| **Capitalization (Schedule Of Capitalization) (Details) - Subsequent Event [Member] - Aqua Illinois [Member] $ in Thousands** | 1 Months Ended |
|-------------------------------------------------------------------------------------------------------------------------------|----------------|
||
| **Capitalization [Line Items]**                                                                                               |           |
| Amount                                                                                                                        | $ 100,000      |
| First Mortgage Bond Maturing 2032 [Member]                                                                                    |           |
| **Capitalization [Line Items]**                                                                                               |           |
| Amount                                                                                                                        | $ 25,000       |
| Interest Rate                                                                                                                 | 3.64%          |
| Maturity                                                                                                                      | 2032           |
| First Mortgage Bond Maturing 2037 [Member]                                                                                    |           |
| **Capitalization [Line Items]**                                                                                               |           |
| Amount                                                                                                                        | $ 6,000        |
| Interest Rate                                                                                                                 | 3.89%          |
| Maturity                                                                                                                      | 2037           |
| First Mortgage Bond Maturing 2038 [Member]                                                                                    |           |
| **Capitalization [Line Items]**                                                                                               |           |
| Amount                                                                                                                        | $ 15,000       |
| Interest Rate                                                                                                                 | 3.90%          |
| Maturity                                                                                                                      | 2038           |
| First Mortgage Bond Maturing 2047 [Member]                                                                                    |           |
| **Capitalization [Line Items]**                                                                                               |           |
| Amount                                                                                                                        | $ 10,000       |
| Interest Rate                                                                                                                 | 4.18%          |
| Maturity                                                                                                                      | 2047           |
| First Mortgage Bond Maturing 2049 [Member]                                                                                    |           |
| **Capitalization [Line Items]**                                                                                               |           |
| Amount                                                                                                                        | $ 22,000       |
| Interest Rate                                                                                                                 | 4.22%          |
| Maturity                                                                                                                      | 2049           |
| First Mortgage Bond Maturing 2050 [Member]                                                                                    |           |
| **Capitalization [Line Items]**                                                                                               |           |
| Amount                                                                                                                        | $ 22,000       |
| Interest Rate                                                                                                                 | 4.24%          |
| Maturity                                                                                                                      | 2050           |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Contractual interest rate for funds borrowed, under the debt agreement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878Reference 3: 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(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
+ Details**Name:**us-gaap_LongTermDebt**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
+ Details**Name:**us-gaap_ScheduleOfCapitalizationLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Maturity Date, Year
+ References
No definition available.
+ Details**Name:**wtr_DebtInstrumentMaturityDateYear**Namespace Prefix:**wtr_**Data Type:**xbrli:gYearItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DebtInstrumentAxis=wtr_DebtInstrumentDMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DebtInstrumentAxis=wtr_DebtInstrumentEMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------|
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