First Guaranty Bancshares (FGBI) 10-K 16 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 15, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	First Guaranty Bancshares, Inc.
Entity Central Index Key	1,408,534
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 111,683,537
Entity Common Stock, Shares Outstanding		8,807,175
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents:
Cash and due from banks		$ 37,205	$ 17,840
Federal funds sold		823	271
Cash and cash equivalents		38,028	18,111
Investment securities:
Available for sale, at fair value		381,535	397,473
Held to maturity, at cost (estimated fair value of $118,557 and $99,906, respectively)		120,121	101,863
Investment securities		501,656	499,336
Federal Home Loan Bank stock, at cost		2,351	1,816
Loans held for sale		1,308	0
Loans, net of unearned income		1,149,014	948,921
Less: allowance for loan losses		9,225	11,114
Net loans		1,139,789	937,807
Premises and equipment, net		38,020	23,519
Goodwill		3,472	1,999
Intangible assets, net		4,424	1,056
Other real estate, net		1,281	359
Accrued interest receivable		7,982	7,039
Other assets		12,119	9,904
Total Assets		1,750,430	1,500,946
Deposits:
Noninterest-bearing demand		251,617	231,094
Interest-bearing demand		611,677	479,810
Savings		104,661	97,280
Time		581,331	517,997
Total deposits		1,549,286	1,326,181
Short-term borrowings		15,500	6,500
Accrued interest payable		2,488	1,931
Senior long-term debt		22,774	22,100
Junior subordinated debentures		14,664	14,630
Other liabilities		1,735	5,255
Total Liabilities		1,606,447	1,376,597
Common stock:
$1 par value - authorized 100,600,000 shares; issued 8,807,175 and 8,369,424 shares	[1]	8,807	8,369
Surplus		92,268	81,000
Retained earnings		44,464	38,979
Accumulated other comprehensive income (loss)		(1,556)	(3,999)
Total Shareholders' Equity		143,983	124,349
Total Liabilities and Shareholders' Equity		$ 1,750,430	$ 1,500,946
[1]	All share amounts have been restated to reflect the ten percent stock dividend paid December 14, 2017 to shareholders of record as of December 8, 2017.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Investment securities:
Held to maturity, estimated fair value	$ 118,557	$ 118,557	$ 99,906
Common stock:
Common stock, par value (in dollars per share)	$ 1	$ 1	$ 1
Common stock, shares authorized (in shares)	100,600,000	100,600,000	100,600,000
Common stock, shares issued (in shares)	8,807,175	8,807,175	8,369,424
Common stock, dividend paid percentage	10.00%
Common stock, dividend paid date		Dec. 14, 2017
Common stock, dividend record date		Dec. 8, 2017

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income:
Loans (including fees)		$ 54,034	$ 45,495	$ 42,536
Deposits with other banks		178	69	72
Securities (including FHLB stock)		13,325	12,968	13,471
Federal funds sold		9	0	0
Total Interest Income		67,546	58,532	56,079
Interest Expense:
Demand deposits		5,526	2,633	1,419
Savings deposits		201	80	38
Time deposits		7,112	5,954	6,985
Borrowings		1,554	1,473	166
Total Interest Expense		14,393	10,140	8,608
Net Interest Income		53,153	48,392	47,471
Less: Provision for loan losses		3,822	3,705	3,864
Net Interest Income after Provision for Loan Losses		49,331	44,687	43,607
Noninterest Income:
Service charges, commissions and fees		2,589	2,388	2,736
ATM and debit card fees		1,986	1,859	1,779
Net gains on securities		1,397	3,799	3,300
Net gains on sale of loans		311	14	4
Other		2,057	1,395	1,137
Total Noninterest Income		8,340	9,455	8,956
Noninterest Expense:
Salaries and employee benefits		20,113	16,577	15,496
Occupancy and equipment expense		4,505	4,242	3,845
Other		13,903	12,066	11,754
Total Noninterest Expense		38,521	32,885	31,095
Income Before Income Taxes		19,150	21,257	21,468
Less: Provision for income taxes		7,399	7,164	6,963
Net Income		11,751	14,093	14,505
Preferred stock dividends		0	0	(384)
Income Available to Common Shareholders		$ 11,751	$ 14,093	$ 14,121
Per Common Share:
Earnings (in dollars per share)	[1]	$ 1.37	$ 1.68	$ 1.83
Cash dividends paid (in dollars per share)	[1]	$ 0.60	$ 0.58	$ 0.54
Weighted Average Common Shares Outstanding (in shares)		8,608,088	8,369,424	7,714,620
[1]	All share and per share amounts have been restated to reflect the ten percent stock dividend paid December 14, 2017 to shareholders of record as of December 8, 2017.

CONSOLIDATED STATEMENTS OF INC5

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical)	Dec. 14, 2017	Dec. 31, 2017	Dec. 31, 2017
Per Common Share:
Common stock, dividend paid percentage	10.00%	10.00%
Common stock, dividend paid date			Dec. 14, 2017
Common stock, dividend record date			Dec. 8, 2017

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]
Net Income	$ 11,751	$ 14,093	$ 14,505
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) arising during the period	5,098	(955)	1,394
Reclassification adjustments for net gains included in net income	(1,397)	(3,799)	(3,300)
Reclassification of OTTI losses included in net income	0	60	175
Change in unrealized gains (losses) on securities	3,701	(4,694)	(1,731)
Tax impact	(1,258)	1,596	589
Other comprehensive income (loss)	2,443	(3,098)	(1,142)
Comprehensive Income	$ 14,194	$ 10,995	$ 13,363

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands		Preferred Stock [Member]Series C Preferred Stock $1,000 Par [Member]	Common Stock $1 Par [Member]	Surplus [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Total
Balance at Dec. 31, 2014	[1]	$ 39,435	$ 7,615	$ 69,311	$ (54)	$ 23,035	$ 241	$ 139,583
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	0	0	0	14,505	0	14,505
Reclassification of treasury stock under the LCBA	[1],[2]	0	(4)	(7)	54	(43)	0	0
Other comprehensive income		0	0	0	0	0	(1,142)	(1,142)
Preferred stock redeemed, Series C		(39,435)	0	0	0	0	0	(39,435)
Common stock issued in initial public offering	[1]	0	758	11,696	0	(3,110)	0	9,344
Cash dividends on common stock	[1]	0	0	0	0	(4,247)	0	(4,247)
Preferred stock dividends		0	0	0	0	(384)	0	(384)
Balance at Dec. 31, 2015		0	8,369	81,000	0	29,756	(901)	118,224
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	0	0	0	14,093	0	14,093
Other comprehensive income		0	0	0	0	0	(3,098)	(3,098)
Cash dividends on common stock	[1]	0	0	0	0	(4,870)	0	(4,870)
Balance at Dec. 31, 2016		0	8,369	81,000	0	38,979	(3,999)	124,349
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	0	0	0	11,751	0	11,751
Common stock issued in acquisition	[1]	0	438	11,268	0	(1,056)	0	10,650
Other comprehensive income		0	0	0	0	0	2,443	2,443
Cash dividends on common stock	[1]	0	0	0	0	(5,210)	0	(5,210)
Balance at Dec. 31, 2017		$ 0	$ 8,807	$ 92,268	$ 0	$ 44,464	$ (1,556)	$ 143,983
[1]	All share and per share amounts reflect the ten percent stock dividend paid December 14, 2017 to shareholders of record as of December 8, 2017.
[2]	Effective January 1, 2015, companies incorporated under Louisiana law became subject to the Louisiana Business Corporation Act (which replaces the Louisiana Business Corporation Law). Provisions of the Louisiana Business Corporation Act eliminate the concept of treasury stock and provide that shares reacquired by a company are to be treated as authorized but unissued shares. As a result of this change in law, shares previously classified as treasury stock were reclassified as a reduction to issued shares of common stock in the consolidated financial statements as of June 30, 2015, reducing the stated value of common stock and retained earnings.

CONSOLIDATED STATEMENTS OF CHA8

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY [Abstract]
Common stock issued in initial public offering (in shares)			758,027
Cash dividends per share (in dollars per share)	[1]	$ 0.60	$ 0.54
Common stock issued in acquisition (in shares)		437,751
Common stock, dividend paid date		Dec. 14, 2017
Common stock, dividend record date		Dec. 8, 2017
[1]	All share and per share amounts have been restated to reflect the ten percent stock dividend paid December 14, 2017 to shareholders of record as of December 8, 2017.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operating Activities:
Net income	$ 11,751	$ 14,093	$ 14,505
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	3,822	3,705	3,864
Depreciation and amortization	2,444	2,190	1,995
Amortization/Accretion of investments	1,788	2,239	2,036
Gain on sale/call of securities	(1,397)	(3,799)	(3,300)
Other than temporary impairment charge on securities	0	60	175
Gain on sale of assets	(361)	(76)	(6)
Repossessed asset write downs, gains and losses on dispositions	103	243	411
FHLB stock dividends	(23)	(6)	(4)
Net decrease in loans held for sale	347	0	0
Change in other assets and liabilities, net	(6,199)	3,563	(2,461)
Net Cash Provided By Operating Activities	12,275	22,212	17,215
Cash Flows From Investing Activities:
Proceeds from maturities, calls and sales of certificates of deposit	0	1,001	9,250
Proceeds from maturities and calls of HTM securities	11,703	85,875	72,036
Proceeds from maturities, calls and sales of AFS securities	542,894	1,000,905	723,249
Funds invested in HTM securities	(30,530)	(18,563)	(48,318)
Funds Invested in AFS securities	(517,185)	(1,024,632)	(650,698)
Proceeds from sale/redemption of Federal Home Loan Bank stock	0	0	3,554
Funds invested in Federal Home Loan Bank stock	0	(875)	(2,864)
Net increase in loans	(80,816)	(109,467)	(56,000)
Purchases of premises and equipment	(6,814)	(4,109)	(4,400)
Proceeds from sales of premises and equipment	51	983	4
Proceeds from sales of other real estate owned	608	1,098	1,394
Cash paid in excess of cash received in acquisition	(2,907)	0	0
Net Cash (Used In) Provided By Investing Activities	(82,996)	(67,784)	47,207
Cash Flows From Financing Activities:
Net increase (decrease) in deposits	95,879	30,311	(75,969)
Net (decrease) increase in federal funds purchased and short-term borrowings	(700)	4,700	0
Proceeds from long-term borrowings, net of costs	3,750	0	24,969
Repayment of long-term borrowings	(3,081)	(3,730)	(600)
Proceeds from junior subordinated debentures, net of costs	0	0	14,597
Issuance of common stock, net of costs	0	0	9,344
Redemption of preferred stock	0	0	(39,435)
Dividends paid	(5,210)	(4,870)	(4,631)
Net Cash Provided By (Used in) Financing Activities	90,638	26,411	(71,725)
Net Increase (Decrease In) Cash and Cash Equivalents	19,917	(19,161)	(7,303)
Cash and Cash Equivalents at the Beginning of the Period	18,111	37,272	44,575
Cash and Cash Equivalents at the End of the Period	38,028	18,111	37,272
Noncash Activities:
Loans transferred to foreclosed assets	1,374	123	1,184
Common stock issued in acquisition	10,650	0	0
Cash Paid During the Period:
Interest on deposits and borrowed funds	13,836	9,916	8,898
Income taxes	$ 10,700	$ 3,000	$ 8,400

Business and Summary of Signifi

Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Business and Summary of Significant Accounting Policies [Abstract]
Business and Summary of Significant Accounting Policies	Note 1. Business and Summary of Significant Accounting Policies Business First Guaranty Bancshares, Inc. ("First Guaranty") is a Louisiana corporation headquartered in Hammond, LA. First Guaranty owns all of the outstanding shares of common stock of First Guaranty Bank. First Guaranty Bank (the "Bank") is a Louisiana state-chartered commercial bank that provides a diversified range of financial services to consumers and businesses in the communities in which it operates. These services include consumer and commercial lending, mortgage loan origination, the issuance of credit cards and retail banking services. The Bank also maintains an investment portfolio comprised of government, government agency, corporate, and municipal securities. The Bank has twenty-seven banking offices, including one drive-up banking facility, and thirty-eight automated teller machines (ATMs) in Southeast Louisiana, Southwest Louisiana, North Louisiana and North Central Texas. Summary of significant accounting policies The accounting and reporting policies of First Guaranty conform to generally accepted accounting principles and to predominant accounting practices within the banking industry. The more significant accounting and reporting policies are as follows: Consolidation The consolidated financial statements include the accounts of First Guaranty Bancshares, Inc., and its wholly owned subsidiary, First Guaranty Bank. All significant intercompany balances and transactions have been eliminated in consolidation. Acquisition Accounting Acquisitions are accounted for under the purchase method of accounting. Purchased assets, including identifiable intangibles, and assumed liabilities are recorded at their respective acquisition date fair values. If the fair value of net assets purchased exceeds the consideration given, a gain on acquisition is recognized. If the consideration given exceeds the fair value of the net assets received, goodwill is recognized. Fair values are subject to refinement for up to one year after the closing date of an acquisition as information relative to closing date fair values becomes available. Purchased loans acquired in a business combination are recorded at estimated fair value on their purchase date with no carryover of the related allowance for loan losses. See Acquired Loans section below for accounting policy regarding loans acquired in a business combination. Use of estimates The preparation of financial statements in conformity with generally accepted accounting principles requires Management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenue and expense during the reporting periods. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near-term relate to the determination of the allowance for loan losses, the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans, and the valuation of investment securities. In connection with the determination of the allowance for loan losses and real estate owned, First Guaranty obtains independent appraisals for significant properties. Cash and cash equivalents For purposes of reporting cash flows, cash and cash equivalents are defined as cash, due from banks, interest-bearing demand deposits with banks and federal funds sold with maturities of three months or less. Securities First Guaranty reviews its financial position, liquidity and future plans in evaluating the criteria for classifying investment securities. Debt securities that Management has the ability and intent to hold to maturity are classified as held to maturity and carried at cost, adjusted for amortization of premiums and accretion of discounts using methods approximating the interest method. Securities available for sale are stated at fair value. The unrealized difference, if any, between amortized cost and fair value of these AFS securities is excluded from income and is reported, net of deferred taxes, in accumulated other comprehensive income as a part of shareholders' equity. Details of other comprehensive income are reported in the consolidated statements of comprehensive income. Realized gains and losses on securities are computed based on the specific identification method and are reported as a separate component of other income. Amortization of premiums and discounts is included in interest income. Discounts and premiums related to debt securities are amortized using the effective interest rate 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. In estimating other-than-temporary losses, management considers the length of time and extent that fair value has been less than cost and the financial condition and near term prospects of the issuer. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For debt securities that do not meet the aforementioned criteria, the amount of impairment is split into two components as follows: 1) OTTI related to credit loss, which must be recognized in the income statement and 2) OTTI related to other factors, which is recognized in other comprehensive income. 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. For equity securities, the entire amount of impairment is recognized through earnings. Loans held for sale Mortgage loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Net unrealized losses, if any, are recognized through a valuation allowance by charges to income. Loans held for sale have primarily been fixed rate single-family residential mortgage loans under contract to be sold in the secondary market. In most cases, loans in this category are sold within thirty days. Buyers generally have recourse to return a purchased loan under limited circumstances. Recourse conditions may include early payment default, breach of representations or warranties and documentation deficiencies. Mortgage loans held for sale are generally sold with the mortgage servicing rights released. Gains or losses on sales of mortgage loans are recognized based on the differences between the selling price and the carrying value of the related mortgage loans sold. Loans Loans are stated at the principal amounts outstanding, net of unearned income and deferred loan fees. In addition to loans issued in the normal course of business, overdrafts on customer deposit accounts are considered to be loans and reclassified as such. Interest income on all classifications of loans is calculated using the simple interest method on daily balances of the principal amount outstanding. Accrual of interest is discontinued on a loan when Management believes, after considering economic and business conditions and collection efforts, the borrower's financial condition is such that reasonable doubt exists as to the full and timely collection of principal and interest. This evaluation is made for all loans that are 90 days or more contractually past due. When a loan is placed in nonaccrual status, all interest previously accrued but not collected is reversed against current period interest income. Income on such loans is then recognized only to the extent that cash is received and where the future collection of interest and principal is probable. Loans are returned to accrual status when, in the judgment of Management, all principal and interest amounts contractually due are reasonably assured to be collected within a reasonable time frame and when the borrower has demonstrated payment performance of cash or cash equivalents; generally for a period of six months. All loans, except mortgage loans, are considered past due if they are past due 30 days. Mortgage loans are considered past due when two consecutive payments have been missed. Loans that are past due 90-120 days and deemed uncollectible are charged-off. The loan charge off is a reduction of the allowance for loan losses. Troubled Debt Restructurings (TDRs) TDRs are loans in which the borrower is experiencing financial difficulty at the time of restructuring, and the Bank has granted a concession to the borrower. TDRs are undertaken in order to improve the likelihood of recovery on the loan and may take the form of modifications made with the stated interest rate lower than the current market rate for new debt with similar risk, other modifications to the structure of the loan that fall outside of normal underwriting policies and procedures, or in limited circumstances forgiveness of principal and / or interest. TDRs can involve loans remaining on non-accrual, moving to non-accrual, or continuing on accrual status, depending on the individual facts and circumstances of the borrower. TDRs are subject to policies governing accrual and non-accrual evaluation consistent with all other loans as discussed in the "Loans" section above. All loans with the TDR designation are considered to be impaired, even if they are accruing. First Guaranty's policy is to evaluate TDRs that have subsequently been restructured and returned to market terms after 12 months of performance. The evaluation includes a review of the loan file and analysis of the credit to assess the loan terms, including interest rate to insure such terms are consistent with market terms. The loan terms are compared to a sampling of loans with similar terms and risk characteristics, including loans originated by First Guaranty and loans lost to a competitor. The sample provides a guide to determine market terms pursuant to ASC 310-40-50-2. The loan is also evaluated at that time for impairment. A loan determined to be restructured to market terms and not considered impaired will no longer be disclosed as a TDR in the years following the restructuring. These loans will continue to be individually evaluated for impairment. A loan determined to either be restructured to below market terms or to be impaired will remain a TDR. Credit Quality First Guaranty's credit quality indicators are pass, special mention, substandard, and doubtful. Loans included in the pass category are performing loans with satisfactory debt coverage ratios, collateral, payment history, and documentation requirements. Special mention loans have potential weaknesses that deserve close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects. Borrowers may be experiencing adverse operating trends (declining revenues or margins) or an ill proportioned balance sheet (e.g., increasing inventory without an increase in sales, high leverage, tight liquidity). Adverse economic or market conditions, such as interest rate increases or the entry of a new competitor, may also support a special mention rating. Nonfinancial reasons include management problems, pending litigation, an ineffective loan agreement or other material structural weakness, and any other significant deviation from prudent lending practices. A substandard loan is inadequately protected by the paying capacity of the obligor or of the collateral pledged, if any. Loans classified as substandard have a well-defined weakness. They are characterized by the distinct possibility that First Guaranty will sustain some loss if the deficiencies are not corrected. These loans require more intensive supervision. Substandard loans are generally characterized by current or expected unprofitable operations, inadequate debt service coverage, inadequate liquidity, or marginal capitalization. Repayment may depend on collateral or other credit risk mitigates. For some substandard loans, the likelihood of full collection of interest and principal may be in doubt and interest is no longer accrued. Consumer loans that are 90 days or more past due or that are nonaccrual are considered substandard. Doubtful loans have the weaknesses of substandard loans with the additional characteristic that the weaknesses make collection or liquidation in full questionable and there is a high probability of loss based on currently existing facts, conditions and values. A loan is considered impaired when, based on current information and events, it is probable that First Guaranty will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by Management in determining impairment include payment status, collateral value and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower's prior payment record and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis for commercial and construction loans by either the present value of expected future cash flows discounted at the loan's effective interest rate, the loan's obtainable market price or the fair value of the collateral if the loan is collateral dependent. This process is only applied to impaired loans or relationships in excess of $500,000. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, individual consumer and residential loans are not separately identified for impairment disclosures, unless such loans are the subject of a restructuring agreement. Loans that have been restructured in a troubled debt restructuring will continue to be evaluated individually for impairment, including those no longer requiring disclosure. Acquired Loans Loans are recorded at estimated fair value on their purchase date with no carryover of the related allowance for loan losses. Acquired loans are segregated between those with deteriorated credit quality at acquisition and those deemed as performing. To make this determination, Management considers such factors as past due status, nonaccrual status, credit risk ratings, interest rates and collateral position. The fair value of acquired loans deemed performing is determined by discounting cash flows, both principal and interest, for each pool at prevailing market interest rates as well as consideration of inherent potential losses. The difference between the fair value and principal balances due at acquisition date, the fair value discount, is accreted into income over the estimated life of each loan pool. Loans acquired in a business combination are recorded at their estimated fair value on their purchase date with no carryover of the related allowance for loan losses. Performing acquired loans are subsequently evaluated for any required allowance at each reporting date. An allowance for loan losses is calculated using a similar methodology for originated loans. Loan fees and costs Nonrefundable loan origination and commitment fees and direct costs associated with originating loans are deferred and recognized over the lives of the related loans as an adjustment to the loans' yield using the level yield method. Allowance for loan losses The allowance for loan losses is established through a provision for loan losses charged to expense. Loans are charged against the allowance for loan losses when Management believes that the collectability of the principal is unlikely. The allowance, which is based on evaluation of the collectability of loans and prior loan loss experience, is an amount that, in the opinion of Management, reflects the risks inherent in the existing loan portfolio and exists at the reporting date. The evaluations take into consideration a number of subjective factors including changes in the nature and volume of the loan portfolio, historical losses, overall portfolio quality, review of specific problem loans, current economic conditions that may affect a borrower's ability to pay, adequacy of loan collateral and other relevant factors. In addition, regulatory agencies, as an integral part of their examination process, periodically review the estimated losses on loans. Such agencies may require additional recognition of losses based on their judgments about information available to them at the time of their examination. The following are general credit risk factors that affect First Guaranty's loan portfolio segments. These factors do not encompass all risks associated with each loan category. Construction and land development loans have risks associated with interim construction prior to permanent financing and repayment risks due to the future sale of developed property. Farmland and agricultural loans have risks such as weather, government agricultural policies, fuel and fertilizer costs, and market price volatility. 1-4 family, multi-family, and consumer credits are strongly influenced by employment levels, consumer debt loads and the general economy. Non-farm non-residential loans include both owner occupied real estate and non-owner occupied real estate. Common risks associated with these properties is the ability to maintain tenant leases and keep lease income at a level able to service required debt and operating expenses. Commercial and industrial loans generally have non-real estate secured collateral which requires closer monitoring than real estate collateral. Although Management uses available information to recognize losses on loans, because of uncertainties associated with local economic conditions, collateral values and future cash flows on impaired loans, it is reasonably possible that a material change could occur in the allowance for loan losses in the near term. However, the amount of the change that is reasonably possible cannot be estimated. The evaluation of the adequacy of loan collateral is often based upon estimates and appraisals. Because of changing economic conditions, the valuations determined from such estimates and appraisals may also change. Accordingly, First Guaranty may ultimately incur losses that vary from Management's current estimates. Adjustments to the allowance for loan losses will be reported in the period such adjustments become known or can be reasonably estimated. All loan losses are charged to the allowance for loan losses when the loss actually occurs or when the collectability of the principal is unlikely. Recoveries are credited to the allowance at the time of recovery. The allowance consists of specific, general, and unallocated components. The specific component relates to loans that are classified as doubtful, substandard, and impaired. For such loans that are also classified as impaired, an allowance is established when the discounted cash flows (or collateral value or observable market price) of the impaired loan is lower than the carrying value of that loan. Also, a specific reserve is allocated for syndicated loans. The general component covers non-classified loans and special mention loans and is based on historical loss experience adjusted for qualitative factors. An unallocated component is maintained to cover uncertainties that could affect the estimate of probable losses. The allowance for loan losses is reviewed on a monthly basis. The monitoring of credit risk also extends to unfunded credit commitments, such as unused commercial credit lines and letters of credit. A reserve is established as needed for estimates of probable losses on such commitments. Goodwill and intangible assets Goodwill and intangible assets deemed to have indefinite lives are subject to annual impairment tests. First Guaranty's goodwill is tested for impairment on an annual basis, or more often if events or circumstances indicate that there may be impairment. Adverse changes in the economic environment, declining operations, or other factors could result in a decline in the implied fair value of goodwill. If the implied fair value is less than the carrying amount, a loss would be recognized in other non-interest expense to reduce the carrying amount to implied fair value of goodwill. The goodwill impairment test includes two steps that are preceded by a, "step zero", qualitative test. The qualitative test allows Management to assess whether qualitative factors indicate that it is more likely than not that impairment exists. If it is not more likely than not that impairment exists, then no impairment exists and the two step quantitative test would not be necessary. These qualitative indicators include factors such as earnings, share price, market conditions, etc. If the qualitative factors indicate that it is more likely than not that impairment exists, then the two step quantitative test would be necessary. Step one is used to identify potential impairment and compares the estimated fair value of a reporting unit with its carrying amount, including goodwill. If the estimated fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is not considered impaired. If the carrying amount of a reporting unit exceeds its estimated fair value, the second step of the goodwill impairment test is performed to measure the amount of impairment loss, if any. Step two of the goodwill impairment test compares the implied estimated fair value of reporting unit goodwill with the carrying amount of that goodwill. If the carrying amount of goodwill for that reporting unit exceeds the implied fair value of that unit's goodwill, an impairment loss is recognized in an amount equal to that excess. Identifiable intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or legal rights or because the assets are capable of being sold or exchanged either on their own or in combination with the related contract, asset or liability. First Guaranty's intangible assets primarily relate to core deposits. These core deposit intangibles are amortized on a straight-line basis over terms ranging from seven to fifteen years. Management periodically evaluates whether events or circumstances have occurred that impair this deposit intangible. Premises and equipment Premises and equipment are stated at cost, less accumulated depreciation. Depreciation is computed for financial reporting purposes using the straight-line method over the estimated useful lives of the respective assets as follows: Buildings and improvements 10-40 years Equipment, fixtures and automobiles 3-10 years Expenditures for renewals and betterments are capitalized and depreciated over their estimated useful lives. Repairs, maintenance and minor improvements are charged to operating expense as incurred. Gains or losses on disposition, if any, are recorded as a separate line item in noninterest income on the Statements of Income . Other real estate Other real estate includes properties acquired through foreclosure or acceptance of deeds in lieu of foreclosure. These properties are recorded at the lower of the recorded investment in the property or its fair value less the estimated cost of disposition. Any valuation adjustments required prior to foreclosure are charged to the allowance for loan losses. Subsequent to foreclosure, losses on the periodic revaluation of the property are charged to current period earnings as other real estate expense. Costs of operating and maintaining the properties are charged to other real estate expense as incurred. Any subsequent gains or losses on dispositions are credited or charged to income in the period of disposition . Off-balance sheet financial instruments In the ordinary course of business, First Guaranty has entered into commitments to extend credit, including commitments under credit card arrangements, commitments to fund commercial real estate, construction and land development loans secured by real estate, and performance standby letters of credit. Such financial instruments are recorded when they are funded. Income taxes First Guaranty and its subsidiary file a consolidated federal income tax return on a calendar year basis. In lieu of Louisiana state income tax, the Bank is subject to the Louisiana bank shares tax, which is included in noninterest expense in First Guaranty's consolidated financial statements. With few exceptions, First Guaranty is no longer subject to U.S. federal, state or local income tax examinations for years before 2014. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which the deferred tax assets or liabilities are expected to be settled or realized. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be utilized. Comprehensive income Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. Although certain changes in assets and liabilities, such as unrealized gains and losses on available for sale securities, are reported as a separate component of the equity section of the balance sheet, such items along with net income, are components of comprehensive income. The components of other comprehensive income and related tax effects are presented in the Statements of Comprehensive Income. Fair Value Measurements The fair value of a financial instrument is the current amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. A fair value measurement assumes that the transaction to sell the asset or transfer the liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability. Valuation techniques use certain inputs to arrive at fair value. Inputs to valuation techniques are the assumptions that market participants would use in pricing the asset or liability. They may be observable or unobservable. First Guaranty uses a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. See Note 20 for a detailed description of fair value measurements. Transfers of Financial Assets Transfers of financial assets are accounted for as sales, when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (i) the assets have been isolated from First Guaranty, (ii) 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 (iii) First Guaranty does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Earnings per common share Earnings per share represents income available to common shareholders divided by the weighted average number of common shares outstanding during the period. In December of 2017, First Guaranty issued a pro rata, 10% common stock dividend. The shares issued for the stock dividend have been retrospectively factored into the calculation of earnings per share as well as cash dividends paid on common stock and represented on the face of the financial statements. No convertible shares of First Guaranty's stock are outstanding. Operating Segments All of First Guaranty's operations are considered by management to be aggregated into one reportable operating segment. While the chief decision-makers monitor the revenue streams of the various products and services, the identifiable segments are not material. Operations are managed and financial performance is evaluated on a Company-wide basis. Reclassifications Certain reclassifications have been made to prior year end financial statements in order to conform to the classification adopted for reporting in 2017.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2017
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	Note 2. Recent Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, "Leases: Conforming Amendments Related to Leases". This ASU amends the codification regarding leases in order to increase transparency and comparability. The ASU requires companies to recognize lease assets and liabilities on the balance sheet and disclose key information about leasing arrangements. A lessee would recognize a liability to make lease payments and a right-of-use asset representing its right to use the leased asset for the lease term. The ASU is effective for annual and interim periods beginning after December 15, 2018. The adoption of this ASU is not expected to have a material effect on First Guaranty's Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments". This ASU amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. The ASU amendments require the measurement of all expected credit losses for financial assets held at the reporting date be based on historical experience, current conditions, and reasonable and supportable forecasts. The ASU requires assets held at cost basis to reflect the company's current estimate of all expected credit losses. For available for sale debt securities, credit losses should be presented as an allowance rather than as a write-down. In addition, this ASU amends the accounting for purchased financial assets with credit deterioration. This ASU is effective for annual and interim periods beginning after December 15, 2019. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment". This ASU amends the guidance on impairment testing. The ASU eliminates Step 2 from the goodwill impairment test. The annual, or interim, goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. In addition, income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit should be considered when measuring the goodwill impairment loss, if applicable. The ASU also eliminates the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative test, to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. This ASU is effective for annual and interim periods beginning after December 15, 2019. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In March 2017, the FASB issued ASU 2017-08, "Receivables- Nonrefundable Fees and Other Costs, Premium Amortization on Purchased Callable Debt Securities". This ASU shortens the amortization period for certain callable debt securities held at a premium. Specifically, this ASU requires the premium to be amortized to the earliest call date. This ASU does not require an accounting change for securities held at a discount, the discount continues to be amortized to maturity. This ASU is effective for annual and interim periods beginning after December 15, 2018. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In February 2018, the FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income". This ASU provides an option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or portion thereof) is recorded. This ASU requires disclosure of a description of the accounting policy for releasing income tax effects from AOCI; whether election is made to reclassify the stranded income tax effects from the Tax Cuts and Jobs Act; and information about the other income tax effects that are reclassified. This ASU is effective for annual and interim periods beginning after December 15, 2018. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In March 2018, the FASB issued ASU 2018-05, "Income Taxes (Topic 740) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118". This ASU adds SEC paragraphs pursuant to the SEC Staff Accounting Bulletin No. 118, which expresses the view of the staff regarding application of Topic 740, Income Taxes

Merger Transaction

Merger Transaction	12 Months Ended
	Dec. 31, 2017
Merger Transaction [Abstract]
Merger Transaction	Note 3. Merger Transaction Effective at the close of business on June 16, 2017, First Guaranty completed its acquisition of 100% of the outstanding shares of Premier Bancshares, Inc., a Texas corporation ("Premier"), a single bank holding company headquartered in McKinney, Texas and its wholly owned subsidiary, Synergy Bank. This acquisition allows First Guaranty to expand its presence into the North Central Texas market area. Under terms of an agreement and plan of merger dated January 30, 2017, First Guaranty issued 0.119 of a sh 397,988 21.0 The valuations of loans, premises and equipment and core deposit intangible and other assets acquired and liabilities assumed are still preliminary and subject to change. United States generally accepted accounting principles ("U.S. GAAP") provides up to twelve months following the date of acquisition in which management can finalize the fair values of acquired assets and assumed liabilities. Material events that occur during the measurement period will be analyzed to determine if the new information reflected facts and circumstances that existed on the acquisition date. The measurement period ends as soon as First Guaranty receives the information it was seeking about facts and circumstances that existed as of the acquisition date or learns more information is unobtainable. The measurement period is limited to one year from the acquisition date. Once management has finalized the fair values of acquired assets and assumed liabilities within this twelve month period, management considers such values to be the "Day One Fair Values." Based on management's preliminary valuation of the fair value of tangible and intangible assets acquired and liabilities assumed, the purchase price for the Premier acquisition is allocated in the table below. (in thousands) Premier Bancshares, Inc. Cash and due from banks $ 4,542 Federal funds sold 2,855 Securities available for sale 5,892 Loans 128,018 Premises and equipment 9,493 Goodwill 1,474 Intangible assets 3,809 Other real estate 221 Other assets 2,009 Total assets acquired $ 158,313 Deposits 127,228 FHLB borrowings 9,700 Other liabilities 431 Total liabilities assumed $ 137,359 Net assets acquired $ 20,954 The fair value of net assets acquired includes fair value adjustments to certain receivables that were not considered impaired as of the acquisition date. The non-impaired loans excluded from the purchase credit impairment requirements under ASC 310-30 were recorded at an estimated fair value of $123.7 million and had gross contractual amounts receivable of $122.9 million on the date of acquisition. Contractual cash flows not expected to be collected are estimated at $0.5 million. The following pro forma information for the twelve months ended December 31, 2017 and December 31, 2016 reflects First Guaranty's estimated consolidated results of operations as if the acquisition of Premier occurred at January 1, 2016, unadjusted for potential cost savings. (in thousands, except share data) 2017 2016 Net Interest Income $ 55,663 $ 53,190 Noninterest Income 8,540 11,541 Noninterest Expense 42,434 39,395 Net Income 10,885 13,709 Earnings per common share $ 1.24 $ 1.56

Cash and Due from Banks

Cash and Due from Banks	12 Months Ended
	Dec. 31, 2017
Cash and Due from Banks [Abstract]
Cash and Due from Banks	Note 4. Cash and Due from Banks Certain reserves are required to be maintained at the Federal Reserve Bank. There was no reserve requirement as of December 31, 2017 and 2016. At December 31, 2017 First Guaranty had only one account at correspondent banks, excluding the Federal Reserve Bank, that exceeded the FDIC insurable limit of $250,000. This account was over the insurable limit by $0.6 million. At December 31, 2016 First Guaranty had only one account at correspondent banks, excluding the Federal Reserve Bank, that exceeded the FDIC insurable limit of $250,000. This account was over the insurable limit by $4,000.

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Securities [Abstract]
Securities	Note 5. Securities A summary comparison of securities by type at December 31, 2017 and 2016 is shown below. December 31, 2017 December 31, 2016 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for sale: U.S Treasuries $ 19,490 $ - $ (4 ) $ 19,486 $ 29,994 $ - $ - $ 29,994 U.S. Government Agencies 200,052 - (4,069 ) 195,983 183,152 - (4,820 ) 178,332 Corporate debt securities 91,770 661 (946 ) 91,485 132,448 1,624 (2,100 ) 131,972 Mutual funds or other equity securities 500 - (7 ) 493 580 - (7 ) 573 Municipal bonds 37,210 2,434 (75 ) 39,569 28,177 100 (320 ) 27,957 Collateralized mortgage obligations 1,191 - (6 ) 1,185 - - - - Mortgage-backed securities 33,680 - (346 ) 33,334 29,181 - (536 ) 28,645 Total available for sale securities $ 383,893 $ 3,095 $ (5,453 ) $ 381,535 $ 403,532 $ 1,724 $ (7,783 ) $ 397,473 Held to maturity: U.S. Government Agencies $ 28,169 $ - $ (670 ) $ 27,499 $ 18,167 $ - $ (655 ) $ 17,512 Municipal bonds 5,322 15 (12 ) 5,325 - - - - Mortgage-backed securities 86,630 6 (903 ) 85,733 83,696 - (1,302 ) 82,394 Total held to maturity securities $ 120,121 $ 21 $ (1,585 ) $ 118,557 $ 101,863 $ - $ (1,957 ) $ 99,906 The scheduled maturities of securities at December 31, 2017, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities due to call or prepayments. Mortgage-backed securities are not due at a single maturity because of amortization and potential prepayment of the underlying mortgages. For this reason they are presented separately in the maturity table below. December 31, 2017 (in thousands) Amortized Cost Fair Value Available for sale: Due in one year or less $ 29,215 $ 29,233 Due after one year through five years 76,969 76,922 Due after five years through 10 years 217,238 214,769 Over 10 years 25,600 26,092 Subtotal 349,022 347,016 Collateralized mortgage obligations 1,191 1,185 Mortgage-backed Securities 33,680 33,334 Total available for sale securities $ 383,893 $ 381,535 Held to maturity: Due in one year or less $ - $ - Due after one year through five years 5,124 5,057 Due after five years through 10 years 18,485 17,907 Over 10 years 9,882 9,860 Subtotal 33,491 32,824 Mortgage-backed Securities 86,630 85,733 Total held to maturity securities $ 120,121 $ 118,557 The following is a summary of the fair value of securities with gross unrealized losses and an aging of those gross unrealized losses as of the dates indicated: At December 31, 2017 Less Than 12 Months 12 Months or More Total (in thousands) Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Available for sale: U.S. Treasuries 6 $ 19,486 $ (4 ) - $ - $ - 6 $ 19,486 $ (4 ) U.S. Government Agencies 30 62,991 (519 ) 36 132,992 (3,550 ) 66 195,983 (4,069 ) Corporate debt securities 56 19,050 (240 ) 70 22,818 (706 ) 126 41,868 (946 ) Mutual funds or other equity securities 1 493 (7 ) - - - 1 493 (7 ) Municipal bonds 9 4,431 (36 ) 1 1,079 (39 ) 10 5,510 (75 ) Collateralized mortgage obligations 4 936 (6 ) - - - 4 936 (6 ) Mortgage-backed securities 26 14,737 (73 ) 11 18,313 (273 ) 37 33,050 (346 ) Total available for sale securities 132 $ 122,124 $ (885 ) 118 $ 175,202 $ (4,568 ) 250 $ 297,326 $ (5,453 ) Held to maturity: U.S. Government Agencies 4 $ 9,925 $ (75 ) 10 $ 17,574 $ (595 ) 14 $ 27,499 $ (670 ) Municipal bonds 6 3,191 (12 ) - - - 6 3,191 (12 ) Mortgage-backed securities 35 54,186 (515 ) 17 26,852 (388 ) 52 81,038 (903 ) Total held to maturity securities 45 $ 67,302 $ (602 ) 27 $ 44,426 $ (983 ) 72 $ 111,728 $ (1,585 ) At December 31, 2016 Less Than 12 Months 12 Months or More Total (in thousands) Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Available for sale: U.S. Treasuries 3 $ 10,997 $ - - $ - $ - 3 $ 10,997 $ - U.S. Government Agencies 54 178,331 (4,820 ) - - - 54 178,331 (4,820 ) Corporate debt securities 185 61,669 (1,613 ) 26 6,440 (487 ) 211 68,109 (2,100 ) Mutual funds or other equity securities 1 493 (7 ) - - - 1 493 (7 ) Municipal bonds 14 10,210 (320 ) - - - 14 10,210 (320 ) Mortgage-backed securities 16 28,645 (536 ) - - - 16 28,645 (536 ) Total available for sale securities 273 $ 290,345 $ (7,296 ) 26 $ 6,440 $ (487 ) 299 $ 296,785 $ (7,783 ) Held to maturity: U.S. Government Agencies 10 $ 17,512 $ (655 ) - $ - $ - 10 $ 17,512 $ (655 ) Mortgage-backed securities 48 82,394 (1,302 ) - - - 48 82,394 (1,302 ) Total held to maturity securities 58 $ 99,906 $ (1,957 ) - $ - $ - 58 $ 99,906 $ (1,957 ) As of December 31, 2017, 322 of First Guaranty's debt securities had unrealized losses totaling 1.7% of the individual securities' amortized cost basis and 1.4% of First Guaranty's total amortized cost basis of the investment securities portfolio. 145 of the 322 securities had been in a continuous loss position for over 12 months at such date. The 145 securities had an aggregate amortized cost basis of $225.2 million and an unrealized loss of $5.6 million at December 31, 2017. Management has the intent and ability to hold these debt securities until maturity or until anticipated recovery. Securities are evaluated for other-than-temporary impairment at least quarterly and more frequently when economic or market conditions warrant such evaluation. Consideration is given to (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, (iii) the recovery of contractual principal and interest and (iv) the intent and ability of First Guaranty to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value. Investment securities issued by the U.S. Government and Government sponsored enterprises with unrealized losses and the amount of unrealized losses on those investment securities that are the result of changes in market interest rates will not be other-than-temporarily impaired. First Guaranty has the ability and intent to hold these securities until recovery, which may not be until maturity. Corporate debt securities in a loss position consist primarily of corporate bonds issued by businesses in the financial, insurance, utility, manufacturing, industrial, consumer products and oil and gas industries. Two issuers have other-than-temporary impairment losses at December 31, 2017. First Guaranty believes that the remaining issuers will be able to fulfill the obligations of these securities based on evaluations described above. First Guaranty has the ability and intent to hold these securities until they recover, which could be at their maturity dates. During the years ended December 31, 2017,2016, and 2015, First Guaranty recorded OTTI losses on available for sale securities as follows: (in thousands) Year Ended December 31, 2017 Year Ended December 31, 2016 Year Ended December 31, 2015 Total OTTI charge realized and unrealized $ - $ 66 $ 571 OTTI recognized in other comprehensive income (non-credit component) - 6 396 Net impairment losses recognized in earnings (credit component) $ - $ 60 $ 175 There were $0, $0.1 million, and $0.2 million other-than-temporary impairment losses recognized on securities in 2017, 2016 and 2015, respectively. The following table presents a roll-forward of the amount of credit losses on debt securities held by First Guaranty for which a portion of OTTI was recognized in other comprehensive income for the year ended December 31, 2017, 2016, and 2015: (in thousands) Year Ended December 31, 2017 Year Ended December 31, 2016 Year Ended December 31, 2015 Beginning balance of credit losses at beginning of year $ 60 $ 175 $ - Other-than-temporary impairment credit losses on securities not previously OTTI - 60 175 Increases for additional credit losses on securities previously determined to be OTTI - - - Reduction for increases in cash flows - - - Reduction due to credit impaired securities sold or fully settled - (175 ) - Ending balance of cumulative credit losses recognized in earnings at end of year $ 60 $ 60 $ 175 In 2017 there were no other-than-temporary impairment credit losses on securities for which First Guaranty had previously recognized OTTI. For securities that have indications of credit related impairment, management analyzes future expected cash flows to determine if any credit related impairment is evident. Estimated cash flows are determined using management's best estimate of future cash flows based on specific assumptions. The assumptions used to determine the cash flows were based on estimates of loss severity and credit default probabilities. Management reviews reports from credit rating agencies and public filings of issuers. In 2016 there were no other-than-temporary impairment credit losses on securities for which First Guaranty had previously recognized OTTI. The amount related to losses on securities with no previous losses amounted to $0.1 million at December 31, 2016. For securities that have indications of credit related impairment, management analyzes future expected cash flows to determine if any credit related impairment is evident. Estimated cash flows are determined using management's best estimate of future cash flows based on specific assumptions. The assumptions used to determine the cash flows were based on estimates of loss severity and credit default probabilities. Management reviews reports from credit rating agencies and public filings of issuers. The credit related impairment was related to one corporate debt security with a book balance of $0.1 million that experienced declines in its financial performance associated with the utilities industry. This corporate debt security had a non-credit related impairment of approximately $6,000. In 2015 there were no other-than-temporary impairment credit losses on securities for which First Guaranty had previously recognized OTTI. The amount related to losses on securities with no previous losses amounted to $0.2 million at December 31, 2015. The credit related impairment was related to one corporate debt security with a book balance of $0.5 million that experienced declines in its financial performance associated with the mining industry. This corporate debt security had a non-credit related impairment of $0.3 million. This security was sold in 2016. A second corporate debt security had a non-credit related impairment of $0.1 million due to the fact that the issuer went private and liquidity in its debt securities was reduced. Management anticipates receipt of all scheduled cash flows for this security. Non-credit related other-than-temporary impairment losses recognized in other comprehensive income totaled zero in 2017, $6,000 in 2016, and $0.4 million in 2015. The impairment losses in 2016 were related to one available for sale corporate bond security, described above, which had original amortized cost of $0.1 million. The impairment losses in 2015 were related to two available for sale corporate bond securities, described above, which had original amortized cost of $0.8 million. At December 31, 2017 and 2016 the carrying value of pledged securities totaled $412.2 million and $368.2 million, respectively. First Guaranty completed its liquidation of the common stock from a converted preferred security in the third quarter of 2015. The total gains realized on the security were $2.7 million. Gross realized gains on sales of securities were $1.4 million, $3.6 million and $3.3 million (including the sale of the converted preferred security) for the years ended December 31, 2017, 2016 and 2015, respectively. Gross realized losses were $0.1 million, $53,000 and $0.4 million for the years ended December 31, 2017, 2016 and 2015. The tax applicable to these transactions amounted to $0.5 million, $1.3 million, and $1.2 million for 2017, 2016 and 2015, respectively. Proceeds from sales of securities classified as available for sale amounted to $148.0 million, $191.0 million and $290.0 million for the years ended December 31, 2017, 2016 and 2015, respectively. Net unrealized losses on available for sale securities included in accumulated other comprehensive income (loss) ("AOCI"), net of applicable income taxes, totaled $1.6 million at December 31, 2017. At December 31, 2016 net unrealized losses included in AOCI, net of applicable income taxes, totaled $4.0 million. During 2017 and 2016 net gains, net of tax, reclassified out of AOCI into earnings totaled $0.9 million and $2.5 million, respectively. At December 31, 2017, First Guaranty's exposure to investment securities issuers that exceeded 10% of shareholders' equity as follows: At December 31, 2017 (in thousands) Amortized Cost Fair Value U.S. Treasuries $ 19,490 $ 19,486 Federal Home Loan Bank (FHLB) 50,395 49,403 Federal Home Loan Mortgage Corporation (Freddie Mac-FHLMC) 57,569 57,008 Federal National Mortgage Association (Fannie Mae-FNMA) 103,644 101,757 Federal Farm Credit Bank (FFCB) 136,923 134,381 Total $ 368,021 $ 362,035

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Loans [Abstract]
Loans	Note 6. Loans The following table summarizes the components of First Guaranty's loan portfolio as of the dates indicated: December 31, 2017 December 31, 2016 (in thousands except for %) Balance As % of Category Balance As % of Category Real Estate: Construction & land development $ 112,603 9.8 % $ 84,239 8.9 % Farmland 25,691 2.2 % 21,138 2.2 % 1-4 Family 158,733 13.8 % 135,211 14.2 % Multi-family 16,840 1.4 % 12,450 1.3 % Non-farm non-residential 540,231 46.9 % 417,014 43.9 % Total Real Estate 854,098 74.1 % 670,052 70.5 % Non-Real Estate: Agricultural 21,514 1.9 % 23,783 2.5 % Commercial and industrial 220,700 19.2 % 193,969 20.4 % Consumer and other 55,185 4.8 % 63,011 6.6 % Total Non-Real Estate 297,399 25.9 % 280,763 29.5 % Total Loans Before Unearned Income 1,151,497 100.0 % 950,815 100.0 % Unearned income (2,483 ) (1,894 ) Total Loans Net of Unearned Income $ 1,149,014 $ 948,921 The following table summarizes fixed and floating rate loans by contractual maturity, excluding nonaccrual loans, as of December 31, 2017 and December 31, 2016 unadjusted for scheduled principal payments, prepayments, or repricing opportunities. The average life of the loan portfolio may be substantially less than the contractual terms when these adjustments are considered. December 31, 2017 December 31, 2016 (in thousands) Fixed Floating Total Fixed Floating Total One year or less $ 89,383 $ 75,361 $ 164,744 $ 97,713 $ 51,965 $ 149,678 One to five years 390,333 251,135 641,468 352,000 206,676 558,676 Five to 15 years 124,215 70,273 194,488 115,691 46,116 161,807 Over 15 years 70,366 67,881 138,247 53,150 5,830 58,980 Subtotal $ 674,297 $ 464,650 1,138,947 $ 618,554 $ 310,587 929,141 Nonaccrual loans 12,550 21,674 Total Loans Before Unearned Income 1,151,497 950,815 Unearned income (2,483 ) (1,894 ) Total Loans Net of Unearned Income $ 1,149,014 $ 948,921 As of December 31, 2017, $95.4 million of floating rate loans were at their interest rate floor. At December 31, 2016, $127.7 million of floating rate loans were at the floor rate. Nonaccrual loans have been excluded from these totals. The following tables present the age analysis of past due loans for the periods indicated: As of December 31, 2017 (in thousands) 30-89 Days Past Due 90 Days or Greater Past Due Total Past Due Current Total Loans Recorded Investment 90 Days Accruing Real Estate: Construction & land development $ 95 $ 371 $ 466 $ 112,137 $ 112,603 $ - Farmland 175 65 240 25,451 25,691 - 1-4 family 1,481 1,953 3,434 155,299 158,733 - Multi-family - - - 16,840 16,840 - Non-farm non-residential 1,006 3,758 4,764 535,467 540,231 - Total Real Estate 2,757 6,147 8,904 845,194 854,098 - Non-Real Estate: Agricultural 239 1,537 1,776 19,738 21,514 41 Commercial and industrial 630 5,624 6,254 214,446 220,700 798 Consumer and other 463 81 544 54,641 55,185 - Total Non-Real Estate 1,332 7,242 8,574 288,825 297,399 839 Total Loans Before Unearned Income $ 4,089 $ 13,389 $ 17,478 $ 1,134,019 1,151,497 $ 839 Unearned income (2,483 ) Total Loans Net of Unearned Income $ 1,149,014 As of December 31, 2016 (in thousands) 30-89 Days Past Due 90 Days or Greater Past Due Total Past Due Current Total Loans Recorded Investment 90 Days Accruing Real Estate: Construction & land development $ 173 $ 585 $ 758 $ 83,481 $ 84,239 $ 34 Farmland 234 105 339 20,799 21,138 - 1-4 family 1,108 2,387 3,495 131,716 135,211 145 Multi-family - 5,014 5,014 7,436 12,450 - Non-farm non-residential 1,618 2,753 4,371 412,643 417,014 - Total Real Estate 3,133 10,844 13,977 656,075 670,052 179 Non-Real Estate: Agricultural 64 1,958 2,022 21,761 23,783 - Commercial and industrial 552 8,070 8,622 185,347 193,969 - Consumer and other 182 981 1,163 61,848 63,011 - Total Non-Real Estate 798 11,009 11,807 268,956 280,763 - Total Loans Before Unearned Income $ 3,931 $ 21,853 $ 25,784 $ 925,031 950,815 $ 179 Unearned income (1,894 ) Total Loans Net of Unearned Income $ 948,921 The tables above include $12.6 million and $21.7 million of nonaccrual loans for December 31, 2017 and 2016, respectively. See the tables below for more detail on nonaccrual loans. The following is a summary of nonaccrual loans by class for the periods indicated: As of December 31, (in thousands) 2017 2016 Real Estate: Construction & land development $ 371 $ 551 Farmland 65 105 1-4 family 1,953 2,242 Multi-family - 5,014 Non-farm non-residential 3,758 2,753 Total Real Estate 6,147 10,665 Non-Real Estate: Agricultural 1,496 1,958 Commercial and industrial 4,826 8,070 Consumer and other 81 981 Total Non-Real Estate 6,403 11,009 Total Nonaccrual Loans $ 12,550 $ 21,674 The following table identifies the credit exposure of the loan portfolio by specific credit ratings for the periods indicated: As of December 31, 2017 As of December 31, 2016 (in thousands) Pass Special Mention Substandard Doubtful Total Pass Special Mention Substandard Doubtful Total Real Estate: Construction & land development $ 108,200 $ 125 $ 4,278 $ - $ 112,603 $ 79,069 $ 1,162 $ 4,008 $ - $ 84,239 Farmland 25,030 569 92 - 25,691 20,652 381 105 - 21,138 1-4 family 149,426 1,856 7,451 - 158,733 123,191 5,460 6,560 - 135,211 Multi-family 9,366 639 6,835 - 16,840 4,268 1,132 7,050 - 12,450 Non-farm non-residential 520,432 2,490 17,309 - 540,231 392,355 6,406 18,253 - 417,014 Total Real Estate 812,454 5,679 35,965 - 854,098 619,535 14,541 35,976 - 670,052 Non-Real Estate: Agricultural 19,050 995 1,469 - 21,514 20,890 920 1,973 - 23,783 Commercial and industrial 191,784 19,187 5,169 4,560 220,700 182,381 850 3,008 7,730 193,969 Consumer and other 48,225 68 6,892 - 55,185 60,582 1,394 1,035 - 63,011 Total Non-Real Estate 259,059 20,250 13,530 4,560 297,399 263,853 3,164 6,016 7,730 280,763 Total Loans Before Unearned Income $ 1,071,513 $ 25,929 $ 49,495 $ 4,560 1,151,497 $ 883,388 $ 17,705 $ 41,992 $ 7,730 950,815 Unearned income (2,483 ) (1,894 ) Total Loans Net of Unearned Income $ 1,149,014 $ 948,921 Purchased Impaired Loans As part of the acquisition of Premier Bancshares, Inc. on June 16, 2017, First Guaranty purchased credit impaired loans for which there was, at acquisition, evidence of deterioration of credit quality since their origination and it was probable, at acquisition, that all contractually required payments would not be collected. The carrying amount of those loans is as follows at December 31, 2017. (in thousands) As of December 31, 2017 Real Estate: Construction & land development $ 1,135 Farmland 8 1-4 family 50 Multi-family - Non-farm non-residential 2,148 Total Real Estate 3,341 Non-Real Estate: Agricultural - Commercial and industrial 1,017 Consumer and other - Total Non-Real Estate 1,017 Total Carrying Amount $ 4,358 Contractual principal balance $ 5,436 Carrying amount, net of allowance $ 4,358 For those purchased loans disclosed above, First Guaranty did not increase the allowance for loan losses for the year ended December 31, 2017. Where First Guaranty can reasonably estimate the cash flows expected to be collected on the loans, a portion of the purchase discount is allocated to an accretable yield adjustment based upon the present value of the future estimated cash flows versus the current carrying value of the loan and the accretable yield portion is being recognized as interest income over the remaining life of the loan. Where First Guaranty cannot reasonably estimate the cash flows expected to be collected on the loans, it has decided to account for those loans using the cost recovery method of income recognition. As such, no portion of a purchase discount adjustment has been determined to meet the definition of an accretable yield adjustment on those loans accounted for using the cost recovery method. If, in the future, cash flows from the borrower(s) can be reasonably estimated, a portion of the purchase discount would be allocated to an accretable yield adjustment based upon the present value of the future estimated cash flows versus the current carrying value of the loan and the accretable yield portion would be recognized as interest income over the remaining life of the loan. Until such accretable yield can be calculated, under the cost recovery method of income recognition, all payments will be used to reduce the carrying value of the loan and no income will be recognized on the loan until the carrying value is reduced to zero. Any loan accounted for under the cost recovery method is also still included as a non-accrual loan in the amounts presented in the table below. The accretable yield, or income expected to be collected, on the purchased loans above is as follows at December 31, 2017. (in thousands) Year Ended December 31, 2017 Balance, beginning of period $ - Acquisition accretable yield 1,195 Accretion (164 ) Net transfers from nonaccretable difference to accretable yield - Balance, end of period $ 1,031 The contractually required payments of purchased impaired loans totaled $7.5 million, while the cash flow expected to be collected at acquisition totaled $5.0 million, and the fair value of the acquired loans totaled $3.8 million.

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Allowance for Loan Losses [Abstract]
Allowance for Loan Losses	Note 7. Allowance for Loan Losses A summary of changes in the allowance for loan losses, by loan type, for the years ended December 31, 2017, 2016 and 2015 are as follows: As of December 31, 2017 2016 (in thousands) Beginning Allowance (12/31/16) Charge-offs Recoveries Provision Ending Allowance (12/31/17) Beginning Allowance (12/31/15) Charge-offs Recoveries Provision Ending Allowance (12/31/16) Real Estate: Construction & land development $ 1,232 $ - $ 43 $ (647 ) $ 628 $ 962 $ - $ 4 $ 266 $ 1,232 Farmland 19 - - (14 ) 5 54 - - (35 ) 19 1-4 family 1,204 (33 ) 92 (185 ) 1,078 1,771 (244 ) 45 (368 ) 1,204 Multi-family 591 - 40 363 994 557 - 401 (367 ) 591 Non-farm non-residential 3,451 (1,291 ) 85 566 2,811 3,298 (1,373 ) 16 1,510 3,451 Total Real Estate 6,497 (1,324 ) 260 83 5,516 6,642 (1,617 ) 466 1,006 6,497 Non-Real Estate: Agricultural 74 (162 ) 138 137 187 16 (83 ) 113 28 74 Commercial and industrial 3,543 (3,629 ) 30 2,433 2,377 2,527 (579 ) 146 1,449 3,543 Consumer and other 972 (1,247 ) 223 1,177 1,125 230 (635 ) 183 1,194 972 Unallocated 28 - - (8 ) 20 - - - 28 28 Total Non-Real Estate 4,617 (5,038 ) 391 3,739 3,709 2,773 (1,297 ) 442 2,699 4,617 Total $ 11,114 $ (6,362 ) $ 651 $ 3,822 $ 9,225 $ 9,415 $ (2,914 ) $ 908 $ 3,705 $ 11,114 As of December 31, 2015 (in thousands) Beginning Allowance (12/31/14) Charge-offs Recoveries Provision Ending Allowance (12/31/15) Real Estate: Construction & land development $ 702 $ (559 ) $ 5 $ 814 $ 962 Farmland 21 - - 33 54 1-4 family 2,131 (410 ) 94 (44 ) 1,771 Multi-family 813 (947 ) 46 645 557 Non-farm non-residential 2,713 (1,137 ) 5 1,717 3,298 Total Real Estate 6,380 (3,053 ) 150 3,165 6,642 Non-Real Estate: Agricultural 293 (491 ) 3 211 16 Commercial and industrial 1,797 (79 ) 315 494 2,527 Consumer and other 371 (550 ) 151 258 230 Unallocated 264 - - (264 ) - Total Non-Real Estate 2,725 (1,120 ) 469 699 2,773 Total $ 9,105 $ (4,173 ) $ 619 $ 3,864 $ 9,415 Negative provisions are caused by changes in the composition and credit quality of the loan portfolio. The result is an allocation of the loan loss reserve from one category to another. A summary of the allowance and loans individually and collectively evaluated for impairment are as follows: As of December 31, 2017 (in thousands) Allowance Individually Evaluated for Impairment Allowance Collectively Evaluated for Impairment Total Allowance for Credit Losses Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment Total Loans before Unearned Income Real Estate: Construction & land development $ - $ 628 $ 628 $ - $ 112,603 $ 112,603 Farmland - 5 5 - 25,691 25,691 1-4 family - 1,078 1,078 - 158,733 158,733 Multi-family - 994 994 - 16,840 16,840 Non-farm non-residential 236 2,575 2,811 8,990 531,241 540,231 Total Real Estate 236 5,280 5,516 8,990 845,108 854,098 Non-Real Estate: Agricultural 66 121 187 861 20,653 21,514 Commercial and industrial 565 1,812 2,377 5,731 214,969 220,700 Consumer and other - 1,125 1,125 - 55,185 55,185 Unallocated - 20 20 - - - Total Non-Real Estate 631 3,078 3,709 6,592 290,807 297,399 Total $ 867 $ 8,358 $ 9,225 $ 15,582 $ 1,135,915 1,151,497 Unearned Income (2,483 ) Total Loans Net of Unearned Income $ 1,149,014 As of December 31, 2016 (in thousands) Allowance Individually Evaluated for Impairment Allowance Collectively Evaluated for Impairment Total Allowance for Credit Losses Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment Total Loans before Unearned Income Real Estate: Construction & land development $ - $ 1,232 $ 1,232 $ 361 $ 83,878 $ 84,239 Farmland - 19 19 - 21,138 21,138 1-4 family 8 1,196 1,204 1,130 134,081 135,211 Multi-family 164 427 591 5,014 7,436 12,450 Non-farm non-residential 247 3,204 3,451 10,803 406,211 417,014 Total Real Estate 419 6,078 6,497 17,308 652,744 670,052 Non-Real Estate: Agricultural 11 63 74 1,614 22,169 23,783 Commercial and industrial 2,375 1,168 3,543 8,965 185,004 193,969 Consumer and other 193 779 972 924 62,087 63,011 Unallocated - 28 28 - - - Total Non-Real Estate 2,579 2,038 4,617 11,503 269,260 280,763 Total $ 2,998 $ 8,116 $ 11,114 $ 28,811 $ 922,004 950,815 Unearned Income (1,894 ) Total Loans Net of Unearned Income $ 948,921 As of December 31, 2017, 2016 and 2015, First Guaranty had loans totaling $12.6 million, $21.7 million and $20.0 million, respectively, not accruing interest. As of December 31, 2017, 2016 and 2015, First Guaranty had loans past due 90 days or more and still accruing interest totaling $0.8 million, $0.2 million and $0.4 million, respectively. The average outstanding balance of nonaccrual loans in 2017 was $17.3 million compared to $22.5 million in 2016 and $14.9 million in 2015. As of December 31, 2017, First Guaranty has no outstanding commitments to advance additional funds in connection with impaired loans. The following is a summary of impaired loans by class at December 31, 2017: As of December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Interest Income Cash Basis Impaired Loans with no related allowance: Real Estate: Construction & land development $ - $ - $ - $ - $ - $ - Farmland - - - - - - 1-4 family - - - - - - Multi-family - - - - - - Non-farm non-residential 5,771 5,771 - 5,933 248 279 Total Real Estate 5,771 5,771 - 5,933 248 279 Non-Real Estate: Agricultural - - - - - - Commercial and industrial - - - - - - Consumer and other - - - - - - Total Non-Real Estate - - - - - - Total Impaired Loans with no related allowance 5,771 5,771 - 5,933 248 279 Impaired Loans with an allowance recorded: Real estate: Construction & land development - - - - - - Farmland - - - - - - 1-4 family - - - - - - Multi-family - - - - - - Non-farm non-residential 3,219 3,570 236 3,555 183 127 Total Real Estate 3,219 3,570 236 3,555 183 127 Non-Real Estate: Agricultural 861 920 66 1,117 70 17 Commercial and industrial 5,731 9,062 565 8,121 65 84 Consumer and other - - - - - - Total Non-Real Estate 6,592 9,982 631 9,238 135 101 Total Impaired Loans with an allowance recorded 9,811 13,552 867 12,793 318 228 Total Impaired Loans $ 15,582 $ 19,323 $ 867 $ 18,726 $ 566 $ 507 The following is a summary of impaired loans by class at December 31, 2016: As of December 31, 2016 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Interest Income Cash Basis Impaired Loans with no related allowance: Real Estate: Construction & land development $ 361 $ 823 $ - $ 363 $ - $ - Farmland - - - - - - 1-4 family 863 1,196 - 1,044 49 48 Multi-family - - - - - - Non-farm non-residential 8,501 9,430 - 8,949 196 175 Total Real Estate 9,725 11,449 - 10,356 245 223 Non-Real Estate: Agricultural 1,603 1,742 - 1,377 30 - Commercial and industrial - - - - - - Consumer and other 686 685 - 724 18 12 Total Non-Real Estate 2,289 2,427 - 2,101 48 12 Total Impaired Loans with no related allowance 12,014 13,876 - 12,457 293 235 Impaired Loans with an allowance recorded: Real estate: Construction & land development - - - - - - Farmland - - - - - - 1-4 family 267 303 8 279 - - Multi-family 5,014 5,305 164 5,169 - - Non-farm non-residential 2,302 2,296 247 2,334 119 113 Total Real Estate 7,583 7,904 419 7,782 119 113 Non-Real Estate: Agricultural 11 11 11 11 - - Commercial and industrial 8,965 9,117 2,375 9,379 72 72 Consumer and other 238 244 193 289 8 7 Total Non-Real Estate 9,214 9,372 2,579 9,679 80 79 Total Impaired Loans with an allowance recorded 16,797 17,276 2,998 17,461 199 192 Total Impaired Loans $ 28,811 $ 31,152 $ 2,998 $ 29,918 $ 492 $ 427 Troubled Debt Restructurings A Troubled Debt Restructuring ("TDR") is a debt restructuring in which the creditor for economic or legal reasons related to the debtor's financial difficulties grants a concession to the debtor that it would not otherwise consider. The modifications to First Guaranty's TDRs were concessions on the interest rate charged. The effect of the modifications to First Guaranty was a reduction in interest income. These loans were evaluated in First Guaranty's reserve for loan losses. In 2017 and 2016, there were no credit relationships that were restructured in a troubled debt restructuring. The following table is an age analysis of TDRs as of December 31, 2017 and December 31, 2016: Troubled Debt Restructurings December 31, 2017 December 31, 2016 Accruing Loans Accruing Loans (in thousands) Current 30-89 Days Past Due Nonaccrual Total TDRs Current 30-89 Days Past Due Nonaccrual Total TDRs Real Estate: Construction & land development $ - $ - $ 334 $ 334 $ - $ - $ 361 $ 361 Farmland - - - - - - - - 1-4 family - - - - - - - - Multi-family - - - - - - - - Non-farm non-residential 2,138 - - 2,138 2,987 - 100 3,087 Total Real Estate 2,138 - 334 2,472 2,987 - 461 3,448 Non-Real Estate: Agricultural - - - - - - - - Commercial and industrial - - - - - - - - Consumer and other - - - - - - - - Total Non-Real Estate - - - - - - - - Total $ 2,138 $ - $ 334 $ 2,472 $ 2,987 $ - $ 461 $ 3,448 The following table discloses TDR activity for the twelve months ended December 31, 2017. Trouble Debt Restructured Loans Activity Twelve Months Ended December 31, 2017 (in thousands) Beginning balance (December 31, 2016) New TDRs Charge-offs post-modification Transferred to ORE Paydowns Construction to permanent financing Restructured to market terms Other adjustments Ending balance (December 31, 2017) Real Estate: Construction & land development $ 361 $ - $ - $ - $ (27 ) $ - $ - $ - $ 334 Farmland - - - - - - - - - 1-4 family - - - - - - - - - Multi-family - - - - - - - - - Non-farm non-residential 3,087 - (102 ) - (849 ) - - 2 2,138 Total Real Estate 3,448 - (102 ) - (876 ) - - 2 2,472 Non-Real Estate: Agricultural - - - - - - - - - Commercial and industrial - - - - - - - - - Consumer and other - - - - - - - - - Total Non-Real Estate - - - - - - - - - Total Impaired Loans with no related allowance $ 3,448 $ - $ (102 ) $ - $ (876 ) $ - $ - $ 2 $ 2,472 There were no commitments to lend additional funds to debtors whose terms have been modified in a troubled debt restructuring at December 31, 2017.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Premises and Equipment [Abstract]
Premises and Equipment	Note 8. Premises and Equipment The components of premises and equipment at December 31, 2017 and 2016 are as follows: (in thousands) December 31, 2017 December 31, 2016 Land $ 12,875 $ 7,185 Bank premises 31,469 21,229 Furniture and equipment 24,305 21,689 Construction in progress 382 2,106 Acquired value 69,031 52,209 Less: accumulated depreciation 31,011 28,690 Net book value $ 38,020 $ 23,519 Depreciation expense amounted to $1.8 million, $1.7 million and $1.6 million for 2017, 2016 and 2015, respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Intangible Assets [Abstract]
Goodwill and Other Intangible Assets	Note 9. Goodwill and Other Intangible Assets Goodwill and intangible assets deemed to have indefinite lives are no longer amortized, but are subject to impairment testing. Other intangible assets continue to be amortized over their useful lives. Goodwill represents the purchase price over the fair value of net assets acquired from the Homestead Bancorp in 2007 and Premier Bancshares, Inc. in 2017. No impairment charges have been recognized since acquisition. Goodwill totaled $3.5 million and $2.0 million at December 31, 2017 and 2016, respectively. The following table summarizes intangible assets subject to amortization. December 31, 2017 December 31, 2016 (in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Core deposit intangibles $ 12,053 $ 8,804 $ 3,249 $ 9,350 $ 8,372 $ 978 Mortgage servicing rights 1,373 198 1,175 267 189 78 Total $ 13,426 $ 9,002 $ 4,424 $ 9,617 $ 8,561 $ 1,056 The core deposits intangible reflect the value of deposit relationships, including the beneficial rates, which arose from acquisitions. The weighted-average amortization period remaining for the core deposit intangibles is 9.7 years. Amortization expense relating to purchase accounting intangibles totaled $0.4 million, $0.3 million, and $0.3 million for the years ended December 31, 2017, 2016, and 2015, respectively. Amortization expense of the core deposit intangible assets for the next five years is as follows: For the Years Ended Estimated Amortization Expense (in thousands) December 31, 2018 $ 545 December 31, 2019 $ 361 December 31, 2020 $ 361 December 31, 2021 $ 293 December 31, 2022 $ 225

Other Real Estate

Other Real Estate	12 Months Ended
	Dec. 31, 2017
Other Real Estate [Abstract]
Other Real Estate	Note 10. Other Real Estate Other real estate owned consists of the following: (in thousands) December 31, 2017 December 31, 2016 Real Estate Owned Acquired by Foreclosure: Residential $ 23 $ 71 Construction & land development 304 - Non-farm non-residential 954 288 Total Other Real Estate Owned and Foreclosed Property $ 1,281 $ 359

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	Note 11. Deposits A schedule of maturities of all time deposits are as follows: (in thousands) December 31, 2017 2018 $ 357,687 2019 118,902 2020 48,843 2021 16,622 2022 and thereafter 39,277 Total $ 581,331 The table above includes, for December 31, 2017, brokered deposits totaling $9.8 million. The aggregate amount of jumbo time deposits, each with a minimum denomination of $250,000 totaled $266.2 million and $241.4 million at December 31, 2017 and 2016, respectively.

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Borrowings [Abstract]
Borrowings	Note 12. Borrowings Short-term borrowings are summarized as follows: (in thousands) December 31, 2017 December 31, 2016 Federal Home Loan Bank advances $ 15,500 $ 6,500 Line of credit - - Total short-term borrowings $ 15,500 $ 6,500 First Guaranty maintains borrowing relationships with other financial institutions as well as the Federal Home Loan Bank on a short and long-term basis to meet liquidity needs. Short-term borrowings totaled $15.5 million at December 31, 2017 and $6.5 million at December 31, 2016. Short-term borrowing consisted of a line of credit of $6.5 million, with no outstanding balance at December 31, 2017 and collateralized short-term borrowings from the Federal Home Loan Bank totaling $15.5 million at December 31, 2017. Available lines of credit totaled $150.8 million at December 31, 2017 and $133.7 million at December 31, 2016. The following schedule provides certain information about First Guaranty's short-term borrowings for the periods indicated: December 31, (in thousands except for %) 2017 2016 2015 Outstanding at year end $ 15,500 $ 6,500 $ 1,800 Maximum month-end outstanding $ 28,000 $ 25,000 $ 13,800 Average daily outstanding $ 5,833 $ 8,775 $ 4,217 Weighted average rate during the year 1.06 % 0.85 % 2.12 % Weighted average rate at year end 1.51 % 0.65 % 4.50 % Long-term debt is summarized as follows: Senior long-term debt with a commercial bank, priced at floating 3-month LIBOR plus 250 basis points (3.87%), totaled $22.8 million at December 31, 2017 and $21.8 at December 31, 2016. First Guaranty pays $735,294 principal plus interest quarterly. This loan was originated in December 2015 and has a contractual maturity date of December 22, 2020. This long-term debt is secured by a pledge of 85% (4,823,899 shares) of First Guaranty's interest in First Guaranty Bank (a wholly owned subsidiary). First Guaranty modified its existing senior long-term debt in the second quarter of 2017. The modification increased the principal balance to $25.0 million with new net proceeds of $3.8 million. The existing amortization terms and rates remained the same. The $3.8 million in additional proceeds were contributed to First Guaranty Bank for future growth. Senior long-term debt with a commercial bank, priced at Wall Street Journal Prime plus 75 basis points (4.75%), had no outstanding balance at December 31, 2017 and totaled $0.3 million at December 31, 2016. First Guaranty paid $50,000 principal plus interest monthly. This long-term debt was secured by a pledge of 13.2% (735,745 shares) of First Guaranty's interest in First Guaranty Bank (a wholly owned subsidiary). This loan matured on May 12, 2017. Junior subordinated debt, priced at Wall Street Journal Prime plus 75 basis points (4.00%), totaled $14.7 million at December 31, 2017 and $14.6 million at December 31, 2016. First Guaranty pays interest semi-annually for the Fixed Interest Rate Period and quarterly for the Floating Interest Rate Period. The Note is unsecured and ranks junior in right of payment to any senior indebtedness and obligations to general and secured creditors. The Note was originated in December 2015 and is scheduled to mature on December 21, 2025. Subject to limited exceptions, First Guaranty cannot repay the Note until after December 21, 2020. The Note qualifies for treatment as Tier 2 capital for regulatory capital purposes. First Guaranty maintains a revolving line of credit for $6.5 million with an availability of $6.5 million at December 31, 2017. This line of credit is secured by the same collateral as the senior term loan and is priced at 4.50%. At December 31, 2017, letters of credit issued by the FHLB totaling $294.2 million were outstanding and carried as off-balance sheet items, all of which expire in 2018. At December 31, 2016, letters of credit issued by the FHLB totaling $226.1 million were outstanding and carried as off-balance sheet items, all of which expired in 2017. The letters of credit are solely used for pledging towards public fund deposits. The FHLB has a blanket lien on substantially all of the loans in First Guaranty's portfolio which is used to secure borrowing availability from the FHLB. First Guaranty has obtained a subordination agreement from the FHLB on First Guaranty's farmland, agricultural, and commercial and industrial loans. These loans are available to be pledged for additional reserve liquidity. As of December 31, 2017 obligations on senior long-term debt and junior subordinated debentures totaled $37.4 million. The scheduled maturities are as follows: (in thousands) Senior Long-term Debt Junior Subordinated Debentures 2018 $ 2,941 $ - 2019 2,941 - 2020 2,941 - 2021 2,941 - 2022 2,941 - 2023 and thereafter 8,089 15,000 Subtotal $ 22,794 $ 15,000 Debt issuance costs (20 ) (336 ) Total $ 22,774 $ 14,664

Capital Requirements

Capital Requirements	12 Months Ended
	Dec. 31, 2017
Capital Requirements [Abstract]
Capital Requirements	Note 13. Capital Requirements First Guaranty and the Bank are subject to various regulatory capital requirements administered by federal and state banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions that, if undertaken, could have a direct material effect on First Guaranty's financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, First Guaranty and the Bank must meet specific capital guidelines that involve quantitative measures of their assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. Prompt corrective action provisions are not applicable to bank holding companies. Quantitative measures established by regulation to ensure capital adequacy require First Guaranty and the Bank to maintain minimum amounts and ratios of total and Tier 1 capital to risk-weighted assets and of Tier 1 capital to average assets. Management believes, as of December 31, 2017 and 2016, that First Guaranty and the Bank met all capital adequacy requirements. In addition to establishing the minimum regulatory capital requirements, the regulations limit capital distributions and certain discretionary bonus payments to management if the institution does not hold a "capital conservation buffer" consisting of 2.5% of common equity Tier 1 capital to risk-weighted asset above the amount necessary to meet its minimum risk-based capital requirements. The capital conservation buffer requirement is being phased in beginning January 1, 2016 at 0.625% of risk-weighted assets and increasing each year until fully implemented at 2.5% on January 1, 2019. For 2018, the capital conservation buffer will be 1.875% of risk-weighted assets. First Guaranty Bancshares, Inc. capital conservation buffer was 4.14% at December 31, 2017. First Guaranty Bank's capital conservation buffer was 5.07% at December 31, 2017. As of December 31, 2017, the most recent notification from the Federal Deposit Insurance Corporation categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized, an institution must maintain minimum total risk-based, Tier 1 risk-based and Tier 1 leverage ratios as set forth in the following table. There are no conditions or events since the notification that Management believes have changed the Bank's category. First Guaranty's and the Bank's actual capital amounts and ratios as of December 31, 2017 and 2016 are presented in the following table. Actual Minimum Capital Requirements Minimum to be Well Capitalized Under Action Provisions (in thousands except for %) Amount Ratio Amount Ratio Amount Ratio December 31, 2017 Total Risk-based Capital: Consolidated $ 164,545 12.14 % $ 108,427 8.00 % N/A N/A Bank $ 176,398 13.07 % $ 107,961 8.00 % $ 134,951 10.00 % Tier 1 Capital: Consolidated $ 140,320 10.35 % $ 81,320 6.00 % N/A N/A Bank $ 167,173 12.39 % $ 80,971 6.00 % $ 107,961 8.00 % Tier 1 Leverage Capital: Consolidated $ 140,320 8.27 % $ 67,899 4.00 % N/A N/A Bank $ 167,173 9.88 % $ 67,709 4.00 % $ 84,636 5.00 % Common Equity Tier One Capital: Consolidated $ 140,320 10.35 % $ 60,990 4.50 % N/A N/A Bank $ 167,173 12.39 % $ 60,728 4.50 % $ 87,718 6.50 % December 31, 2016 Total Risk-based Capital: Consolidated $ 151,877 12.79 % $ 94,982 8.00 % N/A N/A Bank $ 153,768 12.99 % $ 94,717 8.00 % $ 118,396 10.00 % Tier 1 Capital: Consolidated $ 125,763 10.59 % $ 71,236 6.00 % N/A N/A Bank $ 142,654 12.05 % $ 71,038 6.00 % $ 94,717 8.00 % Tier 1 Leverage Capital: Consolidated $ 125,763 8.68 % $ 57,930 4.00 % N/A N/A Bank $ 142,654 9.88 % $ 57,771 4.00 % $ 72,214 5.00 % Common Equity Tier One Capital: Consolidated $ 125,763 10.59 % $ 53,427 4.50 % N/A N/A Bank $ 142,654 12.05 % $ 53,278 4.50 % $ 76,958 6.50 %

Dividend Restrictions

Dividend Restrictions	12 Months Ended
	Dec. 31, 2017
Dividend Restrictions [Abstract]
Dividend Restrictions	Note 14. Dividend Restrictions The Federal Reserve Bank ("FRB") has stated that, generally, a bank holding company should not maintain a rate of distributions to shareholders unless its available net income has been sufficient to fully fund the distributions, and the prospective rate of earnings retention appears consistent with the bank holding company's capital needs, asset quality and overall financial condition. As a Louisiana corporation, First Guaranty is restricted under the Louisiana corporate law from paying dividends under certain conditions. First Guaranty Bank may not pay dividends or distribute capital assets if it is in default on any assessment due to the FDIC. First Guaranty Bank is also subject to regulations that impose minimum regulatory capital and minimum state law earnings requirements that affect the amount of cash available for distribution. In addition, under the Louisiana Banking Law, dividends may not be paid if it would reduce the unimpaired surplus below 50% of outstanding capital stock in any year. The Bank is restricted under applicable laws in the payment of dividends to an amount equal to current year earnings plus undistributed earnings for the immediately preceding year, unless prior permission is received from the Commissioner of Financial Institutions for the State of Louisiana. Dividends payable by the Bank in 2018 without permission will be limited to 2018 earnings plus the undistributed earnings of $3.2 million from 2017. Accordingly, at January 1, 2018, $167.6 million of First Guaranty's equity in the net assets of the Bank was restricted. In addition, dividends paid by the Bank to First Guaranty would be prohibited if the effect thereof would cause the Bank's capital to be reduced below applicable minimum capital requirements.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Note 15. Related Party Transactions In the normal course of business, First Guaranty and its subsidiary, First Guaranty Bank, have loans, deposits and other transactions with its executive officers, directors and certain business organizations and individuals with which such persons are associated. These transactions are completed with terms no less favorable than current market rates. An analysis of the activity of loans made to such borrowers during the year ended December 31, 2017 and 2016 follows: December 31, (in thousands) 2017 2016 Balance, beginning of year $ 58,279 $ 57,816 Net Increase 24,639 463 Balance, end of year $ 82,918 $ 58,279 Unfunded commitments to First Guaranty and Bank directors and executive officers totaled $17.5 million and $24.9 million at December 31, 2017 and 2016, respectively. At December 31, 2017 First Guaranty and the Bank had deposits from directors and executives totaling $24.6 million. There were no participations in loans purchased from affiliated financial institutions included in First Guaranty's loan portfolio in 2017 or 2016. During the years ended 2017, 2016 and 2015, First Guaranty paid approximately $0.4 million, $0.3 million and $0.2 million, respectively, for printing services and supplies and office furniture and equipment to Champion Industries, Inc., of which Mr. Marshall T. Reynolds, the Chairman of First Guaranty's Board of Directors, is President, Chief Executive Officer, Chairman of the Board of Directors and a major shareholder of Champion. On December 21, 2015, First Guaranty issued a $15.0 million subordinated note (the "Note") to Edgar Ray Smith III, a director of First Guaranty. The Note is for a ten-year term (non-callable for first five years) and Wall Street Journal During the years ended 2017, 2016 and 2015, First Guaranty paid approximately $0.2 million, $0.3 million and $0.2 million, respectively, for architectural services in relation to bank branches to Gasaway Gasaway Bankston Architects, of which bank subsidiary board member Andrew B. Gasaway is part owner.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Employee Benefit Plans [Abstract]
Employee Benefit Plans	Note 16. Employee Benefit Plans First Guaranty has an employee savings plan to which employees, who meet certain service requirements, may defer 1% to 20% of their base salaries, 6% of which may be matched up to 100%, at its sole discretion. Contributions to the savings plan were $240,000, $191,000 and $86,000 in 2017, 2016 and 2015, respectively. First Guaranty has an Employee Stock Ownership Plan ("ESOP") which was frozen in 2010. No contributions were made to the ESOP for the years 2017, 2016 or 2015. As of December 31, 2017, the ESOP held 15,530 shares. First Guaranty is in the process of terminating the plan.

Other Expenses

Other Expenses	12 Months Ended
	Dec. 31, 2017
Other Expenses [Abstract]
Other Expenses	Note 17. Other Expenses The following is a summary of the significant components of other noninterest expense: December 31, (in thousands) 2017 2016 2015 Other noninterest expense: Legal and professional fees $ 3,037 $ 2,185 $ 2,019 Data processing 1,608 1,259 1,184 ATM Fees 1,161 1,044 1,022 Marketing and public relations 1,205 878 848 Taxes - sales, capital and franchise 970 787 717 Operating supplies 496 471 414 Software expense and amortization 923 835 612 Travel and lodging 910 710 818 Telephone 167 177 172 Amortization of core deposits 432 320 320 Donations 322 298 332 Net costs from other real estate and repossessions 306 498 493 Regulatory assessment 726 1,005 1,111 Other 1,640 1,599 1,692 Total other noninterest expense $ 13,903 $ 12,066 $ 11,754 First Guaranty does not capitalize advertising costs. They are expensed as incurred and are included in other noninterest expense on the Consolidated Statements of Income. Advertising expense was $0.7 million, $0.6 million and $0.6 million for 2017, 2016 and 2015, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Income Taxes	Note 18. Income Taxes On December 22, 2017, the Tax Cuts and Jobs Act ("TCJA") was signed into law. The TCJA makes broad and complex changes to the U.S. tax code that affected income tax expense in 2017. The TCJA reduces the U.S. federal corporate income tax rate from 35% to 21% beginning January 1, 2018 and also establishes new tax laws that will affect 2018. ASC 740 requires a company to record the effects of a tax law change in the period of enactment, however, shortly after the enactment of the TCJA, the SEC staff issued SAB 118, which allows a company to record a provisional amount when it does not have the necessary information available, prepared, or analyzed in reasonable detail to complete its accounting for the change in the tax law. The measurement period ends when the company has obtained, prepared and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year. The following is a summary of the provision for income taxes included in the Consolidated Statements of Income: December 31, (in thousands) 2017 2016 2015 Current $ 4,638 $ 8,168 $ 7,347 Deferred 2,761 (1,004 ) (384 ) Total $ 7,399 $ 7,164 $ 6,963 The difference between income taxes computed by applying the statutory federal income tax rate and the provision for income taxes in the financial statements is reconciled as follows: December 31, (in thousands except for %) 2017 2016 2015 Statutory tax rate 35.0 % 35.0 % 35.0 % Federal income taxes at statutory rate $ 6,703 $ 7,440 $ 7,514 Tax exempt municipal income (254 ) (283 ) (436 ) Other (1) 950 7 (115 ) Total $ 7,399 $ 7,164 $ 6,963 (1) Included in other for the year ended December 31, 2017 is $0.9 million related to the estimated net impact from the remeasurement of deferred tax assets and liabilities as a result of the passage of the Tax Cuts and Jobs Act in December 2017. Deferred taxes are recorded based upon differences between the financial statement and tax basis of assets and liabilities, and available tax credit carry forwards. Temporary differences between the financial statement and tax values of assets and liabilities give rise to deferred taxes. The significant components of deferred taxes classified in First Guaranty's Consolidated Balance Sheets at December 31, 2017 and 2016 are as follows: December 31, (in thousands) 2017 2016 Deferred tax assets: Allowance for loan losses $ 1,804 $ 3,890 Other real estate owned 25 60 Unrealized losses on available for sale securities 495 2,060 Net operating loss 1,463 - Other 546 449 Gross deferred tax assets 4,333 6,459 Deferred tax liabilities: Depreciation and amortization (1,688 ) (1,480 ) Core deposit intangibles (662 ) (342 ) Unrealized gains on available for sale securities - - Other (566 ) (376 ) Gross deferred tax liabilities (2,916 ) (2,198 ) Net deferred tax assets $ 1,417 $ 4,261 Net operating loss carryforwards for income tax purposes were $7.0 million as of December 31, 2017 as compared to zero in 2016. The carryforwards were acquired in 2017 in the Premier acquisition and expire from 2027 to 2034, and will be utilized subject to annual Internal Revenue Code Section 382 limitations. ASC 740-10, Income Taxes,

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies [Abstract]
Commitments and Contingencies	Note 19. Commitments and Contingencies Off-balance sheet commitments First Guaranty is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers and to reduce its own exposure to fluctuations in interest rates. These financial instruments include commitments to extend credit and standby and commercial letters of credit. Those instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the Consolidated Balance Sheets. The contract or notional amounts of those instruments reflect the extent of the involvement in particular classes of financial instruments. The exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby and commercial letters of credit is represented by the contractual notional amount of those instruments. Unless otherwise noted, collateral or other security is not required to support financial instruments with credit risk. Set forth below is a summary of the notional amounts of the financial instruments with off-balance sheet risk at December 31, 2017 and December 31, 2016. (in thousands) December 31, 2017 December 31, 2016 Contract Amount Commitments to Extend Credit $ 78,125 $ 56,910 Unfunded Commitments under lines of credit $ 101,344 $ 128,428 Commercial and Standby letters of credit $ 7,886 $ 6,602 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since commitments may expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Each customer's creditworthiness is evaluated on a case-by-case basis. The amount of collateral obtained, if deemed necessary upon extension of credit, is based on Management's credit evaluation of the counterpart. Collateral requirements vary but may include accounts receivable, inventory, property, plant and equipment, residential real estate and commercial properties. Standby and commercial letters of credit are conditional commitments to guarantee the performance of a customer to a third party. These guarantees are primarily issued to support public and private borrowing arrangements, including commercial paper, bond financing and similar transactions. The majority of these guarantees are short-term, one year or less; however, some guarantees extend for up to three years. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities. Collateral requirements are the same as on-balance sheet instruments and commitments to extend credit. There were no losses incurred on off-balance sheet commitments in 2017, 2016 or 2015.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements [Abstract]
Fair Value Measurements	Note 20. Fair Value Measurements The fair value of a financial instrument is the current amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. A fair value measurement assumes that the transaction to sell the asset or transfer the liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability. Valuation techniques use certain inputs to arrive at fair value. Inputs to valuation techniques are the assumptions that market participants would use in pricing the asset or liability. They may be observable or unobservable. First Guaranty uses a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: Level 1 Inputs Level 2 Inputs Level 3 Inputs A description of the valuation methodologies used for instruments measured at fair value follows, as well as the classification of such instruments within the valuation hierarchy. Securities available for sale. Impaired loans . Other real estate owned. Certain non-financial assets and non-financial liabilities are measured at fair value on a non-recurring basis including assets and liabilities related to reporting units measured at fair value in the testing of goodwill impairment, as well as intangible assets and other non-financial long-lived assets measured at fair value for impairment assessment. The following table summarizes financial assets measured at fair value on a recurring basis as of December 31, 2017 and 2016, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: (in thousands) December 31, 2017 December 31, 2016 Available for Sale Securities Fair Value Measurements Using: Level 1:Quoted Prices in Active Markets For Identical Assets $ 19,980 $ 30,487 Level 2: Significant Other Observable Inputs 355,022 347,586 Level 3: Significant Unobservable Inputs 6,533 19,400 Securities available for sale measured at fair value $ 381,535 $ 397,473 First Guaranty's valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While Management believes the methodologies used are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value. The change in Level 1 securities available for sale from December 31, 2016 was due principally to a net decrease in Treasury bills of $10.5 million. The change in Level 2 and Level 3 securities available for sale from December 31, 2016 was due principally due to the transfer of municipal securities from Level 3 to Level 2. The following table reconciles assets measured at fair value on a recurring basis using unobservable inputs ( Level 3 Level 3 Changes (in thousands) December 31, 2017 December 31, 2016 Balance, beginning of year $ 19,400 $ 7,701 Total gains or losses (realized/unrealized): Included in earnings 54 - Included in other comprehensive income - - Purchases, sales, issuances and settlements, net 10,574 11,699 Transfers in and/or out of Level 3 (23,495 ) - Balance as of end of year $ 6,533 $ 19,400 There were no gains or losses for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held as of December 31, 2017. The following table measures financial assets and financial liabilities measured at fair value on a non-recurring basis as of December 31, 2017, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value: (in thousands) At December 31, At December 31, Fair Value Measurements Using: Impaired Loans Level 1: Quoted Prices in Active Markets For Identical Assets $ - $ - Level 2: Significant Other Observable Inputs - 259 Level 3: Significant Unobservable Inputs 12,003 18,559 Impaired loans measured at fair value $ 12,003 $ 18,818 Fair Value Measurements Using: Other Real Estate Owned Level 1: Quoted Prices in Active Markets For Identical Assets $ - $ - Level 2: Significant Other Observable Inputs 1,249 226 Level 3: Significant Unobservable Inputs 32 133 Other real estate owned measured at fair value $ 1,281 $ 359 ASC 825-10 provides First Guaranty with an option to report selected financial assets and liabilities at fair value. The fair value option established by this statement permits First Guaranty to choose to measure eligible items at fair value at specified election dates and report unrealized gains and losses on items for which the fair value option has been elected in earnings at each reporting date subsequent to implementation. First Guaranty has chosen not to elect the fair value option for any items that are not already required to be measured at fair value in accordance with accounting principles generally accepted in the United States.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2017
Financial Instruments [Abstract]
Financial Instruments	Note 21. Financial Instruments Fair value estimates are generally subjective in nature and are dependent upon a number of significant assumptions associated with each instrument or group of similar instruments, including estimates of discount rates, risks associated with specific financial instruments, estimates of future cash flows and relevant available market information. Fair value information is intended to represent an estimate of an amount at which a financial instrument could be exchanged in a current transaction between a willing buyer and seller engaging in an exchange transaction. However, since there are no established trading markets for a significant portion of First Guaranty's financial instruments, First Guaranty may not be able to immediately settle financial instruments; as such, the fair values are not necessarily indicative of the amounts that could be realized through immediate settlement. In addition, the majority of the financial instruments, such as loans and deposits, are held to maturity and are realized or paid according to the contractual agreement with the customer. Quoted market prices are used to estimate fair values when available. However, due to the nature of the financial instruments, in many instances quoted market prices are not available. Accordingly, estimated fair values have been estimated based on other valuation techniques, such as discounting estimated future cash flows using a rate commensurate with the risks involved or other acceptable methods. Fair values are estimated without regard to any premium or discount that may result from concentrations of ownership of financial instruments, possible income tax ramifications or estimated transaction costs. The fair value estimates are subjective in nature and involve matters of significant judgment and, therefore, cannot be determined with precision. Fair values are also estimated at a specific point in time and are based on interest rates and other assumptions at that date. As events change the assumptions underlying these estimates, the fair values of financial instruments will change. Disclosure of fair values is not required for certain items such as lease financing, investments accounted for under the equity method of accounting, obligations of pension and other postretirement benefits, premises and equipment, other real estate, prepaid expenses, the value of long-term relationships with depositors (core deposit intangibles) and other customer relationships, other intangible assets and income tax assets and liabilities. Fair value estimates are presented for existing on- and off-balance sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. In addition, the tax ramifications related to the realization of the unrealized gains and losses have not been considered in the estimates. Accordingly, the aggregate fair value amounts presented do not purport to represent and should not be considered representative of the underlying market or franchise value of First Guaranty. Because the standard permits many alternative calculation techniques and because numerous assumptions have been used to estimate the fair values, reasonable comparison of the fair value information with other financial institutions' fair value information cannot necessarily be made. The methods and assumptions used to estimate the fair values of financial instruments are as follows: Cash and due from banks, interest-bearing deposits with banks, federal funds sold and federal funds purchased These items are generally short-term and the carrying amounts reported in the consolidated balance sheets are a reasonable estimation of the fair values. Investment Securities. Fair values are principally based on quoted market prices. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments or the use of discounted cash flow analyses. Loans Held for Sale. Fair values of mortgage loans held for sale are based on commitments on hand from investors or prevailing market prices. These loans are classified within level 3 of the fair value hierarchy. Loans, net Market values are computed present values using net present value formulas. The present value is the sum of the present value of all projected cash flows on an item at a specified discount rate. The discount rate is set as an appropriate rate index, plus or minus an appropriate spread. These loans are classified within level 3 of the fair value hierarchy. Impaired loans Fair value of impaired loans is measured by either the fair value of the collateral if the loan is collateral dependent (Level 2 or Level 3), or the present value of expected future cash flows, discounted at the loan's effective interest rate (Level 3). Fair value of the collateral is determined by appraisals or by independent valuation. Accrued interest receivable. The carrying amount of accrued interest receivable approximates its fair value. Deposits. Market values are actually computed present values using net present value formulas. The present value is the sum of the present value of all projected cash flows on an item at a specified discount rate. The discount rate is set as an appropriate rate index, plus or minus an appropriate spread. Deposits are classified within level 3 of the fair value hierarchy. Accrued interest payable. The carrying amount of accrued interest payable approximates its fair value. Borrowings The carrying amount of federal funds purchased and other short-term borrowings approximate their fair values. The fair value of First Guaranty's long-term borrowings is computed using net present value formulas. The present value is the sum of the present value of all projected cash flows on an item at a specified discount rate. The discount rate is set as an appropriate rate index, plus or minus an appropriate spread. Borrowings are classified within level 3 of the fair value hierarchy. Other Unrecognized Financial Instruments. The fair value of commitments to extend credit is estimated using the fees charged to enter into similar legally binding agreements, taking into account the remaining terms of the agreements and customers' credit ratings. For fixed-rate loan commitments, fair value also considers the difference between current levels of interest rates and the committed rates. Noninterest-bearing deposits are held at cost. The fair values of letters of credit are based on fees charged for similar agreements or on estimated cost to terminate them or otherwise settle the obligations with the counterparties at the reporting date. At December 31, 2017 and 2016 the fair value of guarantees under commercial and standby letters of credit was not material. The estimated fair values and carrying values of the financial instruments at December 31, 2017 and 2016 are presented in the following table: December 31, 2017 2016 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Assets Cash and cash equivalents $ 38,028 $ 38,028 $ 18,111 $ 18,111 Securities, available for sale $ 381,535 $ 381,535 $ 397,473 $ 397,473 Securities, held to maturity $ 120,121 $ 118,557 $ 101,863 $ 99,906 Federal Home Loan Bank stock $ 2,351 $ 2,351 $ 1,816 $ 1,816 Loans held for sale $ 1,308 $ 1,439 $ - $ - Loans, net $ 1,139,789 $ 1,133,868 $ 937,807 $ 937,495 Accrued interest receivable $ 7,982 $ 7,982 $ 7,039 $ 7,039 Liabilities Deposits $ 1,549,286 $ 1,549,449 $ 1,326,181 $ 1,325,972 Borrowings $ 38,274 $ 38,294 $ 28,600 $ 28,625 Junior subordinated debentures $ 14,664 $ 14,324 $ 14,630 $ 13,909 Accrued interest payable $ 2,488 $ 2,488 $ 1,931 $ 1,931 There is no material difference between the contract amount and the estimated fair value of off-balance sheet items that are primarily comprised of short-term unfunded loan commitments that are generally at market prices.

Concentrations of Credit and Ot

Concentrations of Credit and Other Risks	12 Months Ended
	Dec. 31, 2017
Concentrations of Credit and Other Risks [Abstract]
Concentrations of Credit and Other Risks	Note 22. Concentrations of Credit and Other Risks First Guaranty monitors loan portfolio concentrations by region, collateral type, loan type, and industry on a monthly basis and has established maximum thresholds as a percentage of its capital to ensure that the desired mix and diversification of its loan portfolio is achieved. First Guaranty is compliant with the established thresholds as of December 31, 2017. Personal, commercial and residential loans are granted to customers, most of who reside in northern and southern areas of Louisiana. Although First Guaranty has a diversified loan portfolio, significant portions of the loans are collateralized by real estate located in Tangipahoa Parish and surrounding parishes in Southeast Louisiana. Declines in the Louisiana economy could result in lower real estate values which could, under certain circumstances, result in losses to First Guaranty. The distribution of commitments to extend credit approximates the distribution of loans outstanding. Commercial and standby letters of credit were granted primarily to commercial borrowers. Generally, credit is not extended in excess of $10.0 million to any single borrower or group of related borrowers. Approximately 41.4% of First Guaranty's deposits are derived from local governmental agencies at December 31, 2017. These governmental depositing authorities are generally long-term customers. A number of the depositing authorities are under contractual obligation to maintain their operating funds exclusively with First Guaranty. In most cases, First Guaranty is required to pledge securities or letters of credit issued by the Federal Home Loan Bank to the depositing authorities to collateralize their deposits. Under certain circumstances, the withdrawal of all of, or a significant portion of, the deposits of one or more of the depositing authorities may result in a temporary reduction in liquidity, depending primarily on the maturities and/or classifications of the securities pledged against such deposits and the ability to replace such deposits with either new deposits or other borrowings. Public fund deposits totaled $640.7 million at December 31, 2017.

Litigation

Litigation	12 Months Ended
	Dec. 31, 2017
Litigation [Abstract]
Litigation	Note 23. Litigation First Guaranty is subject to various legal proceedings in the normal course of its business. It is Management's belief that the ultimate resolution of such claims will not have a material adverse effect on First Guaranty's financial position or results of operations.

Condensed Parent Company Inform

Condensed Parent Company Information	12 Months Ended
	Dec. 31, 2017
Condensed Parent Company Information [Abstract]
Condensed Parent Company Information	Note 24. Condensed Parent Company Information The following condensed financial information reflects the accounts and transactions of First Guaranty Bancshares, Inc. for the dates indicated: First Guaranty Bancshares, Inc. Condensed Balance Sheets December 31, (in thousands) 2017 2016 Assets Cash $ 5,214 $ 16,088 Investment in bank subsidiary 170,836 141,241 Investment Securities (available for sale, at fair value) - 80 Other assets 6,086 4,197 Total Assets $ 182,136 $ 161,606 Liabilities and Shareholders' Equity Short-term debt $ - $ - Senior long-term debt 22,774 22,100 Junior subordinated debentures 14,664 14,630 Other liabilities 715 527 Total Liabilities 38,153 37,257 Shareholders' Equity 143,983 124,349 Total Liabilities and Shareholders' Equity $ 182,136 $ 161,606 First Guaranty Bancshares, Inc. Condensed Statements of Income December 31, (in thousands) 2017 2016 2015 Operating Income Dividends received from bank subsidiary $ 10,622 $ 11,858 $ 9,843 Net gains on securities 54 - 2,652 Other income 171 160 261 Total operating income 10,847 12,018 12,756 Operating Expenses Interest expense 1,518 1,444 192 Salaries & Benefits 495 200 172 Other expenses 1,147 948 766 Total operating expenses 3,160 2,592 1,130 Income before income tax benefit and increase in equity in undistributed earnings of subsidiary 7,687 9,426 11,626 Income tax benefit (expense) 834 846 (605 ) Income before increase in equity in undistributed earnings of subsidiary 8,521 10,272 11,021 Increase in equity in undistributed earnings of subsidiary 3,230 3,821 3,484 Net Income 11,751 14,093 14,505 Less preferred stock dividends - - (384 ) Net income available to common shareholders $ 11,751 $ 14,093 $ 14,121 First Guaranty Bancshares, Inc. Condensed Statements of Cash Flows December 31, (in thousands) 2017 2016 2015 Cash flows from operating activities: Net income $ 11,751 $ 14,093 $ 14,505 Adjustments to reconcile net income to net cash provided by operating activities: Increase in equity in undistributed earnings of subsidiary $ (3,230 ) $ (3,821 ) (3,484 ) Depreciation and amortization 43 7 - Gain on sale of securities (54 ) - (2,652 ) Net change in other liabilities 187 318 (28 ) Net change in other assets (1,306 ) (971 ) 396 Net cash provided by operating activities 7,391 9,626 8,737 Cash flows from investing activities: Proceeds from maturities, calls and sales of AFS securities 134 - 4,152 Funds invested in AFS securities - - (10 ) Funds invested in bank subsidiary (3,750 ) - - Cash paid in acquisition (10,108 ) - - Net cash provided by (used in) investing activities (13,724 ) - 4,142 Cash flows from financing activities: Net decrease in short-term borrowings - (1,800 ) - Proceeds from long-term debt, net of costs 3,750 - 24,969 Repayment of long-term debt (3,081 ) (3,730 ) (1,584 ) Proceeds from junior subordinated debentures, net of costs - - 14,597 Issuance of common stock, net of costs - - 9,344 Redemption of preferred stock - - (39,435 ) Dividends paid (5,210 ) (4,870 ) (4,631 ) Net cash (used in) provided by financing activities (4,541 ) (10,400 ) 3,260 Net (decrease) increase in cash and cash equivalents (10,874 ) (774 ) 16,139 Cash and cash equivalents at the beginning of the period 16,088 16,862 723 Cash and cash equivalents at the end of the period $ 5,214 $ 16,088 $ 16,862

Business and Summary of Signi34

Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Business and Summary of Significant Accounting Policies [Abstract]
Consolidation	Consolidation The consolidated financial statements include the accounts of First Guaranty Bancshares, Inc., and its wholly owned subsidiary, First Guaranty Bank. All significant intercompany balances and transactions have been eliminated in consolidation.
Acquisition Accounting	Acquisition Accounting Acquisitions are accounted for under the purchase method of accounting. Purchased assets, including identifiable intangibles, and assumed liabilities are recorded at their respective acquisition date fair values. If the fair value of net assets purchased exceeds the consideration given, a gain on acquisition is recognized. If the consideration given exceeds the fair value of the net assets received, goodwill is recognized. Fair values are subject to refinement for up to one year after the closing date of an acquisition as information relative to closing date fair values becomes available. Purchased loans acquired in a business combination are recorded at estimated fair value on their purchase date with no carryover of the related allowance for loan losses. See Acquired Loans section below for accounting policy regarding loans acquired in a business combination.
Use of Estimates	Use of estimates The preparation of financial statements in conformity with generally accepted accounting principles requires Management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenue and expense during the reporting periods. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near-term relate to the determination of the allowance for loan losses, the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans, and the valuation of investment securities. In connection with the determination of the allowance for loan losses and real estate owned, First Guaranty obtains independent appraisals for significant properties.
Cash and Cash Equivalents	Cash and cash equivalents For purposes of reporting cash flows, cash and cash equivalents are defined as cash, due from banks, interest-bearing demand deposits with banks and federal funds sold with maturities of three months or less.
Securities	Securities First Guaranty reviews its financial position, liquidity and future plans in evaluating the criteria for classifying investment securities. Debt securities that Management has the ability and intent to hold to maturity are classified as held to maturity and carried at cost, adjusted for amortization of premiums and accretion of discounts using methods approximating the interest method. Securities available for sale are stated at fair value. The unrealized difference, if any, between amortized cost and fair value of these AFS securities is excluded from income and is reported, net of deferred taxes, in accumulated other comprehensive income as a part of shareholders' equity. Details of other comprehensive income are reported in the consolidated statements of comprehensive income. Realized gains and losses on securities are computed based on the specific identification method and are reported as a separate component of other income. Amortization of premiums and discounts is included in interest income. Discounts and premiums related to debt securities are amortized using the effective interest rate 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. In estimating other-than-temporary losses, management considers the length of time and extent that fair value has been less than cost and the financial condition and near term prospects of the issuer. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For debt securities that do not meet the aforementioned criteria, the amount of impairment is split into two components as follows: 1) OTTI related to credit loss, which must be recognized in the income statement and 2) OTTI related to other factors, which is recognized in other comprehensive income. 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. For equity securities, the entire amount of impairment is recognized through earnings.
Loans Held for Sale	Loans held for sale Mortgage loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Net unrealized losses, if any, are recognized through a valuation allowance by charges to income. Loans held for sale have primarily been fixed rate single-family residential mortgage loans under contract to be sold in the secondary market. In most cases, loans in this category are sold within thirty days. Buyers generally have recourse to return a purchased loan under limited circumstances. Recourse conditions may include early payment default, breach of representations or warranties and documentation deficiencies. Mortgage loans held for sale are generally sold with the mortgage servicing rights released. Gains or losses on sales of mortgage loans are recognized based on the differences between the selling price and the carrying value of the related mortgage loans sold.
Loans	Loans Loans are stated at the principal amounts outstanding, net of unearned income and deferred loan fees. In addition to loans issued in the normal course of business, overdrafts on customer deposit accounts are considered to be loans and reclassified as such. Interest income on all classifications of loans is calculated using the simple interest method on daily balances of the principal amount outstanding. Accrual of interest is discontinued on a loan when Management believes, after considering economic and business conditions and collection efforts, the borrower's financial condition is such that reasonable doubt exists as to the full and timely collection of principal and interest. This evaluation is made for all loans that are 90 days or more contractually past due. When a loan is placed in nonaccrual status, all interest previously accrued but not collected is reversed against current period interest income. Income on such loans is then recognized only to the extent that cash is received and where the future collection of interest and principal is probable. Loans are returned to accrual status when, in the judgment of Management, all principal and interest amounts contractually due are reasonably assured to be collected within a reasonable time frame and when the borrower has demonstrated payment performance of cash or cash equivalents; generally for a period of six months. All loans, except mortgage loans, are considered past due if they are past due 30 days. Mortgage loans are considered past due when two consecutive payments have been missed. Loans that are past due 90-120 days and deemed uncollectible are charged-off. The loan charge off is a reduction of the allowance for loan losses.
Troubled Debt Restructurings (TDRs)	Troubled Debt Restructurings (TDRs) TDRs are loans in which the borrower is experiencing financial difficulty at the time of restructuring, and the Bank has granted a concession to the borrower. TDRs are undertaken in order to improve the likelihood of recovery on the loan and may take the form of modifications made with the stated interest rate lower than the current market rate for new debt with similar risk, other modifications to the structure of the loan that fall outside of normal underwriting policies and procedures, or in limited circumstances forgiveness of principal and / or interest. TDRs can involve loans remaining on non-accrual, moving to non-accrual, or continuing on accrual status, depending on the individual facts and circumstances of the borrower. TDRs are subject to policies governing accrual and non-accrual evaluation consistent with all other loans as discussed in the "Loans" section above. All loans with the TDR designation are considered to be impaired, even if they are accruing. First Guaranty's policy is to evaluate TDRs that have subsequently been restructured and returned to market terms after 12 months of performance. The evaluation includes a review of the loan file and analysis of the credit to assess the loan terms, including interest rate to insure such terms are consistent with market terms. The loan terms are compared to a sampling of loans with similar terms and risk characteristics, including loans originated by First Guaranty and loans lost to a competitor. The sample provides a guide to determine market terms pursuant to ASC 310-40-50-2. The loan is also evaluated at that time for impairment. A loan determined to be restructured to market terms and not considered impaired will no longer be disclosed as a TDR in the years following the restructuring. These loans will continue to be individually evaluated for impairment. A loan determined to either be restructured to below market terms or to be impaired will remain a TDR.
Credit Quality	Credit Quality First Guaranty's credit quality indicators are pass, special mention, substandard, and doubtful. Loans included in the pass category are performing loans with satisfactory debt coverage ratios, collateral, payment history, and documentation requirements. Special mention loans have potential weaknesses that deserve close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects. Borrowers may be experiencing adverse operating trends (declining revenues or margins) or an ill proportioned balance sheet (e.g., increasing inventory without an increase in sales, high leverage, tight liquidity). Adverse economic or market conditions, such as interest rate increases or the entry of a new competitor, may also support a special mention rating. Nonfinancial reasons include management problems, pending litigation, an ineffective loan agreement or other material structural weakness, and any other significant deviation from prudent lending practices. A substandard loan is inadequately protected by the paying capacity of the obligor or of the collateral pledged, if any. Loans classified as substandard have a well-defined weakness. They are characterized by the distinct possibility that First Guaranty will sustain some loss if the deficiencies are not corrected. These loans require more intensive supervision. Substandard loans are generally characterized by current or expected unprofitable operations, inadequate debt service coverage, inadequate liquidity, or marginal capitalization. Repayment may depend on collateral or other credit risk mitigates. For some substandard loans, the likelihood of full collection of interest and principal may be in doubt and interest is no longer accrued. Consumer loans that are 90 days or more past due or that are nonaccrual are considered substandard. Doubtful loans have the weaknesses of substandard loans with the additional characteristic that the weaknesses make collection or liquidation in full questionable and there is a high probability of loss based on currently existing facts, conditions and values. A loan is considered impaired when, based on current information and events, it is probable that First Guaranty will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by Management in determining impairment include payment status, collateral value and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower's prior payment record and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis for commercial and construction loans by either the present value of expected future cash flows discounted at the loan's effective interest rate, the loan's obtainable market price or the fair value of the collateral if the loan is collateral dependent. This process is only applied to impaired loans or relationships in excess of $500,000. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, individual consumer and residential loans are not separately identified for impairment disclosures, unless such loans are the subject of a restructuring agreement. Loans that have been restructured in a troubled debt restructuring will continue to be evaluated individually for impairment, including those no longer requiring disclosure.
Acquired Loans	Acquired Loans Loans are recorded at estimated fair value on their purchase date with no carryover of the related allowance for loan losses. Acquired loans are segregated between those with deteriorated credit quality at acquisition and those deemed as performing. To make this determination, Management considers such factors as past due status, nonaccrual status, credit risk ratings, interest rates and collateral position. The fair value of acquired loans deemed performing is determined by discounting cash flows, both principal and interest, for each pool at prevailing market interest rates as well as consideration of inherent potential losses. The difference between the fair value and principal balances due at acquisition date, the fair value discount, is accreted into income over the estimated life of each loan pool. Loans acquired in a business combination are recorded at their estimated fair value on their purchase date with no carryover of the related allowance for loan losses. Performing acquired loans are subsequently evaluated for any required allowance at each reporting date. An allowance for loan losses is calculated using a similar methodology for originated loans.
Loan Fees and Costs	Loan fees and costs Nonrefundable loan origination and commitment fees and direct costs associated with originating loans are deferred and recognized over the lives of the related loans as an adjustment to the loans' yield using the level yield method.
Allowance for Loan Losses	Allowance for loan losses The allowance for loan losses is established through a provision for loan losses charged to expense. Loans are charged against the allowance for loan losses when Management believes that the collectability of the principal is unlikely. The allowance, which is based on evaluation of the collectability of loans and prior loan loss experience, is an amount that, in the opinion of Management, reflects the risks inherent in the existing loan portfolio and exists at the reporting date. The evaluations take into consideration a number of subjective factors including changes in the nature and volume of the loan portfolio, historical losses, overall portfolio quality, review of specific problem loans, current economic conditions that may affect a borrower's ability to pay, adequacy of loan collateral and other relevant factors. In addition, regulatory agencies, as an integral part of their examination process, periodically review the estimated losses on loans. Such agencies may require additional recognition of losses based on their judgments about information available to them at the time of their examination. The following are general credit risk factors that affect First Guaranty's loan portfolio segments. These factors do not encompass all risks associated with each loan category. Construction and land development loans have risks associated with interim construction prior to permanent financing and repayment risks due to the future sale of developed property. Farmland and agricultural loans have risks such as weather, government agricultural policies, fuel and fertilizer costs, and market price volatility. 1-4 family, multi-family, and consumer credits are strongly influenced by employment levels, consumer debt loads and the general economy. Non-farm non-residential loans include both owner occupied real estate and non-owner occupied real estate. Common risks associated with these properties is the ability to maintain tenant leases and keep lease income at a level able to service required debt and operating expenses. Commercial and industrial loans generally have non-real estate secured collateral which requires closer monitoring than real estate collateral. Although Management uses available information to recognize losses on loans, because of uncertainties associated with local economic conditions, collateral values and future cash flows on impaired loans, it is reasonably possible that a material change could occur in the allowance for loan losses in the near term. However, the amount of the change that is reasonably possible cannot be estimated. The evaluation of the adequacy of loan collateral is often based upon estimates and appraisals. Because of changing economic conditions, the valuations determined from such estimates and appraisals may also change. Accordingly, First Guaranty may ultimately incur losses that vary from Management's current estimates. Adjustments to the allowance for loan losses will be reported in the period such adjustments become known or can be reasonably estimated. All loan losses are charged to the allowance for loan losses when the loss actually occurs or when the collectability of the principal is unlikely. Recoveries are credited to the allowance at the time of recovery. The allowance consists of specific, general, and unallocated components. The specific component relates to loans that are classified as doubtful, substandard, and impaired. For such loans that are also classified as impaired, an allowance is established when the discounted cash flows (or collateral value or observable market price) of the impaired loan is lower than the carrying value of that loan. Also, a specific reserve is allocated for syndicated loans. The general component covers non-classified loans and special mention loans and is based on historical loss experience adjusted for qualitative factors. An unallocated component is maintained to cover uncertainties that could affect the estimate of probable losses. The allowance for loan losses is reviewed on a monthly basis. The monitoring of credit risk also extends to unfunded credit commitments, such as unused commercial credit lines and letters of credit. A reserve is established as needed for estimates of probable losses on such commitments.
Goodwill and Intangible Assets	Goodwill and intangible assets Goodwill and intangible assets deemed to have indefinite lives are subject to annual impairment tests. First Guaranty's goodwill is tested for impairment on an annual basis, or more often if events or circumstances indicate that there may be impairment. Adverse changes in the economic environment, declining operations, or other factors could result in a decline in the implied fair value of goodwill. If the implied fair value is less than the carrying amount, a loss would be recognized in other non-interest expense to reduce the carrying amount to implied fair value of goodwill. The goodwill impairment test includes two steps that are preceded by a, "step zero", qualitative test. The qualitative test allows Management to assess whether qualitative factors indicate that it is more likely than not that impairment exists. If it is not more likely than not that impairment exists, then no impairment exists and the two step quantitative test would not be necessary. These qualitative indicators include factors such as earnings, share price, market conditions, etc. If the qualitative factors indicate that it is more likely than not that impairment exists, then the two step quantitative test would be necessary. Step one is used to identify potential impairment and compares the estimated fair value of a reporting unit with its carrying amount, including goodwill. If the estimated fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is not considered impaired. If the carrying amount of a reporting unit exceeds its estimated fair value, the second step of the goodwill impairment test is performed to measure the amount of impairment loss, if any. Step two of the goodwill impairment test compares the implied estimated fair value of reporting unit goodwill with the carrying amount of that goodwill. If the carrying amount of goodwill for that reporting unit exceeds the implied fair value of that unit's goodwill, an impairment loss is recognized in an amount equal to that excess. Identifiable intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or legal rights or because the assets are capable of being sold or exchanged either on their own or in combination with the related contract, asset or liability. First Guaranty's intangible assets primarily relate to core deposits. These core deposit intangibles are amortized on a straight-line basis over terms ranging from seven to fifteen years. Management periodically evaluates whether events or circumstances have occurred that impair this deposit intangible.
Premises and Equipment	Premises and equipment Premises and equipment are stated at cost, less accumulated depreciation. Depreciation is computed for financial reporting purposes using the straight-line method over the estimated useful lives of the respective assets as follows: Buildings and improvements 10-40 years Equipment, fixtures and automobiles 3-10 years Expenditures for renewals and betterments are capitalized and depreciated over their estimated useful lives. Repairs, maintenance and minor improvements are charged to operating expense as incurred. Gains or losses on disposition, if any, are recorded as a separate line item in noninterest income on the Statements of Income .
Other Real Estate	Other real estate Other real estate includes properties acquired through foreclosure or acceptance of deeds in lieu of foreclosure. These properties are recorded at the lower of the recorded investment in the property or its fair value less the estimated cost of disposition. Any valuation adjustments required prior to foreclosure are charged to the allowance for loan losses. Subsequent to foreclosure, losses on the periodic revaluation of the property are charged to current period earnings as other real estate expense. Costs of operating and maintaining the properties are charged to other real estate expense as incurred. Any subsequent gains or losses on dispositions are credited or charged to income in the period of disposition .
Off-balance Sheet Financial Instruments	Off-balance sheet financial instruments In the ordinary course of business, First Guaranty has entered into commitments to extend credit, including commitments under credit card arrangements, commitments to fund commercial real estate, construction and land development loans secured by real estate, and performance standby letters of credit. Such financial instruments are recorded when they are funded.
Income Taxes	Income taxes First Guaranty and its subsidiary file a consolidated federal income tax return on a calendar year basis. In lieu of Louisiana state income tax, the Bank is subject to the Louisiana bank shares tax, which is included in noninterest expense in First Guaranty's consolidated financial statements. With few exceptions, First Guaranty is no longer subject to U.S. federal, state or local income tax examinations for years before 2014. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which the deferred tax assets or liabilities are expected to be settled or realized. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be utilized.
Comprehensive Income	Comprehensive income Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. Although certain changes in assets and liabilities, such as unrealized gains and losses on available for sale securities, are reported as a separate component of the equity section of the balance sheet, such items along with net income, are components of comprehensive income. The components of other comprehensive income and related tax effects are presented in the Statements of Comprehensive Income.
Fair Value Measurements	Fair Value Measurements The fair value of a financial instrument is the current amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. A fair value measurement assumes that the transaction to sell the asset or transfer the liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability. Valuation techniques use certain inputs to arrive at fair value. Inputs to valuation techniques are the assumptions that market participants would use in pricing the asset or liability. They may be observable or unobservable. First Guaranty uses a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. See Note 20 for a detailed description of fair value measurements.
Transfers of Financial Assets	Transfers of Financial Assets Transfers of financial assets are accounted for as sales, when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (i) the assets have been isolated from First Guaranty, (ii) 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 (iii) First Guaranty does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Earnings per Common Share	Earnings per common share Earnings per share represents income available to common shareholders divided by the weighted average number of common shares outstanding during the period. In December of 2017, First Guaranty issued a pro rata, 10% common stock dividend. The shares issued for the stock dividend have been retrospectively factored into the calculation of earnings per share as well as cash dividends paid on common stock and represented on the face of the financial statements. No convertible shares of First Guaranty's stock are outstanding.
Operating Segments	Operating Segments All of First Guaranty's operations are considered by management to be aggregated into one reportable operating segment. While the chief decision-makers monitor the revenue streams of the various products and services, the identifiable segments are not material. Operations are managed and financial performance is evaluated on a Company-wide basis.
Reclassifications	Reclassifications Certain reclassifications have been made to prior year end financial statements in order to conform to the classification adopted for reporting in 2017.

