Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesAWR’s effective income tax rate (“ETR”) was 23.2% and 24.6% for the three months ended September 30, 2023 and 2022, respectively, and was 24.3% and 24.1% for the nine months ended September 30, 2023 and 2022, respectively. GSWC’s ETR was 24.9% and 25.5% for the three months ended September 30, 2023 and 2022, respectively, and was 25.3% and 25.2% for the nine months ended September 30, 2023 and 2022, respectively.The AWR and GSWC ETRs differed from the federal corporate statutory tax rate of 21% primarily due to (i) state taxes; (ii) permanent differences, including certain tax effects from stock compensation; (iii) the ongoing amortization of the excess deferred income tax liability; and (iv) differences between book and taxable income that are treated as flowed-through adjustments in accordance with regulatory requirements (principally from plant, rate-case, and compensation-related items). As regulated utilities, GSWC and BVES treat certain temporary differences as being flowed-through in computing its income tax expense consistent with the income tax method used in its CPUC-jurisdiction rate making. Flowed-through items either increase or decrease tax expense and thus impact the ETR.