Income Statement [Abstract] Statement [Table] Statement [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliates Affiliated Entity [Member] Statement [Line Items] Statement [Line Items] Revenue Revenues [Abstract] Transformation Technology Services Revenue Platform and operations License and Services Revenue Total revenue Sales Revenue, Services, Net Expenses Operating Expenses [Abstract] Cost of revenues (exclusive of depreciation and amortization expenses presented separately below) Cost of Goods and Services Sold, Excluding Depreciation and Amortization Cost of Goods and Services Sold, Excluding Depreciation and Amortization Selling, general and administrative expenses Selling, General and Administrative Expense Depreciation and amortization expenses Depreciation, Depletion and Amortization, Nonproduction Goodwill impairment Goodwill, Impairment Loss Total operating expenses Operating Expenses Operating income (loss) Operating Income (Loss) Interest income Investment Income, Interest Interest expense Interest Expense Income (loss) from affiliates Income (Loss) from Equity Method Investments Other income (expense), net Other Nonoperating Income (Expense) Income (loss) before income taxes and non-controlling interests Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Provision (benefit) for income taxes Income Tax Expense (Benefit) Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income (loss) attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income (loss) attributable to Evolent Health, Inc. Net Income (Loss) Attributable to Parent Earnings (Loss) Available for Common Shareholders Earnings (Loss) Available to Common Shareholders [Abstract] Earnings (Loss) Available to Common Shareholders [Abstract] Basic Net Income (Loss) Available to Common Stockholders, Basic Diluted Net Income (Loss) Available to Common Stockholders, Diluted Earnings (Loss) per Common Share Earnings Per Share, Basic and Diluted [Abstract] Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Weighted-Average Common Shares Outstanding Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Investments [Abstract] Schedule of Held-to-maturity Securities [Table] Schedule of Held-to-maturity Securities [Table] Debt Security [Axis] Debt Security [Axis] Major Types of Debt Securities [Domain] Major Types of Debt Securities [Domain] U.S. Treasury bills US Treasury Securities [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 2 Fair Value, Inputs, Level 2 [Member] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Unrealized loss for less than twelve months, Number of Securities Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Unrealized loss for less than twelve months, Fair Value Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Unrealized loss for less than twelve months, Unrealized Losses Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Organizational Transactions [Abstract] Organizational Transactions [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Valence Health Valence Health Inc. [Member] Valence Health Inc. [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Class A Common Class A [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Evolent Health LLC Evolent Health LLC [Member] Evolent Health LLC [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Selling, general and administrative expenses Selling, General and Administrative Expenses [Member] Cost of revenue Cost of Sales [Member] Revenue Sales Revenue, Services, Net [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] As Previously Determined Scenario, Previously Reported [Member] Measurement Period Adjustment Scenario, Adjustment [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer relationships Customer Relationships [Member] Technology Technology-Based Intangible Assets [Member] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] 540 W. Madison Street, Suite 1400 540 W. Madison Street, Suite 1400 [Member] 540 W. Madison Street, Suite 1400 [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Commitments Commitments [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Adjustment for removal of transaction costs Business Acquisition, Pro Forma Adjustments, Removal of Transaction Costs Business Acquisition, Pro Forma Adjustments, Removal of Transaction Costs Percentage of voting interests acquired Business Acquisition, Percentage of Voting Interests Acquired Equity interest issued or issuable (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Percentage of issued and outstanding common stock Business Combination, Consideration Transferred, Percentage of Issued and Outstanding Common Stock Business Combination, Consideration Transferred, Percentage of Issued and Outstanding Common Stock Parent's ownership percentage Noncontrolling Interest, Ownership Percentage by Parent Contingent consideration arrangements (up to) Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High Contingent consideration arrangements fair value Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Fair Value, High Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Fair Value, High Transaction costs Business Acquisition, Transaction Costs Purchase consideration: Business Combination, Consideration Transferred [Abstract] Fair value of Class A common stock issued Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Cash for settlement of software license Business Combination, Consideration Transferred, Other Cash Payments to Acquire Businesses, Gross Total consideration Business Combination, Consideration Transferred Tangible assets acquired: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract] Restricted cash Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Receivables Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Prepaid expenses and other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Other non-current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Favorable leases assumed (net of unfavorable leases) Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease Obligation Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease Obligation Identifiable intangible assets acquired: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract] Identifiable intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Liabilities assumed: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract] Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Liabilities Accrued compensation and employee benefits Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Compensation And Employee Benefits Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Compensation And Employee Benefits Deferred revenue Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue Other long-term liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Net deferred tax liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent Goodwill Goodwill Net assets acquired Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Acquired receivables Business Combination, Acquired Receivables, Gross Contractual Amount Acquired receivables, estimated uncollectible Business Combination, Acquired Receivables, Estimated Uncollectible Useful life Finite-Lived Intangible Asset, Useful Life Deferred tax liabilities Deferred Tax Liabilities, Net Gain (loss) on disposition of assets Gain (Loss) on Disposition of Assets Measurement period adjustment, accrued liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities Measurement period adjustment, goodwill Goodwill, Purchase Accounting Adjustments Accelerated compensation cost Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost Loss from lease abandonment Gain (Loss) From Lease Abandonment Gain (Loss) From Lease Abandonment Remaining lease payments Operating Leases, Future Minimum Payments Due Estimated sublease value Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals Discount rate Fair Value Inputs, Discount Rate Debt Disclosure [Abstract] Long-term Debt Debt Disclosure [Text Block] Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Exchangeable Class B Common Stock Exchangeable Class B Common Stock [Member] Exchangeable Class B Common Stock [Member] Restricted stock and restricted stock units Restricted Stock and Restricted Stock Units [Member] Restricted Stock and Restricted Stock Units [Member] Options Equity Option [Member] Convertible senior notes Convertible Debt Securities [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Number of antidilutive securities excluded from the calculation of earning per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Goodwill and Intangible Assets Disclosure [Abstract] Goodwill [Roll Forward] Goodwill [Roll Forward] Balance as of beginning-of-period Goodwill Acquired Goodwill, Acquired During Period Goodwill impairment Balance as of end-of-period Accounting Policies [Abstract] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Accounting Estimates and Assumptions Use of Estimates, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Operating Segments Segment Reporting, Policy [Policy Text Block] Restricted Cash and Restricted Investments Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Adoption of New Accounting Standards and Adoption of New Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Evolent Health, Selling Stockholders Evolent Health, Selling Stockholders [Member] Evolent Health, Selling Stockholders [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Investor Stockholders Investor Stockholders [Member] Investor Stockholders [Member] Issuance of common stock (in shares) Stock Issued During Period, Shares, New Issues Share price (in usd per share) Share Price Goodwill and Intangible Assets, Net Goodwill and Intangible Assets Disclosure [Text Block] Fair Value Disclosures [Abstract] Summary of assets at fair value on recurring basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Summary of liabilities at fair value on recurring basis Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] Changes in contingent consideration measured at fair value Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Valuation techniques and significant unobservable inputs of Level 3 fair value measurements Fair Value Inputs, Liabilities, Quantitative Information [Table Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance as of beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Additions Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Balance as of end of period New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-09 ASU 2016-09 [Member] ASU 2016-09 [Member] Adjustments for Change in Accounting Principle [Axis] Adjustments for Change in Accounting Principle [Axis] Adjustments for Change in Accounting Principle [Domain] Adjustments for Change in Accounting Principle [Domain] Election to Recognize Share-based Award Forfeitures As They Occur Election to Recognize Share-based Award Forfeitures As They Occur [Member] Election to Recognize Share-based Award Forfeitures As They Occur [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Decrease in retained earnings Retained Earnings (Accumulated Deficit) Increase in net income (loss) Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Schedule of Restricted Cash and Cash Equivalents [Table] Schedule of Restricted Cash and Cash Equivalents [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Restricted Cash and Cash Equivalents [Axis] Restricted Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Letters of credit for facility leases Restricted Cash for Letters of Credit for Facility Leases [Member] Restricted Cash for Letters of Credit for Facility Leases [Member] Collateral with financial institutions Collateral with Financial Institutions [Member] Collateral with Financial Institutions [Member] Restricted Cash and Cash Equivalents Items [Line Items] Restricted Cash and Cash Equivalents Items [Line Items] Tax receivables agreement, percent of tax savings to be paid Tax Receivables Agreement, Percent of Tax Savings to be Paid Tax Receivables Agreement, Percent of Tax Savings to be Paid Rent expense Operating Leases, Rent Expense, Net Letters of credit outstanding, minimum Letters of Credit Outstanding, Amount Payments of stock issuance costs Payments of Stock Issuance Costs Restricted funds Restricted Cash and Cash Equivalents Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior Notes Senior Notes [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Convertible Senior Notes due 2021 Convertible Senior Notes due 2021 [Member] Convertible Senior Notes due 2021 [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Carrying value Convertible Debt Unamortized discount Debt Instrument, Unamortized Discount Principal amount Debt Instrument, Face Amount Remaining amortization period Debt Instrument, Convertible, Remaining Discount Amortization Period Statement of Stockholders' Equity [Abstract] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Non-controlling Interests Noncontrolling Interest [Member] Class A Class B Common Class B [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance (in shares) Shares, Issued Beginning balance, amount Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Cumulative-effect adjustment from adoption of new accounting principle Adjustments to Additional Paid in Capital, Adjustment from Adoption of New Accounting Principle Adjustments to Additional Paid in Capital, Adjustment from Adoption of New Accounting Principle Stock-based compensation expense Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Acceleration of unvested equity awards for Valence Health employees (in shares) Stock Issued During Period, Shares, Acceleration Of Equity Awards As Part Of Business Combination Stock Issued During Period, Shares, Acceleration Of Equity Awards As Part Of Business Combination Acceleration of unvested equity awards for Valence Health employees Stock Issued During Period, Value, Acceleration Of Equity Awards As Part Of Business Combination Stock Issued During Period, Value, Acceleration Of Equity Awards As Part Of Business Combination Exercise of stock options (in shares) Stock Issued During Period, Shares, Share-based Compensation, Gross Exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Restricted stock units vested, net of shares withheld for taxes (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Restricted stock units vested, net of shares withheld for taxes Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Shares retired upon release from Valence Health escrow (in shares) Stock Repurchased and Retired During Period, Shares Shares retired upon release from Valence Health escrow Stock Repurchased and Retired During Period, Value Exchange of Class B common stock (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Exchange of Class B common stock Stock Issued During Period, Value, Conversion of Convertible Securities Tax impact of Class B common stock exchange Stock Issued During Period, Conversion of Convertible Securities, Tax Impact Stock Issued During Period, Conversion of Convertible Securities, Tax Impact Issuance of Class A common stock for business combinations (in shares) Stock Issued During Period, Shares, Acquisitions Issuance of Class A common stock for business combinations Stock Issued During Period, Value, Acquisitions Tax impact of Class A common stock issued for business combination Stock Issued During Period, Value, Acquisitions, Tax Effect Stock Issued During Period, Value, Acquisitions, Tax Effect Reclassification of non-controlling interests Noncontrolling Interest, Increase from Subsidiary Equity Issuance Net income (loss) Ending balance (in shares) Ending balance, amount Schedule of restricted cash and cash equivalents Schedule of Restricted Cash and Cash Equivalents [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock-based compensation expense Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Stock-based awards granted Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block] Equity Method Investments and Joint Ventures [Abstract] Investments In and Advances to Affiliates Equity Method Investments and Joint Ventures Disclosure [Text Block] Concentration Risk [Table] Concentration Risk [Table] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Customer A Customer A [Member] Customer A [Member] Customer B Customer B [Member] Customer B [Member] Customer C Customer C [Member] Customer C [Member] Customer D Customer D [Member] Customer D [Member] Customer E Customer E [Member] Customer E [Member] Customer F Customer F [Member] Customer F [Member] Customer G Customer G [Member] Customer G [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Customer Concentration Risk Customer Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Revenue Sales Revenue, Net [Member] Accounts Receivable Accounts Receivable [Member] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Customer Receivable Financing Receivable [Member] Concentration Risk [Line Items] Concentration Risk [Line Items] Percentage of cash and cash equivalents held with FDIC participating banks Cash, FDIC Insured Amount, Percentage Cash, FDIC Insured Amount, Percentage Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Concentration risk Concentration Risk, Percentage Schedule of goodwill Schedule of Goodwill [Table Text Block] Schedule of intangible assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Summary of major customers Schedules of Concentration of Risk, by Risk Factor [Table Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of allocation of purchase price Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule of net assets acquired Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Business acquisition, pro forma information Business Acquisition, Pro Forma Information [Table Text Block] Effective tax rate Effective Income Tax Rate Reconciliation, Percent Income Tax Contingency [Table] Income Tax Contingency [Table] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Decrease in deferred tax liability related to the book basis compared to the tax basis of partnership interest Deferred Tax Liabilities, Gross Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Restricted cash and restricted investments Restricted Cash and Investments, Current Accounts receivable, net (amounts related to affiliates: 2017 - $6,155; 2016 - $8,258) Accounts Receivable, Net, Current Prepaid expenses and other current assets (amounts related to affiliates: 2017 - $1,110; 2016 - $4,507) Prepaid Expense and Other Assets, Current Investments, at amortized cost Short-term Investments Total current assets Assets, Current Restricted cash and restricted investments Restricted Cash and Investments, Noncurrent Investments in and advances to affiliates Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Property and equipment, net Property, Plant and Equipment, Net Prepaid expenses and other non-current assets Other Assets, Noncurrent Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Total assets Assets LIABILITIES AND SHAREHOLDERS’ EQUITY (DEFICIT) Liabilities and Equity [Abstract] Liabilities Liabilities [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable (amounts related to affiliates: 2017 - $8,593; 2016 - $13,480) Accounts Payable, Current Accrued liabilities (amounts related to affiliates: 2017 - $2,107; 2016 - $3,211) Accrued Liabilities, Current Accrued compensation and employee benefits Employee-related Liabilities, Current Deferred revenue Deferred Revenue, Current Total current liabilities Liabilities, Current Long-term debt, net of discount Long-term Debt Other long-term liabilities Other Liabilities, Noncurrent Deferred tax liabilities, net Deferred Tax Liabilities, Net, Noncurrent Total liabilities Liabilities Commitments and Contingencies (See Note 9) Commitments and Contingencies Shareholders' Equity (Deficit) Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock Common Stock, Value, Issued Additional paid-in-capital Additional Paid in Capital Retained earnings (accumulated deficit) Total shareholders' equity (deficit) attributable to Evolent Health, Inc. Stockholders' Equity Attributable to Parent Non-controlling interests Stockholders' Equity Attributable to Noncontrolling Interest Total shareholders' equity (deficit) Total liabilities and shareholders' equity (deficit) Liabilities and Equity Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Related Party Transactions [Abstract] Related Parties Related Party Transactions Disclosure [Text Block] Corporate bonds Corporate Debt Securities [Member] Amortized Costs Held-to-maturity Securities Gross Unrealized Gains Held-to-maturity Securities, Accumulated Unrecognized Holding Gain Gross Unrealized Losses Held-to-maturity Securities, Accumulated Unrecognized Holding Loss Fair Value Held-to-maturity Securities, Fair Value Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] GPAC Georgia Physicians for Accountable Care, LLC [Member] Georgia Physicians for Accountable Care, LLC [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Economic interest percentage Equity Method Investment, Economic Interest Percentage Equity Method Investment, Economic Interest Percentage Property, Plant and Equipment [Abstract] Summary of property and equipment Property, Plant and Equipment [Table Text Block] Pharmacy benefit management and claims processing services Restricted Cash for Benefit Management Services [Member] Restricted Cash for Benefit Management Services [Member] Other Restricted Cash for Other Contractual Commitments [Member] Restricted Cash for Other Contractual Commitments [Member] Number of operating segments Number of Operating Segments Total restricted cash and restricted investments Non-current restricted investments Restricted Cash and Cash Equivalents, Noncurrent Non-current restricted cash Restricted Cash and Cash Equivalents, Current Total non-current restricted cash and restricted investments Current restricted cash and restricted investments Transactions Business Combination Disclosure [Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Stock options Employee Stock Option [Member] Performance-based stock options Performance Shares [Member] RSUs Restricted Stock Units (RSUs) [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Stock-based awards granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Noncontrolling Interest [Abstract] Schedule of changes in non-controlling interests Schedule of Changes in Noncontrolling Interest [Table Text Block] Schedule of Changes in Noncontrolling Interest [Table Text Block] Earnings (Loss) Per Common Share Earnings Per Share [Text Block] Fair Value Inputs, Liabilities, Quantitative Information [Table] Fair Value Inputs, Liabilities, Quantitative Information [Table] Contingent consideration Contingent Consideration Liability [Member] Contingent Consideration Liability [Member] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Real options approach Real Options Approach Valuation Technique [Member] Real Options Approach Valuation Technique [Member] Real options approach 2018-2021 Real Options Approach Valuation Technique 2018-2021 [Member] Real Options Approach Valuation Technique 2018-2021 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Maximum Maximum [Member] Fair Value Inputs, Liabilities, Quantitative Information [Line Items] Fair Value Inputs, Liabilities, Quantitative Information [Line Items] Contingent consideration, fair value Risk-adjusted expected growth rates Fair Value Inputs, Long-term Revenue Growth Rate Discount rate/time value Theoretical recurring revenue Fair Value Inputs, Long-term Revenue Growth Rate, Theoretical Recurring Revenue Fair Value Inputs, Long-term Revenue Growth Rate, Theoretical Recurring Revenue Accounts receivable, related parties Due from Related Parties, Current Prepaid expenses and other current assets, related parties Prepaid Expense and Other Assets, Current, Related Parties Prepaid Expense and Other Assets, Current, Related Parties Accounts payable, related parties Accounts Payable, Related Parties Accrued liabilities, related parties Due to Related Parties, Current Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, authorized (in shares) Common Stock, Shares Authorized Common stock, issued (in shares) Common Stock, Shares, Issued Common stock, outstanding (in shares) Common Stock, Shares, Outstanding Less: Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Net income (loss) available for common shareholders Weighted-average common shares outstanding (in shares) Convertible preferred stock, shares issued upon conversion (in shares) Convertible Preferred Stock, Shares Issued upon Conversion Due in one year or less, Amortized Cost Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount Due in one year or less, Fair Value Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value Due after one year through five years, Amortized Cost Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount Due after one year through five years, Fair Value Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value Fair Value Statement of Cash Flows [Abstract] Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Loss from affiliates Depreciation and amortization expenses Depreciation, Depletion and Amortization Stock-based compensation expense Share-based Compensation Amortization of deferred financing costs Deferred Income Tax Expense (Benefit) Amortization of deferred financing costs Amortization of Debt Issuance Costs Accretion of bond premium/discounts Accretion Expense Accretion of bond premium/discounts Other Noncash Income (Expense) Changes in assets and liabilities, net of acquisitions: Increase (Decrease) in Operating Capital [Abstract] Accounts receivables, net Increase (Decrease) in Accounts Receivable Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable, net of change in restricted cash and restricted investments Increase (Decrease) in Accounts Payable Accrued liabilities Increase (Decrease) in Accrued Liabilities Accrued compensation and employee benefits Increase (Decrease) in Employee Related Liabilities Deferred revenue Increase (Decrease) in Deferred Revenue Other long-term liabilities Increase (Decrease) in Other Noncurrent Liabilities Net cash provided by (used in) operating activities Net Cash Provided by (Used in) Operating Activities Cash Flows from Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash paid for asset acquisition or business combination Maturities and sales of investments Proceeds from Sale, Maturity and Collection of Investments Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Change in restricted cash and restricted investments Increase (Decrease) in Restricted Cash Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Cash Flows from Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from stock option exercises Proceeds from Stock Options Exercised Taxes withheld for vesting of restricted stock units Payments Related to Tax Withholding for Share-based Compensation Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents as of beginning-of-period Cash and cash equivalents as of end-of-period Supplemental Disclosure of Non-cash Investing and Financing Activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Accrued property and equipment purchases Capital Expenditures Incurred but Not yet Paid Class A common stock issued in connection with business combinations Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued, Value Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued, Value Measurement period adjustments related to business combinations Noncash Or Part Noncash Acquisition, Noncash Financial Or Equity Instrument Consideration, Measurement Period Adjustment Noncash Or Part Noncash Acquisition, Noncash Financial Or Equity Instrument Consideration, Measurement Period Adjustment Change in accrued financing costs related to 2021 Notes Debt Issuance Costs Incurred During Noncash or Partial Noncash Transaction Effects of the March 2017 Secondary Offering Effects of the Secondary [Abstract] Effects of the Secondary [Abstract] Decrease in non-controlling interests as a result of Class B Exchanges Conversion of Stock, Amount Converted Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Computer hardware Computer Equipment [Member] Furniture and equipment Furniture and Fixtures [Member] Internal-use software development costs Software and Software Development Costs [Member] Leasehold improvements Leasehold Improvements [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Total property and equipment Property, Plant and Equipment, Gross Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total property and equipment, net Capitalized computer software additions Capitalized Computer Software, Additions Depreciation expense Depreciation Capitalized computer software, amortization Capitalized Computer Software, Amortization Basis of Presentation, Summary of Significant Accounting Policies and Change in Accounting Principle Basis of Presentation and Significant Accounting Policies [Text Block] Non-controlling Interests Noncontrolling Interest Disclosure [Text Block] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity method investment, shares acquired (in shares) Equity Method Investment, Shares Acquired Equity Method Investment, Shares Acquired Equity method investment, cost Equity Method Investment, Aggregate Cost Equity method investment, ownership percentage Equity Method Investment, Ownership Percentage Revenue related to long-term services agreement Income (Loss) from Equity Method Investments, Services Agreement Income (Loss) from Equity Method Investments, Services Agreement Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Sale of Stock [Axis] Sale of Stock [Axis] Sale of Stock [Domain] Sale of Stock [Domain] Over-Allotment Option Over-Allotment Option [Member] Class of Warrant or Right [Axis] Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Class A Common Stock Pursuant To Class B Exchanges Class A Common Stock Pursuant To Class B Exchanges [Member] Class A Common Stock Pursuant To Class B Exchanges [Member] Investor Stockholders Investor [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Number of shares issued (in shares) Sale of Stock, Number of Shares Issued in Transaction Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Pre-Organization Members Pre-Organization Members [Member] Pre-Organization Members [Member] Organization [Line Items] Variable Interest Entity [Line Items] Evolent Health LLC ownership interest Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest Vestica Vestica [Member] Vestica [Member] Contingent consideration, liability Business Combination, Contingent Consideration, Liability Total consideration Computation of basic and diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of antidilutive securities excluded from computation of earnings per share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Aldera Aldera Holdings, Inc. [Member] Aldera Holdings, Inc. [Member] Consideration transferred (in shares) Prepaid expenses and other current assets Measurement period adjustment, decrease in goodwill (less than $.1 million) Schedule of convertible debt Convertible Debt [Table Text Block] Fair Value Measurement Fair Value Disclosures [Text Block] Property and Equipment, Net Property, Plant and Equipment Disclosure [Text Block] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Adjustments Restatement Adjustment [Member] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Share-based compensation expense Allocated Share-based Compensation Expense Share-based compensation expense capitalized as software development costs Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount Recently Issued Accounting Standards New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Summary investment holdings Summary Investment Holdings [Table Text Block] Investments classified by contractual maturity date Investments Classified by Contractual Maturity Date [Table Text Block] Schedule of unrealized loss on held-to-maturity securities Schedule of Unrealized Loss on Investments [Table Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Stock-based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Face amount Interest rate Debt Instrument, Interest Rate, Stated Percentage Proceeds from issuance of debt Proceeds from Issuance of Debt Debt issuance costs Debt Issuance Costs, Net Repurchase price due to fundamental change as percentage of principal amount Debt Instrument, Repurchase Price Due To Fundamental Change As Percentage Of Principal Amount Debt Instrument, Repurchase Price Due To Fundamental Change As Percentage Of Principal Amount Interest expense Interest Expense, Debt Initial conversion rate per $1000 principal amount Debt Instrument, Convertible, Conversion Ratio Debt conversion denominator shares per principal amount Debt Conversion Denominator Shares Per Principal Amount Debt Conversion Denominator Shares Per Principal Amount Convertible debt carrying value Conversion price (in dollars per share) Debt Instrument, Convertible, Conversion Price Initial conversion amount (in shares) Debt Instrument, Convertible, Number of Equity Instruments Passport University Health Care d/b/a Passport Health Plan [Member] University Health Care d/b/a Passport Health Plan [Member] Number of medicaid and medicare advantage beneficiaries Number of Medicaid and Medicare Advantage Beneficiaries Number of Medicaid and Medicare Advantage Beneficiaries Issuance of common stock (in shares) Stock Issued During Period, Shares, Purchase of Assets Additional equity consideration (up to) Contingent Consideration Classified as Equity, Fair Value Disclosure Term of health plan management and managed care services arrangement Term of Health Plan Management and Managed Care Services Arrangement Term of Health Plan Management and Managed Care Services Arrangement Increase (decrease) in contingent consideration liability Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Fair value of contingent consideration Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Assets Assets, Fair Value Disclosure [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Liabilities Liabilities, Fair Value Disclosure [Abstract] Risk-adjusted recurring revenue compound annual growth rate, period Risk-Adjusted Recurring Revenue Compound Annual Growth Rate, Period Risk-Adjusted Recurring Revenue Compound Annual Growth Rate, Period Pro Forma Adjustments [Axis] Pro Forma Adjustments [Axis] Pro Forma Adjustments [Axis] Pro Forma Adjustments [Domain] Pro Forma Adjustments [Domain] [Domain] for Pro Forma Adjustments [Axis] Recorded In 2016 Recorded In 2016 [Member] Recorded In 2016 [Member] Recorded In 2015 Recorded In 2015 [Member] Recorded In 2015 [Member] Adjustment for removal of contingent liability Business Acquisition, Pro Forma Adjustments, Removal of Contingent Liability Business Acquisition, Pro Forma Adjustments, Removal Of Contingent Liability Adjustment for removal of lease abandonment charge Business Acquisition, Pro Forma Adjustments, Removal of Lease Abandonment Charge Business Acquisition, Pro Forma Adjustments, Removal of Lease Abandonment Charge Revenue Business Acquisition, Pro Forma Revenue Net income (loss) Business Acquisition, Pro Forma Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Business Acquisition, Pro Forma Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income (loss) attributable to noncontrolling interest Business Acquisition, Pro Forma Net Income (Loss) Attributable to Noncontrolling Interest Business Acquisition, Pro Forma Net Income (Loss) Attributable to Noncontrolling Interest Net income (loss) attributable to Evolent Health, Inc. Business Acquisition, Pro Forma Net Income (Loss) Net income (loss) available to common shareholders, basic (in dollars per share) Business Acquisition, Pro Forma Earnings Per Share, Basic Net income (loss) available to common shareholders, diluted (in dollars per share) Business Acquisition, Pro Forma Earnings Per Share, Diluted Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Corporate trade name Trade Names [Member] Technology Developed Technology Rights [Member] Below market lease, net Below Market Leases, Net [Member] Below Market Leases, Net [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Acquired intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Weighted-Average Remaining Useful Life Finite-Lived Intangible Assets, Remaining Amortization Period Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Carrying Value Finite-Lived Intangible Assets, Net Amortization of intangible assets Amortization of Intangible Assets Investments Investment [Text Block] Subsequent Events Subsequent Events [Text Block] Noncontrolling Interest [Table] Noncontrolling Interest [Table] Valence Health and Aldera Valence Health and Aldera [Member] Valence Health and Aldera [Member] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Issuance of common stock for business combinations (in shares) Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward] Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward] Non-controlling interests as of beginning-of-period Cumulative-effect adjustment from adoption of new accounting principle Decrease in non-controlling interests as a result of the exchange of Class B common stock for Class A common stock as part of the March Secondary Offering Noncontrolling Interest, Decrease from Conversion of Shares Noncontrolling Interest, Decrease from Conversion of Shares Non-controlling interests as of end-of-period