Recent Accounting Pronounceme35

Recent Accounting Pronouncements (Policies)	12 Months Ended
	Dec. 31, 2017
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	In February 2016, the FASB issued ASU 2016-02, "Leases: Conforming Amendments Related to Leases". This ASU amends the codification regarding leases in order to increase transparency and comparability. The ASU requires companies to recognize lease assets and liabilities on the balance sheet and disclose key information about leasing arrangements. A lessee would recognize a liability to make lease payments and a right-of-use asset representing its right to use the leased asset for the lease term. The ASU is effective for annual and interim periods beginning after December 15, 2018. The adoption of this ASU is not expected to have a material effect on First Guaranty's Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments". This ASU amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. The ASU amendments require the measurement of all expected credit losses for financial assets held at the reporting date be based on historical experience, current conditions, and reasonable and supportable forecasts. The ASU requires assets held at cost basis to reflect the company's current estimate of all expected credit losses. For available for sale debt securities, credit losses should be presented as an allowance rather than as a write-down. In addition, this ASU amends the accounting for purchased financial assets with credit deterioration. This ASU is effective for annual and interim periods beginning after December 15, 2019. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment". This ASU amends the guidance on impairment testing. The ASU eliminates Step 2 from the goodwill impairment test. The annual, or interim, goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. In addition, income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit should be considered when measuring the goodwill impairment loss, if applicable. The ASU also eliminates the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative test, to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. This ASU is effective for annual and interim periods beginning after December 15, 2019. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In March 2017, the FASB issued ASU 2017-08, "Receivables- Nonrefundable Fees and Other Costs, Premium Amortization on Purchased Callable Debt Securities". This ASU shortens the amortization period for certain callable debt securities held at a premium. Specifically, this ASU requires the premium to be amortized to the earliest call date. This ASU does not require an accounting change for securities held at a discount, the discount continues to be amortized to maturity. This ASU is effective for annual and interim periods beginning after December 15, 2018. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In February 2018, the FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income". This ASU provides an option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or portion thereof) is recorded. This ASU requires disclosure of a description of the accounting policy for releasing income tax effects from AOCI; whether election is made to reclassify the stranded income tax effects from the Tax Cuts and Jobs Act; and information about the other income tax effects that are reclassified. This ASU is effective for annual and interim periods beginning after December 15, 2018. We are currently evaluating the impact of the adoption of this guidance on the Consolidated Financial Statements. In March 2018, the FASB issued ASU 2018-05, "Income Taxes (Topic 740) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118". This ASU adds SEC paragraphs pursuant to the SEC Staff Accounting Bulletin No. 118, which expresses the view of the staff regarding application of Topic 740, Income Taxes

Merger Transaction (Tables)

Merger Transaction (Tables)	12 Months Ended
	Dec. 31, 2017
Merger Transaction [Abstract]
Fair Value of Tangible and Intangible Assets Acquired and Liabilities Assumed	Based on management's preliminary valuation of the fair value of tangible and intangible assets acquired and liabilities assumed, the purchase price for the Premier acquisition is allocated in the table below. (in thousands) Premier Bancshares, Inc. Cash and due from banks $ 4,542 Federal funds sold 2,855 Securities available for sale 5,892 Loans 128,018 Premises and equipment 9,493 Goodwill 1,474 Intangible assets 3,809 Other real estate 221 Other assets 2,009 Total assets acquired $ 158,313 Deposits 127,228 FHLB borrowings 9,700 Other liabilities 431 Total liabilities assumed $ 137,359 Net assets acquired $ 20,954
Pro Forma Information	The following pro forma information for the twelve months ended December 31, 2017 and December 31, 2016 reflects First Guaranty's estimated consolidated results of operations as if the acquisition of Premier occurred at January 1, 2016, unadjusted for potential cost savings. (in thousands, except share data) 2017 2016 Net Interest Income $ 55,663 $ 53,190 Noninterest Income 8,540 11,541 Noninterest Expense 42,434 39,395 Net Income 10,885 13,709 Earnings per common share $ 1.24 $ 1.56

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Securities [Abstract]
Summary Comparison of Securities by Type	A summary comparison of securities by type at December 31, 2017 and 2016 is shown below. December 31, 2017 December 31, 2016 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for sale: U.S Treasuries $ 19,490 $ - $ (4 ) $ 19,486 $ 29,994 $ - $ - $ 29,994 U.S. Government Agencies 200,052 - (4,069 ) 195,983 183,152 - (4,820 ) 178,332 Corporate debt securities 91,770 661 (946 ) 91,485 132,448 1,624 (2,100 ) 131,972 Mutual funds or other equity securities 500 - (7 ) 493 580 - (7 ) 573 Municipal bonds 37,210 2,434 (75 ) 39,569 28,177 100 (320 ) 27,957 Collateralized mortgage obligations 1,191 - (6 ) 1,185 - - - - Mortgage-backed securities 33,680 - (346 ) 33,334 29,181 - (536 ) 28,645 Total available for sale securities $ 383,893 $ 3,095 $ (5,453 ) $ 381,535 $ 403,532 $ 1,724 $ (7,783 ) $ 397,473 Held to maturity: U.S. Government Agencies $ 28,169 $ - $ (670 ) $ 27,499 $ 18,167 $ - $ (655 ) $ 17,512 Municipal bonds 5,322 15 (12 ) 5,325 - - - - Mortgage-backed securities 86,630 6 (903 ) 85,733 83,696 - (1,302 ) 82,394 Total held to maturity securities $ 120,121 $ 21 $ (1,585 ) $ 118,557 $ 101,863 $ - $ (1,957 ) $ 99,906
Investments Classified by Contractual Maturity Date	The scheduled maturities of securities at December 31, 2017, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities due to call or prepayments. Mortgage-backed securities are not due at a single maturity because of amortization and potential prepayment of the underlying mortgages. For this reason they are presented separately in the maturity table below. December 31, 2017 (in thousands) Amortized Cost Fair Value Available for sale: Due in one year or less $ 29,215 $ 29,233 Due after one year through five years 76,969 76,922 Due after five years through 10 years 217,238 214,769 Over 10 years 25,600 26,092 Subtotal 349,022 347,016 Collateralized mortgage obligations 1,191 1,185 Mortgage-backed Securities 33,680 33,334 Total available for sale securities $ 383,893 $ 381,535 Held to maturity: Due in one year or less $ - $ - Due after one year through five years 5,124 5,057 Due after five years through 10 years 18,485 17,907 Over 10 years 9,882 9,860 Subtotal 33,491 32,824 Mortgage-backed Securities 86,630 85,733 Total held to maturity securities $ 120,121 $ 118,557
Schedule of Unrealized Loss on Investments	The following is a summary of the fair value of securities with gross unrealized losses and an aging of those gross unrealized losses as of the dates indicated: At December 31, 2017 Less Than 12 Months 12 Months or More Total (in thousands) Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Available for sale: U.S. Treasuries 6 $ 19,486 $ (4 ) - $ - $ - 6 $ 19,486 $ (4 ) U.S. Government Agencies 30 62,991 (519 ) 36 132,992 (3,550 ) 66 195,983 (4,069 ) Corporate debt securities 56 19,050 (240 ) 70 22,818 (706 ) 126 41,868 (946 ) Mutual funds or other equity securities 1 493 (7 ) - - - 1 493 (7 ) Municipal bonds 9 4,431 (36 ) 1 1,079 (39 ) 10 5,510 (75 ) Collateralized mortgage obligations 4 936 (6 ) - - - 4 936 (6 ) Mortgage-backed securities 26 14,737 (73 ) 11 18,313 (273 ) 37 33,050 (346 ) Total available for sale securities 132 $ 122,124 $ (885 ) 118 $ 175,202 $ (4,568 ) 250 $ 297,326 $ (5,453 ) Held to maturity: U.S. Government Agencies 4 $ 9,925 $ (75 ) 10 $ 17,574 $ (595 ) 14 $ 27,499 $ (670 ) Municipal bonds 6 3,191 (12 ) - - - 6 3,191 (12 ) Mortgage-backed securities 35 54,186 (515 ) 17 26,852 (388 ) 52 81,038 (903 ) Total held to maturity securities 45 $ 67,302 $ (602 ) 27 $ 44,426 $ (983 ) 72 $ 111,728 $ (1,585 ) At December 31, 2016 Less Than 12 Months 12 Months or More Total (in thousands) Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Number of Securities Fair Value Gross Unrealized Losses Available for sale: U.S. Treasuries 3 $ 10,997 $ - - $ - $ - 3 $ 10,997 $ - U.S. Government Agencies 54 178,331 (4,820 ) - - - 54 178,331 (4,820 ) Corporate debt securities 185 61,669 (1,613 ) 26 6,440 (487 ) 211 68,109 (2,100 ) Mutual funds or other equity securities 1 493 (7 ) - - - 1 493 (7 ) Municipal bonds 14 10,210 (320 ) - - - 14 10,210 (320 ) Mortgage-backed securities 16 28,645 (536 ) - - - 16 28,645 (536 ) Total available for sale securities 273 $ 290,345 $ (7,296 ) 26 $ 6,440 $ (487 ) 299 $ 296,785 $ (7,783 ) Held to maturity: U.S. Government Agencies 10 $ 17,512 $ (655 ) - $ - $ - 10 $ 17,512 $ (655 ) Mortgage-backed securities 48 82,394 (1,302 ) - - - 48 82,394 (1,302 ) Total held to maturity securities 58 $ 99,906 $ (1,957 ) - $ - $ - 58 $ 99,906 $ (1,957 )
Schedule of Other than Temporary Impairment Losses on Available-for-Sale Securities	During the years ended December 31, 2017,2016, and 2015, First Guaranty recorded OTTI losses on available for sale securities as follows: (in thousands) Year Ended December 31, 2017 Year Ended December 31, 2016 Year Ended December 31, 2015 Total OTTI charge realized and unrealized $ - $ 66 $ 571 OTTI recognized in other comprehensive income (non-credit component) - 6 396 Net impairment losses recognized in earnings (credit component) $ - $ 60 $ 175
Credit Losses on Debt Securities for which Portion of OTTI Recognized in OCI	The following table presents a roll-forward of the amount of credit losses on debt securities held by First Guaranty for which a portion of OTTI was recognized in other comprehensive income for the year ended December 31, 2017, 2016, and 2015: (in thousands) Year Ended December 31, 2017 Year Ended December 31, 2016 Year Ended December 31, 2015 Beginning balance of credit losses at beginning of year $ 60 $ 175 $ - Other-than-temporary impairment credit losses on securities not previously OTTI - 60 175 Increases for additional credit losses on securities previously determined to be OTTI - - - Reduction for increases in cash flows - - - Reduction due to credit impaired securities sold or fully settled - (175 ) - Ending balance of cumulative credit losses recognized in earnings at end of year $ 60 $ 60 $ 175
Schedule of Exposure to Investment Securities Issuers that Exceeded 10% of Shareholder's Equity	At December 31, 2017, First Guaranty's exposure to investment securities issuers that exceeded 10% of shareholders' equity as follows: At December 31, 2017 (in thousands) Amortized Cost Fair Value U.S. Treasuries $ 19,490 $ 19,486 Federal Home Loan Bank (FHLB) 50,395 49,403 Federal Home Loan Mortgage Corporation (Freddie Mac-FHLMC) 57,569 57,008 Federal National Mortgage Association (Fannie Mae-FNMA) 103,644 101,757 Federal Farm Credit Bank (FFCB) 136,923 134,381 Total $ 368,021 $ 362,035

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Loans [Abstract]
Summary of Components of Loan Portfolio	The following table summarizes the components of First Guaranty's loan portfolio as of the dates indicated: December 31, 2017 December 31, 2016 (in thousands except for %) Balance As % of Category Balance As % of Category Real Estate: Construction & land development $ 112,603 9.8 % $ 84,239 8.9 % Farmland 25,691 2.2 % 21,138 2.2 % 1-4 Family 158,733 13.8 % 135,211 14.2 % Multi-family 16,840 1.4 % 12,450 1.3 % Non-farm non-residential 540,231 46.9 % 417,014 43.9 % Total Real Estate 854,098 74.1 % 670,052 70.5 % Non-Real Estate: Agricultural 21,514 1.9 % 23,783 2.5 % Commercial and industrial 220,700 19.2 % 193,969 20.4 % Consumer and other 55,185 4.8 % 63,011 6.6 % Total Non-Real Estate 297,399 25.9 % 280,763 29.5 % Total Loans Before Unearned Income 1,151,497 100.0 % 950,815 100.0 % Unearned income (2,483 ) (1,894 ) Total Loans Net of Unearned Income $ 1,149,014 $ 948,921
Summary of Fixed and Floating Rate Loans by Contractual Maturity, Excluding Nonaccrual Loans	The following table summarizes fixed and floating rate loans by contractual maturity, excluding nonaccrual loans, as of December 31, 2017 and December 31, 2016 unadjusted for scheduled principal payments, prepayments, or repricing opportunities. The average life of the loan portfolio may be substantially less than the contractual terms when these adjustments are considered. December 31, 2017 December 31, 2016 (in thousands) Fixed Floating Total Fixed Floating Total One year or less $ 89,383 $ 75,361 $ 164,744 $ 97,713 $ 51,965 $ 149,678 One to five years 390,333 251,135 641,468 352,000 206,676 558,676 Five to 15 years 124,215 70,273 194,488 115,691 46,116 161,807 Over 15 years 70,366 67,881 138,247 53,150 5,830 58,980 Subtotal $ 674,297 $ 464,650 1,138,947 $ 618,554 $ 310,587 929,141 Nonaccrual loans 12,550 21,674 Total Loans Before Unearned Income 1,151,497 950,815 Unearned income (2,483 ) (1,894 ) Total Loans Net of Unearned Income $ 1,149,014 $ 948,921
Past due Financing Receivables	The following tables present the age analysis of past due loans for the periods indicated: As of December 31, 2017 (in thousands) 30-89 Days Past Due 90 Days or Greater Past Due Total Past Due Current Total Loans Recorded Investment 90 Days Accruing Real Estate: Construction & land development $ 95 $ 371 $ 466 $ 112,137 $ 112,603 $ - Farmland 175 65 240 25,451 25,691 - 1-4 family 1,481 1,953 3,434 155,299 158,733 - Multi-family - - - 16,840 16,840 - Non-farm non-residential 1,006 3,758 4,764 535,467 540,231 - Total Real Estate 2,757 6,147 8,904 845,194 854,098 - Non-Real Estate: Agricultural 239 1,537 1,776 19,738 21,514 41 Commercial and industrial 630 5,624 6,254 214,446 220,700 798 Consumer and other 463 81 544 54,641 55,185 - Total Non-Real Estate 1,332 7,242 8,574 288,825 297,399 839 Total Loans Before Unearned Income $ 4,089 $ 13,389 $ 17,478 $ 1,134,019 1,151,497 $ 839 Unearned income (2,483 ) Total Loans Net of Unearned Income $ 1,149,014 As of December 31, 2016 (in thousands) 30-89 Days Past Due 90 Days or Greater Past Due Total Past Due Current Total Loans Recorded Investment 90 Days Accruing Real Estate: Construction & land development $ 173 $ 585 $ 758 $ 83,481 $ 84,239 $ 34 Farmland 234 105 339 20,799 21,138 - 1-4 family 1,108 2,387 3,495 131,716 135,211 145 Multi-family - 5,014 5,014 7,436 12,450 - Non-farm non-residential 1,618 2,753 4,371 412,643 417,014 - Total Real Estate 3,133 10,844 13,977 656,075 670,052 179 Non-Real Estate: Agricultural 64 1,958 2,022 21,761 23,783 - Commercial and industrial 552 8,070 8,622 185,347 193,969 - Consumer and other 182 981 1,163 61,848 63,011 - Total Non-Real Estate 798 11,009 11,807 268,956 280,763 - Total Loans Before Unearned Income $ 3,931 $ 21,853 $ 25,784 $ 925,031 950,815 $ 179 Unearned income (1,894 ) Total Loans Net of Unearned Income $ 948,921
Summary of Nonaccrual Loans by Class	The following is a summary of nonaccrual loans by class for the periods indicated: As of December 31, (in thousands) 2017 2016 Real Estate: Construction & land development $ 371 $ 551 Farmland 65 105 1-4 family 1,953 2,242 Multi-family - 5,014 Non-farm non-residential 3,758 2,753 Total Real Estate 6,147 10,665 Non-Real Estate: Agricultural 1,496 1,958 Commercial and industrial 4,826 8,070 Consumer and other 81 981 Total Non-Real Estate 6,403 11,009 Total Nonaccrual Loans $ 12,550 $ 21,674
Credit Exposure of Loan Portfolio, Including Loans Acquired with Deteriorated Credit Quality, by Specific Credit Ratings	The following table identifies the credit exposure of the loan portfolio by specific credit ratings for the periods indicated: As of December 31, 2017 As of December 31, 2016 (in thousands) Pass Special Mention Substandard Doubtful Total Pass Special Mention Substandard Doubtful Total Real Estate: Construction & land development $ 108,200 $ 125 $ 4,278 $ - $ 112,603 $ 79,069 $ 1,162 $ 4,008 $ - $ 84,239 Farmland 25,030 569 92 - 25,691 20,652 381 105 - 21,138 1-4 family 149,426 1,856 7,451 - 158,733 123,191 5,460 6,560 - 135,211 Multi-family 9,366 639 6,835 - 16,840 4,268 1,132 7,050 - 12,450 Non-farm non-residential 520,432 2,490 17,309 - 540,231 392,355 6,406 18,253 - 417,014 Total Real Estate 812,454 5,679 35,965 - 854,098 619,535 14,541 35,976 - 670,052 Non-Real Estate: Agricultural 19,050 995 1,469 - 21,514 20,890 920 1,973 - 23,783 Commercial and industrial 191,784 19,187 5,169 4,560 220,700 182,381 850 3,008 7,730 193,969 Consumer and other 48,225 68 6,892 - 55,185 60,582 1,394 1,035 - 63,011 Total Non-Real Estate 259,059 20,250 13,530 4,560 297,399 263,853 3,164 6,016 7,730 280,763 Total Loans Before Unearned Income $ 1,071,513 $ 25,929 $ 49,495 $ 4,560 1,151,497 $ 883,388 $ 17,705 $ 41,992 $ 7,730 950,815 Unearned income (2,483 ) (1,894 ) Total Loans Net of Unearned Income $ 1,149,014 $ 948,921
Carrying Amount of Purchased Impaired Loans	The carrying amount of those loans is as follows at December 31, 2017. (in thousands) As of December 31, 2017 Real Estate: Construction & land development $ 1,135 Farmland 8 1-4 family 50 Multi-family - Non-farm non-residential 2,148 Total Real Estate 3,341 Non-Real Estate: Agricultural - Commercial and industrial 1,017 Consumer and other - Total Non-Real Estate 1,017 Total Carrying Amount $ 4,358 Contractual principal balance $ 5,436 Carrying amount, net of allowance $ 4,358
Accretable Yield, or Income Expected to be Collected, on Purchased Loans	The accretable yield, or income expected to be collected, on the purchased loans above is as follows at December 31, 2017. (in thousands) Year Ended December 31, 2017 Balance, beginning of period $ - Acquisition accretable yield 1,195 Accretion (164 ) Net transfers from nonaccretable difference to accretable yield - Balance, end of period $ 1,031

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Allowance for Loan Losses [Abstract]
Summary of Changes in Allowance for Loan Losses and Allowance and Loans Individually and Collectively Evaluated for Impairment	A summary of changes in the allowance for loan losses, by loan type, for the years ended December 31, 2017, 2016 and 2015 are as follows: As of December 31, 2017 2016 (in thousands) Beginning Allowance (12/31/16) Charge-offs Recoveries Provision Ending Allowance (12/31/17) Beginning Allowance (12/31/15) Charge-offs Recoveries Provision Ending Allowance (12/31/16) Real Estate: Construction & land development $ 1,232 $ - $ 43 $ (647 ) $ 628 $ 962 $ - $ 4 $ 266 $ 1,232 Farmland 19 - - (14 ) 5 54 - - (35 ) 19 1-4 family 1,204 (33 ) 92 (185 ) 1,078 1,771 (244 ) 45 (368 ) 1,204 Multi-family 591 - 40 363 994 557 - 401 (367 ) 591 Non-farm non-residential 3,451 (1,291 ) 85 566 2,811 3,298 (1,373 ) 16 1,510 3,451 Total Real Estate 6,497 (1,324 ) 260 83 5,516 6,642 (1,617 ) 466 1,006 6,497 Non-Real Estate: Agricultural 74 (162 ) 138 137 187 16 (83 ) 113 28 74 Commercial and industrial 3,543 (3,629 ) 30 2,433 2,377 2,527 (579 ) 146 1,449 3,543 Consumer and other 972 (1,247 ) 223 1,177 1,125 230 (635 ) 183 1,194 972 Unallocated 28 - - (8 ) 20 - - - 28 28 Total Non-Real Estate 4,617 (5,038 ) 391 3,739 3,709 2,773 (1,297 ) 442 2,699 4,617 Total $ 11,114 $ (6,362 ) $ 651 $ 3,822 $ 9,225 $ 9,415 $ (2,914 ) $ 908 $ 3,705 $ 11,114 As of December 31, 2015 (in thousands) Beginning Allowance (12/31/14) Charge-offs Recoveries Provision Ending Allowance (12/31/15) Real Estate: Construction & land development $ 702 $ (559 ) $ 5 $ 814 $ 962 Farmland 21 - - 33 54 1-4 family 2,131 (410 ) 94 (44 ) 1,771 Multi-family 813 (947 ) 46 645 557 Non-farm non-residential 2,713 (1,137 ) 5 1,717 3,298 Total Real Estate 6,380 (3,053 ) 150 3,165 6,642 Non-Real Estate: Agricultural 293 (491 ) 3 211 16 Commercial and industrial 1,797 (79 ) 315 494 2,527 Consumer and other 371 (550 ) 151 258 230 Unallocated 264 - - (264 ) - Total Non-Real Estate 2,725 (1,120 ) 469 699 2,773 Total $ 9,105 $ (4,173 ) $ 619 $ 3,864 $ 9,415 A summary of the allowance and loans individually and collectively evaluated for impairment are as follows: As of December 31, 2017 (in thousands) Allowance Individually Evaluated for Impairment Allowance Collectively Evaluated for Impairment Total Allowance for Credit Losses Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment Total Loans before Unearned Income Real Estate: Construction & land development $ - $ 628 $ 628 $ - $ 112,603 $ 112,603 Farmland - 5 5 - 25,691 25,691 1-4 family - 1,078 1,078 - 158,733 158,733 Multi-family - 994 994 - 16,840 16,840 Non-farm non-residential 236 2,575 2,811 8,990 531,241 540,231 Total Real Estate 236 5,280 5,516 8,990 845,108 854,098 Non-Real Estate: Agricultural 66 121 187 861 20,653 21,514 Commercial and industrial 565 1,812 2,377 5,731 214,969 220,700 Consumer and other - 1,125 1,125 - 55,185 55,185 Unallocated - 20 20 - - - Total Non-Real Estate 631 3,078 3,709 6,592 290,807 297,399 Total $ 867 $ 8,358 $ 9,225 $ 15,582 $ 1,135,915 1,151,497 Unearned Income (2,483 ) Total Loans Net of Unearned Income $ 1,149,014 As of December 31, 2016 (in thousands) Allowance Individually Evaluated for Impairment Allowance Collectively Evaluated for Impairment Total Allowance for Credit Losses Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment Total Loans before Unearned Income Real Estate: Construction & land development $ - $ 1,232 $ 1,232 $ 361 $ 83,878 $ 84,239 Farmland - 19 19 - 21,138 21,138 1-4 family 8 1,196 1,204 1,130 134,081 135,211 Multi-family 164 427 591 5,014 7,436 12,450 Non-farm non-residential 247 3,204 3,451 10,803 406,211 417,014 Total Real Estate 419 6,078 6,497 17,308 652,744 670,052 Non-Real Estate: Agricultural 11 63 74 1,614 22,169 23,783 Commercial and industrial 2,375 1,168 3,543 8,965 185,004 193,969 Consumer and other 193 779 972 924 62,087 63,011 Unallocated - 28 28 - - - Total Non-Real Estate 2,579 2,038 4,617 11,503 269,260 280,763 Total $ 2,998 $ 8,116 $ 11,114 $ 28,811 $ 922,004 950,815 Unearned Income (1,894 ) Total Loans Net of Unearned Income $ 948,921
Summary of Impaired Loans, Excluding Loans Acquired with Deteriorated Credit Quality, by Class	The following is a summary of impaired loans by class at December 31, 2017: As of December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Interest Income Cash Basis Impaired Loans with no related allowance: Real Estate: Construction & land development $ - $ - $ - $ - $ - $ - Farmland - - - - - - 1-4 family - - - - - - Multi-family - - - - - - Non-farm non-residential 5,771 5,771 - 5,933 248 279 Total Real Estate 5,771 5,771 - 5,933 248 279 Non-Real Estate: Agricultural - - - - - - Commercial and industrial - - - - - - Consumer and other - - - - - - Total Non-Real Estate - - - - - - Total Impaired Loans with no related allowance 5,771 5,771 - 5,933 248 279 Impaired Loans with an allowance recorded: Real estate: Construction & land development - - - - - - Farmland - - - - - - 1-4 family - - - - - - Multi-family - - - - - - Non-farm non-residential 3,219 3,570 236 3,555 183 127 Total Real Estate 3,219 3,570 236 3,555 183 127 Non-Real Estate: Agricultural 861 920 66 1,117 70 17 Commercial and industrial 5,731 9,062 565 8,121 65 84 Consumer and other - - - - - - Total Non-Real Estate 6,592 9,982 631 9,238 135 101 Total Impaired Loans with an allowance recorded 9,811 13,552 867 12,793 318 228 Total Impaired Loans $ 15,582 $ 19,323 $ 867 $ 18,726 $ 566 $ 507 The following is a summary of impaired loans by class at December 31, 2016: As of December 31, 2016 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Interest Income Cash Basis Impaired Loans with no related allowance: Real Estate: Construction & land development $ 361 $ 823 $ - $ 363 $ - $ - Farmland - - - - - - 1-4 family 863 1,196 - 1,044 49 48 Multi-family - - - - - - Non-farm non-residential 8,501 9,430 - 8,949 196 175 Total Real Estate 9,725 11,449 - 10,356 245 223 Non-Real Estate: Agricultural 1,603 1,742 - 1,377 30 - Commercial and industrial - - - - - - Consumer and other 686 685 - 724 18 12 Total Non-Real Estate 2,289 2,427 - 2,101 48 12 Total Impaired Loans with no related allowance 12,014 13,876 - 12,457 293 235 Impaired Loans with an allowance recorded: Real estate: Construction & land development - - - - - - Farmland - - - - - - 1-4 family 267 303 8 279 - - Multi-family 5,014 5,305 164 5,169 - - Non-farm non-residential 2,302 2,296 247 2,334 119 113 Total Real Estate 7,583 7,904 419 7,782 119 113 Non-Real Estate: Agricultural 11 11 11 11 - - Commercial and industrial 8,965 9,117 2,375 9,379 72 72 Consumer and other 238 244 193 289 8 7 Total Non-Real Estate 9,214 9,372 2,579 9,679 80 79 Total Impaired Loans with an allowance recorded 16,797 17,276 2,998 17,461 199 192 Total Impaired Loans $ 28,811 $ 31,152 $ 2,998 $ 29,918 $ 492 $ 427
Troubled Debt Restructurings	The following table is an age analysis of TDRs as of December 31, 2017 and December 31, 2016: Troubled Debt Restructurings December 31, 2017 December 31, 2016 Accruing Loans Accruing Loans (in thousands) Current 30-89 Days Past Due Nonaccrual Total TDRs Current 30-89 Days Past Due Nonaccrual Total TDRs Real Estate: Construction & land development $ - $ - $ 334 $ 334 $ - $ - $ 361 $ 361 Farmland - - - - - - - - 1-4 family - - - - - - - - Multi-family - - - - - - - - Non-farm non-residential 2,138 - - 2,138 2,987 - 100 3,087 Total Real Estate 2,138 - 334 2,472 2,987 - 461 3,448 Non-Real Estate: Agricultural - - - - - - - - Commercial and industrial - - - - - - - - Consumer and other - - - - - - - - Total Non-Real Estate - - - - - - - - Total $ 2,138 $ - $ 334 $ 2,472 $ 2,987 $ - $ 461 $ 3,448 The following table discloses TDR activity for the twelve months ended December 31, 2017. Trouble Debt Restructured Loans Activity Twelve Months Ended December 31, 2017 (in thousands) Beginning balance (December 31, 2016) New TDRs Charge-offs post-modification Transferred to ORE Paydowns Construction to permanent financing Restructured to market terms Other adjustments Ending balance (December 31, 2017) Real Estate: Construction & land development $ 361 $ - $ - $ - $ (27 ) $ - $ - $ - $ 334 Farmland - - - - - - - - - 1-4 family - - - - - - - - - Multi-family - - - - - - - - - Non-farm non-residential 3,087 - (102 ) - (849 ) - - 2 2,138 Total Real Estate 3,448 - (102 ) - (876 ) - - 2 2,472 Non-Real Estate: Agricultural - - - - - - - - - Commercial and industrial - - - - - - - - - Consumer and other - - - - - - - - - Total Non-Real Estate - - - - - - - - - Total Impaired Loans with no related allowance $ 3,448 $ - $ (102 ) $ - $ (876 ) $ - $ - $ 2 $ 2,472

