Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Accounting, Policy Basis of Accounting, Policy [Policy Text Block] Leases [Abstract] 2019 Finance Lease, Liability, Payments, Remainder of Fiscal Year 2020 Finance Lease, Liability, Payments, Due Year Two 2021 Finance Lease, Liability, Payments, Due Year Three 2022 Finance Lease, Liability, Payments, Due Year Four 2023 Finance Lease, Liability, Payments, Due Year Five Thereafter Finance Lease, Liability, Payments, Due after Year Five Total Finance Lease, Liability, Payments, Due Less: discount Finance Lease, Liability, Undiscounted Excess Amount Total finance lease liabilities Finance Lease, Liability Statement of Partners' Capital [Abstract] Statement [Table] Partner Type [Axis] Partner Type [Axis] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Limited Partner Limited Partner [Member] General Partner General Partner [Member] Partners' Capital General Partner and Limited Partner [Member] Parties who together hold 100% interest in the partnership – General Partner interest 51%; Limited Partner interest 49% Partner Capital Components [Axis] Partner Capital Components [Axis] Partner Capital Components [Domain] Partner Capital Components [Domain] Accumulated Other Comp Income (Loss) AOCI Attributable to Parent [Member] Class of Stock [Axis] Class of Stock [Domain] Common Units Common Units [Member] The capital account balance of the limited partners outstanding common units. The limited partners are partners of a publicly traded limited partnership or master limited partnership. Limited partners have limited liability and do not manage the partnership. Statement [Line Items] Statement [Line Items] Increase (Decrease) in Partners' Capital [Roll Forward] Add (deduct): Adjustments to Additional Paid in Capital [Abstract] Beginning balance Partners' Capital, Including Portion Attributable to Noncontrolling Interest Beginning balance Partners' Capital Cumulative effect adjustment from the implementation of ASC 606 Cumulative Effect of New Accounting Principle in Period of Adoption Net income Net Income (Loss) Attributable to Parent Distributions paid Partners' Capital Account, Distributions Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax Ending balance Ending balance Revenue, Performance Obligation Satisfied over Time [Abstract] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Estimated revenues from contracts with customers from unsatisfied performance obligations as of March 31, 2019 Revenue, Remaining Performance Obligation, Amount Operating revenues which are fixed and determinable (operating leases) Operating Leases, Future Minimum Lease Revenues The total amount of future minimum lease revenues to be recognized in future periods under leasing arrangements for which the lessee is obligated. Total projected operating revenues under committed firm agreements Committed Firm Agreements Projected operating revenues under committed firm agreements. Fixed Fee Revenues Recognized Fixed Fee Revenues Recognized Fixed fee revenues recognized during the period included in projected operating revenues under committed firm agreements. Gas Balancing Arrangements [Abstract] Gas and Liquids Stored Underground and Gas and NGLs Receivables and Payables, Policy Gas Balancing Arrangements, Policy [Policy Text Block] Percent of General Partner Interest Owned by Holding Company (in hundredths) Percent of General Partner Interest Owned by Holding Company The percent of the general partner interest owned by the holding company. Commitments and Contingencies Disclosure [Abstract] Purchase Commitment, Remaining Minimum Amount Committed Purchase Commitment, Remaining Minimum Amount Committed Fair Value Disclosures [Abstract] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Carrying Amount Reported Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Cash and Cash Equivalents - Fair Value Cash and Cash Equivalents, Fair Value Disclosure Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Debt Instrument, Fair Value Disclosure Debt Instrument, Fair Value Disclosure Finance Lease, Liability, Noncurrent Finance Lease, Liability, Noncurrent Unamortized Debt Issuance Expense Unamortized Debt Issuance Expense Fair Value of Financial Instruments, Policy Fair Value of Financial Instruments, Policy [Policy Text Block] Gas Balancing Measurement (in MMBtu) Gas Balancing Measurement (in MMBtu) The amount of gas imbalance in terms of measure (MMBtu) as of the end of the period. Average Market Price of Gas Assumed Average Market Price Of Gas Assumed Average market price of natural gas assumed during the month prior to the balance sheet date and used to calculate the total market value of (1) gas held in storage on behalf of customers, and (2) gas owed to operating subsidiaries due to gas imbalances and gas loaned under parking and lending agreements. Gas Imbalance to Subsidiaries Asset Liability