Cash paid during the period for:
Supplemental Cash Flow Information [Abstract]
Customer [Domain]
Customer [Domain]
Maximum leverage ratio
Debt Instrument, Covenant, Leverage Ratio, Maximum
Debt Instrument, Covenant, Leverage Ratio, Maximum
Letter of credit
Letter of Credit [Member]
Fair Value Hierarchy and NAV [Domain]
Fair Value Hierarchy and NAV [Domain]
Net income attributable to Equitrans Midstream
Net Income (Loss) Attributable to Parent
Consolidated Entities [Axis]
Consolidated Entities [Axis]
Entity Emerging Growth Company
Entity Emerging Growth Company
Increase in mezzanine equity
Temporary Equity, Carrying Amount, Period Increase (Decrease)
Share-based compensation plans (in shares)
Partners' Capital Account, Unit-based Payment Arrangement, Number of Units
Statistical Measurement [Domain]
Statistical Measurement [Domain]
Transaction costs
Business Combination, Acquisition Related Costs
Entity Address, Address Line One
Entity Address, Address Line One
Additional available borrowings
Line Of Credit Facility, Accordion Feature, Increase Limit
Line Of Credit Facility, Accordion Feature, Increase Limit
Capital contribution payable to MVP Joint Venture
Equity Method Investment, Capital Call Notice
Equity Method Investment, Capital Call Notice
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Abstract]
Contract with Customer, Asset and Liability
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]
Entity Filer Category
Entity Filer Category
2019 EQM Term Loan Agreement
2019 EQM Term Loan Agreement [Member]
2019 EQM Term Loan Agreement [Member]
Firm reservation capacity, per day
Oil And Gas, Minimum Volume To Provide
Oil And Gas, Minimum Volume To Provide
Mezzanine equity, preferred shares outstanding (in shares)
Temporary Equity, Shares Outstanding
Other assets
Other Assets, Noncurrent
Investment, Name [Axis]
Investment, Name [Axis]
Segments [Axis]
Segments [Axis]
Net change in cash and cash equivalents
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect
Operating expenses
Equity Method Investment, Summarized Financial Information, Operating Expenses
Equity Method Investment, Summarized Financial Information, Operating Expenses
Document Fiscal Year Focus
Document Fiscal Year Focus
Fiscal quarter ending after December 31, 2022
Debt Covenant Period Three [Member]
Debt Covenant Period Three
Subsequent Event Type [Domain]
Subsequent Event Type [Domain]
Trading price threshold (in usd per share)
Sale Of Units, Convertible Common Stock, Trading Price Threshold
Sale Of Units, Convertible Common Stock, Trading Price Threshold
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amortization of intangible assets
Amortization of intangible assets
Amortization of Intangible Assets
Valuation Approach and Technique [Domain]
Valuation Approach and Technique [Domain]
Potentially dilutive securities (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Amounts transferred during the period
Contract with Customer, Liability, Revenue Recognized
Sale of Stock [Axis]
Sale of Stock [Axis]
Debt Covenant Period [Axis]
Debt Covenant Period [Axis]
Debt Covenant Period
Private Placement
Private Placement [Member]
Accounts receivable
Accounts Receivable, Related Parties
Business Acquisition [Axis]
Business Acquisition [Axis]
Accrued interest
Increase (Decrease) in Interest Payable, Net
Equity Award [Domain]
Award Type [Domain]
Credit Facility [Domain]
Credit Facility [Domain]
ASSETS
Assets [Abstract]
Related Party Transactions [Abstract]
Related Party Transactions [Abstract]
Distributions paid to noncontrolling interest EQM unitholders
Contributions (Distributions) Made To Limited Partner, Cash Distributions Received (Paid) Including Noncontrolling Interest
Contributions (Distributions) Made To Limited Partner, Cash Distributions Received (Paid) Including Noncontrolling Interest
Eureka Midstream, LLC
Eureka Midstream, LLC [Member]
Eureka Midstream, LLC [Member]
EQM Credit Facility
EQM Credit Facility [Member]
EQM Credit Facility [Member]
Discount rate from fair value assumption
Equity Method Investment, Fair Value Assumption, Discount Rate
Equity Method Investment, Fair Value Assumption, Discount Rate
Redemption (in shares)
Equity Instrument Redemption, Shares
Equity Instrument Redemption, Shares
Distributions paid to noncontrolling interest unitholders
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders
Entity Address, City or Town
Entity Address, City or Town
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity, Not Primary Beneficiary [Member]
Retained Deficit
Retained Earnings [Member]
Other income
Equity Method Investment, Summarized Financial Information, Other Income
Equity Method Investment, Summarized Financial Information, Other Income
Debt Instrument [Axis]
Debt Instrument [Axis]
MVP
Mountain Valley Pipeline [Member]
Represents information pertaining to Mountain Valley Pipeline (MVP).
Long-term liabilities:
Liabilities, Noncurrent [Abstract]
Preferred dividends
Less: Preferred dividends
Temporary Equity, Dividends, Adjustment
Related Party [Axis]
Related Party [Axis]
Conversion basis of common stock
Sale Of Units, Convertible Common Stock, Conversion Basis
Sale Of Units, Convertible Common Stock, Conversion Basis
Share Purchase Agreements (as defined in Note 5)
Stock Repurchased and Retired During Period, Value
EQM Merger
Stock Issued During Period, Value, Merger
Stock Issued During Period, Value, Merger
Property, Plant and Equipment
Property, Plant and Equipment [Line Items]
Comprehensive income
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest
Length of pipeline (in miles)
Gas And Oil, Length Of Natural Gas Pipeline
Gas And Oil, Length Of Natural Gas Pipeline
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Entity Interactive Data Current
Entity Interactive Data Current
Deferred revenue
Increase (Decrease) in Deferred Revenue
Same-day swing line advances
Same-Day Swing Line Advances [Member]
Same-Day Swing Line Advances [Member]
Number of operating segments
Number of Operating Segments
Earnings per share of common stock attributable to Equitrans Midstream common shareholders - basic (in dollars per share)
Earnings Per Share, Basic
Pension and other post-retirement benefits liability adjustment, net of tax expense of $12, $10, $36, and $30
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax
Equitrans Midstream
Equitrans Midstream [Member]
Equitrans Midstream [Member]
Revenue from Contract with Customers
Revenue from Contract with Customer [Text Block]
Non-cash activity during the period for:
Noncash or Part Noncash Acquisition, Value of Assets Acquired [Abstract]
Share-based compensation plans, net
Partners' Capital Account, Unit-based Payment Arrangement, Amount
Document Type
Document Type
Schedule of Disaggregated Revenue Information, By Segment
Disaggregation of Revenue [Table Text Block]
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Entity Current Reporting Status
Entity Current Reporting Status
Cumulative Effect, Period of Adoption, Adjustment
Cumulative Effect, Period of Adoption, Adjustment [Member]
Net changes in ownership of consolidated entities
Partners' Capital Account, Limited Partner Changes In Ownership
Partners' Capital Account, Limited Partner Changes In Ownership
Less: Comprehensive income attributable to preferred dividends
Comprehensive Income (Loss), Net of Tax, Attributable to Preferred Shareholders
Comprehensive Income (Loss), Net of Tax, Attributable to Preferred Shareholders
Deferred tax liability
Deferred Tax Liabilities, Net
Other income
Other Noncash Income (Expense)
Contract asset
Contract Assets, Related Parties
Contract Assets, Related Parties
MVC
Gathering revenues supported by MVCs
Minimum Volume Commitment Contract [Member]
Minimum Volume Commitment Contract [Member]
Cumulative quarterly dividend rate
Preferred Stock, Dividend Rate, Percentage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Borrowings outstanding
Long-term Debt, Gross
MVP Holdco Project
MVP Holdco Project [Member]
MVP Holdco Project
Threshold percentage of consideration payable trigger, redemption covenant
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger, Redemption Covenant
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger, Redemption Covenant
Convertible common stock, consecutive trading days
Sale Of Units, Convertible Common Stock, Threshold Consecutive Trading Days
Sale Of Units, Convertible Common Stock, Threshold Consecutive Trading Days
Cash flows from investing activities:
Net Cash Provided by (Used in) Investing Activities [Abstract]
Document Transition Report
Document Transition Report
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Abstract]
Carrying value of series A preferred units
Partners' Capital
Total liabilities, mezzanine equity and shareholders' equity
Liabilities and Equity
AFUDC — equity
Equity Method Investment, Summarized Financial Information, Allowance For Funds Used During Construction, Capitalized Cost Of Equity
Equity Method Investment, Summarized Financial Information, Allowance For Funds Used During Construction, Capitalized Cost of Equity
Contract liability, current
Contract with Customer, Liability, Current
Scenario [Axis]
Scenario [Axis]
Noncontrolling interests
Partners' Capital Attributable to Noncontrolling Interest
2021 Senior Notes
2021 Senior Notes [Member]
2021 Senior Notes
LIABILITIES, MEZZANINE EQUITY AND SHAREHOLDERS' EQUITY
Liabilities and Equity [Abstract]
Accounts payable
Increase (Decrease) in Accounts Payable
Earnings Per Share
Earnings Per Share [Text Block]
Debt Covenant Period [Domain]
Debt Covenant Period [Domain]
Debt Covenant Period [Domain]
Operating income:
Operating Expenses [Abstract]
Ownership interest
Equity Method Investment, Ownership Percentage
Condensed Consolidated Balance Sheets
Equity Method Investment, Summarized Financial Information [Abstract]
Minimum
Minimum [Member]
Schedule of Segment Assets
Reconciliation of Assets from Segment to Consolidated [Table Text Block]
Other assets and other liabilities
Increase (Decrease) in Other Operating Assets and Liabilities, Net
Affiliated Entity
EES
Affiliated Entity [Member]
Cash payment to be made in exchange for fee relief
Oil And Gas, Cash Payment To Be Made In Exchange For Fee Relief
Oil And Gas, Cash Payment To Be Made In Exchange For Fee Relief
Schedule of Revenues from External Customers and Long-Lived Assets [Table]
Schedule of Revenues from External Customers and Long-Lived Assets [Table]
Threshold percentage of consideration payable trigger
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger
Less: Comprehensive income attributable to noncontrolling interests
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest
Water
Water revenues supported by MVCs
Water Services [Member]
Water Services [Member]
Selling, general and administrative
Selling, General and Administrative Expense
Debt issuance costs
Debt Issuance Costs, Net
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]
Redemption of EQM Series A Preferred Units
Stock Redeemed or Called During Period, Value
Payments for redemption of preferred limited partners units
Payments For Redemption Of Preferred Limited Partners Units
Payments For Redemption Of Preferred Limited Partners Units
Cumulative Effect, Period of Adoption [Axis]
Cumulative Effect, Period of Adoption [Axis]
Trading Symbol
Trading Symbol
Amounts recorded during the period
Contract With Customer, Liability, Amount Recorded During Period
Contract With Customer, Liability, Amount Recorded During Period
Current liabilities:
Liabilities, Current [Abstract]
Line of credit
Line of Credit [Member]
EQM Senior notes
Senior Notes [Member]
Level 3
Fair Value, Inputs, Level 3 [Member]
Dividends paid to common shareholders
Payments of Ordinary Dividends, Common Stock
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Other contractual commitments
Contractual Obligation
Letter of credit outstanding
Letters of Credit Outstanding, Amount
Weighted average remaining term
Contract With Customer, Weighted Average Remaining Term
Contract With Customer, Weighted Average Remaining Term
Common stock, no par value, 432,522 and 432,470 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively
Common Stock, Value, Issued
Disaggregation of Revenue
Disaggregation of Revenue [Line Items]
Contract with Customer, Basis of Pricing [Axis]
Contract with Customer, Basis of Pricing [Axis]
Other comprehensive income, net of tax:
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest [Abstract]
Basis of Presentation
Basis of Accounting, Policy [Policy Text Block]
Non-current assets
Assets, Noncurrent
Eureka Midstream Holdings, LLC
Eureka Midstream Holdings, LLC [Member]
Eureka Midstream Holdings, LLC [Member]
Long-Term Contract With Customer, Period Two
Long-Term Contract With Customer, Period Two [Member]
Long-Term Contract With Customer, Period Two
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss), Net of Tax
Accounts receivable, for doubtful accounts
Accounts Receivable, Allowance for Credit Loss, Current
Debt discounts, debt issuance costs and credit facility arrangement fees
Payments of Debt Issuance Costs
Net proceeds from offering
Proceeds from Issuance of Debt
Revenue recognized in excess of amounts invoiced
Revenue Recognized In Excess Of Amounts Received
Revenue Recognized In Excess Of Amounts Received
Ownership [Axis]
Ownership [Axis]
Document Period End Date
Document Period End Date
Common Stock, Cash Shares
Common Stock, Cash Shares [Member]
Common Stock, Cash Shares [Member]
Incremental common shares attributable to dilutive effect of share-based payment arrangements (in shares)
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements
Long-Lived Assets
Revenues from External Customers and Long-Lived Assets [Line Items]
Gathering
Gas Gathering Segment [Member]
Gas Gathering Segment [Member]
Total operating expenses
Costs and Expenses
Contract term
Related Party Transaction, Contract Term
Related Party Transaction, Contract Term
Class of Stock [Axis]
Class of Stock [Axis]
Entity Registrant Name
Entity Registrant Name
Equitrans Midstream Term Loans
Equitrans Midstream Term Loans [Member]
Equitrans Midstream Term Loans [Member]
Net interest expense
Interest Income (Expense), Net
Common Stock, Rate Relief Shares And Cash Shares
Common Stock, Rate Relief Shares And Cash Shares [Member]
Common Stock, Rate Relief Shares And Cash Shares [Member]
Percentage of ownership interest
Equity Method Investment, Ownership Percentage Threshold For Business Decisions
Equity Method Investment, Ownership Percentage Threshold For Business Decisions
Preferred Interest
Notes Receivable, Related Parties
Capital expenditures for segment assets
Payments to Acquire Productive Assets
Other current assets
Prepaid Expense and Other Assets, Current
Maximum amount of short term loans outstanding
Line of Credit Facility, Maximum Amount Outstanding During Period
Operating revenues
Revenue from Related Parties
Accrued liabilities
Accrued Liabilities, Current
Dividends declared per common share (in dollars per share)
Common Stock, Dividends, Per Share, Declared
Operating revenues
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax
6.00% Senior Notes Due July 1, 2025
6.00% Senior Notes Due July 1, 2025 [Member]
6.00% Senior Notes Due July 1, 2025
Net interest income
Equity Method Investment, Summarized Financial Information, Interest Income
Equity Method Investment, Summarized Financial Information, Interest Income
Capital contributions to the MVP Joint Venture
Payments to Acquire Interest in Joint Venture
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Axis]
Carrying Value
Reported Value Measurement [Member]
Consolidation Items [Domain]
Consolidation Items [Domain]
Equity [Abstract]
Equity [Abstract]
Measurement Input Type [Domain]
Measurement Input Type [Domain]
Partners' capital account, cumulative distributions
Partners' Capital Account, Cumulative Distributions
Partners' Capital Account, Cumulative Distributions
Common Stock
Common Stock [Member]
Financial Information by Business Segment
Segment Reporting Disclosure [Text Block]
Operating income
Total operating income
Operating Income (Loss)
Property, Plant and Equipment [Table]
Property, Plant and Equipment [Table]
Mezzanine Equity, Restructuring Agreement
Temporary Equity, Stock Issued During Period, Value, New Issues
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Abstract]
Non-cash long-term compensation expense
Share-based Payment Arrangement, Noncash Expense
Cash and cash equivalents
Cash and Cash Equivalents, at Carrying Value
Fees incurred for services
Related Party Transaction, Amounts of Transaction
Dividends (in dollars per share)
Common Stock, Dividends, Per Share, Cash Paid
Long-term Debt, Type [Domain]
Long-term Debt, Type [Domain]
Change in deferred taxes
Increase (Decrease) in Deferred Income Taxes
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]
Equity Method Investment, Nonconsolidated Investee [Axis]
Equity Method Investment, Nonconsolidated Investee [Axis]
Proceeds from revolving credit facility borrowings
Proceeds from Lines of Credit
Capital contributions payable to the MVP Joint Venture
Capital Contribution Payable
Capital Contribution Payable
Long-term debt
Long-term Debt, Fair Value
Share Purchase Agreements (as defined in Note 5) (in shares)
Stock Repurchased and Retired During Period, Shares
Capital expenditures
Payments to Acquire Property, Plant, and Equipment
Valuation Approach and Technique [Axis]
Valuation Approach and Technique [Axis]
Partial Period Distributions on EQM Series A Preferred Units converted in the EQM Merger
Partners' Capital Account, Distributions
Issuance of performance guarantee, remaining capital obligation, percentage
Issuance Of Performance Guarantee, Remaining Capital Obligation, Percentage
Issuance Of Performance Guarantee, Remaining Capital Obligation, Percentage
Investments in Consolidated, Non-Wholly Owned Entities
Partners' Capital Notes Disclosure [Text Block]
Issuance of Equitrans Midstream common stock pursuant to the EQM Merger (as defined in Note 2), net of tax
Issuance of Equitrans Midstream Preferred Shares pursuant to the Restructuring Agreement (as defined in Note 2)
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
Maximum
Maximum [Member]
Capital Unit, Class [Domain]
Capital Unit, Class [Domain]
Total liabilities
Liabilities
MVP Project
MVP Project [Member]
MVP Project [Member]
Legal Entity [Axis]
Legal Entity [Axis]
Mezzanine Equity, Net income (loss)
Temporary Equity, Net Income
Accounts receivable
Increase (Decrease) in Receivables
Award Type [Axis]
Award Type [Axis]
Cash flows from financing activities:
Net Cash Provided by (Used in) Financing Activities [Abstract]
Equitrans Midstream Preferred Shares, 30,018 shares issued and outstanding as of September 30, 2020 and December 31, 2020, respectively.
Mezzanine Equity, beginning balance
Mezzanine Equity, ending balance
Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests
Measurement Input Type [Axis]
Measurement Input Type [Axis]
Consolidation Items [Axis]
Consolidation Items [Axis]
Total common shareholders' equity
Stockholders' Equity Attributable to Parent
Conversion price (in usd per share)
Conversion Price
Conversion Price
Common stock, shares issued (in shares)
Common Stock, Shares, Issued
Investments in Unconsolidated Entity
Equity Method Investments and Joint Ventures Disclosure [Text Block]
Share Purchase Agreement
Share Purchase Agreement [Member]
Share Purchase Agreement [Member]
Payment for retirement of long-term debt
Repayments of Senior Debt
Loss on extinguishment of debt
Gain (Loss) on Extinguishment of Debt
Long-Term Contract With Customer, Period One
Long-Term Contract With Customer, Period One [Member]
Long-Term Contract With Customer, Period One
Cash Shares and Cash Amount (as defined in Note 5)
Payments for Repurchase of Common Stock
Net income
Net Income (Loss), Including Portion Attributable to Noncontrolling interest, Excluding Temporary Equity
Net Income (Loss), Including Portion Attributable to Noncontrolling interest, Excluding Temporary Equity
Derivative instrument, at fair value
Derivative Asset, Noncurrent
Fair Value, Measurement Frequency [Domain]
Measurement Frequency [Domain]
Principal
Debt Instrument, Face Amount
After June 30, 2021 and prior to September 30, 2022
Debt Covenant Period One [Member]
Debt Covenant Period One
Operating and maintenance
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses
Amortization
Capitalized Contract Cost, Amortization
City Area Code
City Area Code
Retained deficit
Retained Earnings (Accumulated Deficit)
Equitrans Preferred Shares
Equitrans Preferred Shares [Member]
Equitrans Preferred Shares
Operating segments
Operating Segments [Member]
EQM Midstream Partners, LP
EQM
EQM Midstream Partners, LP [Member]
EQM Midstream Partners, LP [Member]
Statement of Stockholders' Equity [Abstract]
Statement of Stockholders' Equity [Abstract]
Schedule of Unaudited Condensed Financial Statements for the Investment in Unconsolidated Equity
Equity Method Investments [Table Text Block]
Pension and other post-retirement benefits liability adjustment, net of tax expense
Other Comprehensive (Income) Loss, Including Reclassification From AOCI To Retained Earnings, After Tax
Other Comprehensive (Income) Loss, Including Reclassification From AOCI To Retained Earnings, After Tax
EQT Corporation and Subsidiaries
EQT Corporation and Subsidiaries [Member]
Represents information pertaining to EQT Corporation and subsidiaries.
Income Statement [Abstract]
Income Statement [Abstract]
Amendment Flag
Amendment Flag
Threshold amount of stock price trigger (in shares)
Convertible Common Stock, Threshold Amount Of Stock Price Trigger, Units
Convertible Common Stock, Threshold Amount Of Stock Price Trigger, Units
Fair Value
Estimate of Fair Value Measurement [Member]
Payments on revolving credit facility borrowings
Repayments of Lines of Credit
Related Party Transaction [Axis]
Related Party Transaction [Axis]
Beginning balance
Ending balance
Equity
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest
Income tax expense
Income Tax Expense (Benefit)
2020 Senior Notes
2020 Senior Notes [Member]
2020 Senior Notes
Unsecured Debt
Unsecured Debt [Member]
Proceeds from the issuance of long-term debt
Proceeds from Issuance of Long-term Debt
Interest income from the preferred interest in EQT Energy Supply, LLC (the Preferred Interest)
Less: EQM Series A Preferred Units interest in net income
Interest Income, Related Party
Equity Components [Axis]
Equity Components [Axis]
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Abstract]
Total current assets
Current assets
Assets, Current
Disaggregation of Revenue [Table]
Disaggregation of Revenue [Table]
Sale of Stock [Domain]
Sale of Stock [Domain]
Investment cap
Equity Method Investments, Capped Investment
Equity Method Investments, Capped Investment
Beneficial Owner
Beneficial Owner [Member]
Schedule of Revenue from External Customers and Operating Income and Reconciliation to Net Income
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Schedule of Stock by Class [Table]
Schedule of Stock by Class [Table]
Entity File Number
Entity File Number
Equity Method Investment, Nonconsolidated Investee [Domain]
Equity Method Investment, Nonconsolidated Investee [Domain]
Number of shares purchased
Stock Repurchased During Period, Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures [Abstract]
Capital Units by Class [Axis]
Capital Units by Class [Axis]
Statement of Financial Position [Abstract]
Statement of Financial Position [Abstract]
Other income
Other Nonoperating Income
Schedule of Related Party Transactions
Schedule of Related Party Transactions [Table Text Block]
Current portion of revolving credit facility borrowings
Long-term Debt, Current Maturities
Product and Service [Axis]
Product and Service [Axis]
Threshold trading days
Sale Of Units, Convertible Common Stock, Threshold Trading Days
Sale Of Units, Convertible Common Stock, Threshold Trading Days
Entity Incorporation, State or Country Code
Entity Incorporation, State or Country Code
Small Business Entity
Entity Small Business
Market quoted volatility
Valuation, Market Approach [Member]
Equity Component [Domain]
Equity Component [Domain]
Number of shares purchased (in shares)
Stock Repurchased During Period, Shares
Increase (Decrease) in Partners' Capital
Increase (Decrease) in Partners' Capital [Roll Forward]
Schedule of Equity Method Investments [Table]
Schedule of Equity Method Investments [Table]
Statement
Statement [Line Items]
Revolving credit facility borrowings
Letters of credit outstanding
Long-term Line of Credit, Noncurrent
Contract liability
Increase (Decrease) in Contract with Customer, Liability
Impairment of intangible assets
Impairment of Intangible Assets, Finite-lived
Total
Revenue, Remaining Performance Obligation, Amount
Counterparty Name [Domain]
Counterparty Name [Domain]
Accrued interest
Interest and Dividends Payable, Current
Debt Disclosure [Abstract]
Debt Disclosure [Abstract]
Volumetric-based fee revenues
Gathering firm reservation fees
Time-and-materials Contract [Member]
EQM 4.75% Senior Notes Due 2023
EQM 4.75% Senior Notes Due 2023 [Member]
EQM 4.75% Senior Notes Due 2023 [Member]
Fair Value Measurements
Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block]
Entity Address, State or Province
Entity Address, State or Province
Preferred interest
Notes Receivable, Fair Value Disclosure
Level 2
Fair Value, Inputs, Level 2 [Member]
Pension and other post-retirement benefits liability adjustments, tax expense
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax, Attributable to Parent
Firm reservation capacity, step up per day
Oil And Gas, Minimum Volume To Provide Step Up Amount
Oil And Gas, Minimum Volume To Provide Step Up Amount
Contract liability
Contract liability, noncurrent
Contract with Customer, Liability, Noncurrent
Total shareholders' equity
Partners' Capital, Including Portion Attributable to Noncontrolling Interest
Gain on derivative instrument
Derivative, Gain (Loss) on Derivative, Net
Headquarters
Corporate, Non-Segment [Member]
Segment Reporting [Abstract]
Segment Reporting [Abstract]
Entity [Domain]
Entity [Domain]
6.50% Senior Note Due July 1, 2027
6.50% Senior Note Due July 1, 2027 [Member]
6.50% Senior Note Due July 1, 2027
Customer [Axis]
Customer [Axis]
Cash distributions declared (in dollars per unit)
Distribution Made to Limited Partner, Distributions Declared, Per Unit
Mezzanine equity:
Temporary Equity [Abstract]
Maximum consolidated interest ratio
Debt Instrument, Covenant, Consolidated Interest Ratio, Maximum
Debt Instrument, Covenant, Consolidated Interest Ratio, Maximum
Long-term debt
Senior Notes, Noncurrent
Schedule of Earnings Per Share, Basic and Diluted
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Entity Shell Company
Entity Shell Company
Local Phone Number
Local Phone Number
Scenario, Forecast
Forecast [Member]
Reconciliation of operating income to net income:
Reconciliation of Operating Income to Net Income [Abstract]
Total assets
Total assets
Assets
Investment, Name [Domain]
Investment, Name [Domain]
Deferred income taxes
Deferred Income Taxes and Tax Credits
Distributions to Eureka Midstream Holdings, LLC non-controlling member
Payments to Noncontrolling Interests
Interest, net of amount capitalized
Interest Paid, Excluding Capitalized Interest, Operating Activities
Net income attributable to Equitrans Midstream common shareholders
Net income attributable to Equitrans Midstream common shareholders
Net Income (Loss) Available to Common Stockholders, Basic
Product and Service [Domain]
Product and Service [Domain]
Noncontrolling Interests
Noncontrolling Interest [Member]
Interest rate
Debt Instrument, Interest Rate, Stated Percentage
Derivative Contract [Domain]
Derivative Contract [Domain]
Convertible units
Sale Of Units, Convertible Common Stock, Minimum Convertible Amount
Sale Of Units, Convertible Common Stock, Minimum Convertible Amount
Contract with Customer, Basis of Pricing [Domain]
Contract with Customer, Basis of Pricing [Domain]
Net income attributable to noncontrolling interests
Less: Net income attributable to noncontrolling interests
Net Income (Loss) Attributable to Noncontrolling Interest
Revolving Credit Facility
Revolving Credit Facility [Member]
Payment commitment fees
Payment Of Debt Commitment Fees
Payment Of Debt Commitment Fees
EQM Merger
EQM Merger [Member]
EQM Merger [Member]
Remaining performance obligations, expected timing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Cumulative Effect, Period of Adoption [Domain]
Cumulative Effect, Period of Adoption [Domain]
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Measurement Frequency [Axis]
Measurement Frequency [Axis]
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
Fair Value Measurements, Recurring and Nonrecurring [Table]
Fair Value, Recurring and Nonrecurring [Table]
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-term Debt Instruments [Table]
Entity Tax Identification Number
Entity Tax Identification Number
Estimated aggregate fee relief, year two
Oil And Gas, Estimated Aggregate Fee Relief, Year Two
Oil And Gas, Estimated Aggregate Fee Relief, Year Two
Weighted average common shares outstanding - basic (in shares)
Weighted Average Number of Shares Outstanding, Basic
Earnings per share of common stock attributable to Equitrans Midstream common shareholders - diluted (in dollars per share)
Earnings Per Share, Diluted
Segments [Domain]
Segments [Domain]
Contract with Customer, Duration [Axis]
Contract with Customer, Duration [Axis]
Purchase price (in usd per share)
Sale of Stock, Price Per Share
Dilutive securities (in shares)
Weighted Average Number Diluted Shares Outstanding Adjustment
Investment in unconsolidated entity
Investment in unconsolidated entity
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Accounting Standards Update [Extensible List]
Accounting Standards Update [Extensible Enumeration]
Change in Contract with Customer, Liability
Change in Contract with Customer, Liability [Roll Forward]
Change in Contract with Customer, Liability
4.50% Senior Notes Due 2029
4.50% Senior Notes Due 2029 [Member]
4.50% Senior Notes Due 2029
Threshold percentage of consideration payable trigger, volume weighted average price covenant
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger, Volume Weighted Average Price Covenant
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger, Volume Weighted Average Price Covenant
Net intangible assets
Intangible Assets, Net (Excluding Goodwill)
Comprehensive income attributable to Equitrans Midstream common shareholders
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Balance as of beginning of period
Balance as of end of period
Contract liability
Contract with Customer, Liability
Firm reservation fee revenues
Fixed-price Contract [Member]
Net cash used in financing activities
Net Cash Provided by (Used in) Financing Activities
EQM Merger (in shares)
Stock Issued During Period, Shares, Merger
Stock Issued During Period, Shares, Merger
Deferred income tax liability
Deferred Income Tax Liabilities, Net
Related Party Transaction
Related Party Transaction [Line Items]
Equity income
Equity income
Equity income
Income (Loss) from Equity Method Investments
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Limited partner ownership interest
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest
Accounts payable
Accounts Payable, Current
Impairment of long-lived assets
Impairments of long-lived assets
Impairment, Long-Lived Asset, Held-for-Use
Depreciation
Depreciation
Depreciation, Depletion and Amortization
Estimated aggregate fee relief, year one
Oil And Gas, Estimated Aggregate Fee Relief, Year One
Oil And Gas, Estimated Aggregate Fee Relief, Year One
4.75% Senior Notes Notes Due 2031
4.75% Senior Notes Notes Due 2031 [Member]
4.75% Senior Notes Notes Due 2031
Dividends on common shares
Dividends, Common Stock
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent [Member]
Commitment fees
Debt Related Commitment Fees and Debt Issuance Costs
Balance as of beginning of period
Balance as of end of period
Contract with Customer, Asset, after Allowance for Credit Loss
Convertible Preferred Stock
Convertible Preferred Stock [Member]
Common stock, shares outstanding (in shares)
Beginning balance (in shares)
Ending balance (in shares)
Shares owned (in shares)
Common Stock, Shares, Outstanding
Term Loans
Term Loans [Member]
Term Notes [Member]
Increase (Decrease) in Mezzanine Equity
Increase (Decrease) in Temporary Equity [Roll Forward]
Redemption of EQM Series A Preferred Units (as defined in Note 2)
Payments for Repurchase of Convertible Preferred Stock
Revenues from customers:
Revenues [Abstract]
Number of reporting units
Number of Reporting Units
Dividends on common shares ($0.45 per share) (in shares)
Common Stock Dividends, Shares
Movement in Deferred Revenue [Roll Forward]
Movement in Deferred Revenue [Roll Forward]
Summary of Remaining Performance Obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]
Consolidated Entities [Domain]
Consolidated Entities [Domain]
Merger related cost
Noncash Merger Related Costs
Mezzanine equity, preferred shares issued (in shares)
Temporary Equity, Shares Issued
EQT Midstream Partners LP
EQT Midstream Partners LP [Member]
EQT Midstream Partners LP [Member]
Net property, plant and equipment
Property, Plant and Equipment, Net
Impairments of Long-Lived Assets
Property, Plant and Equipment Disclosure [Text Block]
MVP Joint Venture
MVP Joint Venture [Member]
MVP Joint Venture [Member]
Water Services Letter Agreement
Water Services Letter Agreement [Member]
Water Services Letter Agreement [Member]
Regulatory and other long-term liabilities
Other Liabilities, Noncurrent
Average daily balance of short term loans outstanding
Line of Credit Facility Average Daily Amount Outstanding
Represents the amount of average daily balance outstanding under credit facility.
Debt Instrument
Debt Instrument [Line Items]
Earnings Per Share [Abstract]
Earnings Per Share [Abstract]
Property, plant and equipment
Property, Plant and Equipment, Gross
Related Party Transaction [Domain]
Related Party Transaction [Domain]
Document Quarterly Report
Document Quarterly Report
Premium recognized on redemption
Preferred Stock Redemption Premium
Volatility rate
Derivative Asset, Measurement Input
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Operating expenses:
Costs and Expenses [Abstract]
Increase in quarterly distribution, percent
Incentive Distribution Quarterly Distribution Increasing Percentage Entitlement Level One
Represents the level one of the increasing percentage entitlement of incentive distribution.
Mezzanine Equity, Dividends paid to holders of Equitrans Midstream Preferred Shares
Temporary Equity, Distributions
Temporary Equity, Distributions
Schedule of Related Party Transactions, by Related Party [Table]
Schedule of Related Party Transactions, by Related Party [Table]
Schedule of Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Number of share purchase agreements
Number Of Share Purchase Agreements
Number Of Share Purchase Agreements
Threshold percentage of consideration payable trigger, conversion ratio
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger, Conversion Ratio
Convertible Common Stock, Threshold Percentage Of Consideration Payable Trigger, Conversion Ratio
Document Fiscal Period Focus
Document Fiscal Period Focus
Contract with Customer, Duration [Domain]
Contract with Customer, Duration [Domain]
Effective tax rate
Effective Income Tax Rate Reconciliation, Percent
Series A Preferred Units
Series A Preferred Stock [Member]
Net income
Net income
Net income
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Accounts receivable (net of allowance for credit losses of $2,955 and $4,699 as of September 30, 2021 and December 31, 2020, respectively)
Accounts Receivable, before Allowance for Credit Loss, Current
Counterparty Name [Axis]
Counterparty Name [Axis]
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Current assets:
Assets, Current [Abstract]
Statement of comprehensive income:
Statement of Comprehensive Income [Abstract]
Entity Central Index Key
Entity Central Index Key
Security Exchange Name
Security Exchange Name
Eureka Credit Facility
Eureka Credit Facility [Member]
Eureka Credit Facility [Member]
Weighted average common shares outstanding - diluted (in shares)
Weighted average common stock outstanding - diluted (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Other comprehensive income
Other Comprehensive Income (Loss), Net of Tax
Fair Value, Measurements, Recurring
Fair Value, Recurring [Member]
Principal payments received on the Preferred Interest (as defined in Note 6)
Principal payments received on the Preferred Interest
Proceeds from Collection of Notes Receivable
Income Taxes
Income Tax Disclosure [Text Block]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Axis]
Related Party [Domain]
Related Party [Domain]
Current Fiscal Year End
Current Fiscal Year End Date
Maximum consolidated leverage ratio
Debt Instrument, Covenant, Consolidated Leverage Ratio, Maximum
Debt Instrument, Covenant, Consolidated Leverage Ratio, Maximum
Measurement Basis [Axis]
Measurement Basis [Axis]
Statement of Cash Flows [Abstract]
Statement of Cash Flows [Abstract]
Maximum financial statement exposure
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount
Capital contributions to the MVP Joint Venture
Capital contributions to the MVP Joint Venture
Payments to Acquire Equity Method Investments
Estimated aggregate fee relief, year three
Oil And Gas, Estimated Aggregate Fee Relief, Year Three
Oil And Gas, Estimated Aggregate Fee Relief, Year Three
Class of Stock
Class of Stock [Line Items]
Credit Facility [Axis]
Credit Facility [Axis]
Net cash used in investing activities
Net Cash Provided by (Used in) Investing Activities
Portion at Fair Value Measurement
Portion at Fair Value Measurement [Member]
Changes in other assets and liabilities:
Increase (Decrease) in Operating Capital [Abstract]
Less: accumulated depreciation
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment
Cash flows from operating activities:
Net Cash Provided by (Used in) Operating Activities [Abstract]
Redemption percentage rate
Equity Instrument, Redemption Rate Percentage
Equity Instrument, Redemption Rate Percentage
Henry Hub cash payment
Other Contract [Member]
Financial Statements
Business Description and Accounting Policies [Text Block]
Series A Preferred Units
Series A Preferred Units [Member]
Series A Preferred Units [Member]
Total current liabilities
Current liabilities
Liabilities, Current
Class of Stock [Domain]
Class of Stock [Domain]
Distributions paid to holders of EQM Series A Preferred Units
Dividends paid to holders of Equitrans Midstream Preferred Shares
Payments of Ordinary Dividends, Preferred Stock and Preference Stock
Restructuring Agreement
Redemptions
Partners' Capital Account, Redemptions
Maximum borrowing capacity
Line of Credit Facility, Maximum Borrowing Capacity
Public Owned
Public Owned [Member]
Public Owned [Member]
2019 Term Loan Facility
2019 Term Loan Facility [Member]
2019 Term Loan Facility
Segment Information
Segment Reporting Information [Line Items]
Ownership [Domain]
Ownership [Domain]
Entity Address, Postal Zip Code
Entity Address, Postal Zip Code
Minimum volume commitments invoiced
Contract with Customer, Asset, Reclassified to Receivable
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Title of 12(b) Security
Title of 12(b) Security
Statement [Table]
Statement [Table]
Option to forgo fee relief, year one
Oil And Gas, Option To Forgo Fee Relief, Year One
Oil And Gas, Option To Forgo Fee Relief, Year One
Impairment of property and equipment
Impairment of Oil and Gas Properties
Shareholders' equity:
Partners' Capital [Abstract]
Recently Issued Accounting Standards
New Accounting Pronouncements, Policy [Policy Text Block]
Option to forgo fee relief, year two
Oil And Gas, Option To Forgo Fee Relief, Year Two
Oil And Gas, Option To Forgo Fee Relief, Year Two
MVP Southgate Project
MVP Southgate Project [Member]
MVP Southgate Project [Member]
Statistical Measurement [Axis]
Statistical Measurement [Axis]
Number of lines of business
Number Of Lines Of Business
Number Of Lines Of Business
Subsequent Event
Subsequent Event [Member]
Cover [Abstract]
Cover [Abstract]
Preferred Stock
Preferred Stock [Member]
Goodwill
Goodwill
Transmission
Transmission firm reservation fees
Gas Transmission Segment [Member]
Gas Transmission Segment [Member]
Volatility
Measurement Input, Price Volatility [Member]
Write off of debt issuance cost
Write off of Deferred Debt Issuance Cost
Capitalized share-based compensation cost
Share-based Payment Arrangement, Accrued and Assumed Capital Expenses, Amount
Share-based Payment Arrangement, Accrued and Assumed Capital Expenses, Amount
Scenario, Unspecified [Domain]
Scenario [Domain]
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Subsequent Event Type [Axis]
Subsequent Event Type [Axis]
Phantom Share Units (PSUs)
Phantom Share Units (PSUs) [Member]
Related Party Transactions
Related Party Transactions Disclosure [Text Block]
Discount
Debt Instrument, Unamortized Discount
Con Edison
ConEdison [Member]
ConEdison [Member]
Weighted average annual interest rate
Line of Credit Facility, Interest Rate During Period
Schedule of Depreciation and Amortization and Expenditures for Segment Assets
Schedule of Segment Reporting Information, Depreciation Depletion Amortization and Expenditures for Segment Assets [Table Text Block]
Tabular disclosure of depreciation, depletion and amortization expense and expenditures for segment assets.
Debt
Long-term Debt [Text Block]
Accounting Standards Update 2016-13 [Member]