CapStar Financial (CSTR) 10-K 6 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Mar. 05, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
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		18,457,537
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Current Reporting Status	Yes
Entity Shell Company	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			$ 230,802,508
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s Definitive Proxy Statement relating to the 2020 Annual Meeting of Shareholders, which will be filed within 120 days after December 31, 2019, 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, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 17,726	$ 17,967
Interest-bearing deposits in financial institutions	83,368	76,714
Federal funds sold	175	10,762
Total cash and cash equivalents	101,269	105,443
Securities available-for-sale, at fair value	213,129	243,808
Securities held-to-maturity, fair value of $3,411 and $3,785 at December 31, 2019 and 2018, respectively	3,313	3,734
Loans held for sale (includes $30,740 and $0 measured at fair value at December 31, 2019 and 2018, respectively)	168,222	57,618
Loans	1,420,102	1,429,794
Less allowance for loan losses	(12,604)	(12,113)
Loans, net	1,407,498	1,417,681
Premises and equipment, net	19,184	18,821
Restricted equity securities	13,689	12,038
Accrued interest receivable	5,792	5,964
Goodwill	37,510	37,510
Core deposit intangible, net	6,883	8,538
Other real estate owned, net	1,044	988
Other assets	59,668	51,740
Total assets	2,037,201	1,963,883
Deposits:
Non-interest-bearing	312,096	289,552
Interest-bearing	607,211	434,921
Savings and money market accounts	506,692	497,108
Time	303,452	348,427
Total deposits	1,729,451	1,570,008
Federal Home Loan Bank advances	10,000	125,000
Other liabilities	24,704	14,496
Total liabilities	1,764,155	1,709,504
Shareholders’ equity:
Series A Nonvoting Noncumulative Perpetual Convertible Preferred Stock, $1 par value; 5,000,000 shares authorized; 0 and 878,048 shares issued and outstanding at December 31, 2019 and 2018, respectively		878
Additional paid-in capital	207,083	211,789
Retained earnings	46,218	27,303
Accumulated other comprehensive loss, net of income tax	1,383	(3,316)
Total shareholders’ equity	273,046	254,379
Total liabilities and shareholders’ equity	2,037,201	1,963,883
Voting
Shareholders’ equity:
Common stock	$ 18,362	17,592
Nonvoting
Shareholders’ equity:
Common stock		$ 133

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Securities held to maturity, fair value	$ 3,411,000	$ 3,785,000
Loans held for sale carried at fair value	$ 30,740,000	$ 0
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	878,048
Preferred stock, shares outstanding	0	878,048
Voting
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	18,361,922	17,592,160
Common stock, shares outstanding	18,361,922	17,592,160
Nonvoting
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	5,000,000	5,000,000
Common stock, shares issued	0	132,561
Common stock, shares outstanding	0	132,561

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Loans, including fees	$ 82,828,000	$ 60,751,000	$ 45,601,000
Securities:
Taxable	4,619,000	4,184,000	3,696,000
Tax-exempt	1,438,000	1,201,000	1,230,000
Federal funds sold	26,000	63,000	41,000
Restricted equity securities	755,000	571,000	396,000
Interest-bearing deposits in financial institutions	1,881,000	1,011,000	551,000
Total interest income	91,547,000	67,781,000	51,515,000
Interest expense:
Interest-bearing deposits	7,538,000	4,164,000	2,447,000
Savings and money market accounts	7,266,000	5,446,000	3,188,000
Time deposits	7,542,000	3,940,000	2,445,000
Federal funds purchased	4,000	3,000	13,000
Securities sold under agreements to repurchase	5,000	3,000
Federal Home Loan Bank advances	1,444,000	2,533,000	1,559,000
Total interest expense	23,799,000	16,089,000	9,652,000
Net interest income	67,748,000	51,692,000	41,863,000
Provision for loan losses	761,000	2,842,000	12,870,000
Net interest income after provision for loan losses	66,987,000	48,850,000	28,993,000
Noninterest income:
Noninterest income	9,467,000	5,653,000	6,238,000
Net gain (loss) on sale of securities	(99,000)	3,000	(66,000)
Tri-Net fees, net	2,785,000	1,503,000	1,002,000
Other noninterest income	8,986,000	6,150,000	2,218,000
Total noninterest income	24,274,000	15,459,000	10,908,000
Noninterest expense:
Salaries and employee benefits	35,542,000	28,586,000	20,400,000
Data processing and software	6,961,000	3,835,000	2,786,000
Professional fees	2,102,000	1,608,000	1,522,000
Occupancy	3,345,000	2,336,000	2,025,000
Equipment	3,723,000	2,471,000	2,071,000
Regulatory fees	591,000	1,028,000	1,111,000
Merger related expenses	2,654,000	9,803,000
Amortization of intangibles	1,655,000	465,000	48,000
Other operating	5,422,000	3,355,000	3,802,000
Total noninterest expense	61,995,000	53,487,000	33,765,000
Income before income taxes	29,266,000	10,822,000	6,136,000
Income tax expense	6,844,000	1,167,000	4,635,000
Net income	$ 22,422,000	$ 9,655,000	$ 1,501,000
Per share information:
Basic net income per share of common stock	$ 1.25	$ 0.73	$ 0.13
Diluted net income per share of common stock	$ 1.20	$ 0.67	$ 0.12
Weighted average shares outstanding:
Basic	17,886,164	13,277,614	11,280,580
Diluted	18,613,224	14,480,347	12,803,511
Treasury Management And Other Deposit Service Charges
Noninterest income:
Noninterest income	$ 3,135,000	$ 2,150,000	$ 1,516,000
Mortgage Banking Income
Noninterest income:
Noninterest income	$ 9,467,000	$ 5,653,000	$ 6,238,000

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 22,422	$ 9,655	$ 1,501
Unrealized gains (losses) on securities available-for-sale:
Unrealized holding gains (losses) arising during the period	6,321	(2,491)	4,855
Reclassification adjustment for losses (gains) included in net income	99	(3)	66
Tax effect	(1,678)	652	(1,884)
Net of tax	4,742	(1,842)	3,037
Unrealized losses on securities transferred to held-to-maturity:
Reclassification adjustment for losses included in net income		14	190
Tax effect		(4)	(73)
Net of tax		10	117
Unrealized (losses) gains on cash flow hedges:
Unrealized holding (losses) gains arising during the period	(702)	263	(72)
Reclassification adjustment for losses included in net income	878	920	863
Tax effect	(219)	(140)	(62)
Net of tax	(43)	1,043	729
Other comprehensive income (loss)	4,699	(789)	3,883
Comprehensive income	$ 27,121	$ 8,866	$ 5,384

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($)	Total	Preferred Stock	Common Stock, Voting	Common Stock, Nonvoting	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2016	$ 139,207,000	$ 878,000	$ 11,205,000		$ 116,143,000	$ 17,132,000	$ (6,151,000)
Beginning balance, shares at Dec. 31, 2016			11,204,515
Net issuance of restricted common stock	(244,000)		$ 36,000		(280,000)
Net issuance of restricted common stock, shares			35,714
Stock-based compensation expense	1,061,000				1,061,000
Excess tax benefit from stock compensation	1,011,000		$ 154,000		857,000
Excess tax benefit from stock compensation			154,050
Net exercise of common stock options	527,000		$ 55,000	$ 133,000	339,000
Net exercise of common stock options, shares			55,186	132,561
Reclassification of accumulated other comprehensive income due to tax rate change						259,000	(259,000)
Net income	1,501,000					1,501,000
Other Comprehensive income (loss)	3,883,000						3,883,000
Ending balance at Dec. 31, 2017	146,946,000	878,000	$ 11,450,000	$ 133,000	118,120,000	18,892,000	(2,527,000)
Ending balance, shares at Dec. 31, 2017			11,449,465	132,561
Net issuance of restricted common stock	(445,000)		$ 107,000		(552,000)
Net issuance of restricted common stock, shares			107,640
Stock-based compensation expense	2,079,000				2,079,000
Net exercise of common stock options	3,653,000		$ 667,000		2,986,000
Net exercise of common stock options, shares			666,964
Exercise of common stock warrants	1,606,000		$ 186,000		1,420,000
Exercise of common stock warrants, shares			186,175
Issuance of common stock in conjunction with Athens acquisition, net of issuance costs	92,918,000		$ 5,182,000		87,736,000
Issuance of common stock in conjunction with Athens acquisition, net of issuance costs, shares			5,181,916
Common and preferred stock dividends declared	(1,244,000)					(1,244,000)
Net income	9,655,000					9,655,000
Other Comprehensive income (loss)	(789,000)						(789,000)
Ending balance at Dec. 31, 2018	254,379,000	878,000	$ 17,592,000	$ 133,000	211,789,000	27,303,000	(3,316,000)
Ending balance, shares at Dec. 31, 2018			17,592,160	132,561
Net issuance of restricted common stock	(304,000)		$ (9,000)		(295,000)
Net issuance of restricted common stock, shares			(8,721)
Stock-based compensation expense	1,262,000				1,262,000
Net exercise of common stock options	$ 1,931,000		$ 273,000		1,658,000
Net exercise of common stock options, shares	286,701		272,660
Reclassification of accumulated other comprehensive income due to tax rate change	$ 259,000
Conversion of preferred stock to common stock		$ (878,000)	$ 878,000
Conversion of preferred stock, shares			878,048
Conversion of non-voting common stock to common stock			$ 133,000	$ (133,000)
Conversion of non-voting common stock to common stock, shares			132,561	(132,561)
Repurchase of common stock	(7,836,000)		$ (505,000)		(7,331,000)
Repurchase of common stock, shares			(504,786)
Common and preferred stock dividends declared	(3,507,000)					(3,507,000)
Net income	22,422,000					22,422,000
Other Comprehensive income (loss)	4,699,000						4,699,000
Ending balance at Dec. 31, 2019	$ 273,046,000		$ 18,362,000		$ 207,083,000	$ 46,218,000	$ 1,383,000
Ending balance, shares at Dec. 31, 2019			18,361,922

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement Of Stockholders Equity [Abstract]
Common and preferred stock, dividends per share	$ 0.05	$ 0.04

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 22,422,000	$ 9,655,000	$ 1,501,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for loan losses	761,000	2,842,000	12,870,000
Accretion of discounts on acquired loans and deferred fees	(3,737,000)	(2,978,000)	(1,533,000)
Depreciation and amortization	2,883,000	1,028,000	450,000
Net amortization of premiums on investment securities	807,000	1,007,000	1,259,000
Net loss (gain) on sale of securities	99,000	(3,000)	66,000
Mortgage banking income	(9,467,000)	$ (5,653,000)	$ (6,238,000)
Type of Revenue [Extensible List]		us-gaap:MortgageBankingMember	us-gaap:MortgageBankingMember
Tri-Net fees	(2,785,000)	$ (1,503,000)	$ (1,002,000)
Net gain on sale of loans	(803,000)	(248,000)	(113,000)
Net loss on disposal of premises and equipment			137,000
Net gain on sale of other real estate owned	(3,000)	0	0
Stock-based compensation	1,262,000	2,079,000	1,061,000
Deferred income tax expense	2,585,000	1,175,000	4,385,000
Origination of loans held for sale	(824,021,000)	(516,341,000)	(565,372,000)
Proceeds from loans held for sale	725,669,000	540,448,000	540,123,000
Cash payments arising from operating leases	(1,786,000)
Net (increase) decrease in accrued interest receivable and other assets	(10,461,000)	1,395,000	(1,760,000)
Net increase (decrease) in accrued interest payable and other liabilities	11,887,000	682,000	(2,448,000)
Net cash provided by (used in) operating activities	(84,688,000)	33,585,000	(16,614,000)
Activities in securities available-for-sale:
Purchases	(59,473,000)	(44,787,000)	(30,525,000)
Sales	68,068,000	38,322,000	46,762,000
Maturities, prepayments and calls	27,624,000	19,245,000	18,828,000
Activities in securities held-to-maturity:
Maturities, prepayments and calls	395,000		1,560,000
Purchase of restricted equity securities	(1,651,000)	(12,000)	(2,774,000)
Net increase (decrease) in loans	13,782,000	(139,124,000)	(20,916,000)
Purchase of premises and equipment	(1,582,000)	(4,244,000)	(1,075,000)
Proceeds from sale of other real estate owned	127,000
Proceeds from sale of premises and equipment			3,000
Proceeds from BOLI death benefit		3,416,000
Cash received from acquisitions, net		12,053,000
Net cash provided by (used in) investing activities	47,290,000	(115,131,000)	11,863,000
Cash flows from financing activities:
Net increase (decrease) in deposits	159,443,000	45,622,000	(8,857,000)
Proceeds from Federal Home Loan Bank advances	75,000,000	125,000,000	135,000,000
Payments on Federal Home Loan Bank advances	(190,000,000)	(70,000,000)	(120,000,000)
Repurchase of common stock	(7,836,000)
Exercise of common stock options and warrants, net of repurchase of restricted shares	1,627,000	4,814,000	1,294,000
Termination of interest rate swap agreement	(1,503,000)
Common and preferred stock dividends paid	(3,507,000)	(1,244,000)
Net cash provided by financing activities	33,224,000	104,192,000	7,437,000
Net increase (decrease) in cash and cash equivalents	(4,174,000)	22,646,000	2,686,000
Cash and cash equivalents at beginning of period	105,443,000	82,797,000	80,111,000
Cash and cash equivalents at end of period	101,269,000	105,443,000	82,797,000
Supplemental disclosures of cash paid:
Interest paid	24,216,000	15,378,000	9,540,000
Income taxes	716,000	1,716,000	1,047,000
Supplemental disclosures of noncash transactions:
Transfer of loans to other real estate	180,000	0	0
Loans charged off to the allowance for loan and lease losses	798,000	$ 4,954,000	12,769,000
Conversion of preferred stock and non-voting common stock	1,011,000
Lease liabilities arising from obtaining right-of-use assets	$ 13,512,000
Securities transferred from held-to-maturity to available-for-sale			41,665,000
Loans transferred from held-for-sale to held-for-investment			$ 507,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 and for each of the three years in the period ended December 31, 2019 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 24 - 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 $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, 2019 (dollars in thousands): Fair Value Aggregate Unpaid Principal Balance Difference 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, 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 six classes of loans for financial reporting purposes: commercial real estate, consumer real estate, construction and land development, commercial and industrial, consumer 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. 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 33 quarter look-back period as of December 31, 2017. Subsequently, the Company increased its look-back period for a total of 37 quarters and 41 quarters as of December 31, 2018 and 2019, 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 $340,000 and $102,000 for the years ended December 31, 2019 and 2018, respectively. There were no servicing fees for the year ended December 31, 2017. 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. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. 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. The Company has selected October 31st as the date to perform the annual impairment test. 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, 2016 through 2019. 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 vest, and the corresponding aggregate expense is adjusted to reflect the elapsed portion of the performance period. Advertising Costs Advertising costs are expensed as incurred. Advertising expense was approximately $370,000, $383,000 and $310,000 for the years ended December 31, 2019, 2018 and 2017, respectively and is included in other operating expenses on the Consolidated Statements of Income. 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 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

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Acquisition	NOTE 2 – ACQUISITIONS On October 1, 2018, the Company acquired 100% of the outstanding common shares of Athens Bancshares Company (“Athens”), the bank holding company for Athens Federal Community Bank, National Association (“Athens Federal”). Under the terms of the acquisition, Athens common shareholders received 2.864 shares of the Company’s common stock in exchange for each share of Athens common stock. With the acquisition, the Company further expanded its franchise into the East Tennessee market. Athens’ results of operations were included in the Company’s results beginning October 1, 2018. Acquisition related costs of $9,803,000 are included in the Company’s income statement for the year ended December 31, 2018. The fair value of the common shares issued as part of the consideration paid for Athens was determined by the closing price of the Company’s common shares immediately preceding the acquisition date. Goodwill of $31,291,000 arising from the acquisition consisted largely of synergies and the cost savings resulting from the combining of the operations of the companies. Goodwill associated with the Athens acquisition is not amortizable for book or tax purposes. The following table summarizes the consideration paid for Athens and the amounts of the assets acquired and liabilities assumed recognized at the acquisition date (in thousands): As recorded by Athens Bancshares Initial fair value adjustments Measurement period adjustments As recorded by CapStar Financial Holdings Assets: Cash and cash equivalents $ 12,053 $ — $ — $ 12,053 Securities 67,342 84 (a) — 67,426 Loans, gross 349,597 (4,764 ) (b) — 344,833 Allowance for loan losses (4,039 ) 4,039 (c) — — Premises and equipment, net 7,637 1,571 (d) — 9,208 Core deposit intangible 2,758 6,222 (e) — 8,980 Other 29,566 944 (f) — 30,510 Total $ 464,914 $ 8,096 $ — $ 473,010 Liabilities: Deposits $ 404,027 $ 493 (g) $ — $ 404,520 Other 5,363 1,500 (h) — 6,863 Total $ 409,390 $ 1,993 $ — $ 411,383 Net identifiable assets acquired $ 61,627 Total cost of acquisition: Value of stock issued $ 86,538 Value of rolled stock options 6,380 Total cost of acquisition $ 92,918 $ 92,918 Goodwill recorded related to acquisition $ 31,291 (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 Athens’ 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 Athens’ existing allowance for loan losses. (d) The amount represents the adjustment of the net book value of Athens’ premises and equipment to their estimated fair value. (e) The amount represents the net adjustment of removing Athens’ existing core deposit intangible from prior acquisitions and 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 fair value of mortgage servicing rights acquired and the deferred tax asset recognized on the fair value adjustments on Athens acquired assets and assumed liabilities. (g) The amount represents the adjustment necessary because the weighted average interest rate of Athens’ 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. (h) The amount represents the liability assumed in connection with the merger agreement whereby the Company will make a $1,500,000 charitable contribution to the Athens Foundation over a three year period. The following unaudited pro forma financial information presents the combined results of the Company and Athens as if the acquisition had occurred as of January 1, 2017, 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 and Athens constituted a single entity during such periods (in thousands, except share data): Pro forma combined twelve months ended December 31, 2018 Pro forma combined twelve months ended December 31, 2017 Net interest income $ 66,935 $ 59,148 Noninterest income 20,692 17,540 Total revenue 87,627 76,688 Net income 21,167 5,851 Per share information: Basic net income per share of common stock $ 1.24 $ 0.36 Diluted net income per share of common stock $ 1.14 $ 0.32

