Statistical Measurement [Domain] Statistical Measurement [Domain] Debt Instrument, Redemption, Period Four Debt Instrument, Redemption, Period Four [Member] Non-cash settlement of warrant liabilities Noncash Or Part Noncash Settlement Of Warrant Liabilities Noncash Or Part Noncash Settlement Of Warrant Liabilities Restricted cash Restricted Cash, Current Award Timing Predetermined Award Timing Predetermined [Flag] 2025 (remaining) Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Entity File Number Entity File Number Additional Paid-in Capital Additional Paid-in Capital [Member] Interest Rate Swap Interest Rate Swap [Member] Number of liquefaction trains under development Number Of Liquefaction Trains Under Development Number Of Liquefaction Trains Under Development Tabular List, Table Tabular List [Table Text Block] Leases [Abstract] CD Credit Facility CD Credit Facility [Member] Represents CD Credit Facility. Accounts payable Increase (Decrease) in Accounts Payable Amortization of debt issuance costs Noncash Interest Expense And Amortization of Debt Issuance Costs Noncash Interest Expense And Amortization of Debt Issuance Costs Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Net loss per common share - basic (in usd per share) Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Schedule of Line of Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Subsidiary or Equity Method Investee, Sale of Stock, Type [Table] Warrant, Tranche B Warrant, Tranche B [Member] Warrant, Tranche B Accrued Liabilities and Other Liabilities [Abstract] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Adjustment to Compensation, Amount Adjustment to Compensation Amount Share-based compensation expense Share-Based Payment Arrangement, Noncash Expense Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Total stockholders’ equity Total stockholders' equity Equity, Attributable to Parent Insider Trading Policies and Procedures [Line Items] Share-based payment arrangement, expense Share-Based Payment Arrangement, Expense Schedule of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Common stock, authorized (in shares) Common Stock, Shares Authorized Number of consecutive renewal term Lessee, Operating Lease, Number Of Consecutive Renewal Term Lessee, Operating Lease, Number Of Consecutive Renewal Term Current assets: Assets, Current [Abstract] Total liabilities and equity Liabilities and Equity Number of additional payments Paid-In Kind Interest, Elected, Number Of Additional Interest Payments Paid-In Kind Interest, Elected, Number Of Additional Interest Payments Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Cover [Abstract] Maximum Maximum [Member] Less: net (loss) income attributable to non-controlling interest Net Income (Loss) Attributable to Noncontrolling Interest Schedule of Lessee, Operating Lease, Liability, to be Paid, Maturity Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Restricted Stock Restricted Stock [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Treasury Stock Treasury Stock, Common [Member] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Class of Warrant or Right [Axis] Class of Warrant or Right [Axis] 6.72% Senior Secured Loans due 2033 6.72% Senior Secured Loans [Member] 6.72% Senior Secured Loans Present value of lease liabilities Operating Lease, Liability Costs associated with repayment of debt Costs Associated With Repayments Of Debt Costs Associated With Repayments Of Debt Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Debt Instrument, Redemption, Period One Debt Instrument, Redemption, Period One [Member] Liabilities Liabilities [Abstract] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Liquefied natural gas export authorized, mass Liquefied Natural Gas Export Authorized, Mass Liquefied Natural Gas Export Authorized, Mass Depreciation and amortization expense Depreciation, Depletion and Amortization, Nonproduction Entity Shell Company Entity Shell Company Other non-current liabilities Non-Current Common Stock Warrant Liabilities Amount of non-current common stock warrant liabilities. Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Schedule of Long-Term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Proceeds from debt issuance Proceeds from Issuance of Debt Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Schedule of Cash Flow, Supplemental Disclosures Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount 2028 Lessee, Operating Lease, Liability, to be Paid, Year Three Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Line of Credit Facility [Table] Line of Credit Facility [Table] Name Measure Name Operating leases Operating Lease, Liability, Current Document Fiscal Period Focus Document Fiscal Period Focus Award Timing Method Award Timing Method [Text Block] Award Type Award Type [Axis] Total assets Assets Trading Symbol Trading Symbol 2029 Lessee, Operating Lease, Liability, to be Paid, Year Four Geographical [Domain] Geographical [Domain] Debt instrument, covenant, historical debt service coverage ratio, minimum Debt Instrument Covenant, Historical Debt Service Coverage Ratio, Minimum Requirement for minimum historical debt service coverage ratio under debt instrument. Entity Address, City or Town Entity Address, City or Town Operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Days used to determine VWAP Number Of Days Used To Determine Volume Weighted Average Trading Price Number Of Days Used To Determine Volume Weighted Average Trading Price Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding 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] Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Restricted cash Restricted Cash and Cash Equivalent Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Common stock, outstanding (in shares) Common Stock, Shares, Outstanding PEO PEO [Member] Corporate and other Corporate Segment and Other Operating Segment [Member] 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] 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] 12.00% Corporate Credit Agreement due 2030 12.00% Corporate Credit Agreement [Member] 12.00% Corporate Credit Agreement Schedule of Product Information [Table] Nature of Operation, Product Information, Concentration of Risk [Table] Accumulated Deficit Retained Earnings [Member] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Share-Based Payment Arrangement [Abstract] Cash, cash equivalents and restricted cash – beginning of period Cash, cash equivalents and restricted cash – end of period Total cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Interest rate on outstanding balance Debt Instrument, Basis Spread on Variable Rate CD Senior Working Capital Facility CD Senior Working Capital Facility [Member] Represents CD Senior Working Capital Facility. Taxes Taxes Payable, Current Derivatives Derivative Liability, Noncurrent Preferred stock, issued (in shares) Preferred Stock, Shares Issued Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Accruals for acquisition of property, plant and equipment Accrued Liabilities, Acquisition Of Property, Plant And Equipment Future cash outflow to pay for purchases of fixed assets that have occurred, included in accrued liabilities. Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Interest per contractual rate Interest Expense, Debt, Excluding Amortization Total property, plant and equipment, at cost Property, Plant and Equipment, Gross Net (loss) income attributable to NextDecade Corporation Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Derivative, notional amount Derivative, Notional Amount Organization, Consolidation and Presentation of Financial Statements [Abstract] Amortization of leases Operating Lease, Right-of-Use Asset, Periodic Reduction Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] City Area Code City Area Code Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Debt instrument, prepayment penalty percentage Debt Instrument, Redemption Price, Percentage Accrued and other current liabilities Total accrued and other current liabilities Accrued Liabilities, Current Commitments and Contingencies Disclosure [Abstract] Investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] General and administrative expense General and Administrative Expense Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash used in operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Debt instrument, covenant, minimum percentage of projected principal amount outstanding be hedged Debt Instrument Covenant, Minimum Percentage Of Projected Principal Amount Outstanding Be Hedged Represents minimum percentage of projected principal amount outstanding to be hedged required by debt instrument. Preferred stock, par or stated value (in usd per share) Preferred Stock, Par or Stated Value Per Share Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Long-Term Debt, Type [Axis] Long-Term Debt, Type [Axis] Depreciation Depreciation Debt Instrument, Redemption, Period Three Debt Instrument, Redemption, Period Three [Member] Equity Components [Axis] Equity Components [Axis] Property, Plant and Equipment [Table] Property, Plant and Equipment [Line Items] Initial Warrants Initial Warrants [Member] Initial Warrants Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Variable Interest Entity Variable Interest Entity Disclosure [Text Block] Other Performance Measure, Amount Other Performance Measure, Amount Entity Address, State or Province Entity Address, State or Province Receipt of equity commitments Noncontrolling Interest, Increase from Sale of Parent Equity Interest Total current liabilities Liabilities, Current Capitalized interest Interest Costs Capitalized Adjustment Derivative Instrument [Axis] Derivative Instrument [Axis] Individual: Individual [Axis] Schedule of Accrued Expenses and Other Current Liabilities Schedule of Accrued Expenses and Other Current Liabilities [Table Text Block] Tabular disclosure of accrued expenses and other current liabilities. Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Corporate fixed asset retirements Settlement of Asset Retirement Obligations Through Noncash Payments, Amount 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] Derivatives Derivative Asset, Noncurrent Receipt of equity commitments Proceeds from Noncontrolling Interests Document Fiscal Year Focus Document Fiscal Year Focus Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Entity Interactive Data Current Entity Interactive Data Current Operating lease costs Operating Lease, Cost Equity [Abstract] Exercise of common stock warrants Stock Issued During Period, Value, Warrants Exercised Stock Issued During Period, Value, Warrants Exercised Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Other non-current assets Other Assets, Noncurrent Accrued interest Interest Payable, Current Entity Central Index Key Entity Central Index Key PEO Name PEO Name Revenues Revenues Number of liquefaction trains, remanded without vacatur Number Of Liquefaction Trains, Remanded Without Vacatur Number Of Liquefaction Trains, Remanded Without Vacatur 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] Supplemental Cash Flow Elements [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Corporate Credit Agreement Corporate Credit Agreement [Member] Corporate Credit Agreement Arrangement Duration Trading Arrangement Duration Corporate Credit Facility Corporate Credit Facility [Member] Corporate Credit Facility Debt issuance costs Payment of Financing and Stock Issuance Costs Other Other General Expense Exercise price (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Share-based Compensation Share-Based Payment Arrangement [Text Block] Unamortized debt issuance costs Debt Issuance Cost, Gross, Noncurrent Assets Assets [Abstract] Debt, net Total debt, net Long-Term Debt, Excluding Current Maturities Credit Facility [Axis] Credit Facility [Axis] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Number of liquefaction trains Number Of Liquefaction Trains Number Of Liquefaction Trains Loss on debt extinguishment Loss on extinguishment of debt Gain (Loss) on Extinguishment of Debt Credit Facility [Domain] Credit Facility [Domain] Stockholders’ equity Equity, Attributable to Parent [Abstract] 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] Accrued liabilities for debt and equity issuance costs Accrued Liabilities, Debt And Equity Issuance Costs The amount of liabilities accrued for debt and equity issuance costs. Warrant, Tranche A Warrant, Tranche A [Member] Warrant, Tranche A Entity Address, Address Line One Entity Address, Address Line One Shares repurchased related to share-based compensation Treasury Stock, Value, Acquired, Cost Method Development expense Research and Development Expense Debt instrument, interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Accrued expenses and other liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Operating leases Operating Lease, Liability, Noncurrent Senior Secured Loans Senior Secured Loans [Member] Represents senior secured loans. Derivatives Derivative Instruments and Hedging Activities Disclosure [Text Block] Fair Value as of Grant Date Award Grant Date Fair Value Rio Grande LNG Facility under construction Oil and Gas Properties [Member] Property, Plant and Equipment [Abstract] Entity Registrant Name Entity Registrant Name Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Other interest costs Interest Expense, Other 7.11% Senior Secured Loans due 2047 7.11% Senior Secured Loans [Member] 7.11% Senior Secured Loans Debt Instrument, Redemption, Period Two Debt Instrument, Redemption, Period Two [Member] Document Quarterly Report Document Quarterly Report Estimated Fair Value Long-Term Debt, Fair Value Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Volume weighted average trading price threshold, minimum (in dollars per share) Volume Weighted Average Trading Price Threshold, Minimum Volume Weighted Average Trading Price Threshold, Minimum 2027 Lessee, Operating Lease, Liability, to be Paid, Year Two Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Schedule of Debt Schedule of Debt [Table Text Block] Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Restatement Determination Date: Restatement Determination Date [Axis] Non-PEO NEO Non-PEO NEO [Member] Letters of credit issued Letters of Credit Outstanding, Amount Name Trading Arrangement, Individual Name Award Type [Domain] Award Type [Domain] 2026 Lessee, Operating Lease, Liability, to be Paid, Year One Variable Interest Entity, Measure of Activity [Abstract] Non-controlling interest Equity, Attributable to Noncontrolling Interest Equity Awards Adjustments Equity Awards Adjustments [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Compensation Amount Outstanding Recovery Compensation Amount Senior Secured Notes Senior Secured Notes [Member] Represents senior secured notes Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name Accrued Liabilities and Other Current Liabilities Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Employee Stock Employee Stock [Member] Share-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Treasury stock: 3.2 million shares and 3.1 million respectively, at cost Treasury Stock, Value Performance Shares Performance Shares [Member] Available commitment Line of Credit Facility, Remaining Borrowing Capacity Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Percentage of payments eligible to be paid-in kind Percentage Of Payments Eligible To Be Paid-In Kind Percentage Of Payments Eligible To Be Paid-In Kind Warrants purchased (in shares) Class of Warrant or Right, Number of Securities Called by Warrants or Rights Warrant, Tranche [Domain] Warrant, Tranche [Domain] Warrant, Tranche [Domain] Less: accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Company Selected Measure Name Company Selected Measure Name Debt Debt Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Senior Secured Notes and Loans Senior Secured Notes and Loans [Member] Represents senior secured notes and loans. Accounts payable Accounts Payable, Current Operating lease, payments Operating Lease, Payments Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Thereafter Lessee, Operating Lease, Liability, To Be Paid, After Year Four Lessee, Operating Lease, Liability, To Be Paid, After Year Four All Executive Categories All Executive Categories [Member] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Weighted average shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Commitments and contingencies (Note 10) Commitments and Contingencies Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Derivative [Table] Derivative [Table] Entity Small Business Entity Small Business Non-controlling Interest Noncontrolling Interest [Member] Preferred stock, outstanding (in shares) Preferred Stock, Shares Outstanding CC Amendment Warrants CC Amendment Warrants [Member] CC Amendment Warrants Document Transition Report Document Transition Report Total interest cost Interest Costs Incurred Preferred stock, $0.0001 par value, 0.5 million authorized: none outstanding Preferred Stock, Value, Outstanding Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Acquisition of other non-current assets Investing Activities Other Noncurrent Assets The amount of investing activities regarding other non-current assets. Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] CD Credit Facility and TCF Credit Facility CD Credit Facility and TCF Credit Facility [Member] Represents CD Credit Facility and TCF Credit Facility. Operating leases Increase (Decrease) in Operating Lease Liability Total equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Document Type Document Type Service-based and performance based restricted stock outstanding (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number Name Outstanding Recovery, Individual Name Rio Grande Liquefied Natural Gas Facility Rio Grande Liquefied Natural Gas Facility [Member] Rio Grande Liquefied Natural Gas Facility Additional paid-in-capital Additional Paid in Capital Derivative Contract [Domain] Derivative Contract [Domain] Service Based Restricted Stock Member Service Based Restricted Stock Member [Member] Service Based Restricted Stock Member All Individuals All Individuals [Member] Long-Term Debt, Type [Domain] Long-Term Debt, Type [Domain] Acquisition of property, plant and equipment Payments to Acquire Property, Plant, and Equipment Name Forgone Recovery, Individual Name Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] 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] Balance per Consolidated Balance Sheets: Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] Weighted Average Fixed Interest Rate Paid Derivative, Fixed Interest Rate Accounts payable for acquisition of property, plant and equipment Accounts Payable, Acquisition Of Property, Plant And Equipment Future cash outflow to pay for purchases of fixed assets that have occurred, included in accounts payable. TCF Credit Facility TCF Credit Facility [Member] Represents TCF Credit Facility. Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Derivative [Abstract] Schedule of Interest Rate Swaps Outstanding Schedule of Derivative Instruments [Table Text Block] Net loss attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Derivative settlements Net Cash Provided By Settlement Of Derivative Instruments The cash inflow provided by derivative instruments during the period, which are classified as operating activities. Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Current liabilities: Liabilities, Current [Abstract] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Geographical [Axis] Geographical [Axis] Other Increase (Decrease) in Other Operating Assets and Liabilities, Net Total operating expenses Operating Expenses Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Outstanding balance Long-Term Line of Credit Net loss per common share - diluted (in usd per share) Earnings Per Share, Diluted Warrant, Tranche [Axis] Warrant, Tranche [Axis] Warrant, Tranche Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Title of 12(b) Security Title of 12(b) Security Treasury stock, common (in shares) Treasury Stock, Common, Shares Interest elected to be paid-in-kind Paid-in-Kind Interest Reclassification from other non-current assets to property, plant and equipment Reclassification From Other Non-Current Assets To Property, Plant And Equipment Reclassification From Other Non-Current Assets To Property, Plant And Equipment Background and Basis of Presentation Business Description and Basis of Presentation [Text Block] Total other (expense) income Nonoperating Income (Expense) 6.58% Senior Secured Notes due 2047 6.58% Senior Secured Notes [Member] 6.58% Senior Secured Notes Schedule of Interest Income and Interest Expense Disclosure Interest Income and Interest Expense Disclosure [Table Text Block] Discount to present value Lessee, Operating Lease, Liability, Undiscounted Excess Amount Award Timing Disclosures [Line Items] Number of liquefaction trains authorized Number Of Liquefaction Trains Authorized Number Of Liquefaction Trains Authorized Total debt Carrying Amount Long-Term Debt, Gross Employee compensation expense Employee-related Liabilities, Current Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Total undiscounted lease payments Lessee, Operating Lease, Liability, to be Paid Renewal term (in years) Lessee, Operating Lease, Renewal Term Stockholders' Equity Equity [Text Block] Net (loss) income Net (loss) income attributable to NextDecade Corporation Net Income (Loss) Attributable to Parent Derivative gain (loss) Derivative loss (gain) Gain (Loss) on Derivative Instruments, Net, Pretax Expiration Date Trading Arrangement Expiration Date Other accrued liabilities Other Accrued Liabilities, Current Product Information [Line Items] Product Information [Line Items] Property, plant and equipment, net Total property, plant and equipment, net Property, Plant and Equipment, Net Preferred stock, authorized (in shares) Preferred Stock, Shares Authorized Shares repurchased related to share-based compensation Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Entity Current Reporting Status Entity Current Reporting Status Term of contract (in years) Lessee, Operating Lease, Term of Contract Derivative [Line Items] Derivative [Line Items] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Total operating loss Operating Income (Loss) Line of Credit Line of Credit [Member] Consolidated Entities [Domain] Consolidated Entities [Domain] Accumulated deficit Retained Earnings (Accumulated Deficit) Corporate fixed asset retirements Gain (Loss) on Disposition of Property Plant Equipment CC Amendment Corporate Credit Amendment [Member] Corporate Credit Amendment Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] 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] Executive Category: Executive Category [Axis] Repayment of debt Repayments of Debt Total interest expense Interest Expense, Operating and Nonoperating Current Fiscal Year End Date Current Fiscal Year End Date 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] Statement [Table] Statement [Table] Other income (expense), net Other Nonoperating Income (Expense) Derivative liability Derivative Liability Adjustment to reconcile net (loss) income to net cash 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] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Warrants issued in connection with Debt (Note 6) Adjustments to Additional Paid in Capital, Warrant Issued 6.67% Senior Secured Notes due 2033 6.67% Senior Secured Notes [Member] 6.67% Senior Secured Notes Stock options outstanding (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount All Adjustments to Compensation All Adjustments to Compensation [Member] Amendment Flag Amendment Flag Leases Lessee, Operating Leases [Text Block] Termination Date Trading Arrangement Termination Date Number of tranches Warrant, Number Of Tranches Warrant, Number Of Tranches Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Deferred financing fees Debt Issuance Costs, Noncurrent, Net Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Weighted average discount rate — percent Operating Lease, Weighted Average Discount Rate, Percent Debt instrument, covenant, repurchase price, percentage Debt Instrument, Covenant Repurchase Price Percentage Represents repurchase price to repurchasing debt as a percentage under debt instrument. Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Weighted average shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Supplemental Cash Flows Cash Flow, Supplemental Disclosures [Text Block] Warrants and rights outstanding Warrants and Rights Outstanding Subsequent Events [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Amortization of debt issuance costs Amortization of Debt Issuance Costs Other (expense) income: Nonoperating Income (Expense) [Abstract] Entity Tax Identification Number Entity Tax Identification Number Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Rio Grande Rio Grande [Member] Information pertaining to Rio Grande. Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount 6.85% Senior Secured Notes due 2047 6.85% Senior Secured Notes [Member] 6.85% Senior Secured Loans Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Consolidated Entities [Axis] Consolidated Entities [Axis] Common stock, par or stated value (in usd per share) Common Stock, Par or Stated Value Per Share Common stock, issued (in shares) Common Stock, Shares, Issued Weighted average remaining lease term — years Operating Lease, Weighted Average Remaining Lease Term Rio Grande LNG Facility costs Business Acquisition, Deferred Transaction Costs, Current The amount of transaction costs deferred under business acquisition. Interest expense, net Interest Expense, Nonoperating Trading Arrangement: Trading Arrangement [Axis] Derivatives Derivative Asset, Current Total Shareholder Return Amount Total Shareholder Return Amount Subsequent Events Subsequent Events [Text Block] Insider Trading Arrangements [Line Items] Security Exchange Name Security Exchange Name Total liabilities Liabilities Commitment fees on undrawn balance Line of Credit Facility, Commitment Fee Percentage Line of credit Total Facility Size Line of Credit Facility, Maximum Borrowing Capacity Common stock, $0.0001 par value, 480.0 million authorized: 260.9 million and 260.2 million outstanding, respectively Common Stock, Value, Outstanding Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Operating expenses: Operating Expenses [Abstract] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Statement [Line Items] Statement [Line Items] Reduction in senior working capital facility Extinguishment of Debt, Amount Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Common Stock Common Stock [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Net (decrease) increase in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation