XML 72 R61.htm IDEA: XBRL DOCUMENT
v3.25.3

REGULATORY LIABILITIES - Regulatory Liabilities (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024 | Dec. 31, 2017
--- | --- | --- | ---
REGULATORY LIABILITIES [Abstract] |  |  |
Regulatory liabilities | $ 26,725 | $ 30,267 | $ 22,800
Utility Plant Retirement Cost Obligation [Member] |  |  |
REGULATORY LIABILITIES [Abstract] |  |  |
Regulatory liabilities | 207 | 279 |
Deferred Settlement Refunds [Member] |  |  |
REGULATORY LIABILITIES [Abstract] |  |  |
Regulatory liabilities | 0 | 2,496 |
Deferred Income Taxes [Member] |  |  |
REGULATORY LIABILITIES [Abstract] |  |  |
Regulatory liabilities | $ 26,518 | $ 27,492 |

X
- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 405 -Name Accounting Standards Codification -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477571/980-405-25-1 + Details
Name: | us-gaap_RegulatoryLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=artna_DeferredSettlementRefundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_DeferredIncomeTaxChargesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |