Document and Entity Information [Abstract] Document And Entity Information [Abstract] Statement [Table] Statement [Line Items] Document Type Trading Symbol 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 Small Business Entity Emerging Growth Company Entity Common Stock, Shares Outstanding 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 and unbilled revenues, net Inventory, materials and supplies Prepayments and other current assets Assets Held-for-sale, Not Part of Disposal Group, Current Assets held for sale Total current assets Total current assets Regulatory Assets Noncurrent Regulatory assets Deferred Costs and Other Assets Deferred charges and other assets, net Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Investment in joint venture Goodwill Balance Balance Goodwill Total Assets Total assets Total assets Liabilities and Equity Stockholders' equity: Common stock authorized and issued Common stock at $.50 par value, authorized 300,000,000 shares, issued 180,998,152 and 180,700,251 as of September 30, 2018 and December 31, 2017 Common stock, $.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, 3,058,273 and 2,986,308 shares as of September 30, 2018 and December 31, 2017 Treasury stock, at cost Accumulated Other Comprehensive Income Loss Net Of Tax Accumulated other comprehensive income Accumulated other comprehensive income 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 14) Current liabilities: Current portion of long-term debt Loans payable Accounts payable Bank Overdrafts Book overdraft Interest Payable, Current Accrued interest Accrued taxes 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 Other Liabilities Noncurrent Other Liabilities, Other than Long-term Debt, Noncurrent 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 Net Income [Abstract] Operating revenues Revenue Cost and expenses: Operating expenses: Utilities Operating Expense Maintenance And Operations Operations and maintenance Operations and maintenance expense Depreciation Amortization Taxes other than income taxes Total taxes other than income Total expenses Total operating expenses Operating income Operating income Operating income (loss) Other expense (income): Interest expense, net Public Utilities Allowance For Funds Used During Construction Additions Allowance for funds used during construction Allowance for funds used during construction Gain Loss On Sale Of Other Assets Gain on sale of other assets Net Income (Loss) Attributable to Noncontrolling Interest, Joint Venture Partners Equity earnings in joint venture Other Nonoperating Income (Expense) Other Income from continuing operations before income taxes Income before income taxes Provision for income taxes Provision for income taxes Net income attributable to common shareholders Net income Net income Net income (loss) 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 Cash dividends declared per common share Consolidated Statements Of Comprehensive Income [Abstract] Other comprehensive income, net of tax: Unrealized holding gain on investments, net of income tax Unrealized holding gain on investments, net of tax expense of $22 for the three months, and $73 for the nine months ended September 30, 2017, respectively Comprehensive income Comprehensive income Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax Income taxes arising from net unrealized holding gain on investments 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] Bank Note At One Point Nine Two One Percent [Member] Bank Note At One Point Nine Two One Percent [Member] Bank notes at 2.48% and 3.5% due 2019 and 2020 [Member] Notes Ranges B [Member] Notes Ranges B [Member] Notes at 3.01% and 3.59% due 2027 and 2041 [Member] Notes Ranging From four point six two percentage to four point eight seven percentage [Member] Notes Ranging From Four Point Six Two Percentage To Four Point Eight Seven Percentage [Member] Notes Ranging From 4.62% To 4.87%, due 2018 through 2024 [Member] Notes Ranging From Five Point Zero One Percentage To Five Point Nine Five Percentage [Member] Notes Ranging From Five Point Zero One Percentage To Five Point Nine Five Percentage [Member] Notes Ranging From 5.20% To 5.95%, due 2018 through 2037 [Member] Long-term debt: Secured Debt Long-term debt of subsidiaries Other Notes Payable, Noncurrent Notes payable to bank under revolving credit agreement, variable rate, due 2021 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 Range [Axis] Range [Member] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Long Term Debt Of Subsidiaries Ten Point Zero Zero Percentage To Ten Point Nine Nine Percentage [Member] Long Term Debt Of Subsidiaries Ten Point Zero Zero Percentage To Ten Point Nine Nine Percentage [Member] Long-Term Debt Of Subsidiaries 10.00% To 10.99% [Member] Revolving Credit Agreement, Due B Revolving Credit Agreement Due B [Member] Revolving Credit Agreement, Due 2021 [Member] Notes B [Member] Notes B [Member] Notes at 3.01% due 2027 [Member] Notes C [Member] Notes C [Member] Notes at 3.59% due 2041 [Member] Interest Rate Interest rate Debt Instrument, Maturity Date, Year Debt Instrument, Maturity Date, Year Maturity date Consolidated Statement 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] Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Income [Member] Dividends paid Dividends Issuance of common stock under dividend reinvestment plan (32,863 shares) Repurchase of stock (414,869 shares) Repurchase of stock (71,965 shares) Stock granted during period, value share-based compensation Equity compensation plan (190,062 shares) Stock Issued During Period, Value, Stock Options Exercised Exercise of stock options (74,976 shares) 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 Cumulative Effect on Retained Earnings, Net of Tax Cumulative effect of change in accounting principle - financial instruments Other Consolidated Statement Of Equity (Parenthetical) [Abstract] Sale Of Stock, Shares Issuance of common stock under dividend reinvestment plan, 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 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 Loss on sale of market-based business unit Net decrease in receivables, inventory 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 $2,550 and $2,533 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 market-based business unit and 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 proceeds of short-term debt Proceeds from long-term debt Repayments of long-term debt Repayments of long-term debt Change in cash overdraft position Proceeds from issuing common stock 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 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 Goodwill [Abstract] Goodwill And Intangible Assets Disclosure Text Block Goodwill Acquisitions [Abstract] Business Combination Disclosure [Text Block] Acquisitions