Carrying amount as of the balance sheet date of amounts expected to be recovered under the terms of insurance contracts.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_EstimatedInsuranceRecoveries
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124440162&loc=d3e12021-110248

+ Details

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cash inflow for proceeds from settlement of insurance claim, classified as operating activities. Excludes insurance settlement classified as investing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 16
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3337-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21B
-URI http://asc.fasb.org/extlink&oid=123570139&loc=SL94080549-108585

+ Details

Name:	us-gaap_ProceedsFromInsuranceSettlementOperatingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.24)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_SelfInsuranceReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business Combination, Customer Rate Credits

+ References

No definition available.

+ Details

Name:	wtrg_BusinessCombinationCustomerRateCredits
Namespace Prefix:	wtrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business Combination, Pipeline Cost

+ References

No definition available.

+ Details

Name:	wtrg_BusinessCombinationPipelineCost
Namespace Prefix:	wtrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business Combination, Pipeline Term

+ References

No definition available.

+ Details

Name:	wtrg_BusinessCombinationPipelineTerm
Namespace Prefix:	wtrg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Commitments And Contingencies [Line Items]

+ References

No definition available.

+ Details

Name:	wtrg_CommitmentsAndContingenciesLineItems
Namespace Prefix:	wtrg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=wtrg_PeoplesGasAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=wtrg_WastewaterUtilitySystemsInVariousStatesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=wtrg_AquaPennsylvaniaIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=wtrg_NaturalGasUtilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=wtrg_CustomerRateCreditsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments And Contingencies (Details) - USD ($) $ in Thousands		9 Months Ended
	Aug. 03, 2020	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Commitments And Contingencies [Line Items]
Aggregate amount accrued for loss contingencies		$ 18,102
Amount probable of recovery through insurance		3,015
Insurance reserve for employee medical benefit program		$ 2,470
Insurance proceeds	$ 2,874
Peoples Gas Acquisition [Member]
Commitments And Contingencies [Line Items]
Pipeline term		7 years
Pipeline cost		$ 120,000
Customer rate credits		$ 23,004
Water And Wastewater Utility Systems [Member] \| Aqua Pennsylvania, Inc [Member]
Commitments And Contingencies [Line Items]
Customer rate credits				$ 4,080
Natural Gas Utility [Member]
Commitments And Contingencies [Line Items]
Customer rate credits			$ 18,924
Customer Rate Credits [Member] \| Natural Gas Utility [Member]
Commitments And Contingencies [Line Items]
Customer rate credits			$ 23,004