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[Text Block] Commitments and contingencies (Note 12) Commitments and Contingencies Option Indexed to Issuer's Equity, Type [Domain] Option Indexed to Issuer's Equity, Type [Domain] Total revenue Total revenue Revenues Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Accounts payable and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Increase / (decrease) in: Increase (Decrease) in Operating Liabilities [Abstract] Counterparty Name [Axis] Counterparty Name [Axis] Liabilities and Stockholders' Equity Liabilities and Equity [Abstract] REINSURANCE Reinsurance [Text Block] Schedule of Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring 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Claims paid Liability for Unpaid Claims, Claims Paid Liability for Unpaid Claims, Claims Paid Cash, cash equivalents, restricted cash and cash equivalents—beginning of period Cash, cash equivalents, restricted cash and cash equivalents—end of period Total cash, cash equivalents and restricted cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Direct claims incurred Policyholder Benefits and Claims Incurred, Direct Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Base Rate Base Rate [Member] Premiums And Other Receivables, Allowance For Credit Loss Premiums And Other Receivables, Allowance For Credit Loss [Table Text Block] Premiums And Other Receivables, Allowance For Credit Loss Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Effects of Reinsurance [Table] Effects of Reinsurance [Table] 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 Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument [Axis] Debt Instrument [Axis] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Debt conversion, inducement payment, equity consideration Debt Conversion, Inducement Payment, Equity Consideration, Amount Debt Conversion, Inducement Payment, Equity Consideration, Amount Conversion of Class B shares to Class A shares (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Prior years Liability for Unpaid Claims, Incurred Claims, Prior Year Liability for Unpaid Claims, Incurred Claims, Prior Year 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 Basic (in dollars per share) Earnings Per Share, Basic Total current assets Assets, Current Investment income Net investment income Net Investment Income And Realized Gains (Losses) On Investments Net Investment Income And Realized Gains (Losses) On Investments Insider Trading Arrangements [Line Items] Loss contingency, damages awarded, settlement funds withheld, percent Loss Contingency, Damages Awarded, Settlement Funds Withheld, Percent Loss Contingency, Damages Awarded, Settlement Funds Withheld, Percent Long-term debt Long-Term Debt, Excluding Current Maturities Award Type Award Type [Axis] Reinsurance premiums ceded, percentage Quota Share Reinsurance Program, Percentage of Premiums Ceded Quota Share Reinsurance Program, Percentage of Premiums Ceded Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accounts receivable (net of allowance for credit losses of $55,298 and $7,226) Accounts Receivable, after Allowance for Credit Loss, Current Accumulated deficit Retained Earnings (Accumulated Deficit) Threshold trading days Debt Instrument, Convertible, Threshold Trading Days 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 Fair Value Investments Debt Securities, Available-for-Sale Payables to CMS Payables To Centers For Medicare And Medicaid Services Payables To Centers For Medicare And Medicaid Services Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Member acquisition and servicing costs Selling, General And Administration Expense, Member Acquisition And Servicing Costs Selling, General And Administration Expense, Member Acquisition And Servicing Costs Reclassification Reclassification, Comparability Adjustment [Policy Text Block] Insurance [Abstract] Risk adjustment payable, beginning balance Risk adjustment payable, ending balance Risk Adjustment Payable Risk Adjustment Payable Coupon interest expense Interest Expense, Debt, Excluding Amortization Premium taxes, exchange fees, and other taxes and fees Selling, General And Administration Expense, Taxes And Fees Selling, General And Administration Expense, Taxes And Fees Advanced premium tax credit payable Advanced Premium Tax Credit Payable Advanced Premium Tax Credit Payable Equity Awards Adjustments Equity Awards Adjustments [Member] Assumed premiums Assumed Premiums Earned Number of businesses acquired Business Combination, Number of Businesses Acquired Total liabilities and stockholders' equity Liabilities and Equity Net realized capital gains Realized Investment Gains (Losses) Stock options to purchase common stock Stock options Share-Based Payment Arrangement, Option [Member] Noncontrolling interests Equity, Attributable to Noncontrolling Interest Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Related Party [Domain] Related and Nonrelated Parties [Domain] Tabular List, Table Tabular List [Table Text Block] Restricted cash and cash equivalents Restricted Cash and Cash Equivalent, Noncurrent Additional paid-in capital Additional Paid in Capital Current year Liability for Unpaid Claims, Incurred Claims, Current Year Liability for Unpaid Claims, Incurred Claims, Current Year Less: Reinsurance recoverable Add: Reinsurance recoverable Reinsurance Recoverable for Unpaid Claims and Claims Adjustments Reinsurance recoverable Increase (Decrease) in Reinsurance Recoverable BENEFITS PAYABLE Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Effect of convertible senior notes (in shares) Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities Name Awards Close in Time to MNPI Disclosures, Individual Name 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] Depreciation and amortization General and Administrative Expense Stock price (in dollars per share) Sale of Stock, Price Per Share Less, recoveries collected Premiums And Other Receivables, Recoveries Collected Premiums And Other Receivables, Recoveries Collected Loss contingency, damages awarded, settlement funds distributed, percent Loss Contingency, Damages Awarded, Settlement Funds Distributed, Percent Loss Contingency, Damages Awarded, Settlement Funds Distributed, Percent Unusual Risk or Uncertainty [Line Items] Unusual Risk or Uncertainty [Line Items] Adjustment to Compensation: Adjustment to Compensation [Axis] Assumed reinsurance claims Policyholder Benefits and Claims Incurred, Assumed, Net Of Adjustments Policyholder Benefits and Claims Incurred, Assumed, Net Of Adjustments Class of Stock [Domain] Class of Stock [Domain] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Interest payments Interest Paid, Excluding Capitalized Interest, Operating Activity Purchase of property, equipment, and capitalized software Payments to Acquire Productive Assets 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 Total investments, amortized cost Investments, Amortized Cost Investments, Amortized Cost Name Measure Name Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Number of Securities Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions Debt Instrument [Line Items] Debt Instrument [Line Items] 7.25% Convertible Senior Notes Due 2031 7.25% Convertible Senior Notes Due 2031 [Member] 7.25% Convertible Senior Notes Due 2031 CAE paid Claims Adjustment Expense, Claims Paid Claims Adjustment Expense, Claims Paid Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Total Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Total [Abstract] Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Total Benefits payable Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve Additional paid-in capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Prior years Claims Adjustment Expense, Incurred Claims, Prior Year Claims Adjustment Expense, Incurred Claims, Prior Year RESTRICTED CASH AND RESTRICTED DEPOSITS Restricted Assets Disclosure [Text Block] Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and Cash Equivalent All other SG&A Selling, General And Administration Expense, All Other Servicing Costs Selling, General And Administration Expense, All Other Servicing Costs Company Selected Measure Amount Company Selected Measure Amount Claims incurred Liability for Unpaid Claims, Incurred Claims Liability for Unpaid Claims, Incurred Claims Investments, Debt and Equity Securities [Abstract] Depreciation and amortization expense Depreciation, Depletion and Amortization Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Issuance of common stock from equity incentive plans (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Net income (loss) Net income (loss) Net income (loss) attributable to Oscar Health, Inc. Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Gross Investment income Gross Investment Income, Operating Current Assets: Assets, Current [Abstract] Non-PEO NEO Non-PEO NEO [Member] Entity Address, Address Line One Entity Address, Address Line One Total operating expenses Benefits, Losses and Expenses Income tax expense (benefit) Income Tax Expense (Benefit) Risks and Uncertainties [Abstract] Net risk adjustment payable, beginning balance Net risk adjustment payable, ending balance Risk Adjustment, Net Risk Adjustment, Net Award Timing Method Award Timing Method [Text Block] Increase in cash, cash equivalents and restricted 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 (loss) attributable to Oscar Health, Inc. Net income (loss) attributable to Oscar Health, Inc. - basic Net Income (Loss) Attributable to Parent Line of credit facility, accordion feature, increase limit Line of Credit Facility, Accordion Feature, Increase Limit Line of credit facility, accordion feature, increase limit, subject to certain conditions by obtaining additional commitments from existing and/or new lenders. Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] Restatement Determination Date: Restatement Determination Date [Axis] Fixed maturity securities Debt Securities, Available-For-Sale [Member] Debt Securities, Available-For-Sale Proceeds from exercise of stock options and stock purchase agreement Proceeds from Stock Options Exercised Prior years Claims Adjustment Expense, Claims Paid, Prior Year Claims Adjustment Expense, Claims Paid, Prior Year Risk Adjustment Period [Domain] Risk Adjustment Period [Domain] Risk Adjustment Period [Domain] Certificates of deposit Certificates of Deposit [Member] Risk Adjustment Period [Axis] Risk Adjustment, Period [Axis] Risk Adjustment, Period Receivables from CMS Receivables From Centers For Medicare And Medicaid Services Receivables From Centers For Medicare And Medicaid Services Reinsurance ceding commissions Reinsurance Recoverable, Ceded Commissions Reinsurance Recoverable, Ceded Commissions Threshold consecutive trading days Debt Instrument, Convertible, Threshold Consecutive Trading Days Revenue Revenues [Abstract] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Effect of convertible senior notes Dilutive Securities, Effect on Basic Earnings Per Share, Dilutive Convertible Securities Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract]