Franklin Financial Network (FSB) 10-K 11 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 28, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	FRFN
Entity Registrant Name	FRANKLIN FINANCIAL NETWORK INC.
Entity Central Index Key	1407067
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		7,817,385
Entity Public Float			$54,260,354

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
ASSETS
Cash and due from financial institutions	$49,347	$18,217
Certificates of deposit at other financial institutions	250
Securities available for sale	395,705	268,515
Securities held to maturity (fair value 2014-$53,741 and 2013-$54,004)	53,332	56,575
Loans held for sale, at fair value	18,462	10,694
Loans	787,188	421,304
Allowance for loan losses	-6,680	-4,900
Net loans	780,508	416,404
Restricted equity securities, at cost	5,349	3,032
Premises and equipment, net	9,664	4,138
Accrued interest receivable	3,545	2,396
Bank owned life insurance	11,664	8,232
Deferred tax asset	6,780	3,995
Buildings held for sale	4,080
Foreclosed assets	715	181
Servicing rights, net	3,053	2,640
Goodwill	9,124	157
Core deposit intangible, net	2,698
Other assets	1,551	1,198
Total assets	1,355,827	796,374
Deposits
Non-interest bearing	150,337	52,686
Interest bearing	1,021,896	628,614
Total deposits	1,172,233	681,300
Federal funds purchased and repurchase agreements	39,078	24,291
Federal Home Loan Bank advances	19,000	23,000
Accrued interest payable	421	222
Other liabilities	3,296	2,398
Total liabilities	1,234,028	731,211
Shareholders' equity
Senior non-cumulative preferred stock, no par value, $10,000 liquidation value: Series A, 1,000,000 shares authorized; 10,000 shares issued and outstanding at December 31, 2014 and December 31, 2013, respectively	10,000	10,000
Common stock, no par value; 10,000,000 shares authorized; 7,756,411 and 4,862,875 issued at December 31, 2014 and December 31 2013, respectively	94,251	52,638
Retained earnings	15,372	7,058
Accumulated other comprehensive income (loss)	2,176	-4,533
Total shareholders' equity	121,799	65,163
Total liabilities and shareholders' equity	$1,355,827	$796,374

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Held-to-maturity securities, fair value	$53,741		$54,004
Preferred stock, par value	$0		$0
Preferred stock, liquidation value	$10,000		$10,000
Preferred stock, shares authorized	1,000,000		1,000,000
Preferred stock, shares issued	10,000		10,000
Preferred stock, shares outstanding	10,000		10,000
Common stock, par value	$0		$0
Common stock shares authorized	10,000,000	[1]	10,000,000	[1]
Common stock shares issued	7,756,411		4,862,875
[1]	(1) On February 26, 2015, shareholders approved the Articles of Amendment to the Company's Charter to increase the number of authorized shares of the Corporation's Common Stock from 10,000,000 to 20,000,000.

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Interest income and dividends
Loans, including fees	$33,585	$20,094
Securities:
Taxable	9,459	4,655
Tax-Exempt	81	67
Dividends on restricted equity securities	227	126
Federal funds sold and other	80	40
Total interest income and dividends	43,432	24,982
Interest expense
Deposits	5,301	3,693
Federal funds purchased and repurchase agreements	176	144
Federal Home Loan Bank advances	262	100
Total Interest Expense	5,739	3,937
Net interest income	37,693	21,045
Provision for loan losses	2,374	907
Net interest income after provision for loan losses	35,319	20,138
Noninterest income
Service charges on deposit accounts	53	52
Other service charges and fees	1,777	1,112
Net gains on sale of loans	5,814	4,403
Investment services	639	241
Loan servicing fees, net	254	-365
Gain on sale of securities	259	88
Other	1,255	1,288
Total noninterest income	10,051	6,819
Noninterest expense
Salaries and employee benefits	19,160	13,142
Occupancy and equipment	4,729	2,731
FDIC assessment expense	600	354
Net loss on sale and write-down of foreclosed assets	96	223
Marketing	728	283
Professional fees	2,040	596
Other	4,469	2,333
Total noninterest expense	31,822	19,662
Income before income tax expense	13,548	7,295
Income tax expense	5,134	2,734
Net income	8,414	4,561
Dividends paid on Series A preferred stock	-100	-109
Net income available to common shareholders	$8,314	$4,452
Earnings per share:
Basic	$1.32	$1.13
Diluted	$1.27	$1.10

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$8,414	$4,561
Unrealized gains/losses on securities:
Unrealized holding gain (loss) arising during the period	11,131	-8,763
Reclassification adjustment for gains included in net income	-259	-88
Net unrealized gains (losses)	10,872	-8,851
Tax effect	-4,163	3,389
Total other comprehensive income (loss)	6,709	-5,462
Comprehensive income (loss)	$15,123	($901)

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Shareholders' Equity (USD $)	Total	Series A Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
In Thousands					Series A Preferred Stock [Member]
Beginning balance at Dec. 31, 2012	$51,356	$10,000	$37,821	$2,606		$929
Exercise of common stock warrants, 3,024 shares	36		36
Exercise of common stock options	58		58
Issuance of 1,153,847 shares of common stock, net of stock offering costs of $809	14,191		14,191
Dividends paid on Series A preferred stock	-109				-109
Stock based compensation expense	364		364
Stock issued in conjunction with 401(k) employer match	227		227
Stock issued in conjunction with stock option exchange	-142		-142
Excess tax benefit from exchange of stock options	83		83
Net income	4,561			4,561
Other comprehensive income	-5,462					-5,462
Ending balance at Dec. 31, 2013	65,163	10,000	52,638	7,058		-4,533
Exercise of common stock options	236		236
Dividends paid on Series A preferred stock	-100				-100
Stock based compensation expense	611		611
Stock issued in conjunction with 401(k) employer match	275		275
Stock (2,766,191 shares) and stock options (137,280 options) issued related to MidSouth Bank acquisition, net of stock issuance costs of $514	40,462		40,462
Excess tax benefit from exchange of stock options	29		29
Net income	8,414			8,414
Other comprehensive income	6,709					6,709
Ending balance at Dec. 31, 2014	$121,799	$10,000	$94,251	$15,372		$2,176

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Exercise of common stock warrants, number of shares		3,024
Exercise of common stock options, number of shares	23,809	5,755
Proceeds from issuance of common stock, net of offering costs		$809
Stock issued in conjunction with 401(k) employer match, number of shares	20,345	17,596
Stock issued in conjunction with stock option exchange, number of shares		32,814
MidSouth Bank [Member]
Common stock, shares	2,766,191
Exercise of common stock options, number of shares	137,280
Proceeds from issuance of common stock, net of offering costs	514
Common Stock [Member]
Proceeds from issuance of common stock, net of offering costs		809
Issuance of common stock		1,153,847
Common Stock [Member] | MidSouth Bank [Member]
Common stock, shares	2,766,191
Exercise of common stock options, number of shares	137,280
Proceeds from issuance of common stock, net of offering costs	514

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income	$8,414	$4,561
Adjustments to reconcile net income to net cash from operating activities
Depreciation and amortization on premises and equipment	931	653
Accretion of purchase accounting adjustments	-1,589
Net amortization of securities	2,596	4,199
Amortization of loan servicing right asset	727	1,265
Amortization of core deposit intangible	362
Increase (decrease) in impairment of servicing asset		-90
Provision for loan losses	2,374	907
Deferred income tax benefit	-130	-396
Excess tax benefit related to the exchange of stock options		-83
Excess tax benefit related to the exercise of stock options	-29
Origination of loans held for sale	-262,955	-307,592
Proceeds from sale of loans held for sale	266,932	315,242
Net gain on sale of loans	-5,814	-4,403
Gain on sale of available for sale securities	-259	-88
Income from bank owned life insurance	-288	-268
Loss on sale and write down of foreclosed assets	96	223
Stock-based compensation	611	364
Compensation expense related to common stock issued to 401(k) plan	275	227
Loss on disposal of non-bank subsidiary	32
Net change in:
Accrued interest receivable and other assets	-82	249
Accrued interest payable and other liabilities	-274	542
Net cash from operating activities	11,930	15,512
Available for sale securities:
Sales	44,181	16,290
Purchases	-198,452	-189,962
Maturities, prepayments and calls	93,339	78,650
Held to maturity securities:
Purchases	-8,601	-28,937
Maturities, prepayments and calls	11,551	5,840
Net change in loans	-181,928	-122,572
Purchase of restricted equity securities	-745	-774
Proceeds from sale of foreclosed assets	1,166	2,477
Purchases of premises and equipment, net	-3,887	-1,847
Decrease in interest bearing deposits in financial institutions		100
Net cash provided from sale of non-bank subsidiary	205	100
Net cash acquired from acquisition (See Note 2)	12,197
Net cash from investing activities	-230,974	-240,735
Cash flows from financing activities
Increase in deposits	246,629	166,657
(Decrease) increase in federal funds purchased and repurchase agreements	13,894	22,689
Proceeds from Federal Home Loan Bank advances	15,000	40,000
Repayment of Federal Home Loan Bank advances	-25,000	-25,000
Proceeds from exercise of common stock warrants		36
Proceeds from exercise of common stock options, includes excess tax benefit	265	58
Cash paid in conjunction with stock option exchange		-59
Proceeds from issuance of common stock, net of offering costs	-514	14,191
Dividends paid on preferred stock	-100	-109
Net cash from financing activities	250,174	218,463
Net change in cash and cash equivalents	31,130	-6,760
Cash and cash equivalents at beginning of period	18,217	24,977
Cash and cash equivalents at end of period	49,347	18,217
Supplemental information:
Interest paid	5,540	4,023
Income taxes paid	5,692	2,750
Non-cash supplemental information:
Fair value of stock and stock options issued related to MidSouth Bank acquisition (See Note 2)	40,976
Transfers from loans to foreclosed assets	1,273	761
Transfer from additional paid-in-capital to common stock		$426

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Nature of Operations and Principles of Consolidation: The consolidated financial statements include Franklin Financial Network, Inc. and its wholly owned subsidiary, Franklin Synergy Bank, together referred to as “the Company.” Intercompany transactions and balances are eliminated in consolidation.
	Franklin Financial Network, Inc. was incorporated under the laws of the State of Tennessee on April 5, 2007. Franklin Synergy Bank was incorporated under the laws of the State of Tennessee and received its Certificate of Authority from the Tennessee Department of Financial Institutions and approval of FDIC insurance on November 2, 2007. Franklin Synergy Bank is also a Federal Reserve member bank.
	The Company provides financial services through its offices in Franklin, Brentwood, Spring Hill, Murfreesboro and Smyrna, Tennessee. Its primary deposit products are checking, savings, and certificate of deposit accounts, and its primary lending products are commercial and residential construction, commercial, installment loans and lines secured by home equity. Substantially all loans are secured by specific items of collateral including commercial and residential real estate, business assets, and consumer assets. Commercial loans are expected to be repaid by cash flow from operations of businesses. There are no significant concentrations of loans to any one industry or customer. However, the customers’ ability to repay their loans is dependent on the real estate and general economic conditions in the area. The Company also focuses on electronic banking products such as internet banking, remote deposit capture and lockbox services.
	The Company purchased the assets of Banc Compliance Group LLC in May 2008 forming a wholly-owned subsidiary, Banc Compliance Group, Inc., which provided bank compliance and consulting services to community banks. The Company sold the assets of Banc Compliance Group, Inc. at December 31, 2014.
	On July 1, 2014 the Company completed its acquisition of MidSouth Bank, which was merged with and became part of Franklin Synergy Bank.
	Use of Estimates: To prepare financial statements in conformity with accounting principles generally accepted in the United States of America management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ.
	Cash Flows: Cash and cash equivalents include cash, deposits with other financial institutions with maturities under 90 days, and federal funds sold. Net cash flows are reported for customer loan and deposit transactions, interest bearing deposits in other financial institutions and federal funds purchased.
	Interest-Bearing Deposits in Financial Institutions: Interest-bearing deposits in other financial institutions mature within one year and are carried at cost.
	Securities: Debt securities are classified as held to maturity and carried at amortized cost when management has the positive intent and ability to hold them to maturity. Debt securities are classified as available for sale when they might be sold before maturity. Securities available for sale are carried at fair value, with unrealized holding gains and losses reported in other comprehensive income, net of tax.
	Interest income includes amortization of purchase premium or discount. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage backed securities where prepayments are anticipated. Gains and losses on sales are recorded on the trade date and determined using the specific identification method.
	Management evaluates securities for other-than-temporary impairment (OTTI) at least on a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. Management 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 these criteria is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For 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. 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: Loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value, as determined by outstanding commitments from investors. Net unrealized losses, if any, are recorded as a valuation allowance and charged to earnings.
	Certain loans held for sale are sold with servicing rights retained. The carrying value of loans sold with retained servicing is reduced by the amount allocated to the servicing right. Gains and losses on sales of loans are based on the difference between the selling price and the carrying value of the related loan sold.
	Loans: 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 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.
	Interest income on mortgage and commercial loans is discontinued at the time the loan is 90 days delinquent unless the loan is well-secured and in process of collection. Past due status is based on the 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. Nonaccrual 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. A loan is moved to non-accrual status in accordance with the Company’s policy, typically after 90 days of non-payment.
	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. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured.
	Concentration of Credit Risk: Most of the Company’s business activity is with customers located within Williamson County. Therefore, the Company’s exposure to credit risk is significantly affected by changes in the economy in the Williamson County area.
	Purchased Credit Impaired Loans: The Company purchases individual loans and groups of loans, some of which have shown evidence of credit deterioration since origination. These purchased credit impaired loans are recorded at the amount paid, such that there is no carryover of the seller’s allowance for loan losses. After acquisition, losses are recognized by an increase in the allowance for loan losses.
	Such purchased credit impaired loans are accounted for individually or aggregated into pools of loans based on common risk characteristics such as, credit score, loan type, and date of origination. 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 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).
	Allowance for Loan Losses: The allowance for loan losses is a valuation allowance for probable incurred credit losses. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. Management estimates the allowance balance required using past loan loss experience, the nature and volume of the portfolio, information about specific borrower situations and estimated collateral values, economic conditions, and other factors. 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.
	The allowance consists of specific and general components. The specific component relates to loans that are individually classified as impaired. A loan is 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 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 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.
	If a loan is impaired, a portion of the allowance is allocated so that the loan is reported, net, at the present value of estimated future cash flows using the loan’s existing rate or at the fair value of collateral if repayment is expected solely from the collateral
	Troubled debt restructurings are separately identified for impairment disclosures and are measured at the present value of estimated future cash flows using the loan’s effective rate at inception. If a troubled debt restructuring is considered to be a collateral dependent loan, the loan is reported, net, at the fair value of the collateral. For troubled debt restructurings that subsequently default, the Company determines the amount of reserve in accordance with the accounting policy for the allowance for loan losses.
	The general component covers non-impaired loans and is based on historical loss experience adjusted for current factors. The historical loss experience is determined by portfolio segment and is based on a combination of the Bank’s loss history and loss history from the Bank’s peer group over the past three years. This actual loss experience is supplemented with other economic factors based on the risks present for each portfolio segment. These economic factors include consideration of the following: levels of and trends in delinquencies and impaired loans; levels of and trends in charge-offs and recoveries; trends in volume and terms of loans; effects of any changes in risk selection and underwriting standards; other changes in lending policies, procedures, and practices; experience, ability, and depth of lending management and other relevant staff; national and local economic trends and conditions; industry conditions; and effects of changes in credit concentrations. The following portfolio segments have been identified:
	Construction and land development loans include loans to finance the process of improving loans preparatory to erecting new structures or the on-site construction of industrial, commercial, residential or farm buildings. Construction and land development loans also include loans secured by vacant land, except land known to be used or usable for agricultural purposes. Construction loans generally are made for relatively short terms. They generally are more vulnerable to changes in economic conditions. Further, the nature of these loans is such that they are more difficult to evaluate and monitor. The risk of loss on a construction loan is dependent largely upon the accuracy of the initial estimate of the property’s value upon completion of the project and the estimated cost (including interest) of the project. Periodic site inspections are made on construction loans.
	Commercial real estate loans include loans secured by non-residential real estate, including farmland and improvements thereon. Often these loans are made to single borrowers or groups of related borrowers, and the repayment of these loans largely depends on the results of operations and management of these properties. Adverse economic conditions may affect the repayment ability of these loans.
	Residential real estate loans include loans secured by residential real estate, including single-family and multi-family dwellings. Mortgage title insurance and hazard insurance are normally required. Adverse economic conditions in the Company’s market area may reduce borrowers’ ability to repay these loans and may reduce the collateral securing these loans.
	Commercial and industrial loans include loans for commercial, industrial or agricultural purposes to business enterprises that are not secured by real estate. Commercial loans are typically made on the basis of the borrower’s ability to repay from the cash flow of the borrower’s business. Commercial and Agriculture loans are generally secured by accounts receivable, inventory and equipment. The collateral securing loans may depreciate over time, may be difficult to appraise and may fluctuate in value based on the success of the business.
	Consumer and other loans include loans to individuals for household, family and other personal expenditures that are not secured by real estate. Consumer loans are generally secured by customer deposit accounts, vehicles and other household goods. The collateral securing consumer loans may depreciate over time.
	Servicing Rights: When loans are sold with servicing retained, servicing rights are initially recorded at fair value with the income statement effect recorded in gain on sale of loans. Fair value is based on market prices for comparable servicing contracts. 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 assets 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 loan servicing fees on the income statement. 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 as loan servicing fees, 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 mortgage loan servicing fee income. Late fees and ancillary fees related to loan servicing are not material.
	Transfers of Financial Assets: Transfers of financial assets are accounted for as sales, when control over the assets has been relinquished. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
	Foreclosed Assets: Assets acquired through or instead of loan foreclosure are initially recorded at fair value less costs to sell when acquired, establishing a new cost basis. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating costs after acquisition are expensed.
	Assets Held for Sale: Assets held for sale are stated at fair value less estimated costs to sell at the time the assets are determined to be held for sale. If fair value declines subsequent to designation, a valuation allowance is recorded through expense. Operating costs after designation are expensed.
	Premises and Equipment: Premises and equipment are stated at cost less accumulated depreciation and are depreciated using the straight-line method. Depreciation periods are shorter of the asset’s useful life or lease period, ranging from three to fifteen years.
	Restricted Equity Securities: The Bank is a member of the Federal Reserve Bank (FRB) and the Federal Home Loan Bank (FHLB) system. Members of the FHLB are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest in additional amounts. The stock ownership in FRB and FHLB are carried at cost, classified as restricted securities, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income.
	Company Owned Life Insurance: The Company has purchased life insurance policies on certain key executives. Company 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.
	Goodwill and Other Intangible Assets: Goodwill resulting from business combinations after January 1, 2009, 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. The Company has selected December 31 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 and acquired customer relationship intangible assets arising from whole bank and branch acquisitions are amortized on an accelerated method over their estimated useful lives, which range from 7 to 10 years.
	Long-Term Assets: Premises and equipment and other long-term 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.
	Loan Commitments and Related Financial Instruments: Financial instruments include off-balance sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded.
	Mortgage Banking Derivatives: Commitments to fund mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these mortgage loans are accounted for as free standing derivatives. Fair values of these mortgage derivatives are estimated based on changes in mortgage interest rates from the date the interest on the loan is locked. The Company enters into forward commitments for the future delivery of mortgage loans 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 net gains on sale of mortgage loans.
	Stock-Based Compensation: Compensation cost is recognized for stock options and restricted stock awards issued to employees, based on the fair value of these awards at the date of grant. 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 cost is recognized over the required service period, generally defined as the vesting period. For awards with graded vesting, compensation cost is recognized on a straight-line basis over the requisite service period for the entire award.
	Income Taxes: Income tax expense or benefit 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 recognizes interest and/or penalties related to income tax matters in income tax expense.
	Retirement Plans: Employee 401(k) and profit sharing plan expense is the amount of matching contributions. The matching contributions are paid with employer stock. An annual stock valuation is performed for the employer stock match calculation.
	Comprehensive Income: Comprehensive income consists of net income and other comprehensive income. Other comprehensive income includes unrealized gains and losses on securities available for sale which is recognized as a separate component of equity.
	Earnings Per Common Share: Basic earnings per common share is net income available to common shareholders divided by the weighted average number of common shares outstanding during the period. All outstanding unvested share-based payment awards that contain rights to non-forfeitable dividends are considered participating securities for this calculation. Diluted earnings per common share includes the dilutive effect of additional potential common shares issuable under stock options and warrants. Earnings and dividends per share are restated for all stock splits and stock dividends through the date of issuance of the financial statements.
	Loss Contingencies: Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe there now are such matters that will have a material effect on the financial statements.
	Restrictions on Cash: Cash on hand or on deposit with the Federal Reserve Bank was required to meet regulatory reserve and clearing requirements.
	Dividend Restriction: Banking regulations require maintaining certain capital levels and may limit the dividends paid by the bank to the holding company or by the holding company to shareholders.
	Fair Value of Financial Instruments: 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 the estimates.
	Operating Segments: While the chief decision-makers monitor the revenue streams of the various products and services, operations are managed and financial performance is evaluated on a Company-wide basis. Operating segments are aggregated into one as operating results for all segments are similar. Accordingly, all of the financial service operations are considered by management to be aggregated in one reportable operating segment.
	Reclassifications: Some items in the prior year financial statements were reclassified to conform to the current presentation. Reclassifications had no effect on prior year net income or shareholders’ equity.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Acquisitions	NOTE 2 - ACQUISITIONS
	Acquisition of MidSouth Bank
	On July 1, 2014 the Company completed the acquisition of MidSouth Bank (“MidSouth”), pursuant to the terms of the Agreement and Plan of Reorganization and Bank Merger (the “merger agreement”) dated November 19, 2013.
	The acquisition was accounted for under the acquisition method of accounting in accordance with ASC Topic 805, Business Combinations. The Company recognized goodwill on this acquisition of $9,124, after consideration of a measurement period adjustment discussed below, which is nondeductible for tax purposes as this acquisition was a nontaxable transaction. The goodwill is calculated based on the fair values of the assets acquired and liabilities assumed as of the acquisition date. Fair value estimates are based on the information available, and are subject to change for up to one year after the closing date of the acquisition as additional information relative to closing date fair values becomes available.
	The Company acquired 100% of the outstanding preferred and common stock of MidSouth. The purchase price consisted of both cash and stock. MidSouth’s common shareholders received 0.425926 shares of FFN common stock for each share of MidSouth common stock. MidSouth’s preferred shareholders received 0.851852 shares of FFN common stock for each share of MidSouth preferred stock. Each MidSouth Series 2009A warrant holder received 0.18 shares of FFN common stock for each MidSouth Series 2009A warrant, and each Series 2011-A warrant holder received 0.146667 shares of FFN common stock for each MidSouth Series 2011-A warrant. In lieu of issuing fractional shares of FFN common stock, FFN paid former MidSouth shareholders an amount in cash determined by multiplying (i) $13.50 by (ii) the fraction of a share (rounded to the nearest ten thousandth when expressed in decimal form) of FFN common stock.
	MidSouth common stock options were converted into options to purchase shares of FFN common stock based on the 0.425926 exchange ratio, with the new exercise price becoming the exercise price of the MidSouth options divided by the exchange ratio. On the date of the merger, 2,766,191 shares of FFN common stock were exchanged for the common and preferred stock, and common stock warrants of MidSouth in accordance with the proration and allocation procedures contained in the merger agreement and as noted above. Subsequently, cash totaling $100 was paid to dissenting MidSouth shareholders representing 7,427 shares of FFN common stock. In addition, $18 of cash was paid to MidSouth shareholders for fractional shares in accordance with the merger agreement.
	Based on a valuation of the FFN’s common stock as of July 1, 2014, the resulting purchase price was $41,094. The following table summarizes the purchase price calculation:
		Number of			Per share			Number of FFN
		MidSouth shares			exchange			shares—as
		outstanding			ratio			exchanged
	Common Shares		3,873			0.425926			1,650
	Convertible Voting Preferred Stock, 2009-A		1,018			0.851852			867
	Convertible Voting Preferred Stock, 2011-A		242			0.851852			206
	Series 2009-A Stock Warrants (strike price $3.25)		193			0.185185			36
	Series 2011-A Stock Warrants (strike price $3.68)		44			0.153333			7
									2,766
	Multiplied by FFN common stock value at acquisition date							$	14.5
	Fair value of FFN common stock issued (“Stock Consideration”)							$	40,110
	Cash consideration paid for fractional shares								18
	Cash consideration paid for dissenting shares								100
	Fair value of MidSouth stock options converted to FFN stock options								866
	Total acquisition consideration							$	41,094
	On July 1, 2014 the Company purchased MidSouth. As previously disclosed, the fair values initially assigned to the assets acquired and liabilities assumed were preliminary and subject to refinement for up to one year after the closing date of the acquisition as new information relative to closing date fair values becomes available. Based on appraisals received subsequent to the acquisition date, the Company adjusted its initial fair value estimate of foreclosed assets that were acquired. The table below summarizes the fair value of the assets purchased, including goodwill, and liabilities assumed as of the July 1, 2014 purchase date.
	In Thousands	July 1, 2014			Measurement			July 1, 2014
		(as initially reported)			Period			(as adjusted)
					Adjustments
	Assets:
	Cash and due from banks	$	1,369		$	—		$	1,369
	Interest-bearing accounts at other financial institutions		10,946						10,946
	Securities, available-for-sale		57,431						57,431
	Loans held for sale		7,071						7,071
	Loans		184,345						184,345
	Certificates of deposit at other financial institutions		250						250
	Restricted equity securities		1,572						1,572
	Bank premises and equipment, net		6,650						6,650
	Bank-owned life insurance		3,144						3,144
	Accrued interest receivable		728						728
	Foreclosed assets		800			(260	)		540
	Core deposit intangible		3,060						3,060
	Deferred tax asset		6,753			100			6,853
	Goodwill		8,964			160			9,124
	Other assets		747						747
	Total assets acquired	$	293,830		$	—		$	293,830
	Liabilities:
	Deposits	$	244,415		$	—		$	244,415
	Short-term borrowings		6,893						6,893
	Other liabilities		1,428						1,428
	Total liabilities assumed	$	252,736		$	—		$	252,736
	At December 31, 2014, there were no circumstances or significant changes that have occurred in the last six months of 2014 related to the acquisition of MidSouth that, in management’s assessment, would necessitate recording impairment of goodwill.
	In the acquisition, the Company purchased $184,345 of loans at fair value, net of $7,347 estimated discount to the outstanding principal balance. Of the total loans acquired, management identified loans totaling $5,527 as credit impaired. All loans that were on non-accrual status and all loan relationships that were identified as substandard or impaired as of the acquisition date were considered by management to be credit-impaired and are accounted for pursuant to ASC Topic 310-30. The table below summarizes the total contractually required principal and interest cash payments, management’s estimate of expected total cash payments and fair value of the loans as of July 1, 2014 for purchased credit-impaired (“PCI”) loans. Contractually required principal and interest payments have been adjusted for estimated prepayments.
	Contractually required principal and interest	$	8,510
	Non-accretable difference		(1,745	)
	Cash flows expected to be collected		6,765
	Accretable yield		(1,238	)
	Total purchased credit-impaired loans	$	5,527
	The table below presents information with respect to the fair value of acquired loans, as well as their unpaid principal balance at acquisition date.
		Unpaid			Fair
		Principal			Value
		Balance
	Loans:
	Residential real estate	$	39,425		$	38,618
	Commercial real estate		82,465			80,566
	Construction and land development		43,766			42,454
	Commercial loans		16,311			15,352
Consumer and other loans		1,865			1,828
Purchased credit-impaired		7,860			5,527
Total earning assets	$	191,692		$	184,345
In its assumption of the deposit liabilities, the Company believed the deposits assumed from the acquisition have an intangible value. The Company applied ASC Topic 805, which prescribes the accounting for goodwill and other intangible assets such as core deposit intangibles, in a business combination. The Company determined the estimated fair value of the core deposit intangible asset totaled $3,060, which will be amortized utilizing an accelerated amortization method over an estimated economic life of 8.2 years. When determining the valuation amount, deposits were analyzed based on factors such as type of deposit, deposit retention, interest rates and age of deposit relationships.
The following table represents acquired intangible assets at December 31, 2014 and 2013:
	2014						2013
	Gross Carrying			Accumulated			Gross Carrying		Accumulated
	Amount			Amortization			Amount		Amortization
Acquired intangible assets:
Core deposit intangibles	$	3,060		$	(362	)	$	—	$	—
Aggregate amortization expense was $362 for 2014. There was no amortization expense for 2013.
The following table presents estimated amortization expense for each of the next five years:
2015	$	655
2016		564
2017		473
2018		382
2019		291
Pro-forma information
Pro-forma data for the years ended December 31, 2014 and 2013 listed in the table below presents pro-forma information as if the MidSouth acquisition occurred at the beginning of 2013.
	Years ended
	December 31,
	2014			2013
Net interest income	$	41,312		$	32,022
Net income available to common shareholders		8,055			5,722
Earnings per share—basic	$	1.04		$	0.88
Earnings per share—diluted	$	1.02		$	0.87
Supplemental pro forma earnings for 2014 were adjusted to exclude $2,157 of acquisition-related costs incurred in 2014, $1,478 of discount accretion and $250 of premium amortization related to the fair value adjustments to acquisition-date assets and liabilities. Supplemental pro forma earnings for 2013 were adjusted to include these items, as appropriate.

Securities

Securities	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Securities	NOTE 3 - SECURITIES
	The following table summarizes the amortized cost and fair value of the available for sale securities portfolio at December 31, 2014 and 2013 and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss).
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
	December 31, 2014
	U.S. government sponsored entities and agencies	$	30,070		$	417		$	(314	)	$	30,173
	U.S. Treasury securities		20,000			—			—			20,000
	Mortgage-backed securities: residential		335,677			4,593			(1,203	)		339,067
	Mortgage-backed securities: commercial		6,432			33			—			6,465
	Total	$	392,179		$	5,043		$	(1,517	)	$	395,705
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
	December 31, 2013
	U.S. government sponsored entities and agencies	$	16,029		$	—		$	(1,305	)	$	14,724
	Mortgage-backed securities: residential		259,831			1,560			(7,600	)		253,791
	Total	$	275,860		$	1,560		$	(8,905	)	$	268,515
	The amortized cost and fair value of the held to maturity securities portfolio at December 31, 2014 and 2013 and the corresponding amounts of gross unrecognized gains and losses were as follows:
		Amortized			Gross			Gross			Fair
		Cost			Unrecognized			Unrecognized			Value
					Gains			Losses
	December 31, 2014
	U.S. government sponsored entities and agencies	$	5,550		$	162		$	(87	)	$	5,625
	Mortgage backed securities: residential		38,587			555			(562	)		38,580
	State and political subdivisions		9,195			351			(10	)		9,536
	Total	$	53,332		$	1,068		$	(659	)	$	53,741
		Gross			Gross			Gross			Fair
		Amortized			Unrecognized			Unrecognized			Value
		Cost			Gains			Losses
	December 31, 2013
	U.S. government sponsored entities and agencies	$	8,225		$	12		$	(484	)	$	7,753
	Mortgage backed securities: residential		39,043			293			(2,061	)		37,275
	State and political subdivisions		9,307			89			(420	)		8,976
	Total	$	56,575		$	394		$	(2,965	)	$	54,004
	Sales of available for sale securities were as follows:
		2014			2013
	Proceeds	$	44,181		$	16,290
	Gross gains		422			163
	Gross losses		(163	)		(75	)
	The amortized cost and fair value of the investment securities portfolio are shown by contractual maturity. Securities not due at a single maturity date, primarily mortgage-backed securities, are shown separately.
		December 31, 2014
		Amortized			Fair
		Cost			Value
	Available for sale
	Three months or less	$	30,000		$	29,999
	Over three months through one year		—			—
	Over one year through five years		—			—
	Over five years through ten years		7,796			7,948
	Over ten years		12,274			12,226
	Mortgage-backed securities: commercial		6,432			6,465
	Mortgage-backed securities: residential		335,677			339,067
	Total	$	392,179		$	395,705
	Held to maturity
	Three months or less	$	250		$	251
	Over one year through five years		1,419			1,478
	Over five years through ten years		1,106			1,127
	Over ten years		11,970			12,305
	Mortgage-backed securities: residential		38,587			38,580
	Total	$	53,332		$	53,741
	Securities pledged at December 31, 2014 and 2013 had a carrying amount of $366,764 and $194,925 and were pledged to secure public deposits and repurchase agreements.
	At December 31, 2014 and 2013, there were no holdings of securities of any one issuer, other than the U.S. government-sponsored entities and agencies, in an amount greater than 10% of shareholders’ equity.
	The following table summarizes the securities with unrealized and unrecognized losses at December 31, 2014 and 2013, aggregated by major security type and length of time in a continuous unrealized loss position:
		Less Than 12 Months						12 Months or Longer						Total
	Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
	Value			Losses			Value			Losses			Value		Losses
December 31, 2014
Available for sale
U.S. government sponsored entities and agencies	$	9,999		$	(1	)	$	8,232		$	(313	)	$	18,231	$	(314	)
Mortgage-backed securities: residential		59,078			(323	)		41,939			(880	)		101,017		(1,203	)
Total available for sale	$	69,077		$	(324	)	$	50,171		$	(1,193	)	$	119,248	$	(1,517	)
	Less Than 12 Months						12 Months or Longer						Total
	Fair			Unrecognized			Fair			Unrecognized			Fair		Unrecognized
	Value			Losses			Value			Losses			Value		Losses
Held to maturity
U.S. government sponsored entities and agencies	$	—		$	—		$	2,913		$	(87	)	$	2,913	$	(87	)
Mortgage-backed securities: residential		5,246			(25	)		13,001			(537	)		18,247		(562	)
State and political subdivisions		507			(1	)		592			(9	)		1,099		(10	)
Total held to maturity	$	5,753		$	(26	)	$	16,506		$	(633	)	$	33,037	$	(659	)
	Less Than 12 Months						12 Months or Longer						Total
	Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
	Value			Losses			Value			Losses			Value		Losses
December 31, 2013
Available for sale
U.S. government sponsored entities and agencies	$	12,983		$	(1,128	)	$	1,741		$	(177	)	$	14,724	$	(1,305	)
Mortgage-backed securities: residential		168,817			(6,762	)		11,721			(838	)		180,538		(7,600	)
Total available for sale	$	181,800		$	(7,890	)	$	13,462		$	(1,015	)	$	195,262	$	(8,905	)
	Less Than 12 Months						12 Months or Longer						Total
	Fair			Unrecognized			Fair			Unrecognized			Fair		Unrecognized
	Value			Losses			Value			Losses			Value		Losses
Held to maturity
U.S. government sponsored entities and agencies	$	6,168		$	(332	)	$	848		$	(152	)	$	7,016	$	(484	)
Mortgage-backed securities: residential		19,952			(1,752	)		4,042			(309	)		23,994		(2,061	)
State and political subdivisions		5,762			(342	)		422			(78	)		6,184		(420	)
Total held to maturity	$	31,882		$	(2,426	)	$	5,312		$	(539	)	$	37,194	$	(2,965	)
Unrealized losses on debt securities have not been recognized into income because the issuers bonds are of high credit quality (rated AA or higher), management does not intend to sell and it is likely that management will not be required to sell the securities prior to their anticipated recovery, and the decline in fair value is largely due to changes in interest rates and other market conditions. The fair value is expected to recover as the bonds approach maturity.

Loans

Loans	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Loans	NOTE 4 - LOANS
	Loans at December 31, 2014 and 2013 were as follows:
		December 31,			December 31,
		2014			2013
	Loans that are not PCI loans
	Construction and land development	$	239,225		$	113,710
	Commercial real estate:
	Nonfarm, nonresidential		240,975			114,852
	Other		5,377			10,350
	Residential real estate:
	Closed-end 1-4 family		130,631			98,615
	Other		83,129			39,851
	Commercial and industrial		76,570			36,397
	Consumer and other		8,025			8,250
	Loans before net deferred loan fees		783,932			422,025
	Deferred loan fees, net		(1,059	)		(721	)
	Total loans that are not PCI loans		782,873			421,304
	PCI loans
	Construction and land development	$	77		$	—
	Commercial real estate:
	Nonfarm, nonresidential		1,798			—
	Other		—			—
	Residential real estate:
	Closed-end 1-4 family		706			—
	Other		108			—
	Commercial and industrial		1,624			—
	Consumer and other		2			—
	Total PCI loans		4,315			—
	Allowance for loan losses		(6,680	)		(4,900	)
	Total loans, net of allowance for loan losses	$	780,508		$	416,404
	The following table presents the activity in the allowance for loan losses by portfolio segment for the years ended December 31, 2014 and 2013:
		Construction			Commercial			Residential			Commercial			Consumer			Total
		and Land			Real			Real			and			and
		Development			Estate			Estate			Industrial			Other
	December 31, 2014
	Allowance for loan losses:
	Beginning balance	$	1,552		$	1,511		$	1,402		$	337		$	98		$	4,900
	Provision for loan losses		1,138			523			385			371			(43	)		2,374
	Loans charged-off		—			(540	)		(61	)		(58	)		—			(659	)
	Recoveries		—			—			65			—			—			65
	Total ending allowance balance	$	2,690		$	1,494		$	1,791		$	650		$	55		$	6,680
		Construction			Commercial			Residential			Commercial			Consumer			Total
		and Land			Real			Real			and			and
		Development			Estate			Estate			Industrial			Other
	December 31, 2013
	Allowance for loan losses:
	Beginning balance	$	1,342		$	1,267		$	893		$	275		$	206		$	3,983
	Provision for loan losses		210			244			480			81			(108	)		907
	Loans charged-off		—			—			(107	)		(19	)		—			(126	)
	Recoveries		—			—			136			—			—			136
	Total ending allowance balance	$	1,552		$	1,511		$	1,402		$	337		$	98		$	4,900
	There was no allowance for loan losses for PCI loans for the years ended December 31, 2014 or 2013.
	The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method as of December 31, 2014 and 2013. Purchased and PCI loans are also included in the table. For purposes of this disclosure, recorded investment in loans excludes accrued interest receivable and loan fees, net due to immateriality.
		Construction			Commercial			Residential			Commercial			Consumer			Total
		and Land			Real			Real			and			and
		Development			Estate			Estate			Industrial			Other
	December 31, 2014
	Allowance for loan losses:
	Ending allowance balance attributable to loans:
	Individually evaluated for impairment	$	—		$	—		$	—		$	18		$	—		$	18
	Collectively evaluated for impairment		2,690			1,494			1,791			632			55			6,662
	Purchased credit-impaired loans		—			—			—			—			—			—
	Total ending allowance balance	$	2,690		$	1,494		$	1,791		$	650		$	55		$	6,680
	Loans:
Individually evaluated for impairment	$	—		$	835		$	93		$	18		$	—		$	946
Collectively evaluated for impairment		239,225			245,517			213,667			76,552			8,025			782,986
Purchased credit-impaired loans		77			1,798			814			1,624			2			4,315
Total ending loans balance	$	239,302		$	248,150		$	214,574		$	78,194		$	8,027		$	788,247
	Construction			Commercial			Residential			Commercial			Consumer			Total
	and Land			Real			Real			and			and
	Development			Estate			Estate			Industrial			Other
December 31, 2013
Allowance for loan losses:
Ending allowance balance attributable to loans:
Individually evaluated for impairment	$	—		$	455		$	93		$	—		$	—		$	548
Collectively evaluated for impairment		1,552			1,056			1,309			337			98			4,352
Total ending allowance balance	$	1,552		$	1,511		$	1,402		$	337		$	98		$	4,900
Loans:
Individually evaluated for impairment	$	—		$	3,361		$	1,262		$	—		$	—		$	4,623
Collectively evaluated for impairment		113,710			121,841			137,204			36,397			8,250			417,402
Total ending loans balance	$	113,710		$	125,202		$	138,466		$	36,397		$	8,250		$	422,025
Loans collectively evaluated for impairment reported at December 31, 2014 include certain loans acquired from MidSouth on July 1, 2014. The acquired loans were recorded at estimated fair value at date of acquisition, which included an estimated credit discount. On July 1, 2014, acquired non-PCI loans were recorded at an estimated fair value of $178,818, comprised of contractually unpaid principal totaling $183,832 net of estimated discounts totaling $5,014 which included both credit and interest rate discount components. Management evaluated these loans for credit deterioration since acquisition and determined that no allowance for loan losses was necessary at December 31, 2014.
The following table presents information related to impaired loans by class of loans as of December 31, 2014 and 2013:
	Unpaid			Recorded			Allowance for
	Principal			Investment			Loan Losses
	Balance						Allocated
December 31, 2014
With no allowance recorded:
Commercial real estate:
Nonfarm, nonresidential	$	2,422		$	835		$	—
Residential real estate:
1-4 family		93			93			—
Subtotal		2,515			928			—
With an allowance recorded:
Commercial and industrial		18			18			18
Subtotal		18			18			18
Total	$	2,533		$	946		$	18
December 31, 2013
With no allowance recorded:
Commercial real estate:
Nonfarm, nonresidential	$	1,986		$	1,986		$	—
Residential real estate:
1-4 family		36			36			—
Subtotal		2,022			2,022			—
With an allowance recorded:
Commercial real estate:
Nonfarm, nonresidential	$	2,480		$	1,375		$	455
Residential real estate:
1-4 family		1,687			1,226			93
Subtotal		4,167			2,601			548
Total	$	6,189		$	4,623		$	548
The following table presents the average recorded investment of impaired loans by class of loans for the years ended December 31, 2014 and 2013:
Average Recorded Investment	2014			2013
With no allowance recorded:
Commercial real estate:
Nonfarm, nonresidential		587			1,986
Residential real estate:
1-4 family		94			37
Commercial and industrial		2			—
Subtotal		683			2,023
With an allowance recorded:
Commercial real estate:
Nonfarm, nonresidential		893			1,375
Residential real estate:
1-4 family		359			1,226
Commercial and industrial		53			—
Subtotal		1,305			2,601
Total	$	1,988		$	4,624
The impact on net interest income for these loans was not material to the Company’s results of operations for the years ended December 31, 2014 and 2013.
The following table presents the recorded investment in nonaccrual and loans past due over 90 days still on accrual by class of loans as of December 31, 2014 and 2013:
	Nonaccrual			Loans Past Due
				Over 90 Days
December 31, 2014
Commercial real estate:
Nonfarm, nonresidential	$	835		$	—
Other		—			—
Residential real estate:
Closed-end1-4 family		—			316
Other		—			—
Construction and land development		—			—
Commercial and industrial		—			—
Total	$	835		$	316
December 31, 2013
Commercial real estate:
Nonfarm, nonresidential	$	1,375		$	—
Residential real estate:
1-4 family		1,226			—
Total	$	2,601		$	—
Nonaccrual 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.
The following table presents the aging of the recorded investment in past due loans as of December 31, 2014 and 2013 by class of loans:
	30-59			60-89			Greater			Total			Loans			PCI			Total
	Days			Days			Than			Past Due			Not			Loans
	Past Due			Past Due			89 Days						Past Due
							Past Due
December 31, 2014
Construction and land development	$	354		$	—		$	—		$	354		$	238,871		$	77		$	239,302
Commercial real estate:
Nonfarm, nonresidential		—			—			835			835			240,140			1,798			242,773
Other		—			—			—			—			5,377			—			5,377
Residential real estate:
Closed-end 1-4 family		299			165			316			780			129,851			706			131,337
Other		52			—			—			52			83,077			108			83,237
Commercial and industrial		—			212			—			212			76,358			1,624			78,194
Consumer and other		—			—			—			—			8,025			2			8,027
	$	705		$	377		$	1,151		$	2,233		$	781,699		$	4,315		$	788,247
	30-59			60-89			Greater			Total			Loans			PCI			Total
	Days			Days			Than			Past Due			Not			Loans
	Past Due			Past Due			89 Days						Past Due
							Past Due
December 31, 2013
Construction and land development	$	—		$	—		$	—		$	—		$	113,710		$	—		$	113,710
Commercial real estate:
Nonfarm, nonresidential		1,985			—			1,375			3,360			111,492			—			114,852
Other		—			—			—			—			10,350			—			10,350
Residential real estate:
Closed end 1-4 family		245			—			1,226			1,471			97,144			—			98,615
Other		—			—			—			—			39,851			—			39,851
Commercial and industrial		—			—			—			—			36,397			—			36,397
Consumer and other		—			—			—			—			8,250			—			8,250
	$	2,230		$	—		$	2,601		$	4,831		$	417,194		$	—		$	422,025
Credit Quality Indicators: 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 loans individually by classifying the loans as to credit risk. This analysis includes non-homogeneous loans, such as commercial and commercial real estate loans as well as non-homogeneous residential real estate loans. This analysis is performed on a quarterly basis. The Company uses the following definitions for risk ratings:
Special Mention. Loans classified as special mention have a potential weakness that deserves management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or of the institution’s credit position at some future date.
Substandard. Loans classified as substandard are inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the institution will sustain some loss if the deficiencies are not corrected.
Loans not meeting the criteria above that are analyzed individually as part of the above described process are considered to be pass rated loans. The following table includes PCI loans, which are included in the “Substandard” column. Based on the most recent analysis performed, the risk category of loans by class of loans is as follows as of December 31, 2014 and 2013:
	Pass			Special			Substandard			Total
				Mention
December 31, 2014
Construction and land development	$	239,225		$	—		$	77		$	239,302
Commercial real estate:
Nonfarm, nonresidential		239,584			—			3,189			242,773
Other		5,377			—			—			5,377
Residential real estate:
Closed-end 1-4 family		128,869			—			2,468			131,337
Other		83,129			—			108			83,237
Commercial and industrial		76,552			—			1,642			78,194
Consumer and other		8,025			—			2			8,027
	$	780,761		$	—		$	7,486		$	788,247
	Pass			Special			Substandard			Total
				Mention
December 31, 2013
Construction and land development	$	113,710		$	—		$	—		$	113,710
Commercial real estate:
Nonfarm, nonresidential		110,938			—			3,914			114,852
Other		10,350			—			—			10,350
Residential real estate:
1-4 family		96,823			—			1,792			98,615
Other		39,851			—			—			39,851
Commercial and industrial		36,397			—			—			36,397
Consumer and other		8,250			—			—			8,250
	$	416,319		$	—		$	5,706		$	422,025
Purchased Credit-Impaired (“PCI”) Loans
Income is recognized on PCI loans pursuant to ASC Topic 310-30. A portion of the fair value discount has been recognized as an accretable yield that is accreted into interest income over the estimated remaining life of the loans. The remaining non-accretable difference represents cash flows not expected to be collected.
The table below summarizes the total contractually required principal and interest cash payments, management’s estimate of expected total cash payments and carrying value of the loans as of December 31, 2014. Contractually required principal and interest payments have been adjusted for estimated prepayments.
	December 31,
	2014
Contractually required principal and interest	$	6,532
Non-accretable difference		(1,270	)
Cash flows expected to be collected		5,262
Accretable yield		(947	)
Carrying value of acquired loans		4,315
Allowance for loan losses		—
Carrying value less allowance for loan losses	$	4,315
For the year ended December 31, 2014, the Company recognized $216 in accretion income from the accretable yield related to acquired PCI loans.
Troubled Debt Restructurings
The Company’s loan portfolio contains no loans that have been modified in a troubled debt restructuring.

Loan_Servicing

Loan Servicing	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Loan Servicing	NOTE 5 - LOAN SERVICING
	Loans serviced for others are not reported as assets. The principal balances of these loans at December 31, 2014 and 2013 are as follows:
		2014			2013
	Loan portfolios serviced for:
	Federal Home Loan Mortgage Corporation	$	414,222		$	348,121
	Other		3,986			5,088
	Custodial escrow balances maintained in connection with serviced loans were $1,968 and $1,607 at year-end 2014 and 2013.
	The related loan servicing rights activity for the years ended December 31, 2014 and 2013 were as follows:
		2014			2013
	Servicing rights:
	Beginning of year	$	2,640		$	2,401
	Additions		1,140			1,414
	Amortized to expense		(727	)		(1,265	)
	Decrease in impairment		—			90
	End of year	$	3,053		$	2,640
	The components of net loan servicing fees for the years ended December 31, 2014 and 2013 were as follows:
		2014			2013
	Loan servicing fees, net:
	Loan servicing fees	$	981		$	810
	Amortization of loan servicing fees		(727	)		(1,265	)
	Decrease in impairment		—			90
	Total	$	254		$	(365	)
	The fair value of servicing rights was estimated by management to be approximately $4,180 at December 31, 2014. Fair value for 2014 was determined using a weighted average discount rate of 10.5% and a weighted average prepayment speed of 10.8%. At December 31, 2013, the fair value of servicing rights was estimated by management to be approximately $3,714. Fair value for 2013 was determined using weighted average discount rate of 10.5% and a weighted average prepayment speed of 8.8%.
	The weighted average amortization period is 6.37 years. Estimated amortization expense for each of the next three years is:
	2015	$	480
	2016		480
	2017		480

Premises_and_Equipment_and_Rel

Premises and Equipment and Related Party Leases	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Premises and Equipment and Related Party Leases	NOTE 6 - PREMISES AND EQUIPMENT AND RELATED PARTY LEASES
	Year-end premises and equipment were as follows:
		2014			2013
	Construction in progress	$	1,128		$	1,044
	Land and land improvements		693			—
	Buildings		1,170			—
	Leasehold improvements		4,804			2,438
	Furniture, fixtures, and equipment		4,129			2,594
	Computer equipment and software		2,223			1,688
			14,147			7,764
	Accumulated depreciation		(4,483	)		(3,626	)
		$	9,664		$	4,138
	Depreciation expense was $931 and $653 for the years ended December 31, 2014 and 2013, respectively.
	Operating Leases: The Company leases most of its branches, loan production, and administrative offices under operating leases. Rent expense was $2,049 and $1,311 for 2014 and 2013, respectively. Rent commitments, over the initial lease terms and intended renewal periods were as follows:
		Related			Other			Total
		Parties
	2015	$	1,798		$	585		$	2,383
	2016		1,839			496			2,335
	2017		1,865			455			2,320
	2018		1,892			412			2,304
	2019		1,919			402			2,321
	Thereafter		17,255			3,397			20,652
	Total	$	26,568		$	5,747		$	32,315
	The Company has entered into agreements to sell three buildings acquired during the acquisition of MidSouth Bank on July 1, 2014 to a related party. As of December 31, 2014, these buildings were classified as held-for-sale and totaled $4,080. These buildings will subsequently be leased by the Company upon completion of the sale. Estimated rent commitments for the 2014 lease additions, over the initial lease terms, are as follows:
		Related			Other			Total
		Parties
	2015	$	313		$	—		$	313
	2016		390			—			390
	2017		431			—			431
	2018		477			—			477
	2019		527			—			527
	Thereafter		6,926			—			6,926
	Total	$	9,064		$	—		$	9,064

Deposits

Deposits	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Deposits	NOTE 7 - DEPOSITS
	At December 31, 2014 and 2013, time deposits in denominations of $250 or greater totaled $105,711 and $82,026, respectively. At December 31, 2014 and 2013, the Company had $371 and $116, respectively, of deposit accounts in overdraft status and thus have been reclassified to loans on the accompanying consolidated balance sheets.
	Scheduled maturities of time deposits for the next five years were as follows:
	2015	$	177,449
	2016		60,154
	2017		29,328
	2018		19,242
	2019		35,008

Federal_Funds_Purchased_and_Re

Federal Funds Purchased and Repurchase Agreements	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Federal Funds Purchased and Repurchase Agreements	NOTE 8 - FEDERAL FUNDS PURCHASED AND REPURCHASE AGREEMENTS
	As of December 31, 2014 and 2013, the Bank had federal funds lines (or the equivalent thereof) with correspondent banks totaling $115,400 and $71,700, respectively. There was $16,825 and $20,825 in outstanding federal funds purchased at December 31, 2014 and 2013, respectively.
	As of December 31, 2014 and 2013, securities sold under agreements to repurchase had an outstanding balance of $22,253 and $3,466, respectively, and are secured by securities with carrying amounts of $26,187 and $8,418, respectively. Securities sold under agreements to repurchase are financing arrangements that mature daily. At maturity the securities underlying the agreements are returned to the Company.
	Information concerning securities sold under agreements to repurchase is summarized as follows:
		2014			2013
	Average daily balance during the year	$	12,792		$	3,525
	Average interest rate during the year		0.58	%		0.71	%
	Maximum month-end balance during the year	$	24,466		$	5,077
	Weighted average interest rate at year end		0.56	%		0.73	%

Federal_Home_Loan_Bank_Advance

Federal Home Loan Bank Advances	12 Months Ended
	Dec. 31, 2014
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank Advances	NOTE 9 - FEDERAL HOME LOAN BANK ADVANCES
	The Bank has established a line of credit with the Federal Home Loan Bank of Cincinnati (“FHLB”), which is secured by a blanket pledge of 1-4 family residential mortgage loans. The extent of the line is dependent, in part, on available collateral. The arrangement is structured so that the carrying value of the loans pledged amounts to 125% on residential 1-4 family loans of the principal balance of the advances from the FHLB.
	At December 31, 2014 and 2013, the Company had received advances from the FHLB totaling $19,000 and $23,000, respectively. At December 31, 2014, the schedule maturities of these advances and interest rates were as follows:
		Scheduled		Weighted
		Maturities		Average
				Rates
	2015	$	2,000		0.7	%
	2016		—		—
	2017		10,000		1.27	%
	2018		7,000		1.61	%
	2019		—		—
	Thereafter		—		—
	Total	$	19,000		1.33	%
	Each FHLB advance is payable at its maturity date, with a prepayment penalty for fixed rate advances. Qualifying loans totaling approximately $148,612 were pledged as security under a blanket pledge agreement with the FHLB at December 31, 2014. Based on this collateral and the Company’s holdings of FHLB stock, the Bank is eligible to borrow up to an additional $38,699 as of December 31, 2014.

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2014
Postemployment Benefits [Abstract]
Benefit Plans	NOTE 10 - BENEFIT PLANS
	A 401(k) benefit plan was adopted to begin benefits on May 1, 2008. The 401(k) benefit plan allows employee contributions of their compensation subject to certain limitations. Employee contributions are matched in the Company’s common stock equal to 100% of the first 2% of the compensation contributed and 50% of the next 4% of the compensation contributed. Expense for the years ending December 31, 2014 and 2013 was $387 and $270, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes
	NOTE 11 - INCOME TAXES
	A reconciliation of the income tax expense for the years ended December 31, 2014 and 2013 to the “expected” tax expense computed by applying the statutory federal income tax rate of 34 percent to income before income tax expense is as follows:
		2014			2013
	Computed “expected” tax expense	$	4,742		$	2,480
	Increase (reduction) in tax expense resulting from:
	State tax expense, net of federal tax effect		593			305
	Effect of statutory rate changes enacted in the current year		(223	)		—
	Non-deductible merger costs		150			—
	Incentive stock options		104			19
	Bank owned life insurance		(101	)		(92	)
	Tax-exempt interest income, net of expense		(49	)		(40	)
	Other		(82	)		62
	Income tax expense	$	5,134		$	2,734
	Income tax expense (benefit) was as follows:
		2014			2013
	Current expense
	Federal	$	4,444		$	2,613
	State		820			517
	Deferred expense
	Federal		(222	)		(343	)
	State		92			(53	)
	Income tax expense	$	5,134		$	2,734
	The sources of deferred income tax assets (liabilities) at December 31, 2013 and 2012 and the tax effect is as follows:
		2014			2013
	Deferred tax assets:
	Organizational and start-up costs	$	155		$	170
	Allowance for loan losses		1,343			1,718
	Unrealized loss on securities		—			2,812
	Net operating loss carry forward		5,290			—
	Purchase accounting fair value adjustments		2,980			—
	Accrued other expenses		340			116
	Nonaccrual loan interest		538			195
	Capital loss carryforward		95			—
	Loan fees		396			266
	Other		389			412
			11,526			5,689
	Valuation allowance		(95	)		—
			11,431			5,689
		2014			2013
	Deferred tax liabilities:
	Mortgage servicing rights		(1,174	)		(975	)
	Premises and equipment		(675	)		(468	)
	Prepaid expenses		(177	)		(71	)
	Unrealized gain on securities		(1,385	)		—
	Purchase accounting fair value adjustments		(1,190	)		—
	Mortgage banking derivatives		(1	)		(123	)
	Other		(49	)		(57	)
			(4,651	)		(1,694	)
	Net deferred tax asset (liability)	$	6,780		$	3,995
	Net operating losses were acquired from the MidSouth Bank acquisition. At December 31, 2014, the net operating loss remaining from the acquisition totaled $15.1 million, which will expire at various dates from 2025 to 2031.
	The Company does not have any uncertain tax positions and does not have any interest and penalties recorded in the income statement for the years ended December 31, 2014 and 2013. The Company and its subsidiary are subject to U.S. federal income tax as well as income tax of the state of Tennessee. The Company is no longer subject to examination by taxing authorities for years before 2011.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 12 - RELATED PARTY TRANSACTIONS
	The Company enters into various credit arrangements with its executive officers, directors and their affiliates. These arrangements generally take the form of commercial lines of credit, personal lines of credit, mortgage loans, term loans or revolving arrangements secured by personal residences.
	Loans to principal officers, directors, and their affiliates during 2014 were as follows:
	Beginning balance	$	6,752
	New loans		2,279
	Effect of changes in composition of related parties		—
	Repayments		(4,495	)
	Ending balance	$	4,536
	Deposits from principal officers, directors, and their affiliates at year end 2014 and 2013 were $5,543 and $7,047.
	The Company entered into a 15-year lease agreement for a branch and administrative facility in downtown Franklin, Tennessee on May 7, 2010. The Company also entered into a 15-year lease for its Berry Farms branch in Franklin, Tennessee, on June 12, 2013 with certain outside directors of the Company. The branch opened during 2013. During 2014, the Company entered into 15-year lease agreements for an addition to its branch and administrative facility in downtown Franklin and for its Cool Springs branch in Franklin, Tennessee. Rent expense attributable to the related party leases in 2013 and 2012, was $1,222 and $559, respectively. Rent commitments to related parties, before considering renewal options that generally are present, are disclosed in Note 6. Another of the Company’s outside directors was paid $3,152 and $1,088 for construction of leasehold improvements during 2014 and 2013. The Company also paid a company affiliated with an outside director $212 and $70 for the procurement of various insurance policies during the years ending December 31, 2014 and 2013.

ShareBased_Payments

Share-Based Payments	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payments	NOTE 13 - SHARE-BASED PAYMENTS
	In connection with the Company’s 2010 private offering, 32,425 warrants were issued to shareholders, one warrant for every twenty shares of common stock purchased. Each warrant allows the shareholders to purchase an additional share of common stock at $12.00 per share. The warrants were issued with an effective date of March 30, 2010 and will be exercisable in whole or in part up to seven years following the date of issuance. The warrants are detachable from the common stock. There were 3,024 warrants exercised during the year ended December 31, 2013, for which the Company received cash proceeds of $36. The exercised warrants had an intrinsic value of $3 at the date of exercise. No warrants were exercised during 2014. At December 31, 2014, there were 31,877 outstanding warrants associated with the 2010 offering.
	In the event the common stock of the Company is to be registered under the Securities Act or is traded on a national securities exchange at $15.00 or more for forty-five (45) consecutive days, the Company may redeem the 2010 warrants at any time thereafter with not less than thirty (30) days’ written notice to the holder of such 2010 warrant, in whole or in part, at a redemption price of $1.00 per warrant; provided, however, that the holder of the 2010 warrant may exercise the 2010 warrant, in whole or in part, during such thirty (30) day period.
	Stock Option Plan: The Company’s 2007 Stock Option Plan (“stock option plan” or the “Plan”), which was shareholder-approved, permitted the grant of share options to its employees, organizers and directors for up to 551,250 shares of common stock. The Plan was amended during April 2010 to increase the number of shares available for issuance to 1,000,000. In April 2013, the Plan was amended to offer additional forms of equity compensation, to change the Plan’s name to the Franklin Financial Network, Inc. 2007 Omnibus Equity Incentive Plan, and to increase the number of authorized shares to 1,500,000. The Company believes that such awards better align the interests of its employees with those of its shareholders. Shareholders approved amendments to the Plan to increase the number of authorized shares to 2,000,000 in June 2014 and to 4,000,000 in February 2015. At December 31, 2014, there were 615,086 authorized shares available for issuance.
	Employee, organizer and director awards are generally granted with an exercise price equal to the market price of the Company’s common stock at the date of grant; those option awards have a vesting period of three to five years and have a ten-year contractual term. The Company assigns discretion to its Board of Directors to make grants either as qualified incentive stock options or as non-qualified stock options. All employee grants are intended to be treated as qualified incentive stock options, if allowable. All other grants are expected to be treated as non-qualified.
	During 2007, the Company granted 33,750 options to its organizers under the Plan. These options were granted in accordance with each organizer’s financial contribution to the Company during its organization period, and will vest over a five year period. No service element was included in the criteria used for determining grant awards. Accordingly, these options are not being expensed as stock-based compensation.
	During 2013, the Company granted employees the option to acquire common shares of the Company, plus a cash award, in exchange for existing vested options held by the employee. Options that were exchanged were surrendered and considered cancelled. As part of this exchange, a total of 166,448 options were cancelled in exchange for 32,814 shares of common stock and cash awards totaling $142.
	The fair value of each option award is estimated on the date of grant using a closed form option valuation (Black-Scholes) model that uses the assumptions noted in the table below. Expected stock price volatility is based on historical volatilities of a peer group. The Company uses historical data to estimate option exercise and post-vesting termination behavior.
	The expected term of options granted represents the period of time that options granted are expected to be outstanding, which takes into account that the options are not transferable. The risk-free interest rate for the expected term of the option is based on the U.S. Treasury yield curve in effect at the time of the grant.
	On the date of the merger, 322,300 MidSouth common stock options were converted into 137,280 options to purchase shares of FFN common stock with an exercise price of $8.57 per option pursuant to the terms of the merger agreement (see Note 2). Using the Black-Scholes option valuation model, the grant date fair value was estimated to be $6.31 per converted option based on the $14.50 fair value per share of FFN common stock at July 1, 2014. No post combination expense was required related to the converted options.
	The fair value of options granted was determined using the following weighted-average assumptions as of grant date.
		2014			2013
	Risk-free interest rate		1.82	%		1.65	%
	Expected term		5.9 years			7.5 years
	Expected stock price volatility		10.87	%		12.63	%
	Dividend yield		0.23	%		0.99	%
	The weighted average fair value of options granted for the years ending December 31, 2014 and 2013 was $4.12 and $1.92, respectively.
	A summary of the activity in the stock option plans for the year ended December 31, 2014 follows:
		Shares			Weighted			Weighted		Aggregate
					Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual
								Term
	Outstanding at beginning of year		946,644		$	11.27			6.81	$	1,635
	Granted		181,680			13.55
	Conversion of pre-existing MidSouth options		137,280			8.57
	Exercised		(23,809	)		9.92
	Forfeited, expired, or cancelled		(31,135	)		12.01
	Outstanding at period end		1,210,660		$	11.32			6.53	$	7,244
	Vested or expected to vest		1,150,127		$	11.32			6.53	$	6,882
	Exercisable at period end		790,098		$	10.62			5.6	$	5,281
	The Company received cash proceeds of $236 for the options exercised during 2014. The exercised options had an intrinsic value of $187 at the date of exercise.
	As of December 31, 2014, there was $671 of total unrecognized compensation cost related to non-vested stock options granted under the Plan. The cost is expected to be recognized over a weighted-average period of 1.6 years.
	Restricted Share Award Plan: Additionally, the Company’s 2007 Omnibus Equity Incentive Plan provides for the granting of restricted share awards and other performance related incentives. During 2014, the Company awarded 87,874 restricted common shares to employees of the Company. When the restricted shares are awarded, a participant receives voting and dividend rights with respect to the shares, but is not able to transfer the shares until the restrictions have lapsed. These awards have a vesting period of three to five years and vest in equal annual installments on the anniversary date of the grant.
	A summary of activity for non-vested restricted share awards for the year ended December 31, 2014 is as follows:
	Non-vested Shares	Shares			Weighted-Average
					Grant-Date
					Fair Value
	Non-vested at December 31, 2013		28,685		$	13
	Granted		87,874			14.15
	Vested		(9,166	)		13
	Forfeited		(4,683	)		14.09
	Non-vested at December 31, 2014		102,710			13.93
	Compensation expense associated with the restricted share awards is recognized on a straight-line basis over the time period that the restrictions associated with the awards lapse based on the total cost of the award at the grant date. As of December 31, 2014, there was $1,635 of total unrecognized compensation cost related to non-vested shares granted under the Plan. The cost is expected to be recognized over a weighted-average period of 3.78 years.

Regulatory_Capital_Matters

Regulatory Capital Matters	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Regulatory Capital Matters	NOTE 14 - REGULATORY CAPITAL MATTERS
	Banks and bank holding companies are subject to regulatory capital requirements administered by federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities, and certain off-balance-sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators. Failure to meet capital requirements can initiate regulatory action. Management believes as of December 31, 2014, the Company and Bank meet all capital adequacy requirements to which they are subject.
	Prompt corrective action regulations provide five classifications: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized, although these terms are not used to represent overall financial condition. If adequately capitalized, regulatory approval is required to accept brokered deposits. If undercapitalized, capital distributions are limited, as is asset growth and expansion, and capital restoration plans are required. At December 31, 2014, the most recent regulatory notifications categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. There are no conditions or events since that notification that management believes have changed the institution’s category. Actual and required capital amounts and ratios are presented below as of December 31, 2014 and 2013 for the Company and Bank.
		Actual					Required					To Be Well
							For Capital					Capitalized Under
							Adequacy Purposes					Prompt Corrective
												Action Regulations
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	December 31, 2014
	Company Total Risk-Based Capital to risk weighted assets	$	114,475		12.3	%	$	74,464		8	%		N/A		N/A
	Company Tier 1 (Core) Capital to risk weighted assets	$	107,795		11.58	%	$	37,232		4	%		N/A		N/A
	Company Tier 1 (Core) Capital to average assets	$	107,795		8.57	%	$	50,291		4	%		N/A		N/A
	Bank Total Risk-Based Capital to risk weighted assets	$	113,830		12.23	%	$	74,447		8	%	$	93,059		10	%
	Bank Tier 1 (Core) Capital to risk weighted assets	$	107,150		11.51	%	$	37,223		4	%	$	55,835		6	%
	Bank Tier 1 (Core) Capital to average assets	$	107,150		8.52	%	$	50,279		4	%	$	62,849		5	%
	December 31, 2013
	Company Total Risk-Based Capital to risk weighted assets	$	74,430		14.81	%	$	40,209		8	%		N/A		N/A
	Company Tier 1 (Core) Capital to risk weighted assets	$	69,530		13.83	%	$	20,105		4	%		N/A		N/A
	Company Tier 1 (Core) Capital to average assets	$	69,530		9.78	%	$	28,449		4	%		N/A		N/A
	Bank Total Risk-Based Capital to risk weighted assets	$	73,305		14.59	%	$	40,192		8	%	$	50,239		10	%
	Bank Tier 1 (Core) Capital to risk weighted assets	$	68,405		13.62	%	$	20,096		4	%	$	30,144		6	%
	Tier 1 (Core) Capital to average assets	$	68,405		9.62	%	$	28,455		4	%	$	35,569		5	%
	Dividend Restrictions: The Company’s principal source of funds for dividend payments is dividends received from the Bank. Banking regulations limit the amount of dividends that may be paid without prior approval of regulatory agencies. Under these regulations, the amount of dividends that may be paid in any calendar year is limited to the current year’s net profits, combined with the retained net profits of the preceding two years, subject to the capital requirements described above. During 2015 the Bank could declare, without prior approval, dividends of approximately $13,836 plus any 2015 net profits retained to the date of declaration.

Fair_Value

Fair Value	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value	NOTE 15 - 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 other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.
	Level 3: Significant unobservable inputs that reflect 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 the fair value of each type of asset and liability:
	Securities: The fair values for investment securities are determined by quoted market prices, if available
	(Level 1). For securities where quoted prices are not available, fair values are calculated based on market prices of similar securities (Level 2). For securities where quoted prices or market prices of similar securities are not available, fair values are calculated using discounted cash flows or other market indicators (Level 3).
	Derivatives: The fair values of derivatives are based on valuation models using observable market data as of the measurement date (Level 2).
	Impaired Loans: The fair value of impaired loans with specific allocations of the allowance for loan losses is generally based on recent real estate appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available. Such adjustments are usually significant and typically result in a Level 3 classification of the inputs for determining fair value. Non-real estate collateral may be valued using an appraisal, net book value per the borrower’s financial statements, or aging reports, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of the valuation, and management’s expertise and knowledge of the client and client’s business, resulting in a Level 3 fair value classification. Impaired loans are evaluated on a quarterly basis for additional impairment and adjusted accordingly. Appraisals for impaired loans are generally obtained annually but may be obtained more frequently based on changing circumstances as part of the aforementioned quarterly evaluation.
	Foreclosed Assets: Assets acquired through or instead of loan foreclosure are initially recorded at fair value less costs to sell when acquired, establishing a new cost basis. These assets are subsequently accounted for at lower of cost or fair value less estimated costs to sell. Fair value is commonly based on recent real estate appraisals which are updated no less frequently than annually. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available. Such adjustments are usually significant and typically result in a Level 3 classification of the inputs for determining fair value. Foreclosed assets are evaluated on a quarterly basis for additional impairment and adjusted accordingly.
	Loans Held For Sale: During 2014 the Company elected the fair value option for loans held for sale to align with other accounting policies related to mortgage banking, such as mortgage banking derivatives. These loans are typically sold to an investor following loan origination and the fair value of such accounts are readily available based on direct quotes from investors or similar transactions experienced in the secondary loan market. Fair value adjustments, as well as realized gains and losses are recorded in current earnings. Fair value is determined by market prices for similar transactions adjusted for specific attributes of that loan.
	Assets and liabilities measured at fair value on a recurring basis, including financial assets and liabilities for which the Company has elected the fair value option, are summarized below:
		Fair Value Measurements at
		December 31, 2014 Using:
		Quoted Prices		Significant			Significant
		in Active		Other			Unobservable
		Markets for		Observable			Inputs
		Identical Assets		Inputs			(Level 3)
		(Level 1)		(Level 2)
	Financial Assets
	Securities available for sale
	U.S. government sponsored entities and agencies	$	—	$	30,173		$	—
	U.S. Treasury Bills		20,000		—			—
	Mortgage-backed securities-residential		—		339,067			—
	Mortgage-backed securities-commercial		—		6,465			—
	State and political subdivisions		—		—			—
	Total securities available for sale	$	20,000	$	375,705		$	—
	Loans held for sale	$	—	$	18,462		$	—
	Mortgage banking derivatives	$	—	$	285		$	—
	Financial Liabilities
	Mortgage banking derivatives	$	—	$	132		$	—
		Fair Value Measurements at
		December 31, 2013 Using:
		Quoted Prices		Significant			Significant
		in Active		Other			Unobservable
		Markets for		Observable			Inputs
		Identical Assets		Inputs			(Level 3)
		(Level 1)		(Level 2)
	Financial Assets
	Securities available for sale
	U.S. government sponsored entities and agencies	$	—	$	14,724		$	—
	Mortgage-backed securities-residential		—		253,791			—
	Total securities available for sale	$	—	$	268,515		$	—
	Mortgage banking derivatives	$	—	$	464		$	—
	As of December 31, 2014, the unpaid principal balance of loans held for sale was $17,898 resulting in an unrealized gain of $564 included in gains on sale of loans. For the year ended December 31, 2014, the change in fair value related to loans held for sale, which is included in gain on sale of loans, increased $564. None of these loans are 90 days or more past due or on nonaccrual as of December 31, 2014. There were no loans held for sale carried at fair value as of December 31, 2013.
	There were no transfers between level 1 and 2 during 2014 and 2013.
	Assets measured at fair value on a non-recurring basis are summarized below:
		Fair Value Measurements at
		December 31, 2013 Using:
		Quoted Prices		Significant			Significant
		in Active		Other			Unobservable
		Markets for		Observable			Inputs
		Identical Assets		Inputs			(Level 3)
		(Level 1)		(Level 2)
	Impaired loans with specific allocations
	Real estate:
	Residential	$	—	$	—		$	1,133
	Commercial		—		—			920
	At December 31, 2014, there were no collateral dependent impaired loans carried of fair value. At December 31, 2013, impaired loans with specific allocations had a carrying amount of $2,601, with a valuation allowance of $548. For year ended December 31, 2013, no additional provision for loan losses was recorded related to impaired loans recorded at fair value of collateral.
	Foreclosed assets measured at fair value less costs to sell, had a net carrying amount of $715 and $181 as of December 31, 2014 and 2013, respectively. There were no properties at December 31, 2014 that had required write-downs to fair value resulting in no write downs for the year ended December 31, 2014. Foreclosed assets measured at fair value less costs to sell were written down to fair value resulting in a write-down of $190 for the year ended December 31, 3013.
	The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2013:
		Fair		Valuation		Unobservable	Range
		Value		Technique(s)			(Weighted
			Input(s)	Average)
Impaired loans:
Residential real estate	$	1,133	Sales comparison		Adjustment for	3%-27%(16%)
					differences between
					comparable sales
Commercial real estate	$	920	Sales comparison		Adjustment for	0%-16%(16%)
					differences between
					comparable sales
The carrying amounts and estimated fair values of financial instruments, at December 31, 2014 and 2013 are as follows:
			Fair Value Measurements at
	Carrying		December 31, 2014 Using:
	Amount		Level 1			Level 2		Level 3		Total
Financial assets
Cash and cash equivalents	$	49,347	$	49,347		$	—	$	—	$	49,347
Securities available for sale		395,705		20,000			375,705		—		395,705
Certificates of deposit held at other financial institutions		250		—			250		—		250
Securities held to maturity		53,332		—			53,741		—		53,741
Loans held for sale		18,462		—			18,462		—		18,462
Net loans		780,508		—			—		782,745		782,745
Restricted equity securities		5,349		n/a			n/a		n/a		n/a
Servicing rights, net		3,053		—			4,180		—		4,180
Accrued interest receivable		3,545		—			1,368		2,177		3,545
Financial liabilities
Deposits	$	1,172,233	$	848,158		$	326,644	$	—	$	1,174,802
Federal funds purchased and repurchase agreements		39,078		—			39,078		—		39,078
Federal Home Loan Bank advances		19,000		—			19,146		—		19,146
Accrued interest payable		421		33			388		—		421
	Carrying		Fair Value Measurements at
	Amount		December 31, 2013 Using:
			Level 1			Level 2		Level 3		Total
Financial assets
Cash and cash equivalents	$	18,217	$	18,217		$	—	$	—	$	18,217
Securities available for sale		268,515		—			268,515		—		268,515
Securities held to maturity		56,575		—			54,004		—		54,004
Loans held for sale		10,694		—			10,694		—		10,694
Net loans		416,404		—			—		415,515		415,515
Restricted equity securities		3,032		n/a			n/a		n/a		n/a
Mortgage servicing rights		2,640		—			3,714		—		3,714
Accrued interest receivable		2,396		—			1,145		1,251		2,396
Financial liabilities
Deposits	$	681,300	$	480,000		$	202,300	$	—	$	682,300
Federal funds purchased and repurchase agreements		24,291		—			24,291		—		24,291
Federal Home Loan Bank advances		23,000		—			23,023		—		23,023
Accrued interest payable		222		17			205		—		222
The methods and assumptions not previously described used to estimate fair value are described as follows:
(a) Cash and Cash Equivalents: The carrying amounts of cash and short-term instruments approximate fair values and are classified as Level 1.
(b) Loans: Fair values of loans, excluding loans held for sale, are estimated as follows: For variable rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values resulting in a Level 3 classification. Fair values for other loans are estimated using discounted cash flow analyses, using interest rates currently being offered for loans with similar terms to borrowers of similar credit quality resulting in a Level 3 classification. Impaired loans are valued at the lower of cost or fair value as described previously. The methods utilized to estimate the fair value of loans do not necessarily represent an exit price.
The fair value of loans held for sale is estimated based upon binding contracts and quotes from third party investors resulting in a Level 2 classification.
(c) Restricted Equity Securities: It is not practical to determine the fair value of Federal Home Loan Bank or Federal Reserve Bank stock due to restrictions placed on its transferability.
(d) Mortgage Servicing Rights: Fair value of mortgage servicing rights is based on valuation models that calculate the present value of estimated net cash flows based on industry market data. The valuation model incorporates assumptions that market participants would use in estimating future net cash flows resulting in a Level 2 classification.
(e) Deposits: The fair values disclosed for demand deposits (e.g., interest and non-interest checking, passbook savings, and certain types of money market accounts) are, by definition, equal to the amount payable on demand at the reporting date (i.e., their carrying amount) resulting in a Level 1 classification. The carrying amounts of fixed-term money market accounts approximate their fair values at the reporting date resulting in a Level 1 classification. Fair values for certificates of deposit are estimated using a discounted cash flows calculation that applies interest rates currently being offered on certificates to a schedule of aggregated expected monthly maturities on time deposits resulting in a Level 2 classification.
(f) Federal Funds Purchased and Repurchase Agreements: The carrying amounts of federal funds purchased, borrowings under repurchase agreements, and other short-term borrowings, generally maturing within ninety days, approximate their fair values resulting in a Level 2 classification.
(g) Federal Home Loan Bank Advances: The fair values of the Company’s long-term borrowings are estimated using discounted cash flow analyses based on the current borrowing rates for similar types of borrowing arrangements resulting in a Level 2 classification.
(h) Accrued Interest Receivable/Payable: The carrying amounts of accrued interest approximate fair value resulting in a Level 1 or Level 2 classification based on the asset/liability that they are associated with.
(i) 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.

Mortgage_Banking_Derivatives

Mortgage Banking Derivatives	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Mortgage Banking Derivatives	NOTE 16 - MORTGAGE BANKING DERIVATIVES
	Commitments to fund certain mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of mortgage loans to third party investors are considered derivatives. It is the Company’s practice to enter into forward commitments for the future delivery of residential mortgage loans when interest rate lock commitments are entered into in order to economically hedge the effect of changes in interest rates resulting from its commitments to fund the loans. These mortgage banking derivatives are not designated in hedge relationships. At year-end 2014, the Company had approximately $28,182 of interest rate lock commitments and approximately $36,849 of forward commitments for the future delivery of residential mortgage loans. The fair value of these mortgage banking derivatives was reflected by a derivative asset and liability of $285 and $132, respectively, at December 31, 2014. At December 31, 2013, the Company had approximately $26,000 of interest rate lock commitments and approximately $27,000 of forward commitments for the future delivery of residential mortgage loans. The fair value of these mortgage banking derivatives was reflected by a derivative asset of $464 at December 31, 2013. Fair values were estimated based on changes in mortgage interest rates from the date of the commitments. Changes in the fair values of these mortgage-banking derivatives are included in net gains on sale of loans.
	The net gains (losses) relating to free-standing derivative instruments used for risk management is summarized below:
		2014			2013
	Forward contracts related to mortgage loans held for sale and interest rate contracts	$	(411	)	$	321
	Interest rate contracts for customers		100			(427	)
	The following table reflects the amount and market value of mortgage banking derivatives included in the consolidated balance sheet as of December 31:
		2014						2013
		Notional			Fair			Notional		Fair
		Amount			Value			Amount		Value
	Included in other assets (liabilities):
	Interest rate contracts for customers	$	28,182		$	285		$	25,789	$	185
	Forward contracts related to	$	36,849		$	(132	)	$	27,288	$	279
	mortgage loans held for sale

Loan_Commitments_and_Other_Rel

Loan Commitments and Other Related Activities	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Loan Commitments and Other Related Activities	NOTE 17 - LOAN COMMITMENTS AND OTHER RELATED ACTIVITIES
	Some financial instruments, such as loan commitments, credit lines, letters of credit, and overdraft protection, are issued to meet customer financing needs. These are agreements to provide credit or to support the credit of others, as long as conditions established in the contract are met, and usually have expiration dates. Commitments may expire without being used. Off-balance-sheet risk to credit loss exists up to the face amount of these instruments, although material losses are not anticipated. The same credit policies are used to make such commitments as are used for loans, including obtaining collateral at exercise of the commitment.
	The contractual amounts of financial instruments with off-balance-sheet risk at year end were as follows:
		2014				2013
		Fixed		Variable		Fixed		Variable
		Rate		Rate		Rate		Rate
	Commitments to make loans	$	27,907	$	275	$	25,189	$	600
	Unused lines of credit		91,301		137,237		53,052		76,166
	Standby letters of credit		1,679		10,410		688		4,961
	Commitments to make loans are generally made for periods of 365 days or less. The fixed rate loan commitments have interest rates ranging from 2.875% to 5.50% and maturities ranging from 15 years to 30 years.

Preferred_Stock

Preferred Stock	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Preferred Stock	NOTE 18 - PREFERRED STOCK
	On September 27, 2011, as part of the Small Business Lending Fund (“SBLF”), the Company entered into a Small Business Lending Fund Securities Purchase Agreement (“SBLF Purchase Agreement”) with the United States Department of the Treasury (“Treasury”). Under the SBLF Purchase Agreement, the Company issued 10,000 shares of preferred stock series A to the Treasury. The preferred stock series A shares qualify as Tier 1 capital and will pay quarterly dividends. The initial dividend is 3.96%. As of December 31, 2014, the dividend rate was 1%. The dividend rate can fluctuate between 1% and 5% during the next four quarters based on the growth in qualified small business loans. As of December 31, 2014 and 2013, the Company had dividends in arrears of $25 and $25, respectively.

Parent_Company_Only_Condensed_

Parent Company Only Condensed Financial Information	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Condensed Financial Information	NOTE 19 - PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION
	Condensed financial information of Franklin Financial Network, Inc. follows:
	CONDENSED BALANCE SHEETS
		December 31,
		2014			2013
	ASSETS
	Cash and cash equivalents	$	496		$	718
	Investment in banking subsidiaries		121,154			63,881
	Investment in and advances to other subsidiaries		—			275
	Other assets		300			348
	Total assets	$	121,950		$	65,222
	LIABILITIES AND EQUITY
	Accrued expenses and other liabilities	$	151		$	59
	Shareholders’ equity		121,799			65,163
	Total liabilities and shareholders’ equity	$	121,950		$	65,222
	CONDENSED STATEMENTS OF INCOME
		Years ended December 31,
		2014			2013
	Dividends from subsidiaries	$	575		$	25
	Other income		235			170
	Other expense		1,499			725
	Loss before income tax and undistributed subsidiary income		(689	)		(530	)
	Income tax expense (benefit)		(324	)		(175	)
	Equity in undistributed subsidiary income		8,779			4,916
	Net income	$	8,414		$	4,561
	NOTE 19 - PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION
	CONDENSED STATEMENTS OF CASH FLOWS
		Years ended December 31,
		2014			2013
	Cash flows from operating activities
	Net income	$	8,414		$	4,561
	Adjustments:
	Equity in undistributed subsidiary income		(8,779	)		(4,916	)
	Excess tax benefit related to the exchange of stock options		(29	)		(11	)
	Stock-based compensation		39			81
	Compensation expense related to common stock issued to 401(k) plan		15			10
	Loss on disposal of subsidiary		32			—
	Change in other assets		77			(74	)
	Change in other liabilities		92			(53	)
	Net cash from operating activities		(139	)		(402	)
	Cash flows from investing activities
	Investments in subsidiaries		(12,396	)		(13,773	)
	Net cash acquired from acquisition		12,197			—
	Net cash from the disposal of subsidiary		205			—
	Net cash from investing activities		6			(13,773	)
	Cash flows from financing activities
	Proceeds from exercise of common stock warrants		—			36
	Proceeds from exercise of common stock options		265			58
	Cash paid for stock option exchange, including tax benefit		—			11
	Proceeds from issuance of common stock, net		(514	)		14,191
	Proceeds from subsidiaries related to issuance of common stock related to 401(k) plan		260			—
	Dividends paid on preferred stock		(100	)		(109	)
	Net cash from financing activities		(89	)		14,187
	Net change in cash and cash equivalents		(222	)		12
	Beginning cash and cash equivalents		718			706
	Ending cash and cash equivalents	$	496		$	718
	Non-cash supplemental information:
	Transfers from subsidiary stock based compensation expense to parent company only additional paid-in capital	$	572		$	430
	Fair value of stock and stock options issued related to MidSouth Bank acquisition (See Note 2)		40,976			—

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 20 - EARNINGS PER SHARE
	The two-class method is used in the calculation of basic and diluted earnings per share. Under the two-class method, earnings available to common shareholders for the period are allocated between common shareholders and participating securities according to dividends declared (or accumulated) and participation rights in undistributed earnings. The factors used in the earnings per share computation follow:
		Year Ended
		December 31,
		2014			2013
	Basic
	Net income available to common shareholders	$	8,314		$	4,452
	Less: earnings allocated to participating securities		(94	)		(20	)
	Net income allocated to common shareholders	$	8,220		$	4,432
	Weighted average common shares outstanding including participating securities		6,320,316			3,933,731
	Less: Participating securities		(71,586	)		(17,563	)
	Average shares		6,248,730			3,916,168
	Basic earnings per common share	$	1.32		$	1.13
	Diluted
	Net income allocated to common shareholders	$	8,220		$	4,432
	Weighted average common shares outstanding for basic earnings per common share		6,248,730			3,916,168
	Add: Dilutive effects of assumed exercises of stock options		230,290			102,027
	Add: Dilutive effects of assumed exercises of stock warrants		6,810			2,481
	Average shares and dilutive potential common shares		6,485,830			4,020,676
	Dilutive earnings per common share	$	1.27		$	1.1
	Stock options for 2,000 and 124,869 shares of common stock were not considered in computing diluted earnings per common share for the year ended December 31, 2014 and 2013, because they were antidilutive.

Capital_Offering

Capital Offering	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Capital Offering	NOTE 21 - CAPITAL OFFERING
	The Company initiated a Private Placement stock offering in September 2013. The offering was priced at $13.00 per share and was completed during November 2013. Common shares issued as part of the offering totaled 1,153,847. Net proceeds were as follows:
	Gross proceeds	$	15,000
	Stock offering costs		(809	)
	Proceeds from issuance of common stock, net	$	14,191
	The proceeds of the offering were used primarily to provide the capital to Franklin Synergy Bank to support continued growth.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	NOTE 22 - SUBSEQUENT EVENTS
	Subsequent to December 31, 2014, the Company has declared cash dividends on preferred shares totaling $25.
	On January 15, 2015, the Company filed a Form S-1 Registration Statement with the SEC for an initial public offering of the Company’s common stock with a proposed minimum offering price of $50 million.
	As discussed in “NOTE 6 – PREMISES AND EQUIPMENT AND RELATED PARTY LEASES,” the Company entered into agreements to sell three buildings acquired on July 1, 2014 as part of the MidSouth acquisition. The sales of these buildings settled on February 19, 2015, and the sale resulted in a gain of $15.
	On February 26, 2015, the Company’s annual shareholders’ meeting was held , and shareholders approved amending: (1) the Company’s Charter, to increase the number of authorized shares of the Company’s Common Stock from 10 million to 20 million; and (2) the Company’s 2007 Omnibus Equity Incentive Plan, to increase the number of shares of the Company’s Common Stock available for issuance under the plan from 2 million to 4 million.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Nature of Operations and Principles of Consolidation	Nature of Operations and Principles of Consolidation: The consolidated financial statements include Franklin Financial Network, Inc. and its wholly owned subsidiary, Franklin Synergy Bank, together referred to as “the Company.” Intercompany transactions and balances are eliminated in consolidation.
	Franklin Financial Network, Inc. was incorporated under the laws of the State of Tennessee on April 5, 2007. Franklin Synergy Bank was incorporated under the laws of the State of Tennessee and received its Certificate of Authority from the Tennessee Department of Financial Institutions and approval of FDIC insurance on November 2, 2007. Franklin Synergy Bank is also a Federal Reserve member bank.
	The Company provides financial services through its offices in Franklin, Brentwood, Spring Hill, Murfreesboro and Smyrna, Tennessee. Its primary deposit products are checking, savings, and certificate of deposit accounts, and its primary lending products are commercial and residential construction, commercial, installment loans and lines secured by home equity. Substantially all loans are secured by specific items of collateral including commercial and residential real estate, business assets, and consumer assets. Commercial loans are expected to be repaid by cash flow from operations of businesses. There are no significant concentrations of loans to any one industry or customer. However, the customers’ ability to repay their loans is dependent on the real estate and general economic conditions in the area. The Company also focuses on electronic banking products such as internet banking, remote deposit capture and lockbox services.
	The Company purchased the assets of Banc Compliance Group LLC in May 2008 forming a wholly-owned subsidiary, Banc Compliance Group, Inc., which provided bank compliance and consulting services to community banks. The Company sold the assets of Banc Compliance Group, Inc. at December 31, 2014.
	On July 1, 2014 the Company completed its acquisition of MidSouth Bank, which was merged with and became part of Franklin Synergy Bank.
Use of Estimates	Use of Estimates: To prepare financial statements in conformity with accounting principles generally accepted in the United States of America management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ.
Cash Flows	Cash Flows: Cash and cash equivalents include cash, deposits with other financial institutions with maturities under 90 days, and federal funds sold. Net cash flows are reported for customer loan and deposit transactions, interest bearing deposits in other financial institutions and federal funds purchased.
Interest-Bearing Deposits in Financial Institutions	Interest-Bearing Deposits in Financial Institutions: Interest-bearing deposits in other financial institutions mature within one year and are carried at cost.
Securities	Securities: Debt securities are classified as held to maturity and carried at amortized cost when management has the positive intent and ability to hold them to maturity. Debt securities are classified as available for sale when they might be sold before maturity. Securities available for sale are carried at fair value, with unrealized holding gains and losses reported in other comprehensive income, net of tax.
	Interest income includes amortization of purchase premium or discount. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage backed securities where prepayments are anticipated. Gains and losses on sales are recorded on the trade date and determined using the specific identification method.
	Management evaluates securities for other-than-temporary impairment (OTTI) at least on a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. Management 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 these criteria is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For 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. 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	Loans Held for Sale: Loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value, as determined by outstanding commitments from investors. Net unrealized losses, if any, are recorded as a valuation allowance and charged to earnings.
	Certain loans held for sale are sold with servicing rights retained. The carrying value of loans sold with retained servicing is reduced by the amount allocated to the servicing right. Gains and losses on sales of loans are based on the difference between the selling price and the carrying value of the related loan sold.
Loans	Loans: 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 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.
	Interest income on mortgage and commercial loans is discontinued at the time the loan is 90 days delinquent unless the loan is well-secured and in process of collection. Past due status is based on the 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. Nonaccrual 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. A loan is moved to non-accrual status in accordance with the Company’s policy, typically after 90 days of non-payment.
	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. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured.
Concentration of Credit Risk	Concentration of Credit Risk: Most of the Company’s business activity is with customers located within Williamson County. Therefore, the Company’s exposure to credit risk is significantly affected by changes in the economy in the Williamson County area.
Purchased Credit Impaired Loans	Purchased Credit Impaired Loans: The Company purchases individual loans and groups of loans, some of which have shown evidence of credit deterioration since origination. These purchased credit impaired loans are recorded at the amount paid, such that there is no carryover of the seller’s allowance for loan losses. After acquisition, losses are recognized by an increase in the allowance for loan losses.
	Such purchased credit impaired loans are accounted for individually or aggregated into pools of loans based on common risk characteristics such as, credit score, loan type, and date of origination. 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 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).
Allowance for Loan Losses	Allowance for Loan Losses: The allowance for loan losses is a valuation allowance for probable incurred credit losses. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. Management estimates the allowance balance required using past loan loss experience, the nature and volume of the portfolio, information about specific borrower situations and estimated collateral values, economic conditions, and other factors. 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.
	The allowance consists of specific and general components. The specific component relates to loans that are individually classified as impaired. A loan is 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 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 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.
	If a loan is impaired, a portion of the allowance is allocated so that the loan is reported, net, at the present value of estimated future cash flows using the loan’s existing rate or at the fair value of collateral if repayment is expected solely from the collateral
	Troubled debt restructurings are separately identified for impairment disclosures and are measured at the present value of estimated future cash flows using the loan’s effective rate at inception. If a troubled debt restructuring is considered to be a collateral dependent loan, the loan is reported, net, at the fair value of the collateral. For troubled debt restructurings that subsequently default, the Company determines the amount of reserve in accordance with the accounting policy for the allowance for loan losses.
	The general component covers non-impaired loans and is based on historical loss experience adjusted for current factors. The historical loss experience is determined by portfolio segment and is based on a combination of the Bank’s loss history and loss history from the Bank’s peer group over the past three years. This actual loss experience is supplemented with other economic factors based on the risks present for each portfolio segment. These economic factors include consideration of the following: levels of and trends in delinquencies and impaired loans; levels of and trends in charge-offs and recoveries; trends in volume and terms of loans; effects of any changes in risk selection and underwriting standards; other changes in lending policies, procedures, and practices; experience, ability, and depth of lending management and other relevant staff; national and local economic trends and conditions; industry conditions; and effects of changes in credit concentrations. The following portfolio segments have been identified:
	Construction and land development loans include loans to finance the process of improving loans preparatory to erecting new structures or the on-site construction of industrial, commercial, residential or farm buildings. Construction and land development loans also include loans secured by vacant land, except land known to be used or usable for agricultural purposes. Construction loans generally are made for relatively short terms. They generally are more vulnerable to changes in economic conditions. Further, the nature of these loans is such that they are more difficult to evaluate and monitor. The risk of loss on a construction loan is dependent largely upon the accuracy of the initial estimate of the property’s value upon completion of the project and the estimated cost (including interest) of the project. Periodic site inspections are made on construction loans.
	Commercial real estate loans include loans secured by non-residential real estate, including farmland and improvements thereon. Often these loans are made to single borrowers or groups of related borrowers, and the repayment of these loans largely depends on the results of operations and management of these properties. Adverse economic conditions may affect the repayment ability of these loans.
	Residential real estate loans include loans secured by residential real estate, including single-family and multi-family dwellings. Mortgage title insurance and hazard insurance are normally required. Adverse economic conditions in the Company’s market area may reduce borrowers’ ability to repay these loans and may reduce the collateral securing these loans.
	Commercial and industrial loans include loans for commercial, industrial or agricultural purposes to business enterprises that are not secured by real estate. Commercial loans are typically made on the basis of the borrower’s ability to repay from the cash flow of the borrower’s business. Commercial and Agriculture loans are generally secured by accounts receivable, inventory and equipment. The collateral securing loans may depreciate over time, may be difficult to appraise and may fluctuate in value based on the success of the business.
	Consumer and other loans include loans to individuals for household, family and other personal expenditures that are not secured by real estate. Consumer loans are generally secured by customer deposit accounts, vehicles and other household goods. The collateral securing consumer loans may depreciate over time.
Servicing Rights	Servicing Rights: When loans are sold with servicing retained, servicing rights are initially recorded at fair value with the income statement effect recorded in gain on sale of loans. Fair value is based on market prices for comparable servicing contracts. 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 assets 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 loan servicing fees on the income statement. 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 as loan servicing fees, 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 mortgage loan servicing fee income. Late fees and ancillary fees related to loan servicing are not material.
Transfers of Financial Assets	Transfers of Financial Assets: Transfers of financial assets are accounted for as sales, when control over the assets has been relinquished. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Foreclosed Assets	Foreclosed Assets: Assets acquired through or instead of loan foreclosure are initially recorded at fair value less costs to sell when acquired, establishing a new cost basis. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating costs after acquisition are expensed.
Assets Held for Sale	Assets Held for Sale: Assets held for sale are stated at fair value less estimated costs to sell at the time the assets are determined to be held for sale. If fair value declines subsequent to designation, a valuation allowance is recorded through expense. Operating costs after designation are expensed.
Premises and Equipment	Premises and Equipment: Premises and equipment are stated at cost less accumulated depreciation and are depreciated using the straight-line method. Depreciation periods are shorter of the asset’s useful life or lease period, ranging from three to fifteen years.
Restricted Equity Securities	Restricted Equity Securities: The Bank is a member of the Federal Reserve Bank (FRB) and the Federal Home Loan Bank (FHLB) system. Members of the FHLB are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest in additional amounts. The stock ownership in FRB and FHLB are carried at cost, classified as restricted securities, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income.
Company Owned Life Insurance	Company Owned Life Insurance: The Company has purchased life insurance policies on certain key executives. Company 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.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets: Goodwill resulting from business combinations after January 1, 2009, 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. The Company has selected December 31 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 and acquired customer relationship intangible assets arising from whole bank and branch acquisitions are amortized on an accelerated method over their estimated useful lives, which range from 7 to 10 years.
Long-Term Assets	Long-Term Assets: Premises and equipment and other long-term 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.
Loan Commitments and Related Financial Instruments	Loan Commitments and Related Financial Instruments: Financial instruments include off-balance sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded.
Mortgage Banking Derivatives	Mortgage Banking Derivatives: Commitments to fund mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these mortgage loans are accounted for as free standing derivatives. Fair values of these mortgage derivatives are estimated based on changes in mortgage interest rates from the date the interest on the loan is locked. The Company enters into forward commitments for the future delivery of mortgage loans 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 net gains on sale of mortgage loans.
Stock-Based Compensation	Stock-Based Compensation: Compensation cost is recognized for stock options and restricted stock awards issued to employees, based on the fair value of these awards at the date of grant. 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 cost is recognized over the required service period, generally defined as the vesting period. For awards with graded vesting, compensation cost is recognized on a straight-line basis over the requisite service period for the entire award.
Income Taxes	Income Taxes: Income tax expense or benefit 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 recognizes interest and/or penalties related to income tax matters in income tax expense.
Retirement Plans	Retirement Plans: Employee 401(k) and profit sharing plan expense is the amount of matching contributions. The matching contributions are paid with employer stock. An annual stock valuation is performed for the employer stock match calculation.
Comprehensive Income	Comprehensive Income: Comprehensive income consists of net income and other comprehensive income. Other comprehensive income includes unrealized gains and losses on securities available for sale which is recognized as a separate component of equity.
Earnings Per Common Share	Earnings Per Common Share: Basic earnings per common share is net income available to common shareholders divided by the weighted average number of common shares outstanding during the period. All outstanding unvested share-based payment awards that contain rights to non-forfeitable dividends are considered participating securities for this calculation. Diluted earnings per common share includes the dilutive effect of additional potential common shares issuable under stock options and warrants. Earnings and dividends per share are restated for all stock splits and stock dividends through the date of issuance of the financial statements.
Loss Contingencies	Loss Contingencies: Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe there now are such matters that will have a material effect on the financial statements.
Restrictions on Cash	Restrictions on Cash: Cash on hand or on deposit with the Federal Reserve Bank was required to meet regulatory reserve and clearing requirements.
Dividend Restriction	Dividend Restriction: Banking regulations require maintaining certain capital levels and may limit the dividends paid by the bank to the holding company or by the holding company to shareholders.
Fair Value of Financial Instruments	Fair Value of Financial Instruments: 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 the estimates.
Operating Segments	Operating Segments: While the chief decision-makers monitor the revenue streams of the various products and services, operations are managed and financial performance is evaluated on a Company-wide basis. Operating segments are aggregated into one as operating results for all segments are similar. Accordingly, all of the financial service operations are considered by management to be aggregated in one reportable operating segment.
Reclassifications	Reclassifications: Some items in the prior year financial statements were reclassified to conform to the current presentation. Reclassifications had no effect on prior year net income or shareholders’ equity.

