Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2018
Accounting Policies [Abstract]
BASIS OF PRESENTATION AND PRINCIPLES OF CONSOLIDATION	A. Basis of Presentation and Principles of Consolidation The consolidated financial statements of The Hanover Insurance Group, Inc. (“THG” or the “Company”), include the accounts of The Hanover Insurance Company (“Hanover Insurance”) and Citizens Insurance Company of America (“Citizens”), THG’s principal property and casualty companies; and other insurance and non-insurance subsidiaries. These legal entities conduct their operations through several business segments discussed in Note 14 – “Segment Information”. The consolidated financial statements also include the Company’s discontinued operations, consisting primarily of Chaucer Holdings Limited (“Chaucer”), a specialist insurance underwriting group which operates through the Society and Corporation of Lloyd’s (“Lloyd’s”), and the Company’s accident and health and former life insurance businesses. All intercompany accounts and transactions have been eliminated. On December 28, 2018, the Company completed the sale of Chaucer to China Reinsurance (Group) Corporation (“China Re”). The sale of the Chaucer-related Irish entity was completed on February 14, 2019 for proceeds of $28 million. The sale of the Australian entities for proceeds of $13 million is pending, subject only to local regulatory approval, and is expected to close in the first quarter of 2019. Accordingly, as of December 31, 2018 and for all prior periods presented in this Annual Report on Form 10-K, Chaucer’s accounts have been classified as discontinued operations in the Consolidated Statements of Income and as held-for-sale in the Consolidated Balance Sheets (See Note 2 – “Discontinued Operations”). The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America (“U.S. GAAP”) requires the Company 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 amount of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the opinion of the Company’s management these financial statements reflect all adjustments, consisting of normal recurring items necessary for a fair presentation of the financial position and results of operations.
INVESTMENTS	B. Investments Fixed maturities are classified as available-for-sale and are carried at fair value, with unrealized gains and losses, net of taxes, reported in accumulated other comprehensive income (“AOCI”), a separate component of shareholders’ equity. The amortized cost of fixed maturities is adjusted for amortization of premiums and accretion of discounts to maturity. Equity securities are carried at fair value. Effective January 1, 2018, in accordance with the provisions of Accounting Standards Codification (“ASC”) Update No. 2016-01, (Subtopic 825-10) Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”), increases and decreases in fair value are reported in net income. Previously, equity securities were classified as available-for-sale and unrealized gains and losses, net of taxes, were reported in AOCI. See Section O – “New Accounting Pronouncements” below. Other investments consist primarily of mortgage participations and limited partnerships. Mortgage participations represent interests in commercial mortgage loans originated and serviced by a third-party of which the Company shares, on a pro-rata basis, in all related cash flows of the underlying mortgage loans. Prior to May 2018, certain reacquisition rights, which are no longer in effect, and which were previously retained by the third-party in the loan participations required that these investments be accounted for as secured borrowings under ASC 860, Transfers and Servicing (“ASC 860”). Mortgage participations are stated at unpaid principal balances adjusted for deferred fees or expenses, net of reserves. Reserves on mortgages are established and are collectively evaluated based on losses expected by the Company for loans that may not be collectible in full. In establishing reserves, the Company considers, among other things, the estimated fair value of the underlying collateral. Investments in limited partnerships include interests in private equity funds. Effective January 1, 2018, in accordance with the provisions of ASC Update No. 2016-01, when the Company’s interest in the partnership is so minor that it exercises virtually no influence over operating and financial policies, the limited partnership investment is accounted for at fair value with unrealized gains and losses reported in net income. Previously, such investments were accounted for under the cost method. All other investments in limited partnership interests are accounted for in accordance with the equity method of accounting. Net investment income includes interest, dividends, and income from limited partnership interests. Interest income is recognized based on the effective yield method which includes the amortization of premiums and accretion of discounts. The effective yield used to determine the amortization for fixed maturities subject to prepayment risk, such as mortgage-backed and asset-backed securities, is recalculated and adjusted periodically based upon actual historical and projected future cash flows. The adjustment to yields for highly rated prepayable fixed maturities is accounted for using the retrospective method. The adjustment to yields for all other prepayable fixed maturities is accounted for using the prospective method. Fixed maturities and mortgage participations that are delinquent are placed on non-accrual status, and thereafter interest income is recognized only when cash payments are received. Realized investment gains and losses on sales are reported as a component of revenues based upon specific identification of the investment assets sold. When an other-than-temporary decline in value of a specific investment is deemed to have occurred, and a charge to earnings is required, the Company recognizes a realized investment loss. Changes in the fair value of equity securities are reported in net realized and unrealized investment gains (losses), including increases and decreases in fair value on securities that are still held and realized gains and losses on securities that have been sold. Prior to the sale of Chaucer on December 28, 2018, the Company also held investments in overseas deposits; such deposits were maintained in overseas funds and were managed exclusively by Lloyd’s. These funds were required in order to protect policyholders in overseas markets and enabled the Company to operate in these markets. Net investment income and realized and unrealized investment gains (losses) related to overseas deposits are included in income (loss) from Chaucer business within discontinued operations. The Company reviews investments in an unrealized loss position to identify other-than-temporary declines in value. When an other-than-temporary decline in value of a debt security is deemed to have occurred, the Company must assess whether it intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis. If the debt security meets either of these two criteria, an other-than-temporary impairment (“OTTI”) is recognized in earnings equal to the entire difference between the security’s amortized cost basis and its fair value at the impairment measurement date. If the Company does not intend to sell the debt security and it is not more likely than not the Company will be required to sell the security before recovery of its amortized cost basis, the credit loss portion of an OTTI is recorded through earnings while the portion attributable to all other factors is recorded separately as a component of other comprehensive income. The amount of the OTTI that relates to credit is estimated by comparing the amortized cost of the fixed maturity security with the net present value of the security’s projected future cash flows, discounted at the effective interest rate implicit in the investment prior to impairment. The non-credit portion of the impairment is equal to the difference between the fair value and the net present value of the security’s cash flows at the impairment measurement date. Once an OTTI has been recognized, the new amortized cost basis of the security is equal to the previous amortized cost less the amount of OTTI recognized in earnings.
FINANCIAL INSTRUMENTS	C. Financial Instruments In the normal course of business, the Company may enter into transactions involving various types of financial instruments, including debt, investments such as fixed maturities, equity securities and mortgage loans, investment and loan commitments, swap contracts, option contracts, forward contracts and futures contracts. These instruments involve credit risk and could also be subject to risk of loss due to interest rate and foreign currency fluctuation. The Company evaluates and monitors each financial instrument individually and, when appropriate, obtains collateral or other security to minimize losses.
CASH AND CASH EQUIVALENTS	D. Cash and Cash Equivalents Cash and cash equivalents includes cash on hand, amounts due from banks and highly liquid debt instruments purchased with an original maturity of three months or less.
DEFERRED ACQUISITION COSTS	E. Deferred Acquisition Costs Acquisition costs consist of commissions, underwriting costs and other costs, which vary with, and are primarily related to, the successful production of premiums. Acquisition costs are deferred and amortized over the terms of the insurance policies. Deferred acquisition costs (“DAC”) for each operating segment are reviewed to determine if the costs are recoverable from future income, including investment income. If such costs are determined to be unrecoverable, they are expensed at the time of determination. Although recoverability of DAC is not assured, the Company believes it is more likely than not that all of these costs will be recovered. The amount of DAC considered recoverable, however, could be reduced in the near term if the estimates of total revenues discussed above are reduced or permanently impaired as a result of a disposition of a line of business. The amount of amortization of DAC could be revised in the near term if any of the estimates discussed above are revised.
REINSURANCE RECOVERABLES	F. Reinsurance Recoverables The Company shares certain insurance risks it has underwritten, through the use of reinsurance contracts, with various insurance entities. Reinsurance accounting is followed for ceded transactions when the risk transfer provisions of ASC 944, Financial Services – Insurance (“ASC 944”), have been met. As a result, when the Company experiences loss or claims events that are subject to a reinsurance contract, reinsurance recoverables are recorded. The amount of the reinsurance recoverable can vary based on the terms of the reinsurance contract, the size of the individual loss or claim, or the aggregate amount of all losses or claims in a particular line or book of business or an aggregate amount associated with a particular accident year. The valuation of losses or claims recoverable depends on whether the underlying loss or claim is a reported loss or claim, or an incurred but not reported loss. For reported losses and claims, the Company values reinsurance recoverables at the time the underlying loss or claim is recognized, in accordance with contract terms. For incurred but not reported losses, the Company estimates the amount of reinsurance recoverables based on the terms of the reinsurance contracts and historical reinsurance recovery information and applies that information to the gross loss reserve. Amounts recoverable from reinsurers are estimated in a manner consistent with the claim liability associated with the reinsured business and the balance is disclosed separately in the financial statements. However, the ultimate amount of the reinsurance recoverable is not known until all losses and claims are settled. Allowances are established for amounts deemed uncollectible and reinsurance recoverables are recorded net of these allowances. The Company evaluates the financial condition of its reinsurers and monitors concentration risk to minimize its exposure to significant credit losses from individual reinsurers.
PROPERTY, EQUIPMENT AND CAPITALIZED SOFTWARE	G. Property, Equipment and Capitalized Software Property, equipment, leasehold improvements and capitalized software are recorded at cost, less accumulated depreciation and amortization. Depreciation is generally provided using the straight-line method over the estimated useful lives of the related assets, which generally range from 3 to 30 years. The estimated useful life for capitalized software is generally 5 to 7 years. Amortization of leasehold improvements is provided using the straight-line method over the lesser of the term of the leases or the estimated useful life of the improvements. The Company tests for the recoverability of long-lived assets whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company recognizes impairment losses only to the extent that the carrying amounts of long-lived assets exceed the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the assets. When an impairment loss occurs, the Company reduces the carrying value of the asset to fair value and no longer depreciates the asset. Fair values are estimated using discounted cash flow analysis.
GOODWILL AND INTANGIBLE ASSETS	H. GOODWILL AND INTANGIBLE ASSETS In accordance with the provisions of ASC 350, Intangibles- Goodwill and Other, the Company carries its goodwill at cost, net of amortization accumulated prior to January 1, 2002, and net of impairments. Increases to goodwill are generated through acquisition and represent the excess of the cost of an acquisition over the fair value of net assets acquired, including any intangibles acquired. Since January 1, 2002, goodwill is no longer amortized but rather, is reviewed for impairment. Additionally, acquisitions can also produce intangible assets, which have either a definite or indefinite life. Intangible assets with definite lives are amortized over that life, whereas those intangible assets determined to have an indefinite life are reviewed at least annually for impairment. The Company tests for the recoverability of goodwill and intangible assets with indefinite lives annually or whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company recognizes impairment losses only to the extent that the carrying amounts of reporting units with goodwill exceed the fair value. The amount of the impairment loss that would be recognized is determined based upon the excess of the carrying value of goodwill compared to the implied fair value of the goodwill, as determined with respect to all assets and liabilities of the reporting unit. The Company has performed its annual review of goodwill and intangible assets with indefinite lives for impairment in the fourth quarters of 2018 and 2017 with no impairments recognized. At December 31, 2018 and 2017, the Company held goodwill of $178.8 million and intangible assets with indefinite lives of $15.0 million.
LIABILITIES FOR LOSSES, LAE, AND UNEARNED PREMIUMS	I. LIABILITIES FOR LOSSES, LAE, AND UNEARNED PREMIUMS Liabilities for outstanding claims, losses and loss adjustment expenses (“LAE”) are estimates of payments to be made for reported losses and LAE and estimates of losses and LAE incurred but not reported. These liabilities are determined using case basis evaluations and statistical analyses of historical loss patterns and represent estimates of the ultimate cost of all losses incurred but not paid. These estimates are continually reviewed and adjusted as necessary; adjustments are reflected in current operations. Estimated amounts of salvage and subrogation on unpaid losses are deducted from the liability for unpaid claims. Premiums for direct and assumed business are reported as earned on a pro-rata basis over the contract period. The unexpired portion of these premiums is recorded as unearned premiums. All losses, LAE and unearned premium liabilities are based on the various estimates discussed in this note. Although the adequacy of these amounts cannot be assured, the Company believes that it is more likely than not that these liabilities and accruals will be sufficient to meet future obligations of policies in force. The amount of liabilities and accruals, however, could be revised in the near-term if the estimates discussed above are revised.
DEBT	J. Debt The Company’s debt at December 31, 2018 includes senior debentures, subordinated debentures, and collateralized borrowings with the Federal Home Loan Bank (“FHLB”). Debt instruments are carried at principal amount borrowed, net of any applicable unamortized discounts and issuance costs. See Note 6 – “Debt and Credit Arrangements”.
PREMIUM, PREMIUM RECEIVABLE, FEE REVENUE AND RELATED EXPENSES	K. Premium, Premium Receivable, Fee Revenue and Related Expenses Insurance premiums written are generally recorded at the policy inception and are primarily earned on a pro-rata basis over the terms of the policies for all products. Premiums written may also include estimates that are derived from multiple sources, which include the historical experience of the underlying business, similar businesses and available industry information. These estimates are regularly reviewed and updated, and any resulting adjustments are included in the current year’s results. Unearned premium reserves represent the portion of premiums written that relates to the unexpired terms of the underlying in-force insurance policies and reinsurance contracts. Premium receivables reflect the unpaid balance of premium written as of the balance sheet date. Premium receivables are generally short-term in nature and are reported net of an allowance for estimated uncollectible premium accounts. The Company reviews its receivables for collectability at the balance sheet date. The allowance for uncollectible accounts was not material as of December 31, 2018 and 2017. Ceded premiums are charged to income over the applicable term of the various reinsurance contracts with third-party reinsurers. Reinsurance reinstatement premiums, when required, are recognized in the same period as the loss event that gave rise to the reinstatement premiums. Losses and related expenses are matched with premiums, resulting in their recognition over the lives of the contracts. This matching is accomplished through estimated and unpaid losses and amortization of deferred acquisition costs.
INCOME TAXES	L. Income Taxes The Company is subject to the tax laws and regulations of the U.S. and foreign countries in which it operates. The Company files a consolidated U.S. federal income tax return that includes the holding company and its U.S. subsidiaries. Generally, taxes are accrued at the U.S. statutory tax rate for income from the U.S. operations. In December 2017, the Tax Cuts and Jobs Act (“TCJA”) was enacted, which reduced the U.S. statutory rate from 35% to 21%, effective January 1, 2018. See Note 7 – “Income Taxes” for a discussion of this new law. The Company accrues taxes on certain non-U.S. income that is subject to U.S. tax at the enacted U.S. tax rate. Foreign tax credits, where available, are utilized to offset U.S. tax as permitted. The Company’s accounting for income taxes represents its best estimate of various events and transactions. Deferred income taxes are generally recognized when assets and liabilities have different values for financial statement and tax reporting purposes, and for other temporary taxable and deductible differences as defined by ASC 740, Income Taxes (“ASC 740”). These temporary differences are measured at the balance sheet date using enacted tax rates expected to apply to taxable income in the years the temporary differences are expected to reverse. These differences result primarily from insurance reserves, deferred acquisition costs, investments, and employee benefit plans. The realization of deferred tax assets depends upon the existence of sufficient taxable income within the carryback or carryforward periods under the tax law in the applicable tax jurisdiction. Consideration is given to all available positive and negative evidence, including reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial operations. Valuation allowances are established if, based on available information, it is determined that it is more likely than not that all or some portion of the deferred tax assets will not be realized. Changes in valuation allowances are generally reflected in income tax expense or as an adjustment to other comprehensive income (loss) depending on the nature of the item for which the valuation allowance is being recorded.
STOCK-BASED COMPENSATION	M. Stock-Based Compensation The Company recognizes the fair value of compensation costs for all share-based payments, including employee stock options, in the financial statements. Unvested awards are generally expensed on a straight line basis, by tranche, over the vesting period of the award. The Company’s stock-based compensation plans are discussed further in Note 11 – “Stock-Based Compensation Plans”.
EARNINGS PER SHARE	N. Earnings Per Share Earnings per share (“EPS”) for the years ended December 31, 2018, 2017 and 2016 is based on a weighted average of the number of shares outstanding during each year. Basic and diluted EPS is computed by dividing income available to common stockholders by the weighted average number of shares outstanding for the period. The weighted average shares outstanding used to calculate basic EPS differ from the weighted average shares outstanding used in the calculation of diluted EPS due to the effect of dilutive employee stock options, nonvested stock grants and other contingently issuable shares. If the effect of such items is antidilutive, the weighted average shares outstanding used to calculate diluted EPS are equal to those used to calculate basic EPS. Options to purchase shares of common stock whose exercise prices are greater than the average market price of the common shares are not included in the computation of diluted earnings per share because the effect would be antidilutive.
NEW ACCOUNTING PRONOUNCEMENTS	O. New Accounting Pronouncements Recently Implemented Standards In February 2018, the Financial Accounting Standards Board (“FASB”) issued ASC Update No. 2018-02 (Topic 220) Income Statement – Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASC update allows for a reclassification into retained earnings of the stranded tax effects in AOCI resulting from the enactment of the TCJA. Current guidance requires the effect of a change in tax laws or rates on deferred tax balances to be reported in income from continuing operations in the accounting period that includes the period of enactment, even if the related income tax effects were originally charged or credited directly to AOCI. The amount of the reclassification would include the effect of the change in the U.S. federal corporate income tax rate on the gross deferred tax amounts at the date of the enactment of the TCJA related to items in AOCI. The updated guidance is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. The Company early adopted this guidance effective January 1, 2018 with a cumulative effect adjustment, which reclassified $6.5 million of benefits from AOCI to retained earnings with no overall impact on the Company’s financial position. In March 2017, the FASB issued ASC Update No. 2017-07, (Topic 715) Compensation – Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. This guidance requires that an employer report in its income statement the service cost component of both net periodic pension and net periodic postretirement benefit cost in the same line item or items as other compensation costs arising from services rendered by pertinent employees during the period, and present in the income statement separately from the other components of benefit cost, if appropriate under the company’s current presentation of its income statement. Additionally, the guidance allows only the service cost component to be eligible for capitalization when applicable. The updated guidance is effective for annual and interim periods beginning after December 15, 2017, and should be applied retrospectively for the presentation of the service cost component and other components of net periodic pension cost and net periodic postretirement benefit cost in the income statement, and prospectively for the capitalization of the service cost component of net periodic cost in assets. The Company implemented this guidance effective January 1, 2018. The effect of implementing this guidance was not material to the Company’s financial position or results of operations as the Company does not have any service cost remaining related to its pension and postretirement plans. In January 2017, the FASB issued ASC Update No. 2017-01, (Topic 805) Business Combinations – Clarifying the Definition of a Business. The amendments in this update provide a more robust framework to use in determining when a set of assets and activities constitute a business. This guidance narrows the definition of a business by providing specific requirements that contribute to the creation of outputs that must be present to be considered a business. The guidance further clarifies the appropriate accounting when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets is that of an acquisition (disposition) of assets, not a business. This framework will reduce the number of transactions that an entity must further evaluate to determine whether transactions are business combinations or asset acquisitions. The updated guidance is effective for interim and annual periods beginning after December 15, 2017, and should be applied on a prospective basis. Early adoption is permitted only for transactions that have not been reported in financial statements that have been issued. The Company implemented this guidance effective January 1, 2018. The implementation of this guidance did not have an effect on the Company’s financial position or results of operations. In November 2016, the FASB issued ASC Update No. 2016-18 (Topic 230) Statement of Cash Flows – Restricted Cash (a consensus of the FASB Emerging Issues Task Force). The amendments in this update require that restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. Current GAAP does not include specific guidance on the cash flow classification and presentation of changes in restricted cash. The updated guidance is effective for interim and annual periods beginning after December 15, 2017 and is required to be applied using a retrospective transition method to each period presented. The Company implemented this guidance effective January 1, 2018. Implementing this guidance did not have an impact on the Company’s statement of cash flows, as restricted cash, if any, has already been included in total cash and cash equivalents. In October 2016, the FASB issued ASC Update No. 2016-16, (Topic 740) Income Taxes – Intra-Entity Transfers of Assets Other Than Inventory. Under current GAAP, the tax effects of intra-entity transfers of assets (intercompany sales) are deferred until the assets are sold to an outside party or otherwise recovered through use. This ASC update eliminates this deferral of taxes for assets other than inventory and requires the recognition of taxes when the transfer occurs. The updated guidance is effective for interim and annual periods beginning after December 15, 2017, and should be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings. Early adoption is permitted, but this election must be made in the first interim period of the adoption year. The Company implemented this guidance effective January 1, 2018. Implementation of this guidance did not have a net impact on the Company’s financial position or results of operations. In August 2016, the FASB issued ASC Update No. 2016-15, (Topic 230) Classification of Certain Cash Receipts and Cash Payments. This ASC update provides specific guidance on the presentation of certain cash flow items where there is currently diversity in practice, including, but not limited to, debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, and distributions received from equity method investees. The updated guidance is effective for interim and annual periods beginning after December 15, 2017, and should be applied retrospectively unless impracticable. The Company implemented this guidance effective January 1, 2018. The adoption of ASC Update No. 2016-15 did not have a significant impact on the Company’s statement of cash flows. In January 2016, the FASB issued ASC Update No. 2016-01, (Subtopic 825-10) Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”). This ASC update requires unconsolidated equity investments to be measured at fair value with changes in the fair value recognized in net income, except for those accounted for under the equity method. This update eliminates the cost method for equity investments without readily determinable fair values, replacing it with other methods, including the use of Net Asset Value (“NAV”). Additionally, when a public entity is required to measure fair value for disclosure purposes and holds financial instruments measured at amortized cost, the updated guidance requires these instruments to be measured using exit price. It also requires financial assets and financial liabilities to be presented separately in the notes to the financial statements, grouped by measurement category and form of financial asset. The updated guidance is effective for annual periods beginning after December 15, 2017. In February 2018, the FASB issued ASC Update No. 2018-03, (Subtopic 825-10) Technical Corrections and Improvements to Financial Instruments – Overall. This ASC update clarifies the transition method for equity investments without readily determinable fair values. Specifically, if an entity elects to measure these investments at cost, less impairment, adjusted for changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer (the “measurement alternative”), then transition is prospective. For all others, transition is modified retrospective, requiring a cumulative effect adjustment. This ASU is effective for annual periods beginning after December 15, 2017, and interim periods within those years beginning after June 15, 2018. Early adoption is permitted for interim periods beginning after December 15, 2017 as long as ASU No. 2016-01 has been adopted. The Company implemented this guidance effective January 1, 2018 concurrent with ASU No. 2016-01 for certain limited partnerships without readily determinable fair values. The implementation of these standards resulted in a benefit to retained earnings, through a cumulative effect adjustment, of $97.8 million, including a reclassification of after-tax unrealized gains of $95.2 million from AOCI and an adjustment of $2.6 million of gains to record partnership investments at NAV. In May 2014, the FASB issued ASC Update No. 2014-09, (Topic 606) Revenue from Contracts with Customers. This ASC was issued to clarify the principles for recognizing revenue. Insurance contracts and financial instrument transactions are not within the scope of this updated guidance, and; therefore, only an insignificant amount of the Company’s revenue is subject to this updated guidance. In August 2015, the FASB issued ASC Update No. 2015-14, (Topic 606) Revenue from Contracts with Customers, which deferred the effective date of ASC Update No. 2014-09 by one year. Accordingly, the updated guidance is effective for periods beginning after December 15, 2017. The Company implemented this guidance effective January 1, 2018. The effect of implementing this guidance was not material to the Company’s financial position or results of operations. Recently Issued Standards In August 2018, the FASB issued ASC Update No. 2018-15, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASC Update No. 2018-15”). This ASC update requires the capitalization of implementation costs incurred in a hosting arrangement that is a service contract consistent with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The guidance also requires an entity to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting agreement, and apply impairment guidance consistent with long-lived assets. ASC Update No. 2018-15 also provides specific guidelines related to the presentation of these capitalized implementation costs and related expenses in the financial statements. The updated guidance is effective for interim and annual periods beginning after December 15, 2019, and should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. Early adoption is permitted, including interim periods. The Company does not expect the adoption of ASC Update No. 2018-15 to have a material impact on its financial position or results of operations. In August 2018, the FASB issued ASC Update No. 2018-14 (Topic 715-20) Compensation – Retirement Benefits – Defined Benefit Plans – General – Disclosure Framework – Changes to the Disclosure Requirements for the Defined Benefit Plans. This ASC update modifies disclosures related to defined benefit pension or other postretirement plans. This ASC update removes the disclosure of amounts in accumulated other comprehensive income expected to be recognized over the next fiscal year and the effects of a one percentage point change of health care cost trends on net periodic benefit costs and postretirement benefit obligations and clarifies the specific requirements of disclosures related to the project benefit obligation and accumulated benefit obligation. This ASC Update also adds disclosures related to weighted average crediting rates for cash balance plans and requires disclosure of an explanation of any significant gains and losses related to changes in benefit obligations for the period. The amendments in this ASC update are effective for fiscal years ending after December 15, 2020, and should be applied on a retrospective basis to all periods presented. Early adoption is permitted. Implementing this guidance is not expected to have an impact on the Company’s financial position or results of operations as the update is disclosure related. In August 2018, the FASB issued ASC Update No. 2018-13 (Topic 820) Fair Value Measurement, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. The update removes the requirement for disclosure of the following: 1) the amount and reasons for transfers between level 1 and level 2 of the fair value hierarchy, 2) the policy for timing of transfers between levels, and 3) the valuation processes for level 3 fair value measurements. This update also added a requirement to disclose the changes in unrealized gains and losses for the period included in other comprehensive income for recurring level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop level 3 fair value measurements, in addition to other fair value disclosure modifications. The updated guidance is effective for interim and annual periods beginning after December 15, 2019, and should be applied prospectively for certain of the disclosure requirements and retrospectively to all periods presented upon the effective date for other disclosure requirements. An entity is permitted to early adopt any removed or modified disclosures upon issuance of the update and delay adoption of additional disclosures until periods beginning after December 15, 2019, the effective date of the standard. Implementing this guidance is not expected to have an impact on the Company’s financial position or results of operations as the update is disclosure related. In March 2017, the FASB issued ASC Update No. 2017-08, (Subtopic 310-20) Receivables – Nonrefundable Fees and Other Costs: Premium Amortization on Purchased Callable Debt Securities. This guidance shortens the amortization period of premiums on certain purchased callable debt securities to the earliest call date. The updated guidance is effective for annual and interim periods beginning after December 15, 2018, and should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Early adoption is permitted, including adoption in an interim period. The Company does not expect the adoption of ASC Update No. 2017-08 will have a material effect on its financial position or results of operations. In January 2017, the FASB issued ASC Update No. 2017-04, (Topic 350) Intangibles – Goodwill and Other: Simplifying the Test for Goodwill Impairment. This guidance eliminates step 2 from the goodwill impairment test. Instead, an entity should perform its goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, including any applicable income tax effects, and recognize an impairment for the amount by which the carrying amount exceeds the reporting unit’s fair value. However, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The updated guidance is effective for annual or interim goodwill impairment tests performed in fiscal years 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 does not expect the adoption of ASC Update No. 2017-04 to have a material impact on its financial position or results of operations. In June 2016, the FASB issued ASC Update No. 2016-13, (Topic 326) Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments. This ASC update introduces new guidance for the accounting for credit losses on financial instruments within its scope. A new model, referred to as the current expected credit losses model, requires an entity to determine credit-related impairment losses for financial instruments held at amortized cost and to estimate these expected credit losses over the life of an exposure (or pool of exposures). The estimate of expected credit losses should consider both historical and current information, reasonable and supportable forecasts, as well as estimates of prepayments. The estimated credit losses and subsequent adjustment to such loss estimates will be recorded through an allowance account which is deducted from the amortized cost of the financial instrument, with the offset recorded in current earnings. ASC No. 2016-13 also modifies the impairment model for available-for-sale debt securities. The new model will require an estimate of expected credit losses only when the fair value is below the amortized cost of the asset, thus the length of time the fair value of an available-for-sale debt security has been below the amortized cost will no longer affect the determination of whether a credit loss exists. In addition, credit losses on available-for-sale debt securities will be limited to the difference between the security’s amortized cost basis and its fair value. In November 2018, the FASB issued ASC Update No. 2018-19, Codification Improvements to Topic 326, Financial Instruments–Credit Losses, which explicitly states that receivables arising from operating leases are not within the scope of Subtopic 326-20. ASC Update No. 2016-13 and related guidance is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted for periods beginning after December 15, 2018. The Company expects to adopt ASC Update No. 2016-13 on January 1, 2020 and is evaluating the impact on its financial position and results of operations, which it does not expect to be material. In February 2016, the FASB issued ASC Update No. 2016-02, (Topic 842) Leases. This ASC update requires a lessee to recognize a right-of-use asset, which represents the lessee’s right to use a specified asset for the lease term, and a corresponding lease liability, which represents a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis, for all leases that extend beyond 12 months. For finance or capital leases, interest on the lease liability will be recognized separately from amortization of the right-of-use asset in the statements of income and comprehensive income. In addition, the repayment of the principal portion of the lease liability will be classified as a financing activity while the interest component will be included in the operating section of the statement of cash flows. For operating leases, the asset and liability will be amortized as a single lease cost, such that the cost of the lease is allocated over the lease term, on a generally straight-line basis, with all cash flows included within operating activities in the statement of cash flows. ASC Update No. 2016-02 requires that implementation of this guidance be through a modified retrospective transition approach. In July 2018, the FASB issued ASC Update No. 2018-11, (Topic 842) Leases Targeted Improvements, which provides entities with an additional transition method to adopt ASC Update No. 2016-02. Under this optional transition method, an entity can initially apply the new guidance at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The Company will implement this guidance effective January 1, 2019 using the optional transition method provided in ASC Update No. 2018-11 and will elect to utilize the practical expedient package available in ASC Update 2016-02. The effect of implementing this guidance is expected to increase total assets and liabilities each by approximately $35 million on January 1, 2019, which is not material to the Company’s financial position. Furthermore, implementation of this guidance is not expected to have a material impact on the Company’s results of operations.
RECLASSIFICATIONS	Q. Reclassifications Certain prior year amounts have been reclassified to conform to the current year presentation.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

BASIS OF PRESENTATION AND PRINCIPLES OF CONSOLIDATION

A. Basis of Presentation and Principles of Consolidation

The consolidated financial statements of The Hanover Insurance Group, Inc. (“THG” or the “Company”), include the accounts of The Hanover Insurance Company (“Hanover Insurance”) and Citizens Insurance Company of America (“Citizens”), THG’s principal property and casualty companies; and other insurance and non-insurance subsidiaries. These legal entities conduct their operations through several business segments discussed in Note 14 – “Segment Information”. The consolidated financial statements also include the Company’s discontinued operations, consisting primarily of Chaucer Holdings Limited (“Chaucer”), a specialist insurance underwriting group which operates through the Society and Corporation of Lloyd’s (“Lloyd’s”), and the Company’s accident and health and former life insurance businesses. All intercompany accounts and transactions have been eliminated. On December 28, 2018, the Company completed the sale of Chaucer to China Reinsurance (Group) Corporation (“China Re”). The sale of the Chaucer-related Irish entity was completed on February 14, 2019 for proceeds of $28 million. The sale of the Australian entities for proceeds of $13 million is pending, subject only to local regulatory approval, and is expected to close in the first quarter of 2019. Accordingly, as of December 31, 2018 and for all prior periods presented in this Annual Report on Form 10-K, Chaucer’s accounts have been classified as discontinued operations in the Consolidated Statements of Income and as held-for-sale in the Consolidated Balance Sheets (See Note 2 – “Discontinued Operations”).

The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America (“U.S. GAAP”) requires the Company 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 amount of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the opinion of the Company’s management these financial statements reflect all adjustments, consisting of normal recurring items necessary for a fair presentation of the financial position and results of operations.

INVESTMENTS

B. Investments

Fixed maturities are classified as available-for-sale and are carried at fair value, with unrealized gains and losses, net of taxes, reported in accumulated other comprehensive income (“AOCI”), a separate component of shareholders’ equity. The amortized cost of fixed maturities is adjusted for amortization of premiums and accretion of discounts to maturity.

Equity securities are carried at fair value. Effective January 1, 2018, in accordance with the provisions of Accounting Standards Codification (“ASC”) Update No. 2016-01, (Subtopic 825-10) Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”), increases and decreases in fair value are reported in net income. Previously, equity securities were classified as available-for-sale and unrealized gains and losses, net of taxes, were reported in AOCI. See Section O – “New Accounting Pronouncements” below.

Other investments consist primarily of mortgage participations and limited partnerships. Mortgage participations represent interests in commercial mortgage loans originated and serviced by a third-party of which the Company shares, on a pro-rata basis, in all related cash flows of the underlying mortgage loans. Prior to May 2018, certain reacquisition rights, which are no longer in effect, and which were previously retained by the third-party in the loan participations required that these investments be accounted for as secured borrowings under ASC 860, Transfers and Servicing (“ASC 860”). Mortgage participations are stated at unpaid principal balances adjusted for deferred fees or expenses, net of reserves. Reserves on mortgages are established and are collectively evaluated based on losses expected by the Company for loans that may not be collectible in full. In establishing reserves, the Company considers, among other things, the estimated fair value of the underlying collateral.

Investments in limited partnerships include interests in private equity funds. Effective January 1, 2018, in accordance with the provisions of ASC Update No. 2016-01, when the Company’s interest in the partnership is so minor that it exercises virtually no influence over operating and financial policies, the limited partnership investment is accounted for at fair value with unrealized gains and losses reported in net income. Previously, such investments were accounted for under the cost method. All other investments in limited partnership interests are accounted for in accordance with the equity method of accounting.

Net investment income includes interest, dividends, and income from limited partnership interests. Interest income is recognized based on the effective yield method which includes the amortization of premiums and accretion of discounts. The effective yield used to determine the amortization for fixed maturities subject to prepayment risk, such as mortgage-backed and asset-backed securities, is recalculated and adjusted periodically based upon actual historical and projected future cash flows. The adjustment to yields for highly rated prepayable fixed maturities is accounted for using the retrospective method. The adjustment to yields for all other prepayable fixed maturities is accounted for using the prospective method. Fixed maturities and mortgage participations that are delinquent are placed on non-accrual status, and thereafter interest income is recognized only when cash payments are received.

Realized investment gains and losses on sales are reported as a component of revenues based upon specific identification of the investment assets sold. When an other-than-temporary decline in value of a specific investment is deemed to have occurred, and a charge to earnings is required, the Company recognizes a realized investment loss. Changes in the fair value of equity securities are reported in net realized and unrealized investment gains (losses), including increases and decreases in fair value on securities that are still held and realized gains and losses on securities that have been sold.

Prior to the sale of Chaucer on December 28, 2018, the Company also held investments in overseas deposits; such deposits were maintained in overseas funds and were managed exclusively by Lloyd’s. These funds were required in order to protect policyholders in overseas markets and enabled the Company to operate in these markets. Net investment income and realized and unrealized investment gains (losses) related to overseas deposits are included in income (loss) from Chaucer business within discontinued operations.

The Company reviews investments in an unrealized loss position to identify other-than-temporary declines in value. When an other-than-temporary decline in value of a debt security is deemed to have occurred, the Company must assess whether it intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis. If the debt security meets either of these two criteria, an other-than-temporary impairment (“OTTI”) is recognized in earnings equal to the entire difference between the security’s amortized cost basis and its fair value at the impairment measurement date. If the Company does not intend to sell the debt security and it is not more likely than not the Company will be required to sell the security before recovery of its amortized cost basis, the credit loss portion of an OTTI is recorded through earnings while the portion attributable to all other factors is recorded separately as a component of other comprehensive income. The amount of the OTTI that relates to credit is estimated by comparing the amortized cost of the fixed maturity security with the net present value of the security’s projected future cash flows, discounted at the effective interest rate implicit in the investment prior to impairment. The non-credit portion of the impairment is equal to the difference between the fair value and the net present value of the security’s cash flows at the impairment measurement date. Once an OTTI has been recognized, the new amortized cost basis of the security is equal to the previous amortized cost less the amount of OTTI recognized in earnings.

FINANCIAL INSTRUMENTS

C. Financial Instruments

In the normal course of business, the Company may enter into transactions involving various types of financial instruments, including debt, investments such as fixed maturities, equity securities and mortgage loans, investment and loan commitments, swap contracts, option contracts, forward contracts and futures contracts. These instruments involve credit risk and could also be subject to risk of loss due to interest rate and foreign currency fluctuation. The Company evaluates and monitors each financial instrument individually and, when appropriate, obtains collateral or other security to minimize losses.

CASH AND CASH EQUIVALENTS

D. Cash and Cash Equivalents

Cash and cash equivalents includes cash on hand, amounts due from banks and highly liquid debt instruments purchased with an original maturity of three months or less.

DEFERRED ACQUISITION COSTS

E. Deferred Acquisition Costs

Acquisition costs consist of commissions, underwriting costs and other costs, which vary with, and are primarily related to, the successful production of premiums. Acquisition costs are deferred and amortized over the terms of the insurance policies.

Deferred acquisition costs (“DAC”) for each operating segment are reviewed to determine if the costs are recoverable from future income, including investment income. If such costs are determined to be unrecoverable, they are expensed at the time of determination. Although recoverability of DAC is not assured, the Company believes it is more likely than not that all of these costs will be recovered. The amount of DAC considered recoverable, however, could be reduced in the near term if the estimates of total revenues discussed above are reduced or permanently impaired as a result of a disposition of a line of business. The amount of amortization of DAC could be revised in the near term if any of the estimates discussed above are revised.

REINSURANCE RECOVERABLES

F. Reinsurance Recoverables

The Company shares certain insurance risks it has underwritten, through the use of reinsurance contracts, with various insurance entities. Reinsurance accounting is followed for ceded transactions when the risk transfer provisions of ASC 944, Financial Services – Insurance (“ASC 944”), have been met. As a result, when the Company experiences loss or claims events that are subject to a reinsurance contract, reinsurance recoverables are recorded. The amount of the reinsurance recoverable can vary based on the terms of the reinsurance contract, the size of the individual loss or claim, or the aggregate amount of all losses or claims in a particular line or book of business or an aggregate amount associated with a particular accident year. The valuation of losses or claims recoverable depends on whether the underlying loss or claim is a reported loss or claim, or an incurred but not reported loss. For reported losses and claims, the Company values reinsurance recoverables at the time the underlying loss or claim is recognized, in accordance with contract terms. For incurred but not reported losses, the Company estimates the amount of reinsurance recoverables based on the terms of the reinsurance contracts and historical reinsurance recovery information and applies that information to the gross loss reserve. Amounts recoverable from reinsurers are estimated in a manner consistent with the claim liability associated with the reinsured business and the balance is disclosed separately in the financial statements. However, the ultimate amount of the reinsurance recoverable is not known until all losses and claims are settled. Allowances are established for amounts deemed uncollectible and reinsurance recoverables are recorded net of these allowances. The Company evaluates the financial condition of its reinsurers and monitors concentration risk to minimize its exposure to significant credit losses from individual reinsurers.

PROPERTY, EQUIPMENT AND CAPITALIZED SOFTWARE

G. Property, Equipment and Capitalized Software

Property, equipment, leasehold improvements and capitalized software are recorded at cost, less accumulated depreciation and amortization. Depreciation is generally provided using the straight-line method over the estimated useful lives of the related assets, which generally range from 3 to 30 years. The estimated useful life for capitalized software is generally 5 to 7 years. Amortization of leasehold improvements is provided using the straight-line method over the lesser of the term of the leases or the estimated useful life of the improvements.

The Company tests for the recoverability of long-lived assets whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company recognizes impairment losses only to the extent that the carrying amounts of long-lived assets exceed the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the assets. When an impairment loss occurs, the Company reduces the carrying value of the asset to fair value and no longer depreciates the asset. Fair values are estimated using discounted cash flow analysis.

GOODWILL AND INTANGIBLE ASSETS

H. GOODWILL AND INTANGIBLE ASSETS

In accordance with the provisions of ASC 350, Intangibles- Goodwill and Other, the Company carries its goodwill at cost, net of amortization accumulated prior to January 1, 2002, and net of impairments. Increases to goodwill are generated through acquisition and represent the excess of the cost of an acquisition over the fair value of net assets acquired, including any intangibles acquired. Since January 1, 2002, goodwill is no longer amortized but rather, is reviewed for impairment. Additionally, acquisitions can also produce intangible assets, which have either a definite or indefinite life. Intangible assets with definite lives are amortized over that life, whereas those intangible assets determined to have an indefinite life are reviewed at least annually for impairment.

The Company tests for the recoverability of goodwill and intangible assets with indefinite lives annually or whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company recognizes impairment losses only to the extent that the carrying amounts of reporting units with goodwill exceed the fair value. The amount of the impairment loss that would be recognized is determined based upon the excess of the carrying value of goodwill compared to the implied fair value of the goodwill, as determined with respect to all assets and liabilities of the reporting unit. The Company has performed its annual review of goodwill and intangible assets with indefinite lives for impairment in the fourth quarters of 2018 and 2017 with no impairments recognized. At December 31, 2018 and 2017, the Company held goodwill of $178.8 million and intangible assets with indefinite lives of $15.0 million.

LIABILITIES FOR LOSSES, LAE, AND UNEARNED PREMIUMS

I. LIABILITIES FOR LOSSES, LAE, AND UNEARNED PREMIUMS

Liabilities for outstanding claims, losses and loss adjustment expenses (“LAE”) are estimates of payments to be made for reported losses and LAE and estimates of losses and LAE incurred but not reported. These liabilities are determined using case basis evaluations and statistical analyses of historical loss patterns and represent estimates of the ultimate cost of all losses incurred but not paid. These estimates are continually reviewed and adjusted as necessary; adjustments are reflected in current operations. Estimated amounts of salvage and subrogation on unpaid losses are deducted from the liability for unpaid claims.

Premiums for direct and assumed business are reported as earned on a pro-rata basis over the contract period. The unexpired portion of these premiums is recorded as unearned premiums.

All losses, LAE and unearned premium liabilities are based on the various estimates discussed in this note. Although the adequacy of these amounts cannot be assured, the Company believes that it is more likely than not that these liabilities and accruals will be sufficient to meet future obligations of policies in force. The amount of liabilities and accruals, however, could be revised in the near-term if the estimates discussed above are revised.

DEBT

J. Debt

The Company’s debt at December 31, 2018 includes senior debentures, subordinated debentures, and collateralized borrowings with the Federal Home Loan Bank (“FHLB”). Debt instruments are carried at principal amount borrowed, net of any applicable unamortized discounts and issuance costs. See Note 6 – “Debt and Credit Arrangements”.

PREMIUM, PREMIUM RECEIVABLE, FEE REVENUE AND RELATED EXPENSES

K. Premium, Premium Receivable, Fee Revenue and Related Expenses

Insurance premiums written are generally recorded at the policy inception and are primarily earned on a pro-rata basis over the terms of the policies for all products. Premiums written may also include estimates that are derived from multiple sources, which include the historical experience of the underlying business, similar businesses and available industry information. These estimates are regularly reviewed and updated, and any resulting adjustments are included in the current year’s results. Unearned premium reserves represent the portion of premiums written that relates to the unexpired terms of the underlying in-force insurance policies and reinsurance contracts. Premium receivables reflect the unpaid balance of premium written as of the balance sheet date. Premium receivables are generally short-term in nature and are reported net of an allowance for estimated uncollectible premium accounts. The Company reviews its receivables for collectability at the balance sheet date. The allowance for uncollectible accounts was not material as of December 31, 2018 and 2017. Ceded premiums are charged to income over the applicable term of the various reinsurance contracts with third-party reinsurers. Reinsurance reinstatement premiums, when required, are recognized in the same period as the loss event that gave rise to the reinstatement premiums. Losses and related expenses are matched with premiums, resulting in their recognition over the lives of the contracts. This matching is accomplished through estimated and unpaid losses and amortization of deferred acquisition costs.

INCOME TAXES

L. Income Taxes

The Company is subject to the tax laws and regulations of the U.S. and foreign countries in which it operates. The Company files a consolidated U.S. federal income tax return that includes the holding company and its U.S. subsidiaries. Generally, taxes are accrued at the U.S. statutory tax rate for income from the U.S. operations. In December 2017, the Tax Cuts and Jobs Act (“TCJA”) was enacted, which reduced the U.S. statutory rate from 35% to 21%, effective January 1, 2018. See Note 7 – “Income Taxes” for a discussion of this new law. The Company accrues taxes on certain non-U.S. income that is subject to U.S. tax at the enacted U.S. tax rate. Foreign tax credits, where available, are utilized to offset U.S. tax as permitted.

The Company’s accounting for income taxes represents its best estimate of various events and transactions.

Deferred income taxes are generally recognized when assets and liabilities have different values for financial statement and tax reporting purposes, and for other temporary taxable and deductible differences as defined by ASC 740, Income Taxes (“ASC 740”). These temporary differences are measured at the balance sheet date using enacted tax rates expected to apply to taxable income in the years the temporary differences are expected to reverse. These differences result primarily from insurance reserves, deferred acquisition costs, investments, and employee benefit plans.

The realization of deferred tax assets depends upon the existence of sufficient taxable income within the carryback or carryforward periods under the tax law in the applicable tax jurisdiction. Consideration is given to all available positive and negative evidence, including reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial operations. Valuation allowances are established if, based on available information, it is determined that it is more likely than not that all or some portion of the deferred tax assets will not be realized. Changes in valuation allowances are generally reflected in income tax expense or as an adjustment to other comprehensive income (loss) depending on the nature of the item for which the valuation allowance is being recorded.

STOCK-BASED COMPENSATION

M. Stock-Based Compensation

The Company recognizes the fair value of compensation costs for all share-based payments, including employee stock options, in the financial statements. Unvested awards are generally expensed on a straight line basis, by tranche, over the vesting period of the award. The Company’s stock-based compensation plans are discussed further in Note 11 – “Stock-Based Compensation Plans”.

EARNINGS PER SHARE

N. Earnings Per Share

Earnings per share (“EPS”) for the years ended December 31, 2018, 2017 and 2016 is based on a weighted average of the number of shares outstanding during each year. Basic and diluted EPS is computed by dividing income available to common stockholders by the weighted average number of shares outstanding for the period. The weighted average shares outstanding used to calculate basic EPS differ from the weighted average shares outstanding used in the calculation of diluted EPS due to the effect of dilutive employee stock options, nonvested stock grants and other contingently issuable shares. If the effect of such items is antidilutive, the weighted average shares outstanding used to calculate diluted EPS are equal to those used to calculate basic EPS.

Options to purchase shares of common stock whose exercise prices are greater than the average market price of the common shares are not included in the computation of diluted earnings per share because the effect would be antidilutive.

NEW ACCOUNTING PRONOUNCEMENTS

O. New Accounting Pronouncements

Recently Implemented Standards

In February 2018, the Financial Accounting Standards Board (“FASB”) issued ASC Update No. 2018-02 (Topic 220) Income Statement – Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASC update allows for a reclassification into retained earnings of the stranded tax effects in AOCI resulting from the enactment of the TCJA. Current guidance requires the effect of a change in tax laws or rates on deferred tax balances to be reported in income from continuing operations in the accounting period that includes the period of enactment, even if the related income tax effects were originally charged or credited directly to AOCI. The amount of the reclassification would include the effect of the change in the U.S. federal corporate income tax rate on the gross deferred tax amounts at the date of the enactment of the TCJA related to items in AOCI. The updated guidance is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. The Company early adopted this guidance effective January 1, 2018 with a cumulative effect adjustment, which reclassified $6.5 million of benefits from AOCI to retained earnings with no overall impact on the Company’s financial position.

In March 2017, the FASB issued ASC Update No. 2017-07, (Topic 715) Compensation – Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. This guidance requires that an employer report in its income statement the service cost component of both net periodic pension and net periodic postretirement benefit cost in the same line item or items as other compensation costs arising from services rendered by pertinent employees during the period, and present in the income statement separately from the other components of benefit cost, if appropriate under the company’s current presentation of its income statement. Additionally, the guidance allows only the service cost component to be eligible for capitalization when applicable. The updated guidance is effective for annual and interim periods beginning after December 15, 2017, and should be applied retrospectively for the presentation of the service cost component and other components of net periodic pension cost and net periodic postretirement benefit cost in the income statement, and prospectively for the capitalization of the service cost component of net periodic cost in assets. The Company implemented this guidance effective January 1, 2018. The effect of implementing this guidance was not material to the Company’s financial position or results of operations as the Company does not have any service cost remaining related to its pension and postretirement plans.

In January 2017, the FASB issued ASC Update No. 2017-01, (Topic 805) Business Combinations – Clarifying the Definition of a Business. The amendments in this update provide a more robust framework to use in determining when a set of assets and activities constitute a business. This guidance narrows the definition of a business by providing specific requirements that contribute to the creation of outputs that must be present to be considered a business. The guidance further clarifies the appropriate accounting when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets is that of an acquisition (disposition) of assets, not a business. This framework will reduce the number of transactions that an entity must further evaluate to determine whether transactions are business combinations or asset acquisitions. The updated guidance is effective for interim and annual periods beginning after December 15, 2017, and should be applied on a prospective basis. Early adoption is permitted only for transactions that have not been reported in financial statements that have been issued. The Company implemented this guidance effective January 1, 2018. The implementation of this guidance did not have an effect on the Company’s financial position or results of operations.

In November 2016, the FASB issued ASC Update No. 2016-18 (Topic 230) Statement of Cash Flows – Restricted Cash (a consensus of the FASB Emerging Issues Task Force). The amendments in this update require that restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. Current GAAP does not include specific guidance on the cash flow classification and presentation of changes in restricted cash. The updated guidance is effective for interim and annual periods beginning after December 15, 2017 and is required to be applied using a retrospective transition method to each period presented. The Company implemented this guidance effective January 1, 2018. Implementing this guidance did not have an impact on the Company’s statement of cash flows, as restricted cash, if any, has already been included in total cash and cash equivalents.

In October 2016, the FASB issued ASC Update No. 2016-16, (Topic 740) Income Taxes – Intra-Entity Transfers of Assets Other Than Inventory. Under current GAAP, the tax effects of intra-entity transfers of assets (intercompany sales) are deferred until the assets are sold to an outside party or otherwise recovered through use. This ASC update eliminates this deferral of taxes for assets other than inventory and requires the recognition of taxes when the transfer occurs. The updated guidance is effective for interim and annual periods beginning after December 15, 2017, and should be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings. Early adoption is permitted, but this election must be made in the first interim period of the adoption year. The Company implemented this guidance effective January 1, 2018. Implementation of this guidance did not have a net impact on the Company’s financial position or results of operations.

In August 2016, the FASB issued ASC Update No. 2016-15, (Topic 230) Classification of Certain Cash Receipts and Cash Payments. This ASC update provides specific guidance on the presentation of certain cash flow items where there is currently diversity in practice, including, but not limited to, debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, and distributions received from equity method investees. The updated guidance is effective for interim and annual periods beginning after December 15, 2017, and should be applied retrospectively unless impracticable. The Company implemented this guidance effective January 1, 2018. The adoption of ASC Update No. 2016-15 did not have a significant impact on the Company’s statement of cash flows.

In January 2016, the FASB issued ASC Update No. 2016-01, (Subtopic 825-10) Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU No. 2016-01”). This ASC update requires unconsolidated equity investments to be measured at fair value with changes in the fair value recognized in net income, except for those accounted for under the equity method. This update eliminates the cost method for equity investments without readily determinable fair values, replacing it with other methods, including the use of Net Asset Value (“NAV”). Additionally, when a public entity is required to measure fair value for disclosure purposes and holds financial instruments measured at amortized cost, the updated guidance requires these instruments to be measured using exit price. It also requires financial assets and financial liabilities to be presented separately in the notes to the financial statements, grouped by measurement category and form of financial asset. The updated guidance is effective for annual periods beginning after December 15, 2017. In February 2018, the FASB issued ASC Update No. 2018-03, (Subtopic 825-10) Technical Corrections and Improvements to Financial Instruments – Overall. This ASC update clarifies the transition method for equity investments without readily determinable fair values. Specifically, if an entity elects to measure these investments at cost, less impairment, adjusted for changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer (the “measurement alternative”), then transition is prospective. For all others, transition is modified retrospective, requiring a cumulative effect adjustment. This ASU is effective for annual periods beginning after December 15, 2017, and interim periods within those years beginning after June 15, 2018. Early adoption is permitted for interim periods beginning after December 15, 2017 as long as ASU No. 2016-01 has been adopted. The Company implemented this guidance effective January 1, 2018 concurrent with ASU No. 2016-01 for certain limited partnerships without readily determinable fair values. The implementation of these standards resulted in a benefit to retained earnings, through a cumulative effect adjustment, of $97.8 million, including a reclassification of after-tax unrealized gains of $95.2 million from AOCI and an adjustment of $2.6 million of gains to record partnership investments at NAV.