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Premises and Equipment [Abstract]
Premises and Equipment	The components of premises and equipment at December 31, 2017 and 2016 are as follows: (in thousands) December 31, 2017 December 31, 2016 Land $ 12,875 $ 7,185 Bank premises 31,469 21,229 Furniture and equipment 24,305 21,689 Construction in progress 382 2,106 Acquired value 69,031 52,209 Less: accumulated depreciation 31,011 28,690 Net book value $ 38,020 $ 23,519

Goodwill and Other Intangible41

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Intangible Assets [Abstract]
Finite-lived Intangible Assets	The following table summarizes intangible assets subject to amortization. December 31, 2017 December 31, 2016 (in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Core deposit intangibles $ 12,053 $ 8,804 $ 3,249 $ 9,350 $ 8,372 $ 978 Mortgage servicing rights 1,373 198 1,175 267 189 78 Total $ 13,426 $ 9,002 $ 4,424 $ 9,617 $ 8,561 $ 1,056
Amortization Expense of Core Deposit Intangible Assets for Next Five Years	Amortization expense of the core deposit intangible assets for the next five years is as follows: For the Years Ended Estimated Amortization Expense (in thousands) December 31, 2018 $ 545 December 31, 2019 $ 361 December 31, 2020 $ 361 December 31, 2021 $ 293 December 31, 2022 $ 225

Other Real Estate (Tables)

Other Real Estate (Tables)	12 Months Ended
	Dec. 31, 2017
Other Real Estate [Abstract]
Components of Other Real Estate Owned	Other real estate owned consists of the following: (in thousands) December 31, 2017 December 31, 2016 Real Estate Owned Acquired by Foreclosure: Residential $ 23 $ 71 Construction & land development 304 - Non-farm non-residential 954 288 Total Other Real Estate Owned and Foreclosed Property $ 1,281 $ 359

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Schedule of Maturities of All Time Deposits	A schedule of maturities of all time deposits are as follows: (in thousands) December 31, 2017 2018 $ 357,687 2019 118,902 2020 48,843 2021 16,622 2022 and thereafter 39,277 Total $ 581,331

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Borrowings [Abstract]
Schedule of Short-term Borrowings	Short-term borrowings are summarized as follows: (in thousands) December 31, 2017 December 31, 2016 Federal Home Loan Bank advances $ 15,500 $ 6,500 Line of credit - - Total short-term borrowings $ 15,500 $ 6,500
Short-term Borrowings	The following schedule provides certain information about First Guaranty's short-term borrowings for the periods indicated: December 31, (in thousands except for %) 2017 2016 2015 Outstanding at year end $ 15,500 $ 6,500 $ 1,800 Maximum month-end outstanding $ 28,000 $ 25,000 $ 13,800 Average daily outstanding $ 5,833 $ 8,775 $ 4,217 Weighted average rate during the year 1.06 % 0.85 % 2.12 % Weighted average rate at year end 1.51 % 0.65 % 4.50 %
Obligations on Senior Long-term Debt and Junior Subordinated Debentures	As of December 31, 2017 obligations on senior long-term debt and junior subordinated debentures totaled $37.4 million. The scheduled maturities are as follows: (in thousands) Senior Long-term Debt Junior Subordinated Debentures 2018 $ 2,941 $ - 2019 2,941 - 2020 2,941 - 2021 2,941 - 2022 2,941 - 2023 and thereafter 8,089 15,000 Subtotal $ 22,794 $ 15,000 Debt issuance costs (20 ) (336 ) Total $ 22,774 $ 14,664

Capital Requirements (Tables)

Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2017
Capital Requirements [Abstract]
Actual and Required Capital Amounts and Ratios	First Guaranty's and the Bank's actual capital amounts and ratios as of December 31, 2017 and 2016 are presented in the following table. Actual Minimum Capital Requirements Minimum to be Well Capitalized Under Action Provisions (in thousands except for %) Amount Ratio Amount Ratio Amount Ratio December 31, 2017 Total Risk-based Capital: Consolidated $ 164,545 12.14 % $ 108,427 8.00 % N/A N/A Bank $ 176,398 13.07 % $ 107,961 8.00 % $ 134,951 10.00 % Tier 1 Capital: Consolidated $ 140,320 10.35 % $ 81,320 6.00 % N/A N/A Bank $ 167,173 12.39 % $ 80,971 6.00 % $ 107,961 8.00 % Tier 1 Leverage Capital: Consolidated $ 140,320 8.27 % $ 67,899 4.00 % N/A N/A Bank $ 167,173 9.88 % $ 67,709 4.00 % $ 84,636 5.00 % Common Equity Tier One Capital: Consolidated $ 140,320 10.35 % $ 60,990 4.50 % N/A N/A Bank $ 167,173 12.39 % $ 60,728 4.50 % $ 87,718 6.50 % December 31, 2016 Total Risk-based Capital: Consolidated $ 151,877 12.79 % $ 94,982 8.00 % N/A N/A Bank $ 153,768 12.99 % $ 94,717 8.00 % $ 118,396 10.00 % Tier 1 Capital: Consolidated $ 125,763 10.59 % $ 71,236 6.00 % N/A N/A Bank $ 142,654 12.05 % $ 71,038 6.00 % $ 94,717 8.00 % Tier 1 Leverage Capital: Consolidated $ 125,763 8.68 % $ 57,930 4.00 % N/A N/A Bank $ 142,654 9.88 % $ 57,771 4.00 % $ 72,214 5.00 % Common Equity Tier One Capital: Consolidated $ 125,763 10.59 % $ 53,427 4.50 % N/A N/A Bank $ 142,654 12.05 % $ 53,278 4.50 % $ 76,958 6.50 %

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	An analysis of the activity of loans made to such borrowers during the year ended December 31, 2017 and 2016 follows: December 31, (in thousands) 2017 2016 Balance, beginning of year $ 58,279 $ 57,816 Net Increase 24,639 463 Balance, end of year $ 82,918 $ 58,279

Other Expenses (Tables)

Other Expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Other Expenses [Abstract]
Summary of Significant Components of Other Noninterest Expense	The following is a summary of the significant components of other noninterest expense: December 31, (in thousands) 2017 2016 2015 Other noninterest expense: Legal and professional fees $ 3,037 $ 2,185 $ 2,019 Data processing 1,608 1,259 1,184 ATM Fees 1,161 1,044 1,022 Marketing and public relations 1,205 878 848 Taxes - sales, capital and franchise 970 787 717 Operating supplies 496 471 414 Software expense and amortization 923 835 612 Travel and lodging 910 710 818 Telephone 167 177 172 Amortization of core deposits 432 320 320 Donations 322 298 332 Net costs from other real estate and repossessions 306 498 493 Regulatory assessment 726 1,005 1,111 Other 1,640 1,599 1,692 Total other noninterest expense $ 13,903 $ 12,066 $ 11,754

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Summary of Provision for Income Taxes	The following is a summary of the provision for income taxes included in the Consolidated Statements of Income: December 31, (in thousands) 2017 2016 2015 Current $ 4,638 $ 8,168 $ 7,347 Deferred 2,761 (1,004 ) (384 ) Total $ 7,399 $ 7,164 $ 6,963
Effective Income Tax Rate Reconciliation	The difference between income taxes computed by applying the statutory federal income tax rate and the provision for income taxes in the financial statements is reconciled as follows: December 31, (in thousands except for %) 2017 2016 2015 Statutory tax rate 35.0 % 35.0 % 35.0 % Federal income taxes at statutory rate $ 6,703 $ 7,440 $ 7,514 Tax exempt municipal income (254 ) (283 ) (436 ) Other (1) 950 7 (115 ) Total $ 7,399 $ 7,164 $ 6,963 (1) Included in other for the year ended December 31, 2017 is $0.9 million related to the estimated net impact from the remeasurement of deferred tax assets and liabilities as a result of the passage of the Tax Cuts and Jobs Act in December 2017.
Components of Deferred Tax Assets and Liabilities	The significant components of deferred taxes classified in First Guaranty's Consolidated Balance Sheets at December 31, 2017 and 2016 are as follows: December 31, (in thousands) 2017 2016 Deferred tax assets: Allowance for loan losses $ 1,804 $ 3,890 Other real estate owned 25 60 Unrealized losses on available for sale securities 495 2,060 Net operating loss 1,463 - Other 546 449 Gross deferred tax assets 4,333 6,459 Deferred tax liabilities: Depreciation and amortization (1,688 ) (1,480 ) Core deposit intangibles (662 ) (342 ) Unrealized gains on available for sale securities - - Other (566 ) (376 ) Gross deferred tax liabilities (2,916 ) (2,198 ) Net deferred tax assets $ 1,417 $ 4,261

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies [Abstract]
Summary of Notional Amounts of Financial Instruments with Off-Balance Sheet Risk	Set forth below is a summary of the notional amounts of the financial instruments with off-balance sheet risk at December 31, 2017 and December 31, 2016. (in thousands) December 31, 2017 December 31, 2016 Contract Amount Commitments to Extend Credit $ 78,125 $ 56,910 Unfunded Commitments under lines of credit $ 101,344 $ 128,428 Commercial and Standby letters of credit $ 7,886 $ 6,602

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements [Abstract]
Fair Value, Assets Measured on Recurring Basis	The following table summarizes financial assets measured at fair value on a recurring basis as of December 31, 2017 and 2016, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: (in thousands) December 31, 2017 December 31, 2016 Available for Sale Securities Fair Value Measurements Using: Level 1:Quoted Prices in Active Markets For Identical Assets $ 19,980 $ 30,487 Level 2: Significant Other Observable Inputs 355,022 347,586 Level 3: Significant Unobservable Inputs 6,533 19,400 Securities available for sale measured at fair value $ 381,535 $ 397,473
Fair value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following table reconciles assets measured at fair value on a recurring basis using unobservable inputs ( Level 3 Level 3 Changes (in thousands) December 31, 2017 December 31, 2016 Balance, beginning of year $ 19,400 $ 7,701 Total gains or losses (realized/unrealized): Included in earnings 54 - Included in other comprehensive income - - Purchases, sales, issuances and settlements, net 10,574 11,699 Transfers in and/or out of Level 3 (23,495 ) - Balance as of end of year $ 6,533 $ 19,400
Fair Value Measurements, Nonrecurring	The following table measures financial assets and financial liabilities measured at fair value on a non-recurring basis as of December 31, 2017, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value: (in thousands) At December 31, At December 31, Fair Value Measurements Using: Impaired Loans Level 1: Quoted Prices in Active Markets For Identical Assets $ - $ - Level 2: Significant Other Observable Inputs - 259 Level 3: Significant Unobservable Inputs 12,003 18,559 Impaired loans measured at fair value $ 12,003 $ 18,818 Fair Value Measurements Using: Other Real Estate Owned Level 1: Quoted Prices in Active Markets For Identical Assets $ - $ - Level 2: Significant Other Observable Inputs 1,249 226 Level 3: Significant Unobservable Inputs 32 133 Other real estate owned measured at fair value $ 1,281 $ 359

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Financial Instruments [Abstract]
Schedule of Estimated Fair Values and Carrying Values of Financial Instruments	The estimated fair values and carrying values of the financial instruments at December 31, 2017 and 2016 are presented in the following table: December 31, 2017 2016 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Assets Cash and cash equivalents $ 38,028 $ 38,028 $ 18,111 $ 18,111 Securities, available for sale $ 381,535 $ 381,535 $ 397,473 $ 397,473 Securities, held to maturity $ 120,121 $ 118,557 $ 101,863 $ 99,906 Federal Home Loan Bank stock $ 2,351 $ 2,351 $ 1,816 $ 1,816 Loans held for sale $ 1,308 $ 1,439 $ - $ - Loans, net $ 1,139,789 $ 1,133,868 $ 937,807 $ 937,495 Accrued interest receivable $ 7,982 $ 7,982 $ 7,039 $ 7,039 Liabilities Deposits $ 1,549,286 $ 1,549,449 $ 1,326,181 $ 1,325,972 Borrowings $ 38,274 $ 38,294 $ 28,600 $ 28,625 Junior subordinated debentures $ 14,664 $ 14,324 $ 14,630 $ 13,909 Accrued interest payable $ 2,488 $ 2,488 $ 1,931 $ 1,931

Condensed Parent Company Info52

Condensed Parent Company Information (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Parent Company Information [Abstract]
Condensed Balance Sheets	First Guaranty Bancshares, Inc. Condensed Balance Sheets December 31, (in thousands) 2017 2016 Assets Cash $ 5,214 $ 16,088 Investment in bank subsidiary 170,836 141,241 Investment Securities (available for sale, at fair value) - 80 Other assets 6,086 4,197 Total Assets $ 182,136 $ 161,606 Liabilities and Shareholders' Equity Short-term debt $ - $ - Senior long-term debt 22,774 22,100 Junior subordinated debentures 14,664 14,630 Other liabilities 715 527 Total Liabilities 38,153 37,257 Shareholders' Equity 143,983 124,349 Total Liabilities and Shareholders' Equity $ 182,136 $ 161,606
Condensed Statements of Income	First Guaranty Bancshares, Inc. Condensed Statements of Income December 31, (in thousands) 2017 2016 2015 Operating Income Dividends received from bank subsidiary $ 10,622 $ 11,858 $ 9,843 Net gains on securities 54 - 2,652 Other income 171 160 261 Total operating income 10,847 12,018 12,756 Operating Expenses Interest expense 1,518 1,444 192 Salaries & Benefits 495 200 172 Other expenses 1,147 948 766 Total operating expenses 3,160 2,592 1,130 Income before income tax benefit and increase in equity in undistributed earnings of subsidiary 7,687 9,426 11,626 Income tax benefit (expense) 834 846 (605 ) Income before increase in equity in undistributed earnings of subsidiary 8,521 10,272 11,021 Increase in equity in undistributed earnings of subsidiary 3,230 3,821 3,484 Net Income 11,751 14,093 14,505 Less preferred stock dividends - - (384 ) Net income available to common shareholders $ 11,751 $ 14,093 $ 14,121
Condensed Statements of Cash Flows	First Guaranty Bancshares, Inc. Condensed Statements of Cash Flows December 31, (in thousands) 2017 2016 2015 Cash flows from operating activities: Net income $ 11,751 $ 14,093 $ 14,505 Adjustments to reconcile net income to net cash provided by operating activities: Increase in equity in undistributed earnings of subsidiary $ (3,230 ) $ (3,821 ) (3,484 ) Depreciation and amortization 43 7 - Gain on sale of securities (54 ) - (2,652 ) Net change in other liabilities 187 318 (28 ) Net change in other assets (1,306 ) (971 ) 396 Net cash provided by operating activities 7,391 9,626 8,737 Cash flows from investing activities: Proceeds from maturities, calls and sales of AFS securities 134 - 4,152 Funds invested in AFS securities - - (10 ) Funds invested in bank subsidiary (3,750 ) - - Cash paid in acquisition (10,108 ) - - Net cash provided by (used in) investing activities (13,724 ) - 4,142 Cash flows from financing activities: Net decrease in short-term borrowings - (1,800 ) - Proceeds from long-term debt, net of costs 3,750 - 24,969 Repayment of long-term debt (3,081 ) (3,730 ) (1,584 ) Proceeds from junior subordinated debentures, net of costs - - 14,597 Issuance of common stock, net of costs - - 9,344 Redemption of preferred stock - - (39,435 ) Dividends paid (5,210 ) (4,870 ) (4,631 ) Net cash (used in) provided by financing activities (4,541 ) (10,400 ) 3,260 Net (decrease) increase in cash and cash equivalents (10,874 ) (774 ) 16,139 Cash and cash equivalents at the beginning of the period 16,088 16,862 723 Cash and cash equivalents at the end of the period $ 5,214 $ 16,088 $ 16,862

Business and Summary of Signi53

Business and Summary of Significant Accounting Policies (Details)	Dec. 14, 2017	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)OfficeFacilityATMPaymentSegment
Business and Summary of Significant Accounting Policies [Abstract]
Number of banking offices | Office			27
Number of drive up banking facility | Facility			1
Number of automated teller machines (ATMs) | ATM			38
Acquisition Accounting [Abstract]
Maximum period of fair value refinement after closing date of acquisition			1 year
Loans [Abstract]
Past due period after which evaluation is made for discontinuation of interest accrual on loan			90 days
Period of payment performance after which loans are returned to accrual status			6 months
Troubled Debt Restructurings (TDRs) [Abstract]
Period of performance, after which the Company evaluates TDRs that have subsequently been restructured and returned to market terms			12 months
Credit Quality [Abstract]
Minimum balance of impaired loans over which impairment method is applied | $		$ 500,000	$ 500,000
Earnings per common share [Abstract]
Common stock, dividend paid percentage	10.00%	10.00%
Operating Segments [Abstract]
Number of reportable operating segments | Segment			1
Minimum [Member]
Loans [Abstract]
Threshold period past due for charge-off of loans			90 days
Maximum [Member]
Loans [Abstract]
Threshold period past due for charge-off of loans			120 days
Single-Family Residential [Member] | Fixed Rate Residential Mortgage [Member]
Loans held for sale [Abstract]
Period within which loans are sold in secondary market			30 days
All Loans Except Mortgage Loans [Member]
Loans [Abstract]
Past due period after which loans are considered past due			30 days
Mortgage Loans [Member]
Loans [Abstract]
Number of consecutive payments missed after which loans are considered past due | Payment			2
Building and Improvements [Member] | Minimum [Member]
Premises and equipment [Abstract]
Estimated useful life			10 years
Building and Improvements [Member] | Maximum [Member]
Premises and equipment [Abstract]
Estimated useful life			40 years
Equipment, Fixtures and Automobiles [Member] | Minimum [Member]
Premises and equipment [Abstract]
Estimated useful life			3 years
Equipment, Fixtures and Automobiles [Member] | Maximum [Member]
Premises and equipment [Abstract]
Estimated useful life			10 years
Core Deposits [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period			7 years
Core Deposits [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period			15 years
Consumer Loans [Member]
Credit Quality [Abstract]
Period past due after which loans are considered substandard			90 days

Merger Transaction (Details)

Merger Transaction (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 14, 2017	Jun. 16, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Common stock, dividend paid percentage	10.00%		10.00%
Acquired assets and liabilities at fair value [Abstract]
Goodwill			$ 3,472	$ 3,472	$ 1,999
Premier Bancshares, Inc. [Member]
Business Acquisition [Line Items]
Percentage of outstanding shares acquired		100.00%
Number of shares of common stock issued for each share of acquired entity (in shares)		0.119
Total number of shares of common stock issued in acquisition (in shares)		397,988
Share price (in dollars per share)		$ 25.86
Common stock, dividend paid percentage			10.00%
Acquisition value paid in cash		$ 10,300
Acquired assets and liabilities at fair value [Abstract]
Cash and due from banks		4,542
Federal funds sold		2,855
Securities available for sale		5,892
Loans		128,018
Premises and equipment		9,493
Goodwill		1,474
Intangible assets		3,809
Other real estate		221
Other assets		2,009
Total assets acquired		158,313
Deposits		127,228
FHLB borrowings		9,700
Other liabilities		431
Total liabilities assumed		137,359
Net assets acquired		20,954
Acquired receivables not considered impaired [Abstract]
Non-impaired loans excluded from purchase credit impairment guidance, estimated fair value		123,700
Non-impaired loans excluded from purchase credit impairment guidance, gross contractual amount		122,900
Non-impaired loans excluded from purchase credit impairment guidance, estimated uncollectible		500
Pro forma information [Abstract]
Net Interest Income				55,663	53,190
Noninterest Income				8,540	11,541
Noninterest Expense				42,434	39,395
Net Income				$ 10,885	$ 13,709
Earnings per common share (in dollars per share)				$ 1.24	$ 1.56
Premier Bancshares, Inc. [Member] | Core Deposits [Member]
Acquired assets and liabilities at fair value [Abstract]
Intangible assets		$ 2,700

Cash and Due from Banks (Detail

Cash and Due from Banks (Details)	Dec. 31, 2017USD ($)Account	Dec. 31, 2016USD ($)Account
Cash and Due from Banks [Abstract]
Reserve maintained at Federal Reserve Bank	$ 0	$ 0
Number of accounts that exceeded FDIC insurable limit | Account	1	1
FDIC insurable limit	$ 250,000	$ 250,000
Balance in excess of FDIC insurable limit	$ 600,000	$ 4,000

Securities, Summary Comparison

Securities, Summary Comparison of Securities by Type (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	$ 383,893	$ 403,532
Gross unrealized gains	3,095	1,724
Gross unrealized losses	(5,453)	(7,783)
Fair value	381,535	397,473
Held to Maturity Securities [Abstract]
Amortized cost	120,121	101,863
Gross unrealized gains	21	0
Gross unrealized losses	(1,585)	(1,957)
Fair value	118,557	99,906
U.S. Treasuries [Member]
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	19,490	29,994
Gross unrealized gains	0	0
Gross unrealized losses	(4)	0
Fair value	19,486	29,994
U.S. Government Agencies [Member]
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	200,052	183,152
Gross unrealized gains	0	0
Gross unrealized losses	(4,069)	(4,820)
Fair value	195,983	178,332
Corporate Debt Securities [Member]
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	91,770	132,448
Gross unrealized gains	661	1,624
Gross unrealized losses	(946)	(2,100)
Fair value	91,485	131,972
Mutual Funds or Other Equity Securities [Member]
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	500	580
Gross unrealized gains	0	0
Gross unrealized losses	(7)	(7)
Fair value	493	573
Municipal Bonds [Member]
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	37,210	28,177
Gross unrealized gains	2,434	100
Gross unrealized losses	(75)	(320)
Fair value	39,569	27,957
Collateralized Mortgage Obligations [Member]
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	1,191	0
Gross unrealized gains	0	0
Gross unrealized losses	(6)	0
Fair value	1,185	0
Mortgage-backed Securities [Member]
Available for Sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized cost	33,680	29,181
Gross unrealized gains	0	0
Gross unrealized losses	(346)	(536)
Fair value	33,334	28,645
US Government Agencies [Member]
Held to Maturity Securities [Abstract]
Amortized cost	28,169	18,167
Gross unrealized gains	0	0
Gross unrealized losses	(670)	(655)
Fair value	27,499	17,512
Municipal Bonds [Member]
Held to Maturity Securities [Abstract]
Amortized cost	5,322	0
Gross unrealized gains	15	0
Gross unrealized losses	(12)	0
Fair value	5,325	0
Mortgage-backed Securities [Member]
Held to Maturity Securities [Abstract]
Amortized cost	86,630	83,696
Gross unrealized gains	6	0
Gross unrealized losses	(903)	(1,302)
Fair value	$ 85,733	$ 82,394

Securities, Scheduled Maturitie

Securities, Scheduled Maturities of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available for Sale Securities, Debt Maturities, Amortized Cost [Abstract]
Due in one year or less	$ 29,215
Due after one year through five years	76,969
Due after five years through 10 years	217,238
Over 10 years	25,600
Subtotal	349,022
Amortized cost	383,893
Available for Sale Securities, Debt Maturities, Fair Value [Abstract]
Due in one year or less	29,233
Due after one year through five years	76,922
Due after five years through 10 years	214,769
Over 10 years	26,092
Subtotal	347,016
Fair value	381,535
Held to Maturity Securities, Debt Maturities, Amortized Cost [Abstract]
Due in one year or less	0
Due after one year through five years	5,124
Due after five years through 10 years	18,485
Over 10 years	9,882
Subtotal	33,491
Mortgage-backed securities	86,630
Amortized cost	120,121	$ 101,863
Held to Maturity Securities, Debt Maturities, Fair Value [Abstract]
Due in one year or less	0
Due after one year through five years	5,057
Due after five years through 10 years	17,907
Over 10 years	9,860
Subtotal	32,824
Mortgage-backed securities	85,733
Fair value	118,557	$ 99,906
Collateralized Mortgage Obligations [Member]
Available for Sale Securities, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	1,191
Available for Sale Securities, Debt Maturities, Fair Value [Abstract]
Without single maturity date	1,185
Mortgage-backed Securities [Member]
Available for Sale Securities, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	33,680
Available for Sale Securities, Debt Maturities, Fair Value [Abstract]
Without single maturity date	$ 33,334

Securities, Summary of Securiti

Securities, Summary of Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2017USD ($)Security	Dec. 31, 2016USD ($)Security
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	132	273
Less than 12 months, fair value	$ 122,124	$ 290,345
Less than 12 months, gross unrealized losses	$ (885)	$ (7,296)
12 months or more, number of securities | Security	118	26
12 months or more, fair value	$ 175,202	$ 6,440
12 months or more, gross unrealized losses	$ (4,568)	$ (487)
Total, number of securities | Security	250	299
Total, fair value	$ 297,326	$ 296,785
Total, gross unrealized losses	$ (5,453)	$ (7,783)
Held to Maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of securities | Security	45	58
Less than 12 months, fair value	$ 67,302	$ 99,906
Less than 12 months, gross unrealized losses	$ (602)	$ (1,957)
12 months or more, number of securities | Security	27	0
12 months or more, fair value	$ 44,426	$ 0
12 months or more, gross unrealized losses	$ (983)	$ 0
Total, number of securities | Security	72	58
Total, fair value	$ 111,728	$ 99,906
Total, gross unrealized losses	$ (1,585)	$ (1,957)
Securities Disclosures [Abstract]
Number of debt securities with unrealized losses | Security	322
Unrealized losses on debt securities in continuous loss position as percentage of total individual securities' amortized cost basis	1.70%
Unrealized losses on debt securities in continuous loss position as percentage of amortized cost basis of investment securities portfolio	1.40%
Number of debt securities in continuous loss position for over 12 months | Security	145
Debt securities in a continuous loss position for over 12 months, amortized cost basis	$ 225,200
Debt securities in a continuous loss position for over 12 months, unrealized loss	$ 5,600
U.S. Treasuries [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	6	3
Less than 12 months, fair value	$ 19,486	$ 10,997
Less than 12 months, gross unrealized losses	$ (4)	$ 0
12 months or more, number of securities | Security	0	0
12 months or more, fair value	$ 0	$ 0
12 months or more, gross unrealized losses	$ 0	$ 0
Total, number of securities | Security	6	3
Total, fair value	$ 19,486	$ 10,997
Total, gross unrealized losses	$ (4)	$ 0
U.S. Government Agencies [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	30	54
Less than 12 months, fair value	$ 62,991	$ 178,331
Less than 12 months, gross unrealized losses	$ (519)	$ (4,820)
12 months or more, number of securities | Security	36	0
12 months or more, fair value	$ 132,992	$ 0
12 months or more, gross unrealized losses	$ (3,550)	$ 0
Total, number of securities | Security	66	54
Total, fair value	$ 195,983	$ 178,331
Total, gross unrealized losses	$ (4,069)	$ (4,820)
Corporate Debt Securities [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	56	185
Less than 12 months, fair value	$ 19,050	$ 61,669
Less than 12 months, gross unrealized losses	$ (240)	$ (1,613)
12 months or more, number of securities | Security	70	26
12 months or more, fair value	$ 22,818	$ 6,440
12 months or more, gross unrealized losses	$ (706)	$ (487)
Total, number of securities | Security	126	211
Total, fair value	$ 41,868	$ 68,109
Total, gross unrealized losses	$ (946)	$ (2,100)
Mutual Funds or Other Equity Securities [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	1	1
Less than 12 months, fair value	$ 493	$ 493
Less than 12 months, gross unrealized losses	$ (7)	$ (7)
12 months or more, number of securities | Security	0	0
12 months or more, fair value	$ 0	$ 0
12 months or more, gross unrealized losses	$ 0	$ 0
Total, number of securities | Security	1	1
Total, fair value	$ 493	$ 493
Total, gross unrealized losses	$ (7)	$ (7)
Municipal Bonds [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	9	14
Less than 12 months, fair value	$ 4,431	$ 10,210
Less than 12 months, gross unrealized losses	$ (36)	$ (320)
12 months or more, number of securities | Security	1	0
12 months or more, fair value	$ 1,079	$ 0
12 months or more, gross unrealized losses	$ (39)	$ 0
Total, number of securities | Security	10	14
Total, fair value	$ 5,510	$ 10,210
Total, gross unrealized losses	$ (75)	$ (320)
Collateralized Mortgage Obligations [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	4
Less than 12 months, fair value	$ 936
Less than 12 months, gross unrealized losses	$ (6)
12 months or more, number of securities | Security	0
12 months or more, fair value	$ 0
12 months or more, gross unrealized losses	$ 0
Total, number of securities | Security	4
Total, fair value	$ 936
Total, gross unrealized losses	$ (6)
Mortgage-backed Securities [Member]
Summary of Fair Value of Securities with Gross Unrealized Losses and Aging of Gross Unrealized Losses [Abstract]
Less than 12 months, number of securities | Security	26	16
Less than 12 months, fair value	$ 14,737	$ 28,645
Less than 12 months, gross unrealized losses	$ (73)	$ (536)
12 months or more, number of securities | Security	11	0
12 months or more, fair value	$ 18,313	$ 0
12 months or more, gross unrealized losses	$ (273)	$ 0
Total, number of securities | Security	37	16
Total, fair value	$ 33,050	$ 28,645
Total, gross unrealized losses	$ (346)	$ (536)
US Government Agencies [Member]
Held to Maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of securities | Security	4	10
Less than 12 months, fair value	$ 9,925	$ 17,512
Less than 12 months, gross unrealized losses	$ (75)	$ (655)
12 months or more, number of securities | Security	10	0
12 months or more, fair value	$ 17,574	$ 0
12 months or more, gross unrealized losses	$ (595)	$ 0
Total, number of securities | Security	14	10
Total, fair value	$ 27,499	$ 17,512
Total, gross unrealized losses	$ (670)	$ (655)
Municipal Bonds [Member]
Held to Maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of securities | Security	6
Less than 12 months, fair value	$ 3,191
Less than 12 months, gross unrealized losses	$ (12)
12 months or more, number of securities | Security	0
12 months or more, fair value	$ 0
12 months or more, gross unrealized losses	$ 0
Total, number of securities | Security	6
Total, fair value	$ 3,191
Total, gross unrealized losses	$ (12)
Mortgage-backed Securities [Member]
Held to Maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of securities | Security	35	48
Less than 12 months, fair value	$ 54,186	$ 82,394
Less than 12 months, gross unrealized losses	$ (515)	$ (1,302)
12 months or more, number of securities | Security	17	0
12 months or more, fair value	$ 26,852	$ 0
12 months or more, gross unrealized losses	$ (388)	$ 0
Total, number of securities | Security	52	48
Total, fair value	$ 81,038	$ 82,394
Total, gross unrealized losses	$ (903)	$ (1,302)

Securities, Other Than Temporar

Securities, Other Than Temporary Impairments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Issuer	Dec. 31, 2016USD ($)Security	Dec. 31, 2015USD ($)Security
OTTI losses recorded on available for sale securities [Abstract]
Total OTTI charge realized and unrealized	$ 0	$ 66	$ 571
OTTI recognized in other comprehensive income (non-credit component)	0	6	396
Net impairment losses recognized in earnings (credit component)	0	60	175
Other than temporary impairment losses	0	60	175
Book balance of securities with credit related OTTI losses	383,893	403,532
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance of credit losses at beginning of year	60	175	0
Other-than-temporary impairment credit losses on securities not previously OTTI	0	60	175
Increases for additional credit losses on securities previously determined to be OTTI	0	0	0
Reduction for increases in cash flows	0	0	0
Reduction due to credit impaired securities sold or fully settled	0	(175)	0
Ending balance of cumulative credit losses recognized in earnings at end of year	$ 60	$ 60	$ 175
Available-for-sale Securities [Member] | Corporate Bond Securities [Member]
OTTI losses recorded on available for sale securities [Abstract]
Number of securities with credit related OTTI losses | Security		1	2
Book balance of securities with credit related OTTI losses		$ 100	$ 800
Available-for-sale Securities [Member] | Corporate Debt Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Number of issuers having other-than-temporary impairment losses | Issuer	2
Available-for-sale Securities [Member] | Corporate Debt Securities One [Member]
OTTI losses recorded on available for sale securities [Abstract]
OTTI recognized in other comprehensive income (non-credit component)		$ 6	$ 300
Number of securities with credit related OTTI losses | Security		1	1
Book balance of securities with credit related OTTI losses		$ 100	$ 500
Available-for-sale Securities [Member] | Corporate Debt Securities Two [Member]
OTTI losses recorded on available for sale securities [Abstract]
OTTI recognized in other comprehensive income (non-credit component)			$ 100

Securities, Pledged Securities

Securities, Pledged Securities and Realized and Unrealized Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Securities [Abstract]
Carrying value of pledged securities		$ 412,200	$ 368,200
Total gains realized on security	$ 2,700	1,397	3,799	$ 3,300
Gross realized gains		1,400	3,600	3,300
Gross realized losses		100	53	400
Tax (benefit) provision applicable to these realized net (losses)/gains		500	1,300	1,200
Proceeds from sales of securities		148,000	191,000	$ 290,000
Net unrealized gains (losses) on available-for-sale securities included in AOCI , net of applicable income taxes		(1,600)	(4,000)
Gains reclassified out of AOCI into earnings, net of tax		$ 900	$ 2,500

Securities, Exposure to Investm

Securities, Exposure to Investment Securities Issuers That Exceeded 10 Percent of Stockholders' Equity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Exposure to investment securities issuers that exceeded 10% of shareholders' equity [Abstract]
Amortized cost	$ 501,656	$ 499,336
Stockholders' Equity, Total [Member]
Exposure to investment securities issuers that exceeded 10% of shareholders' equity [Abstract]
Amortized cost	368,021
Fair value	362,035
Stockholders' Equity, Total [Member] | U.S. Treasuries [Member]
Exposure to investment securities issuers that exceeded 10% of shareholders' equity [Abstract]
Amortized cost	19,490
Fair value	19,486
Stockholders' Equity, Total [Member] | Federal Home Loan Bank (FHLB) [Member]
Exposure to investment securities issuers that exceeded 10% of shareholders' equity [Abstract]
Amortized cost	50,395
Fair value	49,403
Stockholders' Equity, Total [Member] | Federal Home Loan Mortgage Corporation (Freddie Mac-FHLMC) [Member]
Exposure to investment securities issuers that exceeded 10% of shareholders' equity [Abstract]
Amortized cost	57,569
Fair value	57,008
Stockholders' Equity, Total [Member] | Federal National Mortgage Association (Fannie Mae-FNMA) [Member]
Exposure to investment securities issuers that exceeded 10% of shareholders' equity [Abstract]
Amortized cost	103,644
Fair value	101,757
Stockholders' Equity, Total [Member] | Federal Farm Credit Bank (FFCB) [Member]
Exposure to investment securities issuers that exceeded 10% of shareholders' equity [Abstract]
Amortized cost	136,923
Fair value	$ 134,381

Loans, Components of Loan Portf

Loans, Components of Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Balance [Abstract]
Total loans before unearned income	$ 1,151,497	$ 950,815
Unearned income	(2,483)	(1,894)
Total loans net of unearned income	$ 1,149,014	$ 948,921
As % of Category [Abstract]
Percent of category	100.00%	100.00%
Real Estate [Member]
Balance [Abstract]
Total loans before unearned income	$ 854,098	$ 670,052
As % of Category [Abstract]
Percent of category	74.10%	70.50%
Real Estate [Member] | Construction & Land Development [Member]
Balance [Abstract]
Total loans before unearned income	$ 112,603	$ 84,239
As % of Category [Abstract]
Percent of category	9.80%	8.90%
Real Estate [Member] | Farmland [Member]
Balance [Abstract]
Total loans before unearned income	$ 25,691	$ 21,138
As % of Category [Abstract]
Percent of category	2.20%	2.20%
Real Estate [Member] | 1 - 4-family [Member]
Balance [Abstract]
Total loans before unearned income	$ 158,733	$ 135,211
As % of Category [Abstract]
Percent of category	13.80%	14.20%
Real Estate [Member] | Multifamily [Member]
Balance [Abstract]
Total loans before unearned income	$ 16,840	$ 12,450
As % of Category [Abstract]
Percent of category	1.40%	1.30%
Real Estate [Member] | Non-Farm Non-Residential [Member]
Balance [Abstract]
Total loans before unearned income	$ 540,231	$ 417,014
As % of Category [Abstract]
Percent of category	46.90%	43.90%
Non-Real Estate [Member]
Balance [Abstract]
Total loans before unearned income	$ 297,399	$ 280,763
As % of Category [Abstract]
Percent of category	25.90%	29.50%
Non-Real Estate [Member] | Agricultural [Member]
Balance [Abstract]
Total loans before unearned income	$ 21,514	$ 23,783
As % of Category [Abstract]
Percent of category	1.90%	2.50%
Non-Real Estate [Member] | Commercial and Industrial [Member]
Balance [Abstract]
Total loans before unearned income	$ 220,700	$ 193,969
As % of Category [Abstract]
Percent of category	19.20%	20.40%
Non-Real Estate [Member] | Consumer and Other [Member]
Balance [Abstract]
Total loans before unearned income	$ 55,185	$ 63,011
As % of Category [Abstract]
Percent of category	4.80%	6.60%

Loans, Fixed and Floating Rate

Loans, Fixed and Floating Rate Loans by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivables, Fixed and Floating Rate Loans by Contractual Maturity [Abstract]
One year or less	$ 164,744	$ 149,678
One to five years	641,468	558,676
Five to 15 years	194,488	161,807
Over 15 years	138,247	58,980
Subtotal	1,138,947	929,141
Nonaccrual loans	12,550	21,674
Total loans before unearned income	1,151,497	950,815
Unearned income	(2,483)	(1,894)
Total loans net of unearned income	1,149,014	948,921
Fixed Rate Loans [Member]
Financing Receivables, Fixed and Floating Rate Loans by Contractual Maturity [Abstract]
One year or less	89,383	97,713
One to five years	390,333	352,000
Five to 15 years	124,215	115,691
Over 15 years	70,366	53,150
Subtotal	674,297	618,554
Floating Rate Loans [Member]
Financing Receivables, Fixed and Floating Rate Loans by Contractual Maturity [Abstract]
One year or less	75,361	51,965
One to five years	251,135	206,676
Five to 15 years	70,273	46,116
Over 15 years	67,881	5,830
Subtotal	464,650	310,587
Loans at interest rate floor	$ 95,400	$ 127,700

Loans, Receivables Past Due (De

Loans, Receivables Past Due (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	$ 17,478	$ 25,784
Current	1,134,019	925,031
Total loans before unearned income	1,151,497	950,815
Recorded investment 90 days accruing	839	179	$ 410
Unearned income	(2,483)	(1,894)
Total loans net of unearned income	1,149,014	948,921
30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	4,089	3,931
90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	13,389	21,853
Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	8,904	13,977
Current	845,194	656,075
Total loans before unearned income	854,098	670,052
Recorded investment 90 days accruing	0	179
Real Estate [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	2,757	3,133
Real Estate [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	6,147	10,844
Real Estate [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	466	758
Current	112,137	83,481
Total loans before unearned income	112,603	84,239
Recorded investment 90 days accruing	0	34
Real Estate [Member] | Construction & Land Development [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	95	173
Real Estate [Member] | Construction & Land Development [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	371	585
Real Estate [Member] | Farmland [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	240	339
Current	25,451	20,799
Total loans before unearned income	25,691	21,138
Recorded investment 90 days accruing	0	0
Real Estate [Member] | Farmland [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	175	234
Real Estate [Member] | Farmland [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	65	105
Real Estate [Member] | 1 - 4-family [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	3,434	3,495
Current	155,299	131,716
Total loans before unearned income	158,733	135,211
Recorded investment 90 days accruing	0	145
Real Estate [Member] | 1 - 4-family [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	1,481	1,108
Real Estate [Member] | 1 - 4-family [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	1,953	2,387
Real Estate [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	0	5,014
Current	16,840	7,436
Total loans before unearned income	16,840	12,450
Recorded investment 90 days accruing	0	0
Real Estate [Member] | Multifamily [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	0	0
Real Estate [Member] | Multifamily [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	0	5,014
Real Estate [Member] | Non-Farm Non-Residential [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	4,764	4,371
Current	535,467	412,643
Total loans before unearned income	540,231	417,014
Recorded investment 90 days accruing	0	0
Real Estate [Member] | Non-Farm Non-Residential [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	1,006	1,618
Real Estate [Member] | Non-Farm Non-Residential [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	3,758	2,753
Non-Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	8,574	11,807
Current	288,825	268,956
Total loans before unearned income	297,399	280,763
Recorded investment 90 days accruing	839	0
Non-Real Estate [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	1,332	798
Non-Real Estate [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	7,242	11,009
Non-Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	1,776	2,022
Current	19,738	21,761
Total loans before unearned income	21,514	23,783
Recorded investment 90 days accruing	41	0
Non-Real Estate [Member] | Agricultural [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	239	64
Non-Real Estate [Member] | Agricultural [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	1,537	1,958
Non-Real Estate [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	6,254	8,622
Current	214,446	185,347
Total loans before unearned income	220,700	193,969
Recorded investment 90 days accruing	798	0
Non-Real Estate [Member] | Commercial and Industrial [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	630	552
Non-Real Estate [Member] | Commercial and Industrial [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	5,624	8,070
Non-Real Estate [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	544	1,163
Current	54,641	61,848
Total loans before unearned income	55,185	63,011
Recorded investment 90 days accruing	0	0
Non-Real Estate [Member] | Consumer and Other [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	463	182
Non-Real Estate [Member] | Consumer and Other [Member] | 90 Days or Greater [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due	$ 81	$ 981

Loans, Nonaccrual Loans (Detail

Loans, Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 12,550	$ 21,674
Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	6,147	10,665
Real Estate [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	371	551
Real Estate [Member] | Farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	65	105
Real Estate [Member] | 1 - 4-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,953	2,242
Real Estate [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	0	5,014
Real Estate [Member] | Non-Farm Non-Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	3,758	2,753
Non-Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	6,403	11,009
Non-Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,496	1,958
Non-Real Estate [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	4,826	8,070
Non-Real Estate [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 81	$ 981

Loans, Credit Exposure of Portf

Loans, Credit Exposure of Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	$ 1,151,497	$ 950,815
Unearned income	(2,483)	(1,894)
Total loans net of unearned income	1,149,014	948,921
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	1,071,513	883,388
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	25,929	17,705
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	49,495	41,992
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	4,560	7,730
Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	854,098	670,052
Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	812,454	619,535
Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	5,679	14,541
Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	35,965	35,976
Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	0	0
Real Estate [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	112,603	84,239
Real Estate [Member] | Construction & Land Development [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	108,200	79,069
Real Estate [Member] | Construction & Land Development [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	125	1,162
Real Estate [Member] | Construction & Land Development [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	4,278	4,008
Real Estate [Member] | Construction & Land Development [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	0	0
Real Estate [Member] | Farmland [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	25,691	21,138
Real Estate [Member] | Farmland [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	25,030	20,652
Real Estate [Member] | Farmland [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	569	381
Real Estate [Member] | Farmland [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	92	105
Real Estate [Member] | Farmland [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	0	0
Real Estate [Member] | 1 - 4-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	158,733	135,211
Real Estate [Member] | 1 - 4-family [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	149,426	123,191
Real Estate [Member] | 1 - 4-family [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	1,856	5,460
Real Estate [Member] | 1 - 4-family [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	7,451	6,560
Real Estate [Member] | 1 - 4-family [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	0	0
Real Estate [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	16,840	12,450
Real Estate [Member] | Multifamily [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	9,366	4,268
Real Estate [Member] | Multifamily [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	639	1,132
Real Estate [Member] | Multifamily [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	6,835	7,050
Real Estate [Member] | Multifamily [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	0	0
Real Estate [Member] | Non-Farm Non-Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	540,231	417,014
Real Estate [Member] | Non-Farm Non-Residential [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	520,432	392,355
Real Estate [Member] | Non-Farm Non-Residential [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	2,490	6,406
Real Estate [Member] | Non-Farm Non-Residential [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	17,309	18,253
Real Estate [Member] | Non-Farm Non-Residential [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	0	0
Non-Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	297,399	280,763
Non-Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	259,059	263,853
Non-Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	20,250	3,164
Non-Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	13,530	6,016
Non-Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	4,560	7,730
Non-Real Estate [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	21,514	23,783
Non-Real Estate [Member] | Agricultural [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	19,050	20,890
Non-Real Estate [Member] | Agricultural [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	995	920
Non-Real Estate [Member] | Agricultural [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	1,469	1,973
Non-Real Estate [Member] | Agricultural [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	0	0
Non-Real Estate [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	220,700	193,969
Non-Real Estate [Member] | Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	191,784	182,381
Non-Real Estate [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	19,187	850
Non-Real Estate [Member] | Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	5,169	3,008
Non-Real Estate [Member] | Commercial and Industrial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	4,560	7,730
Non-Real Estate [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	55,185	63,011
Non-Real Estate [Member] | Consumer and Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	48,225	60,582
Non-Real Estate [Member] | Consumer and Other [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	68	1,394
Non-Real Estate [Member] | Consumer and Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	6,892	1,035
Non-Real Estate [Member] | Consumer and Other [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans before unearned income	$ 0	$ 0

Loans, Purchased Impaired Loans

Loans, Purchased Impaired Loans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Financing Receivable, Impaired [Line Items]
Carrying amount	$ 4,358
Contractual principal balance	5,436
Carrying amount, net of allowance	4,358
Schedule of Accretable Yield, Expected Income Collected on Purchased Loan [Roll Forward]
Balance, beginning of period	0
Acquisition accretable yield	1,195
Accretion	(164)
Net transfers from nonaccretable difference to accretable yield	0
Balance, end of period	1,031
Contractually required payments of purchased impaired loans	7,500
Cash flow expected to be collected at acquisition	5,000
Fair value of acquired loans	3,800
Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	3,341
Real Estate [Member] | Construction & Land Development [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	1,135
Real Estate [Member] | Farmland [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	8
Real Estate [Member] | 1 - 4 Family [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	50
Real Estate [Member] | Multi-Family [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	0
Real Estate [Member] | Non-Farm Non-Residential [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	2,148
Non-Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	1,017
Non-Real Estate [Member] | Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	0
Non-Real Estate [Member] | Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	1,017
Non-Real Estate [Member] | Consumer and Other [Member]
Financing Receivable, Impaired [Line Items]
Carrying amount	$ 0

Allowance for Loan Losses, Summ

Allowance for Loan Losses, Summary of Changes in Allowance for Loan Losses, by Portfolio Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	$ 11,114	$ 9,415	$ 9,105
Charge-offs	(6,362)	(2,914)	(4,173)
Recoveries	651	908	619
Provision	3,822	3,705	3,864
Ending allowance	9,225	11,114	9,415
Real Estate [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	6,497	6,642	6,380
Charge-offs	(1,324)	(1,617)	(3,053)
Recoveries	260	466	150
Provision	83	1,006	3,165
Ending allowance	5,516	6,497	6,642
Real Estate [Member] | Construction & Land Development [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	1,232	962	702
Charge-offs	0	0	(559)
Recoveries	43	4	5
Provision	(647)	266	814
Ending allowance	628	1,232	962
Real Estate [Member] | Farmland [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	19	54	21
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(14)	(35)	33
Ending allowance	5	19	54
Real Estate [Member] | 1 - 4-family [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	1,204	1,771	2,131
Charge-offs	(33)	(244)	(410)
Recoveries	92	45	94
Provision	(185)	(368)	(44)
Ending allowance	1,078	1,204	1,771
Real Estate [Member] | Multi-family [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	591	557	813
Charge-offs	0	0	(947)
Recoveries	40	401	46
Provision	363	(367)	645
Ending allowance	994	591	557
Real Estate [Member] | Non-Farm Non-Residential [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	3,451	3,298	2,713
Charge-offs	(1,291)	(1,373)	(1,137)
Recoveries	85	16	5
Provision	566	1,510	1,717
Ending allowance	2,811	3,451	3,298
Non-Real Estate [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	4,617	2,773	2,725
Charge-offs	(5,038)	(1,297)	(1,120)
Recoveries	391	442	469
Provision	3,739	2,699	699
Ending allowance	3,709	4,617	2,773
Non-Real Estate [Member] | Agricultural [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	74	16	293
Charge-offs	(162)	(83)	(491)
Recoveries	138	113	3
Provision	137	28	211
Ending allowance	187	74	16
Non-Real Estate [Member] | Commercial and Industrial [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	3,543	2,527	1,797
Charge-offs	(3,629)	(579)	(79)
Recoveries	30	146	315
Provision	2,433	1,449	494
Ending allowance	2,377	3,543	2,527
Non-Real Estate [Member] | Consumer and Other [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	972	230	371
Charge-offs	(1,247)	(635)	(550)
Recoveries	223	183	151
Provision	1,177	1,194	258
Ending allowance	1,125	972	230
Non-Real Estate [Member] | Unallocated [Member]
Summary of changes in allowance for loan losses, by portfolio type [Roll Forward]
Beginning allowance	28	0	264
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(8)	28	(264)
Ending allowance	$ 20	$ 28	$ 0

Allowance for Loan Losses, Su69

Allowance for Loan Losses, Summary of Allowance and Loans Individually and Collectively Evaluated for Impairment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	$ 867	$ 2,998
Allowance collectively evaluated for impairment	8,358	8,116
Total allowance for credit losses	9,225	11,114	$ 9,415	$ 9,105
Loans individually evaluated for impairment	15,582	28,811
Loans collectively evaluated for impairment	1,135,915	922,004
Total loans before unearned income	1,151,497	950,815
Unearned income	(2,483)	(1,894)
Total loans net of unearned income	1,149,014	948,921
Financing receivable recorded investment not accruing interest	12,600	21,700	20,000
Financing receivable, recorded investment, 90 days past due and still accruing	839	179	410
Financing receivable average recorded investment nonaccrual status	17,300	22,500	14,900
Real Estate [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	236	419
Allowance collectively evaluated for impairment	5,280	6,078
Total allowance for credit losses	5,516	6,497	6,642	6,380
Loans individually evaluated for impairment	8,990	17,308
Loans collectively evaluated for impairment	845,108	652,744
Total loans before unearned income	854,098	670,052
Financing receivable, recorded investment, 90 days past due and still accruing	0	179
Real Estate [Member] | Construction & Land Development [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	0	0
Allowance collectively evaluated for impairment	628	1,232
Total allowance for credit losses	628	1,232	962	702
Loans individually evaluated for impairment	0	361
Loans collectively evaluated for impairment	112,603	83,878
Total loans before unearned income	112,603	84,239
Financing receivable, recorded investment, 90 days past due and still accruing	0	34
Real Estate [Member] | Farmland [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	0	0
Allowance collectively evaluated for impairment	5	19
Total allowance for credit losses	5	19	54	21
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	25,691	21,138
Total loans before unearned income	25,691	21,138
Financing receivable, recorded investment, 90 days past due and still accruing	0	0
Real Estate [Member] | 1 - 4-family [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	0	8
Allowance collectively evaluated for impairment	1,078	1,196
Total allowance for credit losses	1,078	1,204	1,771	2,131
Loans individually evaluated for impairment	0	1,130
Loans collectively evaluated for impairment	158,733	134,081
Total loans before unearned income	158,733	135,211
Financing receivable, recorded investment, 90 days past due and still accruing	0	145
Real Estate [Member] | Multi-family [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	0	164
Allowance collectively evaluated for impairment	994	427
Total allowance for credit losses	994	591	557	813
Loans individually evaluated for impairment	0	5,014
Loans collectively evaluated for impairment	16,840	7,436
Total loans before unearned income	16,840	12,450
Financing receivable, recorded investment, 90 days past due and still accruing	0	0
Real Estate [Member] | Non-Farm Non-Residential [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	236	247
Allowance collectively evaluated for impairment	2,575	3,204
Total allowance for credit losses	2,811	3,451	3,298	2,713
Loans individually evaluated for impairment	8,990	10,803
Loans collectively evaluated for impairment	531,241	406,211
Total loans before unearned income	540,231	417,014
Financing receivable, recorded investment, 90 days past due and still accruing	0	0
Non-Real Estate [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	631	2,579
Allowance collectively evaluated for impairment	3,078	2,038
Total allowance for credit losses	3,709	4,617	2,773	2,725
Loans individually evaluated for impairment	6,592	11,503
Loans collectively evaluated for impairment	290,807	269,260
Total loans before unearned income	297,399	280,763
Financing receivable, recorded investment, 90 days past due and still accruing	839	0
Non-Real Estate [Member] | Agricultural [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	66	11
Allowance collectively evaluated for impairment	121	63
Total allowance for credit losses	187	74	16	293
Loans individually evaluated for impairment	861	1,614
Loans collectively evaluated for impairment	20,653	22,169
Total loans before unearned income	21,514	23,783
Financing receivable, recorded investment, 90 days past due and still accruing	41	0
Non-Real Estate [Member] | Commercial and Industrial [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	565	2,375
Allowance collectively evaluated for impairment	1,812	1,168
Total allowance for credit losses	2,377	3,543	2,527	1,797
Loans individually evaluated for impairment	5,731	8,965
Loans collectively evaluated for impairment	214,969	185,004
Total loans before unearned income	220,700	193,969
Financing receivable, recorded investment, 90 days past due and still accruing	798	0
Non-Real Estate [Member] | Consumer and Other [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	0	193
Allowance collectively evaluated for impairment	1,125	779
Total allowance for credit losses	1,125	972	230	371
Loans individually evaluated for impairment	0	924
Loans collectively evaluated for impairment	55,185	62,087
Total loans before unearned income	55,185	63,011
Financing receivable, recorded investment, 90 days past due and still accruing	0	0
Non-Real Estate [Member] | Unallocated [Member]
Summary of allowance and loans individually and collectively evaluated for impairment [Abstract]
Allowance individually evaluated for impairment	0	0
Allowance collectively evaluated for impairment	20	28
Total allowance for credit losses	20	28	$ 0	$ 264
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	0	0
Total loans before unearned income	$ 0	$ 0

Allowance for Loan Losses, Impa

Allowance for Loan Losses, Impaired Loans by Class (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Impaired loans with no related allowance [Abstract]
Recorded investment	$ 5,771	$ 12,014
Unpaid principal balance	5,771	13,876
Average recorded investment	5,933	12,457
Interest income recognized	248	293
Interest income cash basis	279	235
Impaired loans with an allowance recorded [Abstract]
Recorded investment	9,811	16,797
Unpaid principal balance	13,552	17,276
Related allowance	867	2,998
Average recorded investment	12,793	17,461
Interest income recognized	318	199
Interest income cash basis	228	192
Total impaired loans [Abstract]
Recorded investment	15,582	28,811
Unpaid principal balance	19,323	31,152
Related allowance	867	2,998
Average recorded investment	18,726	29,918
Interest income recognized	566	492
Interest income cash basis	507	427
Real Estate [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	5,771	9,725
Unpaid principal balance	5,771	11,449
Average recorded investment	5,933	10,356
Interest income recognized	248	245
Interest income cash basis	279	223
Impaired loans with an allowance recorded [Abstract]
Recorded investment	3,219	7,583
Unpaid principal balance	3,570	7,904
Related allowance	236	419
Average recorded investment	3,555	7,782
Interest income recognized	183	119
Interest income cash basis	127	113
Total impaired loans [Abstract]
Related allowance	236	419
Real Estate [Member] | Construction & Land Development [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	361
Unpaid principal balance	0	823
Average recorded investment	0	363
Interest income recognized	0	0
Interest income cash basis	0	0
Impaired loans with an allowance recorded [Abstract]
Recorded investment	0	0
Unpaid principal balance	0	0
Related allowance	0	0
Average recorded investment	0	0
Interest income recognized	0	0
Interest income cash basis	0	0
Total impaired loans [Abstract]
Related allowance	0	0
Real Estate [Member] | Farmland [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	0
Unpaid principal balance	0	0
Average recorded investment	0	0
Interest income recognized	0	0
Interest income cash basis	0	0
Impaired loans with an allowance recorded [Abstract]
Recorded investment	0	0
Unpaid principal balance	0	0
Related allowance	0	0
Average recorded investment	0	0
Interest income recognized	0	0
Interest income cash basis	0	0
Total impaired loans [Abstract]
Related allowance	0	0
Real Estate [Member] | 1 - 4-family [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	863
Unpaid principal balance	0	1,196
Average recorded investment	0	1,044
Interest income recognized	0	49
Interest income cash basis	0	48
Impaired loans with an allowance recorded [Abstract]
Recorded investment	0	267
Unpaid principal balance	0	303
Related allowance	0	8
Average recorded investment	0	279
Interest income recognized	0	0
Interest income cash basis	0	0
Total impaired loans [Abstract]
Related allowance	0	8
Real Estate [Member] | Multi-family [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	0
Unpaid principal balance	0	0
Average recorded investment	0	0
Interest income recognized	0	0
Interest income cash basis	0	0
Impaired loans with an allowance recorded [Abstract]
Recorded investment	0	5,014
Unpaid principal balance	0	5,305
Related allowance	0	164
Average recorded investment	0	5,169
Interest income recognized	0	0
Interest income cash basis	0	0
Total impaired loans [Abstract]
Related allowance	0	164
Real Estate [Member] | Non-Farm Non-Residential [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	5,771	8,501
Unpaid principal balance	5,771	9,430
Average recorded investment	5,933	8,949
Interest income recognized	248	196
Interest income cash basis	279	175
Impaired loans with an allowance recorded [Abstract]
Recorded investment	3,219	2,302
Unpaid principal balance	3,570	2,296
Related allowance	236	247
Average recorded investment	3,555	2,334
Interest income recognized	183	119
Interest income cash basis	127	113
Total impaired loans [Abstract]
Related allowance	236	247
Non-Real Estate [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	2,289
Unpaid principal balance	0	2,427
Average recorded investment	0	2,101
Interest income recognized	0	48
Interest income cash basis	0	12
Impaired loans with an allowance recorded [Abstract]
Recorded investment	6,592	9,214
Unpaid principal balance	9,982	9,372
Related allowance	631	2,579
Average recorded investment	9,238	9,679
Interest income recognized	135	80
Interest income cash basis	101	79
Total impaired loans [Abstract]
Related allowance	631	2,579
Non-Real Estate [Member] | Agricultural [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	1,603
Unpaid principal balance	0	1,742
Average recorded investment	0	1,377
Interest income recognized	0	30
Interest income cash basis	0	0
Impaired loans with an allowance recorded [Abstract]
Recorded investment	861	11
Unpaid principal balance	920	11
Related allowance	66	11
Average recorded investment	1,117	11
Interest income recognized	70	0
Interest income cash basis	17	0
Total impaired loans [Abstract]
Related allowance	66	11
Non-Real Estate [Member] | Commercial and Industrial [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	0
Unpaid principal balance	0	0
Average recorded investment	0	0
Interest income recognized	0	0
Interest income cash basis	0	0
Impaired loans with an allowance recorded [Abstract]
Recorded investment	5,731	8,965
Unpaid principal balance	9,062	9,117
Related allowance	565	2,375
Average recorded investment	8,121	9,379
Interest income recognized	65	72
Interest income cash basis	84	72
Total impaired loans [Abstract]
Related allowance	565	2,375
Non-Real Estate [Member] | Consumer and Other [Member]
Impaired loans with no related allowance [Abstract]
Recorded investment	0	686
Unpaid principal balance	0	685
Average recorded investment	0	724
Interest income recognized	0	18
Interest income cash basis	0	12
Impaired loans with an allowance recorded [Abstract]
Recorded investment	0	238
Unpaid principal balance	0	244
Related allowance	0	193
Average recorded investment	0	289
Interest income recognized	0	8
Interest income cash basis	0	7
Total impaired loans [Abstract]
Related allowance	$ 0	$ 193

Allowance for Loan Losses, Age

Allowance for Loan Losses, Age Analysis of TDRs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Contract	Dec. 31, 2016USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of troubled debt restructurings | Contract	0	0
Total TDRs	$ 2,472	$ 3,448
Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	334	461
Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	2,138	2,987
30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	2,472	3,448
Real Estate [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	334	461
Real Estate [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	2,138	2,987
Real Estate [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	334	361
Real Estate [Member] | Construction & Land Development [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	334	361
Real Estate [Member] | Construction & Land Development [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Construction & Land Development [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Farmland [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Farmland [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Farmland [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Farmland [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | 1 - 4-family [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | 1 - 4-family [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | 1 - 4-family [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | 1 - 4-family [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Multifamily [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Multifamily [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Multifamily [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Real Estate [Member] | Non-Farm Non-Residential [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	2,138	3,087
Real Estate [Member] | Non-Farm Non-Residential [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	100
Real Estate [Member] | Non-Farm Non-Residential [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	2,138	2,987
Real Estate [Member] | Non-Farm Non-Residential [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Agricultural [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Agricultural [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Agricultural [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Commercial and Industrial [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Commercial and Industrial [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Commercial and Industrial [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Consumer and Other [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Consumer and Other [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Consumer and Other [Member] | Current and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	0	0
Non-Real Estate [Member] | Consumer and Other [Member] | 30-89 Days Past Due and Still Accruing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRs	$ 0	$ 0

Allowance for Loan Losses, TDR

Allowance for Loan Losses, TDR Activity (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
TDR activity [Roll Forward]
Beginning balance	$ 3,448
New TDRs	0
Charge-offs post-modification	(102)
Transferred to ORE	0
Paydowns	(876)
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	2
Ending balance	2,472
Real Estate [Member]
TDR activity [Roll Forward]
Beginning balance	3,448
New TDRs	0
Charge-offs post-modification	(102)
Transferred to ORE	0
Paydowns	(876)
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	2
Ending balance	2,472
Real Estate [Member] | Construction & Land Development [Member]
TDR activity [Roll Forward]
Beginning balance	361
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	(27)
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	334
Real Estate [Member] | Farmland [Member]
TDR activity [Roll Forward]
Beginning balance	0
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	0
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	0
Real Estate [Member] | 1 - 4-family [Member]
TDR activity [Roll Forward]
Beginning balance	0
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	0
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	0
Real Estate [Member] | Multifamily [Member]
TDR activity [Roll Forward]
Beginning balance	0
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	0
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	0
Real Estate [Member] | Non-Farm Non-Residential [Member]
TDR activity [Roll Forward]
Beginning balance	3,087
New TDRs	0
Charge-offs post-modification	(102)
Transferred to ORE	0
Paydowns	(849)
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	2
Ending balance	2,138
Non-Real Estate [Member]
TDR activity [Roll Forward]
Beginning balance	0
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	0
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	0
Non-Real Estate [Member] | Agricultural [Member]
TDR activity [Roll Forward]
Beginning balance	0
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	0
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	0
Non-Real Estate [Member] | Commercial and Industrial [Member]
TDR activity [Roll Forward]
Beginning balance	0
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	0
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	0
Non-Real Estate [Member] | Consumer and Other [Member]
TDR activity [Roll Forward]
Beginning balance	0
New TDRs	0
Charge-offs post-modification	0
Transferred to ORE	0
Paydowns	0
Construction to permanent financing	0
Restructured to market terms	0
Other adjustments	0
Ending balance	$ 0

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Acquired value	$ 69,031	$ 52,209
Less: accumulated depreciation	31,011	28,690
Net book value	38,020	23,519
Depreciation expense	1,800	1,700	$ 1,600
Land [Member]
Property, Plant and Equipment [Line Items]
Acquired value	12,875	7,185
Bank Premises [Member]
Property, Plant and Equipment [Line Items]
Acquired value	31,469	21,229
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Acquired value	24,305	21,689
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Acquired value	$ 382	$ 2,106

Goodwill and Other Intangible74

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Other Intangible Assets [Abstract]
Impairment charges recognized on the Company's intangible assets	$ 0
Goodwill	3,472	$ 1,999
Finite-lived Intangible Assets [Roll Forward]
Gross Carrying Amount	13,426	9,617
Accumulated Amortization	9,002	8,561
Net Carrying Amount	4,424	1,056
Amortization expense	400	300	$ 300
Amortization expense of core deposit intangible assets for next five years [Abstract]
December 31, 2018	545
December 31, 2019	361
December 31, 2020	361
December 31, 2021	293
December 31, 2022	225
Core Deposits Intangibles [Member]
Finite-lived Intangible Assets [Roll Forward]
Gross Carrying Amount	12,053	9,350
Accumulated Amortization	8,804	8,372
Net Carrying Amount	$ 3,249	978
Weighted-average amortization	9 years 8 months 12 days
Mortgage Servicing Rights [Member]
Finite-lived Intangible Assets [Roll Forward]
Gross Carrying Amount	$ 1,373	267
Accumulated Amortization	198	189
Net Carrying Amount	$ 1,175	$ 78

Other Real Estate (Details)

Other Real Estate (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Real Estate Owned Acquired by Foreclosure [Abstract]
Residential	$ 23	$ 71
Construction & land development	304	0
Non-farm non-residential	954	288
Total Other Real Estate Owned and Foreclosed Property	$ 1,281	$ 359

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Maturities of time deposits [Abstract]
2,018	$ 357,687
2,019	118,902
2,020	48,843
2,021	16,622
2022 and thereafter	39,277
Total	581,331	$ 517,997
Brokered deposits	9,800
Aggregate amount of time deposits in denominations of $250,000 or more	$ 266,200	$ 241,400

Borrowings, Short-term Borrowin

Borrowings, Short-term Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Short-term borrowings [Abstract]
Federal Home Loan Bank Advances	$ 15,500	$ 6,500
Line of credit	0	0
Total short-term borrowings	15,500	6,500	$ 1,800
Available lines of credit including FHLB	150,800	133,700
Schedule of certain information short-term borrowings [Abstract]
Outstanding at year end	15,500	6,500	1,800
Maximum month-end outstanding	28,000	25,000	13,800
Average daily outstanding	$ 5,833	$ 8,775	$ 4,217
Weighted average rate during the year	1.06%	0.85%	2.12%
Weighted average rate at year end	1.51%	0.65%	4.50%

Borrowings, Long-term Debt (Det

Borrowings, Long-term Debt (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term debt outstanding		$ 37,400,000
Net proceeds from issuance of long term debt		3,750,000	$ 0	$ 24,969,000
First Guaranty Bancshares, Inc. [Member]
Debt Instrument [Line Items]
Net proceeds from issuance of long term debt		3,750,000	0	24,969,000
Payments to Acquire Additional Interest in Subsidiaries	$ 3,750,000	3,750,000	0	$ 0
Senior Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term debt outstanding		$ 22,774,000
Debt instrument, face amount	25,000,000
Net proceeds from issuance of long term debt	$ 3,750,000
Senior Long-term Debt [Member] | Wall Street Journal Prime Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		0.75%
Interest rate		4.75%
Long-term debt outstanding		$ 0	300,000
Periodic principal payment		$ 50,000
Principal payment frequency		monthly
Debt maturity date		May 12, 2017
Percentage of interest used in secured pledge borrowings		13.20%
Number of shares used in secured pledge borrowings (in shares)		735,745
Senior Long-term Debt [Member] | Floating 3-Month LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		2.50%
Interest rate		3.87%
Long-term debt outstanding		$ 22,800,000	21,800,000
Periodic principal payment		$ 735,294
Principal payment frequency		quarterly
Debt maturity date		Dec. 22, 2020
Percentage of interest used in secured pledge borrowings		85.00%
Number of shares used in secured pledge borrowings (in shares)		4,823,899
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term debt outstanding		$ 14,664,000
Junior Subordinated Debt [Member] | Wall Street Journal Prime Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		0.75%
Interest rate		4.00%
Long-term debt outstanding		$ 14,700,000	$ 14,600,000
Debt maturity date		Dec. 21, 2025
Junior Subordinated Debt [Member] | Wall Street Journal Prime Rate [Member] | Fixed Interest Rate Period [Member]
Debt Instrument [Line Items]
Principal payment frequency		semi-annually
Junior Subordinated Debt [Member] | Wall Street Journal Prime Rate [Member] | Floating Interest Rate Period [Member]
Debt Instrument [Line Items]
Principal payment frequency		quarterly

Borrowings, Line of Credit and

Borrowings, Line of Credit and Letters of Credit (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity	$ 150.8	$ 133.7
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	6.5
Line of credit facility, remaining borrowing capacity	$ 6.5
Line of credit facility, interest rate	4.50%
Federal Home Loan Bank (FHLB) [Member] | Letters of Credit [Member]
Line of Credit Facility [Line Items]
Letters of credit amount at FHLB	$ 294.2	$ 226.1

Borrowings, Obligations on Long

Borrowings, Obligations on Long-term Debt (Details) $ in Thousands	Dec. 31, 2017USD ($)
Obligations on senior long-term debt and junior subordinated debentures [Abstract]
Total	$ 37,400
Senior Long-term Debt [Member]
Obligations on senior long-term debt and junior subordinated debentures [Abstract]
2,018	2,941
2,019	2,941
2,020	2,941
2,021	2,941
2,022	2,941
2023 and thereafter	8,089
Subtotal	22,794
Debt issuance costs	(20)
Total	22,774
Junior Subordinated Debentures [Member]
Obligations on senior long-term debt and junior subordinated debentures [Abstract]
2,018	0
2,019	0
2,020	0
2,021	0
2,022	0
2023 and thereafter	15,000
Subtotal	15,000
Debt issuance costs	(336)
Total	$ 14,664

Capital Requirements (Details)

Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation percentage	4.14%
Total Risk-based Capital, Amount [Abstract]
Actual Amount	$ 164,545	$ 151,877
Minimum Capital Requirement	$ 108,427	$ 94,982
Total Risk-based Capital, Ratio [Abstract]
Actual Ratio	12.14%	12.79%
Minimum Capital Requirement	8.00%	8.00%
Tier 1 Capital, Amount [Abstract]
Actual Amount	$ 140,320	$ 125,763
Minimum Capital Requirement	$ 81,320	$ 71,236
Tier 1 Capital, Ratio [Abstract]
Actual Ratio	10.35%	10.59%
Minimum Capital Requirement	6.00%	6.00%
Tier 1 Leverage Capital, Amount [Abstract]
Actual Amount	$ 140,320	$ 125,763
Minimum Capital Requirement	$ 67,899	$ 57,930
Tier 1 Leverage Capital, Ratio [Abstract]
Actual Ratio	8.27%	8.68%
Minimum Capital Requirement	4.00%	4.00%
Common Equity Tier One Capital, Amount [Abstract]
Actual Amount	$ 140,320	$ 125,763
Minimum Capital Requirement	$ 60,990	$ 53,427
Common Equity Tier One Capital, Ratio [Abstract]
Actual Ratio	10.35%	10.59%
Minimum Capital Requirement	4.50%	4.50%
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation percentage	5.07%
Total Risk-based Capital, Amount [Abstract]
Actual Amount	$ 176,398	$ 153,768
Minimum Capital Requirement	107,961	94,717
Minimum to be Well Capitalized Under Action Provisions	$ 134,951	$ 118,396
Total Risk-based Capital, Ratio [Abstract]
Actual Ratio	13.07%	12.99%
Minimum Capital Requirement	8.00%	8.00%
Minimum to be Well Capitalized Under Action Provisions	10.00%	10.00%
Tier 1 Capital, Amount [Abstract]
Actual Amount	$ 167,173	$ 142,654
Minimum Capital Requirement	80,971	71,038
Minimum to be Well Capitalized Under Action Provisions	$ 107,961	$ 94,717
Tier 1 Capital, Ratio [Abstract]
Actual Ratio	12.39%	12.05%
Minimum Capital Requirement	6.00%	6.00%
Minimum to be Well Capitalized Under Action Provisions	8.00%	8.00%
Tier 1 Leverage Capital, Amount [Abstract]
Actual Amount	$ 167,173	$ 142,654
Minimum Capital Requirement	67,709	57,771
Minimum to be Well Capitalized Under Action Provisions	$ 84,636	$ 72,214
Tier 1 Leverage Capital, Ratio [Abstract]
Actual Ratio	9.88%	9.88%
Minimum Capital Requirement	4.00%	4.00%
Minimum to be Well Capitalized Under Action Provisions	5.00%	5.00%
Common Equity Tier One Capital, Amount [Abstract]
Actual Amount	$ 167,173	$ 142,654
Minimum Capital Requirement	60,728	53,278
Minimum to be Well Capitalized Under Action Provisions	$ 87,718	$ 76,958
Common Equity Tier One Capital, Ratio [Abstract]
Actual Ratio	12.39%	12.05%
Minimum Capital Requirement	4.50%	4.50%
Minimum to be Well Capitalized Under Action provisions	6.50%	6.50%

Dividend Restrictions (Details)

Dividend Restrictions (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Dividend Restrictions [Abstract]
Percentage of outstanding capital stock, maximum	50.00%
Undistributed earnings	$ 3.2
Restricted investments	$ 167.6

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	Dec. 21, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related party activity of loans [Abstract]
Balance, beginning of year		$ 58,279,000	$ 57,816,000
Net Increase		24,639,000	463,000
Balance, end of year		82,918,000	58,279,000	$ 57,816,000
Directors and Executive Officers [Member]
Related party activity of loans [Abstract]
Deposit from related party		24,600,000
Directors and Executive Officers [Member] | Unfunded Loan Commitment [Member]
Related party activity of loans [Abstract]
Balance, beginning of year		24,900,000
Balance, end of year		17,500,000	24,900,000
Champion Industries, Inc. [Member]
Related party activity of loans [Abstract]
Expenses from transactions with related party		$ 400,000	300,000	200,000
Edgar Ray Smith III [Member] | Subordinated Debt [Member]
Related party activity of loans [Abstract]
Debt instrument, face amount	$ 15,000,000
Debt instrument, term		10 years
Interest amount		$ 600,000	600,000
Edgar Ray Smith III [Member] | Subordinated Debt [Member] | Fixed Interest Rate Period [Member]
Related party activity of loans [Abstract]
Debt instrument, term		5 years
Debt instrument, non-callable term		5 years
Debt instrument, interest rate	4.00%
Edgar Ray Smith III [Member] | Subordinated Debt [Member] | Floating Interest Rate Period [Member]
Related party activity of loans [Abstract]
Debt instrument, term		5 years
Edgar Ray Smith III [Member] | Subordinated Debt [Member] | Floating Interest Rate Period [Member] | Wall Street Journal Prime Rate [Member]
Related party activity of loans [Abstract]
Debt instrument, basis spread on variable rate	0.75%
Gasaway Gasaway Bankston [Member]
Related party activity of loans [Abstract]
Expenses from transactions with related party		$ 200,000	$ 300,000	$ 200

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Benefit Plans [Abstract]
Deferment percentage of base salary, minimum	1.00%
Deferment percentage of base salary, maximum	20.00%
Employer matching contribution	6.00%
Maximum employer matching contribution percentage	100.00%
Contributions to savings plan	$ 240,000	$ 191,000	$ 86,000
Contributions made to ESOP	$ 0	$ 0	$ 0
Shares held under ESOP (in shares)	15,530

Other Expenses (Details)

Other Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other noninterest expense [Abstract]
Legal and professional fees	$ 3,037	$ 2,185	$ 2,019
Data processing	1,608	1,259	1,184
ATM Fees	1,161	1,044	1,022
Marketing and public relations	1,205	878	848
Taxes - sales, capital and franchise	970	787	717
Operating supplies	496	471	414
Software expense and amortization	923	835	612
Travel and lodging	910	710	818
Telephone	167	177	172
Amortization of core deposits	432	320	320
Donations	322	298	332
Net costs from other real estate and repossessions	306	498	493
Regulatory assessment	726	1,005	1,111
Other	1,640	1,599	1,692
Total other noninterest expense	13,903	12,066	11,754
Advertising expense	$ 700	$ 600	$ 600

Income Taxes (Details)

Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Summary of provision for income taxes [Abstract]
Current		$ 4,638,000		$ 8,168,000	$ 7,347,000
Deferred		2,761,000		(1,004,000)	(384,000)
Total		$ 7,399,000		$ 7,164,000	$ 6,963,000
Effective income tax rate reconciliation [Abstract]
Statutory tax rate		35.00%		35.00%	35.00%
Federal income taxes at statutory rate		$ 6,703,000		$ 7,440,000	$ 7,514,000
Tax exempt municipal income		(254,000)		(283,000)	(436,000)
Other		950,000	[1]	7,000	(115,000)
Total		7,399,000		7,164,000	6,963,000
Estimated net impact from remeasurement of deferred tax assets and liabilities		900,000
Deferred tax assets [Abstract]
Allowance for loan losses		1,804,000		3,890,000
Other real estate owned		25,000		60,000
Unrealized losses on available for sale securities		495,000		2,060,000
Net operating loss		1,463,000		0
Other		546,000		449,000
Gross deferred tax assets		4,333,000		6,459,000
Deferred tax liabilities [Abstract]
Depreciation and amortization		(1,688,000)		(1,480,000)
Core deposit intangibles		(662,000)		(342,000)
Unrealized gains on available for sale securities		0		0
Other		(566,000)		(376,000)
Gross deferred tax liabilities		(2,916,000)		(2,198,000)
Net deferred tax assets		1,417,000		4,261,000
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		7,000		0
Income tax uncertainties [Abstract]
Income tax penalties expense		0		0	0
Interest on income taxes expense		0		0	0
Income tax penalties accrued		0		0	0
Interest on income taxes accrued		$ 0		$ 0	$ 0
Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Expiration date		Dec. 31, 2027
Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Expiration date		Dec. 31, 2034
Plan [Member]
Effective income tax rate reconciliation [Abstract]
Statutory tax rate	21.00%
[1]	Included in other for the year ended December 31, 2017 is $0.9 million related to the estimated net impact from the remeasurement of deferred tax assets and liabilities as a result of the passage of the Tax Cuts and Jobs Act in December 2017.

Commitments and Contingencies87

Commitments and Contingencies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Extension period of majority of short-term borrowing	1 year
Maximum extension period of short-term borrowing	3 years
Losses incurred on off-balance sheet commitments	$ 0	$ 0	$ 0
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional value	78,125,000	56,910,000
Unfunded Commitment under Lines of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional value	101,344,000	128,428,000
Commercial and Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional value	$ 7,886,000	$ 6,602,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Assets measured on recurring basis [Abstract]
Securities available for sale measured at fair value	$ 381,535	$ 397,473
Reconciliation assets measured at fair value on a recurring basis using unobservable inputs (Level 3) [Roll Forward]
Balance, beginning of year	19,400	7,701
Total gains or losses (realized/unrealized) [Abstract]
Included in earnings	54	0
Included in other comprehensive income	0	0
Purchases, sales, issuances and settlements, net	10,574	11,699
Transfers in and/or out of Level 3	(23,495)	0
Balance as of end of year	6,533	19,400
Level 1: Quoted Prices in Active Markets For Identical Assets [Member] | Treasury Bills [Member]
Assets measured on recurring basis [Abstract]
Net decrease in available for sale securities	(10,500)
Recurring Basis [Member]
Assets measured on recurring basis [Abstract]
Securities available for sale measured at fair value	381,535	397,473
Recurring Basis [Member] | Level 1: Quoted Prices in Active Markets For Identical Assets [Member]
Assets measured on recurring basis [Abstract]
Securities available for sale measured at fair value	19,980	30,487
Recurring Basis [Member] | Level 2: Significant Other Observable Inputs [Member]
Assets measured on recurring basis [Abstract]
Securities available for sale measured at fair value	355,022	347,586
Recurring Basis [Member] | Level 3: Significant Unobservable Inputs [Member]
Assets measured on recurring basis [Abstract]
Securities available for sale measured at fair value	6,533	19,400
Non-Recurring Basis [Member]
Assets measured on a nonrecurring basis [Abstract]
Impaired loans measured at fair value	12,003	18,818
Other real estate owned measured at fair value	1,281	359
Non-Recurring Basis [Member] | Level 1: Quoted Prices in Active Markets For Identical Assets [Member]
Assets measured on a nonrecurring basis [Abstract]
Impaired loans measured at fair value	0	0
Other real estate owned measured at fair value	0	0
Non-Recurring Basis [Member] | Level 2: Significant Other Observable Inputs [Member]
Assets measured on a nonrecurring basis [Abstract]
Impaired loans measured at fair value	0	259
Other real estate owned measured at fair value	1,249	226
Non-Recurring Basis [Member] | Level 3: Significant Unobservable Inputs [Member]
Assets measured on a nonrecurring basis [Abstract]
Impaired loans measured at fair value	12,003	18,559
Other real estate owned measured at fair value	$ 32	$ 133

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Securities available for sale measured at fair value	$ 381,535	$ 397,473
Securities, held to maturity	118,557	99,906
Accrued interest receivable	7,982	7,039
Carrying Value [Member]
Assets [Abstract]
Cash and cash equivalents	38,028	18,111
Securities available for sale measured at fair value	381,535	397,473
Securities, held to maturity	120,121	101,863
Federal Home Loan Bank stock	2,351	1,816
Loans held for sale	1,308	0
Loans, net	1,139,789	937,807
Accrued interest receivable	7,982	7,039
Liabilities [Abstract]
Deposits	1,549,286	1,326,181
Borrowings	38,274	28,600
Junior subordinated debentures	14,664	14,630
Accrued interest payable	2,488	1,931
Estimated Fair Value [Member]
Assets [Abstract]
Cash and cash equivalents	38,028	18,111
Securities available for sale measured at fair value	381,535	397,473
Securities, held to maturity	118,557	99,906
Federal Home Loan Bank stock	2,351	1,816
Loans held for sale	1,439	0
Loans, net	1,133,868	937,495
Accrued interest receivable	7,982	7,039
Liabilities [Abstract]
Deposits	1,549,449	1,325,972
Borrowings	38,294	28,625
Junior subordinated debentures	14,324	13,909
Accrued interest payable	$ 2,488	$ 1,931

Concentrations of Credit and 90

Concentrations of Credit and Other Risks (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)Deposit
Concentrations of Credit and Other Risks [Abstract]
Commercial and standby letters of credit	$ 10
Percentage of entity deposits	41.40%
Number of deposits of depositing authorities | Deposit	1
Public fund deposits	$ 640.7

Condensed Parent Company Info91

Condensed Parent Company Information, Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	[1]
Assets [Abstract]
Available for sale, at fair value	$ 381,535	$ 397,473
Other assets	12,119	9,904
Total Assets	1,750,430	1,500,946
Liabilities and Shareholders' Equity [Abstract]
Short-term debt	15,500	6,500	$ 1,800
Senior long-term debt	22,774	22,100
Junior subordinated debentures	14,664	14,630
Other liabilities	1,735	5,255
Total Liabilities	1,606,447	1,376,597
Shareholders' Equity	143,983	124,349	$ 118,224	$ 139,583
Total Liabilities and Shareholders' Equity	1,750,430	1,500,946
First Guaranty Bancshares, Inc. [Member]
Assets [Abstract]
Cash	5,214	16,088
Investment in bank subsidiary	170,836	141,241
Available for sale, at fair value	0	80
Other assets	6,086	4,197
Total Assets	182,136	161,606
Liabilities and Shareholders' Equity [Abstract]
Short-term debt	0	0
Senior long-term debt	22,774	22,100
Junior subordinated debentures	14,664	14,630
Other liabilities	715	527
Total Liabilities	38,153	37,257
Shareholders' Equity	143,983	124,349
Total Liabilities and Shareholders' Equity	$ 182,136	$ 161,606
[1]	All share and per share amounts reflect the ten percent stock dividend paid December 14, 2017 to shareholders of record as of December 8, 2017.

Condensed Parent Company Info92

Condensed Parent Company Information, Condensed Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Income [Abstract]
Net gains on securities	$ 2,700	$ 1,397	$ 3,799	$ 3,300
Operating Expenses [Abstract]
Interest expense		14,393	10,140	8,608
Salaries & Benefits		20,113	16,577	15,496
Income Before Income Taxes		19,150	21,257	21,468
Income tax benefit (expense)		(7,399)	(7,164)	(6,963)
Net Income		11,751	14,093	14,505
Less preferred stock dividends		0	0	(384)
Income Available to Common Shareholders		11,751	14,093	14,121
First Guaranty Bancshares, Inc. [Member]
Operating Income [Abstract]
Dividends received from bank subsidiary		10,622	11,858	9,843
Net gains on securities		54	0	2,652
Other income		171	160	261
Total operating income		10,847	12,018	12,756
Operating Expenses [Abstract]
Interest expense		1,518	1,444	192
Salaries & Benefits		495	200	172
Other expenses		1,147	948	766
Total operating expenses		3,160	2,592	1,130
Income Before Income Taxes		7,687	9,426	11,626
Income tax benefit (expense)		834	846	(605)
Income before increase in equity in undistributed earnings of subsidiary		8,521	10,272	11,021
Increase in equity in undistributed earnings of subsidiary		3,230	3,821	3,484
Net Income		11,751	14,093	14,505
Less preferred stock dividends		0	0	(384)
Income Available to Common Shareholders		$ 11,751	$ 14,093	$ 14,121

Condensed Parent Company Info93

Condensed Parent Company Information, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities [Abstract]
Net income		$ 11,751	$ 14,093	$ 14,505
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Depreciation and amortization		2,444	2,190	1,995
Gain on sale of securities		(1,397)	(3,799)	(3,300)
Net Cash Provided By Operating Activities		12,275	22,212	17,215
Cash flows from investing activities [Abstract]
Proceeds from maturities, calls and sales of AFS securities		542,894	1,000,905	723,249
Funds invested in AFS securities		(517,185)	(1,024,632)	(650,698)
Net Cash (Used In) Provided By Investing Activities		(82,996)	(67,784)	47,207
Cash flows from financing activities [Abstract]
Net decrease in short-term borrowings		(700)	4,700	0
Proceeds from long-term debt, net of costs		3,750	0	24,969
Repayment of long-term debt		(3,081)	(3,730)	(600)
Proceeds from junior subordinated debentures, net of costs		0	0	14,597
Issuance of common stock, net of costs		0	0	9,344
Redemption of preferred stock		0	0	(39,435)
Dividends paid		(5,210)	(4,870)	(4,631)
Net Cash Provided By (Used in) Financing Activities		90,638	26,411	(71,725)
Net Increase (Decrease In) Cash and Cash Equivalents		19,917	(19,161)	(7,303)
Cash and Cash Equivalents at the Beginning of the Period		18,111	37,272	44,575
Cash and Cash Equivalents at the End of the Period		38,028	18,111	37,272
First Guaranty Bancshares, Inc. [Member]
Cash flows from operating activities [Abstract]
Net income		11,751	14,093	14,505
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Increase in equity in undistributed earnings of subsidiary		(3,230)	(3,821)	(3,484)
Depreciation and amortization		43	7	0
Gain on sale of securities		(54)	0	(2,652)
Net change in other liabilities		187	318	(28)
Net change in other assets		(1,306)	(971)	396
Net Cash Provided By Operating Activities		7,391	9,626	8,737
Cash flows from investing activities [Abstract]
Proceeds from maturities, calls and sales of AFS securities		134	0	4,152
Funds invested in AFS securities		0	0	(10)
Funds invested in bank subsidiary	$ (3,750)	(3,750)	0	0
Cash paid in acquisition		(10,108)	0	0
Net Cash (Used In) Provided By Investing Activities		(13,724)	0	4,142
Cash flows from financing activities [Abstract]
Net decrease in short-term borrowings		0	(1,800)	0
Proceeds from long-term debt, net of costs		3,750	0	24,969
Repayment of long-term debt		(3,081)	(3,730)	(1,584)
Proceeds from junior subordinated debentures, net of costs		0	0	14,597
Issuance of common stock, net of costs		0	0	9,344
Redemption of preferred stock		0	0	(39,435)
Dividends paid		(5,210)	(4,870)	(4,631)
Net Cash Provided By (Used in) Financing Activities		(4,541)	(10,400)	3,260
Net Increase (Decrease In) Cash and Cash Equivalents		(10,874)	(774)	16,139
Cash and Cash Equivalents at the Beginning of the Period		16,088	16,862	723
Cash and Cash Equivalents at the End of the Period		$ 5,214	$ 16,088	$ 16,862