Name:	artna_EmployeeBenefitPlanDiscretionaryContribution
Namespace Prefix:	artna_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage of employee contribution discretionary to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	artna_EmployeeBenefitPlanEmployeeContributionDiscretionaryPercentage
Namespace Prefix:	artna_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of employee contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	artna_EmployeeBenefitPlanEmployeeContributionPercentageOfCompensation
Namespace Prefix:	artna_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

The age at which participants become eligible for contributions under employee benefit plan.

No definition available.

Name:	artna_EmployeeBenefitPlanEmployerContributionParticipantsAge
Namespace Prefix:	artna_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The age at which participants for U.S. become eligible for contributions under employee benefit plan.

No definition available.

Name:	artna_EmployeeBenefitPlanEmployerContributionParticipantsAgeForUS
Namespace Prefix:	artna_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Percentage rate at which the employer contributes to the employee benefit plan, generally based on eligible compensation or another specified participant measure.

No definition available.

Name:	artna_EmployeeBenefitPlanEmployerContributionPercentage
Namespace Prefix:	artna_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

Amount of matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	artna_EmployeeBenefitPlanMatchingContribution
Namespace Prefix:	artna_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Period of repayment of loan, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	artna_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingTerm
Namespace Prefix:	artna_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Period of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	artna_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRatePeriod
Namespace Prefix:	artna_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Percentage of investment election minimum investment rate contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	artna_EmployeeBenefitPlanParticipantContributionInvestmentElectionMinimumInvestmentRate
Namespace Prefix:	artna_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of minimum selected investment rate contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	artna_EmployeeBenefitPlanParticipantContributionMinimumSelectedInvestmentRate
Namespace Prefix:	artna_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

The maximum age at which a participant in an employee benefit plan becomes eligible to make super catch-up contributions.

No definition available.

Name:	artna_EmployeeBenefitPlanParticipantSuperCatchUpContributionMaximumAge
Namespace Prefix:	artna_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

The minimum age at which a participant in an employee benefit plan becomes eligible to make super catch-up contributions.

No definition available.

Name:	artna_EmployeeBenefitPlanParticipantSuperCatchUpContributionMinimumAge
Namespace Prefix:	artna_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

Amount of service contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	artna_EmployeeBenefitPlanServiceContribution
Namespace Prefix:	artna_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Interest rate on debt of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-02)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 235
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479143/962-235-S50-1

Name:	us-gaap-ebp_EmployeeBenefitPlanDebtInterestRate
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-SubTopic 205
-Topic 962
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Name:	us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Name:	us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Amount of plan asset, in forfeited nonvested account, no longer allocated to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Name:	us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccount
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of decrease in forfeited nonvested account of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from employer contribution.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(5)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Name:	us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccountDecreaseForEmployerContribution
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Percentage of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow to total participant account balance.

Name:	us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of maximum pretax annual compensation that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), is permitted to contribute to total pretax annual compensation.

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Interest rate on participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(D)
-Publisher DOL-EBSA