NOTES TO CONSOLIDATED FINANCIAL STATEMENTS - Continued Unum Group and Subsidiaries Note 1 - Significant Accounting Policies - Continued 120 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 $83.8 million and $88.7 million at December 31, 2020 and 2019, respectively. The accumulated amortization for value of business acquired was $153.7 million and $144.1 million as of December 31, 2020 and 2019, respectively. 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 $1,239.9 million and $1,195.3 million as of December 31, 2020 and 2019, respectively. 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.  Loss recognition testing is performed on an annual basis, or more frequently if appropriate, using best estimate assumptions as to future experience as of the date of the test. Insurance contracts are grouped for each major product line within a segment when we perform the loss recognition tests. If loss recognition testing indicates that deferred acquisition costs are not recoverable, the deficiency is charged to expense. 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. Internal replacement transactions wherein the modification does not substantially change the policy are accounted for as continuations of the replaced contracts. Unamortized deferred acquisition costs from the original policy continue to be amortized over the expected life of the new policy, and the costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Internal replacement transactions, principally on group contracts, 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. Unamortized deferred acquisition costs on the original policy that was replaced are immediately expensed, and the costs of acquiring the new policy are capitalized and amortized in accordance with our accounting policies for deferred acquisition costs. Deferred acquisition costs related to non-interest sensitive policies are amortized in proportion to the premium income we expect to receive over the lives of the policies. Deferred acquisition costs related to interest sensitive policies are amortized over the lives of the policies in relation to the present value of estimated gross profits from surrender charges, mortality margins, investment returns, and expense margins. Deviations from projections result in a change to the rate of amortization in the period during which such events occur. Generally, the amortization periods for these policies approximate the estimated lives of the policies. 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. Deferred acquisition costs are subject to recoverability testing at the time of policy issue and loss recognition testing in subsequent years. that were previously established at December 31, 2019. The allowance increased $15.0 million during the year ended December 31, 2020, primarily due to the uncertainty of collectability resulting from the impacts of COVID-19, partially offset by premium due write-offs and a decrease in the premium due balance. The primary factors considered in establishing the additional allowance were the recent increase in unemployment levels and the general uncertainty around the financial condition of some of our customers.