Loans	170,567	191,205
Total loans evaluated for impairment	171,656	192,515
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	191	564
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	277	254
Nonaccrual Loans	133	152
Current Loans	17,894	41,515
Total loans evaluated for impairment	18,304	41,921
Consumer and other | Financing Receivables, 30 to 89 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due and Still Accruing	$ 277	$ 254

LOANS AND ALLOWANCE FOR LOAN _7

LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired Loans by Loan Class (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
With no related allowance recorded:
Recorded investment with no related allowance recorded	$ 28,252	$ 27,445
Unpaid principal balance with no related allowance recorded	28,473	27,940
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	21,947	27,891
Impaired financing receivable, with related allowance, unpaid principal balance	22,448	28,285
Related Allowance	5,193	6,775
Total:
Recorded Investment	50,199	55,336
Unpaid Principal Balance	50,921	56,225
Related Allowance	5,193	6,775
PCI Loans
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment		2,039
Impaired financing receivable, with related allowance, unpaid principal balance		2,959
Related Allowance		659
Total:
Recorded Investment		2,039
Unpaid Principal Balance		2,959
Related Allowance		659
Commercial and industrial
With no related allowance recorded:
Recorded investment with no related allowance recorded	5,986	5,721
Unpaid principal balance with no related allowance recorded	6,126	6,136
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	10,691	7,812
Impaired financing receivable, with related allowance, unpaid principal balance	11,086	7,286
Related Allowance	4,435	3,480
Total:
Recorded Investment	16,677	13,533
Unpaid Principal Balance	17,212	13,422
Related Allowance	4,435	3,480
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
Paycheck Protection Program (PPP)
With no related allowance recorded:
Recorded investment with no related allowance recorded	0
Unpaid principal balance with no related allowance recorded	0
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	0
Impaired financing receivable, with related allowance, unpaid principal balance	0
Related Allowance	0
Total:
Recorded Investment	0
Unpaid Principal Balance	0
Related Allowance	0
Real estate | Commercial real estate (including multi-family residential)
With no related allowance recorded:
Recorded investment with no related allowance recorded	20,833	19,478
Unpaid principal balance with no related allowance recorded	20,914	19,558
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	5,810	5,335
Impaired financing receivable, with related allowance, unpaid principal balance	5,810	5,335
Related Allowance	381	459
Total:
Recorded Investment	26,643	24,813
Unpaid Principal Balance	26,724	24,893
Related Allowance	381	459
Real estate | Commercial real estate construction and land development
With no related allowance recorded:
Recorded investment with no related allowance recorded	53	0
Unpaid principal balance with no related allowance recorded	53	0
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	3,367	12,142
Impaired financing receivable, with related allowance, unpaid principal balance	3,367	12,142
Related Allowance	221	2,085
Total:
Recorded Investment	3,420	12,142
Unpaid Principal Balance	3,420	12,142
Related Allowance	221	2,085
Real estate | 1-4 family residential (including home equity)
With no related allowance recorded:
Recorded investment with no related allowance recorded	1,353	2,000
Unpaid principal balance with no related allowance recorded	1,353	2,000
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	1,156	0
Impaired financing receivable, with related allowance, unpaid principal balance	1,262	0
Related Allowance	78	0
Total:
Recorded Investment	2,509	2,000
Unpaid Principal Balance	2,615	2,000
Related Allowance	78	0
Real estate | Residential construction
With no related allowance recorded:
Recorded investment with no related allowance recorded	0	208
Unpaid principal balance with no related allowance recorded	0	208
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	898	537
Impaired financing receivable, with related allowance, unpaid principal balance	898	537
Related Allowance	53	66
Total:
Recorded Investment	898	745
Unpaid Principal Balance	898	745
Related Allowance	53	66
Consumer and other
With no related allowance recorded:
Recorded investment with no related allowance recorded	27	38
Unpaid principal balance with no related allowance recorded	27	38
With an allowance recorded:
Impaired financing receivable, with related allowance, recorded investment	25	26
Impaired financing receivable, with related allowance, unpaid principal balance	25	26
Related Allowance	25	26
Total:
Recorded Investment	52	64
Unpaid Principal Balance	52	64
Related Allowance	$ 25	$ 26

