Dividend Limitations	12 Months Ended
	Dec. 31, 2021
Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract]
Dividend Limitations	Dividend LimitationsGSWC is prohibited from paying dividends if, after giving effect to the dividend, its total indebtedness to capitalization ratio (as defined) would be more than 0.6667-to-1. Dividends in the amount of $38.3 million, $22.5 million and $20.2 million were paid to AWR by GSWC during the years 2021, 2020 and 2019, respectively.  The ability of AWR, GSWC, BVESI and ASUS to pay dividends is also restricted by California law. Under California law, AWR, GSWC, BVESI and ASUS are each permitted to distribute dividends to its shareholders so long as the Board of Directors determines, in good faith, that either: (i) the value of the corporation’s assets equals or exceeds the sum of its total liabilities immediately after the dividend, or (ii) its retained earnings equals or exceeds the amount of the distribution.  Under the least restrictive of the California tests, approximately $685.9 million was available to pay dividends to AWR’s shareholders at December 31, 2021. Approximately $615.7 million was available for GSWC to pay dividends to AWR at December 31, 2021.