CapStar Financial (CSTR) 10-K 5 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 04, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	CSTR
Entity Registrant Name	CAPSTAR FINANCIAL HOLDINGS, INC.
Entity Central Index Key	0001676479
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		22,083,729
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Current Reporting Status	Yes
Entity Shell Company	false
ICFR Auditor Attestation Flag	false
Entity File Number	001-37886
Entity Tax Identification Number	81-1527911
Entity Address, Address Line One	1201 Demonbreun Street
Entity Address, Address Line Two	Suite 700
Entity Address, City or Town	Nashville
Entity Address, State or Province	TN
Entity Address, Postal Zip Code	37203
City Area Code	615
Local Phone Number	732-6400
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	TN
Title of 12(b) Security	Common Stock, $1.00 par value per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Entity Voluntary Filers	No
Entity Well Known Seasoned Issuer	No
Entity Public Float			$ 219,626,256
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s Definitive Proxy Statement relating to the 2021 Annual Meeting of Shareholders, which will be filed within 120 days after December 31, 2020, are incorporated by reference into Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets
Cash and due from banks	$ 49,980	$ 17,726
Interest-bearing deposits in financial institutions	227,459	83,368
Federal funds sold		175
Total cash and cash equivalents	277,439	101,269
Securities available-for-sale, at fair value	486,215	213,129
Securities held-to-maturity, fair value of $2,504 and $3,411 at December 31, 2020 and 2019, respectively	2,407	3,313
Loans held for sale (includes $97,303 and $30,740 measured at fair value at December 31, 2020 and 2019, respectively)	179,669	168,222
Loans	1,891,019	1,420,102
Less allowance for loan losses	(23,245)	(12,604)
Loans, net	1,867,774	1,407,498
Premises and equipment, net	26,689	19,184
Restricted equity securities	15,562	13,689
Accrued interest receivable	8,771	5,792
Goodwill	41,068	37,510
Core deposit intangible, net	8,630	6,883
Other real estate owned, net	523	1,044
Other assets	72,259	59,668
Total assets	2,987,006	2,037,201
Deposits:
Noninterest-bearing	662,934	312,096
Interest-bearing	844,101	607,211
Savings and money market accounts	591,438	506,692
Time	469,528	303,452
Total deposits	2,568,001	1,729,451
Federal Home Loan Bank advances	10,000	10,000
Subordinated debt	29,423
Other liabilities	36,096	24,704
Total liabilities	2,643,520	1,764,155
Shareholders’ equity:
Additional paid-in capital	246,890	207,083
Retained earnings	66,879	46,218
Accumulated other comprehensive income, net of income tax	7,728	1,383
Total shareholders’ equity	343,486	273,046
Total liabilities and shareholders’ equity	2,987,006	2,037,201
Voting
Shareholders’ equity:
Common stock	$ 21,989	$ 18,362

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Securities held to maturity, fair value	$ 2,504	$ 3,411
Loans held for sale carried at fair value	$ 97,303	$ 30,740
Voting
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	25,000,000	25,000,000
Common stock, shares issued	21,988,803	18,361,922
Common stock, shares outstanding	21,988,803	18,361,922

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest income:
Loans, including fees	$ 84,272,000	$ 82,828,000	$ 60,751,000
Securities:
Taxable	4,863,000	4,619,000	4,184,000
Tax-exempt	1,342,000	1,438,000	1,201,000
Federal funds sold		26,000	63,000
Restricted equity securities	576,000	755,000	571,000
Interest-bearing deposits in financial institutions	799,000	1,881,000	1,011,000
Total interest income	91,852,000	91,547,000	67,781,000
Interest expense:
Interest-bearing deposits	3,868,000	7,538,000	4,164,000
Savings and money market accounts	5,196,000	7,266,000	5,446,000
Time deposits	5,317,000	7,542,000	3,940,000
Federal funds purchased		4,000	3,000
Securities sold under agreements to repurchase		5,000	3,000
Federal Home Loan Bank advances	356,000	1,444,000	2,533,000
Subordinated notes	792,000
Total interest expense	15,529,000	23,799,000	16,089,000
Net interest income	76,323,000	67,748,000	51,692,000
Provision for loan losses	11,479,000	761,000	2,842,000
Net interest income after provision for loan losses	64,844,000	66,987,000	48,850,000
Noninterest income:
Noninterest income	25,034,000	9,467,000	5,653,000
Tri-Net fees	3,693,000	2,785,000	1,503,000
Net gain (loss) on sale of securities	125,000	(99,000)	3,000
Other noninterest income	4,717,000	3,507,000	4,356,000
Total noninterest income	43,248,000	24,274,000	15,459,000
Noninterest expense:
Salaries and employee benefits	45,252,000	35,542,000	28,586,000
Data processing and software	8,865,000	6,961,000	3,835,000
Professional fees	2,224,000	2,102,000	1,608,000
Occupancy	3,590,000	3,345,000	2,336,000
Equipment	3,195,000	3,723,000	2,471,000
Regulatory fees	1,261,000	591,000	1,028,000
Acquisition related expenses	5,390,000	2,654,000	9,803,000
Amortization of intangibles	1,824,000	1,655,000	465,000
Other operating	5,760,000	5,422,000	3,355,000
Total noninterest expense	77,361,000	61,995,000	53,487,000
Income before income taxes	30,731,000	29,266,000	10,822,000
Income tax expense	6,035,000	6,844,000	1,167,000
Net income	$ 24,696,000	$ 22,422,000	$ 9,655,000
Per share information:
Basic net income per share of common stock	$ 1.22	$ 1.25	$ 0.73
Diluted net income per share of common stock	$ 1.22	$ 1.20	$ 0.67
Weighted average shares outstanding:
Basic	20,162,038	17,886,164	13,277,614
Diluted	20,185,589	18,613,224	14,480,347
SBA Loans
Noninterest income:
Net gain (loss) on sale of securities	$ 1,440,000	$ 803,000	$ 248,000
Treasury Management And Other Deposit Service Charges
Noninterest income:
Noninterest income	3,494,000	3,135,000	2,150,000
Interchange and Debit Card Transaction Fees
Noninterest income:
Noninterest income	3,172,000	3,251,000	752,000
Mortgage Banking Income
Noninterest income:
Noninterest income	25,034,000	9,467,000	5,653,000
Wealth Management Fees
Noninterest income:
Noninterest income	$ 1,573,000	$ 1,425,000	$ 794,000

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 24,696	$ 22,422	$ 9,655
Unrealized gains (losses) on securities available-for-sale:
Unrealized holding gains (losses) arising during the period	4,968	6,321	(2,491)
Reclassification adjustment for (gains) losses included in net income	(125)	99	(3)
Tax effect	(1,177)	(1,678)	652
Net of tax	3,666	4,742	(1,842)
Unrealized losses on securities transferred to held-to-maturity:
Reclassification adjustment for losses included in net income			14
Tax effect			(4)
Net of tax			10
Unrealized (losses) gains on cash flow hedges:
Unrealized holding (losses) gains arising during the period		(702)	263
Reclassification adjustment for losses included in net income	2,679	878	920
Tax effect		(219)	(140)
Net of tax	2,679	(43)	1,043
Other comprehensive income (loss)	6,345	4,699	(789)
Comprehensive income	$ 31,041	$ 27,121	$ 8,866

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Athens Bancshares	Preferred Stock	Common Stock, Voting	Common Stock, VotingAthens Bancshares	Common Stock, Nonvoting	Additional Paid-in Capital	Additional Paid-in CapitalAthens Bancshares	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Beginning balance at Dec. 31, 2017	$ 146,946		$ 878	$ 11,450		$ 133	$ 118,120		$ 18,892	$ (2,527)
Beginning balance, shares at Dec. 31, 2017				11,449,465		132,561
Net issuance of restricted common stock	(445)			$ 107			(552)
Net issuance of restricted common stock, shares				107,640
Stock-based compensation expense	2,079						2,079
Net exercise of common stock options	3,653			$ 667			2,986
Net exercise of common stock options, shares				666,964
Exercise of common stock warrants	1,606			$ 186			1,420
Exercise of common stock warrants, shares				186,175
Issuance of common stock in conjunction with acquisition		$ 92,918			$ 5,182			$ 87,736
Issuance of common stock in conjunction with acquisition, shares					5,181,916
Common and preferred stock dividends declared	(1,244)								(1,244)
Net income	9,655								9,655
Other Comprehensive income (loss)	(789)									(789)
Ending balance at Dec. 31, 2018	254,379		878	$ 17,592		$ 133	211,789		27,303	(3,316)
Ending balance, shares at Dec. 31, 2018				17,592,160		132,561
Net issuance of restricted common stock	(304)			$ (9)			(295)
Net issuance of restricted common stock, shares				(8,721)
Stock-based compensation expense	1,262						1,262
Net exercise of common stock options	1,931			$ 273			1,658
Net exercise of common stock options, shares				272,660
Common and preferred stock dividends declared	(3,507)								(3,507)
Conversion of preferred stock to common stock			$ (878)	$ 878
Conversion of preferred stock, shares				878,048
Conversion of non-voting common stock to common stock				$ 133		$ (133)
Conversion of non-voting common stock to common stock, shares				132,561		(132,561)
Repurchase of common stock	(7,836)			$ (505)			(7,331)
Repurchase of common stock, shares				(504,786)
Net income	22,422								22,422
Other Comprehensive income (loss)	4,699									4,699
Ending balance at Dec. 31, 2019	273,046			$ 18,362			207,083		46,218	1,383
Ending balance, shares at Dec. 31, 2019				18,361,922
Net issuance of restricted common stock	(43)			$ 122			(165)
Net issuance of restricted common stock, shares				122,381
Stock-based compensation expense	1,223						1,223
Net exercise of common stock options	$ 106			$ 21			85
Net exercise of common stock options, shares	24,613			20,582
Issuance of common stock in conjunction with acquisition	$ 43,585			$ 3,632			39,953
Issuance of common stock in conjunction with acquisition, shares				3,631,718
Common stock dividends declared	(4,035)								(4,035)
Repurchase of common stock	(1,437)			$ (148)			(1,289)
Repurchase of common stock, shares				(147,800)
Net income	24,696								24,696
Other Comprehensive income (loss)	6,345									6,345
Ending balance at Dec. 31, 2020	$ 343,486			$ 21,989			$ 246,890		$ 66,879	$ 7,728
Ending balance, shares at Dec. 31, 2020				21,988,803

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Stockholders Equity [Abstract]
Common and preferred stock, dividends per share	$ 0.20	$ 0.20	$ 0.08

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 24,696	$ 22,422	$ 9,655
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for loan losses	11,479	761	2,842
Accretion of discounts on acquired loans and deferred fees	(5,290)	(3,737)	(2,978)
Depreciation and amortization	3,201	2,883	1,028
Net amortization of premiums on investment securities	1,563	807	1,007
Net (gain) loss on sale of securities	(125)	99	(3)
Mortgage banking income	$ (25,034)	$ (9,467)	$ (5,653)
Type of Revenue [Extensible List]	us-gaap:MortgageBankingMember	us-gaap:MortgageBankingMember	us-gaap:MortgageBankingMember
Tri-Net fees	$ (3,693)	$ (2,785)	$ (1,503)
Net gain on sale of loans	(1,440)	(803)	(248)
Net gain on disposal of premises and equipment	(303)
Net gain on sale of other real estate owned	(273)	(3)	0
Stock-based compensation	1,223	1,262	2,079
Deferred income tax expense	(4,339)	2,585	1,175
Origination of loans held for sale	(1,355,961)	(824,021)	(516,341)
Proceeds from loans held for sale	1,370,441	725,669	540,448
Cash payments arising from operating leases	(1,814)	(1,786)
Amortization of debt issuance expense	36
Net decrease (increase) in accrued interest receivable and other assets	2,894	(10,461)	1,395
Net increase in accrued interest payable and other liabilities	6,790	11,887	682
Net cash provided by (used in) operating activities	24,051	(84,688)	33,585
Cash flows from investing activities:
Purchases	(340,962)	(59,473)	(44,787)
Sales	78,385	68,068	38,322
Maturities, prepayments and calls	91,616	27,624	19,245
Maturities, prepayments and calls	881	395	0
Purchase of restricted equity securities	(783)	(1,651)	(12)
Net (increase) decrease in loans	(167,716)	13,782	(139,124)
Purchase of premises and equipment	(417)	(1,582)	(4,244)
Proceeds from sale of premises and equipment	3,286
Proceeds from BOLI death benefit			3,416
Proceeds from sale of other real estate	1,817	127
Cash paid for acquisitions	(27,278)
Cash received from acquisitions	90,760		12,053
Net cash (used in) provided by investing activities	(270,411)	47,290	(115,131)
Cash flows from financing activities:
Net increase in deposits	395,873	159,443	45,622
Proceeds from Federal Home Loan Bank advances	680,000	75,000	125,000
Payments on Federal Home Loan Bank advances	(680,000)	(190,000)	(70,000)
Proceeds from issuance of subordinated notes, net of debt issuance expense	29,387
Repurchase of common stock	(1,437)	(7,836)
Exercise of common stock options and warrants, net of repurchase of restricted shares	63	1,627	4,814
Common stock dividends paid	(4,035)	(3,507)	(1,244)
Termination of interest rate swap agreement and related reclassification adjustment for unrealized losses included in income	2,679	(1,503)
Net cash provided by financing activities	422,530	33,224	104,192
Net increase (decrease) in cash and cash equivalents	176,170	(4,174)	22,646
Cash and cash equivalents at beginning of period	101,269	105,443	82,797
Cash and cash equivalents at end of period	277,439	101,269	105,443
Supplemental disclosures of cash paid:
Interest paid	15,551	24,216	15,378
Income taxes	10,353	716	1,716
Supplemental disclosures of noncash transactions:
Transfer of loans to other real estate	452	180	0
Loans charged off to the allowance for loan losses	1,226	798	4,954
Lease liabilities arising from obtaining right-of-use assets	668	13,512
Unrealized gains (losses) on securities available for sale	3,666	4,742	(1,842)
Loans transferred from held-for-sale to held-for-investment	2,800		507
Assets acquired, net of cash	423,983		460,957
Liabilities assumed	447,412		411,383
Goodwill	$ 3,558		$ 31,291
Conversion of preferred stock and non-voting common stock		$ 1,011

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1 – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The consolidated financial statements as of December 31, 2020 and 2019 and for each of the three years in the period ended December 31, 2020 include CapStar Financial Holdings, Inc. and it’s wholly owned subsidiary, CapStar Bank (the “Bank”, together referred to as the “Company”). Significant intercompany transactions and accounts are eliminated in consolidation. On February 5, 2016, CapStar Financial Holdings, Inc. acquired all of the Bank’s issued and outstanding shares of common stock, preferred stock, common stock options and warrants, and the Bank became the wholly owned subsidiary of CapStar Financial Holdings, Inc. (the “Share Exchange”). The consolidated financial statements of the Company have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) and conform to general practices within the banking industry. Business Combinations The Company accounts for business combinations using the acquisition method of accounting. The accounts of an acquired entity are included as of the date of acquisition, and any excess of purchase price over the fair value of the net assets acquired is capitalized as goodwill. Under this method, all identifiable assets acquired, including purchased loans, and liabilities assumed are recorded at fair value. The Company typically issues common stock and/or pays cash for an acquisition, depending on the terms of the acquisition agreement. The value of shares of common stock issued is determined based on the market price of the stock as of the closing of the acquisition. Nature of Operations Through the Bank, the Company provides full banking services to consumer and corporate customers located primarily in Tennessee. The Bank operates under a state bank charter and is a member of the Federal Reserve System. As a state member bank, the Bank is subject to regulations of the Tennessee Department of Financial Institutions, the Board of Governors of the Federal Reserve System (the “Federal Reserve”), and the Federal Deposit Insurance Corporation. Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan losses, determination of impairment of intangible assets, including goodwill, the valuation of our investment portfolio and deferred tax assets. Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, interest-bearing deposits in financial institutions and federal funds sold. Generally, federal funds sold are purchased and sold for one-day periods. The Company maintains deposits in excess of the federal insurance amounts with other financial institutions. Management makes deposits only with financial institutions it considers to be financially sound. Securities The Bank accounts for securities under the provisions of Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 320, Investments – Debt and Equity Securities Securities Held-to-Maturity - Debt securities are classified as held-to-maturity securities when the Bank has the positive intent and ability to hold the securities to maturity. Securities held to maturity are carried at amortized cost. Trading Securities - Debt and equity securities that are bought and held principally for the purpose of selling them in the near term are classified as trading securities and reported at fair value, with unrealized gains and losses included in earnings. No securities have been classified as trading securities. Securities Available-for-Sale - Debt securities not classified as either held-to-maturity securities or trading securities are classified as available for sale securities. Securities available for sale are carried at estimated fair value with unrealized gains and losses excluded from earnings and reported as a separate component of shareholders’ equity in other comprehensive income (loss). Interest income includes amortization of purchase premiums or discounts. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Realized gains and losses from the sales of securities are recorded on the trade date and determined using the specific-identification method. Management evaluates securities for other-than-temporary impairment (“OTTI”) on at least a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. For securities in an unrealized loss position, management considers the extent and duration of the unrealized loss, the financial condition and near-term prospects of the issuer and any collateral underlying the relevant security. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For debt securities that do not meet the aforementioned criteria, the amount of impairment is split into two components as follows: (1) OTTI related to credit loss, which must be recognized in the income statement and (2) OTTI related to other factors, which is recognized in other comprehensive income (loss). The credit loss is defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis. Loans Held For Sale and Fair Value Option The Company classifies loans as loans held for sale when originated with the intent to sell. As of April 1, 2019, the Company elected the fair value option for all residential mortgage loans originated with the intent to sell. This election allows for a more effective offset of the changes in fair values of the loans and the derivative instruments used to economically hedge them without the burden of complying with the requirements for hedge accounting. The Company has not elected the fair value option for other loans held for sale primarily because they are not economically hedged using derivative instruments. The fair value of residential mortgage loans originated with the intent to sell is based on traded market prices of similar assets. Other loans held for sale that are recorded at lower of cost or fair value may be carried at fair value on a nonrecurring basis when the fair value is less than cost. For further information, see Note 23 - Fair Value. The Company does not securitize mortgage loans. If the Company sells loans with servicing rights retained, the carrying value of the mortgage loan sold is reduced by the amount allocated to the servicing right. Fair values of residential mortgage loans held for sale are based on traded market prices of similar assets. The changes in fair value are recorded as a component of mortgage banking income and included gains of $2.5 million for the year ended December 31, 2020 and $0.6 million for the year ended December 31, 2019. There were no loans held for sale recorded at fair value as of December 31, 2018. The following table summarizes the difference between the fair value and the aggregate unpaid principal balance for residential real estate loans held for sale as of December 31, 2020 and 2019 (dollars in thousands): Fair Value Aggregate Unpaid Principal Balance Difference December 31, 2020 Residential mortgage loans held for sale $ 97,303 $ 94,248 $ 3,055 December 31, 2019 Residential mortgage loans held for sale 30,740 30,178 562 Tri-Net Fees Tri-Net fees are derived from the origination, with the intent to sell, of commercial real estate loans to third-party investors. All of these loan sales transfer servicing rights to the buyer. Realized gains and losses are recognized when legal title of the loan has transferred to the investor and sales proceeds have been received and are reflected in the accompanying statements of income in Tri-Net fees, net of related costs such as commission expenses. Loans that have not been sold at period end are classified as held for sale on the balance sheet and recorded at the lower of aggregate cost or fair value. Net unrealized losses, if any, are recorded as a valuation allowance and charged to earnings. Loans The Company has seven classes of loans for financial reporting purposes: commercial real estate, consumer real estate, construction and land development, commercial and industrial, consumer, PPP, and other. The appropriate classification is determined based on the underlying collateral utilized to secure each loan. Commercial real estate loans are categorized as such based on investor exposures where repayment is largely dependent upon the operation, refinance, or sale of the underlying real estate. Commercial real estate also includes owner occupied commercial real estate. Consumer real estate consists primarily of 1-4 family residential properties including home equity lines of credit. Construction and land development loans include loans where the repayment is dependent on the successful completion and operation and/or sale of the related real estate project. Construction and land development loans include 1-4 family construction projects and commercial construction endeavors such as warehouses, apartments, office and retail space and land acquisition and development. Commercial and industrial loans include loans to business enterprises issued for commercial, industrial and/or other professional purposes. Consumer loans include all loans issued to individuals not included in the consumer real estate class. PPP loans originated through the CARES act and include partially, or fully forgivable loans used to cover payroll costs, rent, interest, utilities, and other qualifiable expenses. Other loans include all loans not included in the classes of loans above and leases. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal balance outstanding, net of purchase premiums and discounts, deferred loan fees and costs, and an allowance for loan losses. Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level-yield method without anticipating prepayments. The accrual of interest on loans is discontinued at the time the loan is 90 days past due unless the credit is well secured and in process of collection. Consumer loans and any accrued interest is typically charged off no later than 180 days past due. Past due status is based on contractual terms of the loan. In all cases, loans are placed on nonaccrual or charged off at an earlier date if collection of principal or interest is considered doubtful and collection is highly questionable. Amortization of deferred loan fees is discontinued when a loan is placed on nonaccrual status. All interest accrued but not received for loans placed on nonaccrual is reversed against interest income. Interest received on such loans is accounted for on the cash-basis or cost-recovery method, until qualifying for return to accrual status. Under the cost-recovery method, interest income is not recognized until the loan balance is reduced to zero. Under the cash-basis method, interest income is recorded when the payment is received in cash. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. Loans can also be returned to accrual status when they become well secured and in the process of collection. Acquired Loans Acquired loans are accounted for under the acquisition method of accounting. The acquired loans are recorded at their estimated fair values as of the acquisition date. Fair value of acquired loans is determined using a discounted cash flow model based on assumptions regarding the amount and timing of principal and interest payments, estimated prepayments, estimated default rates, estimated loss severity in the event of defaults, and current market rates. Estimated credit losses are included in the determination of fair value; therefore, an allowance for loan losses is not recorded on the acquisition date. An acquired loan is considered purchased credit impaired when there is evidence of credit deterioration since origination and it is probable at the date of acquisition that the Bank will be unable to collect all contractually required payments. Purchased credit impaired loans are accounted for individually or aggregated into pools of loans based on common risk characteristics such as loan type and risk rating. The Company estimates the amount and timing of expected cash flows for each loan or pool, and the expected cash flows in excess of amount paid (fair value) is recorded as interest income over the remaining life of the loan or pool (accretable yield). The excess of the loan’s or pool’s contractual principal and interest over expected cash flows is not recorded (nonaccretable difference). Over the life of the loan or pool, expected cash flows continue to be estimated. If the present value of expected cash flows is less than the carrying amount, a loss is recorded as a provision for loan losses. If the present value of expected cash flows is greater than the carrying amount, it is recognized as part of future interest income. Acquired non-impaired loans are recorded at their initial fair value and adjusted for subsequent advances, pay downs, amortization or accretion of any premium or discount on purchase, charge-offs and additional provisioning that may be required. Allowance for Loan Losses The allowance for loan losses (“ALL”) is maintained at a level that management believes to be adequate to absorb expected loan losses inherent in the loan portfolio as of the balance sheet date. The allowance for loan losses is a valuation allowance for estimated credit losses inherent in the loan and lease portfolio, increased by the provision for loan losses and decreased by charge-offs, net of recoveries. Quarterly, the Company estimates the allowance required using peer group loss experience, the nature and volume of the portfolio, information about specific borrower situations and estimated collateral values, economic conditions, and other factors. The Company’s historical loss experience is based on the actual loss history by class of loan for comparable peer institutions due to the Company’s limited loss history. Allocations of the allowance may be made for specific loans, but the entire allowance is available for any loan that, in management’s judgment, should be charged off. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries are credited to the allowance for loan losses. The Company also considers the results of the external independent loan review when assessing the adequacy of the allowance and incorporates relevant loan review results in the loan impairment and overall adequacy of allowance determinations. Furthermore, regulatory agencies periodically review the Company’s allowance for loan losses and may require the Company to record adjustments to the allowance based on their judgment of information available to them at the time of their examinations. Additional considerations are included in the determination of the adequacy of the allowance based on the continuous review conducted by relationship managers and credit department personnel. The Company’s loan policy requires that each customer relationship wherein total exposure exceeds $1.5 million be subject to a formal credit review at least annually. Should these reviews identify potential collection concerns, appropriate adjustments to the allowance may be made. The allowance consists of specific and general components as discussed below. While the allowance consists of separate components, these terms are primarily used to describe a process. Both portions of the allowance are available to provide for inherent losses in the entire portfolio. Specific Component The specific component relates to loans that are individually determined to be impaired when, based on current information and events, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Loans for which the terms have been modified resulting in a concession, and for which the borrower is experiencing financial difficulties, are considered troubled debt restructurings (“TDRs”) and classified as impaired. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Loans meeting any of the following criteria are individually evaluated for impairment: risk rated substandard (as defined in Note 4), on non-accrual status or past due greater than 90 days. If a loan is impaired, a portion of the allowance is allocated based on the present value of estimated future cash flows using the loan’s existing rate or at the fair value of collateral less costs to sell if repayment is expected solely from the collateral. Changes to the valuation allowance are recorded as a component of the provision for loan losses. TDRs are individually evaluated for impairment and included in the separately identified impairment disclosures. TDRs are measured at the present value of estimated future cash flows using the loan’s effective rate at inception. If a TDR is considered to be a collateral dependent loan, the loan is reported, net, at the fair value of the collateral less costs to sell. General Component The general component of the allowance for loan losses covers loans that are collectively evaluated for impairment. Large groups of homogeneous loans are collectively evaluated for impairment, and accordingly, they are not included in the separately identified impairment disclosures. The general allowance component also includes loans that are individually identified for impairment evaluation but are not considered impaired. The general component is based on historical loss experience adjusted for current factors. Due to the Company’s limited loss history, the historical loss experience is based on the actual loss history by class of loan for comparable peer institutions. The Company utilized a 37 quarter look-back period as of December 31, 2018. Subsequently, the Company increased its look-back period to a total of 41 quarters and 45 quarters as of December 31, 2019 and 2020, respectively. In the current economic environment, management believes the extension of the look-back period was necessary in order to capture sufficient loss observations to develop a reliable loss estimate of credit losses. This extension of the historical look-back period to capture the historical loss experience of peer banks was applied to all classes and segments of our loan portfolio. The actual loss experience is supplemented with other environmental factors that capture changes in trends, conditions, and other relevant factors that may cause estimated credit losses as of the evaluation date to differ from historical loss experience. The allocation for environmental factors is by nature subjective. These amounts represent estimated probable inherent credit losses, which exist but have not been captured in the historical loss experience. The environmental factors include consideration of the following: changes in lending policies and procedures, economic conditions, nature and volume of the portfolio, experience of lending management, volume and severity of past due loans, quality of the loan review system, value of underlying collateral for collateral dependent loans, concentrations, and other external factors. Servicing Rights When mortgage loans are sold with servicing retained, servicing rights are initially recorded at fair value with the income statement effect recorded in other noninterest income. Fair value is based on market prices for comparable mortgage servicing contracts, when available or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. All classes of servicing assets are subsequently measured using the amortization method which requires servicing rights to be amortized into non-interest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. Servicing rights are evaluated for impairment based upon the fair value of the rights as compared to carrying amount. Impairment is determined by stratifying rights into groupings based on predominant risk characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance for an individual grouping, to the extent that fair value is less than the carrying amount. If the Company later determines that all or a portion of the impairment no longer exists for a particular grouping, a reduction of the allowance may be recorded as an increase to income. Changes in valuation allowances are reported with other noninterest income on the income statement and the associated asset is included in other assets on the Consolidated Balance Sheet. The fair values of servicing rights are subject to significant fluctuations as a result of changes in estimated and actual prepayment speeds and default rates and losses. Servicing fee income, which is reported on the income statement within other noninterest income, is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal; or a fixed amount per loan and are recorded as income when earned. The amortization of mortgage servicing rights is netted against loan servicing fee income. Net servicing fees totaled $148,000, $340,000, and $102,000 for the years ended December 31, 2020, 2019, and 2018 respectively. Impairment charges associated with these servicing rights amounted to $238,000 and $211,000 for the years ended December 31, 2020 and 2019, respectively. There were no impairment charges for the year ended December 31, 2018. Late fees and ancillary fees related to loan servicing are not material. Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed principally by the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized by the straight-line method based on the shorter of the asset lives or the expected lease terms. Useful lives for premises and equipment range from one to thirty-nine years. These assets are reviewed for impairment when events indicate their carrying amount may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value. Leases In February 2016, the FASB issued a new accounting standard update (ASU 2016-02, Leases (Topic 842)), which requires for all operating leases the recognition of a right-of-use ("ROU") asset and a corresponding lease liability, in the Consolidated Balance Sheet. For short term leases (term of 12 months or less), a lessee is permitted to make an accounting election not to recognize lease assets and lease liabilities. The lease cost will be allocated over the lease term on a straight-line basis. There were further amendments, including practical expedients, with the issuance of ASU 2018-01, “Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842” in January 2018. In July 2018, the FASB issued ASU No. 2018-11, "Leases (Topic 842): Targeted Improvements", which provides for the option to apply the new leasing standard to all open leases as of the adoption date, on a prospective basis. On January 1, 2019, the Company adopted the new accounting standard ASU 2016-02, Leases (Topic 842) and all the related amendments ("new lease standard", "ASC 842" or "ASU 2016-02") utilizing the practical expedient to apply the new lease standard as of January 1, 2019 on a prospective basis. The Company also elected the "package of expedients" and elected as an accounting policy to exclude recording ROU assets and lease liabilities for leases that meet the definition of short-term leases. In addition to excluding short-term leases, the Company has implemented an accounting policy in which non-lease components are not separated from lease components in the measurement of ROU assets and lease liabilities for all lease contracts. The Company recognized $12.8 million in ROU assets and $13.4 million in lease liabilities as a result of applying the new lease standard as an adjustment to the opening consolidated balance sheet on January 1, 2019. The ROU assets and lease liabilities are included in other assets and other liabilities, respectively on the Consolidated Balance Sheet. See Note 7—Leases for additional disclosures related to leases. Bank Owned Life Insurance The Bank has purchased life insurance policies on certain key executives. Bank owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement. Bank owned life insurance is included in other assets on the Consolidated Balance Sheet. Securities Sold under Agreements to Repurchase The Bank enters into sales of securities under agreements to repurchase at a specified future date. Such repurchase agreements are considered financing arrangements and, accordingly, the obligation to repurchase assets sold is reflected as a liability in the balance sheets of the Bank. Repurchase agreements are collateralized by debt securities which are owned and under the control of the Bank and are included in other liabilities on the Consolidated Balance Sheet. Goodwill and Other Intangible Assets Goodwill resulting from business combinations is generally determined as the excess of the fair value of the consideration transferred, plus the fair value of any noncontrolling interests in the acquiree, over the fair value of the net assets acquired and liabilities assumed as of the acquisition date. Goodwill and intangible assets acquired in a purchase business combination and determined to have an indefinite useful life are not amortized, but tested for impairment at least annually or more frequently if events and circumstances exists that indicate that a goodwill impairment test should be performed. Qualitative factors are assessed to first determine if it is more likely than not (more than 50%) that the carrying value of goodwill is less than fair value. At October 31, 2020, as a result of market volatility caused by the COVID-19 pandemic, the company determined it did not satisfy the more likely than not qualitative assessment that the fair value of the reporting unit exceeded its carrying value, including goodwill. As a result, the Company elected to perform a quantitative assessment, which included a combination of quoted market prices of the Company’s stock, prices of comparable businesses, discounted cash flows and other techniques. Based upon the results of the quantitative assessment, we determined the fair value of the reporting unit exceeded the carrying value, resulting in no impairment. Intangible assets with definite useful lives are amortized over their estimated useful lives to their estimated residual values. Goodwill is the only intangible asset with an indefinite life on the balance sheet. Other intangible assets consist of core deposit intangible assets arising from whole bank acquisitions and are amortized on an accelerated method over their estimated useful lives, which range from six to ten years. Other Real Estate Owned Other real estate owned (“OREO”) includes assets that have been acquired in satisfaction of debt through foreclosure and are recorded at estimated fair value less the estimated cost of disposition. Fair value is based on independent appraisals and other relevant factors. Valuation adjustments required at foreclosure are charged to the allowance for loan losses. Subsequent to foreclosure, additional losses resulting from the periodic revaluation of the property are charged to other real estate expense. Costs of operating and maintaining the properties and any gains or losses recognized on disposition are also included in other real estate expense. Improvements made to properties are capitalized if the expenditures are expected to be recovered upon the sale of the properties. Restricted Equity Securities The Bank is a member of the FHLB system. Members are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest additional amounts. FHLB stock is carried at cost, classified as a restricted equity security, and periodically evaluated for impairment based on an assessment of the ultimate recovery of par value. Both cash and stock dividends are reported as interest income. The Bank is also a member of the Federal Reserve System, and as such, holds stock of the Federal Reserve Bank of Atlanta (“Federal Reserve Bank”). Federal Reserve Bank stock is carried at cost, classified as a restricted equity security, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as interest income. Income Taxes Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company’s tax returns remain open to audit under the statute of limitations by the IRS and various states for the years ended December 31, 2017 through 2020. It is the Company’s policy to recognize interest and/or penalties related to income tax matters in income tax expense. Stock-Based Compensation Stock-based compensation expense is recognized based on the fair value of the portion of stock-based payment awards that are ultimately expected to vest, reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods, if actual forfeitures differ from those estimates. A Black-Scholes model is utilized to estimate the fair value of stock options, while the market price of the Company’s common stock at the date of grant is used for restricted stock awards. Compensation expense is recognized over the required service period, generally defined as the vesting period. For awards with graded vesting, compensation expense is recognized on a straight-line basis over the requisite service period for the entire award. For awards with performance vesting criteria, anticipated performance is projected to determine the number of awards expected to v

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisition	NOTE 2 – ACQUISITIONS FCB Merger Effective July 1, 2020, pursuant to the Agreement and Plan of Merger, dated as of January 23, 2020 (the “FCB Merger Agreement”), by and between the Company and FCB Corporation, a Tennessee corporation (“FCB”), FCB was merged with and into CapStar, with CapStar continuing as the surviving entity (the “FCB Merger”). Immediately following the FCB Merger, The First National Bank of Manchester, a national banking association and a wholly owned subsidiary of FCB, merged with and into CapStar Bank, a Tennessee chartered bank and a wholly owned subsidiary of CapStar (the “FNBM Merger”), with CapStar Bank continuing as the surviving entity in the FNBM Merger. Subject to the terms and conditions set forth in the FCB Merger Agreement, at the effective time of the FCB Merger, shares of common stock, par value $10.00 per share, of FCB (“FCB Common Stock”) issued and outstanding immediately prior to the completion of the FCB Merger (other than shares of FCB Common Stock owned or held by FCB, CapStar and their subsidiaries (in each case, other than shares of FCB Common Stock held in a fiduciary or agency capacity or in satisfaction of debts previously contracted) were collectively converted into the right to receive in the aggregate 2,966,918 shares of common stock, par value $1.00 per share, of CapStar (“CapStar Common Stock”), with cash (without interest) in lieu of fractional shares, and $22.2 million in cash, without interest BOW Merger Effective July 1, 2020, following the FCB Merger, pursuant to the Plan of Bank Merger, dated as of January 23, 2020 (the “BOW Merger Agreement,” and together with the FCB Merger Agreement, the “Merger Agreements”), by and among CapStar, CapStar Bank and The Bank of Waynesboro, a Tennessee chartered bank (“BOW”), BOW was merged with and into CapStar Bank, with CapStar Bank continuing as the surviving entity (the “BOW Merger,” and together with the FCB Merger, the “Mergers”). On the terms and subject to the conditions set forth in the BOW Merger Agreement, at the effective time of the BOW Merger, shares of common stock, par value $10.00 per share, of BOW (“BOW Common Stock”) issued and outstanding immediately prior to the completion of the BOW Merger (other than shares of BOW Common Stock owned or held by CapStar, CapStar Bank, BOW and their subsidiaries (in each case, other than shares of BOW Common Stock held in a fiduciary or agency capacity or in satisfaction of debts previously contracted)) were collectively converted into the right to receive in the aggregate 664,800 shares of CapStar Common Stock, with cash (without interest) in lieu of fractional shares, and $5.1 million in cash, without interest. Total acquisition consideration resulting from the Mergers amounted to approximately $70.9 million With the acquisitions, the Company further expanded its franchise in the Middle Tennessee market. FCB’s and BOW’s results of operations were included in the Company’s results beginning July 1, 2020. Acquisition related costs of $5.4 million are included in the Company’s consolidated statements of income for the year ended December 31, 2020. The fair value of the common shares issued as part of the consideration paid for the Mergers was determined by the closing price of the Company’s common shares immediately preceding the acquisition date Goodwill of $3.6 million associated with the Mergers is not amortizable As recorded by FCB Corporation and BOW Initial fair value adjustments Measurement period adjustments As recorded by CapStar Financial Holdings Assets: Cash and cash equivalents $ 90,760 $ — $ — $ 90,760 Securities 98,536 159 (a) — 98,695 Loans, gross 296,992 (2,318 ) (b) — 294,674 Allowance for loan losses (4,544 ) 4,544 (c) — — Premises and equipment, net 9,907 1,540 (d) — 11,447 Core deposit intangible — 3,570 (e) — 3,570 Other 16,514 (917 ) (f) — 15,597 Total $ 508,165 $ 6,578 $ — $ 514,743 Liabilities: Deposits $ 440,025 $ 2,652 (g) $ — $ 442,677 Other 4,735 — — 4,735 Total $ 444,760 $ 2,652 $ — $ 447,412 Net identifiable assets acquired $ 67,331 Total cost of acquisition: Value of stock issued $ 43,611 Cash consideration paid 27,278 Total cost of acquisition $ 70,889 Goodwill recorded related to acquisition $ 3,558 (a) The amount represents the fair value adjustment of securities that were subsequently sold. (b) The amount represents the adjustment of the net book value of the acquired loans to their estimated fair value based on interest rates and expected cash flows at the date of acquisition. (c) The amount represents the removal of FCB and BOW’s existing allowance for loan losses. (d) The amount represents the adjustment of the net book value of acquired premises and equipment to their estimated fair value. (e) The amount represents the adjustment of recording the fair value of the core deposit intangible representing the intangible value of the deposit base acquired and the fair value of the customer relationship. (f) The amount represents the net adjustment of the deferred tax asset recognized on the fair value adjustments on acquired assets and assumed liabilities. (g) The amount represents the adjustment necessary because the weighted average interest rate of acquired time deposits exceeded the cost of similar funding at the time of acquisition. The fair value adjustment will be amortized to reduce future interest expense over the life of the portfolio. The following unaudited pro forma financial information presents the combined results of the Company, FCB and BOW as if the acquisition had occurred as of January 1, 2019, after giving effect to certain adjustments, including amortization of the core deposit intangible, and related income tax effects. The pro forma financial information does not necessarily reflect the results of operations that would have occurred had the Company, FCB and BOW constituted a single entity during such periods (in thousands, except share data): Pro forma combined twelve months ended December 31, 2020 Pro forma combined twelve months ended December 31, 2019 Net interest income $ 73,571 $ 87,523 Noninterest income 44,453 27,375 Total revenue 118,024 114,898 Net income 25,927 28,989 Per share information: Basic net income per share of common stock $ 1.29 $ 1.35 Diluted net income per share of common stock $ 1.28 $ 1.30

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Investment Securities	NOTE 3 – INVESTMENT SECURITIES Investment securities have been classified in the balance sheet according to management’s intent. The Company’s classification of securities at December 31, 2020 and 2019 was as follows (in thousands): December 31, 2020 December 31, 2019 Amortized Cost Gross unrealized gains Gross unrealized (losses) Estimated fair value Amortized Cost Gross unrealized gains Gross unrealized (losses) Estimated fair value Securities available-for-sale: U. S. government agency securities $ 16,158 $ 258 $ (25 ) $ 16,391 $ 10,421 $ 4 $ (94 ) $ 10,331 State and municipal securities 89,081 2,928 (81 ) 91,928 44,053 1,927 (20 ) 45,960 Mortgage-backed securities 332,014 4,892 (543 ) 336,363 137,305 1,834 (460 ) 138,679 Asset-backed securities 3,325 — (132 ) 3,193 3,325 — (128 ) 3,197 Other debt securities 37,608 819 (87 ) 38,340 14,839 141 (18 ) 14,962 Total $ 478,186 $ 8,897 $ (868 ) $ 486,215 $ 209,943 $ 3,906 $ (720 ) $ 213,129 Securities held-to-maturity: State and municipal securities $ 2,407 $ 97 $ — $ 2,504 $ 3,313 $ 98 $ — $ 3,411 Total $ 2,407 $ 97 $ — $ 2,504 $ 3,313 $ 98 $ — $ 3,411 The amortized cost and fair value of debt and equity securities at December 31, 2020, by contractual maturity, are shown below (in thousands). Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. Available-for-sale Held-to-maturity Amortized cost Estimated fair value Amortized cost Estimated fair value Due in less than one year $ 13,611 $ 13,708 $ 600 $ 609 Due one to five years 49,584 50,889 1,807 1,895 Due five to ten years 78,024 80,437 — — Due beyond ten years 1,639 1,627 — — Mortgage-backed securities 332,014 336,363 — — Asset-backed securities 3,314 3,191 — — $ 478,186 $ 486,215 $ 2,407 $ 2,504 Results from sales of debt and equity securities were as follows (in thousands): Year ended December 31 2020 2019 2018 Proceeds $ 78,385 $ 68,068 $ 38,322 Gross gains 148 49 116 Gross losses (23 ) (148 ) (113 ) The table above does not include activity from maturities, prepayments or calls on debt or equity securities. Securities with a market value of $163,515,000 and $70,350,000 at December 31, 2020 and 2019, respectively, were pledged to collateralize public deposits, derivative positions and Federal Home Loan Bank advances. At December 31, 2020 and 2019 there were no holdings of securities of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10% of shareholders’ equity. The following tables show the Company’s securities with unrealized losses, aggregated by major security type and length of time in a continuous unrealized loss position (in thousands): Less than 12 months 12 months or more Total December 31, 2020 Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses U. S. government agency securities $ — $ — $ — $ — $ — $ — State and municipal securities 10,463 (80 ) — — 10,463 (80 ) Mortgage-backed securities 102,280 (505 ) 1,449 (63 ) 103,729 (568 ) Asset-backed securities — — 3,193 (133 ) 3,193 (133 ) Other debt securities 6,103 (87 ) — — 6,103 (87 ) Total temporarily impaired securities $ 118,846 $ (672 ) $ 4,642 $ (196 ) $ 123,488 $ (868 ) December 31, 2019 U. S. government agency securities $ 6,694 $ (51 ) $ 1,637 $ (43 ) $ 8,331 $ (94 ) State and municipal securities 2,356 (12 ) 814 (8 ) 3,170 (20 ) Mortgage-backed securities 30,570 (136 ) 21,364 (324 ) 51,934 (460 ) Asset-backed securities — — 3,197 (128 ) 3,197 (128 ) Other debt securities 3,012 (16 ) 1,502 (2 ) 4,514 (18 ) Total temporarily impaired securities $ 42,632 $ (215 ) $ 28,514 $ (505 ) $ 71,146 $ (720 ) Declines in the fair value of securities below their cost that are deemed to be other-than-temporary are reflected in earnings as realized losses to the extent the impairment is related to credit losses. The amount of the impairment of available for sale securities related to other factors is recognized in other comprehensive income (loss). In estimating other-than-temporary impairment losses, management considers, among other things, the length of time and the extent to which the fair value has been less than cost, the financial condition and near-term prospects of the issuer and the intent and ability of the Company to hold the security for a period of time sufficient to allow for any anticipated recovery in fair value. The unrealized losses shown above are primarily due to increases in market rates over the yields available at the time of purchase of the underlying securities and not credit quality. Because the Company does not intend to sell these securities and it is more likely than not that the Company will not be required to sell the securities before recovery of their amortized cost bases, which may be maturity, the Company does not consider these securities to be other than temporarily impaired at December 31, 2020 . There were no other-than-temporary impairments for the years ended December 31, 2020 , 2019 or 201 8 .

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Loans and Allowance for Loan and Lease Losses	NOTE 4 – LOANS AND ALLOWANCE FOR LOAN LOSSES Loans at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Commercial real estate $ 643,832 $ 559,899 Consumer real estate 343,791 256,097 Construction and land development 174,859 143,111 Commercial and industrial 630,775 394,408 Consumer 44,279 28,426 Other 53,483 38,161 Total 1,891,019 1,420,102 Allowance for loan losses (23,245 ) (12,604 ) Total loans, net $ 1,867,774 $ 1,407,498 The CARES Act created a new guaranteed, unsecured loan program under the SBA called the Payroll Protection Program (“PPP”), which the Company participates in, to fund operational costs of eligible businesses, organizations and self-employed persons during the pandemic period. The SBA has guaranteed 100% of the amounts loaned under the PPP by lenders to eligible small businesses. One of the notable features of the PPP is that borrowers are eligible for loan forgiveness if certain conditions are met related to retaining staff and if loan amounts are used to cover eligible expenses, such as payroll, mortgage interest, rents and utilities payments. These loans have a two-year Additionally, PPP borrowers are not required to pay any fees to the government or the lender and the loans may be repaid by the borrower at any time. The SBA, however, will pay lenders a processing fee based on the size of the PPP loan, ranging from 1% to 5% of the loan. Unamortized fees associated with PPP loans included in total loans were $4.0 million as of December 31, 2020. These fees are deferred and amortized over the life of the loan. PPP fees recognized as income totaled $3.6 million for the year ended December 31, 2020. The adequacy of the allowance for loan losses (“ALL”) is assessed at the end of each quarter. The ALL includes a specific component related to loans that are individually evaluated for impairment and a general component related to loans that are segregated into homogenous pools and collectively evaluated for impairment. The ALL factors applied to these pools are an estimate of probable incurred losses based on management’s evaluation of historical net losses from loans with similar characteristics, which are adjusted by management to reflect current events, trends, and conditions. The adjustments include consideration of the following: changes in lending policies and procedures, economic conditions, nature and volume of the portfolio, experience of lending management, volume and severity of past due loans, quality of the loan review system, value of underlying collateral for collateral dependent loans, concentrations, and other external factors. The Company’s evaluation of other external factors included consideration of the novel coronavirus (“COVID-19”) global pandemic and the resulting impact on the Company’s loan portfolio as of December 31, 2020, which is largely uncertain due to rapidly evolving conditions. At December 31, 2020 , variable-rate and fixed-rate loans totaled $ and $ , respec tively. At December 31, 201 9 , variable-rate and fixed-rate loans totaled $ and $ , respectively. The Company categorizes loans into risk categories based on relevant information about the ability of borrowers to service their debt such as: current financial information, historical payment experience, credit documentation, public information, and current economic trends, among other factors. The Company analyzes all commercial loans, and consumer relationships with an outstanding balance greater than $500,000, individually and assigns each loan a risk rating. This analysis is performed on a continual basis by the relationship managers and credit department personnel. On at least an annual basis an independent party performs a formal credit risk review of a sample of the loan portfolio. Among other things, this review assesses the appropriateness of the loan’s risk rating. The Company uses the following definitions for risk ratings: Special Mention – A special mention asset possesses deficiencies or potential weaknesses deserving of management’s attention. If uncorrected, such weaknesses or deficiencies may expose the Company to an increased risk of loss in the future. Substandard – A substandard asset is inadequately protected by the current sound net worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified must have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the Company will sustain some loss if deficiencies are not corrected. Loss potential, while existing in the aggregate amount of substandard assets, does not have to exist in individual assets classified substandard. Doubtful – A doubtful asset has all weaknesses inherent in one classified substandard, with the added characteristic that weaknesses make collection or liquidation in full, on the basis of existing facts, conditions, and values, highly questionable and improbable. The probability of loss is extremely high, but certain important and reasonable specific pending factors which may work to the advantage and strengthening of the asset exist, therefore, its classification as an estimated loss is deferred until a more exact status may be determined. Pending factors include proposed merger, acquisition or liquidation procedures, capital injection, perfecting liens on additional collateral, and refinancing plans. Loans not falling into the criteria above are considered to be pass-rated loans. The Company utilizes six loan grades within the pass risk rating. The following table provides the risk category of loans by applicable class of loans as of December 31, 2020 and 2019 (in thousands): Non-impaired Loans December 31, 2020 Pass Special Mention Substandard Doubtful Total Loans Total Commercial real estate $ 601,133 $ 33,046 $ 2,933 $ — $ 1,179 $ 638,291 Consumer real estate 323,072 1,375 1,122 — 1,707 327,276 Construction and land development 169,315 5,153 19 — 102 174,589 Commercial and industrial 576,096 25,855 25,666 — 168 627,785 Consumer 41,640 4 18 2 7 41,671 Other 52,949 — 66 — — 53,015 Purchased Credit Impaired 23,899 — 4,412 81 — 28,392 Total $ 1,788,104 $ 65,433 $ 34,236 $ 83 $ 3,163 $ 1,891,019 December 31, 2019 Commercial real estate $ 551,929 $ 915 $ 4,438 $ — $ 2,507 $ 559,789 Consumer real estate 252,952 503 1,551 — 483 255,489 Construction and land development 142,978 — 16 — 112 143,106 Commercial and industrial 370,475 14,341 8,241 — 487 393,544 Consumer 28,382 6 15 — 5 28,408 Other 38,161 — — — — 38,161 Purchased Credit Impaired — — 1,605 — — 1,605 Total $ 1,384,877 $ 15,765 $ 15,866 $ — $ 3,594 $ 1,420,102 The following tables detail the changes in the ALL for the years ending December 31, 2020, 2019 and 2018 by loan classification (in thousands): Commercial real estate Consumer real estate Construction and land development Commercial and industrial Consumer Other Total Year ended December 31, 2020 Balance, beginning of period $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Charged-off loans — (49 ) — (728 ) (172 ) (277 ) (1,226 ) Recoveries 10 14 — 235 76 53 388 Provision for loan losses 3,740 635 1,418 5,127 179 380 11,479 Balance, end of period $ 7,349 $ 1,831 $ 3,476 $ 9,708 $ 305 $ 576 $ 23,245 Year ended December 31, 2019 Balance, beginning of period $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 Charged-off loans — (39 ) — (455 ) (164 ) (140 ) (798 ) Recoveries 23 20 — 380 82 23 528 Provision for loan losses 267 245 (373 ) 113 199 310 761 Balance, end of period $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Year ended December 31, 2018 Balance, beginning of period $ 3,324 $ 1,063 $ 1,628 $ 7,209 $ 91 $ 406 $ 13,721 Charged-off loans — — — (4,831 ) (84 ) (39 ) (4,954 ) Recoveries 22 4 — 395 75 8 504 Provision for loan losses (37 ) (62 ) 803 2,263 23 (148 ) 2,842 Balance, end of period $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 A breakdown of the ALL and the loan portfolio by loan category at December 31, 2020 and 2019 follows (in thousands): Commercial real estate Consumer real estate Construction and land development Commercial and industrial Consumer Other Total December 31, 2020 Allowance for Loan Losses: Collectively evaluated for impairment $ 7,349 $ 1,831 $ 3,410 $ 9,708 $ 305 $ 576 $ 23,179 Individually evaluated for impairment — — 66 — — — 66 Purchased credit impaired — — — — — — — Balances, end of period $ 7,349 $ 1,831 $ 3,476 $ 9,708 $ 305 $ 576 $ 23,245 Loans: Collectively evaluated for impairment $ 637,112 $ 325,569 $ 174,487 $ 627,617 $ 41,664 $ 53,015 $ 1,859,464 Individually evaluated for impairment 1,179 1,707 102 168 7 — 3,163 Purchased credit impaired 5,541 16,515 270 2,990 2,608 468 28,392 Balances, end of period $ 643,832 $ 343,791 $ 174,859 $ 630,775 $ 44,279 $ 53,483 $ 1,891,019 December 31, 2019 Allowance for Loan Losses: Collectively evaluated for impairment $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Individually evaluated for impairment — — — — — — — Purchased credit impaired — — — — — — — Balances, end of period $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Loans: Collectively evaluated for impairment $ 557,282 $ 255,006 $ 142,994 $ 393,057 $ 28,403 $ 38,161 $ 1,414,903 Individually evaluated for impairment 2,507 483 112 487 5 — 3,594 Purchased credit impaired 110 608 5 864 18 — 1,605 Balances, end of period $ 559,899 $ 256,097 $ 143,111 $ 394,408 $ 28,426 $ 38,161 $ 1,420,102 The following table presents the allocation of the ALL for each respective loan category with the corresponding percentage of loans in each category to total loans, net of deferred fees as of December 31, 2020 and 2019. PPP loans included in commercial and industrial loans in the below table do not have a corresponding ALL as they are fully guaranteed by the SBA December 31, 2020 December 31, 2019 Amount Percent of total loans Amount Percent of total loans Commercial real estate $ 7,349 0.39 % $ 3,599 0.25 % Consumer real estate 1,831 0.10 % 1,231 0.09 % Construction and land development 3,476 0.18 % 2,058 0.14 % Commercial and industrial 9,708 0.51 % 5,074 0.36 % Consumer 305 0.02 % 222 0.02 % Other 576 0.03 % 420 0.03 % Total allowance for loan and lease losses $ 23,245 1.23 % $ 12,604 0.89 % The following table presents information related to impaired loans, excluding purchased credit impaired (“PCI”) loans, December 31, 2020 December 31, 2019 Recorded investment Unpaid principal balance Related allowance Recorded investment Unpaid principal balance Related allowance With no related allowance recorded: Commercial real estate $ 1,179 $ 1,176 $ — $ 2,507 $ 2,446 $ — Consumer real estate 1,707 1,608 — 483 497 — Construction and land development — — — 112 117 — Commercial and industrial 168 457 — 487 710 — Consumer 7 7 — 5 5 — Other — — — — — — Subtotal 3,061 3,248 — 3,594 3,775 — With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development 102 102 66 — — — Commercial and industrial — — — — — — Consumer — — — — — — Other — — — — — — Subtotal 102 102 66 — — — Total $ 3,163 $ 3,350 $ 66 $ 3,594 $ 3,775 $ — The recorded investment in loans excludes accrued interest receivable and loan origination fees, net due to immateriality. For purposes of this disclosure, the unpaid principal balance is not reduced for partial charge-offs. The following table presents information related to the average recorded investment and interest income recognized on impaired loans, excluding PCI loans, for the years ended December 31, 2020, 2019 and 2018 (in thousands): Year Ended Year Ended Year Ended December 31, 2020 December 31, 2019 December 31, 2018 Average recorded investment Interest income recognized Average recorded investment Interest income recognized Average recorded investment Interest income recognized With no related allowance recorded: Commercial real estate $ 1,198 $ 66 $ 2,574 $ 313 $ 1,198 $ 158 Consumer real estate 1,975 66 1,037 105 185 — Construction and land development — — 119 4 94 2 Commercial and industrial 121 1 824 440 5,557 121 Consumer 8 — 23 2 7 — Other — — — — — — Subtotal 3,302 133 4,577 864 7,041 281 With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development 107 — — — — — Commercial and industrial — — — — — — Consumer — — — — — — Other — — — — — — Subtotal 107 — — — — — Total $ 3,409 $ 133 $ 4,577 $ 864 $ 7,041 $ 281 There was no interest income recognized on a cash basis for impaired loans for the years ended December 31, 2020, 2019 or 2018. Non-accrual loans and loans past due 90 days still on accrual include both smaller balance homogeneous loans that are collectively evaluated for impairment and individually classified impaired loans. Impaired loans include commercial loans that are individually evaluated for impairment and deemed impaired (i.e., individually classified impaired loans) as well as TDRs for all loan classifications. The following table presents the aging of the recorded investment in past-due loans as of December 31, 2020 and 2019 by class of loans (in thousands): 30 - 59 60 - 89 Greater Than Days Days 89 Days Total Loans Not December 31, 2020 Past Due Past Due Past Due Past Due Past Due Total Commercial real estate $ 409 $ — $ 1,176 $ 1,585 $ 636,706 $ 638,291 Consumer real estate 6,084 1,596 687 8,367 318,909 327,276 Construction and land development 2,670 745 — 3,415 171,174 174,589 Commercial and industrial 1,734 38 1,595 3,367 624,418 627,785 Consumer 270 40 7 317 41,354 41,671 Other 252 38 — 290 52,725 53,015 Purchased credit impaired 1,372 1,554 901 3,827 24,565 28,392 Total $ 12,791 $ 4,011 $ 4,366 $ 21,168 $ 1,869,851 $ 1,891,019 December 31, 2019 Commercial real estate $ 372 $ — $ — $ 372 $ 559,417 $ 559,789 Consumer real estate 3,567 408 501 4,476 251,013 255,489 Construction and land development 653 — — 653 142,453 143,106 Commercial and industrial 1,277 8 440 1,725 391,819 393,544 Consumer 67 — 26 93 28,315 28,408 Other — — — — 38,161 38,161 Purchased credit impaired 75 81 149 305 1,300 1,605 Total $ 6,011 $ 497 $ 1,116 $ 7,624 $ 1,412,478 $ 1,420,102 The following table presents the recorded investment in non-accrual loans, past due loans over 89 days and accruing and troubled debt restructurings by class of loans as of December 31, 2020 and 2019 (in thousands): Past Due Over 89 Days Troubled Debt Non-Accrual and Accruing Restructurings December 31, 2020 Commercial real estate $ 130 $ 1,176 $ 1,928 Consumer real estate 1,821 342 — Construction and land development 107 — — Commercial and industrial 470 1,205 — Consumer 9 5 — Other — — — Purchased credit impaired 2,279 567 — Total $ 4,816 $ 3,295 $ 1,928 December 31, 2019 Commercial real estate $ — $ — $ 2,446 Consumer real estate 292 12 — Construction and land development 102 — — Commercial and industrial 427 — 271 Consumer — 26 — Other — — — Purchased credit impaired 643 — — Total $ 1,464 $ 38 $ 2,717 As of December 31, 2020 and 2019 all loans classified as nonperforming were deemed to be impaired. As of December 31, 2020 and 2019 the Company had recorded investments in TDR of $1.9 million and $2.7 million, respectively. The Company did not allocate a specific allowance for those loans at December 31, 2020 or 2019 and there were no commitments to lend additional amounts. Loans accounted for as TDR include modifications from original terms such as those due to bankruptcy proceedings, certain modifications of amortization periods or extended suspension of principal payments due to customer financial difficulties. In order to determine whether a borrower is experiencing financial difficulty, an evaluation is performed of the probability that the borrower will be in payment default on any of its debt in the foreseeable future without the modification. This evaluation is performed under the Company’s loan policy. Loans accounted for as TDR are individually evaluated for impairment. In accordance with interagency guidance, short term deferrals granted due to the COVID-19 pandemic are not considered TDRs unless the borrower was experiencing financial difficulty prior to the pandemic. The following table presents loans by class modified as TDR that occurred during the years ended December 31, 2020 and December 31, 2019 (in thousands). There were no TDR loans identified during the year ended December 31, 2018. Year Ended December 31, 2020 Number of contracts Pre modification outstanding recorded investment Post modification outstanding recorded investment, net of related allowance 2020 Commercial real estate — $ — $ — Consumer real estate 2 721 685 Construction and land development — — — Commercial and industrial — — — Consumer — — — Other — — — Total 2 $ 721 $ 685 2019 Commercial real estate 1 $ 1,228 $ 1,228 Consumer real estate — — — Construction and land development — — — Commercial and industrial 1 271 271 Consumer — — — Other — — — Total 2 $ 1,499 $ 1,499 There were no TDR for which there was a payment default within the twelve months following the modification during the years ended December 31, 2020, 2019 or 2018. A loan is considered to be in payment default once it is 30 days contractually past due under the modified terms. Acquired Loans On July 1, 2020, the Company acquired FCB and BOW (see Note 2 for more information). As a result of the acquisitions, the Company recorded loans with a fair value of $294.7 million. Of those loans, $33.6 million were considered to be purchased credit impaired (“PCI”) loans, which are loans for which it is probable at the acquisition date that all contractually required payments will not be collected. The remaining loans are considered to be purchased non-impaired loans and their related fair value discount or premium is recognized as an adjustment to yield over the remaining life of each loan. The following table relates to acquired FCB and BOW PCI loans and summarizes the contractually required payments, which includes principal and interest, expected cash flows to be collected, and the fair value of acquired PCI loans at the acquisition date (in thousands): FCB and BOW acquired on July 1, 2020 Contractually required payments $ 42,443 Nonaccretable difference 4,501 Cash flows expected to be collected at acquisition 37,942 Accretable yield 4,349 Fair value of PCI loans at acquisition date $ 33,593 The following table relates to acquired FCB and BOW purchased non-impaired loans and provides the contractually required payments, fair value, and estimate of contractual cash flows not expected to be collected at the acquisition date (in thousands): FCB and BOW acquired on July 1, 2020 Contractually required payments $ 296,527 Fair value of acquired loans at acquisition date 260,701 Contractual cash flows not expected to be collected 3,718 The following table presents changes in the carrying value of PCI loans (in thousands): For the year ended December 31, 2020 Balance at beginning of period $ 1,605 Additions due to the acquisitions 33,593 Change due to payments received and accretion (6,806 ) Balance at end of period $ 28,392 The following table presents changes in the accretable yield for PCI loans (in thousands): For the year ended December 31, 2020 Balance at beginning of period $ 915 Additions due to the acquisitions 4,349 Accretion (1,196 ) Balance at end of period $ 4,068 PCI loans had no impact on the ALL for the years ended December 31, 2020, 2019 or 2018. Leases The Company has entered into various direct finance leases. The leases are reported as part of other loans. The lease terms vary from five years to six years. The components of the direct financing leases as of December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Total minimum lease payments receivable $ — $ 59 Less: — Unearned income — (1 ) Net leases $ — $ 58 There are no future minimum lease payments receivable under the direct financing leases as of December 31, 2020.

Loan Servicing

Loan Servicing	12 Months Ended
	Dec. 31, 2020
Transfers And Servicing [Abstract]
Loan Servicing	NOTE 5 – LOAN SERVICING Mortgage loans serviced for the Federal Home Loan Mortgage Corporation (“FHLMC”) are not reported as assets. The principal balance of these loans at December 31, 2020 and 2019 was $254.9 million and $196.9 million, respectively. Custodial escrow balances maintained in connection with serviced loans was $1,459,000 and $324,000 at December 31, 2020 and 2019, respectively. Activity for loan servicing rights and the related valuation allowance are summarized as follows (in thousands): For the year ended December 31, 2020 For the year ended December 31, 2019 Loan servicing rights: Balance at beginning of period $ 1,755 $ 1,736 Additions 466 381 Amortized to offset other noninterest income (587 ) (362 ) Balance at end of period $ 1,634 $ 1,755 Valuation allowance: Balance at beginning of period $ (211 ) $ — Additions expensed — — Reductions credited to other noninterest income — — Direct write-downs (238 ) (211 ) Balance at end of period $ (449 ) $ (211 )

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Premises and Equipment	NOTE 6 – PREMISES AND EQUIPMENT Premises and equipment at December 31, 2020 and 2019 are summarized as follows (in thousands): Range of useful lives December 31, 2020 December 31, 2019 Land Not applicable $ 6,885 $ 4,303 Buildings 39 years 19,461 13,331 Leasehold improvements 1 to 17 years 939 939 Furniture and equipment 1 to 7 years 6,910 4,633 Fixed assets in process Not applicable 1,995 — 36,190 23,206 Less accumulated depreciation and amortization (9,501 ) (4,022 ) $ 26,689 $ 19,184 Premises and equipment depreciation and amortization expense for the years ended December 31, 2020, 2019 and 2018 totaled $1,375,000, $1,219,000 and $516,000, respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	NOTE 7 – LEASES The Company leases certain premises and equipment under operating leases that expire at various dates, through 2032, and in most instances, include options to renew or extend at market rates and terms. At December 31, 2020, the Company had lease liabilities totaling $11.9 million and right-of-use assets totaling $11.2 million related to these leases. Lease liabilities and right-of-use assets are reflected in other liabilities and other assets, respectively. At December 31, 2020, the weighted average remaining lease term for operating leases was 9.7 years and the weighted average discount rate used in the measurement of operating lease liabilities was 3.4%. Lease costs were as follows (in thousands): December 31, 2020 December 31, 2019 Operating lease cost $ 1,946 $ 1,868 Short-term lease cost — — Variable lease cost — — Total lease cost $ 1,946 $ 1,868 There were no sale and leaseback transactions, leveraged leases, or lease transactions with related parties during the year ended December 31, 2020 or 2019. A maturity analysis of operating lease liabilities and reconciliation of the undiscounted cash flows to the total operating lease liability is as follows (in thousands): December 31, 2020 Lease payments due: 2021 $ 1,726 2022 1,605 2023 1,558 2024 1,266 2025 1,234 2026 and thereafter 6,581 Total undiscounted cash flows 13,970 Discount on cash flows (2,030 ) Total lease liability $ 11,940

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	NOTE 8 – GOODWILL AND INTANGIBLE ASSETS Goodwill The change in goodwill during the years ended December 31, 2020 and 2019 was as follows (in thousands): 2020 2019 Beginning of year $ 37,510 $ 37,510 Acquired goodwill 3,558 — Impairment — — End of year $ 41,068 $ 37,510 Goodwill represents the excess of the purchase price over the sum of the estimated fair values of the tangible and identifiable intangible assets acquired less the estimated fair value of the liabilities assumed. Goodwill has an indefinite useful life and is evaluated for impairment annually or more frequently if events and circumstances indicate that the asset might be impaired. An impairment loss is recognized to the extent that the carrying amount exceeds the asset’s fair value. Qualitative factors are assessed to first determine if it is more likely than not (more than 50%) that the carrying value of goodwill is less than fair value. At October 31, 2020, as a result of market volatility caused by the COVID-19 pandemic, the company determined it did not satisfy the more likely than not qualitative assessment that the fair value of the reporting unit exceeded its carrying value, including goodwill. As a result, the Company elected to perform a quantitative assessment, which included a combination of quoted market prices of the Company’s stock, prices of comparable businesses, discounted cash flows and other techniques. Based upon the results of the quantitative assessment, we determined the fair value of the reporting unit exceeded the carrying value, resulting in no impairment. Acquired Intangible Assets Acquired intangible assets at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets: Core deposit intangibles $ 12,837 $ (4,207 ) $ 9,267 $ (2,384 ) For the years ended December 31, 2020, 2019 and 2018, respectively, amortization expense was $1,824,000, $1,655,000 and $465,000. Estimated amortization expense for each of the next five years is as follows (in thousands): Year ending December 31: 2021 $ 1,939 2022 1,690 2023 1,441 2024 1,192 2025 943 Thereafter 1,425 Total $ 8,630

Other Real Estate Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2020
Other Real Estate [Abstract]
Other Real Estate Owned	NOTE 9 – OTHER REAL ESTATE OWNED Other real estate owned activity was as follows (in thousands): 2020 2019 2018 Beginning balance $ 1,044 $ 988 $ — Additions due to acquisitions 571 — 988 Loans transferred to other real estate owned 452 180 — Direct write-downs — — — Sales of other real estate owned (1,544 ) (124 ) — End of year $ 523 $ 1,044 $ 988 There was no valuation allowance allocated to properties held for the years ended December 31, 2020, 2019 and 2018. Expenses related to other real estate owned during the years ended December 31, 2020, 2019 and 2018, respectively include (in thousands): 2020 2019 2018 Net gain on sales $ (273 ) $ (3 ) $ — Provision for unrealized losses — — — Operating expenses, net of rental income — — — Total $ (273 ) $ (3 ) $ —

Deposits

Deposits	12 Months Ended
	Dec. 31, 2020
Deposits [Abstract]
Deposits	NOTE 10 – DEPOSITS Time deposits that exceed the FDIC deposit insurance limit of $250,000 at December 31, 2020 and 2019 were $64,110,000 and $53,481,000, respectively. Scheduled maturities of time deposits for the next five years and thereafter are as follows (in thousands): Maturity: 2021 $ 377,164 2022 51,160 2023 20,136 2024 13,753 2025 6,702 Thereafter 613 $ 469,528 At December 31, 2020 and 2019, the Company had $558,000 and $148,000, respectively of deposit accounts in overdraft status that were reclassified to loans in the accompanying balance sheets.

Short-Term Borrowings and Long-

Short-Term Borrowings and Long-Term Debt	12 Months Ended
	Dec. 31, 2020
Federal Home Loan Banks [Abstract]
Short-Term Borrowings and Long-Term Debt	NOTE 11 – SHORT-TERM BORROWINGS AND LONG-TERM DEBT Short-Term Borrowings The Company had short-term borrowings totaling $10,000,000 at December 31, 2020 and 2019, via various advances. These advances are non-callable; interest payments are due monthly, with principal due at maturity. The following is a summary of the contractual maturities and average effective rates of outstanding advances (dollars in thousands): December 31, 2020 December 31, 2019 Year Amount Interest Rates Amount Interest Rates 2020 $ — — $ 10,000 2.05 % 2021 10,000 0.33 % — — Total $ 10,000 0.33 % $ 10,000 2.05 % Advances from the FHLB are collateralized by investment securities with a market value of $2.3 million, FHLB stock and certain commercial and residential real estate mortgage loans totaling $808.4 million under a blanket mortgage collateral agreement. At December 31, 2020, the amount of available credit from the FHLB totaled $433.9 million. Subordinated Notes The Company issued $30.0 million of fixed-to-floating rate subordinated notes during the third quarter of 2020, which were recorded net of issuance costs of $0.6 million, that mature June 30, 2030. Beginning on or after June 30, 2025, the Company may redeem the notes, in whole or in part, at their principal amount plus any accrued and unpaid interest. The notes have a fixed interest rate of 5.25% per annum for the first five years. Thereafter, the interest rate will reset quarterly to an interest rate per annum equal to a benchmark rate (which is expected to be Three-Month Term SOFR) plus 513 basis points. The carrying value of subordinated notes was $29.4 million at December 31, 2020. There were no subordinated notes at December 31, 2019.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	NOTE 12 – ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The following were changes in accumulated other comprehensive income (loss) by component, net of tax, for the years ended December 31, 2020 and 2019 (in thousands): Unrealized Gains Gains and and Losses Losses on on Available Cash Flow for Sale Year Ended December 31, 2020 Hedges Securities Total Beginning balance $ (2,679 ) $ 4,062 $ 1,383 Other comprehensive income (loss) before reclassification, net of tax — 3,758 3,758 Amounts reclassified from accumulated other comprehensive income (loss), net of tax 2,679 (92 ) 2,587 Net current period other comprehensive income (loss) 2,679 3,666 6,345 Ending balance $ — $ 7,728 $ 7,728 Year Ended December 31, 2019 Beginning balance $ (2,636 ) $ (680 ) $ (3,316 ) Other comprehensive income (loss) before reclassification, net of tax 826 4,815 5,641 Amounts reclassified from accumulated other comprehensive income (loss), net of tax (869 ) (73 ) (942 ) Net current period other comprehensive income (loss) (43 ) 4,742 4,699 Ending balance $ (2,679 ) $ 4,062 $ 1,383 The following were significant amounts reclassified out of each component of accumulated other comprehensive income (loss) for the years ended December 31, 2020, 2019 and 2018 (in thousands): Affected Line Item Details about Accumulated Other Year Ended Year Ended Year Ended in the Statement Where Comprehensive Income Components December 31, 2020 December 31, 2019 December 31, 2018 Net Income is Presented Realized losses on cash flow hedges $ (2,466 ) $ (635 ) $ (441 ) Interest expense – savings and money market accounts (213 ) (243 ) (479 ) Interest expense - Federal Home Loan Bank advances — 9 72 Income tax benefit $ (2,679 ) $ (869 ) $ (848 ) Net of tax Realized gains and (losses) on available-for-sale securities $ 125 $ (99 ) $ 3 Net gain (loss) on sale of securities (33 ) 26 (1 ) Income tax (expense) benefit $ 92 $ (73 ) $ 2 Net of tax Realized losses on securities transferred to held-to-maturity $ — $ — $ (14 ) Interest income - securities — — 4 Income tax benefit $ — $ — $ (10 ) Net of tax

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 13 – INCOME TAXES The components of income tax expense are summarized as follows (in thousands): 2020 2019 2018 Current: Federal $ 8,822 $ 3,215 $ 15 State 1,552 1,044 (23 ) 10,374 4,259 (8 ) Deferred: Federal (3,523 ) 2,039 872 State (816 ) 546 303 (4,339 ) 2,585 1,175 Total $ 6,035 $ 6,844 $ 1,167 A reconciliation of actual income tax expense in the financial statements to the “expected” tax expense (computed by applying the statutory federal income tax rate of 21% to income before income taxes) for the years ended December 31, 2020, 2019 and 2018 is as follows (in thousands): 2020 2019 2018 Computed "expected" tax expense $ 6,454 $ 6,146 $ 2,272 State income taxes, net of effect of federal income taxes 582 1,256 221 Tax-exempt interest income (278 ) (302 ) (298 ) Earnings on bank owned life insurance contracts (186 ) (173 ) (559 ) Disallowed expenses 69 84 93 Excess tax benefits related to stock compensation 91 (57 ) (857 ) Nondeductible acquisition expenses 132 — 281 CARES act net operating loss carryback (772 ) — — Other (57 ) (110 ) 14 Total $ 6,035 $ 6,844 $ 1,167 The effective tax rate compared favorably to the statutory federal rate of 21% and Tennessee excise tax rate of 6.5% primarily due to the enactment of new Net Operating Loss (“NOL”) provisions under the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”). The CARES Act permits NOLs arising in taxable years beginning after December 31, 2017 and before January 1, 2021 to be carried back five taxable years. This enabled the Company to carry back losses incurred during the taxable year 2018 to prior years with a higher statutory tax rate, creating a permanent tax rate benefit. As a result, the Company recorded an income tax benefit of $0.8 million related to the permanent tax rate benefit during the period ended March 31, 2020. In addition to the permanent tax rate benefit, the effective tax rate compared favorably to the statutory rate due to investments in qualified municipal securities, company owned life insurance, state tax credits, net of the effect of certain non-deductible expenses and the recognition of excess tax benefits related to stock compensation. Significant items that gave rise to deferred taxes at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Deferred tax assets: Allowance for loan losses $ 5,040 $ 2,935 Net operating loss carryforward 527 738 Organization and preopening costs 261 359 Stock-based compensation 48 200 Acquired loans 939 871 Accrued contributions 288 247 Acquired deposits 459 — Accrued compensation 3,159 22 Other 148 167 Deferred tax assets 10,869 5,539 Deferred tax liabilities: Depreciation 1,633 804 Goodwill 311 154 Unrealized gain on securities available-for-sale 2,009 833 Amortization of core deposit intangible 1,608 1,052 Other acquired assets 509 — Other 201 568 Deferred tax liabilities 6,271 3,411 Net deferred tax asset $ 4,598 $ 2,128 At December 31, 2020, the Company had federal net operating loss carryforwards of approximately $2,511,000, which expire at various dates from 2030 to 2032. Deferred tax assets are fully recognized because the benefits are more likely than not to be realized based on management’s estimation of future taxable earnings. There were no significant unrecognized income tax benefits as of December 31, 2020 or 2019. As of December 31, 2020 and 2019 the Company had no accrued interest or penalties related to uncertain tax positions.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 14 – COMMITMENTS AND CONTINGENCIES In the normal course of business, the Company has outstanding commitments and contingent liabilities, such as commitments to extend credit and standby letters of credit, which are not included in the accompanying financial statements. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instruments for commitments to extend credit and standby letters of credit is represented by the contractual or notional amount of those instruments. The Company uses the same credit policies in making such commitments as it does for instruments that are included in the balance sheet. The following table sets forth outstanding financial instruments whose contract amounts represent credit risk as of December 31, 2020 and 2019 (in thousands): Contract or notional amount December 31, 2020 December 31, 2019 Financial instruments whose contract amounts represent credit risk: Unused commitments to extend credit $ 804,520 $ 672,933 Standby letters of credit 10,403 9,634 Total $ 814,923 $ 682,567 The Company is party to litigation and claims arising in the normal course of business. Management believes that the liabilities, if any, arising from such litigation and claims as of December 31, 2020, will not have a material impact on the financial statements of the Company.

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2020
Risks And Uncertainties [Abstract]
Concentration of Credit Risk	NOTE 15 – CONCENTRATION OF CREDIT RISK Substantially all of the Company’s loans, commitments, and standby letters of credit have been granted to customers in the Company’s market areas. The concentrations of credit by type of loan are set forth in Note 4 to the financial statements. At December 31, 2020 and 2019, the Company’s cash and due from banks, federal funds sold and interest-bearing deposits in financial institutions aggregated $243,000,000 and $86,000,000, respectively, in excess of insured limits.

Regulatory Matters And Restrict

Regulatory Matters And Restrictions On Dividends	12 Months Ended
	Dec. 31, 2020
Banking And Thrift Interest [Abstract]
Regulatory Matters And Restrictions On Dividends	NOTE 16 – REGULATORY MATTERS AND RESTRICTIONS ON DIVIDENDS The Company and the Bank are subject to regulatory capital requirements administered by the Federal Reserve and the Bank is also subject to the regulatory capital requirements of the Tennessee Department of Financial Institutions. Failure to meet capital requirements can initiate certain mandatory – and possibly additional discretionary – actions by regulators that could, in that event, have a material adverse effect on the institutions’ financial statements. The relevant regulations require the Company and the Bank to meet specific capital adequacy guidelines that involve quantitative measures of their assets, liabilities and certain off-balance-sheet items as calculated under regulatory accounting principles. The capital classifications of the Company and the Bank are also subject to qualitative judgments by their regulators about components, risk weightings, and other factors. Those qualitative judgments could also affect the capital status of the Company and the Bank and the amount of dividends the Company and the Bank may distribute. The final rules implementing the Basel Committee on Companying Supervision’s capital guidelines for U.S. Banks (Basel III rules) became effective for the Company on January 1, 2015 with full compliance with all of the requirements being phased in over a multi-year schedule, and fully phased in by January 1, 2019. The net unrealized gain or loss on available for sale securities is not included in computing regulatory capital. Management believes as of December 31, 2020, the Company and the Bank met all regulatory capital adequacy requirements to which they are subject. The Federal Deposit Insurance Corporation Improvement Act of 1991 establishes a system of “prompt corrective action” to resolve the problems of undercapitalized insured depository institutions. Under this system, federal banking regulators have established five capital categories: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized, although these terms are not used to represent overall financial condition. Federal banking regulators are required to take various mandatory supervisory actions and are authorized to take other discretionary actions with respect to institutions in the three undercapitalized categories. The severity of the action depends upon the capital category in which the institution is placed. For example, institutions in all three undercapitalized categories are automatically restricted from paying distributions and management fees, whereas only an institution that is significantly undercapitalized or critically undercapitalized is restricted in its compensation paid to senior executive officers. Generally, subject to a narrow exception, the banking regulator must appoint a receiver or conservator for an institution that is critically undercapitalized. At December 31, 2020 and 2019, the Company and the Bank were well capitalized under the regulatory framework for prompt corrective action. There have been no conditions or events since that notification that management believes have changed the Company’s or the Bank’s category. The Company’s and the Bank’s capital amounts and ratios are presented in the following table (dollars in thousands): Actual Minimum capital requirement (1) Minimum to be well-capitalized (2) Amount Ratio Amount Ratio Amount Ratio At December 31, 2020: Total capital to risk-weighted assets: CapStar Financial Holdings, Inc. $ 338,426 16.03 % $ 168,910 8.0 % N/A N/A CapStar Bank 324,152 15.36 168,808 8.0 211,010 10.0 Tier I capital to risk-weighted assets: CapStar Financial Holdings, Inc. 285,439 13.52 126,682 6.0 N/A N/A CapStar Bank 300,588 14.25 126,606 6.0 168,808 8.0 Common equity Tier 1 capital to risk weighted assets: CapStar Financial Holdings, Inc. 285,439 13.52 95,012 4.5 N/A N/A CapStar Bank 284,088 13.46 94,954 4.5 137,156 6.5 Tier I capital to average assets: CapStar Financial Holdings, Inc. 285,439 9.60 118,877 4.0 N/A N/A CapStar Bank 300,588 10.12 118,780 4.0 148,476 5.0 At December 31, 2019: Total capital to risk-weighted assets: CapStar Financial Holdings, Inc. $ 237,857 13.45 % $ 141,436 8.0 % N/A N/A CapStar Bank 224,443 12.70 141,388 8.0 176,735 10.0 Tier I capital to risk-weighted assets: CapStar Financial Holdings, Inc. 225,074 12.73 106,077 6.0 N/A N/A CapStar Bank 211,660 11.98 106,041 6.0 141,388 8.0 Common equity Tier 1 capital to risk weighted assets: CapStar Financial Holdings, Inc. 225,074 12.73 79,558 4.5 N/A N/A CapStar Bank 195,160 11.04 79,531 4.5 114,878 6.5 Tier I capital to average assets: CapStar Financial Holdings, Inc. 225,074 11.37 79,201 4.0 N/A N/A CapStar Bank 211,660 10.70 79,150 4.0 98,938 5.0 (1) For the calendar year 2020, the Company was required to maintain a capital conservation buffer of Tier 1 common equity capital in excess of minimum risk-based capital ratios by at least 1.875% to avoid limits on capital distributions and certain discretionary bonus payments to executive officers and similar employees. (2) For the Company to be well-capitalized, the Bank must be well-capitalized and the Company must not be subject to any written agreement, order, capital directive, or prompt corrective action directive issued by the Federal Reserve to meet and maintain a specific capital level for any capital measure. Under Tennessee banking law, the Bank is subject to restrictions on the payment of dividends. Banking regulations limit the amount of dividends that may be paid without prior approval of the Tennessee Department of Financial Institutions. Under these regulations, the amount of dividends that may be paid in any calendar year without prior approval of the Tennessee Department of Financial Institutions is limited to the current year’s net income, combined with the retained net income of the preceding two years, subject to the capital requirements described above. The Bank’s payment of dividends may also be affected or limited by other factors, such as the requirement to maintain adequate capital above regulatory guidelines. The federal banking agencies have indicated that paying dividends that deplete a depository institution’s capital base to an inadequate level would be an unsafe and unsound banking practice. Under the Federal Deposit Insurance Corporation Improvement Act of 1991, a depository institution may not pay any dividends if payment would cause it to become undercapitalized or if it already is undercapitalized. Moreover, the federal agencies have issued policy statements that provide that Company holding companies and insured banks should generally only pay dividends out of current operating earnings. Based on these regulations, the Bank was eligible to pay $49.6 million and $35.8 million of dividends as of December 31, 2020 and 2019, respectively. The Bank paid the Company $4.1 million of dividends during 2020.

Nonvoting and Series A Preferre

Nonvoting and Series A Preferred Stock and Stock Warrants	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Nonvoting and Series A Preferred Stock and Stock Warrants	NOTE 17 – NONVOTING AND SERIES A PREFERRED STOCK AND STOCK WARRANTS Nonvoting Common Stock The Company has authorized 5,000,000 shares of its common stock as nonvoting common stock. The nonvoting common stock has the same rights and privileges as the common stock other than the nonvoting designation. Under certain conditions, as outlined in the Company’s charter, the nonvoting stock may be converted, on a one-to-one basis, to common stock. In conjunction with the Company’s initial public offering, 79,166 shares of nonvoting common stock were issued and simultaneously converted to common stock on a one-to-one basis as further described under “Warrants” below. During 2019, 132,561 shares of nonvoting common stock were converted to common stock. As a result, at December 31, 2020, there were no shares of nonvoting common stock outstanding. Preferred Stock In conjunction with its initial capital issuance in 2008, the Bank issued 1,609,756 shares of Series A Preferred Stock to certain shareholders. During 2016, coinciding with the Company’s initial public offering, 731,707 preferred shares were converted to common shares. During 2019, 878,048 preferred shares were converted to common shares. As a result, at December 31, 2020, there was no Series A Preferred Stock outstanding.

Stock Options and Restricted Sh

Stock Options and Restricted Shares	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options and Restricted Shares	NOTE 18 – STOCK OPTIONS AND RESTRICTED SHARES During 2008, the board of directors of the Company approved the CapStar Bank 2008 Stock Incentive Plan. Following the formation of CapStar Financial Holdings, Inc. in 2016, and in connection with the Share Exchange, the outstanding awards of restricted stock and stock options under the CapStar Bank 2008 Stock Incentive Plan were exchanged for similar awards of restricted stock and stock options issued by CapStar Financial Holdings, Inc. under the Stock Incentive Plan (the “Plan”), which the board of directors adopted in 2016. The Plan provides for the grant of stock-based incentives, including stock options, restricted stock units, performance awards and restricted stock, to employees, directors and service providers that are subject to forfeiture until vesting conditions have been satisfied by the award recipient under the terms of the award. The Plan is intended to help align the interests of employees and our shareholders and reward our employees for improved Company performance. The Plan reserved 1,569,475 shares of stock for issuance of stock incentives. Stock incentives include both restricted stock and stock option grants. During 2018 the board of directors approved the addition of 400,000 shares of stock for issuance of stock incentives under the Plan. Total shares issuable under the plan were 242,325 at December 31, 2020. The Company has recognized stock-based compensation expense, within salaries and employee benefits for employees, and within other non-interest expense for directors, in the consolidated statements of income as follows (in thousands): For the year ended December 31, 2020 2019 2018 Stock-based compensation expense before income taxes $ 1,223 $ 1,262 $ 2,079 Less: deferred tax benefit (320 ) (330 ) (543 ) Reduction of net income $ 903 $ 932 $ 1,536 Restricted Shares , Restricted Stock Units, and Performance Stock Units We grant time-vested restricted stock units and performance stock units to certain key employees and directors under our stock award plan. Compensation expense is recognized over the vesting period of the awards based on the fair value of the stock at the issue date. Those granted after January 1, 2020, vest ratably over a two or three-year Performance stock units vest based upon the attainment of certain performance metrics over a three-year The recipients have the right to vote and receive dividends but cannot sell, transfer, assign, pledge, hypothecate, or otherwise encumber the restricted stock until the shares have vested. A summary of the changes in the Company’s nonvested stock awards for 2020 follows: Weighted Average Restricted Grant Date Nonvested Shares Shares Fair Value Nonvested at beginning of period 84,697 $ 17.44 Granted 144,557 13.73 Vested (76,715 ) 16.50 Forfeited (4,125 ) 14.45 Nonvested at end of period 148,414 $ 14.39 As of December 31, 2020, there was $1.3 million of total unrecognized compensation cost related to nonvested shares granted under the Plan. The cost is expected to be recognized over a weighted-average period of 1.5 years. The total fair value of shares vested during the years ended December 31, 2020, 2019 and 2018 was $997,000, $,1,352,000 and $2,804,000, respectively. Stock Options Option awards are generally granted with an exercise price equal to the fair value of the Company’s common stock at the date of grant. Option awards generally have a three year vesting period and a ten year contractual term. The fair value of each option grant is estimated on the date of grant using the Black-Scholes option pricing model that uses the assumptions noted in the table below. Expected volatility is based on calculations performed by management using industry data. The expected term of options granted was calculated using the “simplified” method for plain vanilla options as permitted under authoritative literature. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The fair value of options granted was determined using the following weighted average assumptions as of the grant date. There were no options granted during 2020. The Company granted 50,000 options during 2019. 2019 Dividend yield 1.35 % Expected term (in years) 6.50 Expected stock price volatility 29.55 % Risk-free interest rate 2.25 % A summary of the activity in stock options for 2020 follows: Weighted Weighted Average Average Remaining Exercise Contractual Shares Price Term (years) Outstanding at beginning of period 271,202 $ 11.22 Granted — — Exercised (24,613 ) 6.75 Forfeited or expired (20,000 ) 10.92 Outstanding at end of period 226,589 $ 11.73 3.9 Fully vested and expected to vest 226,589 $ 11.73 3.9 Exercisable at end of period 193,255 $ 11.19 3.1 Information related to stock options during 2020, 2019 and 2018 follows: 2020 2019 2018 Intrinsic value of options exercised $ 188,662 $ 2,478,086 $ 7,654,738 Cash received from option exercises 105,847 1,930,737 6,897,845 Tax benefit realized from option exercises 16,524 103,847 846,725 Weighted average fair value of options granted — 5.35 — As of December 31, 2020, there was $124,000 of total unrecognized compensation cost related to nonvested stock options granted under the Plan. The cost is expected to be recognized over a weighted-average period of 1.4 years.

Employment Contracts

Employment Contracts	12 Months Ended
	Dec. 31, 2020
Employment Contracts Disclosure [Abstract]
Employment Contracts	NOTE 19 – EMPLOYMENT CONTRACTS The Company has entered into employment contracts with certain senior executives with various expiration dates. Most of the contracts have an option for annual renewal by mutual agreement. The agreements specify that in certain terminating events the Company will be obligated to provide certain benefits and pay each of the senior executives severance based on their annual salaries. These terminating events include termination of employment without “Cause” (as defined in the agreements) or in certain other circumstances specified in the agreements.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plans	NOTE 20 – EMPLOYEE BENEFIT PLANS The Company has a Retirement Savings 401(k) Plan in which employees may participate. The Company has elected a safe harbor 401(k) plan and as such is required to make an annual contribution of 3% of the employees’ salaries annually. An employee does not have to contribute to receive the employer contribution. In addition, the Company may make an additional discretionary contribution up to 6% of the employees’ salaries annually. For the years ended December 31, 2020, 2019 and 2018, the Company contributed $801,000, $874,000 and $639,000, respectively, to the 401(k) Plan. The Company also has a Health Reimbursement Plan in place to offset the cost of healthcare deductibles for employees. At the end of the year, up to one-half of the unused balance in the employee’s account will be available for the following year up to a maximum of the deductible for that employee.

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments	NOTE 21 – DERIVATIVE INSTRUMENTS The Company utilizes interest rate swap agreements as part of its asset liability management strategy to help manage its interest rate risk position. The notional amount of the interest rate swaps does not represent amounts exchanged by the parties. The amount exchanged is determined by reference to the notional amount and the other terms of the individual interest rate swap agreements. Interest Rate Swaps Designated as Cash Flow Hedges There were no interest rate swaps designated as cash flow hedges as of December 31, 2020 or 2019. The company previously terminated an interest rate swap during 2019, which resulted in a termination fee of $1.5 million which continued to be amortized as the corresponding hedged items, consisting of LIBOR-based brokered deposits and FHLB borrowings, were expected to remain outstanding until the initial maturities of the terminated swaps. However, during the year ended December 31, 2020, it was determined that in light of the Company’s surplus liquidity position this funding was expected to be terminated at the next renewal date and thus the previously terminated interest rate swaps which had been designated as cash flow hedges were no longer deemed effective, therefore, remaining unrealized losses of $1.9 million included in accumulated other comprehensive income were recognized in net income. There are no unrealized gains or losses in accumulated other comprehensive income as of December 31, 2020. Other Interest Rate Swaps The Company also enters into swaps to facilitate customer transactions and meet their financing needs. Upon entering into these transactions the Company enters into offsetting positions with large U.S. financial institutions in order to minimize risk to the Company. A summary of the Company’s customer related interest rate swaps is as follows (in thousands): December 31, 2020 December 31, 2019 Notional Estimated Notional Estimated amount fair value amount fair value Interest rate swap agreements: Pay fixed/receive variable swaps $ 59,946 $ (2,740 ) $ 45,053 $ (926 ) Pay variable/receive fixed swaps 59,946 2,740 45,053 926 Total $ 119,892 $ — $ 90,106 $ — Mortgage Banking Derivatives The Company enters into various derivative agreements with customers in the form of interest-rate lock commitments which are commitments to originate mortgage loans whereby the interest rate on the loan is determined prior to funding and the customers have locked into that interest rate. The derivatives are valued using a model that utilizes market interest rates and other unobservable inputs. Changes in the fair value of these commitments due to fluctuations in interest rates that are to be originated to our loans held for sale portfolio are economically hedged through the use of forward sale commitments of mortgage-backed securities. The gains and losses arising from this derivative activity are reflected in current period earnings under mortgage banking income. Interest rate lock commitments are valued using a model with significant unobservable market parameters. Forward sale commitments are valued based on quoted prices for similar assets in an active market with inputs that are observable. The net gains (losses) relating to mortgage banking derivative instruments included in mortgage banking income were as follows (dollars in thousands): For the year ended For the year ended December 31, 2020 December 31, 2019 Mortgage loan interest rate lock commitments $ 1,959 $ 648 Mortgage-backed securities forward sales commitments (478 ) (148 ) Total $ 1,481 $ 500 There were no gains or losses relating to mortgage banking derivative instruments for the year ended December 31, 2018. The amount and fair value of mortgage banking derivatives included in the consolidated balance sheets was as follows (dollars in thousands): December 31, 2020 December 31, 2019 Notional Estimated Notional Estimated amount fair value amount fair value Included in other assets: Mortgage loan interest rate lock commitments $ 88,303 $ 2,607 $ 44,694 $ 648 Included in other liabilities: Mortgage-backed securities forward sales commitments $ 87,000 $ (626 ) $ 38,500 $ (148 )