LOANS AND ALLOWANCE FOR LOAN _8

LOANS AND ALLOWANCE FOR LOAN LOSSES - Average Impaired Loans and Interest Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	$ 50,667	$ 37,860	$ 50,841	$ 38,368
Interest Income Recognized	190	230	575	452
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	16,997	12,280	17,302	12,575
Interest Income Recognized	62	75	164	167
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	0	0	0	0
Interest Income Recognized	0	0	0	0
Paycheck Protection Program (PPP)
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	26,710	19,589	26,825	19,781
Interest Income Recognized	74	98	307	193
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	3,436	4,661	3,289	4,664
Interest Income Recognized	50	57	97	88
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	2,529	1,293	2,547	1,310
Interest Income Recognized	3	0	6	4
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	940	0	822	0
Interest Income Recognized	0	0	0	0
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Average Recorded Investment	55	37	56	38
Interest Income Recognized	$ 1	$ 0	$ 1	$ 0

LOANS AND ALLOWANCE FOR LOAN _9

LOANS AND ALLOWANCE FOR LOAN LOSSES - Risk Category of Loans by Class (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 4,583,656	$ 3,915,310
Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	4,241,373	3,713,792
Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	217,194	89,879
Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	44,309	25,251
Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	80,627	86,310
Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	153	78
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	651,430	689,360
Commercial and industrial | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	582,937	641,696
Commercial and industrial | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	27,633	14,170
Commercial and industrial | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	11,877	9,121
Commercial and industrial | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	28,830	24,295
Commercial and industrial | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	153	78
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	8,304
Mortgage warehouse | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	8,304
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
Paycheck Protection Program (PPP)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	695,772	0
Paycheck Protection Program (PPP) | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	695,772
Paycheck Protection Program (PPP) | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0
Paycheck Protection Program (PPP) | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0
Paycheck Protection Program (PPP) | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0
Paycheck Protection Program (PPP) | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	1,956,116	1,873,782
Real estate | Commercial real estate (including multi-family residential) | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	1,745,562	1,775,789
Real estate | Commercial real estate (including multi-family residential) | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	143,848	47,762
Real estate | Commercial real estate (including multi-family residential) | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	26,487	9,289
Real estate | Commercial real estate (including multi-family residential) | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	40,219	40,942
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	386,865	410,471
Real estate | Commercial real estate construction and land development | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	368,788	388,151
Real estate | Commercial real estate construction and land development | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	15,488	9,583
Real estate | Commercial real estate construction and land development | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	639
Real estate | Commercial real estate construction and land development | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	2,589	12,098
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	703,513	698,957
Real estate | 1-4 family residential (including home equity) | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	662,551	669,288
Real estate | 1-4 family residential (including home equity) | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	27,384	15,798
Real estate | 1-4 family residential (including home equity) | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	5,668	5,844
Real estate | 1-4 family residential (including home equity) | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	7,910	8,027
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	171,656	192,515
Real estate | Residential construction | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	168,087	189,209
Real estate | Residential construction | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	2,671	2,560
Real estate | Residential construction | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	0	0
Real estate | Residential construction | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	898	746
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	18,304	41,921
Consumer and other | Pass
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	17,676	41,355
Consumer and other | Watch
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	170	6
Consumer and other | Special Mention
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	277	358
Consumer and other | Substandard
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	181	202
Consumer and other | Doubtful
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 0	$ 0

LOANS AND ALLOWANCE FOR LOAN_10

LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019
Allowance for loan losses:
Balance, beginning of period	$ 37,511	$ 27,123	$ 29,438	$ 26,331
Provision for loan losses	10,669	1,407	21,659	2,409
Charge-offs	(582)	(645)	(3,714)	(971)
Recoveries	44	55	259	171
Net charge-offs	(538)	(590)	(3,455)	(800)
Balance, end of period	47,642	27,940	47,642	27,940
Allowance for loan losses related to:
Individually evaluated for impairment					$ 5,193	$ 6,775
Collectively evaluated for impairment					42,449	22,663
Total allowance for loan losses	37,511	27,940	29,438	26,331	47,642	29,438
Recorded investment in loans:
Individually evaluated for impairment					50,199	55,336
Collectively evaluated for impairment					4,533,457	3,859,974
Total loans evaluated for impairment					4,583,656	3,915,310
Commercial and industrial
Allowance for loan losses:
Balance, beginning of period	10,164	8,999	8,818	8,351
Provision for loan losses	3,517	(457)	5,382	346
Charge-offs	(358)	(342)	(1,092)	(588)
Recoveries	44	55	259	146
Net charge-offs	(314)	(287)	(833)	(442)
Balance, end of period	13,367	8,255	13,367	8,255
Allowance for loan losses related to:
Individually evaluated for impairment					4,435	4,139
Collectively evaluated for impairment					8,932	4,679
Total allowance for loan losses	13,367	8,255	8,818	8,351	13,367	8,818
Recorded investment in loans:
Individually evaluated for impairment					16,677	15,572
Collectively evaluated for impairment					634,753	673,788
Total loans evaluated for impairment					651,430	689,360
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 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					0	8,304
Total loans evaluated for impairment					0	8,304
Paycheck Protection Program (PPP)
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 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					695,772	0
Total loans evaluated for impairment					695,772	0
Commercial Real Estate Portfolio Segment | Commercial real estate (including multi-family residential)
Allowance for loan losses:
Balance, beginning of period	16,751	11,739	11,170	11,901
Provision for loan losses	4,131	1,201	9,856	1,116
Charge-offs	7	0	(137)	(80)
Recoveries	0	0	0	3
Net charge-offs	7	0	(137)	(77)
Balance, end of period	20,889	12,940	20,889	12,940
Allowance for loan losses related to:
Individually evaluated for impairment					381	459
Collectively evaluated for impairment					20,508	10,711
Total allowance for loan losses	20,889	12,940	11,170	11,901	20,889	11,170
Recorded investment in loans:
Individually evaluated for impairment					26,643	24,813
Collectively evaluated for impairment					1,929,473	1,848,969
Total loans evaluated for impairment					1,956,116	1,873,782
Commercial Real Estate Portfolio Segment | Commercial real estate construction and land development
Allowance for loan losses:
Balance, beginning of period	2,989	2,289	4,421	2,724
Provision for loan losses	982	(32)	1,714	(467)
Charge-offs	(106)	0	(2,270)	0
Recoveries	0	0	0	0
Net charge-offs	(106)	0	(2,270)	0
Balance, end of period	3,865	2,257	3,865	2,257
Allowance for loan losses related to:
Individually evaluated for impairment					221	2,085
Collectively evaluated for impairment					3,644	2,336
Total allowance for loan losses	3,865	2,257	4,421	2,724	3,865	4,421
Recorded investment in loans:
Individually evaluated for impairment					3,420	12,142
Collectively evaluated for impairment					383,445	398,329
Total loans evaluated for impairment					386,865	410,471
Commercial Real Estate Portfolio Segment | 1-4 family residential (including home equity)
Allowance for loan losses:
Balance, beginning of period	6,058	2,895	3,852	2,242
Provision for loan losses	1,609	776	3,905	1,429
Charge-offs	(125)	(295)	(215)	(295)
Recoveries	0	0	0	0
Net charge-offs	(125)	(295)	(215)	(295)
Balance, end of period	7,542	3,376	7,542	3,376
Allowance for loan losses related to:
Individually evaluated for impairment					78	0
Collectively evaluated for impairment					7,464	3,852
Total allowance for loan losses	7,542	3,376	3,852	2,242	7,542	3,852
Recorded investment in loans:
Individually evaluated for impairment					2,509	2,000
Collectively evaluated for impairment					701,004	696,957
Total loans evaluated for impairment					703,513	698,957
Commercial Real Estate Portfolio Segment | Residential construction
Allowance for loan losses:
Balance, beginning of period	1,431	1,124	1,057	1,040
Provision for loan losses	372	(120)	746	(36)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net charge-offs	0	0	0	0
Balance, end of period	1,803	1,004	1,803	1,004
Allowance for loan losses related to:
Individually evaluated for impairment					53	66
Collectively evaluated for impairment					1,750	991
Total allowance for loan losses	1,803	1,004	1,057	1,040	1,803	1,057
Recorded investment in loans:
Individually evaluated for impairment					898	745
Collectively evaluated for impairment					170,758	191,770
Total loans evaluated for impairment					171,656	192,515
Consumer and other
Allowance for loan losses:
Balance, beginning of period	118	77	120	73
Provision for loan losses	58	39	56	21
Charge-offs	0	(8)	0	(8)
Recoveries	0	0	0	22
Net charge-offs	0	(8)	0	14
Balance, end of period	176	108	176	108
Allowance for loan losses related to:
Individually evaluated for impairment					25	26
Collectively evaluated for impairment					151	94
Total allowance for loan losses	$ 176	$ 108	$ 120	$ 73	176	120
Recorded investment in loans:
Individually evaluated for impairment					52	64
Collectively evaluated for impairment					18,252	41,857
Total loans evaluated for impairment					$ 18,304	$ 41,921

LOANS AND ALLOWANCE FOR LOAN_11

LOANS AND ALLOWANCE FOR LOAN LOSSES - Loans Modified in a Troubled Debt Restructuring (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)contract	Jun. 30, 2019USD ($)contract	Jun. 30, 2020USD ($)contract	Jun. 30, 2019USD ($)contract
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	9	2	16	10
Pre-Modification of Outstanding Recorded Investment	$ 2,550	$ 359	$ 3,804	$ 1,304
Post Modification of Outstanding Recorded Investment	$ 2,550	$ 359	$ 3,804	$ 1,304
Paycheck Protection Program (PPP)
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
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	6	1	11	7
Pre-Modification of Outstanding Recorded Investment	$ 899	$ 56	$ 2,004	$ 567
Post Modification of Outstanding Recorded Investment	$ 899	$ 56	$ 2,004	$ 567
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	1	0	1
Pre-Modification of Outstanding Recorded Investment	$ 0	$ 303	$ 0	$ 303
Post Modification of Outstanding Recorded Investment	$ 0	$ 303	$ 0	$ 303
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	1	0	1	0
Pre-Modification of Outstanding Recorded Investment	$ 830	$ 0	$ 830	$ 0
Post Modification of Outstanding Recorded Investment	$ 830	$ 0	$ 830	$ 0
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Number of Contracts | contract	2	0	3	1
Pre-Modification of Outstanding Recorded Investment	$ 821	$ 0	$ 940	$ 396
Post Modification of Outstanding Recorded Investment	$ 821	$ 0	$ 940	$ 396
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	1
Pre-Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 30	$ 38
Post Modification of Outstanding Recorded Investment	$ 0	$ 0	$ 30	$ 38

LOANS AND ALLOWANCE FOR LOAN_12

LOANS AND ALLOWANCE FOR LOAN LOSSES - Schedule of Principal and Interest Deferrals Associated with Loan Modifications Related to COVID 19 (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 4,583,656	$ 3,915,310
Deferred Loan Balance	$ 1,187,423
Percentage of Total Deferrals	100.00%
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 651,430	689,360
Deferred Loan Balance	$ 134,073
Percentage of Total Deferrals	11.30%
Mortgage warehouse
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 0	8,304
Percentage of Total Deferrals	0.00%
Paycheck Protection Program (PPP)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 695,772	0
Percentage of Total Deferrals	0.00%
Real estate | Commercial real estate (including multi-family residential)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 1,956,116	1,873,782
Deferred Loan Balance	$ 793,115
Percentage of Total Deferrals	66.80%
Real estate | Commercial real estate construction and land development
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 386,865	410,471
Deferred Loan Balance	$ 101,456
Percentage of Total Deferrals	8.50%
Real estate | 1-4 family residential (including home equity)
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 703,513	698,957
Deferred Loan Balance	$ 139,565
Percentage of Total Deferrals	11.80%
Real estate | Residential construction
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 171,656	192,515
Deferred Loan Balance	$ 18,017
Percentage of Total Deferrals	1.50%
Consumer and other
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 18,304	$ 41,921
Deferred Loan Balance	$ 1,197
Percentage of Total Deferrals	0.10%

LEASES - Narrative (Details)

LEASES - Narrative (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2020USD ($)	Sep. 30, 2019USD ($)Property	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)BranchLocationandOfficeSpace	Jun. 30, 2019USD ($)
Lessee Lease Description [Line Items]
Number of leased branch locations and office space along with equipment | BranchLocationandOfficeSpace				14
Operating lease, existence of option to extend				true
Operating lease, cost	$ 763		$ 777	$ 1,584	$ 1,547
Allegiance Bank
Lessee Lease Description [Line Items]
Number of leased properties | Property		2
Operating lease, cost		$ 10,700
Maximum
Lessee Lease Description [Line Items]
Lessee, operating Lease, term of contract	12 months			12 months
Operating lease renewal term	5 years			5 years
Minimum
Lessee Lease Description [Line Items]
Operating lease renewal term	1 year			1 year

LEASES - Supplemental Lease Inf

LEASES - Supplemental Lease Information (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Balance Sheet:
Operating lease right of use asset classified as premises and equipment	$ 10,435	$ 11,180
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	$ 10,711	$ 11,477
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities	us-gaap:OtherLiabilities
Weighted average lease term, in years	5 years 2 months 15 days	5 years 6 months 10 days
Weighted average discount rate	3.11%	3.19%

LEASES - Summary of Lease Costs

LEASES - Summary of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement:
Operating lease cost	$ 763	$ 777	$ 1,584	$ 1,547
Short-term lease cost	36	183	50	374
Sublease income	(12)	(18)	(30)	(36)
Total operating lease costs	$ 787	$ 942	$ 1,604	$ 1,885

LEASES - Maturity Analysis of L

LEASES - Maturity Analysis of Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Lease payments due:
Within one year	$ 2,856	$ 2,867
After one but within two years	2,652	2,608
After two but within three years	1,864	2,204
After three but within four years	1,627	1,596
After four but within five years	817	1,131
After five years	1,830	2,162
Total lease payments	11,646	12,568
Discount on cash flows	935	1,091
Total lease liability	$ 10,711	$ 11,477

FAIR VALUE - Carrying Amounts a

FAIR VALUE - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 618,751	$ 372,545
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	266,400	346,248
Available for sale securities	618,751	372,545
Loans held for investment, net of allowance	4,536,014	3,885,872
Accrued interest receivable	32,795	15,468
Deposits	4,700,711	4,068,101
Accrued interest payable	3,293	4,326
Borrowed funds	255,509	75,503
Subordinated debt	108,061	107,799
Interest rate swap	1,575
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	266,400	346,248
Available for sale securities	618,751	372,545
Loans held for investment, net of allowance	4,495,391	3,918,210
Accrued interest receivable	32,795	15,468
Deposits	4,721,264	4,073,031
Accrued interest payable	3,293	4,326
Borrowed funds	257,442	83,302
Subordinated debt	102,928	109,607
Interest rate swap	1,575
Estimated Fair Value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	266,400	346,248
Available for sale securities	0	0
Loans held for investment, net of allowance	0	0
Accrued interest receivable	2	13
Deposits	0	0
Accrued interest payable	0	0
Borrowed funds	0	0
Subordinated debt	0	0
Interest rate swap	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	618,751	372,545
Loans held for investment, net of allowance	0	0
Accrued interest receivable	4,558	1,783
Deposits	4,721,264	4,073,031
Accrued interest payable	3,293	4,326
Borrowed funds	257,442	83,302
Subordinated debt	102,928	109,607
Interest rate swap	1,575
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	4,495,391	3,918,210
Accrued interest receivable	28,235	13,672
Deposits	0	0
Accrued interest payable	0	0
Borrowed funds	0	0
Subordinated debt	0	$ 0
Interest rate swap	$ 0

FAIR VALUE - Fair Values for As

FAIR VALUE - Fair Values for Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 618,751,000	$ 372,545,000
U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	28,002,000	29,475,000
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	346,037,000	87,537,000
Agency mortgage-backed pass-through securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	99,369,000	106,168,000
Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	101,486,000	107,342,000
Corporate bonds and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	43,857,000	42,023,000
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	618,751,000	372,545,000
Financial liabilities		0
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	618,751,000	372,545,000
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	28,002,000	29,475,000
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	28,002,000	29,475,000
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	346,037,000	87,537,000
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	346,037,000	87,537,000
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	99,369,000	106,168,000
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	99,369,000	106,168,000
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	101,486,000	107,342,000
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	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	101,486,000	107,342,000
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	0
Recurring Basis | Corporate bonds and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	43,857,000	42,023,000
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	43,857,000	42,023,000
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
Recurring Basis | Interest rate swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	1,575,000
Recurring Basis | Interest rate swap | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	0
Recurring Basis | Interest rate swap | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	1,575,000
Recurring Basis | Interest rate swap | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	$ 0

FAIR VALUE - Narrative (Details

FAIR VALUE - Narrative (Details)	6 Months Ended
	Jun. 30, 2020USD ($)Property	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total reported fair value of impaired loans based on collateral valuations	$ 50,199,000		$ 55,336,000
Impaired financing receivable, with related allowance, recorded investment	21,947,000		27,891,000
Related allowance	5,193,000		6,775,000
Real estate acquired through foreclosure	$ 11,847,000		8,337,000
Foreclosed Commercial Real Estate Property
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of properties | Property	3
Tract of Vacant 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
Rural Homestead
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of properties | Property	1
Impaired Loans with Specific Allocation of Allowance | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of estimated selling and closing costs of collateral	5.00%
Impaired Loans with Specific Allocation of Allowance | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of estimated selling and closing costs of collateral	10.00%
Other Real Estate Owned | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of estimated selling and closing costs of collateral	5.00%
Other Real Estate Owned | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of estimated selling and closing costs of collateral	10.00%
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total reported fair value of impaired loans based on collateral valuations	$ 16,800,000		21,100,000
Impaired financing receivable, with related allowance, recorded investment	21,900,000		27,900,000
Related allowance	5,200,000		6,800,000
Real estate acquired through foreclosure	11,800,000		8,300,000
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities			$ 0
Transfers of assets between Level 1 and Level 2	0	$ 0
Transfers of assets between Level 2 and Level 1	0	0
Transfers of assets into Level 3	0	0
Transfers of assets out of Level 3	0	0
Transfers of liabilities between Level 1 and Level 2	0	0
Transfers of liabilities between Level 2 and Level 3	0	0
Transfers of liabilities into Level 3	0	0
Transfers of liabilities out of Level 3	$ 0	$ 0

FAIR VALUE - Assets Measured at

FAIR VALUE - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - Nonrecurring Basis - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
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 | PCI Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:		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 | 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 1 | 1-4 family residential (including home equity)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0
Level 1 | Residential construction
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 | PCI Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:		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 | 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 | 1-4 family residential (including home equity)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	0
Level 2 | Residential construction
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	11,847	8,337
Assets and liabilities are measured at fair value, nonrecurring basis	28,601	29,453
Level 3 | PCI Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:		1,380
Level 3 | Commercial and industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	6,256	4,332
Level 3 | Commercial real estate (including multi-family residential)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	5,429	4,876
Level 3 | Commercial real estate construction and land development
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	3,146	10,057
Level 3 | 1-4 family residential (including home equity)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	1,078
Level 3 | Residential construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans:	$ 845	$ 471

DEPOSITS - Narrative (Details)

DEPOSITS - Narrative (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Deposit Liabilities [Abstract]
Time deposits, at or above FDIC insurance limit	$ 250
Time deposits 250,000 or more	615,200	$ 485,800
Brokered deposits	$ 385,900	$ 263,500

DEPOSITS - Time Deposits by Mat

DEPOSITS - Time Deposits by Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Deposit Liabilities [Abstract]
Within one year	$ 862,957
After one but within two years	226,874
After two but within three years	112,381
After three but within four years	45,778
After four but within five years	52,803
Total	$ 1,300,793	$ 1,190,583

DERIVATIVE INSTRUMENTS - Summar

DERIVATIVE INSTRUMENTS - Summary of Cash Flow Hedge Relationships (Detail) - Interest rate swap - Other Liabilities - Cash Flow Hedging - Designated as Hedging Instrument	6 Months Ended
	Jun. 30, 2020USD ($)
Derivatives Fair Value [Line Items]
Weighted Average Maturity (In Years)	4 years 9 months 10 days
Weighted Average Pay Rate	0.64%
Receive Rate	3 month LIBOR
Notional Amount	$ 100,000,000
Estimated Fair Value	$ (1,575,000)

DERIVATIVE INSTRUMENTS - Effect

DERIVATIVE INSTRUMENTS - Effect of Cash Flow Hedge Relationship on Statement of Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income (Loss)	$ (1,245)	$ (1,245)
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swap
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income (Loss)	$ (1,245)	$ (1,245)

DERIVATIVE INSTRUMENTS - Narrat

DERIVATIVE INSTRUMENTS - Narrative (Details) - Cash Flow Hedging - Designated as Hedging Instrument $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2020USD ($)
Derivative Instruments Gain Loss [Line Items]
Unrealized gain reclassified as reduction of interest expense during the next twelve months	$ 131	$ 131
Gains/Losses, net of tax reclassified from accumulated other comprehensive income into net income	$ 103	$ 103

BORROWINGS AND BORROWING CAPA_2

BORROWINGS AND BORROWING CAPACITY - Narrative (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Dec. 28, 2018
Revolving Credit Agreement
Debt Instrument [Line Items]
Outstanding amount	$ 15,600,000
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	3.00%
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	$ 1,750,000,000
Remaining borrowing capacity	1,230,000,000
Outstanding amount	515,500,000
Letters of credit, outstanding amount	275,500,000
Federal Home Loan Bank of Dallas | Expire in Remaining Month of 2020
Debt Instrument [Line Items]
Letters of credit, outstanding amount	42,900,000
Federal Home Loan Bank of Dallas | Expire in 2022
Debt Instrument [Line Items]
Letters of credit, outstanding amount	53,200,000
Federal Home Loan Bank of Dallas | Expire in 2021
Debt Instrument [Line Items]
Letters of credit, outstanding amount	179,400,000
Federal Home Loan Bank of Dallas | Short-term Debt
Debt Instrument [Line Items]
Federal Home Loan Bank, advances	$ 240,000,000
Federal Home Loan Bank of Dallas | Short-term Debt | Weighted Average
Debt Instrument [Line Items]
Federal Home Loan Bank, advances, interest rate	0.86%

SUBORDINATED DEBT - Narrative (

SUBORDINATED DEBT - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended		6 Months Ended
	Sep. 30, 2019	Dec. 31, 2017	Jun. 30, 2020	Jan. 01, 2015
Subordinated Borrowing [Line Items]
Junior subordinated debt owed to trusts			$ 11,341
Subordinated Notes | Fixed-to-Floating Rate Subordinated Notes
Subordinated Borrowing [Line Items]
Debt instrument, face amount	$ 60,000	$ 40,000
Issuance price, percentage	100.00%	100.00%
Proceeds from issuance of debt	$ 58,600	$ 39,400
Stated percentage	4.70%	5.25%
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
Debt instrument, carrying value			$ 9,600
Debt instrument, unamortized discount				$ 2,500

SUBORDINATED DEBT - Summary of

SUBORDINATED DEBT - Summary of Pertinent Information Related to Junior Subordinated Debentures (Details)	6 Months Ended
	Jun. 30, 2020USD ($)
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	0.31026%
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 June 30, 2020 was 0.31026%.

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income tax expense	$ 2,054,000	$ 3,681,000	$ 2,897,000	$ 6,778,000
Effective income tax rate reconciliation, percent	17.20%	20.50%	17.80%	20.10%
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		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
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	$ 914	$ 882	$ 1,700	$ 1,500
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	$ 232		$ 232
Weighted average period over which unrecognized compensation			7 months 24 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Unrecognized compensation cost	5,400		$ 5,400
Weighted average period over which unrecognized compensation			2 years 7 months 28 days
Equity instruments other than options, grants in period (in shares)			59,662
Share awards granted (in shares)			60,000
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			2 years
Weighted average period over which unrecognized compensation			2 years 4 months 2 days
Service period			1 year
Share awards granted (in shares)			46,243		34,628
Unrecognized compensation expense	$ 1,600		$ 1,600

STOCK BASED COMPENSATION - Stoc

STOCK BASED COMPENSATION - Stock Option Plans Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Number of Options
Options outstanding, beginning balance (in shares)	616
Options exercised (in shares)	(86)
Options forfeited (in shares)	(2)
Options outstanding, ending balance (in shares)	528	616
Number of options vested and exercisable (in shares)	498
Weighted Average Exercise Price
Options outstanding, beginning balance (in dollars per share)	$ 19.90
Options exercised (in dollars per share)	15.22
Options forfeited (in dollars per share)	21.60
Options outstanding, ending balance (in dollars per share)	20.61	$ 19.90
Weighted Average Exercise Price, Options vested and exercisable (in dollars per share)	$ 19.82
Weighted Average Remaining Contractual Term, Options outstanding	3 years 8 months 19 days	4 years
Weighted Average Remaining Contractual Term, Options vested and exercisable	3 years 6 months 14 days
Aggregate Intrinsic Value, Options outstanding	$ 2,521	$ 10,904
Aggregate Intrinsic Value, Options vested and exercisable	$ 2,775

STOCK BASED COMPENSATION - Summ

STOCK BASED COMPENSATION - Summary of Restricted Stock Activity (Details) - Restricted Stock shares in Thousands	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Number of Shares
Nonvested share awards outstanding, beginning balance (in shares) | shares	167
Share awards granted (in shares) | shares	60
Share awards vested (in shares) | shares	(35)
Unvested share awards forfeited or cancelled (in shares) | shares	(6)
Nonvested share awards outstanding, ending balance (in shares) | shares	186
Weighted Average Grant Date Fair Value
Nonvested share awards outstanding, beginning balance (in dollars per share) | $ / shares	$ 36.23
Share awards granted (in dollars per share) | $ / shares	22.47
Share awards vested (in dollars per share) | $ / shares	33.62
Unvested share awards forfeited or cancelled (in dollars per share) | $ / shares	38.69
Nonvested share awards outstanding, ending balance | $ / shares	$ 32.23

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	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	$ 649,813	$ 518,254
Variable Rate	509,737	535,779
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	637,924	507,411
Variable Rate	504,261	531,470
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	11,889	10,843
Variable Rate	$ 5,476	$ 4,309

OFF-BALANCE SHEET ARRANGEMENT_4

OFF-BALANCE SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES - Narrative (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
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	2 years 8 months 26 days	3 years 7 months 2 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	8.25%	8.40%
Weighted Average
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet fixed rate loan commitments, interest rate	5.09%	5.32%

REGULATORY CAPITAL MATTERS - Na

REGULATORY CAPITAL MATTERS - Narrative (Details)	Dec. 31, 2018
Banking And Thrift [Abstract]
Capital conservation buffer	2.50%

REGULATORY CAPITAL MATTERS - Ac

REGULATORY CAPITAL MATTERS - Actual and Required Capital (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Total Capital
Capital	$ 620,363	$ 596,684
Capital to Risk Weighted Assets	15.17%	14.83%
Capital Required for Capital Adequacy	$ 327,178	$ 321,775
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Plus Capital Conservation Buffer	$ 429,422	$ 422,330
Plus Capital Conservation Buffer to Risk Weighted Assets	10.50%	10.50%
Common Equity Tier 1 Capital
Common Equity Tier 1 Risk Based Capital	$ 464,661	$ 459,447
Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	11.36%	11.42%
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy	$ 184,038	$ 180,999
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	$ 286,281	$ 281,553
Plus Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	7.00%	7.00%
Tier 1 Capital
Tier 1 Risk Based Capital	$ 474,242	$ 468,972
Tier 1 Risk Based Capital to Risk Weighted Assets	11.60%	11.66%
Tier 1 Risk Based Capital Required for Capital Adequacy	$ 245,384	$ 241,331
Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Plus Tier 1 Risk Based Capital	$ 347,627	$ 341,886
Plus Tier 1 Risk Based Capital to Risk Weighted Assets	8.50%	8.50%
Tier 1 Capital
Tier 1 Leverage Capital	$ 474,242	$ 468,972
Tier 1 Leverage Capital to Average Assets	8.83%	10.02%
Tier 1 Leverage Capital Required for Capital Adequacy	$ 214,867	$ 187,146
Tier 1 Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Plus Tier 1 Leverage Capital	$ 214,867	$ 187,146
Plus Tier 1 Leverage Capital to Average Assets	4.00%	4.00%
Allegiance Bank
Total Capital
Capital	$ 612,044	$ 578,425
Capital to Risk Weighted Assets	14.97%	14.39%
Capital Required for Capital Adequacy	$ 326,970	$ 321,556
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Plus Capital Conservation Buffer	$ 429,149	$ 422,043
Plus Capital Conservation Buffer to Risk Weighted Assets	10.50%	10.50%
Capital Required to be Well Capitalized	$ 408,713	$ 401,945
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	$ 524,722	$ 509,372
Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	12.84%	12.67%
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy	$ 183,921	$ 180,875
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	$ 286,099	$ 281,362
Plus Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	7.00%	7.00%
Common Equity Tier 1 Risk Based Capital Required to be Well Capitalized	$ 265,664	$ 261,265
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	$ 524,722	$ 509,372
Tier 1 Risk Based Capital to Risk Weighted Assets	12.84%	12.67%
Tier 1 Risk Based Capital Required for Capital Adequacy	$ 245,228	$ 241,167
Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Plus Tier 1 Risk Based Capital	$ 347,406	$ 341,654
Plus Tier 1 Risk Based Capital to Risk Weighted Assets	8.50%	8.50%
Tier 1 Risk Based Capital Required to be Well Capitalized	$ 326,970	$ 321,556
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	$ 524,722	$ 509,372
Tier 1 Leverage Capital to Average Assets	9.77%	10.89%
Tier 1 Leverage Capital Required for Capital Adequacy	$ 214,758	$ 187,018
Tier 1 Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Plus Tier 1 Leverage Capital	$ 214,758	$ 187,018
Plus Tier 1 Leverage Capital to Average Assets	4.00%	4.00%
Tier 1 Leverage Capital Required to be Well Capitalized	$ 268,447	$ 233,773
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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income attributable to shareholders	$ 9,907	$ 14,248	$ 13,423	$ 26,926
Basic:
Weighted average shares outstanding (in shares)	20,414	21,257	20,413	21,494
Weighted average shares outstanding (in dollars per share)	$ 0.49	$ 0.67	$ 0.66	$ 1.25
Diluted:
Dilutive effect of stock option exercises (in shares)	100	289	159	286
Total (in shares)	20,514	21,546	20,572	21,780
Total (in dollars per share)	$ 0.48	$ 0.66	$ 0.65	$ 1.24

EARNINGS PER COMMON SHARE - Nar

EARNINGS PER COMMON SHARE - Narrative (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
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)	71,990	41,875