Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Long-term Debt: Long-Term Debt, Unclassified [Abstract] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Less Accumulated Depreciation Public Utilities, Property, Plant and Equipment, Accumulated Depreciation Short-Term Debt, Type [Axis] Short-Term Debt, Type [Axis] Title of 12(b) Security Title of 12(b) Security Industrial Industrial Customers [Member] Industrial Customers Carrying Amount Reported Value Measurement [Member] Subsequent Event Subsequent Event [Member] Non-utility Assets - Net Non-Utility Assets, Net, Noncurrent Represents the amount of non-utility assets - net. Earnings Applicable to Common Stock, Diluted Earnings Applicable to Common Stock Net Income (Loss) Available to Common Stockholders, Diluted Document Fiscal Year Focus Document Fiscal Year Focus Adjustment to Compensation, Amount Adjustment to Compensation Amount Customer [Axis] Customer [Axis] Segment Reporting [Abstract] Segment Reporting [Abstract] Depreciation: Depreciation [Abstract] Common Stock, No Par Value, authorized 40,000, issued 18,577 and 18,521 in 2026 and 2025, respectively Common Stock, Value, Issued Payment of Grantee Withholding Taxes in Exchange for Restricted Stock Payment, Tax Withholding, Share-Based Payment Arrangement State corporate net income tax rates Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Employee Benefit Plans Retirement Benefits [Text Block] Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Expected Return on Assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Shares Authorized Common Stock, Value Authorized Common stock value authorized. Restricted Stock Award - Net - Employees (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Employee Benefit Plans Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Regulatory Liabilities Regulatory Liability, Noncurrent SUPPLEMENTAL DISCLOSURE OF CASH FLOWS INFORMATION: Income Tax Paid, after Refund Received [Abstract] Amendment Flag Amendment Flag CURRENT LIABILITIES: Liabilities, Current [Abstract] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Period for approved recovery of costs Approved Recovery Of Costs, Period Approved Recovery Of Costs, Period Equity Portion of Allowance for Funds Used During Construction (AFUDC) Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Loss Contingencies [Table] Loss Contingencies [Table] Weighted Average Interest Rates Short-Term Debt, Weighted Average Interest Rate, over Time State Revolving Trust Notes State Revolving Trust Notes [Member] State Revolving Trust Notes [Member] Rate and Regulatory Matters (Details) [Line Items] Rate and Regulatory Matters (Details) [Line Items] Rate and Regulatory Matters (Details) [Line Items] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Entity Address, State or Province Entity Address, State or Province Rates and Regulatory Matters Public Utilities Disclosure [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Total Capital Expenditures Segment Reporting, Long-Lived Asset, Expenditure for Addition Asset Acquisition [Axis] Asset Acquisition [Axis] OTHER Liabilities, Noncurrent [Abstract] Approved recovery of costs Approved Recovery Of Costs, Amount Approved Recovery Of Costs, Amount Basic (in shares) Earnings Applicable to Common Stock, Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Retirement Benefits [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] TOTAL CAPITALIZATION Capitalization, Long-Term Debt and Equity Regulatory Assets Regulatory Asset, Noncurrent Loss Contingencies [Line Items] Loss Contingencies [Line Items] Average purchase of gallons a day under agreement (in mgd) Purchase Obligation, Volume Per Day The average purchase of gallons. Number of reportable segments Number of Reportable Segments TOTAL CURRENT LIABILITIES Liabilities, Current Short-Term Debt, Type [Domain] Short-Term Debt, Type [Domain] Entity Address, City or Town Entity Address, City or Town Acquisition of assets Asset Acquisition, Consideration Transferred Schedule of Supplemental Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Class of Stock [Axis] Class of Stock [Axis] Payment of Preferred Dividends Payments of Ordinary Dividends, Preferred Stock and Preference Stock Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Earnings Applicable to Common Stock, Basic Net Income (Loss) Available to Common Stockholders, Basic Dividend Reinvestment & Common Stock Purchase Plan Stock Issued During Period, Value, Dividend Reinvestment Plan Other Income: Other Income: Nonoperating Income (Expense) [Abstract] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Aggregate lines of credit Maximum Line of Credit Facility, Maximum Borrowing Capacity Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Current Portion of Long-term Debt Less: Current Portion of Long-term Debt Long-Term Debt, Current Maturities Subsequent Event Type [Axis] Subsequent Event Type [Axis] Restricted Stock Award - Board of Directors (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Recent Accounting Guidance New Accounting Pronouncements, Policy [Policy Text Block] NJWSA Untreated Water Agreement New Jersey Water Supply Authority Untreated Water Agreement [Member] New Jersey Water Supply Authority Agreement Litigation Case [Axis] Litigation Case [Axis] Tidewater Customers Tidewater Utilities, Inc. Customers [Member] Tidewater Utilities, Inc. Customers Schedule of Segment Transactions Segment Reporting [Table Text Block] $7.00 Series Preferred Dividend Convertible Preferred Dividends, Net of Tax Common Shares Outstanding: Assets, Average Outstanding [Abstract] Carrying amount of debt Long-Term Debt Short-Term Debt [Abstract] Short-Term Debt [Abstract] Dividend Reinvestment & Common Stock Purchase Plan (in shares) Stock Issued During Period, Shares, Dividend Reinvestment Plan Document Period End Date Document Period End Date Changes in Assets and Liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] NET CASH USED IN INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Cumulative preferred stock, nonredeemable shares outstanding (in shares) Preferred stock, outstanding (in shares) Preferred Stock, Shares Outstanding Treated Water Treated Water [Member] Treated Water Borrowing amount Debt Instrument, Face Amount Unbilled Revenues Increase (Decrease) in Contract with Customer, Asset Basic: Earnings Per Share, Basic [Abstract] Capitalization Equity [Text Block] Security Exchange Name Security Exchange Name Consolidated Purchased Water Total Costs Cost of Purchased Water Water Production Public Utilities, Property, Plant and Equipment, Generation or Processing Supplemental Cash Flows Information Cash Flow, Supplemental Disclosures [Text Block] Shares Authorized Preferred Stock, Value Authorized Preferred stock value authorized. Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Company cash contributions to Pension Plan Payment for Pension Benefits Earnings Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Earnings per share of Common Stock: Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Trading Symbol Trading Symbol 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] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Accrued Taxes Accrued Income Taxes, Current Approved increase amount in revenues Public Utilities, Approved Rate Increase (Decrease), Amount Company Selected Measure Name Company Selected Measure Name Sale of Stock [Domain] Sale of Stock [Domain] Purchase Commitment, Excluding Long-Term Commitment [Axis] Purchase Commitment, Excluding Long-Term Commitment [Axis] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Purchased Water: Utilities Operating Expense [Abstract] SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITY: Noncash Investing and Financing Items [Abstract] Diluted: Earnings Per Share, Diluted [Abstract] SUBTOTAL LONG-TERM DEBT Long-Term Debt, Gross Depreciation and Amortization Depreciation, Depletion and Amortization, Nonproduction CASH FLOWS FROM OPERATING ACTIVITIES: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Diluted (in shares) Adjusted Earnings Applicable to Common Stock, Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Cash dividends on Common Stock (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Line of Credit Facility [Table] Line of Credit Facility [Table] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Pinelands Wastewater Company Pinelands Wastewater Company [Member] Pinelands Wastewater Company Provision for Deferred Income Taxes and Investment Tax Credits Deferred Income Taxes and Tax Credits DSIC Distribution System Improvement Charge [Member] Distribution System Improvement Charge Foundational Filing NJBPU Treated Water Agreement New Jersey Board Of Public Utilities Treated Water Agreement [Member] New Jersey Board Of Public Utilities Treated Water Agreement Outstanding Short-Term Debt Regulated Regulated Segment [Member] Regulated [Member] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Other Assets and Liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Amortizing Secured Notes and State Revolving Trust Notes Secured Notes And State Revolving Trust Notes [Member] Amortizing Secured Notes And State Revolving Trust Notes Award Timing Predetermined Award Timing Predetermined [Flag] Treated Cost Of Untreated Water Refers to cost of untreated water during the period. UTILITY PLANT - NET Public Utilities, Property, Plant and Equipment, Net Average purchase of gallons Average Purchase Of Gallons The average purchase of gallons. Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Effective tax rate percentage Effective Income Tax Rate Reconciliation, Percent Middlesex Middlesex [Member] Middlesex December 2025 Delaware State Revolving Fund December 2025 Delaware State Revolving Fund [Member] December 2025 Delaware State Revolving Fund All Executive Categories All Executive Categories [Member] Regulated Operations [Abstract] Regulated Operations [Abstract] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Wholesale Wholesale Customers [Member] Wholesale Customers FMBs Long-Term Debt, Fair Value Schedule of Employee Retirement Benefit Plans Schedule of Net Benefit Costs [Table Text Block] Depreciation Depreciation Depreciation Plan Name [Domain] Plan Name [Domain] Asset Acquisition [Domain] Asset Acquisition [Domain] Operating Lease Right of Use Asset Operating Lease, Right-of-Use Asset Cumulative preferred stock, price (in dollars per share) Convertible preferred stock, conversion price (in dollars per share) Preferred Stock, Convertible, Conversion Price Operating Income: Operating Income (Loss) [Abstract] Rate and Regulatory Matters (Details) [Table] Rate and Regulatory Matters (Details) [Table] Rate and Regulatory Matters (Details) [Table] Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Approved increase percentage in rates Public Utilities, Approved Rate Increase (Decrease), Percentage Number of customers served Asset Acquisition, Number Of Customers Served Number Of Customers Serviced Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Business Segment Data Segment Reporting [Text Block] Minimum Minimum Minimum [Member] Payment of Common Dividends Payments of Ordinary Dividends, Common Stock Expiration Date Trading Arrangement Expiration Date NET CHANGES IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation Refund credited amount Public Utilities, Approved Rate, Refund Credit Amount Public Utilities, Approved Rate, Refund Credit Amount Schedule of Operating Revenues Disaggregation of Revenue [Table Text Block] Company cash contributions to Other Benefits Plan Payment for Other Postretirement Benefits Maximum percentage of costs to be recovered Requested Recovery Of Costs, Maximum, Percentage Requested Recovery Of Costs, Maximum, Percentage Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Regulatory Proceeding [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] TOTAL OTHER LIABILITIES Other Liabilities Unbilled Revenues Unbilled Receivables, Current General Public Utilities, Property, Plant and Equipment, Common Public utilities, requested rate increase (decrease), amount Public Utilities, Requested Rate Increase (Decrease), Amount Net Periodic Benefit Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Proceeds from Issuance of Common Stock Total net proceeds from shares issued and sold under agreement Proceeds from Issuance of Common Stock Common stock, authorized (in shares) Common Stock, Shares Authorized Number of shares issued and sold under agreement (in shares) Sale of Stock, Number of Shares Issued in Transaction Exercise Price Award Exercise Price Restricted Stock Award -Net-Employees Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures CASH FLOWS FROM INVESTING ACTIVITIES: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Segment Reporting [Line Items] Segment Reporting [Line Items] Document Quarterly Report Document Quarterly Report Number of debt instruments Number Of Debt Instruments Number Of Debt Instruments 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] Segments [Domain] Segments [Domain] Redemption of Long-term Debt Repayments of Long-Term Debt Convertible Preferred Stock $7.00 Series Convertible Preferred Stock [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Secured Debt Secured Debt [Member] Aggregate gross sales price Sale of Stock, Consideration Received on Transaction Adoption Date Trading Arrangement Adoption Date Cash Dividends on Common Stock Dividends, Common Stock, Cash Balance at beginning of period Balance at end of period Equity, Attributable to Parent Interest rate Debt Instrument, Interest Rate, Stated Percentage Total Other Income, net Other Income Nonoperating Income (Expense) Employee Benefit Plans Employee Benefit Plans Employee Benefit Plans. Accrued Taxes Increase (Decrease) in Accrued Taxes Payable NJBPU New Jersey Board Of Public Utilities [Member] New Jersey Board Of Public Utilities ASSETS Assets [Abstract] Regulatory Agency [Axis] Regulatory Agency [Axis] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Middlesex and Pinelands Middlesex Water Company, Pinelands Water Company And Pinelands Wastewater Company [Member] Middlesex Water Company, Pinelands Water Company And Pinelands Wastewater Company Common Stock Issuance Expense Payments of Stock Issuance Costs Insider Trading Policies and Procedures [Line Items] Regulatory Agency [Domain] Regulatory Agency [Domain] Regulated Tariff Sales Regulated Tariff-Based Services [Member] Regulated Tariff-Based Water And Wastewater Utility Services Construction Advances and Contributions-Net Proceeds from (Payment for) Other Financing Activity Allowance for credit losses Accounts Receivable, Allowance for Credit Loss, Current Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Schedule of Lines of Credit Schedule of Line of Credit Facilities [Table Text Block] Regulatory Assets Regulatory Asset, Current Debt repaid Repayments of Debt Commitments and Contingent Liabilities Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Entity Central Index Key Entity Central Index Key Shares Outstanding Common Stock, Value, Outstanding All Adjustments to Compensation All Adjustments to Compensation [Member] Schedule of Carrying Amount and Fair Value of First Mortgage Bonds (FMBs) Schedule of Capitalization [Table Text Block] Equity [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] NET CASH PROVIDED BY OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Cash Dividends on Preferred Stock Dividends, Preferred Stock, Cash Operating Expenses: Operating Expenses [Abstract] Inter-segment Elimination Intersegment Eliminations [Member] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] City Area Code City Area Code RESIC Resiliency And Environmental System Improvement Charge [Member] Resiliency And Environmental System Improvement Charge Foundational Filing Other Taxes: Taxes, Miscellaneous [Abstract] All Individuals All Individuals [Member] Name Forgone Recovery, Individual Name Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Weighted average price per share of shares issued and sold under agreement (in dollars per share) Sale Of Stock, Weighted Average Price Per Share Sale Of Stock, Weighted Average Price Per Share Statement [Line Items] Statement [Line Items] TOTAL ASSETS Consolidated Assets Assets Entity [Domain] Entity [Domain] Effective Income Tax Rate Reconciliation [Line Items] Effective Income Tax Rate Reconciliation [Line Items] Preferred stock, issued (in shares) Cumulative preferred stock, nonredeemable shares issued (in shares) Preferred Stock, Shares Issued Pinewood Acres Water Utility Assets Pinewood Acres Water Utility Assets [Member] Pinewood Acres Water Utility Assets Operating Segments Operating Segments [Member] Interest Charges Interest Expense, Nonoperating Consolidated Other Operations and Maintenance Expenses Utilities Operating Expense, Maintenance And Operations, Other Utilities Operating Expense, Maintenance And Operations, Other TOTAL COMMON EQUITY Partners' Capital Bank of America Bank Of America Uncommitted Line Of Credit [Member] Bank of America [Member] At-The-Market Program Common Stock Issuance (in shares) Number of common shares issued (in shares) Stock Issued During Period, Shares, New Issues PEO PEO [Member] Other Non-Regulated Revenues Unregulated Operating Revenue, Other Represent the amount of other non regulated revenues. Prepayments Increase (Decrease) in Prepaid Expense Conversion of Preferred Stock into Common Stock Preferred Stock Conversions, Inducements Southern Shores Southern Shores Water Company, LLC [Member] Southern Shores Water Company, LLC Measurement Basis [Axis] Measurement Basis [Axis] Other Other Liabilities, Noncurrent Retirement Plan Type [Axis] Retirement Plan Type [Axis] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Other Operations and Maintenance Expenses: Utilities Operating Expense, Maintenance and Operations [Abstract] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Retained Earnings Retained Earnings [Member] Lease Obligations Operating Lease, Liability, Noncurrent Total Operating Expenses Operating Expenses Allowance for Funds Used During Construction Public Utilities, Allowance for Funds Used During Construction, Additions Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock outstanding (in shares) Balance at beginning of period (in shares) Balance at end of period (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Deferred Debt Issuance Expense Payments of Debt Issuance Costs Diluted (in dollars per share) Diluted EPS (in dollars per share) Earnings Per Share, Diluted Entity Current Reporting Status Entity Current Reporting Status NET CASH PROVIDED BY FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Litigation Case [Domain] Litigation Case [Domain] Shares Outstanding Preferred Stock, Value, Outstanding Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Operations and Maintenance Utilities Operating Expense, Maintenance and Operations September 2024 Delaware SRF September 2024 Delaware State Revolving Fund [Member] Delaware State Revolving Fund Adjustments to Reconcile Net Income to Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Amortizing Secured Notes Secured Notes [Member] Amortizing Secured Notes $7.00 Series Preferred Dividend (in shares) Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock Total Revenue from Contracts with Customers Revenue from Contract with Customer, Excluding Assessed Tax CASH FLOWS FROM FINANCING ACTIVITIES: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Available Line of Credit Facility, Remaining Borrowing Capacity Aggregate gross sales price of shares remaining to be issued under agreement Sale Of Stock, Remaining Consideration Receivable On Transaction Sale Of Stock, Remaining Consideration Receivable On Transaction Other Regulated Revenues Regulated Operating Revenue, Other Interest Cost Defined Benefit Plan, Interest Cost DEPSC Delaware Public Service Commission [Member] Delaware Public Service Commission Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Schedule of Recently Issued Accounting Standards Accounting Standards Update and Change in Accounting Principle [Table Text Block] Fair Value Estimate of Fair Value Measurement [Member] Revenue Recognition from Contracts with Customers Revenue from Contract with Customer [Text Block] At-The-Market Program Common Stock Issuance At-the-market program common stock issuance Stock Issued During Period, Value, New Issues Prepayments Prepaid Expense, Current Expected cash contributions over remainder of the current year Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Segment Reporting [Table] Segment Reporting [Table] Income Taxes: Income Tax Expense (Benefit), Continuing Operations [Abstract] Sale of Stock [Axis] Sale of Stock [Axis] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating Income Operating Income Operating Income (Loss) Cash Paid During the Nine Months for: Interest Paid, Including Capitalized Interest, Operating and Investing Activities [Abstract] Residential Residential Customers [Member] Residential Customers Current Fiscal Year End Date Current Fiscal Year End Date Advances for Construction Construction Payable Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount 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] Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Service Cost Defined Benefit Plan, Service Cost Net Short-term Bank Borrowings Proceeds from (Repayments of) Short-Term Debt Notes Payable Notes Payable, Current, Excluding Current Maturities Notes Payable, Current, Excluding Current Maturities Other Taxes Consolidated Other Taxes Taxes, Other Recovery of Erroneously Awarded Compensation Disclosure [Line Items] LSLR Lead Service Line Replacement Plan [Member] Lead Service Line Replacement Plan Measure: Measure [Axis] PNC Bank PNC Bank Committed Line Of Credit [Member] PNC Bank [Member] Materials & Supplies Increase (Decrease) in Raw Materials, Packaging Materials and Supplies Inventories Equity Components [Axis] Equity Components [Axis] Accounts Receivable Increase (Decrease) in Accounts Receivable Product and Service [Domain] Product and Service [Domain] CoBank CoBank, ACB Committed Line Of Credit [Member] CoBank, ACB Committed Line Of Credit Income Taxes Income Tax Paid, after Refund Received Class of Stock [Line Items] Class of Stock [Line Items] CONTRIBUTIONS IN AID OF CONSTRUCTION Contributions in Aid of Construction Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] June 2026 ACB (CoBank) Revolving Fund June 2026 ACB (CoBank) Revolving Fund [Member] June 2026 ACB (CoBank) Revolving Fund CAPITALIZATION: Capitalization, Long-Term Debt and Equity [Abstract] Entity Interactive Data Current Entity Interactive Data Current Accumulated Deferred Income Taxes Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Average Number of Average Number Of [Abstract] Average Number Of Entity Small Business Entity Small Business Common stock shares issued not disclosed Common Stock Shares Issued Not Disclosed Common Stock Shares Issued Not Disclosed TOTAL Public Utilities, Property, Plant and Equipment, Plant in Service Less: Unamortized Debt Expense Debt Instrument, Unamortized Discount Termination Date Trading Arrangement Termination Date Effective Income Tax Rate Reconciliation [Table] Effective Income Tax Rate Reconciliation [Table] Statutory federal tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other Other Liabilities, Current Other Other Assets, Noncurrent Document Type Document Type Accrued Interest Accrued Liabilities, Current Purchase Commitment, Excluding Long-Term Commitment [Domain] Purchase Commitment, Excluding Long-Term Commitment [Domain] Schedule of Purchased Water Costs Purchase Commitment, Excluding Long-Term Commitment [Table Text Block] Fair Value as of Grant Date Award Grant Date Fair Value Nonredeemable Preferred Stock $7.00 Series Nonredeemable Preferred Stock, $7.00 Series [Member] Nonredeemable Preferred Stock, $7.00 Series Commercial Commercial Customers [Member] Commercial Customers Utility Plant Expenditures, Including AFUDC of $847 in 2026 and $483 in 2025 Payment For Utility Plant Capital Expenditures Payment For Utility Plan Expenditures Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Proceeds from Issuance of Long-term Debt Debt drawn down Proceeds from Issuance of Long-Term Debt Local Phone Number Local Phone Number Other Benefits Other Postretirement Benefits Plan [Member] Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Registrant Name Entity Registrant Name Middlesex And Pinelands Customers Middlesex Water Company, Pinelands Water Company And Pinelands Wastewater Company Customers [Member] Middlesex Water Company, Pinelands Water Company And Pinelands Wastewater Company Customers Non-Regulated Contract Operations Unregulated Service Contracts [Member] Non-Regulated Operation And Maintenance Contracts For Services On Water And Wastewater Systems Owned By Others Common equity ratio Public Utilities, Approved Equity Capital Structure, Percentage Income before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] COMMITMENTS AND CONTINGENT LIABILITIES (Note 7) Commitments and Contingencies Operating Revenues Total Revenue Revenues Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Construction Agreement Construction Agreement [Member] Construction Agreement CAPITALIZATION AND LIABILITIES Liabilities and Equity [Abstract] All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Acquisition of Water Systems Payments to Acquire Water Systems PEO Name PEO Name Accrued Interest Increase (Decrease) in Accrued Liabilities Utility Plant received as Construction Advances and Contributions Contribution of Property Short-Term Debt [Table] Short-Term Debt [Table] TOTAL OTHER ASSETS Other Assets Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Legal Entity [Axis] Legal Entity [Axis] CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT BEGINNING OF PERIOD CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Preferred Stock Dividend Requirements Preferred Dividend Preferred Stock Dividends, Income Statement Impact Accounts Payable Increase (Decrease) in Accounts Payable Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] 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] Debt Instrument [Axis] Debt Instrument [Axis] Increase (decrease) in income taxes Increase (Decrease) In Income Tax Expense (Benefit) Increase (Decrease) In Income Tax Expense (Benefit) Stock Compensation Expense Share-Based Payment Arrangement, Noncash Expense AFUDC-Debt utility plant expenditures Interest Capitalized Interest Paid, Capitalized, Investing Activity Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Axis] Common Stock Issuance Expense Stock Issued During Period, Issuance Costs Stock Issued During Period, Issuance Costs Conversion of $7 Preferred Stock to Common Stock (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Customer [Domain] Customer [Domain] Long-Term Debt, Type [Domain] Long-Term Debt, Type [Domain] Basic (in dollars per share) Basic EPS (in dollars per share) Earnings Per Share, Basic Unearned Revenues and Advanced Service Fees Contract with Customer, Liability, Current TOTAL CURRENT ASSETS Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Period for surcharge filings Surcharge Filing For Qualifying Recovery Costs, Period Surcharge Filing For Qualifying Recovery Costs, Period Long-term Debt TOTAL LONG-TERM DEBT Long-Term Debt, Excluding Current Maturities Award Type Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] October 2026 Delaware State Revolving Fund October 2026 Delaware State Revolving Fund [Member] October 2026 Delaware State Revolving Fund Accounts Receivable, net of allowance for uncollectible accounts of $3,074 and $1,625, respectively Accounts Receivable, after Allowance for Credit Loss, Current Retained Earnings Retained Earnings (Accumulated Deficit) Schedule of Weighted Average Daily Amounts of Borrowings Outstanding and Weighted Average Interest Rates Schedule of Short-Term Debt [Table Text Block] Product and Service [Axis] Product and Service [Axis] Untreated Cost Of Treated Water Refers to cost of treated water during the period. Restricted Cash Restricted Cash, Noncurrent 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] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Pension Benefits Pension Plan [Member] Short-Term Debt [Line Items] Short-Term Debt [Line Items] Number of entities approved for corporate reorganization Public Utilities, Approved Corporate Reorganization, Number Of Entities Public Utilities, Approved Corporate Reorganization, Number Of Entities Common Stock Common Stock [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Middlesex Water Company Investment Plan Middlesex Water Company Investment Plan [Member] Middlesex Water Company Investment Plan Weighted average interest rate Short-Term Debt, Weighted Average Interest Rate, at Point in Time Loans Payable Loans Payable [Member] UTILITY PLANT: Public Utilities, Property, Plant and Equipment, Net [Abstract] Equity Awards Adjustments Equity Awards Adjustments [Member] Common Stock, No Par Value Common Stock No Par Value [Abstract] Common Stock No Par Value Maximum value of costs to be recovered Requested Recovery Of Costs, Maximum, Amount Requested Recovery Of Costs, Maximum, Amount TOTAL CAPITALIZATION AND LIABILITIES Liabilities and Equity May 2024 Delaware SRF May 2024 Delaware State Revolving Fund [Member] May 2024 Delaware State Revolving Fund Employee Stock Option Share-Based Payment Arrangement, Option [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Cumulative Preferred Stock, No Par Value: Cumulative Preferred Stock No Par Value [Abstract] Cumulative Preferred Stock No Par Value Construction Work in Progress Public Utilities, Property, Plant and Equipment, Construction Work in Progress Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] MDL Lawsuit Multi-District Litigation Lawsuit [Member] Multi-District Litigation Lawsuit Tidewater Tidewater Utilities, Inc. [Member] Tidewater Utilities, Inc. Plan Name [Axis] Plan Name [Axis] Fire Protection Fire Protection Customers [Member] Fire-Protection Customers Number of unit condominium community entity provides water service to Water Service Provided, Number Of Units In Condominium Community Water Service Provided, Number Of Units In Condominium Community Tabular List, Table Tabular List [Table Text Block] Non – Regulated Non-Regulated Segment [Member] Non - Regulated [Member] Other Income, net Other Nonoperating Income (Expense) ATM Equity Sales Agreement At-The-Market Equity Offering [Member] At-The-Market Equity Offering First Mortgage Bonds FMBs First Mortgage Bonds [Member] First Mortgage Bonds [Member] Name Awards Close in Time to MNPI Disclosures, Individual Name Average Daily Amounts Outstanding Line of Credit Facility, Average Outstanding Amount 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] OTHER ASSETS: Assets, Noncurrent [Abstract] Conversion of $7 Preferred Stock to Common Stock Stock Issued During Period, Value, Conversion of Convertible Securities Preferred stock, authorized (in shares) Cumulative preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Materials and Supplies (at average cost) Inventory, Raw Materials and Supplies, Gross Capital Expenditures: Segment Reporting, Other Disclosure [Abstract] Preferred Stock, No Par Value; authorized 120; issued 11 and 13 in 2026 and 2025, respectively TOTAL PREFERRED STOCK Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Class of Stock [Domain] Class of Stock [Domain] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Interest Interest Paid, Excluding Capitalized Interest, Operating Activity Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Adjusted Earnings Applicable to Common Stock, Diluted Net Income (Loss) Available to Common Stockholders, Diluted, Adjusted Represents the amount of adjusted earnings applicable to common stock. June 2026 Delaware State Revolving Fund June 2026 Delaware State Revolving Fund [Member] June 2026 Delaware State Revolving Fund Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Name Measure Name Income Taxes Income Tax Disclosure [Text Block] Accounts Payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Entity Filer Category Entity Filer Category Supplemental Cash Flow Elements [Abstract] Name Trading Arrangement, Individual Name Cash and Cash Equivalents Cash and Cash Equivalent Company Selected Measure Amount Company Selected Measure Amount Short-term Borrowings Short-Term Debt [Text Block] Stock, Class of Stock [Table] Stock, Class of Stock [Table] Statement of Partners' Capital [Abstract] Statement of Partners' Capital [Abstract] Cash Surrender Value of Life Insurance Life Insurance, Corporate or Bank Owned, Change in Value CURRENT ASSETS: Assets, Current [Abstract] Non-PEO NEO Non-PEO NEO [Member] Entity Address, Address Line One Entity Address, Address Line One Transmission and Distribution Public Utilities, Property, Plant and Equipment, Transmission and Distribution Income Taxes Consolidated Income Taxes Income Tax Expense (Benefit) Estimated future expenditure obligation Purchase Obligation Pinelands Water Company Pinelands Water Company [Member] Pinelands Water Company Award Timing Method Award Timing Method [Text Block] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Net Income: Net Income (Loss) Attributable to Parent [Abstract] Construction Advances Construction Advances [Member] Construction Advances Amortization of Unrecognized Losses (Gains) Defined Benefit Plan, Amortization of Gain (Loss) Settlement payments received Proceeds from Legal Settlements Net Income Net Income Consolidated Net Income Net Income (Loss) Attributable to Parent Long-Term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] Return on equity Public Utilities, Approved Return on Equity, Percentage Restatement Determination Date: Restatement Determination Date [Axis] Regulatory Liabilities Regulatory Liability, Current Add: Premium on Issuance of Long-term Debt Debt Instrument, Unamortized Premium Restricted Stock Award - Board of Directors Stock Issued During Period, Value, Restricted Stock Award, Gross Nonredeemable Preferred Stock $4.75 Series Nonredeemable Preferred Stock, $4.75 Series [Member] Nonredeemable Preferred Stock, $4.75 Series Employee Benefit Plans - Schedule of Employee Retirement Benefit Plans (Details) [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Accrued Payables for Utility Plant Accrued Payables For Utility Plant The amount of accrued payables for utility plant. Operating Revenues: Revenues [Abstract] Basis of Presentation and Recent Developments Basis of Presentation and Significant Accounting Policies [Text Block] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block]