Accounting Policies	9 Months Ended
Sep. 30, 2018
Accounting Policies [Abstract]
Accounting Policies	ACCOUNTING POLICIES In the opinion of the management of Arrow Financial Corporation (Arrow, the Company, we, or us), the accompanying unaudited interim consolidated financial statements contain all of the adjustments necessary to present fairly the financial position as of September 30, 2018, December 31, 2017 and September 30, 2017; the results of operations for the three- and nine-month periods ended September 30, 2018 and 2017; the consolidated statements of comprehensive income for the three- and nine-month periods ended September 30, 2018 and 2017; the changes in stockholders' equity for the nine-month periods ended September 30, 2018 and 2017; and the cash flows for the nine-month periods ended September 30, 2018 and 2017. All such adjustments are of a normal recurring nature. Management’s Use of Estimates -The preparation of the consolidated financial statements in conformity with accounting principles generally accepted in the United States of America 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 consolidated financial statements and the reported amounts of income and expenses during the reporting period. Our most significant estimate is the allowance for loan losses. Other estimates include the evaluation of other-than-temporary impairment of investment securities, goodwill impairment, pension and other postretirement liabilities and an analysis of a need for a valuation allowance for deferred tax assets. Actual results could differ from those estimates. A material estimate that is particularly susceptible to significant change in the near term is the allowance for loan losses. In connection with the determination of the allowance for loan losses, management obtains appraisals for properties. The allowance for loan losses is management’s best estimate of probable loan losses incurred as of the balance sheet date. While management uses available information to recognize losses on loans, future adjustments to the allowance for loan losses may be necessary based on changes in economic conditions. The unaudited interim consolidated financial statements should be read in conjunction with the audited annual consolidated financial statements of Arrow for the year ended December 31, 2017, included in Arrow's Annual Report on Form 10-K for the year ended December 31, 2017. Recently Adopted and Recently Issued Accounting Standards The following accounting standards have been adopted in the first nine months of 2018: ASU 2014-09 "Revenue from Contracts With Customers" (Topic 606) was adopted as of January 1, 2018. For additional information, see Revenue Recognition under Significant Accounting Policy Update in this Note. ASU 2016-01 "Recognition and Measurement of Financial Assets and Financial Liabilities" (Subtopic 825-10) significantly changed the income statement impact of equity investments. For Arrow, the standard became effective for the first quarter of 2018, and requires that equity investments be measured at fair value, with changes in fair value recognized in net income. The cumulative effect of the January 1, 2018 adoption was an increase to retained earnings of $331 thousand with a corresponding decrease to Accumulated Other Comprehensive Loss. For periods prior to January 1, 2018, equity securities were classified as available-for-sale and stated at fair value with unrealized gains and losses reported as a separate component of accumulated other comprehensive income, net of tax. ASU 2016-01 also emphasized the existing requirement to use exit prices to measure fair value for disclosure purposes and clarifies that entities not make use of a practicability exception in determining the fair value of loans. Accordingly, the Company refined the calculation used to determine the disclosed fair value of its loans as part of adopting this standard. See Note 9 to the unaudited interim consolidated financial statements titled Fair Value of Financial Instruments. ASU 2016-15 "Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments" (Topic 230) will reduce existing diversity in practice with respect to eight specific cash flow issues. Arrow adopted this ASU in the first quarter of 2018. ASU 2017-01 "Business Combinations" (Topic 805) defines when a set of assets and activities constitutes a business for the purposes of determining whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The amendments in this update allow for a business to consist of inputs, processes, and the ability to create output. For Arrow, the standard became effective in the first quarter of 2018. This update had no effect on its accounting for acquisitions and dispositions of businesses. ASU 2017-07 "Compensation-Retirement Benefits" (Topic 715) improves the presentation of net periodic pension cost and net periodic post-retirement benefit cost by requiring that an employer disaggregate the service cost component from the other components of net benefit cost. For Arrow, the standard became effective in the first quarter of 2018. In accordance with the practical expedient adoption method, for all periods presented Arrow used the amounts disclosed in the retirement plans footnote for the prior period retrospective reclassification of the non-service cost components from salaries and benefits to other operating expenses. The adoption of this change in accounting for pension costs did not have a material impact on its financial position or the results of operations. ASU 2017-09 "Compensation-Stock Compensation" (Topic 718) provides guidance about which changes to the terms and conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The guidance highlights the requirements for applying modification accounting and the exception criteria relating to changes in share-based payment terms. For Arrow, the standard became effective in the first quarter of 2018. The adoption of this change in accounting for share-based payment awards did not have a material impact on its financial position or the results of operations in periods subsequent to its adoption. The following accounting standards have been issued and will become effective for the Company at a future date: In February 2016, the FASB issued ASU 2016-02, "Leases" (Topic 842) which requires lessees to recognize right-of-use assets and lease liabilities on the balance sheet for all leases with terms longer than 12 months. For a lease with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize a right-of-use asset and lease liability. Additionally, when measuring assets and liabilities arising from a lease, optional payments should be included only if the lessee is reasonably certain to exercise an option to extend the lease, exercise a purchase option or not exercise an option to terminate the lease. In January 2018, the FASB issued ASU 2018-01, Leases (Topic 842): "Land Easement Practical Expedient for Transition to Topic 842". In July 2018, the FASB issued ASU 2018-10 "Codification Improvements to Topic 842, Leases" which provided clarification on certain components of the original guidance, including that the rate implicit in the lease cannot be less than zero. Also in July 2018, the FASB issued ASU 2018-11 "Targeted Improvements" to Leases (Topic 842) which amends the original guidance to allow for the adoption of this standard to be applied retrospectively at the beginning of the period of adoption, which will be January 1, 2019 for Arrow, through a cumulative-effect adjustment to the balance sheet, including retained earnings, as of January 1, 2019. Practical expedients may be elected that would not require Arrow to reassess whether an existing contract contains a lease, to reassess existing leases between operating leases and finance leases and to not reassess initial direct costs for any existing leases. If elected, these practical expedients must be applied together. An entity may also elect a practical expedient, which must be applied consistently to all of its leases, to use hindsight in determining the lease term when considering lessee options to extend or terminate the lease and in assessing impairment in the right-of-use asset. In addition, a lessor may make an accounting policy election, by class of underlying asset, to not separate nonlease components from lease components and account for these components as a single lease component. Early adoption of this standard is permitted in any interim or annual period. The Company expects to adopt the new lease standard on January 1, 2019 through a cumulative-effect adjustment without revising prior comparative periods, and elect the practical expedients available to effectively account for leases commenced prior to the effective date. The Company expects assets and liabilities to increase between $7 million and $9 million at the January 1, 2019 adoption date, with no material impact to operating lease expense in its Consolidated Statements of Income. In June 2016, the FASB issued ASU 2016-13 "Financial Instruments - Credit Losses" (Topic 326) which will change the way financial entities measure expected credit losses for financial assets, primarily loans. Under this ASU, the "incurred loss" model will be replaced with an "expected loss" model which will recognize losses over the life of the instrument and requires consideration of a broader range of reasonable and supportable information. Currently, credit losses on available-for-sale securities reduce the carrying value of the instrument and cannot be reversed. Under this ASU, the amount of the credit loss is carried as a valuation allowance and can be reversed. The standard also requires expanded credit quality disclosures. For Arrow, the standard is effective for the first quarter of 2020 and early adoption is allowed in 2019. The Company plans on adopting the standard in the first quarter of 2020, in order to maximize the accumulation of data needed to calculate the new current expected credit loss ("CECL") methodologies. The ASU describes several acceptable methodologies for calculating expected losses on a loan or a pool of loans and requires additional disclosures. The initial adjustment will not be reported in earnings, but as the cumulative effect of a change in accounting principle. The FASB’s Transition Research Group for credit losses still has several outstanding unresolved questions, some of which may have a significant impact on CECL calculations. The Company continues its implementation efforts with the development and testing of various methods within its core model, developing forecast scenarios, monitoring of guidance interpretations and consideration of relevant internal controls and processes. This will likely have the effect of increasing the allowance for loan and lease losses and reducing shareholders' equity, the extent of which will depend upon the nature and characteristics of the Company's loan portfolio and economic conditions and forecasts at the adoption date. The Company expects to remain a well-capitalized financial institution under current regulatory calculations. In January 2017, the FASB issued ASU 2017-04 "Intangibles-Goodwill and Other" (Topic 350) which simplifies the procedures for evaluating impairment of goodwill. Prior to the adoption of this standard, entities were required to perform procedures to determine the fair value of the underlying assets and liabilities for determining the fair value of assets and liabilities in a business combination. This additional step to impairment testing has been eliminated. Under this ASU, entities will perform goodwill impairment testing by comparing the fair value of a reporting unit to its carrying value. For Arrow, the standard becomes effective in the first quarter of 2019, however, early adoption is permitted. This amendment will not affect the assessment of goodwill impairment since the Company currently performs the analysis of comparing carrying value to fair value of its reporting units that have goodwill and the Company has not had to perform a Step 2 Impairment Test to date. In March 2017, the FASB issued ASU 2017-08 "Receivables-Nonrefundable Fees and Other Costs" which amends the amortization period for certain purchased callable debt securities held at a premium. This shortens the amortization period for the premium to the earliest call date. Under GAAP, entities generally amortize the premium as an adjustment of yield over the contractual life of the instrument. For Arrow, the standard becomes effective in the first quarter of 2019. The Company does not expect that the adoption of this change in accounting for certain callable debt securities will have a material impact on its financial position or the results of operations in periods subsequent to its adoption. In August 2018, the FASB issued ASU 2018-13 "Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement" which as part of its disclosure framework, the FASB has eliminated, amended and added disclosure requirements for fair value measurements. The following disclosure requirements were eliminated: Amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; the policy of the timing of transfers between levels of the fair value hierarchy; the valuation processes for Level 3 fair value measurements. For public companies such as Arrow, the following new disclosures will be required: Changes in unrealized gains and losses for the period included in other comprehensive income (OCI); the range and weighted average of significant unobservable inputs used; alternatively, a company may choose to disclose other quantitative information if it determines that it is a more reasonable and rational method that reflects the distribution of unobservable inputs used. For Arrow, the standard becomes effective in the first quarter of 2020. The Company does not expect that the adoption of this change in fair value disclosure will have a material impact on its financial position or the results of operations in periods subsequent to its adoption. In August 2018, the FASB issued ASU 2018-14 "Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans" which applies to all companies that provide defined benefit pension or other postretirement benefit plans for their employees. Certain disclosure requirements have been eliminated such as reporting the amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next year, and reporting the effects of a one-percentage-point change in the assumed healthcare cost trend rate on the aggregate of the service cost and interest cost components of net periodic benefit cost and on the benefit obligation for postretirement healthcare benefits. New required disclosures for reporting the weighted-average interest rate used to credit cash balance and similar plans that have a promised interest credit, the reasons for significant gains and losses affecting benefit obligations and other requirements for reporting aggregate information related to pension plans. For Arrow, the standard becomes effective at December 31, 2020. The Company does not expect that the adoption of this change affecting defined benefit plan disclosures will have a material impact on its financial position or the results of operations. In August 2018, the FASB issued ASU 2018-15 "Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract" which will require companies to defer potentially significant, specified implementation costs incurred in a cloud computing arrangement that are often expensed under current US GAAP. For Arrow, the standard becomes effective at January 1, 2020. The Company is in the process of assessing the impact of this new accounting standard on its financial position and the results of operations in periods subsequent to its adoption. Significant Accounting Policy Update: Revenue Recognition - Accounting Standard Codification ("ASC") Topic 606, "Revenue from Contracts with Customers," establishes principles for reporting information about the nature, amount, timing and uncertainty of revenue and cash flows arising from the entity's contracts to provide goods or services to customers. The core principle of Topic 606 requires an entity to recognize revenue in a way that depicts the transfer of goods or services promised to a customer in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services as performance obligations are satisfied. The Company adopted Topic 606 as of January 1, 2018 using the modified retrospective approach. The Company has determined that revenue from specific types of fiduciary activities and insurance commissions are within the scope of this guidance. Under prior GAAP, revenue from fiduciary activities was recognized from settling client estates over the time period the work was performed. With the adoption of Topic 606, revenue is now recognized when the performance obligation is completed, which is when the settlement of the client estate is closed. The impact of this change in revenue recognition was not material to the Company's consolidated financial statements. Under prior GAAP when clients elected to pay premiums on property and casualty insurance policies in installments, revenue was recognized when the premiums were billed. With the adoption of Topic 606, this type of revenue is recognized when the performance obligation is substantially completed, i.e., when the insurance policy is issued. The impact of this change in revenue recognition was not material to the Company's consolidated financial statements. The cumulative effect of the adoption of Topic 606 related to the previously described fiduciary activities and insurance commissions was a decrease in retained earnings by $102 thousand as of January 1, 2018. The majority of the Company's revenue-generating transactions are not subject to ASC Topic 606, including revenue generated from financial instruments, such as loans and investment securities which are presented in its consolidated income statements as components of net interest income. The following is a description of principal activities from which the Company generates its revenue from noninterest income sources that are within the scope of ASC Topic 606: Income from Fiduciary Activities: represents revenue derived mainly through the management of client investments which is based on the market value of the covered assets and the fee schedule contained in the applicable account management agreement. Since the revenue is mainly based on the market value of assets, this amount can be volatile as financial markets increase and decrease based on various economic factors. The terms of the account management agreements generally specify that the performance obligations are completed each quarter. Accordingly, the Company mainly recognizes revenue from fiduciary activities on a quarterly basis. Fees for Other Services to Customers: represents general service fees for monthly deposit account maintenance and account activity plus fees from other deposit-based services. Revenue is recognized when the performance obligation is completed, which is generally on a monthly basis for account maintenance services, or upon the completion of a deposit-related transaction. Payment for these performance obligations is generally received at the time the performance obligations are satisfied. Insurance Commissions: represents commissions and fees paid by insurance carriers for both property and casualty insurance policies, and for services performed for employment benefits clients. Revenue from the property and casualty insurance business is recognized when the performance obligation is satisfied, which is generally the effective date of the bound coverage since there are no significant performance obligations remaining. Revenue from the employment benefit brokerage business is recognized when the benefit servicing performance obligations are satisfied, generally on a monthly basis.

ACCOUNTING POLICIES

In the opinion of the management of Arrow Financial Corporation (Arrow, the Company, we, or us), the accompanying unaudited interim consolidated financial statements contain all of the adjustments necessary to present fairly the financial position as of September 30, 2018, December 31, 2017 and September 30, 2017; the results of operations for the three- and nine-month periods ended September 30, 2018 and 2017; the consolidated statements of comprehensive income for the three- and nine-month periods ended September 30, 2018 and 2017; the changes in stockholders' equity for the nine-month periods ended September 30, 2018 and 2017; and the cash flows for the nine-month periods ended September 30, 2018 and 2017. All such adjustments are of a normal recurring nature.

Management’s Use of Estimates -The preparation of the consolidated financial statements in conformity with accounting principles generally accepted in the United States of America 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 consolidated financial statements and the reported amounts of income and expenses during the reporting period. Our most significant estimate is the allowance for loan losses. Other estimates include the evaluation of other-than-temporary impairment of investment securities, goodwill impairment, pension and other postretirement liabilities and an analysis of a need for a valuation allowance for deferred tax assets. Actual results could differ from those estimates.

A material estimate that is particularly susceptible to significant change in the near term is the allowance for loan losses. In connection with the determination of the allowance for loan losses, management obtains appraisals for properties. The allowance for loan losses is management’s best estimate of probable loan losses incurred as of the balance sheet date. While management uses available information to recognize losses on loans, future adjustments to the allowance for loan losses may be necessary based on changes in economic conditions.

The unaudited interim consolidated financial statements should be read in conjunction with the audited annual consolidated financial statements of Arrow for the year ended December 31, 2017, included in Arrow's Annual Report on Form 10-K for the year ended December 31, 2017.

Recently Adopted and Recently Issued Accounting Standards

The following accounting standards have been adopted in the first nine months of 2018:

ASU 2014-09 "Revenue from Contracts With Customers" (Topic 606) was adopted as of January 1, 2018. For additional information, see Revenue Recognition under Significant Accounting Policy Update in this Note.

ASU 2016-01 "Recognition and Measurement of Financial Assets and Financial Liabilities" (Subtopic 825-10) significantly changed the income statement impact of equity investments. For Arrow, the standard became effective for the first quarter of 2018, and requires that equity investments be measured at fair value, with changes in fair value recognized in net income. The cumulative effect of the January 1, 2018 adoption was an increase to retained earnings of $331 thousand with a corresponding decrease to Accumulated Other Comprehensive Loss. For periods prior to January 1, 2018, equity securities were classified as available-for-sale and stated at fair value with unrealized gains and losses reported as a separate component of accumulated other comprehensive income, net of tax. ASU 2016-01 also emphasized the existing requirement to use exit prices to measure fair value for disclosure purposes and clarifies that entities not make use of a practicability exception in determining the fair value of loans. Accordingly, the Company refined the calculation used to determine the disclosed fair value of its loans as part of adopting this standard. See Note 9 to the unaudited interim consolidated financial statements titled Fair Value of Financial Instruments.

ASU 2016-15 "Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments" (Topic 230) will reduce existing diversity in practice with respect to eight specific cash flow issues. Arrow adopted this ASU in the first quarter of 2018.

ASU 2017-01 "Business Combinations" (Topic 805) defines when a set of assets and activities constitutes a business for the purposes of determining whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The amendments in this update allow for a business to consist of inputs, processes, and the ability to create output. For Arrow, the standard became effective in the first quarter of 2018. This update had no effect on its accounting for acquisitions and dispositions of businesses.

ASU 2017-07 "Compensation-Retirement Benefits" (Topic 715) improves the presentation of net periodic pension cost and net periodic post-retirement benefit cost by requiring that an employer disaggregate the service cost component from the other components of net benefit cost. For Arrow, the standard became effective in the first quarter of 2018. In accordance with the practical expedient adoption method, for all periods presented Arrow used the amounts disclosed in the retirement plans footnote for the prior period retrospective reclassification of the non-service cost components from salaries and benefits to other operating expenses. The adoption of this change in accounting for pension costs did not have a material impact on its financial position or the results of operations.

ASU 2017-09 "Compensation-Stock Compensation" (Topic 718) provides guidance about which changes to the terms and conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The guidance highlights the requirements for applying modification accounting and the exception criteria relating to changes in share-based payment terms. For Arrow, the standard became effective in the first quarter of 2018. The adoption of this change in accounting for share-based payment awards did not have a material impact on its financial position or the results of operations in periods subsequent to its adoption.

The following accounting standards have been issued and will become effective for the Company at a future date:

In February 2016, the FASB issued ASU 2016-02, "Leases" (Topic 842) which requires lessees to recognize right-of-use assets and lease liabilities on the balance sheet for all leases with terms longer than 12 months. For a lease with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize a right-of-use asset and lease liability. Additionally, when measuring assets and liabilities arising from a lease, optional payments should be included only if the lessee is reasonably certain to exercise an option to extend the lease, exercise a purchase option or not exercise an option to terminate the lease. In January 2018, the FASB issued ASU 2018-01, Leases (Topic 842): "Land Easement Practical Expedient for Transition to Topic 842". In July 2018, the FASB issued ASU 2018-10 "Codification Improvements to Topic 842, Leases" which provided clarification on certain components of the original guidance, including that the rate implicit in the lease cannot be less than zero. Also in July 2018, the FASB issued ASU 2018-11 "Targeted Improvements" to Leases (Topic 842) which amends the original guidance to allow for the adoption of this standard to be applied retrospectively at the beginning of the period of adoption, which will be January 1, 2019 for Arrow, through a cumulative-effect adjustment to the balance sheet, including retained earnings, as of January 1, 2019. Practical expedients may be elected that would not require Arrow to reassess whether an existing contract contains a lease, to reassess existing leases between operating leases and finance leases and to not reassess initial direct costs for any existing leases. If elected, these practical expedients must be applied together. An entity may also elect a practical expedient, which must be applied consistently to all of its leases, to use hindsight in determining the lease term when considering lessee options to extend or terminate the lease and in assessing impairment in the right-of-use asset. In addition, a lessor may make an accounting policy election, by class of underlying asset, to not separate nonlease components from lease components and account for these components as a single lease component. Early adoption of this standard is permitted in any interim or annual period. The Company expects to adopt the new lease standard on January 1, 2019 through a cumulative-effect adjustment without revising prior comparative periods, and elect the practical expedients available to effectively account for leases commenced prior to the effective date. The Company expects assets and liabilities to increase between $7 million and $9 million at the January 1, 2019 adoption date, with no material impact to operating lease expense in its Consolidated Statements of Income.

In June 2016, the FASB issued ASU 2016-13 "Financial Instruments - Credit Losses" (Topic 326) which will change the way financial entities measure expected credit losses for financial assets, primarily loans. Under this ASU, the "incurred loss" model will be replaced with an "expected loss" model which will recognize losses over the life of the instrument and requires consideration of a broader range of reasonable and supportable information. Currently, credit losses on available-for-sale securities reduce the carrying value of the instrument and cannot be reversed. Under this ASU, the amount of the credit loss is carried as a valuation allowance and can be reversed. The standard also requires expanded credit quality disclosures. For Arrow, the standard is effective for the first quarter of 2020 and early adoption is allowed in 2019. The Company plans on adopting the standard in the first quarter of 2020, in order to maximize the accumulation of data needed to calculate the new current expected credit loss ("CECL") methodologies. The ASU describes several acceptable methodologies for calculating expected losses on a loan or a pool of loans and requires additional disclosures. The initial adjustment will not be reported in earnings, but as the cumulative effect of a change in accounting principle. The FASB’s Transition Research Group for credit losses still has several outstanding unresolved questions, some of which may have a significant impact on CECL calculations. The Company continues its implementation efforts with the development and testing of various methods within its core model, developing forecast scenarios, monitoring of guidance interpretations and consideration of relevant internal controls and processes. This will likely have the effect of increasing the allowance for loan and lease losses and reducing shareholders' equity, the extent of which will depend upon the nature and characteristics of the Company's loan portfolio and economic conditions and forecasts at the adoption date. The Company expects to remain a well-capitalized financial institution under current regulatory calculations.

In January 2017, the FASB issued ASU 2017-04 "Intangibles-Goodwill and Other" (Topic 350) which simplifies the procedures for evaluating impairment of goodwill. Prior to the adoption of this standard, entities were required to perform procedures to determine the fair value of the underlying assets and liabilities for determining the fair value of assets and liabilities in a business combination. This additional step to impairment testing has been eliminated. Under this ASU, entities will perform goodwill impairment testing by comparing the fair value of a reporting unit to its carrying value. For Arrow, the standard becomes effective in the first quarter of 2019, however, early adoption is permitted. This amendment will not affect the assessment of goodwill impairment since the Company currently performs the analysis of comparing carrying value to fair value of its reporting units that have goodwill and the Company has not had to perform a Step 2 Impairment Test to date.

In March 2017, the FASB issued ASU 2017-08 "Receivables-Nonrefundable Fees and Other Costs" which amends the amortization period for certain purchased callable debt securities held at a premium. This shortens the amortization period for the premium to the earliest call date. Under GAAP, entities generally amortize the premium as an adjustment of yield over the contractual life of the instrument. For Arrow, the standard becomes effective in the first quarter of 2019. The Company does not expect that the adoption of this change in accounting for certain callable debt securities will have a material impact on its financial position or the results of operations in periods subsequent to its adoption.

In August 2018, the FASB issued ASU 2018-13 "Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement" which as part of its disclosure framework, the FASB has eliminated, amended and added disclosure requirements for fair value measurements. The following disclosure requirements were eliminated: Amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; the policy of the timing of transfers between levels of the fair value hierarchy; the valuation processes for Level 3 fair value measurements. For public companies such as Arrow, the following new disclosures will be required: Changes in unrealized gains and losses for the period included in other comprehensive income (OCI); the range and weighted average of significant unobservable inputs used; alternatively, a company may choose to disclose other quantitative information if it determines that it is a more reasonable and rational method that reflects the distribution of unobservable inputs used. For Arrow, the standard becomes effective in the first quarter of 2020. The Company does not expect that the adoption of this change in fair value disclosure will have a material impact on its financial position or the results of operations in periods subsequent to its adoption.

In August 2018, the FASB issued ASU 2018-14 "Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans" which applies to all companies that provide defined benefit pension or other postretirement benefit plans for their employees. Certain disclosure requirements have been eliminated such as reporting the amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next year, and reporting the effects of a one-percentage-point change in the assumed healthcare cost trend rate on the aggregate of the service cost and interest cost components of net periodic benefit cost and on the benefit obligation for postretirement healthcare benefits. New required disclosures for reporting the weighted-average interest rate used to credit cash balance and similar plans that have a promised interest credit, the reasons for significant gains and losses affecting benefit obligations and other requirements for reporting aggregate information related to pension plans. For Arrow, the standard becomes effective at December 31, 2020. The Company does not expect that the adoption of this change affecting defined benefit plan disclosures will have a material impact on its financial position or the results of operations.

In August 2018, the FASB issued ASU 2018-15 "Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract" which will require companies to defer potentially significant, specified implementation costs incurred in a cloud computing arrangement that are often expensed under current US GAAP. For Arrow, the standard becomes effective at January 1, 2020. The Company is in the process of assessing the impact of this new accounting standard on its financial position and the results of operations in periods subsequent to its adoption.

Significant Accounting Policy Update:

Revenue Recognition - Accounting Standard Codification ("ASC") Topic 606, "Revenue from Contracts with Customers," establishes principles for reporting information about the nature, amount, timing and uncertainty of revenue and cash flows arising from the entity's contracts to provide goods or services to customers. The core principle of Topic 606 requires an entity to recognize revenue in a way that depicts the transfer of goods or services promised to a customer in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services as performance obligations are satisfied.

The Company adopted Topic 606 as of January 1, 2018 using the modified retrospective approach. The Company has determined that revenue from specific types of fiduciary activities and insurance commissions are within the scope of this guidance. Under prior GAAP, revenue from fiduciary activities was recognized from settling client estates over the time period the work was performed. With the adoption of Topic 606, revenue is now recognized when the performance obligation is completed, which is when the settlement of the client estate is closed. The impact of this change in revenue recognition was not material to the Company's consolidated financial statements. Under prior GAAP when clients elected to pay premiums on property and casualty insurance policies in installments, revenue was recognized when the premiums were billed. With the adoption of Topic 606, this type of revenue is recognized when the performance obligation is substantially completed, i.e., when the insurance policy is issued. The impact of this change in revenue recognition was not material to the Company's consolidated financial statements. The cumulative effect of the adoption of Topic 606 related to the previously described fiduciary activities and insurance commissions was a decrease in retained earnings by $102 thousand as of January 1, 2018.

The majority of the Company's revenue-generating transactions are not subject to ASC Topic 606, including revenue generated from financial instruments, such as loans and investment securities which are presented in its consolidated income statements as components of net interest income. The following is a description of principal activities from which the Company generates its revenue from noninterest income sources that are within the scope of ASC Topic 606:

Income from Fiduciary Activities: represents revenue derived mainly through the management of client investments which is based on the market value of the covered assets and the fee schedule contained in the applicable account management agreement. Since the revenue is mainly based on the market value of assets, this amount can be volatile as financial markets increase and decrease based on various economic factors. The terms of the account management agreements generally specify that the performance obligations are completed each quarter. Accordingly, the Company mainly recognizes revenue from fiduciary activities on a quarterly basis.

Fees for Other Services to Customers: represents general service fees for monthly deposit account maintenance and account activity plus fees from other deposit-based services. Revenue is recognized when the performance obligation is completed, which is generally on a monthly basis for account maintenance services, or upon the completion of a deposit-related transaction. Payment for these performance obligations is generally received at the time the performance obligations are satisfied.

Insurance Commissions: represents commissions and fees paid by insurance carriers for both property and casualty insurance policies, and for services performed for employment benefits clients. Revenue from the property and casualty insurance business is recognized when the performance obligation is satisfied, which is generally the effective date of the bound coverage since there are no significant performance obligations remaining. Revenue from the employment benefit brokerage business is recognized when the benefit servicing performance obligations are satisfied, generally on a monthly basis.