| **Schedule 1 - Condensed Parent Company Financial Statements (Condensed Statements of Cash Flows) (Details) (USD $)In Thousands, unless otherwise specified** | 12 Months Ended                                                                                                              |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------|
||
| **Condensed Cash Flow Statements, Captions [Line Items]**                                                                                                     |                                                                                                                         |   |   |   |   |
| Net cash flows from operating activities                                                                                                                      | $ 363,788us-gaap_NetCashProvidedByUsedInOperatingActivities                                                                  | $ 367,819us-gaap_NetCashProvidedByUsedInOperatingActivities | $ 368,407us-gaap_NetCashProvidedByUsedInOperatingActivities |   |   |
| Property, plant and equipment additions                                                                                                                       | (328,605)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment                                                                  | (307,908)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment | (347,098)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment | (324,360)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment | (306,216)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment |
| Acquisitions of utility systems and other, net                                                                                                                | (14,616)us-gaap_PaymentsToAcquireWasteWaterSystems                                                                           | (14,997)us-gaap_PaymentsToAcquireWasteWaterSystems | (121,248)us-gaap_PaymentsToAcquireWasteWaterSystems |   |   |
| Net proceeds from the sale of utility system and other assets                                                                                                 | 558wtr_ProceedsFromSaleOfUtilitySystemAndOther                                                                               | 5,315wtr_ProceedsFromSaleOfUtilitySystemAndOther | 3,819wtr_ProceedsFromSaleOfUtilitySystemAndOther |   |   |
| Other                                                                                                                                                         | 279us-gaap_PaymentsForProceedsFromOtherInvestingActivities                                                                   | 76us-gaap_PaymentsForProceedsFromOtherInvestingActivities | (1,512)us-gaap_PaymentsForProceedsFromOtherInvestingActivities |   |   |
| Net cash flows used in investing activities                                                                                                                   | (292,501)us-gaap_NetCashProvidedByUsedInInvestingActivities                                                                  | (221,563)us-gaap_NetCashProvidedByUsedInInvestingActivities | (364,675)us-gaap_NetCashProvidedByUsedInInvestingActivities |   |   |
| Net repayments of short-term debt                                                                                                                             | (18,342)us-gaap_ProceedsFromRepaymentsOfShortTermDebt                                                                        | (43,643)us-gaap_ProceedsFromRepaymentsOfShortTermDebt | (27,388)us-gaap_ProceedsFromRepaymentsOfShortTermDebt |   |   |
| Proceeds from long-term debt                                                                                                                                  | 317,699us-gaap_ProceedsFromIssuanceOfLongTermDebt                                                                            | 263,834us-gaap_ProceedsFromIssuanceOfLongTermDebt | 300,109us-gaap_ProceedsFromIssuanceOfLongTermDebt |   |   |
| Repayments of long-term debt                                                                                                                                  | (253,192)us-gaap_RepaymentsOfLongTermDebt                                                                                    | (300,323)us-gaap_RepaymentsOfLongTermDebt | (202,203)us-gaap_RepaymentsOfLongTermDebt |   |   |
| Change in cash overdraft position                                                                                                                             | (322)us-gaap_ProceedsFromRepaymentsOfBankOverdrafts                                                                          | 9,872us-gaap_ProceedsFromRepaymentsOfBankOverdrafts | (10,929)us-gaap_ProceedsFromRepaymentsOfBankOverdrafts |   |   |
| Proceeds from issuing common stock                                                                                                                            |                                                                                                                         | 10,290us-gaap_ProceedsFromIssuanceOfCommonStock | 13,190us-gaap_ProceedsFromIssuanceOfCommonStock |   |   |
| Proceeds from exercised stock options                                                                                                                         | 7,296us-gaap_ProceedsFromStockOptionsExercised                                                                               | 25,698us-gaap_ProceedsFromStockOptionsExercised | 14,598us-gaap_ProceedsFromStockOptionsExercised |   |   |
| Share-based compensation windfall tax benefits                                                                                                                | 1,422us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities                                                   | 2,420us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities |   |   |   |
| Repurchase of common stock                                                                                                                                    | (15,756)us-gaap_PaymentsForRepurchaseOfCommonStock                                                                           | (12,823)us-gaap_PaymentsForRepurchaseOfCommonStock | (1,464)us-gaap_PaymentsForRepurchaseOfCommonStock |   |   |
| Dividends paid on common stock                                                                                                                                | (112,106)us-gaap_PaymentsOfDividendsCommonStock                                                                              | (102,889)us-gaap_PaymentsOfDividendsCommonStock | (93,423)us-gaap_PaymentsOfDividendsCommonStock | (87,133)us-gaap_PaymentsOfDividendsCommonStock | (80,907)us-gaap_PaymentsOfDividendsCommonStock |
| Other                                                                                                                                                         | (793)us-gaap_ProceedsFromPaymentsForOtherFinancingActivities                                                                 |   |   |   |   |
| Net cash flows used in financing activities                                                                                                                   | (72,207)us-gaap_NetCashProvidedByUsedInFinancingActivities                                                                   | (146,719)us-gaap_NetCashProvidedByUsedInFinancingActivities | (6,415)us-gaap_NetCashProvidedByUsedInFinancingActivities |   |   |
| Net decrease in cash and cash equivalents                                                                                                                     | (920)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease                                                                    | (463)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease | (2,683)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease |   |   |
| Cash and cash equivalents at beginning of year                                                                                                                | 5,058us-gaap_CashAndCashEquivalentsAtCarryingValue                                                                           | 5,521us-gaap_CashAndCashEquivalentsAtCarryingValue | 8,204us-gaap_CashAndCashEquivalentsAtCarryingValue |   |   |
| Cash and cash equivalents at end of year                                                                                                                      | 4,138us-gaap_CashAndCashEquivalentsAtCarryingValue                                                                           | 5,058us-gaap_CashAndCashEquivalentsAtCarryingValue | 5,521us-gaap_CashAndCashEquivalentsAtCarryingValue | 8,204us-gaap_CashAndCashEquivalentsAtCarryingValue |   |
| Aqua America, Inc. [Member]                                                                                                                                   |                                                                                                                         |   |   |   |   |
| **Condensed Cash Flow Statements, Captions [Line Items]**                                                                                                     |                                                                                                                         |   |   |   |   |
| Net cash flows from operating activities                                                                                                                      | 114,465us-gaap_NetCashProvidedByUsedInOperatingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                  | 159,144us-gaap_NetCashProvidedByUsedInOperatingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | 44,097us-gaap_NetCashProvidedByUsedInOperatingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Acquisitions of utility systems and other, net                                                                                                                | (9,329)us-gaap_PaymentsToAcquireWasteWaterSystems/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                          | (266)us-gaap_PaymentsToAcquireWasteWaterSystems/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | (105,160)us-gaap_PaymentsToAcquireWasteWaterSystems/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Net proceeds from the sale of utility system and other assets                                                                                                 |                                                                                                                         |   | 79,560wtr_ProceedsFromSaleOfUtilitySystemAndOther/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Decrease (increase) in investment of subsidiary                                                                                                               | 744wtr_IncreaseDecreaseInInvestmentOfSubsidiary/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                            | 50,337wtr_IncreaseDecreaseInInvestmentOfSubsidiary/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | (54,574)wtr_IncreaseDecreaseInInvestmentOfSubsidiary/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Other                                                                                                                                                         | (733)us-gaap_PaymentsForProceedsFromOtherInvestingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember               | (267)us-gaap_PaymentsForProceedsFromOtherInvestingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | (3,681)us-gaap_PaymentsForProceedsFromOtherInvestingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Net cash flows used in investing activities                                                                                                                   | (9,318)us-gaap_NetCashProvidedByUsedInInvestingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                  | 49,804us-gaap_NetCashProvidedByUsedInInvestingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | (83,855)us-gaap_NetCashProvidedByUsedInInvestingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Net repayments of short-term debt                                                                                                                             |                                                                                                                         |   | (5,000)us-gaap_ProceedsFromRepaymentsOfShortTermDebt/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Proceeds from long-term debt                                                                                                                                  | 170,790us-gaap_ProceedsFromIssuanceOfLongTermDebt/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                          | 98,956us-gaap_ProceedsFromIssuanceOfLongTermDebt/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | 210,317us-gaap_ProceedsFromIssuanceOfLongTermDebt/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Repayments of long-term debt                                                                                                                                  | (156,000)us-gaap_RepaymentsOfLongTermDebt/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                                  | (230,600)us-gaap_RepaymentsOfLongTermDebt/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | (99,212)us-gaap_RepaymentsOfLongTermDebt/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Proceeds from issuing common stock                                                                                                                            |                                                                                                                         | 10,290us-gaap_ProceedsFromIssuanceOfCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | 13,190us-gaap_ProceedsFromIssuanceOfCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Proceeds from exercised stock options                                                                                                                         | 7,296us-gaap_ProceedsFromStockOptionsExercised/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                             | 25,698us-gaap_ProceedsFromStockOptionsExercised/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | 14,598us-gaap_ProceedsFromStockOptionsExercised/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Share-based compensation windfall tax benefits                                                                                                                | 1,422us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | 2,420us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |   |
| Repurchase of common stock                                                                                                                                    | (15,756)us-gaap_PaymentsForRepurchaseOfCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                         | (12,823)us-gaap_PaymentsForRepurchaseOfCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | (1,464)us-gaap_PaymentsForRepurchaseOfCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Dividends paid on common stock                                                                                                                                | (112,106)us-gaap_PaymentsOfDividendsCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                            | (102,889)us-gaap_PaymentsOfDividendsCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | (93,423)us-gaap_PaymentsOfDividendsCommonStock/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Other                                                                                                                                                         | (793)us-gaap_ProceedsFromPaymentsForOtherFinancingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember               |   |   |   |   |
| Net cash flows used in financing activities                                                                                                                   | (105,147)us-gaap_NetCashProvidedByUsedInFinancingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                | (208,948)us-gaap_NetCashProvidedByUsedInFinancingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember | 39,006us-gaap_NetCashProvidedByUsedInFinancingActivities/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Net decrease in cash and cash equivalents                                                                                                                     |                                                                                                                         |   | (752)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |
| Cash and cash equivalents at beginning of year                                                                                                                |                                                                                                                         |   | $ 752us-gaap_CashAndCashEquivalentsAtCarryingValue/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |   |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3044-108585
+ Details**Name:**us-gaap_CashAndCashEquivalentsAtCarryingValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3521-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 230 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6450594&loc=d3e33268-110906
+ Details**Name:**us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CondensedCashFlowStatementsCaptionsLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash inflow from realized tax benefit related to deductible compensation cost reported on the entity's tax return for equity instruments in excess of the compensation cost for those instruments recognized for financial reporting purposes.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 20 -Section 55 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=32706628&loc=d3e11374-113907
+ Details**Name:**us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3521-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 26 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3574-108585
+ Details**Name:**us-gaap_NetCashProvidedByUsedInFinancingActivities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3521-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 26 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3574-108585
+ Details**Name:**us-gaap_NetCashProvidedByUsedInInvestingActivities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3521-108585Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585
+ Details**Name:**us-gaap_NetCashProvidedByUsedInOperatingActivities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash outflow or inflow from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3095-108585Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3098-108585
+ Details**Name:**us-gaap_PaymentsForProceedsFromOtherInvestingActivities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow to reacquire common stock during the period.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585
+ Details**Name:**us-gaap_PaymentsForRepurchaseOfCommonStock**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585
+ Details**Name:**us-gaap_PaymentsOfDividendsCommonStock**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585
+ Details**Name:**us-gaap_PaymentsToAcquirePropertyPlantAndEquipment**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for the purchase of waste water systems which includes the waste treatment and disposal facility and equipment to households and industry.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585
+ Details**Name:**us-gaap_PaymentsToAcquireWasteWaterSystems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow from the additional capital contribution to the entity.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585
+ Details**Name:**us-gaap_ProceedsFromIssuanceOfCommonStock**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585
+ Details**Name:**us-gaap_ProceedsFromIssuanceOfLongTermDebt**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash inflow or outflow from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3095-108585Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3098-108585
+ Details**Name:**us-gaap_ProceedsFromPaymentsForOtherFinancingActivities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash inflow or outflow from the excess drawing from an existing cash balance, which will be honored by the bank but reflected as a loan to the drawer.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3095-108585Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3098-108585
+ Details**Name:**us-gaap_ProceedsFromRepaymentsOfBankOverdrafts**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash inflow or outflow for borrowing having initial term of repayment within one year or the normal operating cycle, if longer.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3098-108585
+ Details**Name:**us-gaap_ProceedsFromRepaymentsOfShortTermDebt**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585
+ Details**Name:**us-gaap_ProceedsFromStockOptionsExercised**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228
+ Details**Name:**us-gaap_RepaymentsOfLongTermDebt**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
(Increase) decrease in investment of subsidiary.
+ References
No definition available.
+ Details**Name:**wtr_IncreaseDecreaseInInvestmentOfSubsidiary**Namespace Prefix:**wtr_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Proceeds from sale of utility system and other
+ References
No definition available.
+ Details**Name:**wtr_ProceedsFromSaleOfUtilitySystemAndOther**Namespace Prefix:**wtr_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**dei_LegalEntityAxis=us-gaap_ParentCompanyMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |