Document and Entity Information [Abstract] Document And Entity Information [Abstract] Statement [Table] Statement [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Trading Symbol Entity Well-known Seasoned Issuer Entity Current Reporting Status Entity Voluntary Filers Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Public Float Entity Common Stock, Shares Outstanding Consolidated Balance Sheets [Abstract] Assets Property, plant and equipment, at cost Total property, plant and equipment Less: accumulated depreciation Net property, plant and equipment Net property, plant and equipment Current assets: Cash and cash equivalents Cash and cash equivalents at end of year Cash and cash equivalents at beginning of year Accounts receivable and unbilled revenues, net Accounts receivable, net Inventory, materials and supplies Prepaid Expense and Other Assets, Current Prepayments and other current assets Assets of Disposal Group, Including Discontinued Operation, 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 Investment in subsidiaries Goodwill Balance Balance Goodwill Total assets Total assets Liabilities and Equity Aqua America stockholders' equity: Common stock at $.50 par value, authorized 300,000,000 shares ,issued 142,225,713 and 140,943,621 in 2013 and 2012 Common stock at $.50 par value, authorized 300,000,000 shares, issued 181,151,827 and 180,700,251 in 2018 and 2017 Common stock, $.50 par value Additional Paid In Capital Common Stock Capital in excess of par value Retained Earnings Accumulated Deficit Retained earnings Aqua Pennsylvania's retainied earnings including minority interest Treasury stock, at cost Treasury stock, at cost, 3,060,206 and 2,986,308 shares in 2018 and 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 Total stockholders' equity Stockholders' equity Debt Instrument Carrying Amount Noncurrent Debt Instrument Carrying Amount Noncurrent Long-term debt, excluding current portion Debt Issuance Costs, Noncurrent, Net Less: debt issuance costs Long Term Debt Noncurrent Long-term debt, excluding current portion, net of debt issuance costs Long-term debt, excluding current portion, net of debt issuance costs Long-term debt, excluding current portion, net of debt issuance costs Commitments and contingencies 2009 Commitments and contingencies (See Note 9) Current liabilities: Current portion of long-term debt Loans payable Accounts payable Bank Overdrafts Book overdraft Interest Payable, Current Accrued interest Accrued taxes Derivative Instruments and Hedges, Liabilities Interest rate swap agreements 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 Other liabilities 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, authorized Common stock, shares issued Treasury stock, shares Treasury 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 Total taxes other than income taxes Taxes other than income taxes Total expenses Total operating expenses Operating income Operating income (loss) Operating income Operating income Other expense (income): Interest Expense 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 Derivative Instruments, Net, Pretax Interest rate swap agreements Change in fair value of interest rate swap agreements Gain Loss On Sale Of Other Assets Gain 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 Expense Other Other (income) expense Other Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Loss before equity in earnings of subsidiaries and income taxes Income before income taxes Provision for income taxes (benefit) Provision for income taxes (benefit) Total tax expense Net income attributable to common shareholders Net income Net income (loss) Net income Net Income Per Common Share and Equity per Commn Share [Abstract] Net income per common share: Earnings Per Share Basic Basic net income (loss) per common share Basic Earnings Per Share Diluted Diluted net income (loss) per common share 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 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 $102, and $21, for the years ended December 31, 2017, and 2016, respectively Reclassification adjustment for (gains) losses reported in net income Reclassification of gain on sale of investment to net income, net of tax expense of $30 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 Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Tax Income tax expense arising from reclassification adjustment for loss (gain) reported in net income Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax Pre-tax gain of reclassification adjustment for gain reported in net income 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 One [Member] Long Term Debt Of Subsidiaries One [Member] Long Term Debt of Subsidiaries 0.00% to 0.99% [Member] Long Term Debt of Subsidiaries Two [Member] Long Term Debt Of Subsidiaries Two [Member] Long Term Debt of Subsidiaries 1.00% to 1.99% [Member] Long Term Debt of Subsidiaries Three [Member] Long Term Debt Of Subsidiaries Three [Member] Long Term Debt of Subsidiaries 2.00% to 2.99% [Member] Long Term Debt of Subsidiaries Four [Member] Long Term Debt Of Subsidiaries Four [Member] Long Term Debt of Subsidiaries 3.00% to 3.99% [Member] Long Term Debt of Subsidiaries Five [Member] Long Term Debt Of Subsidiaries Five [Member] Long Term Debt of Subsidiaries 4.00% to 4.99% [Member] Long Term Debt of Subsidiaries Six [Member] Long Term Debt Of Subsidiaries Six [Member] Long Term Debt of Subsidiaries 5.00% to 5.99% [Member] Long Term Debt of Subsidiaries Seven [Member] Long Term Debt Of Subsidiaries Seven [Member] Long Term Debt of Subsidiaries 6.00% to 6.99% [Member] Long Term Debt of Subsidiaries Eight [Member] Long Term Debt Of Subsidiaries Eight [Member] Long Term Debt of Subsidiaries 7.00% to 7.99% [Member] Long Term Debt of Subsidiaries Nine [Member] Long Term Debt Of Subsidiaries Nine [Member] Long Term Debt of Subsidiaries 8.00% to 8.99% [Member] Long Term Debt of Subsidiaries Ten [Member] Long Term Debt Of Subsidiaries Ten [Member] Long Term Debt of Subsidiaries 9.00% to 9.99% [Member] Long Term Debt of Subsidiaries Eleven [Member] Long Term Debt Of Subsidiaries Eleven [Member] Long-Term Debt Of Subsidiaries 10.00% To 10.99% [Member] Unsecured Notes B [Member] Unsecured Notes B [Member] Notes Ranging From 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 2019 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 2020 through 2037 [Member] Long-term debt of subsidiaries (substantially collateralized by utility plant): Debt Instrument, Principal Outstanding Debt instrument principal outstanding Long-term debt1 Long-term debt 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 Long-term debt and capital lease obligations Total long-term debt Total capitalization Total capitalization Range [Axis] Range [Member] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Notes Payable Under Revolving Credit [Member] Notes Payable Under Revolving Credit [Member] Notes payable to bank under revolving credit agreement, variable rate, due 2023 [Member] Mortgage Bonds, Interest Rate, Stated Percentage Interest Rate Range 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] Common Stock [Member] Common Stock [Member] Retained Earnings [Member] Retained Earnings [Member] Treasury Stock [Member] Treasury Stock [Member] Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Income [Member] Total equity Balance Balance Other Comprehensive Income (Loss), Net of Tax Other comprehensive income (loss), net of income tax Dividends Dividends declared Stock Issued During Period, Value, Acquisitions Stock issued for acquisition Issuance of common stock under dividend reinvestment plan 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 Employee stock plan tax benefits Cumulative Effect of New Accounting Principle in Period of Adoption Cumulative effect of change in accounting principle - windfall tax benefit Adjustments to Additional Paid in Capital, Other Other Consolidated Statement Of Equity (Parenthetical) [Abstract] Other Comprehensive Income (Loss), Tax Other comprehensive income (loss) tax Cash dividends declared per common share Dividend declared per common share Stock Issued During Period, Shares, Acquisitions Stock issued for acquisition, shares Sale Of Stock, Shares Sale of stock, shares Stock Repurchased During Period, 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 Flows [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 Total deferred income taxes Provision for doubtful accounts Share Based Compensation Stock-based compensation Gain (Loss) on Sale of Business Loss (gain) on sale of utility system and 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 $3,332, $3,578, and $2,220 Capital expenditures Payments to Acquire Waste Water Systems Acquisitions of utility systems and other, net Proceeds from sale of utility system and other Proceeds from sale of utility system and other Net proceeds from the sale of utility systems and other assets Other 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 (repayments) 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 Share-based compensation windfall tax benefits Share-based compensation windfall tax benefits 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