In May 2014, the FASB issued ASC Update No. 2014-09, (Topic 606) Revenue from Contracts with Customers. This ASC was issued to clarify the principles for recognizing revenue. Insurance contracts and financial instrument transactions are not within the scope of this updated guidance, and; therefore, only an insignificant amount of the Company’s revenue is subject to this updated guidance. In August 2015, the FASB issued ASC Update No. 2015-14, (Topic 606) Revenue from Contracts with Customers, which deferred the effective date of ASC Update No. 2014-09 by one year. Accordingly, the updated guidance is effective for periods beginning after December 15, 2017. The Company implemented this guidance effective January 1, 2018. The effect of implementing this guidance was not material to the Company’s financial position or results of operations.

Recently Issued Standards

In August 2018, the FASB issued ASC Update No. 2018-15, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASC Update No. 2018-15”). This ASC update requires the capitalization of implementation costs incurred in a hosting arrangement that is a service contract consistent with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The guidance also requires an entity to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting agreement, and apply impairment guidance consistent with long-lived assets. ASC Update No. 2018-15 also provides specific guidelines related to the presentation of these capitalized implementation costs and related expenses in the financial statements. The updated guidance is effective for interim and annual periods beginning after December 15, 2019, and should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. Early adoption is permitted, including interim periods. The Company does not expect the adoption of ASC Update No. 2018-15 to have a material impact on its financial position or results of operations.

In August 2018, the FASB issued ASC Update No. 2018-14 (Topic 715-20) Compensation – Retirement Benefits – Defined Benefit Plans – General – Disclosure Framework – Changes to the Disclosure Requirements for the Defined Benefit Plans. This ASC update modifies disclosures related to defined benefit pension or other postretirement plans. This ASC update removes the disclosure of amounts in accumulated other comprehensive income expected to be recognized over the next fiscal year and the effects of a one percentage point change of health care cost trends on net periodic benefit costs and postretirement benefit obligations and clarifies the specific requirements of disclosures related to the project benefit obligation and accumulated benefit obligation. This ASC Update also adds disclosures related to weighted average crediting rates for cash balance plans and requires disclosure of an explanation of any significant gains and losses related to changes in benefit obligations for the period. The amendments in this ASC update are effective for fiscal years ending after December 15, 2020, and should be applied on a retrospective basis to all periods presented. Early adoption is permitted. Implementing this guidance is not expected to have an impact on the Company’s financial position or results of operations as the update is disclosure related.

In August 2018, the FASB issued ASC Update No. 2018-13 (Topic 820) Fair Value Measurement, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. The update removes the requirement for disclosure of the following: 1) the amount and reasons for transfers between level 1 and level 2 of the fair value hierarchy, 2) the policy for timing of transfers between levels, and 3) the valuation processes for level 3 fair value measurements. This update also added a requirement to disclose the changes in unrealized gains and losses for the period included in other comprehensive income for recurring level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop level 3 fair value measurements, in addition to other fair value disclosure modifications. The updated guidance is effective for interim and annual periods beginning after December 15, 2019, and should be applied prospectively for certain of the disclosure requirements and retrospectively to all periods presented upon the effective date for other disclosure requirements. An entity is permitted to early adopt any removed or modified disclosures upon issuance of the update and delay adoption of additional disclosures until periods beginning after December 15, 2019, the effective date of the standard. Implementing this guidance is not expected to have an impact on the Company’s financial position or results of operations as the update is disclosure related.

In March 2017, the FASB issued ASC Update No. 2017-08, (Subtopic 310-20) Receivables – Nonrefundable Fees and Other Costs: Premium Amortization on Purchased Callable Debt Securities. This guidance shortens the amortization period of premiums on certain purchased callable debt securities to the earliest call date. The updated guidance is effective for annual and interim periods beginning after December 15, 2018, and should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Early adoption is permitted, including adoption in an interim period. The Company does not expect the adoption of ASC Update No. 2017-08 will have a material effect on its financial position or results of operations.

In January 2017, the FASB issued ASC Update No. 2017-04, (Topic 350) Intangibles – Goodwill and Other: Simplifying the Test for Goodwill Impairment. This guidance eliminates step 2 from the goodwill impairment test. Instead, an entity should perform its goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, including any applicable income tax effects, and recognize an impairment for the amount by which the carrying amount exceeds the reporting unit’s fair value. However, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The updated guidance is effective for annual or interim goodwill impairment tests performed in fiscal years 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 does not expect the adoption of ASC Update No. 2017-04 to have a material impact on its financial position or results of operations.

In June 2016, the FASB issued ASC Update No. 2016-13, (Topic 326) Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments. This ASC update introduces new guidance for the accounting for credit losses on financial instruments within its scope. A new model, referred to as the current expected credit losses model, requires an entity to determine credit-related impairment losses for financial instruments held at amortized cost and to estimate these expected credit losses over the life of an exposure (or pool of exposures). The estimate of expected credit losses should consider both historical and current information, reasonable and supportable forecasts, as well as estimates of prepayments. The estimated credit losses and subsequent adjustment to such loss estimates will be recorded through an allowance account which is deducted from the amortized cost of the financial instrument, with the offset recorded in current earnings. ASC No. 2016-13 also modifies the impairment model for available-for-sale debt securities. The new model will require an estimate of expected credit losses only when the fair value is below the amortized cost of the asset, thus the length of time the fair value of an available-for-sale debt security has been below the amortized cost will no longer affect the determination of whether a credit loss exists. In addition, credit losses on available-for-sale debt securities will be limited to the difference between the security’s amortized cost basis and its fair value. In November 2018, the FASB issued ASC Update No. 2018-19, Codification Improvements to Topic 326, Financial Instruments–Credit Losses, which explicitly states that receivables arising from operating leases are not within the scope of Subtopic 326-20. ASC Update No. 2016-13 and related guidance is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted for periods beginning after December 15, 2018. The Company expects to adopt ASC Update No. 2016-13 on January 1, 2020 and is evaluating the impact on its financial position and results of operations, which it does not expect to be material.

In February 2016, the FASB issued ASC Update No. 2016-02, (Topic 842) Leases. This ASC update requires a lessee to recognize a right-of-use asset, which represents the lessee’s right to use a specified asset for the lease term, and a corresponding lease liability, which represents a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis, for all leases that extend beyond 12 months. For finance or capital leases, interest on the lease liability will be recognized separately from amortization of the right-of-use asset in the statements of income and comprehensive income. In addition, the repayment of the principal portion of the lease liability will be classified as a financing activity while the interest component will be included in the operating section of the statement of cash flows. For operating leases, the asset and liability will be amortized as a single lease cost, such that the cost of the lease is allocated over the lease term, on a generally straight-line basis, with all cash flows included within operating activities in the statement of cash flows. ASC Update No. 2016-02 requires that implementation of this guidance be through a modified retrospective transition approach. In July 2018, the FASB issued ASC Update No. 2018-11, (Topic 842) Leases Targeted Improvements, which provides entities with an additional transition method to adopt ASC Update No. 2016-02. Under this optional transition method, an entity can initially apply the new guidance at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The Company will implement this guidance effective January 1, 2019 using the optional transition method provided in ASC Update No. 2018-11 and will elect to utilize the practical expedient package available in ASC Update 2016-02. The effect of implementing this guidance is expected to increase total assets and liabilities each by approximately $35 million on January 1, 2019, which is not material to the Company’s financial position. Furthermore, implementation of this guidance is not expected to have a material impact on the Company’s results of operations.

RECLASSIFICATIONS

Q. Reclassifications

Certain prior year amounts have been reclassified to conform to the current year presentation.