Columbia Banking System, Inc. (the “Corporation,” “we,” “our,” “Columbia” or the “Company”) is the holding company for Columbia State Bank (“Columbia Bank” or the “Bank”) and Columbia Trust Company (“Columbia Trust”). The Bank provides a full range of financial services through 146 branch locations, including 71 in the State of Washington, 61 in Oregon and 14 in Idaho. Columbia Trust provides fiduciary, agency, trust and related services, and life insurance products. Because the Bank comprises substantially all of the business of the Corporation, references to the “Company” mean the Corporation, the Bank and Columbia Trust together. The Corporation is approved as a bank holding company pursuant to the Gramm-Leach-Bliley Act of 1999.

The Company’s accounting and reporting policies conform to GAAP and practices in the financial services industry. To prepare the financial statements in conformity with GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements, and income and expenses during the reporting period. Circumstances and events that differ significantly from those underlying our estimates and assumptions could cause actual financial results to differ from our estimates. The most significant estimates included in the financial statements relate to the ALLL, business combinations and goodwill impairment.

Securities are classified based on management’s intention on the date of purchase. All securities are classified as available for sale and are presented at fair value. Unrealized gains or losses on securities available for sale are excluded from net income but are included as separate components of other comprehensive income, net of taxes. Purchase premiums or discounts on securities available for sale are amortized or accreted into income using the interest method over the terms of the individual securities. The Company performs a quarterly assessment to determine whether a decline in fair value below amortized cost is other-than-temporary. Amortized cost includes adjustments made to the cost of an investment for accretion, amortization, collection of cash and previous other-than-temporary impairment recognized in earnings. Other-than-temporary impairment exists when it is more likely than not that the Company will be unable to recover the entire amortized cost basis of the security.

In performing the quarterly assessment for debt securities, management considers whether or not the Company expects to recover the entire amortized cost basis of the security. In addition, management also considers whether it is more likely than not that it will not have to sell the security before recovery of its cost basis. If the Company intends to sell a security or it is more likely than not it will be required to sell a security prior to recovery of its cost basis, the entire amount of impairment is recognized in earnings. If the Company does not intend to sell the security or it is not more likely than not it will be required to sell the security prior to recovery of its cost basis, the credit loss component of impairment is recognized in earnings and impairment associated with non-credit factors, such as market liquidity, is recognized in “Other comprehensive income (loss), net of tax.” A credit loss is the difference between the cost basis of the security and the present value of cash flows expected to be collected, discounted at the security’s effective interest rate at the date of acquisition. The cost basis of an other-than-temporarily impaired security is written down by the amount of impairment recognized in earnings. The new cost basis is not adjusted for subsequent recoveries in fair value. However, the difference between the new amortized cost basis and the cash flows expected to be collected is accreted as interest income. The total other-than-temporary impairment, if any, is presented in the Consolidated Statements of Income with a reduction for the amount of other-than-temporary impairment that is recognized in “Other Comprehensive Income,” if any.

The Company holds shares of Class B stock issued by the FHLB, which has been designated as FHLB membership stock or FHLB activity based stock in accordance with the capital plan of the FHLB. Membership stock is stock we are required to purchase and hold as a condition of membership in the FHLB. The Company’s membership stock purchase requirement is measured as a percentage of our year end assets, subject to a $10 million cap. Class B stock may be redeemed, subject to certain limitations, on five years’ written notice to the FHLB. Activity based stock is stock we are required to purchase and hold in order to obtain an advance or participate in FHLB mortgage programs. The Company’s activity based stock purchase requirement is measured as a percentage of our advance proceeds. Our FHLB stock is carried at par value because the shares are issued, transferred, redeemed, and repurchased by the FHLB at a par value of $100. The FHLB stock is subject to recoverability testing per the Financial Services-Depository and Lending topic of the FASB ASC.

Loans, excluding PCI loans, are generally carried at the unpaid principal balance, net of purchase premiums, purchase discounts and net deferred loan fees. Net deferred loan fees include nonrefundable loan origination fees less direct loan origination costs. Net deferred loan fees, purchase premiums and purchase discounts are amortized into interest income using either the interest method or straight-line method over the terms of the loans, adjusted for actual prepayments. The interest method is used for all loans except revolving loans, for which the straight-line method is used. Interest income is accrued as earned. Fees related to lending activities, other than the origination or purchase of loans, are recognized as noninterest income during the period the related services are performed.

