ORGANIZATION AND OPERATIONS	12 Months Ended
ORGANIZATION AND OPERATIONS	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND OPERATIONS	ORGANIZATION AND OPERATIONS California Water Service Group (Company) is a holding company that provides water utility and other related services in California, Washington, New Mexico, Hawaii and Texas through its wholly-owned and non-wholly owned subsidiaries. California Water Service Company (Cal Water), Washington Water Service Company (Washington Water), New Mexico Water Service Company (New Mexico Water), and Hawaii Water Service Company, Inc. (Hawaii Water) provide regulated utility services under the rules and regulations of their respective state's regulatory commissions (jointly referred to as the Commissions). CWS Utility Services and HWS Utility Services LLC provide non-regulated water utility and utility-related services. TWSC, Inc. (Texas Water) holds regulated and contracted wastewater utilities. The Company operates in one reportable segment, providing water and related utility services. Basis of Presentation The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and include the Company's accounts and those of its wholly and non-wholly owned subsidiaries. The non-wholly owned subsidiary refers to a 92.2% owned subsidiary of Texas Water and is consolidated using the voting interest model as the Company owns a majority of the voting interests in the non-wholly owned subsidiary. All intercompany transactions and balances have been eliminated from the consolidated financial statements. In the opinion of management, the consolidated financial statements reflect all adjustments that are necessary to provide a fair presentation of the results for the periods covered. The preparation of the Company's consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the consolidated balance sheet dates and the reported amounts of revenues and expenses for the periods presented. These include, but are not limited to, estimates and assumptions used in determining the Company's regulatory asset and liability balances based upon probability assessments of regulatory recovery, utility plant useful lives, revenues earned but not yet billed, asset retirement obligations, allowance for credit losses, pension and other employee benefit plan liabilities, and income tax-related assets and liabilities. Actual results could differ from these estimates. Noncontrolling Interests Noncontrolling interests in the Company’s consolidated financial statements represents the 7.8% interest not owned by Texas Water in a consolidated subsidiary. Texas Water obtained control over the subsidiary on May 1, 2021. Since the Company controls this subsidiary, its financial statements are consolidated with those of the Company, and the noncontrolling owner’s 7.8% share of the subsidiary’s net assets and results of operations is deducted and reported as noncontrolling interests on the consolidated balance sheets and as net loss attributable to noncontrolling interests in the consolidated statements of operations. The Company reports noncontrolling interests in consolidated entities as a component of equity separate from the Company’s equity. The Company’s net income attributable to California Water Service Group excludes a net loss attributable to the noncontrolling interests. Reclassifications Certain prior year amounts have been reclassified for consistency with the current year presentation. Such reclassifications have no impact on previously reported assets, liabilities, net income, equity, or cash flows. As of December 31, 2021, $3.5 million of uninsured loss reserve was reclassified from Accrued and deferred compensation to Uninsured loss reserve within the Other Accrued Liabilities table in Note 9. This change had no impact to previously reported liabilities. For the years ended December 31, 2021 and 2020, $61.5 million and $55.8 million of Multiple residential revenue was reclassified from Residential to Multiple residential within the table in Note 2. These changes had no impact to previously reported operating revenue.