Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2018
Accounting Policies [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation United Community Banks, Inc. (the “Holding Company”) is a bank holding company subject to the regulation of the Board of Governors of the Federal Reserve System (the “Federal Reserve”) whose principal business is conducted by its wholly-owned commercial bank subsidiary, United Community Bank (the “Bank”). United is subject to regulation under the Bank Holding Company Act of 1956. The consolidated financial statements include the accounts of the Holding Company, the Bank and other wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. The Bank is a Georgia state chartered commercial bank that serves both rural and metropolitan markets in Georgia, South Carolina, North Carolina and Tennessee and provides a full range of banking services. The Bank is insured and subject to the regulation of the Federal Deposit Insurance Corporation (“FDIC”) and is also subject to the regulation of the Georgia Department of Banking and Finance.
Use of Estimates	Use of Estimates In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the dates of the balance sheet and revenue and expenses for the years then ended. Actual results could differ significantly from those estimates. Material estimates that are particularly susceptible to significant change are the determination of the allowance for loan losses, the valuation of acquired loans, the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans, the valuation of goodwill and separately identifiable intangible assets associated with mergers and acquisitions, and the valuation of deferred tax assets.
Operating Segments	Operating Segments Operating segments are components of a business about which separate financial information is available and evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assessing performance. Public companies are required to report certain financial information about operating segments in interim and annual financial statements. United’s community banking operations are divided among geographic regions and local community banks within those regions. Those regions and banks have similar economic characteristics and are therefore considered to be one operating segment. Additionally management assessed other operating units to determine if they should be classified and reported as segments. They include Mortgage, Advisory Services and Commercial Banking Solutions. Each was assessed for separate reporting on both a qualitative and a quantitative basis in accordance with Financial Accounting Standards Boards (“FASB”) Accounting Standards Codification (“ASC”) Topic 280 Segment Reporting (“ASC 280”). Qualitatively, these business units are currently operating in the same geographic footprint as the community banks and face many of the same customers as the community banks. While the chief operating decision maker does have some limited production information for these entities, that information is not complete since it does not include a full allocation of revenue, costs and capital from key corporate functions. The business units are currently viewed more as a product line extension of the community banks. However, management will continue to evaluate these business units for separate reporting as facts and circumstances change. On a quantitative basis, ASC 280 provides a threshold of 10% of Revenue, Net Income or Assets where a breach of any of these thresholds would trigger segment reporting. Under this requirement none of the entities reached the threshold.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents include amounts due from banks, interest-bearing deposits in banks, federal funds sold, commercial paper, reverse repurchase agreements and short-term investments and are carried at cost. Federal funds are generally sold for one-day periods, interest-bearing deposits in banks are available on demand and commercial paper investments and reverse repurchase agreements mature within a period of less than 90 days. A portion of the cash on hand and on deposit with the Federal Reserve Bank of Atlanta was required to meet regulatory reserve requirements. The terms of securitizations acquired with NLFC require various restricted cash accounts. These cash accounts were funded from either a portion of the proceeds from the issuance of notes or from the collections on leases and loans that were conveyed in the securitization. These restricted cash accounts provide additional collateral to the note holders under specific provisions of the securitizations which govern when funds in these accounts may be released as well as conditions under which collections on contracts transferred to the securitizations may be used to fund deposits into the restricted cash accounts.
Investment Securities	Investment Securities United classifies its debt securities in one of three categories: trading, held-to-maturity or available-for-sale. United does not currently hold any trading securities that are bought and held principally for the purpose of selling them in the near term. Held-to-maturity securities are those securities for which United has the ability and intent to hold until maturity. All other securities are classified as available-for-sale. Held-to-maturity securities are recorded at cost, adjusted for the amortization or accretion of premiums or discounts. Available-for-sale securities are recorded at fair value. Unrealized holding gains and losses, net of the related tax effect, on available-for-sale securities are reported in other comprehensive income as a separate component of shareholders’ equity until realized. Transfers of securities between categories are recorded at fair value at the date of transfer. Unrealized holding gains or losses associated with transfers of securities from available-for-sale to held-to-maturity are included in the balance of accumulated other comprehensive income in the consolidated balance sheets. These unrealized holding gains or losses are amortized into income over the remaining life of the security as an adjustment to the yield in a manner consistent with the amortization or accretion of the original purchase premium or discount on the associated security. Management evaluates investment securities for other than temporary impairment on a quarterly basis. A decline in the fair value of available-for-sale and held-to-maturity securities below cost that is deemed other than temporary is charged to earnings for a decline in value deemed to be credit related. The decline in value attributed to non-credit related factors is recognized in other comprehensive income and a new cost basis for the security is established. Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to the yield. Realized gains and losses for securities classified as available-for-sale and held-to-maturity are included in net income and derived using the specific identification method for determining the cost of the securities sold. Equity securities are included in other assets on the consolidated balance sheets. Those with readily determinable fair values are carried at fair value with changes in fair value recognized in net income. Those without readily determinable fair values include, among others, Federal Home Loan Bank (“FHLB”) stock held to meet FHLB requirements related to outstanding advances and Community Reinvestment Act (“CRA”) equity investments, including those where the returns are primarily derived from low income housing tax credits (“LIHTC”). Our investment in FHLB stock is accounted for using the cost method of accounting. Our LIHTC investments are accounted for using the proportional amortization method of accounting for qualified affordable housing investments which results in the amortization being reported as a component of income tax expense. Our obligations related to unfunded commitments for our LIHTC investments are reported in other liabilities. Our other CRA investments are accounted for using the equity method of accounting. As conditions warrant, we review our investments for impairment and will adjust the carrying value of the investment if it is deemed to be impaired.
Loans Held for Sale	Loans Held for Sale United has elected the fair value option for most of its newly originated mortgage loans held for sale in order to reduce certain timing differences and match changes in fair values of the loans with changes in the fair value of derivative instruments used to economically hedge them. Also included in loans held for sale at December 31, 2017 were $4.61 million in loans received through the acquisition of Four Oaks FinCorp, Inc. that United held with the intent to sell. Those loans were carried on the balance sheet at the lower of cost or fair value.
Loans and Leases	Loans and Leases With the exception of purchased loans that are recorded at fair value on the date of acquisition, loans are stated at principal amount outstanding, net of any unearned revenue and net of any deferred loan fees and costs. Interest on loans is primarily calculated by using the simple interest method on daily balances of the principal amount outstanding. Equipment Financing Lease Receivables: Equipment financing lease receivables are recorded as the sum of the future minimum lease payments, initial deferred costs and estimated or contractual residual values less unearned income and security deposits. The determination of residual value is derived from a variety of sources including equipment valuation services, appraisals, and publicly available market data on recent sales transactions on similar equipment. The length of time until contract termination, the cyclical nature of equipment values and the limited marketplace for re-sale of certain leased assets are important variables considered in making this determination. Interest income is recognized as earned using the effective interest method. Direct fees and costs associated with the origination of leases are deferred and included as a component of equipment financing receivables. Net deferred fees or costs are recognized as an adjustment to interest income over the contractual life of the lease using the effective interest method. Purchased Loans With Evidence of Credit Deterioration: United from time to time purchases loans, primarily through business combination transactions. Some of those purchased loans show evidence of credit deterioration since origination and are accounted for pursuant to ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality. These purchased credit impaired (“PCI”) loans are recorded at their estimated fair value at date of purchase. After acquisition, further losses evidenced by decreases in expected cash flows are recognized by an increase in the allowance for loan losses. PCI loans are aggregated into pools of loans based on common risk characteristics such as the type of loan, payment status, or collateral type. United estimates the amount and timing of expected cash flows for each purchased loan pool and the expected cash flows in excess of the amount paid are recorded as interest income over the remaining life of the pool (accretable yield). The excess of the pool’s contractual principal and interest over expected cash flows is not recorded (nonaccretable difference). Over the life of the loan pool, expected cash flows continue to be estimated. If the present value of expected cash flows is less than the carrying amount, a loss is recorded. If the present value of expected cash flows is greater than the carrying amount, it is recognized as part of future interest revenue. Nonaccrual Loans: The accrual of interest is discontinued when a loan becomes 90 days past due and is not well collateralized and in the process of collection, or when management believes, after considering economic and business conditions and collection efforts, that the principal or interest will not be collectible in the normal course of business. Past due status is based on contractual terms of the loan. When a loan is placed on nonaccrual status, previously accrued and uncollected interest is charged against interest revenue on loans. Interest payments are applied to reduce the principal balance on nonaccrual loans. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current, there is a sustained period of repayment performance and future payments are reasonably assured. Nonaccrual loans include smaller balance homogeneous loans that are collectively evaluated for impairment and individually classified impaired loans. Contractually delinquent PCI loans are not classified as nonaccrual as long as the related discount continues to be accreted. Impaired Loans: With the exception of PCI loans, a loan is considered impaired when, based on current events and circumstances, it is probable that all amounts due, according to the contractual terms of the loan, will not be collected. Individually impaired loans are measured based on the present value of expected future cash flows, discounted at the loan’s effective interest rate, at the loan’s observable market price, or the fair value of the collateral if the loan is collateral dependent. Interest revenue on impaired loans is discontinued when the loans meet the criteria for nonaccrual status. 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 considered 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 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. PCI loans are considered to be impaired when it is probable that United will be unable to collect all the cash flows expected at acquisition, plus additional cash flows expected to be collected arising from changes in estimates after acquisition. Loans that are accounted for in pools are evaluated collectively for impairment on a pool by pool basis based on expected pool cash flows. Discounts continue to be accreted as long as there are expected future cash flows in excess of the current carrying amount of the specifically-reviewed loan or pool. Concentration of Credit Risk: Most of United’s business activity is with customers located within the markets where it has banking operations. Therefore, United’s exposure to credit risk is significantly affected by changes in the economy within its markets. Approximately 74% of United’s loan portfolio is secured by real estate and is therefore susceptible to changes in real estate valuations.
Allowance for Credit Losses	Allowance for Credit Losses The allowance for credit losses includes the allowance for loan losses and the allowance for unfunded commitments included in other liabilities. Increases to the allowance for loan losses and allowance for unfunded commitments are established through a provision for credit losses charged to income. Loans are charged down against the allowance for loan losses when available information confirms that the collectability of the principal is unlikely. The allowance for loan losses represents an amount, which, in management’s judgment, is adequate to absorb probable losses on existing loans as of the date of the balance sheet. The allowance for unfunded commitments represents expected losses on unfunded commitments and is reported in the consolidated balance sheets in other liabilities. The allowance for loan losses is composed of general reserves, specific reserves, and PCI reserves. General reserves are determined by applying loss percentages to the individual loan categories that are based on actual historical loss experience. Additionally, the general economic and business conditions affecting key lending areas, credit quality trends, collateral values, loan volumes and concentrations, seasoning of the loan portfolio, the findings of internal and external credit reviews and results from external bank regulatory examinations are considered in this evaluation. The need for specific reserves is evaluated on nonaccrual loan relationships greater than $500,000 and all troubled debt restructurings (“TDRs”). The specific reserves are determined on a loan-by-loan basis based on management’s evaluation of United’s exposure for each credit, given the current payment status of the loan and the value of any underlying collateral. Loans for which specific reserves are provided are excluded from the calculation of general reserves. For PCI loans, a valuation allowance is established when it is probable that the Company will be unable to collect all the cash flows expected at acquisition plus additional cash flows expected to be collected arising from changes in estimate after acquisition. The allocation of the allowance for loan losses is based on historical data, subjective judgment and estimates and, therefore, is not necessarily indicative of the specific amounts or loan categories in which charge-offs may ultimately occur. For purposes of determining general reserves, United segments the loan portfolio into broad categories with similar risk elements. Those categories and their specific risks are described below. Owner occupied commercial real estate – Loans in this category are susceptible to declines in occupancy rates, business failure and general economic conditions. Income producing commercial real estate – Common risks for this loan category are declines in general economic conditions, declines in real estate value and lack of suitable alternative use for the property. Commercial & industrial – Risks to this loan category include industry concentrations and the inability to monitor the condition of the collateral which often consists of inventory, accounts receivable and other non-real estate assets. Equipment and inventory obsolescence can also pose a risk. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt. Commercial construction – Risks common to commercial construction loans are cost overruns, changes in market demand for property, inadequate long-term financing arrangements and declines in real estate values. Equipment financing - Risks associated with equipment financing are similar to those described for commercial and industrial loans, including general economic conditions, as well as appropriate lien priority on equipment, equipment obsolescence and the general mobility of the collateral. Residential mortgage – Residential mortgage loans are susceptible to weakening general economic conditions and increases in unemployment rates and declining real estate values. Home equity lines of credit – Risks common to home equity lines of credit are general economic conditions, including an increase in unemployment rates, and declining real estate values which reduce or eliminate the borrower’s home equity. Residential construction – Residential construction loans are susceptible to the same risks as residential mortgage loans. Changes in market demand for property leads to longer marketing times resulting in higher carrying costs, declining values, and higher interest rates. Consumer direct – Risks common to consumer direct loans include regulatory risks, unemployment and changes in local economic conditions as well as the inability to monitor collateral consisting of personal property. Indirect auto - Risks common to indirect auto loans include unemployment and changes in local economic conditions as well as the inability to monitor collateral. Management outsources a significant portion of its loan review to ensure objectivity in the loan review process and to challenge and corroborate the loan grading system. The loan review function provides additional analysis used in determining the adequacy of the allowance for loan losses. To supplement the outsourced loan review, management also has an internal loan review department that is independent of the lending function. Management believes the allowance for loan losses is appropriate at December 31, 2018. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary based on changes in economic conditions. In addition, various regulatory agencies, as an integral part of their examination process, periodically review United’s allowance for loan losses.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation. Depreciation is computed primarily using the straight line method over the estimated useful lives of the related assets. Costs incurred for maintenance and repairs are expensed as incurred. The range of estimated useful lives for buildings and improvements is 10 to 40 years, for land improvements, 10 years, and for furniture and equipment, 3 to 10 years. United periodically reviews the carrying value of premises and equipment for impairment whenever events or circumstances indicate that the carrying amount of such assets may not be fully recoverable.
Foreclosed Properties (Other Real Estate Owned, or OREO)	Foreclosed Properties (Other Real Estate Owned, or “OREO”) Foreclosed property is initially recorded at fair value, less cost to sell. If the fair value, less cost to sell at the time of foreclosure is less than the loan balance, the deficiency is recorded as a loan charge-off against the allowance for loan losses. If the fair value, less cost to sell, of the foreclosed property decreases during the holding period, a valuation allowance is established with a charge to operating expenses. When the foreclosed property is sold, a gain or loss is recognized on the sale for the difference between the sales proceeds and the carrying amount of the property. Financed sales of foreclosed property are accounted for in accordance with ASC Topic 610, Subtopic 20, Gains and losses from the derecognition of nonfinancial assets (“ASC 610-20”).
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill is an asset representing the future economic benefits from other assets acquired that are not individually identified and separately recognized. Goodwill is measured as the excess of the consideration transferred, net of the fair value of identifiable assets acquired and liabilities assumed at the acquisition date. Goodwill is not amortized, but instead is tested for impairment annually or more frequently if events or circumstances exist that indicate a goodwill impairment test should be performed. Other intangible assets, which are initially recorded at fair value, consist of core deposit intangible assets and noncompete agreements resulting from acquisitions. Core deposit intangible assets are amortized on a sum-of-the-years-digits basis over their estimated useful lives. Noncompete agreements are amortized on a straight line basis over their estimated useful lives. Management evaluates other intangible assets for impairment whenever events or changes in circumstances indicate the carrying amount of the asset may not be recoverable.
Transfers of Financial Assets	Transfers of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been relinquished. Control over transferred assets is deemed to be surrendered when the assets have been isolated from United, 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 United does not maintain effective control over the transferred assets through an agreement to repurchase them before maturity.
Servicing Rights	Servicing Rights United records a separate servicing asset for Small Business Administration (“SBA”) loans, United States Department of Agriculture (“USDA”) loans, and residential mortgage loans when the loan is sold but servicing is retained. This asset represents the right to service the loans and receive a fee in compensation. Servicing assets are initially recorded at their fair value as a component of the sale proceeds. The fair value of the servicing assets is based on an analysis of discounted cash flows that incorporates estimates of (1) market servicing costs, (2) market-based prepayment rates, and (3) market profit margins. Servicing assets are included in other assets. United has elected to subsequently measure the servicing assets for government guaranteed loans at fair value. There is no aggregation of the loans into pools for the valuation of the servicing asset, but rather the servicing asset value is measured at a loan level. Effective January 1, 2017, management elected to begin measuring residential mortgage servicing rights at fair value. The cumulative effect adjustment of this election to retained earnings, net of income tax effect, was $437,000. Prior to 2017, impairment valuations were based on projections using a discounted cash flow method that included assumptions regarding prepayments, interest rates, servicing costs and other factors. Impairment was measured on a disaggregated basis for each stratum of the servicing rights, which was segregated based on predominant risk characteristics including interest rate and loan type. Subsequent increases in value were recognized to the extent of previously recorded impairment for each stratum. The rate of prepayment of loans serviced is the most significant estimate involved in the measurement process. Estimates of prepayment rates are based on market expectations of future prepayment rates, industry trends, and other considerations. Actual prepayment rates will differ from those projected by management due to changes in a variety of economic factors, including prevailing interest rates and the availability of alternative financing sources to borrowers. If actual prepayments of the loans being serviced were to occur more quickly than projected, the carrying value of servicing assets might have to be written down through a charge to earnings in the current period. If actual prepayments of the loans being serviced were to occur more slowly than had been projected, the carrying value of servicing assets could increase, and servicing income would exceed previously projected amounts.
Bank Owned Life Insurance	Bank Owned Life Insurance United has purchased life insurance policies on certain key executives and members of management. United has also received life insurance policies on members of acquired bank management teams through acquisitions of other banks. Bank owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other changes or other amounts due that are probable at settlement.
Loan Commitments and Related Financial Instruments	Loan Commitments and Related Financial Instruments Financial instruments include off-balance sheet credit instruments such as commitments to make loans and commercial letters of credit issued to meet customer financing needs. The face amount for these items represents the exposure to loss before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded.
Revenue from Contracts with Customers	Revenue from Contracts with Customers In addition to lending and related activities, United offers various services to customers that generate revenue, certain of which are governed by ASC Topic 606 Revenue from Contracts with Customers (“ASC 606”). United’s services that fall within the scope of ASC 606 are presented within noninterest income and include service charges and fees, brokerage fees, and other transaction-based fees. Revenue is recognized when the transactions occur or as services are performed over primarily monthly or quarterly periods. Payment is typically received in the period the transactions occur. Fees may be fixed or, where applicable, based on a percentage of transaction size.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recorded for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Future tax benefits are recognized to the extent that realization of such benefits is more likely than not. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which the assets and liabilities are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income taxes during the period that includes the enactment date. In the event the future tax consequences of differences between the financial reporting bases and the tax bases of assets and liabilities results in deferred tax assets, an evaluation of the probability of being able to realize the future benefits indicated by such asset is required. A valuation allowance is provided for the portion of the deferred tax asset when it is more likely than not that some or all of the deferred tax asset will not be realized. In assessing the realizability of the deferred tax assets, management considers the scheduled reversals of deferred tax liabilities, projected future taxable earnings and prudent and feasible tax planning strategies. Management weighs both the positive and negative evidence, giving more weight to evidence that can be objectively verified. The income tax benefit or expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50 percent likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. United recognizes interest and / or penalties related to income tax matters in income tax expense.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities United’s interest rate risk management strategy incorporates the use of derivative instruments to minimize fluctuations in net income that are caused by interest rate volatility. The objective is to manage interest rate sensitivity by modifying the repricing or maturity characteristics of certain balance sheet assets and liabilities so that net interest revenue is not, on a material basis, adversely affected by movements in interest rates. United views this strategy as a prudent management of interest rate risk, such that net income is not exposed to undue risk presented by changes in interest rates. In carrying out this part of its interest rate risk management strategy, management uses derivatives, primarily interest rate swaps. Interest rate swaps generally involve the exchange of fixed- and variable-rate interest payments between two parties, based on a common notional principal amount and maturity date. United has also occasionally used interest rate caps to serve as an economic macro hedge of exposure to rising interest rates. In addition, United originates certain residential mortgage loans with the intention of selling these loans. Between the time United enters into an interest-rate lock commitment to originate a residential mortgage loan that is to be held for sale and the time the loan is funded and eventually sold, the Company is subject to the risk of variability in market prices. United also enters into forward sale agreements to mitigate risk and to protect the expected gain on the eventual loan sale. The commitments to originate residential mortgage loans and forward loan sales commitments are freestanding derivative instruments. To accommodate customers, United enters into interest rate swaps or caps with certain commercial loan customers, with offsetting positions to dealers under a back-to-back swap/cap program. In addition, United occasionally enters into credit risk participation agreements with counterparty banks to accept a portion of the credit risk related to interest rate swaps. This allows customers to execute an interest rate swap with one bank while allowing for the distribution of the credit risk among participating members. Credit risk participation agreements arise when United contracts with other financial institutions, as a guarantor, to share credit risk associated with certain interest rate swaps. These agreements provide for reimbursement of losses resulting from a third party default on the underlying swap. These transactions are typically executed in conjunction with a participation in a loan with the same customer. Collateral used to support the credit risk for the underlying lending relationship is also available to offset the risk of the credit risk participation. United classifies its derivative financial instruments as either (1) a hedge of an exposure to changes in the fair value of a recorded asset or liability (“fair value hedge”), (2) a hedge of an exposure to changes in the cash flows of a recognized asset, liability or forecasted transaction (“cash flow hedge”), or (3) derivatives not designated as accounting hedges. Changes in the fair value of derivatives not designated as hedges are recognized in current period earnings. United has master netting agreements with the derivatives dealers with which it does business, but reflects gross assets and liabilities on the consolidated balance sheets. United uses the “long-haul method” to assess hedge effectiveness. Management documents, both at inception and over the life of the hedge, at least quarterly, its analysis of actual and expected hedge effectiveness. This analysis includes techniques such as regression analysis and hypothetical derivatives to demonstrate that the hedge has been, and is expected to be, highly effective in offsetting corresponding changes in the fair value or cash flows of the hedged item. For a qualifying fair value hedge, changes in the value of derivatives that have been highly effective as hedges are recognized in current period earnings along with the corresponding changes in the fair value of the designated hedged item attributable to the risk being hedged. For a qualifying cash flow hedge, the portion of changes in the fair value of the derivatives that have been highly effective are recognized in other comprehensive income until the related cash flows from the hedged item are recognized in earnings. For fair value hedges and cash flow hedges, ineffectiveness is recognized in the same income statement line as interest accruals on the hedged item to the extent that changes in the value of the derivative instruments do not perfectly offset changes in the value of the hedged items. If the hedge ceases to be highly effective, United discontinues hedge accounting and recognizes the changes in fair value in current period earnings. If a derivative that qualifies as a fair value or cash flow hedge is terminated or the designation removed, the realized or then unrealized gain or loss is recognized into income over the life of the hedged item (fair value hedge) or over the time when the hedged item was forecasted to impact earnings (cash flow hedge). Immediate recognition in earnings is required upon sale or extinguishment of the hedged item (fair value hedge) or if it is probable that the hedged cash flows will not occur (cash flow hedge). By using derivative instruments, United is exposed to credit and market risk. If the counterparty fails to perform, credit risk is represented by the fair value gain in a derivative. When the fair value of a derivative contract is positive, this situation generally indicates that the counterparty is obligated to pay United, and, therefore, creates a repayment risk for United. When the fair value of a derivative contract is negative, United is obligated to pay the counterparty and, therefore, has no repayment risk. United minimizes the credit risk in derivative instruments by entering into transactions with high-quality counterparties that are reviewed periodically by management. United also requires the counterparties to pledge cash as collateral to cover the net exposure. All newly eligible derivatives entered into are cleared through a central clearinghouse, which reduces counterparty exposure. Derivative activities are monitored by the Asset/Liability Management Committee (“ALCO”) as part its oversight of asset/liability and treasury functions. ALCO is responsible for implementing various hedging strategies that are developed through its analysis of data from financial simulation models and other internal and industry sources. The resulting hedging strategies are then incorporated into the overall interest-rate risk management process. United recognizes the fair value of derivatives as assets or liabilities in the financial statements. The accounting for the changes in the fair value of a derivative depends on the intended use of the derivative instrument at inception. The change in fair value of instruments used as fair value hedges is accounted for in the net income of the period simultaneous with accounting for the fair value change of the item being hedged. The change in fair value of the effective portion of cash flow hedges is accounted for in other comprehensive income rather than net income. Changes in fair value of derivative instruments that are not designated as a hedge are accounted for in the net income of the period of the change.
Acquisition Activities	Acquisition Activities United accounts for business combinations under the acquisition method of accounting. Assets acquired and liabilities assumed are measured and recorded at fair value at the date of acquisition, including identifiable intangible assets. If the fair value of net assets purchased exceeds the fair value of consideration paid, a bargain purchase gain is recognized at the date of acquisition. Conversely, if the consideration paid exceeds the fair value of the net assets acquired, goodwill is recognized at the acquisition date. Fair values are subject to refinement for a period not to exceed one year after the closing date of an acquisition as information relative to closing date fair values becomes available. The determination of the fair value of loans acquired takes into account credit quality deterioration and probability of loss; therefore, the related allowance for loan losses is not carried forward. All identifiable intangible assets that are acquired in a business combination are recognized at fair value on the acquisition date. Identifiable intangible assets are recognized separately if they arise from contractual or other legal rights or if they are separable (i.e., capable of being sold, transferred, licensed, rented, or exchanged separately from the entity). Deposit liabilities and the related depositor relationship intangible assets may be exchanged in observable exchange transactions. As a result, the depositor relationship intangible asset is considered identifiable, because the separability criterion has been met.
Earnings Per Common Share	Earnings Per Common Share Basic earnings per common share is net income available to common shareholders divided by the weighted average number of shares of common stock outstanding during the period. All outstanding unvested share-based payment awards that contain rights to nonforfeitable dividends are considered participating securities for this calculation. Additionally, shares issuable to participants in United’s deferred compensation plan are considered to be participating securities for purposes of calculating basic earnings per share. Accordingly, net income available to common shareholders is calculated pursuant to the two-class method, whereby net income is allocated between common shareholders and participating securities. Diluted earnings per common share includes the dilutive effect of additional potential shares of common stock issuable under stock options, unvested restricted stock without nonforfeitable rights to dividends, warrants and securities convertible into common stock.
Loss Contingencies	Loss Contingencies Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe there are such matters that will have a material effect on the financial statements.
Dividend Restrictions	Dividend Restrictions Banking regulations require maintaining certain capital levels and may limit dividends paid by the Bank to the Holding Company or by the Holding Company to shareholders. Specifically, dividends paid by the Bank to the Holding Company require pre-approval of the Georgia Department of Banking and Finance and the FDIC during periods in which the Bank has an accumulated deficit (negative retained earnings).
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair values of financial instruments are estimated using relevant market information and other assumptions as more fully disclosed in Note 23. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect these estimates.
Stock-Based Compensation	Stock-Based Compensation United uses the fair value method of recognizing expense for stock-based compensation based on the fair value of option and restricted stock awards at the date of grant. United accounts for forfeitures as they occur.
Reclassifications	Reclassifications Certain amounts have been reclassified to conform to the 2018 presentation.
Accounting Standards Updates	Accounting Standards Updates In February 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842). This guidance was further modified in 2018 by ASU No. 2018-10, Codification Improvements to Topic 842 Leases, ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, and ASU No. 2018-20, Leases (Topic 842): Narrow-Scope Improvements for Lessors. These standards require a lessee to recognize in the consolidated balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. United adopted the standard on January 1, 2019 using the optional transition method, which allowed for a modified retrospective method of adoption with a cumulative effect adjustment to shareholders’ equity without restating comparable periods. United also elected the relief package of practical expedients for which there is no requirement to reassess existence of leases, their classification, and initial direct costs as well as an exemption for short-term leases with a term of less than one year, whereby United does not recognize a lease liability or right-of-use asset on the consolidated balance sheet but instead recognizes lease payments as an expense over the lease term as appropriate. The adoption of this guidance resulted in recognition of a right-of-use asset of $23.7 million, a lease liability of $26.7 million and a reduction of shareholders’ equity of $738,000. In the opinion of management, the changes described above resulting from the adoption of the standard did not have a material impact on the consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This guidance was further modified in November 2018 by ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments - Credit Losses. The new guidance replaces the incurred loss impairment methodology in current GAAP with an expected credit loss methodology and requires consideration of a broader range of information to determine credit loss estimates. Financial assets measured at amortized cost will be presented at the net amount expected to be collected by using an allowance for credit losses. Purchased credit impaired loans will receive an allowance account at the acquisition date that represents a component of the purchase price allocation. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses, with such allowance limited to the amount by which fair value is below amortized cost. Application of this update will primarily be on a modified retrospective approach, although the guidance for debt securities for which an other-than-temporary impairment has been recognized before the effective date and for loans previously covered by ASC 310-30, Receivables – Loans and Debt Securities Acquired with Deteriorated Credit Quality will be applied on a prospective basis. For public entities, this update is effective for fiscal years beginning after December 15, 2019. Upon adoption, United expects that the allowance for credit losses may be higher given the change to estimated losses for the estimated life of the financial asset; however, management is still in the process of determining the impact. Management has formed a steering committee and completed a gap assessment and a full project plan. The steering committee has selected a software provider and is in the process of populating relevant data, building models and documenting processes and controls in preparation for a loan-focused parallel run in the first quarter of 2019. United expects to run a full parallel run for the remaining three quarters of 2019 to ensure it is prepared for implementation by the effective date. During monthly steering committee meetings, management regularly reviews project status, gap remediation efforts and project priorities. In March 2017, the FASB issued ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. This update shortens the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. For securities held at a discount, the discount will continue to be amortized to maturity. For public entities, this update is effective for fiscal years beginning after December 15, 2018, with modified retrospective application. The adoption of this update on January 1, 2019 did not have a material impact on the consolidated financial statements. In August 2017, The FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This update expands and refines hedge accounting for both nonfinancial and financial risk components and aligns the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. This update also makes certain targeted improvements to simplify the application of hedge accounting guidance and ease the administrative burden of hedge documentation requirements and assessing hedge effectiveness. For public entities, this update is effective for fiscal years beginning after December 15, 2018. For cash flow and net investment hedges existing at the date of adoption, an entity should apply a cumulative-effect adjustment related to eliminating the separate measurement of ineffectiveness to accumulated other comprehensive income with a corresponding adjustment to the opening balance of retained earnings. The amended presentation and disclosure guidance is required prospectively. The adoption of this update on January 1, 2019 did not have a material impact on the consolidated financial statements. In May 2018, the FASB issued ASU No. 2018-06, Codification Improvements to Topic 942, Financial Services - Depository and Lending. This update superseded outdated guidance related to the Office of the Comptroller of the Currency’s Banking Circular 202, Accounting for Net Deferred Tax Charges. United does not expect the new guidance to have a material impact on the consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. This update expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. As a result, nonemployee share-based payment awards will be measured at the grant-date fair value of the equity instruments that an entity is obligated to issue when the service has been rendered, subject to the probability of satisfying performance conditions when applicable. For public entities, this update is effective for fiscal years beginning after December 15, 2018. The adoption of the new guidance on January 1, 2019 did not have a material impact on the consolidated financial statements as United does not currently grant equity awards to nonemployees other than directors and does not anticipate doing so. In June 2018, the FASB issued ASU No. 2018-08, Not for Profit Entities (Topic 958): Clarifying the Scope and the Accounting Guidance for Contributions Received and Contributions Made. This update clarifies the guidance about whether a transfer of assets (or the reduction, settlement or cancellation of liabilities) is a contribution or an exchange transaction. In addition, the guidance clarifies the determination of whether a transaction is conditional. For public entities, this update is effective for contributions made in fiscal years beginning after December 15, 2018. The adoption of the new guidance on January 1, 2019 did not have a material impact on the consolidated financial statements. In July 2018, the FASB issued ASU No. 2018-09, Codification Improvements to address stakeholder suggestions for minor corrections and clarifications within the codification. The transition and effective date guidance is based on the facts and circumstances of each amendment. Some of the amendments in this update do not require transition guidance and will be effective upon issuance of this update. However, many of the amendments in this update do have transition guidance with effective dates for annual periods beginning after December 15, 2018, for public business entities. The adoption of the new guidance on January 1, 2019 did not have a material impact on the consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. The update removes disclosures that are no longer considered cost beneficial, modifies certain requirements of disclosures, and adds disclosure requirements identified as relevant. For public entities, this guidance is effective for fiscal years ending after December 15, 2019 and, depending on the provision, requires either prospective or retrospective application to prior periods presented. United does not expect the new guidance to have a material impact on the consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans. The update removes disclosures that are no longer considered cost beneficial, clarifies specific requirements of disclosures, and adds disclosure requirements identified as relevant. For public entities, this guidance is effective for fiscal years ending after December 15, 2020 and requires retrospective application to prior periods presented. United does not expect the new guidance to have a material impact on the consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract (a consensus of the FASB Emerging Issues Task Force). This update aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal use software. For public entities, this guidance is effective for fiscal years ending after December 15, 2019 with either retrospective or prospective application. United does not expect the new guidance to have a material impact on the consolidated financial statements. In October 2018, the FASB issued ASU No. 2018-16, Derivatives and Hedging (Topic 815): Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes. This update permits the use of the OIS rate based on SOFR as a U.S. benchmark interest rate for hedge accounting purposes. For public entities, this guidance is effective for fiscal years beginning after December 15, 2018 and should be applied on a prospective basis for qualifying new or redesignated hedging relationships. The adoption of this update on January 1, 2019 did not have a material impact on the consolidated financial statements. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities. In addition to expanding the private company accounting alternative for applying variable interest entities (“VIE”) guidance, this update modifies the evaluation of decision-making fees for all entities applying VIE guidance. For public entities, this guidance is effective for fiscal years beginning after December 31, 2019 with retrospective application. United does not expect the new guidance to have a material impact on the consolidated financial statements. Standards Adopted in 2018 In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers. This ASU provides guidance on the recognition of revenue from contracts with customers. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance was effective for public entities for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, and was applied retrospectively either to each prior reporting period or with a cumulative effect recognized at the date of initial application. On January 1, 2018, United adopted ASU 2014-09 and all subsequent amendments to the ASU (collectively, ASC 606) using the modified retrospective approach. Because the guidance did not apply to revenue associated with financial instruments, including loans, leases, derivatives and securities, and revenue sources within scope were not materially affected, the new revenue recognition guidance did not have a material impact on the consolidated financial statements. In January 2016, the FASB issued ASU 2016-1, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities. The guidance in this update requires that equity investments (except those accounted for under the equity method of accounting) be measured at fair value with changes in fair value recognized in net income. However, an entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The guidance also simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. In addition, the guidance addresses various disclosure and presentation issues related to financial instruments. For public entities, this update was effective for fiscal years beginning after December 15, 2017 with early application permitted. The adoption of this update did not have a material impact on the consolidated financial statements. There was no opening balance sheet adjustment as a result of the adoption and the remainder of the standard was applied prospectively. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (a consensus of the FASB Emerging Issues Task Force). This ASU requires that the statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. This guidance was effective for public entities for fiscal years beginning after December 15, 2017, including interim periods within that reporting period, and was applied retrospectively to each period presented. The adoption of this update did not have a material impact on the consolidated financial statements. There was no adjustment to prior periods as a result of the adoption. In March 2017, the FASB issued ASU No. 2017-07, Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. This ASU requires that an employer disaggregate the service cost component from the other components of net benefit cost. The amendments also provide explicit guidance on how to present the service cost component and the other components of net benefit cost and allow only the service cost component to be eligible for capitalization. For public entities, this update was effective for fiscal years beginning after December 15, 2017, with retrospective presentation of the service cost and other components and prospective application for any capitalization of service cost. The adoption of this update did not have a material impact on the consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting. This update clarifies which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. Specifically, modification accounting should be applied unless the fair value of the modified award is the same as the original award immediately before modification, the vesting conditions of the modified award are the same as the original award immediately before modification, and the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before modification. For public entities, this update is effective for fiscal years beginning after December 15, 2017, with prospective application. The adoption of this update did not have a material impact on the consolidated financial statements.