Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial reporting. Accordingly, they do not include all of the information and footnotes required by GAAP for annual financial statements. We have omitted certain footnote disclosures that would substantially duplicate the disclosures in our 2020 Annual Report on Form 10-K, unless the information contained in those disclosures materially changed or is required by GAAP. Certain prior year amounts have been reclassified to conform to the current year presentation. In the opinion of management, all adjustments, including normal recurring adjustments, necessary for a fair statement of the consolidated financial statements as of and for the three and six months ended June 30, 2021 and 2020 have been recorded. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2021, or any other period. These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements as of and for the year ended December 31, 2020 included in our 2020 Annual Report on Form 10-K.
Foreign Currency	Certain of our subsidiaries operate outside of the United States and have functional currencies other than the U.S. dollar (“USD”). We translate the assets and liabilities of those subsidiaries to USD using the exchange rate in effect at the end of the period. We translate the revenues and expenses of those subsidiaries to USD using the average exchange rates in effect during the period. The net effect of these translation adjustments is included in “Foreign currency translation adjustments” in our consolidated statements of comprehensive income.
Cash and Cash Equivalents	Cash and Cash Equivalents: We control a number of bank accounts that are used exclusively to hold customer funds for the administration of customer benefits, and we have cash and cash equivalents on deposit to meet certain regulatory requirements. These amounts totaled $248 and $170 at June 30, 2021 and December 31, 2020, respectively, and are included in the cash and cash equivalents line on our consolidated balance sheets.
Investment, Policy	Investments: We classify fixed maturity securities in our investment portfolio as “available-for-sale” and report those securities at fair value. Certain fixed maturity securities are available to support current operations and, accordingly, we classify such investments as current assets without regard to their contractual maturity. Investments used to satisfy contractual, regulatory or other requirements are classified as long-term, without regard to contractual maturity. If a fixed maturity security is in an unrealized loss position and we have the intent to sell the fixed maturity security, or it is more likely than not that we will have to sell the fixed maturity security before recovery of its amortized cost basis, we write down the fixed maturity security’s cost basis to fair value and record an impairment loss in our consolidated statements of income. For impaired fixed maturity securities that we do not intend to sell or if it is more likely than not that we will not have to sell such securities, but we expect that we will not fully recover the amortized cost basis, we recognize the credit component of the impairment as an allowance for credit loss in our consolidated balance sheets and record an impairment loss in our consolidated statements of income. The non-credit component of the impairment is recognized in accumulated other comprehensive (loss) income. Furthermore, unrealized losses entirely caused by non-credit-related factors related to fixed maturity securities for which we expect to fully recover the amortized cost basis continue to be recognized in accumulated other comprehensive (loss) income. The credit component of an impairment is determined primarily by comparing the net present value of projected future cash flows with the amortized cost basis of the fixed maturity security. The net present value is calculated by discounting our best estimate of projected future cash flows at the effective interest rate implicit in the fixed maturity security at the date of purchase. For mortgage-backed and asset-backed securities, cash flow estimates are based on assumptions regarding the underlying collateral, including prepayment speeds, vintage, type of underlying asset, geographic concentrations, default rates, recoveries and changes in value. For all other securities, cash flow estimates are driven by assumptions regarding probability of default, including changes in credit ratings and estimates regarding timing and amount of recoveries associated with a default. For asset-backed securities included in fixed maturity securities, we recognize income using an effective yield 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 the securities is adjusted to the amount that would have existed had the new effective yield been applied since the purchase date of the securities. Such adjustments are reported within net investment income. The changes in fair value of our marketable equity securities are recognized in our results of operations within net realized gains and losses on financial instruments. Certain marketable equity securities are held to satisfy contractual obligations, and are reported under the caption “Other invested assets” in our consolidated balance sheets. We have corporate-owned life insurance policies on certain participants in our deferred compensation plans and other members of management. The cash surrender value of the corporate-owned life insurance policies is reported under the caption “Other invested assets” in our consolidated balance sheets. We use the equity method of accounting for investments in companies in which our ownership interest may enable us to influence the operating or financial decisions of the investee company. Our proportionate share of equity in net income of these unconsolidated affiliates is reported within net investment income. The equity method investments are reported under the caption “Other invested assets” in our consolidated balance sheets. Investment income is recorded when earned. All securities sold resulting in investment gains and losses are recorded on the trade date. Realized gains and losses are determined on the basis of the cost or amortized cost of the specific securities sold. We participate in securities lending programs whereby marketable securities in our investment portfolio are transferred to independent brokers or dealers in exchange for cash and securities collateral. We recognize the collateral as an asset, which is reported under the caption “Other current assets” in our consolidated balance sheets, and we record a corresponding liability for the obligation to return the collateral to the borrower, which is reported under the caption “Other current liabilities” in our consolidated balance sheets. The securities on loan are reported in the applicable investment category on our consolidated balance sheets. Unrealized gains or losses on securities lending collateral are included in accumulated other comprehensive (loss) income as a separate component of shareholders’ equity. The market value of loaned securities and that of the collateral pledged can fluctuate in non-synchronized fashions. To the extent the loaned securities’ value appreciates faster or depreciates slower than the value of the collateral pledged, we are exposed to the risk of the shortfall. As a primary mitigating mechanism, the loaned securities and collateral pledged are marked to market on a daily basis and the shortfall, if any, is collected accordingly. Secondarily, the collateral level is set at 102% of the value of the loaned securities, which provides a cushion before any shortfall arises. The investment of the cash collateral is subject to market risk, which is managed by limiting the investments to higher quality and shorter duration instruments.
Receivable	Receivables: Receivables are reported net of amounts for expected credit losses. The allowance for doubtful accounts is based on historical collection trends, future forecasts and our judgment regarding the ability to collect specific accounts. Premium receivables include the uncollected amounts from insured groups, individuals and government programs. Premium receivables are reported net of an allowance for doubtful accounts of $152 and $146 at June 30, 2021 and December 31, 2020, respectively. Self-funded receivables include administrative fees, claims and other amounts due from self-funded customers. Self-funded receivables are reported net of an allowance for doubtful accounts of $91 and $54 at June 30, 2021 and December 31, 2020, respectively. Other receivables include pharmacy rebates, provider advances, claims recoveries, reinsurance receivables, proceeds due from brokers on investment trades, accrued investment income, and other miscellaneous amounts due to us. These receivables are reported net of an allowance for doubtful accounts of $479 and $374 at June 30, 2021 and December 31, 2020, respectively.
Revenue Recognition	Revenue Recognition: For our fee-based contracts, we had no material contract assets, contract liabilities or deferred contract costs recorded on our consolidated balance sheet at June 30, 2021. For the three and six months ended June 30, 2021, revenue recognized from performance obligations related to prior periods, such as due to changes in transaction price, was not material. For contracts that have an original expected duration of greater than one year, revenue expected to be recognized in future periods related to unfulfilled contractual performance obligations and contracts with variable consideration related to undelivered performance obligations is not material.
New Accounting Pronouncements	Recently Adopted Accounting Guidance: In January 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2021-01, Reference Rate Reform (Topic 848) (“ASU 2021-01”). The amendments in ASU 2021-01 provide optional expedients and exceptions for applying GAAP to contract modifications and hedging relationships, subject to meeting certain criteria, that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of the reference rate reform. The provisions must be applied at a Topic, Subtopic, or Industry Subtopic level for all transactions other than derivatives, which may be applied at a hedging relationship level. We adopted ASU 2021-01 on January 7, 2021 and the adoption did not have an impact on our consolidated financial position, results of operations or cash flows. In October 2020, the FASB issued Accounting Standards Update No. 2020-08, Codification Improvements to Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs (“ASU 2020-08”). The amendments in ASU 2020-08 clarify when an entity should assess whether a callable debt security is within the scope of accounting guidance, which impacts the amortization period for nonrefundable fees and other costs. ASU 2020-08 became effective for interim and annual reporting periods beginning after December 15, 2020. The amendments are to be applied on a prospective basis as of the beginning of the period of adoption for existing or newly purchased callable debt securities. We adopted ASU 2020-08 on January 1, 2021, and the adoption did not have an impact on our consolidated financial position, results of operations or cash flows. In December 2019, the FASB issued Accounting Standards Update No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). The amendments in ASU 2019-12 remove certain exceptions to the general principles in Accounting Standards Codification Topic 740. The amendments also clarify and amend existing guidance to improve consistent application. The amendments became effective for our annual reporting periods beginning after December 15, 2020. The transition method (retrospective, modified retrospective, or prospective basis) related to the amendments depends on the applicable guidance, and all amendments for which there is no transition guidance specified are to be applied on a prospective basis. We adopted ASU 2019-12 on January 1, 2021, and the adoption did not have an impact on our consolidated financial position, results of operations or cash flows. Recent Accounting Guidance Not Yet Adopted: In November 2020, the FASB issued Accounting Standards Update No. 2020-11, Financial Services—Insurance (Topic 944): Effective Date and Early Application (“ASU 2020-11”). The amendments in ASU 2020-11 make changes to the effective date and early application of Accounting Standards Update No. 2018-12, Financial Services—Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts (“ASU 2018-12”), which was issued in November 2018. The amendments in ASU 2020-11 have extended the original effective date by one year, and now the amendments are required for our interim and annual reporting periods beginning after December 15, 2022. The amendments in ASU 2018-12 make changes to a variety of areas to simplify or improve the existing recognition, measurement, presentation and disclosure requirements for long-duration contracts issued by an insurance entity. The amendments require insurers to annually review the assumptions they make about their policyholders and update the liabilities for future policy benefits if the assumptions change. The amendments also simplify the amortization of deferred contract acquisition costs and add new disclosure requirements about the assumptions insurers use to measure their liabilities and how they may affect future cash flows. The amendments related to the liability for future policy benefits for traditional and limited-payment contracts and deferred acquisition costs are to be applied to contracts in force as of the beginning of the earliest period presented, with an option to apply such amendments retrospectively with a cumulative-effect adjustment to the opening balance of retained earnings as of the earliest period presented. The amendments for market risk benefits are to be applied retrospectively. We are currently evaluating the effects the adoption of ASU 2020-11 and ASU 2018-12 will have on our consolidated financial position, results of operations, cash flows, and related disclosures. In August 2020, the FASB issued Accounting Standards Update No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (“ASU 2020-06”). The amendments eliminate two of the three accounting models that require separate accounting for convertible features of debt securities, simplify the contract settlement assessment for equity classification, require the use of the if-converted method for all convertible instruments in the diluted earnings per share calculation and expand disclosure requirements. The amendments are effective for our annual and interim reporting periods beginning after December 15, 2021, with early adoption permitted for reporting periods beginning after December 15, 2020. The guidance can be applied on a full retrospective basis to all periods presented or a modified retrospective basis with a cumulative effect adjustment to the opening balance of retained earnings during the period of adoption. We are currently evaluating the effects the adoption of ASU 2020-06 will have on our consolidated financial statements and disclosures.

Basis of Presentation and Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2021

Basis of Presentation: The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial reporting. Accordingly, they do not include all of the information and footnotes required by GAAP for annual financial statements. We have omitted certain footnote disclosures that would substantially duplicate the disclosures in our 2020 Annual Report on Form 10-K, unless the information contained in those disclosures materially changed or is required by GAAP. Certain prior year amounts have been reclassified to conform to the current year presentation. In the opinion of management, all adjustments, including normal recurring adjustments, necessary for a fair statement of the consolidated financial statements as of and for the three and six months ended June 30, 2021 and 2020 have been recorded. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2021, or any other period. These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements as of and for the year ended December 31, 2020 included in our 2020 Annual Report on Form 10-K.

Foreign Currency

Certain of our subsidiaries operate outside of the United States and have functional currencies other than the U.S. dollar (“USD”). We translate the assets and liabilities of those subsidiaries to USD using the exchange rate in effect at the end of the period. We translate the revenues and expenses of those subsidiaries to USD using the average exchange rates in effect during the period. The net effect of these translation adjustments is included in “Foreign currency translation adjustments” in our consolidated statements of comprehensive income.

Cash and Cash Equivalents

Cash and Cash Equivalents: We control a number of bank accounts that are used exclusively to hold customer funds for the administration of customer benefits, and we have cash and cash equivalents on deposit to meet certain regulatory requirements. These amounts totaled $248 and $170 at June 30, 2021 and December 31, 2020, respectively, and are included in the cash and cash equivalents line on our consolidated balance sheets.

Investment, Policy

Investments: We classify fixed maturity securities in our investment portfolio as “available-for-sale” and report those securities at fair value. Certain fixed maturity securities are available to support current operations and, accordingly, we classify such investments as current assets without regard to their contractual maturity. Investments used to satisfy contractual, regulatory or other requirements are classified as long-term, without regard to contractual maturity.

If a fixed maturity security is in an unrealized loss position and we have the intent to sell the fixed maturity security, or it is more likely than not that we will have to sell the fixed maturity security before recovery of its amortized cost basis, we write down the fixed maturity security’s cost basis to fair value and record an impairment loss in our consolidated statements of income. For impaired fixed maturity securities that we do not intend to sell or if it is more likely than not that we will not have to sell such securities, but we expect that we will not fully recover the amortized cost basis, we recognize the credit component of the impairment as an allowance for credit loss in our consolidated balance sheets and record an impairment loss in our consolidated statements of income. The non-credit component of the impairment is recognized in accumulated other comprehensive (loss) income. Furthermore, unrealized losses entirely caused by non-credit-related factors related to fixed maturity securities for which we expect to fully recover the amortized cost basis continue to be recognized in accumulated other comprehensive (loss) income.

The credit component of an impairment is determined primarily by comparing the net present value of projected future cash flows with the amortized cost basis of the fixed maturity security. The net present value is calculated by discounting our best estimate of projected future cash flows at the effective interest rate implicit in the fixed maturity security at the date of purchase. For mortgage-backed and asset-backed securities, cash flow estimates are based on assumptions regarding the underlying collateral, including prepayment speeds, vintage, type of underlying asset, geographic concentrations, default rates, recoveries and changes in value. For all other securities, cash flow estimates are driven by assumptions regarding probability of default, including changes in credit ratings and estimates regarding timing and amount of recoveries associated with a default.

For asset-backed securities included in fixed maturity securities, we recognize income using an effective yield 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 the securities is adjusted to the amount that would have existed had the new effective yield been applied since the purchase date of the securities. Such adjustments are reported within net investment income.

The changes in fair value of our marketable equity securities are recognized in our results of operations within net realized gains and losses on financial instruments. Certain marketable equity securities are held to satisfy contractual obligations, and are reported under the caption “Other invested assets” in our consolidated balance sheets.

We have corporate-owned life insurance policies on certain participants in our deferred compensation plans and other members of management. The cash surrender value of the corporate-owned life insurance policies is reported under the caption “Other invested assets” in our consolidated balance sheets.

We use the equity method of accounting for investments in companies in which our ownership interest may enable us to influence the operating or financial decisions of the investee company. Our proportionate share of equity in net income of these unconsolidated affiliates is reported within net investment income. The equity method investments are reported under the caption “Other invested assets” in our consolidated balance sheets.

Investment income is recorded when earned. All securities sold resulting in investment gains and losses are recorded on the trade date. Realized gains and losses are determined on the basis of the cost or amortized cost of the specific securities sold.

We participate in securities lending programs whereby marketable securities in our investment portfolio are transferred to independent brokers or dealers in exchange for cash and securities collateral. We recognize the collateral as an asset, which is reported under the caption “Other current assets” in our consolidated balance sheets, and we record a corresponding liability for the obligation to return the collateral to the borrower, which is reported under the caption “Other current liabilities” in our consolidated balance sheets. The securities on loan are reported in the applicable investment category on our consolidated balance sheets. Unrealized gains or losses on securities lending collateral are included in accumulated other comprehensive (loss) income as a separate component of shareholders’ equity. The market value of loaned securities and that of the collateral pledged can fluctuate in non-synchronized fashions. To the extent the loaned securities’ value appreciates faster or depreciates slower than the value of the collateral pledged, we are exposed to the risk of the shortfall. As a primary mitigating mechanism, the loaned securities and collateral pledged are marked to market on a daily basis and the shortfall, if any, is collected accordingly. Secondarily, the collateral level is set at 102% of the value of the loaned securities, which provides a cushion before any shortfall arises. The investment of the cash collateral is subject to market risk, which is managed by limiting the investments to higher quality and shorter duration instruments.

Receivable

Receivables: Receivables are reported net of amounts for expected credit losses. The allowance for doubtful accounts is based on historical collection trends, future forecasts and our judgment regarding the ability to collect specific accounts.

Premium receivables include the uncollected amounts from insured groups, individuals and government programs. Premium receivables are reported net of an allowance for doubtful accounts of $152 and $146 at June 30, 2021 and December 31, 2020, respectively.

Self-funded receivables include administrative fees, claims and other amounts due from self-funded customers. Self-funded receivables are reported net of an allowance for doubtful accounts of $91 and $54 at June 30, 2021 and December 31, 2020, respectively.

Other receivables include pharmacy rebates, provider advances, claims recoveries, reinsurance receivables, proceeds due from brokers on investment trades, accrued investment income, and other miscellaneous amounts due to us. These receivables are reported net of an allowance for doubtful accounts of $479 and $374 at June 30, 2021 and December 31, 2020, respectively.

Revenue Recognition

Revenue Recognition: For our fee-based contracts, we had no material contract assets, contract liabilities or deferred contract costs recorded on our consolidated balance sheet at June 30, 2021. For the three and six months ended June 30, 2021, revenue recognized from performance obligations related to prior periods, such as due to changes in transaction price, was not material. For contracts that have an original expected duration of greater than one year, revenue expected to be recognized in future periods related to unfulfilled contractual performance obligations and contracts with variable consideration related to undelivered performance obligations is not material.

New Accounting Pronouncements

Recently Adopted Accounting Guidance: In January 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2021-01, Reference Rate Reform (Topic 848) (“ASU 2021-01”). The amendments in ASU 2021-01 provide optional expedients and exceptions for applying GAAP to contract modifications and hedging relationships, subject to meeting certain criteria, that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of the reference rate reform. The provisions must be applied at a Topic, Subtopic, or Industry Subtopic level for all transactions other than derivatives, which may be applied at a hedging relationship level. We adopted ASU 2021-01 on January 7, 2021 and the adoption did not have an impact on our consolidated financial position, results of operations or cash flows.

In October 2020, the FASB issued Accounting Standards Update No. 2020-08, Codification Improvements to Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs (“ASU 2020-08”). The amendments in ASU 2020-08 clarify when an entity should assess whether a callable debt security is within the scope of accounting guidance, which impacts the amortization period for nonrefundable fees and other costs. ASU 2020-08 became effective for interim and annual reporting periods beginning after December 15, 2020. The amendments are to be applied on a prospective basis as of the beginning of

the period of adoption for existing or newly purchased callable debt securities. We adopted ASU 2020-08 on January 1, 2021, and the adoption did not have an impact on our consolidated financial position, results of operations or cash flows.

In December 2019, the FASB issued Accounting Standards Update No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). The amendments in ASU 2019-12 remove certain exceptions to the general principles in Accounting Standards Codification Topic 740. The amendments also clarify and amend existing guidance to improve consistent application. The amendments became effective for our annual reporting periods beginning after December 15, 2020. The transition method (retrospective, modified retrospective, or prospective basis) related to the amendments depends on the applicable guidance, and all amendments for which there is no transition guidance specified are to be applied on a prospective basis. We adopted ASU 2019-12 on January 1, 2021, and the adoption did not have an impact on our consolidated financial position, results of operations or cash flows.

Recent Accounting Guidance Not Yet Adopted: In November 2020, the FASB issued Accounting Standards Update No. 2020-11, Financial Services—Insurance (Topic 944): Effective Date and Early Application (“ASU 2020-11”). The amendments in ASU 2020-11 make changes to the effective date and early application of Accounting Standards Update No. 2018-12, Financial Services—Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts (“ASU 2018-12”), which was issued in November 2018. The amendments in ASU 2020-11 have extended the original effective date by one year, and now the amendments are required for our interim and annual reporting periods beginning after December 15, 2022. The amendments in ASU 2018-12 make changes to a variety of areas to simplify or improve the existing recognition, measurement, presentation and disclosure requirements for long-duration contracts issued by an insurance entity. The amendments require insurers to annually review the assumptions they make about their policyholders and update the liabilities for future policy benefits if the assumptions change. The amendments also simplify the amortization of deferred contract acquisition costs and add new disclosure requirements about the assumptions insurers use to measure their liabilities and how they may affect future cash flows. The amendments related to the liability for future policy benefits for traditional and limited-payment contracts and deferred acquisition costs are to be applied to contracts in force as of the beginning of the earliest period presented, with an option to apply such amendments retrospectively with a cumulative-effect adjustment to the opening balance of retained earnings as of the earliest period presented. The amendments for market risk benefits are to be applied retrospectively. We are currently evaluating the effects the adoption of ASU 2020-11 and ASU 2018-12 will have on our consolidated financial position, results of operations, cash flows, and related disclosures.

In August 2020, the FASB issued Accounting Standards Update No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (“ASU 2020-06”). The amendments eliminate two of the three accounting models that require separate accounting for convertible features of debt securities, simplify the contract settlement assessment for equity classification, require the use of the if-converted method for all convertible instruments in the diluted earnings per share calculation and expand disclosure requirements. The amendments are effective for our annual and interim reporting periods beginning after December 15, 2021, with early adoption permitted for reporting periods beginning after December 15, 2020. The guidance can be applied on a full retrospective basis to all periods presented or a modified retrospective basis with a cumulative effect adjustment to the opening balance of retained earnings during the period of adoption. We are currently evaluating the effects the adoption of ASU 2020-06 will have on our consolidated financial statements and disclosures.