Spirit of Texas Bancshares (STXB) 10-Q 30 Apr 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 26, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Trading Symbol	STXB
Entity Registrant Name	Spirit of Texas Bancshares, Inc.
Entity Central Index Key	0001499453
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	false
Entity Common Stock, Shares Outstanding		17,145,575
Entity Shell Company	false
Title of 12(b) Security	Common Stock, no par value
Security Exchange Name	NASDAQ
Entity File Number	001-38484
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	90-0499552
Entity Address, Address Line One	1836 Spirit of Texas Way
Entity Address, City or Town	Conroe
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77301
City Area Code	936
Local Phone Number	521-1836
Document Quarterly Report	true
Document Transition Report	false

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Assets:
Cash and due from banks		$ 28,879	$ 31,396
Interest-bearing deposits in other banks		40,687	231,638
Total cash and cash equivalents		69,566	263,034
Investment securities:
Available for sale securities, at fair value		442,576	212,420
Equity investments, at fair value		23,741	24,000
Total investment securities		466,317	236,420
Loans held for sale		1,192	1,470
Loans:
Loans held for investment	[1]	2,430,594	2,388,532
Less: allowance for loan and lease losses		(16,314)	(16,026)
Loans, net		2,414,280	2,372,506
Premises and equipment, net		81,379	83,348
Accrued interest receivable		10,588	11,199
Other real estate owned and repossessed assets			133
Goodwill		77,681	77,681
Core deposit intangible		6,995	7,818
SBA servicing asset		2,821	2,953
Deferred tax asset, net		2,213	1,085
Bank-owned life insurance		16,057	15,969
Federal Home Loan Bank and other bank stock, at cost		5,727	5,718
Right of use asset		6,058
Other assets		9,338	5,425
Total assets		3,170,212	3,084,759
Transaction accounts:
Noninterest-bearing		800,233	727,543
Interest-bearing		1,149,781	1,092,934
Total transaction accounts		1,950,014	1,820,477
Time deposits		647,536	638,658
Total deposits		2,597,550	2,459,135
Accrued interest payable		1,160	1,303
Short-term borrowings			10,000
Long-term borrowings		191,686	242,020
Operating lease liability		6,231
Other liabilities		7,827	11,522
Total liabilities		2,804,454	2,723,980
Commitments and contingencies (Note 14)
Stockholders' Equity:
Common stock, no par value; 50 million shares authorized; 18,442,821 and 18,329,593 shares issued; 17,136,553 and 17,081,831 shares outstanding		300,591	298,850
Retained earnings		85,246	76,683
Accumulated other comprehensive income (loss)		(3,224)	1,005
Treasury stock, 1,306,268 and 1,247,762 shares repurchased		(16,855)	(15,759)
Total stockholders' equity		365,758	360,779
Total liabilities and stockholders' equity		$ 3,170,212	$ 3,084,759
[1]	Organic loans balance includes $(11.9) million and $(8.2) million of deferred fees, cost, premium and discount as of March 31, 2021 and December 31, 2020, respectively.

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares, issued	18,442,821	18,329,593
Common stock, shares, outstanding	17,136,553	17,081,831
Treasury stock, shares repurchased	1,306,268	1,247,762

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest income:
Interest and fees on loans	$ 29,829	$ 27,409
Interest and dividends on investment securities	1,115	504
Other interest income	225	900
Total interest income	31,169	28,813
Interest expense:
Interest on deposits	2,327	4,507
Interest on FHLB advances and other borrowings	1,003	508
Total interest expense	3,330	5,015
Net interest income	27,839	23,798
Provision for loan losses	1,086	1,171
Net interest income after provision for loan losses	26,753	22,627
Noninterest income:
Service charges and fees	1,434	1,311
SBA loan servicing fees	324	10
Mortgage referral fees	274	202
Swap referral fees	430	580
Gain on sales of loans, net	254	464
Gain on sales of investment securities	5
Other noninterest (loss) income	(102)	145
Total noninterest income	2,619	2,712
Noninterest expense:
Salaries and employee benefits	9,220	11,789
Occupancy and equipment expenses	2,662	2,315
Professional services	524	895
Data processing and network	1,229	743
Regulatory assessments and insurance	535	402
Amortization of intangibles	823	946
Advertising	78	153
Marketing	93	160
Telephone expense	499	407
Conversion expense		1,477
Other operating expenses	971	1,673
Total noninterest expense	16,634	20,960
Income before income tax expense	12,738	4,379
Income tax expense	2,652	305
Net income	$ 10,086	$ 4,074
Earnings per common share:
Basic	$ 0.59	$ 0.22
Diluted	$ 0.58	$ 0.22
Weighted average common shares outstanding:
Basic	17,103,981	18,184,110
Diluted	17,518,029	18,441,977

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 10,086	$ 4,074
Other comprehensive (loss) income:
Unrealized net holding gains (losses) on investment securities available for sale, net of (tax) and benefit of $1,460 and $(17), respectively	(5,490)	65
Reclassification adjustment for realized (gains) losses on investment securities available for sale included in net income, net of taxes of $1 and $0, respectively	(4)
Change in accumulated gain on effective cash flow hedge derivatives, net of tax of $(336)	1,265
Total other comprehensive (loss) income	(4,229)	65
Total comprehensive income	$ 5,857	$ 4,139

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Unrealized net holding gains (losses) on investment securities available for sale, (tax) and benefit	$ 1,460	$ (17)
Reclassification adjustment for realized (gains) losses on investment securities available for sale included in net income, tax	1	$ 0
Change in accumulated gain on effective cash flow hedge derivatives, net of tax	$ (336)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income
Balance at Dec. 31, 2019	$ 345,705	$ 297,188	$ 48,139	$ (289)	$ 667
Balance (in shares) at Dec. 31, 2019		18,258,222
Net income	4,074		4,074
Exercise of stock options and warrants	401	$ 401
Exercise of stock options and warrants (in shares)		32,000
Stock-based compensation	377	$ 377
Treasury stock purchases	(4,805)			(4,805)
Treasury stock purchases (in shares)		(321,210)
Other comprehensive income (loss)	65				65
Balance at Mar. 31, 2020	345,817	$ 297,966	52,213	(5,094)	732
Balance (in shares) at Mar. 31, 2020		17,969,012
Balance at Dec. 31, 2020	360,779	$ 298,850	76,683	(15,759)	1,005
Balance (in shares) at Dec. 31, 2020		17,081,831
Net income	10,086		10,086
Common stock dividends declared($0.07 per share)	(1,523)		(1,523)
Exercise of stock options and warrants	1,534	$ 1,534
Exercise of stock options and warrants (in shares)		113,228
Stock-based compensation	207	$ 207
Treasury stock purchases	(1,096)			(1,096)
Treasury stock purchases (in shares)		(58,506)
Other comprehensive income (loss)	(4,229)				(4,229)
Balance at Mar. 31, 2021	$ 365,758	$ 300,591	$ 85,246	$ (16,855)	$ (3,224)
Balance (in shares) at Mar. 31, 2021		17,136,553

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) (Parenthetical)	3 Months Ended
	Mar. 31, 2021$ / shares
Statement Of Stockholders Equity [Abstract]
Common stock dividends declared per share	$ 0.09

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows From Operating Activities:
Net income	$ 10,086	$ 4,074
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	1,086	1,171
Depreciation and amortization	1,108	1,104
Net amortization (accretion) of premium (discount) on investment securities	532	(86)
Amortization of core deposit intangible	823	946
Accretion of discount on retained SBA loans	(243)	(333)
Deferred tax expense	214	1,017
Originations of loans held for sale	(1,729)	(9,380)
Proceeds from loans held for sale	2,209	6,109
Net gains on sale of loans held for sale	(155)	(464)
Gain on sale of investment securities	(5)
Loss on sale of other real estate owned	3
Fair value adjustment on SBA servicing asset	170	405
Stock-based compensation	207	377
Increase in cash surrender value of BOLI	(88)	(89)
Net change in operating assets and liabilities:
Net change in accrued interest receivable	595	(94)
Net change in accrued interest payable	(140)	(40)
Net change in other assets	(1,610)	(30)
Net change in other liabilities	(2,139)	(286)
Net cash provided by operating activities	10,924	4,401
Cash Flows From Investing Activities:
Purchases of investment securities available for sale	(754,235)
Sales of investment securities available for sale	6,918
Paydown and maturities of investment securities available for sale	509,721	2,386
Purchase of FHLB and other bank stock	(9)	(46)
Sale of FHLB and other bank stock		2,696
Proceeds from the sale of loans held for investment	45,193	50,208
Net change in loans	(91,357)	(39,375)
Proceeds from the sale of other real estate owned	130
Purchase of premises and equipment	(1,171)	(2,353)
Net cash received from branch sale	60
Net cash (paid) in business combination		(129,461)
Net cash (used in) investing activities	(284,750)	(115,945)
Cash Flows From Financing Activities:
Net change in deposits	143,372	9,508
Proceeds from long-term borrowings		10,950
Repayment of long-term borrowings	(50,339)	(11,654)
Proceeds from short-term borrowings		10,000
Repayment of short-term borrowings	(10,000)
Net change in secured borrowings	(34)	(1,160)
Common stock dividends	(3,079)
Purchase of treasury stock	(1,096)	(4,805)
Exercise of stock options and warrants	1,534	401
Net cash provided by financing activities	80,358	13,240
Net Change in Cash and Cash Equivalents	(193,468)	(98,304)
Cash and Cash Equivalents at Beginning of Period	263,034	325,957
Cash and Cash Equivalents at End of Period	69,566	227,653
Supplemental Disclosures of Cash Flow Information:
Interest paid	3,473	5,016
Income taxes paid	$ 5,100
Supplemental disclosure of noncash investing and financing activities:
Transfer of loans to other real estate owned and repossessed assets		78
Fair value of assets acquired in business combination, excluding cash		270,873
Goodwill recorded		12,499
Liabilities assumed in business combination		$ 139,721

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations Spirit of Texas Bancshares, Inc. (“Spirit” or the “Company”) is a Texas corporation and registered bank holding company headquartered in Conroe, Texas that provides, through its bank subsidiary, Spirit of Texas Bank SSB (the “Bank”), a variety of financial services to individuals and corporate customers that are largely located or conducting business in Texas, and which operate in primarily agricultural, light industrial and commercial areas. Risks and Uncertainties COVID-19 Pandemic In December 2019, a novel strain of coronavirus (“COVID-19”) was reported to have surfaced in Wuhan, China, and has since spread worldwide. In March 2020, the World Health Organization declared COVID-19 a global pandemic and the United States declared a National Public Health Emergency. The ongoing COVID-19 pandemic has severely impacted the level of economic activity in the local, national and global economies and financial markets. During the first and second quarters of 2020, many businesses in Texas and throughout the United States were temporarily closed due to social distancing and/or shelter in place orders. As of March 31, 2021, businesses in Texas have been allowed to re-open; however, the Company and its customers continue to be adversely affected by the COVID-19 pandemic. The extent to which the COVID-19 pandemic negatively impacts the Company's business, results of operations, and financial condition, as well as its regulatory capital and liquidity ratios, is unknown at this time and will depend on future developments, including the scope and duration of the pandemic and actions taken by governmental authorities and other third parties in response to the pandemic. If the pandemic is sustained, it may further adversely impact the Company and impair the ability of the Company's customers to fulfill their contractual obligations to the Company. This could materially and adversely affect the Company’s business operations, asset valuations, financial condition, and results of operations. For additional risks related to the COVID-19 pandemic, see “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2020, and the Company’s other filings with the Securities and Exchange Commission (the “SEC”). In response to the pandemic, the President of the United States signed into law the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”). This legislation aims to provide relief for individuals and businesses that have been negatively impacted by the coronavirus pandemic. Section 4013 of the CARES Act provides financial institutions the opportunity to opt out of applying the “troubled debt restructuring” (“TDR”) accounting guidance in the Financial Accounting Standards Board’s (“FASB”) Accounting Standard Codification (“ASC”) 310-40 for certain loan modifications. Loan modifications made between March 1, 2020 and the earlier of i) 60 days after the end of the national emergency proclamation or ii) December 31, 2020. Section 541 of the Consolidated Appropriations Act, 2021, amended Section 4013 of the CARES Act to extend this relief to the earlier of i) 60 days after the end of the national emergency proclamation or ii) January 1, 2022. A financial institution may elect to suspend U.S. generally accepted accounting principles (“GAAP”) only for a loan that was not more than 30 days past due as of December 31, 2019. The Bank adopted this provision. Additionally, the CARES Act contained provisions that impact federal income taxes including but not limited to an extension to pay and file federal tax returns, bonus depreciation on qualified improvement property and the ability to carry back certain net operating losses to a prior year. The Bank utilized the filing and payment extension and net operating loss carryback provisions. Basis of Presentation The consolidated financial statements include the accounts of the Company and the Bank. All significant intercompany balances and transactions have been eliminated in consolidation. The accounting and financial reporting policies the Company follows conform, in all material respects, to GAAP and to general practices with the financial services industry. The Company has evaluated subsequent events for potential recognition and/or disclosure through the date these consolidated financial statements were issued. Recently Issued Accounting Pronouncements ASU 2020-06, “Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40)” – Issued in August 2020, Accounting Standards Update (“ASU”) No. 2020-06 addresses accounting complexities regarding convertible debt instruments and the derivatives scope exception for contracts in an entity’s own equity. The ASU reduces the number of available accounting models for convertible debt instruments in an attempt to reduce complexity and variation in practice. Additionally, the ASU improves the applicability of the derivatives scope exception for contracts in an entity’s own equity by clarifying settlement guidance and balance sheet classification. ASU 2020-06 is effective for public entities for fiscal years beginning after December 15, 2021 and for and for all other entities in fiscal years beginning after December 15, 2023. Management does not believe adoption of this ASU will have a material impact on the consolidated financial statements given that the Company does not currently hold any convertible debt instruments or any in-scope derivative contracts. ASU 2019-11, “Financial Instruments-Credit Losses: Codification Improvements Topic 326” – Issued in November 2019, ASU No. 2019-11 clarifies and addresses specific issues about certain aspects of the amendments in ASU 2016-13. For the Company, the provisions of this ASU are effective for fiscal years beginning after December 15, 2022 including interim periods within those fiscal years. See the discussions regarding the adoption of ASU 2016-13 below. ASU 2019-10, “Financial Instruments-Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842)” – Issued in November 2019, ASU No. 2019-10 addresses the change in philosophy to the effective dates including amendments issued after the issuance of the original ASUs. See the discussions regarding the adoption of ASU 2016-13 and ASU 2016-02 below. ASU 2019-04, “Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments” – Issued in April 2019, ASU No. 2019-04 clarifies a number of issues discussed at the June 2018 and November 2018 Credit Losses Transition Resource Group meetings. The clarifications address a variety of identified issues including but not limited to the treatment of accrued interest receivable as it relates to the allowance for credit losses, transfers between loan classifications and categories, recoveries, and using projections of future interest rate environments in expected cash flow calculations. Management is evaluating these clarifications concurrently with our assessment of ASU 2016-13. ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” Issued in June 2016, ASU 2016-13 will add FASB ASC Topic 326, “Financial Instruments-Credit Losses,” and finalizes amendments to FASB ASC Subtopic 825-15, “Financial Instruments-Credit Losses.” The amendments of ASU 2016-13 are intended to provide financial statement users with more decision-useful information related to expected credit losses on financial instruments and other commitments to extend credit by replacing the current incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. The amendments of ASU 2016-13 eliminate the probable initial recognition threshold and, in turn, reflect an entity’s current estimate of all expected credit losses. ASU 2016-13 does not specify the method for measuring expected credit losses, and an entity is allowed to apply methods that reasonably reflect its expectations of the credit loss estimate. Additionally, the amendments of ASU 2016-13 require that credit losses on available for sale debt securities be presented as an allowance rather than as a write-down. The amendments of ASU 2016-13 were originally effective for public entities for interim and annual periods beginning after December 15, 2019 and for all other entities for periods beginning after December 15, 2020. Issued in November 2019, ASU 2019-10, “ ” alters the effective date of ASU 2016-13 for private companies. Under the provisions of ASU 2019-10, ASU 2016-13 is now effective for fiscal years beginning after December 15, 2022 including interim periods within those years for non-public business entities. Earlier application is permitted for interim and annual periods beginning after December 15, 2018. Management has elected to adopt this ASU using the updated private company effective date and is currently evaluating the impact this ASU will have on the consolidated financial statements and that evaluation will depend on economic conditions and the composition of the Company’s loan and lease portfolio at the time of adoption. ASU 2016-02, “Leases (Topic 842).” Issued in February 2016, ASU No. 2016-02 was issued by the FASB to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and by disclosing key information about leasing arrangements. ASU 2016-02 will, among other things, require lessees to recognize a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 does not significantly change lease accounting requirements applicable to lessors; however, the ASU contains some targeted improvements that are intended to align, where necessary, lessor accounting with the lessee accounting model and with the updated revenue recognition guidance issued in 2014. The amendments of ASU 2016-02 are effective for public entities for interim and annual periods beginning after December 15, 2018 and for other entities for periods beginning after December 15, 2019. The adoption of this ASU will result in an increase to the Consolidated Balance Sheets for right-of-use assets and associated lease liabilities for operating leases in which the Company is the lessee. Under current accounting standards, all of the Company's leases are classified as operating leases and, as such, are not recognized on the Company's Consolidated Balance Sheet. Additionally, in July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases and ASU No. 2018-11, Leases, Targeted Improvements. The amendments in these updates provide additional clarification and implementation guidance on certain aspects of ASU 2016-02 and have the same effective and transition requirements as ASU 2016-02. Specifically, ASU 2018-11 creates an additional transition method option allowing entities to record a cumulative effect adjustment to opening retained earnings in the year of adoption. In December 2018, the FASB further issued ASU 2018-20, Leases (Topic 842) Narrow-Scope Improvements for Lessors . The amendments in this update permits lessors to make an accounting policy election to not evaluate whether certain sales taxes and other similar taxes are lessor costs or lessee costs and instead account for the costs as if they were lessee costs. Additionally, the amendment requires lessors to exclude from variable payments, and therefore revenue, lessor costs paid by lessees directly to third parties. The amendments also require lessors to account for costs excluded from the consideration of a contract that are paid by the lessor and reimbursed by the lessee as variable payments. In March 2019, the FASB also issued ASU 2019-01, Leases (Topic 842) Codification Improvements, to further clarify certain identified issues regarding implementation of ASU 2016-02. Specifically, the amendments in ASU 2019-01 clarify the determination of fair value of underlying assets by lessors that are not manufacturers or dealers, the cash flow presentation of sales-type or direct financing leases, and transition disclosures for interim periods. Issued in November 2019, ASU 2019-10, “ Financial Instruments-Credit Losses, Derivatives and Hedging, and Leases ” alters the effective date of ASU 2016-02 for private companies. Under the provisions of ASU 2019-10, ASU 2016-02 is now effective for fiscal years beginning after December 15, 2020 including interim periods within those years for non-public business entities. Management adopted these ASUs using the private company effective date of January 1, 2021 using the modified retrospective approach. The Company did not utilize any optional practical expedients in conjunction with adoption. At January 1, 2021, the Company recorded a lease liability of $ 6.6 million and a right of use asset of $ 6.4 million . See Note 8 for additional discussion.

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Revenue Recognition	NOTE 2. REVENUE RECOGNITION Spirit accounts for revenue from contracts with customers in accordance with FASB ASC Topic 606, “Revenue from Contracts with Customers,” which provides that revenue be recognized in a manner that depicts the transfer of goods or services to a customer in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. Revenue from contracts with customers is recognized either over time as performance obligations are fulfilled, or at a point in time when control of the goods or services are transferred to the customer. Spirit’s noninterest income, excluding all of U.S. Small Business Administration (“SBA”) loan servicing fees, gain on sales of loans, net, and gain on sales of investment securities, are considered within the scope of FASB ASC Topic 606. Each category of in-scope revenue streams is discussed below. Deposit Accounts Core Service Charges Core service charges on deposit accounts consist of account analysis fees (i.e., net fees earned on analyzed business and public checking accounts) and monthly service fees. The Company’s performance obligation for account analysis fees and monthly service fees is generally satisfied, and the related revenue recognized, over the period in which the service is provided. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to customers’ accounts. Deposit Account Transaction Based Fee Income Transaction based fee income on deposit accounts consists of variable revenue streams associated with activities which a deposit account holder may initiate on a transaction by transaction basis. The majority of transaction based fee income arises from interchange revenue received when deposit customers use a debit card for a point of sale transaction over a third-party card payment network. Interchange revenue is recorded net of related interchange expenses in the month in which the transaction occurs. Merchant services income is realized through a third party service provider who is contracted by the Bank under a referral arrangement. Such fees represent fees charged to merchants to process their debit card transactions, in addition to account management fees. The third-party service provider also issues credit cards as private label in the Company's name in exchange for a referral fee. Fees are earned and recorded in the same period as the referral occurs and the card is issued. Other transaction based service charges on deposit accounts include revenue from processing wire transfers, issuing cashier’s checks, processing check orders, and renting safe deposit boxes. The Company’s performance obligation related to these service charges is largely satisfied, and related revenue recognized, when the services are rendered or upon completion. Payment is typically received immediately or charged to the customers’ account in the period the service is provided. Safe deposit box rental fees are charged to the customer on an annual basis and recognized upon receipt of payment. The Company determined that since rentals and renewals occur fairly consistently over time, revenue is recognized on a basis consistent with the duration of the performance obligation. Referral Fees Spirit utilizes third-party vendors to provide services to the Company and its customers that are not economically feasible to provide on a stand-alone basis. These services include access to the secondary market for mortgage loans not held for investment and providing interest rate swaps to customers interested in hedging interest rate risk. In exchange for providing these third-party vendors with new customers, Spirit receives a referral fee. With respect to mortgage referral fees, the Company’s performance obligation is satisfied when the referred customer closes a mortgage loan with the third-party vendor and payment of the referral fee is typically received immediately. Swap referral fees are recognized when an existing or new loan customer enters into a swap agreement with the third-party vendor. Spirit is not a counterparty to the swap, and the performance obligation is satisfied at the time the swap agreement is signed. Payment of the referral fee is received within three days of the signed swap agreement. The following presents non-interest income, segregated by revenue streams in-scope and out-of-scope of Topic 606, for the three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 Non-Interest Income In-scope of Topic 606 Deposit accounts core service charges $ 357 $ 211 Deposit account transaction based fee income 1,077 1,100 Swap referral fees 430 580 Mortgage referral fees 274 202 Non-Interest Income (in-scope of Topic 606) 2,138 2,093 Non-Interest Income (out-of-scope of Topic 606) 481 619 Total Non-Interest Income $ 2,619 $ 2,712 Contract Balances A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration (resulting in a contract receivable) or before payment is due (resulting in a contract asset). A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment (or payment is due) from the customer. The Company’s non-interest revenue streams are largely based on transactional activity, or standard month-end revenue accruals. Consideration is often received immediately or shortly after the Company satisfies its performance obligation and revenue is recognized. The Company does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances. The Company did not have any significant contract balances at March 31, 2021 or December 31, 2020. Contract Acquisition Costs In connection with the adoption of FASB ASC Topic 606, an entity is required to capitalize, and subsequently amortize into expense, certain incremental costs of obtaining a contract with a customer if these costs are expected to be recovered. The incremental costs of obtaining a contract are those costs that an entity incurs to obtain a contract with a customer that it would not have incurred if the contract had not been obtained (for example, sales commission). The Company utilizes the practical expedient which allows entities to immediately expense contract acquisition costs when the asset that would have resulted from capitalizing these costs would have been amortized in one year or less. The Company has not capitalized any contract acquisition costs for the three months ending March 31, 2021 or 2020.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2021
Investments Debt And Equity Securities [Abstract]
Investment Securities	NOTE 3. INVESTMENT SECURITIES The amortized cost, gross unrealized gains and losses and approximate fair values of securities available for sale are as follows: Amortized Unrealized Fair March 31, 2021 Cost Gains Losses Value (Dollars in thousands) Available for sale: U.S. Treasury securities $ - $ - — $ - State and municipal obligations 34,541 71 203 34,409 Residential mortgage-backed securities 370,937 5 6,233 364,709 Corporate Bonds 42,745 848 135 43,458 Total available for sale $ 448,223 $ 924 $ 6,571 $ 442,576 Amortized Unrealized Fair December 31, 2020 Cost Gains Losses Value (Dollars in thousands) Available for sale: State and municipal obligations $ 36,258 $ 927 $ - $ 37,185 Residential mortgage-backed securities 132,130 278 267 132,142 Corporate bonds and other debt securities 42,768 433 109 43,093 Total available for sale $ 211,156 $ 1,638 $ 376 $ 212,420 Taxable interest and dividends on investment securities were $957 thousand and $465 thousand for the three months ended March 31, 2021 and 2020, respectively. Tax-exempt interest and dividends on investment securities were $158 thousand and $39 thousand for the three months ended March 31, 2021 and 2020, respectively. There were $138.6 million and $91.5 million of securities pledged to collateralize public funds at March 31, 2021 The amortized cost and estimated fair value of securities available for sale, by contractual maturity, are as follows for the period presented: Amortized Fair March 31, 2021 Cost Value (Dollars in thousands) Available for sale: Due in one year or less $ 317 $ 318 Due after one year through five years 9,471 9,555 Due after five years through ten years 31,021 31,687 Due after ten years 36,477 36,307 Residential mortgage-backed securities 370,937 364,709 Total available for sale $ 448,223 $ 442,576 For purposes of the maturity table, residential mortgage-backed securities, the principal of which are repaid periodically, are presented as a single amount. The expected lives of these securities will differ from contractual maturities because borrowers may have the right to prepay the underlying loans with or without prepayment penalties. The following tables present the estimated fair values and gross unrealized losses on investment securities available for sale, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position as of the periods presented: Less than 12 Months 12 Months or More Total March 31, 2021 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Treasury securities $ — $ — $ — $ — $ — $ — State and municipal obligations 20,837 203 — — 20,837 203 Residential mortgage-backed securities 332,775 6,233 — — 332,775 6,233 Corporate Bonds 3,637 135 — — 3,637 135 Total available for sale $ 357,249 $ 6,571 $ — $ — $ 357,249 $ 6,571 Less than 12 Months 12 Months or More Total December 31, 2020 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Treasury securities $ — $ — $ — $ — $ - $ - State and municipal obligations — — — — — — Residential mortgage-backed securities 53,598 267 — — 53,598 267 Corporate bonds and other debt securities 17,087 109 — — 17,087 109 Total available for sale $ 70,685 $ 376 $ - $ - $ 70,685 $ 376 At March 31, 2021, the Company’s securities portfolio consisted of 108 securities, 74 of which were in an unrealized loss position. None of the 74 securities in an unrealized loss position at March 31, 2021 were in an unrealized loss position for more than 12 months. The Company monitors its investment securities for other-than-temporary-impairment (“OTTI”). Impairment is evaluated on an individual security basis considering numerous factors, and its relative significance. The Company has evaluated the nature of unrealized losses in the investment securities portfolio to determine if OTTI exists. The unrealized losses relate to changes in market interest rates and specific market conditions that do not represent credit-related impairments. Furthermore, the Company does not intend to sell nor is it more likely than not that it will be required to sell these investments before the recovery of their amortized cost basis. Management has completed an assessment of each security in an unrealized loss position for credit impairment and has determined that no individual security was other-than-temporarily impaired at March 31, 2021. The following describes the basis under which the Company has evaluated OTTI: U.S. Treasury Securities, and Residential Mortgage-Backed Securities (“MBS”): The unrealized losses associated with U.S. Treasury securities, and residential MBS are primarily driven by changes in interest rates. These securities have either an explicit or implicit U.S. government guarantee. At March 31, 2021, the unrealized losses for these securities resulted primarily from changes in interest rates and spreads. Sales proceeds from the sale of available for sale securities for the three months ended March 31, 2021 were $6.9 million, which resulted in gross realized gains of $5 thousand. There were no securities sold for the three months ended March 31, 2020. Equity Investments: Equity investments at fair value consist of an investment in the CCM Community Impact Bond Fund. At March 31, 2021 and December 31, 2020, the fair value of equity securities totaled $23.7 million and $24.0 million, respectively. Subsequent changes in fair value are recognized in other noninterest income. For the three months ended March 31, 2021 a loss of $400 thousand was included in other noninterest income. There were no fair value changes for the three months ended March 31, 2020.

Loans

Loans	3 Months Ended
	Mar. 31, 2021
Receivables [Abstract]
Loans	NOTE 4. LOANS Total loans held in portfolio consisted of the following at March 31, 2021 and December 31, 2020: March 31, 2021 Acquired Loans (1) Organic Loans Total Loans (Dollars in thousands) Commercial and industrial loans (2) $ 51,240 $ 648,656 $ 699,896 Real estate: 1-4 single family residential loans 87,876 261,032 348,908 Construction, land and development 59,458 285,099 344,557 Commercial real estate loans (including multifamily) 343,979 620,363 964,342 Consumer loans and leases 2,370 7,249 9,619 Municipal and other loans 5,170 58,102 63,272 Total loans held in portfolio (3) $ 550,093 $ 1,880,501 $ 2,430,594 December 31, 2020 Acquired Loans (1) Organic Loans Total Loans (Dollars in thousands) Commercial and industrial loans (2) $ 53,857 $ 521,129 $ 574,986 Real estate: 1-4 single family residential loans 93,840 270,299 364,139 Construction, land and development 131,734 283,754 415,488 Commercial real estate loans (including multifamily) 333,489 623,254 956,743 Consumer loans and leases 3,088 8,650 11,738 Municipal and other loans 6,103 59,335 65,438 Total loans held in portfolio (3) $ 622,111 $ 1,766,421 $ 2,388,532 (1) Acquired loans include loans acquired in the acquisitions of Comanche, National Corporation, First Beeville Financial Corporation, and Chandler Bancorp, Inc. and its subsidiary, Citizens State Bank (together, “Citizens”), and the Simmons Bank branch acquisition. All loans originated after acquisition close date are included in organic loans. (2 ) Organic loans b alance includes $ million and $ million of the unguaranteed port ion of SBA loans as of March 31 , 202 1 and December 31, 20 20 , respectively. (3 ) Organic loans balance includes $(11.9) million and $(8.2) million of deferred fees, cost, premium and discount as of March 31, 2021 and December 31, 2020, respectively. At March 31, 2021 and December 31, 2020, the Company had pledged loans as collateral for Federal Home Loan Bank (“FHLB”) advances of $971.5 million and $927.3 million, respectively. Additionally, at March 31, 2021 and December 31, 2020, the Company had pledged loans as collateral associated with the Paycheck Protection Program Liquidity Facility (“PPPLF”) of $100.1 million and $149.8 million, respectively. The Company originates and sells loans secured by the SBA. The Company retains the unguaranteed portion of the loan and servicing on the loans sold and receives a fee based upon the principal balance outstanding. During the three months ended March 31, 2021 and 2020, the Company sold approximately $2.0 million and $5.6 million, respectively, in SBA loans to third parties. The loan sales resulted in realized gains of $155 thousand and $464 thousand for the three months ended March 31, 2021 and 2020, respectively. During the fourth quarter of 2020 and continuing into the first quarter of 2021, we originated loans to qualified mid-sized businesses under the Main Street Lending Program administered by the Federal Reserve Bank of Boston special purpose vehicle. Under the terms of the program 95 percent of the loan balance is purchased by the Federal Reserve Bank of Boston special purpose vehicle one day following origination. During the three months ended March 31, 2021, the Company sold approximately $10.5 million of loans to the Federal Reserve Bank of Boston special purpose vehicle. The loan sales resulted in realized gains of $99 thousand for the three months ended March 31, 2021. At March 31, 2021 and December 31, 2020, the unpaid principal balance of loans serviced for others related to the Main Street Lending Program was $410.8 million and $400.3 million, respectively. In April 2020, we began originating loans to qualified small businesses under the Paycheck Protection Program (the “PPP”) administered by the SBA under the provisions of the CARES Act. Total PPP loans originated by the Bank as of March 31, 2021 were $366.5 million and are included in the commercial and industrial segment of our loan portfolio. These loans are fully guaranteed by the SBA, carry a contractual term of two to five years and an interest rate of 1.00%. In conjunction with originating PPP loans, the Company has $6.7 million of deferred origination fees, net of costs at March 31, 2021 which will be recognized over the 2.3 year weighted average life of the loans or at the date of forgiveness if earlier. In conjunction with the PPP, we are also currently participating in the PPPLF which extends loans to banks who are loaning money to small businesses under the PPP. The amount of borrowings under the PPPLF as of March 31, 2021 was $100.1 million and is non-recourse and secured by the amount of the PPP loans we originate. The maturity date of a borrowing under the PPPLF is equal to the maturity date of the PPP loan pledged to secure the borrowing and would be accelerated (i) if the underlying PPP loan goes into default and is sold to the SBA to realize on the SBA guarantee or (ii) to the extent that any loan forgiveness reimbursement is received from the SBA. Borrowings under the PPPLF are included in long-term liabilities on the consolidated balance sheet and bear interest at a rate of 0.35%. Additionally, a bank may exclude all PPP loans pledged as collateral to the PPPLF from its average total consolidated assets for the purposes of calculating its leverage ratio, while PPP loans that are not pledged as collateral to the PPPLF will be included. Due to the rights retained on certain loan participations sold, the Company is deemed to have retained effective control over these loans under ASC 860, “Transfers and Servicing.” These loans can no longer be reported as sold, and must be reported on the balance sheet as loans held for investment regardless of whether the Company intends to exercise its rights. These loans are reported as loans held for investment with the offsetting liability recorded as long-term borrowings. The amount of secured borrowings included in loans held for investment and long-term borrowings at March 31, 2021 and December 31, 2020 was $4.0 million. Loans serviced for others are not included in the accompanying balance sheets. The unpaid principal balances of loans serviced for others, including SBA loans, were $186.4 million and $193.3 million at March 31, 2021 and December 31, 2020, respectively. In the ordinary course of business, the Company makes loans to executive officers and directors. Loans to these related parties, including companies in which they are principal owners, are as follows for the periods presented: Three Months Ended March 31, 2021 2020 (Dollars in thousands) Principal outstanding, beginning of year $ 7,581 $ 6,005 Additions (reductions) of affiliations — — New loans made in current year 972 1,719 Repayments (1,775 ) (277 ) Principal outstanding, end of year $ 6,778 $ 7,447 There were $2.0 million in unfunded commitments to related parties at March 31, 2021. There were $1.8 million in unfunded commitments to related parties at December 31, 2020.

Allowance for Loan and Lease Lo

Allowance for Loan and Lease Losses	3 Months Ended
	Mar. 31, 2021
Receivables [Abstract]
Allowance for Loan and Lease Losses	NOTE 5. ALLOWANCE FOR LOAN AND LEASE LOSSES The allowance for loan and lease losses is a reserve established through a provision for loan losses charged to expense, which represents management’s best estimate of probable losses that have been incurred within the existing portfolio of loans. The allowance, in the judgment of management, is necessary to reserve for estimated loan losses and risks inherent in the loan portfolio. The methodology is based on historical loss experience by type of credit and internal risk grade, changes in the composition and volume of the portfolio, and specific loss allocations, with adjustments for current events and conditions. The Company’s process for determining the appropriate level of the allowance for loan and lease losses is designated to account for credit deterioration as it occurs. At March 31, 2021, purchased credit impaired loans totalled $694 thousand and the Company believes that all contractual principal and interest will be received. Purchased credit impaired loans are not included in the impaired loans disclosure within this Note. At March 31, 2021 no provision for loan losses has been recorded for PPP loans. These loans are fully guaranteed by the SBA and therefore carry a zero percent reserve. PPP loans also carry a put-back provision in the event that a PPP loan is fraudulently originated and the Bank is at fault. Management does not deem a put-back reserve necessary at this time. The following tables present information related to allowance for loan and lease losses for the periods presented: Allowance Rollforward Three Months Ended March 31, 2021 Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Commercial and industrial loans $ 9,086 $ (807 ) $ 15 $ 1,388 $ 9,682 Real estate: 1-4 single family residential loans 147 — — (63 ) 84 Construction, land and development loans 1,744 — — 142 1,886 Commercial real estate loans (including multifamily) 4,843 — — (387 ) 4,456 Consumer loans and leases 145 (20 ) 12 (24 ) 113 Municipal and other loans 61 — 2 30 93 Ending allowance balance $ 16,026 $ (827 ) $ 29 $ 1,086 $ 16,314 Allowance Rollforward Three Months Ended March 31, 2020 Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Commercial and industrial loans $ 4,078 $ (254 ) $ 4 $ 656 $ 4,484 Real estate: 1-4 single family residential loans 31 — — 4 35 Construction, land and development loans 1,055 — — 238 1,293 Commercial real estate loans (including multifamily) 1,451 — — 298 1,749 Consumer loans and leases 68 (52 ) 12 23 51 Municipal and other loans 54 — 2 (48 ) 8 Ending allowance balance $ 6,737 $ (306 ) $ 18 $ 1,171 $ 7,620 Credit Quality Indicators In evaluating credit risk, the Company looks at multiple factors; however, management considers delinquency status to be the most meaningful indicator of the credit quality of 1-4 single family residential, home equity loans and lines of credit and consumer loans. Delinquency statistics are updated at least monthly. Internal risk ratings are considered the most meaningful indicator of credit quality for commercial, construction, land and development and commercial real estate loans. Internal risk ratings are updated on a continuous basis. The following tables present an aging analysis of the recorded investment for delinquent loans by portfolio and segment for the periods presented: Accruing March 31, 2021 Current 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) Commercial and industrial loans $ 693,533 $ 374 $ — $ — $ 5,989 $ 699,896 Real estate: 1-4 single family residential loans 346,360 1,459 250 — 839 348,908 Construction, land and development 344,204 — — 136 217 344,557 Commercial real estate loans (including multifamily) 960,352 1,276 136 — 2,578 964,342 Consumer loans and leases 9,459 53 — — 107 9,619 Municipal and other loans 63,254 — — — 18 63,272 Total loans $ 2,417,162 $ 3,162 $ 386 $ 136 $ 9,748 $ 2,430,594 Accruing December 31, 2020 Current 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) Commercial and industrial loans $ 567,491 $ 2,295 $ 271 $ - $ 4,929 $ 574,986 Real estate: 1-4 single family residential loans 362,505 99 28 — 1,507 364,139 Construction, land and development 415,135 136 — — 217 415,488 Commercial real estate loans (including multifamily) 953,823 1,084 — — 1,836 956,743 Consumer loans and leases 11,618 8 4 — 108 11,738 Municipal and other loans 65,416 — 22 — — 65,438 Total loans $ 2,375,988 $ 3,622 $ 325 $ - $ 8,597 $ 2,388,532 There was one loan 90 days or more past due and still accruing at March 31, 2021 with a recorded investment of $136 thousand. There were no loans 90 days or more past due and still accruing at December 31, 2020. All loans with active deferral periods related to the COVID-19 pandemic are excluded from nonaccrual and days past due reporting. At March 31, 2021, non-accrual loans that were 30 to 59 days past due equaled $842 thousand, non-accrual loans that were 60 to 89 days past due equaled $116 thousand and non-accrual loans that were 90 days or more past due equaled $5.1 million. At December 31, 2020, non-accrual loans that were 30 to 59 days past due were $930 thousand, non-accrual loans that were 60 to 89 days past due equaled $545 thousand, and non-accrual loans that were 90 days or more past due equaled $2.2 million. Loans exhibiting potential credit weaknesses that deserve management’s close attention and that if left uncorrected may result in deterioration of the repayment capacity of the borrower are categorized as special mention. Loans with well-defined credit weaknesses including payment defaults, declining collateral values, frequent overdrafts, operating losses, increasing balance sheet leverage, inadequate cash flow, project cost overruns, unreasonable construction delays, past due real estate taxes or exhausted interest reserves are assigned an internal risk rating of substandard. Loans classified as substandard can be on an accrual or non-accrual basis, as determined by its unique characteristics. A loan with a weakness so severe that collection in full is highly questionable or improbable will be assigned an internal risk rating of doubtful. The following tables summarize the Company’s loans by key indicators of credit quality for the periods presented: March 31, 2021 Pass Special Mention Substandard Doubtful (Dollars in thousands) Commercial and industrial loans $ 681,046 $ 2,167 $ 16,581 $ 102 Real estate: 1-4 single family residential loans 346,298 479 2,131 — Construction, land and development 336,232 7,232 1,093 — Commercial real estate loans (including multifamily) 915,581 36,046 12,715 — Consumer loans and leases 9,512 — 103 4 Municipal and other loans 59,162 4,012 98 — Total loans $ 2,347,831 $ 49,936 $ 32,721 $ 106 December 31, 2020 Pass Special Mention Substandard Doubtful (Dollars in thousands) Commercial and industrial loans $ 554,685 $ 1,332 $ 18,723 $ 246 Real estate: 1-4 single family residential loans 360,337 - 3,802 — Construction, land and development 411,151 4,120 217 — Commercial real estate loans (including multifamily) 935,865 10,913 9,965 — Consumer loans and leases 11,626 — 112 — Municipal and other loans 62,273 3,085 80 — Total loans $ 2,335,937 $ 19,450 $ 32,899 $ 246 Internal risk ratings and other credit metrics are key factors in identifying loans to be individually evaluated for impairment and impact management’s estimates of loss factors used in determining the amount of the allowance for loan and lease losses. The following tables show the Company’s investment in loans disaggregated based on the method of evaluating impairment for the periods presented: Loans - Recorded Investment Allowance for Credit Loss March 31, 2021 Individually Evaluated for Impairment Collectively Evaluated for Impairment Individually Evaluated for Impairment Collectively Evaluated for Impairment (Dollars in thousands) Commercial and industrial loans $ 6,033 $ 693,863 $ 4,712 $ 4,970 Real estate: 1-4 single family residential loans 965 347,943 1 83 Construction, land and development 217 344,340 — 1,886 Commercial real estate loans (including multifamily) 2,578 961,764 770 3,686 Consumer loans and leases 107 9,512 107 6 Municipal and other loans 70 63,202 52 41 Total loans $ 9,970 $ 2,420,624 $ 5,642 $ 10,672 Loans - Recorded Investment Allowance for Credit Loss December 31, 2020 Individually Evaluated for Impairment Collectively Evaluated for Impairment Individually Evaluated for Impairment Collectively Evaluated for Impairment (Dollars in thousands) Commercial and industrial loans $ 4,978 $ 570,008 $ 3,488 $ 5,598 Real estate: 1-4 single family residential loans 1,637 362,502 1 146 Construction, land and development 217 415,271 — 1,744 Commercial real estate loans (including multifamily) 1,837 954,906 500 4,343 Consumer loans and leases 108 11,630 90 55 Municipal and other loans 52 65,386 — 61 Total loans $ 8,829 $ 2,379,703 $ 4,079 $ 11,947 The following tables set forth certain information regarding the Company’s impaired loans that were evaluated for specific reserves for the periods presented: Impaired Loans - With Allowance Impaired Loans - With no Allowance March 31, 2021 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) Commercial and industrial loans $ 5,089 $ 5,127 $ 4,712 $ 944 $ 980 Real estate: 1-4 single family residential loans 4 4 1 961 956 Construction, land and development — — — 217 215 Commercial real estate loans (including multifamily) 1,284 1,274 770 1,294 1,294 Consumer loans and leases 107 107 107 — — Municipal and other loans 52 52 52 18 17 Total loans $ 6,536 $ 6,564 $ 5,642 $ 3,434 $ 3,462 Impaired Loans - With Allowance Impaired Loans - With no Allowance December 31, 2020 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) Commercial and industrial loans $ 4,407 $ 4,453 $ 3,488 $ 566 $ 571 Real estate: 1-4 single family residential loans 5 5 1 1,632 1,612 Construction, land and development — — — 217 215 Commercial real estate loans (including multifamily) 1,308 1,281 500 528 528 Consumer loans and leases 90 90 90 24 28 Municipal and other loans — — — 52 52 Total loans $ 5,810 $ 5,829 $ 4,079 $ 3,019 $ 3,006 Three Months Ended March 31, 2021 2020 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (Dollars in thousands) Commercial and industrial loans $ 6,700 $ 1 $ 5,247 $ — Real estate: 1-4 single family residential loans 967 1 2,102 — Construction, land and development 217 — 216 — Commercial real estate loans (including multifamily) 2,574 — 2,270 — Consumer loans and leases 105 — 39 — Municipal and other loans 72 — — — Total loans $ 10,635 $ 2 $ 9,874 $ — Troubled Debt Restructurings: The following table provides a summary of troubled debt restructurings (“TDRs”) based upon delinquency status, all of which are considered impaired, for the periods presented: March 31, 2021 December 31, 2020 Number of contracts Recorded Investment Number of contracts Recorded Investment (Dollars in thousands) Performing TDRs: Commercial and industrial loans 2 $ 46 2 $ 49 Real estate: 1-4 single family residential loans 3 126 3 130 Construction, land and development — — — — Commercial real estate loans (including multifamily) — — — — Consumer loans and leases — — — — Municipal and other loans 1 52 1 52 Total performing TDRs 6 224 6 231 Nonperforming TDRs 7 435 14 652 Total TDRs 13 $ 659 20 $ 883 Allowance attributable to TDRs $ 419 $ 421 The following table summarizes TDRs, and includes newly designated TDRs as well as modifications made to existing TDRs, for the periods presented. Modifications may include, but are not limited to, granting a material extension of time, entering into a forbearance agreement, adjusting the interest rate, accepting interest only payments for an extended period of time, a change in the amortization period or a combination of any of these. Post-modification balances represent the recorded investment at the end of Day 2 in which the modification was made. The CARES Act includes a provision for the Company to opt out of applying the TDR accounting guidance in ASC 310-40 for certain loan modifications. Loan modifications made between March 1, 2020 and the earlier of ( i) January 1, 2022 or ( ii) 60 days after the President declares a termination of the COVID-19 national emergency are eligible for this relief if the related loans were not more than 30 days past due as of December 31, 2019. Loans with an unpaid principal balance of $ 11.6 million remained in a ctive deferral periods at March 31, 2021. Three Months Ended March 31, 2021 2020 Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Related Allowance Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Related Allowance (Dollars in thousands) Commercial and industrial loans — $ — $ — $ — 4 $ 168 $ 168 $ 56 Real estate: 1-4 single family residential loans — — — — — — — — Construction, land and development — — — — — — — — Commercial real estate loans (including multifamily) 2 321 321 — — — — — Consumer loans and leases — — — — — — — — Municipal and other loans — — — — — — — — There have been no defaults of troubled debt restructurings that took place within the three months ended March 31, 2021 and 2020.

Goodwill and Intangibles

Goodwill and Intangibles	3 Months Ended
	Mar. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangibles	NOTE 6. GOODWILL AND INTANGIBLES Goodwill and other intangible assets, which consist of core deposit intangibles, are summarized as follows: Three Months Ended March 31, 2021 Year Ended December 31, 2020 (Dollars in thousands) Beginning goodwill $ 77,681 $ 68,503 Arising from business combination — 11,456 Measurement Period Adjustments — (2,278 ) Ending goodwill $ 77,681 $ 77,681 Core deposit intangible 19,722 19,722 Arising from business combination — — Less: Accumulated amortization (12,727 ) (11,904 ) Core deposit intangible, net $ 6,995 $ 7,818 Amortization expense for core deposit intangibles for the three months ended March 31, 2021 and 2020 totaled $823 thousand and $946 thousand, respectively. The estimated amount of amortization expense for core deposit intangibles to be recognized over the next five fiscal years is as follows: Type of intangibles Remainder of 2021 2022 2023 2024 2025 2026 (Dollars in thousands) Core deposit intangible $ 2,271 $ 2,212 $ 1,495 $ 744 $ 200 $ 73

SBA Servicing Asset

SBA Servicing Asset	3 Months Ended
	Mar. 31, 2021
Transfers And Servicing Of Financial Assets [Abstract]
SBA Servicing Asset	NOTE 7. SBA SERVICING ASSET SBA servicing assets are recognized separately when rights are acquired through the sale of the guaranteed portion of SBA loans. These servicing rights are initially measured at fair value at the date of sale and included in the gain on sale. Updated fair values are obtained from an independent third party on a quarterly basis and adjustments are presented in SBA loan servicing fees on the consolidated statements of income. To determine the fair value of SBA servicing rights, the Company uses market prices for comparable servicing contracts, when available, or alternatively, uses a valuation model that calculates the present value of estimated future net servicing income. Loans serviced for others are not included in the accompanying balance sheets. The unpaid principal balances of SBA loans serviced for others were $186.4 million and $193.3 million at March 31, 2021 and December 31, 2020, respectively. SBA loan servicing fees were $324 thousand and $10 thousand for the three months ended March 31, 2021 and 2020, respectively. The risks inherent in the SBA servicing asset relate primarily to changes in prepayments that result from shifts in interest rates. The following summarizes the activity pertaining to SBA servicing rights, which are in the consolidated balance sheets, for the three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 (Dollars in thousands) Beginning balance $ 2,953 $ 3,355 Origination of servicing assets 38 105 Change in fair value: Due to run-off (135 ) (140 ) Due to market changes (35 ) (265 ) Ending balance $ 2,821 $ 3,055

Leases

Leases	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Leases	NOTE 8. LEASES ASU 2016-02, “Leases (Topic 842),” became effective for the Company on January 1, 2021. The Company adopted FASB ASC Topic 842 utilizing the modified retrospective transition approach prescribed by ASU 2018-11, “ Leases (Topic 842): Targeted Improvements”. Once the Company identifies and determines certain contracts are leases according to FASB ASC Topic 842, the Company classifies it as an operating or a finance lease and recognizes a right-of-use (ROU) asset and a lease liability at the lease commencement date. The lease liability represents the present value of the lease payments that remain unpaid as of the commencement date and ROU is the initial lease liability recognized for the lease plus any lease payments made to the lessor at or before the commencement date as well as any initial direct costs less any lease incentives received. The Company does not have any finance leases at March 31, 2021. The Company has operating leases for its office branches, operations offices, and certain equipment utilized at those properties. Property leases typically have original lease terms ranging from 1 to 10 years, some of which may also include an option to extend the lease beyond the original lease term. The Company includes renewal and termination options within the lease term if deemed reasonably certain of exercise. The remainder of the lease portfolio is comprised of equipment leases that have remaining lease terms of 1 year to 3 years. Operating leases may vary in term and, from time to time, include incentives and/or rent escalations. Examples of these type of incentives may include periods of “free” rent and leasehold improvement incentives. The Company recognizes incentives on a straight-line basis over the lease term as a reduction or increase to rent expense, as applicable, within occupancy and equipment expenses in the consolidated statements of income. As of March 31, 2021, the Company’s operating lease ROU asset and operating lease liability totaled $6.1 million and $ 6.2 million, respectively. The Company’s leases typically have one or more renewal options included in the lease contract. Due to the nature of the Company’s leases, for leases with renewal options available, the Company evaluates each lease to determine if exercise of the renewal option is reasonably certain. In order to calculate its ROU assets and lease liabilities, FASB AC Topic 842 requires the Company to use the rate of interest implicit in the lease when readily determinable. If the rate implicit in the lease is not readily determinable, the Company is required to use its incremental borrowing rate, which is the rate of interest the Company would have to pay to borrow on a collateralized basis over a similar term in a similar economic environment. The Company was un able to determine the implicit interest rate in any of the leases and therefore used its incremental borrowing rate. The table below presents additional information related to the Company’s leases as of March 31, 2021: March 31, 2021 Weighted-average remaining term (in years) - operating leases 4.37 Weighted-average discount rate - operating leases (1) 4.00 % (1) The incremental borrowing rate used to calculate the lease liability was determined based on facts and circumstances of the economic environment and the Company's credit standing as of the effective date of ASC 842. Additionally, the total lease term and total lease payments were also considered in determining the rate. The Company’s leases have remaining lease terms of one to 10 years, with a weighted average lease term of 4.37 years at March 31, 2021. The following is a schedule of the Company’s operating lease liabilities by contractual maturity as of March 31, 2021: (Dollars in thousands) 2021 (excluding 3 months ended March 31, 2021) 1,645 2022 1,643 2023 1,009 2024 812 2025 625 Thereafter 883 Total Lease Payments 6,617 Less: Imputed Interest 386 Total present value of lease liabilities 6,231 Total operating lease costs of $821 thousand for the three months ended March 31, 2021, were included as part of occupancy and equipment expense. The below table shows the supplemental cash flow information related to the Company’s operating leases for the three months ended March 31, 2021: March 31, 2021 (Dollars in thousands) Operating cash flows (fixed payments) included in occupancy and equipment expenses $ 571 Operating cash flows (liability reduction) included in occupancy and equipment expenses 507

Deposits

Deposits	3 Months Ended
	Mar. 31, 2021
Deposits By Component Alternative [Abstract]
Deposits	NOTE 9. DEPOSITS The following table sets forth the Company’s deposits by category for the periods presented: March 31, 2021 December 31, 2020 (Dollars in thousands) Noninterest-bearing demand deposits $ 800,233 $ 727,543 Interest-bearing demand deposits 485,863 472,075 Interest-bearing NOW accounts 9,904 10,288 Savings and money market accounts 654,014 610,571 Time deposits 647,536 638,658 Total deposits $ 2,597,550 $ 2,459,135 Time deposits $100,000 and greater $ 503,736 $ 515,738 Time deposits $250,000 and greater 203,363 190,236 Related party deposits (executive officers and directors) 24,027 18,767 The aggregate amount of overdraft demand deposits reclassified to loans was $67 thousand and $88 thousand at March 31, 2021 and December 31, 2020, respectively. The aggregate amount of maturities for time deposits for each of the five years following the latest balance sheet date totaled $542.5 million, $79.6 million, $12.2 million, $6.7 million and $6.6 million, respectively. The Company held no brokered certificates of deposit as of March 31, 2021 and December 31, 2020.

FHLB and Other Borrowings

FHLB and Other Borrowings	3 Months Ended
	Mar. 31, 2021
Federal Home Loan Banks [Abstract]
FHLB and Other Borrowings	NOTE 10. FHLB AND OTHER BORROWINGS The FHLB allows us to borrow, both short and long-term, on a blanket floating lien status collateralized by certain securities and loans. At March 31, 2021 and December 31, 2020, the Company had pledged loans as collateral for FHLB advances of $971.5 million and $927.3 million, respectively. At March 31, 2021, the Company had additional capacity to borrow from the FHLB of $668.8 million. Short-term borrowings Short-term FHLB borrowings : At March 31, 2021, the Company had no short-term FHLB borrowings. As of December 31, 2020, the Company had $10 million of short term FHLB borrowings with an average interest rate of 0.70%. All short-term FHLB borrowings outstanding at December 31, 2020 had fixed interest rates. Long-term borrowings Line of Credit : The Company entered into an unsecured line of credit with a third party lender in May 2017 which allowed it to borrow up to $20.0 million. The interest rate on the facility is LIBOR plus 4.00% per annum, and unpaid principal and interest is due at the stated maturity on May 12, 2022. The line of credit may be prepaid at any time without penalty, so long as such prepayment includes the payment of all interest accrued through the date of the repayments, and, in the case of prepayment of the entire loan, the amount of attorneys’ fees and disbursements of the lender. During 2019, the line of credit was increased to a total borrowing capacity of $50.0 million. There were no outstanding advances at March 31, 2021 or December 30, 2020. Long-term FHLB borrowings : Long-term borrowings from the FHLB outstanding for the periods presented are as follows: Range of Weighted Range of Weighted March 31, Contractual Average December 31, Contractual Average 2021 Interest Rates Interest Rate 2020 Interest Rates Interest Rate (Dollars in thousands) Repayable during the years ending December 31, 2021 8,502 1.48% - 2.99% 0.77 % 8,636 1.48% - 2.99% 1.73 % 2022 4,516 2.04% - 2.99% 1.56 % 4,584 1.86% - 2.99% 2.23 % 2023 6,315 2.31% - 2.99% 1.09 % 6,489 1.86% - 2.99% 2.44 % 2024 10,610 2.07% - 2.99% 1.56 % 10,723 1.86% - 2.99% 2.62 % 2025 2,614 1.86% - 2.99% 0.62 % 2,649 1.86% - 2.99% 2.26 % 2026-2032 18,744 2.10% - 2.99% 1.27 % 18,809 2.10% - 2.99% 2.26 % Total long-term FHLB borrowings $ 51,301 $ 51,890 For the three months ended March 31, 2021 and the year ended December 31, 2020, the Company maintained long-term borrowings with the FHLB averaging $60.9 million and $65.0 million, respectively, with an average cost of approximately 2.29%. Substantially all long-term FHLB borrowings outstanding at March 31, 2021 and December 31, 2020 had fixed interest rates. At both March 31, 2021 and December 31, 2020, $16 million of FHLB borrowings outstanding were callable. The Company maintained five, unsecured Federal Funds lines of credit with commercial banks which provide for extensions of credit with an availability to borrow up to an aggregate $105.0 million as of March 31, 2021. There were no advances under these lines of credit outstanding as of March 31, 2021. Paycheck Protection Program Liquidity Facility: In conjunction with the PPP, we are also currently participating in the Federal Reserve's PPPLF which extends loans to banks that are loaning money to small businesses under the PPP. The amount outstanding at March 31, 2021 was $100.1 million and is non-recourse and secured by the amount of the PPP loans we originated. The maturity date of a borrowing under the PPPLF is equal to the maturity date of the PPP loan pledged to secure the borrowing and would be accelerated (i) if the underlying PPP loan goes into default and is sold to the SBA to realize on the SBA guarantee or (ii) to the extent that any loan forgiveness reimbursement is received from the SBA. Borrowings under the PPPLF are included in long-term liabilities on the Company’s consolidated balance sheet and bear interest at a rate of 0.35%. Subordinated Notes: On July 24, 2020, the Company issued $37 million aggregate principal amount of 6.00% fixed-to-floating rate subordinated notes due 2030 (the “Notes”). The Notes initially bear interest at a fixed annual rate of 6.00%, payable quarterly, in arrears, to, but excluding, July 31, 2025. From and including July 31, 2025, to, but excluding, the maturity date or earlier redemption date, the interest rate will reset quarterly to an interest rate per annum equal to a benchmark rate, which is expected to be the then-current three-month Secured Overnight Financing Rate, as published by the Federal Reserve Bank of New York (provided, that in the event the benchmark rate is less than zero, the benchmark rate will be deemed to be zero) plus 592 basis points, payable quarterly , in arrears. The amount outstanding at March 31, 2021 was $ 37.0 million . Secured borrowings : Due to the rights retained on certain loan participations sold, the Company is deemed to have retained effective control over these loans under FASB ASC Topic 860, “Transfers and Servicing”, and therefore these participations sold must be accounted for as a secured borrowing. At March 31, 2021, total secured borrowings were $4.0 million which are included in loans held for investment and long-term borrowings. At December 31, 2020, total secured borrowings were $4.0 million which are included in loans held for investment and long-term borrowings. None of the secured borrowings mature in the next five years following the latest balance sheet date

Stock-Based Compensation and Ot

Stock-Based Compensation and Other Benefit Plans	3 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation and Other Benefit Plans	NOTE 11. STOCK-BASED COMPENSATION AND OTHER BENEFIT PLANS Spirit of Texas Bancshares, Inc. 2008 Stock Plan (the “2008 Stock Plan”) Option activity for the period indicated is summarized as follows: 2008 Stock Plan Options Weighted Average Exercise Price Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Life (Years) Outstanding at January 1, 2021 840,872 $ - Granted — Exercised (103,400 ) $ 14.07 $ 852 Forfeited (260 ) $ 14.15 Expired — — Outstanding at March 31, 2021 737,212 $ 13.40 6,569 3.23 Vested and exercisable at March 31, 2021 715,884 $ 13.40 6,379 3.17 The total unrecognized compensation cost of $22 thousand related to the 2008 Stock Plan for the share awards outstanding at March 31, 2021 will be recognized over a weighted average remaining period of 0.40 years. Spirit of Texas Bancshares, Inc. 2017 Stock Plan (the “2017 Stock Plan”) Option activity for the period indicated is summarized as follows: 2017 Stock Plan Options Weighted Average Exercise Price Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Life (Years) Outstanding at January 1, 2021 197,714 $ - Granted — — — Exercised (2,000 ) 15 15 Forfeited — $ - Expired — — Outstanding at March 31, 2021 195,714 $ 17.58 926 6.47 Vested and exercisable at March 31, 2021 121,147 $ 16.66 684 6.28 The total unrecognized compensation cost of $280 thousand related to the 2017 Stock Plan for the share awards outstanding at March 31, 2021 will be recognized over a weighted average remaining period of 1.86 years. 2017 Stock Plan – Restricted Stock Unit Awards On January 1, 2021, the Company granted a total of 6,107 restricted stock units to employees and directors that vest in full (i.e., cliff vesting) on the five year anniversary of the grant date. The fair value of the restricted stock units on the grant date was $103 thousand and will be recognized as compensation expense over the requisite vesting period ending on the respective five year anniversary of the restricted stock unit award’s grant date. The following table presents the activity during the period related to restricted stock units from the 2017 Stock Plan: 2017 Stock Plan Restricted Stock Unit Awards Shares Weighted Average Grant Date Fair Value Outstanding at January 1, 2021 200,239 $ 13.31 Granted 6,107 16.80 Vested (1,591 ) 23.23 Forfeited (1,500 ) 9.02 Outstanding at March 31, 2021 203,255 $ 13.91 A summary of selected data related to stock-based compensation expense for the three months ended March 31, 2021 and 2020 are as follows: Restricted Stock Unit Awards March 31, 2021 2020 (Dollars in thousands) Stock-based compensation expense $ 145 $ 237 Unrecognized compensation expense related to stock-based compensation $ 2,287 $ 1,064 Weighted-average life over which expense is expected to be recognized (years) 4.02 3.82 Warrants In connection with the acquisition of Oasis Bank in 2012, the Company issued warrants for 19,140 shares of stock (the “Oasis Bank Warrants”). The Oasis Bank Warrants are exercisable at $12.84 per share and expire in November 2022 Oasis Warrants Warrants Weighted Average Exercise Price Aggregate Intrinsic Value (thousands) Weighted Average Remaining Contractual Life (Years) Outstanding at January 1, 2021 19,140 $ 12.84 Granted — — Exercised (3,828 ) 12.84 $ 36 Forfeited (1) — — Expired — — Outstanding at March 31, 2021 15,312 $ 12.84 $ 145 1.67 Vested and exercisable at March 31, 2021 15,312 $ 12.84 $ 145 1.67

Basic and Diluted Earnings Per

Basic and Diluted Earnings Per Common Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Common Share	NOTE 12. BASIC AND DILUTED EARNINGS PER COMMON SHARE The following table presents the computation of basic and diluted earnings per share for the periods presented: Three Months Ended March 31, 2021 2020 (Dollars in thousands, except per share data) Net income available to common stockholders $ 10,086 $ 4,074 Weighted average number of common shares - basic 17,103,981 18,184,110 Effect of dilutive securities: Employee stock-based compensation awards and warrants 414,048 257,867 Weighted average number of common shares - diluted 17,518,029 18,441,977 Basic earnings per common share $ 0.59 $ 0.22 Diluted earnings per common share $ 0.58 $ 0.22 Anti-dilutive warrants and stock options 76,712 -

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 13. INCOME TAXES The effective tax rates for the three months ended March 31, 2021 and 2020 were 20.8% and 7.0%, respectively. The effective tax rate for the three months ended March 31, 2020 was favorably impacted by a discrete income tax benefit in the amount of $575 thousand driven by the Company’s

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 14. COMMITMENTS AND CONTINGENCIES The Company issues off-balance sheet financial instruments in connection with its lending activities and to meet the financing needs of its customers. These financial instruments include commitments to fund loans and lines of credit as well as commercial and standby letters of credit. These commitments expose the Company to varying degrees of credit and market risk which are essentially the same as those involved in extending loans to customers. The Company follows the same credit policies in making commitments as it does for instruments recorded on the Company’s consolidated balance sheet. Collateral is obtained based on management’s assessment of the customer’s credit risk. The Company’s exposure to credit loss is represented by the contractual amount of these commitments. As of and for both periods ending March 31, 2021 and December 31, 2020, the Company’s reserve for unfunded commitments totaled $90 Fees collected on off-balance sheet financial instruments represent the fair value of those commitments and are deferred and amortized over their term. Financial Instruments Commitments Unfunded commitments are as follows for the periods presented: March 31, 2021 December 31, 2020 (Dollars in thousands) Unfunded loan commitments $ 311,418 $ 309,411 Commercial and standby letters of credit 3,041 3,272 Total $ 314,459 $ 312,683 Unfunded loan commitments: Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if it is deemed necessary by the Company upon extension of credit, is based upon management’s credit evaluation of the counterparty. Collateral held varies but may include accounts receivable, inventory, property, plant and equipment, and income-producing commercial properties. Commercial and standby letters of credit: Letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. Letters of credit are primarily issued to support trade transactions or guarantee arrangements. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The Company generally holds collateral supporting those commitments if deemed necessary. Other Commitments and Contingencies Legal Proceedings The Company, from time to time, is involved as plaintiff or defendant in various legal actions arising in the normal course of business. While the ultimate outcome of any such proceedings cannot be predicted with certainty, it is the opinion of management, based upon advice of legal counsel, that no proceedings exist, either individually or in the aggregate, which, if determined adversely to the Company, would have a material effect on the Company’s consolidated balance sheet, results of operations or cash flows.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 15. FAIR VALUE MEASUREMENTS When determining the fair value measurements for assets and liabilities and the related fair value hierarchy, the Company considers the principal or most advantageous market in which it would transact and the assumptions that market participants would use when pricing the asset or liability. When possible, the Company looks to active and observable markets to price identical assets or liabilities. When identical assets and liabilities are not traded in active markets, the Company looks to market observable data for similar assets and liabilities. It is the Company’s policy to maximize the use of observable inputs, minimize the use of unobservable inputs and use unobservable inputs to measure fair value to the extent that observable inputs are not available. The need to use unobservable inputs generally results from the lack of market liquidity, resulting in diminished observability of both actual trades and assumptions that would otherwise be available to value these instruments, or the value of the underlying collateral is not market observable. Although third party price indications may be available for an asset or liability, limited trading activity would make it difficult to support the observability of these quotations. Financial Instruments Carried at Fair Value on a Recurring Basis The following is a description of the valuation methodologies used for financial instruments measured at fair value on a recurring basis, as well as the general classification of each instrument under the valuation hierarchy. Investment Securities—Investment securities available for sale are carried at fair value on a recurring basis. When available, fair value is based on quoted prices for the identical security in an active market and as such, would be classified as Level 1. If quoted market prices are not available, fair values are estimated using quoted prices of securities with similar characteristics, discounted cash flows or matrix pricing models. Investment securities available for sale for which Level 1 valuations are not available are classified as Level 2, and include U.S. government agencies and sponsored enterprises obligations and agency mortgage-backed securities; state and municipal obligations; asset-backed securities; and corporate debt and other securities. Pricing of these securities is generally spread driven. Observable inputs that may impact the valuation of these securities include benchmark yield curves, credit spreads, reported trades, dealer quotes, bids, issuer spreads, current rating, historical constant prepayment rates, historical voluntary prepayment rates, structural and waterfall features of individual securities, published collateral data, and for certain securities, historical constant default rates and default severities. SBA Servicing Asset—The SBA Servicing Asset is carried at fair value on a recurring basis. To determine the fair value of SBA servicing rights, The Company uses market prices for comparable servicing contracts, when available, or alternatively, uses a valuation model that calculates the present value of estimated future net servicing income. In using this valuation method, the Company incorporates assumptions that market participants would use in estimating future net servicing income, which includes estimates of the cost to service, the discount rate, custodial earnings rate, an inflation rate, ancillary income, prepayment speeds, default rates, late fees and losses. The SBA Servicing Asset is classified as Level 3. The following tables present the assets and liabilities measured at fair value on a recurring basis for the periods presented: March 31, 2021 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: State and municipal obligations — 34,409 — 34,409 Residential mortgage-backed securities — 364,709 — 364,709 SBA servicing rights — — 2,821 2,821 Equity securities at fair value 23,741 — — 23,741 Corporate Bonds — 43,458 — 43,458 Customer interest rate swaps — 1,492 — 1,492 Cash flow hedge derivative — 1,601 — 1,601 Liabilities: Correspondent interest rate swaps — 1,492 — 1,492 Total $ 23,741 $ 447,161 $ 2,821 $ 473,723 December 31, 2020 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: State and municipal obligations — 37,185 — 37,185 Residential mortgage-backed securities — 132,142 — 132,142 SBA servicing rights — — 2,953 2,953 Equity securities at fair value 24,000 24,000 Corporate Bonds — 43,093 43,093 Customer interest rate swaps — 3,009 3,009 Liabilities: Correspondent interest rate swaps — 3,009 3,009 Total $ 24,000 $ 218,438 $ 2,953 $ 245,391 There were no transfers of financial assets between levels of the fair value hierarchy during the three months ended March 31, 2021. Financial Instruments Measured at Fair Value on a Non-Recurring Basis The following is a description of the methodologies used to estimate the fair values of assets and liabilities measured at fair value on a non-recurring basis, and the level within the fair value hierarchy in which those measurements are typically classified. Impaired loans and other real estate owned (“OREO”)—The carrying amount of collateral dependent impaired loans is typically based on the fair value of the underlying collateral, which may be real estate or other business assets, less estimated costs to sell. The carrying value of OREO is initially measured based on the fair value, less estimated cost to sell, of the real estate acquired in foreclosure and subsequently adjusted to the lower of cost or estimated fair value, less estimated cost to sell. Fair values of real estate collateral are typically based on real estate appraisals which utilize market and income valuation techniques incorporating both observable and unobservable inputs. When current appraisals are not available, the Company may use brokers’ price opinions, home price indices, or other available information about changes in real estate market conditions to adjust the latest appraised value available. These adjustments to appraised values may be subjective and involve significant management judgment. The fair value of collateral consisting of other business assets is generally based on appraisals that use market approaches to valuation, incorporating primarily unobservable inputs. Fair value measurements related to collateral dependent impaired loans and OREO are classified within Level 3 of the fair value hierarchy. The following tables provide information about certain assets measured at fair value on a non-recurring basis: Estimated Fair Value March 31, 2021 December 31, 2020 (Dollars in thousands) Assets (classified in Level 3): Impaired loans $ 7,337 $ 4,948 Other real estate and repossessed assets - 133 Impairment charges resulting from the non-recurring changes in fair value of underlying collateral of impaired loans are included in the provision for loan losses in the consolidated statement of income. Impairment charges resulting from the non-recurring changes in fair value of OREO are included in other real estate and acquired assets resolution expenses in the consolidated statement of income. The following tables show significant unobservable inputs used in the recurring and non-recurring fair value measurements of Level 3 assets: Level 3 Asset Fair Value Valuation Technique Unobservable Inputs Range/Weighted Average March 31, 2021 Non-recurring: Impaired loans $ 7,337 Third party appraisals Collateral discounts 0.0% - 100.0% (41.9%) Other real estate owned - Third party appraisals Collateral discounts and estimated cost to sell 10.0 % Recurring: SBA servicing assets 2,821 Discounted cash flows Conditional prepayment rate 12.6 % Discount rate 10.0 % December 31, 2020 Non-recurring: Impaired loans $ 4,948 Third party appraisals Collateral discounts 0.0% - 100.0% (34.1%) Other real estate owned 133 Third party appraisals Collateral discounts and estimated cost to sell 10.0 % Recurring: SBA servicing assets 2,953 Discounted cash flows Conditional prepayment rate 12.5 % Discount rate 10.0 % The carrying amounts and estimated fair values, as well as the level within the fair value hierarchy, of the Company’s financial instruments are as follows for the periods presented: March 31, 2021 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 69,566 $ 69,566 $ 69,566 $ — $ — Equity investments at fair value 23,741 23,741 23,741 Available for sale securities 442,576 442,576 — 442,576 — FHLB and other bank stock 5,727 5,727 — 5,727 — Loans, net 2,414,280 2,399,909 — — 2,399,909 Loans held for sale 1,192 1,279 — 1,279 — Accrued interest receivable 10,588 10,588 — 10,588 — Bank-owned life insurance 16,057 16,057 — 16,057 — SBA servicing rights 2,821 2,821 — — 2,821 Customer interest rate swaps 1,492 1,492 — 1,492 — Cash flow hedge derivative 1,601 1,601 — 1,601 — Financial Liabilities: Deposits $ 2,597,550 $ 2,557,023 $ — $ 2,557,023 $ — Accrued interest payable 1,160 1,160 — 1,160 — Long-term borrowings 191,686 196,417 — 196,417 — Correspondent interest rate swaps 1,492 1,492 — 1,492 — December 31, 2020 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 263,034 $ 263,034 $ 263,034 $ — $ — Equity investments at fair value 24,000 24,000 $ 24,000 $ — $ — Available for sale securities 212,420 212,420 — 212,420 — FHLB and other bank stock 5,718 5,718 — 5,718 — Loans, net 2,372,506 2,364,646 — — 2,364,646 Loans held for sale 1,470 1,598 — 1,598 — Accrued interest receivable 11,199 11,199 — 11,199 — Bank-owned life insurance 15,969 15,969 — 15,969 — SBA servicing rights 2,953 2,953 — — 2,953 Customer interest rate swaps 3,009 3,009 - 3,009 - Financial Liabilities: Deposits $ 2,459,135 $ 2,427,412 $ — $ 2,427,412 $ — Accrued interest payable 1,303 1,303 — 1,303 — Short-term borrowings 10,000 10,136 — 10,136 — Long-term borrowings 242,020 245,311 — 245,311 — Correspondent interest rate swaps 3,009 3,009 — 3,009 — Certain financial instruments are carried at amounts that approximate fair value due to their short-term nature and generally negligible credit risk. Financial instruments for which fair value approximates the carrying amount at March 31, 2021 and December 31, 2020, include cash and cash equivalents and accrued interest receivable and payable.

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2021
Derivative Instrument Detail [Abstract]
Derivative Financial Instruments	NOTE 16. DERIVATIVE FINANCIAL INSTRUMENTS The Company offers a loan hedging program to certain loan customers. Through this program, the Company originates a variable rate loan with the customer. The Company and the customer will then enter into a fixed interest rate swap. Lastly, an identical offsetting swap is entered into by the Company with a correspondent bank. These “back-to-back” swap arrangements are intended to offset each other and allow the Company to book a variable rate loan, while providing the customer with a contract for fixed interest payments. In these arrangements, the Company’s net cash flow is equal to the interest income received from the variable rate loan originated with the customer. These customer swaps are not designated as hedging instruments and are recorded at fair value in other assets and other liabilities. The changes in fair value is recognized in the income statement in other income and fees. The Company is required to hold cash as collateral for the swaps. Total cash held as collateral for swaps was $3.0 million and $2.6 million at March 31, 2021 and December 31, 2020, respectively. At March 31, 2021 and December 31, 2020 interest rate swaps related to the Company’s loan hedging program that were outstanding is presented in the following table: March 31, 2021 December 31, 2020 (Dollars in thousands) Interest rate swaps on loans with customers Notional amount $ 85,618 $ 85,696 Weighted average remaining term (years) 4.33 4.58 Receive fixed rate (weighted average) 3.31 % 4.23 % Pay variable rate (weighted average) 4.52 % 4.52 % Estimated fair value $ 1,492 $ 3,009 March 31, 2021 December 31, 2020 (Dollars in thousands) Interest rate swaps on loans with correspondents Notional amount $ 85,618 $ 85,696 Weighted average remaining term (years) 4.33 4.58 Receive fixed rate (weighted average) 4.52 % 4.23 % Pay variable rate (weighted average) 3.31 % 4.52 % Estimated fair value $ 1,492 $ 3,009 Interest rate swaps with correspondents are subject to a master netting agreement. The Company has elected to net interest rate swap positions on the consolidated balance sheet. On January 6, 2021, we entered into an $80.0 million 0.5515% pay-fixed receive-float forward starting interest rate swap in order to hedge our risk of variability in cash flows (future interest payments) attributable to changes in the 1-month Federal Funds benchmark interest rate from interest rate swap (the hedging instrument) was designated and qualifies under hedge accounting as a cash flow hedge. The hedge is highly effective, and any future changes in value will be recorded in Other Comprehensive Income until the time that the underlying cash flows (future interest payments) are recorded in the income statement. The hedge is expected to remain highly effective and effectiveness will be assessed periodically throughout the term of the hedge relationship. At March 31, 2021, the Company recorded $1.3 million in Other Comprehensive Income related to the interest rate swap

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Spirit of Texas Bancshares, Inc. (“Spirit” or the “Company”) is a Texas corporation and registered bank holding company headquartered in Conroe, Texas that provides, through its bank subsidiary, Spirit of Texas Bank SSB (the “Bank”), a variety of financial services to individuals and corporate customers that are largely located or conducting business in Texas, and which operate in primarily agricultural, light industrial and commercial areas.
Risks and Uncertainties	Risks and Uncertainties COVID-19 Pandemic In December 2019, a novel strain of coronavirus (“COVID-19”) was reported to have surfaced in Wuhan, China, and has since spread worldwide. In March 2020, the World Health Organization declared COVID-19 a global pandemic and the United States declared a National Public Health Emergency. The ongoing COVID-19 pandemic has severely impacted the level of economic activity in the local, national and global economies and financial markets. During the first and second quarters of 2020, many businesses in Texas and throughout the United States were temporarily closed due to social distancing and/or shelter in place orders. As of March 31, 2021, businesses in Texas have been allowed to re-open; however, the Company and its customers continue to be adversely affected by the COVID-19 pandemic. The extent to which the COVID-19 pandemic negatively impacts the Company's business, results of operations, and financial condition, as well as its regulatory capital and liquidity ratios, is unknown at this time and will depend on future developments, including the scope and duration of the pandemic and actions taken by governmental authorities and other third parties in response to the pandemic. If the pandemic is sustained, it may further adversely impact the Company and impair the ability of the Company's customers to fulfill their contractual obligations to the Company. This could materially and adversely affect the Company’s business operations, asset valuations, financial condition, and results of operations. For additional risks related to the COVID-19 pandemic, see “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2020, and the Company’s other filings with the Securities and Exchange Commission (the “SEC”). In response to the pandemic, the President of the United States signed into law the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”). This legislation aims to provide relief for individuals and businesses that have been negatively impacted by the coronavirus pandemic. Section 4013 of the CARES Act provides financial institutions the opportunity to opt out of applying the “troubled debt restructuring” (“TDR”) accounting guidance in the Financial Accounting Standards Board’s (“FASB”) Accounting Standard Codification (“ASC”) 310-40 for certain loan modifications. Loan modifications made between March 1, 2020 and the earlier of i) 60 days after the end of the national emergency proclamation or ii) December 31, 2020. Section 541 of the Consolidated Appropriations Act, 2021, amended Section 4013 of the CARES Act to extend this relief to the earlier of i) 60 days after the end of the national emergency proclamation or ii) January 1, 2022. A financial institution may elect to suspend U.S. generally accepted accounting principles (“GAAP”) only for a loan that was not more than 30 days past due as of December 31, 2019. The Bank adopted this provision. Additionally, the CARES Act contained provisions that impact federal income taxes including but not limited to an extension to pay and file federal tax returns, bonus depreciation on qualified improvement property and the ability to carry back certain net operating losses to a prior year. The Bank utilized the filing and payment extension and net operating loss carryback provisions.
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of the Company and the Bank. All significant intercompany balances and transactions have been eliminated in consolidation. The accounting and financial reporting policies the Company follows conform, in all material respects, to GAAP and to general practices with the financial services industry. The Company has evaluated subsequent events for potential recognition and/or disclosure through the date these consolidated financial statements were issued.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements ASU 2020-06, “Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40)” – Issued in August 2020, Accounting Standards Update (“ASU”) No. 2020-06 addresses accounting complexities regarding convertible debt instruments and the derivatives scope exception for contracts in an entity’s own equity. The ASU reduces the number of available accounting models for convertible debt instruments in an attempt to reduce complexity and variation in practice. Additionally, the ASU improves the applicability of the derivatives scope exception for contracts in an entity’s own equity by clarifying settlement guidance and balance sheet classification. ASU 2020-06 is effective for public entities for fiscal years beginning after December 15, 2021 and for and for all other entities in fiscal years beginning after December 15, 2023. Management does not believe adoption of this ASU will have a material impact on the consolidated financial statements given that the Company does not currently hold any convertible debt instruments or any in-scope derivative contracts. ASU 2019-11, “Financial Instruments-Credit Losses: Codification Improvements Topic 326” – Issued in November 2019, ASU No. 2019-11 clarifies and addresses specific issues about certain aspects of the amendments in ASU 2016-13. For the Company, the provisions of this ASU are effective for fiscal years beginning after December 15, 2022 including interim periods within those fiscal years. See the discussions regarding the adoption of ASU 2016-13 below. ASU 2019-10, “Financial Instruments-Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842)” – Issued in November 2019, ASU No. 2019-10 addresses the change in philosophy to the effective dates including amendments issued after the issuance of the original ASUs. See the discussions regarding the adoption of ASU 2016-13 and ASU 2016-02 below. ASU 2019-04, “Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments” – Issued in April 2019, ASU No. 2019-04 clarifies a number of issues discussed at the June 2018 and November 2018 Credit Losses Transition Resource Group meetings. The clarifications address a variety of identified issues including but not limited to the treatment of accrued interest receivable as it relates to the allowance for credit losses, transfers between loan classifications and categories, recoveries, and using projections of future interest rate environments in expected cash flow calculations. Management is evaluating these clarifications concurrently with our assessment of ASU 2016-13. ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” Issued in June 2016, ASU 2016-13 will add FASB ASC Topic 326, “Financial Instruments-Credit Losses,” and finalizes amendments to FASB ASC Subtopic 825-15, “Financial Instruments-Credit Losses.” The amendments of ASU 2016-13 are intended to provide financial statement users with more decision-useful information related to expected credit losses on financial instruments and other commitments to extend credit by replacing the current incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. The amendments of ASU 2016-13 eliminate the probable initial recognition threshold and, in turn, reflect an entity’s current estimate of all expected credit losses. ASU 2016-13 does not specify the method for measuring expected credit losses, and an entity is allowed to apply methods that reasonably reflect its expectations of the credit loss estimate. Additionally, the amendments of ASU 2016-13 require that credit losses on available for sale debt securities be presented as an allowance rather than as a write-down. The amendments of ASU 2016-13 were originally effective for public entities for interim and annual periods beginning after December 15, 2019 and for all other entities for periods beginning after December 15, 2020. Issued in November 2019, ASU 2019-10, “ ” alters the effective date of ASU 2016-13 for private companies. Under the provisions of ASU 2019-10, ASU 2016-13 is now effective for fiscal years beginning after December 15, 2022 including interim periods within those years for non-public business entities. Earlier application is permitted for interim and annual periods beginning after December 15, 2018. Management has elected to adopt this ASU using the updated private company effective date and is currently evaluating the impact this ASU will have on the consolidated financial statements and that evaluation will depend on economic conditions and the composition of the Company’s loan and lease portfolio at the time of adoption. ASU 2016-02, “Leases (Topic 842).” Issued in February 2016, ASU No. 2016-02 was issued by the FASB to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and by disclosing key information about leasing arrangements. ASU 2016-02 will, among other things, require lessees to recognize a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 does not significantly change lease accounting requirements applicable to lessors; however, the ASU contains some targeted improvements that are intended to align, where necessary, lessor accounting with the lessee accounting model and with the updated revenue recognition guidance issued in 2014. The amendments of ASU 2016-02 are effective for public entities for interim and annual periods beginning after December 15, 2018 and for other entities for periods beginning after December 15, 2019. The adoption of this ASU will result in an increase to the Consolidated Balance Sheets for right-of-use assets and associated lease liabilities for operating leases in which the Company is the lessee. Under current accounting standards, all of the Company's leases are classified as operating leases and, as such, are not recognized on the Company's Consolidated Balance Sheet. Additionally, in July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases and ASU No. 2018-11, Leases, Targeted Improvements. The amendments in these updates provide additional clarification and implementation guidance on certain aspects of ASU 2016-02 and have the same effective and transition requirements as ASU 2016-02. Specifically, ASU 2018-11 creates an additional transition method option allowing entities to record a cumulative effect adjustment to opening retained earnings in the year of adoption. In December 2018, the FASB further issued ASU 2018-20, Leases (Topic 842) Narrow-Scope Improvements for Lessors . The amendments in this update permits lessors to make an accounting policy election to not evaluate whether certain sales taxes and other similar taxes are lessor costs or lessee costs and instead account for the costs as if they were lessee costs. Additionally, the amendment requires lessors to exclude from variable payments, and therefore revenue, lessor costs paid by lessees directly to third parties. The amendments also require lessors to account for costs excluded from the consideration of a contract that are paid by the lessor and reimbursed by the lessee as variable payments. In March 2019, the FASB also issued ASU 2019-01, Leases (Topic 842) Codification Improvements, to further clarify certain identified issues regarding implementation of ASU 2016-02. Specifically, the amendments in ASU 2019-01 clarify the determination of fair value of underlying assets by lessors that are not manufacturers or dealers, the cash flow presentation of sales-type or direct financing leases, and transition disclosures for interim periods. Issued in November 2019, ASU 2019-10, “ Financial Instruments-Credit Losses, Derivatives and Hedging, and Leases ” alters the effective date of ASU 2016-02 for private companies. Under the provisions of ASU 2019-10, ASU 2016-02 is now effective for fiscal years beginning after December 15, 2020 including interim periods within those years for non-public business entities. Management adopted these ASUs using the private company effective date of January 1, 2021 using the modified retrospective approach. The Company did not utilize any optional practical expedients in conjunction with adoption. At January 1, 2021, the Company recorded a lease liability of $ 6.6 million and a right of use asset of $ 6.4 million . See Note 8 for additional discussion.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Schedule of Non-Interest Income, Segregated by Revenue Streams in-Scope and Out-of-Scope of Topic 606	The following presents non-interest income, segregated by revenue streams in-scope and out-of-scope of Topic 606, for the three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 Non-Interest Income In-scope of Topic 606 Deposit accounts core service charges $ 357 $ 211 Deposit account transaction based fee income 1,077 1,100 Swap referral fees 430 580 Mortgage referral fees 274 202 Non-Interest Income (in-scope of Topic 606) 2,138 2,093 Non-Interest Income (out-of-scope of Topic 606) 481 619 Total Non-Interest Income $ 2,619 $ 2,712

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2021
Investments Debt And Equity Securities [Abstract]
Schedule of Fair Values of Securities Available for Sale	The amortized cost, gross unrealized gains and losses and approximate fair values of securities available for sale are as follows: Amortized Unrealized Fair March 31, 2021 Cost Gains Losses Value (Dollars in thousands) Available for sale: U.S. Treasury securities $ - $ - — $ - State and municipal obligations 34,541 71 203 34,409 Residential mortgage-backed securities 370,937 5 6,233 364,709 Corporate Bonds 42,745 848 135 43,458 Total available for sale $ 448,223 $ 924 $ 6,571 $ 442,576 Amortized Unrealized Fair December 31, 2020 Cost Gains Losses Value (Dollars in thousands) Available for sale: State and municipal obligations $ 36,258 $ 927 $ - $ 37,185 Residential mortgage-backed securities 132,130 278 267 132,142 Corporate bonds and other debt securities 42,768 433 109 43,093 Total available for sale $ 211,156 $ 1,638 $ 376 $ 212,420
Schedule of Securities Available for Sale by Contractual Maturity	The amortized cost and estimated fair value of securities available for sale, by contractual maturity, are as follows for the period presented: Amortized Fair March 31, 2021 Cost Value (Dollars in thousands) Available for sale: Due in one year or less $ 317 $ 318 Due after one year through five years 9,471 9,555 Due after five years through ten years 31,021 31,687 Due after ten years 36,477 36,307 Residential mortgage-backed securities 370,937 364,709 Total available for sale $ 448,223 $ 442,576
Schedule of Investment Securities Available for Sale and Aggregated by Investment Category and Length of Time Individual Securities in Continuous Unrealized Loss Position	The following tables present the estimated fair values and gross unrealized losses on investment securities available for sale, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position as of the periods presented: Less than 12 Months 12 Months or More Total March 31, 2021 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Treasury securities $ — $ — $ — $ — $ — $ — State and municipal obligations 20,837 203 — — 20,837 203 Residential mortgage-backed securities 332,775 6,233 — — 332,775 6,233 Corporate Bonds 3,637 135 — — 3,637 135 Total available for sale $ 357,249 $ 6,571 $ — $ — $ 357,249 $ 6,571 Less than 12 Months 12 Months or More Total December 31, 2020 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Treasury securities $ — $ — $ — $ — $ - $ - State and municipal obligations — — — — — — Residential mortgage-backed securities 53,598 267 — — 53,598 267 Corporate bonds and other debt securities 17,087 109 — — 17,087 109 Total available for sale $ 70,685 $ 376 $ - $ - $ 70,685 $ 376

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2021
Receivables [Abstract]
Summary of Total Loans Held in Portfolio	Total loans held in portfolio consisted of the following at March 31, 2021 and December 31, 2020: March 31, 2021 Acquired Loans (1) Organic Loans Total Loans (Dollars in thousands) Commercial and industrial loans (2) $ 51,240 $ 648,656 $ 699,896 Real estate: 1-4 single family residential loans 87,876 261,032 348,908 Construction, land and development 59,458 285,099 344,557 Commercial real estate loans (including multifamily) 343,979 620,363 964,342 Consumer loans and leases 2,370 7,249 9,619 Municipal and other loans 5,170 58,102 63,272 Total loans held in portfolio (3) $ 550,093 $ 1,880,501 $ 2,430,594 December 31, 2020 Acquired Loans (1) Organic Loans Total Loans (Dollars in thousands) Commercial and industrial loans (2) $ 53,857 $ 521,129 $ 574,986 Real estate: 1-4 single family residential loans 93,840 270,299 364,139 Construction, land and development 131,734 283,754 415,488 Commercial real estate loans (including multifamily) 333,489 623,254 956,743 Consumer loans and leases 3,088 8,650 11,738 Municipal and other loans 6,103 59,335 65,438 Total loans held in portfolio (3) $ 622,111 $ 1,766,421 $ 2,388,532 (1) Acquired loans include loans acquired in the acquisitions of Comanche, National Corporation, First Beeville Financial Corporation, and Chandler Bancorp, Inc. and its subsidiary, Citizens State Bank (together, “Citizens”), and the Simmons Bank branch acquisition. All loans originated after acquisition close date are included in organic loans. (2 ) Organic loans b alance includes $ million and $ million of the unguaranteed port ion of SBA loans as of March 31 , 202 1 and December 31, 20 20 , respectively. (3 ) Organic loans balance includes $(11.9) million and $(8.2) million of deferred fees, cost, premium and discount as of March 31, 2021 and December 31, 2020, respectively.
Summary of Loans to Related Parties and Principal Owners	In the ordinary course of business, the Company makes loans to executive officers and directors. Loans to these related parties, including companies in which they are principal owners, are as follows for the periods presented: Three Months Ended March 31, 2021 2020 (Dollars in thousands) Principal outstanding, beginning of year $ 7,581 $ 6,005 Additions (reductions) of affiliations — — New loans made in current year 972 1,719 Repayments (1,775 ) (277 ) Principal outstanding, end of year $ 6,778 $ 7,447

Allowance for Loan and Lease _2

Allowance for Loan and Lease Losses (Tables)	3 Months Ended
	Mar. 31, 2021
Receivables [Abstract]
Allowance for Loan and Lease Losses	The following tables present information related to allowance for loan and lease losses for the periods presented: Allowance Rollforward Three Months Ended March 31, 2021 Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Commercial and industrial loans $ 9,086 $ (807 ) $ 15 $ 1,388 $ 9,682 Real estate: 1-4 single family residential loans 147 — — (63 ) 84 Construction, land and development loans 1,744 — — 142 1,886 Commercial real estate loans (including multifamily) 4,843 — — (387 ) 4,456 Consumer loans and leases 145 (20 ) 12 (24 ) 113 Municipal and other loans 61 — 2 30 93 Ending allowance balance $ 16,026 $ (827 ) $ 29 $ 1,086 $ 16,314 Allowance Rollforward Three Months Ended March 31, 2020 Beginning Balance Charge-offs Recoveries Provision Ending Balance (Dollars in thousands) Commercial and industrial loans $ 4,078 $ (254 ) $ 4 $ 656 $ 4,484 Real estate: 1-4 single family residential loans 31 — — 4 35 Construction, land and development loans 1,055 — — 238 1,293 Commercial real estate loans (including multifamily) 1,451 — — 298 1,749 Consumer loans and leases 68 (52 ) 12 23 51 Municipal and other loans 54 — 2 (48 ) 8 Ending allowance balance $ 6,737 $ (306 ) $ 18 $ 1,171 $ 7,620
Summary of Aging Analysis of Recorded Investment for Delinquent Loans by Portfolio and Segment	The following tables present an aging analysis of the recorded investment for delinquent loans by portfolio and segment for the periods presented: Accruing March 31, 2021 Current 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) Commercial and industrial loans $ 693,533 $ 374 $ — $ — $ 5,989 $ 699,896 Real estate: 1-4 single family residential loans 346,360 1,459 250 — 839 348,908 Construction, land and development 344,204 — — 136 217 344,557 Commercial real estate loans (including multifamily) 960,352 1,276 136 — 2,578 964,342 Consumer loans and leases 9,459 53 — — 107 9,619 Municipal and other loans 63,254 — — — 18 63,272 Total loans $ 2,417,162 $ 3,162 $ 386 $ 136 $ 9,748 $ 2,430,594 Accruing December 31, 2020 Current 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) Commercial and industrial loans $ 567,491 $ 2,295 $ 271 $ - $ 4,929 $ 574,986 Real estate: 1-4 single family residential loans 362,505 99 28 — 1,507 364,139 Construction, land and development 415,135 136 — — 217 415,488 Commercial real estate loans (including multifamily) 953,823 1,084 — — 1,836 956,743 Consumer loans and leases 11,618 8 4 — 108 11,738 Municipal and other loans 65,416 — 22 — — 65,438 Total loans $ 2,375,988 $ 3,622 $ 325 $ - $ 8,597 $ 2,388,532
Summary of Loans by Key Indicators of Credit Quality	The following tables summarize the Company’s loans by key indicators of credit quality for the periods presented: March 31, 2021 Pass Special Mention Substandard Doubtful (Dollars in thousands) Commercial and industrial loans $ 681,046 $ 2,167 $ 16,581 $ 102 Real estate: 1-4 single family residential loans 346,298 479 2,131 — Construction, land and development 336,232 7,232 1,093 — Commercial real estate loans (including multifamily) 915,581 36,046 12,715 — Consumer loans and leases 9,512 — 103 4 Municipal and other loans 59,162 4,012 98 — Total loans $ 2,347,831 $ 49,936 $ 32,721 $ 106 December 31, 2020 Pass Special Mention Substandard Doubtful (Dollars in thousands) Commercial and industrial loans $ 554,685 $ 1,332 $ 18,723 $ 246 Real estate: 1-4 single family residential loans 360,337 - 3,802 — Construction, land and development 411,151 4,120 217 — Commercial real estate loans (including multifamily) 935,865 10,913 9,965 — Consumer loans and leases 11,626 — 112 — Municipal and other loans 62,273 3,085 80 — Total loans $ 2,335,937 $ 19,450 $ 32,899 $ 246
Summary of Investment in Loans Disaggregated Based on Method of Evaluating Impairment	The following tables show the Company’s investment in loans disaggregated based on the method of evaluating impairment for the periods presented: Loans - Recorded Investment Allowance for Credit Loss March 31, 2021 Individually Evaluated for Impairment Collectively Evaluated for Impairment Individually Evaluated for Impairment Collectively Evaluated for Impairment (Dollars in thousands) Commercial and industrial loans $ 6,033 $ 693,863 $ 4,712 $ 4,970 Real estate: 1-4 single family residential loans 965 347,943 1 83 Construction, land and development 217 344,340 — 1,886 Commercial real estate loans (including multifamily) 2,578 961,764 770 3,686 Consumer loans and leases 107 9,512 107 6 Municipal and other loans 70 63,202 52 41 Total loans $ 9,970 $ 2,420,624 $ 5,642 $ 10,672 Loans - Recorded Investment Allowance for Credit Loss December 31, 2020 Individually Evaluated for Impairment Collectively Evaluated for Impairment Individually Evaluated for Impairment Collectively Evaluated for Impairment (Dollars in thousands) Commercial and industrial loans $ 4,978 $ 570,008 $ 3,488 $ 5,598 Real estate: 1-4 single family residential loans 1,637 362,502 1 146 Construction, land and development 217 415,271 — 1,744 Commercial real estate loans (including multifamily) 1,837 954,906 500 4,343 Consumer loans and leases 108 11,630 90 55 Municipal and other loans 52 65,386 — 61 Total loans $ 8,829 $ 2,379,703 $ 4,079 $ 11,947
Summary of Information Regarding Impaired Loans Evaluated for Specific Reserves	The following tables set forth certain information regarding the Company’s impaired loans that were evaluated for specific reserves for the periods presented: Impaired Loans - With Allowance Impaired Loans - With no Allowance March 31, 2021 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) Commercial and industrial loans $ 5,089 $ 5,127 $ 4,712 $ 944 $ 980 Real estate: 1-4 single family residential loans 4 4 1 961 956 Construction, land and development — — — 217 215 Commercial real estate loans (including multifamily) 1,284 1,274 770 1,294 1,294 Consumer loans and leases 107 107 107 — — Municipal and other loans 52 52 52 18 17 Total loans $ 6,536 $ 6,564 $ 5,642 $ 3,434 $ 3,462 Impaired Loans - With Allowance Impaired Loans - With no Allowance December 31, 2020 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) Commercial and industrial loans $ 4,407 $ 4,453 $ 3,488 $ 566 $ 571 Real estate: 1-4 single family residential loans 5 5 1 1,632 1,612 Construction, land and development — — — 217 215 Commercial real estate loans (including multifamily) 1,308 1,281 500 528 528 Consumer loans and leases 90 90 90 24 28 Municipal and other loans — — — 52 52 Total loans $ 5,810 $ 5,829 $ 4,079 $ 3,019 $ 3,006 Three Months Ended March 31, 2021 2020 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (Dollars in thousands) Commercial and industrial loans $ 6,700 $ 1 $ 5,247 $ — Real estate: 1-4 single family residential loans 967 1 2,102 — Construction, land and development 217 — 216 — Commercial real estate loans (including multifamily) 2,574 — 2,270 — Consumer loans and leases 105 — 39 — Municipal and other loans 72 — — — Total loans $ 10,635 $ 2 $ 9,874 $ —
Summary of Troubled Debt Restructurings (TDRs) Based Upon Delinquency Status	The following table provides a summary of troubled debt restructurings (“TDRs”) based upon delinquency status, all of which are considered impaired, for the periods presented: March 31, 2021 December 31, 2020 Number of contracts Recorded Investment Number of contracts Recorded Investment (Dollars in thousands) Performing TDRs: Commercial and industrial loans 2 $ 46 2 $ 49 Real estate: 1-4 single family residential loans 3 126 3 130 Construction, land and development — — — — Commercial real estate loans (including multifamily) — — — — Consumer loans and leases — — — — Municipal and other loans 1 52 1 52 Total performing TDRs 6 224 6 231 Nonperforming TDRs 7 435 14 652 Total TDRs 13 $ 659 20 $ 883 Allowance attributable to TDRs $ 419 $ 421
Summary of Newly Designated TDRs and Modifications to Existing TDRs	The following table summarizes TDRs, and includes newly designated TDRs as well as modifications made to existing TDRs, for the periods presented. Modifications may include, but are not limited to, granting a material extension of time, entering into a forbearance agreement, adjusting the interest rate, accepting interest only payments for an extended period of time, a change in the amortization period or a combination of any of these. Post-modification balances represent the recorded investment at the end of Day 2 in which the modification was made. The CARES Act includes a provision for the Company to opt out of applying the TDR accounting guidance in ASC 310-40 for certain loan modifications. Loan modifications made between March 1, 2020 and the earlier of ( i) January 1, 2022 or ( ii) 60 days after the President declares a termination of the COVID-19 national emergency are eligible for this relief if the related loans were not more than 30 days past due as of December 31, 2019. Loans with an unpaid principal balance of $ 11.6 million remained in a ctive deferral periods at March 31, 2021. Three Months Ended March 31, 2021 2020 Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Related Allowance Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Related Allowance (Dollars in thousands) Commercial and industrial loans — $ — $ — $ — 4 $ 168 $ 168 $ 56 Real estate: 1-4 single family residential loans — — — — — — — — Construction, land and development — — — — — — — — Commercial real estate loans (including multifamily) 2 321 321 — — — — — Consumer loans and leases — — — — — — — — Municipal and other loans — — — — — — — —

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill and Other Intangible Assets	Goodwill and other intangible assets, which consist of core deposit intangibles, are summarized as follows: Three Months Ended March 31, 2021 Year Ended December 31, 2020 (Dollars in thousands) Beginning goodwill $ 77,681 $ 68,503 Arising from business combination — 11,456 Measurement Period Adjustments — (2,278 ) Ending goodwill $ 77,681 $ 77,681 Core deposit intangible 19,722 19,722 Arising from business combination — — Less: Accumulated amortization (12,727 ) (11,904 ) Core deposit intangible, net $ 6,995 $ 7,818
Schedule of Estimated Amortization Expense for Intangibles	The estimated amount of amortization expense for core deposit intangibles to be recognized over the next five fiscal years is as follows: Type of intangibles Remainder of 2021 2022 2023 2024 2025 2026 (Dollars in thousands) Core deposit intangible $ 2,271 $ 2,212 $ 1,495 $ 744 $ 200 $ 73

SBA Servicing Asset (Tables)

SBA Servicing Asset (Tables)	3 Months Ended
	Mar. 31, 2021
Transfers And Servicing Of Financial Assets [Abstract]
Summary of Activity Pertaining to SBA Servicing Rights	The following summarizes the activity pertaining to SBA servicing rights, which are in the consolidated balance sheets, for the three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 (Dollars in thousands) Beginning balance $ 2,953 $ 3,355 Origination of servicing assets 38 105 Change in fair value: Due to run-off (135 ) (140 ) Due to market changes (35 ) (265 ) Ending balance $ 2,821 $ 3,055

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Schedule of Additional Information Related to Company's Leases	The table below presents additional information related to the Company’s leases as of March 31, 2021: March 31, 2021 Weighted-average remaining term (in years) - operating leases 4.37 Weighted-average discount rate - operating leases (1) 4.00 % (1) The incremental borrowing rate used to calculate the lease liability was determined based on facts and circumstances of the economic environment and the Company's credit standing as of the effective date of ASC 842. Additionally, the total lease term and total lease payments were also considered in determining the rate.
Schedule of Company's Operating Lease Liabilities by Contractual Maturity	The following is a schedule of the Company’s operating lease liabilities by contractual maturity as of March 31, 2021: (Dollars in thousands) 2021 (excluding 3 months ended March 31, 2021) 1,645 2022 1,643 2023 1,009 2024 812 2025 625 Thereafter 883 Total Lease Payments 6,617 Less: Imputed Interest 386 Total present value of lease liabilities 6,231
Schedule of Supplemental Cash Flow Information Related to Company's Operating Leases	The below table shows the supplemental cash flow information related to the Company’s operating leases for the three months ended March 31, 2021: March 31, 2021 (Dollars in thousands) Operating cash flows (fixed payments) included in occupancy and equipment expenses $ 571 Operating cash flows (liability reduction) included in occupancy and equipment expenses 507

Deposits (Tables)