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 was as follows (in thousands): December 31, 2019 December 31, 2018 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 $ 10,421 $ 4 $ (94 ) $ 10,331 $ 11,053 $ — $ (347 ) $ 10,706 State and municipal securities 44,053 1,927 (20 ) 45,960 62,142 765 (981 ) 61,926 Mortgage-backed securities 137,305 1,834 (460 ) 138,679 146,547 776 (3,165 ) 144,158 Asset-backed securities 3,325 — (128 ) 3,197 15,437 4 (157 ) 15,284 Other debt securities 14,839 141 (18 ) 14,962 11,863 71 (200 ) 11,734 Total $ 209,943 $ 3,906 $ (720 ) $ 213,129 $ 247,042 $ 1,616 $ (4,850 ) $ 243,808 Securities held-to-maturity: State and municipal securities $ 3,313 $ 98 $ — $ 3,411 $ 3,734 $ 54 $ (3 ) $ 3,785 Total $ 3,313 $ 98 $ — $ 3,411 $ 3,734 $ 54 $ (3 ) $ 3,785 During the third quarter of 2013, approximately $36,789,000 of available for sale securities were transferred to the held to maturity category. The transfers of the securities into the held to maturity category from the available for sale category were made at fair value at the date of transfer. The unrealized holding loss at the date of the transfer continues to be reported in a separate component of shareholders’ equity and is being amortized over the remaining life of the securities as an adjustment of yield in a manner consistent with the amortization of the premiums and discounts. During the fourth quarter of 2017, approximately $41,665,000 of held to maturity securities were transferred to the available for sale category. The Company was able to make the transfer due to early adoption of ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities. The amortized cost and fair value of debt and equity securities at December 31, 2019, 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 $ 9,805 $ 9,909 $ 881 $ 884 Due one to five years 28,593 29,230 2,432 2,527 Due five to ten years 29,545 30,758 — — Due beyond ten years 1,370 1,356 — — Mortgage-backed securities 137,305 138,679 — — Asset-backed securities 3,325 3,197 — — $ 209,943 $ 213,129 $ 3,313 $ 3,411 Results from sales of debt and equity securities were as follows (in thousands): Year ended December 31 2019 2018 2017 Proceeds $ 68,068 $ 38,322 $ 46,762 Gross gains 49 116 124 Gross losses (148 ) (113 ) (190 ) The table above does not include activity from maturities, prepayments or calls on debt or equity securities. Securities with a market value of $70,350,000 and $171,542,000 at December 31, 2019 and 2018, respectively, were pledged to collateralize public deposits, derivative positions and Federal Home Loan Bank advances. At December 31, 2019 and 2018 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, 2019 Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses 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 ) December 31, 2018 U. S. government agency securities $ — $ — $ 10,706 $ (347 ) $ 10,706 $ (347 ) State and municipal securities 13,455 (212 ) 17,376 (772 ) 30,831 (984 ) Mortgage-backed securities 7,075 (17 ) 87,232 (3,148 ) 94,307 (3,165 ) Asset-backed securities 8,262 (145 ) 2,439 (12 ) 10,701 (157 ) Other debt securities 5,362 (200 ) — — 5,362 (200 ) Total temporarily impaired securities $ 34,154 $ (574 ) $ 117,753 $ (4,279 ) $ 151,907 $ (4,853 ) 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, 2019. There were no other-than-temporary impairments for the years ended December 31, 2019, 2018 or 2017.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Loans and Allowance for Loan and Lease Losses	NOTE 4 – LOANS AND ALLOWANCE FOR LOAN LOSSES Loans at December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Commercial real estate $ 559,899 $ 550,446 Consumer real estate 256,097 253,562 Construction and land development 143,111 174,670 Commercial and industrial 394,408 404,600 Consumer 28,426 25,615 Other 38,161 20,901 Total 1,420,102 1,429,794 Allowance for loan losses (12,604 ) (12,113 ) Total loans, net $ 1,407,498 $ 1,417,681 At December 31, 2019, variable-rate and fixed-rate loans totaled $785,329,000 and $634,773,000, respectively. At December 31, 2018, variable-rate and fixed-rate loans totaled $827,491,000 and $602,404,000, 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, 2019 and 2018 (in thousands): Non-impaired Loans December 31, 2019 Pass Special Mention Substandard Total Non-impaired Total Loans Total Commercial real estate $ 551,929 $ 915 $ 4,438 $ 557,282 $ 2,617 $ 559,899 Consumer real estate 252,952 503 1,551 255,006 1,091 256,097 Construction and land development 142,978 — 16 142,994 117 143,111 Commercial and industrial 370,475 14,341 8,241 393,057 1,351 394,408 Consumer 28,382 6 15 28,403 23 28,426 Other 38,161 — — 38,161 — 38,161 Total $ 1,384,877 $ 15,765 $ 14,261 $ 1,414,903 $ 5,199 $ 1,420,102 December 31, 2018 Commercial real estate $ 547,616 $ 177 $ 1,262 $ 549,055 $ 1,391 $ 550,446 Consumer real estate 249,273 1,676 1,691 252,640 922 253,562 Construction and land development 174,591 52 19 174,662 8 174,670 Commercial and industrial 388,719 7,790 6,545 403,054 1,546 404,600 Consumer 25,556 1 27 25,584 31 25,615 Other 20,901 — — 20,901 — 20,901 Total $ 1,406,656 $ 9,696 $ 9,544 $ 1,425,896 $ 3,898 $ 1,429,794 None of the Company’s loans had a risk rating of “Doubtful” as of December 31, 2019 or 2018. The following tables detail the changes in the ALL for the years ending December 31, 2019, 2018 and 2017 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, 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 Year ended December 31, 2017 Balance, beginning of period $ 2,655 $ 1,013 $ 1,574 $ 5,618 $ 76 $ 698 $ 11,634 Charged-off loans — — — (12,769 ) — — (12,769 ) Recoveries 9 — — 1,865 112 — 1,986 Provision for loan losses 660 50 54 12,495 (97 ) (292 ) 12,870 Balance, end of period $ 3,324 $ 1,063 $ 1,628 $ 7,209 $ 91 $ 406 $ 13,721 A breakdown of the ALL and the loan portfolio by loan category at December 31, 2019 and 2018 follows (in thousands): Commercial real estate Consumer real estate Construction and land development Commercial and industrial Consumer Other Total 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 — — — — — — — Acquired with deteriorated credit quality — — — — — — — 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 Acquired with deteriorated credit quality 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 December 31, 2018 Allowance for Loan Losses: Collectively evaluated for impairment $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 Individually evaluated for impairment — — — — — — — Loans acquired with deteriorated credit quality — — — — — — — Balances, end of period $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 Loans: Collectively evaluated for impairment $ 549,055 $ 252,640 $ 174,662 $ 403,054 $ 25,584 $ 20,901 $ 1,425,896 Individually evaluated for impairment 1,278 183 — 817 — — 2,278 Acquired with deteriorated credit quality 113 739 8 729 31 — 1,620 Balances, end of period $ 550,446 $ 253,562 $ 174,670 $ 404,600 $ 25,615 $ 20,901 $ 1,429,794 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, 2019 and 2018 (dollars in thousands): December 31, 2019 December 31, 2018 Amount Percent of total loans Amount Percent of total loans Commercial real estate $ 3,599 0.25 % $ 3,309 0.23 % Consumer real estate 1,231 0.09 % 1,005 0.07 % Construction and land development 2,058 0.14 % 2,431 0.17 % Commercial and industrial 5,074 0.36 % 5,036 0.35 % Consumer 222 0.02 % 105 0.01 % Other 420 0.03 % 227 0.02 % Total allowance for loan and lease losses $ 12,604 0.89 % $ 12,113 0.85 % The following table presents information related to impaired loans as of and for the years ended December 31, 2019 and 2018 (in thousands): December 31, 2019 December 31, 2018 Recorded investment Unpaid principal balance Related allowance Recorded investment Unpaid principal balance Related allowance With no related allowance recorded: Commercial real estate $ 2,617 $ 2,621 $ — $ 1,391 $ 1,775 $ — Consumer real estate 1,091 1,327 — 922 1,204 — Construction and land development 117 132 — 8 18 — Commercial and industrial 1,351 2,173 — 1,546 6,350 — Consumer 23 41 — 31 56 — Other — — — — — — Subtotal 5,199 6,294 — 3,898 9,403 — With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development — — — — — — Commercial and industrial — — — — — — Consumer — — — — — — Other — — — — — — Subtotal — — — — — — Total $ 5,199 $ 6,294 $ — $ 3,898 $ 9,403 $ — 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 for the years ended December 31, 2019, 2018 and 2017 (in thousands): Year Ended Year Ended Year Ended December 31, 2019 December 31, 2018 December 31, 2017 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 $ 2,574 $ 313 $ 1,198 $ 158 $ 1,258 $ — Consumer real estate 1,037 105 185 — — — Construction and land development 119 4 94 2 — — Commercial and industrial 824 440 5,557 121 — — Consumer 23 2 7 — — — Other — — — — — — Subtotal 4,577 864 7,041 281 1,258 — With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development — — — — — — Commercial and industrial — — — — 2,077 — Consumer — — — — — — Other — — — — — — Subtotal — — — — 2,077 — Total $ 4,577 $ 864 $ 7,041 $ 281 $ 3,335 $ — There was no interest income recognized on a cash basis for impaired loans for the years ended December 31, 2019, 2018 or 2017. 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, 2019 and 2018 by class of loans (in thousands): 30 - 59 60 - 89 Greater Than Days Days 89 Days Total Loans Not December 31, 2019 Past Due Past Due Past Due Past Due Past Due Total Commercial real estate $ 372 $ — $ — $ 372 $ 559,527 $ 559,899 Consumer real estate 3,642 474 643 4,759 251,338 256,097 Construction and land development 653 15 — 668 142,443 143,111 Commercial and industrial 1,277 8 440 1,725 392,683 394,408 Consumer 67 — 33 100 28,326 28,426 Other — — — — 38,161 38,161 Total $ 6,011 $ 497 $ 1,116 $ 7,624 $ 1,412,478 $ 1,420,102 December 31, 2018 Commercial real estate $ 300 $ 227 $ — $ 527 $ 549,919 $ 550,446 Consumer real estate 69 75 775 919 252,643 253,562 Construction and land development — — — — 174,670 174,670 Commercial and industrial 54 — — 54 404,546 404,600 Consumer 52 — 43 95 25,520 25,615 Other — — — — 20,901 20,901 Total $ 475 $ 302 $ 818 $ 1,595 $ 1,428,199 $ 1,429,794 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, 2019 and 2018 (in thousands): Past Due Over 89 Days Troubled Debt Non-Accrual and Accruing Restructurings December 31, 2019 Commercial real estate $ — $ — $ 2,446 Consumer real estate 894 12 — Construction and land development 117 — — Commercial and industrial 440 — 271 Consumer 13 26 — Other — — — Total $ 1,464 $ 38 $ 2,717 December 31, 2018 Commercial real estate $ — $ — $ 1,391 Consumer real estate 1,187 214 — Construction and land development 19 — — Commercial and industrial 817 — — Consumer 55 — — Other — — — Total $ 2,078 $ 214 $ 1,391 As of December 31, 2019 and 2018 all loans classified as nonperforming were deemed to be impaired. As of December 31, 2019 and 2018 the Company had recorded investments in TDR of $2.7 million and $1.4 million, respectively. The Company did not allocate a specific allowance for those loans at December 31, 2019 or 2018 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. The following table presents loans by class modified as TDR that occurred during the year ended December 31, 2019 (in thousands). There were no TDR identified during the years ended December 31, 2018 or 2017. Year Ended December 31, 2019 Number of contracts Pre modification outstanding recorded investment Post modification outstanding recorded investment, net of related allowance 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, 2019, 2018 or 2017. A loan is considered to be in payment default once it is 30 days contractually past due under the modified terms. Acquired Loans On October 1, 2018, the Company acquired Athens (see Note 2 for more information). As a result of the acquisition, the Company recorded loans with a fair value of $344.8 million. Of those loans, $1.7 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 Athens 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): Athens Bancshares acquisition on October 1, 2018 Contractually required payments $ 3,151 Nonaccretable difference (1,049 ) Cash flows expected to be collected at acquisition 2,102 Accretable yield (436 ) Fair value of PCI loans at acquisition date $ 1,666 The following table relates to acquired Athens 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): Athens Bancshares acquisition on October 1, 2018 Contractually required payments $ 404,692 Fair value of acquired loans at acquisition date 343,167 Contractual cash flows not expected to be collected 1,807 The following table presents changes in the carrying value of PCI loans (in thousands): For the year ended December 31, 2019 Balance at beginning of period $ 1,620 Change due to payments received and accretion (15 ) Change due to loan charge-offs — Other — Balance at end of period $ 1,605 The following table presents changes in the accretable yield for PCI loans (in thousands): For the year ended December 31, 2019 Balance at beginning of period $ 440 Accretion (570 ) Reclassification from (to) nonaccretable difference 1,045 Other, net — Balance at end of period $ 915 PCI loans had no impact on the ALL for the years ended December 31, 2019, 2018 or 2017. 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, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Total minimum lease payments receivable $ 59 $ 379 Less: Unearned income (1 ) (19 ) Net leases $ 58 $ 360 The future minimum lease payments receivable under the direct financing leases as of December 31, 2019 were as follows (in thousands): Year ending December 31: 2020 $ 58 2021 — 2022 — 2023 — 2024 — $ 58

Loan Servicing

Loan Servicing	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 was $196.9 million and $170.1 million, respectively. These servicing rights were acquired in our acquisition of Athens. Custodial escrow balances maintained in connection with serviced loans was $324,000 and $462,000 at December 31, 2019 and 2018, respectively. Activity for loan servicing rights and the related valuation allowance are summarized as follows (in thousands): For the year ended December 31, 2019 Loan servicing rights: Balance at beginning of period $ 1,736 Additions 381 Disposals — Amortized to offset other noninterest income (362 ) Change in valuation allowance (211 ) Balance at end of period $ 1,544 Valuation allowance: Balance at beginning of period $ — Additions expensed — Reductions credited to other noninterest income — Direct write-downs (211 ) Balance at end of period $ (211 )

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Premises and Equipment	NOTE 6 – PREMISES AND EQUIPMENT Premises and equipment at December 31, 2019 and 2018 are summarized as follows (in thousands): Range of useful lives December 31, 2019 December 31, 2018 Land Not applicable $ 4,303 $ 2,997 Buildings 39 years 13,331 9,965 Leasehold improvements 1 to 17 years 939 939 Furniture and equipment 1 to 7 years 4,633 3,730 Fixed assets in process Not applicable — 4,023 23,206 21,654 Less accumulated depreciation and amortization (4,022 ) (2,833 ) $ 19,184 $ 18,821 Premises and equipment depreciation and amortization expense for the years ended December 31, 2019, 2018 and 2017 totaled $1,219,000, $516,000 and $401,000, respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
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, 2019, the Company had lease liabilities totaling $12.5 million and right-of-use assets totaling $11.7 million related to these leases. Lease liabilities and right-of-use assets are reflected in other liabilities and other assets, respectively. At December 31, 2019, the weighted average remaining lease term for operating leases was 10.7 years and the weighted average discount rate used in the measurement of operating lease liabilities was 3.52%. Lease costs were as follows (in thousands): December 31, 2019 Operating lease cost $ 1,868 Short-term lease cost — Variable least cost — Total lease cost $ 1,868 Rent expense for the year ended December 31, 2018, prior to the adoption of ASU 2016-02 was $1,677,000. There were no sale and leaseback transactions, leveraged leases, or lease transactions with related parties during the year ended December 31, 2019 or 2018. 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, 2019 Lease payments due: 2020 $ 1,562 2021 1,590 2022 1,476 2023 1,425 2024 1,130 2025 and thereafter 7,710 Total undiscounted cash flows 14,893 Discount on cash flows (2,442 ) Total lease liability $ 12,451

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 was as follows (in thousands): 2019 2018 Beginning of year $ 37,510 $ 6,219 Acquired goodwill — 31,291 Impairment — — End of year $ 37,510 $ 37,510 Impairment exists when a reporting unit’s carrying value of goodwill exceeds its fair value. At October 31, 2019, the Company’s reporting unit had positive equity and the Company elected to perform a qualitative assessment to determine if it was more likely than not that the fair value of the reporting unit exceeded its carrying value, including goodwill. The qualitative assessment indicated that it was more likely than not that the fair value of the reporting unit exceeded its carrying value, resulting in no impairment. Acquired Intangible Assets Acquired intangible assets at December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets: Core deposit intangibles $ 9,267 $ (2,384 ) $ 9,267 $ (729 ) Aggregate amortization expense was $1,655,000 for 2019, $465,000 for 2018 and $48,000 for 2017. Estimated amortization expense for each of the next five years is as follows (in thousands): Year ending December 31: 2020 $ 1,477 2021 1,299 2022 1,121 2023 943 2024 764 Thereafter 1,279 Total $ 6,883

Other Real Estate Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2019
Other Real Estate [Abstract]
Other Real Estate Owned	NOTE 9 – OTHER REAL ESTATE OWNED Other real estate owned activity was as follows (in thousands): 2019 2018 2017 Beginning balance $ 988 $ — $ — Additions due to acquisition of Athens Bancshares — 988 — Loans transferred to other real estate owned 180 — — Direct write-downs — — — Sales of other real estate owned (124 ) — — End of year $ 1,044 $ 988 $ — There was no valuation allowance allocated to properties held for the years ended December 31, 2019, 2018 and 2017. Expenses related to other real estate owned during the years ended December 31, 2019, 2018 and 2017, respectively include (in thousands): 2019 2018 2017 Net (gain) loss on sales $ (3 ) $ — $ — Provision for unrealized losses — — — Operating expenses, net of rental income — — — Total $ (3 ) $ — $ —

Deposits

Deposits	12 Months Ended
	Dec. 31, 2019
Deposits [Abstract]
Deposits	NOTE 10 – DEPOSITS Time deposits that exceed the FDIC deposit insurance limit of $250,000 at December 31, 2019 and 2018 were $53,481,000 and $98,086,000, respectively. Scheduled maturities of time deposits for the next five years and thereafter are as follows (in thousands): Maturity: 2020 $ 222,163 2021 53,077 2022 16,255 2023 8,369 2024 2,975 Thereafter 613 $ 303,452 At December 31, 2019 and 2018, the Company had $148,000 and $193,000, respectively of deposit accounts in overdraft status that were reclassified to loans in the accompanying balance sheets.

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances	12 Months Ended
	Dec. 31, 2019
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank Advances	NOTE 11 – FEDERAL HOME LOAN BANK ADVANCES The Company had outstanding borrowings totaling $10,000,000 and $125,000,000 at December 31, 2019 and 2018, respectively, 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, 2019 December 31, 2018 Year Amount Interest Rates Amount Interest Rates 2019 — — 125,000 2.48 % 2020 10,000 2.05 % — — 2021 — — — — 2022 — — — — 2023 — — — — 2024 — — — — Thereafter — — — — Total $ 10,000 2.05 % $ 125,000 2.48 % Advances from the FHLB are collateralized by investment securities with a market value of $4.1 million, FHLB stock and certain commercial and residential real estate mortgage loans totaling $683.1 million under a blanket mortgage collateral agreement. At December 31, 2019, the amount of available credit from the FHLB totaled $201.4 million.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 (in thousands): Unrealized Gains Unrealized Gains and and Losses Losses on Losses on on Available Securities Cash Flow for Sale Transferred to Year Ended December 31, 2019 Hedges Securities Held to Maturity Total 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 Year Ended December 31, 2018 Beginning Balance $ (3,679 ) $ 1,162 $ (10 ) $ (2,527 ) Other comprehensive income (loss) before reclassification, net of tax 1,891 (1,844 ) 20 67 Amounts reclassified from accumulated other comprehensive income (loss), net of tax (848 ) 2 (10 ) (856 ) Net current period other comprehensive income (loss) 1,043 (1,842 ) 10 (789 ) Ending Balance $ (2,636 ) $ (680 ) $ — $ (3,316 ) The following were significant amounts reclassified out of each component of accumulated other comprehensive income (loss) for the years ended December 31, 2019, 2018 and 2017 (in thousands): Affected Line Item Details about Accumulated Other Year Ended Year Ended Year Ended in the Statement Where Comprehensive Income Components December 31, 2019 December 31, 2018 December 31, 2017 Net Income is Presented Unrealized losses on cash flow hedges $ (635 ) $ (441 ) $ (430 ) Interest expense - money market (243 ) (479 ) (429 ) Interest expense - Federal Home Loan Bank advances 9 72 89 Income tax benefit $ (869 ) $ (848 ) $ (770 ) Net of tax Unrealized gains and (losses) on available-for-sale securities $ (99 ) $ 3 $ (66 ) Net gain (loss) on sale of securities 26 (1 ) 25 Income tax (expense) benefit $ (73 ) $ 2 $ (41 ) Net of tax Unrealized losses on securities transferred to held-to-maturity $ — $ (14 ) $ (190 ) Interest income - securities — 4 73 Income tax benefit $ — $ (10 ) $ (117 ) Net of tax

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 13 – INCOME TAXES The components of income tax expense are summarized as follows (in thousands): 2019 2018 2017 Current: Federal $ 3,215 $ 15 $ 214 State 1,044 (23 ) 36 4,259 (8 ) 250 Deferred: Federal 2,039 872 4,218 State 546 303 167 2,585 1,175 4,385 Total $ 6,844 $ 1,167 $ 4,635 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, 2019, 2018 and 2017 is as follows (in thousands): 2019 2018 2017 Computed "expected" tax expense $ 6,146 $ 2,272 $ 2,086 State income taxes, net of effect of federal income taxes 1,256 221 134 Tax-exempt interest income (302 ) (298 ) (418 ) Earnings on bank owned life insurance contracts (173 ) (559 ) (197 ) Disallowed expenses 84 93 86 Excess tax benefits related to stock compensation (57 ) (857 ) (632 ) Write-down of deferred tax assets due to tax reform — — 3,562 Nondeductible merger expenses — 281 — Other (110 ) 14 14 Total $ 6,844 $ 1,167 $ 4,635 As a result of the Tax Cuts and Jobs Act of 2017 that was signed into law December 2017, the Company revalued its net deferred tax asset position. This revaluation resulted in a $3.6 million decrease in net deferred tax assets and a corresponding increase to income tax expense for the year ended December 31, 2017. Significant items that gave rise to deferred taxes at December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Deferred tax assets: Allowance for loan losses $ 2,935 $ 2,795 Net operating loss carryforward 738 2,002 Organization and preopening costs 359 457 Stock-based compensation 200 835 Acquired loans 871 1,319 Unrealized loss on securities available-for-sale — 845 Accrued contributions 247 207 Other 189 685 Deferred tax assets 5,539 9,145 Deferred tax liabilities: Depreciation 804 645 Goodwill 154 81 Unrealized gain on securities available-for-sale 833 — Amortization of core deposit intangible 1,052 1,398 Other 568 411 Deferred tax liabilities 3,411 2,535 Net deferred tax asset $ 2,128 $ 6,610 At December 31, 2019, the Company had federal net operating loss carryforwards of approximately $3,011,000, 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, 2019 or 2018. As of December 31, 2019 and 2018 the Company had no accrued interest or penalties related to uncertain tax positions.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 (in thousands): Contract or notional amount December 31, 2019 December 31, 2018 Financial instruments whose contract amounts represent credit risk: Unused commitments to extend credit $ 672,933 $ 707,675 Standby letters of credit 9,634 12,273 Total $ 682,567 $ 719,948 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, 2019, 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, 2019
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, 2019 and 2018, the Company’s cash and due from banks, federal funds sold and interest-bearing deposits in financial institutions aggregated $86,000,000 and $89,000,000, respectively, in excess of insured limits.

Regulatory Matters And Restrict

Regulatory Matters And Restrictions On Dividends	12 Months Ended
	Dec. 31, 2019
Banking And Thrift [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, 2019, 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, 2019 and 2018, 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, 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 At December 31, 2018: Total capital to risk-weighted assets: CapStar Financial Holdings, Inc. $ 222,030 12.84 % $ 138,336 8.0 % N/A N/A CapStar Bank 201,972 11.68 138,294 8.0 172,868 10.0 Tier I capital to risk-weighted assets: CapStar Financial Holdings, Inc. 209,738 12.13 103,752 6.0 N/A N/A CapStar Bank 189,680 10.97 103,721 6.0 138,294 8.0 Common equity Tier 1 capital to risk weighted assets: CapStar Financial Holdings, Inc. 200,738 11.61 77,814 4.5 N/A N/A CapStar Bank 173,180 10.02 77,791 4.5 112,364 6.5 Tier I capital to average assets: CapStar Financial Holdings, Inc. 209,738 11.06 75,867 4.0 N/A N/A CapStar Bank 189,680 10.01 75,828 4.0 94,785 5.0 (1) For the calendar year 2019, 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 $35.8 million and $22.2 million of dividends as of December 31, 2019 and 2018, respectively. The Bank paid the Company $3.5 million of dividends during 2019 and this amount was paid out to shareholders by the Company during 2019.

Nonvoting and Series A Preferre

Nonvoting and Series A Preferred Stock and Stock Warrants	12 Months Ended
	Dec. 31, 2019
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, 2019, 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, 2019, there was no Series A Preferred Stock outstanding. Warrants In conjunction with the issuance of the 1,609,756 shares of the Series A Preferred Stock, the holders of such stock were issued 500,000 warrants to purchase shares of the Company’s nonvoting common stock at a purchase price of $10.25 per share. The warrants were exercisable at any time and expired ten years from the date of grant of July 14, 2008. As of December 31, 2019, all of these warrants have been exercised and none of these warrants remain outstanding. As part of the initial capital issuance in 2008, each organizer of the Company (“Organizers”) who became a director of the Company received a warrant to purchase, at the purchase price of $10.00 per share, 10,000 shares of the Company’s common stock. These warrants were issued in compliance with the FDIC’s policy on noncash compensation in recognition of the Organizers considerable contribution of time, expertise, and capital. The Company issued warrants to purchase 60,000 shares of common stock to these organizers. The warrants expired ten years from date of grant of July 14, 2008. As of December 31, 2019, all of these warrants have been exercised and no warrants remain outstanding. In addition, each subscriber for shares who is a Tennessee resident or any entity controlled by a Tennessee resident and invested a minimum of $500,000 in the offering, received a warrant to purchase additional shares of common stock equal to 5% of accepted subscriptions at the purchase price of $10.00 per share. The Company issued warrants to purchase 238,319 shares of common stock to these subscribers. The warrants expired ten years from date of grant of July 14, 2008. As of December 31, 2019, all of these warrants have been exercised and no warrants remain outstanding.

Shareholders' Agreement

Shareholders' Agreement	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Shareholders' Agreement	NOTE 18 – SHAREHOLDERS’ AGREEMENT Pursuant to the terms of the SARSA, we received a request from certain shareholders party to the SARSA to register 3,652,094 shares of our common stock on a registration statement on Form S-3 (the “Registration Statement”) in December 2018. The Registration Statement was filed with the SEC on December 21, 2018. Subsequently, during 2019, the Corsair Funds exited their positions in the Company’s shares.

Stock Options and Restricted Sh

Stock Options and Restricted Shares	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options and Restricted Shares	NOTE 19 – 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 362,757 at December 31, 2019. 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, 2019 2018 2017 Stock-based compensation expense before income taxes $ 1,262 $ 2,079 $ 1,061 Less: deferred tax benefit (330 ) (543 ) (406 ) Reduction of net income $ 932 $ 1,536 $ 655 Restricted Shares Compensation expense is recognized over the vesting period of the awards based on the fair value of the stock at the issue date. 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. Restricted shares fully vest on the third anniversary of the grant date. A summary of the changes in the Company’s nonvested restricted shares for 2019 follows: Weighted Average Restricted Grant Date Nonvested Shares Shares Fair Value Nonvested at beginning of period 157,616 $ 17.00 Granted 31,683 15.86 Vested (83,062 ) 15.93 Forfeited (21,540 ) 17.72 Nonvested at end of period 84,697 $ 17.44 As of December 31, 2019, there was $1,564,000 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 1.6 years. The total fair value of shares vested during the years ended December 31, 2019, 2018 and 2017 was $1,352,000, $2,804,000 and $1,174,000, 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. The Company granted 50,000 options during 2019. There were no options granted during 2018. 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 2019 follows: Weighted Weighted Average Average Remaining Exercise Contractual Shares Price Term (years) Outstanding at beginning of period 507,903 $ 8.66 Granted 50,000 14.84 Exercised (286,701 ) 7.33 Forfeited or expired — — Outstanding at end of period 271,202 $ 11.22 4.9 Fully vested and expected to vest 271,086 $ 11.22 4.9 Exercisable at end of period 214,952 $ 10.32 3.8 Information related to stock options during 2019, 2018 and 2017 follows: 2019 2018 2017 Intrinsic value of options exercised $ 2,478,086 $ 7,654,738 $ 2,010,536 Cash received from option exercises 1,930,737 6,897,845 2,013,840 Tax benefit realized from option exercises 103,847 846,725 774,056 Weighted average fair value of options granted 5.35 — — As of December 31, 2019, there was $216,000 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 2.4 years.

Employment Contracts

Employment Contracts	12 Months Ended
	Dec. 31, 2019
Employment Contracts Disclosure [Abstract]
Employment Contracts	NOTE 20 – 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, 2019
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plans	NOTE 21 – 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, 2019, 2018 and 2017, the Company contributed $874,000, $639,000 and $550,000, 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, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments	NOTE 22 – 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, 2019. A forward starting interest rate swap with a notional amount totaling $20 million as of December 31, 2018 was designated as a cash flow hedge of certain liabilities and was determined to be fully effective during all periods presented. As such, no amount of ineffectiveness was included in net income. Therefore, the aggregate fair value of the swaps was recorded in other liabilities with changes in fair value recorded in other comprehensive income. The Company terminated the interest rate swap during 2019, which resulted in a termination fee of $1.5 million. Cash flow swaps that have been terminated resulting in cash settlement equal to previously unrealized gains or losses are included in accumulated other comprehensive income and are being amortized to net income over the remaining contractual terms of the swaps. Summary information about the interest-rate swaps designated as cash flow hedges was as follows (dollars in thousands): December 31, 2019 December 31, 2018 Notional amounts $ — $ 20,000 Weighted average pay rates — 3.54 % Weighted average receive rates — 3 month LIBOR Weighted average maturity — 4.5 years Fair value $ — $ (836 ) Amount of unrealized loss recognized in accumulated other comprehensive income, net of tax $ — $ (617 ) Pursuant to its interest rate swap agreements, the Company pledged collateral to the counterparties in the form of investment securities with a carrying value of $2,038,000 at December 31, 2018. There was no collateral posted to or from the counterparties as of December 31, 2019. 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, 2019 December 31, 2018 Notional Estimated Notional Estimated amount fair value amount fair value Interest rate swap agreements: Pay fixed/receive variable swaps $ 45,053 $ (926 ) $ 29,126 $ 24 Pay variable/receive fixed swaps 45,053 926 29,126 (24 ) Total $ 90,106 $ — $ 58,252 $ — 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 December 31, 2019 Mortgage loan interest rate lock commitments $ 648 Mortgage-backed securities forward sales commitments (148 ) Total $ 500 There were no gains or losses relating to mortgage banking derivative instruments for the years ended December 31, 2018 and 2017. The amount and fair value of mortgage banking derivatives included in the consolidated balance sheets was as follows (dollars in thousands): December 31, 2019 December 31, 2018 Notional Estimated Notional Estimated amount fair value amount fair value Included in other assets: Mortgage loan interest rate lock commitments $ 44,694 $ 648 $ — $ — Included in other liabilities: Mortgage-backed securities forward sales commitments $ 38,500 $ 148 $ — $ —

Related Party

Related Party	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related Party	NOTE 23 – 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, 2019 or 2018. Activity within these loans during the years ended December 31, 2019 and 2018 was as follows (in thousands): Total commitment Total funded commitment 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 Year ended December 31, 2018 Beginning of period $ 49,409 $ 21,890 New commitments/draw downs 3,631 1,038 Repayments (8,228 ) (7,483 ) End of period $ 44,812 $ 15,445 Deposits from directors, executive officers, significant shareholders and their affiliates at December 31, 2019 and 2018 were $13.7 million and $11.4 million, respectively.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value	NOTE 24 – 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 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, 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 — Mortage-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 — Derivative assets: Non-hedging derivatives: Interest rate swaps - customer related 926 — 926 — Mortgage loan interest rate lock commitments 648 — — 648 Liabilities: Derivative liabilities: Non-hedging derivatives: Interest rate swaps - customer related (926 ) — (926 ) — Mortgage-backed securities forward sales commitments (148 ) — (148 ) — Fair value measurements at December 31, 2018 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 $ 10,706 $ — $ 10,706 $ — Obligations of states and political subdivisions 61,926 — 61,926 — Mortage-backed securities-residential 144,158 — 144,158 — Asset-backed securities 15,284 — 15,284 — Other debt securities 11,734 — 11,734 — Derivatives: Interest rate swaps - customer related 494 — 494 — Liabilities: Derivatives: Interest rate swaps - customer related (494 ) — (494 ) — Interest rate swaps - cash flow hedges (836 ) — (836 ) — 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 nine months ended December 31, 2019 and 2018 (dollars in thousands): Mortgage Loan Interest Rate Lock Commitments 2019 2018 Balance of recurring Level 3 assets at January 1st $ — $ — Total gains or losses for the period: Included in mortgage banking income 648 — Balance of recurring Level 3 assets at December 31st $ 648 $ — The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2019 (dollars in thousands). There were no Level 3 fair value measurements at December 31, 2018. 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%) There were no assets measured at fair value on a nonrecurring basis at December 31, 2019 and 2018. Fair Value of Financial Instruments The carrying value and estimated fair values of the Company’s financial instruments at December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 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 $ 101,094 $ 101,094 $ 94,681 $ 94,681 Level 1 Federal funds sold 175 175 10,762 10,762 Level 1 Securities available-for-sale 213,129 213,129 243,808 243,808 Level 2 Securities held-to-maturity 3,313 3,411 3,734 3,785 Level 2 Loans held for sale 168,222 169,072 57,618 58,596 Level 2 Restricted equity securities 13,689 N/A 12,038 N/A N/A Loans 1,420,102 1,414,757 1,429,794 1,442,082 Level 3 Accrued interest receivable 5,792 5,792 5,964 5,964 Level 2 Other assets 36,393 36,393 34,489 34,489 Level 2 / Level 3 Financial liabilities: Deposits 1,729,451 1,730,206 1,570,008 1,572,880 Level 3 Federal Home Loan Bank advances 10,000 10,014 125,000 126,548 Level 2 Other liabilities 1,394 1,394 2,753 2,753 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 The fair value of fixed rate Federal Home Loan Bank Advances 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, 2019
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Parent Company Only Financial Information	NOTE 25 – PARENT COMPANY ONLY FINANCIAL INFORMATION The following information presents the condensed balance sheet, statement of income, and cash flows of CapStar Financial Holdings, Inc. as of and for the year ended December 31, 2019 and 2018 (in thousands). Condensed Balance Sheets December 31, 2019 December 31, 2018 Assets Cash and cash equivalents $ 12,874 $ 19,918 Investment in consolidated subsidiary 259,632 234,263 Other assets 578 499 Total assets $ 273,084 $ 254,680 Liabilities and Shareholders’ Equity Other liabilities $ 38 301 Total shareholders’ equity 273,046 254,379 Total liabilities and shareholders’ equity $ 273,084 $ 254,680 Condensed Income Statements Year Ended Year Ended December 31, 2019 December 31, 2018 Income - dividends from subsidiary $ 3,530 $ 1,225 Expenses 1,083 1,054 Income before income taxes and equity in undistributed net income of subsidiary 2,447 171 Income tax benefit (262 ) (242 ) Income before equity in undistributed net income of subsidiary 2,709 413 Equity in undistributed net income of subsidiary 19,713 9,242 Net income $ 22,422 $ 9,655 Condensed Statements of Cash Flows Year Ended Year Ended December 31, 2019 December 31, 2018 Cash flows from operating activities: Net income $ 22,422 $ 9,655 Adjustments to reconcile net income to net cash provided by operating activities: Increase in other assets (78 ) (221 ) Increase (Decrease) in other liabilities (263 ) 181 Equity in undistributed net income of subsidiary (19,713 ) (9,242 ) Net cash provided by operating activities 2,368 373 Cash flows from investing activities: Cash received from acquisitions, net — 1,421 Net cash provided by investing activities — 1,421 Cash flows from financing activities: Repurchase of common stock (7,836 ) — Exercise of common stock options and warrants 1,931 5,260 Common and preferred stock dividends paid (3,507 ) (1,244 ) Net cash provided by (used in) financing activities (9,412 ) 4,016 Net increase (decrease) in cash and cash equivalents (7,044 ) 5,810 Cash and cash equivalents at beginning of period 19,918 14,108 Cash and cash equivalents at end of period $ 12,874 $ 19,918

Quarterly Financial Results (Un

Quarterly Financial Results (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Results (Unaudited)	NOTE 26 – QUARTERLY FINANCIAL RESULTS (UNAUDITED) The following is a summary of quarterly financial results (unaudited) for 2019, 2018 and 2017: First Quarter Second Quarter Third Quarter Fourth Quarter 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 before income tax expense 6,126 7,570 8,538 7,034 Income tax expense 1,346 1,814 2,072 1,613 Net income $ 4,780 $ 5,756 $ 6,466 $ 5,421 Net income per share, basic $ 0.27 $ 0.33 $ 0.36 $ 0.30 Net income 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 ) 2017 Interest income $ 11,979 $ 12,891 $ 13,521 $ 13,124 Interest expense 2,047 2,320 2,678 2,606 Net interest income 9,932 10,571 10,843 10,518 Provision for loan losses 3,405 9,690 (195 ) (30 ) Net interest income after provision for loan losses 6,527 881 11,038 10,548 Noninterest income 2,133 2,666 3,372 2,736 Noninterest expense 8,376 8,217 8,475 8,699 Net income (loss) before income tax expense 284 (4,670 ) 5,935 4,585 Income tax expense (benefit) (47 ) (1,328 ) 1,516 4,494 Net income (loss) $ 331 $ (3,342 ) $ 4,419 $ 91 Net income (loss) per share, basic $ 0.03 $ (0.30 ) $ 0.39 $ 0.01 Net income (loss) per share, diluted $ 0.03 $ (0.26 ) $ 0.35 $ 0.01

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	NOTE 27 – SUBSEQUENT EVENTS On January 23, 2020, we announced the signing of definitive merger agreements with FCB Corporation (“FCB”), its wholly owned subsidiary The First National Bank of Manchester (“FNBM”), and The Bank of Waynesboro (“BOW”) providing for FCB to merge with and into CapStar Financial Holdings, Inc. and for FNBM and BOW to merge with and into CapStar Bank. Under the terms of the merger agreements, FCB and BOW shareholders will receive 3,634,218 CapStar common shares and $26.4 million in cash, subject to certain adjustments, totaling $85.1 million based on the closing price of CapStar’s common stock on January 22, 2020. Pending regulatory and shareholder approvals and the satisfaction of certain other customary closing conditions, the acquisition is expected to be finalized in late second or early third quarter of 2020. As of December 31, 2019, FCB and BOW had total combined assets of $467 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements as of December 31, 2019 and 2018 and for each of the three years in the period ended December 31, 2019 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 24 - 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 $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, 2019 (dollars in thousands): Fair Value Aggregate Unpaid Principal Balance Difference 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, 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 six classes of loans for financial reporting purposes: commercial real estate, consumer real estate, construction and land development, commercial and industrial, consumer 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. 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 33 quarter look-back period as of December 31, 2017. Subsequently, the Company increased its look-back period for a total of 37 quarters and 41 quarters as of December 31, 2018 and 2019, 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 $340,000 and $102,000 for the years ended December 31, 2019 and 2018, respectively. There were no servicing fees for the year ended December 31, 2017. 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. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. 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. The Company has selected October 31st as the date to perform the annual impairment test. 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, 2016 through 2019. 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 $370,000, $383,000 and $310,000 for the years ended December 31, 2019, 2018 and 2017, 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 risk to the Bank. These swaps are derivatives, but are not designated as hedging instruments. The Bank may also utilize forward starting 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. The Bank was required to have a reserve balance of $73,444,000, $63,890,000, and $43,940,000 at December 31, 2019, 2018 and 2017, respectively. 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, 2018 and 2017.
Subsequent Events	Subsequent Events The Company has evaluated subsequent events for recognition and disclosure through March __, 2020, 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, 2019, 2018 or December 31, 2017. 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, 2019 2018 2017 Basic net income per share calculation: Numerator – Net income $ 22,422 $ 9,655 $ 1,501 Denominator – Average common shares outstanding 17,886,164 13,277,614 11,280,580 Basic net income per share $ 1.25 $ 0.73 $ 0.13 Diluted net income per share calculation: Numerator – Net income $ 22,422 $ 9,655 $ 1,501 Denominator – Average common shares outstanding 17,886,164 13,277,614 11,280,580 Dilutive shares contingently issuable 727,060 1,202,733 1,522,931 Average diluted common shares outstanding 18,613,224 14,480,347 12,803,511 Diluted net income per share $ 1.20 $ 0.67 $ 0.12
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 from 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 will be effective for the Company for reporting periods beginning after December 15, 2019. The Company does not expect these amendments to have a material effect on its 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 2018-02, Income Statement: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, the FASB Issued (2018-02), Income Statement (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income 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 will be 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 will be effective for the Company for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company does not expect these amendments to have a material effect on its 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, 2019
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, 2019 (dollars in thousands): Fair Value Aggregate Unpaid Principal Balance Difference 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, 2019 2018 2017 Basic net income per share calculation: Numerator – Net income $ 22,422 $ 9,655 $ 1,501 Denominator – Average common shares outstanding 17,886,164 13,277,614 11,280,580 Basic net income per share $ 1.25 $ 0.73 $ 0.13 Diluted net income per share calculation: Numerator – Net income $ 22,422 $ 9,655 $ 1,501 Denominator – Average common shares outstanding 17,886,164 13,277,614 11,280,580 Dilutive shares contingently issuable 727,060 1,202,733 1,522,931 Average diluted common shares outstanding 18,613,224 14,480,347 12,803,511 Diluted net income per share $ 1.20 $ 0.67 $ 0.12

Acquisition (Tables)

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Schedule of Consideration Paid and Amounts of Assets Acquired and Liabilities Assumed	The following table summarizes the consideration paid for Athens and the amounts of the assets acquired and liabilities assumed recognized at the acquisition date (in thousands): As recorded by Athens Bancshares Initial fair value adjustments Measurement period adjustments As recorded by CapStar Financial Holdings Assets: Cash and cash equivalents $ 12,053 $ — $ — $ 12,053 Securities 67,342 84 (a) — 67,426 Loans, gross 349,597 (4,764 ) (b) — 344,833 Allowance for loan losses (4,039 ) 4,039 (c) — — Premises and equipment, net 7,637 1,571 (d) — 9,208 Core deposit intangible 2,758 6,222 (e) — 8,980 Other 29,566 944 (f) — 30,510 Total $ 464,914 $ 8,096 $ — $ 473,010 Liabilities: Deposits $ 404,027 $ 493 (g) $ — $ 404,520 Other 5,363 1,500 (h) — 6,863 Total $ 409,390 $ 1,993 $ — $ 411,383 Net identifiable assets acquired $ 61,627 Total cost of acquisition: Value of stock issued $ 86,538 Value of rolled stock options 6,380 Total cost of acquisition $ 92,918 $ 92,918 Goodwill recorded related to acquisition $ 31,291 (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 Athens’ 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 Athens’ existing allowance for loan losses. (d) The amount represents the adjustment of the net book value of Athens’ premises and equipment to their estimated fair value. (e) The amount represents the net adjustment of removing Athens’ existing core deposit intangible from prior acquisitions and 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 fair value of mortgage servicing rights acquired and the deferred tax asset recognized on the fair value adjustments on Athens acquired assets and assumed liabilities. (g) The amount represents the adjustment necessary because the weighted average interest rate of Athens’ 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. (h) The amount represents the liability assumed in connection with the merger agreement whereby the Company will make a $1,500,000 charitable contribution to the Athens Foundation over a three year period.
Schedule of Unaudited Pro Forma Financial Information	The following unaudited pro forma financial information presents the combined results of the Company and Athens as if the acquisition had occurred as of January 1, 2017, 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 and Athens constituted a single entity during such periods (in thousands, except share data): Pro forma combined twelve months ended December 31, 2018 Pro forma combined twelve months ended December 31, 2017 Net interest income $ 66,935 $ 59,148 Noninterest income 20,692 17,540 Total revenue 87,627 76,688 Net income 21,167 5,851 Per share information: Basic net income per share of common stock $ 1.24 $ 0.36 Diluted net income per share of common stock $ 1.14 $ 0.32

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Summary of Company's Classification of Securities	The Company’s classification of securities at December 31, 2019 and 2018 was as follows (in thousands): December 31, 2019 December 31, 2018 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 $ 10,421 $ 4 $ (94 ) $ 10,331 $ 11,053 $ — $ (347 ) $ 10,706 State and municipal securities 44,053 1,927 (20 ) 45,960 62,142 765 (981 ) 61,926 Mortgage-backed securities 137,305 1,834 (460 ) 138,679 146,547 776 (3,165 ) 144,158 Asset-backed securities 3,325 — (128 ) 3,197 15,437 4 (157 ) 15,284 Other debt securities 14,839 141 (18 ) 14,962 11,863 71 (200 ) 11,734 Total $ 209,943 $ 3,906 $ (720 ) $ 213,129 $ 247,042 $ 1,616 $ (4,850 ) $ 243,808 Securities held-to-maturity: State and municipal securities $ 3,313 $ 98 $ — $ 3,411 $ 3,734 $ 54 $ (3 ) $ 3,785 Total $ 3,313 $ 98 $ — $ 3,411 $ 3,734 $ 54 $ (3 ) $ 3,785
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, 2019, 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 $ 9,805 $ 9,909 $ 881 $ 884 Due one to five years 28,593 29,230 2,432 2,527 Due five to ten years 29,545 30,758 — — Due beyond ten years 1,370 1,356 — — Mortgage-backed securities 137,305 138,679 — — Asset-backed securities 3,325 3,197 — — $ 209,943 $ 213,129 $ 3,313 $ 3,411
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 2019 2018 2017 Proceeds $ 68,068 $ 38,322 $ 46,762 Gross gains 49 116 124 Gross losses (148 ) (113 ) (190 )
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, 2019 Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses 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 ) December 31, 2018 U. S. government agency securities $ — $ — $ 10,706 $ (347 ) $ 10,706 $ (347 ) State and municipal securities 13,455 (212 ) 17,376 (772 ) 30,831 (984 ) Mortgage-backed securities 7,075 (17 ) 87,232 (3,148 ) 94,307 (3,165 ) Asset-backed securities 8,262 (145 ) 2,439 (12 ) 10,701 (157 ) Other debt securities 5,362 (200 ) — — 5,362 (200 ) Total temporarily impaired securities $ 34,154 $ (574 ) $ 117,753 $ (4,279 ) $ 151,907 $ (4,853 )

Loans and Allowance for Loan _2

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Summary of Loans	Loans at December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Commercial real estate $ 559,899 $ 550,446 Consumer real estate 256,097 253,562 Construction and land development 143,111 174,670 Commercial and industrial 394,408 404,600 Consumer 28,426 25,615 Other 38,161 20,901 Total 1,420,102 1,429,794 Allowance for loan losses (12,604 ) (12,113 ) Total loans, net $ 1,407,498 $ 1,417,681
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, 2019 and 2018 (in thousands): Non-impaired Loans December 31, 2019 Pass Special Mention Substandard Total Non-impaired Total Loans Total Commercial real estate $ 551,929 $ 915 $ 4,438 $ 557,282 $ 2,617 $ 559,899 Consumer real estate 252,952 503 1,551 255,006 1,091 256,097 Construction and land development 142,978 — 16 142,994 117 143,111 Commercial and industrial 370,475 14,341 8,241 393,057 1,351 394,408 Consumer 28,382 6 15 28,403 23 28,426 Other 38,161 — — 38,161 — 38,161 Total $ 1,384,877 $ 15,765 $ 14,261 $ 1,414,903 $ 5,199 $ 1,420,102 December 31, 2018 Commercial real estate $ 547,616 $ 177 $ 1,262 $ 549,055 $ 1,391 $ 550,446 Consumer real estate 249,273 1,676 1,691 252,640 922 253,562 Construction and land development 174,591 52 19 174,662 8 174,670 Commercial and industrial 388,719 7,790 6,545 403,054 1,546 404,600 Consumer 25,556 1 27 25,584 31 25,615 Other 20,901 — — 20,901 — 20,901 Total $ 1,406,656 $ 9,696 $ 9,544 $ 1,425,896 $ 3,898 $ 1,429,794
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, 2019, 2018 and 2017 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, 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 Year ended December 31, 2017 Balance, beginning of period $ 2,655 $ 1,013 $ 1,574 $ 5,618 $ 76 $ 698 $ 11,634 Charged-off loans — — — (12,769 ) — — (12,769 ) Recoveries 9 — — 1,865 112 — 1,986 Provision for loan losses 660 50 54 12,495 (97 ) (292 ) 12,870 Balance, end of period $ 3,324 $ 1,063 $ 1,628 $ 7,209 $ 91 $ 406 $ 13,721 A breakdown of the ALL and the loan portfolio by loan category at December 31, 2019 and 2018 follows (in thousands): Commercial real estate Consumer real estate Construction and land development Commercial and industrial Consumer Other Total 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 — — — — — — — Acquired with deteriorated credit quality — — — — — — — 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 Acquired with deteriorated credit quality 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 December 31, 2018 Allowance for Loan Losses: Collectively evaluated for impairment $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 Individually evaluated for impairment — — — — — — — Loans acquired with deteriorated credit quality — — — — — — — Balances, end of period $ 3,309 $ 1,005 $ 2,431 $ 5,036 $ 105 $ 227 $ 12,113 Loans: Collectively evaluated for impairment $ 549,055 $ 252,640 $ 174,662 $ 403,054 $ 25,584 $ 20,901 $ 1,425,896 Individually evaluated for impairment 1,278 183 — 817 — — 2,278 Acquired with deteriorated credit quality 113 739 8 729 31 — 1,620 Balances, end of period $ 550,446 $ 253,562 $ 174,670 $ 404,600 $ 25,615 $ 20,901 $ 1,429,794
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, 2019 and 2018 (dollars in thousands): December 31, 2019 December 31, 2018 Amount Percent of total loans Amount Percent of total loans Commercial real estate $ 3,599 0.25 % $ 3,309 0.23 % Consumer real estate 1,231 0.09 % 1,005 0.07 % Construction and land development 2,058 0.14 % 2,431 0.17 % Commercial and industrial 5,074 0.36 % 5,036 0.35 % Consumer 222 0.02 % 105 0.01 % Other 420 0.03 % 227 0.02 % Total allowance for loan and lease losses $ 12,604 0.89 % $ 12,113 0.85 %
Summary of Information Related to Impaired Loans	The following table presents information related to impaired loans as of and for the years ended December 31, 2019 and 2018 (in thousands): December 31, 2019 December 31, 2018 Recorded investment Unpaid principal balance Related allowance Recorded investment Unpaid principal balance Related allowance With no related allowance recorded: Commercial real estate $ 2,617 $ 2,621 $ — $ 1,391 $ 1,775 $ — Consumer real estate 1,091 1,327 — 922 1,204 — Construction and land development 117 132 — 8 18 — Commercial and industrial 1,351 2,173 — 1,546 6,350 — Consumer 23 41 — 31 56 — Other — — — — — — Subtotal 5,199 6,294 — 3,898 9,403 — With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development — — — — — — Commercial and industrial — — — — — — Consumer — — — — — — Other — — — — — — Subtotal — — — — — — Total $ 5,199 $ 6,294 $ — $ 3,898 $ 9,403 $ — The following table presents information related to the average recorded investment and interest income recognized on impaired loans for the years ended December 31, 2019, 2018 and 2017 (in thousands): Year Ended Year Ended Year Ended December 31, 2019 December 31, 2018 December 31, 2017 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 $ 2,574 $ 313 $ 1,198 $ 158 $ 1,258 $ — Consumer real estate 1,037 105 185 — — — Construction and land development 119 4 94 2 — — Commercial and industrial 824 440 5,557 121 — — Consumer 23 2 7 — — — Other — — — — — — Subtotal 4,577 864 7,041 281 1,258 — With an allowance recorded: Commercial real estate — — — — — — Consumer real estate — — — — — — Construction and land development — — — — — — Commercial and industrial — — — — 2,077 — Consumer — — — — — — Other — — — — — — Subtotal — — — — 2,077 — Total $ 4,577 $ 864 $ 7,041 $ 281 $ 3,335 $ —
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, 2019 and 2018 by class of loans (in thousands): 30 - 59 60 - 89 Greater Than Days Days 89 Days Total Loans Not December 31, 2019 Past Due Past Due Past Due Past Due Past Due Total Commercial real estate $ 372 $ — $ — $ 372 $ 559,527 $ 559,899 Consumer real estate 3,642 474 643 4,759 251,338 256,097 Construction and land development 653 15 — 668 142,443 143,111 Commercial and industrial 1,277 8 440 1,725 392,683 394,408 Consumer 67 — 33 100 28,326 28,426 Other — — — — 38,161 38,161 Total $ 6,011 $ 497 $ 1,116 $ 7,624 $ 1,412,478 $ 1,420,102 December 31, 2018 Commercial real estate $ 300 $ 227 $ — $ 527 $ 549,919 $ 550,446 Consumer real estate 69 75 775 919 252,643 253,562 Construction and land development — — — — 174,670 174,670 Commercial and industrial 54 — — 54 404,546 404,600 Consumer 52 — 43 95 25,520 25,615 Other — — — — 20,901 20,901 Total $ 475 $ 302 $ 818 $ 1,595 $ 1,428,199 $ 1,429,794
Schedule of Recorded In Non Accrual Loans, Past Due Loans over 89 Days and Accruing and Troubled Debt Restructurings	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, 2019 and 2018 (in thousands): Past Due Over 89 Days Troubled Debt Non-Accrual and Accruing Restructurings December 31, 2019 Commercial real estate $ — $ — $ 2,446 Consumer real estate 894 12 — Construction and land development 117 — — Commercial and industrial 440 — 271 Consumer 13 26 — Other — — — Total $ 1,464 $ 38 $ 2,717 December 31, 2018 Commercial real estate $ — $ — $ 1,391 Consumer real estate 1,187 214 — Construction and land development 19 — — Commercial and industrial 817 — — Consumer 55 — — Other — — — Total $ 2,078 $ 214 $ 1,391
Schedule of Loans by Class Modified as TDR	The following table presents loans by class modified as TDR that occurred during the year ended December 31, 2019 (in thousands). Year Ended December 31, 2019 Number of contracts Pre modification outstanding recorded investment Post modification outstanding recorded investment, net of related allowance 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 Athens Bancshares expected at acquisition date	The following table relates to acquired Athens 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): Athens Bancshares acquisition on October 1, 2018 Contractually required payments $ 3,151 Nonaccretable difference (1,049 ) Cash flows expected to be collected at acquisition 2,102 Accretable yield (436 ) Fair value of PCI loans at acquisition date $ 1,666
Summary of contractually required payments for Athens Bancshares not expected at acquisition date	The following table relates to acquired Athens 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): Athens Bancshares acquisition on October 1, 2018 Contractually required payments $ 404,692 Fair value of acquired loans at acquisition date 343,167 Contractual cash flows not expected to be collected 1,807
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, 2019 Balance at beginning of period $ 1,620 Change due to payments received and accretion (15 ) Change due to loan charge-offs — Other — Balance at end of period $ 1,605 The following table presents changes in the accretable yield for PCI loans (in thousands): For the year ended December 31, 2019 Balance at beginning of period $ 440 Accretion (570 ) Reclassification from (to) nonaccretable difference 1,045 Other, net — Balance at end of period $ 915
Schedule of Components of Direct Financing Leases	The components of the direct financing leases as of December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Total minimum lease payments receivable $ 59 $ 379 Less: Unearned income (1 ) (19 ) Net leases $ 58 $ 360
Summary of Future Minimum Lease Payments Receivable under Direct Financing Leases	The future minimum lease payments receivable under the direct financing leases as of December 31, 2019 were as follows (in thousands): Year ending December 31: 2020 $ 58 2021 — 2022 — 2023 — 2024 — $ 58

Loan Servicing (Tables)

Loan Servicing (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 Loan servicing rights: Balance at beginning of period $ 1,736 Additions 381 Disposals — Amortized to offset other noninterest income (362 ) Change in valuation allowance (211 ) Balance at end of period $ 1,544 Valuation allowance: Balance at beginning of period $ — Additions expensed — Reductions credited to other noninterest income — Direct write-downs (211 ) Balance at end of period $ (211 )

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Summary of Premises and Equipment	Premises and equipment at December 31, 2019 and 2018 are summarized as follows (in thousands): Range of useful lives December 31, 2019 December 31, 2018 Land Not applicable $ 4,303 $ 2,997 Buildings 39 years 13,331 9,965 Leasehold improvements 1 to 17 years 939 939 Furniture and equipment 1 to 7 years 4,633 3,730 Fixed assets in process Not applicable — 4,023 23,206 21,654 Less accumulated depreciation and amortization (4,022 ) (2,833 ) $ 19,184 $ 18,821

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Summary of Lease Costs	Lease costs were as follows (in thousands): December 31, 2019 Operating lease cost $ 1,868 Short-term lease cost — Variable least cost — Total lease cost $ 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, 2019 Lease payments due: 2020 $ 1,562 2021 1,590 2022 1,476 2023 1,425 2024 1,130 2025 and thereafter 7,710 Total undiscounted cash flows 14,893 Discount on cash flows (2,442 ) Total lease liability $ 12,451

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Change in Goodwill	The change in goodwill during the years ended December 31, 2019 and 2018 was as follows (in thousands): 2019 2018 Beginning of year $ 37,510 $ 6,219 Acquired goodwill — 31,291 Impairment — — End of year $ 37,510 $ 37,510
Summary of Acquired Intangible Assets	Acquired intangible assets at December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets: Core deposit intangibles $ 9,267 $ (2,384 ) $ 9,267 $ (729 )
Summary of Estimated Amortization Expense	Estimated amortization expense for each of the next five years is as follows (in thousands): Year ending December 31: 2020 $ 1,477 2021 1,299 2022 1,121 2023 943 2024 764 Thereafter 1,279 Total $ 6,883

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2019
Other Real Estate [Abstract]
Summary of Other Real Estate Owned Activity	Other real estate owned activity was as follows (in thousands): 2019 2018 2017 Beginning balance $ 988 $ — $ — Additions due to acquisition of Athens Bancshares — 988 — Loans transferred to other real estate owned 180 — — Direct write-downs — — — Sales of other real estate owned (124 ) — — End of year $ 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, 2019, 2018 and 2017, respectively include (in thousands): 2019 2018 2017 Net (gain) loss on sales $ (3 ) $ — $ — Provision for unrealized losses — — — Operating expenses, net of rental income — — — Total $ (3 ) $ — $ —

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2019
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: 2020 $ 222,163 2021 53,077 2022 16,255 2023 8,369 2024 2,975 Thereafter 613 $ 303,452

Federal Home Loan Bank Advanc_2

Federal Home Loan Bank Advances (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 December 31, 2018 Year Amount Interest Rates Amount Interest Rates 2019 — — 125,000 2.48 % 2020 10,000 2.05 % — — 2021 — — — — 2022 — — — — 2023 — — — — 2024 — — — — Thereafter — — — — Total $ 10,000 2.05 % $ 125,000 2.48 %

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 (in thousands): Unrealized Gains Unrealized Gains and and Losses Losses on Losses on on Available Securities Cash Flow for Sale Transferred to Year Ended December 31, 2019 Hedges Securities Held to Maturity Total 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 Year Ended December 31, 2018 Beginning Balance $ (3,679 ) $ 1,162 $ (10 ) $ (2,527 ) Other comprehensive income (loss) before reclassification, net of tax 1,891 (1,844 ) 20 67 Amounts reclassified from accumulated other comprehensive income (loss), net of tax (848 ) 2 (10 ) (856 ) Net current period other comprehensive income (loss) 1,043 (1,842 ) 10 (789 ) Ending Balance $ (2,636 ) $ (680 ) $ — $ (3,316 )
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, 2019, 2018 and 2017 (in thousands): Affected Line Item Details about Accumulated Other Year Ended Year Ended Year Ended in the Statement Where Comprehensive Income Components December 31, 2019 December 31, 2018 December 31, 2017 Net Income is Presented Unrealized losses on cash flow hedges $ (635 ) $ (441 ) $ (430 ) Interest expense - money market (243 ) (479 ) (429 ) Interest expense - Federal Home Loan Bank advances 9 72 89 Income tax benefit $ (869 ) $ (848 ) $ (770 ) Net of tax Unrealized gains and (losses) on available-for-sale securities $ (99 ) $ 3 $ (66 ) Net gain (loss) on sale of securities 26 (1 ) 25 Income tax (expense) benefit $ (73 ) $ 2 $ (41 ) Net of tax Unrealized losses on securities transferred to held-to-maturity $ — $ (14 ) $ (190 ) Interest income - securities — 4 73 Income tax benefit $ — $ (10 ) $ (117 ) Net of tax

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The components of income tax expense are summarized as follows (in thousands): 2019 2018 2017 Current: Federal $ 3,215 $ 15 $ 214 State 1,044 (23 ) 36 4,259 (8 ) 250 Deferred: Federal 2,039 872 4,218 State 546 303 167 2,585 1,175 4,385 Total $ 6,844 $ 1,167 $ 4,635
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, 2019, 2018 and 2017 is as follows (in thousands): 2019 2018 2017 Computed "expected" tax expense $ 6,146 $ 2,272 $ 2,086 State income taxes, net of effect of federal income taxes 1,256 221 134 Tax-exempt interest income (302 ) (298 ) (418 ) Earnings on bank owned life insurance contracts (173 ) (559 ) (197 ) Disallowed expenses 84 93 86 Excess tax benefits related to stock compensation (57 ) (857 ) (632 ) Write-down of deferred tax assets due to tax reform — — 3,562 Nondeductible merger expenses — 281 — Other (110 ) 14 14 Total $ 6,844 $ 1,167 $ 4,635
Schedule of Deferred Tax Assets and Liabilities	Significant items that gave rise to deferred taxes at December 31, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 Deferred tax assets: Allowance for loan losses $ 2,935 $ 2,795 Net operating loss carryforward 738 2,002 Organization and preopening costs 359 457 Stock-based compensation 200 835 Acquired loans 871 1,319 Unrealized loss on securities available-for-sale — 845 Accrued contributions 247 207 Other 189 685 Deferred tax assets 5,539 9,145 Deferred tax liabilities: Depreciation 804 645 Goodwill 154 81 Unrealized gain on securities available-for-sale 833 — Amortization of core deposit intangible 1,052 1,398 Other 568 411 Deferred tax liabilities 3,411 2,535 Net deferred tax asset $ 2,128 $ 6,610

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 (in thousands): Contract or notional amount December 31, 2019 December 31, 2018 Financial instruments whose contract amounts represent credit risk: Unused commitments to extend credit $ 672,933 $ 707,675 Standby letters of credit 9,634 12,273 Total $ 682,567 $ 719,948

Regulatory Matters And Restri_2

Regulatory Matters And Restrictions On Dividends (Tables)	12 Months Ended
	Dec. 31, 2019
Banking And Thrift [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, 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 At December 31, 2018: Total capital to risk-weighted assets: CapStar Financial Holdings, Inc. $ 222,030 12.84 % $ 138,336 8.0 % N/A N/A CapStar Bank 201,972 11.68 138,294 8.0 172,868 10.0 Tier I capital to risk-weighted assets: CapStar Financial Holdings, Inc. 209,738 12.13 103,752 6.0 N/A N/A CapStar Bank 189,680 10.97 103,721 6.0 138,294 8.0 Common equity Tier 1 capital to risk weighted assets: CapStar Financial Holdings, Inc. 200,738 11.61 77,814 4.5 N/A N/A CapStar Bank 173,180 10.02 77,791 4.5 112,364 6.5 Tier I capital to average assets: CapStar Financial Holdings, Inc. 209,738 11.06 75,867 4.0 N/A N/A CapStar Bank 189,680 10.01 75,828 4.0 94,785 5.0 (1) For the calendar year 2019, 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, 2019
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, 2019 2018 2017 Stock-based compensation expense before income taxes $ 1,262 $ 2,079 $ 1,061 Less: deferred tax benefit (330 ) (543 ) (406 ) Reduction of net income $ 932 $ 1,536 $ 655
Summary of Changes in Company's Nonvested Restricted Shares	A summary of the changes in the Company’s nonvested restricted shares for 2019 follows: Weighted Average Restricted Grant Date Nonvested Shares Shares Fair Value Nonvested at beginning of period 157,616 $ 17.00 Granted 31,683 15.86 Vested (83,062 ) 15.93 Forfeited (21,540 ) 17.72 Nonvested at end of period 84,697 $ 17.44
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. The Company granted 50,000 options during 2019. There were no options granted during 2018. 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 2019 follows: Weighted Weighted Average Average Remaining Exercise Contractual Shares Price Term (years) Outstanding at beginning of period 507,903 $ 8.66 Granted 50,000 14.84 Exercised (286,701 ) 7.33 Forfeited or expired — — Outstanding at end of period 271,202 $ 11.22 4.9 Fully vested and expected to vest 271,086 $ 11.22 4.9 Exercisable at end of period 214,952 $ 10.32 3.8
Information Related to Stock Options	Information related to stock options during 2019, 2018 and 2017 follows: 2019 2018 2017 Intrinsic value of options exercised $ 2,478,086 $ 7,654,738 $ 2,010,536 Cash received from option exercises 1,930,737 6,897,845 2,013,840 Tax benefit realized from option exercises 103,847 846,725 774,056 Weighted average fair value of options granted 5.35 — —

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Summary of Interest-Rate Swaps Designated as Cash Flow Hedges	Summary information about the interest-rate swaps designated as cash flow hedges was as follows (dollars in thousands): December 31, 2019 December 31, 2018 Notional amounts $ — $ 20,000 Weighted average pay rates — 3.54 % Weighted average receive rates — 3 month LIBOR Weighted average maturity — 4.5 years Fair value $ — $ (836 ) Amount of unrealized loss recognized in accumulated other comprehensive income, net of tax $ — $ (617 )
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, 2019 December 31, 2018 Notional Estimated Notional Estimated amount fair value amount fair value Interest rate swap agreements: Pay fixed/receive variable swaps $ 45,053 $ (926 ) $ 29,126 $ 24 Pay variable/receive fixed swaps 45,053 926 29,126 (24 ) Total $ 90,106 $ — $ 58,252 $ —
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 December 31, 2019 Mortgage loan interest rate lock commitments $ 648 Mortgage-backed securities forward sales commitments (148 ) Total $ 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, 2019 December 31, 2018 Notional Estimated Notional Estimated amount fair value amount fair value Included in other assets: Mortgage loan interest rate lock commitments $ 44,694 $ 648 $ — $ — Included in other liabilities: Mortgage-backed securities forward sales commitments $ 38,500 $ 148 $ — $ —

Related Party (Tables)

Related Party (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 or 2018. Activity within these loans during the years ended December 31, 2019 and 2018 was as follows (in thousands): Total commitment Total funded commitment 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 Year ended December 31, 2018 Beginning of period $ 49,409 $ 21,890 New commitments/draw downs 3,631 1,038 Repayments (8,228 ) (7,483 ) End of period $ 44,812 $ 15,445

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2019
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, 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 — Mortage-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 — Derivative assets: Non-hedging derivatives: Interest rate swaps - customer related 926 — 926 — Mortgage loan interest rate lock commitments 648 — — 648 Liabilities: Derivative liabilities: Non-hedging derivatives: Interest rate swaps - customer related (926 ) — (926 ) — Mortgage-backed securities forward sales commitments (148 ) — (148 ) — Fair value measurements at December 31, 2018 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 $ 10,706 $ — $ 10,706 $ — Obligations of states and political subdivisions 61,926 — 61,926 — Mortage-backed securities-residential 144,158 — 144,158 — Asset-backed securities 15,284 — 15,284 — Other debt securities 11,734 — 11,734 — Derivatives: Interest rate swaps - customer related 494 — 494 — Liabilities: Derivatives: Interest rate swaps - customer related (494 ) — (494 ) — Interest rate swaps - cash flow hedges (836 ) — (836 ) —
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 nine months ended December 31, 2019 and 2018 (dollars in thousands): Mortgage Loan Interest Rate Lock Commitments 2019 2018 Balance of recurring Level 3 assets at January 1st $ — $ — Total gains or losses for the period: Included in mortgage banking income 648 — Balance of recurring Level 3 assets at December 31st $ 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, 2019 (dollars in thousands). There were no Level 3 fair value measurements at December 31, 2018. 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%)
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, 2019 and 2018 were as follows (in thousands): December 31, 2019 December 31, 2018 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 $ 101,094 $ 101,094 $ 94,681 $ 94,681 Level 1 Federal funds sold 175 175 10,762 10,762 Level 1 Securities available-for-sale 213,129 213,129 243,808 243,808 Level 2 Securities held-to-maturity 3,313 3,411 3,734 3,785 Level 2 Loans held for sale 168,222 169,072 57,618 58,596 Level 2 Restricted equity securities 13,689 N/A 12,038 N/A N/A Loans 1,420,102 1,414,757 1,429,794 1,442,082 Level 3 Accrued interest receivable 5,792 5,792 5,964 5,964 Level 2 Other assets 36,393 36,393 34,489 34,489 Level 2 / Level 3 Financial liabilities: Deposits 1,729,451 1,730,206 1,570,008 1,572,880 Level 3 Federal Home Loan Bank advances 10,000 10,014 125,000 126,548 Level 2 Other liabilities 1,394 1,394 2,753 2,753 Level 3

Parent Company Only Financial_2

Parent Company Only Financial Information (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets December 31, 2019 December 31, 2018 Assets Cash and cash equivalents $ 12,874 $ 19,918 Investment in consolidated subsidiary 259,632 234,263 Other assets 578 499 Total assets $ 273,084 $ 254,680 Liabilities and Shareholders’ Equity Other liabilities $ 38 301 Total shareholders’ equity 273,046 254,379 Total liabilities and shareholders’ equity $ 273,084 $ 254,680
Condensed Income Statements	Condensed Income Statements Year Ended Year Ended December 31, 2019 December 31, 2018 Income - dividends from subsidiary $ 3,530 $ 1,225 Expenses 1,083 1,054 Income before income taxes and equity in undistributed net income of subsidiary 2,447 171 Income tax benefit (262 ) (242 ) Income before equity in undistributed net income of subsidiary 2,709 413 Equity in undistributed net income of subsidiary 19,713 9,242 Net income $ 22,422 $ 9,655
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows Year Ended Year Ended December 31, 2019 December 31, 2018 Cash flows from operating activities: Net income $ 22,422 $ 9,655 Adjustments to reconcile net income to net cash provided by operating activities: Increase in other assets (78 ) (221 ) Increase (Decrease) in other liabilities (263 ) 181 Equity in undistributed net income of subsidiary (19,713 ) (9,242 ) Net cash provided by operating activities 2,368 373 Cash flows from investing activities: Cash received from acquisitions, net — 1,421 Net cash provided by investing activities — 1,421 Cash flows from financing activities: Repurchase of common stock (7,836 ) — Exercise of common stock options and warrants 1,931 5,260 Common and preferred stock dividends paid (3,507 ) (1,244 ) Net cash provided by (used in) financing activities (9,412 ) 4,016 Net increase (decrease) in cash and cash equivalents (7,044 ) 5,810 Cash and cash equivalents at beginning of period 19,918 14,108 Cash and cash equivalents at end of period $ 12,874 $ 19,918

Quarterly Financial Results (_2

Quarterly Financial Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Financial Results (Unaudited)	The following is a summary of quarterly financial results (unaudited) for 2019, 2018 and 2017: First Quarter Second Quarter Third Quarter Fourth Quarter 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 before income tax expense 6,126 7,570 8,538 7,034 Income tax expense 1,346 1,814 2,072 1,613 Net income $ 4,780 $ 5,756 $ 6,466 $ 5,421 Net income per share, basic $ 0.27 $ 0.33 $ 0.36 $ 0.30 Net income 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 ) 2017 Interest income $ 11,979 $ 12,891 $ 13,521 $ 13,124 Interest expense 2,047 2,320 2,678 2,606 Net interest income 9,932 10,571 10,843 10,518 Provision for loan losses 3,405 9,690 (195 ) (30 ) Net interest income after provision for loan losses 6,527 881 11,038 10,548 Noninterest income 2,133 2,666 3,372 2,736 Noninterest expense 8,376 8,217 8,475 8,699 Net income (loss) before income tax expense 284 (4,670 ) 5,935 4,585 Income tax expense (benefit) (47 ) (1,328 ) 1,516 4,494 Net income (loss) $ 331 $ (3,342 ) $ 4,419 $ 91 Net income (loss) per share, basic $ 0.03 $ (0.30 ) $ 0.39 $ 0.01 Net income (loss) per share, diluted $ 0.03 $ (0.26 ) $ 0.35 $ 0.01

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019USD ($)Securityshares	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)shares	Jan. 01, 2019USD ($)
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	41 quarters	37 quarters	33 quarter
Noninterest income	$ 9,467,000	$ 5,653,000	$ 6,238,000
Operating lease, right-of-use asset	11,700,000	12,800,000		$ 12,800,000
Operating lease, liability	$ 12,451,000	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	$ 63,890,000	$ 43,940,000
Antidilutive stock options excluded from diluted earnings per share | shares	0	0	0
Cumulative-effect adjustment to retained earnings		$ 600,000
Income tax effects, accumulated other comprehensive income to retained earnings, amount	$ 259,000
Other Operating Expenses
Summary Of Significant Accounting Policies [Line Items]
Advertising expense	$ 370,000	383,000	$ 310,000
IRS
Summary Of Significant Accounting Policies [Line Items]
Open to audit	2016 2017 2018 2019
States
Summary Of Significant Accounting Policies [Line Items]
Open to audit	2016 2017 2018 2019
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	$ 340,000	102,000	$ 0
Residential mortgage loans held for sale
Summary Of Significant Accounting Policies [Line Items]
Mortgage banking income	600,000
Residential mortgage loans held for sale	$ 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, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	$ 30,740,000	$ 0
Aggregate Unpaid Principal Balance	30,178,000
Difference	$ 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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Basic net income per share calculation:
Numerator – Net income													$ 22,422	$ 9,655	$ 1,501
Denominator – Average common shares outstanding													17,886,164	13,277,614	11,280,580
Basic net income per share	$ 0.30	$ 0.36	$ 0.33	$ 0.27	$ (0.04)	$ 0.30	$ 0.30	$ 0.27	$ 0.01	$ 0.39	$ (0.30)	$ 0.03	$ 1.25	$ 0.73	$ 0.13
Diluted net income per share calculation:
Numerator – Net income													$ 22,422	$ 9,655	$ 1,501
Denominator – Average common shares outstanding													17,886,164	13,277,614	11,280,580
Dilutive shares contingently issuable													727,060	1,202,733	1,522,931
Average diluted common shares outstanding													18,613,224	14,480,347	12,803,511
Diluted net income per share	$ 0.29	$ 0.35	$ 0.31	$ 0.25	$ (0.04)	$ 0.28	$ 0.27	$ 0.25	$ 0.01	$ 0.35	$ (0.26)	$ 0.03	$ 1.20	$ 0.67	$ 0.12

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - Athens Bancshares - USD ($)	Dec. 31, 2018	Oct. 01, 2018
Business Acquisition [Line Items]
Percentage of voting interests acquired		100.00%
Common stock exchange ratio		2.864
Acquisition related costs	$ 9,803,000
Goodwill		$ 31,291,000

Acquisition - Schedule of Consi

Acquisition - Schedule of Consideration Paid and Amounts of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Oct. 01, 2018	Dec. 31, 2017
Total cost of acquisition:
Goodwill	$ 37,510	$ 37,510		$ 6,219
Athens Bancshares
Assets:
Cash and cash equivalents			$ 12,053
Securities			67,426
Loans, gross			344,833
Premises and equipment, net			9,208
Core deposit intangible			8,980
Other			30,510
Total			473,010
Liabilities:
Deposits			404,520
Other			6,863
Total			411,383
Net identifiable assets acquired			61,627
Total cost of acquisition:
Total cost of acquisition	92,918
Goodwill			31,291
Athens Bancshares | As recorded by Athens Bancshares
Assets:
Cash and cash equivalents			12,053
Securities			67,342
Loans, gross			349,597
Allowance for loan losses			(4,039)
Premises and equipment, net			7,637
Core deposit intangible			2,758
Other			29,566
Total			464,914
Liabilities:
Deposits			404,027
Other			5,363
Total			409,390
Athens Bancshares | Initial Fair Value Adjustment
Assets:
Securities			84
Loans, gross			(4,764)
Allowance for loan losses			4,039
Premises and equipment, net			1,571
Core deposit intangible			6,222
Other			944
Total			8,096
Liabilities:
Deposits			493
Other			1,500
Total			$ 1,993
Total cost of acquisition:
Total cost of acquisition	92,918
Athens Bancshares | Initial Fair Value Adjustment | Rolled Stock Options
Total cost of acquisition:
Total cost of acquisition	6,380
Athens Bancshares | Common Stock | Initial Fair Value Adjustment
Total cost of acquisition:
Total cost of acquisition	$ 86,538

Acquisition - Schedule of Con_2

Acquisition - Schedule of Consideration Paid and Amounts of Assets Acquired and Liabilities Assumed (Parenthetical) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Athens Bancshares
Business Acquisition [Line Items]
Charitable contribution	$ 1,500,000

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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Net interest income	$ 16,581	$ 17,156	$ 17,008	$ 17,002	$ 17,716	$ 11,543	$ 11,587	$ 10,846	$ 10,518	$ 10,843	$ 10,571	$ 9,932	$ 67,748	$ 51,692	$ 41,863
Noninterest income	5,719	6,788	7,032	4,735	6,387	3,218	2,765	3,088	2,736	3,372	2,666	2,133	24,274	15,459	10,908
Net income	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 91	$ 4,419	$ (3,342)	$ 331	$ 22,422	$ 9,655	$ 1,501
Per share information:
Basic net income per share of common stock	$ 0.30	$ 0.36	$ 0.33	$ 0.27	$ (0.04)	$ 0.30	$ 0.30	$ 0.27	$ 0.01	$ 0.39	$ (0.30)	$ 0.03	$ 1.25	$ 0.73	$ 0.13
Diluted net income per share of common stock	$ 0.29	$ 0.35	$ 0.31	$ 0.25	$ (0.04)	$ 0.28	$ 0.27	$ 0.25	$ 0.01	$ 0.35	$ (0.26)	$ 0.03	$ 1.20	$ 0.67	$ 0.12
Athens Bancshares
Business Acquisition [Line Items]
Net interest income														$ 66,935	$ 59,148
Noninterest income														20,692	17,540
Total revenue														87,627	76,688
Net income														$ 21,167	$ 5,851
Per share information:
Basic net income per share of common stock														$ 1.24	$ 0.36
Diluted net income per share of common stock														$ 1.14	$ 0.32

Investment Securities - Summary

Investment Securities - Summary of Company's Classification of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Securities available for sale [Abstract]
Amortized Cost	$ 209,943	$ 247,042
Gross unrealized gains	3,906	1,616
Gross unrealized (losses)	(720)	(4,850)
Estimated fair value	213,129	243,808
Securities held to maturity [Abstract]
Amortized Cost	3,313	3,734
Gross unrealized gains	98	54
Gross unrealized (losses)		(3)
Estimated fair value	3,411	3,785
U. S. government agency securities
Securities available for sale [Abstract]
Amortized Cost	10,421	11,053
Gross unrealized gains	4
Gross unrealized (losses)	(94)	(347)
Estimated fair value	10,331	10,706
State and municipal securities
Securities available for sale [Abstract]
Amortized Cost	44,053	62,142
Gross unrealized gains	1,927	765
Gross unrealized (losses)	(20)	(981)
Estimated fair value	45,960	61,926
Securities held to maturity [Abstract]
Amortized Cost	3,313	3,734
Gross unrealized gains	98	54
Gross unrealized (losses)		(3)
Estimated fair value	3,411	3,785
Mortgage-backed securities
Securities available for sale [Abstract]
Amortized Cost	137,305	146,547
Gross unrealized gains	1,834	776
Gross unrealized (losses)	(460)	(3,165)
Estimated fair value	138,679	144,158
Asset-backed securities
Securities available for sale [Abstract]
Amortized Cost	3,325	15,437
Gross unrealized gains		4
Gross unrealized (losses)	(128)	(157)
Estimated fair value	3,197	15,284
Other debt securities
Securities available for sale [Abstract]
Amortized Cost	14,839	11,863
Gross unrealized gains	141	71
Gross unrealized (losses)	(18)	(200)
Estimated fair value	$ 14,962	$ 11,734

Investment Securities - Additio

Investment Securities - Additional Information (Details) - USD ($)	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2013	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities transferred to held to maturity		$ 36,789,000
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			$ 70,350,000	$ 171,542,000
Accounting Standards Update 2017-12
Schedule Of Available For Sale Securities [Line Items]
Held to maturity securities transferred to available for sale securities	$ 41,665,000

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, 2019	Dec. 31, 2018
Available-for-sale, Amortized cost [Abstract]
Due in less than one year	$ 9,805
Due one to five years	28,593
Due five to ten years	29,545
Due beyond ten years	1,370
Amortized Cost	209,943	$ 247,042
Available-for-sale, Estimated fair value [Abstract]
Due in less than one year	9,909
Due one to five years	29,230
Due five to ten years	30,758
Due beyond ten years	1,356
Estimated fair value	213,129	243,808
Held-to-maturity, Amortized cost [Abstract]
Due in less than one year	881
Due one to five years	2,432
Amortized Cost	3,313	3,734
Securities held to maturity [Abstract]
Due in less than one year	884
Due one to five years	2,527
Estimated fair value	3,411	3,785
Mortgage-backed securities
Available-for-sale, Amortized cost [Abstract]
Amortized cost	137,305
Amortized Cost	137,305	146,547
Available-for-sale, Estimated fair value [Abstract]
Estimated fair value	138,679
Estimated fair value	138,679	144,158
Asset-backed securities
Available-for-sale, Amortized cost [Abstract]
Amortized cost	3,325
Amortized Cost	3,325	15,437
Available-for-sale, Estimated fair value [Abstract]
Estimated fair value	3,197
Estimated fair value	$ 3,197	$ 15,284

Investment Securities - Summa_3

Investment Securities - Summary of Sale of Debt and Equity Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Proceeds	$ 68,068	$ 38,322	$ 46,762
Gross gains	49	116	124
Gross losses	$ (148)	$ (113)	$ (190)

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, 2019	Dec. 31, 2018
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	$ 42,632	$ 34,154
Less than 12 months, Gross unrealized (losses)	(215)	(574)
12 months or more, Estimated fair value	28,514	117,753
12 months or more, Gross unrealized losses	(505)	(4,279)
Total, Estimated fair value	71,146	151,907
Total, Gross unrealized losses	(720)	(4,853)
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	10,706
12 months or more, Gross unrealized losses	(43)	(347)
Total, Estimated fair value	8,331	10,706
Total, Gross unrealized losses	(94)	(347)
State and municipal securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	2,356	13,455
Less than 12 months, Gross unrealized (losses)	(12)	(212)
12 months or more, Estimated fair value	814	17,376
12 months or more, Gross unrealized losses	(8)	(772)
Total, Estimated fair value	3,170	30,831
Total, Gross unrealized losses	(20)	(984)
Mortgage-backed securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	30,570	7,075
Less than 12 months, Gross unrealized (losses)	(136)	(17)
12 months or more, Estimated fair value	21,364	87,232
12 months or more, Gross unrealized losses	(324)	(3,148)
Total, Estimated fair value	51,934	94,307
Total, Gross unrealized losses	(460)	(3,165)
Asset-backed securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value		8,262
Less than 12 months, Gross unrealized (losses)		(145)
12 months or more, Estimated fair value	3,197	2,439
12 months or more, Gross unrealized losses	(128)	(12)
Total, Estimated fair value	3,197	10,701
Total, Gross unrealized losses	(128)	(157)
Other debt securities
Available-for-sale securities, continuous unrealized loss position [Abstract]
Less than 12 months, Estimated fair value	3,012	5,362
Less than 12 months, Gross unrealized (losses)	(16)	(200)
12 months or more, Estimated fair value	1,502
12 months or more, Gross unrealized losses	(2)
Total, Estimated fair value	4,514	5,362
Total, Gross unrealized losses	$ (18)	$ (200)

Loans and Allowance for Loan _3

Loans and Allowance for Loan Losses - Summary of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans And Leases Receivable Disclosure [Line Items]
Total loans	$ 1,420,102	$ 1,429,794
Allowance for loan losses	(12,604)	(12,113)	$ (13,721)	$ (11,634)
Loans, net	1,407,498	1,417,681
Commercial real estate
Loans And Leases Receivable Disclosure [Line Items]
Total loans	559,899	550,446
Allowance for loan losses	(3,599)	(3,309)	(3,324)	(2,655)
Consumer real estate
Loans And Leases Receivable Disclosure [Line Items]
Total loans	256,097	253,562
Allowance for loan losses	(1,231)	(1,005)	(1,063)	(1,013)
Construction and land development
Loans And Leases Receivable Disclosure [Line Items]
Total loans	143,111	174,670
Allowance for loan losses	(2,058)	(2,431)	(1,628)	(1,574)
Commercial and industrial
Loans And Leases Receivable Disclosure [Line Items]
Total loans	394,408	404,600
Allowance for loan losses	(5,074)	(5,036)	(7,209)	(5,618)
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Total loans	28,426	25,615
Allowance for loan losses	(222)	(105)	(91)	(76)
Other
Loans And Leases Receivable Disclosure [Line Items]
Total loans	38,161	20,901
Allowance for loan losses	$ (420)	$ (227)	$ (406)	$ (698)

Loans and Allowance for Loan _4

Loans and Allowance for Loan Losses - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019USD ($)Contract	Dec. 31, 2018USD ($)Contract	Dec. 31, 2017USD ($)Contract	Oct. 01, 2018USD ($)
Loans And Leases Receivable Disclosure [Line Items]
Variable-rate loans	$ 785,329,000	$ 827,491,000
Fixed-rate loans	634,773,000	602,404,000
Minimum loan amount for loans analyzed by credit risk	500,000
Total loans	1,420,102,000	1,429,794,000
Interest income recognized on a cash basis for impaired loans	0	0	$ 0
Investments in TDR	2,700,000	1,400,000
Additional commitments related to TDR	$ 0	$ 0
New TDR identified during the period | Contract	2	0	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				$ 344,800,000
Minimum
Loans And Leases Receivable Disclosure [Line Items]
Lease term	5 years
Maximum
Loans And Leases Receivable Disclosure [Line Items]
Lease term	6 years
Purchased Credit Impaired
Loans And Leases Receivable Disclosure [Line Items]
Recorded loans with a fair value				$ 1,700,000
Troubled Debt Restructurings
Loans And Leases Receivable Disclosure [Line Items]
Specific allowance related to loans	$ 0	$ 0
Doubtful
Loans And Leases Receivable Disclosure [Line Items]
Total loans	$ 0	$ 0

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, 2019	Dec. 31, 2018
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 1,420,102	$ 1,429,794
Total Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	5,199	3,898
Performing Financial Instruments
Financing Receivable Recorded Investment [Line Items]
Total loans	1,414,903	1,425,896
Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	1,384,877	1,406,656
Performing Financial Instruments | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	15,765	9,696
Performing Financial Instruments | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	14,261	9,544
Commercial real estate
Financing Receivable Recorded Investment [Line Items]
Total loans	559,899	550,446
Commercial real estate | Total Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	2,617	1,391
Commercial real estate | Performing Financial Instruments
Financing Receivable Recorded Investment [Line Items]
Total loans	557,282	549,055
Commercial real estate | Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	551,929	547,616
Commercial real estate | Performing Financial Instruments | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	915	177
Commercial real estate | Performing Financial Instruments | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	4,438	1,262
Consumer real estate
Financing Receivable Recorded Investment [Line Items]
Total loans	256,097	253,562
Consumer real estate | Total Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	1,091	922
Consumer real estate | Performing Financial Instruments
Financing Receivable Recorded Investment [Line Items]
Total loans	255,006	252,640
Consumer real estate | Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	252,952	249,273
Consumer real estate | Performing Financial Instruments | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	503	1,676
Consumer real estate | Performing Financial Instruments | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	1,551	1,691
Construction and land development
Financing Receivable Recorded Investment [Line Items]
Total loans	143,111	174,670
Construction and land development | Total Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	117	8
Construction and land development | Performing Financial Instruments
Financing Receivable Recorded Investment [Line Items]
Total loans	142,994	174,662
Construction and land development | Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	142,978	174,591
Construction and land development | Performing Financial Instruments | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans		52
Construction and land development | Performing Financial Instruments | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	16	19
Commercial and industrial
Financing Receivable Recorded Investment [Line Items]
Total loans	394,408	404,600
Commercial and industrial | Total Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	1,351	1,546
Commercial and industrial | Performing Financial Instruments
Financing Receivable Recorded Investment [Line Items]
Total loans	393,057	403,054
Commercial and industrial | Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	370,475	388,719
Commercial and industrial | Performing Financial Instruments | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	14,341	7,790
Commercial and industrial | Performing Financial Instruments | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	8,241	6,545
Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans	28,426	25,615
Consumer | Total Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans	23	31
Consumer | Performing Financial Instruments
Financing Receivable Recorded Investment [Line Items]
Total loans	28,403	25,584
Consumer | Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	28,382	25,556
Consumer | Performing Financial Instruments | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	6	1
Consumer | Performing Financial Instruments | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	15	27
Other
Financing Receivable Recorded Investment [Line Items]
Total loans	38,161	20,901
Other | Performing Financial Instruments
Financing Receivable Recorded Investment [Line Items]
Total loans	38,161	20,901
Other | Performing Financial Instruments | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 38,161	$ 20,901

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
	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		$ 12,113				$ 13,721				$ 11,634	$ 12,113	$ 13,721	$ 11,634
Charged-off loans											(798)	(4,954)	(12,769)
Recoveries											528	504	1,986
Provision for loan losses	$ (125)	886	$ 1,514	$ 481	$ 169	678	$ (30)	$ (195)	$ 9,690	3,405	761	2,842	12,870
Ending Balance			12,113				13,721				12,604	12,113	13,721
Commercial real estate
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		3,309				3,324				2,655	3,309	3,324	2,655
Recoveries											23	22	9
Provision for loan losses											267	(37)	660
Ending Balance			3,309				3,324				3,599	3,309	3,324
Consumer real estate
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		1,005				1,063				1,013	1,005	1,063	1,013
Charged-off loans											(39)
Recoveries											20	4
Provision for loan losses											245	(62)	50
Ending Balance			1,005				1,063				1,231	1,005	1,063
Construction and land development
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		2,431				1,628				1,574	2,431	1,628	1,574
Provision for loan losses											(373)	803	54
Ending Balance			2,431				1,628				2,058	2,431	1,628
Commercial and industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		5,036				7,209				5,618	5,036	7,209	5,618
Charged-off loans											(455)	(4,831)	(12,769)
Recoveries											380	395	1,865
Provision for loan losses											113	2,263	12,495
Ending Balance			5,036				7,209				5,074	5,036	7,209
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		105				91				76	105	91	76
Charged-off loans											(164)	(84)
Recoveries											82	75	112
Provision for loan losses											199	23	(97)
Ending Balance			105				91				222	105	91
Other
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		$ 227				$ 406				$ 698	227	406	698
Charged-off loans											(140)	(39)
Recoveries											23	8
Provision for loan losses											310	(148)	(292)
Ending Balance			$ 227				$ 406				$ 420	$ 227	$ 406

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, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Loan Losses:
Collectively evaluated for impairment	$ 12,604	$ 12,113
Allowance for Loan Losses, Ending Balance	12,604	12,113	$ 13,721	$ 11,634
Loans:
Collectively evaluated for impairment	1,414,903	1,425,896
Individually evaluated for impairment	3,594	2,278
Acquired with deteriorated credit quality	1,605	1,620
Total	1,420,102	1,429,794
Commercial real estate
Allowance for Loan Losses:
Collectively evaluated for impairment	3,599	3,309
Allowance for Loan Losses, Ending Balance	3,599	3,309	3,324	2,655
Loans:
Collectively evaluated for impairment	557,282	549,055
Individually evaluated for impairment	2,507	1,278
Acquired with deteriorated credit quality	110	113
Total	559,899	550,446
Consumer real estate
Allowance for Loan Losses:
Collectively evaluated for impairment	1,231	1,005
Allowance for Loan Losses, Ending Balance	1,231	1,005	1,063	1,013
Loans:
Collectively evaluated for impairment	255,006	252,640
Individually evaluated for impairment	483	183
Acquired with deteriorated credit quality	608	739
Total	256,097	253,562
Construction and land development
Allowance for Loan Losses:
Collectively evaluated for impairment	2,058	2,431
Allowance for Loan Losses, Ending Balance	2,058	2,431	1,628	1,574
Loans:
Collectively evaluated for impairment	142,994	174,662
Individually evaluated for impairment	112
Acquired with deteriorated credit quality	5	8
Total	143,111	174,670
Commercial and industrial
Allowance for Loan Losses:
Collectively evaluated for impairment	5,074	5,036
Allowance for Loan Losses, Ending Balance	5,074	5,036	7,209	5,618
Loans:
Collectively evaluated for impairment	393,057	403,054
Individually evaluated for impairment	487	817
Acquired with deteriorated credit quality	864	729
Total	394,408	404,600
Consumer
Allowance for Loan Losses:
Collectively evaluated for impairment	222	105
Allowance for Loan Losses, Ending Balance	222	105	91	76
Loans:
Collectively evaluated for impairment	28,403	25,584
Individually evaluated for impairment	5
Acquired with deteriorated credit quality	18	31
Total	28,426	25,615
Other
Allowance for Loan Losses:
Collectively evaluated for impairment	420	227
Allowance for Loan Losses, Ending Balance	420	227	$ 406	$ 698
Loans:
Collectively evaluated for impairment	38,161	20,901
Total	$ 38,161	$ 20,901

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, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 12,604	$ 12,113	$ 13,721	$ 11,634
Allowance for loan and lease losses, Percentage of total loans	0.89%	0.85%
Commercial real estate
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 3,599	$ 3,309	3,324	2,655
Allowance for loan and lease losses, Percentage of total loans	0.25%	0.23%
Consumer real estate
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 1,231	$ 1,005	1,063	1,013
Allowance for loan and lease losses, Percentage of total loans	0.09%	0.07%
Construction and land development
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 2,058	$ 2,431	1,628	1,574
Allowance for loan and lease losses, Percentage of total loans	0.14%	0.17%
Commercial and industrial
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 5,074	$ 5,036	7,209	5,618
Allowance for loan and lease losses, Percentage of total loans	0.36%	0.35%
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 222	$ 105	91	76
Allowance for loan and lease losses, Percentage of total loans	0.02%	0.01%
Other
Loans And Leases Receivable Disclosure [Line Items]
Allowance for loan and lease losses, Amount	$ 420	$ 227	$ 406	$ 698
Allowance for loan and lease losses, Percentage of total loans	0.03%	0.02%

Loans and Allowance for Loan _9

Loans and Allowance for Loan Losses - Summary of Information Related to Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	$ 5,199	$ 3,898
Impaired loans with no related allowance recorded, Unpaid principal balance	6,294	9,403
Recorded investment	5,199	3,898
Unpaid principal balance	6,294	9,403
Commercial real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	2,617	1,391
Impaired loans with no related allowance recorded, Unpaid principal balance	2,621	1,775
Consumer real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	1,091	922
Impaired loans with no related allowance recorded, Unpaid principal balance	1,327	1,204
Construction and land development
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	117	8
Impaired loans with no related allowance recorded, Unpaid principal balance	132	18
Commercial and industrial
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	1,351	1,546
Impaired loans with no related allowance recorded, Unpaid principal balance	2,173	6,350
Consumer
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Recorded investment	23	31
Impaired loans with no related allowance recorded, Unpaid principal balance	$ 41	$ 56

Loans and Allowance for Loan_10

Loans and Allowance for Loan Losses - Summary of Average Recorded Investment and Interest Income Recognized on Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	$ 4,577	$ 7,041	$ 1,258
Impaired loans with no related allowance recorded, Interest income recognized	864	281
Impaired loans with an allowance recorded, Average recorded investment			2,077
Average recorded investment	4,577	7,041	3,335
Interest income recognized	864	281
Commercial real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	2,574	1,198	1,258
Impaired loans with no related allowance recorded, Interest income recognized	313	158
Consumer real estate
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	1,037	185
Impaired loans with no related allowance recorded, Interest income recognized	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
Commercial and industrial
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	824	5,557
Impaired loans with no related allowance recorded, Interest income recognized	440	121
Impaired loans with an allowance recorded, Average recorded investment			$ 2,077
Consumer
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, Average recorded investment	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, 2019	Dec. 31, 2018
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	$ 7,624	$ 1,595
Loans Not Past Due	1,412,478	1,428,199
Total	1,420,102	1,429,794
Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	372	527
Loans Not Past Due	559,527	549,919
Total	559,899	550,446
Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	4,759	919
Loans Not Past Due	251,338	252,643
Total	256,097	253,562
Construction and land development
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	668
Loans Not Past Due	142,443	174,670
Total	143,111	174,670
Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,725	54
Loans Not Past Due	392,683	404,546
Total	394,408	404,600
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	100	95
Loans Not Past Due	28,326	25,520
Total	28,426	25,615
Other
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Not Past Due	38,161	20,901
Total	38,161	20,901
30 - 59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	6,011	475
30 - 59 Days Past Due | Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	372	300
30 - 59 Days Past Due | Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	3,642	69
30 - 59 Days Past Due | Construction and land development
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	653
30 - 59 Days Past Due | Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,277	54
30 - 59 Days Past Due | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	67	52
60 - 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	497	302
60 - 89 Days Past Due | Commercial real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		227
60 - 89 Days Past Due | Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	474	75
60 - 89 Days Past Due | Construction and land development
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	15
60 - 89 Days Past Due | Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	8
Greater than 89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,116	818
Greater than 89 Days Past Due | Consumer real estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	643	775
Greater than 89 Days Past Due | Commercial and industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	440
Greater than 89 Days Past Due | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	$ 33	$ 43

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, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	$ 1,464	$ 2,078
Past Due Over 89 Days and Accruing	38	214
Troubled Debt Restructurings	2,717	1,391
Commercial real estate
Accounts Notes And Loans Receivable [Line Items]
Troubled Debt Restructurings	2,446	1,391
Consumer real estate
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	894	1,187
Past Due Over 89 Days and Accruing	12	214
Construction and Land Development
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	117	19
Commercial and industrial
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	440	817
Troubled Debt Restructurings	271
Consumer
Accounts Notes And Loans Receivable [Line Items]
Non-Accrual	13	$ 55
Past Due Over 89 Days and Accruing	$ 26

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, 2019USD ($)Contract	Dec. 31, 2018Contract	Dec. 31, 2017Contract
Financing Receivable Modifications [Line Items]
Number of contracts | Contract	2	0	0
Pre modification outstanding recorded investment	$ 1,499
Post modification outstanding recorded investment, net of related allowance	$ 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
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 the contractually required payments (Details) - Athens Bancshares $ in Thousands	Oct. 01, 2018USD ($)
Purchased Credit Impaired
Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Movement Schedule [Line Items]
Contractually required payments	$ 3,151
Nonaccretable difference	(1,049)
Cash flows expected to be collected at acquisition	2,102
Accretable yield	(436)
Fair value of PCI loans at acquisition date	1,666
Purchased Non Impaired [Member]
Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Movement Schedule [Line Items]
Contractually required payments	404,692
Fair value of PCI loans at acquisition date	343,167
Contractual cash flows not expected to be collected	$ 1,807

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, 2019USD ($)
Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Movement Schedule [Line Items]
Balance, beginning , carrying value	$ 1,620
Change due to payments received and accretion	(15)
Balance, ending, carrying value	1,605
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	440
Accretion	(570)
Reclassification from (to) nonaccretable difference	1,045
Balance, ending, carrying value	$ 915

Loans and Allowance for Loan_16

Loans and Allowance for Loan Losses - Schedule of Components of Direct Financing Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Total minimum lease payments receivable	$ 59	$ 379
Less: Unearned income	(1)	(19)
Net leases	$ 58	$ 360

Loans and Allowance for Loan_17

Loans and Allowance for Loan Losses - Summary of Future Minimum Lease Payments Receivable under Direct Financing Leases (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
2020	$ 58
Future minimum lease payments receivable	$ 58

Loan Servicing - Additional Inf

Loan Servicing - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Transfers And Servicing [Abstract]
Loan principal balance	$ 196,900,000	$ 170,100,000
Custodial escrow balances maintained In connection with serviced loans	$ 324,000	$ 462,000

Loan Servicing - Schedule of Ac

Loan Servicing - Schedule of Activity for Loan Servicing Rights and Related Valuation Allowance (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Loan servicing rights:
Balance at beginning of period	$ 1,736
Additions	381
Amortized to offset other noninterest income	(362)
Change in valuation allowance	(211)
Balance at end of period	1,544
Valuation allowance:
Direct write-downs	(211)
Balance at end of period	$ (211)

Premises and Equipment - Summar

Premises and Equipment - Summary of Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Premises and equipment, gross	$ 23,206	$ 21,654
Less accumulated depreciation and amortization	(4,022)	(2,833)
Premises and equipment, net	$ 19,184	18,821
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	$ 13,331	9,965
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	$ 4,633	3,730
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	$ 4,303	2,997
Fixed Assets In Process
Property Plant And Equipment [Line Items]
Premises and equipment, gross		$ 4,023

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Premises and equipment depreciation and amortization expense	$ 1,219,000	$ 516,000	$ 401,000

Leases - Additional Information

Leases - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Leases [Abstract]
Operating lease, expiration year	2032
Operating lease, liability	$ 12,451,000	$ 13,400,000	$ 13,400,000
Operating lease, right-of-use asset	$ 11,700,000	12,800,000	$ 12,800,000
Operating lease, weighted average remaining lease term	10 years 8 months 12 days
Operating lease, weighted average discount rate, percent	3.52%
Operating leases, rent expense	$ 1,677,000
Sale and leaseback transaction	$ 0	$ 0

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating lease cost	$ 1,868
Total lease cost	$ 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, 2019	Jan. 01, 2019	Dec. 31, 2018
Lease payments due:
2020	$ 1,562
2021	1,590
2022	1,476
2023	1,425
2024	1,130
2025 and thereafter	7,710
Total undiscounted cash flows	14,893
Discount on cash flows	(2,442)
Operating lease, liability	$ 12,451	$ 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, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning of year	$ 37,510	$ 6,219
Acquired goodwill	0	31,291
Impairment	0	0
End of year	$ 37,510	$ 37,510

Goodwill And Intangible Asset_3

Goodwill And Intangible Assets - Summary of Acquired Intangible Assets (Details) - Core Deposit - USD ($) $ in Thousands	Mar. 03, 2020	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 9,267	$ 9,267
Accumulated Amortization	$ (2,384)	$ (729)

Goodwill And Intangible Asset_4

Goodwill And Intangible Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Aggregate amortization expense	$ 1,655,000	$ 465,000	$ 48,000

Goodwill And Intangible Asset_5

Goodwill And Intangible Assets - Summary of Estimated Amortization Expense (Details) $ in Thousands	Dec. 31, 2018USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2020	$ 1,477
2021	1,299
2022	1,121
2023	943
2024	764
Thereafter	1,279
Total	$ 6,883

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, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Real Estate Roll Forward
Beginning balance	$ 988	$ 0	$ 0
Additions due to acquisition of Athens Bancshares	0	988	0
Loans transferred to other real estate owned	180	0	0
Direct write-downs	0	0	0
Sales of other real estate owned	(124)	0	0
End of year	$ 1,044	$ 988	$ 0

Other Real Estate Owned - Addit

Other Real Estate Owned - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Real Estate [Abstract]
Net (gain) loss on sales	$ (3)	$ 0	$ 0
Provision for unrealized losses	0	0	0
Operating expenses, net of rental income	0	0	0
Total	$ (3)	$ 0	$ 0

Deposits - Additional Informati

Deposits - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
FDIC deposit insurance limit	$ 250,000	$ 250,000
Time deposits	53,481,000	98,086,000
Deposit accounts in overdraft status reclassified to loans	$ 148,000	$ 193,000

Deposits - Scheduled Maturities

Deposits - Scheduled Maturities of Time Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Maturities Of Time Deposits [Abstract]
2020	$ 222,163
2021	53,077
2022	16,255
2023	8,369
2024	2,975
Thereafter	613
Total	$ 303,452	$ 348,427

Federal Home Loan Bank Advanc_3

Federal Home Loan Bank Advances - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank Advances [Line Items]
Outstanding borrowings	$ 10,000,000	$ 125,000,000
Investment securities, FHLB stock and commercial and residential real estate mortgage loans
Federal Home Loan Bank Advances [Line Items]
Federal Home Loan Bank Advances Collateralized Investment Securities Value	4,100,000
Mortgage loans collateralized amount	683,100,000
Amount of available credit	$ 201,400,000

Federal Home Loan Bank Advanc_4

Federal Home Loan Bank Advances - Summary of Contractual Maturities and Average Effective Rates of Outstanding Advances (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank Advances Maturities Summary [Abstract]
2019		$ 125,000,000
2020	$ 10,000,000
Total amount	$ 10,000,000	$ 125,000,000
2019		2.48%
2020	2.05%
Total interest rates	2.05%	2.48%

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, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ 254,379	$ 146,946	$ 139,207
Other comprehensive income (loss) before reclassification, net of tax	5,641	67
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(942)	(856)
Other comprehensive income (loss)	4,699	(789)	3,883
Ending balance	273,046	254,379	146,946
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(2,636)	(3,679)
Other comprehensive income (loss) before reclassification, net of tax	826	1,891
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(869)	(848)
Other comprehensive income (loss)	(43)	1,043
Ending balance	(2,679)	(2,636)	(3,679)
Unrealized Gains and Losses on Available for Sale Securities
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(680)	1,162
Other comprehensive income (loss) before reclassification, net of tax	4,815	(1,844)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(73)	2
Other comprehensive income (loss)	4,742	(1,842)
Ending balance	4,062	(680)	1,162
Unrealized Losses on Securities Transferred to Held to Maturity
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(10)
Other comprehensive income (loss) before reclassification, net of tax		20
Amounts reclassified from accumulated other comprehensive income (loss), net of tax		(10)
Other comprehensive income (loss)		10
Ending balance			(10)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(3,316)	(2,527)	(6,151)
Other comprehensive income (loss)	4,699	(789)	3,883
Ending balance	$ 1,383	$ (3,316)	$ (2,527)

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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Net gain (loss) on sale of securities													$ (99)	$ 3	$ (66)
Interest expense - Federal Home Loan Bank advances													(1,444)	(2,533)	(1,559)
Income tax (expense) benefit	$ (1,613)	$ (2,072)	$ (1,814)	$ (1,346)	$ 535	$ (554)	$ (665)	$ (483)	$ (4,494)	$ (1,516)	$ 1,328	$ 47	(6,844)	(1,167)	(4,635)
Net income	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 91	$ 4,419	$ (3,342)	$ 331	22,422	9,655	1,501
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Losses on Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest expense money market													(635)	(441)	(430)
Interest expense - Federal Home Loan Bank advances													(243)	(479)	(429)
Income tax (expense) benefit													9	72	89
Net income													(869)	(848)	(770)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized 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													(99)	3	(66)
Income tax (expense) benefit													26	(1)	25
Net income													$ (73)	2	(41)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Losses on Securities Transferred to Held to Maturity
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest income - securities														(14)	(190)
Income tax (expense) benefit														4	73
Net income														$ (10)	$ (117)

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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal													$ 3,215	$ 15	$ 214
State													1,044	(23)	36
Total Current tax expense (Benefit)													4,259	(8)	250
Deferred:
Federal													2,039	872	4,218
State													546	303	167
Total deferred tax expense (Benefit)													2,585	1,175	4,385
Total	$ 1,613	$ 2,072	$ 1,814	$ 1,346	$ (535)	$ 554	$ 665	$ 483	$ 4,494	$ 1,516	$ (1,328)	$ (47)	$ 6,844	$ 1,167	$ 4,635

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Federal statutory income tax rate	21.00%	21.00%	21.00%
Decrease in net deferred tax assets due to tax reforms			$ 3,562,000
Increase in income tax expense due to tax reforms			$ 3,600,000
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	$ 3,011,000
Federal net operating loss carryforwards, start year	2030
Federal net operating loss carryforwards, end year	2032

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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Computed "expected" tax expense													$ 6,146	$ 2,272	$ 2,086
State income taxes, net of effect of federal income taxes													1,256	221	134
Tax-exempt interest income													(302)	(298)	(418)
Earnings on bank owned life insurance contracts													(173)	(559)	(197)
Disallowed expenses													84	93	86
Excess tax benefits related to stock compensation													(57)	(857)	(632)
Write-down of deferred tax assets due to tax reform															3,562
Nondeductible merger expenses														281
Other													(110)	14	14
Total	$ 1,613	$ 2,072	$ 1,814	$ 1,346	$ (535)	$ 554	$ 665	$ 483	$ 4,494	$ 1,516	$ (1,328)	$ (47)	$ 6,844	$ 1,167	$ 4,635

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for loan losses	$ 2,935	$ 2,795
Net operating loss carryforward	738	2,002
Organization and preopening costs	359	457
Stock-based compensation	200	835
Acquired loans	871	1,319
Unrealized loss on securities available-for-sale		845
Accrued contributions	247	207
Other	189	685
Deferred tax assets	5,539	9,145
Deferred tax liabilities:
Depreciation	804	645
Goodwill	154	81
Unrealized gain on securities available-for-sale	833
Amortization of core deposit intangible	1,052	1,398
Other	568	411
Deferred tax liabilities	3,411	2,535
Net deferred tax asset	$ 2,128	$ 6,610

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Financial Instruments Representing Credit Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Unused commitments to extend credit	$ 672,933	$ 707,675
Standby letters of credit	9,634	12,273
Total	$ 682,567	$ 719,948

Concentration of Credit Risk -

Concentration of Credit Risk - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Cash due from banks, federal funds sold and interest bearing deposits	$ 101,269,000	$ 105,443,000
Excess Of Insured Limits
Concentration Risk [Line Items]
Cash due from banks, federal funds sold and interest bearing deposits	$ 86,000,000	$ 89,000,000

Regulatory Matters And Restri_3

Regulatory Matters And Restrictions On Dividends - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)Capital	Dec. 31, 2018USD ($)
Banking And Thrift [Abstract]
Number of capital categories | Capital	5
Dividends	$ 35.8	$ 22.2
Dividends paid	$ 3.5

Regulatory Matters And Restri_4

Regulatory Matters And Restrictions On Dividends - Schedule of Capital Amounts and Ratios (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
CapStar Financial Holdings, Inc.
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital to risk-weighted assets, actual amount		$ 237,857	$ 222,030
Tier I capital to risk-weighted assets, actual amount		225,074	209,738
Tier I capital to average assets, actual amount		$ 225,074	$ 209,738
Total capital to risk-weighted assets, actual ratio		13.45%	12.84%
Tier I capital to risk-weighted assets, actual ratio		12.73%	12.13%
Tier I capital to average assets, actual ratio		11.37%	11.06%
Total capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 141,436	$ 138,336
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	106,077	103,752
Tier I capital to average assets, minimum capital requirement amount	[1]	$ 79,201	$ 75,867
Total capital to risk-weighted assets, minimum capital requirement ratio	[1]	8.00%	8.00%
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	6.00%	6.00%
Tier I capital to average assets, minimum capital requirement ratio	[1]	4.00%	4.00%
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		$ 225,074	$ 200,738
Tier I capital to risk-weighted assets, actual ratio		12.73%	11.61%
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 79,558	$ 77,814
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	4.50%	4.50%
CapStar Bank
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital to risk-weighted assets, actual amount		$ 224,443	$ 201,972
Tier I capital to risk-weighted assets, actual amount		211,660	189,680
Tier I capital to average assets, actual amount		$ 211,660	$ 189,680
Total capital to risk-weighted assets, actual ratio		12.70%	11.68%
Tier I capital to risk-weighted assets, actual ratio		11.98%	10.97%
Tier I capital to average assets, actual ratio		10.70%	10.01%
Total capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 141,388	$ 138,294
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	106,041	103,721
Tier I capital to average assets, minimum capital requirement amount	[1]	$ 79,150	$ 75,828
Total capital to risk-weighted assets, minimum capital requirement ratio	[1]	8.00%	8.00%
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	6.00%	6.00%
Tier I capital to average assets, minimum capital requirement ratio	[1]	4.00%	4.00%
Total capital to risk-weighted assets, minimum to be well capitalized amount	[2]	$ 176,735	$ 172,868
Tier I capital to risk-weighted assets, minimum to be well capitalized amount	[2]	141,388	138,294
Tier I capital to average assets, minimum to be well capitalized amount	[2]	$ 98,938	$ 94,785
Total capital to risk-weighted assets, minimum to be well capitalized ratio	[2]	10.00%	10.00%
Tier I capital to risk-weighted assets, minimum to be well capitalized ratio	[2]	8.00%	8.00%
Tier I capital to average assets, minimum to be well capitalized ratio	[2]	5.00%	5.00%
CapStar Bank | Common Stock
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier I capital to risk-weighted assets, actual amount		$ 195,160	$ 173,180
Tier I capital to risk-weighted assets, actual ratio		11.04%	10.02%
Tier I capital to risk-weighted assets, minimum capital requirement amount	[1]	$ 79,531	$ 77,791
Tier I capital to risk-weighted assets, minimum capital requirement ratio	[1]	4.50%	4.50%
Tier I capital to risk-weighted assets, minimum to be well capitalized amount	[2]	$ 114,878	$ 112,364
Tier I capital to risk-weighted assets, minimum to be well capitalized ratio	[2]	6.50%	6.50%
[1]	For the calendar year 2019, 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, 2019
Banking And Thrift [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) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2016	Jul. 14, 2008
Class Of Stock [Line Items]
Preferred stock, shares issued	0	878,048
Preferred stock, shares outstanding	0	878,048
Expire period	10 years
Warrants grant date	Jul. 14, 2008
Warrants outstanding	0
Investor
Class Of Stock [Line Items]
Warrants issued to purchase common stock	238,319
Purchase price of share	$ 10
Expire period	10 years
Warrants grant date	Jul. 14, 2008
Warrants outstanding	0
Share issuance descriptions	Each subscriber for shares who is a Tennessee resident or any entity controlled by a Tennessee resident and invested a minimum of $500,000 in the offering, received a warrant to purchase additional shares of common stock equal to 5% of accepted subscriptions at the purchase price of $10.00 per share.
Accepted percentage of subscription on purchase price	5.00%
Investor | Minimum
Class Of Stock [Line Items]
Common stock subscription, value	$ 500,000,000
Director
Class Of Stock [Line Items]
Warrants issued to purchase common stock	10,000
Warrants purchase price	$ 10
Organizer
Class Of Stock [Line Items]
Warrants issued to purchase common stock	60,000
Expire period	10 years
Warrants grant date	Jul. 14, 2008
Warrants outstanding	0
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
Class Of Stock [Line Items]
Common stock, shares authorized	5,000,000	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	132,561
Warrants issued to purchase common stock				500,000
Purchase price of share				$ 10.25
Nonvoting | 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

Shareholders' Agreement - Addit

Shareholders' Agreement - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019Nomineeshares	Dec. 21, 2018shares
Share Based Compensation [Abstract]
Shareholders' agreement date	Aug. 22, 2016
Number of nominee | Nominee	1
Registrable securities	500,000
Number of additional shares registered		3,652,094

Stock Options and Restricted _3

Stock Options and Restricted Shares - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost	$ 1,564,000
Total fair value of shares vested	$ 1,352,000	$ 2,804,000	$ 1,174,000
Vesting period	3 years
Contractual term	10 years
Options granted	50,000	0
Total unrecognized compensation cost	$ 216,000
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 7 months 6 days
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cost expected to be recognized over a weighted-average period	2 years 4 months 24 days
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	362,757
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, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based compensation expense before income taxes	$ 1,262	$ 2,079	$ 1,061
Less: deferred tax benefit	(330)	(543)	(406)
Reduction of net income	$ 932	$ 1,536	$ 655

Stock Options and Restricted _5

Stock Options and Restricted Shares - Summary of Changes in Company's Nonvested Restricted Shares (Details)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Restricted Shares, Abstract
Restricted Shares, Nonvested Beginning Balance | shares	157,616
Restricted Shares, Granted | shares	31,683
Restricted Shares, Vested | shares	(83,062)
Restricted Shares, Forfeited | shares	(21,540)
Restricted Shares, Nonvested Ending Balance | shares	84,697
Weighted Average Grant Date Fair Value, Abstract
Weighted Average Grant Date Fair Value, Nonvested Beginning Balance | $ / shares	$ 17
Weighted Average Grant Date Fair Value, Granted | $ / shares	15.86
Weighted Average Grant Date Fair Value, Vested | $ / shares	15.93
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	17.72
Weighted Average Grant Date Fair Value, Nonvested Ending Balance | $ / shares	$ 17.44

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, 2019	Dec. 31, 2018
Shares, Abstract
Shares Outstanding, Beginning Balance	507,903
Shares Outstanding, Granted	50,000	0
Shares Outstanding, Exercised	(286,701)
Shares Outstanding, Ending Balance	271,202	507,903
Shares, Fully Vested and Expected to Vest	271,086
Shares, Exercisable at End of Period	214,952
Weighted Average Exercise Price, Abstract
Weighted Average Exercise Price Outstanding, Beginning Balance	$ 8.66
Weighted Average Exercise Price Outstanding, Granted	14.84
Weighted Average Exercise Price Outstanding, Exercised	7.33
Weighted Average Exercise Price Outstanding, Ending Balance	11.22	$ 8.66
Weighted Average Exercise Price, Fully vested and expected to vest	11.22
Weighted Average Exercise Price, Exercisable at End of Period	$ 10.32
Weighted Average Remaining Contractual Term (year), Abstract
Weighted Average Remaining Contractual Term Outstanding	4 years 10 months 24 days
Weighted Average Remaining Contractual Term, Fully Vested and Expected to Vest	4 years 10 months 24 days
Weighted Average Remaining Contractual Term, Exercisable at End of Period	3 years 9 months 18 days

Stock Options and Restricted _8

Stock Options and Restricted Shares - Information Related to Stock Options (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Intrinsic value of options exercised	$ 2,478,086	$ 7,654,738	$ 2,010,536
Cash received from option exercises	1,930,737	6,897,845	2,013,840
Tax benefit realized from option exercises	$ 103,847	$ 846,725	$ 774,056
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, 2019	Dec. 31, 2018	Dec. 31, 2017
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	$ 874,000	$ 639,000	$ 550,000

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Details) - Designated as Hedging Instrument - Interest Rate Swaps - Cash Flow Hedges - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments [Line Items]
Notional amount	$ 0	$ 20,000,000
Derivative termination fees	1,500,000
Investment securities pledged collateral to counterparties		2,038,000
Investment securities pledged collateral from counterparties	$ 0
Gains (losses) relating to mortgage banking derivative instruments		$ 0	$ 0

Derivative Instruments - Summar

Derivative Instruments - Summary of Interest-Rate Swaps Designated as Cash Flow Hedges (Details) - Designated as Hedging Instrument - Cash Flow Hedges - Interest Rate Swaps - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019
Derivative Instruments [Line Items]
Notional amounts	$ 20,000,000	$ 0
Weighted average pay rates	3.54%
Weighted average receive rates	3 month LIBOR
Weighted average maturity	4 years 6 months
Fair value	$ (836,000)
Amount of unrealized loss recognized in accumulated other comprehensive income, net of tax	$ (617,000)

Derivative Instruments - Summ_2

Derivative Instruments - Summary of Customer Related Interest Rate Swaps (Details) - Interest Rate Swaps - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments [Line Items]
Interest rate swap, Notional amount	$ 90,106,000	$ 58,252,000
Pay fixed/receive variable swaps
Derivative Instruments [Line Items]
Interest rate swap, Notional amount	45,053,000	29,126,000
Interest rate swap, Estimated fair value	(926,000)	24,000
Pay variable/receive fixed swaps
Derivative Instruments [Line Items]
Interest rate swap, Notional amount	45,053,000	29,126,000
Interest rate swap, Estimated fair value	$ 926,000	$ (24,000)

Derivative Instruments - Summ_3

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

Derivative Instruments - Summ_4

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

Related Party - Additional Info

Related Party - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
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	$ 13,700,000	$ 11,400,000

Related Party - Schedule of Rel

Related Party - Schedule of Related Party Transactions Activity within Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Total Commitment
Related Party Transaction [Line Items]
Beginning of period	$ 44,812	$ 49,409
New commitments/draw downs	9,336	3,631
Repayments	(32,333)	(8,228)
End of period	21,815	44,812
Total Funded Commitment
Related Party Transaction [Line Items]
Beginning of period	15,445	21,890
New commitments/draw downs	2,515	1,038
Repayments	(7,287)	(7,483)
End of period	$ 10,673	$ 15,445

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other real estate owned	$ 0	$ 0
Loans held for sale carried at fair value	30,740,000	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	$ 0

Fair Value - Summary of Assets

Fair Value - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Assets:
Securities available-for-sale, at fair value	$ 213,129,000	$ 243,808,000
Loans held for sale carried at fair value	30,740,000	0
Obligations of States and Political Subdivisions
Assets:
Securities available-for-sale, at fair value	45,960,000	61,926,000
Asset-backed securities
Assets:
Securities available-for-sale, at fair value	3,197,000	15,284,000
Other debt securities
Assets:
Securities available-for-sale, at fair value	14,962,000	11,734,000
Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives
Derivative assets:
Residential mortgage loans held for sale	648,000
Fair Value Measurements Recurring Basis
Assets:
Loans held for sale carried at fair value	168,222,000
Fair Value Measurements Recurring Basis | U.S. Government-sponsored Agencies
Assets:
Securities available-for-sale, at fair value	10,331,000	10,706,000
Fair Value Measurements Recurring Basis | Obligations of States and Political Subdivisions
Assets:
Securities available-for-sale, at fair value	45,960,000	61,926,000
Fair Value Measurements Recurring Basis | Mortgage-backed Securities-residential
Assets:
Securities available-for-sale, at fair value	138,679,000	144,158,000
Fair Value Measurements Recurring Basis | Asset-backed securities
Assets:
Securities available-for-sale, at fair value	3,197,000	15,284,000
Fair Value Measurements Recurring Basis | Other debt securities
Assets:
Securities available-for-sale, at fair value	14,962,000	11,734,000
Fair Value Measurements Recurring Basis | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives
Derivative assets:
Residential mortgage loans held for sale	648,000
Fair Value Measurements Recurring Basis | Forward Sales Commitments | Non-hedging derivatives
Derivative liabilities:
Mortgage-backed securities forward sales commitments	(148,000)
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2)
Assets:
Loans held for sale carried at fair value	168,222,000
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | U.S. Government-sponsored Agencies
Assets:
Securities available-for-sale, at fair value	10,331,000	10,706,000
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	45,960,000	61,926,000
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Mortgage-backed Securities-residential
Assets:
Securities available-for-sale, at fair value	138,679,000	144,158,000
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Assets:
Securities available-for-sale, at fair value	3,197,000	15,284,000
Fair Value Measurements Recurring Basis | Significant Other Observable Inputs (Level 2) | Other debt securities
Assets:
Securities available-for-sale, at fair value	14,962,000	11,734,000
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	(148,000)
Fair Value Measurements Recurring Basis | Significant Unobservable Inputs (Level 3) | Mortgage Loan Interest Rate Lock Commitments | Non-hedging derivatives
Derivative assets:
Residential mortgage loans held for sale	648,000
Fair Value Measurements Recurring Basis | Interest Rate Swaps - Customer Related | Non-hedging derivatives
Derivative assets:
Interest rate swaps - customer related	926,000	494,000
Derivative liabilities:
Total derivative liabilities	(926,000)	(494,000)
Fair Value Measurements Recurring Basis | Interest Rate Swaps - Customer Related | Significant Other Observable Inputs (Level 2) | Non-hedging derivatives
Derivative assets:
Interest rate swaps - customer related	926,000	494,000
Derivative liabilities:
Total derivative liabilities	$ (926,000)	(494,000)
Fair Value Measurements Recurring Basis | Interest Rate Swaps - Cash Flow Hedges
Derivative liabilities:
Total derivative liabilities		(836,000)
Fair Value Measurements Recurring Basis | Interest Rate Swaps - Cash Flow Hedges | Significant Other Observable Inputs (Level 2)
Derivative liabilities:
Total derivative liabilities		$ (836,000)

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 $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Included in mortgage banking income	$ 648
Balance of recurring Level 3 assets at December 31st	$ 648

Fair Value - Summary of Quantit

Fair Value - Summary of Quantitative Information About Level 3 Fair Value Measurements on Recurring Basis (Details) - Significant Unobservable Inputs (Level 3) - Mortgage Loan Interest Rate Lock Commitments - Non-hedging derivatives $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Residential mortgage loans held for sale	$ 648
Valuation Technique(s)	Consensus pricing
Unobservable Input(s)	Origination pull-through rate
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable inputs range	0.0068
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable inputs range	0.0095
Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable inputs range	0.0083

Fair Value - Summary of Carryin

Fair Value - Summary of Carrying Value and Fair Values of the Company's Financial Instruments (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Oct. 01, 2018
Financial assets:
Securities available-for-sale	$ 213,129,000	$ 243,808,000
Securities held to maturity, fair value	3,411,000	3,785,000
Loans held for sale carried at fair value	30,740,000	0
Loans			$ 344,800,000
Carrying amount
Financial assets:
Cash and due from banks, interest-bearing deposits in financial institutions	101,094,000	94,681,000
Federal funds sold	175,000	10,762,000
Securities available-for-sale	213,129,000	243,808,000
Securities held to maturity, fair value	3,313,000	3,734,000
Loans held for sale carried at fair value	168,222,000	57,618,000
Restricted equity securities	13,689,000	12,038,000
Loans	1,420,102,000	1,429,794,000
Accrued interest receivable	5,792,000	5,964,000
Other assets	36,393,000	34,489,000
Financial liabilities:
Deposits	1,729,451,000	1,570,008,000
Federal Home Loan Bank advances	10,000,000	125,000,000
Other liabilities	1,394,000	2,753,000
Fair value
Financial assets:
Loans	1,414,757,000	1,442,082,000
Fair value | Level 1
Financial assets:
Cash and due from banks, interest-bearing deposits in financial institutions	101,094,000	94,681,000
Federal funds sold	175,000	10,762,000
Fair value | Level 2
Financial assets:
Securities available-for-sale	213,129,000	243,808,000
Securities held to maturity, fair value	3,411,000	3,785,000
Loans held for sale carried at fair value	169,072,000	58,596,000
Accrued interest receivable	5,792,000	5,964,000
Financial liabilities:
Federal Home Loan Bank advances	10,014,000	126,548,000
Fair value | Level 2 / Level 3
Financial assets:
Other assets	36,393,000	34,489,000
Fair value | Level 3
Financial liabilities:
Deposits	1,730,206,000	1,572,880,000
Other liabilities	$ 1,394,000	$ 2,753,000

Parent Company Only Financial_3

Parent Company Only Financial Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Other assets	$ 59,668	$ 51,740
Total assets	2,037,201	1,963,883
Liabilities and Shareholders’ Equity
Other liabilities	24,704	14,496
Total shareholders’ equity	273,046	254,379	$ 146,946	$ 139,207
Total liabilities and shareholders’ equity	2,037,201	1,963,883
CapStar Financial Holdings, Inc.
Assets
Cash and cash equivalents	12,874	19,918
Investment in consolidated subsidiary	259,632	234,263
Other assets	578	499
Total assets	273,084	254,680
Liabilities and Shareholders’ Equity
Other liabilities	38	301
Total shareholders’ equity	273,046	254,379
Total liabilities and shareholders’ equity	$ 273,084	$ 254,680

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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income tax benefit	$ 1,613	$ 2,072	$ 1,814	$ 1,346	$ (535)	$ 554	$ 665	$ 483	$ 4,494	$ 1,516	$ (1,328)	$ (47)	$ 6,844	$ 1,167	$ 4,635
Net income	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 91	$ 4,419	$ (3,342)	$ 331	22,422	9,655	$ 1,501
CapStar Financial Holdings, Inc.
Income - dividends from subsidiary													3,530	1,225
Expenses													1,083	1,054
Income before income taxes and equity in undistributed net income of subsidiary													2,447	171
Income tax benefit													(262)	(242)
Income before equity in undistributed net income of subsidiary													2,709	413
Equity in undistributed net income of subsidiary													19,713	9,242
Net income													$ 22,422	$ 9,655

Parent Company Only Financial_5

Parent Company Only Financial Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	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, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 91	$ 4,419	$ (3,342)	$ 331	$ 22,422	$ 9,655	$ 1,501
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Net cash provided by (used in) operating activities													(84,688)	33,585	(16,614)
Cash flows from investing activities:
Cash received from acquisitions, net														12,053
Net cash provided by (used in) investing activities													47,290	(115,131)	11,863
Cash flows from financing activities:
Repurchase of common stock													(7,836)
Common and preferred stock dividends paid													(3,507)	(1,244)
Net cash provided by financing activities													33,224	104,192	7,437
Net increase (decrease) in cash and cash equivalents													(4,174)	22,646	2,686
Cash and cash equivalents at beginning of period				105,443				82,797				$ 80,111	105,443	82,797	80,111
Cash and cash equivalents at end of period	101,269				105,443				82,797				101,269	105,443	82,797
CapStar Financial Holdings, Inc.
Cash flows from operating activities:
Net income													22,422	9,655
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Increase in other assets													(78)	(221)
Increase (Decrease) in other liabilities													(263)	181
Equity in undistributed net income of subsidiary													(19,713)	(9,242)
Net cash provided by (used in) operating activities													2,368	373
Cash flows from investing activities:
Cash received from acquisitions, net														1,421
Net cash provided by (used in) investing activities														1,421
Cash flows from financing activities:
Repurchase of common stock													(7,836)
Exercise of common stock options and warrants													1,931	5,260
Common and preferred stock dividends paid													(3,507)	(1,244)
Net cash provided by financing activities													(9,412)	4,016
Net increase (decrease) in cash and cash equivalents													(7,044)	5,810
Cash and cash equivalents at beginning of period				$ 19,918				$ 14,108					19,918	14,108
Cash and cash equivalents at end of period	$ 12,874				$ 19,918				$ 14,108				$ 12,874	$ 19,918	$ 14,108

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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 22,205	$ 23,216	$ 23,158	$ 22,967	$ 22,900	$ 15,782	$ 15,354	$ 13,744	$ 13,124	$ 13,521	$ 12,891	$ 11,979	$ 91,547	$ 67,781	$ 51,515
Interest expense	5,624	6,060	6,150	5,965	5,184	4,239	3,767	2,898	2,606	2,678	2,320	2,047	23,799	16,089	9,652
Net interest income	16,581	17,156	17,008	17,002	17,716	11,543	11,587	10,846	10,518	10,843	10,571	9,932	67,748	51,692	41,863
Provision for loan losses		(125)		886	1,514	481	169	678	(30)	(195)	9,690	3,405	761	2,842	12,870
Net interest income after provision for loan losses	16,581	17,281	17,008	16,116	16,202	11,062	11,418	10,168	10,548	11,038	881	6,527	66,987	48,850	28,993
Noninterest income	5,719	6,788	7,032	4,735	6,387	3,218	2,765	3,088	2,736	3,372	2,666	2,133	24,274	15,459	10,908
Noninterest expense	15,266	15,531	16,470	14,725	23,832	10,070	10,005	9,580	8,699	8,475	8,217	8,376	61,995	53,487	33,765
Income before income taxes	7,034	8,538	7,570	6,126	(1,243)	4,210	4,178	3,676	4,585	5,935	(4,670)	284	29,266	10,822	6,136
Income tax expense	1,613	2,072	1,814	1,346	(535)	554	665	483	4,494	1,516	(1,328)	(47)	6,844	1,167	4,635
Net income	$ 5,421	$ 6,466	$ 5,756	$ 4,780	$ (708)	$ 3,656	$ 3,513	$ 3,193	$ 91	$ 4,419	$ (3,342)	$ 331	$ 22,422	$ 9,655	$ 1,501
Net income (loss) per share, basic	$ 0.30	$ 0.36	$ 0.33	$ 0.27	$ (0.04)	$ 0.30	$ 0.30	$ 0.27	$ 0.01	$ 0.39	$ (0.30)	$ 0.03	$ 1.25	$ 0.73	$ 0.13
Net income (loss) per share, diluted	$ 0.29	$ 0.35	$ 0.31	$ 0.25	$ (0.04)	$ 0.28	$ 0.27	$ 0.25	$ 0.01	$ 0.35	$ (0.26)	$ 0.03	$ 1.20	$ 0.67	$ 0.12

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Thousands	Jan. 22, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Total combined assets		$ 2,037,201	$ 1,963,883
FCB and BOW
Subsequent Event [Line Items]
Total combined assets		$ 467,000
Subsequent Events | Merger Agreement
Subsequent Event [Line Items]
Number of shares issuable	3,634,218
Cash	$ 26,400
Total consideration	$ 85,100