Signficant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2023
Accounting policies and error corrections [Abstract]
Basis of Presentation	Basis of Presentation: The accompanying consolidated financial statements of Unum Group and its subsidiaries (the Company) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). Such accounting principles differ from statutory accounting principles (see Note 18). Intercompany transactions have been eliminated.
Use of Estimates	Use of Estimates: The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Such estimates and assumptions could change in the future as more information becomes known, which could impact the amounts reported and disclosed herein. In accordance with standard practice, we regularly review the methodology used in the development of all key estimates. As a result of this review, in 2022, we updated our estimate of the unearned premium reserve for certain of our product lines to utilize a gross unearned premium reserve rather than a net unearned premium reserve. The effect of this change in estimate was to decrease 2022 premium income by $13.4 million and decrease commissions by $1.0 million. This resulted in a decrease to net income of $9.8 million and a decrease to both basic and diluted earnings per share by $0.05.
Fixed Maturity Securities	Fixed Maturity Securities: Fixed maturity securities include long-term bonds and redeemable preferred stocks. Our fixed maturity securities are classified as available-for-sale and reported at fair value. Changes in the fair value of available-for-sale fixed maturity securities, except for amounts related to impairment and credit losses recognized in earnings, are reported as a component of other comprehensive income, net of income tax. Realized investment gains or losses are based upon specific identification of the investments sold. Interest income is recorded as part of net investment income when earned, using an effective yield method giving effect to amortization of premium and accretion of discount. Included within fixed maturity securities are mortgage-backed and asset-backed securities. We recognize investment income on these securities using a constant effective yield based on projected prepayments of the underlying loans and the estimated economic life of the securities. Actual prepayment experience is reviewed periodically, and effective yields are recalculated when differences arise between prepayments originally projected and the actual prepayments received and currently projected. The effective yield is recalculated on a retrospective basis, and the adjustment is reflected in net investment income. For fixed maturity securities on which collection of investment income is uncertain, we discontinue the accrual of investment income and recognize investment income when interest and dividends are received. Payment terms specified for fixed maturity securities may include a prepayment penalty for unscheduled payoff of the investment. Prepayment penalties are recognized as investment income when received. In determining when a decline in fair value below amortized cost of a fixed maturity security is a credit loss, we evaluate available information, both positive and negative, in reaching our conclusions. In particular, we consider the strength of the issuer's balance sheet, its debt obligations and near-term funding requirements, cash flow and liquidity, the profitability of its core businesses, the availability of marketable assets which could be sold to increase liquidity, its industry fundamentals and regulatory environment, and its access to capital markets. Although all available and applicable factors are considered in our analysis, our expectation of recovering the entire amortized cost basis of the security, whether we intend to sell the security, whether it is more likely than not that we will be required to sell the security before recovery of its amortized cost, and whether the security is current on principal and interest payments are the most critical factors in determining whether impairments represent credit losses. The significance of the decline in value is also an important factor, but we generally do not record an impairment loss based solely on this factor, since often other more relevant factors will impact our evaluation of a security. For securities with a decline in fair value below amortized cost which we intend to sell or more likely than not will be required to sell before recovery in value, the amortized cost of the investment is written down to fair value through earnings, and an impairment loss is recognized in the current period. For securities that we believe are impaired and which we do not intend to sell and it is not more likely than not that we will be required to sell before recovery in value, we calculate an allowance for credit losses recognized in earnings which generally represents the difference between the amortized cost of the security and the present value of our best estimate of cash flows expected to be collected, discounted using the effective interest rate implicit in the security at the date of acquisition and limited by the difference between amortized cost and fair value of the security. For fixed maturity securities for which we have recognized an allowance for credit loss through earnings, if through subsequent evaluation there is a significant increase in expected cash flows, the allowance is reduced and is recognized as a reduction to credit losses in the current period. When an allowance for credit losses on a fixed maturity security is recognized, we designate non-accrual status for those securities. We reverse all previously accrued interest through interest income and use a cash basis method for recognizing any future payments received. See Notes 2 and 3.
Mortgage Loans	Mortgage Loans: Mortgage loans are generally held for investment and are carried at amortized cost less an allowance for expected credit losses. Interest income is accrued on the principal amount of the loan based on the loan's contractual interest rate. Prepayment penalties are recognized as investment income when received. For mortgage loans on which collection of interest income is uncertain, we discontinue the accrual of interest and recognize it in the period when an interest payment is received. We typically do not resume the accrual of interest on mortgage loans on nonaccrual status until there are significant improvements in the underlying financial condition of the borrower. We consider a loan to be delinquent if full payment is not received in accordance with the contractual terms of the loan. We evaluate each of our mortgage loans individually for impairment and assign an internal credit quality rating based on a comprehensive rating system used to evaluate the credit risk of the loan. Although all available and applicable factors are considered in our analysis, loan-to-value and debt service coverage ratios are the most critical factors in determining impairment. We estimate an allowance for credit losses that we expect to incur over the life of our mortgage loans using a probability of default method. For each loan, we estimate the probability that the loan will default before its maturity (probability of default) and the amount of the loss if the loan defaults (loss given default). These two factors result in an expected loss percentage that is applied to the amortized cost of each loan to determine the expected credit loss. As we are typically the original underwriter of the mortgage loans, the amortized cost generally equals the principal amount of the loan. We measure losses on defaults of our mortgage loans as the excess amortized cost of the mortgage loan over the fair value of the underlying collateral in the event that we foreclose on the loan or over the expected future cash flows of the loan if we retain the mortgage loan until payoff. We do not purchase mortgage loans with existing credit impairments. In estimating the probability of default, we consider historical experience, current market conditions, and reasonable and supportable forecasts about the future market conditions. We utilize our historical loan experience in combination with a large third-party industry database for a period of time that aligns with the average life of our loans based on the maturity dates of the loans and prepayment experience. Our model utilizes an industry database of the historical loss experience based on our actual portfolio characteristics such as loan-to-value, debt service coverage, collateral type, geography, and late payment history. In addition, because we actively manage our portfolio, we may extend the term of a loan in certain situations and will accordingly extend the maturity date in the estimate of probability of default. In estimating the loss given default, we primarily consider the type and value of collateral and secondarily the expected liquidation costs and time to recovery. The primary market factors that we consider in our forecast of future market conditions are gross domestic product, unemployment rates, interest rates, inflation, commercial real estate values, household formation, and retail sales. We also forecast certain loan specific factors such as growth in the fair value and net operating income of collateral by property type. We include our estimate of these factors over a two-year period and for the remainder of the loans’ estimated lives, adjusted for estimated prepayments. Past the two-year forecast period, we revert to the historical assumptions ratably by the end of the fifth year of the loan after which we utilize only historical assumptions. We utilize various scenarios to estimate our allowance for expected losses ranging from a base case scenario that reflects normal market conditions to a severe case scenario that reflects adverse market conditions. We will adjust our allowance each period to utilize the scenario or weighting of the scenarios that best reflects our view of current market conditions. Additions and reductions to our allowance for credit losses on mortgage loans are reported as a component of net investment gains and losses. See Note 3.
Policy Loans	Policy Loans: Policy loans are presented at the unpaid balances directly related to policyholders. Interest income is accrued on the principal amount of the loan based on the loan's contractual interest rate. Included in policy loans are $3,322.5 million and $3,312.5 million of policy loans ceded to reinsurers at December 31, 2023 and 2022, respectively.
Investments	Other Long-term Investments: Other long-term investments are comprised primarily of private equity partnerships, real estate, perpetual preferred stock, common stock, and tax credit partnerships. Our investments in private equity partnerships are passive in nature and represent funds that are primarily invested in private credit, private equity, and real assets. We account for our investments in these partnerships using either the equity method or at fair value through net income depending on the level of ownership and the degree of our influence over partnership operating and financial policies. For investments in partnerships accounted for under the equity method, we report our investments at our share of the partnership's net asset value (NAV) and record our portion of partnership earnings as a component of net investment income. For investments in partnerships accounted for at fair value through net income, we also report our investments at our share of the partnership's NAV as a practical expedient for fair value with increases or decreases recorded as a component of net investment income. Distributions received from the funds arise from income generated by the underlying investments as well as the liquidation of the underlying investments and there is generally not a public market for these investments. Investment real estate is primarily comprised of property held for the production of income and property held for sale. Property held for the production of income is carried at cost less accumulated depreciation and any write-downs to fair value for impairment losses. Depreciation is recorded on a straight-line basis over the estimated useful life of the asset. A review for impairment is made whenever events or circumstances indicate that the carrying value may not be recoverable. An impairment loss is recognized when the carrying value of the property exceeds the expected undiscounted cash flows generated from the property, at which point the carrying value is written down to an estimated fair value. Real estate held for sale is carried at the lower of depreciated cost or fair value less estimated selling costs and is not further depreciated once classified as such. Our perpetual preferred stocks are valued at fair value, based on quoted market prices, where available. For preferred stocks not actively traded, fair values are estimated using values obtained from independent pricing services. Our investments in common stock are valued at fair value. Our shares of Federal Home Loan Bank (FHLB) common stock are carried at cost, which approximates fair value. Tax credit partnerships in which we have invested were formed for the purpose of investing in the construction and rehabilitation of low-income housing. Because the partnerships are structured such that there is no return of principal, the primary sources of investment return from our tax credit partnerships are tax credits and tax benefits derived from passive losses on the investments, both of which may exhibit variability over the life of the investment. These partnerships are accounted for using either the proportional or the effective yield method, depending primarily on whether the tax credits are guaranteed through a letter of credit, a tax indemnity agreement, or another similar arrangement. Tax credits received from these partnerships are reported in our consolidated statements of income as either a reduction of premium tax or a reduction of income tax. The amortization of the principal amount invested in these partnerships is reported as a component of either premium tax or income tax. See Notes 2 and 3 for further discussion of our other long-term investments. Short-term Investments: Short-term investments are carried at cost. Short-term investments include investments maturing within one year of purchase, such as corporate commercial paper and Treasury bills, bank term deposits, and other cash accounts and cash equivalents earning interest.
Cash and Bank Deposits	Cash and Bank Deposits: Cash and bank deposits include cash on hand and non-interest bearing cash and deposit accounts.
Derivative Financial Instruments	Derivative Financial Instruments: Derivative financial instruments (including certain derivative instruments embedded in other contracts) are recognized as either other long-term investments or other liabilities in our consolidated balance sheets and are reported at fair value. The accounting for a derivative depends on whether it has been designated and qualifies as part of a hedging relationship, and further, on the type of hedging relationship. To qualify for hedge accounting, at the inception of the hedging transaction, we formally document the risk management objective and strategy for undertaking the hedging transaction, as well as the designation of the hedge as either a fair value hedge or a cash flow hedge. Included in this documentation is how the hedging instrument is expected to hedge the designated risk(s) related to specific assets or liabilities on the balance sheet or to specific forecasted transactions as well as a description of the method that will be used to retrospectively and prospectively assess the hedging instrument's effectiveness. A derivative designated as a hedging instrument must be assessed as being highly effective in offsetting the designated risk(s) of the hedged item. Hedge effectiveness is formally assessed at inception and periodically throughout the life of the designated hedging relationship, using qualitative and quantitative methods. Qualitative methods include comparison of critical terms of the derivative to the hedged item. Quantitative methods include regression or other statistical analysis of changes in fair value or cash flows associated with the hedge relationship. Changes in the fair value of a derivative designated as a fair value hedge and changes in the fair value of the hedged item attributable to the risk being hedged are recognized in earnings as a component of net investment gain or loss during the period of change in fair value. For gains or losses on the derivative instrument that are excluded from the assessment of hedge effectiveness, those gains and losses are recognized in other comprehensive income or loss and amortized into earnings in the same income statement line as the related hedged item. The gain or loss on the termination of a fair value hedge is recognized in earnings as a component of net investment gain or loss during the period in which the termination occurs. When interest rate swaps are used in hedge accounting relationships, periodic settlements are recorded in the same income statement line as the related settlements of the hedged items. Changes in the fair value of a derivative designated as a cash flow hedge are reported in other comprehensive income and reclassified into earnings and reported on the same income statement line item as the hedged item and in the same period or periods during which the hedged item affects earnings. The gain or loss on the termination of an effective cash flow hedge is reported in other comprehensive income and reclassified into earnings and reported on the same income statement line item as the hedged item and in the same period or periods during which the hedged item affects earnings. Gains or losses on the termination of ineffective fair value or cash flow hedges are reported in earnings as a component of net investment gain or loss. In the event a hedged item is disposed of or the anticipated transaction being hedged is no longer likely to occur, we will terminate the related derivative and recognize the gain or loss on termination in current earnings as a component of net investment gain or loss. In the event a hedged item is disposed of subsequent to the termination of the hedging transaction, we reclassify any remaining gain or loss on the hedge out of accumulated other comprehensive income into earnings as a component of the same income statement line item wherein we report the gain or loss on disposition of the hedged item. For a derivative not designated as a hedging instrument, changes in the fair value of the derivative, together with the payment of periodic fees, if applicable, are recognized in the same income statement line item as the hedged item during the period of change in fair value. Cash flows related to derivative contracts are included in the consolidated statements of cash flows, coinciding with the timing of the hedged item. Cash inflows are included as a component of proceeds from sales and maturities of other investments. Cash outflows are included as a component of purchases of other investments. In our consolidated balance sheets, we do not offset fair value amounts recognized for derivatives executed with the same counterparty under a master netting agreement and fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral arising from those master netting agreements. See Notes 2, 3, and 4.
Fair Value Measurement	Fair Value Measurement: Certain assets and liabilities are reported at fair value in our consolidated balance sheets and in our notes to our consolidated financial statements. We define fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Therefore, fair value represents an exit price, not an entry price. The exit price objective applies regardless of our intent and/or ability to sell the asset or transfer the liability at the measurement date. Assets or liabilities with readily available actively quoted prices or for which fair value can be measured from actively quoted prices in active markets generally have more pricing observability and less judgment utilized in measuring fair value. When actively quoted prices are not available, fair values are based on quoted prices in markets that are not active, quoted prices for similar but not identical assets or liabilities, or other observable inputs. If observable inputs are not available, unobservable inputs and/or adjustments to observable inputs requiring management judgment are used to determine fair value. We categorize our assets and liabilities measured at estimated fair value into a three-level hierarchy, based on the significance of the inputs. The fair value hierarchy gives the highest priority to inputs which are unadjusted and represent quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). See Note 2.
Allowance for Credit Losses on Premiums Receivable	Allowance for Credit Losses on Premiums Receivable: We establish an allowance for credit losses on premiums receivable, which is deducted from the gross amount of our receivable balance, to present the net amount we expect to collect on this asset. The allowance is forward-looking in nature and is calculated based on considerations regarding both historical events and future expectations. Periodic changes in the allowance are recorded through earnings. The allowance on our premiums receivable is primarily determined using an aging analysis as well as historical lapse and delinquency rates by line of business, adjusted for key factors that may impact our future expectation of premium receipts such as changes in customer demographics, business practices, economic conditions, and product offerings. We write off premiums receivable amounts when determined to be uncollectible, which is based on various factors, including the aging of premiums receivable past the due date and specific communication with customers. At December 31, 2023 and 2022, the allowance for expected credit losses on premium receivables was $29.5 million and $32.5 million, respectively, on gross premium receivables of $612.4 million and $557.6 million, respectively. The allowance decreased $3.0 million and $1.7 million during the years ended December 31, 2023, and 2022, respectively. The decreases were driven primarily by improvements in the age of premiums receivable.
Deferred Acquisition Costs	Deferred Acquisition Costs: Incremental direct costs associated with the successful acquisition of new or renewal insurance contracts have been deferred. Such costs include commissions, other agency compensation, certain selection and policy issue expenses, and certain field expenses. Acquisition costs that do not vary with the production of new business, such as commissions on group products which are generally level throughout the life of the policy, are excluded from deferral. Our insurance contracts are grouped by product type and contract issue year into cohorts consistent with the grouping used to estimate the related contract liabilities. DAC is amortized on a constant level basis over the life of the policy. For all products, in-force volume metrics are used as the constant level basis. The lapse and mortality assumptions used to amortize DAC for our traditional long-duration products are consistent with the assumptions used to estimate the liability for future policy benefits. The underlying assumptions used to determine DAC amortization are updated concurrently with any related assumption changes for the liability for future policy benefits and changes in estimates are recognized prospectively over the remaining expected term of the related contracts. Amortization expense is adjusted based on actual versus expected experience through an adjustment to the prospective rate of amortization. For certain products, policyholders can elect to modify product benefits, features, rights, or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacement transactions, principally on group contracts. Internal replacement transactions wherein the modification does not substantially change the policy are accounted for as continuations of the replaced contracts. The original policy continues to be reflected as an in force policy within its original cohort. The policy's expected life then impacts the amortization of remaining unamortized deferred acquisition costs within its cohort. The costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Internal replacement transactions that result in a policy that is substantially changed are accounted for as an extinguishment of the original policy and the issuance of a new policy. The original policy that was replaced is terminated from its original cohort and this termination is reflected in the amortization rate of remaining unamortized deferred acquisition costs for the cohort. The costs of acquiring the new policy are capitalized and amortized as part of a new cohort. See note 8.
Goodwill	Goodwill: Goodwill is the excess of the amount paid to acquire a business over the fair value of the net assets acquired. We review the carrying amount of goodwill for impairment on an annual basis, or more frequently if events or changes in circumstances indicate that the carrying amount might not be recoverable. Goodwill impairment testing compares the fair value of a reporting unit with its carrying amount, including goodwill. If the fair value of the reporting unit to which the goodwill relates is less than the carrying amount of the reporting unit, an impairment charge is recognized for the amount by which the carrying amount exceeds the fair value of the reporting unit in an amount not to exceed the total amount of goodwill allocated to the reporting unit.
Property and Equipment	Property and Equipment: Property and equipment is reported at cost less accumulated depreciation, which is calculated on the straight-line method over the estimated useful life. The accumulated depreciation for property and equipment was $1,422.8 million and $1,328.7 million as of December 31, 2023 and 2022, respectively.
Value of Business Acquired	Value of Business Acquired: Value of business acquired represents the present value of future profits recorded in connection with the acquisition of a block of insurance policies. The asset is amortized based upon expected future premium income for non-interest sensitive insurance policies and estimated future gross profits from surrender charges, mortality margins, investment returns, and expense margins for interest sensitive insurance policies. The value of business acquired, which is included in other assets in our consolidated balance sheets, was $63.9 million and $62.9 million at December 31, 2023 and 2022, respectively. The accumulated amortization for value of business acquired was $161.8 million and $150.3 million as of December 31, 2023 and 2022, respectively. The amortization of value of business acquired, which is included in other expenses in the consolidated statements of income, was $5.2 million, $4.9 million, and $5.7 million for the years ended December 31, 2023, 2022, and 2021, respectively. We periodically review the carrying amount of value of business acquired and it is subject to recoverability testing on an annual basis, or more frequently, if appropriate.
Reserves for Policy and Contract Benefits	Future Policy Benefits: Liabilities for future policy benefits represent the cost of claims that we estimate we will eventually pay to our policyholders which includes policy liabilities for claims not yet incurred and for claims that have been incurred or are estimated to have been incurred but not yet reported to us. Liabilities for future policy benefits also include the related expenses for our non interest-sensitive life and accident and health products. The liability for future policy benefits is calculated based on the present value of the estimated future policy benefits less the present value of estimated future net premiums collected. Net premiums represent the portion of the gross premium required to provide for all benefits and expenses, excluding acquisition costs or any costs that are required to be charged to expense as incurred. In calculating the liability for future policy benefits, our long-duration contracts are grouped into cohorts by product type and contract issue year. The calculation of the liability for future policy benefits involves numerous assumptions including assumptions related to discount rate, lapses, mortality, and morbidity. The discount rate assumptions were initially set based on the expected investment yield of the assets supporting the reserves at the transition date of accounting standards update (ASU) 2018-12, which was January 1, 2021, for policies originally issued on or before the transition date. The discount rate assumptions for new cohorts established after the transition date, are initially set based on the policy issuance date or policy renewal date, and are based on an upper-medium grade fixed-income instrument, which is generally equivalent to a single-A interest rate matched to the duration of our insurance liabilities. As cohorts are grouped by product type and issue year, a weighted average discount rate is utilized as policies are issued or renewed throughout the year. We utilize a reference portfolio of fixed-income instruments that have been A-rated by one of the major credit rating agencies. For products with liability cash flows that exceed the duration of observable single-A fixed income instruments, we use the last market observable yield and use extrapolation approaches to determine yield assumptions for durations beyond the last market observable duration. For the discount rate assumptions for products in our Unum International segment, we utilize observable market data in the local debt markets in the UK and Poland. The initial, also referred to as the original, discount rate assumptions established for each cohort are used to determine interest accretion which is reported as a component of policy benefits on the statements of income. After policy issuance or policy renewal, the discount rate assumptions are updated quarterly and used to update the liability at each reporting date to the current discount rate, with the corresponding change reflected as the change in the effect of discount rate assumptions on the liability for future policy benefits, net of reinsurance, on the statement of changes in other comprehensive income (loss). Policyholder lapse and mortality assumptions reflect the probability that an insureds’ coverage is discontinued due to lapsation or death of the insured. For our life insurance products, mortality assumptions also reflect the probability that a benefit payment occurs. Policyholder lapse and mortality assumptions are based on our actual historical experience adjusted for future expectations. Claim incidence and claim resolution rate assumptions related to morbidity and mortality are based on actual experience or industry standards adjusted as appropriate to reflect our actual experience and future expectations. The claim incidence rate assumption is the rate at which new claims are submitted and the development of this assumption may involve many factors, including the age of the insured, the insured's occupation or industry, the benefit plan design, and certain external factors such as consumer confidence and levels of unemployment. The claim resolution rate assumption is the probability that a claim will close due to recovery or death of the insured and is used to estimate how long benefits will be paid on an open claim. Certain product lines may utilize additional assumptions in calculating the liability for future policy benefits in addition to those listed above such as premium rate increases for long-term care, benefit offsets for long-term disability, and claim costs for voluntary benefits. Claim costs capture the combined effect of the incidence rate, the expected level of benefit to be paid, and the claim resolution rate. Cash flow assumptions are reviewed and updated, as needed, at least annually. Assumptions may be updated more frequently if necessary based on trending experience and future expectations. On a quarterly basis, cohort level cash flow measures are updated based on the emergence of actual experience. The updated cash flows are used to determine the updated net premiums and the net premium ratio, which is the present value of benefits and related expenses divided by the present value of gross premiums. The updated net premium ratio is used to calculate the updated liability for future policy benefits as of the beginning of the year, at the original discount rate. The change in the liability for future policy benefits, at the original discount rate, as of the beginning of the period, resulting from changes in cash flow assumptions and resulting from the emergence of actual experience from expected experience, is reflected as the policy benefits - remeasurement loss (gain) in the consolidated statements of income. The impact of all other changes in the liability for future policy benefits are reflected as policy benefits in the consolidated statements of income. For most products, a net premium methodology is applied to each cohort to estimate the liability for claims not yet incurred in which discounted gross benefits are compared to discounted gross premiums. In this methodology, actual experience to date is combined with projected future cash flows to determine a net premium ratio for each cohort. The future cash flows include the costs of future expected claims as well as future cash flows on claims that have already been incurred. The net premium ratio is then used to estimate the liability for future policy benefits. The liability for future policy benefits represents the present value of future claims and associated expenses less the present value of future net premiums, which is derived by multiplying the present value of future gross premium by the net premium ratio. For our group products in the Unum US and Unum International segments, we evaluate the liability for future policy benefits required for active policies in comparison to incurred claims. Given the term nature of the products, their renewal features, and level funding nature of the premium for these products, we have determined that the liability value is generally zero for policies that are not on claim. For these products, our liability for future policy benefit values are limited to the liability associated with claims incurred as of the valuation date. Multiple estimation methods exist to establish liabilities for the incurred claim component of future policy benefits. Available reserving methods utilized to calculate these liabilities include the tabular reserve method, the paid loss development method, the incurred loss development method, the count and severity method, and the expected claim cost method. No single method is better than the others in all situations and for all product lines. The estimation methods we have chosen are those that we believe produce the most accurate and reliable liability. We use a tabular reserve methodology on reported claims for our Unum US group long-term disability and individual disability claims as well as for our Closed Block long-term care claims. Under the tabular reserve methodology, the liability for reported claims is based on certain characteristics of the actual reported claimants and their related policy provisions, such as age, length of time disabled, and medical diagnosis, as well as assumptions regarding claim duration, discount rate, and policy benefit offsets. We believe the tabular reserve method is the most accurate to calculate long-term liabilities and allows us to use the most available known facts about each claim. Incurred, but not reported (IBNR) liabilities for future policy benefits for our longer-term products are calculated using the count and severity method using historical patterns of the claims to be reported and the associated claim costs. For Unum US group short-term disability products, an estimate of the value of future payments to be made on claims already submitted, as well as on IBNR claims, is determined in aggregate using a paid loss development method rather than on the individual claimant basis that we use for reported claims on longer-term products. The average length of time between the event triggering a claim under a policy and the final resolution of those claims is much shorter for these products and results in less estimation variability. Liabilities for claims for Unum US group life and accidental death and dismemberment products are related primarily to death claims reported but not yet paid, IBNR death claims, and a liability for waiver of premium benefits in the event the policyholder becomes disabled. The death claim liability is based on the actual face amount to be paid, the IBNR liability is calculated using the count and severity method based on historical patterns of the claims, and the waiver of premium benefits liability is calculated using the tabular reserve methodology. Liabilities for claims related to the group and individual dental and vision products reported in our Unum US and Colonial Life segments have a short claim payout period. As a result, the liabilities, which primarily represent IBNR and a small amount of claims pending payment, are calculated using the paid loss development method. Liabilities for future policy benefits supporting the group products within our Unum International segment are calculated using generally the same methodology that we use for Unum US group disability and group life liabilities. Liabilities for future policy benefits for our Unum UK group life dependent product, which provides an annuity to the beneficiary upon the death of an employee, are calculated using discounted cash flows, based on our assumptions for claim duration and discount rates. The assumptions used in calculating liabilities for future policy benefits for this segment are based on standard country-specific industry experience, adjusted for our own experience. Certain products in the Colonial Life segment and the Unum US voluntary benefits product line have shorter-term benefits, which generally have less estimation variability than our longer-term products because of the shorter claim payout period. Our liabilities for future policy benefits for these lines of business are predominantly determined using the incurred loss development method based on our own experience. The incurred loss development method uses the historical patterns of payments by loss date to predict future claim payments for each loss date. Where the incurred loss development method may not be appropriate, we estimate the incurred claims using an expected claim cost per policy or other measure of exposure. See note 6.
Policyholders' Account Balances	Policyholders' Account Balances: Policyholders' account balances primarily include our universal life and corporate-owned life insurance products. Policyholders' account balances reflect customer deposits and interest credited less cost of insurance, administration expenses, surrender charges, and customer withdrawals. Our unearned revenue reserve, claim reserves and certain other reserves related to our universal life products and corporate-owned life insurance products are also reported as a component of policyholders’ account balances. Policyholders' account balances require loss recognition testing. We perform loss recognition tests on these reserves annually, or more frequently if appropriate, using best estimate assumptions as of the date of the test, without a provision for adverse deviation. We group the policy reserves for each major product line within a reporting segment when we perform the loss recognition tests. If the excess of the present value of projected future benefits and claim settlement expenses over the present value of projected future gross premiums is greater than the existing policy reserves less any unearned revenue reserve or value of business acquired, the existing policy reserves would be increased to immediately recognize the insufficiency. This becomes the new basis for reserves going forward, subject to future loss recognition testing. Anticipated investment income, based on our anticipated portfolio yield rates after consideration for defaults and investment expenses, is considered when performing loss recognition testing for long-duration contracts. See note 7.
Policyholders' Funds	Other Policyholders' Funds: Other policyholders' funds represent customer deposits plus interest credited at contract rates. We control interest rate risk by investing in quality assets which have an aggregate duration that closely matches the expected duration of the liabilities.
Income Tax	Income Tax: Deferred taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial statement purposes and the amounts used for income tax purposes. Deferred taxes have been measured using enacted statutory income tax rates and laws that are currently in effect. We record adjustments to our deferred taxes resulting from tax rate changes through income as of the date of enactment. We record deferred tax assets for tax positions taken in the U.S. and other tax jurisdictions based on our assessment of whether a position is more likely than not to be sustained upon examination based solely on its technical merits. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized. We record tax expense related to Global Intangible Low-Taxed Income in the period in which it is incurred. We follow an aggregate portfolio approach to release disproportionate tax effects from accumulated other comprehensive income upon disposal of an entire business segment's portfolio. See Note 9.
Short-term and Long-term Debt	Short-term and Long-term Debt: Debt is generally carried at the unpaid principal balance, net of unamortized discount or premium and deferred debt issuance costs. Short-term debt consists of debt due within the next twelve months, including that portion of debt otherwise classified as long-term. The amortization of the original issue discount or premium as well as deferred debt issuance costs are recognized as a component of interest expense over the period the debt is expected to be outstanding. See Note 10.
Right-of-Use Asset (ROU) and Lease Liability	Right-of-Use Asset (ROU) and Lease Liability: ROU assets represent our right to use an underlying asset for a specified lease term and are included in other assets in our consolidated balance sheet. Lease liabilities represent the present value of lease payments that we are obligated to pay arising from a lease and are included in other liabilities in our consolidated balance sheet. We determine if an arrangement is a lease at inception through a formal process that evaluates our right to control the use of an identified asset for a period of time in exchange for consideration. We account for the lease and non-lease components of our building leases separately and have elected to use the available practical expedient to account for the lease and non-lease components of our equipment leases as a single component. All of our leases are classified as operating. For each operating lease, we calculate a lease liability at commencement date based on the present value of lease payments over the lease term and a corresponding ROU asset, adjusted for lease incentives. We do not recognize right-of-use assets and lease liabilities that arise from short-term leases for any class of underlying asset. We consider the likelihood of renewal in determining the lease terms for the calculation of the ROU asset and lease liability. As most of our leases do not provide an implicit rate of interest, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. We use the implicit rate of interest when readily determinable. Operating lease cost is calculated on a straight-line basis over the lease term and is included in other expenses in our consolidated statements of income. We amortize the ROU asset over the lease term on a pattern determined by the difference between the straight-line lease liability expense and the accretion of the imputed interest calculated on the lease liability. See Note 17.
Separation of Lease and Nonlease Components	We account for the lease and non-lease components of our building leases separately and have elected to use the available practical expedient to account for the lease and non-lease components of our equipment leases as a single component.
Short-term Leases	We do not recognize right-of-use assets and lease liabilities that arise from short-term leases for any class of underlying asset.
Treasury Stock and Retirement of Common Stock	Treasury Stock and Retirement of Common Stock: Treasury stock is reflected as a reduction of stockholders' equity at cost. When shares are retired, the par value is removed from common stock, and the excess of the repurchase price over par is allocated between additional paid-in capital and retained earnings. See Note 12.
Revenue Recognition	Revenue Recognition: Our non-interest sensitive life and accident and health products are long-duration contracts, and premium income is recognized as revenue when due from policyholders. If the contracts are experience rated, the estimated ultimate premium is recognized as revenue over the period of the contract. The estimated ultimate premium, which is revised to reflect current experience, is based on estimated claim costs, expenses, and profit margins. For interest sensitive products, the amounts collected from policyholders are considered deposits, and only the deductions during the period for cost of insurance, policy administration, and surrenders are included in revenue. Policyholders' funds represent funds deposited by contract holders and are not included in revenue.
Revenue from Service Fees	Fees from our solutions business, which include leave management services and administrative-services only (ASO) business are reported as other income when services are rendered.
Reinsurance	Reinsurance: We routinely enter into reinsurance agreements with other insurance companies to spread risk and thereby limit losses from large exposures. For each of our reinsurance agreements, we determine if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. If we determine that a reinsurance agreement does not expose the reinsurer to a reasonable possibility of a significant loss from insurance risk, we record the agreement using the deposit method of accounting. Reinsurance activity is accounted for on a basis consistent with the terms of the reinsurance contracts and the accounting used for the original policies issued. Premium income, policy benefits, and policy benefits - remeasurement gain or loss are presented in our consolidated statements of income net of reinsurance ceded. Ceded liabilities for future policy benefits, policyholders' account balances and unearned premiums are reported on a gross basis in our consolidated balance sheets, as are ceded policy loans. Our reinsurance recoverable includes the balances due from reinsurers under the terms of the reinsurance agreements for these ceded balances as well as settlement amounts currently due. For ceded reinsurance transactions occurring after January 1, 2021, the transition date of ASU 2018-12, in accordance with the provisions of the ASU related to non-contemporaneous reinsurance, we are required to establish the ceded reserves using an upper-medium grade fixed-income instrument as of the reinsurance transaction date. However, the direct reserves for the reinsured block are calculated using the original discount rate utilized as of the transition date. Both the direct and ceded reserves are then remeasured at each reporting period using a current discount rate reflective of an upper-medium grade fixed-income instrument, with the changes recognized in other comprehensive income(loss). While the total equity impact is neutral, the different original discount rates utilized for direct and ceded reserves result in disproportionate earnings impacts. Where applicable, gains or costs recognized on reinsurance transactions are generally deferred and amortized into earnings based upon expected future premium income for non-interest sensitive insurance policies and estimated future gross profits for interest sensitive insurance policies. Gains or costs recognized on reinsurance transactions for non-interest sensitive products for which we no longer receive premiums are generally deferred and amortized into earnings based upon expected claim reserve patterns. The cost of reinsurance included in other assets in our consolidated balance sheets at December 31, 2023 and 2022 was $549.4 million and $593.5 million. The deferred gain on reinsurance included in other liabilities in our consolidated balance sheets at December 31, 2023 and 2022 was $8.8 million and $3.1 million, respectively. Under ceded reinsurance agreements wherein we are not relieved of our legal liability to our policyholders, if the assuming reinsurer is unable to meet its obligations, we remain contingently liable. We evaluate the financial condition of reinsurers and monitor concentration of credit risk to minimize this exposure. We may also require assets in trust, letters of credit, or other acceptable collateral to support our reinsurance recoverable balances. We estimate an allowance for expected credit losses for our reinsurance recoverable balance using a probability of default approach which incorporates key inputs and assumptions regarding market factors, counterparty credit ratings, and collateral received. When calculating our allowance, we apply these market factors to the net amount of our credit exposure, which considers collateral arrangements such as letters of credit and trust accounts. We evaluate the factors used to determine our allowance on a quarterly basis to consider material changes in our assumptions and make adjustments accordingly. The allowance for expected credit losses on reinsurance recoverables was $1.7 million at both December 31, 2023 and 2022. In 2022, the allowance decreased $0.6 million primarily due to changes in the composition of the related receivable. See Note 14.
Premium Tax Expense	Premium Tax Expense: Premium tax expense is included in other expenses in the consolidated statements of income. For the years ended December 31, 2023, 2022, and 2021, premium tax expense was $183.5 million, $169.3 million, and $166.0 million, respectively.
Stock-Based Compensation	Stock-Based Compensation: Restricted stock units and stock success units are valued based on the fair value of common stock at the grant date. The fair value of performance units and cash incentive units is based on the Monte-Carlo valuation model. We evaluate whether there are any events which would require an adjustment to the price of common stock at the grant date. No adjustments have been made to any grant date prices for any awards as of December 31, 2023 or 2022. Stock-based awards are expensed over the requisite service period, or for performance units over the requisite service period, or remaining service period, if and when it becomes probable that the performance conditions will be satisfied, with an offsetting increase to additional paid-in capital in stockholders' equity. The expense for certain of our awards is subject to accelerated recognition over the implicit service period for employees who have met the criteria for retirement eligibility. Forfeitures of stock-based awards are recognized as they occur. See Note 13.
Earnings Per Share	Earnings Per Share: We compute basic earnings per share by dividing net income by the weighted average number of common shares outstanding for the period. Earnings per share assuming dilution is computed by dividing net income by the weighted average number of shares outstanding for the period plus the shares representing the dilutive effect of stock-based awards. In computing earnings per share assuming dilution, only potential common shares resulting from stock-based awards that are dilutive (those that reduce earnings per share) are included. We use the treasury stock method to account for the effect of nonvested stock awards on the computation of earnings per share assuming dilution. See Note 12.
Translation of Foreign Curency	Translation of Foreign Currency: Revenues and expenses of our foreign operations are translated at average exchange rates. Assets and liabilities are translated at the rate of exchange on the balance sheet dates. The translation gain or loss is generally reported in accumulated other comprehensive income, net of income tax. We do not provide for deferred taxes to the extent unremitted foreign earnings are deemed permanently invested.
Accounting for Participating Individual Life Insurance	Accounting for Participating Individual Life Insurance: Participating policies issued by one of our subsidiaries prior to its 1986 conversion from a mutual to a stock life insurance company will remain participating as long as the policies remain in-force. A Participation Fund Account (PFA) was established for the benefit of all such individual participating life and annuity policies and contracts. The assets of the PFA provide for the benefit, dividend, and certain expense obligations of the participating individual life insurance policies and annuity contracts. The assets of the PFA were $244.4 million and $250.2 million at December 31, 2023 and 2022, respectively.

Signficant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Accounting policies and error corrections [Abstract]

Basis of Presentation: The accompanying consolidated financial statements of Unum Group and its subsidiaries (the Company) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). Such accounting principles differ from statutory accounting principles (see Note 18). Intercompany transactions have been eliminated.

Use of Estimates

Use of Estimates: The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Such estimates and assumptions could change in the future as more information becomes known, which could impact the amounts reported and disclosed herein.

In accordance with standard practice, we regularly review the methodology used in the development of all key estimates. As a result of this review, in 2022, we updated our estimate of the unearned premium reserve for certain of our product lines to utilize a gross unearned premium reserve rather than a net unearned premium reserve. The effect of this change in estimate was to decrease 2022 premium income by $13.4 million and decrease commissions by $1.0 million. This resulted in a decrease to net income of $9.8 million and a decrease to both basic and diluted earnings per share by $0.05.

Fixed Maturity Securities

Fixed Maturity Securities: Fixed maturity securities include long-term bonds and redeemable preferred stocks. Our fixed maturity securities are classified as available-for-sale and reported at fair value. Changes in the fair value of available-for-sale fixed maturity securities, except for amounts related to impairment and credit losses recognized in earnings, are reported as a component of other comprehensive income, net of income tax. Realized investment gains or losses are based upon specific identification of the investments sold.

Interest income is recorded as part of net investment income when earned, using an effective yield method giving effect to amortization of premium and accretion of discount. Included within fixed maturity securities are mortgage-backed and asset-backed securities. We recognize investment income on these securities using a constant effective yield based on projected prepayments of the underlying loans and the estimated economic life of the securities. Actual prepayment experience is reviewed periodically, and effective yields are recalculated when differences arise between prepayments originally projected and the actual prepayments received and currently projected. The effective yield is recalculated on a retrospective basis, and the adjustment is reflected in net investment income. For fixed maturity securities on which collection of investment income is uncertain, we discontinue the accrual of investment income and recognize investment income when interest and dividends are received. Payment terms specified for fixed maturity securities may include a prepayment penalty for unscheduled payoff of the investment. Prepayment penalties are recognized as investment income when received.

In determining when a decline in fair value below amortized cost of a fixed maturity security is a credit loss, we evaluate available information, both positive and negative, in reaching our conclusions. In particular, we consider the strength of the issuer's balance sheet, its debt obligations and near-term funding requirements, cash flow and liquidity, the profitability of its core businesses, the availability of marketable assets which could be sold to increase liquidity, its industry fundamentals and regulatory environment, and its access to capital markets. Although all available and applicable factors are considered in our analysis, our expectation of recovering the entire amortized cost basis of the security, whether we intend to sell the security, whether it is more likely than not that we will be required to sell the security before recovery of its amortized cost, and whether the security is current on principal and interest payments are the most critical factors in determining whether impairments represent credit losses. The significance of the decline in value is also an important factor, but we generally do not record an impairment loss based solely on this factor, since often other more relevant factors will impact our evaluation of a security.

For securities with a decline in fair value below amortized cost which we intend to sell or more likely than not will be required to sell before recovery in value, the amortized cost of the investment is written down to fair value through earnings, and an impairment loss is recognized in the current period. For securities that we believe are impaired and which we do not intend to sell and it is not more likely than not that we will be required to sell before recovery in value, we calculate an allowance for credit losses recognized in earnings which generally represents the difference between the amortized cost of the security and the

present value of our best estimate of cash flows expected to be collected, discounted using the effective interest rate implicit in the security at the date of acquisition and limited by the difference between amortized cost and fair value of the security. For fixed maturity securities for which we have recognized an allowance for credit loss through earnings, if through subsequent evaluation there is a significant increase in expected cash flows, the allowance is reduced and is recognized as a reduction to credit losses in the current period. When an allowance for credit losses on a fixed maturity security is recognized, we designate non-accrual status for those securities. We reverse all previously accrued interest through interest income and use a cash basis method for recognizing any future payments received. See Notes 2 and 3.

Mortgage Loans

Mortgage Loans: Mortgage loans are generally held for investment and are carried at amortized cost less an allowance for expected credit losses. Interest income is accrued on the principal amount of the loan based on the loan's contractual interest rate. Prepayment penalties are recognized as investment income when received. For mortgage loans on which collection of interest income is uncertain, we discontinue the accrual of interest and recognize it in the period when an interest payment is received. We typically do not resume the accrual of interest on mortgage loans on nonaccrual status until there are significant improvements in the underlying financial condition of the borrower. We consider a loan to be delinquent if full payment is not received in accordance with the contractual terms of the loan.

We evaluate each of our mortgage loans individually for impairment and assign an internal credit quality rating based on a comprehensive rating system used to evaluate the credit risk of the loan. Although all available and applicable factors are considered in our analysis, loan-to-value and debt service coverage ratios are the most critical factors in determining impairment. We estimate an allowance for credit losses that we expect to incur over the life of our mortgage loans using a probability of default method. For each loan, we estimate the probability that the loan will default before its maturity (probability of default) and the amount of the loss if the loan defaults (loss given default). These two factors result in an expected loss percentage that is applied to the amortized cost of each loan to determine the expected credit loss. As we are typically the original underwriter of the mortgage loans, the amortized cost generally equals the principal amount of the loan. We measure losses on defaults of our mortgage loans as the excess amortized cost of the mortgage loan over the fair value of the underlying collateral in the event that we foreclose on the loan or over the expected future cash flows of the loan if we retain the mortgage loan until payoff. We do not purchase mortgage loans with existing credit impairments.

In estimating the probability of default, we consider historical experience, current market conditions, and reasonable and supportable forecasts about the future market conditions. We utilize our historical loan experience in combination with a large third-party industry database for a period of time that aligns with the average life of our loans based on the maturity dates of the loans and prepayment experience. Our model utilizes an industry database of the historical loss experience based on our actual portfolio characteristics such as loan-to-value, debt service coverage, collateral type, geography, and late payment history. In addition, because we actively manage our portfolio, we may extend the term of a loan in certain situations and will accordingly extend the maturity date in the estimate of probability of default. In estimating the loss given default, we primarily consider the type and value of collateral and secondarily the expected liquidation costs and time to recovery.

The primary market factors that we consider in our forecast of future market conditions are gross domestic product, unemployment rates, interest rates, inflation, commercial real estate values, household formation, and retail sales. We also forecast certain loan specific factors such as growth in the fair value and net operating income of collateral by property type. We include our estimate of these factors over a two-year period and for the remainder of the loans’ estimated lives, adjusted for estimated prepayments. Past the two-year forecast period, we revert to the historical assumptions ratably by the end of the fifth year of the loan after which we utilize only historical assumptions.

We utilize various scenarios to estimate our allowance for expected losses ranging from a base case scenario that reflects normal market conditions to a severe case scenario that reflects adverse market conditions. We will adjust our allowance each period to utilize the scenario or weighting of the scenarios that best reflects our view of current market conditions. Additions and reductions to our allowance for credit losses on mortgage loans are reported as a component of net investment gains and losses. See Note 3.

Policy Loans

Policy Loans: Policy loans are presented at the unpaid balances directly related to policyholders. Interest income is accrued on the principal amount of the loan based on the loan's contractual interest rate. Included in policy loans are $3,322.5 million and $3,312.5 million of policy loans ceded to reinsurers at December 31, 2023 and 2022, respectively.

Investments

Other Long-term Investments: Other long-term investments are comprised primarily of private equity partnerships, real estate, perpetual preferred stock, common stock, and tax credit partnerships.

Our investments in private equity partnerships are passive in nature and represent funds that are primarily invested in private credit, private equity, and real assets. We account for our investments in these partnerships using either the equity method or at fair value through net income depending on the level of ownership and the degree of our influence over partnership operating and financial policies. For investments in partnerships accounted for under the equity method, we report our investments at our share of the partnership's net asset value (NAV) and record our portion of partnership earnings as a component of net investment income. For investments in partnerships accounted for at fair value through net income, we also report our investments at our share of the partnership's NAV as a practical expedient for fair value with increases or decreases recorded as a component of net investment income. Distributions received from the funds arise from income generated by the underlying investments as well as the liquidation of the underlying investments and there is generally not a public market for these investments.

Investment real estate is primarily comprised of property held for the production of income and property held for sale. Property held for the production of income is carried at cost less accumulated depreciation and any write-downs to fair value for impairment losses. Depreciation is recorded on a straight-line basis over the estimated useful life of the asset. A review for impairment is made whenever events or circumstances indicate that the carrying value may not be recoverable. An impairment loss is recognized when the carrying value of the property exceeds the expected undiscounted cash flows generated from the property, at which point the carrying value is written down to an estimated fair value. Real estate held for sale is carried at the lower of depreciated cost or fair value less estimated selling costs and is not further depreciated once classified as such.

Our perpetual preferred stocks are valued at fair value, based on quoted market prices, where available. For preferred stocks not actively traded, fair values are estimated using values obtained from independent pricing services. Our investments in common stock are valued at fair value. Our shares of Federal Home Loan Bank (FHLB) common stock are carried at cost, which approximates fair value.

Tax credit partnerships in which we have invested were formed for the purpose of investing in the construction and rehabilitation of low-income housing. Because the partnerships are structured such that there is no return of principal, the primary sources of investment return from our tax credit partnerships are tax credits and tax benefits derived from passive losses on the investments, both of which may exhibit variability over the life of the investment. These partnerships are accounted for using either the proportional or the effective yield method, depending primarily on whether the tax credits are guaranteed through a letter of credit, a tax indemnity agreement, or another similar arrangement. Tax credits received from these partnerships are reported in our consolidated statements of income as either a reduction of premium tax or a reduction of income tax. The amortization of the principal amount invested in these partnerships is reported as a component of either premium tax or income tax.

See Notes 2 and 3 for further discussion of our other long-term investments.

Short-term Investments: Short-term investments are carried at cost. Short-term investments include investments maturing within one year of purchase, such as corporate commercial paper and Treasury bills, bank term deposits, and other cash accounts and cash equivalents earning interest.

Cash and Bank Deposits

Cash and Bank Deposits: Cash and bank deposits include cash on hand and non-interest bearing cash and deposit accounts.

Derivative Financial Instruments

Derivative Financial Instruments: Derivative financial instruments (including certain derivative instruments embedded in other contracts) are recognized as either other long-term investments or other liabilities in our consolidated balance sheets and are reported at fair value. The accounting for a derivative depends on whether it has been designated and qualifies as part of a hedging relationship, and further, on the type of hedging relationship. To qualify for hedge accounting, at the inception of the hedging transaction, we formally document the risk management objective and strategy for undertaking the hedging transaction, as well as the designation of the hedge as either a fair value hedge or a cash flow hedge. Included in this documentation is how the hedging instrument is expected to hedge the designated risk(s) related to specific assets or liabilities on the balance sheet or to specific forecasted transactions as well as a description of the method that will be used to retrospectively and prospectively assess the hedging instrument's effectiveness.

A derivative designated as a hedging instrument must be assessed as being highly effective in offsetting the designated risk(s) of the hedged item. Hedge effectiveness is formally assessed at inception and periodically throughout the life of the designated hedging relationship, using qualitative and quantitative methods. Qualitative methods include comparison of critical terms of the derivative to the hedged item. Quantitative methods include regression or other statistical analysis of changes in fair value or cash flows associated with the hedge relationship.

Changes in the fair value of a derivative designated as a fair value hedge and changes in the fair value of the hedged item attributable to the risk being hedged are recognized in earnings as a component of net investment gain or loss during the period of change in fair value. For gains or losses on the derivative instrument that are excluded from the assessment of hedge effectiveness, those gains and losses are recognized in other comprehensive income or loss and amortized into earnings in the same income statement line as the related hedged item. The gain or loss on the termination of a fair value hedge is recognized in earnings as a component of net investment gain or loss during the period in which the termination occurs. When interest rate swaps are used in hedge accounting relationships, periodic settlements are recorded in the same income statement line as the related settlements of the hedged items.

Changes in the fair value of a derivative designated as a cash flow hedge are reported in other comprehensive income and reclassified into earnings and reported on the same income statement line item as the hedged item and in the same period or periods during which the hedged item affects earnings. The gain or loss on the termination of an effective cash flow hedge is reported in other comprehensive income and reclassified into earnings and reported on the same income statement line item as the hedged item and in the same period or periods during which the hedged item affects earnings.

Gains or losses on the termination of ineffective fair value or cash flow hedges are reported in earnings as a component of net investment gain or loss. In the event a hedged item is disposed of or the anticipated transaction being hedged is no longer likely to occur, we will terminate the related derivative and recognize the gain or loss on termination in current earnings as a component of net investment gain or loss. In the event a hedged item is disposed of subsequent to the termination of the hedging transaction, we reclassify any remaining gain or loss on the hedge out of accumulated other comprehensive income into earnings as a component of the same income statement line item wherein we report the gain or loss on disposition of the hedged item.

For a derivative not designated as a hedging instrument, changes in the fair value of the derivative, together with the payment of periodic fees, if applicable, are recognized in the same income statement line item as the hedged item during the period of change in fair value.

Cash flows related to derivative contracts are included in the consolidated statements of cash flows, coinciding with the timing of the hedged item. Cash inflows are included as a component of proceeds from sales and maturities of other investments. Cash outflows are included as a component of purchases of other investments.

In our consolidated balance sheets, we do not offset fair value amounts recognized for derivatives executed with the same counterparty under a master netting agreement and fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral arising from those master netting agreements. See Notes 2, 3, and 4.

Fair Value Measurement

Fair Value Measurement: Certain assets and liabilities are reported at fair value in our consolidated balance sheets and in our notes to our consolidated financial statements. We define fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Therefore, fair value represents an exit price, not an entry price. The exit price objective applies regardless of our intent and/or ability to sell the asset or transfer the liability at the measurement date. Assets or liabilities with readily available actively quoted prices or for which fair value can be measured from actively quoted prices in active markets generally have more pricing observability and less judgment utilized in measuring fair value. When actively quoted prices are not available, fair values are based on quoted prices in markets that are not active, quoted prices for similar but not identical assets or liabilities, or other observable inputs. If observable inputs are not available, unobservable inputs and/or adjustments to observable inputs requiring management judgment are used to determine fair value. We categorize our assets and liabilities measured at estimated fair value into a three-level hierarchy, based on the significance of the inputs. The fair value hierarchy gives the highest priority to inputs which are unadjusted and represent quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). See Note 2.

Allowance for Credit Losses on Premiums Receivable

Allowance for Credit Losses on Premiums Receivable: We establish an allowance for credit losses on premiums receivable, which is deducted from the gross amount of our receivable balance, to present the net amount we expect to collect on this asset. The allowance is forward-looking in nature and is calculated based on considerations regarding both historical events and future expectations. Periodic changes in the allowance are recorded through earnings.

The allowance on our premiums receivable is primarily determined using an aging analysis as well as historical lapse and delinquency rates by line of business, adjusted for key factors that may impact our future expectation of premium receipts such as changes in customer demographics, business practices, economic conditions, and product offerings. We write off premiums receivable amounts when determined to be uncollectible, which is based on various factors, including the aging of premiums receivable past the due date and specific communication with customers. At December 31, 2023 and 2022, the allowance for expected credit losses on premium receivables was $29.5 million and $32.5 million, respectively, on gross premium receivables of $612.4 million and $557.6 million, respectively. The allowance decreased $3.0 million and $1.7 million during the years ended December 31, 2023, and 2022, respectively. The decreases were driven primarily by improvements in the age of premiums receivable.

Deferred Acquisition Costs

Deferred Acquisition Costs: Incremental direct costs associated with the successful acquisition of new or renewal insurance contracts have been deferred. Such costs include commissions, other agency compensation, certain selection and policy issue expenses, and certain field expenses. Acquisition costs that do not vary with the production of new business, such as commissions on group products which are generally level throughout the life of the policy, are excluded from deferral.

Our insurance contracts are grouped by product type and contract issue year into cohorts consistent with the grouping used to estimate the related contract liabilities. DAC is amortized on a constant level basis over the life of the policy. For all products, in-force volume metrics are used as the constant level basis. The lapse and mortality assumptions used to amortize DAC for our traditional long-duration products are consistent with the assumptions used to estimate the liability for future policy benefits. The underlying assumptions used to determine DAC amortization are updated concurrently with any related assumption changes for the liability for future policy benefits and changes in estimates are recognized prospectively over the remaining expected term of the related contracts. Amortization expense is adjusted based on actual versus expected experience through an adjustment to the prospective rate of amortization.

For certain products, policyholders can elect to modify product benefits, features, rights, or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacement transactions, principally on group contracts. Internal replacement transactions wherein the modification does not substantially change the policy are accounted for as continuations of the replaced contracts. The original policy continues to be reflected as an in force policy within its original cohort. The policy's expected life then impacts the amortization of remaining unamortized deferred acquisition costs within its cohort. The costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Internal replacement transactions that result in a policy that is substantially changed are accounted for as an extinguishment of the original policy and the issuance of a new policy. The original policy that was replaced is terminated from its original cohort and this termination is reflected in the amortization rate of remaining unamortized deferred acquisition costs for the cohort. The costs of acquiring the new policy are capitalized and amortized as part of a new cohort. See note 8.

Goodwill

Goodwill: Goodwill is the excess of the amount paid to acquire a business over the fair value of the net assets acquired. We review the carrying amount of goodwill for impairment on an annual basis, or more frequently if events or changes in circumstances indicate that the carrying amount might not be recoverable. Goodwill impairment testing compares the fair value of a reporting unit with its carrying amount, including goodwill. If the fair value of the reporting unit to which the goodwill relates is less than the carrying amount of the reporting unit, an impairment charge is recognized for the amount by which the carrying amount exceeds the fair value of the reporting unit in an amount not to exceed the total amount of goodwill allocated to the reporting unit.

Property and Equipment

Property and Equipment: Property and equipment is reported at cost less accumulated depreciation, which is calculated on the straight-line method over the estimated useful life. The accumulated depreciation for property and equipment was $1,422.8 million and $1,328.7 million as of December 31, 2023 and 2022, respectively.

Value of Business Acquired

Value of Business Acquired: Value of business acquired represents the present value of future profits recorded in connection with the acquisition of a block of insurance policies. The asset is amortized based upon expected future premium income for non-interest sensitive insurance policies and estimated future gross profits from surrender charges, mortality margins, investment returns, and expense margins for interest sensitive insurance policies. The value of business acquired, which is included in other assets in our consolidated balance sheets, was $63.9 million and $62.9 million at December 31, 2023 and 2022, respectively. The accumulated amortization for value of business acquired was $161.8 million and $150.3 million as of December 31, 2023 and 2022, respectively.

The amortization of value of business acquired, which is included in other expenses in the consolidated statements of income, was $5.2 million, $4.9 million, and $5.7 million for the years ended December 31, 2023, 2022, and 2021, respectively. We periodically review the carrying amount of value of business acquired and it is subject to recoverability testing on an annual basis, or more frequently, if appropriate.

Reserves for Policy and Contract Benefits

Future Policy Benefits: Liabilities for future policy benefits represent the cost of claims that we estimate we will eventually pay to our policyholders which includes policy liabilities for claims not yet incurred and for claims that have been incurred or are estimated to have been incurred but not yet reported to us. Liabilities for future policy benefits also include the related expenses for our non interest-sensitive life and accident and health products. The liability for future policy benefits is calculated based on the present value of the estimated future policy benefits less the present value of estimated future net premiums collected. Net premiums represent the portion of the gross premium required to provide for all benefits and expenses, excluding acquisition costs or any costs that are required to be charged to expense as incurred. In calculating the liability for future policy benefits, our long-duration contracts are grouped into cohorts by product type and contract issue year.

The calculation of the liability for future policy benefits involves numerous assumptions including assumptions related to discount rate, lapses, mortality, and morbidity. The discount rate assumptions were initially set based on the expected investment yield of the assets supporting the reserves at the transition date of accounting standards update (ASU) 2018-12, which was January 1, 2021, for policies originally issued on or before the transition date. The discount rate assumptions for new cohorts established after the transition date, are initially set based on the policy issuance date or policy renewal date, and are based on an upper-medium grade fixed-income instrument, which is generally equivalent to a single-A interest rate matched to the duration of our insurance liabilities. As cohorts are grouped by product type and issue year, a weighted average discount rate is utilized as policies are issued or renewed throughout the year. We utilize a reference portfolio of fixed-income instruments that have been A-rated by one of the major credit rating agencies. For products with liability cash flows that exceed the duration of observable single-A fixed income instruments, we use the last market observable yield and use extrapolation approaches to determine yield assumptions for durations beyond the last market observable duration. For the discount rate assumptions for products in our Unum International segment, we utilize observable market data in the local debt markets in the UK and Poland.

The initial, also referred to as the original, discount rate assumptions established for each cohort are used to determine interest accretion which is reported as a component of policy benefits on the statements of income. After policy issuance or policy renewal, the discount rate assumptions are updated quarterly and used to update the liability at each reporting date to the current discount rate, with the corresponding change reflected as the change in the effect of discount rate assumptions on the liability for future policy benefits, net of reinsurance, on the statement of changes in other comprehensive income (loss). Policyholder lapse and mortality assumptions reflect the probability that an insureds’ coverage is discontinued due to lapsation or death of the insured. For our life insurance products, mortality assumptions also reflect the probability that a benefit payment occurs. Policyholder lapse and mortality assumptions are based on our actual historical experience adjusted for future expectations. Claim incidence and claim resolution rate assumptions related to morbidity and mortality are based on actual experience or industry standards adjusted as appropriate to reflect our actual experience and future expectations. The claim incidence rate assumption is the rate at which new claims are submitted and the development of this assumption may involve many factors, including the age of the insured, the insured's occupation or industry, the benefit plan design, and certain external factors such as consumer confidence and levels of unemployment. The claim resolution rate assumption is the probability that a claim will close due to recovery or death of the insured and is used to estimate how long benefits will be paid on an open claim. Certain product lines may utilize additional assumptions in calculating the liability for future policy benefits in addition to those listed above such as premium rate increases for long-term care, benefit offsets for long-term disability, and claim costs for voluntary benefits. Claim costs capture the combined effect of the incidence rate, the expected level of benefit to be paid, and the claim resolution rate.

Cash flow assumptions are reviewed and updated, as needed, at least annually. Assumptions may be updated more frequently if necessary based on trending experience and future expectations. On a quarterly basis, cohort level cash flow measures are updated based on the emergence of actual experience. The updated cash flows are used to determine the updated net premiums and the net premium ratio, which is the present value of benefits and related expenses divided by the present value of gross premiums. The updated net premium ratio is used to calculate the updated liability for future policy benefits as of the beginning of the year, at the original discount rate. The change in the liability for future policy benefits, at the original discount rate, as of the beginning of the period, resulting from changes in cash flow assumptions and resulting from the emergence of actual experience from expected experience, is reflected as the policy benefits - remeasurement loss (gain) in the consolidated statements of income. The impact of all other changes in the liability for future policy benefits are reflected as policy benefits in the consolidated statements of income.

For most products, a net premium methodology is applied to each cohort to estimate the liability for claims not yet incurred in which discounted gross benefits are compared to discounted gross premiums. In this methodology, actual experience to date is combined with projected future cash flows to determine a net premium ratio for each cohort. The future cash flows include the costs of future expected claims as well as future cash flows on claims that have already been incurred. The net premium ratio is then used to estimate the liability for future policy benefits. The liability for future policy benefits represents the present value of future claims and associated expenses less the present value of future net premiums, which is derived by multiplying the present value of future gross premium by the net premium ratio.

For our group products in the Unum US and Unum International segments, we evaluate the liability for future policy benefits required for active policies in comparison to incurred claims. Given the term nature of the products, their renewal features, and level funding nature of the premium for these products, we have determined that the liability value is generally zero for policies that are not on claim. For these products, our liability for future policy benefit values are limited to the liability associated with claims incurred as of the valuation date.

Multiple estimation methods exist to establish liabilities for the incurred claim component of future policy benefits. Available reserving methods utilized to calculate these liabilities include the tabular reserve method, the paid loss development method, the incurred loss development method, the count and severity method, and the expected claim cost method. No single method is better than the others in all situations and for all product lines. The estimation methods we have chosen are those that we believe produce the most accurate and reliable liability.

We use a tabular reserve methodology on reported claims for our Unum US group long-term disability and individual disability claims as well as for our Closed Block long-term care claims. Under the tabular reserve methodology, the liability for reported claims is based on certain characteristics of the actual reported claimants and their related policy provisions, such as age, length of time disabled, and medical diagnosis, as well as assumptions regarding claim duration, discount rate, and policy benefit offsets. We believe the tabular reserve method is the most accurate to calculate long-term liabilities and allows us to use the most available known facts about each claim. Incurred, but not reported (IBNR) liabilities for future policy benefits for our longer-term products are calculated using the count and severity method using historical patterns of the claims to be reported and the associated claim costs. For Unum US group short-term disability products, an estimate of the value of future payments to be made on claims already submitted, as well as on IBNR claims, is determined in aggregate using a paid loss development method rather than on the individual claimant basis that we use for reported claims on longer-term products. The average length of time between the event triggering a claim under a policy and the final resolution of those claims is much shorter for these products and results in less estimation variability.

Liabilities for claims for Unum US group life and accidental death and dismemberment products are related primarily to death claims reported but not yet paid, IBNR death claims, and a liability for waiver of premium benefits in the event the policyholder becomes disabled. The death claim liability is based on the actual face amount to be paid, the IBNR liability is calculated using the count and severity method based on historical patterns of the claims, and the waiver of premium benefits liability is calculated using the tabular reserve methodology.

Liabilities for claims related to the group and individual dental and vision products reported in our Unum US and Colonial Life segments have a short claim payout period. As a result, the liabilities, which primarily represent IBNR and a small amount of claims pending payment, are calculated using the paid loss development method.

Liabilities for future policy benefits supporting the group products within our Unum International segment are calculated using generally the same methodology that we use for Unum US group disability and group life liabilities. Liabilities for future policy benefits for our Unum UK group life dependent product, which provides an annuity to the beneficiary upon the death of an employee, are calculated using discounted cash flows, based on our assumptions for claim duration and discount rates. The assumptions used in calculating liabilities for future policy benefits for this segment are based on standard country-specific industry experience, adjusted for our own experience.

Certain products in the Colonial Life segment and the Unum US voluntary benefits product line have shorter-term benefits, which generally have less estimation variability than our longer-term products because of the shorter claim payout period. Our liabilities for future policy benefits for these lines of business are predominantly determined using the incurred loss development method based on our own experience. The incurred loss development method uses the historical patterns of payments by loss date to predict future claim payments for each loss date. Where the incurred loss development method may not be appropriate, we estimate the incurred claims using an expected claim cost per policy or other measure of exposure. See note 6.

Policyholders' Account Balances

Policyholders' Account Balances: Policyholders' account balances primarily include our universal life and corporate-owned life insurance products. Policyholders' account balances reflect customer deposits and interest credited less cost of insurance, administration expenses, surrender charges, and customer withdrawals. Our unearned revenue reserve, claim reserves and certain other reserves related to our universal life products and corporate-owned life insurance products are also reported as a component of policyholders’ account balances. Policyholders' account balances require loss recognition testing. We perform loss recognition tests on these reserves annually, or more frequently if appropriate, using best estimate assumptions as of the date of the test, without a provision for adverse deviation. We group the policy reserves for each major product line within a reporting segment when we perform the loss recognition tests. If the excess of the present value of projected future benefits and claim settlement expenses over the present value of projected future gross premiums is greater than the existing policy reserves less any unearned revenue reserve or value of business acquired, the existing policy reserves would be increased to immediately recognize the insufficiency. This becomes the new basis for reserves going forward, subject to future loss recognition testing. Anticipated investment income, based on our anticipated portfolio yield rates after consideration for defaults and investment expenses, is considered when performing loss recognition testing for long-duration contracts. See note 7.

Policyholders' Funds

Other Policyholders' Funds: Other policyholders' funds represent customer deposits plus interest credited at contract rates. We control interest rate risk by investing in quality assets which have an aggregate duration that closely matches the expected duration of the liabilities.

Income Tax

Income Tax: Deferred taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial statement purposes and the amounts used for income tax purposes. Deferred taxes have been measured using enacted statutory income tax rates and laws that are currently in effect. We record adjustments to our deferred taxes resulting from tax rate changes through income as of the date of enactment. We record deferred tax assets for tax positions taken in the U.S. and other tax jurisdictions based on our assessment of whether a position is more likely than not to be sustained upon examination based solely on its technical merits. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized. We record tax expense related to Global Intangible Low-Taxed Income in the period in which it is incurred. We follow an aggregate portfolio approach to release disproportionate tax effects from accumulated other comprehensive income upon disposal of an entire business segment's portfolio. See Note 9.

Short-term and Long-term Debt

Short-term and Long-term Debt: Debt is generally carried at the unpaid principal balance, net of unamortized discount or premium and deferred debt issuance costs. Short-term debt consists of debt due within the next twelve months, including that portion of debt otherwise classified as long-term. The amortization of the original issue discount or premium as well as deferred debt issuance costs are recognized as a component of interest expense over the period the debt is expected to be outstanding. See Note 10.

Right-of-Use Asset (ROU) and Lease Liability

Right-of-Use Asset (ROU) and Lease Liability: ROU assets represent our right to use an underlying asset for a specified lease term and are included in other assets in our consolidated balance sheet. Lease liabilities represent the present value of lease payments that we are obligated to pay arising from a lease and are included in other liabilities in our consolidated balance sheet.

We determine if an arrangement is a lease at inception through a formal process that evaluates our right to control the use of an identified asset for a period of time in exchange for consideration. We account for the lease and non-lease components of our building leases separately and have elected to use the available practical expedient to account for the lease and non-lease components of our equipment leases as a single component. All of our leases are classified as operating. For each operating lease, we calculate a lease liability at commencement date based on the present value of lease payments over the lease term and a corresponding ROU asset, adjusted for lease incentives. We do not recognize right-of-use assets and lease liabilities that arise from short-term leases for any class of underlying asset.

We consider the likelihood of renewal in determining the lease terms for the calculation of the ROU asset and lease liability. As most of our leases do not provide an implicit rate of interest, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. We use the implicit rate of interest when readily determinable.

Operating lease cost is calculated on a straight-line basis over the lease term and is included in other expenses in our consolidated statements of income. We amortize the ROU asset over the lease term on a pattern determined by the difference between the straight-line lease liability expense and the accretion of the imputed interest calculated on the lease liability. See Note 17.

Separation of Lease and Nonlease Components

We account for the lease and non-lease components of our building leases separately and have elected to use the available practical expedient to account for the lease and non-lease components of our equipment leases as a single component.

Short-term Leases

We do not recognize right-of-use assets and lease liabilities that arise from short-term leases for any class of underlying asset.

Treasury Stock and Retirement of Common Stock

Treasury Stock and Retirement of Common Stock: Treasury stock is reflected as a reduction of stockholders' equity at cost. When shares are retired, the par value is removed from common stock, and the excess of the repurchase price over par is allocated between additional paid-in capital and retained earnings. See Note 12.

Revenue Recognition

Revenue Recognition: Our non-interest sensitive life and accident and health products are long-duration contracts, and premium income is recognized as revenue when due from policyholders. If the contracts are experience rated, the estimated ultimate premium is recognized as revenue over the period of the contract. The estimated ultimate premium, which is revised to reflect current experience, is based on estimated claim costs, expenses, and profit margins.

For interest sensitive products, the amounts collected from policyholders are considered deposits, and only the deductions during the period for cost of insurance, policy administration, and surrenders are included in revenue. Policyholders' funds represent funds deposited by contract holders and are not included in revenue.

Revenue from Service Fees

Fees from our solutions business, which include leave management services and administrative-services only (ASO) business are reported as other income when services are rendered.

Reinsurance

Reinsurance: We routinely enter into reinsurance agreements with other insurance companies to spread risk and thereby limit losses from large exposures. For each of our reinsurance agreements, we determine if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. If we determine that a reinsurance agreement does not expose the reinsurer to a reasonable possibility of a significant loss from insurance risk, we record the agreement using the deposit method of accounting.

Reinsurance activity is accounted for on a basis consistent with the terms of the reinsurance contracts and the accounting used for the original policies issued. Premium income, policy benefits, and policy benefits - remeasurement gain or loss are presented in our consolidated statements of income net of reinsurance ceded. Ceded liabilities for future policy benefits, policyholders' account balances and unearned premiums are reported on a gross basis in our consolidated balance sheets, as are ceded policy loans. Our reinsurance recoverable includes the balances due from reinsurers under the terms of the reinsurance agreements for these ceded balances as well as settlement amounts currently due.

For ceded reinsurance transactions occurring after January 1, 2021, the transition date of ASU 2018-12, in accordance with the provisions of the ASU related to non-contemporaneous reinsurance, we are required to establish the ceded reserves using an upper-medium grade fixed-income instrument as of the reinsurance transaction date. However, the direct reserves for the reinsured block are calculated using the original discount rate utilized as of the transition date. Both the direct and ceded reserves are then remeasured at each reporting period using a current discount rate reflective of an upper-medium grade fixed-income instrument, with the changes recognized in other comprehensive income(loss). While the total equity impact is neutral, the different original discount rates utilized for direct and ceded reserves result in disproportionate earnings impacts.

Where applicable, gains or costs recognized on reinsurance transactions are generally deferred and amortized into earnings based upon expected future premium income for non-interest sensitive insurance policies and estimated future gross profits for interest sensitive insurance policies. Gains or costs recognized on reinsurance transactions for non-interest sensitive products for which we no longer receive premiums are generally deferred and amortized into earnings based upon expected claim reserve patterns. The cost of reinsurance included in other assets in our consolidated balance sheets at December 31, 2023 and 2022 was $549.4 million and $593.5 million. The deferred gain on reinsurance included in other liabilities in our consolidated balance sheets at December 31, 2023 and 2022 was $8.8 million and $3.1 million, respectively.

Under ceded reinsurance agreements wherein we are not relieved of our legal liability to our policyholders, if the assuming reinsurer is unable to meet its obligations, we remain contingently liable. We evaluate the financial condition of reinsurers and monitor concentration of credit risk to minimize this exposure. We may also require assets in trust, letters of credit, or other acceptable collateral to support our reinsurance recoverable balances. We estimate an allowance for expected credit losses for our reinsurance recoverable balance using a probability of default approach which incorporates key inputs and assumptions regarding market factors, counterparty credit ratings, and collateral received. When calculating our allowance, we apply these market factors to the net amount of our credit exposure, which considers collateral arrangements such as letters of credit and trust accounts. We evaluate the factors used to determine our allowance on a quarterly basis to consider material changes in our assumptions and make adjustments accordingly. The allowance for expected credit losses on reinsurance recoverables was $1.7 million at both December 31, 2023 and 2022. In 2022, the allowance decreased $0.6 million primarily due to changes in the composition of the related receivable. See Note 14.

Premium Tax Expense

Premium Tax Expense: Premium tax expense is included in other expenses in the consolidated statements of income. For the years ended December 31, 2023, 2022, and 2021, premium tax expense was $183.5 million, $169.3 million, and $166.0 million, respectively.

Stock-Based Compensation

Stock-Based Compensation: Restricted stock units and stock success units are valued based on the fair value of common stock at the grant date. The fair value of performance units and cash incentive units is based on the Monte-Carlo valuation model. We evaluate whether there are any events which would require an adjustment to the price of common stock at the grant date. No adjustments have been made to any grant date prices for any awards as of December 31, 2023 or 2022. Stock-based awards are expensed over the requisite service period, or for performance units over the requisite service period, or remaining service period, if and when it becomes probable that the performance conditions will be satisfied, with an offsetting increase to additional paid-in capital in stockholders' equity. The expense for certain of our awards is subject to accelerated recognition over the implicit service period for employees who have met the criteria for retirement eligibility. Forfeitures of stock-based awards are recognized as they occur. See Note 13.

Earnings Per Share

Earnings Per Share: We compute basic earnings per share by dividing net income by the weighted average number of common shares outstanding for the period. Earnings per share assuming dilution is computed by dividing net income by the weighted average number of shares outstanding for the period plus the shares representing the dilutive effect of stock-based awards. In computing earnings per share assuming dilution, only potential common shares resulting from stock-based awards that are dilutive (those that reduce earnings per share) are included. We use the treasury stock method to account for the effect of nonvested stock awards on the computation of earnings per share assuming dilution. See Note 12.

Translation of Foreign Curency

Translation of Foreign Currency: Revenues and expenses of our foreign operations are translated at average exchange rates. Assets and liabilities are translated at the rate of exchange on the balance sheet dates. The translation gain or loss is generally reported in accumulated other comprehensive income, net of income tax. We do not provide for deferred taxes to the extent unremitted foreign earnings are deemed permanently invested.

Accounting for Participating Individual Life Insurance

Accounting for Participating Individual Life Insurance: Participating policies issued by one of our subsidiaries prior to its 1986 conversion from a mutual to a stock life insurance company will remain participating as long as the policies remain in-force. A Participation Fund Account (PFA) was established for the benefit of all such individual participating life and annuity policies and contracts. The assets of the PFA provide for the benefit, dividend, and certain expense obligations of the participating individual life insurance policies and annuity contracts. The assets of the PFA were $244.4 million and $250.2 million at December 31, 2023 and 2022, respectively.