Deposits (Tables)	3 Months Ended
	Mar. 31, 2021
Deposits By Component Alternative [Abstract]
Summary of Deposits by Category	The following table sets forth the Company’s deposits by category for the periods presented: March 31, 2021 December 31, 2020 (Dollars in thousands) Noninterest-bearing demand deposits $ 800,233 $ 727,543 Interest-bearing demand deposits 485,863 472,075 Interest-bearing NOW accounts 9,904 10,288 Savings and money market accounts 654,014 610,571 Time deposits 647,536 638,658 Total deposits $ 2,597,550 $ 2,459,135 Time deposits $100,000 and greater $ 503,736 $ 515,738 Time deposits $250,000 and greater 203,363 190,236 Related party deposits (executive officers and directors) 24,027 18,767

FHLB and Other Borrowings (Tabl

FHLB and Other Borrowings (Tables)	3 Months Ended
	Mar. 31, 2021
Federal Home Loan Banks [Abstract]
Schedule of Long-Term Borrowings from FHLB Outstanding	Long-term borrowings from the FHLB outstanding for the periods presented are as follows: Range of Weighted Range of Weighted March 31, Contractual Average December 31, Contractual Average 2021 Interest Rates Interest Rate 2020 Interest Rates Interest Rate (Dollars in thousands) Repayable during the years ending December 31, 2021 8,502 1.48% - 2.99% 0.77 % 8,636 1.48% - 2.99% 1.73 % 2022 4,516 2.04% - 2.99% 1.56 % 4,584 1.86% - 2.99% 2.23 % 2023 6,315 2.31% - 2.99% 1.09 % 6,489 1.86% - 2.99% 2.44 % 2024 10,610 2.07% - 2.99% 1.56 % 10,723 1.86% - 2.99% 2.62 % 2025 2,614 1.86% - 2.99% 0.62 % 2,649 1.86% - 2.99% 2.26 % 2026-2032 18,744 2.10% - 2.99% 1.27 % 18,809 2.10% - 2.99% 2.26 % Total long-term FHLB borrowings $ 51,301 $ 51,890

Stock-Based Compensation and _2

Stock-Based Compensation and Other Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Activity Related to Restricted Stock Units	The following table presents the activity during the period related to restricted stock units from the 2017 Stock Plan: 2017 Stock Plan Restricted Stock Unit Awards Shares Weighted Average Grant Date Fair Value Outstanding at January 1, 2021 200,239 $ 13.31 Granted 6,107 16.80 Vested (1,591 ) 23.23 Forfeited (1,500 ) 9.02 Outstanding at March 31, 2021 203,255 $ 13.91
Summary of Stock Based Compensation Expense	A summary of selected data related to stock-based compensation expense for the three months ended March 31, 2021 and 2020 are as follows: Restricted Stock Unit Awards March 31, 2021 2020 (Dollars in thousands) Stock-based compensation expense $ 145 $ 237 Unrecognized compensation expense related to stock-based compensation $ 2,287 $ 1,064 Weighted-average life over which expense is expected to be recognized (years) 4.02 3.82
Oasis Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Warrant Activity	Activity for the Oasis Bank Warrants for the period indicated is summarized as follows: Oasis Warrants Warrants Weighted Average Exercise Price Aggregate Intrinsic Value (thousands) Weighted Average Remaining Contractual Life (Years) Outstanding at January 1, 2021 19,140 $ 12.84 Granted — — Exercised (3,828 ) 12.84 $ 36 Forfeited (1) — — Expired — — Outstanding at March 31, 2021 15,312 $ 12.84 $ 145 1.67 Vested and exercisable at March 31, 2021 15,312 $ 12.84 $ 145 1.67
2008 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Option Activity	Option activity for the period indicated is summarized as follows: 2008 Stock Plan Options Weighted Average Exercise Price Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Life (Years) Outstanding at January 1, 2021 840,872 $ - Granted — Exercised (103,400 ) $ 14.07 $ 852 Forfeited (260 ) $ 14.15 Expired — — Outstanding at March 31, 2021 737,212 $ 13.40 6,569 3.23 Vested and exercisable at March 31, 2021 715,884 $ 13.40 6,379 3.17
2017 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Option Activity	Option activity for the period indicated is summarized as follows: 2017 Stock Plan Options Weighted Average Exercise Price Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Contractual Life (Years) Outstanding at January 1, 2021 197,714 $ - Granted — — — Exercised (2,000 ) 15 15 Forfeited — $ - Expired — — Outstanding at March 31, 2021 195,714 $ 17.58 926 6.47 Vested and exercisable at March 31, 2021 121,147 $ 16.66 684 6.28

Basic and Diluted Earnings Pe_2

Basic and Diluted Earnings Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Earnings Per Share	The following table presents the computation of basic and diluted earnings per share for the periods presented: Three Months Ended March 31, 2021 2020 (Dollars in thousands, except per share data) Net income available to common stockholders $ 10,086 $ 4,074 Weighted average number of common shares - basic 17,103,981 18,184,110 Effect of dilutive securities: Employee stock-based compensation awards and warrants 414,048 257,867 Weighted average number of common shares - diluted 17,518,029 18,441,977 Basic earnings per common share $ 0.59 $ 0.22 Diluted earnings per common share $ 0.58 $ 0.22 Anti-dilutive warrants and stock options 76,712 -

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Schedule of Unfunded Commitments	Unfunded commitments are as follows for the periods presented: March 31, 2021 December 31, 2020 (Dollars in thousands) Unfunded loan commitments $ 311,418 $ 309,411 Commercial and standby letters of credit 3,041 3,272 Total $ 314,459 $ 312,683

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables present the assets and liabilities measured at fair value on a recurring basis for the periods presented: March 31, 2021 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: State and municipal obligations — 34,409 — 34,409 Residential mortgage-backed securities — 364,709 — 364,709 SBA servicing rights — — 2,821 2,821 Equity securities at fair value 23,741 — — 23,741 Corporate Bonds — 43,458 — 43,458 Customer interest rate swaps — 1,492 — 1,492 Cash flow hedge derivative — 1,601 — 1,601 Liabilities: Correspondent interest rate swaps — 1,492 — 1,492 Total $ 23,741 $ 447,161 $ 2,821 $ 473,723 December 31, 2020 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: State and municipal obligations — 37,185 — 37,185 Residential mortgage-backed securities — 132,142 — 132,142 SBA servicing rights — — 2,953 2,953 Equity securities at fair value 24,000 24,000 Corporate Bonds — 43,093 43,093 Customer interest rate swaps — 3,009 3,009 Liabilities: Correspondent interest rate swaps — 3,009 3,009 Total $ 24,000 $ 218,438 $ 2,953 $ 245,391
Schedule of Assets Measured at Fair Value on Non-Recurring Basis	The following tables provide information about certain assets measured at fair value on a non-recurring basis: Estimated Fair Value March 31, 2021 December 31, 2020 (Dollars in thousands) Assets (classified in Level 3): Impaired loans $ 7,337 $ 4,948 Other real estate and repossessed assets - 133
Significant Unobservable Inputs Used in Recurring and Non-Recurring Fair Value Measurements	The following tables show significant unobservable inputs used in the recurring and non-recurring fair value measurements of Level 3 assets: Level 3 Asset Fair Value Valuation Technique Unobservable Inputs Range/Weighted Average March 31, 2021 Non-recurring: Impaired loans $ 7,337 Third party appraisals Collateral discounts 0.0% - 100.0% (41.9%) Other real estate owned - Third party appraisals Collateral discounts and estimated cost to sell 10.0 % Recurring: SBA servicing assets 2,821 Discounted cash flows Conditional prepayment rate 12.6 % Discount rate 10.0 % December 31, 2020 Non-recurring: Impaired loans $ 4,948 Third party appraisals Collateral discounts 0.0% - 100.0% (34.1%) Other real estate owned 133 Third party appraisals Collateral discounts and estimated cost to sell 10.0 % Recurring: SBA servicing assets 2,953 Discounted cash flows Conditional prepayment rate 12.5 % Discount rate 10.0 %
Summary of Carrying Amounts and Estimated Fair Values of Financial Instruments	The carrying amounts and estimated fair values, as well as the level within the fair value hierarchy, of the Company’s financial instruments are as follows for the periods presented: March 31, 2021 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 69,566 $ 69,566 $ 69,566 $ — $ — Equity investments at fair value 23,741 23,741 23,741 Available for sale securities 442,576 442,576 — 442,576 — FHLB and other bank stock 5,727 5,727 — 5,727 — Loans, net 2,414,280 2,399,909 — — 2,399,909 Loans held for sale 1,192 1,279 — 1,279 — Accrued interest receivable 10,588 10,588 — 10,588 — Bank-owned life insurance 16,057 16,057 — 16,057 — SBA servicing rights 2,821 2,821 — — 2,821 Customer interest rate swaps 1,492 1,492 — 1,492 — Cash flow hedge derivative 1,601 1,601 — 1,601 — Financial Liabilities: Deposits $ 2,597,550 $ 2,557,023 $ — $ 2,557,023 $ — Accrued interest payable 1,160 1,160 — 1,160 — Long-term borrowings 191,686 196,417 — 196,417 — Correspondent interest rate swaps 1,492 1,492 — 1,492 — December 31, 2020 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 263,034 $ 263,034 $ 263,034 $ — $ — Equity investments at fair value 24,000 24,000 $ 24,000 $ — $ — Available for sale securities 212,420 212,420 — 212,420 — FHLB and other bank stock 5,718 5,718 — 5,718 — Loans, net 2,372,506 2,364,646 — — 2,364,646 Loans held for sale 1,470 1,598 — 1,598 — Accrued interest receivable 11,199 11,199 — 11,199 — Bank-owned life insurance 15,969 15,969 — 15,969 — SBA servicing rights 2,953 2,953 — — 2,953 Customer interest rate swaps 3,009 3,009 - 3,009 - Financial Liabilities: Deposits $ 2,459,135 $ 2,427,412 $ — $ 2,427,412 $ — Accrued interest payable 1,303 1,303 — 1,303 — Short-term borrowings 10,000 10,136 — 10,136 — Long-term borrowings 242,020 245,311 — 245,311 — Correspondent interest rate swaps 3,009 3,009 — 3,009 —

Derivative Financial Instrume_2

Derivative Financial Instruments (Table)	3 Months Ended
	Mar. 31, 2021
Derivative Instrument Detail [Abstract]
Summary of Interest Rate Swaps Related to Company's Loan Hedging Program	At March 31, 2021 and December 31, 2020 interest rate swaps related to the Company’s loan hedging program that were outstanding is presented in the following table: March 31, 2021 December 31, 2020 (Dollars in thousands) Interest rate swaps on loans with customers Notional amount $ 85,618 $ 85,696 Weighted average remaining term (years) 4.33 4.58 Receive fixed rate (weighted average) 3.31 % 4.23 % Pay variable rate (weighted average) 4.52 % 4.52 % Estimated fair value $ 1,492 $ 3,009 March 31, 2021 December 31, 2020 (Dollars in thousands) Interest rate swaps on loans with correspondents Notional amount $ 85,618 $ 85,696 Weighted average remaining term (years) 4.33 4.58 Receive fixed rate (weighted average) 4.52 % 4.23 % Pay variable rate (weighted average) 3.31 % 4.52 % Estimated fair value $ 1,492 $ 3,009

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Jan. 01, 2021
Subsidiary Sale Of Stock [Line Items]
Right of use asset	$ 6,058
Operating lease liability	$ 6,231
Minimum | Accounting Standards Update 2016-02
Subsidiary Sale Of Stock [Line Items]
Right of use asset		$ 6,600
Operating lease liability		6,600
Maximum | Accounting Standards Update 2016-02
Subsidiary Sale Of Stock [Line Items]
Right of use asset		6,400
Operating lease liability		$ 6,400

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Non-Interest Income, Segregated by Revenue Streams in-Scope and Out-of-Scope of Topic 606 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Noninterest income:
Non-Interest Income	$ 2,619	$ 2,712
Accounting Standards Update 2014-09
Noninterest income:
Non-Interest Income (in-scope of Topic 606)	2,138	2,093
Out-of-scope of Topic 606
Noninterest income:
Non-Interest Income	481	619
Deposit accounts core service charges | Accounting Standards Update 2014-09
Noninterest income:
Non-Interest Income (in-scope of Topic 606)	357	211
Deposit account transaction based fee income | Accounting Standards Update 2014-09
Noninterest income:
Non-Interest Income (in-scope of Topic 606)	1,077	1,100
Swap referral fees | Accounting Standards Update 2014-09
Noninterest income:
Non-Interest Income (in-scope of Topic 606)	430	580
Mortgage referral fees | Accounting Standards Update 2014-09
Noninterest income:
Non-Interest Income (in-scope of Topic 606)	$ 274	$ 202

Investment Securities - Schedul

Investment Securities - Schedule of Fair Values of Securities Available for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Securities available for sale, Amortized Cost	$ 448,223	$ 211,156
Securities available for sale, Unrealized Gains	924	1,638
Securities available for sale, Unrealized Losses	6,571	376
Available for sale securities, at fair value	442,576	212,420
Corporate Bonds
Schedule Of Available For Sale Securities [Line Items]
Securities available for sale, Amortized Cost	42,745
Securities available for sale, Unrealized Gains	848
Securities available for sale, Unrealized Losses	135
Available for sale securities, at fair value	43,458
State and Municipal Obligations
Schedule Of Available For Sale Securities [Line Items]
Securities available for sale, Amortized Cost	34,541	36,258
Securities available for sale, Unrealized Gains	71	927
Securities available for sale, Unrealized Losses	203
Available for sale securities, at fair value	34,409	37,185
Residential Mortgage-backed Securities
Schedule Of Available For Sale Securities [Line Items]
Securities available for sale, Amortized Cost	370,937	132,130
Securities available for sale, Unrealized Gains	5	278
Securities available for sale, Unrealized Losses	6,233	267
Available for sale securities, at fair value	$ 364,709	132,142
Corporate Bonds and Other Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Securities available for sale, Amortized Cost		42,768
Securities available for sale, Unrealized Gains		433
Securities available for sale, Unrealized Losses		109
Available for sale securities, at fair value		$ 43,093

Investment Securities - Additio

Investment Securities - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021USD ($)Security	Mar. 31, 2020USD ($)Security	Dec. 31, 2020USD ($)
Investments Debt And Equity Securities [Abstract]
Taxable interest and dividends on investment securities	$ 957,000	$ 465,000
Tax-exempt interest on investment securities	158,000	$ 39,000
Available for sale securities pledged	$ 138,600,000		$ 91,500,000
Debt Securities, Available-for-sale, Restriction Type [Extensible List]	us-gaap:CollateralPledgedMember		us-gaap:CollateralPledgedMember
Available for sale, securities number of positions | Security	108
Available for sale, securities in unrealized loss positions, number of positions | Security	74
Available for sale, securities in unrealized loss positions, number of positions, more than 12 months | Security	0
Available for sale securities, gross realized gain (loss), excluding other than temporary impairments	$ 0
Sales of investment securities available for sale	6,918,000
Gross realized gains	5,000
Number of securities sold | Security		0
Equity investments, at fair value	23,741,000		$ 24,000,000
Other noninterest income	$ 400,000
Fair value changes		$ 0

Investment Securities - Sched_2

Investment Securities - Schedule of Securities Available for Sale by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Available for sale:
Due in one year or less, Amortized Cost	$ 317
Due after one year through five years, Amortized Cost	9,471
Due after five years through ten years, Amortized Cost	31,021
Due after ten years, Amortized Cost	36,477
Total available for sale, Amortized Cost	448,223	$ 211,156
Available for sale:
Due in one year or less, Fair Value	318
Due after one year through five years. Fair Value	9,555
Due after five years through ten years. Fair Value	31,687
Due after ten years. Fair Value	36,307
Total available for sale, Fair Value	442,576	212,420
Residential Mortgage-backed Securities
Available for sale:
Total available for sale, Amortized Cost	370,937	132,130
Available for sale:
Total available for sale, Fair Value	$ 364,709	$ 132,142

Investment Securities - Sched_3

Investment Securities - Schedule of Investment Securities Available for Sale and Aggregated by Investment Category and Length of Time Individual Securities in Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Investment Securities, Available for sale, Fair Value, Less than 12 Months	$ 357,249	$ 70,685
Investment Securities, Available for sale, Unrealized Loss, Less than 12 Months	6,571	376
Investment Securities, Available for sale, Fair Value	357,249	70,685
Investment Securities, Available for sale, Unrealized Loss	6,571	376
Corporate Bonds
Schedule Of Available For Sale Securities [Line Items]
Investment Securities, Available for sale, Fair Value, Less than 12 Months	3,637
Investment Securities, Available for sale, Unrealized Loss, Less than 12 Months	135
Investment Securities, Available for sale, Fair Value	3,637
Investment Securities, Available for sale, Unrealized Loss	135
State and Municipal Obligations
Schedule Of Available For Sale Securities [Line Items]
Investment Securities, Available for sale, Fair Value, Less than 12 Months	20,837
Investment Securities, Available for sale, Unrealized Loss, Less than 12 Months	203
Investment Securities, Available for sale, Fair Value	20,837
Investment Securities, Available for sale, Unrealized Loss	203
Residential Mortgage-backed Securities
Schedule Of Available For Sale Securities [Line Items]
Investment Securities, Available for sale, Fair Value, Less than 12 Months	332,775	53,598
Investment Securities, Available for sale, Unrealized Loss, Less than 12 Months	6,233	267
Investment Securities, Available for sale, Fair Value	332,775	53,598
Investment Securities, Available for sale, Unrealized Loss	$ 6,233	267
Corporate Bonds and Other Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Investment Securities, Available for sale, Fair Value, Less than 12 Months		17,087
Investment Securities, Available for sale, Unrealized Loss, Less than 12 Months		109
Investment Securities, Available for sale, Fair Value		17,087
Investment Securities, Available for sale, Unrealized Loss		$ 109

Loans - Summary of Total Loans

Loans - Summary of Total Loans Held in Portfolio (Details) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[1]	$ 2,430,594	$ 2,388,532
Commercial and Industrial Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[2]	699,896	574,986
Consumer Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		9,619	11,738
Municipal and Other Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		63,272	65,438
Acquired Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[1],[3]	550,093	622,111
Acquired Loans | Commercial and Industrial Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[2],[3]	51,240	53,857
Acquired Loans | Consumer Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[3]	2,370	3,088
Acquired Loans | Municipal and Other Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[3]	5,170	6,103
Organic Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[1]	1,880,501	1,766,421
Organic Loans | Commercial and Industrial Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[2]	648,656	521,129
Organic Loans | Consumer Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		7,249	8,650
Organic Loans | Municipal and Other Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		58,102	59,335
Real Estate | 1-4 Single Family Residential Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		348,908	364,139
Real Estate | Construction, Land and Development
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		344,557	415,488
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		964,342	956,743
Real Estate | Acquired Loans | 1-4 Single Family Residential Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[3]	87,876	93,840
Real Estate | Acquired Loans | Construction, Land and Development
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[3]	59,458	131,734
Real Estate | Acquired Loans | Commercial Real Estate Loans (Including Multifamily)
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio	[3]	343,979	333,489
Real Estate | Organic Loans | 1-4 Single Family Residential Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		261,032	270,299
Real Estate | Organic Loans | Construction, Land and Development
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		285,099	283,754
Real Estate | Organic Loans | Commercial Real Estate Loans (Including Multifamily)
Accounts Notes And Loans Receivable [Line Items]
Total loans held in portfolio		$ 620,363	$ 623,254
[1]	Organic loans balance includes $(11.9) million and $(8.2) million of deferred fees, cost, premium and discount as of March 31, 2021 and December 31, 2020, respectively.
[2]	Organic loans b alance includes $ million and $ million of the unguaranteed port ion of SBA loans as of March 31 , 202 1 and December 31, 20 20 , respectively.
[3]	Acquired loans include loans acquired in the acquisitions of Comanche, National Corporation, First Beeville Financial Corporation, and Chandler Bancorp, Inc. and its subsidiary, Citizens State Bank (together, “Citizens”), and the Simmons Bank branch acquisition.  All loans originated after acquisition close date are included in organic loans.

Loans - Summary of Total Loan_2

Loans - Summary of Total Loans Held in Portfolio (Parenthetical) (Details) - Organic Loans - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Deferred fees, cost, premium and discount	$ (11.9)	$ (8.2)
SBA Loans
Accounts Notes And Loans Receivable [Line Items]
Unguaranteed portion of U.S loans	$ 67.4	$ 70.8

Loans - Additional Information

Loans - Additional Information (Details) - USD ($)		3 Months Ended		12 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Pledged loans, collateral for FHLB advances		$ 971,500,000		$ 927,300,000
Pledged loans, collateral under PPPLF		100,100,000		149,800,000
Servicing loans sold		410,800,000		400,300,000
Realized gains on servicing loans sold		$ 99,000
Percentage of loan balance purchased		95.00%
Unpaid principal balances of loans serviced		$ 10,500,000
Amount outstanding	[1]	2,430,594,000		2,388,532,000
Unfunded commitments to related parties		314,459,000		312,683,000
Executive Officers and Directors
Accounts Notes And Loans Receivable [Line Items]
Unfunded commitments to related parties		2,000,000		1,800
Loan Held for Investment and Long-term Borrowings
Accounts Notes And Loans Receivable [Line Items]
Secured borrowings		4,000,000		4,000,000
Consumer Mortgage Loans
Accounts Notes And Loans Receivable [Line Items]
Recorded mortgage loans in process of foreclosure		0		0
SBA Loans
Accounts Notes And Loans Receivable [Line Items]
Unpaid principal balances of loans serviced		186,400,000		$ 193,300,000
Paycheck protection program loans under CARES Act		$ 366,500,000
PPP loan interest rate		1.00%
Deferred origination fees		$ 6,700,000
Weighted average life of debt		2 years 3 months 18 days
Amount outstanding		$ 100,100,000
Interest rate		0.35%
SBA Loans | Minimum
Accounts Notes And Loans Receivable [Line Items]
Paycheck protection program loans contractual term		2 years
SBA Loans | Maximum
Accounts Notes And Loans Receivable [Line Items]
Paycheck protection program loans contractual term		5 years
SBA Loans | Third Party
Accounts Notes And Loans Receivable [Line Items]
Servicing loans sold		$ 2,000,000	$ 5,600,000
Realized gains on servicing loans sold		$ 155,000	$ 464,000
[1]	Organic loans balance includes $(11.9) million and $(8.2) million of deferred fees, cost, premium and discount as of March 31, 2021 and December 31, 2020, respectively.

Loans - Summary of Loans to Rel

Loans - Summary of Loans to Related Parties and Principal Owners (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Receivables [Abstract]
Principal outstanding, beginning of year	$ 7,581	$ 6,005
New loans made in current year	972	1,719
Repayments	(1,775)	(277)
Principal outstanding, end of year	$ 6,778	$ 7,447

Allowance for Loan and Lease _3

Allowance for Loan and Lease Losses - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021USD ($)Loan	Mar. 31, 2020USD ($)Loan	Dec. 31, 2020USD ($)Loan
Financing Receivable Recorded Investment Past Due [Line Items]
Provision for loan losses	$ 1,086,000	$ 1,171,000
Recorded investment, 90 days past due and still accruing	136,000
Non-accrual loans, Past due	$ 9,748,000		$ 8,597,000
Number of restructured loans, defaulted | Loan	0	0
Covid-19
Financing Receivable Recorded Investment Past Due [Line Items]
Description of Loan modifications	Loan modifications made between March 1, 2020 and the earlier of (i) January 1, 2022 or (ii) 60 days after the President declares a termination of the COVID-19 national emergency are eligible for this relief if the related loans were not more than 30 days past due as of December 31, 2019.
Payments remaining in deferral	$ 11,600,000
Financing Receivables, Past Due Greater Than 90 Days or More and Still Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, 90 days past due and still accruing number of loans | Loan	1		0
Non-accrual loans, Past due	$ 5,100,000		$ 2,200,000
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans, Past due	842,000		930,000
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans, Past due	116,000		$ 545,000
Paycheck Protection Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Provision for loan losses	$ 0
Percentage Reserve	0.00%
Purchased Credit Impaired Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Impaired loans	$ 694,000

Allowance for Loan and Lease _4

Allowance for Loan and Lease Losses - Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Loans And Leases Receivable Disclosure [Line Items]
Beginning Balance	$ 16,026	$ 6,737
Charge-offs	(827)	(306)
Recoveries	29	18
Provision	1,086	1,171
Ending Balance	16,314	7,620
Commercial and Industrial Loans
Loans And Leases Receivable Disclosure [Line Items]
Beginning Balance	9,086	4,078
Charge-offs	(807)	(254)
Recoveries	15	4
Provision	1,388	656
Ending Balance	9,682	4,484
Real Estate | 1-4 Single Family Residential Loans
Loans And Leases Receivable Disclosure [Line Items]
Beginning Balance	147	31
Provision	(63)	4
Ending Balance	84	35
Real Estate | Construction, Land and Development Loans
Loans And Leases Receivable Disclosure [Line Items]
Beginning Balance	1,744	1,055
Provision	142	238
Ending Balance	1,886	1,293
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Loans And Leases Receivable Disclosure [Line Items]
Beginning Balance	4,843	1,451
Provision	(387)	298
Ending Balance	4,456	1,749
Consumer Loans and Leases
Loans And Leases Receivable Disclosure [Line Items]
Beginning Balance	145	68
Charge-offs	(20)	(52)
Recoveries	12	12
Provision	(24)	23
Ending Balance	113	51
Municipal and Other Loans
Loans And Leases Receivable Disclosure [Line Items]
Beginning Balance	61	54
Recoveries	2	2
Provision	30	(48)
Ending Balance	$ 93	$ 8

Allowance for Loan and Lease _5

Allowance for Loan and Lease Losses - Summary of Aging Analysis of Recorded Investment for Delinquent Loans by Portfolio and Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Current	$ 2,417,162	$ 2,375,988
Recorded investment, Non-accrual	9,748	8,597
Recorded investment, Total	2,430,594	2,388,532
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	3,162	3,622
Recorded investment, Non-accrual	842	930
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	386	325
Recorded investment, Non-accrual	116	545
Financing Receivables, Past Due Greater Than 90 Days or More and Still Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	136
Recorded investment, Non-accrual	5,100	2,200
Commercial and Industrial Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Current	693,533	567,491
Recorded investment, Non-accrual	5,989	4,929
Recorded investment, Total	699,896	574,986
Commercial and Industrial Loans | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	374	2,295
Commercial and Industrial Loans | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due		271
Real Estate | 1-4 Single Family Residential Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Current	346,360	362,505
Recorded investment, Non-accrual	839	1,507
Recorded investment, Total	348,908	364,139
Real Estate | 1-4 Single Family Residential Loans | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	1,459	99
Real Estate | 1-4 Single Family Residential Loans | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	250	28
Real Estate | Construction, Land and Development
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Current	344,204	415,135
Recorded investment, Non-accrual	217	217
Recorded investment, Total	344,557	415,488
Real Estate | Construction, Land and Development | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due		136
Real Estate | Construction, Land and Development | Financing Receivables, Past Due Greater Than 90 Days or More and Still Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	136
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Current	960,352	953,823
Recorded investment, Non-accrual	2,578	1,836
Recorded investment, Total	964,342	956,743
Real Estate | Commercial Real Estate Loans (Including Multifamily) | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	1,276	1,084
Real Estate | Commercial Real Estate Loans (Including Multifamily) | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	136
Consumer Loans and Leases
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Current	9,459	11,618
Recorded investment, Non-accrual	107	108
Recorded investment, Total	9,619	11,738
Consumer Loans and Leases | Financing Receivables, 30 to 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due	53	8
Consumer Loans and Leases | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due		4
Municipal and Other Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Current	63,254	65,416
Recorded investment, Non-accrual	18
Recorded investment, Total	$ 63,272	65,438
Municipal and Other Loans | Financing Receivables, 60 to 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Recorded investment, Accruing, Past due		$ 22

Allowance for Loan and Lease _6

Allowance for Loan and Lease Losses - Summary of Loans by Key Indicators of Credit Quality (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 2,430,594	$ 2,388,532
Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	2,347,831	2,335,937
Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	49,936	19,450
Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	32,721	32,899
Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans	106	246
Commercial and Industrial Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	699,896	574,986
Commercial and Industrial Loans | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	681,046	554,685
Commercial and Industrial Loans | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	2,167	1,332
Commercial and Industrial Loans | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	16,581	18,723
Commercial and Industrial Loans | Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans	102	246
Real Estate | 1-4 Single Family Residential Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	348,908	364,139
Real Estate | 1-4 Single Family Residential Loans | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	346,298	360,337
Real Estate | 1-4 Single Family Residential Loans | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	479
Real Estate | 1-4 Single Family Residential Loans | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	2,131	3,802
Real Estate | Construction, Land and Development
Financing Receivable Recorded Investment [Line Items]
Total loans	344,557	415,488
Real Estate | Construction, Land and Development | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	336,232	411,151
Real Estate | Construction, Land and Development | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	7,232	4,120
Real Estate | Construction, Land and Development | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	1,093	217
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Financing Receivable Recorded Investment [Line Items]
Total loans	964,342	956,743
Real Estate | Commercial Real Estate Loans (Including Multifamily) | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	915,581	935,865
Real Estate | Commercial Real Estate Loans (Including Multifamily) | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	36,046	10,913
Real Estate | Commercial Real Estate Loans (Including Multifamily) | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	12,715	9,965
Consumer Loans and Leases
Financing Receivable Recorded Investment [Line Items]
Total loans	9,619	11,738
Consumer Loans and Leases | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	9,512	11,626
Consumer Loans and Leases | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	103	112
Consumer Loans and Leases | Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans	4
Municipal and Other Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	63,272	65,438
Municipal and Other Loans | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	59,162	62,273
Municipal and Other Loans | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	4,012	3,085
Municipal and Other Loans | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 98	$ 80

Allowance for Loan and Lease _7

Allowance for Loan and Lease Losses - Summary of Investment in Loans Disaggregated Based on Method of Evaluating Impairment (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable Allowance For Credit Losses [Line Items]
Loans - Recorded Investment, Individually Evaluated for Impairment	$ 9,970	$ 8,829
Loans - Recorded Investment, Collectively Evaluated for Impairment	2,420,624	2,379,703
Allowance for Credit Loss, Individually Evaluated for Impairment	5,642	4,079
Allowance for Credit Loss, Collectively Evaluated for Impairment	10,672	11,947
Commercial and Industrial Loans
Financing Receivable Allowance For Credit Losses [Line Items]
Loans - Recorded Investment, Individually Evaluated for Impairment	6,033	4,978
Loans - Recorded Investment, Collectively Evaluated for Impairment	693,863	570,008
Allowance for Credit Loss, Individually Evaluated for Impairment	4,712	3,488
Allowance for Credit Loss, Collectively Evaluated for Impairment	4,970	5,598
Real Estate | 1-4 Single Family Residential Loans
Financing Receivable Allowance For Credit Losses [Line Items]
Loans - Recorded Investment, Individually Evaluated for Impairment	965	1,637
Loans - Recorded Investment, Collectively Evaluated for Impairment	347,943	362,502
Allowance for Credit Loss, Individually Evaluated for Impairment	1	1
Allowance for Credit Loss, Collectively Evaluated for Impairment	83	146
Real Estate | Construction, Land and Development
Financing Receivable Allowance For Credit Losses [Line Items]
Loans - Recorded Investment, Individually Evaluated for Impairment	217	217
Loans - Recorded Investment, Collectively Evaluated for Impairment	344,340	415,271
Allowance for Credit Loss, Collectively Evaluated for Impairment	1,886	1,744
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Financing Receivable Allowance For Credit Losses [Line Items]
Loans - Recorded Investment, Individually Evaluated for Impairment	2,578	1,837
Loans - Recorded Investment, Collectively Evaluated for Impairment	961,764	954,906
Allowance for Credit Loss, Individually Evaluated for Impairment	770	500
Allowance for Credit Loss, Collectively Evaluated for Impairment	3,686	4,343
Consumer Loans and Leases
Financing Receivable Allowance For Credit Losses [Line Items]
Loans - Recorded Investment, Individually Evaluated for Impairment	107	108
Loans - Recorded Investment, Collectively Evaluated for Impairment	9,512	11,630
Allowance for Credit Loss, Individually Evaluated for Impairment	107	90
Allowance for Credit Loss, Collectively Evaluated for Impairment	6	55
Municipal and Other Loans
Financing Receivable Allowance For Credit Losses [Line Items]
Loans - Recorded Investment, Individually Evaluated for Impairment	70	52
Loans - Recorded Investment, Collectively Evaluated for Impairment	63,202	65,386
Allowance for Credit Loss, Individually Evaluated for Impairment	52
Allowance for Credit Loss, Collectively Evaluated for Impairment	$ 41	$ 61

Allowance for Loan and Lease _8

Allowance for Loan and Lease Losses - Summary of Information Regarding Impaired Loans Evaluated for Specific Reserves (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Financing Receivable Impaired [Line Items]
Impaired Loans - With Allowance, Recorded Investment	$ 6,536		$ 5,810
Impaired Loans - With Allowance, Unpaid Principal Balance	6,564		5,829
Impaired Loans - With Allowance, Related Allowance	5,642		4,079
Impaired Loans - With no Allowance, Recorded Investment	3,434		3,019
Impaired Loans - With no Allowance, Unpaid Principal Balance	3,462		3,006
Average Recorded Investment	10,635	$ 9,874
Interest Income Recognized	2
Commercial and Industrial Loans
Financing Receivable Impaired [Line Items]
Impaired Loans - With Allowance, Recorded Investment	5,089		4,407
Impaired Loans - With Allowance, Unpaid Principal Balance	5,127		4,453
Impaired Loans - With Allowance, Related Allowance	4,712		3,488
Impaired Loans - With no Allowance, Recorded Investment	944		566
Impaired Loans - With no Allowance, Unpaid Principal Balance	980		571
Average Recorded Investment	6,700	5,247
Interest Income Recognized	1
Real Estate | 1-4 Single Family Residential Loans
Financing Receivable Impaired [Line Items]
Impaired Loans - With Allowance, Recorded Investment	4		5
Impaired Loans - With Allowance, Unpaid Principal Balance	4		5
Impaired Loans - With Allowance, Related Allowance	1		1
Impaired Loans - With no Allowance, Recorded Investment	961		1,632
Impaired Loans - With no Allowance, Unpaid Principal Balance	956		1,612
Average Recorded Investment	967	2,102
Interest Income Recognized	1
Real Estate | Construction, Land and Development
Financing Receivable Impaired [Line Items]
Impaired Loans - With no Allowance, Recorded Investment	217		217
Impaired Loans - With no Allowance, Unpaid Principal Balance	215		215
Average Recorded Investment	217	216
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Financing Receivable Impaired [Line Items]
Impaired Loans - With Allowance, Recorded Investment	1,284		1,308
Impaired Loans - With Allowance, Unpaid Principal Balance	1,274		1,281
Impaired Loans - With Allowance, Related Allowance	770		500
Impaired Loans - With no Allowance, Recorded Investment	1,294		528
Impaired Loans - With no Allowance, Unpaid Principal Balance	1,294		528
Average Recorded Investment	2,574	2,270
Consumer Loans and Leases
Financing Receivable Impaired [Line Items]
Impaired Loans - With Allowance, Recorded Investment	107		90
Impaired Loans - With Allowance, Unpaid Principal Balance	107		90
Impaired Loans - With Allowance, Related Allowance	107		90
Impaired Loans - With no Allowance, Recorded Investment			24
Impaired Loans - With no Allowance, Unpaid Principal Balance			28
Average Recorded Investment	105	$ 39
Municipal and Other Loans
Financing Receivable Impaired [Line Items]
Impaired Loans - With Allowance, Recorded Investment	52
Impaired Loans - With Allowance, Unpaid Principal Balance	52
Impaired Loans - With Allowance, Related Allowance	52
Impaired Loans - With no Allowance, Recorded Investment	18		52
Impaired Loans - With no Allowance, Unpaid Principal Balance	17		$ 52
Average Recorded Investment	$ 72

Allowance for Loan and Lease _9

Allowance for Loan and Lease Losses - Summary of Troubled Debt Restructurings (TDRs) Based Upon Delinquency Status (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021USD ($)Contract	Mar. 31, 2020Contract	Dec. 31, 2020USD ($)Contract
Financing Receivable Modifications [Line Items]
Number of contracts	13		20
Recorded Investment | $	$ 659		$ 883
Allowance attributable to TDRs | $	$ 419		$ 421
Commercial and Industrial Loans
Financing Receivable Modifications [Line Items]
Number of contracts		4
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Financing Receivable Modifications [Line Items]
Number of contracts	2
Performing TDRs
Financing Receivable Modifications [Line Items]
Number of contracts	6		6
Recorded Investment | $	$ 224		$ 231
Performing TDRs | Commercial and Industrial Loans
Financing Receivable Modifications [Line Items]
Number of contracts	2		2
Recorded Investment | $	$ 46		$ 49
Performing TDRs | Real Estate | 1-4 Single Family Residential Loans
Financing Receivable Modifications [Line Items]
Number of contracts	3		3
Recorded Investment | $	$ 126		$ 130
Performing TDRs | Municipal and Other Loans
Financing Receivable Modifications [Line Items]
Number of contracts	1		1
Recorded Investment | $	$ 52		$ 52
Nonperforming TDRs
Financing Receivable Modifications [Line Items]
Number of contracts	7		14
Recorded Investment | $	$ 435		$ 652

Allowance for Loan and Lease_10

Allowance for Loan and Lease Losses - Summary of Newly Designated TDRs and Modifications to Existing TDRs (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021USD ($)Contract	Mar. 31, 2020USD ($)Contract	Dec. 31, 2020Contract
Financing Receivable Modifications [Line Items]
Number of contracts | Contract	13		20
Commercial and Industrial Loans
Financing Receivable Modifications [Line Items]
Number of contracts | Contract		4
Pre-Modification Outstanding Recorded Investment		$ 168
Post-Modification Outstanding Recorded Investment		168
Related Allowance		$ 56
Real Estate | Commercial Real Estate Loans (Including Multifamily)
Financing Receivable Modifications [Line Items]
Number of contracts | Contract	2
Pre-Modification Outstanding Recorded Investment	$ 321
Post-Modification Outstanding Recorded Investment	$ 321

Goodwill and Intangibles - Sche

Goodwill and Intangibles - Schedule of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Mar. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning goodwill	$ 68,503
Arising from business combination	11,456
Measurement Period Adjustments	(2,278)
Ending goodwill	77,681
Core deposit intangible	19,722	$ 19,722
Less: Accumulated amortization	(11,904)	(12,727)
Core deposit intangible, net	$ 7,818	$ 6,995

Goodwill and Intangibles - Addi

Goodwill and Intangibles - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 823	$ 946
Core Deposit Intangible
Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 823	$ 946

Goodwill and Intangibles - Sc_2

Goodwill and Intangibles - Schedule of Estimated Amortization Expense for Intangibles (Details) - Core Deposit Intangible $ in Thousands	Mar. 31, 2021USD ($)
Finite Lived Intangible Assets [Line Items]
Remainder of 2021	$ 2,271
2022	2,212
2023	1,495
2024	744
2025	200
2026	$ 73

SBA Servicing Asset - Additiona

SBA Servicing Asset - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Servicing Assets At Fair Value [Line Items]
Unpaid principal balances of loans serviced	$ 10,500
SBA Loans
Servicing Assets At Fair Value [Line Items]
Unpaid principal balances of loans serviced	186,400		$ 193,300
Loan expenses	$ 324	$ 10

SBA Servicing Asset - Summary o

SBA Servicing Asset - Summary of Activity Pertaining to SBA Servicing Rights (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Transfers And Servicing Of Financial Assets [Abstract]
Beginning balance	$ 2,953	$ 3,355
Origination of servicing assets	38	105
Change in fair value:
Due to run-off	(135)	(140)
Due to market changes	(35)	(265)
Ending balance	$ 2,821	$ 3,055

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Lessee Lease Description [Line Items]
Lessee, operating lease, existence of option to extend	true
Lessee, operating lease, existence of option to terminate	true
Right of use asset	$ 6,058
Operating lease liability	$ 6,231
Weighted average lease term	4 years 4 months 13 days
Operating lease costs	$ 821
Minimum
Lessee Lease Description [Line Items]
Operating lease, remaining lease terms	1 year
Minimum | Property
Lessee Lease Description [Line Items]
Operating lease term	1 year
Minimum | Equipment
Lessee Lease Description [Line Items]
Operating lease, remaining lease terms	1 year
Maximum
Lessee Lease Description [Line Items]
Operating lease, remaining lease terms	10 years
Maximum | Property
Lessee Lease Description [Line Items]
Operating lease term	10 years
Maximum | Equipment
Lessee Lease Description [Line Items]
Operating lease, remaining lease terms	3 years

Leases - Schedule of Additional

Leases - Schedule of Additional Information Related to Company's Leases (Details)	Mar. 31, 2021
Leases [Abstract]
Weighted-average remaining term (in years) - operating leases	4 years 4 months 13 days
Weighted-average discount rate - operating leases	4.00%	[1]
[1]	The incremental borrowing rate used to calculate the lease liability was determined based on facts and circumstances of the economic environment and the Company's credit standing as of the effective date of ASC 842. Additionally, the total lease term and total lease payments were also considered in determining the rate.

Leases - Schedule of Company's

Leases - Schedule of Company's Operating Lease Liabilities by Contractual Maturity (Details) $ in Thousands	Mar. 31, 2021USD ($)
Contractual Obligation Fiscal Year Maturity Schedule [Abstract]
2021 (excluding 3 months ended March 31, 2021)	$ 1,645
2022	1,643
2023	1,009
2024	812
2025	625
Thereafter	883
Total Lease Payments	6,617
Less: Imputed Interest	386
Operating lease liability	$ 6,231

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information Related to Company's Operating Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Leases [Abstract]
Operating cash flows (fixed payments) included in occupancy and equipment expenses	$ 571
Operating cash flows (liability reduction) included in occupancy and equipment expenses	$ 507

Deposits - Summary of Deposits

Deposits - Summary of Deposits by Category (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Deposits By Component Alternative [Abstract]
Noninterest-bearing demand deposits	$ 800,233	$ 727,543
Interest-bearing demand deposits	485,863	472,075
Interest-bearing NOW accounts	9,904	10,288
Savings and money market accounts	654,014	610,571
Time deposits	647,536	638,658
Total deposits	2,597,550	2,459,135
Time deposits $100,000 and greater	503,736	515,738
Time deposits $250,000 and greater	203,363	190,236
Related party deposits (executive officers and directors)	$ 24,027	$ 18,767

Deposits - Additional Informati

Deposits - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Deposits By Component Alternative [Abstract]
Aggregate amount of overdraft demand deposits reclassified to loans	$ 67,000	$ 88,000
Aggregate amount of maturities for time deposits, period	5 years
Aggregate amount of maturities for time deposits, year one	$ 542,500,000
Aggregate amount of maturities for time deposits, year two	79,600,000
Aggregate amount of maturities for time deposits, year three	12,200,000
Aggregate amount of maturities for time deposits, year four	6,700,000
Aggregate amount of maturities for time deposits, year five	6,600,000
Brokered certificates of deposits	$ 0	$ 0

FHLB and Other Borrowings - Add

FHLB and Other Borrowings - Additional Information (Details)		Jul. 24, 2020USD ($)	May 31, 2017USD ($)	Mar. 31, 2021USD ($)LineOfCredit	Dec. 31, 2020USD ($)
Federal Home Loan Bank Advances [Line Items]
Pledged loans, collateral for FHLB advances				$ 971,500,000	$ 927,300,000
FHLB maximum borrowing capacity				668,800,000
Amount outstanding	[1]			2,430,594,000	2,388,532,000
Loan Held for Investment and Long-term Borrowings
Federal Home Loan Bank Advances [Line Items]
Secured borrowings				4,000,000	4,000,000
Subordinated Notes Due 2030
Federal Home Loan Bank Advances [Line Items]
Interest rate		6.00%
Fixed floating rate of subordinated notes		6.00%
Proceeds from issuance of subordinated debt		$ 37,000,000
Frequency of payment		quarterly
Amount outstanding				37,000,000
Secured Debt
Federal Home Loan Bank Advances [Line Items]
Aggregate amount of maturities for secured borrowings, year one				0
Aggregate amount of maturities for secured borrowings, year two				0
Aggregate amount of maturities for secured borrowings, year three				0
Aggregate amount of maturities for secured borrowings, year four				0
Aggregate amount of maturities for secured borrowings, year five				0
Paycheck Protection Program Liquidity Facility
Federal Home Loan Bank Advances [Line Items]
Amount outstanding				$ 100,100,000
Interest rate				0.35%
Unsecured Line Of Credit
Federal Home Loan Bank Advances [Line Items]
Maximum borrowing capacity				$ 105,000,000
Line of credit facility, drawn amount				$ 0
Number of lines of credit | LineOfCredit				5
Third Party Lender | Unsecured Line Of Credit
Federal Home Loan Bank Advances [Line Items]
Maximum borrowing capacity			$ 20,000,000
Line of credit facility, expiration date			May 12, 2022
Line of credit facility, remaining borrowing capacity					50,000,000
Line of credit facility, drawn amount				$ 0	0
Third Party Lender | Unsecured Line Of Credit | London Interbank Offered Rate (LIBOR)
Federal Home Loan Bank Advances [Line Items]
Debt instrument basis spread on variable rate			4.00%
Short-term Debt
Federal Home Loan Bank Advances [Line Items]
FHLB borrowings				0	$ 10,000,000
FHLB borrowings, average interest rate					0.70%
Long-term Debt
Federal Home Loan Bank Advances [Line Items]
FHLB borrowings				$ 60,900,000	$ 65,000,000
FHLB borrowings, average interest rate				2.29%
FHLB outstanding callable				$ 16,000,000	$ 16,000,000
[1]	Organic loans balance includes $(11.9) million and $(8.2) million of deferred fees, cost, premium and discount as of March 31, 2021 and December 31, 2020, respectively.

FHLB and Other Borrowings - Sch

FHLB and Other Borrowings - Schedule of Long-Term Borrowings from FHLB Outstanding (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
Due in remainder of fiscal year	$ 8,502
Due in next twelve	4,516	$ 8,636
Due in year two	6,315	4,584
Due in year three	10,610	6,489
Due in year four	2,614	10,723
Due in year five	18,744	2,649
Due in year six		18,809
Total long-term FHLB borrowings	$ 51,301	$ 51,890
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Weighted average interest rate, remainder of fiscal year	0.77%
Weighted average interest rate, with in one year	1.56%	1.73%
Weighted average interest rate, year two	1.09%	2.23%
Weighted average interest rate, year three	1.56%	2.44%
Weighted average interest rate, year four	0.62%	2.62%
Weighted average interest rate, year five	1.27%	2.26%
Weighted average interest rate, year six		2.26%
Minimum | 2021
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	1.48%	1.48%
Minimum | 2022
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.04%	1.86%
Minimum | 2023
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.31%	1.86%
Minimum | 2024
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.07%	1.86%
Minimum | 2026-2032
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.10%	2.10%
Minimum | 2025
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	1.86%	1.86%
Maximum | 2021
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.99%	2.99%
Maximum | 2022
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.99%	2.99%
Maximum | 2023
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.99%	2.99%
Maximum | 2024
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.99%	2.99%
Maximum | 2026-2032
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.99%	2.99%
Maximum | 2025
Federal Home Loan Bank, Advances by Interest Rate Type, by Maturity [Abstract]
Range of contractual interest rate	2.99%	2.99%

Stock-Based Compensation and _3

Stock-Based Compensation and Other Benefit Plans - Summary of Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
2008 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options, Outstanding	840,872
Options, Exercised	(103,400)
Options, Forfeited	(260)
Options, Outstanding	737,212
Options, Vested and exercisable	715,884
Weighted Average Exercise Price, Exercised | $ / shares	$ 14.07
Weighted Average Exercise Price, Forfeited | $ / shares	14.15
Weighted Average Exercise Price, Outstanding | $ / shares	13.40
Weighted Average Exercise Price, Vested and exercisable | $ / shares	$ 13.40
Aggregate Intrinsic Value, Exercised | $	$ 852
Aggregate Intrinsic Value, Outstanding | $	6,569
Vested and exercisable at March 31, 2021 | $	$ 6,379
Weighted Average Remaining Contractual Life (Years), Outstanding	3 years 2 months 23 days
Weighted Average Remaining Contractual Life (Years), Vested and Exercisable	3 years 2 months 1 day
2017 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options, Outstanding	197,714
Options, Exercised	(2,000)
Options, Outstanding	195,714
Options, Vested and exercisable	121,147
Weighted Average Exercise Price, Exercised | $ / shares	$ 15
Weighted Average Exercise Price, Outstanding | $ / shares	17.58
Weighted Average Exercise Price, Vested and exercisable | $ / shares	$ 16.66
Aggregate Intrinsic Value, Exercised | $	$ 15
Aggregate Intrinsic Value, Outstanding | $	926
Vested and exercisable at March 31, 2021 | $	$ 684
Weighted Average Remaining Contractual Life (Years), Outstanding	6 years 5 months 19 days
Weighted Average Remaining Contractual Life (Years), Vested and Exercisable	6 years 3 months 10 days

Stock-Based Compensation and _4

Stock-Based Compensation and Other Benefit Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2021	Mar. 31, 2021	Mar. 31, 2020
Oasis Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Warrants shares, issue		19,140
Warrant exercise price		$ 12.84
Warrants exercisable expire date		Nov. 30, 2022
2008 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost		$ 22
Compensation cost recognized weighted average remaining period		4 months 24 days
2017 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost		$ 280
Compensation cost recognized weighted average remaining period		1 year 10 months 9 days
2017 Stock Plan | Restricted Stock Unit Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost		$ 2,287	$ 1,064
Compensation cost recognized weighted average remaining period		4 years 7 days	3 years 9 months 25 days
Restricted stock units granted	6,107	6,107
Fair value of restricted stock	$ 103

Stock-Based Compensation and _5

Stock-Based Compensation and Other Benefit Plans - Summary of Activity Related to Restricted Stock Units (Details) - 2017 Stock Plan - Restricted Stock Unit Awards - $ / shares	Jan. 01, 2021	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Outstanding, Beginning balance	200,239	200,239
Shares, Granted	6,107	6,107
Shares, Vested		(1,591)
Shares, Forfeited		(1,500)
Shares, Outstanding, Ending balance		203,255
Weighted-Average Grant Date Fair Value, Outstanding	$ 13.31	$ 13.31
Weighted-Average Grant Date Fair Value, Granted		16.80
Weighted-Average Grant Date Fair Value, Vested		23.23
Weighted-Average Grant Date Fair Value, Forfeited		9.02
Weighted-Average Grant Date Fair Value, Outstanding		$ 13.91

Stock Based Compensation and Ot

Stock Based Compensation and Other Benefit Plans - Summary of Stock Based Compensation Expense (Details) - 2017 Stock Plan - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to stock-based compensation	$ 280
Weighted-average life over which expense is expected to be recognized (years)	1 year 10 months 9 days
Restricted Stock Unit Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 145	$ 237
Unrecognized compensation expense related to stock-based compensation	$ 2,287	$ 1,064
Weighted-average life over which expense is expected to be recognized (years)	4 years 7 days	3 years 9 months 25 days

Stock-Based Compensation and _6

Stock-Based Compensation and Other Benefit Plans - Summary of Activity for the Oasis Bank Warrants (Details) - Oasis Warrants $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Warrants, Outstanding | shares	19,140
Warrants, Exercised | shares	(3,828)
Warrants, Outstanding | shares	15,312
Warrants, Vested and exercisable | shares	15,312
Weighted Average Exercise Price, Outstanding | $ / shares	$ 12.84
Weighted Average Exercise Price, Exercised | $ / shares	12.84
Weighted Average Exercise Price, Outstanding | $ / shares	12.84
Weighted Average Exercise Price, Vested and exercisable | $ / shares	$ 12.84
Aggregate Intrinsic Value, Exercised | $	$ 36
Aggregate Intrinsic Value, Outstanding | $	145
Aggregate Intrinsic Value, Vested and exercisable | $	$ 145
Weighted Average Remaining Contractual Life (Years), Outstanding	1 year 8 months 1 day
Weighted Average Remaining Contractual Life (Years), Vested and Exercisable	1 year 8 months 1 day

Basic and Diluted Earnings Pe_3

Basic and Diluted Earnings Per Common Share - Schedule of Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net income available to common stockholders	$ 10,086	$ 4,074
Weighted average number of common shares - basic	17,103,981	18,184,110
Effect of dilutive securities:
Employee stock-based compensation awards and warrants	414,048	257,867
Weighted average number of common shares - diluted	17,518,029	18,441,977
Basic earnings per common share	$ 0.59	$ 0.22
Diluted earnings per common share	$ 0.58	$ 0.22
Anti-dilutive warrants and stock options	76,712

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Effective tax rate	20.80%	7.00%
Discrete income tax benefit		$ 575

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Unfunded Commitments | Commitments for Exposure to Credit Loss
Loss Contingencies [Line Items]
Reserve for unfunded commitments	$ 90	$ 90

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Unfunded Commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Supply Commitment [Line Items]
Unfunded commitments, Total	$ 314,459	$ 312,683
Commercial and Standby Letters of Credit
Supply Commitment [Line Items]
Unfunded commitments, Total	3,041	3,272
Unfunded Loan Commitments
Supply Commitment [Line Items]
Unfunded commitments, Total	$ 311,418	$ 309,411

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Total available for sale, Fair Value	$ 442,576	$ 212,420
State and Municipal Obligations
Assets:
Total available for sale, Fair Value	34,409	37,185
Residential Mortgage-backed Securities
Assets:
Total available for sale, Fair Value	364,709	132,142
Level 2
Assets:
Total available for sale, Fair Value	442,576	212,420
Corporate Bonds
Assets:
Total available for sale, Fair Value	43,458
Fair Value Measurements on Recurring Basis
Assets:
Total available for sale, Fair Value	473,723	245,391
Fair Value Measurements on Recurring Basis | State and Municipal Obligations
Assets:
Total available for sale, Fair Value	34,409	37,185
Fair Value Measurements on Recurring Basis | Residential Mortgage-backed Securities
Assets:
Total available for sale, Fair Value	364,709	132,142
Fair Value Measurements on Recurring Basis | SBA Servicing Rights
Assets:
Total available for sale, Fair Value	2,821	2,953
Fair Value Measurements on Recurring Basis | Equity Securities at Fair Value
Assets:
Total available for sale, Fair Value	23,741	24,000
Fair Value Measurements on Recurring Basis | Customer Interest Rate Swaps
Assets:
Total available for sale, Fair Value	1,492	3,009
Fair Value Measurements on Recurring Basis | Cash Flow Hedge Derivative
Assets:
Total available for sale, Fair Value	1,601
Fair Value Measurements on Recurring Basis | Correspondent Interest Rate Swaps
Liabilities:
Total available for sale, Fair Value	1,492	3,009
Fair Value Measurements on Recurring Basis | Level 1
Assets:
Total available for sale, Fair Value	23,741	24,000
Fair Value Measurements on Recurring Basis | Level 1 | Equity Securities at Fair Value
Assets:
Total available for sale, Fair Value	23,741	24,000
Fair Value Measurements on Recurring Basis | Level 2
Assets:
Total available for sale, Fair Value	447,161	218,438
Fair Value Measurements on Recurring Basis | Level 2 | State and Municipal Obligations
Assets:
Total available for sale, Fair Value	34,409	37,185
Fair Value Measurements on Recurring Basis | Level 2 | Residential Mortgage-backed Securities
Assets:
Total available for sale, Fair Value	364,709	132,142
Fair Value Measurements on Recurring Basis | Level 2 | Customer Interest Rate Swaps
Assets:
Total available for sale, Fair Value	1,492	3,009
Fair Value Measurements on Recurring Basis | Level 2 | Cash Flow Hedge Derivative
Assets:
Total available for sale, Fair Value	1,601
Fair Value Measurements on Recurring Basis | Level 2 | Correspondent Interest Rate Swaps
Liabilities:
Total available for sale, Fair Value	1,492	3,009
Fair Value Measurements on Recurring Basis | Level 3
Assets:
Total available for sale, Fair Value	2,821	2,953
Fair Value Measurements on Recurring Basis | Level 3 | SBA Servicing Rights
Assets:
Total available for sale, Fair Value	2,821	2,953
Fair Value Measurements on Recurring Basis | Corporate Bonds
Assets:
Total available for sale, Fair Value	43,458	43,093
Fair Value Measurements on Recurring Basis | Corporate Bonds | Level 2
Assets:
Total available for sale, Fair Value	$ 43,458	$ 43,093

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021USD ($)
Fair Value Disclosures [Abstract]
Fair value, assets, level 1 to level 2 transfers	$ 0
Fair value, assets, level 2 to level 1 transfers	0
Fair value, assets, transfers into level 3	0
Fair value, assets, transfers out of level 3	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Assets Measured at Fair Value on Non-Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets (classified in Level 3):
Other real estate owned and repossessed assets		$ 133
Level 3 | Fair Value Measurements on Non-Recurring Basis
Assets (classified in Level 3):
Impaired loans	$ 7,337	4,948
Other real estate owned and repossessed assets		$ 133

Fair Value Measurements - Signi

Fair Value Measurements - Significant Unobservable Inputs Used in Recurring and Non-Recurring Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other real estate owned		$ 133
SBA servicing asset	$ 2,821	2,953	$ 3,055	$ 3,355
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
SBA servicing asset	2,821	2,953
Level 3 | Fair Value Measurements on Non-Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 7,337	4,948
Other real estate owned		$ 133
Level 3 | Fair Value Measurements on Non-Recurring Basis | Weighted Average | Collateral Discounts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range/Weighted Average	41.90%	34.10%
Level 3 | Fair Value Measurements on Non-Recurring Basis | Weighted Average | Collateral Discounts and Estimated Cost to Sell
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range/Weighted Average	10.00%	10.00%
Level 3 | Fair Value Measurements on Non-Recurring Basis | Minimum | Collateral Discounts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range/Weighted Average	0.00%	0.00%
Level 3 | Fair Value Measurements on Non-Recurring Basis | Maximum | Collateral Discounts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range/Weighted Average	100.00%	100.00%
Level 3 | Fair Value Measurements on Non-Recurring Basis | Third Party Appraisals
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 7,337	$ 4,948
Other real estate owned		$ 133
Level 3 | Fair Value Measurements on Recurring Basis | Weighted Average | Conditional Prepayment Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range/Weighted Average	12.60%	12.50%
Level 3 | Fair Value Measurements on Recurring Basis | Weighted Average | Discount Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range/Weighted Average	10.00%	10.00%
Level 3 | Fair Value Measurements on Recurring Basis | Discounted Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
SBA servicing asset	$ 2,821	$ 2,953

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Financial Assets:
Total available for sale, Fair Value	$ 442,576	$ 212,420
SBA servicing rights	2,821	2,953	$ 3,055	$ 3,355
Level 1
Financial Assets:
Cash and cash equivalents	69,566	263,034
Equity investments at fair value	23,741	24,000
Level 2
Financial Assets:
Total available for sale, Fair Value	442,576	212,420
FHLB and other bank stock	5,727	5,718
Loans held for sale	1,279	1,598
Accrued interest receivable	10,588	11,199
Bank-owned life insurance	16,057	15,969
Customer interest rate swaps	1,492	3,009
Cash flow hedge derivative	1,601
Financial Liabilities:
Deposits	2,557,023	2,427,412
Accrued interest payable	1,160	1,303
Short-term borrowings		10,136
Long-term borrowings	196,417	245,311
Correspondent interest rate swaps	1,492	3,009
Level 3
Financial Assets:
Loans, net	2,399,909	2,364,646
SBA servicing rights	2,821	2,953
Carrying Value
Financial Assets:
Cash and cash equivalents	69,566	263,034
Equity investments at fair value	23,741	24,000
Total available for sale, Fair Value	442,576	212,420
FHLB and other bank stock	5,727	5,718
Loans, net	2,414,280	2,372,506
Loans held for sale	1,192	1,470
Accrued interest receivable	10,588	11,199
Bank-owned life insurance	16,057	15,969
SBA servicing rights	2,821	2,953
Customer interest rate swaps	1,492	3,009
Cash flow hedge derivative	1,601
Financial Liabilities:
Deposits	2,597,550	2,459,135
Accrued interest payable	1,160	1,303
Short-term borrowings		10,000
Long-term borrowings	191,686	242,020
Correspondent interest rate swaps	1,492	3,009
Fair Value
Financial Assets:
Cash and cash equivalents	69,566	263,034
Equity investments at fair value	23,741	24,000
Total available for sale, Fair Value	442,576	212,420
FHLB and other bank stock	5,727	5,718
Loans, net	2,399,909	2,364,646
Loans held for sale	1,279	1,598
Accrued interest receivable	10,588	11,199
Bank-owned life insurance	16,057	15,969
SBA servicing rights	2,821	2,953
Customer interest rate swaps	1,492	3,009
Cash flow hedge derivative	1,601
Financial Liabilities:
Deposits	2,557,023	2,427,412
Accrued interest payable	1,160	1,303
Short-term borrowings		10,136
Long-term borrowings	196,417	245,311
Correspondent interest rate swaps	$ 1,492	$ 3,009

Derivative Financial Instrume_3

Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Jan. 06, 2021	Dec. 31, 2020
Derivatives Fair Value [Line Items]
Changes in value of hedging instrument recorded in other comprehensive income	$ (1,265)
Interest Rate Swap
Derivatives Fair Value [Line Items]
Total cash held as collateral for swaps	3,000		$ 2,600
Amount of pay-fixed receive-float forward		$ 80,000
Interest rate of pay-fixed receive-float forward		0.5515%
Changes in value of hedging instrument recorded in other comprehensive income	$ 1,300

Derivative Financial Instrume_4

Derivative Financial Instruments - Summary of Interest Rate Swaps Related to Company's Loan Hedging Program (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Interest Rate Swaps on Loans with Customers
Derivatives Fair Value [Line Items]
Notional amount	$ 85,618	$ 85,696
Weighted average remaining term (years)	4 years 3 months 29 days	4 years 6 months 29 days
Receive fixed rate (weighted average)	3.31%	4.23%
Pay variable rate (weighted average)	4.52%	4.52%
Estimated fair value	$ 1,492	$ 3,009
Interest Rate Swaps on Loans with Correspondents
Derivatives Fair Value [Line Items]
Notional amount	$ 85,618	$ 85,696
Weighted average remaining term (years)	4 years 3 months 29 days	4 years 6 months 29 days
Receive fixed rate (weighted average)	4.52%	4.23%
Pay variable rate (weighted average)	3.31%	4.52%
Estimated fair value	$ 1,492	$ 3,009