Related Party

Related Party	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party	NOTE 22 – RELATED PARTY The Company may enter into loan transactions with certain directors, executive officers, significant shareholders, and their affiliates. Such transactions were made in the ordinary course of business on substantially the same terms, including interest rates and collateral, as those prevailing at the same time for comparable transactions with persons not affiliated with the Company, and did not, in the opinion of management, involve more than normal credit risk or present other unfavorable features. None of these loans were impaired at December 31, 2020 or 2019. Activity within these loans during the years ended December 31, 2020 and 2019 was as follows (in thousands): Total commitment Total funded commitment Year ended December 31, 2020 Beginning of period $ 21,815 $ 10,673 New commitments/draw downs 200 2,798 Repayments (3,991 ) (3,689 ) End of period $ 18,024 $ 9,782 Year ended December 31, 2019 Beginning of period $ 44,812 $ 15,445 New commitments/draw downs 9,336 2,515 Repayments (32,333 ) (7,287 ) End of period $ 21,815 $ 10,673 Deposits from directors, executive officers, significant shareholders and their affiliates at December 31, 2020 and 2019 were $38.5 million and $13.7 million, respectively.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value	NOTE 23 – FAIR VALUE Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. There are three levels of inputs that may be used to measure fair values: Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active markets that the entity has the ability to access as of the measurement date. Level 2: Significant observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Level 3: Significant unobservable inputs that reflect a reporting entity’s own assumptions about the assumptions that market participants would use in pricing an asset or liability. The Company used the following methods and significant assumptions to estimate fair value: Investment Securities Derivatives-Interest Rate Swaps Impaired Loans Other Real Estate Owned Loans Held For Sale Derivatives-Mortgage Loan Interest Rate Lock Commitments rates are applied to the fair value of the unclosed mortgage pipeline, resulting in a Level 3 fair value classification. The pull through rate is a statistical analysis of our actual rate lock fallout history to determine the sensitivity of the residential mortgage loan pipeline compared to interest rate changes and other deterministic values. New market prices are applied based on updated loan characteristics and new fallout ratios (i.e., the inverse of the pull through rate) are applied accordingly. Significant increases (decreases) in the pull through rate in isolation result in a significantly higher (lower) fair value measurement. Changes to the fair value of interest rate lock commitments are recognized based on interest rate changes, changes in the probability that the commitment will be exercised, and the passage of time. Derivatives-Mortgage-Backed Securities Forward Sales Commitments . Assets and liabilities measured at fair value on a recurring basis are summarized below (in thousands): Fair value measurements at December 31, 2020 Quoted prices in active Significant markets for other Significant identical observable unobservable Carrying assets inputs inputs Value (Level 1) (Level 2) (Level 3) Assets: Securities available-for-sale: U.S. government-sponsored agencies $ 16,390 $ — $ 16,390 $ — Obligations of states and political subdivisions 91,930 — 91,930 — Mortgage-backed securities-residential 336,361 — 336,361 — Asset-backed securities 3,193 — 3,193 — Other debt securities 38,341 — 38,341 — Loans held for sale 97,303 — 97,303 — Derivative assets: Non-hedging derivatives: Interest rate swaps - customer related 2,740 — 2,740 — Mortgage loan interest rate lock commitments 2,607 — — 2,607 Liabilities: Derivative liabilities: Non-hedging derivatives: Derivative Liabilities - customer related (2,740 ) — (2,740 ) — Mortgage-backed securities forward sales commitments (626) — (626) — Fair value measurements at December 31, 2019 Quoted prices in active Significant markets for other Significant identical observable unobservable Carrying assets inputs inputs Value (Level 1) (Level 2) (Level 3) Assets: Securities available-for-sale: U.S. government-sponsored agencies $ 10,331 $ — $ 10,331 $ — Obligations of states and political subdivisions 45,960 — 45,960 — Mortgage-backed securities-residential 138,679 — 138,679 — Asset-backed securities 3,197 — 3,197 — Other debt securities 14,962 — 14,962 — Loans held for sale 168,222 168,222 Derivatives: Derivative Liabilities - customer related 926 — 926 — Mortgage loan interest rate lock commitments 648 — — 648 Liabilities: Derivatives: Derivative Liabilities - customer related (926 ) — (926 ) — Mortgage-backed securities forward sales commitments (148 ) — (148 ) — The table below presents a reconciliation of all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the year ended December 31, 2020 and 2019 (dollars in thousands): Mortgage Loan Interest Rate Lock Commitments 2020 2019 Balance of recurring Level 3 assets at January 1st $ 648 $ — Total gains or losses for the period: Included in mortgage banking income 1,959 648 Balance of recurring Level 3 assets at December 31st $ 2,607 $ 648 The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2020 (dollars in thousands). Range Fair Valuation (Weighted- December 31, 2020 Value Technique(s) Unobservable Input(s) Average) Assets: Non-hedging derivatives: Mortgage loan interest rate lock commitments $ 2,607 Consensus pricing Origination pull-through rate 54% - 91% (74%) Range Fair Valuation (Weighted- December 31, 2019 Value Technique(s) Unobservable Input(s) Average) Assets: Non-hedging derivatives: Mortgage loan interest rate lock commitments $ 648 Consensus pricing Origination pull-through rate 68% - 95% (83%) Assets measured at fair value on a nonrecurring basis are summarized below (in thousands): There were no assets measured at fair value on a nonrecurring basis at December 31, 2019. Fair value measurements at December 31, 2020 Quoted prices in active Significant markets for other Significant identical observable unobservable Carrying assets inputs inputs Value (level 1) (level 2) (level 3) Assets: Impaired loans: Construction and land development $ 36 $ — $ — $ 36 The following table presents quantitative information about Level 3 fair value measurements for assets measured at fair value on a nonrecurring basis (dollars in thousands): Fair Valuation Unobservable Weighted- December 31, 2020 Value Technique(s) Input(s) Average Impaired loans: Construction and land development $ 36 Sales comparison approach Appraisal discounts 10% Fair Value of Financial Instruments The carrying value and estimated fair values of the Company’s financial instruments at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Carrying Carrying Fair value amount Fair value amount Fair value level of input Financial assets: Cash and due from banks, interest-bearing deposits in financial institutions $ 277,439 $ 277,439 $ 101,094 $ 101,094 Level 1 Federal funds sold — — 175 175 Level 1 Securities available-for-sale 486,215 486,215 213,129 213,129 Level 2 Securities held-to-maturity 2,407 2,504 3,313 3,411 Level 2 Loans held for sale 179,669 180,698 168,222 169,072 Level 2 Restricted equity securities 15,562 N/A 13,689 N/A N/A Loans 1,891,019 1,900,647 1,420,102 1,414,757 Level 3 Accrued interest receivable 8,771 8,771 5,792 5,792 Level 2 Other assets 46,381 46,381 36,393 36,393 Level 2 / Level 3 Financial liabilities: Deposits 2,568,001 2,472,860 1,729,451 1,730,206 Level 3 Federal Home Loan Bank advances and other borrowings 39,423 41,400 10,000 10,014 Level 2 Other liabilities 3,334 3,334 1,394 1,394 Level 3 The methods and assumptions, not previously presented, used to estimate fair values are described as follows: (a) Cash and Due from Banks, Interest-Bearing Deposits in Financial Institutions For these short-term instruments, the carrying amount is a reasonable estimate of fair value. (b) Federal Funds Sold Federal funds sold clear on a daily basis. For this reason, the carrying amount is a reasonable estimate of fair value. (c) Restricted Equity Securities It is not practical to determine the fair value of restricted securities due to restrictions placed on their transferability. (d) Loans, net In accordance with the adoption of ASU 2016-01, the fair value of loans is measured using an exit price notion. Fair values for impaired loans are estimated using discounted cash flow models or based on the fair value of the underlying collateral. (e) Accrued interest receivable The carrying amount of accrued interest approximates fair value. (f) Other Assets Included in other assets are bank owned life insurance and certain interest rate swap agreements. The fair values of interest rate swap agreements are based on independent pricing services that utilize pricing models with observable market inputs. For bank owned life insurance, the carrying amount is based on the cash surrender value and is a reasonable estimate of fair value. (g) Deposits The fair value of demand deposits, savings accounts and certain money market deposits is the amount payable on demand at the reporting date. The fair value of certificates of deposit is estimated by discounted cash flow models, using current market interest rates offered on certificates with similar remaining maturities. (h) Federal Home Loan Bank Advances and Other Borrowings The fair value of fixed rate Federal Home Loan Bank Advances and other borrowings is estimated using discounted cash flow models, using current market interest rates offered on certificates, advances and other borrowings with similar remaining maturities. (i) Other Liabilities Included in other liabilities are accrued interest payable and certain interest rate swap agreements. The fair values of interest rate swap agreements are based on independent pricing services that utilize pricing models with observable market inputs. The carrying amounts of accrued interest approximate fair value. (j) Off-Balance Sheet Instruments Fair values for off-balance sheet, credit-related financial instruments are based on fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the counterparties’ credit standing. The fair value of commitments is not material. (k) Limitations Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instruments. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular instrument. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Fair value estimates are based on estimating on and off-balance sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. For example, fixed assets are not considered financial instruments and their value has not been incorporated into the fair value estimates. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in the estimates.

Parent Company Only Financial I

Parent Company Only Financial Information	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Parent Company Only Financial Information	NOTE 24 – PARENT COMPANY ONLY FINANCIAL INFORMATION The following information presents the condensed balance sheets, statements of income, and statements of cash flows of CapStar Financial Holdings, Inc. as of and for the year ended December 31, 2020 and 2019 (in thousands). Condensed Balance Sheets December 31, 2020 December 31, 2019 Assets Cash and cash equivalents $ 13,176 $ 12,874 Investment in consolidated subsidiary 358,635 259,632 Other assets 1,163 578 Total assets $ 372,974 $ 273,084 Liabilities and Shareholders’ Equity Subordinated debt $ 29,423 $ — Other liabilities 65 38 Total shareholders’ equity 343,486 273,046 Total liabilities and shareholders’ equity $ 372,974 $ 273,084 Condensed Income Statements Year Ended Year Ended December 31, 2020 December 31, 2019 Income - dividends from subsidiary $ 4,075 $ 3,530 Interest expense subordinated debt 792 — Other expenses 1,373 1,083 Income before income taxes and equity in undistributed net income of subsidiary 1,910 2,447 Income tax benefit (552 ) (262 ) Income before equity in undistributed net income of subsidiary 2,462 2,709 Equity in undistributed net income of subsidiary 22,234 19,713 Net income $ 24,696 $ 22,422 Condensed Statements of Cash Flow Year Ended Year Ended December 31, 2020 December 31, 2019 Cash flows from operating activities: Net income $ 24,696 $ 22,422 Adjustments to reconcile net income to net cash provided by operating activities: Increase in other assets (2,962 ) (3,304 ) Increase (decrease) in other liabilities 27 (263 ) Equity in undistributed net income of subsidiary (22,234 ) (19,713 ) Net cash used in by operating activities (473 ) (858 ) Cash flows from investing activities: Cash paid for acquisitions (27,278 ) — Dividends received from CapStar Bank 4,075 3,530 Net cash (used in) provided by investing activities (23,203 ) 3,530 Cash flows from financing activities: Issuance of subordinated debt 29,387 — Repurchase of common stock (1,437 ) (7,836 ) Exercise of common stock options and warrants 63 1,627 Common stock dividends paid (4,035 ) (3,507 ) Net cash provided by (used in) financing activities 23,978 (9,716 ) Net increase (decrease) in cash and cash equivalents 302 (7,044 ) Cash and cash equivalents at beginning of period 12,874 19,918 Cash and cash equivalents at end of period $ 13,176 $ 12,874

Quarterly Financial Results (Un

Quarterly Financial Results (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Results (Unaudited)	NOTE 25 – QUARTERLY FINANCIAL RESULTS (UNAUDITED) The following is a summary of quarterly financial results (unaudited) for 2020, 2019 and 2018: First Quarter Second Quarter Third Quarter Fourth Quarter 2020 Interest income $ 21,738 $ 20,741 $ 24,642 $ 24,731 Interest expense 5,077 3,066 4,986 2,400 Net interest income 16,661 17,675 19,656 22,331 Provision for loan losses 7,553 1,624 2,119 184 Net interest income after provision for loan losses 9,108 16,051 17,537 22,147 Noninterest income 5,874 10,823 14,804 11,748 Noninterest expense 14,211 18,934 22,739 21,478 Net income before income tax expense 771 7,940 9,602 12,417 Income tax expense (575 ) 1,759 2,115 2,736 Net income $ 1,346 $ 6,181 $ 7,487 $ 9,681 Net income per share, basic $ 0.07 $ 0.34 $ 0.34 $ 0.44 Net income per share, diluted $ 0.07 $ 0.34 $ 0.34 $ 0.44 2019 Interest income $ 22,967 $ 23,158 $ 23,216 $ 22,205 Interest expense 5,965 6,150 6,060 5,624 Net interest income 17,002 17,008 17,156 16,581 Provision for loan losses 886 — (125 ) — Net interest income after provision for loan losses 16,116 17,008 17,281 16,581 Noninterest income 4,735 7,032 6,788 5,719 Noninterest expense 14,725 16,470 15,531 15,266 Net income (loss) before income tax expense 6,126 7,570 8,538 7,034 Income tax expense (benefit) 1,346 1,814 2,072 1,613 Net income (loss) $ 4,780 $ 5,756 $ 6,466 $ 5,421 Net income (loss) per share, basic $ 0.27 $ 0.33 $ 0.36 $ 0.30 Net income (loss) per share, diluted $ 0.25 $ 0.31 $ 0.35 $ 0.29 2018 Interest income $ 13,744 $ 15,354 $ 15,782 $ 22,900 Interest expense 2,898 3,767 4,239 5,184 Net interest income 10,846 11,587 11,543 17,716 Provision for loan losses 678 169 481 1,514 Net interest income after provision for loan losses 10,168 11,418 11,062 16,202 Noninterest income 3,088 2,765 3,218 6,387 Noninterest expense 9,580 10,005 10,070 23,832 Net income (loss) before income tax expense 3,676 4,178 4,210 (1,243 ) Income tax expense (benefit) 483 665 554 (535 ) Net income (loss) $ 3,193 $ 3,513 $ 3,656 $ (708 ) Net income (loss) per share, basic $ 0.27 $ 0.30 $ 0.30 $ (0.04 ) Net income (loss) per share, diluted $ 0.25 $ 0.27 $ 0.28 $ (0.04 )

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements as of December 31, 2020 and 2019 and for each of the three years in the period ended December 31, 2020 include CapStar Financial Holdings, Inc. and it’s wholly owned subsidiary, CapStar Bank (the “Bank”, together referred to as the “Company”). Significant intercompany transactions and accounts are eliminated in consolidation. On February 5, 2016, CapStar Financial Holdings, Inc. acquired all of the Bank’s issued and outstanding shares of common stock, preferred stock, common stock options and warrants, and the Bank became the wholly owned subsidiary of CapStar Financial Holdings, Inc. (the “Share Exchange”). The consolidated financial statements of the Company have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) and conform to general practices within the banking industry.
Business Combinations	Business Combinations The Company accounts for business combinations using the acquisition method of accounting. The accounts of an acquired entity are included as of the date of acquisition, and any excess of purchase price over the fair value of the net assets acquired is capitalized as goodwill. Under this method, all identifiable assets acquired, including purchased loans, and liabilities assumed are recorded at fair value.
Nature of Operations	Nature of Operations Through the Bank, the Company provides full banking services to consumer and corporate customers located primarily in Tennessee. The Bank operates under a state bank charter and is a member of the Federal Reserve System. As a state member bank, the Bank is subject to regulations of the Tennessee Department of Financial Institutions, the Board of Governors of the Federal Reserve System (the “Federal Reserve”), and the Federal Deposit Insurance Corporation.
Estimates	Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan losses, determination of impairment of intangible assets, including goodwill, the valuation of our investment portfolio and deferred tax assets.
Cash and Cash Equivalents	Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, interest-bearing deposits in financial institutions and federal funds sold. Generally, federal funds sold are purchased and sold for one-day periods. The Company maintains deposits in excess of the federal insurance amounts with other financial institutions. Management makes deposits only with financial institutions it considers to be financially sound.
Securities	Securities The Bank accounts for securities under the provisions of Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 320, Investments – Debt and Equity Securities Securities Held-to-Maturity - Debt securities are classified as held-to-maturity securities when the Bank has the positive intent and ability to hold the securities to maturity. Securities held to maturity are carried at amortized cost. Trading Securities - Debt and equity securities that are bought and held principally for the purpose of selling them in the near term are classified as trading securities and reported at fair value, with unrealized gains and losses included in earnings. No securities have been classified as trading securities. Securities Available-for-Sale - Debt securities not classified as either held-to-maturity securities or trading securities are classified as available for sale securities. Securities available for sale are carried at estimated fair value with unrealized gains and losses excluded from earnings and reported as a separate component of shareholders’ equity in other comprehensive income (loss). Interest income includes amortization of purchase premiums or discounts. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Realized gains and losses from the sales of securities are recorded on the trade date and determined using the specific-identification method. Management evaluates securities for other-than-temporary impairment (“OTTI”) on at least a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. For securities in an unrealized loss position, management considers the extent and duration of the unrealized loss, the financial condition and near-term prospects of the issuer and any collateral underlying the relevant security. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For debt securities that do not meet the aforementioned criteria, the amount of impairment is split into two components as follows: (1) OTTI related to credit loss, which must be recognized in the income statement and (2) OTTI related to other factors, which is recognized in other comprehensive income (loss). The credit loss is defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis.
Loans Held For Sale and Fair Value Option	Loans Held For Sale and Fair Value Option The Company classifies loans as loans held for sale when originated with the intent to sell. As of April 1, 2019, the Company elected the fair value option for all residential mortgage loans originated with the intent to sell. This election allows for a more effective offset of the changes in fair values of the loans and the derivative instruments used to economically hedge them without the burden of complying with the requirements for hedge accounting. The Company has not elected the fair value option for other loans held for sale primarily because they are not economically hedged using derivative instruments. The fair value of residential mortgage loans originated with the intent to sell is based on traded market prices of similar assets. Other loans held for sale that are recorded at lower of cost or fair value may be carried at fair value on a nonrecurring basis when the fair value is less than cost. For further information, see Note 23 - Fair Value. The Company does not securitize mortgage loans. If the Company sells loans with servicing rights retained, the carrying value of the mortgage loan sold is reduced by the amount allocated to the servicing right. Fair values of residential mortgage loans held for sale are based on traded market prices of similar assets. The changes in fair value are recorded as a component of mortgage banking income and included gains of $2.5 million for the year ended December 31, 2020 and $0.6 million for the year ended December 31, 2019. There were no loans held for sale recorded at fair value as of December 31, 2018. The following table summarizes the difference between the fair value and the aggregate unpaid principal balance for residential real estate loans held for sale as of December 31, 2020 and 2019 (dollars in thousands): Fair Value Aggregate Unpaid Principal Balance Difference December 31, 2020 Residential mortgage loans held for sale $ 97,303 $ 94,248 $ 3,055 December 31, 2019 Residential mortgage loans held for sale 30,740 30,178 562
Tri-Net Fees	Tri-Net Fees Tri-Net fees are derived from the origination, with the intent to sell, of commercial real estate loans to third-party investors. All of these loan sales transfer servicing rights to the buyer. Realized gains and losses are recognized when legal title of the loan has transferred to the investor and sales proceeds have been received and are reflected in the accompanying statements of income in Tri-Net fees, net of related costs such as commission expenses. Loans that have not been sold at period end are classified as held for sale on the balance sheet and recorded at the lower of aggregate cost or fair value. Net unrealized losses, if any, are recorded as a valuation allowance and charged to earnings.
Loans	Loans The Company has seven classes of loans for financial reporting purposes: commercial real estate, consumer real estate, construction and land development, commercial and industrial, consumer, PPP, and other. The appropriate classification is determined based on the underlying collateral utilized to secure each loan. Commercial real estate loans are categorized as such based on investor exposures where repayment is largely dependent upon the operation, refinance, or sale of the underlying real estate. Commercial real estate also includes owner occupied commercial real estate. Consumer real estate consists primarily of 1-4 family residential properties including home equity lines of credit. Construction and land development loans include loans where the repayment is dependent on the successful completion and operation and/or sale of the related real estate project. Construction and land development loans include 1-4 family construction projects and commercial construction endeavors such as warehouses, apartments, office and retail space and land acquisition and development. Commercial and industrial loans include loans to business enterprises issued for commercial, industrial and/or other professional purposes. Consumer loans include all loans issued to individuals not included in the consumer real estate class. PPP loans originated through the CARES act and include partially, or fully forgivable loans used to cover payroll costs, rent, interest, utilities, and other qualifiable expenses. Other loans include all loans not included in the classes of loans above and leases. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal balance outstanding, net of purchase premiums and discounts, deferred loan fees and costs, and an allowance for loan losses. Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level-yield method without anticipating prepayments. The accrual of interest on loans is discontinued at the time the loan is 90 days past due unless the credit is well secured and in process of collection. Consumer loans and any accrued interest is typically charged off no later than 180 days past due. Past due status is based on contractual terms of the loan. In all cases, loans are placed on nonaccrual or charged off at an earlier date if collection of principal or interest is considered doubtful and collection is highly questionable. Amortization of deferred loan fees is discontinued when a loan is placed on nonaccrual status. All interest accrued but not received for loans placed on nonaccrual is reversed against interest income. Interest received on such loans is accounted for on the cash-basis or cost-recovery method, until qualifying for return to accrual status. Under the cost-recovery method, interest income is not recognized until the loan balance is reduced to zero. Under the cash-basis method, interest income is recorded when the payment is received in cash. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. Loans can also be returned to accrual status when they become well secured and in the process of collection.
Acquired Loans	Acquired Loans Acquired loans are accounted for under the acquisition method of accounting. The acquired loans are recorded at their estimated fair values as of the acquisition date. Fair value of acquired loans is determined using a discounted cash flow model based on assumptions regarding the amount and timing of principal and interest payments, estimated prepayments, estimated default rates, estimated loss severity in the event of defaults, and current market rates. Estimated credit losses are included in the determination of fair value; therefore, an allowance for loan losses is not recorded on the acquisition date. An acquired loan is considered purchased credit impaired when there is evidence of credit deterioration since origination and it is probable at the date of acquisition that the Bank will be unable to collect all contractually required payments. Purchased credit impaired loans are accounted for individually or aggregated into pools of loans based on common risk characteristics such as loan type and risk rating. The Company estimates the amount and timing of expected cash flows for each loan or pool, and the expected cash flows in excess of amount paid (fair value) is recorded as interest income over the remaining life of the loan or pool (accretable yield). The excess of the loan’s or pool’s contractual principal and interest over expected cash flows is not recorded (nonaccretable difference). Over the life of the loan or pool, expected cash flows continue to be estimated. If the present value of expected cash flows is less than the carrying amount, a loss is recorded as a provision for loan losses. If the present value of expected cash flows is greater than the carrying amount, it is recognized as part of future interest income. Acquired non-impaired loans are recorded at their initial fair value and adjusted for subsequent advances, pay downs, amortization or accretion of any premium or discount on purchase, charge-offs and additional provisioning that may be required.
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses (“ALL”) is maintained at a level that management believes to be adequate to absorb expected loan losses inherent in the loan portfolio as of the balance sheet date. The allowance for loan losses is a valuation allowance for estimated credit losses inherent in the loan and lease portfolio, increased by the provision for loan losses and decreased by charge-offs, net of recoveries. Quarterly, the Company estimates the allowance required using peer group loss experience, the nature and volume of the portfolio, information about specific borrower situations and estimated collateral values, economic conditions, and other factors. The Company’s historical loss experience is based on the actual loss history by class of loan for comparable peer institutions due to the Company’s limited loss history. Allocations of the allowance may be made for specific loans, but the entire allowance is available for any loan that, in management’s judgment, should be charged off. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries are credited to the allowance for loan losses. The Company also considers the results of the external independent loan review when assessing the adequacy of the allowance and incorporates relevant loan review results in the loan impairment and overall adequacy of allowance determinations. Furthermore, regulatory agencies periodically review the Company’s allowance for loan losses and may require the Company to record adjustments to the allowance based on their judgment of information available to them at the time of their examinations. Additional considerations are included in the determination of the adequacy of the allowance based on the continuous review conducted by relationship managers and credit department personnel. The Company’s loan policy requires that each customer relationship wherein total exposure exceeds $1.5 million be subject to a formal credit review at least annually. Should these reviews identify potential collection concerns, appropriate adjustments to the allowance may be made. The allowance consists of specific and general components as discussed below. While the allowance consists of separate components, these terms are primarily used to describe a process. Both portions of the allowance are available to provide for inherent losses in the entire portfolio. Specific Component The specific component relates to loans that are individually determined to be impaired when, based on current information and events, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Loans for which the terms have been modified resulting in a concession, and for which the borrower is experiencing financial difficulties, are considered troubled debt restructurings (“TDRs”) and classified as impaired. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Loans meeting any of the following criteria are individually evaluated for impairment: risk rated substandard (as defined in Note 4), on non-accrual status or past due greater than 90 days. If a loan is impaired, a portion of the allowance is allocated based on the present value of estimated future cash flows using the loan’s existing rate or at the fair value of collateral less costs to sell if repayment is expected solely from the collateral. Changes to the valuation allowance are recorded as a component of the provision for loan losses. TDRs are individually evaluated for impairment and included in the separately identified impairment disclosures. TDRs are measured at the present value of estimated future cash flows using the loan’s effective rate at inception. If a TDR is considered to be a collateral dependent loan, the loan is reported, net, at the fair value of the collateral less costs to sell. General Component The general component of the allowance for loan losses covers loans that are collectively evaluated for impairment. Large groups of homogeneous loans are collectively evaluated for impairment, and accordingly, they are not included in the separately identified impairment disclosures. The general allowance component also includes loans that are individually identified for impairment evaluation but are not considered impaired. The general component is based on historical loss experience adjusted for current factors. Due to the Company’s limited loss history, the historical loss experience is based on the actual loss history by class of loan for comparable peer institutions. The Company utilized a 37 quarter look-back period as of December 31, 2018. Subsequently, the Company increased its look-back period to a total of 41 quarters and 45 quarters as of December 31, 2019 and 2020, respectively. In the current economic environment, management believes the extension of the look-back period was necessary in order to capture sufficient loss observations to develop a reliable loss estimate of credit losses. This extension of the historical look-back period to capture the historical loss experience of peer banks was applied to all classes and segments of our loan portfolio. The actual loss experience is supplemented with other environmental factors that capture changes in trends, conditions, and other relevant factors that may cause estimated credit losses as of the evaluation date to differ from historical loss experience. The allocation for environmental factors is by nature subjective. These amounts represent estimated probable inherent credit losses, which exist but have not been captured in the historical loss experience. The environmental factors include consideration of the following: changes in lending policies and procedures, economic conditions, nature and volume of the portfolio, experience of lending management, volume and severity of past due loans, quality of the loan review system, value of underlying collateral for collateral dependent loans, concentrations, and other external factors.
Servicing Rights	Servicing Rights When mortgage loans are sold with servicing retained, servicing rights are initially recorded at fair value with the income statement effect recorded in other noninterest income. Fair value is based on market prices for comparable mortgage servicing contracts, when available or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. All classes of servicing assets are subsequently measured using the amortization method which requires servicing rights to be amortized into non-interest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. Servicing rights are evaluated for impairment based upon the fair value of the rights as compared to carrying amount. Impairment is determined by stratifying rights into groupings based on predominant risk characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance for an individual grouping, to the extent that fair value is less than the carrying amount. If the Company later determines that all or a portion of the impairment no longer exists for a particular grouping, a reduction of the allowance may be recorded as an increase to income. Changes in valuation allowances are reported with other noninterest income on the income statement and the associated asset is included in other assets on the Consolidated Balance Sheet. The fair values of servicing rights are subject to significant fluctuations as a result of changes in estimated and actual prepayment speeds and default rates and losses. Servicing fee income, which is reported on the income statement within other noninterest income, is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal; or a fixed amount per loan and are recorded as income when earned. The amortization of mortgage servicing rights is netted against loan servicing fee income. Net servicing fees totaled $148,000, $340,000, and $102,000 for the years ended December 31, 2020, 2019, and 2018 respectively. Impairment charges associated with these servicing rights amounted to $238,000 and $211,000 for the years ended December 31, 2020 and 2019, respectively. There were no impairment charges for the year ended December 31, 2018. Late fees and ancillary fees related to loan servicing are not material.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed principally by the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized by the straight-line method based on the shorter of the asset lives or the expected lease terms. Useful lives for premises and equipment range from one to thirty-nine years. These assets are reviewed for impairment when events indicate their carrying amount may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value.
Leases	Leases In February 2016, the FASB issued a new accounting standard update (ASU 2016-02, Leases (Topic 842)), which requires for all operating leases the recognition of a right-of-use ("ROU") asset and a corresponding lease liability, in the Consolidated Balance Sheet. For short term leases (term of 12 months or less), a lessee is permitted to make an accounting election not to recognize lease assets and lease liabilities. The lease cost will be allocated over the lease term on a straight-line basis. There were further amendments, including practical expedients, with the issuance of ASU 2018-01, “Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842” in January 2018. In July 2018, the FASB issued ASU No. 2018-11, "Leases (Topic 842): Targeted Improvements", which provides for the option to apply the new leasing standard to all open leases as of the adoption date, on a prospective basis. On January 1, 2019, the Company adopted the new accounting standard ASU 2016-02, Leases (Topic 842) and all the related amendments ("new lease standard", "ASC 842" or "ASU 2016-02") utilizing the practical expedient to apply the new lease standard as of January 1, 2019 on a prospective basis. The Company also elected the "package of expedients" and elected as an accounting policy to exclude recording ROU assets and lease liabilities for leases that meet the definition of short-term leases. In addition to excluding short-term leases, the Company has implemented an accounting policy in which non-lease components are not separated from lease components in the measurement of ROU assets and lease liabilities for all lease contracts. The Company recognized $12.8 million in ROU assets and $13.4 million in lease liabilities as a result of applying the new lease standard as an adjustment to the opening consolidated balance sheet on January 1, 2019. The ROU assets and lease liabilities are included in other assets and other liabilities, respectively on the Consolidated Balance Sheet. See Note 7—Leases for additional disclosures related to leases.
Bank Owned Life Insurance	Bank Owned Life Insurance The Bank has purchased life insurance policies on certain key executives. Bank owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement. Bank owned life insurance is included in other assets on the Consolidated Balance Sheet.
Securities Sold under Agreements to Repurchase	Securities Sold under Agreements to Repurchase The Bank enters into sales of securities under agreements to repurchase at a specified future date. Such repurchase agreements are considered financing arrangements and, accordingly, the obligation to repurchase assets sold is reflected as a liability in the balance sheets of the Bank. Repurchase agreements are collateralized by debt securities which are owned and under the control of the Bank and are included in other liabilities on the Consolidated Balance Sheet.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill resulting from business combinations is generally determined as the excess of the fair value of the consideration transferred, plus the fair value of any noncontrolling interests in the acquiree, over the fair value of the net assets acquired and liabilities assumed as of the acquisition date. Goodwill and intangible assets acquired in a purchase business combination and determined to have an indefinite useful life are not amortized, but tested for impairment at least annually or more frequently if events and circumstances exists that indicate that a goodwill impairment test should be performed. Qualitative factors are assessed to first determine if it is more likely than not (more than 50%) that the carrying value of goodwill is less than fair value. At October 31, 2020, as a result of market volatility caused by the COVID-19 pandemic, the company determined it did not satisfy the more likely than not qualitative assessment that the fair value of the reporting unit exceeded its carrying value, including goodwill. As a result, the Company elected to perform a quantitative assessment, which included a combination of quoted market prices of the Company’s stock, prices of comparable businesses, discounted cash flows and other techniques. Based upon the results of the quantitative assessment, we determined the fair value of the reporting unit exceeded the carrying value, resulting in no impairment. Intangible assets with definite useful lives are amortized over their estimated useful lives to their estimated residual values. Goodwill is the only intangible asset with an indefinite life on the balance sheet. Other intangible assets consist of core deposit intangible assets arising from whole bank acquisitions and are amortized on an accelerated method over their estimated useful lives, which range from six to ten years.
Other Real Estate Owned	Other Real Estate Owned Other real estate owned (“OREO”) includes assets that have been acquired in satisfaction of debt through foreclosure and are recorded at estimated fair value less the estimated cost of disposition. Fair value is based on independent appraisals and other relevant factors. Valuation adjustments required at foreclosure are charged to the allowance for loan losses. Subsequent to foreclosure, additional losses resulting from the periodic revaluation of the property are charged to other real estate expense. Costs of operating and maintaining the properties and any gains or losses recognized on disposition are also included in other real estate expense. Improvements made to properties are capitalized if the expenditures are expected to be recovered upon the sale of the properties.
Restricted Equity Securities	Restricted Equity Securities The Bank is a member of the FHLB system. Members are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest additional amounts. FHLB stock is carried at cost, classified as a restricted equity security, and periodically evaluated for impairment based on an assessment of the ultimate recovery of par value. Both cash and stock dividends are reported as interest income. The Bank is also a member of the Federal Reserve System, and as such, holds stock of the Federal Reserve Bank of Atlanta (“Federal Reserve Bank”). Federal Reserve Bank stock is carried at cost, classified as a restricted equity security, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as interest income.
Income Taxes	Income Taxes Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company’s tax returns remain open to audit under the statute of limitations by the IRS and various states for the years ended December 31, 2017 through 2020. It is the Company’s policy to recognize interest and/or penalties related to income tax matters in income tax expense.
Share-Based Compensation	Stock-Based Compensation Stock-based compensation expense is recognized based on the fair value of the portion of stock-based payment awards that are ultimately expected to vest, reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods, if actual forfeitures differ from those estimates. A Black-Scholes model is utilized to estimate the fair value of stock options, while the market price of the Company’s common stock at the date of grant is used for restricted stock awards. Compensation expense is recognized over the required service period, generally defined as the vesting period. For awards with graded vesting, compensation expense is recognized on a straight-line basis over the requisite service period for the entire award. For awards with performance vesting criteria, anticipated performance is projected to determine the number of awards expected to vest, and the corresponding aggregate expense is adjusted to reflect the elapsed portion of the performance period.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred. Advertising expense was approximately $400,000, $370,000 and $383,000 for the years ended December 31, 2020, 2019 and 2018, respectively and is included in other operating expenses on the Consolidated Statements of Income.
Off-Balance Sheet Financial Instruments	Off-Balance Sheet Financial Instruments In the ordinary course of business, the Bank has entered into off-balance-sheet financial instruments consisting of commitments to extend credit and standby letters of credit. Such financial instruments are recorded in the financial statements when they are funded or related fees are incurred or received.
Derivative Instruments	Derivative Instruments Derivative instruments are recorded on the balance sheet at their respective fair values. The accounting for changes in fair value (i.e., gains or losses) of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship. If the derivative instrument is not designated as a hedge, the gain or loss on the derivative instrument is recognized in earnings in the period of change. The Bank enters into interest rate swaps (“swaps”) to facilitate customer transactions and meet their financing needs. Upon entering into these arrangements to meet customer needs, the Bank enters into offsetting positions with large U.S. financial institutions in order to minimize market risk to the Bank. These swaps are derivatives, but are not designated as hedging instruments. The Bank may also utilize cash flow hedges to manage its future interest rate exposure. These derivative contracts are designated as hedges and, as such, changes in the fair value of these derivative instruments are recorded in other comprehensive income (loss). The Bank prepares written hedge documentation for all derivatives which are designated as hedges. The written hedge documentation includes identification of, among other items, the risk management objective, hedging instrument, hedged item and methodologies for assessing and measuring hedge effectiveness and ineffectiveness, along with support for management’s assertion that the hedge will be highly effective. The effective portion of the changes in the fair value of a derivative that is highly effective and that has been designated and qualifies as a cash flow hedge are initially recorded in accumulated other comprehensive income (loss) and subsequently reclassified into earnings in the same period during which the hedged item affects earnings. The ineffective portion, if any, would be recognized in current period earnings. The Bank discontinues hedge accounting when it determines that the derivative is no longer effective in offsetting changes in the cash flows of the hedged item, the derivative is settled or terminates, or treatment of the derivative as a hedge is no longer appropriate or intended. When hedge accounting is discontinued, subsequent changes in fair value of the derivative are recorded as non-interest income. When a cash flow hedge is discontinued but the hedged cash flows or forecasted transactions are still expected to occur, gains or losses that were accumulated in other comprehensive income (loss) are amortized into earnings over the same periods which the hedged transactions will affect earnings. Cash flows resulting from the derivative financial instruments that are accounted for as hedges are classified in the cash flow statement in the same category as the cash flows of the items being hedged. Commitments to fund mortgage loans “interest rate locks” to be sold into the secondary market and forward commitments for the sale of mortgage-backed securities are accounted for as free standing derivatives. The fair value of the interest rate lock is recorded at the time the commitment to fund the mortgage loan is executed and is adjusted for the expected exercise of the commitment before the loan is funded. Fair values of these mortgage derivatives are estimated based on changes in mortgage interest rates from the date the interest rate on the loan is locked. The Company enters into forward commitments for the sale of mortgage-backed securities when interest rate locks are entered into, in order to hedge the change in interest rates resulting from its commitments to fund the loans. Changes in the fair values of these derivatives are included in mortgage banking income.
Comprehensive Income	Comprehensive Income Comprehensive income consists of net income and other comprehensive income (loss). Other comprehensive income includes unrealized gains and losses on securities available for sale, unrealized gains and losses on securities transferred to held to maturity and unrealized gains and losses on cash flow hedges which are also recognized as separate components of equity. The Bank’s policy is to release the income tax effects of items in accumulated other comprehensive income (loss) when the item is realized.
Fair Value Measurements	Fair Value Measurements Fair values of financial instruments are estimated using relevant market information and other assumptions, as more fully disclosed in a separate note. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect these estimates.
Restriction on Cash Balances	Restriction on Cash Balances Regulation D of the Federal Reserve Act requires that banks maintain reserve balances with their applicable Federal Reserve Bank based principally on the type and amount of their deposits. On March 15, 2020, the Board of the Federal Reserve reduced reserve requirement ratios to zero percent effective March 26, 2020. This action eliminated reserve requirements for all depository institutions. The Bank was required to have a reserve balance of $73,444,000 at December 31, 2019. The reserve balance that the Bank must maintain at the Federal Reserve Bank of Atlanta is included in interest-bearing deposits in financial institutions as of December 31, 2019.
Subsequent Events	Subsequent Events The Company has evaluated subsequent events for recognition and disclosure through March 5, 2021, which is the date the financial statements were available to be issued.
Income Per Common Share	Income Per Common Share Basic net income per share available to common stockholders (“EPS”) is computed by dividing net income available to common stockholders by the weighted average shares of common stock outstanding for the period. Diluted EPS reflects the dilution that could occur if securities or other contracts to issue common stock were exercised or converted. The difference between basic and diluted weighted average shares outstanding is attributable to convertible preferred stock, common stock options and warrants. The dilutive effect of outstanding convertible preferred stock, common stock options and warrants is reflected in diluted EPS by application of the treasury stock method. No antidilutive stock options were excluded from calculation for the years ended December 31, 2020, 2019 or December 31, 2018. The following is a summary of the basic and diluted earnings per share calculation for each of the following years (in thousands except share data): Year Ended December 31, 2020 2019 2018 Basic net income per share calculation: Numerator – Net income $ 24,696 $ 22,422 $ 9,655 Denominator – Average common shares outstanding 20,162,038 17,886,164 13,277,614 Basic net income per share $ 1.22 $ 1.25 $ 0.73 Diluted net income per share calculation: Numerator – Net income $ 24,696 $ 22,422 $ 9,655 Denominator – Average common shares outstanding 20,162,038 17,886,164 13,277,614 Dilutive shares contingently issuable 23,551 727,060 1,202,733 Average diluted common shares outstanding 20,185,589 18,613,224 14,480,347 Diluted net income per share $ 1.22 $ 1.20 $ 0.67
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements ASU 2014-09, Revenue from Contracts with Customers In May 2014, the FASB issued guidance to change the recognition of revenue from contracts with customers. The core principle of the new guidance is that an entity should recognize revenue to reflect the transfer of goods and services to customers in an amount equal to the consideration the entity receives or expects to receive. The guidance was effective for the Company for reporting periods beginning after December 15, 2017. The Company applied the guidance using a modified retrospective approach. The Company's revenue is comprised of net interest income and noninterest income. The scope of the guidance explicitly excludes net interest income as well as many other revenues for financial assets and liabilities including loans, leases, securities, and derivatives. Accordingly, the majority of our revenues will not be affected. The Company performed an assessment of our revenue contracts related to revenue streams that are within the scope of the standard. Our accounting policies did not change materially since the principles of revenue recognition from the ASU were largely consistent with existing guidance and current practices applied by our businesses. We did not identify material changes to the timing or amount of revenue recognition. The Company records revenue from contracts with customers in accordance with Accounting Standards Codification Topic 606, “Revenue from Contracts with Customers” (“Topic 606”). Under Topic 606, the Company must identify the contract with a customer, identify the performance obligations in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize revenue when (or as) the Company satisfies a performance obligation. Significant revenue has not been recognized in the current reporting period that results from performance obligations satisfied in previous periods. The Company’s primary sources of revenue are derived from interest and dividends earned on loans, investment securities, and other financial instruments that are not within the scope of Topic 606. The Company evaluated the nature of its contracts with customers and determined that further disaggregation of revenue from contracts with customers into more granular categories beyond what is presented in the Consolidated Statements of Income was not necessary. The Company generally fully satisfies its performance obligations on its contracts with customers as services are rendered and the transaction prices are typically fixed; charged either on a periodic basis or based on activity. Our accounting policies did not change materially since the principles of revenue recognition f ro m the Accounting Standards Update were largely consistent with existing guidance and current practices applied by our business. A description of the Company’s revenue streams accounted for under Topic 606 follows: Treasury management and other deposit service charges: The Company earns fees from its deposit customers for transaction based, account maintenance, and overdraft services. Transaction based fees are recognized at the time the transaction is executed as that is the point in time the Company fulfills the customer’s request. Account maintenance fees are earned over the course of a month, representing the period over which the Company satisfies its performance obligation. Overdraft fees are recognized at the point in time that the overdraft occurs. Service charges on deposits are withdrawn from the customer’s account balance. Interchange income: Included in other noninterest income are interchange fees, which the Company earns from debit cardholder transactions conducted through various payment networks. Interchange fees from cardholder transactions represent a percentage of the underlying transaction value and are recognized daily, concurrently with the transaction processing series provided to the cardholder. Gains/Losses on Sales of OREO: The Company records a gain or loss from the sale of OREO when control of the property transfers to the buyer, which generally occurs at the time of an executed deed. When the Company finances the sale of OREO to the buyer, the Company assesses whether the buyer is committed to perform their obligation under the contract and whether collectability of the transaction price is probable. Once these criteria are met, the OREO asset is derecognized and the gain or loss on sale is recorded upon the transfer of control of the property to the buyer. In determining the gain or loss on the sale, the Company adjusts the transaction price and related gain (loss) on sale if a significant financing component is present. ASU 2016-02, Leases In February 2016, the FASB amended the Leases topic of the Accounting Standards Codification to revise certain aspects of recognition, measurement, presentation, and disclosure of leasing transactions. The amendments were effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted the guidance using the modified retrospective method and practical expedients for transition. The practical expedients allow the Company to largely account for our existing leases consistent with current guidance except for the incremental balance sheet recognition for lessees. The Company evaluated the new guidance and its impact on the Company’s financial statements. Based on leases outstanding at December 31, 2018, the impact of adoption on January 1, 2019 was recording a lease liability of approximately $13.4 million, a right-of-use asset of approximately $12.8 million, and elimination of deferred rent of approximately $0.6 million. ASU 2016-13, Financial Instruments – Credit Losses In June 2016, the FASB issued guidance to change the accounting for credit losses and modify the impairment model for certain debt securities. The amendments were originally supposed to be effective for the Company for reporting periods beginning after December 15, 2019 with early adoption permitted for all organizations for periods beginning after December 15, 2018. However, in November 2019, the FASB issued ASU 2019-10, Financial Instruments — Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates ASU 2017-04, Simplifying the Test of Goodwill Impairment In January 2017, the FASB amended the Goodwill and Other Topic of the Accounting Standards Codification to simplify the accounting for goodwill impairment for public business entities and other entities that have goodwill reported in their financial statements and have not elected the private company alternative for the subsequent measurement of goodwill. The amendment removes Step 2 of the goodwill impairment test. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The effective date and transition requirements for the technical corrections were effective for the Company for reporting periods beginning after December 15, 2019. These amendments did not have a material effect on the Company’s financial statements. ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities In August 2017, the FASB amended the requirements of the Derivatives and Hedging Topic of the Accounting Standards Codification to improve the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. The amendments were effective for the Company for interim and annual periods beginning after December 15, 2018. Early adoption was permitted. The Company adopted this standard December 1, 2017. There was no material effect on the financial statements. ASU 2018-07, Compensation – Stock Compensation In June 2018, the FASB amended the Compensation—Stock Compensation Topic of the Accounting Standards Codification. The amendments expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The guidance was effective for the Company for reporting periods beginning after December 15, 2018. There was no material effect on the financial statements. ASU 2019-04 ― Applicable to entities that hold financial instruments: In April 2019, the FASB issued guidance that clarifies and improves areas of guidance related to the recently issued standards on credit losses, hedging, and recognition and measurement of financial instruments. The amendments related to credit losses were effective for the Company for reporting periods beginning after December 15, 2019. The amendments related to hedging were effective for the Company for interim and annual periods beginning after December 15, 2018. The amendments related to recognition and measurement of financial instruments were effective for the Company for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. These amendments did not have a material effect on the financial statements. ASU 2019-05 ― Applicable to entities that hold financial instruments: In May 2019, the FASB issued guidance to provide entities with an option to irrevocably elect the fair value option, applied on an instrument-by-instrument basis for eligible instruments, upon adoption of ASU 2016-13, Measurement of Credit Losses on Financial Instruments. The amendments will be effective for the Company upon adoption of ASU 2016-13 in fiscal year 2023. The Company does not expect these amendments to have a material effect on its financial statements. ASU 2019-12 ― Applicable to entities within the scope of Topic 740, Income Taxes: In December 2019, the FASB issued guidance to simplify accounting for income taxes by removing specific technical exceptions that often produce information investors have a hard time understanding. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The amendments are effective for fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Early adoption is permitted. The Company does not expect these amendments to have a material effect on its financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Difference Between the Fair Value and Aggregate Unpaid Principal Balance	The following table summarizes the difference between the fair value and the aggregate unpaid principal balance for residential real estate loans held for sale as of December 31, 2020 and 2019 (dollars in thousands): Fair Value Aggregate Unpaid Principal Balance Difference December 31, 2020 Residential mortgage loans held for sale $ 97,303 $ 94,248 $ 3,055 December 31, 2019 Residential mortgage loans held for sale 30,740 30,178 562
Summary of the Basic and Diluted Earnings Per Share	The following is a summary of the basic and diluted earnings per share calculation for each of the following years (in thousands except share data): Year Ended December 31, 2020 2019 2018 Basic net income per share calculation: Numerator – Net income $ 24,696 $ 22,422 $ 9,655 Denominator – Average common shares outstanding 20,162,038 17,886,164 13,277,614 Basic net income per share $ 1.22 $ 1.25 $ 0.73 Diluted net income per share calculation: Numerator – Net income $ 24,696 $ 22,422 $ 9,655 Denominator – Average common shares outstanding 20,162,038 17,886,164 13,277,614 Dilutive shares contingently issuable 23,551 727,060 1,202,733 Average diluted common shares outstanding 20,185,589 18,613,224 14,480,347 Diluted net income per share $ 1.22 $ 1.20 $ 0.67

Acquisition (Tables)

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Consideration Paid and Amounts of Assets Acquired and Liabilities Assumed	The following table summarizes the consideration paid for the Mergers and the amounts of the assets acquired and liabilities assumed recognized at the acquisition date (in thousands). As recorded by FCB Corporation and BOW Initial fair value adjustments Measurement period adjustments As recorded by CapStar Financial Holdings Assets: Cash and cash equivalents $ 90,760 $ — $ — $ 90,760 Securities 98,536 159 (a) — 98,695 Loans, gross 296,992 (2,318 ) (b) — 294,674 Allowance for loan losses (4,544 ) 4,544 (c) — — Premises and equipment, net 9,907 1,540 (d) — 11,447 Core deposit intangible — 3,570 (e) — 3,570 Other 16,514 (917 ) (f) — 15,597 Total $ 508,165 $ 6,578 $ — $ 514,743 Liabilities: Deposits $ 440,025 $ 2,652 (g) $ — $ 442,677 Other 4,735 — — 4,735 Total $ 444,760 $ 2,652 $ — $ 447,412 Net identifiable assets acquired $ 67,331 Total cost of acquisition: Value of stock issued $ 43,611 Cash consideration paid 27,278 Total cost of acquisition $ 70,889 Goodwill recorded related to acquisition $ 3,558 (a) The amount represents the fair value adjustment of securities that were subsequently sold. (b) The amount represents the adjustment of the net book value of the acquired loans to their estimated fair value based on interest rates and expected cash flows at the date of acquisition. (c) The amount represents the removal of FCB and BOW’s existing allowance for loan losses. (d) The amount represents the adjustment of the net book value of acquired premises and equipment to their estimated fair value. (e) The amount represents the adjustment of recording the fair value of the core deposit intangible representing the intangible value of the deposit base acquired and the fair value of the customer relationship. (f) The amount represents the net adjustment of the deferred tax asset recognized on the fair value adjustments on acquired assets and assumed liabilities. (g) The amount represents the adjustment necessary because the weighted average interest rate of acquired time deposits exceeded the cost of similar funding at the time of acquisition. The fair value adjustment will be amortized to reduce future interest expense over the life of the portfolio.
Schedule of Unaudited Pro Forma Financial Information	The following unaudited pro forma financial information presents the combined results of the Company, FCB and BOW as if the acquisition had occurred as of January 1, 2019, after giving effect to certain adjustments, including amortization of the core deposit intangible, and related income tax effects. The pro forma financial information does not necessarily reflect the results of operations that would have occurred had the Company, FCB and BOW constituted a single entity during such periods (in thousands, except share data): Pro forma combined twelve months ended December 31, 2020 Pro forma combined twelve months ended December 31, 2019 Net interest income $ 73,571 $ 87,523 Noninterest income 44,453 27,375 Total revenue 118,024 114,898 Net income 25,927 28,989 Per share information: Basic net income per share of common stock $ 1.29 $ 1.35 Diluted net income per share of common stock $ 1.28 $ 1.30

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Summary of Company's Classification of Securities	The Company’s classification of securities at December 31, 2020 and 2019 was as follows (in thousands): December 31, 2020 December 31, 2019 Amortized Cost Gross unrealized gains Gross unrealized (losses) Estimated fair value Amortized Cost Gross unrealized gains Gross unrealized (losses) Estimated fair value Securities available-for-sale: U. S. government agency securities $ 16,158 $ 258 $ (25 ) $ 16,391 $ 10,421 $ 4 $ (94 ) $ 10,331 State and municipal securities 89,081 2,928 (81 ) 91,928 44,053 1,927 (20 ) 45,960 Mortgage-backed securities 332,014 4,892 (543 ) 336,363 137,305 1,834 (460 ) 138,679 Asset-backed securities 3,325 — (132 ) 3,193 3,325 — (128 ) 3,197 Other debt securities 37,608 819 (87 ) 38,340 14,839 141 (18 ) 14,962 Total $ 478,186 $ 8,897 $ (868 ) $ 486,215 $ 209,943 $ 3,906 $ (720 ) $ 213,129 Securities held-to-maturity: State and municipal securities $ 2,407 $ 97 $ — $ 2,504 $ 3,313 $ 98 $ — $ 3,411 Total $ 2,407 $ 97 $ — $ 2,504 $ 3,313 $ 98 $ — $ 3,411
Summary of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	The amortized cost and fair value of debt and equity securities at December 31, 2020, by contractual maturity, are shown below (in thousands). Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. Available-for-sale Held-to-maturity Amortized cost Estimated fair value Amortized cost Estimated fair value Due in less than one year $ 13,611 $ 13,708 $ 600 $ 609 Due one to five years 49,584 50,889 1,807 1,895 Due five to ten years 78,024 80,437 — — Due beyond ten years 1,639 1,627 — — Mortgage-backed securities 332,014 336,363 — — Asset-backed securities 3,314 3,191 — — $ 478,186 $ 486,215 $ 2,407 $ 2,504
Summary of Sale of Debt and Equity Securities	Results from sales of debt and equity securities were as follows (in thousands): Year ended December 31 2020 2019 2018 Proceeds $ 78,385 $ 68,068 $ 38,322 Gross gains 148 49 116 Gross losses (23 ) (148 ) (113 )
Summary of Securities with Unrealized Losses Aggregated by Major Security Type and Length of Time Continuous Unrealized Loss Position	The following tables show the Company’s securities with unrealized losses, aggregated by major security type and length of time in a continuous unrealized loss position (in thousands): Less than 12 months 12 months or more Total December 31, 2020 Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses U. S. government agency securities $ — $ — $ — $ — $ — $ — State and municipal securities 10,463 (80 ) — — 10,463 (80 ) Mortgage-backed securities 102,280 (505 ) 1,449 (63 ) 103,729 (568 ) Asset-backed securities — — 3,193 (133 ) 3,193 (133 ) Other debt securities 6,103 (87 ) — — 6,103 (87 ) Total temporarily impaired securities $ 118,846 $ (672 ) $ 4,642 $ (196 ) $ 123,488 $ (868 ) December 31, 2019 U. S. government agency securities $ 6,694 $ (51 ) $ 1,637 $ (43 ) $ 8,331 $ (94 ) State and municipal securities 2,356 (12 ) 814 (8 ) 3,170 (20 ) Mortgage-backed securities 30,570 (136 ) 21,364 (324 ) 51,934 (460 ) Asset-backed securities — — 3,197 (128 ) 3,197 (128 ) Other debt securities 3,012 (16 ) 1,502 (2 ) 4,514 (18 ) Total temporarily impaired securities $ 42,632 $ (215 ) $ 28,514 $ (505 ) $ 71,146 $ (720 )

Loans and Allowance for Loan _2

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Summary of Loans	Loans at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Commercial real estate $ 643,832 $ 559,899 Consumer real estate 343,791 256,097 Construction and land development 174,859 143,111 Commercial and industrial 630,775 394,408 Consumer 44,279 28,426 Other 53,483 38,161 Total 1,891,019 1,420,102 Allowance for loan losses (23,245 ) (12,604 ) Total loans, net $ 1,867,774 $ 1,407,498
Summary of Risk Category of Loans by Applicable Class of Loans	The following table provides the risk category of loans by applicable class of loans as of December 31, 2020 and 2019 (in thousands): Non-impaired Loans December 31, 2020 Pass Special Mention Substandard Doubtful Total Loans Total Commercial real estate $ 601,133 $ 33,046 $ 2,933 $ — $ 1,179 $ 638,291 Consumer real estate 323,072 1,375 1,122 — 1,707 327,276 Construction and land development 169,315 5,153 19 — 102 174,589 Commercial and industrial 576,096 25,855 25,666 — 168 627,785 Consumer 41,640 4 18 2 7 41,671 Other 52,949 — 66 — — 53,015 Purchased Credit Impaired 23,899 — 4,412 81 — 28,392 Total $ 1,788,104 $ 65,433 $ 34,236 $ 83 $ 3,163 $ 1,891,019 December 31, 2019 Commercial real estate $ 551,929 $ 915 $ 4,438 $ — $ 2,507 $ 559,789 Consumer real estate 252,952 503 1,551 — 483 255,489 Construction and land development 142,978 — 16 — 112 143,106 Commercial and industrial 370,475 14,341 8,241 — 487 393,544 Consumer 28,382 6 15 — 5 28,408 Other 38,161 — — — — 38,161 Purchased Credit Impaired — — 1,605 — — 1,605 Total $ 1,384,877 $ 15,765 $ 15,866 $ — $ 3,594 $ 1,420,102
Summary of Changes and Breakdown of Allowance for Loan Losses and Loan Portfolio by Loan Category	The following tables detail the changes in the ALL for the years ending December 31, 2020, 2019 and 2018 by loan classification (in thousands): Commercial real estate Consumer real estate Construction and land development Commercial and industrial Consumer Other Total Year ended December 31, 2020 Balance, beginning of period $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Charged-off loans — (49 ) — (728 ) (172 ) (277 ) (1,226 ) Recoveries 10 14 — 235 76 53 388 Provision for loan losses 3,740 635 1,418 5,127 179 380 11,479 Balance, end of period $ 7,349 $ 1,831 $ 3,476 $ 9,708 $ 305 $ 576 $ 23,245 Year ended December 31, 2019 Balance, beginning of period $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 Charged-off loans — (39 ) — (455 ) (164 ) (140 ) (798 ) Recoveries 23 20 — 380 82 23 528 Provision for loan losses 267 245 (373 ) 113 199 310 761 Balance, end of period $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Year ended December 31, 2018 Balance, beginning of period $ 3,324 $ 1,063 $ 1,628 $ 7,209 $ 91 $ 406 $ 13,721 Charged-off loans — — — (4,831 ) (84 ) (39 ) (4,954 ) Recoveries 22 4 — 395 75 8 504 Provision for loan losses (37 ) (62 ) 803 2,263 23 (148 ) 2,842 Balance, end of period $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 A breakdown of the ALL and the loan portfolio by loan category at December 31, 2020 and 2019 follows (in thousands): Commercial real estate Consumer real estate Construction and land development Commercial and industrial Consumer Other Total December 31, 2020 Allowance for Loan Losses: Collectively evaluated for impairment $ 7,349 $ 1,831 $ 3,410 $ 9,708 $ 305 $ 576 $ 23,179 Individually evaluated for impairment — — 66 — — — 66 Purchased credit impaired — — — — — — — Balances, end of period $ 7,349 $ 1,831 $ 3,476 $ 9,708 $ 305 $ 576 $ 23,245 Loans: Collectively evaluated for impairment $ 637,112 $ 325,569 $ 174,487 $ 627,617 $ 41,664 $ 53,015 $ 1,859,464 Individually evaluated for impairment 1,179 1,707 102 168 7 — 3,163 Purchased credit impaired 5,541 16,515 270 2,990 2,608 468 28,392 Balances, end of period $ 643,832 $ 343,791 $ 174,859 $ 630,775 $ 44,279 $ 53,483 $ 1,891,019 December 31, 2019 Allowance for Loan Losses: Collectively evaluated for impairment $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Individually evaluated for impairment — — — — — — — Purchased credit impaired — — — — — — — Balances, end of period $ 3,599 $ 1,231 $ 2,058 $ 5,074 $ 222 $ 420 $ 12,604 Loans: Collectively evaluated for impairment $ 557,282 $ 255,006 $ 142,994 $ 393,057 $ 28,403 $ 38,161 $ 1,414,903 Individually evaluated for impairment 2,507 483 112 487 5 — 3,594 Purchased credit impaired 110 608 5 864 18 — 1,605 Balances, end of period $ 559,899 $ 256,097 $ 143,111 $ 394,408 $ 28,426 $ 38,161 $ 1,420,102
Allocation of ALL with Corresponding Percentage of Loans in Each Category to Total Loans, Net of Deferred Fee	The following table presents the allocation of the ALL for each respective loan category with the corresponding percentage of loans in each category to total loans, net of deferred fees as of December 31, 2020 and 2019. PPP loans included in commercial and industrial loans in the below table do not have a corresponding ALL as they are fully guaranteed by the SBA December 31, 2020 December 31, 2019 Amount Percent of total loans Amount Percent of total loans Commercial real estate $ 7,349 0.39 % $ 3,599 0.25 % Consumer real estate 1,831 0.10 % 1,231 0.09 % Construction and land development 3,476 0.18 % 2,058 0.14 % Commercial and industrial 9,708 0.51 % 5,074 0.36 % Consumer 305 0.02 % 222 0.02 % Other 576 0.03 % 420 0.03 % Total allowance for loan and lease losses $ 23,245 1.23 % $ 12,604 0.89 %
Summary of Information Related to Impaired Loans Excluding Purchased Credit Impaired (PCI) Loans	The following table presents information related to impaired loans, excluding purchased credit impaired (“PCI”) loans, December 31, 2020 December 31, 2019 Recorded investment Unpaid principal balance Related allowance Recorded investment Unpaid principal balance Related allowance With no related allowance recorded: Commercial real estate $ 1,179 $ 1,176 $ — $ 2,507 $ 2,446 $ — Consumer real estate 1,707 1,608 — 483 497 — Construction and land development — — — 112 117 — Commercial and industrial 168 457 — 487 710 — Consumer 7 7 — 5 5 — Other — — — — — — Subtotal 3,061 3,248 — 3,594 3,775 — With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development 102 102 66 — — — Commercial and industrial — — — — — — Consumer — — — — — — Other — — — — — — Subtotal 102 102 66 — — — Total $ 3,163 $ 3,350 $ 66 $ 3,594 $ 3,775 $ — The following table presents information related to the average recorded investment and interest income recognized on impaired loans, excluding PCI loans, for the years ended December 31, 2020, 2019 and 2018 (in thousands): Year Ended Year Ended Year Ended December 31, 2020 December 31, 2019 December 31, 2018 Average recorded investment Interest income recognized Average recorded investment Interest income recognized Average recorded investment Interest income recognized With no related allowance recorded: Commercial real estate $ 1,198 $ 66 $ 2,574 $ 313 $ 1,198 $ 158 Consumer real estate 1,975 66 1,037 105 185 — Construction and land development — — 119 4 94 2 Commercial and industrial 121 1 824 440 5,557 121 Consumer 8 — 23 2 7 — Other — — — — — — Subtotal 3,302 133 4,577 864 7,041 281 With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development 107 — — — — — Commercial and industrial — — — — — — Consumer — — — — — — Other — — — — — — Subtotal 107 — — — — — Total $ 3,409 $ 133 $ 4,577 $ 864 $ 7,041 $ 281
Schedule of Aging of Recorded Investment in Past-due Loans, by Class of Loans	The following table presents the aging of the recorded investment in past-due loans as of December 31, 2020 and 2019 by class of loans (in thousands): 30 - 59 60 - 89 Greater Than Days Days 89 Days Total Loans Not December 31, 2020 Past Due Past Due Past Due Past Due Past Due Total Commercial real estate $ 409 $ — $ 1,176 $ 1,585 $ 636,706 $ 638,291 Consumer real estate 6,084 1,596 687 8,367 318,909 327,276 Construction and land development 2,670 745 — 3,415 171,174 174,589 Commercial and industrial 1,734 38 1,595 3,367 624,418 627,785 Consumer 270 40 7 317 41,354 41,671 Other 252 38 — 290 52,725 53,015 Purchased credit impaired 1,372 1,554 901 3,827 24,565 28,392 Total $ 12,791 $ 4,011 $ 4,366 $ 21,168 $ 1,869,851 $ 1,891,019 December 31, 2019 Commercial real estate $ 372 $ — $ — $ 372 $ 559,417 $ 559,789 Consumer real estate 3,567 408 501 4,476 251,013 255,489 Construction and land development 653 — — 653 142,453 143,106 Commercial and industrial 1,277 8 440 1,725 391,819 393,544 Consumer 67 — 26 93 28,315 28,408 Other — — — — 38,161 38,161 Purchased credit impaired 75 81 149 305 1,300 1,605 Total $ 6,011 $ 497 $ 1,116 $ 7,624 $ 1,412,478 $ 1,420,102
Schedule of Non-Accrual Loans, Past Due Loans over 89 Days and Accruing and Troubled Debt Restructurings by Class of Loans	The following table presents the recorded investment in non-accrual loans, past due loans over 89 days and accruing and troubled debt restructurings by class of loans as of December 31, 2020 and 2019 (in thousands): Past Due Over 89 Days Troubled Debt Non-Accrual and Accruing Restructurings December 31, 2020 Commercial real estate $ 130 $ 1,176 $ 1,928 Consumer real estate 1,821 342 — Construction and land development 107 — — Commercial and industrial 470 1,205 — Consumer 9 5 — Other — — — Purchased credit impaired 2,279 567 — Total $ 4,816 $ 3,295 $ 1,928 December 31, 2019 Commercial real estate $ — $ — $ 2,446 Consumer real estate 292 12 — Construction and land development 102 — — Commercial and industrial 427 — 271 Consumer — 26 — Other — — — Purchased credit impaired 643 — — Total $ 1,464 $ 38 $ 2,717
Schedule of Loans by Class Modified as TDR	The following table presents loans by class modified as TDR that occurred during the years ended December 31, 2020 and December 31, 2019 (in thousands). Year Ended December 31, 2020 Number of contracts Pre modification outstanding recorded investment Post modification outstanding recorded investment, net of related allowance 2020 Commercial real estate — $ — $ — Consumer real estate 2 721 685 Construction and land development — — — Commercial and industrial — — — Consumer — — — Other — — — Total 2 $ 721 $ 685 2019 Commercial real estate 1 $ 1,228 $ 1,228 Consumer real estate — — — Construction and land development — — — Commercial and industrial 1 271 271 Consumer — — — Other — — — Total 2 $ 1,499 $ 1,499
Summary of Contractually Required Payments for FCB and BOW Mergers Expected at Acquisition Date	The following table relates to acquired FCB and BOW PCI loans and summarizes the contractually required payments, which includes principal and interest, expected cash flows to be collected, and the fair value of acquired PCI loans at the acquisition date (in thousands): FCB and BOW acquired on July 1, 2020 Contractually required payments $ 42,443 Nonaccretable difference 4,501 Cash flows expected to be collected at acquisition 37,942 Accretable yield 4,349 Fair value of PCI loans at acquisition date $ 33,593
Summary of Contractually Required Payments for FCB and BOW Mergers Not Expected at Acquisition Date	The following table relates to acquired FCB and BOW purchased non-impaired loans and provides the contractually required payments, fair value, and estimate of contractual cash flows not expected to be collected at the acquisition date (in thousands): FCB and BOW acquired on July 1, 2020 Contractually required payments $ 296,527 Fair value of acquired loans at acquisition date 260,701 Contractual cash flows not expected to be collected 3,718
Schedule of Activity in Purchased Credit Impaired Loans	The following table presents changes in the carrying value of PCI loans (in thousands): For the year ended December 31, 2020 Balance at beginning of period $ 1,605 Additions due to the acquisitions 33,593 Change due to payments received and accretion (6,806 ) Balance at end of period $ 28,392 The following table presents changes in the accretable yield for PCI loans (in thousands): For the year ended December 31, 2020 Balance at beginning of period $ 915 Additions due to the acquisitions 4,349 Accretion (1,196 ) Balance at end of period $ 4,068
Schedule of Components of Direct Financing Leases	The components of the direct financing leases as of December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Total minimum lease payments receivable $ — $ 59 Less: — Unearned income — (1 ) Net leases $ — $ 58

Loan Servicing (Tables)

Loan Servicing (Tables)	12 Months Ended
	Dec. 31, 2020
Transfers And Servicing [Abstract]
Schedule of Activity for Loan Servicing Rights and Related Valuation Allowance	Activity for loan servicing rights and the related valuation allowance are summarized as follows (in thousands): For the year ended December 31, 2020 For the year ended December 31, 2019 Loan servicing rights: Balance at beginning of period $ 1,755 $ 1,736 Additions 466 381 Amortized to offset other noninterest income (587 ) (362 ) Balance at end of period $ 1,634 $ 1,755 Valuation allowance: Balance at beginning of period $ (211 ) $ — Additions expensed — — Reductions credited to other noninterest income — — Direct write-downs (238 ) (211 ) Balance at end of period $ (449 ) $ (211 )

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Summary of Premises and Equipment	Premises and equipment at December 31, 2020 and 2019 are summarized as follows (in thousands): Range of useful lives December 31, 2020 December 31, 2019 Land Not applicable $ 6,885 $ 4,303 Buildings 39 years 19,461 13,331 Leasehold improvements 1 to 17 years 939 939 Furniture and equipment 1 to 7 years 6,910 4,633 Fixed assets in process Not applicable 1,995 — 36,190 23,206 Less accumulated depreciation and amortization (9,501 ) (4,022 ) $ 26,689 $ 19,184

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Summary of Lease Costs	Lease costs were as follows (in thousands): December 31, 2020 December 31, 2019 Operating lease cost $ 1,946 $ 1,868 Short-term lease cost — — Variable lease cost — — Total lease cost $ 1,946 $ 1,868
Maturity Analysis of Operating Lease Liabilities and Reconciliation of Undiscounted Cash Flows	A maturity analysis of operating lease liabilities and reconciliation of the undiscounted cash flows to the total operating lease liability is as follows (in thousands): December 31, 2020 Lease payments due: 2021 $ 1,726 2022 1,605 2023 1,558 2024 1,266 2025 1,234 2026 and thereafter 6,581 Total undiscounted cash flows 13,970 Discount on cash flows (2,030 ) Total lease liability $ 11,940

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Change in Goodwill	The change in goodwill during the years ended December 31, 2020 and 2019 was as follows (in thousands): 2020 2019 Beginning of year $ 37,510 $ 37,510 Acquired goodwill 3,558 — Impairment — — End of year $ 41,068 $ 37,510
Summary of Acquired Intangible Assets	Acquired intangible assets at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets: Core deposit intangibles $ 12,837 $ (4,207 ) $ 9,267 $ (2,384 )
Summary of Estimated Amortization Expense	Estimated amortization expense for each of the next five years is as follows (in thousands): Year ending December 31: 2021 $ 1,939 2022 1,690 2023 1,441 2024 1,192 2025 943 Thereafter 1,425 Total $ 8,630

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2020
Other Real Estate [Abstract]
Summary of Other Real Estate Owned Activity	Other real estate owned activity was as follows (in thousands): 2020 2019 2018 Beginning balance $ 1,044 $ 988 $ — Additions due to acquisitions 571 — 988 Loans transferred to other real estate owned 452 180 — Direct write-downs — — — Sales of other real estate owned (1,544 ) (124 ) — End of year $ 523 $ 1,044 $ 988
Summary of Expenses Related to Other Real Estate Owned	Expenses related to other real estate owned during the years ended December 31, 2020, 2019 and 2018, respectively include (in thousands): 2020 2019 2018 Net gain on sales $ (273 ) $ (3 ) $ — Provision for unrealized losses — — — Operating expenses, net of rental income — — — Total $ (273 ) $ (3 ) $ —

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2020
Deposits [Abstract]
Scheduled Maturities of Time Deposits	Scheduled maturities of time deposits for the next five years and thereafter are as follows (in thousands): Maturity: 2021 $ 377,164 2022 51,160 2023 20,136 2024 13,753 2025 6,702 Thereafter 613 $ 469,528

Short-Term Borrowings and Lon_2

Short-Term Borrowings and Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Federal Home Loan Banks [Abstract]
Summary of Contractual Maturities and Average Effective Rates of Outstanding Advances	The following is a summary of the contractual maturities and average effective rates of outstanding advances (dollars in thousands): December 31, 2020 December 31, 2019 Year Amount Interest Rates Amount Interest Rates 2020 $ — — $ 10,000 2.05 % 2021 10,000 0.33 % — — Total $ 10,000 0.33 % $ 10,000 2.05 %

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Summary of Changes in Accumulated Other Comprehensive Income (Loss) by Component, Net of Tax	The following were changes in accumulated other comprehensive income (loss) by component, net of tax, for the years ended December 31, 2020 and 2019 (in thousands): Unrealized Gains Gains and and Losses Losses on on Available Cash Flow for Sale Year Ended December 31, 2020 Hedges Securities Total Beginning balance $ (2,679 ) $ 4,062 $ 1,383 Other comprehensive income (loss) before reclassification, net of tax — 3,758 3,758 Amounts reclassified from accumulated other comprehensive income (loss), net of tax 2,679 (92 ) 2,587 Net current period other comprehensive income (loss) 2,679 3,666 6,345 Ending balance $ — $ 7,728 $ 7,728 Year Ended December 31, 2019 Beginning balance $ (2,636 ) $ (680 ) $ (3,316 ) Other comprehensive income (loss) before reclassification, net of tax 826 4,815 5,641 Amounts reclassified from accumulated other comprehensive income (loss), net of tax (869 ) (73 ) (942 ) Net current period other comprehensive income (loss) (43 ) 4,742 4,699 Ending balance $ (2,679 ) $ 4,062 $ 1,383
Summary of Significant Amounts Reclassified out off Accumulated Other Comprehensive Income (Loss)	The following were significant amounts reclassified out of each component of accumulated other comprehensive income (loss) for the years ended December 31, 2020, 2019 and 2018 (in thousands): Affected Line Item Details about Accumulated Other Year Ended Year Ended Year Ended in the Statement Where Comprehensive Income Components December 31, 2020 December 31, 2019 December 31, 2018 Net Income is Presented Realized losses on cash flow hedges $ (2,466 ) $ (635 ) $ (441 ) Interest expense – savings and money market accounts (213 ) (243 ) (479 ) Interest expense - Federal Home Loan Bank advances — 9 72 Income tax benefit $ (2,679 ) $ (869 ) $ (848 ) Net of tax Realized gains and (losses) on available-for-sale securities $ 125 $ (99 ) $ 3 Net gain (loss) on sale of securities (33 ) 26 (1 ) Income tax (expense) benefit $ 92 $ (73 ) $ 2 Net of tax Realized losses on securities transferred to held-to-maturity $ — $ — $ (14 ) Interest income - securities — — 4 Income tax benefit $ — $ — $ (10 ) Net of tax

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The components of income tax expense are summarized as follows (in thousands): 2020 2019 2018 Current: Federal $ 8,822 $ 3,215 $ 15 State 1,552 1,044 (23 ) 10,374 4,259 (8 ) Deferred: Federal (3,523 ) 2,039 872 State (816 ) 546 303 (4,339 ) 2,585 1,175 Total $ 6,035 $ 6,844 $ 1,167
Schedule of Reconciliation of Actual Income Tax Expense	A reconciliation of actual income tax expense in the financial statements to the “expected” tax expense (computed by applying the statutory federal income tax rate of 21% to income before income taxes) for the years ended December 31, 2020, 2019 and 2018 is as follows (in thousands): 2020 2019 2018 Computed "expected" tax expense $ 6,454 $ 6,146 $ 2,272 State income taxes, net of effect of federal income taxes 582 1,256 221 Tax-exempt interest income (278 ) (302 ) (298 ) Earnings on bank owned life insurance contracts (186 ) (173 ) (559 ) Disallowed expenses 69 84 93 Excess tax benefits related to stock compensation 91 (57 ) (857 ) Nondeductible acquisition expenses 132 — 281 CARES act net operating loss carryback (772 ) — — Other (57 ) (110 ) 14 Total $ 6,035 $ 6,844 $ 1,167
Schedule of Deferred Tax Assets and Liabilities	Significant items that gave rise to deferred taxes at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Deferred tax assets: Allowance for loan losses $ 5,040 $ 2,935 Net operating loss carryforward 527 738 Organization and preopening costs 261 359 Stock-based compensation 48 200 Acquired loans 939 871 Accrued contributions 288 247 Acquired deposits 459 — Accrued compensation 3,159 22 Other 148 167 Deferred tax assets 10,869 5,539 Deferred tax liabilities: Depreciation 1,633 804 Goodwill 311 154 Unrealized gain on securities available-for-sale 2,009 833 Amortization of core deposit intangible 1,608 1,052 Other acquired assets 509 — Other 201 568 Deferred tax liabilities 6,271 3,411 Net deferred tax asset $ 4,598 $ 2,128

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Schedule of Financial Instruments Representing Credit Risk	The following table sets forth outstanding financial instruments whose contract amounts represent credit risk as of December 31, 2020 and 2019 (in thousands): Contract or notional amount December 31, 2020 December 31, 2019 Financial instruments whose contract amounts represent credit risk: Unused commitments to extend credit $ 804,520 $ 672,933 Standby letters of credit 10,403 9,634 Total $ 814,923 $ 682,567

Regulatory Matters And Restri_2

Regulatory Matters And Restrictions On Dividends (Tables)	12 Months Ended
	Dec. 31, 2020
Banking And Thrift Interest [Abstract]
Schedule of Capital Amounts and Ratios	The Company’s and the Bank’s capital amounts and ratios are presented in the following table (dollars in thousands): Actual Minimum capital requirement (1) Minimum to be well-capitalized (2) Amount Ratio Amount Ratio Amount Ratio At December 31, 2020: Total capital to risk-weighted assets: CapStar Financial Holdings, Inc. $ 338,426 16.03 % $ 168,910 8.0 % N/A N/A CapStar Bank 324,152 15.36 168,808 8.0 211,010 10.0 Tier I capital to risk-weighted assets: CapStar Financial Holdings, Inc. 285,439 13.52 126,682 6.0 N/A N/A CapStar Bank 300,588 14.25 126,606 6.0 168,808 8.0 Common equity Tier 1 capital to risk weighted assets: CapStar Financial Holdings, Inc. 285,439 13.52 95,012 4.5 N/A N/A CapStar Bank 284,088 13.46 94,954 4.5 137,156 6.5 Tier I capital to average assets: CapStar Financial Holdings, Inc. 285,439 9.60 118,877 4.0 N/A N/A CapStar Bank 300,588 10.12 118,780 4.0 148,476 5.0 At December 31, 2019: Total capital to risk-weighted assets: CapStar Financial Holdings, Inc. $ 237,857 13.45 % $ 141,436 8.0 % N/A N/A CapStar Bank 224,443 12.70 141,388 8.0 176,735 10.0 Tier I capital to risk-weighted assets: CapStar Financial Holdings, Inc. 225,074 12.73 106,077 6.0 N/A N/A CapStar Bank 211,660 11.98 106,041 6.0 141,388 8.0 Common equity Tier 1 capital to risk weighted assets: CapStar Financial Holdings, Inc. 225,074 12.73 79,558 4.5 N/A N/A CapStar Bank 195,160 11.04 79,531 4.5 114,878 6.5 Tier I capital to average assets: CapStar Financial Holdings, Inc. 225,074 11.37 79,201 4.0 N/A N/A CapStar Bank 211,660 10.70 79,150 4.0 98,938 5.0 (1) For the calendar year 2020, the Company was required to maintain a capital conservation buffer of Tier 1 common equity capital in excess of minimum risk-based capital ratios by at least 1.875% to avoid limits on capital distributions and certain discretionary bonus payments to executive officers and similar employees. (2) For the Company to be well-capitalized, the Bank must be well-capitalized and the Company must not be subject to any written agreement, order, capital directive, or prompt corrective action directive issued by the Federal Reserve to meet and maintain a specific capital level for any capital measure.

Stock Options and Restricted _2

Stock Options and Restricted Shares (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Company Recognized Stock-Based Compensation Expense	The Company has recognized stock-based compensation expense, within salaries and employee benefits for employees, and within other non-interest expense for directors, in the consolidated statements of income as follows (in thousands): For the year ended December 31, 2020 2019 2018 Stock-based compensation expense before income taxes $ 1,223 $ 1,262 $ 2,079 Less: deferred tax benefit (320 ) (330 ) (543 ) Reduction of net income $ 903 $ 932 $ 1,536
Summary of Changes in Company's Nonvested Stock Awards	A summary of the changes in the Company’s nonvested stock awards for 2020 follows: Weighted Average Restricted Grant Date Nonvested Shares Shares Fair Value Nonvested at beginning of period 84,697 $ 17.44 Granted 144,557 13.73 Vested (76,715 ) 16.50 Forfeited (4,125 ) 14.45 Nonvested at end of period 148,414 $ 14.39
Summary of Fair Value of Options Granted Using Weighted Average Assumptions	The fair value of options granted was determined using the following weighted average assumptions as of the grant date. There were no options granted during 2020. The Company granted 50,000 options during 2019. 2019 Dividend yield 1.35 % Expected term (in years) 6.50 Expected stock price volatility 29.55 % Risk-free interest rate 2.25 %
Summary of Activity in Stock Options	A summary of the activity in stock options for 2020 follows: Weighted Weighted Average Average Remaining Exercise Contractual Shares Price Term (years) Outstanding at beginning of period 271,202 $ 11.22 Granted — — Exercised (24,613 ) 6.75 Forfeited or expired (20,000 ) 10.92 Outstanding at end of period 226,589 $ 11.73 3.9 Fully vested and expected to vest 226,589 $ 11.73 3.9 Exercisable at end of period 193,255 $ 11.19 3.1
Information Related to Stock Options	Information related to stock options during 2020, 2019 and 2018 follows: 2020 2019 2018 Intrinsic value of options exercised $ 188,662 $ 2,478,086 $ 7,654,738 Cash received from option exercises 105,847 1,930,737 6,897,845 Tax benefit realized from option exercises 16,524 103,847 846,725 Weighted average fair value of options granted — 5.35 —

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Summary of Customer Related Interest Rate Swaps	A summary of the Company’s customer related interest rate swaps is as follows (in thousands): December 31, 2020 December 31, 2019 Notional Estimated Notional Estimated amount fair value amount fair value Interest rate swap agreements: Pay fixed/receive variable swaps $ 59,946 $ (2,740 ) $ 45,053 $ (926 ) Pay variable/receive fixed swaps 59,946 2,740 45,053 926 Total $ 119,892 $ — $ 90,106 $ —
Summary of Net Gains (Losses) Relating to Mortgage Banking Derivative Instruments Included in Mortgage Banking Income	The net gains (losses) relating to mortgage banking derivative instruments included in mortgage banking income were as follows (dollars in thousands): For the year ended For the year ended December 31, 2020 December 31, 2019 Mortgage loan interest rate lock commitments $ 1,959 $ 648 Mortgage-backed securities forward sales commitments (478 ) (148 ) Total $ 1,481 $ 500
Summary of Amount and Fair Value of Mortgage Banking Derivative Instruments Included in Consolidated Balance Sheets	The amount and fair value of mortgage banking derivatives included in the consolidated balance sheets was as follows (dollars in thousands): December 31, 2020 December 31, 2019 Notional Estimated Notional Estimated amount fair value amount fair value Included in other assets: Mortgage loan interest rate lock commitments $ 88,303 $ 2,607 $ 44,694 $ 648 Included in other liabilities: Mortgage-backed securities forward sales commitments $ 87,000 $ (626 ) $ 38,500 $ (148 )

Related Party (Tables)

Related Party (Tables)	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Schedule of Related Party Transactions Activity within Loans	The Company may enter into loan transactions with certain directors, executive officers, significant shareholders, and their affiliates. Such transactions were made in the ordinary course of business on substantially the same terms, including interest rates and collateral, as those prevailing at the same time for comparable transactions with persons not affiliated with the Company, and did not, in the opinion of management, involve more than normal credit risk or present other unfavorable features. None of these loans were impaired at December 31, 2020 or 2019. Activity within these loans during the years ended December 31, 2020 and 2019 was as follows (in thousands): Total commitment Total funded commitment Year ended December 31, 2020 Beginning of period $ 21,815 $ 10,673 New commitments/draw downs 200 2,798 Repayments (3,991 ) (3,689 ) End of period $ 18,024 $ 9,782 Year ended December 31, 2019 Beginning of period $ 44,812 $ 15,445 New commitments/draw downs 9,336 2,515 Repayments (32,333 ) (7,287 ) End of period $ 21,815 $ 10,673

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis are summarized below (in thousands): Fair value measurements at December 31, 2020 Quoted prices in active Significant markets for other Significant identical observable unobservable Carrying assets inputs inputs Value (Level 1) (Level 2) (Level 3) Assets: Securities available-for-sale: U.S. government-sponsored agencies $ 16,390 $ — $ 16,390 $ — Obligations of states and political subdivisions 91,930 — 91,930 — Mortgage-backed securities-residential 336,361 — 336,361 — Asset-backed securities 3,193 — 3,193 — Other debt securities 38,341 — 38,341 — Loans held for sale 97,303 — 97,303 — Derivative assets: Non-hedging derivatives: Interest rate swaps - customer related 2,740 — 2,740 — Mortgage loan interest rate lock commitments 2,607 — — 2,607 Liabilities: Derivative liabilities: Non-hedging derivatives: Derivative Liabilities - customer related (2,740 ) — (2,740 ) — Mortgage-backed securities forward sales commitments (626) — (626) — Fair value measurements at December 31, 2019 Quoted prices in active Significant markets for other Significant identical observable unobservable Carrying assets inputs inputs Value (Level 1) (Level 2) (Level 3) Assets: Securities available-for-sale: U.S. government-sponsored agencies $ 10,331 $ — $ 10,331 $ — Obligations of states and political subdivisions 45,960 — 45,960 — Mortgage-backed securities-residential 138,679 — 138,679 — Asset-backed securities 3,197 — 3,197 — Other debt securities 14,962 — 14,962 — Loans held for sale 168,222 168,222 Derivatives: Derivative Liabilities - customer related 926 — 926 — Mortgage loan interest rate lock commitments 648 — — 648 Liabilities: Derivatives: Derivative Liabilities - customer related (926 ) — (926 ) — Mortgage-backed securities forward sales commitments (148 ) — (148 ) —
Reconciliation of Assets Measured at Fair Value on Recurring Basis using Significant Unobservable Inputs (Level 3)	The table below presents a reconciliation of all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the year ended December 31, 2020 and 2019 (dollars in thousands): Mortgage Loan Interest Rate Lock Commitments 2020 2019 Balance of recurring Level 3 assets at January 1st $ 648 $ — Total gains or losses for the period: Included in mortgage banking income 1,959 648 Balance of recurring Level 3 assets at December 31st $ 2,607 $ 648
Summary of Quantitative Information About Level 3 Fair Value Measurements for Assets Measured at Fair Value on Recurring and Non-recurring Basis	The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2020 (dollars in thousands). Range Fair Valuation (Weighted- December 31, 2020 Value Technique(s) Unobservable Input(s) Average) Assets: Non-hedging derivatives: Mortgage loan interest rate lock commitments $ 2,607 Consensus pricing Origination pull-through rate 54% - 91% (74%) Range Fair Valuation (Weighted- December 31, 2019 Value Technique(s) Unobservable Input(s) Average) Assets: Non-hedging derivatives: Mortgage loan interest rate lock commitments $ 648 Consensus pricing Origination pull-through rate 68% - 95% (83%) The following table presents quantitative information about Level 3 fair value measurements for assets measured at fair value on a nonrecurring basis (dollars in thousands): Fair Valuation Unobservable Weighted- December 31, 2020 Value Technique(s) Input(s) Average Impaired loans: Construction and land development $ 36 Sales comparison approach Appraisal discounts 10%
Summary of Assets Measured at Fair Value on a Nonrecurring Basis	Assets measured at fair value on a nonrecurring basis are summarized below (in thousands): There were no assets measured at fair value on a nonrecurring basis at December 31, 2019. Fair value measurements at December 31, 2020 Quoted prices in active Significant markets for other Significant identical observable unobservable Carrying assets inputs inputs Value (level 1) (level 2) (level 3) Assets: Impaired loans: Construction and land development $ 36 $ — $ — $ 36
Summary of Carrying Value and Fair Values of the Company's Financial Instruments	The carrying value and estimated fair values of the Company’s financial instruments at December 31, 2020 and 2019 were as follows (in thousands): December 31, 2020 December 31, 2019 Carrying Carrying Fair value amount Fair value amount Fair value level of input Financial assets: Cash and due from banks, interest-bearing deposits in financial institutions $ 277,439 $ 277,439 $ 101,094 $ 101,094 Level 1 Federal funds sold — — 175 175 Level 1 Securities available-for-sale 486,215 486,215 213,129 213,129 Level 2 Securities held-to-maturity 2,407 2,504 3,313 3,411 Level 2 Loans held for sale 179,669 180,698 168,222 169,072 Level 2 Restricted equity securities 15,562 N/A 13,689 N/A N/A Loans 1,891,019 1,900,647 1,420,102 1,414,757 Level 3 Accrued interest receivable 8,771 8,771 5,792 5,792 Level 2 Other assets 46,381 46,381 36,393 36,393 Level 2 / Level 3 Financial liabilities: Deposits 2,568,001 2,472,860 1,729,451 1,730,206 Level 3 Federal Home Loan Bank advances and other borrowings 39,423 41,400 10,000 10,014 Level 2 Other liabilities 3,334 3,334 1,394 1,394 Level 3

Parent Company Only Financial_2

Parent Company Only Financial Information (Tables)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets December 31, 2020 December 31, 2019 Assets Cash and cash equivalents $ 13,176 $ 12,874 Investment in consolidated subsidiary 358,635 259,632 Other assets 1,163 578 Total assets $ 372,974 $ 273,084 Liabilities and Shareholders’ Equity Subordinated debt $ 29,423 $ — Other liabilities 65 38 Total shareholders’ equity 343,486 273,046 Total liabilities and shareholders’ equity $ 372,974 $ 273,084
Condensed Income Statements	Condensed Income Statements Year Ended Year Ended December 31, 2020 December 31, 2019 Income - dividends from subsidiary $ 4,075 $ 3,530 Interest expense subordinated debt 792 — Other expenses 1,373 1,083 Income before income taxes and equity in undistributed net income of subsidiary 1,910 2,447 Income tax benefit (552 ) (262 ) Income before equity in undistributed net income of subsidiary 2,462 2,709 Equity in undistributed net income of subsidiary 22,234 19,713 Net income $ 24,696 $ 22,422
Condensed Statements of Cash Flow	Condensed Statements of Cash Flow Year Ended Year Ended December 31, 2020 December 31, 2019 Cash flows from operating activities: Net income $ 24,696 $ 22,422 Adjustments to reconcile net income to net cash provided by operating activities: Increase in other assets (2,962 ) (3,304 ) Increase (decrease) in other liabilities 27 (263 ) Equity in undistributed net income of subsidiary (22,234 ) (19,713 ) Net cash used in by operating activities (473 ) (858 ) Cash flows from investing activities: Cash paid for acquisitions (27,278 ) — Dividends received from CapStar Bank 4,075 3,530 Net cash (used in) provided by investing activities (23,203 ) 3,530 Cash flows from financing activities: Issuance of subordinated debt 29,387 — Repurchase of common stock (1,437 ) (7,836 ) Exercise of common stock options and warrants 63 1,627 Common stock dividends paid (4,035 ) (3,507 ) Net cash provided by (used in) financing activities 23,978 (9,716 ) Net increase (decrease) in cash and cash equivalents 302 (7,044 ) Cash and cash equivalents at beginning of period 12,874 19,918 Cash and cash equivalents at end of period $ 13,176 $ 12,874

Quarterly Financial Results (_2

Quarterly Financial Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Financial Results (Unaudited)	The following is a summary of quarterly financial results (unaudited) for 2020, 2019 and 2018: First Quarter Second Quarter Third Quarter Fourth Quarter 2020 Interest income $ 21,738 $ 20,741 $ 24,642 $ 24,731 Interest expense 5,077 3,066 4,986 2,400 Net interest income 16,661 17,675 19,656 22,331 Provision for loan losses 7,553 1,624 2,119 184 Net interest income after provision for loan losses 9,108 16,051 17,537 22,147 Noninterest income 5,874 10,823 14,804 11,748 Noninterest expense 14,211 18,934 22,739 21,478 Net income before income tax expense 771 7,940 9,602 12,417 Income tax expense (575 ) 1,759 2,115 2,736 Net income $ 1,346 $ 6,181 $ 7,487 $ 9,681 Net income per share, basic $ 0.07 $ 0.34 $ 0.34 $ 0.44 Net income per share, diluted $ 0.07 $ 0.34 $ 0.34 $ 0.44 2019 Interest income $ 22,967 $ 23,158 $ 23,216 $ 22,205 Interest expense 5,965 6,150 6,060 5,624 Net interest income 17,002 17,008 17,156 16,581 Provision for loan losses 886 — (125 ) — Net interest income after provision for loan losses 16,116 17,008 17,281 16,581 Noninterest income 4,735 7,032 6,788 5,719 Noninterest expense 14,725 16,470 15,531 15,266 Net income (loss) before income tax expense 6,126 7,570 8,538 7,034 Income tax expense (benefit) 1,346 1,814 2,072 1,613 Net income (loss) $ 4,780 $ 5,756 $ 6,466 $ 5,421 Net income (loss) per share, basic $ 0.27 $ 0.33 $ 0.36 $ 0.30 Net income (loss) per share, diluted $ 0.25 $ 0.31 $ 0.35 $ 0.29 2018 Interest income $ 13,744 $ 15,354 $ 15,782 $ 22,900 Interest expense 2,898 3,767 4,239 5,184 Net interest income 10,846 11,587 11,543 17,716 Provision for loan losses 678 169 481 1,514 Net interest income after provision for loan losses 10,168 11,418 11,062 16,202 Noninterest income 3,088 2,765 3,218 6,387 Noninterest expense 9,580 10,005 10,070 23,832 Net income (loss) before income tax expense 3,676 4,178 4,210 (1,243 ) Income tax expense (benefit) 483 665 554 (535 ) Net income (loss) $ 3,193 $ 3,513 $ 3,656 $ (708 ) Net income (loss) per share, basic $ 0.27 $ 0.30 $ 0.30 $ (0.04 ) Net income (loss) per share, diluted $ 0.25 $ 0.27 $ 0.28 $ (0.04 )

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020USD ($)Securityshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares	Jan. 01, 2019USD ($)
Summary Of Significant Accounting Policies [Line Items]
Date of acquisition	Feb. 5, 2016
Number of Securities | Security	3
Accrual of interest on loans due discontinued period	90 days
Minimum loan losses exposure for formal credit review	$ 1,500,000
Look-back period	45 quarters	41 quarters	37 quarter
Noninterest income	$ 25,034,000	$ 9,467,000	$ 5,653,000
Servicing rights impairment charges	238,000	211,000	0
Operating lease, right-of-use asset	11,200,000		12,800,000	$ 12,800,000
Operating lease, liability	$ 11,940,000		$ 13,400,000	$ 13,400,000
Income tax examination description	A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.
Tax benefit from income tax examination	$ 0
Restricted balance of cash reserve with Federal Reserve Bank		$ 73,444,000
Antidilutive stock options excluded from diluted earnings per share | shares	0	0	0
Cumulative-effect adjustment to retained earnings	$ 66,879,000	$ 46,218,000
Cumulative Effect, Period of Adoption, Adjustment | Restatement Adjustment
Summary Of Significant Accounting Policies [Line Items]
Cumulative-effect adjustment to retained earnings			$ 600,000
Other Operating Expenses
Summary Of Significant Accounting Policies [Line Items]
Advertising expense	$ 400,000	370,000	383,000
IRS
Summary Of Significant Accounting Policies [Line Items]
Open to audit	2017 2018 2019 2020
States
Summary Of Significant Accounting Policies [Line Items]
Open to audit	2017 2018 2019 2020
Accounting Standards Update 2016-02
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2019
Accounting Standards Update 2017-12
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Dec. 1, 2017
Change in accounting principle accounting standards update immaterial effect	true
Minimum
Summary Of Significant Accounting Policies [Line Items]
Premises and equipment, useful lives	1 year
Income tax benefit recognized percentage	50.00%
Minimum | Core Deposit
Summary Of Significant Accounting Policies [Line Items]
Intangible assets, useful lives	6 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Premises and equipment, useful lives	39 years
Maximum | Core Deposit
Summary Of Significant Accounting Policies [Line Items]
Intangible assets, useful lives	10 years
Bank Servicing
Summary Of Significant Accounting Policies [Line Items]
Noninterest income	$ 148,000	340,000	102,000
Residential mortgage loans held for sale
Summary Of Significant Accounting Policies [Line Items]
Mortgage banking income	2,500,000	600,000
Residential mortgage loans held for sale	$ 97,303,000	$ 30,740,000	$ 0
Consumer Loan
Summary Of Significant Accounting Policies [Line Items]
Accrual of interest on loans due charged off	180 days

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Difference Between the Fair Value and Aggregate Unpaid Principal Balance (Details) - Residential mortgage loans held for sale - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	$ 97,303,000	$ 30,740,000	$ 0
Aggregate Unpaid Principal Balance	94,248,000	30,178,000
Difference	$ 3,055,000	$ 562,000

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic net income per share calculation:
Numerator – Net income													$ 24,696	$ 22,422	$ 9,655
Denominator – Average common shares outstanding													20,162,038	17,886,164	13,277,614
Basic net income per share	$ 0.44	$ 0.34	$ 0.34	$ 0.07	$ 0.30	$ 0.36	$ 0.33	$ 0.27	$ (0.04)	$ 0.30	$ 0.30	$ 0.27	$ 1.22	$ 1.25	$ 0.73
Diluted net income per share calculation:
Numerator – Net income													$ 24,696	$ 22,422	$ 9,655
Denominator – Average common shares outstanding													20,162,038	17,886,164	13,277,614
Dilutive shares contingently issuable													23,551	727,060	1,202,733
Average diluted common shares outstanding													20,185,589	18,613,224	14,480,347
Diluted net income per share	$ 0.44	$ 0.34	$ 0.34	$ 0.07	$ 0.29	$ 0.35	$ 0.31	$ 0.25	$ (0.04)	$ 0.28	$ 0.27	$ 0.25	$ 1.22	$ 1.20	$ 0.67

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jul. 01, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Acquisition related expenses		$ 5,390	$ 2,654	$ 9,803
FCB Merger
Business Acquisition [Line Items]
Common stock, par value	$ 1
Common stock shares	2,966,918
Value of shares in lieu of shares	$ 22,200
Bow Merger
Business Acquisition [Line Items]
Common stock shares	664,800
Value of shares in lieu of shares	$ 5,100
Total acquisition consideration	70,900
FCB Merger and Bow Merger
Business Acquisition [Line Items]
Acquisition related expenses		$ 5,400
Goodwill	$ 3,600
FCB Common Stock | FCB Merger
Business Acquisition [Line Items]
Common stock, par value	$ 10
BOW Common Stock | Bow Merger
Business Acquisition [Line Items]
Common stock, par value	$ 10

Acquisition - Schedule of Consi

Acquisition - Schedule of Consideration Paid and Amounts of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jul. 01, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total cost of acquisition:
Goodwill		$ 41,068	$ 37,510	$ 37,510
FCB Merger and Bow Merger
Assets:
Cash and cash equivalents	$ 90,760
Securities	98,695
Loans, gross	294,674
Premises and equipment, net	11,447
Core deposit intangible	3,570
Other	15,597
Total	514,743
Liabilities:
Deposits	442,677
Other	4,735
Total	447,412
Net identifiable assets acquired	67,331
Total cost of acquisition:
Total cost of acquisition	70,889
Goodwill	3,558
FCB Merger and Bow Merger | Common Stock
Total cost of acquisition:
Total cost of acquisition	43,611
FCB Merger and Bow Merger | Rolled Stock Options
Total cost of acquisition:
Total cost of acquisition	27,278
FCB Merger and Bow Merger | As recorded by FCB Corporation and BOW
Assets:
Cash and cash equivalents	90,760
Securities	98,536
Loans, gross	296,992
Allowance for loan losses	(4,544)
Premises and equipment, net	9,907
Other	16,514
Total	508,165
Liabilities:
Deposits	440,025
Other	4,735
Total	444,760
FCB Merger and Bow Merger | Initial Fair Value Adjustment
Assets:
Securities	159
Loans, gross	(2,318)
Allowance for loan losses	4,544
Premises and equipment, net	1,540
Core deposit intangible	3,570
Other	(917)
Total	6,578
Liabilities:
Deposits	2,652
Total	$ 2,652

Acquisition - Schedule of Unaud

Acquisition - Schedule of Unaudited Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Net interest income	$ 22,331	$ 19,656	$ 17,675	$ 16,661	$ 16,581	$ 17,156	$ 17,008	$ 17,002	$ 17,716	$ 11,543	$ 11,587	$ 10,846	$ 76,323	$ 67,748	$ 51,692
Noninterest income	11,748	14,804	10,823	5,874	5,719	6,788	7,032	4,735	6,387	3,218	2,765	3,088	43,248	24,274	15,459
Net income	$ 9,681	$ 7,487	$ 6,181	$ 1,346	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 24,696	$ 22,422	$ 9,655
Per share information:
Basic net income per share of common stock	$ 0.44	$ 0.34	$ 0.34	$ 0.07	$ 0.30	$ 0.36	$ 0.33	$ 0.27	$ (0.04)	$ 0.30	$ 0.30	$ 0.27	$ 1.22	$ 1.25	$ 0.73
Diluted net income per share of common stock	$ 0.44	$ 0.34	$ 0.34	$ 0.07	$ 0.29	$ 0.35	$ 0.31	$ 0.25	$ (0.04)	$ 0.28	$ 0.27	$ 0.25	$ 1.22	$ 1.20	$ 0.67
FCB Merger and Bow Merger
Business Acquisition [Line Items]
Net interest income													$ 73,571	$ 87,523
Noninterest income													44,453	27,375
Total revenue													118,024	114,898
Net income													$ 25,927	$ 28,989
Per share information:
Basic net income per share of common stock													$ 1.29	$ 1.35
Diluted net income per share of common stock													$ 1.28	$ 1.30

