| **Commitments And Contingencies (Schedule Of Rent Expense Under Operating Leases) (Details) - USD ($) $ in Thousands** | 12 Months Ended |
|------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| **Commitments And Contingencies [Abstract]**                                                                           |            |   |   |
| Operating leases expense                                                                                               | $ 2,569         | $ 2,241 | $ 2,776 |
| Purchased water under long-term agreements                                                                             | 6,065           | 8,558 | 13,955 |
| Water treatment expense under contractual agreement                                                                    | $ 970           | $ 945 | $ 940 |

| X                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.
+ References
No definition available.
+ Details**Name:**us-gaap_LeaseAndRentalExpense**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Purchased water under long-term agreements.
+ References
No definition available.
+ Details**Name:**wtr_PurchasedWaterUnderLongTermAgreements**Namespace Prefix:**wtr_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Water treatment expense under contractual agreement.
+ References
No definition available.
+ Details**Name:**wtr_WaterTreatmentExpenseUnderContractualAgreement**Namespace Prefix:**wtr_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |