Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2025
Accounting Policies [Abstract]
Nature of Operations and Basis of Presentation	Nature of Operations: American States Water Company (“AWR”) is the parent company of Golden State Water Company (“GSWC”), Bear Valley Electric Service Inc. (“BVES”), and American States Utility Services, Inc. (“ASUS”) (and its subsidiaries, Fort Bliss Water Services Company (“FBWS”), Old Dominion Utility Services, Inc. (“ODUS”), Terrapin Utility Services, Inc. (“TUS”), Palmetto State Utility Services, Inc. (“PSUS”), Old North Utility Services, Inc. (“ONUS”), Emerald Coast Utility Services, Inc. (“ECUS”), Fort Riley Utility Services, Inc. (“FRUS”), Bay State Utility Services LLC (“BSUS”), and Patuxent River Utility Services LLC (“PRUS”)). AWR and its subsidiaries may be collectively referred to as “the Company.” AWR, through its wholly owned subsidiaries, serves over one million people in ten states. GSWC and BVES are both California public utilities. GSWC engages in the purchase, production, distribution and sale of water throughout California serving approximately 265,000 customer connections. BVES distributes electricity in several San Bernardino County mountain communities in California serving approximately 25,000 customer connections. The California Public Utilities Commission (“CPUC”) regulates GSWC’s and BVES’s businesses in matters including properties, rates, services, facilities, and transactions between GSWC, BVES, and their affiliates. In August 2023, GSWC entered into an agreement, subject to CPUC approval, to purchase from a developer the water and wastewater system assets located in California’s Central Coast region. This is a new planned community, which will serve up to approximately 1,300 customers at full build out, which is anticipated to occur by 2034 under the current construction schedule, barring any future delays. On December 5, 2024, the CPUC approved a final decision granting GSWC’s Certificates of Public Convenience and Necessity that will establish rates for water and sewer services, including GSWC’s recovery of the purchase price through future customer rates. After receiving CPUC approval and finalizing other closing procedures in May 2025, the parties completed the closing of the transaction, which included the initial installation and conveyance of the water and wastewater system assets of $10.7 million by the developer, a non-cash transaction to the Registrant recorded during the second quarter of 2025 that resulted in an increase in GSWC's utility plant with corresponding increases in advances for and contributions in aid of construction. GSWC began serving a few customers during the second quarter in connection with this transaction. In the future, GSWC will take ownership of the incremental water and wastewater system assets in phases as they are completed and ready to accommodate new connections. ASUS, through its wholly owned subsidiaries, operates, maintains and performs construction activities (including renewal and replacement capital work) on water and/or wastewater systems at various U.S. military bases pursuant to initial 50-year firm fixed-price contracts with the U.S. government and one 15-year contract with the U.S. government. These contracts are subject to annual economic price adjustments and modifications for changes in circumstances, changes in laws and regulations, and additions to the contract value for new construction of facilities at the military bases. ASUS also from time to time performs construction services on military bases as a subcontractor. There is no direct regulatory oversight by the CPUC over AWR or the operations, rates or services provided by ASUS or any of its wholly owned subsidiaries. Basis of Presentation: The consolidated financial statements and notes hereto are presented in a combined report filed by two separate Registrants: AWR and GSWC. References in this report to “Registrant” are to AWR and GSWC, collectively, unless otherwise specified. AWR owns all of the outstanding common shares of GSWC, BVES and ASUS. ASUS owns all of the outstanding equity of its subsidiaries. The consolidated financial statements of AWR include the accounts of AWR and its subsidiaries. These financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Intercompany transactions and balances have been eliminated in AWR’s consolidated financial statements. The consolidated financial statements included herein have been prepared by Registrant, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). The December 31, 2024 condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by GAAP. The preparation of the consolidated financial statements 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 date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. In the opinion of management, all adjustments consisting of normal, recurring items, and estimates necessary for a fair statement of the results for the interim periods have been made. It is suggested that these consolidated financial statements be read in conjunction with the consolidated financial statements and the notes thereto included in the Form 10-K for the year ended December 31, 2024 filed with the SEC.
Related Party and Intercompany Transactions	Related Party and Intercompany Transactions: GSWC, BVES and ASUS provide and/or receive various support services to and from their parent, AWR, and among themselves. GSWC allocates certain corporate office administrative and general costs to its affiliates, BVES and ASUS, using allocation factors approved by the CPUC. GSWC allocated corporate office administrative and general costs to BVES of approximately $0.8 million and $0.7 million during the three months ended June 30, 2025 and 2024, respectively, and $1.9 million and $1.7 million during the six month periods ended June 30, 2025 and 2024, respectively. GSWC also allocated corporate office administrative and general costs to ASUS of approximately $1.2 million and $2.8 million for each of the three and six month periods ended June 30, 2025 and 2024, respectively. When necessary, AWR will make capital contributions to its regulated utilities in order to maintain the CPUC-authorized capital structure. In May 2025, GSWC issued 3.6500 Common Shares to AWR for total proceeds of $50.0 million. GSWC used the proceeds from the stock issuance to pay down outstanding borrowings under its revolving credit facility, as discussed below under Liquidity and Financing Activities.
Liquidity and Financing Activities	Liquidity and Financing Activities: On February 27, 2024, AWR entered into an Equity Distribution Agreement with third-party sales agents, under which AWR may offer and sell its Common Shares, from time to time at its sole discretion, through an at-the-market (“ATM”) offering program having an aggregate gross offering price of up to $200 million over a three-year period and pursuant to AWR’s effective shelf registration statement on Form S-3. AWR intends to use the net proceeds from these sales, after deducting commissions on such sales and offering expenses, for general corporate purposes, including, but not limited to, repayment of debt and equity contributions to its subsidiaries. During the three months ended June 30, 2024, AWR sold 227,667 Common Shares, through its ATM offering program and raised proceeds of $16.8 million, net of $0.3 million in commissions paid under the terms of the Equity Distribution Agreement. AWR also incurred $0.1 million of other expenses during the three months ended June 30, 2024, which included primarily legal and other costs to support this ATM offering program. There were no Common Shares issued during the three months ended June 30, 2025 under the ATM offering program. During the six months ended June 30, 2025 and 2024, AWR sold 334,548 and 455,648 Common Shares, respectively, through the ATM offering program and raised proceeds of $25.8 million, net of $0.4 million in commissions paid, and $33.0 million, net of $0.5 million in commissions paid, respectively. AWR also incurred $0.2 million and $0.1 million of other expenses during the six months ended June 30, 2025, and 2024, respectively, which was primarily legal and other costs. As of June 30, 2025, approximately $82.9 million remains available for sale under the ATM offering program. AWR and GSWC each have credit agreements with a term of five years, which were scheduled to mature in June 2028. As of June 30, 2025, the credit agreements provided AWR and GSWC unsecured revolving credit facilities with borrowing capacities of $195.0 million and $200.0 million, respectively. Under the terms of the credit agreements, as of June 30, 2025, the borrowing capacities for AWR and GSWC may be expanded up to an additional $30.0 million and $75.0 million, respectively, subject to the lenders’ approval. On May 6, 2025, AWR and GSWC both executed amendments to their credit agreements to extend their credit facility terms from June 2028 to June 2029. In addition, as part of its amendment, AWR expanded its credit facility borrowing capacity from $165.0 million to $195.0 million through an existing bank from the original syndicate group and the addition of a new bank to the existing syndicate group participating in AWR’s credit facility. AWR’s credit facility is primarily used to provide support to AWR (parent) and ASUS. As of June 30, 2025, AWR’s outstanding borrowings under its credit facility of $143.0 million have been classified as non-current liabilities on AWR’s Consolidated Balance Sheet. GSWC’s credit facility provides support for its water operations and is considered a short-term debt arrangement by the CPUC. Therefore, pursuant to the CPUC’s requirements, borrowings under GSWC’s credit facility are required to be paid-off in full within a 24-month period. GSWC’s next pay-off period ends in May 2027. Accordingly, GSWC’s outstanding borrowings under the credit facility of $9.0 million as of June 30, 2025 have been classified as non-current liabilities in AWR’s Consolidated Balance Sheet and GSWC’s Balance Sheet. On March 13, 2025, the CPUC issued a final decision in GSWC’s financing application, which approves, among other items, GSWC’s request to issue up to $750.0 million of new long-term debt and equity securities. Following approval of the new financing application, on May 29, 2025, GSWC completed the issuance of $100.0 million of unsecured private-placement notes consisting of: $75.0 million aggregated principal Series A Senior Notes at a coupon rate of 5.30% due May 29, 2032 and $25.0 million aggregated principal Series B Senior Notes at a coupon rate of 5.65% due May 29, 2037. GSWC used the proceeds from this debt issuance and the proceeds of the previously mentioned equity issuance to pay down all outstanding borrowings under its revolving credit facility. Interest payments on the new notes are due semiannually on May 29 and November 29 each year, commencing November 29, 2025. The private placement notes rank equally with GSWC’s other unsecured and unsubordinated debt. GSWC may, at its option, redeem all or portions of the private placement notes at any time upon written notice, subject to payment of a make-whole premium. Pursuant to the terms of these notes and consistent with GSWC's other private placement notes, GSWC must maintain a total indebtedness to capitalization ratio of less than 0.6667-to-1 and a total indebtedness to earnings before income taxes, depreciation and amortization (“EBITDA”) of less than 8-to-1. BVES has a separate revolving credit facility without a parent guaranty that supports its electric operations and capital expenditures with a borrowing capacity of $65.0 million, and expires on July 1, 2026. BVES’s revolving credit facility is considered a short-term debt arrangement by the CPUC. Therefore, pursuant to the CPUC’s requirements, borrowings under this credit facility are required to be fully paid off within a 24-month period, after which, BVES may borrow under the credit facility again. BVES’s next pay-off period ends in March 2027. On February 12, 2025, BVES issued $50.0 million in unsecured private-placement notes, which will mature on February 12, 2030. BVES used the proceeds from these notes to pay off all outstanding amounts under its revolving credit facility at the time of the notes’ issuance, thereby satisfying the CPUC’s requirement. As of June 30, 2025, there is $1.0 million in outstanding borrowings under BVES’s separate revolving credit facility classified as non-current liabilities on AWR’s Consolidated Balance Sheet.
Recent Accounting Pronouncements	Recent Accounting Pronouncements: In December 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update 2023-09 (Improvements to Income Tax Disclosures) requiring public entities to provide more disclosures primarily related to the income tax rate reconciliation and income taxes paid. The guidance also eliminates certain existing disclosure requirements related to uncertain tax positions and unrecognized deferred tax liabilities. The guidance is effective for annual periods beginning after December 15, 2024 and will be applied prospectively to the annual income tax disclosures starting with Registrant’s Annual Report on Form 10-K for the year ended December 31, 2025. Registrant is currently evaluating the impact of this standard on its annual income tax disclosures. In November 2024, the FASB issued Accounting Standards Update 2024-03, (Disaggregation of Income Statement Expenses) requiring public entities to disclose additional information about specific expense categories in the notes to the financial statements on an interim and annual basis. The guidance will be effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with early adoption permitted. Registrant is currently evaluating the impact of adopting this standard.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2025

Nature of Operations and Basis of Presentation

Nature of Operations: American States Water Company (“AWR”) is the parent company of Golden State Water Company (“GSWC”), Bear Valley Electric Service Inc. (“BVES”), and American States Utility Services, Inc. (“ASUS”) (and its subsidiaries, Fort Bliss Water Services Company (“FBWS”), Old Dominion Utility Services, Inc. (“ODUS”), Terrapin Utility Services, Inc. (“TUS”), Palmetto State Utility Services, Inc. (“PSUS”), Old North Utility Services, Inc. (“ONUS”), Emerald Coast Utility Services, Inc. (“ECUS”), Fort Riley Utility Services, Inc. (“FRUS”), Bay State Utility Services LLC (“BSUS”), and Patuxent River Utility Services LLC (“PRUS”)). AWR and its subsidiaries may be collectively referred to as “the Company.” AWR, through its wholly owned subsidiaries, serves over one million people in ten states.

GSWC and BVES are both California public utilities. GSWC engages in the purchase, production, distribution and sale of water throughout California serving approximately 265,000 customer connections. BVES distributes electricity in several San Bernardino County mountain communities in California serving approximately 25,000 customer connections. The California Public Utilities Commission (“CPUC”) regulates GSWC’s and BVES’s businesses in matters including properties, rates, services, facilities, and transactions between GSWC, BVES, and their affiliates.

In August 2023, GSWC entered into an agreement, subject to CPUC approval, to purchase from a developer the water and wastewater system assets located in California’s Central Coast region. This is a new planned community, which will serve up to approximately 1,300 customers at full build out, which is anticipated to occur by 2034 under the current construction schedule, barring any future delays. On December 5, 2024, the CPUC approved a final decision granting GSWC’s Certificates of Public Convenience and Necessity that will establish rates for water and sewer services, including GSWC’s recovery of the purchase price through future customer rates. After receiving CPUC approval and finalizing other closing procedures in May 2025, the parties completed the closing of the transaction, which included the initial installation and conveyance of the water and wastewater system assets of $10.7 million by the developer, a non-cash transaction to the Registrant recorded during the second quarter of 2025 that resulted in an increase in GSWC's utility plant with corresponding increases in advances for and contributions in aid of construction. GSWC began serving a few customers during the second quarter in connection with this transaction. In the future, GSWC will take ownership of the incremental water and wastewater system assets in phases as they are completed and ready to accommodate new connections.

ASUS, through its wholly owned subsidiaries, operates, maintains and performs construction activities (including renewal and replacement capital work) on water and/or wastewater systems at various U.S. military bases pursuant to initial 50-year firm fixed-price contracts with the U.S. government and one 15-year contract with the U.S. government. These contracts are subject to annual economic price adjustments and modifications for changes in circumstances, changes in laws and regulations, and additions to the contract value for new construction of facilities at the military bases. ASUS also from time to time performs construction services on military bases as a subcontractor.

There is no direct regulatory oversight by the CPUC over AWR or the operations, rates or services provided by ASUS or any of its wholly owned subsidiaries.

Basis of Presentation: The consolidated financial statements and notes hereto are presented in a combined report filed by two separate Registrants: AWR and GSWC. References in this report to “Registrant” are to AWR and GSWC, collectively, unless otherwise specified. AWR owns all of the outstanding common shares of GSWC, BVES and ASUS. ASUS owns all of the outstanding equity of its subsidiaries. The consolidated financial statements of AWR include the accounts of AWR and its subsidiaries. These financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Intercompany transactions and balances have been eliminated in AWR’s consolidated financial statements.

The consolidated financial statements included herein have been prepared by Registrant, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). The December 31, 2024 condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by GAAP. The preparation of the consolidated financial statements 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 date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. In the opinion of management, all adjustments consisting of normal, recurring items, and estimates necessary for a fair statement of the results for the interim periods have been made. It is suggested that these consolidated financial statements be read in conjunction with the consolidated financial statements and the notes thereto included in the Form 10-K for the year ended December 31, 2024 filed with the SEC.

Related Party and Intercompany Transactions: GSWC, BVES and ASUS provide and/or receive various support services to and from their parent, AWR, and among themselves. GSWC allocates certain corporate office administrative and general costs to its affiliates, BVES and ASUS, using allocation factors approved by the CPUC. GSWC allocated corporate office administrative and general costs to BVES of approximately $0.8 million and $0.7 million during the three months ended June 30, 2025 and 2024, respectively, and $1.9 million and $1.7 million during the six month periods ended June 30, 2025 and 2024, respectively. GSWC also allocated corporate office administrative and general costs to ASUS of approximately $1.2 million and $2.8 million for each of the three and six month periods ended June 30, 2025 and 2024, respectively.

When necessary, AWR will make capital contributions to its regulated utilities in order to maintain the CPUC-authorized capital structure. In May 2025, GSWC issued 3.6500 Common Shares to AWR for total proceeds of $50.0 million. GSWC used the proceeds from the stock issuance to pay down outstanding borrowings under its revolving credit facility, as discussed below under Liquidity and Financing Activities.

Liquidity and Financing Activities

Liquidity and Financing Activities: On February 27, 2024, AWR entered into an Equity Distribution Agreement with third-party sales agents, under which AWR may offer and sell its Common Shares, from time to time at its sole discretion, through an at-the-market (“ATM”) offering program having an aggregate gross offering price of up to $200 million over a three-year period and pursuant to AWR’s effective shelf registration statement on Form S-3. AWR intends to use the net proceeds from these sales, after deducting commissions on such sales and offering expenses, for general corporate purposes, including, but not limited to, repayment of debt and equity contributions to its subsidiaries. During the three months ended June 30, 2024, AWR sold 227,667 Common Shares, through its ATM offering program and raised proceeds of $16.8 million, net of $0.3 million in commissions paid under the terms of the Equity Distribution Agreement. AWR also incurred $0.1 million of other expenses during the three months ended June 30, 2024, which included primarily legal and other costs to support this ATM offering program. There were no Common Shares issued during the three months ended June 30, 2025 under the ATM offering program. During the six months ended June 30, 2025 and 2024, AWR sold 334,548 and 455,648 Common Shares, respectively, through the ATM offering program and raised proceeds of $25.8 million, net of $0.4 million in commissions paid, and $33.0 million, net of $0.5 million in commissions paid, respectively. AWR also incurred $0.2 million and $0.1 million of other expenses during the six months ended June 30, 2025, and 2024, respectively, which was primarily legal and other costs. As of June 30, 2025, approximately $82.9 million remains available for sale under the ATM offering program.

AWR and GSWC each have credit agreements with a term of five years, which were scheduled to mature in June 2028. As of June 30, 2025, the credit agreements provided AWR and GSWC unsecured revolving credit facilities with borrowing capacities of $195.0 million and $200.0 million, respectively. Under the terms of the credit agreements, as of June 30, 2025, the borrowing capacities for AWR and GSWC may be expanded up to an additional $30.0 million and $75.0 million, respectively, subject to the lenders’ approval. On May 6, 2025, AWR and GSWC both executed amendments to their credit agreements to extend their credit facility terms from June 2028 to June 2029. In addition, as part of its amendment, AWR expanded its credit facility borrowing capacity from $165.0 million to $195.0 million through an existing bank from the original syndicate group and the addition of a new bank to the existing syndicate group participating in AWR’s credit facility. AWR’s credit facility is primarily used to provide support to AWR (parent) and ASUS. As of June 30, 2025, AWR’s outstanding borrowings under its credit facility of $143.0 million have been classified as non-current liabilities on AWR’s Consolidated Balance Sheet. GSWC’s credit facility provides support for its water operations and is considered a short-term debt arrangement by the CPUC. Therefore, pursuant to the CPUC’s requirements, borrowings under GSWC’s credit facility are required to be paid-off in full within a 24-month period. GSWC’s next pay-off period ends in May 2027. Accordingly, GSWC’s outstanding borrowings under the credit facility of $9.0 million as of June 30, 2025 have been classified as non-current liabilities in AWR’s Consolidated Balance Sheet and GSWC’s Balance Sheet.

On March 13, 2025, the CPUC issued a final decision in GSWC’s financing application, which approves, among other items, GSWC’s request to issue up to $750.0 million of new long-term debt and equity securities. Following approval of the new financing application, on May 29, 2025, GSWC completed the issuance of $100.0 million of unsecured private-placement notes consisting of: $75.0 million aggregated principal Series A Senior Notes at a coupon rate of 5.30% due May 29, 2032 and $25.0 million aggregated principal Series B Senior Notes at a coupon rate of 5.65% due May 29, 2037. GSWC used the proceeds from this debt issuance and the proceeds of the previously mentioned equity issuance to pay down all outstanding borrowings under its revolving credit facility. Interest payments on the new notes are due semiannually on May 29 and November 29 each year, commencing November 29, 2025. The private placement notes rank equally with GSWC’s other unsecured and unsubordinated debt. GSWC may, at its option, redeem all or portions of the private placement notes at any time upon written notice, subject to payment of a make-whole premium. Pursuant to the terms of these notes and consistent with GSWC's other private placement notes, GSWC must maintain a total indebtedness to capitalization ratio of less than 0.6667-to-1 and a total indebtedness to earnings before income taxes, depreciation and amortization (“EBITDA”) of less than 8-to-1.

BVES has a separate revolving credit facility without a parent guaranty that supports its electric operations and capital expenditures with a borrowing capacity of $65.0 million, and expires on July 1, 2026. BVES’s revolving credit facility is considered a short-term debt arrangement by the CPUC. Therefore, pursuant to the CPUC’s requirements, borrowings under this credit facility are required to be fully paid off within a 24-month period, after which, BVES may borrow under the credit facility again. BVES’s next pay-off period ends in March 2027. On February 12, 2025, BVES issued $50.0 million in unsecured private-placement notes, which will mature on February 12, 2030. BVES used the proceeds from these notes to pay off all outstanding amounts under its revolving credit facility at the time of the notes’ issuance, thereby satisfying the CPUC’s requirement. As of June 30, 2025, there is $1.0 million in outstanding borrowings under BVES’s separate revolving credit facility classified as non-current liabilities on AWR’s Consolidated Balance Sheet.

Recent Accounting Pronouncements

Recent Accounting Pronouncements: In December 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update 2023-09 (Improvements to Income Tax Disclosures) requiring public entities to provide more disclosures primarily related to the income tax rate reconciliation and income taxes paid. The guidance also eliminates certain existing disclosure requirements related to uncertain tax positions and unrecognized deferred tax liabilities. The guidance is effective for annual periods beginning after December 15, 2024 and will be applied prospectively to the annual income tax disclosures starting with Registrant’s Annual Report on Form 10-K for the year ended December 31, 2025. Registrant is currently evaluating the impact of this standard on its annual income tax disclosures.

In November 2024, the FASB issued Accounting Standards Update 2024-03, (Disaggregation of Income Statement Expenses) requiring public entities to disclose additional information about specific expense categories in the notes to the financial statements on an interim and annual basis. The guidance will be effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with early adoption permitted. Registrant is currently evaluating the impact of adopting this standard.