XML 70 R56.htm IDEA: XBRL DOCUMENT
v3.20.4

REGULATORY PROCEEDINGS (Details) - USD ($) $ in Millions |  |  |  |  |  | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | ---
Nov. 20, 2020 | May 29, 2020 | Nov. 15, 2019 | May 29, 2019 | Nov. 28, 2018 | Jun. 30, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Other Proceedings [Abstract] |  |  |  |  |  |  |  |  |
Cumulative DSIC Rate | 7.50% | 7.50% | 7.50% | 7.41% | 5.55% |  |  |  |
Net Eligible Plant Improvements - Cumulative Dollars | $ 43.1 | $ 43.1 | $ 43.1 | $ 43.1 | $ 30.4 |  |  |  |
Delaware [Member] |  |  |  |  |  |  |  |  |
Water and Wastewater Rates [Abstract] |  |  |  |  |  |  |  |  |
Temporary annual rate increase subject to 15% gross water sales limitation |  |  |  |  |  |  | $ 2.5 |  |
Percentage of gross water sales |  |  |  |  |  |  | 15.00% |  |
Period to complete rate case by law |  |  |  |  |  |  | 7 months |  |
Percentage of rate relief allowed should a rate case not complete |  |  |  |  |  |  | 15.00% |  |
Revenue returned to customers as a result of TCJA |  |  |  |  |  | $ 3.8 |  |  |
Other Proceedings [Abstract] |  |  |  |  |  |  |  |  |
Distribution System Improvement Charge rate increase applied between base rate filings |  |  |  |  |  |  | 7.50% |  |
Distribution System Improvement Charge rate increase within a 12-month period |  |  |  |  |  |  | 5.00% |  |
Artesian Water [Member] |  |  |  |  |  |  |  |  |
Other Proceedings [Abstract] |  |  |  |  |  |  |  |  |
Revenue earned in DSIC rate increases |  |  |  |  |  |  | $ 5.0 | $ 4.3 | $ 2.8

X
- Definition For a first temporary increase in revenue basis, maximum temporary annual rate charge increase subject to specific gross water sales limitation. + References No definition available. + Details
Name: | artna_AmountOfTemporaryRateIncreasePerRateSettingProcess
Namespace Prefix: | artna_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Ceiling percentage of Distribution System Improvement Charge rate subject to amount billed to customers. + References No definition available. + Details
Name: | artna_DistributionSystemImprovementChargeRateCeilingPercentage
Namespace Prefix: | artna_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Conditional percentage maximum for increasing Distribution System Improvement Charge rate within a 12-month period. + References No definition available. + Details
Name: | artna_DistributionSystemImprovementChargeRateConditionalIncrease
Namespace Prefix: | artna_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Increase amount based on eligible plant improvements since the last rate increase. + References No definition available. + Details
Name: | artna_IncreaseAmountBasedOnEligiblePlantImprovementsSinceLastRateIncrease
Namespace Prefix: | artna_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | artna_OtherProceedingsAbstract
Namespace Prefix: | artna_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of Distribution System Improvement Charge rate increase application filed by company to regulatory. + References No definition available. + Details
Name: | artna_PercentageOfDistributionSystemImprovementChargeRateIncreaseApplicationFiledByCompanyToRegulatory
Namespace Prefix: | artna_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition For a first temporary annual rate increase in revenue basis, maximum percentage of gross water sales increase allowed subject to specific dollar amount limitation. + References No definition available. + Details
Name: | artna_PercentageOfGrossWaterSalesMaximumTemporaryAnnualRateIncreaseSubjectToCeilingLimitation
Namespace Prefix: | artna_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of relief that utility may put into effect if condition for rate case period completion not fulfilled by law. + References No definition available. + Details
Name: | artna_PercentageOfReliefIfRateCasePeriodConditionNotFulfill
Namespace Prefix: | artna_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period within which rate change case is to complete, by law, after which, entire requested rate relief may go into effect. + References No definition available. + Details
Name: | artna_PeriodToCompleteRateChangeApplicationCaseByLaw
Namespace Prefix: | artna_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Revenue earned due to Distribution System Improvement Charge rate increase. + References No definition available. + Details
Name: | artna_RevenueEarnedInDistributionSystemImprovementCharge
Namespace Prefix: | artna_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue refunded to customers as a result of TCJA tax benefits during the period. + References No definition available. + Details
Name: | artna_RevenueReturnedToCustomersAsAResultOfTCJATaxBenefit
Namespace Prefix: | artna_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | artna_WaterAndWastewaterRatesAbstract
Namespace Prefix: | artna_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_DE
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=artna_ArtesianWaterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |