SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Description of Business Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac), which operates in the United States (Aflac U.S.) and as a branch in Japan (Aflac Japan). American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents. Additionally, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. Our insurance operations in the United States and our branch in Japan service the two markets for our insurance business. Aflac Japan's revenues, including realized gains and losses on its investment portfolio, accounted for 71% of the Company's total revenues in 2016, compared with 70% in 2015 and 72% in 2014. The percentage of the Company's total assets attributable to Aflac Japan was 83% at both December 31, 2016 and 2015. Basis of Presentation We prepare our financial statements in accordance with U.S. generally accepted accounting principles (GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards Codification^TM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates when recording transactions resulting from business operations based on currently available information. The most significant items on our balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments, deferred policy acquisition costs, liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates will be revised and reflected in operating results. Although some variability is inherent in these estimates, we believe the amounts provided are adequate. The consolidated financial statements include the accounts of the Parent Company, its subsidiaries and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated. Significant Accounting Policies Translation of Foreign Currencies: The functional currency of Aflac Japan's insurance operations is the Japanese yen. We translate our yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. We include in earnings the realized currency exchange gains and losses resulting from foreign currency transactions. We have designated a majority of the Parent Company's yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and designated foreign currency forwards and options as derivative hedges of the foreign currency exposure of our investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income. Insurance Revenue and Expense Recognition: The supplemental health and life insurance policies we issue are classified as long-duration contracts. The contract provisions generally cannot be changed or canceled during the contract period; however, we may adjust premiums for supplemental health policies issued in the United States within prescribed guidelines and with the approval of state insurance regulatory authorities. Insurance premiums for most of the Company's health and life policies, including cancer, accident, hospital, critical illness, dental, vision, term life, whole life, long-term care and disability, are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. When revenues are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to premium revenues during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs. Premiums from the Company's products with limited-pay features, including term life, whole life, WAYS, and child endowment, are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. Any gross premium in excess of the net premium is deferred and recorded in earnings, such that profits are recognized in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method. At the policyholder's option, customers can also pay discounted advanced premiums for certain of our products. Advanced premiums are deferred and recognized when due from policyholders over the regularly scheduled premium payment period. The calculation of deferred policy acquisition costs (DAC) and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, we review our actuarial assumptions and deferrable acquisition costs each year and revise them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, we evaluate DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. We have not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K. Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings. Cash and Cash Equivalents: Cash and cash equivalents include cash on hand, money market instruments and other debt instruments with a maturity of 90 days or less when purchased. Investments: Our debt securities consist of fixed-maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that we have the ability and intent to hold to maturity or redemption and are carried at amortized cost. All other fixed-maturity debt securities, our perpetual securities and our equity securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt and perpetual securities, or the purchase cost for equity securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, plus the unamortized unrealized gains and losses on debt securities transferred to the held-to-maturity portfolio, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income. Amortized cost of debt and perpetual securities is based on our purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt and perpetual securities we purchase at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount. We have investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. We are the primary beneficiary of certain VIEs, and therefore consolidate these entities in our financial statements. While the VIEs generally operate within a defined set of documents, there are certain powers that are retained by us that are considered significant in our conclusion that we are the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral or, for collateralized debt obligations (CDOs), the reference credits to include in the structure; the ability to obtain the underlying collateral in the event of default; and the ability to appoint or dismiss key parties in the structure. In particular, our powers surrounding the underlying collateral were considered to be the most significant powers since those most significantly impact the economics of the VIE. We have no obligation to provide any continuing financial support to any of the entities in which we are the primary beneficiary. Our maximum loss is limited to our original investment. Neither we nor any of our creditors have the ability to obtain the underlying collateral, nor do we have control over the instruments in the VIEs, unless there is an event of default. For those entities where we are the primary beneficiary, the assets consolidated are fixed-maturity securities, perpetual securities, equity securities, and derivative instruments; collateral consisting of these asset classes is reported separately with the caption "- consolidated variable interest entities" on our balance sheet. For the mortgage- and asset-backed securities held in our fixed maturities portfolio, we recognize income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income. We use the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings. Securities transactions are accounted for based on values as of the trade date of the transaction. An investment in a fixed maturity, perpetual security or equity security is impaired if the fair value falls below book value. We regularly review our entire investment portfolio for declines in value. Our fixed maturities and investment-grade perpetual securities investments are evaluated for other-than-temporary impairment using our debt impairment model. Our debt impairment model focuses on the ultimate collection of the cash flows from our investments and whether we have the intent to sell or if it is more likely than not we would be required to sell the security prior to recovery of its amortized cost. The determination of the amount of impairments under this model is based upon our periodic evaluation and assessment of known and inherent risks associated with the respective securities. Such evaluations and assessments are revised as conditions change and new information becomes available. When determining our intention to sell a security prior to recovery of its fair value to amortized cost, we evaluate facts and circumstances such as, but not limited to, future cash flow needs, decisions to reposition our security portfolio, and risk profile of individual investment holdings. We perform ongoing analyses of our liquidity needs, which includes cash flow testing of our policy liabilities, debt maturities, projected dividend payments and other cash flow and liquidity needs. Our cash flow testing includes extensive duration analysis of our investment portfolio and policy liabilities. Based on our analyses, we have concluded that we have sufficient excess cash flows to meet our liquidity needs without selling any of our investments prior to their maturity. The determination of whether an impairment in value of our debt securities is other than temporary is based largely on our evaluation of the issuer's creditworthiness. We must apply considerable judgment in determining the likelihood of the security recovering in value while we own it. Factors that may influence this include the overall level of interest rates, credit spreads, the credit quality of the underlying issuer, and other factors. This process requires consideration of risks which can be controlled to a certain extent, such as credit risk, and risks which cannot be controlled, such as interest rate risk and foreign currency risk. If, after monitoring and analyses, management believes that fair value will not recover to amortized cost prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once a security is considered to be other-than-temporarily impaired, the impairment loss is separated into two separate components: the portion of the impairment related to credit and the portion of the impairment related to factors other than credit. We recognize a charge to earnings for the credit-related portion of other-than-temporary impairments. Impairments related to factors other than credit are charged to earnings in the event we intend to sell the security prior to the recovery of its amortized cost or if it is more likely than not that we would be required to dispose of the security prior to recovery of its amortized cost; otherwise, non-credit-related other-than-temporary impairments are charged to other comprehensive income. Our investments in perpetual securities that are rated below investment grade and equity securities are evaluated for other-than-temporary impairment under our equity impairment model. Our equity impairment model focuses on the severity of a security's decline in fair value coupled with the length of time the fair value of the security has been below amortized cost and the financial condition and near-term prospects of the issuer. For equity securities that have declines in value that are deemed to be temporary, we make an assertion as to our ability and intent to retain the security until recovery. Once identified, these equity securities are restricted from trading unless authorized based upon significant events that could not have been foreseen at the time we asserted our ability and intent to retain the security until recovery. If management believes that the equity security will not recover prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once an equity security is considered to be other-than-temporarily impaired, its fair value on that date becomes the new cost basis and the impairment loss is recognized in earnings. We lend fixed-maturity securities to financial institutions in short-term security lending transactions. These securities continue to be carried as investment assets on our balance sheet during the terms of the loans and are not reported as sales. We receive cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. Other investments include policy loans, middle market loans, commercial mortgage loans, and other short-term investments with maturities of one year or less, but greater than 90 days, at the time of purchase. We invest in middle market loans through participation rights, and commercial mortgage loans that are accounted for as loan receivables and recorded at amortized cost on the acquisition date. Since we have the intent and ability to hold these loan receivables for the foreseeable future or until they mature, they are considered held for investment and are carried at adjusted amortized cost in the other investments line on our consolidated balance sheets. The adjusted amortized cost of the loan receivables reflects allowances for expected incurred losses estimated based on past events and current economic conditions as of each reporting date. Other short-term investments are stated at amortized cost, which approximates estimated fair value. Derivatives and Hedging: Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are interest rate swaps, foreign currency swaps, credit default swaps (CDSs), foreign currency forwards, foreign currency options, and options on interest rate swaps (or interest rate swaptions). Interest rate and foreign currency swaps are used within VIEs to hedge the risk arising from interest rate and currency exchange risk, while the CDSs are used to increase the yield and improve the diversification of the portfolio. Foreign currency forwards and options are used in hedging foreign exchange risk on U.S. dollar-denominated investments in Aflac Japan's portfolio. Foreign currency forwards and options are used to hedge certain portions of forecasted cash flows denominated in yen. Interest rate swaps are used to hedge the variability of interest cash flows associated with our variable interest rate notes. Cross-currency interest rate swaps, also referred to as foreign currency swaps, are used to economically convert certain U.S. dollar-denominated note obligations into yen-denominated principal and interest obligations. Interest rate swaptions have been used to hedge interest rate risk for certain U.S. dollar-denominated available-for-sale securities. We do not use derivatives for trading purposes, nor do we engage in leveraged derivative transactions. From time to time, we purchase certain investments that contain an embedded derivative. We assess whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If we deem that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If we have elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings. For those relationships where we seek hedge accounting, we formally document all relationships between hedging instruments and hedged items, as well as our risk-management objectives and strategies for undertaking various hedge transactions. This process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or liabilities on the balance sheet. We also assess, both at inception and on an ongoing basis, whether the derivatives and non-derivative financial instruments used in hedging activities are highly effective in offsetting changes in fair values or cash flows of the hedged items. The assessment of hedge effectiveness determines the accounting treatment of noncash changes in fair value. Changes in the fair value of any of our derivatives that are designated and qualify as cash flow hedges are recorded in other comprehensive income as long as they are deemed effective. Any hedge ineffectiveness is recorded immediately in current period earnings within derivative and other gains (losses). Periodic derivative net coupon settlements are recorded in the line item of the consolidated statements of earnings in which the cash flows of the hedged item are recorded. Changes in the estimated fair value of derivative instruments that are designated and qualify as fair value hedges, including amounts measured as ineffectiveness, and changes in the estimated fair value of the hedged item related to the designated risk being hedged, are reported in current earnings within derivative and other gains (losses). We have designated the majority of the Parent Company's yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and designated certain derivatives as hedges of the foreign currency exposure to our investment in Aflac Japan. At the beginning of each quarter, we make our net investment hedge designation. If the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than our net investment in Aflac Japan, the hedge is deemed to be effective, and the exchange effect on the yen-denominated liabilities and the change in estimated fair value of the derivatives are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed our net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds our investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses). Derivatives that are not designated as hedges are carried at fair value with all changes in fair value recorded in current period earnings within derivative and other gains (losses). We include the fair value of all freestanding derivatives in either other assets or other liabilities on the balance sheet. We receive and pledge cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. We generally can repledge or resell collateral obtained by us, although we do not typically exercise such rights. Securities received as collateral are not recognized unless we were to exercise our right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that we have pledged as collateral continue to be carried as investment assets on our balance sheet. Freestanding derivatives are carried at estimated fair value in our consolidated balance sheets either as other assets or as other liabilities. See Note 5 for a discussion on how we determine the fair value of our derivatives. Accruals on derivatives are typically recorded in accrued investment income or within other liabilities in the consolidated balance sheets. If a derivative is not designated as an accounting hedge or its use in managing risk does not qualify for hedge accounting, changes in the estimated fair value of the derivative are generally reported within derivative and other gains(losses), which is a component of realized investment gains (losses). The fluctuations in estimated fair value of derivatives that have not been designated for hedge accounting can result in volatility in net earnings. To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated risk of the hedged item. At the inception of the hedging relationship for hedges we elect to designate for hedge accounting treatment, we formally document all relationships between hedging instruments and hedged items, as well as our risk-management objective and strategy for undertaking each hedge transaction. We document the designation of each hedge as either (i) a hedge of the variability of cash flows to be received or paid related to a recognized asset or liability or the hedge of a forecasted transaction ("cash flow hedge"); (ii) a hedge of the estimated fair value of a recognized asset or liability ("fair value hedge"); or (iii) a hedge of a net investment in a foreign operation. The documentation process includes linking derivatives and nonderivatives that are designated as hedges to specific assets or groups of assets or liabilities on the statement of financial position or to specific forecasted transactions and defining the effectiveness and ineffectiveness testing methods to be used. At the hedge's inception and on an ongoing quarterly basis, we also formally assess whether the derivatives that are used in hedging transactions have been, and are expected to continue to be, highly effective in offsetting their designated risk. Hedge effectiveness is assessed using qualitative and quantitative methods. For assessing hedge effectiveness of cash flow hedges, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression or other statistical analysis of changes in cash flows associated with the hedge relationship. Hedge ineffectiveness of the hedge relationships on our VIE cash flow hedges is measured each reporting period using the “Hypothetical Derivative Method.” For derivative instruments that are designated and qualify as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing hedge ineffectiveness are recognized in current earnings within derivative and other gains (losses). All components of each derivative's gain or loss are included in the assessment of hedge effectiveness. For assessing hedge effectiveness of fair value hedges, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression or other statistical analysis of changes in fair value associated with the hedge relationship. Hedge ineffectiveness of the hedge relationships is measured each reporting period using the dollar offset method. For derivative instruments that are designated and qualify as fair value hedges, changes in the estimated fair value of the derivative, including amounts measured as ineffectiveness, and changes in the estimated fair value of the hedged item related to the designated risk being hedged, are reported in current earnings within derivative and other gains (losses). When assessing the effectiveness of our fair value hedges, we exclude the changes in fair value related to the difference between the spot and the forward rate on our foreign currency forwards and the time value of options. For the hedge of our net investment in Aflac Japan, we have designated Parent Company yen-denominated liabilities as non-derivative hedging instruments and have designated certain foreign currency forwards and options as derivative hedging instruments. We make our net investment hedge designation at the beginning of each quarter. For assessing hedge effectiveness of net investment hedges, if the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than our net investment in Aflac Japan, the hedge is deemed to be effective. If the hedge is effective, the related exchange effect on the yen-denominated liabilities is reported in the unrealized foreign currency component of other comprehensive income. For derivatives designated as net investment hedges, Aflac follows the forward-rate method. According to that method, all changes in fair value, including changes related to the forward-rate component of foreign currency forward contracts and the time value of foreign currency options, are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed our net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds our investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses). We discontinue hedge accounting prospectively when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the estimated cash flows or fair value of a hedged item; (2) the derivative is de-designated as a hedging instrument; or (3) the derivative expires or is sold, terminated or exercised. When hedge accounting is discontinued on a cash flow hedge or fair value hedge, the derivative is carried in the consolidated balance sheets at its estimated fair value, with changes in estimated fair value recognized in current period earnings. For discontinued cash flow hedges, including those where the derivative is sold, terminated or exercised, amounts previously deferred in other comprehensive income (loss) are reclassified into earnings when earnings are impacted by the cash flow of the hedged item. Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring new business are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual premium income to total anticipated premium income. Anticipated premium income is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition. For some 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 replacements. The Company performs a two-stage analysis of the internal replacements to determine if the modification is substantive to the base policy. The stages of evaluation are as follows: 1) determine if the modification is integrated with the base policy, and 2) if it is integrated, determine if the resulting contract is substantially changed. For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. 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. Examples include conversions of same age bands, certain family coverage changes, pricing era changes (decrease), and ordinary life becomes reduced paid-up and certain reinstatements. An internal replacement transaction that results in a policy that is substantially changed is accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy 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. Further, the policy reserves are evaluated based on the new policy features, and any change (up or down) necessary is recognized at the date of contract change/modification. Examples include conversions-higher age bands, certain family coverage changes, pricing era changes (increase), lapse & re-issue, certain reinstatements and certain contract conversions. Riders can be considered internal replacements that are either integrated or non-integrated resulting in either substantially changed or substantially unchanged treatment. Riders are evaluated based on the specific facts and circumstances of the rider and are considered expansion of the existing benefits with additional premium required. Non-integrated riders to existing contracts do not change the Company's profit expectations for the related products and are treated as a new policy establishment for incremental coverage. We measure the recoverability of DAC and the adequacy of our policy reserves annually by performing gross premium valuations on our business. (See the following discussion for further information regarding policy reserves.) Policy Liabilities: Future policy benefits represent claims that are expected to occur in the future and are computed by a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect our experience, including a provision for adverse deviation. These assumptions are generally established and considered locked at policy inception. These assumptions may only be unlocked in certain circumstances based on the results of periodic DAC recoverability and premium deficiency testing. Unpaid policy claims are estimates computed on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. We regularly adjust these estimates as new claims experience emerges and reflect the changes in operating results in the year such adjustments are made. Other policy liabilities consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period. For internal replacements that are determined to not be substantially unchanged, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract; however, for internal replacements that are considered substantially unchanged, no changes to the reserves are recognized. Reinsurance: We enter into reinsurance agreements with other companies in the normal course of business. 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. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded. See Note 8 of the Notes to the Consolidated Financial Statements for additional information. Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing our income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which we expect the temporary differences to reverse. We record deferred tax assets for tax positions taken based on our assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized. Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. We recognize a charge for our estimated share of the industry's obligation once it is determinable. We review the estimated liability for policyholder protection corporation contributions on an annual basis and report any adjustments in Aflac Japan's expenses. In the United States, each state has a guaranty association that supports insolvent insurers operating in those states. To date, our state guaranty association assessments have not been material. Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. We use the weighted-average purchase cost to determine the cost of treasury stock that is reissued. We include any gains and losses in additional paid-in capital when treasury stock is reissued. Share-Based Compensation: We measure compensation cost related to our share-based payment transactions at fair value on the grant date, and we recognize those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award. Earnings Per Share: We compute basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards. Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity. New Accounting Pronouncements Recently Adopted Accounting Pronouncements Business Combinations - Simplifying the Accounting for Measurement-Period Adjustments: In September 2015, the FASB issued guidance requiring that an acquirer recognize adjustments to estimated amounts that are identified during the measurement period in the reporting period in which the adjustments are determined. In the same period’s financial statements, the acquirer is required to record income effects of the adjustments as if the accounting had been completed at the acquisition date. The acquirer is also required to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the estimated amounts had been recognized as of the acquisition date. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Financial Services - Insurance - Disclosures about Short-Duration Contracts: In May 2015, the FASB issued updated guidance requiring enhanced disclosures by all insurance entities that issue short-duration contracts. The amendments require insurance entities to disclose for annual reporting periods information about the liability for unpaid claims and claim adjustment expenses. The amendments also require insurance entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for unpaid claims and claim adjustment expenses. In addition, the amendments require insurance entities to disclose for annual and interim reporting periods a roll-forward of the liability for unpaid claims and claim adjustment expenses. For health insurance claims, the amendments require the disclosure of the total of incurred-but-not-reported liabilities and expected development on reported claims included in the liability for unpaid claims and claim adjustment expenses. We adopted this guidance as of December 31, 2016, and have no insurance contracts classified as short-duration. The adoption of this guidance did not have a significant impact on our disclosures. Fair Value Measurement - Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent): In May 2015, the FASB issued updated guidance that removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The amendments also remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. Rather, those disclosures are limited to investments for which the entity has elected to measure the fair value using that practical expedient. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our disclosures. Interest - Imputation of Interest - Simplifying the Presentation of Debt Issuance Costs: In April 2015, the FASB issued updated guidance to simplify presentation of debt issuance costs. The updated guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this amendment. In August 2015, the FASB issued updated Securities and Exchange Commission (SEC) Staff guidance pertaining to the presentation of debt issuance costs related to line-of-credit arrangements. The guidance states that an entity may defer and present debt issuance costs as an asset, subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. We retrospectively adopted this guidance as of January 1, 2016. The retrospective adoption of this accounting standard resulted in a $40 million reduction to notes payable and other assets as of December 31, 2015, the earliest balance sheet date presented in the period of adoption, but did not have a significant impact on our financial position, results of operations, or disclosures. Consolidation - Amendments to the Consolidation Analysis: In February 2015, the FASB issued updated guidance that affects evaluation of whether limited partnerships and similar legal entities (limited liability corporations and securitization structures, etc.) are VIEs, evaluation of whether fees paid to a decision maker or a service provider are a variable interest, and evaluation of the effect of fee arrangements and the effect of related parties on the determination of the primary beneficiary under the VIE model for consolidation. The updated guidance eliminates the presumption that a general partner should consolidate a limited partnership. Limited partnership and similar legal entities that provide partners with either substantive kick-out rights or substantive participating rights over the general partner will now be evaluated under the voting interest model rather than the VIE model for consolidation. In situations where no single party has a controlling financial interest in a VIE, the related party relationships under common control should be considered in their entirety in determining whether that common control group has a controlling financial interest in the VIE. We adopted this guidance as of January 1, 2016. The adoption of this guidance impacted our footnote disclosures, but did not have a significant impact on our financial position or results of operations. Derivatives and Hedging - Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity: In November 2014, the FASB issued guidance to clarify how to evaluate the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The guidance also clarifies that an entity should assess the substance of the relevant terms and features when considering how to weight those terms and features. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Presentation of Financial Statements - Going Concern - Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern: In August 2014, the FASB issued this amendment that provides U.S. GAAP guidance on management’s responsibility in evaluating whether there is substantial doubt about a company’s ability to continue as a going concern and about related footnote disclosures. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. The new guidance requires a formal assessment of going concern by management based on criteria prescribed in the new guidance. We adopted this guidance as of December 31, 2016. The adoption of this guidance did not have a significant impact our financial position, results of operations, or disclosures, and no substantial doubt currently exists about the Company’s ability to continue as a going concern. Compensation - Stock Compensation - Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period: In June 2014, the FASB issued this amendment that provides guidance on certain share-based payment awards that require a specific performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance to awards with performance conditions that affect vesting to account for such awards. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Income Statement - Extraordinary and Unusual Items - Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items: In January 2015, the FASB issued updated guidance that eliminates from U.S. GAAP the concept of extraordinary items. Presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be retained. We adopted this guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Receivables - Troubled Debt Restructurings by Creditors - Classification of Certain Government-Guaranteed Mortgage Loans upon Foreclosure: In August 2014, the FASB issued updated guidance for troubled debt restructurings affecting creditors that hold government guaranteed mortgage loans. The guidance requires that a mortgage loan be derecognized and a separate other receivable be recognized upon foreclosure if certain conditions are met. We adopted the guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Transfers and Servicing - Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures: In June 2014, the FASB issued updated guidance for repurchase agreement and security lending transactions to change the accounting for repurchase-to-maturity transactions and linked repurchase financings to be accounted for as secured borrowings, consistent with the accounting for other repurchase agreements. The amendments also require new disclosures to increase transparency about the types of collateral pledged in repurchase agreements and similar transactions accounted for as secured borrowings. We adopted accounting changes for the new guidance as of January 1, 2015, and adopted the required disclosures as of April 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Receivables - Troubled Debt Restructurings by Creditors - Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure: In January 2014, the FASB issued updated guidance for troubled debt restructurings clarifying when an in substance repossession or foreclosure occurs, and when a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan. We adopted the guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Income Taxes - Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists: In July 2013, the FASB issued guidance to amend the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The new guidance states that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. However, to the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. We adopted this guidance as of January 1, 2014. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Other Expenses - Fees Paid to the Federal Government by Health Insurers: In July 2011, the FASB issued guidance on the accounting for fees owed by health insurers as mandated by the Patient Protection and Affordable Care Act as amended by the Health Care and Education Reconciliation Act, which imposes an annual fee on health insurers for each calendar year beginning on or after January 1, 2014. A health insurer's portion of the annual fee is payable by September 30 of the applicable calendar year once the entity provides health insurance for any U.S. health risk in that year. The accounting guidance specifies that the liability for the fee should be estimated and recorded in full in the applicable calendar year in which the fee is payable. We adopted this guidance as of January 1, 2014. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Accounting Pronouncements Pending Adoption Intangibles - Goodwill and Other - Simplifying the Test for Goodwill Impairment: In January 2017, the FASB issued amendments simplifying the subsequent measurement of goodwill. An entity, under this update, is no longer required to perform a hypothetical purchase price allocation to measure goodwill impairment. Instead, the entity should perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. The amendments are effective for public business entities that are U.S. SEC filers for annual or any interim goodwill impairment tests in fiscal years beginning after Dec. 15, 2019. Early adoption is permitted for any goodwill impairment tests performed on testing dates after January 1, 2017. We do not expect the adoption of this guidance to have a significant impact on our financial position, results of operations, or disclosures. Business Combinations - Clarifying the Definition of a Business: In January 2017, the FASB issued amendments clarifying when a set of assets and activities is a business. The amendments provide a screen to determine when a set of assets and activities is not a business. The amendments are effective for public business entities beginning after December 15, 2017, including interim periods within those periods. We do not expect the adoption of this guidance to have a significant impact on our financial position, results of operations, or disclosures. Statement of Cash Flows - Restricted Cash: In November 2016, the FASB issued amendments requiring that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. The amendments are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. We do not expect the adoption of this guidance to have a significant impact on our financial position, results of operations, or disclosures. Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory: In October 2016, the FASB issued amendments that require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The amendments are effective for public business entities for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual reporting periods. Early adoption is permitted. We are evaluating the impact of adoption of this guidance on our financial position, results of operations, or disclosures. Consolidation - Interests Held through Related Parties That Are under Common Control: In October 2016, the FASB issued amendments which clarify the consolidation guidance on how a reporting entity that is the single decision maker of a VIE should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. The amendments are effective for public business entities for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The adoption of this guidance is not expected to have a significant impact on our financial position, results of operations, or disclosures. Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments: In August 2016, the FASB issued amendments that provide guidance on eight specific statement of cash flows classification issues. The amendments are effective for public companies for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted for any interim or annual period. The adoption of this guidance is not expected to have a significant impact on our financial position, results of operations, disclosures, or statements of cash flows. Financial Instruments - Credit Losses - Measurement of Credit Losses on Financial Instruments: In June 2016, the FASB issued amendments that require a financial asset (or a group of financial assets) measured on an amortized cost basis to be presented net of an allowance for credit losses in order to reflect the amount expected to be collected on the financial asset(s). The measurement of expected credit losses is amended by replacing the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform about a credit loss. Credit losses on available-for-sale debt securities will continue to be measured in a manner similar to current GAAP. However, the amendments require that credit losses be presented as an allowance rather than as a writedown. Other amendments include changes to the balance sheet presentation and interest income recognition of purchased financial assets with a more-than-insignificant amount of credit deterioration since origination. The amendments are effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Companies may early adopt this guidance as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We have identified certain financial instruments in scope of this guidance to include certain fixed maturity securities, loans and loan receivables and reinsurance recoverables (See Notes 3 and 8 for current balances of instruments in scope). We are continuing to evaluate the impact of adoption of this guidance on our financial position, results of operations and disclosures. Compensation - Stock Compensation - Improvements to Employee Share-Based Payment Accounting: In March 2016, the FASB issued amendments which simplify several aspects for share-based payment award transactions, including income tax consequences, classification of awards as either liability or equities, and classification on the statement of cash flows. The amendments are effective for public companies for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted for any interim or annual period. The amendment requires prospective recognition of excess tax benefits and deficiencies in the income statement, rather than in paid-in capital. As a result of applying this requirement, we estimate that recognition of excess tax benefits will increase volatility in our statement of operations but will not have a significant impact on our statement of financial position, operations, or disclosures. We continue to evaluate the impact of this guidance as estimates will vary from the actual expense based on changes in actual share price. The amendment also requires all excess tax benefits and tax deficiencies (including tax benefits of dividends on share-based payment awards) to be recognized as income tax expense or benefit in the income statement. The guidance requires modified retrospective transition for settlements on all outstanding awards (both historical and future) that did not give rise to an excess benefit to be recorded through retained earnings on a cumulative-effect basis. We estimate that the adoption of these amendments in the guidance will not have a significant impact on our financial position, results of operations, or disclosures. Additionally, the amendment requires that the minimum statutory tax withholding for all outstanding liability awards be reclassified at the date of adoption to equity (assuming equity classification results from the guidance change), and record a cumulative-effect adjustment to equity on a modified retrospective basis. We estimate that the adoption of these amendments in the guidance will not have a significant impact on our financial position, results of operations, or disclosures. The guidance requires certain reclassifications of balances on the statement of cash flows to or from operating and financing activities. The reclassification guidance will not have a significant impact on our statement of cash flows. The amendment allows an entity to elect whether to use estimates of forfeitures, or to account for forfeitures as they occur, using modified retrospective application. We estimate that the election and adoption of this amendment in the guidance will not have a significant impact on our financial position, results of operations, or disclosures. Investments - Equity Method and Joint Ventures - Simplifying the Transition to the Equity Method of Accounting: In March 2016, the FASB issued amendments which eliminate the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. Per the amendments, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The amendments also require that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive income at the date the investment becomes qualified for use of the equity method. The amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. The amendments should be applied prospectively upon their effective date to increases in the level of ownership interest or degree of influence that result in the adoption of the equity method. Early adoption is permitted. We have evaluated the adoption of this guidance and do not expect the guidance to have a significant impact on our financial position, results of operations, or disclosures. Derivatives and Hedging - Contingent Put and Call Options in Debt Instruments: In March 2016, the FASB issued amendments which clarify what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. Consequently, when a call (put) option is contingently exercisable, an entity does not have to assess whether the event that triggers the ability to exercise a call (put) option is related to interest rates or credit risks. The amendments are effective for public business entities for fiscal years beginning after December 15, 2016 and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We have evaluated the adoption of this guidance and do not expect the guidance to have a significant impact on our financial position, results of operations, or disclosures. Derivatives and Hedging - Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships: In March 2016, the FASB issued amendments which clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria remain intact. The amendments are effective for public business entities for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We have evaluated the adoption of this guidance and do not expect the guidance to have a significant impact on our financial position, results of operations, or disclosures. Leases: In February 2016, the FASB issued updated guidance for accounting for leases. Per the amendments, lessees will be required to recognize all leases on the balance sheet, with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. A right-of-use asset, will be recorded which represents the lessee’s right to use, or to control the use of, a specified asset for a lease term. Under the new guidance, lessor accounting is largely unchanged. The amendments are effective for public companies for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We have identified certain operating leases in scope of this guidance to include office space and equipment leases (See Note 15 for current balances of leases in scope). The leases within scope of this guidance will increase our right-of-use assets recorded on our financial position, however we estimate leases within scope of the guidance to represent less than 1% of our total assets as of December 31, 2016. We estimate that the adoption of this guidance will not have a significant impact on our financial position, results of operations and disclosures. Financial Instruments - Overall - Recognition and Measurement of Financial Assets and Financial Liabilities: In January 2016, the FASB issued guidance to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The main provisions require that equity investments be measured at fair value with changes recognized in net income; that changes in instrument-specific credit risk for financial liabilities that are measured under the fair value option be recognized in other comprehensive income; and that entities would make the assessment of the ability to realize a deferred tax asset (DTA) related to an available-for-sale (AFS) debt security in combination with the entity's other DTAs. The amendments are effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is not permitted, with the exception of the own credit provision if an entity has elected to measure a liability at fair value. We have identified certain financial instruments in scope of this guidance to include certain fixed maturity securities, perpetual securities and equity securities (See Note 3 for current balances of instruments in scope). We estimate that the impact of this guidance will increase volatility in our statement of operations and we are continuing to evaluate the impact of this guidance on our statement of financial position, operations, or disclosures. Revenue from Contracts with Customers: In May 2014, the FASB issued updated guidance that affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB deferred the effective date for this standard to annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Other updates related to the new guidance, which are effective as of the same reporting period, pertain to improvements in certain areas. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods. We have identified revenue in scope of this guidance to include certain revenues associated with affiliated entities in support of our operations. We estimate the revenue within scope of the guidance to represent less than 1% of our total revenues as of December 31, 2016. We estimate that the adoption of this guidance will not have a significant impact on our financial position, results of operations and disclosures. Recent accounting guidance not discussed above is not applicable, did not have, or is not expected to have a material impact to our business.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Description of Business

Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac), which operates in the United States (Aflac U.S.) and as a branch in Japan (Aflac Japan). American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents. Additionally, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. Our insurance operations in the United States and our branch in Japan service the two markets for our insurance business. Aflac Japan's revenues, including realized gains and losses on its investment portfolio, accounted for 71% of the Company's total revenues in 2016, compared with 70% in 2015 and 72% in 2014. The percentage of the Company's total assets attributable to Aflac Japan was 83% at both December 31, 2016 and 2015.

Basis of Presentation

We prepare our financial statements in accordance with U.S. generally accepted accounting principles (GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards Codification^TM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates when recording transactions resulting from business operations based on currently available information. The most significant items on our balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments, deferred policy acquisition costs, liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates will be revised and reflected in operating results. Although some variability is inherent in these estimates, we believe the amounts provided are adequate.

The consolidated financial statements include the accounts of the Parent Company, its subsidiaries and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated.

Significant Accounting Policies

Translation of Foreign Currencies: The functional currency of Aflac Japan's insurance operations is the Japanese yen. We translate our yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. We include in earnings the realized currency exchange gains and losses resulting from foreign currency transactions.

We have designated a majority of the Parent Company's yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and designated foreign currency forwards and options as derivative hedges of the foreign currency exposure of our investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income.

Insurance Revenue and Expense Recognition: The supplemental health and life insurance policies we issue are classified as long-duration contracts. The contract provisions generally cannot be changed or canceled during the contract period; however, we may adjust premiums for supplemental health policies issued in the United States within prescribed guidelines and with the approval of state insurance regulatory authorities.

Insurance premiums for most of the Company's health and life policies, including cancer, accident, hospital, critical illness, dental, vision, term life, whole life, long-term care and disability, are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. When revenues are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to premium revenues during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs.

Premiums from the Company's products with limited-pay features, including term life, whole life, WAYS, and child endowment, are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. Any gross premium in excess of the net premium is deferred and recorded in earnings, such that profits are recognized in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method.

At the policyholder's option, customers can also pay discounted advanced premiums for certain of our products. Advanced premiums are deferred and recognized when due from policyholders over the regularly scheduled premium payment period.

The calculation of deferred policy acquisition costs (DAC) and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, we review our actuarial assumptions and deferrable acquisition costs each year and revise them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, we evaluate DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. We have not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K.

Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings.

Cash and Cash Equivalents: Cash and cash equivalents include cash on hand, money market instruments and other debt instruments with a maturity of 90 days or less when purchased.

Investments: Our debt securities consist of fixed-maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that we have the ability and intent to hold to maturity or redemption and are carried at amortized cost. All other fixed-maturity debt securities, our perpetual securities and our equity securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt and perpetual securities, or the purchase cost for equity securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, plus the unamortized unrealized gains and losses on debt securities transferred to the held-to-maturity portfolio, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income.

Amortized cost of debt and perpetual securities is based on our purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt and perpetual securities we purchase at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount.

We have investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. We are the primary beneficiary of certain VIEs, and therefore consolidate these entities in our financial statements. While the VIEs generally operate within a defined set of documents, there are certain powers that are retained by us that are considered significant in our conclusion that we are the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral or, for collateralized debt obligations (CDOs), the reference credits to include in the structure; the ability to obtain the underlying collateral in the event of default; and the ability to appoint or dismiss key parties in the structure. In particular, our powers surrounding the underlying collateral were considered to be the most significant powers since those most significantly impact the economics of the VIE. We have no obligation to provide any continuing financial support to any of the entities in which we are the primary beneficiary. Our maximum loss is limited to our original investment. Neither we nor any of our creditors have the ability to obtain the underlying collateral, nor do we have control over the instruments in the VIEs, unless there is an event of default. For those entities where we are the primary beneficiary, the assets consolidated are fixed-maturity securities, perpetual securities, equity securities, and derivative instruments; collateral consisting of these asset classes is reported separately with the caption "- consolidated variable interest entities" on our balance sheet.

For the mortgage- and asset-backed securities held in our fixed maturities portfolio, we recognize income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income.

We use the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings. Securities transactions are accounted for based on values as of the trade date of the transaction.

An investment in a fixed maturity, perpetual security or equity security is impaired if the fair value falls below book value. We regularly review our entire investment portfolio for declines in value. Our fixed maturities and investment-grade perpetual securities investments are evaluated for other-than-temporary impairment using our debt impairment model. Our debt impairment model focuses on the ultimate collection of the cash flows from our investments and whether we have the intent to sell or if it is more likely than not we would be required to sell the security prior to recovery of its amortized cost. The determination of the amount of impairments under this model is based upon our periodic evaluation and assessment of known and inherent risks associated with the respective securities. Such evaluations and assessments are revised as conditions change and new information becomes available.

When determining our intention to sell a security prior to recovery of its fair value to amortized cost, we evaluate facts and circumstances such as, but not limited to, future cash flow needs, decisions to reposition our security portfolio, and risk profile of individual investment holdings. We perform ongoing analyses of our liquidity needs, which includes cash flow testing of our policy liabilities, debt maturities, projected dividend payments and other cash flow and liquidity needs. Our cash flow testing includes extensive duration analysis of our investment portfolio and policy liabilities. Based on our analyses, we have concluded that we have sufficient excess cash flows to meet our liquidity needs without selling any of our investments prior to their maturity.

The determination of whether an impairment in value of our debt securities is other than temporary is based largely on our evaluation of the issuer's creditworthiness. We must apply considerable judgment in determining the likelihood of the security recovering in value while we own it. Factors that may influence this include the overall level of interest rates, credit spreads, the credit quality of the underlying issuer, and other factors. This process requires consideration of risks which can be controlled to a certain extent, such as credit risk, and risks which cannot be controlled, such as interest rate risk and foreign currency risk.

If, after monitoring and analyses, management believes that fair value will not recover to amortized cost prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once a security is considered to be other-than-temporarily impaired, the impairment loss is separated into two separate components: the portion of the impairment related to credit and the portion of the impairment related to factors other than credit. We recognize a charge to earnings for the credit-related portion of other-than-temporary impairments. Impairments related to factors other than credit are charged to earnings in the event we intend to sell the security prior to the recovery of its amortized cost or if it is more likely than not that we would be required to dispose of the security prior to recovery of its amortized cost; otherwise, non-credit-related other-than-temporary impairments are charged to other comprehensive income.

Our investments in perpetual securities that are rated below investment grade and equity securities are evaluated for other-than-temporary impairment under our equity impairment model. Our equity impairment model focuses on the severity of a security's decline in fair value coupled with the length of time the fair value of the security has been below amortized cost and the financial condition and near-term prospects of the issuer. For equity securities that have declines in value that are deemed to be temporary, we make an assertion as to our ability and intent to retain the security until recovery. Once identified, these equity securities are restricted from trading unless authorized based upon significant events that could not have been foreseen at the time we asserted our ability and intent to retain the security until recovery.

If management believes that the equity security will not recover prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once an equity security is considered to be other-than-temporarily impaired, its fair value on that date becomes the new cost basis and the impairment loss is recognized in earnings.

We lend fixed-maturity securities to financial institutions in short-term security lending transactions. These securities continue to be carried as investment assets on our balance sheet during the terms of the loans and are not reported as sales. We receive cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral.

Other investments include policy loans, middle market loans, commercial mortgage loans, and other short-term investments with maturities of one year or less, but greater than 90 days, at the time of purchase. We invest in middle market loans through participation rights, and commercial mortgage loans that are accounted for as loan receivables and recorded at amortized cost on the acquisition date. Since we have the intent and ability to hold these loan receivables for the foreseeable future or until they mature, they are considered held for investment and are carried at adjusted amortized cost in the other investments line on our consolidated balance sheets. The adjusted amortized cost of the loan receivables reflects allowances for expected incurred losses estimated based on past events and current economic conditions as of each reporting date. Other short-term investments are stated at amortized cost, which approximates estimated fair value.

Derivatives and Hedging: Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are interest rate swaps, foreign currency swaps, credit default swaps (CDSs), foreign currency forwards, foreign currency options, and options on interest rate swaps (or interest rate swaptions). Interest rate and foreign currency swaps are used within VIEs to hedge the risk arising from interest rate and currency exchange risk, while the CDSs are used to increase the yield and improve the diversification of the portfolio. Foreign currency forwards and options are used in hedging foreign exchange risk on U.S. dollar-denominated investments in Aflac Japan's portfolio. Foreign currency forwards and options are used to hedge certain portions of forecasted cash flows denominated in yen. Interest rate swaps are used to hedge the variability of interest cash flows associated with our variable interest rate notes. Cross-currency interest rate swaps, also referred to as foreign currency swaps, are used to economically convert certain U.S. dollar-denominated note obligations into yen-denominated principal and interest obligations. Interest rate swaptions have been used to hedge interest rate risk for certain U.S. dollar-denominated available-for-sale securities. We do not use derivatives for trading purposes, nor do we engage in leveraged derivative transactions.

From time to time, we purchase certain investments that contain an embedded derivative. We assess whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If we deem that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If we have elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings.

For those relationships where we seek hedge accounting, we formally document all relationships between hedging instruments and hedged items, as well as our risk-management objectives and strategies for undertaking various hedge transactions. This process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or liabilities on the balance sheet. We also assess, both at inception and on an ongoing basis, whether the derivatives and non-derivative financial instruments used in hedging activities are highly effective in offsetting changes in fair values or cash flows of the hedged items. The assessment of hedge effectiveness determines the accounting treatment of noncash changes in fair value.

Changes in the fair value of any of our derivatives that are designated and qualify as cash flow hedges are recorded in other comprehensive income as long as they are deemed effective. Any hedge ineffectiveness is recorded immediately in current period earnings within derivative and other gains (losses). Periodic derivative net coupon settlements are recorded in the line item of the consolidated statements of earnings in which the cash flows of the hedged item are recorded.

Changes in the estimated fair value of derivative instruments that are designated and qualify as fair value hedges, including amounts measured as ineffectiveness, and changes in the estimated fair value of the hedged item related to the designated risk being hedged, are reported in current earnings within derivative and other gains (losses).

We have designated the majority of the Parent Company's yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and designated certain derivatives as hedges of the foreign currency exposure to our investment in Aflac Japan. At the beginning of each quarter, we make our net investment hedge designation. If the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than our net investment in Aflac Japan, the hedge is deemed to be effective, and the exchange effect on the yen-denominated liabilities and the change in estimated fair value of the derivatives are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed our net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds our investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses).

Derivatives that are not designated as hedges are carried at fair value with all changes in fair value recorded in current period earnings within derivative and other gains (losses). We include the fair value of all freestanding derivatives in either other assets or other liabilities on the balance sheet.

We receive and pledge cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. We generally can repledge or resell collateral obtained by us, although we do not typically exercise such rights. Securities received as collateral are not recognized unless we were to exercise our right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that we have pledged as collateral continue to be carried as investment assets on our balance sheet.

Freestanding derivatives are carried at estimated fair value in our consolidated balance sheets either as other assets or as other liabilities. See Note 5 for a discussion on how we determine the fair value of our derivatives. Accruals on derivatives are typically recorded in accrued investment income or within other liabilities in the consolidated balance sheets.

If a derivative is not designated as an accounting hedge or its use in managing risk does not qualify for hedge accounting, changes in the estimated fair value of the derivative are generally reported within derivative and other gains(losses), which is a component of realized investment gains (losses). The fluctuations in estimated fair value of derivatives that have not been designated for hedge accounting can result in volatility in net earnings.

To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated risk of the hedged item. At the inception of the hedging relationship for hedges we elect to designate for hedge accounting treatment, we formally document all relationships between hedging instruments and hedged items, as well as our risk-management objective and strategy for undertaking each hedge transaction. We document the designation of each hedge as either (i) a hedge of the variability of cash flows to be received or paid related to a recognized asset or liability or the hedge of a forecasted transaction ("cash flow hedge"); (ii) a hedge of the estimated fair value of a recognized asset or liability ("fair value hedge"); or (iii) a hedge of a net investment in a foreign operation. The documentation process includes linking derivatives and nonderivatives that are designated as hedges to specific assets or groups of assets or liabilities on the statement of financial position or to specific forecasted transactions and defining the effectiveness and ineffectiveness testing methods to be used. At the hedge's inception and on an ongoing quarterly basis, we also formally assess whether the derivatives that are used in hedging transactions have been, and are expected to continue to be, highly effective in offsetting their designated risk. Hedge effectiveness is assessed using qualitative and quantitative methods.

For assessing hedge effectiveness of cash flow hedges, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression or other statistical analysis of changes in cash flows associated with the hedge relationship. Hedge ineffectiveness of the hedge relationships on our VIE cash flow hedges is measured each reporting period using the “Hypothetical Derivative Method.” For derivative instruments that are designated and qualify as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing hedge ineffectiveness are recognized in current earnings within derivative and other gains (losses). All components of each derivative's gain or loss are included in the assessment of hedge effectiveness.

For assessing hedge effectiveness of fair value hedges, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression or other statistical analysis of changes in fair value associated with the hedge relationship. Hedge ineffectiveness of the hedge relationships is measured each reporting period using the dollar offset method. For derivative instruments that are designated and qualify as fair value hedges, changes in the estimated fair value of the derivative, including amounts measured as ineffectiveness, and changes in the estimated fair value of the hedged item related to the designated risk being hedged, are reported in current earnings within derivative and other gains (losses). When assessing the effectiveness of our fair value hedges, we exclude the changes in fair value related to the difference between the spot and the forward rate on our foreign currency forwards and the time value of options.

For the hedge of our net investment in Aflac Japan, we have designated Parent Company yen-denominated liabilities as non-derivative hedging instruments and have designated certain foreign currency forwards and options as derivative hedging instruments. We make our net investment hedge designation at the beginning of each quarter. For assessing hedge effectiveness of net investment hedges, if the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than our net investment in Aflac Japan, the hedge is deemed to be effective. If the hedge is effective, the related exchange effect on the yen-denominated liabilities is reported in the unrealized foreign currency component of other comprehensive income. For derivatives designated as net investment hedges, Aflac follows the forward-rate method. According to that method, all changes in fair value, including changes related to the forward-rate component of foreign currency forward contracts and the time value of foreign currency options, are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed our net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds our investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses).

We discontinue hedge accounting prospectively when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the estimated cash flows or fair value of a hedged item; (2) the derivative is de-designated as a hedging instrument; or (3) the derivative expires or is sold, terminated or exercised.

When hedge accounting is discontinued on a cash flow hedge or fair value hedge, the derivative is carried in the consolidated balance sheets at its estimated fair value, with changes in estimated fair value recognized in current period earnings. For discontinued cash flow hedges, including those where the derivative is sold, terminated or exercised, amounts previously deferred in other comprehensive income (loss) are reclassified into earnings when earnings are impacted by the cash flow of the hedged item.

Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring new business are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual premium income to total anticipated premium income. Anticipated premium income is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition.

For some 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 replacements. The Company performs a two-stage analysis of the internal replacements to determine if the modification is substantive to the base policy. The stages of evaluation are as follows: 1) determine if the modification is integrated with the base policy, and 2) if it is integrated, determine if the resulting contract is substantially changed.

For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. 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. Examples include conversions of same age bands, certain family coverage changes, pricing era changes (decrease), and ordinary life becomes reduced paid-up and certain reinstatements.

An internal replacement transaction that results in a policy that is substantially changed is accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy 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. Further, the policy reserves are evaluated based on the new policy features, and any change (up or down) necessary is recognized at the date of contract change/modification. Examples include conversions-higher age bands, certain family coverage changes, pricing era changes (increase), lapse & re-issue, certain reinstatements and certain contract conversions.

Riders can be considered internal replacements that are either integrated or non-integrated resulting in either substantially changed or substantially unchanged treatment. Riders are evaluated based on the specific facts and circumstances of the rider and are considered expansion of the existing benefits with additional premium required. Non-integrated riders to existing contracts do not change the Company's profit expectations for the related products and are treated as a new policy establishment for incremental coverage.

We measure the recoverability of DAC and the adequacy of our policy reserves annually by performing gross premium valuations on our business. (See the following discussion for further information regarding policy reserves.)

Policy Liabilities: Future policy benefits represent claims that are expected to occur in the future and are computed by a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect our experience, including a provision for adverse deviation. These assumptions are generally established and considered locked at policy inception. These assumptions may only be unlocked in certain circumstances based on the results of periodic DAC recoverability and premium deficiency testing.

Unpaid policy claims are estimates computed on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. We regularly adjust these estimates as new claims experience emerges and reflect the changes in operating results in the year such adjustments are made.

Other policy liabilities consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period.

For internal replacements that are determined to not be substantially unchanged, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract; however, for internal replacements that are considered substantially unchanged, no changes to the reserves are recognized.

Reinsurance: We enter into reinsurance agreements with other companies in the normal course of business. 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. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded. See Note 8 of the Notes to the Consolidated Financial Statements for additional information.

Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing our income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which we expect the temporary differences to reverse. We record deferred tax assets for tax positions taken based on our assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized.

Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. We recognize a charge for our estimated share of the industry's obligation once it is determinable. We review the estimated liability for policyholder protection corporation contributions on an annual basis and report any adjustments in Aflac Japan's expenses.

In the United States, each state has a guaranty association that supports insolvent insurers operating in those states. To date, our state guaranty association assessments have not been material.

Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. We use the weighted-average purchase cost to determine the cost of treasury stock that is reissued. We include any gains and losses in additional paid-in capital when treasury stock is reissued.

Share-Based Compensation: We measure compensation cost related to our share-based payment transactions at fair value on the grant date, and we recognize those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award.

Earnings Per Share: We compute basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards.

Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity.

New Accounting Pronouncements

Recently Adopted Accounting Pronouncements

Business Combinations - Simplifying the Accounting for Measurement-Period Adjustments: In September 2015, the FASB issued guidance requiring that an acquirer recognize adjustments to estimated amounts that are identified during the measurement period in the reporting period in which the adjustments are determined. In the same period’s financial statements, the acquirer is required to record income effects of the adjustments as if the accounting had been completed at the acquisition date. The acquirer is also required to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the estimated amounts had been recognized as of the acquisition date. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Financial Services - Insurance - Disclosures about Short-Duration Contracts: In May 2015, the FASB issued updated guidance requiring enhanced disclosures by all insurance entities that issue short-duration contracts. The amendments require insurance entities to disclose for annual reporting periods information about the liability for unpaid claims and claim adjustment expenses. The amendments also require insurance entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for unpaid claims and claim adjustment expenses. In addition, the amendments require insurance entities to disclose for annual and interim reporting periods a roll-forward of the liability for unpaid claims and claim adjustment expenses. For health insurance claims, the amendments require the disclosure of the total of incurred-but-not-reported liabilities and expected development on reported claims included in the liability for unpaid claims and claim adjustment expenses. We adopted this guidance as of December 31, 2016, and have no insurance contracts classified as short-duration. The adoption of this guidance did not have a significant impact on our disclosures.

Fair Value Measurement - Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent): In May 2015, the FASB issued updated guidance that removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The amendments also remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. Rather, those disclosures are limited to investments for which the entity has elected to measure the fair value using that practical expedient. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our disclosures.

Interest - Imputation of Interest - Simplifying the Presentation of Debt Issuance Costs: In April 2015, the FASB issued updated guidance to simplify presentation of debt issuance costs. The updated guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this amendment. In August 2015, the FASB issued updated Securities and Exchange Commission (SEC) Staff guidance pertaining to the presentation of debt issuance costs related to line-of-credit arrangements. The guidance states that an entity may defer and present debt issuance costs as an asset, subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. We retrospectively adopted this guidance as of January 1, 2016. The retrospective adoption of this accounting standard resulted in a $40 million reduction to notes payable and other assets as of December 31, 2015, the earliest balance sheet date presented in the period of adoption, but did not have a significant impact on our financial position, results of operations, or disclosures.

Consolidation - Amendments to the Consolidation Analysis: In February 2015, the FASB issued updated guidance that affects evaluation of whether limited partnerships and similar legal entities (limited liability corporations and securitization structures, etc.) are VIEs, evaluation of whether fees paid to a decision maker or a service provider are a variable interest, and evaluation of the effect of fee arrangements and the effect of related parties on the determination of the primary beneficiary under the VIE model for consolidation. The updated guidance eliminates the presumption that a general partner should consolidate a limited partnership. Limited partnership and similar legal entities that provide partners with either substantive kick-out rights or substantive participating rights over the general partner will now be evaluated under the voting interest model rather than the VIE model for consolidation. In situations where no single party has a controlling financial interest in a VIE, the related party relationships under common control should be considered in their entirety in determining whether that common control group has a controlling financial interest in the VIE. We adopted this guidance as of January 1, 2016. The adoption of this guidance impacted our footnote disclosures, but did not have a significant impact on our financial position or results of operations.

Derivatives and Hedging - Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity: In November 2014, the FASB issued guidance to clarify how to evaluate the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The guidance also clarifies that an entity should assess the substance of the relevant terms and features when considering how to weight those terms and features. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Presentation of Financial Statements - Going Concern - Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern: In August 2014, the FASB issued this amendment that provides U.S. GAAP guidance on management’s responsibility in evaluating whether there is substantial doubt about a company’s ability to continue as a going concern and about related footnote disclosures. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. The new guidance requires a formal assessment of going concern by management based on criteria prescribed in the new guidance. We adopted this guidance as of December 31, 2016. The adoption of this guidance did not have a significant impact our financial position, results of operations, or disclosures, and no substantial doubt currently exists about the Company’s ability to continue as a going concern.

Compensation - Stock Compensation - Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period: In June 2014, the FASB issued this amendment that provides guidance on certain share-based payment awards that require a specific performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance to awards with performance conditions that affect vesting to account for such awards. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. We adopted this guidance as of January 1, 2016. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Income Statement - Extraordinary and Unusual Items - Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items: In January 2015, the FASB issued updated guidance that eliminates from U.S. GAAP the concept of extraordinary items. Presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be retained. We adopted this guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Receivables - Troubled Debt Restructurings by Creditors - Classification of Certain Government-Guaranteed Mortgage Loans upon Foreclosure: In August 2014, the FASB issued updated guidance for troubled debt restructurings affecting creditors that hold government guaranteed mortgage loans. The guidance requires that a mortgage loan be derecognized and a separate other receivable be recognized upon foreclosure if certain conditions are met. We adopted the guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Transfers and Servicing - Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures: In June 2014, the FASB issued updated guidance for repurchase agreement and security lending transactions to change the accounting for repurchase-to-maturity transactions and linked repurchase financings to be accounted for as secured borrowings, consistent with the accounting for other repurchase agreements. The amendments also require new disclosures to increase transparency about the types of collateral pledged in repurchase agreements and similar transactions accounted for as secured borrowings. We adopted accounting changes for the new guidance as of January 1, 2015, and adopted the required disclosures as of April 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Receivables - Troubled Debt Restructurings by Creditors - Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure: In January 2014, the FASB issued updated guidance for troubled debt restructurings clarifying when an in substance repossession or foreclosure occurs, and when a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan. We adopted the guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Income Taxes - Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists: In July 2013, the FASB issued guidance to amend the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The new guidance states that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. However, to the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. We adopted this guidance as of January 1, 2014. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Other Expenses - Fees Paid to the Federal Government by Health Insurers: In July 2011, the FASB issued guidance on the accounting for fees owed by health insurers as mandated by the Patient Protection and Affordable Care Act as amended by the Health Care and Education Reconciliation Act, which imposes an annual fee on health insurers for each calendar year beginning on or after January 1, 2014. A health insurer's portion of the annual fee is payable by September 30 of the applicable calendar year once the entity provides health insurance for any U.S. health risk in that year. The accounting guidance specifies that the liability for the fee should be estimated and recorded in full in the applicable calendar year in which the fee is payable. We adopted this guidance as of January 1, 2014. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures.

Accounting Pronouncements Pending Adoption

Intangibles - Goodwill and Other - Simplifying the Test for Goodwill Impairment: In January 2017, the FASB issued amendments simplifying the subsequent measurement of goodwill. An entity, under this update, is no longer required to perform a hypothetical purchase price allocation to measure goodwill impairment. Instead, the entity should perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. The amendments are effective for public business entities that are U.S. SEC filers for annual or any interim goodwill impairment tests in fiscal years beginning after Dec. 15, 2019. Early adoption is permitted for any goodwill impairment tests performed on testing dates after January 1, 2017. We do not expect the adoption of this guidance to have a significant impact on our financial position, results of operations, or disclosures.

Business Combinations - Clarifying the Definition of a Business: In January 2017, the FASB issued amendments clarifying when a set of assets and activities is a business. The amendments provide a screen to determine when a set of assets and activities is not a business. The amendments are effective for public business entities beginning after December 15, 2017, including interim periods within those periods. We do not expect the adoption of this guidance to have a significant impact on our financial position, results of operations, or disclosures.

Statement of Cash Flows - Restricted Cash: In November 2016, the FASB issued amendments requiring that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. The amendments are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. We do not expect the adoption of this guidance to have a significant impact on our financial position, results of operations, or disclosures.

Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory: In October 2016, the FASB issued amendments that require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The amendments are effective for public business entities for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual reporting periods. Early adoption is permitted. We are evaluating the impact of adoption of this guidance on our financial position, results of operations, or disclosures.

Consolidation - Interests Held through Related Parties That Are under Common Control: In October 2016, the FASB issued amendments which clarify the consolidation guidance on how a reporting entity that is the single decision maker of a VIE should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. The amendments are effective for public business entities for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The adoption of this guidance is not expected to have a significant impact on our financial position, results of operations, or disclosures.

Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments: In August 2016, the FASB issued amendments that provide guidance on eight specific statement of cash flows classification issues. The amendments are effective for public companies for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted for any interim or annual period. The adoption of this guidance is not expected to have a significant impact on our financial position, results of operations, disclosures, or statements of cash flows.

Financial Instruments - Credit Losses - Measurement of Credit Losses on Financial Instruments: In June 2016, the FASB issued amendments that require a financial asset (or a group of financial assets) measured on an amortized cost basis to be presented net of an allowance for credit losses in order to reflect the amount expected to be collected on the financial asset(s). The measurement of expected credit losses is amended by replacing the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform about a credit loss. Credit losses on available-for-sale debt securities will continue to be measured in a manner similar to current GAAP. However, the amendments require that credit losses be presented as an allowance rather than as a writedown. Other amendments include changes to the balance sheet presentation and interest income recognition of purchased financial assets with a more-than-insignificant amount of credit deterioration since origination. The amendments are effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Companies may early adopt this guidance as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We have identified certain financial instruments in scope of this guidance to include certain fixed maturity securities, loans and loan receivables and reinsurance recoverables (See Notes 3 and 8 for current balances of instruments in scope). We are continuing to evaluate the impact of adoption of this guidance on our financial position, results of operations and disclosures.

Compensation - Stock Compensation - Improvements to Employee Share-Based Payment Accounting: In March 2016, the FASB issued amendments which simplify several aspects for share-based payment award transactions, including income tax consequences, classification of awards as either liability or equities, and classification on the statement of cash flows. The amendments are effective for public companies for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted for any interim or annual period.

The amendment requires prospective recognition of excess tax benefits and deficiencies in the income statement, rather than in paid-in capital. As a result of applying this requirement, we estimate that recognition of excess tax benefits will increase volatility in our statement of operations but will not have a significant impact on our statement of financial position, operations, or disclosures. We continue to evaluate the impact of this guidance as estimates will vary from the actual expense based on changes in actual share price.

The amendment also requires all excess tax benefits and tax deficiencies (including tax benefits of dividends on share-based payment awards) to be recognized as income tax expense or benefit in the income statement. The guidance requires modified retrospective transition for settlements on all outstanding awards (both historical and future) that did not give rise to an excess benefit to be recorded through retained earnings on a cumulative-effect basis. We estimate that the adoption of these amendments in the guidance will not have a significant impact on our financial position, results of operations, or disclosures.

Additionally, the amendment requires that the minimum statutory tax withholding for all outstanding liability awards be reclassified at the date of adoption to equity (assuming equity classification results from the guidance change), and record a cumulative-effect adjustment to equity on a modified retrospective basis. We estimate that the adoption of these amendments in the guidance will not have a significant impact on our financial position, results of operations, or disclosures.

The guidance requires certain reclassifications of balances on the statement of cash flows to or from operating and financing activities. The reclassification guidance will not have a significant impact on our statement of cash flows.

The amendment allows an entity to elect whether to use estimates of forfeitures, or to account for forfeitures as they occur, using modified retrospective application. We estimate that the election and adoption of this amendment in the guidance will not have a significant impact on our financial position, results of operations, or disclosures.

Investments - Equity Method and Joint Ventures - Simplifying the Transition to the Equity Method of Accounting: In March 2016, the FASB issued amendments which eliminate the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. Per the amendments, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The amendments also require that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive income at the date the investment becomes qualified for use of the equity method. The amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. The amendments should be applied prospectively upon their effective date to increases in the level of ownership interest or degree of influence that result in the adoption of the equity method. Early adoption is permitted. We have evaluated the adoption of this guidance and do not expect the guidance to have a significant impact on our financial position, results of operations, or disclosures.

Derivatives and Hedging - Contingent Put and Call Options in Debt Instruments: In March 2016, the FASB issued amendments which clarify what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. Consequently, when a call (put) option is contingently exercisable, an entity does not have to assess whether the event that triggers the ability to exercise a call (put) option is related to interest rates or credit risks. The amendments are effective for public business entities for fiscal years beginning after December 15, 2016 and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We have evaluated the adoption of this guidance and do not expect the guidance to have a significant impact on our financial position, results of operations, or disclosures.

Derivatives and Hedging - Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships: In March 2016, the FASB issued amendments which clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria remain intact. The amendments are effective for public business entities for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We have evaluated the adoption of this guidance and do not expect the guidance to have a significant impact on our financial position, results of operations, or disclosures.

Leases: In February 2016, the FASB issued updated guidance for accounting for leases. Per the amendments, lessees will be required to recognize all leases on the balance sheet, with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. A right-of-use asset, will be recorded which represents the lessee’s right to use, or to control the use of, a specified asset for a lease term. Under the new guidance, lessor accounting is largely unchanged. The amendments are effective for public companies for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. We have identified certain operating leases in scope of this guidance to include office space and equipment leases (See Note 15 for current balances of leases in scope). The leases within scope of this guidance will increase our right-of-use assets recorded on our financial position, however we estimate leases within scope of the guidance to represent less than 1% of our total assets as of December 31, 2016. We estimate that the adoption of this guidance will not have a significant impact on our financial position, results of operations and disclosures.

Financial Instruments - Overall - Recognition and Measurement of Financial Assets and Financial Liabilities: In January 2016, the FASB issued guidance to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The main provisions require that equity investments be measured at fair value with changes recognized in net income; that changes in instrument-specific credit risk for financial liabilities that are measured under the fair value option be recognized in other comprehensive income; and that entities would make the assessment of the ability to realize a deferred tax asset (DTA) related to an available-for-sale (AFS) debt security in combination with the entity's other DTAs. The amendments are effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is not permitted, with the exception of the own credit provision if an entity has elected to measure a liability at fair value. We have identified certain financial instruments in scope of this guidance to include certain fixed maturity securities, perpetual securities and equity securities (See Note 3 for current balances of instruments in scope). We estimate that the impact of this guidance will increase volatility in our statement of operations and we are continuing to evaluate the impact of this guidance on our statement of financial position, operations, or disclosures.

Revenue from Contracts with Customers: In May 2014, the FASB issued updated guidance that affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB deferred the effective date for this standard to annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Other updates related to the new guidance, which are effective as of the same reporting period, pertain to improvements in certain areas. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods. We have identified revenue in scope of this guidance to include certain revenues associated with affiliated entities in support of our operations. We estimate the revenue within scope of the guidance to represent less than 1% of our total revenues as of December 31, 2016. We estimate that the adoption of this guidance will not have a significant impact on our financial position, results of operations and disclosures.

Recent accounting guidance not discussed above is not applicable, did not have, or is not expected to have a material impact to our business.