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Summary of Purchase Price Calculation	The following table summarizes the purchase price calculation:
		Number of			Per share			Number of FFN
		MidSouth shares			exchange			shares—as
		outstanding			ratio			exchanged
	Common Shares		3,873			0.425926			1,650
	Convertible Voting Preferred Stock, 2009-A		1,018			0.851852			867
	Convertible Voting Preferred Stock, 2011-A		242			0.851852			206
	Series 2009-A Stock Warrants (strike price $3.25)		193			0.185185			36
	Series 2011-A Stock Warrants (strike price $3.68)		44			0.153333			7
									2,766
	Multiplied by FFN common stock value at acquisition date							$	14.5
	Fair value of FFN common stock issued (“Stock Consideration”)							$	40,110
	Cash consideration paid for fractional shares								18
	Cash consideration paid for dissenting shares								100
	Fair value of MidSouth stock options converted to FFN stock options								866
	Total acquisition consideration							$	41,094
Summary of Preliminary Estimates of Fair Value of the Assets Purchased , Including Goodwill, and Liabilities Assumed	The table below summarizes the fair value of the assets purchased, including goodwill, and liabilities assumed as of the July 1, 2014 purchase date.
	In Thousands	July 1, 2014			Measurement			July 1, 2014
		(as initially reported)			Period			(as adjusted)
					Adjustments
	Assets:
	Cash and due from banks	$	1,369		$	—		$	1,369
	Interest-bearing accounts at other financial institutions		10,946						10,946
	Securities, available-for-sale		57,431						57,431
	Loans held for sale		7,071						7,071
	Loans		184,345						184,345
	Certificates of deposit at other financial institutions		250						250
	Restricted equity securities		1,572						1,572
	Bank premises and equipment, net		6,650						6,650
	Bank-owned life insurance		3,144						3,144
	Accrued interest receivable		728						728
	Foreclosed assets		800			(260	)		540
	Core deposit intangible		3,060						3,060
	Deferred tax asset		6,753			100			6,853
	Goodwill		8,964			160			9,124
	Other assets		747						747
	Total assets acquired	$	293,830		$	—		$	293,830
	Liabilities:
	Deposits	$	244,415		$	—		$	244,415
	Short-term borrowings		6,893						6,893
	Other liabilities		1,428						1,428
	Total liabilities assumed	$	252,736		$	—		$	252,736
Contractually Required Principal and Interest Cash Payments, Management's Estimates of Expected Total Cash Payments	The table below summarizes the total contractually required principal and interest cash payments, management’s estimate of expected total cash payments and fair value of the loans as of July 1, 2014 for purchased credit-impaired (“PCI”) loans. Contractually required principal and interest payments have been adjusted for estimated prepayments.
	Contractually required principal and interest	$	8,510
	Non-accretable difference		(1,745	)
	Cash flows expected to be collected		6,765
	Accretable yield		(1,238	)
	Total purchased credit-impaired loans	$	5,527
Summary of Fair Value of Acquired Loans and Unpaid Principal Balance	The table below presents information with respect to the fair value of acquired loans, as well as their unpaid principal balance at acquisition date.
		Unpaid			Fair
		Principal			Value
		Balance
	Loans:
	Residential real estate	$	39,425		$	38,618
	Commercial real estate		82,465			80,566
	Construction and land development		43,766			42,454
	Commercial loans		16,311			15,352
	Consumer and other loans		1,865			1,828
	Purchased credit-impaired		7,860			5,527
	Total earning assets	$	191,692		$	184,345
Schedule of Acquired Intangible Assets	The following table represents acquired intangible assets at December 31, 2014 and 2013:
		2014						2013
		Gross Carrying			Accumulated			Gross Carrying		Accumulated
		Amount			Amortization			Amount		Amortization
	Acquired intangible assets:
	Core deposit intangibles	$	3,060		$	(362	)	$	—	$	—
Schedule of Estimated Amortization Expense	The following table presents estimated amortization expense for each of the next five years:
	2015	$	655
	2016		564
	2017		473
	2018		382
	2019		291
Pro-Forma Financial Information and Actual Results of Acquisition	Pro-forma data for the years ended December 31, 2014 and 2013 listed in the table below presents pro-forma information as if the MidSouth acquisition occurred at the beginning of 2013.
		Years ended
		December 31,
		2014			2013
	Net interest income	$	41,312		$	32,022
	Net income available to common shareholders		8,055			5,722
	Earnings per share—basic	$	1.04		$	0.88
	Earnings per share—diluted	$	1.02		$	0.87

Securities_Tables

Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost and Fair Value of Available for Sale Securities	The following table summarizes the amortized cost and fair value of the available for sale securities portfolio at December 31, 2014 and 2013 and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss).
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
	December 31, 2014
	U.S. government sponsored entities and agencies	$	30,070		$	417		$	(314	)	$	30,173
	U.S. Treasury securities		20,000			—			—			20,000
	Mortgage-backed securities: residential		335,677			4,593			(1,203	)		339,067
	Mortgage-backed securities: commercial		6,432			33			—			6,465
	Total	$	392,179		$	5,043		$	(1,517	)	$	395,705
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
	December 31, 2013
	U.S. government sponsored entities and agencies	$	16,029		$	—		$	(1,305	)	$	14,724
	Mortgage-backed securities: residential		259,831			1,560			(7,600	)		253,791
	Total	$	275,860		$	1,560		$	(8,905	)	$	268,515
Schedule of Amortized Cost and Fair Value of Held to Maturity Securities Portfolio	The amortized cost and fair value of the held to maturity securities portfolio at December 31, 2014 and 2013 and the corresponding amounts of gross unrecognized gains and losses were as follows:
		Amortized			Gross			Gross			Fair
		Cost			Unrecognized			Unrecognized			Value
					Gains			Losses
	December 31, 2014
	U.S. government sponsored entities and agencies	$	5,550		$	162		$	(87	)	$	5,625
	Mortgage backed securities: residential		38,587			555			(562	)		38,580
	State and political subdivisions		9,195			351			(10	)		9,536
	Total	$	53,332		$	1,068		$	(659	)	$	53,741
		Gross			Gross			Gross			Fair
		Amortized			Unrecognized			Unrecognized			Value
		Cost			Gains			Losses
	December 31, 2013
	U.S. government sponsored entities and agencies	$	8,225		$	12		$	(484	)	$	7,753
	Mortgage backed securities: residential		39,043			293			(2,061	)		37,275
	State and political subdivisions		9,307			89			(420	)		8,976
	Total	$	56,575		$	394		$	(2,965	)	$	54,004
Summary of Sales of Available for Sale Securities	Sales of available for sale securities were as follows:
		2014			2013
	Proceeds	$	44,181		$	16,290
	Gross gains		422			163
	Gross losses		(163	)		(75	)
Schedule of Amortized Cost and Fair Value of Investment Securities Portfolio by Contractual Maturity	The amortized cost and fair value of the investment securities portfolio are shown by contractual maturity. Securities not due at a single maturity date, primarily mortgage-backed securities, are shown separately.
		December 31, 2014
		Amortized			Fair
		Cost			Value
	Available for sale
	Three months or less	$	30,000		$	29,999
	Over three months through one year		—			—
	Over one year through five years		—			—
	Over five years through ten years		7,796			7,948
	Over ten years		12,274			12,226
	Mortgage-backed securities: commercial		6,432			6,465
	Mortgage-backed securities: residential		335,677			339,067
	Total	$	392,179		$	395,705
	Held to maturity
	Three months or less	$	250		$	251
	Over one year through five years		1,419			1,478
	Over five years through ten years		1,106			1,127
	Over ten years		11,970			12,305
	Mortgage-backed securities: residential		38,587			38,580
	Total	$	53,332		$	53,741
Schedule of Unrealized Losses and Fair Value by Major Security Type	The following table summarizes the securities with unrealized and unrecognized losses at December 31, 2014 and 2013, aggregated by major security type and length of time in a continuous unrealized loss position:
		Less Than 12 Months						12 Months or Longer						Total
		Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
		Value			Losses			Value			Losses			Value		Losses
	December 31, 2014
	Available for sale
	U.S. government sponsored entities and agencies	$	9,999		$	(1	)	$	8,232		$	(313	)	$	18,231	$	(314	)
	Mortgage-backed securities: residential		59,078			(323	)		41,939			(880	)		101,017		(1,203	)
	Total available for sale	$	69,077		$	(324	)	$	50,171		$	(1,193	)	$	119,248	$	(1,517	)
		Less Than 12 Months						12 Months or Longer						Total
		Fair			Unrecognized			Fair			Unrecognized			Fair		Unrecognized
		Value			Losses			Value			Losses			Value		Losses
	Held to maturity
	U.S. government sponsored entities and agencies	$	—		$	—		$	2,913		$	(87	)	$	2,913	$	(87	)
	Mortgage-backed securities: residential		5,246			(25	)		13,001			(537	)		18,247		(562	)
	State and political subdivisions		507			(1	)		592			(9	)		1,099		(10	)
	Total held to maturity	$	5,753		$	(26	)	$	16,506		$	(633	)	$	33,037	$	(659	)
		Less Than 12 Months						12 Months or Longer						Total
		Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
		Value			Losses			Value			Losses			Value		Losses
	December 31, 2013
	Available for sale
	U.S. government sponsored entities and agencies	$	12,983		$	(1,128	)	$	1,741		$	(177	)	$	14,724	$	(1,305	)
	Mortgage-backed securities: residential		168,817			(6,762	)		11,721			(838	)		180,538		(7,600	)
	Total available for sale	$	181,800		$	(7,890	)	$	13,462		$	(1,015	)	$	195,262	$	(8,905	)
		Less Than 12 Months						12 Months or Longer						Total
		Fair			Unrecognized			Fair			Unrecognized			Fair		Unrecognized
		Value			Losses			Value			Losses			Value		Losses
	Held to maturity
	U.S. government sponsored entities and agencies	$	6,168		$	(332	)	$	848		$	(152	)	$	7,016	$	(484	)
	Mortgage-backed securities: residential		19,952			(1,752	)		4,042			(309	)		23,994		(2,061	)
	State and political subdivisions		5,762			(342	)		422			(78	)		6,184		(420	)
	Total held to maturity	$	31,882		$	(2,426	)	$	5,312		$	(539	)	$	37,194	$	(2,965	)

Loans_Tables

Loans (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Summary of Loans	Loans at December 31, 2014 and 2013 were as follows:
		December 31,			December 31,
		2014			2013
	Loans that are not PCI loans
	Construction and land development	$	239,225		$	113,710
	Commercial real estate:
	Nonfarm, nonresidential		240,975			114,852
	Other		5,377			10,350
	Residential real estate:
	Closed-end 1-4 family		130,631			98,615
	Other		83,129			39,851
	Commercial and industrial		76,570			36,397
	Consumer and other		8,025			8,250
	Loans before net deferred loan fees		783,932			422,025
	Deferred loan fees, net		(1,059	)		(721	)
	Total loans that are not PCI loans		782,873			421,304
	PCI loans
	Construction and land development	$	77		$	—
	Commercial real estate:
	Nonfarm, nonresidential		1,798			—
	Other		—			—
	Residential real estate:
	Closed-end 1-4 family		706			—
	Other		108			—
	Commercial and industrial		1,624			—
	Consumer and other		2			—
	Total PCI loans		4,315			—
	Allowance for loan losses		(6,680	)		(4,900	)
	Total loans, net of allowance for loan losses	$	780,508		$	416,404
Activity in Allowance for Loan Losses by Portfolio Segment	The following table presents the activity in the allowance for loan losses by portfolio segment for the years ended December 31, 2014 and 2013:
		Construction			Commercial			Residential			Commercial			Consumer			Total
		and Land			Real			Real			and			and
		Development			Estate			Estate			Industrial			Other
	December 31, 2014
	Allowance for loan losses:
	Beginning balance	$	1,552		$	1,511		$	1,402		$	337		$	98		$	4,900
	Provision for loan losses		1,138			523			385			371			(43	)		2,374
	Loans charged-off		—			(540	)		(61	)		(58	)		—			(659	)
	Recoveries		—			—			65			—			—			65
	Total ending allowance balance	$	2,690		$	1,494		$	1,791		$	650		$	55		$	6,680
		Construction			Commercial			Residential			Commercial			Consumer			Total
		and Land			Real			Real			and			and
		Development			Estate			Estate			Industrial			Other
	December 31, 2013
	Allowance for loan losses:
	Beginning balance	$	1,342		$	1,267		$	893		$	275		$	206		$	3,983
	Provision for loan losses		210			244			480			81			(108	)		907
	Loans charged-off		—			—			(107	)		(19	)		—			(126	)
	Recoveries		—			—			136			—			—			136
	Total ending allowance balance	$	1,552		$	1,511		$	1,402		$	337		$	98		$	4,900
Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment and Based on Impairment Method	The following table presents the balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method as of December 31, 2014 and 2013. Purchased and PCI loans are also included in the table. For purposes of this disclosure, recorded investment in loans excludes accrued interest receivable and loan fees, net due to immateriality.
		Construction			Commercial			Residential			Commercial			Consumer			Total
		and Land			Real			Real			and			and
		Development			Estate			Estate			Industrial			Other
	December 31, 2014
	Allowance for loan losses:
	Ending allowance balance attributable to loans:
	Individually evaluated for impairment	$	—		$	—		$	—		$	18		$	—		$	18
	Collectively evaluated for impairment		2,690			1,494			1,791			632			55			6,662
	Purchased credit-impaired loans		—			—			—			—			—			—
	Total ending allowance balance	$	2,690		$	1,494		$	1,791		$	650		$	55		$	6,680
	Loans:
	Individually evaluated for impairment	$	—		$	835		$	93		$	18		$	—		$	946
	Collectively evaluated for impairment		239,225			245,517			213,667			76,552			8,025			782,986
	Purchased credit-impaired loans		77			1,798			814			1,624			2			4,315
	Total ending loans balance	$	239,302		$	248,150		$	214,574		$	78,194		$	8,027		$	788,247
		Construction			Commercial			Residential			Commercial			Consumer			Total
		and Land			Real			Real			and			and
		Development			Estate			Estate			Industrial			Other
	December 31, 2013
	Allowance for loan losses:
	Ending allowance balance attributable to loans:
	Individually evaluated for impairment	$	—		$	455		$	93		$	—		$	—		$	548
	Collectively evaluated for impairment		1,552			1,056			1,309			337			98			4,352
	Total ending allowance balance	$	1,552		$	1,511		$	1,402		$	337		$	98		$	4,900
	Loans:
	Individually evaluated for impairment	$	—		$	3,361		$	1,262		$	—		$	—		$	4,623
	Collectively evaluated for impairment		113,710			121,841			137,204			36,397			8,250			417,402
	Total ending loans balance	$	113,710		$	125,202		$	138,466		$	36,397		$	8,250		$	422,025
Summary of Impaired Loans by Class of Loans	The following table presents information related to impaired loans by class of loans as of December 31, 2014 and 2013:
		Unpaid			Recorded			Allowance for
		Principal			Investment			Loan Losses
		Balance						Allocated
	December 31, 2014
	With no allowance recorded:
	Commercial real estate:
	Nonfarm, nonresidential	$	2,422		$	835		$	—
	Residential real estate:
	1-4 family		93			93			—
	Subtotal		2,515			928			—
	With an allowance recorded:
	Commercial and industrial		18			18			18
	Subtotal		18			18			18
	Total	$	2,533		$	946		$	18
	December 31, 2013
	With no allowance recorded:
	Commercial real estate:
	Nonfarm, nonresidential	$	1,986		$	1,986		$	—
	Residential real estate:
	1-4 family		36			36			—
	Subtotal		2,022			2,022			—
	With an allowance recorded:
	Commercial real estate:
	Nonfarm, nonresidential	$	2,480		$	1,375		$	455
	Residential real estate:
	1-4 family		1,687			1,226			93
	Subtotal		4,167			2,601			548
	Total	$	6,189		$	4,623		$	548
Schedule of Recorded Investment in Nonaccrual and Loans Past Due Over 90 Days on Accrual by Class of Loans	The following table presents the recorded investment in nonaccrual and loans past due over 90 days still on accrual by class of loans as of December 31, 2014 and 2013:
		Nonaccrual			Loans Past Due
					Over 90 Days
	December 31, 2014
	Commercial real estate:
	Nonfarm, nonresidential	$	835		$	—
	Other		—			—
	Residential real estate:
	Closed-end1-4 family		—			316
	Other		—			—
	Construction and land development		—			—
	Commercial and industrial		—			—
	Total	$	835		$	316
	December 31, 2013
	Commercial real estate:
	Nonfarm, nonresidential	$	1,375		$	—
	Residential real estate:
	1-4 family		1,226			—
	Total	$	2,601		$	—
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, 2014 and 2013 by class of loans:
		30-59			60-89			Greater			Total			Loans			PCI			Total
		Days			Days			Than			Past Due			Not			Loans
		Past Due			Past Due			89 Days						Past Due
								Past Due
	December 31, 2014
	Construction and land development	$	354		$	—		$	—		$	354		$	238,871		$	77		$	239,302
	Commercial real estate:
	Nonfarm, nonresidential		—			—			835			835			240,140			1,798			242,773
	Other		—			—			—			—			5,377			—			5,377
	Residential real estate:
	Closed-end 1-4 family		299			165			316			780			129,851			706			131,337
	Other		52			—			—			52			83,077			108			83,237
	Commercial and industrial		—			212			—			212			76,358			1,624			78,194
	Consumer and other		—			—			—			—			8,025			2			8,027
		$	705		$	377		$	1,151		$	2,233		$	781,699		$	4,315		$	788,247
		30-59			60-89			Greater			Total			Loans			PCI			Total
		Days			Days			Than			Past Due			Not			Loans
		Past Due			Past Due			89 Days						Past Due
								Past Due
	December 31, 2013
	Construction and land development	$	—		$	—		$	—		$	—		$	113,710		$	—		$	113,710
	Commercial real estate:
	Nonfarm, nonresidential		1,985			—			1,375			3,360			111,492			—			114,852
	Other		—			—			—			—			10,350			—			10,350
	Residential real estate:
	Closed end 1-4 family		245			—			1,226			1,471			97,144			—			98,615
	Other		—			—			—			—			39,851			—			39,851
	Commercial and industrial		—			—			—			—			36,397			—			36,397
	Consumer and other		—			—			—			—			8,250			—			8,250
		$	2,230		$	—		$	2,601		$	4,831		$	417,194		$	—		$	422,025
Summary of Risk Category of Loans by Class of Loans	The following table includes PCI loans, which are included in the “Substandard” column. Based on the most recent analysis performed, the risk category of loans by class of loans is as follows as of December 31, 2014 and 2013:
		Pass			Special			Substandard			Total
					Mention
	December 31, 2014
	Construction and land development	$	239,225		$	—		$	77		$	239,302
	Commercial real estate:
	Nonfarm, nonresidential		239,584			—			3,189			242,773
	Other		5,377			—			—			5,377
	Residential real estate:
	Closed-end 1-4 family		128,869			—			2,468			131,337
	Other		83,129			—			108			83,237
	Commercial and industrial		76,552			—			1,642			78,194
	Consumer and other		8,025			—			2			8,027
		$	780,761		$	—		$	7,486		$	788,247
		Pass			Special			Substandard			Total
					Mention
	December 31, 2013
	Construction and land development	$	113,710		$	—		$	—		$	113,710
	Commercial real estate:
	Nonfarm, nonresidential		110,938			—			3,914			114,852
	Other		10,350			—			—			10,350
	Residential real estate:
	1-4 family		96,823			—			1,792			98,615
	Other		39,851			—			—			39,851
	Commercial and industrial		36,397			—			—			36,397
	Consumer and other		8,250			—			—			8,250
		$	416,319		$	—		$	5,706		$	422,025
Pro-Forma Financial Information and Actual Results of Acquisition	Contractually required principal and interest payments have been adjusted for estimated prepayments.
		December 31,
		2014
	Contractually required principal and interest	$	6,532
	Non-accretable difference		(1,270	)
	Cash flows expected to be collected		5,262
	Accretable yield		(947	)
	Carrying value of acquired loans		4,315
	Allowance for loan losses		—
	Carrying value less allowance for loan losses	$	4,315

Loan_Servicing_Tables

Loan Servicing (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Schedule of Loans Serviced Not Reported as Assets	Loans serviced for others are not reported as assets. The principal balances of these loans at December 31, 2014 and 2013 are as follows:
		2014			2013
	Loan portfolios serviced for:
	Federal Home Loan Mortgage Corporation	$	414,222		$	348,121
	Other		3,986			5,088
Related Loan Servicing Rights Activity
	The related loan servicing rights activity for the years ended December 31, 2014 and 2013 were as follows:
		2014			2013
	Servicing rights:
	Beginning of year	$	2,640		$	2,401
	Additions		1,140			1,414
	Amortized to expense		(727	)		(1,265	)
	Decrease in impairment		—			90
	End of year	$	3,053		$	2,640
Components of Net Loan Servicing Fees	The components of net loan servicing fees for the years ended December 31, 2014 and 2013 were as follows:
		2014			2013
	Loan servicing fees, net:
	Loan servicing fees	$	981		$	810
	Amortization of loan servicing fees		(727	)		(1,265	)
	Decrease in impairment		—			90
	Total	$	254		$	(365	)
Schedule of Estimated Amortization Expense	The weighted average amortization period is 6.37 years. Estimated amortization expense for each of the next three years is:
	2015	$	480
	2016		480
	2017		480

Premises_and_Equipment_and_Rel1

Premises and Equipment and Related Party Leases (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Premises and Equipment	Year-end premises and equipment were as follows:
		2014			2013
	Construction in progress	$	1,128		$	1,044
	Land and land improvements		693			—
	Buildings		1,170			—
	Leasehold improvements		4,804			2,438
	Furniture, fixtures, and equipment		4,129			2,594
	Computer equipment and software		2,223			1,688
			14,147			7,764
	Accumulated depreciation		(4,483	)		(3,626	)
		$	9,664		$	4,138
Summary of Operating Lease Rent Commitments Over the Initial Lease Terms	Rent commitments, over the initial lease terms and intended renewal periods were as follows:
		Related			Other			Total
		Parties
	2015	$	1,798		$	585		$	2,383
	2016		1,839			496			2,335
	2017		1,865			455			2,320
	2018		1,892			412			2,304
	2019		1,919			402			2,321
	Thereafter		17,255			3,397			20,652
	Total	$	26,568		$	5,747		$	32,315
MidSouth Bank [Member]
Summary of Operating Lease Rent Commitments Over the Initial Lease Terms	Estimated rent commitments for the 2014 lease additions, over the initial lease terms, are as follows:
		Related			Other			Total
		Parties
	2015	$	313		$	—		$	313
	2016		390			—			390
	2017		431			—			431
	2018		477			—			477
	2019		527			—			527
	Thereafter		6,926			—			6,926
	Total	$	9,064		$	—		$	9,064

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Schedule of Maturities of Time Deposits	Scheduled maturities of time deposits for the next five years were as follows:
	2015	$	177,449
	2016		60,154
	2017		29,328
	2018		19,242
	2019		35,008

Federal_Funds_Purchased_and_Re1

Federal Funds Purchased and Repurchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Summary of Information Concerning Securities Sold under Agreements to Repurchase	Information concerning securities sold under agreements to repurchase is summarized as follows:
		2014			2013
	Average daily balance during the year	$	12,792		$	3,525
	Average interest rate during the year		0.58	%		0.71	%
	Maximum month-end balance during the year	$	24,466		$	5,077
	Weighted average interest rate at year end		0.56	%		0.73	%

Federal_Home_Loan_Bank_Advance1

Federal Home Loan Bank Advances (Tables)	12 Months Ended
	Dec. 31, 2014
Federal Home Loan Banks [Abstract]
Schedule of Maturities of Advances and Interest Rates	At December 31, 2014 and 2013, the Company had received advances from the FHLB totaling $19,000 and $23,000, respectively. At December 31, 2014, the schedule maturities of these advances and interest rates were as follows:
		Scheduled		Weighted
		Maturities		Average
				Rates
	2015	$	2,000		0.7	%
	2016		—		—
	2017		10,000		1.27	%
	2018		7,000		1.61	%
	2019		—		—
	Thereafter		—		—
	Total	$	19,000		1.33	%

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Summary of Reconciliation of the Income Tax Expense Computed by Statutory Federal Income Tax Rate of 34 Percent to Income Before Income Tax Expense	A reconciliation of the income tax expense for the years ended December 31, 2014 and 2013 to the “expected” tax expense computed by applying the statutory federal income tax rate of 34 percent to income before income tax expense is as follows:
		2014			2013
	Computed “expected” tax expense	$	4,742		$	2,480
	Increase (reduction) in tax expense resulting from:
	State tax expense, net of federal tax effect		593			305
	Effect of statutory rate changes enacted in the current year		(223	)		—
	Non-deductible merger costs		150			—
	Incentive stock options		104			19
	Bank owned life insurance		(101	)		(92	)
	Tax-exempt interest income, net of expense		(49	)		(40	)
	Other		(82	)		62
	Income tax expense	$	5,134		$	2,734
Component of Income Tax Expense Benefit	Income tax expense (benefit) was as follows:
		2014			2013
	Current expense
	Federal	$	4,444		$	2,613
	State		820			517
	Deferred expense
	Federal		(222	)		(343	)
	State		92			(53	)
	Income tax expense	$	5,134		$	2,734
Sources of Deferred Income Tax Assets and Liabilities	The sources of deferred income tax assets (liabilities) at December 31, 2013 and 2012 and the tax effect is as follows:
		2014			2013
	Deferred tax assets:
	Organizational and start-up costs	$	155		$	170
	Allowance for loan losses		1,343			1,718
	Unrealized loss on securities		—			2,812
	Net operating loss carry forward		5,290			—
	Purchase accounting fair value adjustments		2,980			—
	Accrued other expenses		340			116
	Nonaccrual loan interest		538			195
	Capital loss carryforward		95			—
	Loan fees		396			266
	Other		389			412
			11,526			5,689
	Valuation allowance		(95	)		—
			11,431			5,689
		2014			2013
	Deferred tax liabilities:
	Mortgage servicing rights		(1,174	)		(975	)
	Premises and equipment		(675	)		(468	)
	Prepaid expenses		(177	)		(71	)
	Unrealized gain on securities		(1,385	)		—
	Purchase accounting fair value adjustments		(1,190	)		—
	Mortgage banking derivatives		(1	)		(123	)
	Other		(49	)		(57	)
			(4,651	)		(1,694	)
	Net deferred tax asset (liability)	$	6,780		$	3,995

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Schedule of Loans to Principal Officers, Directors, and Their Affiliates	Loans to principal officers, directors, and their affiliates during 2014 were as follows:
	Beginning balance	$	6,752
	New loans		2,279
	Effect of changes in composition of related parties		—
	Repayments		(4,495	)
	Ending balance	$	4,536

ShareBased_Payments_Tables

Share-Based Payments (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Fair Value Assumptions of Stock Options	The fair value of options granted was determined using the following weighted-average assumptions as of grant date.
		2014			2013
	Risk-free interest rate		1.82	%		1.65	%
	Expected term		5.9 years			7.5 years
	Expected stock price volatility		10.87	%		12.63	%
	Dividend yield		0.23	%		0.99	%
Summary of Company's Stock Option Activities	A summary of the activity in the stock option plans for the year ended December 31, 2014 follows:
		Shares			Weighted			Weighted		Aggregate
					Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual
								Term
	Outstanding at beginning of year		946,644		$	11.27			6.81	$	1,635
	Granted		181,680			13.55
	Conversion of pre-existing MidSouth options		137,280			8.57
	Exercised		(23,809	)		9.92
	Forfeited, expired, or cancelled		(31,135	)		12.01
	Outstanding at period end		1,210,660		$	11.32			6.53	$	7,244
	Vested or expected to vest		1,150,127		$	11.32			6.53	$	6,882
	Exercisable at period end		790,098		$	10.62			5.6	$	5,281
Summary of Activity for Nonvested Restricted Share Awards	A summary of activity for non-vested restricted share awards for the year ended December 31, 2014 is as follows:
	Non-vested Shares	Shares			Weighted-Average
					Grant-Date
					Fair Value
	Non-vested at December 31, 2013		28,685		$	13
	Granted		87,874			14.15
	Vested		(9,166	)		13
	Forfeited		(4,683	)		14.09
	Non-vested at December 31, 2014		102,710			13.93

Regulatory_Capital_Matters_Tab

Regulatory Capital Matters (Tables)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Actual and Required Capital Amounts and Ratios	Actual and required capital amounts and ratios are presented below as of December 31, 2014 and 2013 for the Company and Bank.
		Actual					Required					To Be Well
							For Capital					Capitalized Under
							Adequacy Purposes					Prompt Corrective
												Action Regulations
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	December 31, 2014
	Company Total Risk-Based Capital to risk weighted assets	$	114,475		12.3	%	$	74,464		8	%		N/A		N/A
	Company Tier 1 (Core) Capital to risk weighted assets	$	107,795		11.58	%	$	37,232		4	%		N/A		N/A
	Company Tier 1 (Core) Capital to average assets	$	107,795		8.57	%	$	50,291		4	%		N/A		N/A
	Bank Total Risk-Based Capital to risk weighted assets	$	113,830		12.23	%	$	74,447		8	%	$	93,059		10	%
	Bank Tier 1 (Core) Capital to risk weighted assets	$	107,150		11.51	%	$	37,223		4	%	$	55,835		6	%
	Bank Tier 1 (Core) Capital to average assets	$	107,150		8.52	%	$	50,279		4	%	$	62,849		5	%
	December 31, 2013
	Company Total Risk-Based Capital to risk weighted assets	$	74,430		14.81	%	$	40,209		8	%		N/A		N/A
	Company Tier 1 (Core) Capital to risk weighted assets	$	69,530		13.83	%	$	20,105		4	%		N/A		N/A
	Company Tier 1 (Core) Capital to average assets	$	69,530		9.78	%	$	28,449		4	%		N/A		N/A
	Bank Total Risk-Based Capital to risk weighted assets	$	73,305		14.59	%	$	40,192		8	%	$	50,239		10	%
	Bank Tier 1 (Core) Capital to risk weighted assets	$	68,405		13.62	%	$	20,096		4	%	$	30,144		6	%
	Tier 1 (Core) Capital to average assets	$	68,405		9.62	%	$	28,455		4	%	$	35,569		5	%

Fair_Value_Tables

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis, including financial assets and liabilities for which the Company has elected the fair value option, are summarized below:
		Fair Value Measurements at
		December 31, 2014 Using:
		Quoted Prices		Significant			Significant
		in Active		Other			Unobservable
		Markets for		Observable			Inputs
		Identical Assets		Inputs			(Level 3)
		(Level 1)		(Level 2)
	Financial Assets
	Securities available for sale
	U.S. government sponsored entities and agencies	$	—	$	30,173		$	—
	U.S. Treasury Bills		20,000		—			—
	Mortgage-backed securities-residential		—		339,067			—
	Mortgage-backed securities-commercial		—		6,465			—
	State and political subdivisions		—		—			—
	Total securities available for sale	$	20,000	$	375,705		$	—
	Loans held for sale	$	—	$	18,462		$	—
	Mortgage banking derivatives	$	—	$	285		$	—
	Financial Liabilities
	Mortgage banking derivatives	$	—	$	132		$	—
		Fair Value Measurements at
		December 31, 2013 Using:
		Quoted Prices		Significant			Significant
		in Active		Other			Unobservable
		Markets for		Observable			Inputs
		Identical Assets		Inputs			(Level 3)
		(Level 1)		(Level 2)
	Financial Assets
	Securities available for sale
	U.S. government sponsored entities and agencies	$	—	$	14,724		$	—
	Mortgage-backed securities-residential		—		253,791			—
	Total securities available for sale	$	—	$	268,515		$	—
	Mortgage banking derivatives	$	—	$	464		$	—
Assets Measured at Fair Value on Non-Recurring Basis	Assets measured at fair value on a non-recurring basis are summarized below:
		Fair Value Measurements at
		December 31, 2013 Using:
		Quoted Prices		Significant			Significant
		in Active		Other			Unobservable
		Markets for		Observable			Inputs
		Identical Assets		Inputs			(Level 3)
		(Level 1)		(Level 2)
	Impaired loans with specific allocations
	Real estate:
	Residential	$	—	$	—		$	1,133
	Commercial		—		—			920
Quantitative Information about Recurring Level 3 Fair Value Measurements	The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2013:
		Fair		Valuation		Unobservable	Range
		Value		Technique(s)			(Weighted
						Input(s)	Average)
	Impaired loans:
	Residential real estate	$	1,133	Sales comparison		Adjustment for	3%-27%(16%)
						differences between
						comparable sales
	Commercial real estate	$	920	Sales comparison		Adjustment for	0%-16%(16%)
						differences between
						comparable sales
Carrying Amount and Estimated Fair Value of Financial Instruments	The carrying amounts and estimated fair values of financial instruments, at December 31, 2014 and 2013 are as follows:
				Fair Value Measurements at
		Carrying		December 31, 2014 Using:
		Amount		Level 1			Level 2		Level 3		Total
	Financial assets
	Cash and cash equivalents	$	49,347	$	49,347		$	—	$	—	$	49,347
	Securities available for sale		395,705		20,000			375,705		—		395,705
	Certificates of deposit held at other financial institutions		250		—			250		—		250
	Securities held to maturity		53,332		—			53,741		—		53,741
	Loans held for sale		18,462		—			18,462		—		18,462
	Net loans		780,508		—			—		782,745		782,745
	Restricted equity securities		5,349		n/a			n/a		n/a		n/a
	Servicing rights, net		3,053		—			4,180		—		4,180
	Accrued interest receivable		3,545		—			1,368		2,177		3,545
	Financial liabilities
	Deposits	$	1,172,233	$	848,158		$	326,644	$	—	$	1,174,802
	Federal funds purchased and repurchase agreements		39,078		—			39,078		—		39,078
	Federal Home Loan Bank advances		19,000		—			19,146		—		19,146
	Accrued interest payable		421		33			388		—		421
		Carrying		Fair Value Measurements at
		Amount		December 31, 2013 Using:
				Level 1			Level 2		Level 3		Total
	Financial assets
	Cash and cash equivalents	$	18,217	$	18,217		$	—	$	—	$	18,217
	Securities available for sale		268,515		—			268,515		—		268,515
	Securities held to maturity		56,575		—			54,004		—		54,004
	Loans held for sale		10,694		—			10,694		—		10,694
	Net loans		416,404		—			—		415,515		415,515
	Restricted equity securities		3,032		n/a			n/a		n/a		n/a
	Mortgage servicing rights		2,640		—			3,714		—		3,714
	Accrued interest receivable		2,396		—			1,145		1,251		2,396
	Financial liabilities
	Deposits	$	681,300	$	480,000		$	202,300	$	—	$	682,300
	Federal funds purchased and repurchase agreements		24,291		—			24,291		—		24,291
	Federal Home Loan Bank advances		23,000		—			23,023		—		23,023
	Accrued interest payable		222		17			205		—		222

Mortgage_Banking_Derivatives_T

Mortgage Banking Derivatives (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Summary of Net Gains (Losses) Relating to Free-Standing Derivative Instruments Used for Risk Management	The net gains (losses) relating to free-standing derivative instruments used for risk management is summarized below:
		2014			2013
	Forward contracts related to mortgage loans held for sale and interest rate contracts	$	(411	)	$	321
	Interest rate contracts for customers		100			(427	)
Summary of Amount and Market Value of Mortgage Banking Derivatives Included in Consolidated Balance Sheet	The following table reflects the amount and market value of mortgage banking derivatives included in the consolidated balance sheet as of December 31:
		2014						2013
		Notional			Fair			Notional		Fair
		Amount			Value			Amount		Value
	Included in other assets (liabilities):
	Interest rate contracts for customers	$	28,182		$	285		$	25,789	$	185
	Forward contracts related to	$	36,849		$	(132	)	$	27,288	$	279
	mortgage loans held for sale

Loan_Commitments_and_Other_Rel1

Loan Commitments and Other Related Activities (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Contractual Amounts of Financial Instruments with Off-Balance-Sheet Risk	The contractual amounts of financial instruments with off-balance-sheet risk at year end were as follows:
		2014				2013
		Fixed		Variable		Fixed		Variable
		Rate		Rate		Rate		Rate
	Commitments to make loans	$	27,907	$	275	$	25,189	$	600
	Unused lines of credit		91,301		137,237		53,052		76,166
	Standby letters of credit		1,679		10,410		688		4,961

Parent_Company_Only_Condensed_1

Parent Company Only Condensed Financial Information (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	CONDENSED BALANCE SHEETS
		December 31,
		2014			2013
	ASSETS
	Cash and cash equivalents	$	496		$	718
	Investment in banking subsidiaries		121,154			63,881
	Investment in and advances to other subsidiaries		—			275
	Other assets		300			348
	Total assets	$	121,950		$	65,222
	LIABILITIES AND EQUITY
	Accrued expenses and other liabilities	$	151		$	59
	Shareholders’ equity		121,799			65,163
	Total liabilities and shareholders’ equity	$	121,950		$	65,222
Condensed Statements of Income	CONDENSED STATEMENTS OF INCOME
		Years ended December 31,
		2014			2013
	Dividends from subsidiaries	$	575		$	25
	Other income		235			170
	Other expense		1,499			725
	Loss before income tax and undistributed subsidiary income		(689	)		(530	)
	Income tax expense (benefit)		(324	)		(175	)
	Equity in undistributed subsidiary income		8,779			4,916
	Net income	$	8,414		$	4,561
Condensed Statements of Cash Flows	CONDENSED STATEMENTS OF CASH FLOWS
		Years ended December 31,
		2014			2013
	Cash flows from operating activities
	Net income	$	8,414		$	4,561
	Adjustments:
	Equity in undistributed subsidiary income		(8,779	)		(4,916	)
	Excess tax benefit related to the exchange of stock options		(29	)		(11	)
	Stock-based compensation		39			81
	Compensation expense related to common stock issued to 401(k) plan		15			10
	Loss on disposal of subsidiary		32			—
	Change in other assets		77			(74	)
	Change in other liabilities		92			(53	)
	Net cash from operating activities		(139	)		(402	)
	Cash flows from investing activities
	Investments in subsidiaries		(12,396	)		(13,773	)
	Net cash acquired from acquisition		12,197			—
	Net cash from the disposal of subsidiary		205			—
	Net cash from investing activities		6			(13,773	)
	Cash flows from financing activities
	Proceeds from exercise of common stock warrants		—			36
	Proceeds from exercise of common stock options		265			58
	Cash paid for stock option exchange, including tax benefit		—			11
	Proceeds from issuance of common stock, net		(514	)		14,191
	Proceeds from subsidiaries related to issuance of common stock related to 401(k) plan		260			—
	Dividends paid on preferred stock		(100	)		(109	)
	Net cash from financing activities		(89	)		14,187
	Net change in cash and cash equivalents		(222	)		12
	Beginning cash and cash equivalents		718			706
	Ending cash and cash equivalents	$	496		$	718
	Non-cash supplemental information:
	Transfers from subsidiary stock based compensation expense to parent company only additional paid-in capital	$	572		$	430
	Fair value of stock and stock options issued related to MidSouth Bank acquisition (See Note 2)		40,976			—

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of Earning per Share	The factors used in the earnings per share computation follow:
		Year Ended
		December 31,
		2014			2013
	Basic
	Net income available to common shareholders	$	8,314		$	4,452
	Less: earnings allocated to participating securities		(94	)		(20	)
	Net income allocated to common shareholders	$	8,220		$	4,432
	Weighted average common shares outstanding including participating securities		6,320,316			3,933,731
	Less: Participating securities		(71,586	)		(17,563	)
	Average shares		6,248,730			3,916,168
	Basic earnings per common share	$	1.32		$	1.13
	Diluted
	Net income allocated to common shareholders	$	8,220		$	4,432
	Weighted average common shares outstanding for basic earnings per common share		6,248,730			3,916,168
	Add: Dilutive effects of assumed exercises of stock options		230,290			102,027
	Add: Dilutive effects of assumed exercises of stock warrants		6,810			2,481
	Average shares and dilutive potential common shares		6,485,830			4,020,676
	Dilutive earnings per common share	$	1.27		$	1.1

Capital_Offering_Tables

Capital Offering (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Schedule of Net Proceeds	Net proceeds were as follows:
	Gross proceeds	$	15,000
	Stock offering costs		(809	)
	Proceeds from issuance of common stock, net	$	14,191

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Date of acquisition	1-Jul-14
Maturity of cash, deposits with other financial institutions	90 days
Loan past due	90 days
Nonaccrual loans and loans past due	90 days
Non-accrual status	90 days
Tax benefit	50.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of intangible assets	7 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of intangible assets	10 years

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	12 Months Ended	0 Months Ended		9 Months Ended
	Dec. 31, 2014	Jul. 01, 2014	Jun. 30, 2014	Sep. 30, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Acquisition completed date	1-Jul-14
Goodwill	$9,124,000				$157,000
Aggregate amortization expense	362,000				0
Acquisition related costs	2,157,000
Discount accretion	1,478,000
Premium amortization related to the fair value adjustments	250,000
Dissenting Preferred Shares [Member]
Business Acquisition [Line Items]
Common stock issued		7,427
MidSouth Bank [Member]
Business Acquisition [Line Items]
Acquisition completed date	1-Jul-14
Name of the acquired entity	MidSouth Bank
Acquisition agreement date	19-Nov-13
Goodwill		9,124,000
Business acquisition, percentage of shares acquired		100.00%
Lieu of fractional shares description	In lieu of issuing fractional shares of FFN common stock, FFN paid former MidSouth shareholders an amount in cash determined by multiplying (i) $13.50 by (ii) the fraction of a share (rounded to the nearest ten thousandth when expressed in decimal form) of FFN common stock.
Common stock issued		2,766,191
Total consideration paid		41,094,000
Loans acquired at fair value			184,345,000
Estimated discount to outstanding principal loan balance, value			7,347,000
Acquired loans with credit impaired	5,527,000
Core deposit intangible		3,060,000
MidSouth Bank [Member] | Dissenting Preferred Shares [Member]
Business Acquisition [Line Items]
Cash consideration paid		100,000
MidSouth Bank [Member] | Fractional Shares [Member]
Business Acquisition [Line Items]
Cash consideration paid		18,000
MidSouth Bank [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Shares received by acquiree		0.425926
MidSouth Bank [Member] | Preferred Stock [Member]
Business Acquisition [Line Items]
Shares received by acquiree		0.851852
MidSouth Bank [Member] | Series 2009-A Stock Warrants [Member]
Business Acquisition [Line Items]
Shares received by acquiree		0.18
MidSouth Bank [Member] | Series 2011-A Stock Warrants [Member]
Business Acquisition [Line Items]
Shares received by acquiree		0.146667
MidSouth Bank [Member] | Core Deposit Intangibles [Member]
Business Acquisition [Line Items]
Core deposit intangible		3,060,000
Estimated economic life				8 years 2 months 12 days

Acquisitions_Summary_of_Purcha

Acquisitions - Summary of Purchase Price Calculation (Detail) (USD $)	0 Months Ended
In Thousands, except Share data, unless otherwise specified	Jul. 01, 2014
MidSouth Bank [Member]
Business Acquisition [Line Items]
Total FFN common shares exchanged, net	2,766,191
Total Stock Consideration-Fair value of FFN common stock issued	$40,110
Fair value of FFN stock options granted to MidSouth option holders	866
Total acquisition consideration	41,094
MidSouth Bank [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common shares, number of MidSouth shares Outstanding	3,873
Purchase price, per share exchange Ratio	0.425926
Total FFN common shares exchanged, net	1,650
Multiplied by FFN common stock value per share	$14.50
MidSouth Bank [Member] | Convertible Voting Preferred Stock, 2009-A [Member]
Business Acquisition [Line Items]
Convertible voting preferred stock, number of MidSouth shares outstanding	1,018
Purchase price, per share exchange Ratio	0.851852
Total FFN common shares exchanged, net	867
MidSouth Bank [Member] | Convertible Voting Preferred Stock, 2011-A [Member]
Business Acquisition [Line Items]
Convertible voting preferred stock, number of MidSouth shares outstanding	242
Purchase price, per share exchange Ratio	0.851852
Total FFN common shares exchanged, net	206
MidSouth Bank [Member] | Series 2009-A Stock Warrants [Member]
Business Acquisition [Line Items]
Stock warrants, number of MidSouth Shares Outstanding	193
Purchase price, per share exchange Ratio	0.185185
Total FFN common shares exchanged, net	36
MidSouth Bank [Member] | Series 2011-A Stock Warrants [Member]
Business Acquisition [Line Items]
Stock warrants, number of MidSouth Shares Outstanding	44
Purchase price, per share exchange Ratio	0.153333
Total FFN common shares exchanged, net	7
Fractional Shares [Member] | MidSouth Bank [Member]
Business Acquisition [Line Items]
Cash consideration paid	18
Dissenting Preferred Shares [Member]
Business Acquisition [Line Items]
Total FFN common shares exchanged, net	7,427
Dissenting Preferred Shares [Member] | MidSouth Bank [Member]
Business Acquisition [Line Items]
Cash consideration paid	$100

Acquisitions_Summary_of_Purcha1

Acquisitions - Summary of Purchase Price Calculation (Parenthetical) (Detail) (MidSouth Bank [Member], USD $)	Jul. 01, 2014
Series 2009-A Stock Warrants [Member]
Business Acquisition [Line Items]
Stock warrants strike price	$3.25
Series 2011-A Stock Warrants [Member]
Business Acquisition [Line Items]
Stock warrants strike price	$3.68

Acquisitions_Summary_of_Prelim

Acquisitions - Summary of Preliminary Estimates of Fair Value of the Assets Purchased, Including Goodwill and Liabilities Assumed (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jul. 01, 2014
In Thousands, unless otherwise specified
Assets
Goodwill	$9,124	$157
MidSouth Bank [Member]
Assets
Cash and due from banks			1,369
Interest-bearing accounts at other financial institutions			10,946
Securities, available-for-sale			57,431
Loans held for sale			7,071
Loans			184,345
Certificates of deposit at other financial institutions			250
Restricted equity securities			1,572
Bank premises and equipment, net			6,650
Bank-owned life insurance			3,144
Accrued interest receivable			728
Foreclosed assets			540
Core deposit intangible			3,060
Deferred tax asset			6,853
Goodwill			9,124
Other assets			747
Total assets acquired			293,830
Liabilities
Deposits			244,415
Short-term borrowings			6,893
Other liabilities			1,428
Total liabilities assumed			252,736
MidSouth Bank [Member] | As Initially Reported [Member]
Assets
Cash and due from banks			1,369
Interest-bearing accounts at other financial institutions			10,946
Securities, available-for-sale			57,431
Loans held for sale			7,071
Loans			184,345
Certificates of deposit at other financial institutions			250
Restricted equity securities			1,572
Bank premises and equipment, net			6,650
Bank-owned life insurance			3,144
Accrued interest receivable			728
Foreclosed assets			800
Core deposit intangible			3,060
Deferred tax asset			6,753
Goodwill			8,964
Other assets			747
Total assets acquired			293,830
Liabilities
Deposits			244,415
Short-term borrowings			6,893
Other liabilities			1,428
Total liabilities assumed			252,736
MidSouth Bank [Member] | Measurement Period Adjustments [Member]
Assets
Foreclosed assets			-260
Deferred tax asset			100
Goodwill			$160

Acquisitions_Contractually_Req

Acquisitions - Contractually Required Principal and Interest Cash Payments, Management's Estimates of Expected Total Cash Payments (Detail) (USD $)	Dec. 31, 2014	Jul. 01, 2014
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Contractually required principal and interest	$6,532
MidSouth Bank [Member]
Business Acquisition [Line Items]
Contractually required principal and interest		8,510
Non-accretable difference		-1,745
Cash flows expected to be collected		6,765
Accretable yield		-1,238
Total purchased credit-impaired loans		$5,527

Acquisitions_Summary_of_Fair_V

Acquisitions - Summary of Fair Value of Acquired Loans and Unpaid Principal Balance (Detail) (MidSouth Bank [Member], USD $)	Jul. 01, 2014
In Thousands, unless otherwise specified
Unpaid Principal Value [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	$191,692
Unpaid Principal Value [Member] | Residential Real Estate [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	39,425
Unpaid Principal Value [Member] | Commercial Real Estate [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	82,465
Unpaid Principal Value [Member] | Construction and Land Development [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	43,766
Unpaid Principal Value [Member] | Commercial Loans [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	16,311
Unpaid Principal Value [Member] | Consumer and Other Loans [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	1,865
Unpaid Principal Value [Member] | Purchased Credit Impaired [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	7,860
Fair Value [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	184,345
Fair Value [Member] | Residential Real Estate [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	38,618
Fair Value [Member] | Commercial Real Estate [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	80,566
Fair Value [Member] | Construction and Land Development [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	42,454
Fair Value [Member] | Commercial Loans [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	15,352
Fair Value [Member] | Consumer and Other Loans [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	1,828
Fair Value [Member] | Purchased Credit Impaired [Member]
Business Acquisition [Line Items]
Unpaid principal amount and Fair value of acquired loans	$5,527

Acquisitions_Schedule_of_Acqui

Acquisitions - Schedule of Acquired Intangible Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Core deposit intangibles, Gross Carrying Amount	$3,060,000
Core deposit intangibles, Accumulated Amortization	($362,000)	$0

Acquisitions_Schedule_of_Estim

Acquisitions - Schedule of Estimated Amortization Expense (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]
2015	$480
2016	480
2017	480
MidSouth Bank [Member]
Finite-Lived Intangible Assets [Line Items]
2015	655
2016	564
2017	473
2018	382
2019	$291

Acquisitions_ProForma_Financia

Acquisitions - Pro-Forma Financial Information and Actual Results of Acquisition (Detail) (MidSouth Bank [Member], USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
MidSouth Bank [Member]
Business Acquisition [Line Items]
Net interest income	$41,312	$32,022
Net income available to common shareholders	$8,055	$5,722
Earnings per share-basic	$1.04	$0.88
Earnings per share-diluted	$1.02	$0.87

Securities_Summary_of_Amortize

Securities - Summary of Amortized Cost and Fair Value of Available for Sale Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$392,179	$275,860
Gross Unrealized Gains	5,043	1,560
Gross Unrealized Losses	-1,517	-8,905
Fair Value	395,705	268,515
U.S. Government Sponsored Entities and Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	30,070	16,029
Gross Unrealized Gains	417
Gross Unrealized Losses	-314	-1,305
Fair Value	30,173	14,724
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	20,000
Fair Value	20,000
Mortgage-Backed Securities: Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	335,677	259,831
Gross Unrealized Gains	4,593	1,560
Gross Unrealized Losses	-1,203	-7,600
Fair Value	339,067	253,791
Mortgage-Backed Securities: Commercial [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,432
Gross Unrealized Gains	33
Fair Value	$6,465

Securities_Schedule_of_Amortiz

Securities - Schedule of Amortized Cost and Fair Value of Held to Maturity Securities Portfolio (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$53,332	$56,575
Gross Unrecognized Gains	1,068	394
Gross Unrecognized Losses	-659	-2,965
Fair Value	53,741	54,004
U.S. Government Sponsored Entities and Agencies [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	5,550	8,225
Gross Unrecognized Gains	162	12
Gross Unrecognized Losses	-87	-484
Fair Value	5,625	7,753
Mortgage-Backed Securities: Residential [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	38,587	39,043
Gross Unrecognized Gains	555	293
Gross Unrecognized Losses	-562	-2,061
Fair Value	38,580	37,275
State and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	9,195	9,307
Gross Unrecognized Gains	351	89
Gross Unrecognized Losses	-10	-420
Fair Value	$9,536	$8,976

Securities_Summary_of_Sales_of

Securities - Summary of Sales of Available for Sale Securities (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Available-for-sale Securities [Abstract]
Proceeds	$44,181	$16,290
Gross gains	422	163
Gross losses	($163)	($75)

Securities_Schedule_of_Amortiz1

Securities - Schedule of Amortized Cost and Fair Value of Investment Securities Portfolio by Contractual Maturity (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Available for sale
Amortized Cost, Three months or less	$30,000
Amortized Cost, Over three months through one year	0
Amortized Cost, Over one year through five years	0
Amortized Cost, Over five years through ten years	7,796
Amortized Cost, Over ten years	12,274
Amortized Cost	392,179	275,860
Held to maturity
Amortized Cost, Three months or less	250
Amortized Cost, Over one year through five years	1,419
Amortized Cost, Over five years through ten years	1,106
Amortized Cost, Over ten years	11,970
Amortized Cost, Mortgage-backed securities: residential	38,587
Amortized Cost	53,332	56,575
Available for sale
Fair Value, Three months or less	29,999
Fair Value, Over three months through one year	0
Fair Value, Over one year through five years	0
Fair Value, Over five years through ten years	7,948
Fair Value, Over ten years	12,226
Fair Value, Mortgage-backed securities	6,465
Fair Value, Mortgage-backed securities	339,067
Fair Value, Total	395,705	268,515
Held to maturity
Fair Value, Three months or less	251
Fair Value, Over one year through five years	1,478
Fair Value, Over five years through ten years	1,127
Fair Value, Over ten years	12,305
Fair Value, Mortgage-backed securities: residential	38,580
Fair Value, Total	53,741	54,004
Mortgage-Backed Securities: Commercial [Member]
Available for sale
Amortized Cost, Mortgage-backed securities	6,432
Amortized Cost	6,432
Available for sale
Fair Value, Total	6,465
Mortgage-Backed Securities: Residential [Member]
Available for sale
Amortized Cost, Mortgage-backed securities	335,677
Amortized Cost	335,677	259,831
Held to maturity
Amortized Cost	38,587	39,043
Available for sale
Fair Value, Total	339,067	253,791
Held to maturity
Fair Value, Total	$38,580	$37,275

Securities_Additional_Informat

Securities - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Carrying value of pledged securities	$366,764,000	$194,925,000
Other than US Government Sponsored Entities and Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amount of holdings of securities of any one issuer	$0	$0

Securities_Schedule_of_Unreali

Securities - Schedule of Unrealized Losses and Fair Value by Major Security Type (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	$69,077	$181,800
Less Than 12 Months Available for sale Unrealized Losses	-324	-7,890
12 Months or Longer Available for sale Fair Value	50,171	13,462
12 Months or Longer Available for sale Unrealized Losses	-1,193	-1,015
Available for sale Fair Value, Total	119,248	195,262
Available for sale Unrealized Losses, Total	-1,517	-8,905
Less Than 12 Months Held to maturity Fair Value	5,753	31,882
Less Than 12 Months Held to maturity Unrealized Losses	-26	-2,426
12 Months or Longer Held to maturity Fair Value	16,506	5,312
12 Months or Longer Held to maturity Unrealized Losses	-633	-539
Held to maturity Fair Value, Total	33,037	37,194
Held to maturity Unrealized Losses, Total	-659	-2,965
U.S. Government Sponsored Entities and Agencies [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	9,999	12,983
Less Than 12 Months Available for sale Unrealized Losses	-1	-1,128
12 Months or Longer Available for sale Fair Value	8,232	1,741
12 Months or Longer Available for sale Unrealized Losses	-313	-177
Available for sale Fair Value, Total	18,231	14,724
Available for sale Unrealized Losses, Total	-314	-1,305
Less Than 12 Months Held to maturity Fair Value		6,168
Less Than 12 Months Held to maturity Unrealized Losses		-332
12 Months or Longer Held to maturity Fair Value	2,913	848
12 Months or Longer Held to maturity Unrealized Losses	-87	-152
Held to maturity Fair Value, Total	2,913	7,016
Held to maturity Unrealized Losses, Total	-87	-484
Mortgage-Backed Securities: Residential [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Available for Sale Fair Value	59,078	168,817
Less Than 12 Months Available for sale Unrealized Losses	-323	-6,762
12 Months or Longer Available for sale Fair Value	41,939	11,721
12 Months or Longer Available for sale Unrealized Losses	-880	-838
Available for sale Fair Value, Total	101,017	180,538
Available for sale Unrealized Losses, Total	-1,203	-7,600
Less Than 12 Months Held to maturity Fair Value	5,246	19,952
Less Than 12 Months Held to maturity Unrealized Losses	-25	-1,752
12 Months or Longer Held to maturity Fair Value	13,001	4,042
12 Months or Longer Held to maturity Unrealized Losses	-537	-309
Held to maturity Fair Value, Total	18,247	23,994
Held to maturity Unrealized Losses, Total	-562	-2,061
State and Political Subdivisions [Member]
Schedule Of Held To Maturity And Available For Sale Securities [Line Items]
Less Than 12 Months Held to maturity Fair Value	507	5,762
Less Than 12 Months Held to maturity Unrealized Losses	-1	-342
12 Months or Longer Held to maturity Fair Value	592	422
12 Months or Longer Held to maturity Unrealized Losses	-9	-78
Held to maturity Fair Value, Total	1,099	6,184
Held to maturity Unrealized Losses, Total	($10)	($420)

Loans_Summary_of_Loans_Detail

Loans - Summary of Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aging of Recorded Investment, Total	$783,932	$422,025
Deferred loan fees, net	-1,059	-721
Total loans that are not PCI loans	782,873	421,304
Loans	4,315
Allowance for loan losses	-6,680	-4,900	-3,983
Total loans, net of allowance for loan losses	780,508	416,404
PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,315
Construction and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Construction and land development	239,225	113,710
Aging of Recorded Investment, Total	239,225	113,710
Loans	77
Allowance for loan losses	-2,690	-1,552	-1,342
Construction and Land Development [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	77
Commercial Real Estate Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonfarm, nonresidential	240,975	114,852
Aging of Recorded Investment, Total	240,975	114,852
Commercial Real Estate Financing Receivable [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,798
Commercial Real Estate, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other	5,377	10,350
Aging of Recorded Investment, Total	5,377	10,350
Real Estate Residential 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Closed end 1-4 family	130,631	98,615
Aging of Recorded Investment, Total	130,631	98,615
Real Estate Residential 1-4 Family [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	706
Residential Real Estate, Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other	83,129	39,851
Aging of Recorded Investment, Total	83,129	39,851
Residential Real Estate, Other [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	108
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	76,570	36,397
Aging of Recorded Investment, Total	76,570	36,397
Loans	1,624
Allowance for loan losses	-650	-337	-275
Commercial and Industrial [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,624
Consumer Other Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Consumer and other	8,025	8,250
Aging of Recorded Investment, Total	8,025	8,250
Loans	2
Allowance for loan losses	-55	-98	-206
Consumer Other Financing Receivable [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$2

Loans_Activity_in_Allowance_fo

Loans - Activity in Allowance for Loan Losses by Portfolio Segment (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Allowance For Loan Losses [Line Items]
Beginning balance	$4,900	$3,983
Provision for loan losses	2,374	907
Loans charged-off	-659	-126
Recoveries	65	136
Total ending allowance balance	6,680	4,900
Construction and Land Development [Member]
Allowance For Loan Losses [Line Items]
Beginning balance	1,552	1,342
Provision for loan losses	1,138	210
Total ending allowance balance	2,690	1,552
Commercial Real Estate [Member]
Allowance For Loan Losses [Line Items]
Beginning balance	1,511	1,267
Provision for loan losses	523	244
Loans charged-off	-540
Total ending allowance balance	1,494	1,511
Residential Portfolio Segment [Member]
Allowance For Loan Losses [Line Items]
Beginning balance	1,402	893
Provision for loan losses	385	480
Loans charged-off	-61	-107
Recoveries	65	136
Total ending allowance balance	1,791	1,402
Commercial and Industrial [Member]
Allowance For Loan Losses [Line Items]
Beginning balance	337	275
Provision for loan losses	371	81
Loans charged-off	-58	-19
Total ending allowance balance	650	337
Consumer Other Financing Receivable [Member]
Allowance For Loan Losses [Line Items]
Beginning balance	98	206
Provision for loan losses	-43	-108
Total ending allowance balance	$55	$98

Loans_Additional_Information_D

Loans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jul. 01, 2014
Loans [Line Items]
Allowance for loan losses for PCI loans	$0	$0
Unpaid principal amount	2,533,000	6,189,000
Accretion income from accretable yield	216,000
PCI Loans [Member]
Loans [Line Items]
Estimated credit discount			5,014,000
Estimated fair value			178,818,000
Unpaid principal amount			$183,832,000

Loans_Allowance_for_Loan_Losse

Loans - Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment and Based on Impairment Method (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Individually evaluated for impairment	$18	$548
Allowance for loan losses, Collectively evaluated for impairment	6,662	4,352
Total ending allowance balance	6,680	4,900	3,983
Purchased credit-impaired loans	0
Total ending allowance balance	6,680	4,900	3,983
Loans, Individually evaluated for impairment	946	4,623
Loans, Collectively evaluated for impairment	782,986	417,402
Purchased credit-impaired loans	4,315
Total ending loans balance	788,247	422,025
Construction and Land Development [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Collectively evaluated for impairment	2,690	1,552
Total ending allowance balance	2,690	1,552	1,342
Purchased credit-impaired loans	0
Total ending allowance balance	2,690	1,552	1,342
Loans, Collectively evaluated for impairment	239,225	113,710
Purchased credit-impaired loans	77
Total ending loans balance	239,302	113,710
Commercial Real Estate [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Individually evaluated for impairment		455
Allowance for loan losses, Collectively evaluated for impairment	1,494	1,056
Total ending allowance balance	1,494	1,511	1,267
Purchased credit-impaired loans	0
Total ending allowance balance	1,494	1,511	1,267
Loans, Individually evaluated for impairment	835	3,361
Loans, Collectively evaluated for impairment	245,517	121,841
Purchased credit-impaired loans	1,798
Total ending loans balance	248,150	125,202
Residential Portfolio Segment [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Individually evaluated for impairment		93
Allowance for loan losses, Collectively evaluated for impairment	1,791	1,309
Total ending allowance balance	1,791	1,402	893
Purchased credit-impaired loans	0
Total ending allowance balance	1,791	1,402	893
Loans, Individually evaluated for impairment	93	1,262
Loans, Collectively evaluated for impairment	213,667	137,204
Purchased credit-impaired loans	814
Total ending loans balance	214,574	138,466
Commercial and Industrial [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Individually evaluated for impairment	18
Allowance for loan losses, Collectively evaluated for impairment	632	337
Total ending allowance balance	650	337	275
Purchased credit-impaired loans	0
Total ending allowance balance	650	337	275
Loans, Individually evaluated for impairment	18
Loans, Collectively evaluated for impairment	76,552	36,397
Purchased credit-impaired loans	1,624
Total ending loans balance	78,194	36,397
Consumer Other Financing Receivable [Member]
Allowance For Loan Losses And Recorded Investment In Loans [Line Items]
Allowance for loan losses, Collectively evaluated for impairment	55	98
Total ending allowance balance	55	98	206
Purchased credit-impaired loans	0
Total ending allowance balance	55	98	206
Loans, Collectively evaluated for impairment	8,025	8,250
Purchased credit-impaired loans	2
Total ending loans balance	$8,027	$8,250

Loans_Summary_of_Impaired_Loan

Loans - Summary of Impaired Loans by Class of Loans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	$2,515	$2,022
Unpaid Principal Balance	2,533	6,189
Recorded Investment, With no allowance recorded	928	2,022
Recorded Investment	946	4,623
Unpaid Principal Balance, With an allowance recorded	18	4,167
Recorded Investment, With an allowance recorded	18	2,601
Allowance for Loan Losses Allocated	18	548
Average Recorded Investment, With no allowance recorded	683	2,023
Average Recorded Investment, With an allowance recorded	1,305	2,601
Average Recorded Investment	1,988	4,624
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	93
Recorded Investment, With no allowance recorded	93
Unpaid Principal Balance, With an allowance recorded	18
Recorded Investment, With an allowance recorded	18
Allowance for Loan Losses Allocated	18
Average Recorded Investment, With no allowance recorded	2
Average Recorded Investment, With an allowance recorded	53
Commercial Real Estate Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded	2,422	1,986
Recorded Investment, With no allowance recorded	835	1,986
Unpaid Principal Balance, With an allowance recorded		2,480
Recorded Investment, With an allowance recorded		1,375
Allowance for Loan Losses Allocated		455
Average Recorded Investment, With no allowance recorded	587	1,986
Average Recorded Investment, With an allowance recorded	893	1,375
Real Estate Residential 1-4 Family [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no allowance recorded		36
Recorded Investment, With no allowance recorded		36
Unpaid Principal Balance, With an allowance recorded		1,687
Recorded Investment, With an allowance recorded		1,226
Allowance for Loan Losses Allocated		93
Average Recorded Investment, With no allowance recorded	94	37
Average Recorded Investment, With an allowance recorded	$359	$1,226

Loans_Schedule_of_Recorded_Inv

Loans - Schedule of Recorded Investment in Nonaccrual and Loans Past Due Over 90 Days on Accrual by Class of Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Financing Receivable Recorded Investment Nonaccrual Loans [Line Items]
Recorded Investment, Nonaccrual	$835	$2,601
Recorded Investment, Loans Past Due Over 90 Days	316
Commercial Real Estate Financing Receivable [Member]
Financing Receivable Recorded Investment Nonaccrual Loans [Line Items]
Recorded Investment, Nonaccrual	835	1,375
Real Estate Residential 1-4 Family [Member]
Financing Receivable Recorded Investment Nonaccrual Loans [Line Items]
Recorded Investment, Nonaccrual		1,226
Recorded Investment, Loans Past Due Over 90 Days	$316

Loans_Schedule_of_Aging_of_Rec

Loans - Schedule of Aging of Recorded Investment in Past Due Loans by Class of Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, 30-59 Days Past Due	$705	$2,230
Aging of Recorded Investment, 60-89 Days Past Due	377
Aging of Recorded Investment, Greater Than 89 Days Past Due	1,151	2,601
Aging of Recorded Investment, Total Past Due	2,233	4,831
Aging of Recorded Investment, Loans Not Past Due	781,699	417,194
Aging of Recorded Investment, PCI Loans	4,315
Aging of Recorded Investment, Total	783,932	422,025
Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, 30-59 Days Past Due	354
Aging of Recorded Investment, Total Past Due	354
Aging of Recorded Investment, Loans Not Past Due	238,871	113,710
Aging of Recorded Investment, PCI Loans	77
Aging of Recorded Investment, Total	239,225	113,710
Commercial Real Estate Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, 30-59 Days Past Due		1,985
Aging of Recorded Investment, Greater Than 89 Days Past Due	835	1,375
Aging of Recorded Investment, Total Past Due	835	3,360
Aging of Recorded Investment, Loans Not Past Due	240,140	111,492
Aging of Recorded Investment, Total	240,975	114,852
Commercial Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Loans Not Past Due	5,377	10,350
Aging of Recorded Investment, Total	5,377	10,350
Real Estate Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, 30-59 Days Past Due	229	245
Aging of Recorded Investment, 60-89 Days Past Due	165
Aging of Recorded Investment, Greater Than 89 Days Past Due	316	1,226
Aging of Recorded Investment, Total Past Due	780	1,471
Aging of Recorded Investment, Loans Not Past Due	129,851	97,144
Aging of Recorded Investment, Total	130,631	98,615
Residential Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, 30-59 Days Past Due	52
Aging of Recorded Investment, Total Past Due	52
Aging of Recorded Investment, Loans Not Past Due	83,077	39,851
Aging of Recorded Investment, Total	83,129	39,851
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, 60-89 Days Past Due	212
Aging of Recorded Investment, Total Past Due	212
Aging of Recorded Investment, Loans Not Past Due	76,358	36,397
Aging of Recorded Investment, PCI Loans	1,624
Aging of Recorded Investment, Total	76,570	36,397
Consumer Other Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, Loans Not Past Due	8,025	8,250
Aging of Recorded Investment, PCI Loans	2
Aging of Recorded Investment, Total	8,025	8,250
PCI Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	4,315
PCI Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	77
PCI Loans [Member] | Commercial Real Estate Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	1,798
PCI Loans [Member] | Real Estate Residential 1-4 Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	706
PCI Loans [Member] | Residential Real Estate, Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	108
PCI Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	1,624
PCI Loans [Member] | Consumer Other Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aging of Recorded Investment, PCI Loans	$2

Loans_Summary_of_Risk_Category

Loans - Summary of Risk Category of Loans by Class of Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Risk Category Of Loans [Line Items]
Total Loans	$788,247	$422,025
Construction and Land Development [Member]
Risk Category Of Loans [Line Items]
Total Loans	239,302	113,710
Commercial Real Estate Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	242,773	114,852
Commercial Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	5,377	10,350
Real Estate Residential 1-4 Family [Member]
Risk Category Of Loans [Line Items]
Total Loans	131,337	98,615
Residential Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	83,237	39,851
Commercial and Industrial [Member]
Risk Category Of Loans [Line Items]
Total Loans	78,194	36,397
Consumer Other Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	8,027	8,250
Pass [Member]
Risk Category Of Loans [Line Items]
Total Loans	780,761	416,319
Pass [Member] | Construction and Land Development [Member]
Risk Category Of Loans [Line Items]
Total Loans	239,225	113,710
Pass [Member] | Commercial Real Estate Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	239,584	110,938
Pass [Member] | Commercial Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	5,377	10,350
Pass [Member] | Real Estate Residential 1-4 Family [Member]
Risk Category Of Loans [Line Items]
Total Loans	128,869	96,823
Pass [Member] | Residential Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	83,129	39,851
Pass [Member] | Commercial and Industrial [Member]
Risk Category Of Loans [Line Items]
Total Loans	76,552	36,397
Pass [Member] | Consumer Other Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	8,025	8,250
Substandard [Member]
Risk Category Of Loans [Line Items]
Total Loans	7,486	5,706
Substandard [Member] | Construction and Land Development [Member]
Risk Category Of Loans [Line Items]
Total Loans	77
Substandard [Member] | Commercial Real Estate Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	3,189	3,914
Substandard [Member] | Real Estate Residential 1-4 Family [Member]
Risk Category Of Loans [Line Items]
Total Loans	2,468	1,792
Substandard [Member] | Residential Real Estate, Other [Member]
Risk Category Of Loans [Line Items]
Total Loans	108
Substandard [Member] | Commercial and Industrial [Member]
Risk Category Of Loans [Line Items]
Total Loans	1,642
Substandard [Member] | Consumer Other Financing Receivable [Member]
Risk Category Of Loans [Line Items]
Total Loans	$2

Loans_Summary_of_Total_Contrac

Loans - Summary of Total Contractually Required Principal and Interest Cash Payments, Management's Estimate of Expected Total Cash Payments and Carrying Value of Loans (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Receivables [Abstract]
Contractually required principal and interest	$6,532
Non-accretable difference	-1,270
Cash flows expected to be collected	5,262
Accretable yield	-947
Carrying value of acquired loans	4,315
Allowance for loan losses	0
Carrying value less allowance for loan losses	$4,315

Loan_Servicing_Schedule_of_Loa

Loan Servicing - Schedule of Loans Serviced Not Reported as Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Loans Servicing For Institutional Investors [Line Items]
Loan portfolios serviced	$4,180	$3,714
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Loans Servicing For Institutional Investors [Line Items]
Loan portfolios serviced	414,222	348,121
Collateralized Mortgage Backed Securities [Member]
Loans Servicing For Institutional Investors [Line Items]
Loan portfolios serviced	$3,986	$5,088

Loan_Servicing_Additional_Info

Loan Servicing - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Transfers and Servicing [Abstract]
Escrow balances maintained	$1,968	$1,607
Fair value of servicing rights	$4,180	$3,714
Weighted average discount rate	10.50%	10.50%
Weighted average prepayment speed	10.80%	8.80%
Weighted average amortization period	6 years 4 months 13 days

Loan_Servicing_Related_Loan_Se

Loan Servicing - Related Loan Servicing Rights Activity (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Servicing Asset At Amortized Value Additional Disclosures [Abstract]
Beginning of year	$2,640	$2,401
Additions	1,140	1,414
Amortized to expense	-727	-1,265
Decrease in impairment		90
End of year	$3,053	$2,640

Loan_Servicing_Components_of_N

Loan Servicing - Components of Net Loan Servicing Fees (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Transfers and Servicing [Abstract]
Loan servicing fees	$981	$810
Amortization of loan servicing fees	-727	-1,265
Decrease in impairment		90
Total	$254	($365)

Loan_Servicing_Schedule_of_Est

Loan Servicing - Schedule of Estimated Amortization Expense (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
2015	$480
2016	480
2017	$480

Premises_and_Equipment_and_Rel2

Premises and Equipment and Related Party Leases - Summary of Premises and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$14,147	$7,764
Accumulated depreciation	-4,483	-3,626
Property plant and equipment net	9,664	4,138
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	1,128	1,044
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	693
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	1,170
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	4,804	2,438
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	4,129	2,594
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$2,223	$1,688

Premises_and_Equipment_and_Rel3

Premises and Equipment and Related Party Leases - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Jul. 01, 2014
			Buildings
Property Plant And Equipment Capitalized Interest Costs [Abstract]
Depreciation expense	$931	$653
Rent expense	2,049	1,311
Number of buildings agreed to sell			3
Assets held for sale	$4,080

Premises_and_Equipment_and_Rel4

Premises and Equipment and Related Party Leases - Summary of Operating Lease Rent Commitments Over the Initial Lease Terms and Intended Renewal Periods (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Operating And Capital Leases Revenues And Rent Expense [Line Items]
2015	$2,383
2016	2,335
2017	2,320
2018	2,304
2019	2,321
Thereafter	20,652
Total	32,315
MidSouth Bank [Member]
Operating And Capital Leases Revenues And Rent Expense [Line Items]
2015	313
2016	390
2017	431
2018	477
2019	527
Thereafter	6,926
Total	9,064
Related Parties [Member]
Operating And Capital Leases Revenues And Rent Expense [Line Items]
2015	1,798
2016	1,839
2017	1,865
2018	1,892
2019	1,919
Thereafter	17,255
Total	26,568
Related Parties [Member] | MidSouth Bank [Member]
Operating And Capital Leases Revenues And Rent Expense [Line Items]
2015	313
2016	390
2017	431
2018	477
2019	527
Thereafter	6,926
Total	9,064
Other [Member]
Operating And Capital Leases Revenues And Rent Expense [Line Items]
2015	585
2016	496
2017	455
2018	412
2019	402
Thereafter	3,397
Total	$5,747

Deposits_Additional_Informatio

Deposits - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fees And Commissions Income [Abstract]
Time Deposits, $250,000 or More	$105,711	$82,026
Deposit accounts in overdraft status reclassified to loans	$371	$116

Deposits_Schedule_of_Maturitie

Deposits - Schedule of Maturities of Time Deposits (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Maturities of Time Deposits [Abstract]
2015	$177,449
2016	60,154
2017	29,328
2018	19,242
2019	$35,008

Federal_Funds_Purchased_and_Re2

Federal Funds Purchased and Repurchase Agreements - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets Sold under Agreements to Repurchase [Line Items]
Federal Home Loan Bank, Advances, Maximum Amount Available	$38,699
Outstanding federal funds purchased	16,825	20,825
Securities sold under agreements to repurchase,outstanding balance	22,253	3,466
Secured by securities with carrying value	26,187	8,418
Federal Funds Purchased [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Federal Home Loan Bank, Advances, Maximum Amount Available	$115,400	$71,700

Federal_Funds_Purchased_and_Re3

Federal Funds Purchased and Repurchase Agreements - Summary of Information Concerning Securities Sold under Agreements to Repurchase (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Banking and Thrift [Abstract]
Average daily balance during the year	$12,792	$3,525
Average interest rate during the year	0.58%	0.71%
Maximum month-end balance during the year	$24,466	$5,077
Weighted average interest rate at year end	0.56%	0.73%

Federal_Home_Loan_Bank_Advance2

Federal Home Loan Bank Advances - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Federal Home Loan Bank, Advances [Line Items]
Advances received from the FHLB	19,000	$23,000
Loans pledged as security	148,612
Federal Home Loan Bank, Advances, Maximum Amount Available	38,699
Federal Home Loan Bank of Cincinnati [Member]
Federal Home Loan Bank, Advances [Line Items]
Percentage of residential 1-4 family loans equivalent to Carrying value of the loans pledged	125.00%

Federal_Home_Loan_Bank_Advance3

Federal Home Loan Bank Advances - Schedule of Maturities of Advances and Interest Rates (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Federal Home Loan Banks [Abstract]
2015	$2,000
2016	0
2017	10,000
2018	7,000
2019	0
Thereafter	0
Total	$19,000
2015	0.70%
2016	0.00%
2017	1.27%
2018	1.61%
2019	0.00%
Thereafter	0.00%
Total	1.33%

Benefit_Plans_Additional_Infor

Benefit Plans - Additional Information (Detail) (USD $)	12 Months Ended		0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	1-May-08
Postemployment Benefits Disclosure [Line Items]
Expense for the period	$387	$270
Employee Contribution Up to First 2% [Member]
Postemployment Benefits Disclosure [Line Items]
Contribution equivalent to the company's common stock			100.00%
Employee Contribution on Next 4% [Member]
Postemployment Benefits Disclosure [Line Items]
Contribution equivalent to the company's common stock			50.00%

Income_Taxes_Summary_of_Reconc

Income Taxes - Summary of Reconciliation of the Income Tax Expense Computed by Statutory Federal Income Tax Rate of 34 Percent to Income Before Income Tax Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Computed "expected" tax expense	$4,742	$2,480
State tax expense, net of federal tax effect	593	305
Effect of statutory rate changes enacted in the current year	-223
Non-deductible merger costs	150
Incentive stock options	104	19
Bank owned life insurance	-288	-268
Tax-exempt interest income, net of expense	-49	-40
Other	-82	62
Income tax expense	$5,134	$2,734

Income_Taxes_Component_of_Inco

Income Taxes - Component of Income Tax Expense Benefit (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current expense
Federal	$4,444	$2,613
State	820	517
Deferred expense
Federal	-222	-343
State	92	-53
Income tax expense	$5,134	$2,734

Income_Taxes_Sources_of_Deferr

Income Taxes - Sources of Deferred Income Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Organizational and start-up costs	$155	$170
Allowance for loan losses	1,343	1,718
Unrealized loss on securities		2,812
Net operating loss carry forward	5,290
Purchase accounting fair value adjustments	2,980
Accrued other expenses	340	116
Nonaccrual loan interest	538	195
Capital loss carryforward	95
Loan fees	396	266
Other	389	607
Deferred tax assets gross	11,526	5,689
Valuation allowance	-95
Total deferred tax assets	11,431	5,689
Deferred tax liabilities:
Mortgage servicing rights	-1,174	-975
Premises and equipment	-675	-468
Prepaid expenses	-177	-71
Unrealized gain on securities	-1,385
Purchase accounting fair value adjustments	-1,190
Mortgage banking derivatives	-1	-123
Other	-49	-57
Total deferred tax liabilities	-4,651	-1,694
Net deferred tax asset (liability)	$6,780	$3,995

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Line Items]
Uncertain tax positions	$0	$0
Interest and penalties	0	0
MidSouth Bank [Member]
Income Tax Disclosure [Line Items]
Net operating losses acquired from acquisition	$15,100,000
MidSouth Bank [Member] | Minimum [Member]
Income Tax Disclosure [Line Items]
Expiration date of net operating losses acquired from acquisition	2025
MidSouth Bank [Member] | Maximum [Member]
Income Tax Disclosure [Line Items]
Expiration date of net operating losses acquired from acquisition	2031

Related_Party_Transactions_Sch

Related Party Transactions - Schedule of Loans to Principal Officers, Directors, and Their Affiliates (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Related Party Transactions [Abstract]
Beginning balance	$6,752
New loans	2,279
Effect of changes in composition of related parties	0
Repayments	-4,495
Ending balance	$4,536

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Related Party Transaction [Line Items]
Deposits from principal officers, directors, and their affiliates	$7,047		5,543
Rent Expense	1,222	559
Downtown Franklin [Member]
Related Party Transaction [Line Items]
Lease agreement term			15 years
Lease agreement date			7-May-10
Berry Farms Branch [Member]
Related Party Transaction [Line Items]
Lease agreement term			15 years
Lease agreement date			12-Jun-13
Related Parties [Member]
Related Party Transaction [Line Items]
Construction of leasehold improvements	1,088		3,152
Procurement of various insurance policies	$70		212
Downtown Franklin Two [Member]
Related Party Transaction [Line Items]
Lease agreement term			15 years
Cool Springs Franklin [Member]
Related Party Transaction [Line Items]
Lease agreement term			15 years

ShareBased_Payments_Additional

Share-Based Payments - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended	1 Months Ended				9 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2007	Jul. 01, 2014	Jun. 30, 2014	Apr. 30, 2013	Feb. 28, 2015	Apr. 30, 2010	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants exercised	0	3,024
Cash proceeds on warrants exercised		$36
Intrinsic value of warrants exercised		3
Trigger value of 2010 warrant, price per share.	$15								$15
Warrants, contingent redemption price	$1								$1
Vesting period of shares			5 years
Number of shares authorized for issuance	615,086								615,086
Number of options granted			33,750
Number of options cancelled		166,448
Number of options exchanged for common stock		32,814
Cash awards		142
Common stock options converted	137,280
Exercise price of options	$11.32								$11.32
Share-based compensation arrangements by share-based payment award, estimated grant date fair value	$4.12	$1.92
Unrecognized compensation cost, nonvested stock options	671								671
Unrecognized compensation cost, period of recognition	1 year 7 months 6 days
Exercise of stock options	236
Intrinsic value of shares exercised	187
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangements by share-based payment award, estimated grant date fair value				$14.50
Common Stock [Member] | MidSouth Bank [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock options converted				322,300
Options to purchase shares of common stock				137,280
Exercise price of options				$8.57
Share-based compensation arrangements by share-based payment award, estimated grant date fair value				$6.31
2010 Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant shares issued	32,425								32,425
Warrant exercise price per share	$12								$12
Warrants exercisable period	7 years
Warrants outstanding	31,877								31,877
2007 Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options authorized			551,250
Increase in shares authorized						1,500,000
Increased number of authorized shares					2,000,000
Options contractual term	10 years
2007 Stock Option Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	3 years
2007 Stock Option Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	5 years
2007 Stock Option Plan [Member] | Subsequent Events [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increased number of authorized shares							4,000,000
Two Thousand Ten Amended Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options authorized								1,000,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options granted	87,874
Unrecognized compensation cost, nonvested stock options	$1,635								$1,635
Unrecognized compensation cost, period of recognition									3 years 9 months 11 days
Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	3 years
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	5 years

ShareBased_Payments_Fair_Value

Share-Based Payments - Fair Value Assumptions of Stock Options (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	1.82%	1.65%
Expected term	5 years 10 months 24 days	7 years 6 months
Expected stock price volatility	10.87%	12.63%
Dividend yield	0.23%	0.99%

ShareBased_Payments_Summary_of

Share-Based Payments - Summary of Company's Stock Option Activities (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Outstanding, Beginning Balance	946,644
Shares, Granted	181,680
Shares, Conversion of Stock options	137,280
Shares, Exercised	-23,809	-5,755
Shares, Forfeited, expired, or canceled	-31,135
Shares, Outstanding, Ending Balance	1,210,660	946,644
Shares, Vested or expected to vest	1,150,127
Shares, Exercisable at period end	790,098
Weighted Average Exercise Price, Outstanding, Beginning Balance	$11.27
Weighted Average Exercise Price, Granted	$13.55
Weighted Average Exercise Price, Conversion of stock option	$8.57
Weighted Average Exercise Price, Exercised	$9.92
Weighted Average Exercise Price, Forfeited, expired, or cancelled	$12.01
Weighted Average Exercise Price, Outstanding, Ending Balance	$11.32	$11.27
Weighted Average Exercise Price, Vested or expected to vest	$11.32
Weighted Average Exercise Price, Exercisable at period end	$10.62
Weighted Average Remaining Contractual Term, beginning of year	6 years 6 months 11 days	6 years 9 months 22 days
Weighted Average Remaining Contractual Term, Vested or expected to vest	6 years 6 months 11 days
Weighted Average Remaining Contractual Term, Exercisable at period end	5 years 7 months 6 days
Aggregate Intrinsic Value, Outstanding, Beginning Balance	$1,635
Aggregate Intrinsic Value, Outstanding, Ending Balance	7,244	1,635
Aggregate Intrinsic Value, Vested or expected to vest	6,882
Aggregate Intrinsic Value, Exercisable at period end	$5,281

ShareBased_Payments_Summary_of1

Share-Based Payments - Summary of Activity for Nonvested Restricted Share Awards (Detail) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Nonvested, Beginning Balance	28,685
Shares, Granted	87,874
Shares, Vested	-9,166
Shares, Forfeited	-4,683
Shares, Nonvested, Ending Balance	102,710
Weighted-Average Grant-Date Fair Value, Nonvested, Beginning Balance	$13
Weighted-Average Grant-Date Fair Value, Granted	$14.15
Weighted-Average Grant-Date Fair Value, Vested	$13
Weighted-Average Grant-Date Fair Value, Forfeited	$14.09
Weighted-Average Grant-Date Fair Value, Nonvested, Ending Balance	$13.93

Regulatory_Capital_Matters_Act

Regulatory Capital Matters - Actual and Required Capital Amounts and Ratios (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Risk-Based Capital to risk weighted assets, Actual Amount	$113,830	$73,305
Tier 1 (Core) Capital to risk weighted assets, Actual Amount	107,150	68,405
Tier 1 (Core) Capital to average assets, Actual Amount	107,150	68,405
Total Risk-Based Capital to risk weighted assets, Actual Ratio	12.23%	14.59%
Tier 1 (Core) Capital to risk weighted assets, Actual Ratio	11.51%	13.62%
Tier 1 (Core) Capital to average assets, Actual Ratio	8.52%	9.62%
Total Risk-Based Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	74,447	40,192
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	37,223	20,096
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Amount	50,279	28,455
Total Risk-Based Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Ratio	4.00%	4.00%
Total Risk-Based Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Amount	93,059	50,239
Tier 1 (Core) Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Amount	55,835	30,144
Tier 1 (Core) Capital to average assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Amount	62,849	35,569
Total Risk-Based Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	10.00%	10.00%
Tier 1 (Core) Capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	6.00%	6.00%
Tier 1 (Core) Capital to average assets, To Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	5.00%	5.00%
Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Risk-Based Capital to risk weighted assets, Actual Amount	114,475	74,430
Tier 1 (Core) Capital to risk weighted assets, Actual Amount	107,795	69,530
Tier 1 (Core) Capital to average assets, Actual Amount	107,795	69,530
Total Risk-Based Capital to risk weighted assets, Actual Ratio	12.30%	14.81%
Tier 1 (Core) Capital to risk weighted assets, Actual Ratio	11.58%	13.83%
Tier 1 (Core) Capital to average assets, Actual Ratio	8.57%	9.78%
Total Risk-Based Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	74,464	40,209
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Amount	37,232	20,105
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Amount	$50,291	$28,449
Total Risk-Based Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier 1 (Core) Capital to risk weighted assets, Required For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier 1 (Core) Capital to average assets, Required For Capital Adequacy Purposes Ratio	4.00%	4.00%

Regulatory_Capital_Matters_Add

Regulatory Capital Matters - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Description of dividend restriction pertaining to the dividends that the company could declare	13,836 plus any 2015 net profits retained to the date of declaration

Fair_Value_Assets_and_Liabilit

Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$395,705	$268,515
Loans held for sale	18,462	10,694
U.S. Government Sponsored Entities and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	30,173	14,724
U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	20,000
Mortgage-Backed Securities: Residential [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	339,067	253,791
Mortgage-Backed Securities: Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	6,465
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	20,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	20,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	375,705	268,515
Loans held for sale	18,462
Mortgage banking derivatives	285	464
Mortgage banking derivatives	132
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Sponsored Entities and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	30,173	14,724
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities: Residential [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	339,067	253,791
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities: Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$6,465

Fair_Value_Additional_informat

Fair Value - Additional information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value Measurements Of Financial Instruments [Line Items]
Unpaid principal balance of loans held for sale	$2,533,000	$6,189,000
Change in fair value related to loans held for sale	5,814,000	4,403,000
Loans held for sale carried at fair value	18,462,000	10,694,000
Carrying amount of impaired loans with specific allocations	946,000	4,623,000
Valuation allowance for impaired loans	18,000	548,000
Additional provision for loan losses	2,374,000	907,000
Foreclosed assets	715,000	181,000
Write-down value during period	0	190,000
Loans Held For Sale [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Unpaid principal balance of loans held for sale	17,898,000
Change in fair value related to loans held for sale	564,000
Loans held for sale carried at fair value	0
Maximum [Member] | Loans Held For Sale [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Term of loan	90 days
Fair Value [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Loans held for sale carried at fair value	18,462,000	10,694,000
Carrying amount of impaired loans with specific allocations	0	2,601,000
Valuation allowance for impaired loans		548,000
Changes Measurement [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Additional provision for loan losses		$0

Fair_Value_Assets_Measured_at_

Fair Value - Assets Measured at Fair Value on Non-Recurring Basis (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential Portfolio Segment [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans with specific allocations
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial Real Estate [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans with specific allocations
Significant Other Observable Inputs (Level 2) [Member] | Residential Portfolio Segment [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans with specific allocations
Significant Other Observable Inputs (Level 2) [Member] | Commercial Real Estate [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans with specific allocations
Significant Unobservable Inputs (Level 3) [Member] | Residential Portfolio Segment [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans with specific allocations	1,133
Significant Unobservable Inputs (Level 3) [Member] | Commercial Real Estate [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans with specific allocations	$920

Fair_Value_Quantitative_Inform

Fair Value - Quantitative Information about Recurring Level 3 Fair Value Measurements (Detail) (Significant Unobservable Inputs (Level 3) [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Residential Portfolio Segment [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	1,133
Commercial Real Estate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	920
Minimum [Member] | Residential Portfolio Segment [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range (Weighted Average)	3.00%
Minimum [Member] | Commercial Real Estate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range (Weighted Average)	0.00%
Maximum [Member] | Residential Portfolio Segment [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range (Weighted Average)	27.00%
Maximum [Member] | Commercial Real Estate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range (Weighted Average)	16.00%
Weighted Average [Member] | Residential Portfolio Segment [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range (Weighted Average)	16.00%
Weighted Average [Member] | Commercial Real Estate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range (Weighted Average)	16.00%

Fair_Value_Carrying_Amount_and

Fair Value - Carrying Amount and Estimated Fair Value of Financial Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Carrying Amount	$49,347	$18,217	$24,977
Securities available for sale	395,705	268,515
Certificates of deposit held at other financial institutions	250
Securities held to maturity, Carrying Amount	53,332	56,575
Securities held to maturity, Fair Value	53,741	54,004
Loans held for sale, Fair Value	18,462	10,694
Net loans, Carrying Amount	780,508	416,404
Restricted equity securities, Carrying Amount	5,349	3,032
Mortgage servicing rights, Carrying Amount	3,053	2,640
Mortgage servicing rights, Fair Value	4,180	3,714
Accrued interest receivable	3,545	2,396
Deposits, Carrying Amount	1,172,233	681,300
Federal funds purchased and repurchase agreements, Carrying Amount	39,078	24,291
Federal Home Loan Bank advances, Carrying Amount	19,000	23,000
Accrued interest payable	421	222
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents , Fair Value	49,347	18,217
Securities available for sale	395,705	268,515
Certificates of deposit held at other financial institutions, Fair Value	250
Securities held to maturity, Fair Value	53,741	54,004
Loans held for sale, Fair Value	18,462	10,694
Net loans, Fair Value	782,745	415,515
Restricted equity securities, Fair Value	0	0
Mortgage servicing rights, Fair Value	4,180	3,714
Accrued interest receivable	3,545	2,396
Deposits, Fair Value	1,174,802	682,300
Federal funds purchased and repurchase agreements, Fair Value	39,078	24,291
Federal Home Loan Bank advances, Fair Value	19,146	23,023
Accrued interest payable	421	222
Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents , Fair Value	49,347	18,217
Securities available for sale	20,000
Restricted equity securities, Fair Value	0	0
Deposits, Fair Value	848,158	480,000
Accrued interest payable	33	17
Fair Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities available for sale	375,705	268,515
Certificates of deposit held at other financial institutions, Fair Value	250
Securities held to maturity, Fair Value	53,741	54,004
Loans held for sale, Fair Value	18,462	10,694
Restricted equity securities, Fair Value	0	0
Mortgage servicing rights, Fair Value	4,180	3,714
Accrued interest receivable	1,368	1,145
Deposits, Fair Value	326,644	202,300
Federal funds purchased and repurchase agreements, Fair Value	39,078	24,291
Federal Home Loan Bank advances, Fair Value	19,146	23,023
Accrued interest payable	388	205
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net loans, Fair Value	782,745	415,515
Restricted equity securities, Fair Value	0	0
Accrued interest receivable	2,177	1,251
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Carrying Amount	49,347	18,217
Securities available for sale	395,705	268,515
Certificates of deposit held at other financial institutions	250
Securities held to maturity, Carrying Amount	53,332	56,575
Loans held for sale, Carrying Amount	18,462	10,694
Net loans, Carrying Amount	780,508	416,404
Restricted equity securities, Carrying Amount	5,349	3,032
Mortgage servicing rights, Carrying Amount	3,053	2,640
Accrued interest receivable	3,545	2,396
Deposits, Carrying Amount	1,172,233	681,300
Federal funds purchased and repurchase agreements, Carrying Amount	39,078	24,291
Federal Home Loan Bank advances, Carrying Amount	19,000	23,000
Accrued interest payable	$421	$222

Mortgage_Banking_Derivatives_A

Mortgage Banking Derivatives - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]
Derivative assets	$285	$464
Derivative liability	132
Mortgage banking derivatives - interest rate locks [Member]
Derivative [Line Items]
Mortgage banking derivatives	28,182	26,000
Forward Commitments [Member]
Derivative [Line Items]
Mortgage banking derivatives	$36,849	$27,000

Mortgage_Banking_Derivatives_S

Mortgage Banking Derivatives - Summary of Net Gains (Losses) Relating to Free-Standing Derivative Instruments Used for Risk Management (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Forward Contracts [Member]
Derivative [Line Items]
Derivative instruments	($411)	$321
Interest Rate Contract [Member]
Derivative [Line Items]
Derivative instruments	$100	($427)

Mortgage_Banking_Derivatives_S1

Mortgage Banking Derivatives - Summary of Amount and Market Value of Mortgage Banking Derivatives Included in Consolidated Balance Sheet (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	$28,182	$25,789
Fair Value	285	185
Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	36,849	27,288
Fair Value	($132)	$279

Loan_Commitments_and_Other_Rel2

Loan Commitments and Other Related Activities - Summary of Contractual Amounts of Financial Instruments with Off-Balance-Sheet Risk (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments to Make Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	$27,907	$25,189
Variable Rate	275	600
Unused Lines of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	91,301	53,052
Variable Rate	137,237	76,166
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	1,679	688
Variable Rate	$10,410	$4,961

Loan_Commitments_and_Other_Rel3

Loan Commitments and Other Related Activities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
Long-term Purchase Commitment [Line Items]
Commitments to make loans period	365 days or less
Fixed rate loan commitments	2.88%
Fixed rate loan commitments	5.50%
Minimum [Member]
Long-term Purchase Commitment [Line Items]
Fixed rate loan maturity period	15 years
Maximum [Member]
Long-term Purchase Commitment [Line Items]
Fixed rate loan maturity period	30 years

Preferred_Stock_Additional_Inf

Preferred Stock - Additional Information (Detail) (USD $)	0 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Sep. 27, 2011
Class of Stock [Line Items]
Preferred stock share issued	10,000	10,000
Dividend rate	1.00%		3.96%
Dividends in arrears	$25	$25
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock share issued			10,000
Minimum [Member]
Class of Stock [Line Items]
Dividend rate	1.00%
Maximum [Member]
Class of Stock [Line Items]
Dividend rate	5.00%

Recovered_Sheet1

Parent Company only Condensed Financial Information - Condensed Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
ASSETS
Cash and cash equivalents	$49,347	$18,217	$24,977
Other assets	1,551	1,198
Total assets	1,355,827	796,374
LIABILITIES AND EQUITY
Shareholders' equity	121,799	65,163	51,356
Total liabilities and shareholders' equity	1,355,827	796,374
Franklin Financial Network, Inc. [Member]
ASSETS
Cash and cash equivalents	496	718	706
Investment in banking subsidiaries	121,154	63,881
Investment in and advances to other subsidiaries		275
Other assets	300	348
Total assets	121,950	65,222
LIABILITIES AND EQUITY
Accrued expenses and other liabilities	151	59
Shareholders' equity	121,799	65,163
Total liabilities and shareholders' equity	$121,950	$65,222

Recovered_Sheet2

Parent Company only Condensed Financial Information - Condensed Statements of Income (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, Captions [Line Items]
Income tax expense (benefit)	$5,134	$2,734
Net income	8,414	4,561
Franklin Financial Network, Inc. [Member]
Condensed Income Statements, Captions [Line Items]
Dividends from subsidiaries	575	25
Other income	235	170
Other expense	1,499	725
Loss before income tax and undistributed subsidiary income	-689	-530
Income tax expense (benefit)	-324	-175
Equity in undistributed subsidiary income	8,779	4,916
Net income	$8,414	$4,561

Parent_Company_only_Condensed_2

Parent Company only Condensed Financial Information - Condensed Statements of Cash Flows (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income	$8,414	$4,561
Adjustments:
Excess tax benefit related to the exchange of stock options		-83
Stock-based compensation	611	364
Compensation expense related to common stock issued to 401(k) plan	275	227
Loss on disposal of subsidiary	32
Net cash from operating activities	11,930	15,512
Cash flows from investing activities
Net cash acquired from acquisition	12,197
Net cash from investing activities	-230,974	-240,735
Cash flows from financing activities
Proceeds from exercise of common stock warrants		36
Proceeds from exercise of common stock options	236
Cash paid for stock option exchange, including tax benefit		-59
Proceeds from issuance of common stock, net	-514	14,191
Dividends paid on preferred stock	-100	-109
Net cash from financing activities	250,174	218,463
Net change in cash and cash equivalents	31,130	-6,760
Cash and cash equivalents at beginning of period	18,217	24,977
Cash and cash equivalents at end of period	49,347	18,217
Non-cash supplemental information:
Fair value of stock and stock options issued related to MidSouth Bank acquisition (See Note 2)	40,976
Franklin Financial Network, Inc. [Member]
Cash flows from operating activities
Net income	8,414	4,561
Adjustments:
Equity in undistributed subsidiary income	-8,779	-4,916
Excess tax benefit related to the exchange of stock options	-29	-11
Stock-based compensation	39	81
Compensation expense related to common stock issued to 401(k) plan	15	10
Loss on disposal of subsidiary	32
Change in other assets	77	-74
Change in other liabilities	92	-53
Net cash from operating activities	-139	-402
Cash flows from investing activities
Investments in subsidiaries	-12,396	-13,773
Net cash acquired from acquisition	12,197
Net cash from the disposal of subsidiary	205
Net cash from investing activities	6	-13,773
Cash flows from financing activities
Proceeds from exercise of common stock warrants		36
Proceeds from exercise of common stock options	265	58
Cash paid for stock option exchange, including tax benefit		11
Proceeds from issuance of common stock, net	-514	14,191
Proceeds from subsidiaries related to issuance of common stock related to 401(k) plan	260
Dividends paid on preferred stock	-100	-109
Net cash from financing activities	-89	14,187
Net change in cash and cash equivalents	-222	12
Cash and cash equivalents at beginning of period	718	706
Cash and cash equivalents at end of period	496	718
Non-cash supplemental information:
Transfers from subsidiary stock based compensation expense to parent company only additional paid-in capital	$572	$430
Fair value of stock and stock options issued related to MidSouth Bank acquisition (See Note 2)	40,976

Earnings_Per_Share_Computation

Earnings Per Share - Computation of Earnings per Share (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Basic
Net income available to common shareholders	$8,314	$4,452
Less: earnings allocated to participating securities	-94	-20
Net income allocated to common shareholders	8,220	4,432
Weighted average common shares outstanding including participating securities	6,320,316	3,933,731
Less: Participating securities	-71,586	-17,563
Average shares	6,248,730	3,916,168
Basic earnings per common share	$1.32	$1.13
Diluted
Net income allocated to common shareholders	$8,220	$4,432
Weighted average common shares outstanding for basic earnings per common share	6,248,730	3,916,168
Add: Dilutive effects of assumed exercises of stock options	230,290	102,027
Add: Dilutive effects of assumed exercises of stock warrants	6,810	2,481
Average shares and dilutive potential common shares	6,485,830	4,020,676
Dilutive earnings per common share	$1.27	$1.10

Earnings_Per_Share_Additional_

Earnings Per Share - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Stock options to purchase shares of the Company's common stock	2,000	124,869

Capital_Offering_Additional_In

Capital Offering - Additional Information (Detail) (USD $)	Nov. 30, 2013
Equity [Abstract]
Stock offering price per share in private placement	$13
Common shares issued	1,153,847

Capital_Offering_Schedule_of_N

Capital Offering - Schedule of Net Proceeds (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Gross proceeds		$15,000
Stock offering costs		-809
Proceeds from issuance of common stock, net	($514)	$14,191

Sale_of_Subsidiary_Additional_

Sale of Subsidiary - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of subsidiary	($32)
Banc Compliance Group Inc [Member ]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of subsidiary	$32

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)	0 Months Ended
	Jan. 01, 2015	Dec. 31, 2014		Dec. 31, 2013		Jun. 30, 2014	Feb. 26, 2015	Feb. 19, 2015	Jan. 15, 2015
Subsequent Event [Line Items]
Common stock shares authorized		10,000,000	[1]	10,000,000	[1]
2007 Stock Option Plan [Member]
Subsequent Event [Line Items]
Common stock shares available for future issuance						2,000,000
Subsequent Events [Member]
Subsequent Event [Line Items]
Gain on sale of buildings								$15,000
Common stock shares authorized							20,000,000
Cash dividends declared on preferred shares	25,000
Subsequent Events [Member] | 2007 Stock Option Plan [Member]
Subsequent Event [Line Items]
Common stock shares available for future issuance							4,000,000
Subsequent Events [Member] | IPO [Member]
Subsequent Event [Line Items]
Proposed minimum offering price of common stock									$50,000,000
[1]	(1) On February 26, 2015, shareholders approved the Articles of Amendment to the Company's Charter to increase the number of authorized shares of the Corporation's Common Stock from 10,000,000 to 20,000,000.