Nonaccrual loans—Loans are placed on nonaccrual status when a loan becomes contractually past due 90 days with respect to interest or principal unless the loan is both well secured and in the process of collection, or if full collection of interest or principal becomes uncertain. When a loan is placed on nonaccrual status, any accrued and unpaid interest receivable is reversed and the amortization of net deferred loan fees, premiums and discounts ceases. The interest payments received on nonaccrual loans are generally accounted for on the cost-recovery method whereby the interest payment is applied to the principal balances. Loans may be returned to accrual status when improvements in credit quality eliminate the doubt as to the full collectability of both interest and principal and a period of sustained performance has occurred.

Impaired loans—Loans are considered impaired when based on current information and events, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement or when a loan has been modified in a TDR. The assessment for impairment occurs when and while such loans are designated as classified per the Company’s internal risk rating system or when and while such loans are on nonaccrual. All nonaccrual loans greater than $500,000 and all TDR loans are considered impaired and analyzed individually on a quarterly basis. Classified loans with an outstanding balance greater than $500,000 are evaluated for potential impairment on a quarterly basis.

Restructured Loans—A loan is classified as a TDR when a borrower is experiencing financial difficulties that lead to a restructuring of the loan, and the Company grants concessions to the borrower in the restructuring that it would not otherwise consider. These concessions may include interest rate reductions, principal forgiveness, extension of maturity date and other actions intended to minimize potential losses. Generally, a nonaccrual loan that is restructured remains on nonaccrual status for a period of six months to demonstrate that the borrower can meet the restructured terms. If the borrower’s performance under the new terms is not reasonably assured, the loan remains classified as a nonaccrual loan.

Purchased Credit Impaired Loans—Loans acquired with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are accounted for under ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality. In addition, because of the significant discounts associated with certain of the acquired loan portfolios, the Company elected to account for those certain acquired loans under ASC 310-30.

In situations where such loans have similar risk characteristics, loans are aggregated into pools to estimate cash flows. A pool is accounted for as a single asset with a single interest rate, cumulative loss rate and cash flow expectation. Expected cash flows at the acquisition date in excess of the fair value of loans are considered to be accretable yield, which is recognized as interest income over the life of the loan pool using a level yield method if the timing and amount of the future cash flows of the pool is reasonably estimable. Subsequent to the acquisition date, any increases in cash flow over those expected at purchase date in excess of fair value are recorded as interest income prospectively. Any subsequent decreases in cash flow over those expected at purchase date due to credit deterioration are recognized by recording an ALLL on PCI loans. Any disposals of loans, including sales of loans, payments in full or foreclosures result in the removal of the loan from the loan pool at the carrying amount.

The ALLL is an accounting estimate of incurred credit losses in our loan portfolio at the balance sheet date. The provision for loan and lease losses is the expense recognized in the Consolidated Statements of Income to adjust the allowance to the levels deemed appropriate by management, as measured by the Company’s credit loss estimation methodologies.

Loans Collectively Evaluated for Impairment—This measure of estimated credit losses is based upon the loss experience over a historical base period adjusted for a loss emergence period. The loss emergence period is an estimate of the period that it takes, on average, for us to identify the amount of loss incurred for a loan that has suffered a loss-causing event. Management then considers the effects of the following qualitative factors to ensure our allowance reflects the inherent losses in the loan portfolio:

These qualitative factors have a high degree of subjectivity and changes in any of the factors could have a significant impact on our calculation of the allowance. The qualitative adjustment by loan segment is based upon management's assessment of inherent losses within a range between the weighted historical loss factor by segment and the maximum consecutive quarterly losses in the relevant loss emergence period by segment over the historical base period.

Loans Individually Evaluated for Impairment—This measure of estimated credit losses begins if, based upon current information and events, we believe it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement or when a loan has been modified in a TDR. When a loan has been identified as impaired, the amount of impairment will be measured using discounted cash flows, except when it is determined that the remaining source of repayment for the loan is the operation or liquidation of the underlying collateral. In these cases, the current fair value of the collateral, reduced by costs to sell, will be used in place of discounted cash flows. As a final alternative, the observable market price of the loan may be used to assess impairment. The Company predominately uses the fair value of collateral approach based upon a reliable valuation. When the measurement of the impaired loan is less than the recorded amount of the loan, an impairment is recognized by recording a charge-off to the allowance or by designating a specific reserve.

Purchased Credit Impaired Loans—The Company updates its cash flow projections for PCI loans accounted for under ASC 310-30 on a quarterly basis. Assumptions utilized in this process include projections related to probability of default, loss severity, prepayment and recovery lag. Projections related to probability of default and prepayment are calculated utilizing a loan migration analysis. The loan migration analysis is a matrix of probability that is used to estimate the probability of a loan pool transitioning into a particular delinquency state given its delinquency state at the re-measurement date. Loss severity factors are based upon either actual charge-off data within the loan pools or industry averages, and recovery lags are based upon the collateral within the loan pools.

Unfunded Commitments and Letters of Credit—The allowance for unfunded commitments is maintained at a level believed by management to be sufficient to absorb estimated probable losses related to these unfunded credit facilities. The determination of the adequacy of the allowance is based on periodic evaluations of the unfunded credit facilities including an assessment of the probability of commitment usage, credit risk factors for loans outstanding to these same customers, and the terms and expiration dates of the unfunded credit facilities. The allowance for unfunded commitments is included in “Other liabilities” on the Consolidated Balance Sheets, with changes to the balance charged against noninterest expense.

In accordance with ASU 2016-13, the Company was required to adopt ASC 326 as of January 1, 2020. The allowance for credit losses under ASC 326 is an accounting estimate of expected losses over the contractual life of assets carried at amortized cost within the Company’s loan portfolio at the balance sheet date. The ASU requires a financial asset (or group of financial assets) measured at amortized cost to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset to present the net carrying value at the amount expected to be collected on the financial asset.

The quantitative allowance is calculated using a discounted cash flow approach with a probability of default methodology. The probability of default is an assumption derived from regression models which determines the relationship between historical defaults and certain economic variables. The Company determines a reasonable and supportable forecast and applies that forecast to the model to determine defaults over the forecast period. Following the forecast period, the economic variables used to calculate the probability of default revert to a historical average. Other assumptions relevant to the discounted cash flow model to derive the quantitative allowance include the loss given default, which is the estimate of loss for a defaulted loan, and the discount rate applied to future cash flows. The model calculates the net present value of each loan using both the contractual and expected cash flows, respectively.

Land, buildings, leasehold improvements and equipment are stated at cost less accumulated depreciation and amortization. Gains or losses on dispositions are reflected in current operations. Expenditures for improvements and major renewals are capitalized, and ordinary maintenance, repairs and small purchases are charged to “Occupancy” expense in the Consolidated Statements of Income. Depreciation and amortization are computed based on the straight-line method over the estimated useful lives of the various classes of assets. The ranges of useful lives for the principal classes of assets are as follows:

Implementation costs incurred in a hosting arrangement that is a service contract are capitalized based on criteria in ASC 350-40. The capitalized costs are expensed over the term of the hosting arrangement. Capitalized implementation costs in a cloud computing arrangement are included in “Other assets” in the Consolidated Balance Sheets.

OREO is composed of real estate acquired by the Company through either foreclosure or deed in lieu of foreclosure in satisfaction of debt. At acquisition, OREO is recorded at fair value less estimated costs to sell. Any fair value adjustments at acquisition are charged to the allowance, or in the event of a write-up without previous losses charged to the allowance, a credit to earnings is recorded. The fair value of the OREO is based upon a current appraisal or a letter of intent to purchase. Losses that result from the ongoing periodic valuation of these properties are charged to the net cost of operation of OREO in the period in which they are identified. Improvements to OREO are capitalized and holding costs are charged to the net cost of operation of OREO as incurred.

Net assets of companies acquired in a business combination are recorded at fair value at the date of acquisition. Any excess of the purchase price over the fair value of net assets acquired, including identified intangible assets, is recognized as goodwill. Goodwill is reviewed for potential impairment annually, during the third quarter, or, more frequently, if events or circumstances indicate a potential impairment, at the reporting unit level. A reporting unit is an operating segment or one level below an operating segment for which discrete financial information is available and regularly reviewed by management. The Company consists of a single reporting unit. If the fair value of the reporting unit, including goodwill, is determined to be less than the carrying amount of the reporting unit, a further test is required to measure the amount of impairment. If an impairment loss exists, the carrying amount of goodwill is adjusted to a new cost basis. Subsequent reversal of a previously recognized goodwill impairment loss is prohibited.

Identified intangible assets are amortized on an accelerated basis over the period benefited. Intangible assets are also evaluated for impairment if events and circumstances indicate a possible impairment. Such evaluation is based on undiscounted cash flow projections. At December 31, 2019, intangible assets included in the Consolidated Balance Sheets principally consisted of CDI with an original estimated life of 10 years.

The Company determines if a lease is present at the inception of an agreement. Operating leases are capitalized at commencement and are discounted using the Company’s FHLB borrowing rate for a similar term borrowing unless the lease defines an implicit rate within the contract. Leases with original terms of less than 12 months are not capitalized. For operating leases existing prior to January 1, 2019, the rate for the remaining lease term as of January 1, 2019 was used. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. Operating lease right-of-use assets and operating lease liabilities are recognized on the lease commencement date based on the present value of lease payments over the lease term. The lease term includes options to extend or terminate the lease if the Company is reasonably certain that an option will be exercised. Operating leases are included within “Other assets” in the Consolidated Balance Sheets. See Note 10, “Leases” for additional information on leases.

The provision for income taxes includes current and deferred income tax expense on net income adjusted for temporary and permanent differences such as interest income from state and municipal securities and investments in affordable housing tax credits. Deferred tax assets and liabilities are recognized for the expected future tax consequences of existing temporary differences between the financial reporting and tax reporting basis of assets and liabilities using enacted tax laws and rates. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. On a quarterly basis, management evaluates deferred tax assets to determine if these tax benefits are expected to be realized in future periods. This determination is based on facts and circumstances, including the Company’s current and future tax outlook. To the extent a deferred tax asset is no longer considered “more likely than not” to be realized, a valuation allowance is established.

We recognize the tax benefit from uncertain tax positions only if it is more likely than not that the tax positions will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefit is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. We recognize interest and penalties related to unrecognized tax benefits in “Provision for income taxes” in the Consolidated Statements of Income.

The Company’s capital structure includes common shares, restricted common share awards, common share options, and, during a portion of 2017, convertible preferred shares. Restricted common share awards participate in dividends declared on common shares at the same rate as common shares. Convertible preferred shares participated in dividends declared on common shares on an “as if converted” basis. Restricted common share awards and convertible preferred shares are considered participating securities under the EPS topic of the FASB ASC.

The Company calculates EPS using the two-class method. The two-class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common shareholders but does not require the presentation of basic and diluted EPS for securities other than common shares. Under the two-class method, basic EPS is computed by dividing earnings allocated to common shareholders by the weighted average number of common shares outstanding for the period. Earnings allocated to common shareholders represents net income reduced by earnings allocated to participating securities. Diluted EPS is computed in the same manner as basic EPS except that the denominator is increased to include the number of additional common shares that would have been outstanding if certain shares issuable upon exercise of common share options were included unless those additional shares would have been anti-dilutive. For the diluted EPS computation, the treasury stock method is applied and compared to the two-class method and whichever method results in a more dilutive impact is utilized to calculate diluted EPS.

The Company accounts for stock options and stock awards in accordance with the Compensation—Stock Compensation topic of the FASB ASC. Authoritative guidance requires the Company to measure the cost of employee services received in exchange for an award of equity instruments, such as stock options or stock awards, based on the fair value of the award on the grant date. This cost must be recognized in the Consolidated Statements of Income over the vesting period of the award.

The Company issues restricted common share awards which generally vest over a four-year period and have full voting rights. Pursuant to our new equity incentive plan approved in 2018, for any awards issued under the new plan, the holder accrues dividends, which are paid out when the shares vest. For any awards granted prior to the new plan, the holder receives dividends whether or not the shares have vested. Restricted stock is valued at the closing price of the Company’s stock on the date of an award.

In accordance with the Derivatives and Hedging topic of the FASB ASC, the Company recognizes derivatives as assets or liabilities on the Consolidated Balance Sheets at their fair value. The Company periodically enters into interest rate contracts with customers and offsetting contracts with third parties. As these interest rate contracts are not designated as hedges under the Derivatives and Hedging topic of the FASB ASC, the changes in fair value of these instruments are recognized immediately in earnings.

As part of the Company’s overall interest rate risk management, the Company uses an interest rate collar with a notional amount of $500.0 million to mitigate interest rate risk. This collar is designated and qualifies as a cash flow hedge. Gains and losses are recorded in accumulated other comprehensive income to the extent the hedge is effective. Gains and losses are reclassified from accumulated other comprehensive income to earnings in the period the hedged transaction affects earnings and are included in the same income statement line item that the hedged transaction is recorded.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The amendments included in this ASU create a new accounting model for both lessees and lessors. The new guidance requires lessees to recognize lease liabilities, initially measured at the present value of future lease payments, and corresponding right-of-use assets for all leases with lease terms greater than 12 months. The new lease model differs from the old lease accounting model, as the old model does not require such lease liabilities and corresponding right-of-use assets to be recorded for operating leases. The amendments in ASU 2016-02 must be adopted using the modified retrospective approach and will be effective for the first interim or annual period beginning after December 15, 2018. The FASB subsequently issued ASU 2018-11, which allows for an additional (optional) transition method. The Company adopted the new standard effective January 1, 2019 utilizing the transition method allowed under ASU 2018-11 and did not restate comparative periods. The Company elected the package of practical expedients permitted under the transition guidance, which allowed us to carryforward our historical lease classifications and our assessment on whether a contract is or contains a lease. We also elected to keep leases with an initial term of 12 months or less off the balance sheet. The adoption of the new standard resulted in an increase in other assets and an increase in other liabilities of $49.2 million and $48.2 million, respectively. The Company recognized a cumulative effect adjustment of $782 thousand to increase the beginning balance of retained earnings related to previous deferred gains on sale-leaseback transactions.

In August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract. The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The amendments also require the entity to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement, including reasonably certain renewal periods. The amendments in ASU 2018-15 are effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. Early adoption is permitted, including adoption in any interim period. The amendments can be adopted on a prospective or retrospective basis. The Company adopted the new standard effective July 1, 2019 on a prospective basis. The adoption of the new standard resulted in an increase in other assets of $1.5 million.

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes. The guidance issued in this update simplifies the accounting for income taxes by eliminating certain exceptions to the guidance in ASC 740 related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition for deferred tax liabilities for outside basis differences. This ASU also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. The ASU is effective for interim and annual reporting periods beginning after December 15, 2020; early adoption is permitted. The adoption of this ASU is not expected to have a material impact on the Company’s consolidated financial statements.

In April 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments. The amendments in this ASU clarify certain aspects of accounting for credit losses, hedging activities, and financial instruments (addressed by ASUs 2016-01, 2016-13, and 2017-12). Many of the amendments reflect decisions reached at FASB meetings or meetings of the Board’s credit losses transition resource group. Topics covered in this ASU include: accrued interest, transfers between classifications or categories for loans and debt securities, recoveries, reinsurance recoverables, projections of interest rate environments for variable-rate financial instruments, costs to sell when foreclosure is probable, consideration of expected prepayments when determining the effective interest rate, vintage disclosures, extension and renewal options, etc.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments. The amendments included in this ASU require an entity to reflect its current estimate of all expected credit losses for assets held at an amortized cost basis. For available for sale debt securities, credit losses will be measured in a manner similar to current GAAP, however, this ASU requires that credit losses be presented as an allowance rather than as a write-down. In November 2019, the FASB subsequently issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments - Credit Losses. The amendments in the Update require entities to include expected recoveries of the amortized cost basis previously written-off or expected to be written-off in the valuation account for purchased financial assets with credit deterioration. In addition, the amendments in this Update clarify and improve various aspects of the guidance for ASU 2016-13.

Unlike the incurred loss models, the CECL model in ASU 2016-13 does not specify a threshold for the recognition of an impairment allowance. Rather, the Company recognizes an impairment allowance equal to its estimate of lifetime expected credit losses, adjusted for prepayments, for in-scope financial instruments. Accordingly, the impairment allowance measured under the CECL model may change significantly from the impairment allowance measured under the Company’s incurred loss model. The Company engaged a third-party vendor to assist in the CECL calculation and has developed and implemented an internal governance framework. The amendments in ASU 2016-13 and the above ASUs related to Credit Losses are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption was permitted, including adoption in any interim period. The Company adopted the new standards, using a modified retrospective approach, effective January 1, 2020, which resulted in an increase of $1.6 million to its allowance for credit losses, an increase of $1.6 million to its allowance for unfunded commitments and letters of credit and a net-of-tax cumulative-effect adjustment of $2.5 million to decrease the beginning balance of retained earnings.

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. This ASU adds, eliminates and modifies certain disclosure requirements for fair value measurements. Among the changes, entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The ASU is effective for interim and annual reporting periods beginning after December 15, 2019; early adoption is permitted. Entities are also allowed to elect early adoption of the eliminated or modified disclosure requirements and delay adoption of the added disclosure requirements until their effective date. The Company adopted the new standard effective January 1, 2020. As the ASU only revised disclosure requirements, adoption of this ASU did not have a material impact on the Company’s consolidated financial statements.