REGULATORY PROCEEDINGS - Eligible Plant Improvements (Details) - USD ($) $ in Millions	Jan. 01, 2025	Jul. 01, 2024	Dec. 18, 2024
REGULATORY PROCEEDINGS [Abstract]
Cumulative DSIC Rate		0.34%	1.66%
Net Eligible Plant Improvements - Cumulative Dollars	$ 11.7	$ 2.0

Percentage of Distribution System Improvement Charge rate increase application filed by company to regulatory.

No definition available.

Name:	artna_PercentageOfDistributionSystemImprovementChargeRateIncreaseApplicationFiledByCompanyToRegulatory
Namespace Prefix:	artna_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	instant