SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Statistical Measurement [Domain] Statistical Measurement [Domain] Increase due to cash received or receivable, excluding amounts recognized as revenue during the period Contract With Customer, Liability, Increase From Cash Receipts Contract With Customer, Liability, Increase From Cash Receipts Award Timing Predetermined Award Timing Predetermined [Flag] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Other Assets Regulated Entity, Other Assets, Noncurrent [Abstract] Entity File Number Entity File Number Additional Paid-In Capital Additional Paid-in Capital [Member] Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Earnings from equity method investees Earnings from equity method investees Income (Loss) from Equity Method Investments Tabular List, Table Tabular List [Table Text Block] Contingent payments paid Payment For Asset Acquisition Contingent Consideration Asset Payment For Asset Acquisition Contingent Consideration Asset Basic Earnings per Common Share Earnings Per Share, Basic [Abstract] Schedule of Cash Dividends Declared Dividends Declared [Table Text Block] Recently Issued Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Carrying Amount of Fair Value of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] EARNINGS PER SHARE AND DIVIDENDS Earnings Per Share And Dividends [Text Block] Earnings Per Share And Dividends Maximum potential indemnification Guarantor Obligations, Maximum Exposure, Undiscounted Goodwill [Line Items] Goodwill [Line Items] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Measurement Basis [Axis] Measurement Basis [Axis] Net Income Attributable to DT Midstream (in dollars per share) Basic earnings per Common Share (in dollars per share) Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Debt related to issuance and amendment costs, net of amortization Debt Amendment Cost Debt Amendment Cost Number of internal grades of credit quality Financing Receivable, Credit Quality Indicator, Number Of Internal Grades Financing Receivable, Credit Quality Indicator, Number Of Internal Grades Schedule of Availability Under the Revolving Credit Facility Schedule of Line of Credit Facilities [Table Text Block] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] REVENUE Revenue from Contract with Customer [Text Block] Accounts payable Increase (Decrease) in Accounts Payable, Trade Total other comprehensive income, net of tax Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax Schedule of Financial Data by Business Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Remaining performance obligation Revenue, Remaining Performance Obligation, Amount Other Other Assets, Miscellaneous, Noncurrent Adjustment to Compensation, Amount Adjustment to Compensation Amount Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Employee Stock Option Share-Based Payment Arrangement, Option [Member] Notes receivable, originated prior to 2021 Financing Receivable, Excluding Accrued Interest, Originated Two Or More Years Before Current Fiscal Year Financing Receivable, Excluding Accrued Interest, Originated Two Or More Years Before Current Fiscal Year Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Deferred property taxes Prepaid Taxes Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] VIE Variable interest entity, primary beneficiary Variable Interest Entity, Primary Beneficiary [Member] Dividend Amount Dividends, Common Stock, Cash Contributions to equity method investees Payments to Acquire Equity Method Investments Total DT Midstream Equity Equity, Attributable to Parent Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax [Abstract] Insider Trading Policies and Procedures [Line Items] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Surety Bonds Surety Bond [Member] Goodwill and Intangible Assets Disclosure [Abstract] Current Assets Assets, Current [Abstract] Total Liabilities and Equity Liabilities and Equity LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Other (Income) and Deductions Other Nonoperating Income (Expense) [Abstract] Cover [Abstract] Cover [Abstract] Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Maximum Maximum [Member] Schedule of Equity Method Investments [Table] Equity Method Investment [Table] Property Property, Plant and Equipment, Net [Abstract] Less: Net Income Attributable to Noncontrolling Interests Net Income (Loss) Attributable to Noncontrolling Interest Capital expenditures Segment, Expenditure, Addition to Long-Lived Assets Accounting Policies [Abstract] Accounting Policies [Abstract] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount LIABILITIES Liabilities [Abstract] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Income Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Total Other Liabilities Other noncurrent liabilities Other Liabilities, Noncurrent Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Property taxes payable Accrual for Taxes Other than Income Taxes, Current Amount by which the carrying amounts of equity method investments exceeds share of underlying equity in the net assets Equity Method Investment, Difference Between Carrying Amount and Underlying Equity Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating segments Operating Segments [Member] 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 Less: Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Line of Credit Facility [Table] Line of Credit Facility [Table] Comprehensive Income Attributable to DT Midstream Comprehensive Income (Loss), Net of Tax, Attributable to Parent Name Measure Name Letters of credit Letter of Credit [Member] Distributions to noncontrolling interests Payments to Noncontrolling Interests Operating lease liabilities Operating Lease, Liability, Current Deferred income taxes Deferred Income Tax Liabilities, Net Document Fiscal Period Focus Document Fiscal Period Focus Unsecured Debt Unsecured Debt [Member] Award Timing Method Award Timing Method [Text Block] Notes receivables on nonaccrual status Financing Receivable, Excluding Accrued Interest, Nonaccrual Award Type Award Type [Axis] Contract liabilities Contract with Customer, Liability, Noncurrent Total Assets Consolidated assets Consolidated assets Assets Investment, Name [Domain] Investment, Name [Domain] Trading Symbol Trading Symbol Stock-based compensation and other (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Entity Address, City or Town Entity Address, City or Town Operating Activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] 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] Revolving Credit Facility, expiring December 2029 Revolving Credit Facility, Expiring December 2029 [Member] Revolving Credit Facility, Expiring December 2029 Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Principles of Consolidation Consolidation, Variable Interest Entity, Policy [Policy Text Block] Dividends declared on common stock (in dollars per share) Dividend Amount (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Capitalized costs to obtain or fulfill contracts Capitalized Contract Cost, Net Repayment of borrowings under the Revolving Credit Facility Repayments of Lines of Credit 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] Revolving Term Credit Facility Unfunded Loan Commitment [Member] Unamortized debt issuance costs Debt Issuance Costs, Net Level 2 Fair Value, Inputs, Level 2 [Member] Investments in equity method investees Investments As of Equity Method Investments Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Notes receivable — related party Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss, Current Related Party Related Party [Member] Common stock, shares outstanding (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Outstanding REGULATORY MATTERS Schedule of Regulatory Assets and Liabilities [Text Block] Uncollectible expense (recovery) Accounts Receivable, Credit Loss Expense (Reversal) Pipeline Pipeline Segment [Member] Pipeline Segment Property, Plant, and Equipment Property, Plant and Equipment, Policy [Policy Text Block] PEO PEO [Member] Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Interest income Investment Income, Interest Changes in 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] Operating expenses Utilities Operating Expense Retained Earnings Retained Earnings [Member] Prepaid expenses and other Prepaid Expense and Other Assets, Current Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Cash and Cash Equivalents at Beginning of Period Cash and Cash Equivalents at End of Period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Income Tax Expense Income Tax Expense (Benefit) Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Interest payable Increase (Decrease) in Interest Payable, Net Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Intangible assets, net Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Property, plant, and equipment Property, Plant and Equipment, Gross Net Income Net Income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Amortization of operating lease right-of-use assets 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] Maximum consolidated net leverage ratio Debt Instrument, Covenant, Consolidated Net Leverage Ratio, Maximum Debt Instrument, Covenant, Consolidated Net Leverage Ratio, Maximum Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Summary of Contact Liability Activity Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Investing Activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash and cash equivalents from operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Subsequent Event Subsequent Event [Member] Clean Fuels Gathering Asset Acquisition Clean Fuels Gathering Asset Acquisition [Member] Clean Fuels Gather Project Asset Acquisition Equity method investment, non-consolidated investees Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Goodwill Goodwill 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] Gathering Gathering Segment [Member] Gathering Segment Notes receivable - related party Notes Receivable, Fair Value Disclosure Change In Contract With Customer, Liability [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Change In Contract With Customer, Liability Equity Components [Axis] Equity Components [Axis] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Number of reportable segments Number of Reportable Segments Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Axis] Internal grade 1 Internal Grade One [Member] Internal Grade One [Member] Other Liabilities Other Liabilities, Noncurrent [Abstract] Supplemental disclosure of cash information Supplemental Cash Flow Information [Abstract] Other Performance Measure, Amount Other Performance Measure, Amount Regulatory liabilities Regulatory Liability, Noncurrent Entity Address, State or Province Entity Address, State or Province Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Dividends declared on common stock Dividends, Common Stock Related Party [Domain] Related and Nonrelated Parties [Domain] Total Current Liabilities Liabilities, Current Individual: Individual [Axis] Fair Value Fair Value of Financial Instruments, Policy [Policy Text Block] Basic and Diluted Earnings per Common Share Earnings Per Share Reconciliation [Abstract] Other current assets Other Assets, Current Dividends paid on common stock Payments of Ordinary Dividends, Common Stock Regulation Regulatory Assets And Liabilities, Policy [Policy Text Block] Regulatory Assets And Liabilities, Policy Net cash and cash equivalents used for investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Remaining performance obligation, expected timing of satisfaction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 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] Interest, net of interest capitalized Interest Paid, Excluding Capitalized Interest, Operating Activity Contributions from noncontrolling interests Proceeds from Noncontrolling Interests Document Fiscal Year Focus Document Fiscal Year Focus Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Effective tax rates Effective Income Tax Rate Reconciliation, Percent Entity Interactive Data Current Entity Interactive Data Current Equity Method Investment, Nonconsolidated Investee [Axis] Equity Method Investment, Nonconsolidated Investee [Axis] Maximum potential payout Financing Receivable, Maximum Potential Exposure Financing Receivable, Maximum Potential Exposure Carrying Amount Reported Value Measurement [Member] Taxes other than income Taxes, Miscellaneous Stockholders' Equity Equity [Abstract] Contingent payments upon the completion of certain milestones Asset Acquisition, Contingent Consideration, Liability SEGMENT AND RELATED INFORMATION Segment Reporting Disclosure [Text Block] Schedule of Goodwill [Table] Goodwill [Table] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] NEXUS NEXUS Gas Transmission, LLC [Member] NEXUS Gas Transmission, LLC Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Expected debt issuance costs Debt Issuance Cost, Expected Debt Issuance Cost, Expected Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Total Other Assets Other Assets, Noncurrent Interest payable Interest Payable, Current Entity Central Index Key Entity Central Index Key PEO Name PEO Name Operating revenues Total Operating revenues Revenues 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] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Stonewall VIE Variable Interest Entity, Primary Beneficiary, Stonewall Gas Gathering Lateral Pipeline [Member] Variable Interest Entity, Primary Beneficiary, Stonewall Gas Gathering Lateral Pipeline Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fixed-price Contract Fixed-Price Contract [Member] Revolving Credit Facility borrowings Revolving Credit Facility [Member] Arrangement Duration Trading Arrangement Duration Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Long-term notes receivable — related party Long-Term Notes Receivable, Fair Value Disclosure Long-Term Notes Receivable, Fair Value Disclosure Other Other Sundry Liabilities, Noncurrent Contract liabilities Contract with Customer, Liability, Current Segments [Axis] Segments [Axis] 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] Subsequent Event Type [Axis] Subsequent Event Type [Axis] 2031 Notes 2031 Senior Notes [Member] 2031 Senior Notes ASSETS Assets [Abstract] Long-Term Debt, net Long-term 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 Depreciation and Amortization Depreciation, Depletion, and Amortization [Policy Text Block] Debt Instrument [Axis] Debt Instrument [Axis] FAIR VALUE Fair Value Disclosures [Text Block] Credit Facility [Domain] Credit Facility [Domain] 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] Entity Address, Address Line One Entity Address, Address Line One Investments Long-Term Investments [Abstract] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Interest Rate Debt Instrument, Interest Rate, Stated Percentage Investment, Name [Axis] Investment, Name [Axis] Allowance for expected credit loss Accounts Receivable, Allowance for Credit Loss, Current Operating lease liabilities Operating Lease, Liability, Noncurrent 2034 Notes 2034 Senior Notes [Member] 2034 Senior Notes Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Fair Value as of Grant Date Award Grant Date Fair Value Entity Registrant Name Entity Registrant Name Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Schedule of Long-term Debt Outstanding Schedule of Long-Term Debt Instruments [Table Text Block] Average dilutive restricted stock units and performance share awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Vector Vector Pipeline [Member] Vector Pipeline [Member] Regulated Operations [Abstract] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Document Quarterly Report Document Quarterly Report Long-term debt Long-Term Debt, Fair Value Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Past due Financial Asset, Past Due [Member] Counterparty Name [Domain] Counterparty Name [Domain] Number of operating segments Number of Operating Segments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Operation and Maintenance Operation And Maintenance, Policy [Policy Text Block] Operation And Maintenance, Policy New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Accounting Standards Update and Change in Accounting Principle [Abstract] Related Party [Axis] Related and Nonrelated Parties [Axis] Millennium Millennium Pipeline [Member] Millennium Pipeline 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] Contributions from noncontrolling interests Noncontrolling Interest, Increase from Subsidiary Equity Issuance Name Trading Arrangement, Individual Name All Award Types Award Type [Domain] Contract with Customer, Basis of Pricing [Domain] Contract with Customer, Basis of Pricing [Domain] GOODWILL Goodwill Disclosure [Text Block] Noncontrolling interests Equity, Attributable to Noncontrolling Interest Equity Awards Adjustments Equity Awards Adjustments [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Compensation Amount Outstanding Recovery Compensation Amount Long-term debt issued Debt Instrument, Face Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Estimate of Fair Value Measurement [Member] Revenue recognized that was included in the balance at the beginning of the period Contract with Customer, Liability, Revenue Recognized Accrued compensation Increase (Decrease) in Employee Related Liabilities MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Revenues Revenues [Abstract] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Contingent payment recorded as current prepaid asset Asset Acquisition, Contingent Consideration, Asset, Current Asset Acquisition, Contingent Consideration, Asset, Current Stock-based compensation and other APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Segments [Domain] Segments [Domain] Net availability Line of Credit Facility, Remaining Borrowing Capacity Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Revenue Expected to be Recognized in Future Periods Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Amounts outstanding Line of Credit, Current Specific review of probable future collections based on receivable balances, threshold duration Specific Review Of Probable Future Collections Based On Receivable Balances, Threshold Duration Specific Review Of Probable Future Collections Based On Receivable Balances, Threshold Duration Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Company Selected Measure Name Company Selected Measure Name Accrued contingent liabilities Accrual for Environmental Loss Contingencies Fair Value Measurement [Domain] Fair Value Measurement [Domain] Senior Notes Senior Notes [Member] DEBT Debt Disclosure [Text Block] Preferred stock ($0.01 par value, 50,000,000 shares authorized, and no shares issued or outstanding as of March 31, 2026 and December 31, 2025) Preferred Stock, Value, Issued Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Accounts payable Accounts Payable, Current Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] All Executive Categories All Executive Categories [Member] Common stock ($0.01 par value, 550,000,000 shares authorized, and 102,014,118 and 101,673,925 shares issued and outstanding as of March 31, 2026 and December 31, 2025, respectively) Common Stock, Value, Issued COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Diluted (in shares) Average number of common 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] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Entity Small Business Entity Small Business Income Tax Disclosure [Abstract] Operation and maintenance Other Cost and Expense, Operating Noncontrolling Interests Noncontrolling Interest [Member] Consolidated net leverage ratio Debt Instrument, Covenant, Consolidated Net Leverage Ratio Debt Instrument, Covenant, Consolidated Net Leverage Ratio Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Document Transition Report Document Transition Report Equity Method Investments Equity Method Investments [Policy Text Block] Revolving Credit Facility, expiring October 2029 Revolving Credit Facility, Expiring October 2029 [Member] Revolving Credit Facility, Expiring October 2029 % Owned As of Equity Method Investment, Ownership Percentage NEW ACCOUNTING PRONOUNCEMENTS Accounting Standards Update and Change in Accounting Principle [Text Block] South Romeo VIE Variable Interest Entity, Primary Beneficiary, South Romeo Gas Storage Corporation [Member] Variable Interest Entity, Primary Beneficiary, South Romeo Gas Storage Corporation 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 INCOME TAXES Income Tax Disclosure [Text Block] Diluted Earnings per Common Share Earnings Per Share, Diluted [Abstract] Allowance for expected credit loss related to accounts receivable Accounts Receivable, Allowance for Credit Loss Borrowings under the Revolving Credit Facility Proceeds from Lines of Credit Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Asset losses and impairments, net Asset (gains) losses and impairments, net Gain (Loss) on Sale of Assets and Asset Impairment Charges Total Equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Document Type Document Type Level 3 Fair Value, Inputs, Level 3 [Member] Name Outstanding Recovery, Individual Name Loss Contingencies [Table] Loss Contingencies [Table] Accounts payable and other current liabilities Accounts Payable and Other Accrued Liabilities, Current Additional paid-in capital Additional Paid in Capital Asset Acquisition [Domain] Asset Acquisition [Domain] All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Plant and equipment expenditures 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] Long-term notes receivable — related party Other Receivables, Net, Current Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Stock-based compensation tax withholding payments Payment, Tax Withholding, Share-Based Payment Arrangement Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] 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] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Other current and noncurrent assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Level 1 Fair Value, Inputs, Level 1 [Member] Term Loan Credit Agreement Term Loan Credit Agreement [Member] Term Loan Credit Agreement Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Net Income Attributable to DT Midstream (in dollars per share) Diluted earnings per Common Share (in dollars per share) Earnings Per Share, Diluted Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Accounts receivable (net of $— allowance for expected credit loss for each period end) Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Title of 12(b) Security Title of 12(b) Security Supplemental disclosure of non-cash investing and financing activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Amortization expense related to capitalized costs Capitalized Contract Cost, Amortization Earnings Per Share [Abstract] Earnings Per Share [Abstract] Consolidation Items [Domain] Consolidation Items [Domain] Distributions from equity method investees Proceeds from Equity Method Investment, Distribution, Return of Capital Contract liabilities Increase (Decrease) in Contract with Customer, Liability Incremental shares attributable to: Weighted Average Number of Shares Outstanding, Diluted, Adjustment [Abstract] Income taxes, net of refunds received Income Taxes Paid, Net Award Timing Disclosures [Line Items] Long-term debt principal Long-Term Debt, Gross Notes receivable Notes Receivable [Member] Accrued compensation Employee-related Liabilities, Current Contingent payment recorded as long-term prepaid asset Asset Acquisition, Contingent Consideration, Asset, Noncurrent Asset Acquisition, Contingent Consideration, Asset, Noncurrent Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Financing receivables Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Net Income Attributable to DT Midstream Net Income Attributable to DT Midstream Net Income (Loss) Attributable to Parent Subsequent Event [Table] Subsequent Event [Table] Eliminations Intersegment Eliminations [Member] Expiration Date Trading Arrangement Expiration Date Equity Method Investment, Nonconsolidated Investee [Domain] Equity Method Investment, Nonconsolidated Investee [Domain] VIE ownership percentage Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Schedule of Equity Method Investments Equity Method Investments [Table Text Block] Net Property, plant, and equipment Property, plant and equipment, net Property, Plant and Equipment, Net Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Adoption Date Trading Arrangement Adoption Date Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Accounts receivable, net Increase (Decrease) in Accounts Receivable Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Entity Current Reporting Status Entity Current Reporting Status Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Operating Income Operating Income (Loss) Consolidated Entities [Domain] Consolidated Entities [Domain] Retained earnings Retained Earnings (Accumulated Deficit) 2032 Notes 2032 Senior Notes [Member] 2032 Senior Notes 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] Financing Receivables Financing Receivable [Policy Text Block] Current Fiscal Year End Date Current Fiscal Year End Date Subsequent Event Type [Domain] Subsequent Event Type [Domain] 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] Deferred income taxes Deferred Income Tax Expense (Benefit) Adjustments to reconcile Net Income to Net cash and cash equivalents from 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] Temporary step up maximum consolidated net leverage ratio Debt Instrument, Covenant, Consolidated Net Leverage Ratio, Temporary Step-Up Maximum Debt Instrument, Covenant, Consolidated Net Leverage Ratio, Temporary Step-Up Maximum Beginning balance Ending balance Contract with Customer, Liability Dividends from equity method investees Proceeds from Equity Method Investment, Distribution Lessor Accounting Lessor, Leases [Policy Text Block] DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Weighted Average Common Shares Outstanding Weighted Average Number of Shares Outstanding, Diluted [Abstract] All Adjustments to Compensation All Adjustments to Compensation [Member] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Amendment Flag Amendment Flag Termination Date Trading Arrangement Termination Date Consideration value related to consummation or acquisition or investment required to temporarily step up maximum consolidated net leverage ratio Debt Instrument, Covenant, Acquisition Consideration Value Triggering Temporary Step-Up In Maximum Consolidated Net Leverage Ratio Debt Instrument, Covenant, Acquisition Consideration Value Triggering Temporary Step-Up In Maximum Consolidated Net Leverage Ratio Net cash and cash equivalents used for financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Basic (in shares) Average number of common shares outstanding — basic (in shares) Weighted Average Number of Shares Outstanding, Basic Reconciliation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Subsequent Events [Abstract] Subsequent Events [Abstract] Segment Reporting [Abstract] Segment Reporting [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Entity Tax Identification Number Entity Tax Identification Number Asset Acquisition [Axis] Asset Acquisition [Axis] Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Unamortized debt discount Debt Instrument, Unamortized Discount Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Consolidated Entities [Axis] Consolidated Entities [Axis] Common stock, shares issued (in shares) Common Stock, Shares, Issued Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Dividends payable Dividends Payable, Current Schedule of Goodwill Schedule of Goodwill [Table Text Block] Interest expense Interest Expense, Nonoperating Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Income outside scope of ASC 606 Operating Lease, Lease Income Cash paid for: Cash Paid For (Received From) Supplemental Cash Flow Information [Abstract] Cash Paid For Supplemental Cash Flow Information Loss Contingencies [Line Items] Loss Contingencies [Line Items] SUBSEQUENT EVENTS Subsequent Events [Text Block] Foreign currency translation, net of tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Insider Trading Arrangements [Line Items] Security Exchange Name Security Exchange Name Total Liabilities Consolidated liabilities Liabilities Plant and equipment expenditures in accounts payable and other accrued liabilities Capital Expenditures Incurred but Not yet Paid Maximum leverage ratio Debt Instrument, Covenant, Leverage Ratio, Maximum Debt Instrument, Covenant, Leverage Ratio, Maximum Total availability Line of Credit Facility, Maximum Borrowing Capacity 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] Other Other Liabilities, Current Statement [Line Items] Statement [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Consolidation Items [Axis] Consolidation Items [Axis] 2029 Notes 2029 Senior Notes [Member] 2029 Senior Notes Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash Cash and Cash Equivalent Counterparty Name [Axis] Counterparty Name [Axis] Subsequent Event [Line Items] Subsequent Event [Line Items] Common Stock Common Stock [Member] Intangible Assets Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Net Increase in Cash and Cash Equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation