Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Interest coverage ratio Debt Instrument, Covenant, Interest Coverage Ratio, Minimum Debt Instrument, Covenant, Interest Coverage Ratio, Minimum Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Title of 12(b) Security Title of 12(b) Security Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Carrying Amount Reported Value Measurement [Member] Document Fiscal Year Focus Document Fiscal Year Focus Adjustment to Compensation, Amount Adjustment to Compensation Amount Financial Instrument [Axis] Financial Instrument [Axis] Segment Reporting [Abstract] Segment Reporting [Abstract] Schedule of Fair Value of Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Schedule of Long Term Debt Schedule of Long-Term Debt Instruments [Table Text Block] Covenant Period Four Covenant Period Four [Member] Covenant Period Four Credit Facility Line of Credit [Member] Restatement Determination Date Restatement Determination Date Risk adjustment receivable Affordable Care Act, Premium Stabilization Program, Risk Adjustment, Receivable Affordable Care Act, Premium Stabilization Program, Risk Adjustment, Receivable Amounts due government agencies Medical Premium Liability Due To Agency Medical Premium Liability Due to Agency Amendment Flag Amendment Flag Current liabilities: Liabilities, Current [Abstract] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Investment income Net Investment Income Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Asset-backed securities Asset-Backed Securities [Member] Deferred income taxes Increase (Decrease) in Deferred Income Taxes Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Schedule of Cash and Cash Equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Entity Address, State or Province Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Fair value of assets measured on recurring basis Assets, Fair Value Disclosure [Abstract] Denominator for basic net income per share (in shares) Weighted Average Number of Shares Outstanding, Basic Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Due after five years through ten years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Structured Securities Structured Securities [Member] Structured Securities [Member] Contract Rights and Licensing Agreements Contract Rights and Licenses [Member] Contract Rights and Licenses Cash consideration amount Debt Instrument, Debt To Capitalization Ratio, Cash Consideration Amount Debt Instrument, Debt To Capitalization Ratio, Cash Consideration Amount Entity Address, City or Town Entity Address, City or Town Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Fiscal Year Maturity [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount (Level 2) Fair Value, Inputs, Level 2 [Member] Receivable [Domain] Receivable [Domain] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Other operating expenses Other Expenses Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Segment expenses Segment Expenses Segment Expenses Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Deferred revenue Increase (Decrease) in Contract with Customer, Liability Schedule of Operating Segment Information Segment Reporting [Table Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Premium Revenue Recognition and Amounts Due Government Agencies, Minimum MLR, Medical Cost Corridors and Profit Sharing and Risk Adjustment Revenue from Contract with Customer [Policy Text Block] Other comprehensive (loss) gain, net of tax Other comprehensive income (loss), net Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Premium Deficiency Reserve on Loss Contracts Premium Deficiency Reserves on Loss Contracts [Policy Text Block] Premium Deficiency Reserves on Loss Contracts Due after one year through five years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Income taxes Increase (Decrease) in Income Taxes Payable Document Period End Date Document Period End Date Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Net cash (used in) provided by investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Aggregate principal amount Debt Instrument, Face Amount Consolidation and Interim Financial Information Consolidation And Interim Financial Information, Policy [Policy Text Block] Consolidation And Interim Financial Information, Policy [Policy Text Block] Operating expenses: Costs and Expenses [Abstract] Security Exchange Name Security Exchange Name Debt term Debt Instrument, Term Number of states with programs Number Of States With Government-Sponsored Healthcare Programs Number Of States With Government-Sponsored Healthcare Programs Less: effect of income taxes OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax Due after ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Purchases of investments Payments to Acquire Marketable Securities Accumulated other comprehensive (loss) income Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Amortized cost, due one year through five years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year One through Five In a Continuous Loss Position for 12 Months or More, Estimated Fair Value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Net Income Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Earnings Per Share [Abstract] Earnings Per Share [Abstract] Proceeds from sales and maturities of investments Proceeds from Sale and Maturity of Marketable Securities Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Amortized cost, due in one year or less Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Total liabilities Liabilities Trading Symbol Trading Symbol Debt securities, available-for-sale Estimated Fair Value Debt Securities, Available-for-Sale, Excluding Accrued Interest Purchases of property, equipment and capitalized software Payments to Acquire Property, Plant, and Equipment Number of members eligible for the health care programs, approximately Number Of Members Eligible For Government-Sponsored Healthcare Programs Number of members eligible for the health care programs. Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Weighted-average number of shares issued: Weighted Average Number of Shares Outstanding, Basic [Abstract] Company Selected Measure Name Company Selected Measure Name Average maturity period (less than) Investments, Average Maturity Period Investments, Average Maturity Period Schedule of Restricted Cash and Cash Equivalents Restrictions on Cash and Cash Equivalents [Table Text Block] Percent due to medicare, medical loss ratio of marketplace Percent Due To Government Agencies, Medicare, Medical Loss Ratio Of Marketplace Percent Due To Government Agencies, Medicare, Medical Loss Ratio Of Marketplace Term Loans Term Loan [Member] Term Loan [Member] Credit Facility [Domain] Credit Facility [Domain] Medical claims and benefits payable Medical claims and benefits payable, beginning balance Medical claims and benefits payable, ending balance Liability for Claims and Claims Adjustment Expense Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Contract term Health Plan, Contract Term Health Plan, Contract Term Compensation Amount Outstanding Recovery Compensation Amount Medical margin Medical [Member] Medical Individual: Individual [Axis] Denominator for diluted net income per share (in shares) Weighted Average Number of Shares Outstanding, Diluted Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Percent due to medicare, medical loss ratio Percent Due To Government Agencies, Medicare, Medical Loss Ratio And Profit Sharing, Threshold Percent Due To Government Agencies, Marketplace, Medical Loss Ratio And Profit Sharing, Threshold Underlying Security Market Price Change Underlying Security Market Price Change, Percent Property, equipment, and capitalized software, net Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Medicare Medicare [Member] Medicare Government Receivables Government Receivables [Member] Government Receivables [Member] Segment margin Gross Profit Restricted investments Restricted Investments, Noncurrent Award Timing Predetermined Award Timing Predetermined [Flag] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Health Plans Health Plans [Member] Health plans. Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] (Level 1) Fair Value, Inputs, Level 1 [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Debt Instrument Covenant Period [Domain] Debt Instrument Covenant Period [Domain] Debt Instrument Covenant Period [Domain] Stock-based compensation (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements All Executive Categories All Executive Categories [Member] Common stock purchases Stock Repurchased and Retired During Period, Value Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Repayment of credit facility and term loans Repayments of Long-Term Lines of Credit 3.875% Notes due 2030 3.875% Senior Notes Due 2030 [Member] 3.875% Senior Notes Due 2030 4.375% Notes due 2028 4.375% Senior Notes Due 2028 [Member] 4.375% Senior Notes Due 2028 Other comprehensive (loss) gain: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Due in one year or less Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Schedule of Denominators for The Computation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Segments Segment Reporting [Text Block] Investments Investment in Debt and Equity Securities and Other Trading Assets [Text Block] Amount outstanding under letter of credit Long-Term Line of Credit Minimum Minimum [Member] Expiration Date Trading Arrangement Expiration Date Denominator: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Restricted cash and cash equivalents Restricted Cash and Cash Equivalent Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Revenue from external customers Premiums Earned And Service Revenue Premiums Earned And Service Revenue Common stock, shares authorized (in shares) Common Stock, Shares Authorized Covenant Period One Covenant Period One [Member] Covenant Period One Due after ten years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Exercise Price Award Exercise Price Investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Segment Reporting [Line Items] Segment Reporting [Line Items] Available-for-sale, securities maturities and redemptions Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale Document Quarterly Report Document Quarterly Report Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments [Domain] Segments [Domain] Debt securities, sale Proceeds from Sale of Debt Securities, Available-for-Sale Prior years Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years New Credit Agreement New Credit Agreement [Member] New Credit Agreement Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Covenant Period Two Covenant Period Two [Member] Covenant Period Two Estimated Fair Value Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Total operating expenses Costs and Expenses Adoption Date Trading Arrangement Adoption Date Liability for Claims and Claims Adjustment Expense [Line Items] Liability for Claims and Claims Adjustment Expense [Line Items] Debt instrument, interest rate, stated percentage Percentage of contractual interest rate Debt Instrument, Interest Rate, Stated Percentage Total stockholders’ equity Beginning balance Ending balance Equity, Attributable to Parent ASSETS Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Medical Claims and Benefits Payable Medical Claims And Benefits Payable [Text Block] Medical claims and benefits payable. Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Insider Trading Policies and Procedures [Line Items] Other operating revenues Other Operating Income Other, net Proceeds from (Payment for) Other Financing Activity Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Stock-based compensation (in shares) Weighted Average Number Of Shares, Share Based Compensation Weighted Average Number Of Shares, Share Based Compensation Components of medical care costs related to: Components Of Medical Care Costs [Abstract] Components of medical care costs. Current year Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year Total medical care costs Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims Minimum MLR, medical cost corridors and profit sharing liability Medical Premiums Liability, Medical Care Costs Threshold Medical Premiums Liability, Medical Care Costs Threshold Medical claims and benefits payable Increase (Decrease) in Health Care Insurance Liabilities Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Potentially dilutive common shares (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Entity Central Index Key Entity Central Index Key Deferred debt issuance costs Debt Issuance Costs, Noncurrent, Net Common stock, $0.001 par value, 150 million shares authorized; outstanding: 52 million shares at June 30, 2026 and $51 million at December 31, 2025 Common Stock, Value, Outstanding Additional paid-in capital Additional Paid in Capital, Common Stock All Adjustments to Compensation All Adjustments to Compensation [Member] Medicaid Medicaid [Member] Medicaid Other, net Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Income Taxes Income Tax, Policy [Policy Text Block] Net cash provided by (used in) operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Prior years Prior period claims, favorable development Prior Year Claims and Claims Adjustment Expense Stockholders’ equity: Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Liability for Claims and Claims Adjustment Expense [Table] Liability for Claims and Claims Adjustment Expense [Table] Deferred income taxes, net Deferred Income Tax Assets, Net Finance lease liabilities Finance Lease, Liability, Noncurrent Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Net income per share: Earnings Per Share, Basic and Diluted EPS [Abstract] Earnings Per Share, Basic and Diluted EPS City Area Code City Area Code Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Fair value of debt Debt Instrument, Fair Value Disclosure Name Forgone Recovery, Individual Name Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Statement [Line Items] Statement [Line Items] Total assets Assets Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Operating segments Operating Segments [Member] Interest expense Less: interest expense Interest Expense, Nonoperating Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax PEO PEO [Member] In a Continuous Loss Position for 12 Months or More, Total Number of Positions Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions Measurement Basis [Axis] Measurement Basis [Axis] Common stock purchases (in shares) Stock Repurchased and Retired During Period, Shares Investments Marketable Securities, Current Other long-term liabilities Other Liabilities, Noncurrent Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Unrealized investment (loss) gain OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Due in one year or less Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Debt instrument, covenant, debt to capitalization ratio Debt Instrument, Debt To Capitalization Ratio Debt Instrument, Debt To Capitalization Ratio Retained Earnings Retained Earnings [Member] Credit Facility Revolving Credit Facility [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Corporate debt securities Corporate Debt Securities [Member] Net income per share - Diluted (in dollars per share) Earnings Per Share, Diluted Entity Current Reporting Status Entity Current Reporting Status Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Cost of service revenue Cost Of Service Revenue Cost Of Service Revenue Proceeds from borrowings under credit facility and term loans Proceeds from Long-Term Lines of Credit Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Financial Instruments [Domain] Financial Instruments [Domain] 6.500% Notes due February 15, 2031 6.500% Senior Notes Due 2031 [Member] 6.500% Senior Notes Due 2031 Maturity period (less than) Investments, Maturity Period Investments, Maturity Period Provider Networks Provider Networks [Member] Provider Networks Numerator: Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Other revenue Other Income Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Fair Value Estimate of Fair Value Measurement [Member] Other, net Payment for (Proceeds from) Other Investing Activity Basis Of Presentation [Table] Basis Of Presentation [Table] Basis Of Presentation [Table] Segment Reporting [Table] Segment Reporting [Table] Stock purchase excise tax Share Repurchase Program, Excise Tax Payments for medical care costs related to: Payments For Medical Care Costs [Abstract] Payments for medical care costs. Schedule of Investments Schedule of Available-for-Sale Securities Reconciliation [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] In a Continuous Loss Position for Less than 12 Months, Estimated Fair Value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating income Operating Income (Loss) Service margin Service [Member] Term Loans Delayed Draw Term Loan (DDTL) [Member] Current Fiscal Year End Date Current Fiscal Year End Date Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Shares outstanding at the beginning of the period (in shares) Shares, Outstanding, Excluding Restricted Stock Awards Shares, Outstanding, Excluding Restricted Stock Awards Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Share-based compensation Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Schedule of Contractual Maturities of Investments Investments Classified by Contractual Maturity Date [Table Text Block] Impairment Impairment Asset, Impairment Loss Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Measure: Measure [Axis] Incurred but not paid Reinsurance Recoverables, Incurred but Not Reported Claims Premium revenue Premiums Earned, Net Non-current portion of long-term debt Long-Term Debt, Noncurrent, Net Of Unamortized Debt Discount Long-Term Debt, Noncurrent, Net Of Unamortized Debt Discount In a Continuous Loss Position for 12 Months or More, Gross Unrealized Losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Risk adjustments liability Amounts Due to Government Agencies, Risk Adjustment and Part D risk sharing Amounts Due to Government Agencies, Risk Adjustment and Part D risk sharing Equity Components [Axis] Equity Components [Axis] Product and Service [Domain] Product and Service [Domain] Entity Interactive Data Current Entity Interactive Data Current Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Due after one year through five years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Accounts payable, accrued liabilities and other Accounts Payable and Accrued Liabilities, Current Entity Small Business Entity Small Business Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Termination Date Trading Arrangement Termination Date Property, Plant, and Equipment [Line Items] Property, Plant, and Equipment [Line Items] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Current year Current Year Claims and Claims Adjustment Expense Other assets Other Assets, Noncurrent Document Type Document Type Net cash paid in business combinations Payments to Acquire Businesses, Net of Cash Acquired Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value as of Grant Date Award Grant Date Fair Value Government agencies liability Amounts Due To Government Agencies, Medicare, Medical Loss Ratio And Profit Sharing, Threshold Amounts Due To Government Agencies, Medicare, Medical Loss Ratio And Profit Sharing, Threshold Schedule of Available-for-Sale Investments Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Significant Accounting Policies Significant Accounting Policies [Text Block] Change in non-risk and other payables Medical Claims And Benefits Payable, Adjustments, Change In Provider Medical Claims and Benefits Payable, Adjustments, Change in Provider Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name In a Continuous Loss Position for Less than 12 Months, Gross Unrealized Losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Income before income tax expense Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] 3.875% Notes due May 15, 2032 3.875% Senior Notes Due 2032 [Member] 3.875% Senior Notes Due 2032 Total revenue Revenues Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Swingline sub facility Swingline Sub Facility [Member] Swingline Sub Facility Accounts payable, accrued liabilities and other Increase (Decrease) in Accounts Payable and Accrued Liabilities Amounts due government agencies Increase (Decrease) In Medical Premium Liability Due To Agency Increase (Decrease) in Medical Premium Liability Due to Agency Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Receivable Type [Axis] Receivable Type [Axis] Total Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Service revenue Service Revenue Service Revenue Trade name Trade Names [Member] Schedule of Fair Value Measurements of Senior Notes Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Schedule of Components of The Change in Medical Claims and Benefits Payable Components Of Change In Medical Claims And Benefits Payable [Table Text Block] Components Of Change In Medical Claims And Benefits Payable [Table Text Block] Fair Value Measurements Fair Value Disclosures [Text Block] (Level 3) Fair Value, Inputs, Level 3 [Member] Risk adjustment, net receivable (payable) Affordable Care Act, Premium Stabilization Program, Risk Adjustment, Net Receivable Affordable Care Act, Premium Stabilization Program, Risk Adjustment, Receivable (Payable) PEO Name PEO Name Total paid Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid Basis Of Presentation [Line Items] Basis Of Presentation [Line Items] Basis Of Presentation [Line Items] Premium tax revenue Health Care Organization, Premium Tax Revenue Health Care Organization, Premium Tax Revenue Concentrations of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Premium tax expenses Premium Tax Expenses An assessment levied by a state government on the net premium income collected. Cash, cash equivalents, and restricted cash and cash equivalents at beginning of period Cash, cash equivalents, and restricted cash and cash equivalents at end of period Total cash, cash equivalents, and restricted cash and cash equivalents presented in the consolidated statements of cash flows Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Other Other Securities [Member] Other Securities Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Organization and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Debt Instrument [Axis] Debt Instrument [Axis] Share-based compensation Share-Based Payment Arrangement, Noncash Expense Due after five years through ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Net income per share - Basic (in dollars per share) Earnings Per Share, Basic Common stock purchases Payments for Repurchase of Common Stock Deferred revenue Contract with Customer, Liability, Current Mortgage-backed securities Collateralized Mortgage-Backed Securities [Member] Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Long-term debt Total Long-Term Debt, Excluding Current Maturities Award Type Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss Retained earnings Retained Earnings (Accumulated Deficit) Product and Service [Axis] Product and Service [Axis] Stock purchases (in shares) Weighted Average Number of Shares, Common Stock Subject to Repurchase or Cancellation Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Stock Common Stock [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Insurance [Abstract] Receivables Receivable [Policy Text Block] Equity Awards Adjustments Equity Awards Adjustments [Member] Total liabilities and stockholders’ equity Liabilities and Equity Goodwill, and intangible assets, net Intangible Asset, Including Goodwill, after Accumulated Amortization Employee Stock Option Share-Based Payment Arrangement, Option [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Tabular List, Table Tabular List [Table Text Block] Debt Long-Term Debt [Text Block] Risk adjustment receivable (payable) Affordable Care Act, Premium Stabilization Program, Risk Adjustment, (Payable) Affordable Care Act, Premium Stabilization Program, Risk Adjustment, Receivable (Payable) Other Other Operating Income (Expense), Net Name Awards Close in Time to MNPI Disclosures, Individual Name Debt Instrument Covenant Period [Axis] Debt Instrument Covenant Period [Axis] Debt Instrument Covenant Period Amortized cost, due after five years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 5 through 10 Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] General and administrative expenses General and Administrative Expense Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Other Other Program [Member] Other Program Receivables Receivables, Net, Current Property, Plant, and Equipment [Table] Property, Plant, and Equipment [Table] Preferred stock, $0.001 par value; 20 million shares authorized, no shares issued and outstanding Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Mortgage-backed securities Commercial Mortgage-Backed Securities [Member] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Credit Facility [Axis] Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Total assets Assets, Fair Value Disclosure Name Measure Name Insurance Claims Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] 6.250% Notes due 2033 6.250% Senior Notes Due 2033 [Member] 6.250% Senior Notes Due 2033 Pay vs Performance Disclosure [Line Items] Covenant Period Three Covenant Period Three [Member] Covenant Period Three Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] In a Continuous Loss Position for Less than 12 Months, Total Number of Positions Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Marketplace Marketplace [Member] Marketplace Additional Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalent Municipal securities Municipal Securities [Member] Municipal securities. Company Selected Measure Amount Company Selected Measure Amount Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Entity Address, Address Line Two Entity Address, Address Line Two Share-based compensation (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Current assets: Assets, Current [Abstract] Non-PEO NEO Non-PEO NEO [Member] Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Remaining intangible assets Intangible Asset, Finite-Lived, Impairment Loss Income tax expense Income Tax Expense (Benefit) Effect of dilutive securities: Dilutive Securities, Effect on Basic Earnings Per Share [Abstract] Medical care costs Medical care costs Cost of Product and Service Sold Award Timing Method Award Timing Method [Text Block] Net increase (decrease) in cash, cash equivalents, and restricted cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Net income Net income Net income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] Medical loss ratio of marketplace Amount To Government Agencies, Medicare, Medical Loss Ratio Of Marketplace Amount To Government Agencies, Medicare, Medical Loss Ratio Of Marketplace Restatement Determination Date: Restatement Determination Date [Axis] Common Stock, Shares Issued, Not Disclosed Common Stock, Shares Issued, Not Disclosed Common Stock, Shares Issued, Not Disclosed Letter of credit sub-facility Letter Of Credit Sub-Facility [Member] Letter Of Credit Sub-Facility Receivables Increase (Decrease) in Receivables Acquired balances, net of post-acquisition adjustments Liability for Unpaid Claims and Claims Adjustment Expense, Business Acquisitions, Net Of Post-Closing Adjustments Liability for Unpaid Claims and Claims Adjustment Expense, Business Acquisitions, Net Of Post-Closing Adjustments Common stock withheld to settle employee tax obligations Common Stock Withheld to Settle Employee Tax Obligations Common Stock Withheld to Settle Employee Tax Obligations Revenue: Revenues [Abstract] U.S. Treasury notes US Treasury Notes Securities [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block]