Investment Securities - Summary

Investment Securities - Summary of Company's Classification of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Securities available for sale [Abstract]
Amortized Cost	$ 478,186	$ 209,943
Gross unrealized gains	8,897	3,906
Gross unrealized (losses)	(868)	(720)
Estimated fair value	486,215	213,129
Securities held to maturity [Abstract]
Amortized Cost	2,407	3,313
Gross unrealized gains	97	98
Estimated fair value	2,504	3,411
U. S. government agency securities
Securities available for sale [Abstract]
Amortized Cost	16,158	10,421
Gross unrealized gains	258	4
Gross unrealized (losses)	(25)	(94)
Estimated fair value	16,391	10,331
State and municipal securities
Securities available for sale [Abstract]
Amortized Cost	89,081	44,053
Gross unrealized gains	2,928	1,927
Gross unrealized (losses)	(81)	(20)
Estimated fair value	91,928	45,960
Securities held to maturity [Abstract]
Amortized Cost	2,407	3,313
Gross unrealized gains	97	98
Estimated fair value	2,504	3,411
Mortgage-backed securities
Securities available for sale [Abstract]
Amortized Cost	332,014	137,305
Gross unrealized gains	4,892	1,834
Gross unrealized (losses)	(543)	(460)
Estimated fair value	336,363	138,679
Asset-backed securities
Securities available for sale [Abstract]
Amortized Cost	3,325	3,325
Gross unrealized (losses)	(132)	(128)
Estimated fair value	3,193	3,197
Other debt securities
Securities available for sale [Abstract]
Amortized Cost	37,608	14,839
Gross unrealized gains	819	141
Gross unrealized (losses)	(87)	(18)
Estimated fair value	$ 38,340	$ 14,962

Investment Securities - Summa_2

Investment Securities - Summary of Amortized Cost and Fair Value of Debt and Equity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Available-for-sale, Amortized cost [Abstract]
Due in less than one year	$ 13,611
Due one to five years	49,584
Due five to ten years	78,024
Due beyond ten years	1,639
Amortized Cost	478,186	$ 209,943
Available-for-sale, Estimated fair value [Abstract]
Due in less than one year	13,708
Due one to five years	50,889
Due five to ten years	80,437
Due beyond ten years	1,627
Estimated fair value	486,215	213,129
Held-to-maturity, Amortized cost [Abstract]
Due in less than one year	600
Due one to five years	1,807
Amortized Cost	2,407	3,313
Securities held to maturity [Abstract]
Due in less than one year	609
Due one to five years	1,895
Estimated fair value	2,504	3,411
Mortgage-backed securities
Available-for-sale, Amortized cost [Abstract]
Amortized cost	332,014
Amortized Cost	332,014	137,305
Available-for-sale, Estimated fair value [Abstract]
Estimated fair value	336,363
Estimated fair value	336,363	138,679
Asset-backed securities
Available-for-sale, Amortized cost [Abstract]
Amortized cost	3,314
Amortized Cost	3,325	3,325
Available-for-sale, Estimated fair value [Abstract]
Estimated fair value	3,191
Estimated fair value	$ 3,193	$ 3,197

Investment Securities - Summa_3

Investment Securities - Summary of Sale of Debt and Equity Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investments Debt And Equity Securities [Abstract]
Proceeds	$ 78,385	$ 68,068	$ 38,322
Gross gains	148	49	116
Gross losses	$ (23)	$ (148)	$ (113)

Investment Securities - Additio

Investment Securities - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Securities Other Than U S Government and Agencies
Schedule Of Available For Sale Securities [Line Items]
Holdings of securities of any one issuer greater than ten percent of stockholder's equity	$ 0	$ 0
Public Deposits, Derivative Positions and Federal Home Loan Bank Advances
Schedule Of Available For Sale Securities [Line Items]
Market value of securities	$ 163,515,000	$ 70,350,000

Investment Securities - Summa_4

Investment Securities - Summary of Securities with Unrealized Losses Aggregated by Major Security Type and Length of Time Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	$ 118,846	$ 42,632
Less than 12 months, Gross unrealized losses	(672)	(215)
12 months or more, Estimated fair value	4,642	28,514
12 months or more, Gross unrealized losses	(196)	(505)
Total, Estimated fair value	123,488	71,146
Total, Gross unrealized losses	(868)	(720)
U. S. government agency securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value		6,694
Less than 12 months, Gross unrealized losses		(51)
12 months or more, Estimated fair value		1,637
12 months or more, Gross unrealized losses		(43)
Total, Estimated fair value		8,331
Total, Gross unrealized losses		(94)
State and municipal securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	10,463	2,356
Less than 12 months, Gross unrealized losses	(80)	(12)
12 months or more, Estimated fair value		814
12 months or more, Gross unrealized losses		(8)
Total, Estimated fair value	10,463	3,170
Total, Gross unrealized losses	(80)	(20)
Mortgage-backed securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	102,280	30,570
Less than 12 months, Gross unrealized losses	(505)	(136)
12 months or more, Estimated fair value	1,449	21,364
12 months or more, Gross unrealized losses	(63)	(324)
Total, Estimated fair value	103,729	51,934
Total, Gross unrealized losses	(568)	(460)
Asset-backed securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
12 months or more, Estimated fair value	3,193	3,197
12 months or more, Gross unrealized losses	(133)	(128)
Total, Estimated fair value	3,193	3,197
Total, Gross unrealized losses	(133)	(128)
Other debt securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	6,103	3,012
Less than 12 months, Gross unrealized losses	(87)	(16)
12 months or more, Estimated fair value		1,502
12 months or more, Gross unrealized losses		(2)
Total, Estimated fair value	6,103	4,514
Total, Gross unrealized losses	$ (87)	$ (18)

Loans and Allowance for Loan _3

Loans and Allowance for Loan Losses - Summary of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Loans And Leases Receivable Disclosure [Line Items]
Total loans	$ 1,891,019	$ 1,420,102
Allowance for loan losses	(23,245)	(12,604)	$ (12,113)	$ (13,721)
Loans, net	1,867,774	1,407,498
Commercial real estate
Loans And Leases Receivable Disclosure [Line Items]
Total loans	643,832	559,899
Allowance for loan losses	(7,349)	(3,599)	(3,309)	(3,324)
Consumer real estate
Loans And Leases Receivable Disclosure [Line Items]
Total loans	343,791	256,097
Allowance for loan losses	(1,831)	(1,231)	(1,005)	(1,063)
Construction and land development
Loans And Leases Receivable Disclosure [Line Items]
Total loans	174,859	143,111
Allowance for loan losses	(3,476)	(2,058)	(2,431)	(1,628)
Commercial and industrial
Loans And Leases Receivable Disclosure [Line Items]
Total loans	630,775	394,408
Allowance for loan losses	(9,708)	(5,074)	(5,036)	(7,209)
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Total loans	44,279	28,426
Allowance for loan losses	(305)	(222)	(105)	(91)
Other
Loans And Leases Receivable Disclosure [Line Items]
Total loans	53,483	38,161
Allowance for loan losses	$ (576)	$ (420)	$ (227)	$ (406)

Loans and Allowance for Loan _4

Loans and Allowance for Loan Losses - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020USD ($)LoanContract	Dec. 31, 2019USD ($)Contract	Dec. 31, 2018USD ($)Contract	Jul. 01, 2020USD ($)
Loans And Leases Receivable Disclosure [Line Items]
Outstanding balance of loans originated under PPP	$ 1,867,774,000	$ 1,407,498,000
Variable-rate loans	1,199,105,000	785,329,000
Fixed-rate loans	691,914,000	634,773,000
Minimum loan amount for loans analyzed by credit risk	500,000
Interest income recognized on a cash basis for impaired loans	0	0	$ 0
Investments in TDR	1,900,000	2,700,000
Specific allowance related to loans	66,000
Additional commitments related to TDR	$ 0	$ 0
New TDR identified during the period | Contract	2	2	0
TDR, payment default within twelve months | Contract	0	0	0
Loan period considered as payment default	30 days
Recorded loans with a fair value				$ 294,700,000
Future minimum lease payments receivable	$ 0
Purchased Credit Impaired
Loans And Leases Receivable Disclosure [Line Items]
Recorded loans with a fair value				$ 33,600,000
Troubled Debt Restructurings
Loans And Leases Receivable Disclosure [Line Items]
Specific allowance related to loans	$ 0	$ 0
Minimum
Loans And Leases Receivable Disclosure [Line Items]
Lease term	5 years
Maximum
Loans And Leases Receivable Disclosure [Line Items]
Lease term	6 years
Commercial and industrial
Loans And Leases Receivable Disclosure [Line Items]
New TDR identified during the period | Contract		1
Payroll Protection Program
Loans And Leases Receivable Disclosure [Line Items]
Debt instrument, term	2 years
Debt instrument, interest rate	1.00%
Number of funded loans | Loan	1,475
Unamortized fees	$ 4,000,000
Fees recognized as income	$ 3,600,000
Payroll Protection Program | Minimum
Loans And Leases Receivable Disclosure [Line Items]
Percentage of loan processing fee	1.00%
Payroll Protection Program | Maximum
Loans And Leases Receivable Disclosure [Line Items]
Percentage of loan processing fee	5.00%
Payroll Protection Program | Commercial and industrial
Loans And Leases Receivable Disclosure [Line Items]
Outstanding balance of loans originated under PPP	$ 185,500,000

Loans and Allowance for Loan _5

Loans and Allowance for Loan Losses - Summary of Risk Category of Loans by Applicable Class of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Purchased Credit Impaired	$ 28,392	$ 1,605
Total loans	1,891,019	1,420,102
Commercial real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	638,291	559,789
Purchased Credit Impaired	5,541	110
Total loans	643,832	559,899
Consumer real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	327,276	255,489
Purchased Credit Impaired	16,515	608
Total loans	343,791	256,097
Construction and land development
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	174,589	143,106
Purchased Credit Impaired	270	5
Total loans	174,859	143,111
Commercial and industrial
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	627,785	393,544
Purchased Credit Impaired	2,990	864
Total loans	630,775	394,408
Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	41,671	28,408
Purchased Credit Impaired	2,608	18
Total loans	44,279	28,426
Other
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	53,015	38,161
Purchased Credit Impaired	468
Total loans	53,483	38,161
Purchased Credit Impaired
Financing Receivable Recorded Investment [Line Items]
Purchased Credit Impaired	28,392	1,605
Total Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	3,163	3,594
Total Impaired Loans | Commercial real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	1,179	2,507
Total Impaired Loans | Consumer real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	1,707	483
Total Impaired Loans | Construction and land development
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	102	112
Total Impaired Loans | Commercial and industrial
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	168	487
Total Impaired Loans | Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	7	5
Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	1,788,104	1,384,877
Performing Financial Instruments | Pass | Commercial real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	601,133	551,929
Performing Financial Instruments | Pass | Consumer real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	323,072	252,952
Performing Financial Instruments | Pass | Construction and land development
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	169,315	142,978
Performing Financial Instruments | Pass | Commercial and industrial
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	576,096	370,475
Performing Financial Instruments | Pass | Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	41,640	28,382
Performing Financial Instruments | Pass | Other
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	52,949	38,161
Performing Financial Instruments | Pass | Purchased Credit Impaired
Financing Receivable Recorded Investment [Line Items]
Purchased Credit Impaired	23,899
Performing Financial Instruments | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	65,433	15,765
Performing Financial Instruments | Special Mention | Commercial real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	33,046	915
Performing Financial Instruments | Special Mention | Consumer real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	1,375	503
Performing Financial Instruments | Special Mention | Construction and land development
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	5,153
Performing Financial Instruments | Special Mention | Commercial and industrial
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	25,855	14,341
Performing Financial Instruments | Special Mention | Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	4	6
Performing Financial Instruments | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	34,236	15,866
Performing Financial Instruments | Substandard | Commercial real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	2,933	4,438
Performing Financial Instruments | Substandard | Consumer real estate
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	1,122	1,551
Performing Financial Instruments | Substandard | Construction and land development
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	19	16
Performing Financial Instruments | Substandard | Commercial and industrial
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	25,666	8,241
Performing Financial Instruments | Substandard | Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	18	15
Performing Financial Instruments | Substandard | Other
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	66
Performing Financial Instruments | Substandard | Purchased Credit Impaired
Financing Receivable Recorded Investment [Line Items]
Purchased Credit Impaired	4,412	$ 1,605
Performing Financial Instruments | Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans	83
Performing Financial Instruments | Doubtful | Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans excluding purchased credit impaired	2
Performing Financial Instruments | Doubtful | Purchased Credit Impaired
Financing Receivable Recorded Investment [Line Items]
Purchased Credit Impaired	$ 81

Loans and Allowance for Loan _6

Loans and Allowance for Loan Losses - Summary of Changes in Allowance for Loan Losses by Loan Classification (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance				$ 12,604		$ 12,113				$ 13,721	$ 12,604	$ 12,113	$ 13,721
Charged-off loans											(1,226)	(798)	(4,954)
Recoveries											388	528	504
Provision for loan losses	$ 184	$ 2,119	$ 1,624	7,553	$ (125)	886	$ 1,514	$ 481	$ 169	678	11,479	761	2,842
Ending Balance	23,245						12,113				23,245	12,604	12,113
Commercial real estate
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance				3,599		3,309				3,324	3,599	3,309	3,324
Recoveries											10	23	22
Provision for loan losses											3,740	267	(37)
Ending Balance	7,349						3,309				7,349	3,599	3,309
Consumer real estate
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance				1,231		1,005				1,063	1,231	1,005	1,063
Charged-off loans											(49)	(39)
Recoveries											14	20	4
Provision for loan losses											635	245	(62)
Ending Balance	1,831						1,005				1,831	1,231	1,005
Construction and land development
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance				2,058		2,431				1,628	2,058	2,431	1,628
Provision for loan losses											1,418	(373)	803
Ending Balance	3,476						2,431				3,476	2,058	2,431
Commercial and industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance				5,074		5,036				7,209	5,074	5,036	7,209
Charged-off loans											(728)	(455)	(4,831)
Recoveries											235	380	395
Provision for loan losses											5,127	113	2,263
Ending Balance	9,708						5,036				9,708	5,074	5,036
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance				222		105				91	222	105	91
Charged-off loans											(172)	(164)	(84)
Recoveries											76	82	75
Provision for loan losses											179	199	23
Ending Balance	305						105				305	222	105
Other
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance				$ 420		$ 227				$ 406	420	227	406
Charged-off loans											(277)	(140)	(39)
Recoveries											53	23	8
Provision for loan losses											380	310	(148)
Ending Balance	$ 576						$ 227				$ 576	$ 420	$ 227

Loans and Allowance for Loan _7

Loans and Allowance for Loan Losses - Summary of Breakdown of Allowance for Loan Losses and Loan Portfolio by Loan Category (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Loan Losses:
Collectively evaluated for impairment	$ 23,179	$ 12,604
Individually evaluated for impairment	66
Allowance for Loan Losses, Ending Balance	23,245	12,604	$ 12,113	$ 13,721
Loans:
Collectively evaluated for impairment	1,859,464	1,414,903
Individually evaluated for impairment	3,163	3,594
Purchased credit impaired	28,392	1,605
Total	1,891,019	1,420,102
Commercial real estate
Allowance for Loan Losses:
Collectively evaluated for impairment	7,349	3,599
Allowance for Loan Losses, Ending Balance	7,349	3,599	3,309	3,324
Loans:
Collectively evaluated for impairment	637,112	557,282
Individually evaluated for impairment	1,179	2,507
Purchased credit impaired	5,541	110
Total	643,832	559,899
Consumer real estate
Allowance for Loan Losses:
Collectively evaluated for impairment	1,831	1,231
Allowance for Loan Losses, Ending Balance	1,831	1,231	1,005	1,063
Loans:
Collectively evaluated for impairment	325,569	255,006
Individually evaluated for impairment	1,707	483
Purchased credit impaired	16,515	608
Total	343,791	256,097
Construction and land development
Allowance for Loan Losses:
Collectively evaluated for impairment	3,410	2,058
Individually evaluated for impairment	66
Allowance for Loan Losses, Ending Balance	3,476	2,058	2,431	1,628
Loans:
Collectively evaluated for impairment	174,487	142,994
Individually evaluated for impairment	102	112
Purchased credit impaired	270	5
Total	174,859	143,111
Commercial and industrial
Allowance for Loan Losses:
Collectively evaluated for impairment	9,708	5,074
Allowance for Loan Losses, Ending Balance	9,708	5,074	5,036	7,209
Loans:
Collectively evaluated for impairment	627,617	393,057
Individually evaluated for impairment	168	487
Purchased credit impaired	2,990	864
Total	630,775	394,408
Consumer
Allowance for Loan Losses:
Collectively evaluated for impairment	305	222
Allowance for Loan Losses, Ending Balance	305	222	105	91
Loans:
Collectively evaluated for impairment	41,664	28,403
Individually evaluated for impairment	7	5
Purchased credit impaired	2,608	18
Total	44,279	28,426
Other
Allowance for Loan Losses:
Collectively evaluated for impairment	576	420
Allowance for Loan Losses, Ending Balance	576	420	$ 227	$ 406
Loans:
Collectively evaluated for impairment	53,015	38,161
Purchased credit impaired	468
Total	$ 53,483	$ 38,161

Loans and Allowance for Loan _8

Loans and Allowance for Loan Losses - Allocation of ALL with Corresponding Percentage of Loans in Each Category to Total Loans, Net of Deferred Fee (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 23,245	$ 12,604	$ 12,113	$ 13,721
Allowance for loan and lease losses, Percentage of total loans	1.23%	0.89%
Commercial real estate
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 7,349	$ 3,599	3,309	3,324
Allowance for loan and lease losses, Percentage of total loans	0.39%	0.25%
Consumer real estate
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 1,831	$ 1,231	1,005	1,063
Allowance for loan and lease losses, Percentage of total loans	0.10%	0.09%
Construction and land development
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 3,476	$ 2,058	2,431	1,628
Allowance for loan and lease losses, Percentage of total loans	0.18%	0.14%
Commercial and industrial
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 9,708	$ 5,074	5,036	7,209
Allowance for loan and lease losses, Percentage of total loans	0.51%	0.36%
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 305	$ 222	105	91
Allowance for loan and lease losses, Percentage of total loans	0.02%	0.02%
Other
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 576	$ 420	$ 227	$ 406
Allowance for loan and lease losses, Percentage of total loans	0.03%	0.03%

Loans and Allowance for Loan _9

Loans and Allowance for Loan Losses - Summary of Information Related to Impaired Loans, Excluding Purchased Credit Impaired (PCI) Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	$ 3,061	$ 3,594
Impaired loans with no related allowance recorded, Unpaid principal balance	3,248	3,775
Impaired loans with an allowance recorded, Related allowance	66
Impaired loans with an allowance recorded, Recorded investment	102
Impaired loans with an allowance recorded, Unpaid principal balance	102
Recorded investment	3,163	3,594
Unpaid principal balance	3,350	3,775
Commercial real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	1,179	2,507
Impaired loans with no related allowance recorded, Unpaid principal balance	1,176	2,446
Consumer real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	1,707	483
Impaired loans with no related allowance recorded, Unpaid principal balance	1,608	497
Construction and land development
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment		112
Impaired loans with no related allowance recorded, Unpaid principal balance		117
Impaired loans with an allowance recorded, Related allowance	66
Impaired loans with an allowance recorded, Recorded investment	102
Impaired loans with an allowance recorded, Unpaid principal balance	102
Commercial and industrial
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	168	487
Impaired loans with no related allowance recorded, Unpaid principal balance	457	710
Consumer
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	7	5
Impaired loans with no related allowance recorded, Unpaid principal balance	$ 7	$ 5

Loans and Allowance for Loan_10

Loans and Allowance for Loan Losses - Summary of Average Recorded Investment and Interest Income Recognized on Impaired Loans, Excluding PCI Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	$ 3,302	$ 4,577	$ 7,041
Impaired loans with no related allowance recorded, Interest income recognized	133	864	281
Impaired loans with an allowance recorded, Average recorded investment	107
Average recorded investment	3,409	4,577	7,041
Interest income recognized	133	864	281
Commercial real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	1,198	2,574	1,198
Impaired loans with no related allowance recorded, Interest income recognized	66	313	158
Consumer real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	1,975	1,037	185
Impaired loans with no related allowance recorded, Interest income recognized	66	105
Construction and land development
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment		119	94
Impaired loans with no related allowance recorded, Interest income recognized		4	2
Impaired loans with an allowance recorded, Average recorded investment	107
Commercial and industrial
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	121	824	5,557
Impaired loans with no related allowance recorded, Interest income recognized	1	440	121
Consumer
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	$ 8	23	$ 7
Impaired loans with no related allowance recorded, Interest income recognized		$ 2

Loans and Allowance for Loan_11

Loans and Allowance for Loan Losses - Schedule of Aging of Recorded Investment in Past-due Loans, by Class of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	$ 21,168	$ 7,624
Loans Not Past Due	1,869,851	1,412,478
Total purchased credit impaired	28,392	1,605
Total	1,891,019	1,420,102
Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,585	372
Loans Not Past Due	636,706	559,417
Total loans excluding purchased credit impaired	638,291	559,789
Total purchased credit impaired	5,541	110
Total	643,832	559,899
Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	8,367	4,476
Loans Not Past Due	318,909	251,013
Total loans excluding purchased credit impaired	327,276	255,489
Total purchased credit impaired	16,515	608
Total	343,791	256,097
Construction and land development
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	3,415	653
Loans Not Past Due	171,174	142,453
Total loans excluding purchased credit impaired	174,589	143,106
Total purchased credit impaired	270	5
Total	174,859	143,111
Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	3,367	1,725
Loans Not Past Due	624,418	391,819
Total loans excluding purchased credit impaired	627,785	393,544
Total purchased credit impaired	2,990	864
Total	630,775	394,408
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	317	93
Loans Not Past Due	41,354	28,315
Total loans excluding purchased credit impaired	41,671	28,408
Total purchased credit impaired	2,608	18
Total	44,279	28,426
Other
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	290
Loans Not Past Due	52,725	38,161
Total loans excluding purchased credit impaired	53,015	38,161
Total purchased credit impaired	468
Total	53,483	38,161
Purchased credit impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	3,827	305
Loans Not Past Due	24,565	1,300
Total purchased credit impaired	28,392	1,605
30 - 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	12,791	6,011
30 - 59 Days Past Due | Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	409	372
30 - 59 Days Past Due | Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	6,084	3,567
30 - 59 Days Past Due | Construction and land development
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,670	653
30 - 59 Days Past Due | Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,734	1,277
30 - 59 Days Past Due | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	270	67
30 - 59 Days Past Due | Other
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	252
30 - 59 Days Past Due | Purchased credit impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,372	75
60 - 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	4,011	497
60 - 89 Days Past Due | Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,596	408
60 - 89 Days Past Due | Construction and land development
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	745
60 - 89 Days Past Due | Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	38	8
60 - 89 Days Past Due | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	40
60 - 89 Days Past Due | Other
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	38
60 - 89 Days Past Due | Purchased credit impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,554	81
Greater than 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	4,366	1,116
Greater than 89 Days Past Due | Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,176
Greater than 89 Days Past Due | Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	687	501
Greater than 89 Days Past Due | Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,595	440
Greater than 89 Days Past Due | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	7	26
Greater than 89 Days Past Due | Purchased credit impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	$ 901	$ 149

Loans and Allowance for Loan_12

Loans and Allowance for Loan Losses - Schedule of Non-Accrual Loans, Past Due Loans over 89 Days and Accruing and Troubled Debt Restructurings by Class of Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	$ 4,816	$ 1,464
Past Due Over 89 Days and Accruing	3,295	38
Troubled Debt Restructurings	1,928	2,717
Commercial real estate
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	130
Past Due Over 89 Days and Accruing	1,176
Troubled Debt Restructurings	1,928	2,446
Consumer real estate
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	1,821	292
Past Due Over 89 Days and Accruing	342	12
Construction and Land Development
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	107	102
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	470	427
Past Due Over 89 Days and Accruing	1,205
Troubled Debt Restructurings		271
Consumer
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	9
Past Due Over 89 Days and Accruing	5	26
Purchased credit impaired
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	2,279	$ 643
Past Due Over 89 Days and Accruing	$ 567

Loans and Allowance for Loan_13

Loans and Allowance for Loan Losses - Schedule of Loans by Class Modified as TDR (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)Contract	Dec. 31, 2019USD ($)Contract	Dec. 31, 2018Contract
Financing Receivable Modifications [Line Items]
Number of contracts | Contract	2	2	0
Pre modification outstanding recorded investment	$ 721	$ 1,499
Post modification outstanding recorded investment, net of related allowance	$ 685	$ 1,499
Commercial real estate
Financing Receivable Modifications [Line Items]
Number of contracts | Contract		1
Pre modification outstanding recorded investment		$ 1,228
Post modification outstanding recorded investment, net of related allowance		$ 1,228
Consumer real estate
Financing Receivable Modifications [Line Items]
Number of contracts | Contract	2
Pre modification outstanding recorded investment	$ 721
Post modification outstanding recorded investment, net of related allowance	$ 685
Commercial and industrial
Financing Receivable Modifications [Line Items]
Number of contracts | Contract		1
Pre modification outstanding recorded investment		$ 271
Post modification outstanding recorded investment, net of related allowance		$ 271

Loans and Allowance for Loan_14

Loans and Allowance for Loan Losses - Summary of Contractually Required Payments (Details) $ in Thousands	Jul. 01, 2020USD ($)
Purchased Non-impaired Loans
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Acquired During Period [Line Items]
Contractually required payments	$ 296,527
Cash flows expected to be collected at acquisition	3,718
Fair value of PCI loans at acquisition date	260,701
Fair value of acquired loans at acquisition date	260,701
Contractual cash flows not expected to be collected	3,718
FCB and BOW Mergers | Purchased Credit Impaired
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Acquired During Period [Line Items]
Contractually required payments	42,443
Nonaccretable difference	4,501
Cash flows expected to be collected at acquisition	37,942
Accretable yield	4,349
Fair value of PCI loans at acquisition date	33,593
Fair value of acquired loans at acquisition date	33,593
Contractual cash flows not expected to be collected	$ 37,942

Loans and Allowance for Loan_15

Loans and Allowance for Loan Losses - Schedule of Activity in Purchased Credit Impaired Loans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Movement Schedule [Line Items]
Balance, beginning , carrying value	$ 1,605
Additions due to the acquisitions	33,593
Change due to payments received and accretion	(6,806)
Balance, ending, carrying value	28,392
Accretable Yield For PCI Loans
Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Movement Schedule [Line Items]
Balance, beginning , carrying value	915
Additions due to the acquisitions	4,349
Accretion	(1,196)
Balance, ending, carrying value	$ 4,068

Loans and Allowance for Loan_16

Loans and Allowance for Loan Losses - Schedule of Components of Direct Financing Leases (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
Total minimum lease payments receivable	$ 59
Less: Unearned income	(1)
Net leases	$ 58

Loan Servicing - Additional Inf

Loan Servicing - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Transfers And Servicing [Abstract]
Loan principal balance	$ 254,900,000	$ 196,900,000
Custodial escrow balances maintained In connection with serviced loans	$ 1,459,000	$ 324,000

Loan Servicing - Schedule of Ac

Loan Servicing - Schedule of Activity for Loan Servicing Rights and Related Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Loan servicing rights:
Balance at beginning of period	$ 1,755	$ 1,736
Additions	466	381
Amortized to offset other noninterest income	(587)	(362)
Balance at end of period	1,634	1,755
Valuation allowance:
Balance at beginning of period	(211)
Direct write-downs	(238)	(211)
Balance at end of period	$ (449)	$ (211)

Premises and Equipment - Summar

Premises and Equipment - Summary of Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Premises and equipment, gross	$ 36,190	$ 23,206
Less accumulated depreciation and amortization	(9,501)	(4,022)
Premises and equipment, net	$ 26,689	19,184
Minimum
Property Plant And Equipment [Line Items]
Premises and equipment, useful lives	1 year
Maximum
Property Plant And Equipment [Line Items]
Premises and equipment, useful lives	39 years
Buildings
Property Plant And Equipment [Line Items]
Premises and equipment, useful lives	39 years
Premises and equipment, gross	$ 19,461	13,331
Leasehold improvements
Property Plant And Equipment [Line Items]
Premises and equipment, gross	$ 939	939
Leasehold improvements | Minimum
Property Plant And Equipment [Line Items]
Premises and equipment, useful lives	1 year
Leasehold improvements | Maximum
Property Plant And Equipment [Line Items]
Premises and equipment, useful lives	17 years
Furniture and equipment
Property Plant And Equipment [Line Items]
Premises and equipment, gross	$ 6,910	4,633
Furniture and equipment | Minimum
Property Plant And Equipment [Line Items]
Premises and equipment, useful lives	1 year
Furniture and equipment | Maximum
Property Plant And Equipment [Line Items]
Premises and equipment, useful lives	7 years
Land
Property Plant And Equipment [Line Items]
Premises and equipment, gross	$ 6,885	$ 4,303
Fixed Assets In Process
Property Plant And Equipment [Line Items]
Premises and equipment, gross	$ 1,995

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Premises and equipment depreciation and amortization expense	$ 1,375,000	$ 1,219,000	$ 516,000

Leases - Additional Information

Leases - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease, expiration year	2032
Operating lease, liability	$ 11,940,000		$ 13,400,000	$ 13,400,000
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities
Operating lease, right-of-use asset	$ 11,200,000		$ 12,800,000	$ 12,800,000
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets
Operating lease, weighted average remaining lease term	9 years 8 months 12 days
Operating lease, weighted average discount rate, percent	3.40%
Sale and leaseback transaction	$ 0	$ 0

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 1,946	$ 1,868
Total lease cost	$ 1,946	$ 1,868

Leases - Maturity Analysis of O

Leases - Maturity Analysis of Operating Lease Liabilities and Reconciliation of Undiscounted Cash Flows (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jan. 01, 2019	Dec. 31, 2018
Lease payments due:
2021	$ 1,726
2022	1,605
2023	1,558
2024	1,266
2025	1,234
2026 and thereafter	6,581
Total undiscounted cash flows	13,970
Discount on cash flows	(2,030)
Operating lease, liability	$ 11,940	$ 13,400	$ 13,400

Goodwill And Intangible Asset_2

Goodwill And Intangible Assets - Summary of Change In Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning of year	$ 37,510	$ 37,510
Acquired goodwill	3,558	0
Impairment	0	0
End of year	$ 41,068	$ 37,510

Goodwill And Intangible Asset_3

Goodwill And Intangible Assets - Summary of Acquired Intangible Assets (Details) - Core Deposit - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 12,837	$ 9,267
Accumulated Amortization	$ (4,207)	$ (2,384)

Goodwill And Intangible Asset_4

Goodwill And Intangible Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Aggregate amortization expense	$ 1,824,000	$ 1,655,000	$ 465,000

Goodwill And Intangible Asset_5

Goodwill And Intangible Assets - Summary of Estimated Amortization Expense (Details) $ in Thousands	Dec. 31, 2020USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2021	$ 1,939
2022	1,690
2023	1,441
2024	1,192
2025	943
Thereafter	1,425
Total	$ 8,630

Other Real Estate Owned - Summa

Other Real Estate Owned - Summary of Other Real Estate Owned Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Real Estate Roll Forward
Beginning balance	$ 1,044	$ 988	$ 0
Additions due to acquisitions	571	0	988
Loans transferred to other real estate owned	452	180	0
Direct write-downs	0	0	0
Sales of other real estate owned	(1,544)	(124)	0
End of year	$ 523	$ 1,044	$ 988

Other Real Estate Owned - Addit

Other Real Estate Owned - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Real Estate Roll Forward
Valuation allowance allocated to properties	$ 0	$ 0	$ 0

Other Real Estate Owned - Sum_2

Other Real Estate Owned - Summary of Expenses Related to Other Real Estate Owned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Real Estate [Abstract]
Net gain on sales	$ (273)	$ (3)	$ 0
Provision for unrealized losses	0	0	0
Operating expenses, net of rental income	0	0	0
Total	$ (273)	$ (3)	$ 0

Deposits - Additional Informati

Deposits - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Deposits [Abstract]
FDIC deposit insurance limit	$ 250,000	$ 250,000
Time deposits	64,110,000	53,481,000
Deposit accounts in overdraft status reclassified to loans	$ 558,000	$ 148,000

Deposits - Scheduled Maturities

Deposits - Scheduled Maturities of Time Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Maturities Of Time Deposits [Abstract]
2021	$ 377,164
2022	51,160
2023	20,136
2024	13,753
2025	6,702
Thereafter	613
Total	$ 469,528	$ 303,452

Short-Term Borrowings And Lon_3

Short-Term Borrowings And Long-Term Debt - Additional Information (Details)	3 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)BasisPoint	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Short-term borrowings		$ 10,000,000	$ 10,000,000
Proceeds from issuance of subordinated notes, net of debt issuance expense		29,387,000
Subordinated Notes
Debt Instrument [Line Items]
Proceeds from issuance of subordinated notes, net of debt issuance expense	$ 30,000,000
Debt issuance costs		$ 600,000
Maturity date		Jun. 30, 2030
Redemption date		Jun. 30, 2025
Fixed interest rate		5.25%
Debt instrument, frequency of periodic interest payment		quarterly
Debt instrument, description of variable rate basis		The notes have a fixed interest rate of 5.25% per annum for the first five years. Thereafter, the interest rate will reset quarterly to an interest rate per annum equal to a benchmark rate (which is expected to be Three-Month Term SOFR) plus 513 basis points.
Carrying value of subordinated notes		$ 29,400,000	$ 0
Subordinated Notes | SOFR
Debt Instrument [Line Items]
Debt instrument, interest rate plus basis point | BasisPoint		513
Investment securities, FHLB stock and commercial and residential real estate mortgage loans
Debt Instrument [Line Items]
Federal Home Loan Bank Advances Collateralized Investment Securities Value		$ 2,300,000
Mortgage loans collateralized amount		808,400,000
Amount of available credit		$ 433,900,000

Short-Term Borrowings And Lon_4

Short-Term Borrowings And Long-Term Debt - Summary of Contractual Maturities and Average Effective Rates of Outstanding Advances (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
2020		$ 10,000,000
2021	$ 10,000,000
Total amount	$ 10,000,000	$ 10,000,000
2020		2.05%
2021	0.33%
Total interest rates	0.33%	2.05%

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Summary of Changes In Accumulated Other Comprehensive Income (Loss) By Component, Net of Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ 273,046	$ 254,379	$ 146,946
Other comprehensive income (loss) before reclassification, net of tax	3,758	5,641
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	2,587	(942)
Other comprehensive income (loss)	6,345	4,699	(789)
Ending balance	343,486	273,046	254,379
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(2,679)	(2,636)
Other comprehensive income (loss) before reclassification, net of tax		826
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	2,679	(869)
Other comprehensive income (loss)	2,679	(43)
Ending balance		(2,679)	(2,636)
Unrealized Gains and Losses on Available for Sale Securities
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	4,062	(680)
Other comprehensive income (loss) before reclassification, net of tax	3,758	4,815
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(92)	(73)
Other comprehensive income (loss)	3,666	4,742
Ending balance	7,728	4,062	(680)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	1,383	(3,316)	(2,527)
Other comprehensive income (loss)	6,345	4,699	(789)
Ending balance	$ 7,728	$ 1,383	$ (3,316)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Summary of Significant Amounts Reclassified out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest expense-savings and money market accounts													$ (5,196)	$ (7,266)	$ (5,446)
Net gain (loss) on sale of securities													125	(99)	3
Interest expense - Federal Home Loan Bank advances													(356)	(1,444)	(2,533)
Income tax (expense) benefit	$ (2,736)	$ (2,115)	$ (1,759)	$ 575	$ (1,613)	$ (2,072)	$ (1,814)	$ (1,346)	$ 535	$ (554)	$ (665)	$ (483)	(6,035)	(6,844)	(1,167)
Net income	$ 9,681	$ 7,487	$ 6,181	$ 1,346	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	24,696	22,422	9,655
Reclassification out of Accumulated Other Comprehensive Income | Realized Losses on Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest expense-savings and money market accounts													(2,466)	(635)	(441)
Interest expense - Federal Home Loan Bank advances													(213)	(243)	(479)
Income tax (expense) benefit														9	72
Net income													(2,679)	(869)	(848)
Reclassification out of Accumulated Other Comprehensive Income | Realized Gains and (Losses) on Available for Sale Securities
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Net gain (loss) on sale of securities													125	(99)	3
Income tax (expense) benefit													(33)	26	(1)
Net income													$ 92	$ (73)	2
Reclassification out of Accumulated Other Comprehensive Income | Realized Losses on Securities Transferred to Held to Maturity
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest income - securities															(14)
Income tax (expense) benefit															4
Net income															$ (10)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal													$ 8,822	$ 3,215	$ 15
State													1,552	1,044	(23)
Total Current tax expense (Benefit)													10,374	4,259	(8)
Deferred:
Federal													(3,523)	2,039	872
State													(816)	546	303
Total deferred tax expense (Benefit)													(4,339)	2,585	1,175
Total	$ 2,736	$ 2,115	$ 1,759	$ (575)	$ 1,613	$ 2,072	$ 1,814	$ 1,346	$ (535)	$ 554	$ 665	$ 483	$ 6,035	$ 6,844	$ 1,167

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Federal statutory income tax rate	21.00%	21.00%	21.00%
CARES act of 2020, net operating loss carryback period	5 years
CARES act of 2020 net operating loss income tax benefit	$ 800,000
Unrecognized income tax benefits	0	$ 0
Accrued interest related to uncertain tax positions	0	0
Accrued penalties related to uncertain tax positions	0	$ 0
Federal
Income Taxes [Line Items]
Federal net operating loss carryforwards	$ 2,511,000
Federal net operating loss carryforwards, start year	2030
Federal net operating loss carryforwards, end year	2032
Tennessee | State and Local Jurisdiction
Income Taxes [Line Items]
Excise tax rate	6.50%

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Actual Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Computed "expected" tax expense													$ 6,454	$ 6,146	$ 2,272
State income taxes, net of effect of federal income taxes													582	1,256	221
Tax-exempt interest income													(278)	(302)	(298)
Earnings on bank owned life insurance contracts													(186)	(173)	(559)
Disallowed expenses													69	84	93
Excess tax benefits related to stock compensation													91	(57)	(857)
Nondeductible acquisition expenses													132		281
CARES act net operating loss carryback													(772)
Other													(57)	(110)	14
Total	$ 2,736	$ 2,115	$ 1,759	$ (575)	$ 1,613	$ 2,072	$ 1,814	$ 1,346	$ (535)	$ 554	$ 665	$ 483	$ 6,035	$ 6,844	$ 1,167

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Allowance for loan losses	$ 5,040	$ 2,935
Net operating loss carryforward	527	738
Organization and preopening costs	261	359
Stock-based compensation	48	200
Acquired loans	939	871
Accrued contributions	288	247
Acquired deposits	459
Accrued compensation	3,159	22
Other	148	167
Deferred tax assets	10,869	5,539
Deferred tax liabilities:
Depreciation	1,633	804
Goodwill	311	154
Unrealized gain on securities available-for-sale	2,009	833
Amortization of core deposit intangible	1,608	1,052
Other acquired assets	509
Other	201	568
Deferred tax liabilities	6,271	3,411
Net deferred tax asset	$ 4,598	$ 2,128

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Financial Instruments Representing Credit Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Unused commitments to extend credit	$ 804,520	$ 672,933
Standby letters of credit	10,403	9,634
Total	$ 814,923	$ 682,567

Concentration of Credit Risk -

Concentration of Credit Risk - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Concentration Risk [Line Items]
Cash due from banks, federal funds sold and interest bearing deposits	$ 277,439,000	$ 101,269,000
Excess Of Insured Limits
Concentration Risk [Line Items]
Cash due from banks, federal funds sold and interest bearing deposits	$ 243,000,000	$ 86,000,000

Regulatory Matters And Restri_3

Regulatory Matters And Restrictions On Dividends - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)Capital	Dec. 31, 2019USD ($)
Banking And Thrift Interest [Abstract]
Number of capital categories | Capital	5
Dividends	$ 49.6	$ 35.8
Dividends paid	$ 4.1

Regulatory Matters And Restri_4

Regulatory Matters And Restrictions On Dividends - Schedule of Capital Amounts and Ratios (Details) $ in Thousands		Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
CapStar Financial Holdings, Inc.
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital to risk-weighted assets, actual amount		$ 338,426	$ 237,857
Tier I capital to risk-weighted assets, actual amount		285,439	225,074
Tier I capital to average assets, actual amount		$ 285,439	$ 225,074
Total capital to risk-weighted assets, actual ratio		0.1603	0.1345
Tier I capital to risk-weighted assets, actual ratio		0.1352	0.1273
Tier I capital to average assets, actual ratio		0.0960	0.1137
Total capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 168,910	$ 141,436
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	126,682	106,077
Tier I capital to average assets, minimum capital requirement amount	[1]	$ 118,877	$ 79,201
Total capital to risk-weighted assets, minimum capital requirement ratio	[1]	0.080	0.080
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	0.060	0.060
Tier I capital to average assets, minimum capital requirement ratio	[1]	0.040	0.040
CapStar Financial Holdings, Inc. | Common Stock
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier I capital to risk-weighted assets, actual amount		$ 285,439	$ 225,074
Tier I capital to risk-weighted assets, actual ratio		0.1352	0.1273
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 95,012	$ 79,558
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	0.045	0.045
CapStar Bank
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital to risk-weighted assets, actual amount		$ 324,152	$ 224,443
Tier I capital to risk-weighted assets, actual amount		300,588	211,660
Tier I capital to average assets, actual amount		$ 300,588	$ 211,660
Total capital to risk-weighted assets, actual ratio		0.1536	0.1270
Tier I capital to risk-weighted assets, actual ratio		0.1425	0.1198
Tier I capital to average assets, actual ratio		0.1012	0.1070
Total capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 168,808	$ 141,388
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	126,606	106,041
Tier I capital to average assets, minimum capital requirement amount	[1]	$ 118,780	$ 79,150
Total capital to risk-weighted assets, minimum capital requirement ratio	[1]	0.080	0.080
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	0.060	0.060
Tier I capital to average assets, minimum capital requirement ratio	[1]	0.040	0.040
Total capital to risk-weighted assets, minimum to be well capitalized amount	[2]	$ 211,010	$ 176,735
Tier I capital to risk-weighted assets, minimum to be well capitalized amount	[2]	168,808	141,388
Tier I capital to average assets, minimum to be well capitalized amount	[2]	$ 148,476	$ 98,938
Total capital to risk-weighted assets, minimum to be well capitalized ratio	[2]	0.100	0.100
Tier I capital to risk-weighted assets, minimum to be well capitalized ratio	[2]	0.080	0.080
Tier I capital to average assets, minimum to be well capitalized ratio	[2]	0.050	0.050
CapStar Bank | Common Stock
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier I capital to risk-weighted assets, actual amount		$ 284,088	$ 195,160
Tier I capital to risk-weighted assets, actual ratio		0.1346	0.1104
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 94,954	$ 79,531
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	0.045	0.045
Tier I capital to risk-weighted assets, minimum to be well capitalized amount	[2]	$ 137,156	$ 114,878
Tier I capital to risk-weighted assets, minimum to be well capitalized ratio	[2]	0.065	0.065
[1]	For the calendar year 2020, the Company was required to maintain a capital conservation buffer of Tier 1 common equity capital in excess of minimum risk-based capital ratios by at least 1.875% to avoid limits on capital distributions and certain discretionary bonus payments to executive officers and similar employees.
[2]	For the Company to be well-capitalized, the Bank must be well-capitalized and the Company must not be subject to any written agreement, order, capital directive, or prompt corrective action directive issued by the Federal Reserve to meet and maintain a specific capital level for any capital measure.

Regulatory Matters And Restri_5

Regulatory Matters And Restrictions On Dividends - Schedule of Capital Amounts and Ratios (Parenthetical) (Details)	Dec. 31, 2020
Banking And Thrift Interest [Abstract]
Minimum risk based capital ratios	1.875

Nonvoting and Series A Prefer_2

Nonvoting and Series A Preferred Stock and Stock Warrants - Additional Information (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2016	Jul. 14, 2008
Common Stock
Class Of Stock [Line Items]
Preferred shares converted to common stock		878,048
Initial Public Offering | Common Stock
Class Of Stock [Line Items]
Preferred shares converted to common stock			731,707
Nonvoting Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	5,000,000
Common stock, conversion basis	one-to-one basis
Stock issued and converted to common stock		132,561
Common stock, shares outstanding	0
Nonvoting Common Stock | Initial Public Offering
Class Of Stock [Line Items]
Stock issued and converted to common stock	79,166
Series A Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares issued				1,609,756
Preferred stock, shares outstanding	0

Stock Options and Restricted _3

Stock Options and Restricted Shares - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Total unrecognized compensation cost	$ 1,300,000
Total fair value of shares vested	$ 997,000	$ 1,352,000	$ 2,804,000
Contractual term	10 years
Options granted	0	50,000
Total unrecognized compensation cost	$ 124,000
Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cost expected to be recognized over a weighted-average period	1 year 6 months
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cost expected to be recognized over a weighted-average period	1 year 4 months 24 days
Minimum | Time-Vested Restricted Stock Units and Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	2 years
Minimum | Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards earning percentage	0.00%
Maximum | Time-Vested Restricted Stock Units and Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Maximum | Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards earning percentage	188.00%
CapStar Bank 2008 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of stock reserved for issuance of stock incentives	1,569,475
Shares issuable under both restricted share and stock option grants	242,325
CapStar Bank 2008 Stock Incentive Plan | Board of Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of stock reserved for issuance of stock incentives			400,000

Stock Options and Restricted _4

Stock Options and Restricted Shares - Summary of Company Recognized Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based compensation expense before income taxes	$ 1,223	$ 1,262	$ 2,079
Less: deferred tax benefit	(320)	(330)	(543)
Reduction of net income	$ 903	$ 932	$ 1,536

Stock Options and Restricted _5

Stock Options and Restricted Shares - Summary of Changes in Company's Nonvested Stock Awards (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Restricted Shares, Abstract
Restricted Shares, Nonvested Beginning Balance | shares	84,697
Restricted Shares, Granted | shares	144,557
Restricted Shares, Vested | shares	(76,715)
Restricted Shares, Forfeited | shares	(4,125)
Restricted Shares, Nonvested Ending Balance | shares	148,414
Weighted Average Grant Date Fair Value, Abstract
Weighted Average Grant Date Fair Value, Nonvested Beginning Balance | $ / shares	$ 17.44
Weighted Average Grant Date Fair Value, Granted | $ / shares	13.73
Weighted Average Grant Date Fair Value, Vested | $ / shares	16.50
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	14.45
Weighted Average Grant Date Fair Value, Nonvested Ending Balance | $ / shares	$ 14.39

Stock Options and Restricted _6

Stock Options and Restricted Shares - Summary of Fair Value of Options Granted Using Weighted Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Dividend yield	1.35%
Expected term (in years)	6 years 6 months
Expected stock price volatility	29.55%
Risk-free interest rate	2.25%

Stock Options and Restricted _7

Stock Options and Restricted Shares - Summary of Activity in Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Shares, Abstract
Shares Outstanding, Beginning Balance	271,202
Shares Outstanding, Granted	0	50,000
Shares Outstanding, Exercised	(24,613)
Shares Outstanding, Forfeited or Expired	(20,000)
Shares Outstanding, Ending Balance	226,589	271,202
Shares, Fully Vested and Expected to Vest	226,589
Shares, Exercisable at End of Period	193,255
Weighted Average Exercise Price, Abstract
Weighted Average Exercise Price Outstanding, Beginning Balance	$ 11.22
Weighted Average Exercise Price Outstanding, Exercised	6.75
Weighted Average Exercise Price Outstanding, Forfeited or expired	10.92
Weighted Average Exercise Price Outstanding, Ending Balance	11.73	$ 11.22
Weighted Average Exercise Price, Fully vested and expected to vest	11.73
Weighted Average Exercise Price, Exercisable at End of Period	$ 11.19
Weighted Average Remaining Contractual Term (year), Abstract
Weighted Average Remaining Contractual Term Outstanding	3 years 10 months 24 days
Weighted Average Remaining Contractual Term, Fully Vested and Expected to Vest	3 years 10 months 24 days
Weighted Average Remaining Contractual Term, Exercisable at End of Period	3 years 1 month 6 days

Stock Options and Restricted _8

Stock Options and Restricted Shares - Information Related to Stock Options (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Intrinsic value of options exercised	$ 188,662	$ 2,478,086	$ 7,654,738
Cash received from option exercises	105,847	1,930,737	6,897,845
Tax benefit realized from option exercises	$ 16,524	$ 103,847	$ 846,725
Weighted average fair value of options granted		$ 5.35

Employee Benefit Plans- Additio

Employee Benefit Plans- Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Annual contribution percentage	3.00%
Additional discretionary contribution of employees' salary percentage	6.00%
Company's contribution to 401(k) Plan	$ 801,000	$ 874,000	$ 639,000

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Details) - Designated as Hedging Instrument - Interest Rate Swaps - Cash Flow Hedges - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments [Line Items]
Notional amount	$ 0	$ 0
Remaining unrealized gains or losses in accumulated other comprehensive income recognized in net income	1,900,000
Derivative termination fees		$ 1,500,000
Unrealized gains or losses in accumulated other comprehensive income	$ 0
Gains (losses) relating to mortgage banking derivative instruments			$ 0

Derivative Instruments - Summar

Derivative Instruments - Summary of Customer Related Interest Rate Swaps (Details) - Interest Rate Swaps - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments [Line Items]
Notional	$ 119,892,000	$ 90,106,000
Pay fixed/receive variable swaps
Derivative Instruments [Line Items]
Notional	59,946,000	45,053,000
Estimated	(2,740,000)	(926,000)
Pay variable/receive fixed swaps
Derivative Instruments [Line Items]
Notional	59,946,000	45,053,000
Estimated	$ 2,740,000	$ 926,000

Derivative Instruments - Summ_2

Derivative Instruments - Summary of Net Gains (Losses) Relating to Mortgage Banking Derivative Instruments Included in Mortgage Banking Income (Details) - Mortgage Banking Derivative Instruments - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments [Line Items]
Net gains (losses) relating to mortgage banking derivative instruments	$ 1,481	$ 500
Mortgage Loan Interest Rate Lock Commitments
Derivative Instruments [Line Items]
Net gains (losses) relating to mortgage banking derivative instruments	1,959	648
Mortgage-Backed Securities Forward Sales Commitments
Derivative Instruments [Line Items]
Net gains (losses) relating to mortgage banking derivative instruments	$ (478)	$ (148)

Derivative Instruments - Summ_3

Derivative Instruments - Summary of Amount and Fair Value of Mortgage Banking Derivative Instruments Included in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other Assets | Mortgage Loan Interest Rate Lock Commitments
Derivative Instruments [Line Items]
Notional amount, assets	$ 88,303	$ 44,694
Estimated fair value, asset	2,607	648
Other Liabilities | Mortgage-Backed Securities Forward Sales Commitments
Derivative Instruments [Line Items]
Notional amount, liabilities	87,000	38,500
Estimated fair value, liabilities	$ (626)	$ (148)

Related Party - Additional Info

Related Party - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Impairment of loans	$ 0	$ 0
Directors Executive Officers, Shareholders and Affiliates
Related Party Transaction [Line Items]
Deposit from related parties	$ 38,500,000	$ 13,700,000

Related Party - Schedule of Rel

Related Party - Schedule of Related Party Transactions Activity within Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Total Commitment
Related Party Transaction [Line Items]
Beginning of period	$ 21,815	$ 44,812
New commitments/draw downs	200	9,336
Repayments	(3,991)	(32,333)
End of period	18,024	21,815
Total Funded Commitment
Related Party Transaction [Line Items]
Beginning of period	10,673	15,445
New commitments/draw downs	2,798	2,515
Repayments	(3,689)	(7,287)
End of period	$ 9,782	$ 10,673

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other real estate owned	$ 0	$ 0
Fair Value, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets on nonrecurring basis		$ 0

Fair Value - Summary of Assets

Fair Value - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Securities available-for-sale, at fair value	$ 486,215	$ 213,129
Loans held for sale carried at fair value	97,303	30,740
Obligations of States and Political Subdivisions
Assets:
Securities available-for-sale, at fair value	91,928	45,960
Asset-backed securities
Assets:
Securities available-for-sale, at fair value	3,193	3,197
Other debt securities
Assets:
Securities available-for-sale, at fair value	38,340	14,962
Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives
Derivative assets:
Mortgage loan interest rate lock commitments	2,607	648
Fair Value Measurements Recurring Basis
Assets:
Loans held for sale carried at fair value	97,303	168,222
Fair Value Measurements Recurring Basis | U.S. Government-sponsored Agencies
Assets:
Securities available-for-sale, at fair value	16,390	10,331
Fair Value Measurements Recurring Basis | Obligations of States and Political Subdivisions
Assets:
Securities available-for-sale, at fair value	91,930	45,960
Fair Value Measurements Recurring Basis | Mortgage-backed Securities-residential
Assets:
Securities available-for-sale, at fair value	336,361	138,679
Fair Value Measurements Recurring Basis | Asset-backed securities
Assets:
Securities available-for-sale, at fair value	3,193	3,197
Fair Value Measurements Recurring Basis | Other debt securities
Assets:
Securities available-for-sale, at fair value	38,341	14,962
Fair Value Measurements Recurring Basis | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives
Derivative assets:
Mortgage loan interest rate lock commitments	2,607	648
Fair Value Measurements Recurring Basis | Forward Sales Commitments | Non-hedging derivatives
Derivative liabilities:
Mortgage-backed securities forward sales commitments	(626)	(148)
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2)
Assets:
Loans held for sale carried at fair value	97,303	168,222
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | U.S. Government-sponsored Agencies
Assets:
Securities available-for-sale, at fair value	16,390	10,331
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Obligations of States and Political Subdivisions
Assets:
Securities available-for-sale, at fair value	91,930	45,960
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Mortgage-backed Securities-residential
Assets:
Securities available-for-sale, at fair value	336,361	138,679
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Assets:
Securities available-for-sale, at fair value	3,193	3,197
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Other debt securities
Assets:
Securities available-for-sale, at fair value	38,341	14,962
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Forward Sales Commitments | Non-hedging derivatives
Derivative liabilities:
Mortgage-backed securities forward sales commitments	(626)	(148)
Fair Value Measurements Recurring Basis | Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives
Derivative assets:
Mortgage loan interest rate lock commitments	2,607	648
Fair Value Measurements Recurring Basis | Customer Related | Non-hedging derivatives
Derivative assets:
Interest rate swaps - customer related	2,740
Total derivatives		926
Derivative liabilities:
Total derivatives	(2,740)	(926)
Fair Value Measurements Recurring Basis | Customer Related | Significant Other Observable Inputs (Level 2) | Non-hedging derivatives
Derivative assets:
Interest rate swaps - customer related	2,740
Total derivatives		926
Derivative liabilities:
Total derivatives	$ (2,740)	$ (926)

Fair Value - Reconciliation of

Fair Value - Reconciliation of Assets Measured at Fair Value on Recurring Basis using Significant Unobservable Inputs (Level 3) (Details) - Mortgage Loan Interest Rate Lock Commitments - Significant Unobservable Inputs (Level 3) - Fair Value Measurements Recurring Basis - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance of recurring Level 3 assets at January 1st	$ 648
Included in mortgage banking income	1,959	$ 648
Balance of recurring Level 3 assets at December 31st	$ 2,607	$ 648

Fair Value - Summary of Quantit

Fair Value - Summary of Quantitative Information About Level 3 Fair Value Measurements on Recurring and Non-recurring Basis (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Construction and land development | Fair Value, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 36
Significant Unobservable Inputs (Level 3) | Construction and land development | Fair Value, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation Technique(s)	Sales comparison approach
Unobservable Input(s)	Appraisal discounts
Impaired loans	$ 36
Significant Unobservable Inputs (Level 3) | Weighted Average | Construction and land development | Fair Value, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable inputs range	0.0010
Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Mortgage loan interest rate lock commitments	$ 2,607	$ 648
Valuation Technique(s)	Consensus pricing	Consensus pricing
Unobservable Input(s)	Origination pull-through rate	Origination pull-through rate
Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable inputs range	0.0054	0.0068
Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable inputs range	0.0091	0.0095
Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable inputs range	0.0074	0.0083

Fair Value - Summary of Asset_2

Fair Value - Summary of Assets Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Nonrecurring - Construction and land development $ in Thousands	Dec. 31, 2020USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 36
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 36

Fair Value - Summary of Carryin

Fair Value - Summary of Carrying Value and Fair Values of the Company's Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jul. 01, 2020	Dec. 31, 2019
Financial assets:
Securities available-for-sale, at fair value	$ 486,215		$ 213,129
Securities held to maturity, fair value	2,504		3,411
Loans held for sale carried at fair value	97,303		30,740
Loans		$ 294,700
Carrying amount
Financial assets:
Cash and due from banks, interest-bearing deposits in financial institutions	277,439		101,094
Federal funds sold			175
Securities available-for-sale, at fair value	486,215		213,129
Securities held to maturity, fair value	2,407		3,313
Loans held for sale carried at fair value	179,669		168,222
Restricted equity securities	15,562		13,689
Loans	1,891,019		1,420,102
Accrued interest receivable	8,771		5,792
Other assets	46,381		36,393
Financial liabilities:
Deposits	2,568,001		1,729,451
Federal Home Loan Bank advances and other borrowings	39,423		10,000
Other liabilities	3,334		1,394
Fair value | Level 1
Financial assets:
Cash and due from banks, interest-bearing deposits in financial institutions	277,439		101,094
Federal funds sold			175
Fair value | Level 2
Financial assets:
Securities available-for-sale, at fair value	486,215		213,129
Securities held to maturity, fair value	2,504		3,411
Loans held for sale carried at fair value	180,698		169,072
Accrued interest receivable	8,771		5,792
Financial liabilities:
Federal Home Loan Bank advances and other borrowings	41,400		10,014
Fair value | Level 3
Financial assets:
Loans	1,900,647		1,414,757
Financial liabilities:
Deposits	2,472,860		1,730,206
Other liabilities	3,334		1,394
Fair value | Level 2 / Level 3
Financial assets:
Other assets	$ 46,381		$ 36,393

Parent Company Only Financial_3

Parent Company Only Financial Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Other assets	$ 72,259	$ 59,668
Total assets	2,987,006	2,037,201
Liabilities and Shareholders’ Equity
Subordinated debt	29,423
Other liabilities	36,096	24,704
Total shareholders’ equity	343,486	273,046	$ 254,379	$ 146,946
Total liabilities and shareholders’ equity	2,987,006	2,037,201
CapStar Financial Holdings, Inc.
Assets
Cash and cash equivalents	13,176	12,874
Investment in consolidated subsidiary	358,635	259,632
Other assets	1,163	578
Total assets	372,974	273,084
Liabilities and Shareholders’ Equity
Subordinated debt	29,423
Other liabilities	65	38
Total shareholders’ equity	343,486	273,046
Total liabilities and shareholders’ equity	$ 372,974	$ 273,084

Parent Company Only Financial_4

Parent Company Only Financial Information - Condensed Income Statements (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income tax benefit	$ 2,736	$ 2,115	$ 1,759	$ (575)	$ 1,613	$ 2,072	$ 1,814	$ 1,346	$ (535)	$ 554	$ 665	$ 483	$ 6,035	$ 6,844	$ 1,167
Net income	$ 9,681	$ 7,487	$ 6,181	$ 1,346	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	24,696	22,422	$ 9,655
CapStar Financial Holdings, Inc.
Income - dividends from subsidiary													4,075	3,530
Interest expense subordinated debt													792
Other expenses													1,373	1,083
Income before income taxes and equity in undistributed net income of subsidiary													1,910	2,447
Income tax benefit													(552)	(262)
Income before equity in undistributed net income of subsidiary													2,462	2,709
Equity in undistributed net income of subsidiary													22,234	19,713
Net income													$ 24,696	$ 22,422

Parent Company Only Financial_5

Parent Company Only Financial Information - Condensed Statements of Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 9,681	$ 7,487	$ 6,181	$ 1,346	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 24,696	$ 22,422	$ 9,655
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Net cash provided by (used in) operating activities													24,051	(84,688)	33,585
Cash flows from investing activities:
Cash paid for acquisitions													(27,278)
Net cash (used in) provided by investing activities													(270,411)	47,290	(115,131)
Cash flows from financing activities:
Issuance of subordinated debt													29,387
Repurchase of common stock													(1,437)	(7,836)
Net cash provided by financing activities													422,530	33,224	104,192
Net increase (decrease) in cash and cash equivalents													176,170	(4,174)	22,646
Cash and cash equivalents at beginning of period				101,269				105,443				$ 82,797	101,269	105,443	82,797
Cash and cash equivalents at end of period	277,439				101,269				105,443				277,439	101,269	105,443
CapStar Financial Holdings, Inc.
Cash flows from operating activities:
Net income													24,696	22,422
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Increase in other assets													(2,962)	(3,304)
Increase (decrease) in other liabilities													27	(263)
Equity in undistributed net income of subsidiary													(22,234)	(19,713)
Net cash provided by (used in) operating activities													(473)	(858)
Cash flows from investing activities:
Cash paid for acquisitions													(27,278)
Dividends received from CapStar Bank													4,075	3,530
Net cash (used in) provided by investing activities													(23,203)	3,530
Cash flows from financing activities:
Issuance of subordinated debt													29,387
Repurchase of common stock													(1,437)	(7,836)
Exercise of common stock options and warrants													63	1,627
Common stock dividends paid													(4,035)	(3,507)
Net cash provided by financing activities													23,978	(9,716)
Net increase (decrease) in cash and cash equivalents													302	(7,044)
Cash and cash equivalents at beginning of period				$ 12,874				$ 19,918					12,874	19,918
Cash and cash equivalents at end of period	$ 13,176				$ 12,874				$ 19,918				$ 13,176	$ 12,874	$ 19,918

Quarterly Financial Results (_3

Quarterly Financial Results (Unaudited) - Summary of Quarterly Financial Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 24,731	$ 24,642	$ 20,741	$ 21,738	$ 22,205	$ 23,216	$ 23,158	$ 22,967	$ 22,900	$ 15,782	$ 15,354	$ 13,744	$ 91,852	$ 91,547	$ 67,781
Interest expense	2,400	4,986	3,066	5,077	5,624	6,060	6,150	5,965	5,184	4,239	3,767	2,898	15,529	23,799	16,089
Net interest income	22,331	19,656	17,675	16,661	16,581	17,156	17,008	17,002	17,716	11,543	11,587	10,846	76,323	67,748	51,692
Provision for loan losses	184	2,119	1,624	7,553		(125)		886	1,514	481	169	678	11,479	761	2,842
Net interest income after provision for loan losses	22,147	17,537	16,051	9,108	16,581	17,281	17,008	16,116	16,202	11,062	11,418	10,168	64,844	66,987	48,850
Noninterest income	11,748	14,804	10,823	5,874	5,719	6,788	7,032	4,735	6,387	3,218	2,765	3,088	43,248	24,274	15,459
Noninterest expense	21,478	22,739	18,934	14,211	15,266	15,531	16,470	14,725	23,832	10,070	10,005	9,580	77,361	61,995	53,487
Income before income taxes	12,417	9,602	7,940	771	7,034	8,538	7,570	6,126	(1,243)	4,210	4,178	3,676	30,731	29,266	10,822
Income tax expense	2,736	2,115	1,759	(575)	1,613	2,072	1,814	1,346	(535)	554	665	483	6,035	6,844	1,167
Net income	$ 9,681	$ 7,487	$ 6,181	$ 1,346	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 24,696	$ 22,422	$ 9,655
Net income (loss) per share, basic	$ 0.44	$ 0.34	$ 0.34	$ 0.07	$ 0.30	$ 0.36	$ 0.33	$ 0.27	$ (0.04)	$ 0.30	$ 0.30	$ 0.27	$ 1.22	$ 1.25	$ 0.73
Net income (loss) per share, diluted	$ 0.44	$ 0.34	$ 0.34	$ 0.07	$ 0.29	$ 0.35	$ 0.31	$ 0.25	$ (0.04)	$ 0.28	$ 0.27	$ 0.25	$ 1.22	$ 1.20	$ 0.67