Nature of Operations and Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Summary of Significant Accounting Policies	Nature of Operations and Summary of Significant Accounting Policies General Glacier Bancorp, Inc. (“Company”) is a Montana corporation headquartered in Kalispell, Montana. The Company provides a full range of banking services to individuals and businesses in Montana, Idaho, Utah, Washington, Wyoming, Colorado, Arizona and Nevada through its wholly-owned bank subsidiary, Glacier Bank (“Bank”). The Company offers a wide range of banking products and services, including: 1) retail banking; 2) business banking; 3) real estate, commercial, agriculture and consumer loans; and 4) mortgage origination services. The Company serves individuals, small to medium-sized businesses, community organizations and public entities. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change include: 1) the determination of the allowance for loan and lease losses (“ALLL” or “allowance”); 2) the valuation of debt securities; 3) the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans; and 4) the evaluation of goodwill impairment. For the determination of the ALLL and real estate valuation estimates, management obtains independent appraisals (new or updated) for significant items. Estimates relating to investment valuations are obtained from independent third parties. Estimates relating to the evaluation of goodwill for impairment are determined based on internal calculations using significant independent party inputs. Principles of Consolidation The consolidated financial statements of the Company include the parent holding company and the Bank. The Bank consists of sixteen bank divisions, a treasury division, an information technology division and a centralized mortgage division. The treasury division includes the Bank’s investment portfolio and wholesale borrowings, the information technology division includes the Bank’s internal data processing, and the centralized mortgage division includes mortgage loan servicing and secondary market sales. The Bank divisions operate under separate names, management teams and advisory directors. The Company considers the Bank to be its sole operating segment as the Bank 1) engages in similar bank business activity from which it earns revenues and incurs expenses; 2) the operating results of the Bank are regularly reviewed by the Chief Executive Officer (“CEO”) (i.e., the chief operating decision maker) who makes decisions about resources to be allocated to the Bank; and 3) financial information is available for the Bank. All significant inter-company transactions have been eliminated in consolidation. The Bank has subsidiary interests in variable interest entities (“VIE”) for which the Bank has both the power to direct the VIE’s significant activities and the obligation to absorb losses or right to receive benefits of the VIE that could potentially be significant to the VIE. These subsidiary interests are included in the Company’s consolidated financial statements. The Bank also has subsidiary interests in VIEs for which the Bank does not have a controlling financial interest and is not the primary beneficiary. These subsidiary interests are not included in the Company’s consolidated financial statements. The parent holding company owns non-bank subsidiaries that have issued trust preferred securities as Tier 1 capital instruments. The trust subsidiaries are not included in the Company’s consolidated financial statements. The Company's investments in the trust subsidiaries are included in other assets on the Company's statements of financial condition. In July 2019, the Company completed the acquisition of Heritage Bancorp, the bank holding company for Heritage Bank of Nevada, a community bank based in Reno, Nevada (collectively, “Heritage”). In April 2019, the Company completed the acquisition of FNB Bancorp, the holding company for The First National Bank of Layton, a community bank based in Layton, Utah (collectively, “FNB”). In February 2018, the Company completed its acquisition of Inter-Mountain Bancorp., Inc. and its wholly-owned subsidiary, First Security Bank, a community bank based in Bozeman, Montana (collectively, “FSB”). In January 2018, the Company completed its acquisition of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado (collectively, “Collegiate”). In April 2017, the Company completed its acquisition of TFB Bancorp, Inc. and its wholly-owned subsidiary, The Foothills Bank, a community bank based in Yuma, Arizona. The business combinations were accounted for using the acquisition method, with the results of operations included in the Company’s consolidated financial statements as of the acquisition dates. For additional information relating to recent mergers and acquisitions, see Note 22. Pending Acquisition On September 30, 2019, the Company announced the signing of a definitive agreement to acquire State Bank Corp., the parent company of State Bank of Arizona, a community bank based in Lake Havasu City, Arizona (collectively, “SBAZ”). SBAZ provides banking services to individuals and businesses in Arizona with locations in Bullhead City, Cottonwood, Kingman, Lake Havasu City, Phoenix, Prescott Valley and Prescott. As of December 31, 2019, SBAZ had total assets of $677,654,000, gross loans of $439,237,000 and total deposits of $586,688,000. The acquisition has received regulatory approvals, is subject to other customary conditions of closing and is expected to be completed in the first quarter of 2020. Upon closing of the transaction, SBAZ will merge into the Company's Foothills Bank division and will expand the Company's footprint in Arizona to cover all major markets in the state and be a leading community bank in Arizona. Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash held as demand deposits at various banks and the Federal Reserve Bank (“FRB”), interest bearing deposits, federal funds sold, and liquid investments with original maturities of three months or less. The Bank is required to maintain an average reserve balance with either the FRB or in the form of cash on hand. The required reserve balance at December 31, 2019 was $50,055,000. Debt Securities Debt securities for which the Company has the positive intent and ability to hold to maturity are classified as held-to-maturity and are carried at amortized cost. Debt securities held primarily for the purpose of selling in the near term are classified as trading securities and are reported at fair value, with unrealized gains and losses included in income. Debt securities not classified as held-to-maturity or trading are classified as available-for-sale and are reported at fair value with unrealized gains and losses, net of income taxes, as a separate component of other comprehensive income (“OCI”). Premiums and discounts on debt securities are amortized or accreted into income using a method that approximates the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. The Company does not have any debt securities classified as trading securities. The Company reviews and analyzes the various risks that may be present within the investment portfolio on an ongoing basis, including market risk and credit risk. Market risk is the risk to an entity’s financial condition resulting from adverse changes in the value of its holdings arising from movements in interest rates, foreign exchange rates, equity prices or commodity prices. The Company assesses the market risk of individual debt securities as well as the investment portfolio as a whole. Credit risk, broadly defined, is the risk that an issuer or counterparty will fail to perform on an obligation. A debt security is investment grade if the issuer has an adequate capacity to meet its commitment over the expected life of the investment, i.e., the risk of default is low and full and timely repayment of interest and principal is expected. To determine investment grade status for debt securities, the Company conducts due diligence of the creditworthiness of the issuer or counterparty prior to acquisition and ongoing thereafter consistent with the risk characteristics of the security and the overall risk of the investment portfolio. Credit quality due diligence takes into account the extent to which a security is guaranteed by the U.S. government and other agencies of the U.S. government. The depth of the due diligence is based on the complexity of the structure, the size of the security, and takes into account material positions and specific groups of securities or stratifications for analysis and review of similar risk positions. The due diligence includes consideration of payment performance, collateral adequacy, internal analyses, third party research and analytics, external credit ratings and default statistics. For additional information relating to debt securities, see Note 2. Temporary versus Other-Than-Temporary Impairment The Company assesses individual debt securities in its investment portfolio for impairment at least on a quarterly basis, and more frequently when economic or market conditions warrant. A debt security is impaired if the fair value of the security is less than its carrying value at the financial statement date. If impairment is determined to be other-than-temporary, an impairment loss is recognized by reducing the amortized cost for the credit loss portion of the impairment with a corresponding charge to earnings for a like amount. In evaluating impaired debt securities for other-than-temporary impairment losses, management considers 1) the severity and duration of the impairment; 2) the credit ratings of the security; and 3) the overall deal structure, including the Company’s position within the structure, the overall and near term financial performance of the issuer and underlying collateral, delinquencies, defaults, loss severities, recoveries, prepayments, cumulative loss projections, discounted cash flows and fair value estimates. In evaluating debt securities for other-than-temporary impairment losses, management assesses whether the Company intends to sell the security or if it is more-likely-than-not that the Company will be required to sell the debt security. In so doing, management considers contractual constraints, liquidity, capital, asset/liability management and securities portfolio objectives. If impairment is determined to be other-than-temporary and the Company does not intend to sell a debt security, and it is more-likely-than-not the Company will not be required to sell the security before recovery of its cost basis, it recognizes the credit component of an other-than-temporary impairment of a debt security in earnings and the remaining portion (noncredit portion) in OCI, net of tax. For held-to-maturity debt securities, the amount of an other-than-temporary impairment recorded in OCI for the noncredit portion of a previous other-than-temporary impairment is amortized prospectively, as an increase to the carrying amount of the security, over the remaining life of the security on the basis of the timing of future estimated cash flows of the security. If impairment is determined to be other-than-temporary and the Company intends to sell a debt security or it is more-likely-than-not the Company will be required to sell the security before recovery of its cost basis, it recognizes the entire amount of the other-than-temporary impairment in earnings. For debt securities with other-than-temporary impairment, the previous amortized cost basis less the other-than-temporary impairment recognized in earnings shall be the new amortized cost basis of the security. In subsequent periods, the Company accretes into interest income the difference between the new amortized cost basis and cash flows expected to be collected prospectively over the life of the debt security. Loans Held for Sale Loans held for sale generally consist of long-term, fixed rate, conforming, single-family residential real estate loans intended to be sold on the secondary market. Loans held for sale are recorded at fair value as of each balance sheet date. The fair value includes the servicing value of the loans and any change in fair value is recognized in non-interest income. Fair value elections are made at the time of origination or purchase based on the Company’s fair value election policy. Loans Receivable Loans that are intended to be held-to-maturity are reported at the unpaid principal balance less net charge-offs and adjusted for deferred fees and costs on originated loans and unamortized premiums or discounts on acquired loans. Fees and costs on originated loans and premiums or discounts on acquired loans are deferred and subsequently amortized or accreted as a yield adjustment over the expected life of the loan utilizing the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. When a loan is paid off prior to maturity, the remaining fees and costs on originated loans and premiums or discounts on acquired loans are immediately recognized into interest income. The Company’s loan segments, which are based on the purpose of the loan, include residential real estate, commercial, and consumer loans. The Company’s loan classes, a further disaggregation of segments, include residential real estate loans (residential real estate segment), commercial real estate and other commercial loans (commercial segment), and home equity and other consumer loans (consumer segment). Loans that are thirty days or more past due based on payments received and applied to the loan are considered delinquent. Loans are designated non-accrual and the accrual of interest is discontinued when the collection of the contractual principal or interest is unlikely. A loan is typically placed on non-accrual when principal or interest is due and has remained unpaid for ninety days or more. When a loan is placed on non-accrual status, interest previously accrued but not collected is reversed against current period interest income. Subsequent payments on non-accrual loans are applied to the outstanding principal balance if doubt remains as to the ultimate collectability of the loan. Interest accruals are not resumed on partially charged-off impaired loans. For other loans on non-accrual, interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to both principal and interest. The Company considers impaired loans to be the primary credit quality indicator for monitoring the credit quality of the loan portfolio. Loans are designated impaired when, based upon current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement and, therefore, the Company has serious doubts as to the ability of such borrowers to fulfill the contractual obligation. Impaired loans include non-performing loans (i.e., non-accrual loans and accruing loans ninety days or more past due) and accruing loans under ninety days past due where it is probable payments will not be received according to the loan agreement (e.g., troubled debt restructuring). Interest income on accruing impaired loans is recognized using the interest method. The Company measures impairment on a loan-by-loan basis in the same manner for each class within the loan portfolio. An insignificant delay or shortfall in the amounts of payments would not cause a loan or lease to be considered impaired. The Company determines the significance of payment delays and shortfalls on a case-by-case basis, taking into consideration all of the facts and circumstances surrounding the loan and the borrower, including the length and reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest due. A restructured loan is considered a troubled debt restructuring (“TDR”) if 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 Company periodically enters into restructure agreements with borrowers whereby the loans were previously identified as TDRs. When such circumstances occur, the Company carefully evaluates the facts of the subsequent restructure to determine the appropriate accounting and under certain circumstances it may be acceptable not to account for the subsequently restructured loan as a TDR. When assessing whether a concession has been granted by the Company, any prior forgiveness on a cumulative basis is considered a continuing concession. A TDR loan is considered an impaired loan and a specific valuation allowance is established when the fair value of the collateral-dependent loan or present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate based on the original contractual rate) is lower than the carrying value of the impaired loan. The Company has made the following types of loan modifications, some of which were considered a TDR: •reduction of the stated interest rate for the remaining term of the debt; •extension of the maturity date(s) at a stated rate of interest lower than the current market rate for newly originated debt having similar risk characteristics; and •reduction of the face amount of the debt as stated in the debt agreements. The Company recognizes that while borrowers may experience deterioration in their financial condition, many continue to be creditworthy customers who have the willingness and capacity for debt repayment. In determining whether non-restructured or unimpaired loans issued to a single or related party group of borrowers should continue to accrue interest when the borrower has other loans that are impaired or are TDRs, the Company on a quarterly or more frequent basis performs an updated and comprehensive assessment of the willingness and capacity of the borrowers to timely and ultimately repay their total debt obligations, including contingent obligations. Such analysis takes into account current financial information about the borrowers and financially responsible guarantors, if any, including for example: •analysis of global, i.e., aggregate debt service for total debt obligations; •assessment of the value and security protection of collateral pledged using current market conditions and alternative market assumptions across a variety of potential future situations; and •loan structures and related covenants. For additional information relating to loans, see Note 3. Allowance for Loan and Lease Losses Based upon management’s analysis of the Company’s loan portfolio, the balance of the ALLL is an estimate of probable credit losses known and inherent within the Bank’s loan portfolio as of the date of the consolidated financial statements. The ALLL is analyzed at the loan class level and is maintained within a range of estimated losses. Determining the adequacy of the ALLL involves a high degree of judgment and is inevitably imprecise as the risk of loss is difficult to quantify. The determination of the ALLL and the related provision for loan losses is a critical accounting estimate that involves management’s judgments about known relevant internal and external environmental factors that affect loan losses. The balance of the ALLL is highly dependent upon management’s evaluations of borrowers’ current and prospective performance, appraisals and other variables affecting the quality of the loan portfolio. Individually significant loans and major lending areas are reviewed periodically to determine potential problems at an early date. Changes in management’s estimates and assumptions are reasonably possible and may have a material impact upon the Company’s consolidated financial statements, results of operations or capital. Risk characteristics considered in the ALLL analysis applicable to each loan class within the Company's loan portfolio are as follows: Residential Real Estate. Residential real estate loans are secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class include a large number of borrowers, geographic dispersion of market areas and the loans are originated for relatively smaller amounts. Commercial Real Estate. Commercial real estate loans typically involve larger principal amounts, and repayment of these loans is generally dependent on the successful operation of the property securing the loan and/or the business conducted on the property securing the loan. Credit risk in these loans is impacted by the creditworthiness of a borrower, valuation of the property securing the loan and conditions within the local economies in the Company’s diverse, geographic market areas. Commercial. Commercial loans consist of loans to commercial customers for use in financing working capital needs, equipment purchases and business expansions. The loans in this category are repaid primarily from the cash flow of a borrower’s principal business operation. Credit risk in these loans is driven by creditworthiness of a borrower and the economic conditions that impact the cash flow stability from business operations across the Company’s diverse, geographic market areas. Home Equity. Home equity loans consist of junior lien mortgages and first and junior lien lines of credit (revolving open-end and amortizing closed-end) secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the residential property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class are a large number of borrowers, geographic dispersion of market areas and the loans are originated for terms that range from 10 to 15 years. Other Consumer. The other consumer loan portfolio consists of various short-term loans such as automobile loans and loans for other personal purposes. Repayment of these loans is primarily dependent on the personal income of the borrowers. Credit risk is driven by consumer economic factors (such as unemployment and general economic conditions in the Company’s diverse, geographic market area) and the creditworthiness of a borrower. The ALLL consists of a specific valuation allowance component and a general valuation allowance component. The specific component relates to loans that are determined to be impaired and individually evaluated for impairment. The Company measures impairment on a loan-by-loan basis based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except when it is determined that repayment of the loan is expected to be provided solely by the underlying collateral. For impairment based on expected future cash flows, the Company considers all information available as of a measurement date, including past events, current conditions, potential prepayments, and estimated cost to sell when such costs are expected to reduce the cash flows available to repay or otherwise satisfy the loan. For alternative ranges of cash flows, the likelihood of the possible outcomes is considered in determining the best estimate of expected future cash flows. The effective interest rate for a loan restructured in a TDR is based on the original contractual rate. For collateral-dependent loans and real estate loans for which foreclosure or a deed-in-lieu of foreclosure is probable, impairment is measured by the fair value of the collateral, less estimated cost to sell. The fair value of the collateral is determined primarily based upon appraisal or evaluation of the underlying real property value. The general valuation allowance component relates to probable credit losses inherent in the balance of the loan portfolio based on historical loss experience, adjusted for changes in trends and conditions of qualitative or environmental factors. The historical loss experience is based on the previous twelve quarters loss experience by loan class adjusted for risk characteristics in the existing loan portfolio. The same trends and conditions are evaluated for each class within the loan portfolio; however, the risk characteristics are weighted separately at the individual class level based on the Company’s judgment and experience. The changes in trends and conditions evaluated for each class within the loan portfolio include the following: •changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses; •changes in global, national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments; •changes in the nature and volume of the portfolio and in the terms of loans; •changes in experience, ability, and depth of lending management and other relevant staff; •changes in the volume and severity of past due and non-accrual loans; •changes in the quality of the Company’s loan review system; •changes in the value of underlying collateral for collateral-dependent loans; •the existence and effect of any concentrations of credit, and changes in the level of such concentrations; and •the effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in the Company’s existing portfolio. The ALLL is increased by provisions for loan losses which are charged to expense. The portions of loan and overdraft balances determined by management to be uncollectible are charged-off as a reduction of the ALLL and recoveries of amounts previously charged-off are credited as an increase to the ALLL. The Company’s charge-off policy is consistent with bank regulatory standards. Consumer loans generally are charged-off when the loan becomes over 120 days delinquent. Real estate acquired as a result of foreclosure or by deed-in-lieu of foreclosure is classified as other real estate owned (“OREO”) until such time as it is sold. At acquisition date, the assets and liabilities of acquired banks are recorded at their estimated fair values which results in no ALLL carried over from acquired banks. Subsequent to acquisition, an allowance will be recorded on the acquired loan portfolios for further credit deterioration, if any. Premises and Equipment Premises and equipment are accounted for at cost less depreciation. Depreciation is computed on a straight-line method over the estimated useful lives or the term of the related lease. The estimated useful life for office buildings is 15 to 40 years and the estimated useful life for furniture, fixtures, and equipment is 3 to 10 years. Interest is capitalized for any significant building projects. For additional information relating to premises and equipment, see Note 4. Leases The Company leases certain land, premises and equipment from third parties. A lessee lease is classified as an operating lease unless it meets certain criteria (e.g., lease contains option to purchase that Company is reasonably certain to exercise), in which case it is classified as a finance lease. Effective January 1, 2019, operating leases are included in net premises and equipment and other liabilities on the Company’s statements of financial condition and lease expense for lease payments is recognized on a straight-line basis over the lease term. Finance leases are included in net premises and equipment and other borrowed funds on the Company’s statements of financial condition. Right-of-use (“ROU”) assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. An ROU asset represents the right to use the underlying asset for the lease term and also includes any direct costs and payments made prior to lease commencement and excludes lease incentives. When an implicit rate is not available, an incremental borrowing rate based on the information available at commencement date is used in determining the present value of the lease payments. A lease term may include an option to extend or terminate the lease when it is reasonably certain the option will be exercised. The Company accounts for lease and nonlease components (e.g., common-area maintenance) together as a single combined lease component for all asset classes. Short-term leases of 12 months or less are excluded from accounting guidance; as a result, the lease payments are recognized on a straight-line basis over the lease term and the leases are not reflected on the Company’s statements of financial condition. Renewal and termination options are considered when determining short-term leases. Leases are accounted for on an individual lease level. Lease improvements incurred at the inception of the lease are recorded as an asset and depreciated over the initial term of the lease and lease improvements incurred subsequently are depreciated over the remaining term of the lease. The Company also leases certain premises and equipment to third parties. A lessor lease is classified as an operating lease unless it meets certain criteria that would classify it as either a sales-type lease or a direct financing lease. For additional information relating to leases, see Note 4. Other Real Estate Owned Property acquired by foreclosure or deed-in-lieu of foreclosure is initially recorded at fair value, less estimated selling cost, at acquisition date (i.e., cost of the property). The Company is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan upon the occurrence of either the Company obtaining legal title to the property or the borrower conveying all interest in the property through a deed-in-lieu or similar agreement. Fair value is determined as the amount that could be reasonably expected in a current sale between a willing buyer and a willing seller in an orderly transaction between market participants at the measurement date. Subsequent to the initial acquisition, if the fair value of the asset, less estimated selling cost, is less than the cost of the property, a loss is recognized in other expense and the asset carrying value is reduced. Gain or loss on disposition of OREO is recorded in non-interest income or non-interest expense, respectively. In determining the fair value of the properties on the date of transfer and any subsequent estimated losses of net realizable value, the fair value of other real estate acquired by foreclosure or deed-in-lieu of foreclosure is determined primarily based upon appraisal or evaluation of the underlying property value. Long-lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An asset is deemed impaired if the sum of the expected future cash flows is less than the carrying amount of the asset. If impaired, an impairment loss is recognized in other expense to reduce the carrying value of the asset to fair value. At December 31, 2019 and 2018, no long-lived assets were considered materially impaired. Business Combinations and Intangible Assets Acquisition accounting requires the total purchase price to be allocated to the estimated fair values of assets acquired and liabilities assumed, including certain intangible assets. Goodwill is recorded if the purchase price exceeds the net fair value of assets acquired and a bargain purchase gain is recorded in other income if the net fair value of assets acquired exceeds the purchase price. Adjustment of the allocated purchase price may be related to fair value estimates for which all information has not been obtained of the acquired entity known or discovered during the allocation period, the period of time required to identify and measure the fair values of the assets and liabilities acquired in the business combination. The allocation period is generally limited to one year following consummation of a business combination. Core deposit intangible represents the intangible value of depositor relationships resulting from deposit liabilities assumed in acquisitions and is amortized using an accelerated method based on an estimated runoff of the related deposits. The core deposit intangible is evaluated for impairment and recoverability whenever events or changes in circumstances indicate that its carrying amount may not be recoverable, with any changes in estimated useful life accounted for prospectively over the revised remaining life. For additional information relating to core deposit intangibles, see Note 5. The Company tests goodwill for impairment at the reporting unit level annually during the third quarter. The Company has identified that each of the Bank divisions are reporting units (i.e., components of the Glacier Bank operating segment) given that each division has a separate management team that regularly reviews its respective division financial information; however, the reporting units are aggregated into a single reporting unit due to the reporting units having similar economic characteristics. The goodwill of a reporting unit is tested for impairment between annual tests if an event occurs or circumstances change that would more-likely-than-not reduce the fair value of a reporting unit below its carrying amount. Examples of events and circumstances that could trigger the need for interim impairment testing include: •a significant change in legal factors or in the business climate; •an adverse action or assessment by a regulator; •unanticipated competition; •a loss of key personnel; •a more-likely-than-not expectation that a reporting unit or a significant portion of a reporting unit will be sold or otherwise disposed of; and •the testing for recoverability of a significant asset group within a reporting unit. For the goodwill impairment assessment, the Company has the option, prior to the two-step process, to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value. The Company opted to bypass the qualitative assessment for its 2019 and 2018 annual goodwill impairment testing and proceed directly to the two-step goodwill impairment test. The goodwill impairment two-step process requires the Company to make assumptions and judgments regarding fair value. In the first step, the Company calculates an implied fair value based on a control premium analysis. If the implied fair value is less than the carrying value, the second step is completed to compute the impairment amount, if any, by determining the “implied fair value” of goodwill. This determination requires the allocation of the estimated fair value of the reporting units to the assets and liabilities of the reporting units. Any remaining unallocated fair value represents the “implied fair value” of goodwill, which is compared to the corresponding carrying value of goodwill to compute impairment, if any. For additional information relating to goodwill, see Note 5. Equity Securities Non-marketable equity securities primarily consist of Federal Home Loan Bank (“FHLB”) stock. FHLB stock is restricted because such stock may only be sold to FHLB at its par value. Due to restrictive terms, and the lack of a readily determinable fair value, FHLB stock is carried at cost and evaluated for impairment. The investments in FHLB stock are required investments related to the Company’s borrowings from FHLB. FHLB obtains its funding primarily through issuance of consolidated obligations of the FHLB system. The U.S. government does not guarantee these obligations, and each of the regional FHLBs is jointly and severally liable for repayment of each other’s debt. The Company also has an insignificant amount of marketable equity securities that are included in other assets on the Company’s statements of financial condition. Marketable equity securities with readily determinable fair values are measured at fair value and changes in fair value are recognized in other income. Marketable equity securities without readily determinable fair values are carried 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. Bank-Owned Life Insurance The Company maintains bank-owned life insurance policies on certain current and former employees and directors, which are recorded at their cash surrender values as determined by the insurance carriers. The appreciation in the cash surrender value of the policies is recognized as a component of other non-interest income in the Company’s statements of operations. Derivatives and Hedging Activities For asset and liability management purposes, the Company previously entered into interest rate swap agreements to hedge against changes in forecasted cash flows due to interest rate exposures. In September 2019, the Company implemented a balance sheet strategy to increase its net interest income and net interest margin and early terminated its’ pay-fixed interest rate swaps. Prior to termination, the interest rate swaps were recognized as assets or liabilities on the Company’s statements of financial condition and were measured at fair value. Fair value estimates were obtained from third parties and were based on pricing models. The Company did not enter into interest rate swap agreements for trading or speculative purposes. The Company included the impact of bilateral collateral and master netting agreements that allowed the Company to settle all interest rate swap agreements held with a single counterparty on a net basis, and to offset the net interest rate swap derivative position with the related collateral when recognizing interest rate swap derivative assets and liabilities. The Company's interest rate swaps were contracts in which a series of interest payments were exchanged over a prescribed period. The notional amount upon which the interest payments were based was not exchanged. The swap agreements were derivative instruments and converted a portion of the Company’s forecasted variable rate debt to a fixed rate (i.e., cash flow hedge) over the payment term of the interest rate swap. The effective portion of the gain or loss on the cash flow hedging instruments was initially reported as a component of OCI and subsequently reclassified into earnings in the same period during which the transaction affects earnings. For highly effective hedges, the ineffective portion of the gain or loss on derivative instruments, if any, would be amortized over the remaining life the hedging instrument using a systematic and rational method. During the years ended December 31, 2019, 2018, and 2017, the Company’s cash flow hedges were determined to be fully effective. Interest rate derivative financial instruments received hedge accounting treatment only if they were designated as a hedge and were expected to be, and were, highly effective in substantially reducing interest rate risk arising from the assets and liabilities identified as exposing the Company to risk. Derivative financial instruments that did not meet specified hedging criteria were recorded at fair value with changes in fair value recorded in income. The Company’s interest rate swaps were considered highly effective and met the hedge accounting criteria. Cash flows resulting from the interest rate derivative financial instruments that were accounted for as hedges of assets and liabilities were classified in the Company’s cash flow statement in the same category as the cash flows of the items being hedged. For additional information relating to interest rate swap agreements, see Note 10. Revenue Recognition The Company recognizes revenue when services or products are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled. The Company’s principal source of revenue is interest income from debt securities and loans. Revenue from contracts with customers within the scope of Accounting Standards Codification™ (“ASC”) Topic 606 was $69,877,000, $76,664,000, and $69,808,000 for the years ended December 31, 2019, 2018, and 2017, respectively, and largely consisted of revenue from service charges and other fees from deposits (e.g., overdraft fees, ATM fees, debit card fees). Due to the short-term nature of the Company’s contracts with customers, an insignificant amount of receivables related to such revenue was recorded at December 31, 2019 and 2018 and there were no impairment losses recognized. Policies specific to revenue from contracts with customers include the following: Service Charges. Revenue from service charges consists of service charges and fees on deposit accounts under depository agreements with customers to provide access to deposited funds and, when applicable, pay interest on deposits. Service charges on deposit accounts may be transactional or non-transactional in nature. Transactional service charges occur in the form of a service or penalty and are charged upon the occurrence of an event (e.g., overdraft fees, ATM fees, wire transfer fees). Transactional service charges are recognized as services are delivered to and consumed by the customer, or as penalty fees are charged. Non-transactional service charges are charges that are based on a broader service, such as account maintenance fees and dormancy fees, and are recognized on a monthly basis. Debit Card Fees. Revenue from debit card fees includes interchange fee income from debit cards processed through card association networks. Interchange fees represent a portion of a transaction amount that the Company and other involved parties retain to compensate themselves for giving the cardholder immediate access to funds. Interchange rates are generally set by the card association networks and are based on purchase volumes and other factors. The Company records interchange fees as services are provided. Stock-based Compensation Stock-based compensation awards granted, comprised of restricted stock units and stock options, are valued at fair value and compensation cost is recognized on a straight-line basis over the requisite service period of each award. The impact of forfeitures of stock-based compensation awards on compensation expense is recognized as forfeitures occur. For additional information relating to stock-based compensation, see Note 12. Advertising and Promotion Advertising and promotion costs are recognized in the period incurred. Income Taxes The Company’s income tax expense consists of current and deferred income tax expense. Current income tax expense reflects taxes to be paid or refunded for the current period by applying the provisions of enacted tax law to earnings or losses. Deferred income tax expense results from changes in deferred assets and liabilities between periods. The Company recognizes interest and penalties related to income tax matters in income tax expense. Deferred tax assets and liabilities are recognized for estimated future income tax consequences attributable to differences between the financial statement carrying amounts of assets and liabilities and their respective tax bases. The effect on deferred tax assets and liabilities of a change in income tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets are reduced by a valuation allowance if, based on the weight of available evidence, it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The term more-likely-than-not means a likelihood of more than 50 percent. The recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to the Company’s judgment. In assessing the need for a valuation allowance, the Company considers both positive and negative evidence. For additional information relating to income taxes, see Note 15. Comprehensive Income Comprehensive income consists of net income and OCI. OCI includes unrealized gains and losses, net of tax effect, on available-for-sale securities and derivatives used for cash flow hedges. For additional information relating to OCI, see Note 16. Earnings Per Share Basic earnings per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period presented. Diluted earnings per share is computed by including the net increase in shares as if dilutive outstanding stock options were exercised and restricted stock units were vested, using the treasury stock method. For additional information relating to earnings per share, see Note 17. Reclassifications Certain reclassifications have been made to the 2018 and 2017 financial statements to conform to the 2019 presentation. Accounting Guidance Adopted in 2019 The ASC is the Financial Accounting Standards Board’s (“FASB”) officially recognized source of authoritative GAAP applicable to all public and non-public non-governmental entities. Rules and interpretive releases of the Securities and Exchange Commission (“SEC”) under the authority of the federal securities laws are also sources of authoritative GAAP for the Company as an SEC registrant. All other accounting literature is non-authoritative. The following paragraphs provide descriptions of recently adopted Accounting Standards Updates (“ASU”) that may have had a material effect on the Company’s financial position or results of operations. ASU 2017-08 - Receivables - Nonrefundable Fees and Other Costs. In March 2017, FASB amended ASC Subtopic 310-20 to shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments required the premium to be amortized to the earliest call date instead of the maturity date. The amendments did not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The amendments were effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018 and any adjustments were to be reflected as of the beginning of the year that includes the interim period. Entities were to apply the amendments on a modified retrospective basis; therefore, a cumulative-effect reduction to retained earnings of $24,102,000 was recognized as of the January 1, 2019 effective date. The Company’s debt securities that were effected by the amendments were primarily in the state and local governments category. The Company’s accounting policies and procedures were updated to reflect the amendments. ASU 2016-02 - Leases. In February 2016, FASB amended ASC Topic 842 to address several aspects of lease accounting with the significant change being the recognition of lease assets and lease liabilities for leases previously classified as operating leases. The amendments were effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018. The Company has lease agreements for which the amendments required the recognition of a lease liability to make lease payments and an ROU asset which represents its right to use the underlying asset for the lease term. An entity is permitted to elect not to restate its comparative periods in the period of adoption when transitioning to ASC Topic 842 and the Company made this election. In addition, the Company made the following elections related to implementation: 1) to not use hindsight in determining lease terms and in assessing impairment of ROU assets; and 2) to use the practical expedient package, which required no reassessment of whether existing contracts are or contain leases as well as no reassessment of lease classification for existing leases. At the date of adoption, the Company recognized an ROU asset and related lease liability on the Company’s statement of financial condition of $36,178,000 and $38,220,000, respectively. The Company developed new processes to comply with the accounting and disclosure requirements of such amendments and policies and procedures were updated accordingly. Accounting Guidance Pending Adoption at December 31, 2019 The following paragraphs provide descriptions of newly issued but not yet effective ASUs that could have a material effect on the Company’s financial position or results of operations. ASU 2017-04 - Intangibles - Goodwill and Other. In January 2017, FASB amended ASC Topic 350 to simplify the measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Instead, under these amendments, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss should not exceed the total amount of goodwill allocated to that reporting unit. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company has goodwill from prior business combinations and performs an annual impairment test or more frequently if changes or circumstances occur that would more-likely-than-not reduce the fair value of the reporting unit below its carrying value. During the third quarter of 2019, the Company performed its impairment assessment and determined the fair value of the aggregated reporting units exceeded the carrying value, such that the Company’s goodwill was not considered impaired. Although the Company cannot anticipate future goodwill impairment assessments, based on the most recent assessment, it is unlikely that an impairment amount would need to be calculated and, therefore, the Company does not anticipate a material impact from these amendments to the Company’s financial position and results of operations. The current accounting policies and processes are not anticipated to change, except for the elimination of the Step 2 analysis. For additional information regarding goodwill impairment testing, see Note 5. ASU 2016-13 - Financial Instruments - Credit Losses. In June 2016, FASB amended ASC Topic 326 to replace the incurred loss model with a methodology that reflects expected credit losses over the life of the loan and requires consideration of a broader range of reasonable and supportable information to calculate credit loss estimates. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2019. As a result of the adoption of the amendments, the ALLL will be referred to as the allowance for credit losses (“ACL”). The Company has evaluated the impact of these amendments to the Company’s financial position and results of operations and has determined the estimated range of the ACL will be between $125,600,000 and $131,300,000 and the estimated allowance for unfunded commitments will be between $12,800,000 and $13,600,000 upon adoption of the amendments. An adjustment to retained earnings, net of tax, will be required for the difference between such estimated amounts and the balances at December 31, 2019. The estimated impact to retained earnings on the date of adoption is approximately $9,955,000 to $14,808,000. The Company had developed internal implementation controls over the development of the ACL model and resulting financial statement disclosures. As part of the implementation of the amendments, the Company has adjusted its processes and procedures to calculate the ACL, including changes in assumptions and estimates to consider expected credit losses over the life of the loan versus the current accounting practice that utilizes the incurred loss model. The Company has also developed new procedures for determining an allowance for credit losses relating to held-to-maturity debt securities. In addition, the current accounting policy and procedures for other-than-temporary impairment on available-for-sale debt securities were replaced with an allowance approach. The Company engaged a third-party vendor solution and is currently in the final phases of evaluating the solution including model validation, adjusting assumptions utilized, and reviewing the accuracy of the financial statement disclosures. The project team is refining its processes and procedures which will continue during the first quarter of 2020. For additional information on the ALLL, see Note 3.

Glacier Bancorp, Inc. (“Company”) is a Montana corporation headquartered in Kalispell, Montana. The Company provides a full range of banking services to individuals and businesses in Montana, Idaho, Utah, Washington, Wyoming, Colorado, Arizona and Nevada through its wholly-owned bank subsidiary, Glacier Bank (“Bank”). The Company offers a wide range of banking products and services, including: 1) retail banking; 2) business banking; 3) real estate, commercial, agriculture and consumer loans; and 4) mortgage origination services. The Company serves individuals, small to medium-sized businesses, community organizations and public entities.

Material estimates that are particularly susceptible to significant change include: 1) the determination of the allowance for loan and lease losses (“ALLL” or “allowance”); 2) the valuation of debt securities; 3) the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans; and 4) the evaluation of goodwill impairment. For the determination of the ALLL and real estate valuation estimates, management obtains independent appraisals (new or updated) for significant items. Estimates relating to investment valuations are obtained from independent third parties. Estimates relating to the evaluation of goodwill for impairment are determined based on internal calculations using significant independent party inputs.

The consolidated financial statements of the Company include the parent holding company and the Bank. The Bank consists of sixteen bank divisions, a treasury division, an information technology division and a centralized mortgage division. The treasury division includes the Bank’s investment portfolio and wholesale borrowings, the information technology division includes the Bank’s internal data processing, and the centralized mortgage division includes mortgage loan servicing and secondary market sales. The Bank divisions operate under separate names, management teams and advisory directors. The Company considers the Bank to be its sole operating segment as the Bank 1) engages in similar bank business activity from which it earns revenues and incurs expenses; 2) the operating results of the Bank are regularly reviewed by the Chief Executive Officer (“CEO”) (i.e., the chief operating decision maker) who makes decisions about resources to be allocated to the Bank; and 3) financial information is available for the Bank. All significant inter-company transactions have been eliminated in consolidation.

The Bank has subsidiary interests in variable interest entities (“VIE”) for which the Bank has both the power to direct the VIE’s significant activities and the obligation to absorb losses or right to receive benefits of the VIE that could potentially be significant to the VIE. These subsidiary interests are included in the Company’s consolidated financial statements. The Bank also has subsidiary interests in VIEs for which the Bank does not have a controlling financial interest and is not the primary beneficiary. These subsidiary interests are not included in the Company’s consolidated financial statements.

In July 2019, the Company completed the acquisition of Heritage Bancorp, the bank holding company for Heritage Bank of Nevada, a community bank based in Reno, Nevada (collectively, “Heritage”). In April 2019, the Company completed the acquisition of FNB Bancorp, the holding company for The First National Bank of Layton, a community bank based in Layton, Utah (collectively, “FNB”). In February 2018, the Company completed its acquisition of Inter-Mountain Bancorp., Inc. and its wholly-owned subsidiary, First Security Bank, a community bank based in Bozeman, Montana (collectively, “FSB”). In January 2018, the Company completed its acquisition of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado (collectively, “Collegiate”). In April 2017, the Company completed its acquisition of TFB Bancorp, Inc. and its wholly-owned subsidiary, The Foothills Bank, a community bank based in Yuma, Arizona. The business combinations were accounted for using the acquisition method, with the results of operations included in the Company’s consolidated financial statements as of the acquisition dates. For additional information relating to recent mergers and acquisitions, see Note 22.

On September 30, 2019, the Company announced the signing of a definitive agreement to acquire State Bank Corp., the parent company of State Bank of Arizona, a community bank based in Lake Havasu City, Arizona (collectively, “SBAZ”). SBAZ provides banking services to individuals and businesses in Arizona with locations in Bullhead City, Cottonwood, Kingman, Lake Havasu City, Phoenix, Prescott Valley and Prescott. As of December 31, 2019, SBAZ had total assets of $677,654,000, gross loans of $439,237,000 and total deposits of $586,688,000. The acquisition has received regulatory approvals, is subject to other customary conditions of closing and is expected to be completed in the first quarter of 2020. Upon closing of the transaction, SBAZ will merge into the Company's Foothills Bank division and will expand the Company's footprint in Arizona to cover all major markets in the state and be a leading community bank in Arizona.

Debt securities for which the Company has the positive intent and ability to hold to maturity are classified as held-to-maturity and are carried at amortized cost. Debt securities held primarily for the purpose of selling in the near term are classified as trading securities and are reported at fair value, with unrealized gains and losses included in income. Debt securities not classified as held-to-maturity or trading are classified as available-for-sale and are reported at fair value with unrealized gains and losses, net of income taxes, as a separate component of other comprehensive income (“OCI”). Premiums and discounts on debt securities are amortized or accreted into income using a method that approximates the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. The Company does not have any debt securities classified as trading securities.

The Company reviews and analyzes the various risks that may be present within the investment portfolio on an ongoing basis, including market risk and credit risk. Market risk is the risk to an entity’s financial condition resulting from adverse changes in the value of its holdings arising from movements in interest rates, foreign exchange rates, equity prices or commodity prices. The Company assesses the market risk of individual debt securities as well as the investment portfolio as a whole. Credit risk, broadly defined, is the risk that an issuer or counterparty will fail to perform on an obligation. A debt security is investment grade if the issuer has an adequate capacity to meet its commitment over the expected life of the investment, i.e., the risk of default is low and full and timely repayment of interest and principal is expected. To determine investment grade status for debt securities, the Company conducts due diligence of the creditworthiness of the issuer or counterparty prior to acquisition and ongoing thereafter consistent with the risk characteristics of the security and the overall risk of the investment portfolio. Credit quality due diligence takes into account the extent to which a security is guaranteed by the U.S. government and other agencies of the U.S. government. The depth of the due diligence is based on the complexity of the structure, the size of the security, and takes into account material positions and specific groups of securities or stratifications for analysis and review of similar risk positions. The due diligence includes consideration of payment performance, collateral adequacy, internal analyses, third party research and analytics, external credit ratings and default statistics.

The Company assesses individual debt securities in its investment portfolio for impairment at least on a quarterly basis, and more frequently when economic or market conditions warrant. A debt security is impaired if the fair value of the security is less than its carrying value at the financial statement date. If impairment is determined to be other-than-temporary, an impairment loss is recognized by reducing the amortized cost for the credit loss portion of the impairment with a corresponding charge to earnings for a like amount.

In evaluating impaired debt securities for other-than-temporary impairment losses, management considers 1) the severity and duration of the impairment; 2) the credit ratings of the security; and 3) the overall deal structure, including the Company’s position within the structure, the overall and near term financial performance of the issuer and underlying collateral, delinquencies, defaults, loss severities, recoveries, prepayments, cumulative loss projections, discounted cash flows and fair value estimates.

In evaluating debt securities for other-than-temporary impairment losses, management assesses whether the Company intends to sell the security or if it is more-likely-than-not that the Company will be required to sell the debt security. In so doing, management considers contractual constraints, liquidity, capital, asset/liability management and securities portfolio objectives. If impairment is determined to be other-than-temporary and the Company does not intend to sell a debt security, and it is more-likely-than-not the Company will not be required to sell the security before recovery of its cost basis, it recognizes the credit component of an other-than-temporary impairment of a debt security in earnings and the remaining portion (noncredit portion) in OCI, net of tax. For held-to-maturity debt securities, the amount of an other-than-temporary impairment recorded in OCI for the noncredit portion of a previous other-than-temporary impairment is amortized prospectively, as an increase to the carrying amount of the security, over the remaining life of the security on the basis of the timing of future estimated cash flows of the security.

Loans held for sale generally consist of long-term, fixed rate, conforming, single-family residential real estate loans intended to be sold on the secondary market. Loans held for sale are recorded at fair value as of each balance sheet date. The fair value includes the servicing value of the loans and any change in fair value is recognized in non-interest income. Fair value elections are made at the time of origination or purchase based on the Company’s fair value election policy.

Loans that are intended to be held-to-maturity are reported at the unpaid principal balance less net charge-offs and adjusted for deferred fees and costs on originated loans and unamortized premiums or discounts on acquired loans. Fees and costs on originated loans and premiums or discounts on acquired loans are deferred and subsequently amortized or accreted as a yield adjustment over the expected life of the loan utilizing the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. When a loan is paid off prior to maturity, the remaining fees and costs on originated loans and premiums or discounts on acquired loans are immediately recognized into interest income.

Loans that are thirty days or more past due based on payments received and applied to the loan are considered delinquent. Loans are designated non-accrual and the accrual of interest is discontinued when the collection of the contractual principal or interest is unlikely. A loan is typically placed on non-accrual when principal or interest is due and has remained unpaid for ninety days or more. When a loan is placed on non-accrual status, interest previously accrued but not collected is reversed against current period interest income. Subsequent payments on non-accrual loans are applied to the outstanding principal balance if doubt remains as to the ultimate collectability of the loan. Interest accruals are not resumed on partially charged-off impaired loans. For other loans on non-accrual, interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to both principal and interest.

The Company considers impaired loans to be the primary credit quality indicator for monitoring the credit quality of the loan portfolio. Loans are designated impaired when, based upon current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement and, therefore, the Company has serious doubts as to the ability of such borrowers to fulfill the contractual obligation. Impaired loans include non-performing loans (i.e., non-accrual loans and accruing loans ninety days or more past due) and accruing loans under ninety days past due where it is probable payments will not be received according to the loan agreement (e.g., troubled debt restructuring). Interest income on accruing impaired loans is recognized using the interest method. The Company measures impairment on a loan-by-loan basis in the same manner for each class within the loan portfolio. An insignificant delay or shortfall in the amounts of payments would not cause a loan or lease to be considered impaired. The Company determines the significance of payment delays and shortfalls on a case-by-case basis, taking into consideration all of the facts and circumstances surrounding the loan and the borrower, including the length and reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest due.

A restructured loan is considered a troubled debt restructuring (“TDR”) if 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 Company periodically enters into restructure agreements with borrowers whereby the loans were previously identified as TDRs. When such circumstances occur, the Company carefully evaluates the facts of the subsequent restructure to determine the appropriate accounting and under certain circumstances it may be acceptable not to account for the subsequently restructured loan as a TDR. When assessing whether a concession has been granted by the Company, any prior forgiveness on a cumulative basis is considered a continuing concession. A TDR loan is considered an impaired loan and a specific valuation allowance is established when the fair value of the collateral-dependent loan or present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate based on the original contractual rate) is lower than the carrying value of the impaired loan. The Company has made the following types of loan modifications, some of which were considered a TDR:

The Company recognizes that while borrowers may experience deterioration in their financial condition, many continue to be creditworthy customers who have the willingness and capacity for debt repayment. In determining whether non-restructured or unimpaired loans issued to a single or related party group of borrowers should continue to accrue interest when the borrower has other loans that are impaired or are TDRs, the Company on a quarterly or more frequent basis performs an updated and comprehensive assessment of the willingness and capacity of the borrowers to timely and ultimately repay their total debt obligations, including contingent obligations. Such analysis takes into account current financial information about the borrowers and financially responsible guarantors, if any, including for example:

Based upon management’s analysis of the Company’s loan portfolio, the balance of the ALLL is an estimate of probable credit losses known and inherent within the Bank’s loan portfolio as of the date of the consolidated financial statements. The ALLL is analyzed at the loan class level and is maintained within a range of estimated losses. Determining the adequacy of the ALLL involves a high degree of judgment and is inevitably imprecise as the risk of loss is difficult to quantify. The determination of the ALLL and the related provision for loan losses is a critical accounting estimate that involves management’s judgments about known relevant internal and external environmental factors that affect loan losses. The balance of the ALLL is highly dependent upon management’s evaluations of borrowers’ current and prospective performance, appraisals and other variables affecting the quality of the loan portfolio. Individually significant loans and major lending areas are reviewed periodically to determine potential problems at an early date. Changes in management’s estimates and assumptions are reasonably possible and may have a material impact upon the Company’s consolidated financial statements, results of operations or capital.

Residential Real Estate. Residential real estate loans are secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class include a large number of borrowers, geographic dispersion of market areas and the loans are originated for relatively smaller amounts.

Commercial Real Estate. Commercial real estate loans typically involve larger principal amounts, and repayment of these loans is generally dependent on the successful operation of the property securing the loan and/or the business conducted on the property securing the loan. Credit risk in these loans is impacted by the creditworthiness of a borrower, valuation of the property securing the loan and conditions within the local economies in the Company’s diverse, geographic market areas.

Commercial. Commercial loans consist of loans to commercial customers for use in financing working capital needs, equipment purchases and business expansions. The loans in this category are repaid primarily from the cash flow of a borrower’s principal business operation. Credit risk in these loans is driven by creditworthiness of a borrower and the economic conditions that impact the cash flow stability from business operations across the Company’s diverse, geographic market areas.

Home Equity. Home equity loans consist of junior lien mortgages and first and junior lien lines of credit (revolving open-end and amortizing closed-end) secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the residential property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class are a large number of borrowers, geographic dispersion of market areas and the loans are originated for terms that range from 10 to 15 years.

The ALLL consists of a specific valuation allowance component and a general valuation allowance component. The specific component relates to loans that are determined to be impaired and individually evaluated for impairment. The Company measures impairment on a loan-by-loan basis based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except when it is determined that repayment of the loan is expected to be provided solely by the underlying collateral. For impairment based on expected future cash flows, the Company considers all information available as of a measurement date, including past events, current conditions, potential prepayments, and estimated cost to sell when such costs are expected to reduce the cash flows available to repay or otherwise satisfy the loan. For alternative ranges of cash flows, the likelihood of the possible outcomes is considered in determining the best estimate of expected future cash flows. The effective interest rate for a loan restructured in a TDR is based on the original contractual rate. For collateral-dependent loans and real estate loans for which foreclosure or a deed-in-lieu of foreclosure is probable, impairment is measured by the fair value of the collateral, less estimated cost to sell. The fair value of the collateral is determined primarily based upon appraisal or evaluation of the underlying real property value.

The general valuation allowance component relates to probable credit losses inherent in the balance of the loan portfolio based on historical loss experience, adjusted for changes in trends and conditions of qualitative or environmental factors. The historical loss experience is based on the previous twelve quarters loss experience by loan class adjusted for risk characteristics in the existing loan portfolio. The same trends and conditions are evaluated for each class within the loan portfolio; however, the risk characteristics are weighted separately at the individual class level based on the Company’s judgment and experience.

The ALLL is increased by provisions for loan losses which are charged to expense. The portions of loan and overdraft balances determined by management to be uncollectible are charged-off as a reduction of the ALLL and recoveries of amounts previously charged-off are credited as an increase to the ALLL. The Company’s charge-off policy is consistent with bank regulatory standards. Consumer loans generally are charged-off when the loan becomes over 120 days delinquent. Real estate acquired as a result of foreclosure or by deed-in-lieu of foreclosure is classified as other real estate owned (“OREO”) until such time as it is sold.

The Company leases certain land, premises and equipment from third parties. A lessee lease is classified as an operating lease unless it meets certain criteria (e.g., lease contains option to purchase that Company is reasonably certain to exercise), in which case it is classified as a finance lease. Effective January 1, 2019, operating leases are included in net premises and equipment and other liabilities on the Company’s statements of financial condition and lease expense for lease payments is recognized on a straight-line basis over the lease term. Finance leases are included in net premises and equipment and other borrowed funds on the Company’s statements of financial condition. Right-of-use (“ROU”) assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. An ROU asset represents the right to use the underlying asset for the lease term and also includes any direct costs and payments made prior to lease commencement and excludes lease incentives. When an implicit rate is not available, an incremental borrowing rate based on the information available at commencement date is used in determining the present value of the lease payments. A lease term may include an option to extend or terminate the lease when it is reasonably certain the option will be exercised. The Company accounts for lease and nonlease components (e.g., common-area maintenance) together as a single combined lease component for all asset classes. Short-term leases of 12 months or less are excluded from accounting guidance; as a result, the lease payments are recognized on a straight-line basis over the lease term and the leases are not reflected on the Company’s statements of financial condition. Renewal and termination options are considered when determining short-term leases. Leases are accounted for on an individual lease level.

Property acquired by foreclosure or deed-in-lieu of foreclosure is initially recorded at fair value, less estimated selling cost, at acquisition date (i.e., cost of the property). The Company is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan upon the occurrence of either the Company obtaining legal title to the property or the borrower conveying all interest in the property through a deed-in-lieu or similar agreement. Fair value is determined as the amount that could be reasonably expected in a current sale between a willing buyer and a willing seller in an orderly transaction between market participants at the measurement date. Subsequent to the initial acquisition, if the fair value of the asset, less estimated selling cost, is less than the cost of the property, a loss is recognized in other expense and the asset carrying value is reduced. Gain or loss on disposition of OREO is recorded in non-interest income or non-interest expense, respectively. In determining the fair value of the properties on the date of transfer and any subsequent estimated losses of net realizable value, the fair value of other real estate acquired by foreclosure or deed-in-lieu of foreclosure is determined primarily based upon appraisal or evaluation of the underlying property value.

Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An asset is deemed impaired if the sum of the expected future cash flows is less than the carrying amount of the asset. If impaired, an impairment loss is recognized in other expense to reduce the carrying value of the asset to fair value. At December 31, 2019 and 2018, no long-lived assets were considered materially impaired.

Core deposit intangible represents the intangible value of depositor relationships resulting from deposit liabilities assumed in acquisitions and is amortized using an accelerated method based on an estimated runoff of the related deposits. The core deposit intangible is evaluated for impairment and recoverability whenever events or changes in circumstances indicate that its carrying amount may not be recoverable, with any changes in estimated useful life accounted for prospectively over the revised remaining life. For additional information relating to core deposit intangibles, see Note 5.

The Company tests goodwill for impairment at the reporting unit level annually during the third quarter. The Company has identified that each of the Bank divisions are reporting units (i.e., components of the Glacier Bank operating segment) given that each division has a separate management team that regularly reviews its respective division financial information; however, the reporting units are aggregated into a single reporting unit due to the reporting units having similar economic characteristics.

For the goodwill impairment assessment, the Company has the option, prior to the two-step process, to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value. The Company opted to bypass the qualitative assessment for its 2019 and 2018 annual goodwill impairment testing and proceed directly to the two-step goodwill impairment test. The goodwill impairment two-step process requires the Company to make assumptions and judgments regarding fair value. In the first step, the Company calculates an implied fair value based on a control premium analysis. If the implied fair value is less than the carrying value, the second step is completed to compute the impairment amount, if any, by determining the “implied fair value” of goodwill. This determination requires the allocation of the estimated fair value of the reporting units to the assets and liabilities of the reporting units. Any remaining unallocated fair value represents the “implied fair value” of goodwill, which is compared to the corresponding carrying value of goodwill to compute impairment, if any.

Non-marketable equity securities primarily consist of Federal Home Loan Bank (“FHLB”) stock. FHLB stock is restricted because such stock may only be sold to FHLB at its par value. Due to restrictive terms, and the lack of a readily determinable fair value, FHLB stock is carried at cost and evaluated for impairment. The investments in FHLB stock are required investments related to the Company’s borrowings from FHLB. FHLB obtains its funding primarily through issuance of consolidated obligations of the FHLB system. The U.S. government does not guarantee these obligations, and each of the regional FHLBs is jointly and severally liable for repayment of each other’s debt.

The Company also has an insignificant amount of marketable equity securities that are included in other assets on the Company’s statements of financial condition. Marketable equity securities with readily determinable fair values are measured at fair value and changes in fair value are recognized in other income. Marketable equity securities without readily determinable fair values are carried 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.

For asset and liability management purposes, the Company previously entered into interest rate swap agreements to hedge against changes in forecasted cash flows due to interest rate exposures. In September 2019, the Company implemented a balance sheet strategy to increase its net interest income and net interest margin and early terminated its’ pay-fixed interest rate swaps. Prior to termination, the interest rate swaps were recognized as assets or liabilities on the Company’s statements of financial condition and were measured at fair value. Fair value estimates were obtained from third parties and were based on pricing models. The Company did not enter into interest rate swap agreements for trading or speculative purposes.

The Company's interest rate swaps were contracts in which a series of interest payments were exchanged over a prescribed period. The notional amount upon which the interest payments were based was not exchanged. The swap agreements were derivative instruments and converted a portion of the Company’s forecasted variable rate debt to a fixed rate (i.e., cash flow hedge) over the payment term of the interest rate swap. The effective portion of the gain or loss on the cash flow hedging instruments was initially reported as a component of OCI and subsequently reclassified into earnings in the same period during which the transaction affects earnings. For highly effective hedges, the ineffective portion of the gain or loss on derivative instruments, if any, would be amortized over the remaining life the hedging instrument using a systematic and rational method. During the years ended December 31, 2019, 2018, and 2017, the Company’s cash flow hedges were determined to be fully effective.

Interest rate derivative financial instruments received hedge accounting treatment only if they were designated as a hedge and were expected to be, and were, highly effective in substantially reducing interest rate risk arising from the assets and liabilities identified as exposing the Company to risk. Derivative financial instruments that did not meet specified hedging criteria were recorded at fair value with changes in fair value recorded in income. The Company’s interest rate swaps were considered highly effective and met the hedge accounting criteria.

The Company recognizes revenue when services or products are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled. The Company’s principal source of revenue is interest income from debt securities and loans. Revenue from contracts with customers within the scope of Accounting Standards Codification™ (“ASC”) Topic 606 was $69,877,000, $76,664,000, and $69,808,000 for the years ended December 31, 2019, 2018, and 2017, respectively, and largely consisted of revenue from service charges and other fees from deposits (e.g., overdraft fees, ATM fees, debit card fees). Due to the short-term nature of the Company’s contracts with customers, an insignificant amount of receivables related to such revenue was recorded at December 31, 2019 and 2018 and there were no impairment losses recognized. Policies specific to revenue from contracts with customers include the following:

Service Charges. Revenue from service charges consists of service charges and fees on deposit accounts under depository agreements with customers to provide access to deposited funds and, when applicable, pay interest on deposits. Service charges on deposit accounts may be transactional or non-transactional in nature. Transactional service charges occur in the form of a service or penalty and are charged upon the occurrence of an event (e.g., overdraft fees, ATM fees, wire transfer fees). Transactional service charges are recognized as services are delivered to and consumed by the customer, or as penalty fees are charged. Non-transactional service charges are charges that are based on a broader service, such as account maintenance fees and dormancy fees, and are recognized on a monthly basis.

Debit Card Fees. Revenue from debit card fees includes interchange fee income from debit cards processed through card association networks. Interchange fees represent a portion of a transaction amount that the Company and other involved parties retain to compensate themselves for giving the cardholder immediate access to funds. Interchange rates are generally set by the card association networks and are based on purchase volumes and other factors. The Company records interchange fees as services are provided.

Deferred tax assets are reduced by a valuation allowance if, based on the weight of available evidence, it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The term more-likely-than-not means a likelihood of more than 50 percent. The recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to the Company’s judgment. In assessing the need for a valuation allowance, the Company considers both positive and negative evidence. For additional information relating to income taxes, see Note 15.

The ASC is the Financial Accounting Standards Board’s (“FASB”) officially recognized source of authoritative GAAP applicable to all public and non-public non-governmental entities. Rules and interpretive releases of the Securities and Exchange Commission (“SEC”) under the authority of the federal securities laws are also sources of authoritative GAAP for the Company as an SEC registrant. All other accounting literature is non-authoritative. The following paragraphs provide descriptions of recently adopted Accounting Standards Updates (“ASU”) that may have had a material effect on the Company’s financial position or results of operations.

ASU 2017-08 - Receivables - Nonrefundable Fees and Other Costs. In March 2017, FASB amended ASC Subtopic 310-20 to shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments required the premium to be amortized to the earliest call date instead of the maturity date. The amendments did not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The amendments were effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018 and any adjustments were to be reflected as of the beginning of the year that includes the interim period. Entities were to apply the amendments on a modified retrospective basis; therefore, a cumulative-effect reduction to retained earnings of $24,102,000 was recognized as of the January 1, 2019 effective date. The Company’s debt securities that were effected by the amendments were primarily in the state and local governments category. The Company’s accounting policies and procedures were updated to reflect the amendments.

ASU 2016-02 - Leases. In February 2016, FASB amended ASC Topic 842 to address several aspects of lease accounting with the significant change being the recognition of lease assets and lease liabilities for leases previously classified as operating leases. The amendments were effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018. The Company has lease agreements for which the amendments required the recognition of a lease liability to make lease payments and an ROU asset which represents its right to use the underlying asset for the lease term. An entity is permitted to elect not to restate its comparative periods in the period of adoption when transitioning to ASC Topic 842 and the Company made this election. In addition, the Company made the following elections related to implementation: 1) to not use hindsight in determining lease terms and in assessing impairment of ROU assets; and 2) to use the practical expedient package, which required no reassessment of whether existing contracts are or contain leases as well as no reassessment of lease classification for existing leases. At the date of adoption, the Company recognized an ROU asset and related lease liability on the Company’s statement of financial condition of $36,178,000 and $38,220,000, respectively. The Company developed new processes to comply with the accounting and disclosure requirements of such amendments and policies and procedures were updated accordingly.

ASU 2017-04 - Intangibles - Goodwill and Other. In January 2017, FASB amended ASC Topic 350 to simplify the measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Instead, under these amendments, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss should not exceed the total amount of goodwill allocated to that reporting unit. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company has goodwill from prior business combinations and performs an annual impairment test or more frequently if changes or circumstances occur that would more-likely-than-not reduce the fair value of the reporting unit below its carrying value. During the third quarter of 2019, the Company performed its impairment assessment and determined the fair value of the aggregated reporting units exceeded the carrying value, such that the Company’s goodwill was not considered impaired. Although the Company cannot anticipate future goodwill impairment assessments, based on the most recent assessment, it is unlikely that an impairment amount would need to be calculated and, therefore, the Company does not anticipate a material impact from these amendments to the Company’s financial position and results of operations. The current accounting policies and processes are not anticipated to change, except for the elimination of the Step 2 analysis. For additional information regarding goodwill impairment testing, see Note 5.

ASU 2016-13 - Financial Instruments - Credit Losses. In June 2016, FASB amended ASC Topic 326 to replace the incurred loss model with a methodology that reflects expected credit losses over the life of the loan and requires consideration of a broader range of reasonable and supportable information to calculate credit loss estimates. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2019. As a result of the adoption of the amendments, the ALLL will be referred to as the allowance for credit losses (“ACL”). The Company has evaluated the impact of these amendments to the Company’s financial position and results of operations and has determined the estimated range of the ACL will be between $125,600,000 and $131,300,000 and the estimated allowance for unfunded commitments will be between $12,800,000 and $13,600,000 upon adoption of the amendments. An adjustment to retained earnings, net of tax, will be required for the difference between such estimated amounts and the balances at December 31, 2019. The estimated impact to retained earnings on the date of adoption is approximately $9,955,000 to $14,808,000. The Company had developed internal implementation controls over the development of the ACL model and resulting financial statement disclosures. As part of the implementation of the amendments, the Company has adjusted its processes and procedures to calculate the ACL, including changes in assumptions and estimates to consider expected credit losses over the life of the loan versus the current accounting practice that utilizes the incurred loss model. The Company has also developed new procedures for determining an allowance for credit losses relating to held-to-maturity debt securities. In addition, the current accounting policy and procedures for other-than-temporary impairment on available-for-sale debt securities were replaced with an allowance approach. The Company engaged a third-party vendor solution and is currently in the final phases of evaluating the solution including model validation, adjusting assumptions utilized, and reviewing the accuracy of the financial statement disclosures. The project team is refining its processes and procedures which will continue during the first quarter of 2020. For additional information on the ALLL, see Note 3.