Gas Imbalance To Subsidiaries Asset Liability The value of related party gas balancing asset or liability as of the end of the period Natural Gas Liquids Balancing Volume (in MMBbls) (Less than) Natural Gas Liquids Balancing Volume The amount of natural gas liquids imbalance in terms of measure (MMbbls) as of the end of the period. Natural Gas Liquids Imbalance to Subsidiaries Asset Liability Natural Gas Liquids Imbalance to Subsidiaries Asset Liability The value of Natural Gas Liquids balancing asset or liability as of the end of the period. Accounting Policies [Abstract] Right-of-use assets obtained in exchange for lease obligations Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Operating lease liabilities Operating Lease, Liability Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Revenue from Contract with Customer [Abstract] Revenues from Contracts with Customers Revenue from Contract with Customer [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Right-of-use assets operating leases Operating Lease, Right-of-Use Asset Right-of-use assets finance lease Finance Lease, Right-of-Use Asset Finance lease liabilities Operating lease, weighted average remaining lease term (years) Operating Lease, Weighted Average Remaining Lease Term Finance lease, weighted average remaining lease term (years) Finance Lease, Weighted Average Remaining Lease Term Operating lease, weighted average discount rate, percent Operating Lease, Weighted Average Discount Rate, Percent Finance lease, weighted average discount rate, percent Finance Lease, Weighted Average Discount Rate, Percent Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Supplemental Cash Flow Elements [Abstract] Cash paid during the period for: Interest Paid, Including Capitalized Interest, Operating and Investing Activities [Abstract] Interest (net of amount capitalized) Interest Paid, Excluding Capitalized Interest, Operating Activities Non-cash adjustments: Other Noncash Investing and Financing Items [Abstract] Accounts payable and property, plant and equipment Capital Expenditures Incurred but Not yet Paid Statement of Cash Flows [Abstract] Statement [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to cash provided by operations: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Amortization of deferred costs and other Amortization of Deferred Charges Gain on sale of assets and impairments Gain (Loss) on Sale of Assets and Asset Impairment Charges Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Trade and other receivables Increase (Decrease) in Accounts and Other Receivables Gas receivables and storage assets Increase (Decrease) in Gas Balancing Receivable Costs recoverable from customers Increase (Decrease) in Other Regulatory Assets Other assets Increase (Decrease) in Other Operating Assets Trade and other payables Increase (Decrease) in Accounts Payable Gas payables Increase (Decrease) in Balancing Account, Utility Accrued liabilities Increase (Decrease) in Accrued Liabilities Other liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Proceeds from sale of operating assets Proceeds from Sale of Productive Assets Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing Activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from borrowings on revolving credit agreement Proceeds from Long-term Lines of Credit Repayment of borrowings on revolving credit agreement Repayments of Long-term Lines of Credit Principal payment of finance lease obligation Finance Lease, Principal Payments Distributions paid Payments of Ordinary Dividends, Common Stock Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of period Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Boardwalk GP, LP Boardwalk GP, LP [Member] Boardwalk GP, LP [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Related Party Transaction, Expenses from Transactions with Related Party Cash dividends paid to parent company SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees 2019 Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total Lessee, Operating Lease, Liability, Payments, Due Less: discount Lessee, Operating Lease, Liability, Undiscounted Excess Amount Total operating lease liabilities Condensed Financial Information Disclosure [Abstract] Condensed Consolidating Balance Sheet Condensed Balance Sheet [Table Text Block] Condensed Consolidating Statements of Income Condensed Income Statement [Table Text Block] Condensed Consolidating Statements Of Comprehensive Income Condensed Statement of Comprehensive Income [Table Text Block] Condensed Consolidating Statements of Cash Flows Condensed Cash Flow Statement [Table Text Block] Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Reportable Legal Entities Reportable Legal Entities [Member] Eliminations Consolidation, Eliminations [Member] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Parent Guarantor Parent Company [Member] Subsidiary Issuer Subsidiary Issuer [Member] Non-Guarantor Subsidiaries Non-Guarantor Subsidiaries [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Statement of Cash Flows Net cash provided by (used in) operating activities Advances to affiliates, net Payments for (Proceeds from) Other Investing Activities Net cash provided by (used in) investing activities Repayment of borrowings on revolving credit agreement Advances from affiliates, net Proceeds from (Payments for) Other Financing Activities Net cash (used in) provided by financing activities (Decrease) increase in cash and cash equivalents Net income (loss) Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Reclassification adjustment transferred to Net income from cash flow hedges Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Pension and other postretirement benefit costs, net of tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Total Comprehensive Income (Loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Lessee, Finance Leases Lessee, Finance Leases [Text Block] Lessee, Operating Leases Lessee, Operating Leases [Text Block] Lessee Finance Lease Description Lessee, Finance Lease, Description Lessee, Finance Lease, Term of Contract Lessee, Finance Lease, Term of Contract Lessee, Finance Lease, Renewal Term Lessee, Finance Lease, Renewal Term Operating Revenues: Revenues [Abstract] Transportation Transportation Revenue Revenue derived from the regulated generation, transmission and distribution of natural gas. Storage, parking and lending Storage, Parking And Lending Revenue Revenues related to providing storage, parking and lending services to customers. Other Other Revenue Operating revenue other than transportation and storage, parking and lending. Total operating revenues Revenues Operating Costs and Expenses: Operating Costs and Expenses [Abstract] Fuel and transportation Cost of Domestic Regulated Gas Revenue Operation and maintenance Utilities Operating Expense, Maintenance and Operations Administrative and general General and Administrative Expense Other operating costs and expenses Other Cost and Expense, Operating Total operating costs and expenses Operating Expenses Operating (loss) income Operating Income (Loss) Other Deductions (Income): Interest and Debt Expense [Abstract] Interest expense Interest Expense Interest income - affiliates, net Interest Income, Related Party Interest expense - affiliates, net Interest Expense, Related Party Interest income Investment Income, Interest Equity in earnings of subsidiaries Equity in earnings of subsidiaries This is the equity in earnings of subsidiaries. This element is eliminated on consolidation. Miscellaneous other income, net Other Nonoperating Income (Expense) Total other (income) deductions Nonoperating Income (Expense) Income (loss) before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income taxes Income Tax Expense (Benefit) Schedule of Cash Flow, Supplemental Disclosures Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Retirement Benefits [Abstract] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Retirement Plans Pension Plan [Member] PBOP Other Postretirement Benefits Plan [Member] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of unrecognized net loss Defined Benefit Plan, Amortization of Gain (Loss) Settlement charge Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Defined Benefit Plan, Plan Assets, Contributions by Employer Defined Benefit Plan, Plan Assets, Contributions by Employer Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Defined Contribution Plan, Cost Lease Accounting Pronouncements, Policy New Accounting Pronouncements, Policy [Policy Text Block] Supplemental Disclosure of Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Components of Lease Cost Lease, Cost [Table Text Block] Schedule of Supplemental Balance Sheet Information Related To Leases Schedule of Supplemental Balance Sheet Information Related to Leases [Table Text Block] Schedule of supplemental balance sheet information related to leases. Maturity of Operating Lease Liabilities Lessee, Operating Lease, Liability, Maturity [Table Text Block] Maturity of Finance Lease Liabilities Finance Lease, Liability, Maturity [Table Text Block] Operating Leases of Lessee Lessee, Operating Lease, Disclosure [Table Text Block] Employee Benefits Pension and Other Postretirement Benefits Disclosure [Text Block] Gas and Liquids Stored Underground and Gas and NGLs Receivables and Payables Gas and Liquids Stored Underground and Gas and NGLs Receivables and Payables [Text Block] The entire disclosure regarding gas and liquids stored underground and gas and NGLs receivables and payables. New Accounting Pronouncements and Changes in Accounting Principles New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Document and Entity Information [Abstract] Entities [Table] Entity Information [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Current Reporting Status Entity Current Reporting Status Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Unsecured Debt Unsecured Debt [Member] Line of Credit Line of Credit [Member] Debt Instrument [Axis] Debt Instrument, Name [Domain] Amendment No. 1 Credit Agreement - 2016 Amendment No. 1 Credit Agreement - 2016 [Member] Amendment No. 1 to Credit Agreement - 2016 [Member] Amendment No. 2 Credit Agreement - 2017 Amendment No. 2 Credit Agreement - 2017 [Member] Amendment No. 2 Credit Agreement - 2017 Debt Instrument [Line Items] Short-term Debt, Refinanced, Amount Short-term Debt, Refinanced, Amount Short-term Debt, Refinanced, Description Short-term Debt, Refinanced, Description Long-term Debt, Gross Long-term Debt, Gross Debt, Weighted-Average Interest Rate Debt, Weighted Average Interest Rate Debt Instrument, Covenant Compliance Debt Instrument, Covenant Compliance Line of Credit Facility [Abstract] Long-term Line of Credit Line of Credit Facility, Covenant Compliance Line of Credit Facility, Covenant Compliance Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Guarantee of Securities of Subsidiaries Condensed Financial Information of Parent Company Only Disclosure [Text Block] Fair Value Measurements Derivatives and Fair Value [Text Block] Statement of Financial Position [Abstract] Statement [Table] ASSETS Assets [Abstract] Current Assets: Assets, Current [Abstract] Cash and cash equivalents Receivables: Receivables, Net, Current [Abstract] Trade, net Accounts Receivable, Net, Current Other Other Receivables Gas transportation receivables Gas Balancing Asset (Liability) Costs recoverable from customers Regulatory Assets, Current Prepayments Prepaid Expense, Current Other current assets Other Assets, Current Total current assets Assets, Current Property, Plant and Equipment: Property, Plant and Equipment [Abstract] Natural gas transmission and other plant Property, Plant and Equipment, Other, Gross Construction work in progress Construction in Progress, Gross Property, plant and equipment, gross Property, Plant and Equipment, Gross Less—accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, plant and equipment, net Property, Plant and Equipment, Net Other Assets: Other Assets [Abstract] Goodwill Goodwill Gas stored underground Inventory, Gas in Storage Underground, Noncurrent Other Miscellaneous Other Assets, Noncurrent Amount of other noncurrent assets not separately identified on the face of the balance sheet. Total other assets Other Assets, Noncurrent Total Assets Assets LIABILITIES AND PARTNERS' CAPITAL Liabilities and Equity [Abstract] Current Liabilities: Liabilities, Current [Abstract] Payables: Accounts Payable, Current [Abstract] Trade Accounts Payable, Trade, Current Affiliates Accounts Payable, Related Parties, Current Other Accounts Payable, Other, Current Gas payables Gas Balancing Payable, Current Accrued taxes, other Accrual for Taxes Other than Income Taxes, Current Accrued interest Interest Payable, Current Accrued payroll and employee benefits Employee-related Liabilities, Current Construction retainage Construction Payable Deferred income Deferred Revenue, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Long-term debt and finance lease obligation Long-term Debt and Finance Lease Obligations Amount of long-term debt and finance lease obligation due after one year or beyond the normal operating cycle, if longer. Other Liabilities and Deferred Credits: Liabilities, Noncurrent [Abstract] Pension liability Liability, Defined Benefit Pension Plan, Noncurrent Asset retirement obligation Asset Retirement Obligations, Noncurrent Provision for other asset retirement Provision for other asset retirement Noncurrent portion of the estimated cost of removal collected in rates for operations where ASC 980 is applicable. These removal liabilities do not represent an existing legal obligation. Other Other Liabilities, Noncurrent Total other liabilities and deferred credits Liabilities, Noncurrent Commitments and Contingencies Commitments and Contingencies Partners’ Capital: Partners' Capital [Abstract] Partners' capital General and Limited Partners' Capital Account The amount of the general partners and limited partners ownership interests. Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total partners’ capital Total Liabilities and Partners' Capital Liabilities and Equity Schedule of Net Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Subsidiary, Cumulative Percentage Ownership after All Transactions Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions Equity Restrictions Equity Restrictions Other Restricted Assets Other Restricted Assets Restriction to Transfer Funds Restriction to Transfer Funds Assets Receivables Receivables, Net, Current Receivables - affiliate Accounts Receivable, Related Parties, Current Advances to affiliates Due from Related Parties, Current Other current assets Other Current Assets Consolidating Other current assets group for consolidating financial statements. Investment in consolidated subsidiaries Investment in consolidated subsidiaries The investment in consolidated subsidiaries. This amount is eliminated in consolidation. Property, plant and equipment, gross Property, plant and equipment, net Advances to affiliates - noncurrent Due from Related Parties, Noncurrent Other noncurrent assets Other Noncurrent Assets Consolidating Other noncurrent assets grouped together for the purposes of financial statements prepared in accordance with Rule 3-10 of Regulation S-X. Total other assets Total Assets Liabilities and Partners' Capital Payables Accounts Payable, Current Payable to affiliates Advances from affiliates Due to Affiliate, Current Other current liabilities Other Current Liabilities Consolidating Other current liabilities grouped together for the purposes of financial statements prepared in accordance with Rule 3-10 of Regulation S-X. Advances from affiliates - noncurrent Due to Affiliate, Noncurrent Other noncurrent liabilities Other Noncurrent Liabilities Consolidating Other noncurrent liabilities grouped together for the purposes of financial statements prepared in accordance with Rule 3-10 of Regulation S-X. Total partners' capital Statement of Comprehensive Income [Abstract] Other comprehensive income (loss): Total Comprehensive Income Disaggregation of Revenue [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Firm Service Firm Service Contracts [Member] Firm Service Contracts: Firm service that allows customers the ability to reserve a specific amount of pipeline capacity at specified receipt and delivery points on the Partnership's system (transportation service) or customers can reserve a specific amount of storage capacity at specified injection and withdrawal points at the Partnership’s storage facilities (storage service) . Interruptible Service Interruptible Service Contracts [Member] Interruptible Service Contracts: Contracts that agree to transport natural gas or natural gas liquids for a customer when capacity is available. Other revenues Other revenues contracts [Member] Other revenues contracts: Contracts with customers primarily for the sale of excess natural gas or natural gas liquids and brine supply services. Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Number of Reportable Segments Number of Reportable Segments Revenues from Contracts with Customers Revenue from Contract with Customer, Excluding Assessed Tax Other operating revenues Other Operating Revenues Certain revenues earned from operating leases, pipeline management fees and other activities that are not considered central and ongoing major business operations of the Partnership and do not represent revenues earned from contracts with customers. Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Office Space and Equipment Rentals Office Space and Equipment Rentals [Member] Office space and equipment rentals held by a lessee under operating leases. Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Operating Leases, Future Minimum Payments Due Operating lease cost Operating Lease, Cost Short-term lease cost Short-term Lease, Cost Finance Lease, Amortization of right-of-use asset Finance Lease, Right-of-Use Asset, Amortization Finance Lease, Interest on lease liabilities Finance Lease, Interest Expense Total lease cost Lease, Cost Financing Debt Disclosure [Text Block] Income Statement [Abstract] Other Total operating revenues Taxes other than income taxes Taxes, Miscellaneous Operating income Miscellaneous other income, net Total other deductions Income before income taxes Income taxes Net income Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Contract Liabilities Contract with Customer, Asset and Liability [Table Text Block] Remaining Performance Obligation Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Accounts Receivable, Net Accounts Receivable, Net Contract Liability Beginning Balance Contract with Customer, Liability Contracts with Customers, Asset, Gross, Current Contract with Customer, Asset, Gross, Current Cumulative effect adjustment from the implementation of ASC 606 Current Gas Stored Underground Cumulative Effect Decrease The cumulative decrease to Current gas stored underground as a result of a new accounting principle applied in the period of adoption. Revenues recognized that were included in the contract liability balance at the beginning of the period Contract with Customer, Liability, Revenue Recognized Increases due to cash received, excluding amounts recognized as revenues during the period Contract With Customer, Liability, Increase Amount of increase in obligation to transfer good or service to customer for which consideration from customer has been previously received. Contract Liability Ending Balance