LEGAL PROCEEDINGS (Details)	Sep. 30, 2024 Defendant Phase Litigation
LEGAL PROCEEDINGS [Abstract]
Number of multi-district litigations \| Litigation	2
Number of groups of settling defendants \| Defendant	2
Number of phases of settlement claim \| Phase	1

Refers to the number of groups of settling defendants.

No definition available.

Name:	artna_NumberOfGroupsOfSettlingDefendants
Namespace Prefix:	artna_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant