Document And Entity Information [Abstract] Statement [Table] Statement [Line Items] Document Type Document Quarterly Report Document Period End Date Document Fiscal Year Focus Current Fiscal Year End Date Document Transition Report Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security Trading Symbol Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Amendment Flag Document Fiscal Period Focus Entity Central Index Key Consolidated Balance Sheets [Abstract] Assets Property, plant and equipment, at cost Less: accumulated depreciation Net property, plant and equipment Net property, plant and equipment Current assets: Cash and cash equivalents Accounts receivable, net Unbilled Receivables, Current Unbilled revenues Inventory - materials and supplies Energy Related Inventory, Natural Gas in Storage Inventory - gas stored Prepayments and other current assets Regulatory Assets, Current Regulatory assets Total current assets Total current assets Regulatory Assets Noncurrent Regulatory assets Deferred Costs and Other Assets Deferred charges and other assets, net Restricted Cash and Cash Equivalents, Noncurrent Funds restricted for construction activity Goodwill Balance Balance Goodwill Operating Lease, Right-of-Use Asset Operating lease right-of-use assets Intangible Assets, Net (Excluding Goodwill) Intangible assets Total Assets Total assets Total assets Liabilities and Equity Stockholders' equity: Common stock authorized and issued Common stock at $0.50 par value, authorized 600,000,000 shares, issued 265,415,337 and 256,102,388 as of June 30, 2022 and December 31, 2021 Common stock, $0.50 par value Additional Paid In Capital Common Stock Capital in excess of par value Retained Earnings Accumulated Deficit Retained earnings Treasury stock, at cost Treasury stock, at cost, 3,244,664 and 3,234,765 shares as of June 30, 2022 and December 31, 2021 Treasury stock, at cost Total Aqua America stockholders' equity Balance Balance Total stockholders' equity Debt Instrument Carrying Amount Noncurrent Debt Instrument Carrying Amount Noncurrent Long-term debt, excluding current portion Unamortized Debt Issuance Expense Less: debt issuance costs Long Term Debt Noncurrent Long-term debt, excluding current portion, net of debt issuance costs Commitments and contingencies 2009 Commitments and contingencies (See Note 13) Current liabilities: Current portion of long-term debt Loans Payable, Current, Not Included In Current Portion Of Long Term Debt Loans Payable, Current, Not Included In Current Portion Of Long Term Debt Loans payable Accounts payable Bank Overdrafts Book overdraft Interest Payable, Current Accrued interest Accrued taxes Regulatory Liability, Current Regulatory liabilities Accrued Liabilities Current Other accrued liabilities Total current liabilities Total current liabilities Deferred credits and other liabilities: Deferred income taxes and investment tax credits Customers' advances for construction Customers' advances for construction Regulatory Liability Noncurrent Regulatory liabilities Asset Retirement Obligations, Noncurrent Asset retirement obligations Operating Lease, Liability, Noncurrent Operating lease liabilities Postemployment Benefits Liability, Noncurrent Pension and other postretirement benefit liabilities Other Liabilities Noncurrent Other Liabilities, Noncurrent, Less Long Term Debt Liabilities, Noncurrent, Less Long Term Debt Total deferred credits and other liabilities Contributions in aid of construction Total liabilities and stockholders' equity Total liabilities and equity Common stock, par value Common stock, par value Common stock, shares authorized Common stock, shares issued Treasury stock, shares Consolidated Statements Of Operations [Abstract] Operating revenues Revenue Cost and expenses: Operating expenses: Utilities Operating Expense Maintenance And Operations Operations and maintenance Operations and maintenance expense Utilities Operating Expense, Gas and Petroleum Purchased Purchased gas Depreciation Amortization Taxes other than income taxes Total taxes other than income Total expenses Total operating expenses Operating income Operating income Other expense (income): Interest expense Interest Income, Operating Interest income Public Utilities Allowance For Funds Used During Construction Additions Allowance for funds used during construction Gain Loss On Sale Of Other Assets Gain on sale of other assets Other Nonoperating Income (Expense) Other Income from continuing operations before income taxes Income before income taxes Provision for income taxes (benefit) Provision for income taxes Net income attributable to common shareholders Net income Net income Comprehensive income Comprehensive income Net Income Per Common Share [Abstract] Net income per common share: Earnings Per Share Basic Basic Earnings Per Share Diluted Diluted Weighted Average Number of Shares Outstanding Abstract Average common shares outstanding during the period: Basic Average common shares outstanding during the period for basic computation Diluted Average common shares outstanding during the period for diluted computation Consolidated Statements of Capitalization [Abstract] Consolidated Statements Of Capitalization [Abstract] Debt Instrument [Axis] Debt Instrument Name [Domain] Debt Instrument, Name [Domain] Long Term Debt Of Subsidiaries zero point zero zero percentage to zero point nine nine percentage [Member] Long Term Debt Of Subsidiaries Zero Point Zero Zero Percentage To Zero Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 0.00% To 0.99% [Member] Long Term Debt Of Subsidiaries one point zero zero percentage to one point nine nine percentage [Member] Long Term Debt Of Subsidiaries One Point Zero Zero Percentage To One Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 1.00% To 1.99% [Member] Long Term Debt Of Subsidiaries two point zero zero percentage to two point nine nine percentage [Member] Long Term Debt Of Subsidiaries Two Point Zero Zero Percentage To Two Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 2.00% To 2.99% [Member] Long Term Debt Of Subsidiaries three point zero zero percentage to three point nine nine percentage [Member] Long Term Debt Of Subsidiaries Three Point Zero Zero Percentage To Three Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 3.00% To 3.99% [Member] Long Term Debt Of Subsidiaries four point zero zero percentage to four point nine nine percentage [Member] Long Term Debt Of Subsidiaries Four Point Zero Zero Percentage To Four Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 4.00% To 4.99% [Member] Long Term Debt Of Subsidiaries five point zero zero percentage to five point nine nine percentage [Member] Long Term Debt Of Subsidiaries Five Point Zero Zero Percentage To Five Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 5.00% To 5.99% [Member] Long Term Debt Of Subsidiaries six point zero zero percentage to six point nine nine percentage [Member] Long Term Debt Of Subsidiaries Six Point Zero Zero Percentage To Six Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 6.00% To 6.99% [Member] Long Term Debt Of Subsidiaries seven point zero zero percentage to seven point nine nine percentage [Member] Long Term Debt Of Subsidiaries Seven Point Zero Zero Percentage To Seven Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 7.00% To 7.99% [Member] Long Term Debt Of Subsidiaries eight point zero zero percentage to eight point nine nine percentage [Member] Long Term Debt Of Subsidiaries Eight Point Zero Zero Percentage To Eight Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 8.00% To 8.99% [Member] Long Term Debt Of Subsidiaries nine point zero zero percentage to nine point nine nine percentage [Member] Long Term Debt Of Subsidiaries Nine Point Zero Zero Percentage To Nine Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 9.00% To 9.99% [Member] Revolving Credit Agreement, Due B Revolving Credit Agreement Due B [Member] Revolving Credit Agreement, Due 2023 [Member] Amortizing Notes [Member] Amortizing Notes [Member] Amortizing notes at 3.00% due 2022 [Member] Notes BB [Member] Notes Bb [Member] Notes at 2.40% due 2031 [Member] Notes AA [Member] Notes Aa [Member] Notes at 2.704% due 2030 [Member] Notes Ranges B [Member] Notes Ranges B [Member] Notes ranging from 3.01% to 3.59% due 2029 through 2050 [Member] Notes Z [Member] Notes Z [Member] Notes at 4.28%, due 2049 [Member] Notes at 5.30%, due 2052. Notes At Five Point Thirty Percent Due Two Thousand Fifty Two [Member] Notes at 5.30%, due 2052 Notes Ranges C [Member] Notes Ranges C [Member] Notes ranging from 5.64% to 5.95%, due 2022 through 2034 [Member] Long-term debt of subsidiaries (substantially collateralized by utility plant): Secured Debt Long-term debt of subsidiaries Other Notes Payable, Noncurrent Notes payable to bank under revolving credit agreement, variable rate, due Dec 2023 Notes ranging from 4.62% to 4.87%, due 2013 through 2024 Unsecured notes payable Debt Instrument, Principal Outstanding Total long-term debt Total capitalization Total capitalization Statistical Measurement [Axis] Range [Member] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Notes B [Member] Notes B [Member] Notes at 3.01% due 2029 [Member] Notes C [Member] Notes C [Member] Notes at 3.59% due 2050 [Member] Notes F [Member] Notes F [Member] Notes at 5.64% due 2022 [Member] Notes G [Member] Notes G [Member] Notes at 5.95% due 2034 [Member] Interest Rate Interest rate Debt Instrument, Maturity Date, Year Debt Instrument, Maturity Date, Year Maturity date Consolidated Statements Of Equity [Abstract] Statement, Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Parent [Member] Parent [Member] Common Stock [Member] Common Stock [Member] Additional Paid In Capital [Member] Capital In Excess Of Par Value [Member] Retained Earnings [Member] Retained Earnings [Member] Treasury Stock [Member] Treasury Stock [Member] Other Comprehensive Income (Loss), Net of Tax Other comprehensive income, net of income tax of $73 Dividends, Common Stock, Paid-in-kind Dividends declared and paid Dividends paid Dividends declared Issuance of common stock under dividend reinvestment plan (22,170 shares) Issuance of common stock from private placement Adjustments To Additional Paid In Capital, Issuance Of Common Stock Issuance of common stock from stock purchase contracts Stock issued during period Issuance of common stock under dividend reinvestment plan Issuance Of Common Stock From Forward Equity Sale Agreement Issuance Of Common Stock From Forward Equity Sale Agreement Issuance of common stock from forward equity sale agreement Repurchase of stock (414,869 shares) Repurchase of stock Stock granted during period, value share-based compensation Equity compensation plan Stock Issued During Period, Value, Stock Options Exercised Exercise of stock options Treasury Stock Reissued at Lower than Repurchase Price, Share-based Compensation Treasury Stock Reissued at Lower than Repurchase Price, Share-based Compensation Stock-based compensation Other Consolidated Statements Of Equity (Parenthetical) [Abstract] Common Stock, Dividends, Per Share, Cash Paid Cash dividends declared per common share Dividend declared per common share Stock Issued During Period, Shares, Purchase of Assets Issuance of common stock from stock purchase contracts , shares StockIssuedDuringPeriodSharesDividendReinvestmentPlan Issuance of common stock under dividend reinvestment plan, shares Issuance Of Common Stock From Forward Equity Sale Agreement, Shares Issuance Of Common Stock From Forward Equity Sale Agreement, Shares Issuance of common stock from forward equity sale agreement , shares Repurchase Of Stock, Shares Repurchase of stock, shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Equity compensation plan, shares Granted, Number of Share Units Granted Granted, Number of Share Units Equity compensation plan, shares Exercise Of Stock Options, Shares Exercised, Shares Exercise of stock options, shares Consolidated Statements Of Cash Flow [Abstract] Cash flows from operating activities: Adjustments to reconcile net income to net cash flows from operating activities: Adjustments to reconcile net income to net cash flows from operating activities: Depreciation and amortization Deferred Income Tax Expense (Benefit), Total Deferred income taxes Provision for doubtful accounts Share Based Compensation Stock-based compensation Gain (Loss) on Sale of Business Gain on sale of other assets Increase (Decrease) in Inventories, Receivables, And Prepayments Increase (Decrease) in Inventories, Receivables, And Prepayments Net change in receivables, inventory and prepayments Net decrease in payables, accrued interest, accrued taxes and other accrued liabilities Net change in payables, accrued interest, accrued taxes and other accrued liabilities Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Pension and other postretirement benefits contributions Increase Decrease In Other Operating Assets Other Net cash flows from operating activities Net cash flows from operating activities Cash flows from investing activities: Payments to acquire property, plant and equipment Property, plant and equipment additions, including the debt component of allowance for funds used during construction of $3,013 and $1,393 Capital expenditures Payments to Acquire Waste Water Systems Acquisitions of utility systems, net Proceeds from sale of utility system and other Proceeds from sale of utility system and other Net proceeds from the sale of other assets Payments for (Proceeds from) Other Investing Activities Other Net cash flows used in investing activities Net cash flows used in investing activities Cash flows from financing activities: Proceeds from Advances for Construction, Financing Activities Proceeds from Advances for Construction, Financing Activities Customers' advances and contributions in aid of construction Repayments of Advances for Construction, Financing Activities Repayments of Advances for Construction, Financing Activities Repayments of customers' advances Net proceeds (repayments) of short-term debt Net repayments of short-term debt Proceeds from long-term debt Repayments of long-term debt Repayments of long-term debt Proceeds From Repayments Of Bank Overdrafts, Less Short Term Debt Proceeds From Repayments Of Bank Overdrafts, Less Short Term Debt Change in cash overdraft position Proceeds from issuance of common stock under dividend reinvestment plan Proceeds from stock options exercised Proceeds from exercised stock options Payments For Repurchase Of Common Stock Repurchase of common stock Payments Of Dividends Common Stock Dividends paid on common stock Proceeds from (Payments for) Other Financing Activities Other Net cash flows from financing activities Net cash flows from (used in) financing activities Net increase in cash and cash equivalents Net change in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents at end of period Cash and cash equivalents at beginning of period Non-cash investing activities: Property, plant and equipment additions purchased at the period end, but not yet paid for Non-Cash Customer Advances And Contributions In Aid Of Construction Non-Cash Customer Advances And Contributions In Aid Of Construction Non-cash customer advances and contributions in aid of construction Debt component of allowance for funds used during construction Debt component of allowance for funds used during construction Basis Of Presentation [Abstract] Organization Consolidation And Presentation of Financial Statements Disclosure [Text Block] Basis Of Presentation Revenue Recognition [Abstract] Revenue from Contract with Customer [Text Block] Revenue Recognition Acquisitions [Abstract] Business Combination Disclosure [Text Block] Acquisitions Goodwill [Abstract] Goodwill And Intangible Assets Disclosure Text Block Goodwill Capitalization [Abstract] Capitalization Disclosure [Text Block] Capitalization Disclosure [Text Block] Capitalization Financial Instruments [Abstract] Fair Value Disclosures [Text Block] Financial Instruments Earnings Per Share [Text Block] Net Income Per Common Share Stock-Based Compensation [Abstract] Disclosure Of Compensation Related Costs Share Based Payments Text Block Stock-Based Compensation Pension Plans And Other Postretirement Benefits [Abstract] Pension And Other Postretirement Benefits Disclosure [Text Block] Pension Plans And Other Postretirement Benefits Water and Wastewater Rates Rate Activity [Abstract] Public Utilities Disclosure [Text Block] Rate Activity Taxes Other than Income Taxes Taxes Other Than Income Taxes [Abstract] Utilities Operating Expenses, Taxes As In Annual Report [Text Block] Utilities Operating Expenses, Taxes As In Annual Report [Text Block] Taxes Other Than Income Taxes Segment Information [Abstract] Segment Reporting Disclosure [Text Block] Segment Information Commitments And Contingencies [Abstract] Commitments and Contingencies Disclosure [Text Block] Commitments And Contingencies Income Taxes [Abstract] Income Tax Disclosure Text Block Income Taxes Recent Accounting Pronouncements [Abstract] Schedule Of New Accounting Pronouncements And Changes In Accounting Principles [Text Block] Recent Accounting Pronouncements Disaggregation of Revenue [Table Text Block] Schedule Of Disaggregation Of Revenue Schedule of Goodwill [Text Block] Schedule Of Goodwill Available-for-sale Securities [Table Text Block] Summary Of Unrealized Gain And Losses Fair Value, by Balance Sheet Grouping [Text Block] Schedule Of Carrying Amounts And Estimated Fair Values Of Long-Term Debt Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule Of Earnings Per Share Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Award Type and Plan Name [Axis] Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Share-based Compensation Arrangements by Share-based Payment Award, Award Type and Plan Name [Domain] Performance Share Units [Member] Performance Share Units [Member] Performance Share Units [Member] Restricted Stock Units R S U [Member] Restricted Stock Units [Member] Employee Stock Option [Member] Stock Options [Member] Restricted Stock [Member] Restricted Stock [Member] Stock Compensation Plan [Member] Stock Awards [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Summary Of Compensation Costs Schedule of Nonvested Performance-based Units Activity [Table Text Block] Summary Of PSU Transactions Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Summary Of RSU Transactions Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block] Assumptions Used In The Pricing Model Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Summary Of Stock Option Transactions Schedule of Nonvested Share Activity [Table Text Block] Summary Of Nonvested Share Activity Nonvested Restricted Stock Shares Activity [Table Text Block] Summary Of Restricted Stock Transactions Utilities Operating Expenses, Taxes As In Annual Report [Table Text Block] Utilities Operating Expenses, Taxes As In Annual Report [Table Text Block] Components Of Taxes Other Than Income Taxes Reconciliation of Revenue from Segments to Consolidated [Text Block] Company's Segment Information, Continuing Operations Reconciliation of Assets from Segment to Consolidated [Text Block] Company's Segment Information, Assets Disaggregation of Revenue [Table] Product and Service [Axis] Products And Services [Domain] Product and Service [Domain] Water [Member] Water [Member] Water [Member] Wastewater [Member] Wastewater [Member] Wastewater [Member] Natural Gas [Member] Natural Gas [Member] Natural Gas [Member] Other [Member] Other [Member] Other [Member] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Consolidation Eliminations [Member] Other And Eliminations [Member] Customer [Axis] Name Of Major Customer [Domain] Customer [Domain] Residential [Member] Residential [Member] Residential [Member] Commercial [Member] Commercial [Member] Commercial [Member] Fire Protection [Member] Fire Protection [Member] Fire Protection [Member] Industrial [Member] Industrial [Member] Industrial [Member] Gas Transportation [Member] Gas Transportation [Member] Gas Transportation [Member] Other Water [Member] Other Water [Member] Other Water [Member] Other Wastewater [Member] Other Wastewater [Member] Other Wastewater [Member] Other Utility [Member] Other Utility [Member] Other Utility [Member] Alternative Revenue Program [Member] Alternative Revenue Program [Member] Alternative Revenue Program [Member] Disaggregation of Revenue [Line Items] Revenue from Contract with Customer, Excluding Assessed Tax Revenues from contracts with customers Schedule of Business Acquisitions, by Acquisition [Table] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Geographical [Axis] Segment Geographical [Domain] Geographical [Domain] I [L] Illinois [Member] P [A] Pennsylvania [Member] D [E] Delaware [Member] Business Acquisition [Axis] Business Acquisition Acquiree [Domain] Business Acquisition, Acquiree [Domain] Water Utility System [Member] Water Utility System [Member] Water Utility System [Member] Wastewater Utility Systems In Various States [Member] Wastewater Utility Systems In Various States [Member] Water And Wastewater Utility Systems [Member] Wastewater Utility System [Member] Wastewater Utility System [Member] Wastewater Utility System [Member] Business Acquisition [Line Items] Number of customers. Number of customers Number Of Retail Customers Number Of Retail Customers Retail customers Number Of Municipalities Number Of Municipalities Municipalities Business Combination, Consideration Transferred Total purchase price Face Amount Debt instrument, issued Proceeds from Convertible Debt Proceeds from tangible equity units Private Placement, Per Share Private placement, per share Schedule of Goodwill [Table] Statement, Business Segments [Axis] Segment [Domain] Segment [Domain] Corporate And Other [Member] Other [Member] Goodwill [Line Items] Reclassification Of Goodwill, Acquisition Adjustment Reclassification Of Goodwill, Acquisition Adjustment Reclassification to utility plant acquisition adjustment Schedule of Long-term Debt Instruments [Table] LDC Funding LLC [Member] Ldc Funding Llc [Member] LDC Funding LLC [Member] Legal Entity [Axis] Entity [Domain] Entity [Domain] Aqua Ohio, Inc [Member] Aqua Ohio Inc [Member] Aqua Ohio, Inc [Member] Aqua Pennsylvania, Inc [Member] Aqua Pennsylvania Inc [Member] Aqua Pennsylvania, Inc [Member] Long-term Debt, Type [Axis] Longterm Debt Type [Domain] Long-term Debt, Type [Domain] Long-Term Debt [Member] Long Term Debts [Member] Long-Term Debts [Member] Mortgage Bonds [Member] Mortgage Bonds [Member] Mortgage Bonds [Member] Mortgage Bonds 2 [Member] Mortgage Bonds2 [Member] Mortgage Bonds Due 2031 [Member] Mortgage Bonds 3 [Member] Mortgage Bonds3 [Member] Mortgage Bonds Due 2051 [Member] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Unsecured Credit Facility [Member] Unsecured Credit Facility [Member] Unsecured Credit Facility [Member] Scenario [Axis] Scenario Unspecified [Domain] Scenario, Unspecified [Domain] Initial Forward Equity Sale Agreement [Member] Initial Forward Equity Sale Agreement [Member] Initial Forward Equity Sale Agreement [Member] Forward Equity Sale Agreement [Member] Forward Equity Sale Agreement [Member] Forward Equity Sale Agreement [Member] Date [Member] Date [Member] July 30, 2019 [Member] Debt Instrument [Line Items] Proceeds from Issuance of Private Placement Proceeds from private placement Derivative, Forward Price Forward price Stock Purchase Contracts, Shares Settled During Period Stock Purchase Contracts, Shares Settled During Period Stock purchase contracts early settled by holders of the contracts Stock Purchase Contracts, Shares Settled Stock Purchase Contracts, Shares Settled Shares settled Debt Instrument, Convertible, Settlement Debt Instrument, Convertible, Settlement Conversion to shares Debt Instrument, Convertible, If-converted Value in Excess of Principal Initial principal amount Debt Instrument Convertible Beneficial Conversion Feature Per Share Debt Instrument Convertible Beneficial Conversion Feature Per Share Initial principal amount per share Debt Instrument, Convertible, Cash Installment Debt Instrument, Convertible, Cash Installment Cash installment Debt Instrument, Convertible, Cash Installment Rate Debt Instrument, Convertible, Cash Installment Rate Cash installment rate Debt Instrument, Maturity Date Maturity Line of Credit Facility, Maximum Borrowing Capacity Borrowing capacity Payments Of Warrant Issuance Costs Debt issuance expense Debt term Debt Instrument, Maturity Year Debt Instrument, Maturity Year Maturity Year Repayments of Long-Term Lines of Credit Repayment of line of credit Fair Value, by Balance Sheet Grouping [Table] Fair Value Hierarchy and NAV [Axis] Fair Value Measurements Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value Inputs Level1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Loans Payable, Fair Value Disclosure Loans payable Investments, Fair Value Disclosure Mutual funds Equity Securities, FV-NI, Gain (Loss) Net gain recognized during the period on equity securities Equity Securities, FV-NI, Realized Gain (Loss) Less: net gain / loss recognized during the period on equity securities sold during the period Equity Securities, FV-NI, Unrealized Gain (Loss) Unrealized gain recognized during the reporting period on equity securities still held at the reporting date Measurement Basis [Axis] Portion At Fair Value Fair Value Disclosure [Member] Portion at Fair Value Measurement [Member] Carrying Reported Amount Fair Value Disclosure [Member] Carrying Amount [Member] Estimate Of Fair Value Fair Value Disclosure [Member] Estimated Fair Value [Member] Long Term Debt Fair Value Long-term debt Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Employee stock options excluded from calculations of diluted net income per share Average Common Shares Outstanding, Included In Computation Average Common Shares Outstanding, Included In Computation Average common shares outstanding, included in computation Effect of dilutive securities: Incremental Common Shares Attributable to Dilutive Effect of Equity Forward Agreements Forward equity sale agreement Incremental Common Shares Attributable to Share-based Payment Arrangements Employee stock-based compensation Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Two Thousand And Four Omnibus Equity Compensation Plan [Member] Two Thousand And Four Omnibus Equity Compensation Plan [Member] 2004 Plan [Member] Amended and Restated Equity Compensation Plan [Member] Amended And Restated Equity Compensation Plan [Member] Amended and Restated Equity Compensation Plan [Member] Vesting [Axis] Vesting [Domain] Vesting [Domain] Share Based Compensation Award Tranche One [Member] Share-based Payment Arrangement, Tranche One [Member] Share Based Compensation Award Tranche Two [Member] Share-based Payment Arrangement, Tranche Two [Member] Share Based Compensation Award Tranche Three [Member] Share-based Payment Arrangement, Tranche Three [Member] Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Number of shares authorized for issuance Maximum Number Of Shares May Be Issued Pursuant To Stock Awards, Stock Units And Other Stock-Based Awards Maximum Number Of Shares May Be Issued Pursuant To Stock Awards, Stock Units And Other Stock-Based Awards Maximum number of shares may be issued pursuant to stock awards, stock units and other stock-based awards Share-based Compensation Arrangement by Share-based Payment Award, Maximum Shares Per Employee Maximum number of shares subject to grants to any one individual in any one year Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Underlying stock option and restricted stock awards available for grant Performance Period Specified In Grant Performance Period Specified In Grant Performance period specified in grant, in years Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period Granted, Shares Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period Vesting period, start, in years Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Vesting period, in years Restricted Stock Units Restricted Period Restricted Stock Units Restricted Period Restricted period Percentage of target award amount the participant may earn Percentage Of Target Award Amount The Participant May Earn Percentage of target award amount the grantee may earn Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Granted, Weighted Average Fair Value Weighted average fair value of stock awards granted Share based compensation arrangement by share based payment award amortization period of fair value of shares Share based compensation arrangement by share based payment award Amortization Period Of Fair Value of Shares Amortization period of fair value of shares, in months Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Nonvested share units at end of period, Number of Share Units Nonvested share units at beginning of period, Number of Share Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Forfeited, Number of Share Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Stock units vested and issued, Number of Share Units Vested, number of shares Share units vested in prior period and issued in current period, Number of Share Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Nonvested share units at end of period, Weighted Average Fair Value Nonvested share units at beginning of period, Weighted Average Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period, Weighted Average Grant Date Fair Value Forfeited, Weighted Average Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Share units vested, Weighted Average Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost Stock-based compensation within operations and maintenance expenses Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Income tax benefit Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Expected term (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Dividend yield Share-based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Grant Date Fair Value Share-based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Grant Date Fair Value Grant date fair value per option Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Outstanding at end of period, Shares Outstanding at beginning of period, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Forfeited, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Expired, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Exercisable at end of period, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Outstanding at end of period, Weighted Average Exercise Price Outstanding at beginning of period, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Granted, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Forfeited, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Expired, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Exercised, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Exercisable at end of period, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Outstanding at end of period, Weighted Average Remaining Life (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Exercisable at end of period, Weighted Average Remaining Life (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Outstanding at end of period, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Exercisable at end of period, Aggregate Intrinsic Value Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan, Contributions by Employer Cash contributions made by the Company Retirement Plan Type [Axis] Retirement Plan Type [Domain] Defined Benefit Plans and Other Postretirement Benefit Plans [Domain] Pension Plans Defined Benefit [Member] Pension Benefits [Member] Other Postretirement Benefit Plans Defined Benefit [Member] Other Postretirement Benefits [Member] Defined Benefit Plan, Service Cost Service cost Defined Benefit Plan, Interest Cost Interest cost Defined Benefit Plan, Expected Return on Plan Assets Expected return on plan assets Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of prior service cost (credit) Defined benefit plan amortization of actuarial loss. Defined benefit plan amortization of actuarial loss Amortization of actuarial loss Defined Benefit Plan, Net Periodic Benefit Cost Net periodic benefit cost (credit) Water And Wastewater Rates [Table] Water And Wastewater Rates [Table] Year 1 [Member] Year1 [Member] Year 1 [Member] Year 2 [Member] Year2 [Member] Year 2 [Member] Year 3 [Member] Year3 [Member] Year 3 [Member] Illinois and North Carolina [Member] Illinois And North Carolina [Member] Illinois And North Carolina [Member] New Jersey, Ohio And Indiana [Member] New Jersey Ohio And Indiana [Member] New Jersey, Ohio And Indiana [Member] N [C] North Carolina [Member] O [H] Ohio [Member] Water And Wastewater Rates [Line Items] Water And Wastewater Rates [Line Items] Authorized increase in revenue from utility service on an annualized basis. Authorized increase in revenue from utility service Authorized increase in revenue Public Utilities, Approved Rate Increase (Decrease), Amount Base rate increase (decrease) Base rate increase designed to increase total operating revenues on an annual basis Base rate increase designed to increase total operating revenues on an annual basis Distribution System Improvement Charges Reset Level Upon New Base Rates Distribution System Improvement Charges Reset Level Upon New Base Rates Distribution system improvement charges reset level upon new base rates Taxes Other Than Income Taxes [Table] Taxes Other Than Income Taxes [Table] Property [Member] Property [Member] Property [Member] Gross Receipts, Excise and Franchise [Member] Gross Receipts Excise And Franchise [Member] Gross Receipts, Excise And Franchise [Member] Payroll [Member] Payroll [Member] Payroll [Member] Regulatory assessments [Member] Regulatory Assessments [Member] Regulatory Assessments [Member] Pumping Fees [Member] Pumping Fees [Member] Pumping Fees [Member] Other Taxes [Member] Other Taxes [Member] Other [Member] Taxes Other Than Income [Line Items] Taxes Other Than Income [Line Items] Schedule of Segment Reporting Information, by Segment [Table] Segment Reporting Information [Line Items] Number of Operating Segments Operating Segments Number of Reportable Segments Reportable Segments Operating Segments [Member] Regulated [Member] Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Interest expense, net of AFUDC which represents capitalized costs used to finance the construction of utility plants. Interest Expense Net Of Afudc Interest expense, net Non-operating Income Expense Other Non-operating Income Expense Other Other Loss Contingency, Estimate of Possible Loss Aggregate amount accrued for loss contingencies Estimated Insurance Recoveries Amount probable of recovery through insurance Self Insurance Reserve Insurance reserve for employee medical benefit program Proceeds from Insurance Settlement, Operating Activities Insurance proceeds Income Tax Authority [Table] Income Tax Authority [Table] Income Taxes [Line Items] Income Taxes [Line Items] Effective Income Tax Rate, Continuing Operations Effective income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Corporate federal income tax rate Effective Income Tax Rate Reconciliation, at State Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, at State Statutory Income Tax Rate, Percent Contract With Customer, Refund Payments Contract With Customer, Refund Payments Refunded payments Regulatory Liabilities T [X] Texas [Member] Lower Makefield Township [Member] Lower Makefield Township [Member] Lower Makefield Township [Member] Southern Oaks [Member] Southern Oaks [Member] Southern Oaks [Member] Revolving Credit Facility [Member] Revolving Credit Facility [Member] K [Y] Kentucky [Member] Natural Gas Accounts Receivable [Member] Natural Gas Accounts Receivable [Member] Natural Gas Accounts Receivable [Member]