| **Acquisitions (Narrative) (Details)**                            |                 | 1 Months Ended | 3 Months Ended | 12 Months Ended |               |              |
|-------------------------------------------------------------------|-----------------|----------------|----------------|-----------------|---------------|--------------|
||
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Goodwill                                                          |            |           | $ 63,822,000   |            |          |         | $ 2,351,526,000 |   | $ 63,822,000 |   |   |
| Fair value adjustment                                             |            |           |           |            |          |         |   | $ 34,782,000 |   |   |   |
| Operating revenues                                                |            |           |           |            |          |         | 255,585,000 | 201,132,000 |   |   |   |
| Net income                                                        |            |           |           |            |          |         | 51,781,000 | 16,924,000 |   |   |   |
| Water And Wastewater Utility Systems [Member]                     |            |           |           |            |          |         |   |   |   |   |   |
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Number of acquisitions | item                                     |            |           |           |            |          |         |   |   | 7 |   |   |
| Number of customers | customer                                    |            |           |           |            |          |         |   |   | 2,393 |   |   |
| Total purchase price                                              |            |           |           |            |          |         |   |   | $ 9,437,000 |   |   |
| Peoples Gas Acquisition [Member]                                  |            |           |           |            |          |         |   |   |   |   |   |
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Number of customers | customer                                    | 747,000         |           |           |            |          |         |   |   |   |   |   |
| Total purchase price                                              | $ 3,465,344,000 |           |           |            |          |         |   |   |   |   |   |
| Indebtedness                                                      | 1,101,091,000   |           |           |            |          |         |   |   |   | $ 1,101,091,000 |   |
| short-term debt                                                   | 181,000,000     |           |           |            |          |         |   |   |   | 181,000,000 |   |
| Outstanding debt                                                  | $ 920,091,000   |           |           |            |          |         |   |   |   | $ 920,091,000 |   |
| Measurement period                                                | 1 year          |           |           |            |          |         |   |   |   |   |   |
| Fair value of debt                                                | $ 84,569,000    |           |           |            |          |         |   |   |   |   |   |
| Acquisition-related costs                                         |            |           |           |            |          |         | 20,628,000 | 16,464,000 |   |   |   |
| Acquisition-related costs, pre-tax                                |            |           |           |            |          |         | $ 25,197,000 | 21,406,000 |   |   |   |
| Adjustments to acquisition financing                              |            |           |           |            |          |         |   | 35,812,000 |   |   |   |
| Adjustments to acquisition financing, Pre-tax                     |            |           |           |            |          |         |   | 46,129,000 |   |   |   |
| Adjustments to debt                                               |            |           |           |            |          |         |   | 7,084,000 |   |   |   |
| Adjustments to debt, pre-tax                                      |            |           |           |            |          |         |   | 9,962,000 |   |   |   |
| Elimination of management fee                                     |            |           |           |            |          |         |   | 885,000 |   |   |   |
| Elimination of management fee, pre-tax                            |            |           |           |            |          |         |   | 1,245,000 |   |   |   |
| Pipeline term                                                     |            |           |           |            |          |         | 7 years |   |   |   |   |
| Pipeline cost                                                     |            |           |           |            |          |         | $ 120,000,000 |   |   |   |   |
| Customer rate credits                                             |            |           |           |            |          |         | 23,000,000 |   |   |   |   |
| Property, plant and equipment, net                                | 2,468,946,000   |           |           |            |          |         |   |   |   |   |   |
| Goodwill                                                          | $ 2,287,677,000 |           |           |            |          |         |   |   |   |   |   |
| Fair value adjustment                                             |            |           |           |            |          |         |   | 34,782,000 |   |   |   |
| Transaction-related expenses                                      |            |           |           |            |          |         | 25,397,000 | $ 6,646,000 |   |   |   |
| Operating revenues                                                |            |           |           |            |          |         | 38,544,000 |   |   |   |   |
| Net income                                                        |            |           |           |            |          |         | $ 13,398,000 |   |   |   |   |
| Peoples Gas Acquisition [Member] | Bridge Commitment [Member]     |            |           |           |            |          |         |   |   |   |   |   |
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Debt instrument, issued                                           |            |           |           |            |          |         |   |   |   |   | $ 5,100,000,000 |
| Pennsylvania [Member] | Wastewater Utility System [Member]        |            |           |           |            |          |         |   |   |   |   |   |
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Number of customers | customer                                    |            |           |           | 2,106           |          | 4,950        |   |   |   |   |   |
| Total purchase price                                              |            |           |           | $ 29,500,000    |          | $ 21,000,000 |   |   |   |   |   |
| Cheltenham Township [Member] | Wastewater Utility System [Member] |            |           |           |            |          |         |   |   |   |   |   |
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Number of customers | customer                                    |            |           | 9,887          |            |          |         |   |   |   |   |   |
| Total purchase price                                              |            |           | $ 50,250,000   |            |          |         |   |   |   |   |   |
| Property, plant and equipment, net                                |            |           | 44,440,000     |            |          |         |   |   | 44,440,000 |   |   |
| Goodwill                                                          |            |           | $ 5,810,000    |            |          |         |   |   | $ 5,810,000 |   |   |
| Delaware [Member] | Wastewater Utility System [Member]            |            |           |           |            |          |         |   |   |   |   |   |
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Number of customers | customer                                    |            |           |           |            | 16,000        |         |   |   |   |   |   |
| Retail customers | customer                                       |            |           |           |            | 198,000       |         |   |   |   |   |   |
| Municipalities | item                                             |            |           |           |            | 42            |         |   |   |   |   |   |
| Total purchase price                                              |            |           |           |            | $ 276,500,000 |         |   |   |   |   |   |
| Ohio [Member] | Water And Wastewater Utility Systems [Member]     |            |           |           |            |          |         |   |   |   |   |   |
| **Business Acquisition [Line Items]**                             |            |           |           |            |          |         |   |   |   |   |   |
| Number of customers | customer                                    |            | 3,126          |           |            |          |         |   |   |   |   |   |
| Total purchase price                                              |            | $ 7,500,000    |           |            |          |         |   |   |   |   |   |

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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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.
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| - Definition
Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.
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| - Definition
The amount, measured at acquisition-date fair value, of all liabilities assumed that arise from contingencies and were recognized by the entity.
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| - Definition
This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to items of consideration transferred in connection with a business combination for which the initial accounting was incomplete.
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| - Definition
This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to financial liabilities assumed in connection with a business combination for which the initial accounting was incomplete.
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| - Definition
Amount of long-term debt due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.
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Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.
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| - Definition
The amount of property, plant, and equipment recognized as of the acquisition date.
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| - Definition
For transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination, such as related to pre-existing relationships with the acquiree, this element represents the disclosure of the amount of acquisition related costs which have been expensed.
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| - Definition
For transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination, such as related to pre-existing relationships with the acquiree, this element represents the disclosure of the amount of acquisition related costs.
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| - Definition
In a business combination achieved in stages, this element represents the amount of net gain (loss) recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination.
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| - Definition
Face (par) amount of debt instrument at time of issuance.
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| - Definition
Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.
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| - Definition
The number of businesses acquired by the entity during the period.
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No definition available.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).
+ References
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Business Combination, Customer Rate Credits
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No definition available.
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Business Combination, Measurement Period
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No definition available.
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Business Combination, Pipeline Cost
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Business Combination, Pipeline Term
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No definition available.
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Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred, Pre-Tax
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No definition available.
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Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities, Pre-Tax
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No definition available.
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Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Management Fee
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No definition available.
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Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Management Fee, Pre-Tax
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No definition available.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current And Noncurrent Liabilities, Long-term Debt
+ References
No definition available.
+ Details**Name:**wtrg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAndNoncurrentLiabilitiesLongTermDebt**Namespace Prefix:**wtrg_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Costs, Pre Tax
+ References
No definition available.
+ Details**Name:**wtrg_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostsPreTax**Namespace Prefix:**wtrg_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of customers.
+ References
No definition available.
+ Details**Name:**wtrg_NumberOfCustomers**Namespace Prefix:**wtrg_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number Of Municipalities
+ References
No definition available.
+ Details**Name:**wtrg_NumberOfMunicipalities**Namespace Prefix:**wtrg_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number Of Retail Customers
+ References
No definition available.
+ Details**Name:**wtrg_NumberOfRetailCustomers**Namespace Prefix:**wtrg_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_BusinessAcquisitionAxis=wtrg_WastewaterUtilitySystemsInVariousStatesMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_BusinessAcquisitionAxis=wtrg_PeoplesGasAcquisitionMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DebtInstrumentAxis=wtrg_BridgeCommitmentMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**srt_StatementGeographicalAxis=stpr_PA**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_BusinessAcquisitionAxis=wtrg_WastewaterUtilitySystemMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**srt_StatementGeographicalAxis=wtrg_CheltenhamTownshipMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**srt_StatementGeographicalAxis=stpr_DE**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**srt_StatementGeographicalAxis=stpr_OH**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |