Summary of Significant Accounting Policies:	3 Months Ended
Mar. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies: Nature of Operations: American States Water Company (“AWR”) is the parent company of Golden State Water Company (“GSWC”) and American States Utility Services, Inc. (“ASUS”) (and its subsidiaries, Fort Bliss Water Services Company (“FBWS”), Terrapin Utility Services, Inc. (“TUS”), Old Dominion Utility Services, Inc. (“ODUS”), Palmetto State Utility Services, Inc. (“PSUS”) and Old North Utility Services, Inc. (“ONUS”)). The subsidiaries of ASUS may be collectively referred to herein as the “Military Utility Privatization Subsidiaries.” GSWC is a public utility engaged principally in the purchase, production, distribution and sale of water in California serving approximately 258,000 customers. GSWC also distributes electricity in several San Bernardino County mountain communities in California serving approximately 24,000 electric customers through its Bear Valley Electric Service (“BVES”) division. Although Registrant has a diversified base of residential, industrial and other customers, revenues derived from commercial and residential water customers accounted for approximately 90% of total water revenues during the three months ended March 31, 2015 and 2014. The California Public Utilities Commission (“CPUC”) regulates GSWC’s water and electric businesses, in matters including properties, rates, services, facilities and other matters, and transactions by GSWC with its affiliates. AWR’s assets and operating income are primarily those of GSWC. 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 United States military bases pursuant to 50-year firm fixed-price contracts. These contracts are subject to periodic price redeterminations and modifications for changes in circumstances and changes in laws and regulations. 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 thereto are being presented in a combined report being filed by two separate Registrants: AWR and GSWC. References in this report to “Registrant” are to AWR and GSWC, collectively, unless otherwise specified. Certain prior period amounts in the consolidated and GSWC Statements of Cash Flow have been reclassified to conform to the 2015 presentation of "Regulatory assets" as a separate line item. There were also reclassifications of certain prior period amounts in the consolidated Statements of Cash Flow to conform to the 2015 presentation of certain changes as "Unbilled receivable" rather than as "Receivables from the U.S. government." The consolidated financial statements of AWR include the accounts of AWR and its subsidiaries, all of which are wholly owned. These financial statements are prepared in conformity with accounting principles generally accepted in the United States of America. Inter-company transactions and balances have been eliminated in the AWR 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, 2014 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by generally accepted accounting principles ("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 those 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, 2014 filed with the SEC. GSWC's Related Party Transactions: In May 2013, AWR issued an interest bearing promissory note (the "Note") to GSWC for $20.0 million which expires on May 23, 2018. Under the terms of the Note, AWR may borrow from GSWC amounts up to $20.0 million for working capital purposes. AWR agreed to pay any unpaid principal amounts outstanding under the Note, plus accrued interest. As of March 31, 2015, AWR had no amounts outstanding to GSWC under this Note. GSWC and ASUS provide and receive various support services to and from their parent, AWR, and among themselves. GSWC also allocates certain corporate office administrative and general costs to its affiliate, ASUS, using allocation factors approved by the CPUC. During the three months ended March 31, 2015 and 2014, GSWC allocated to ASUS approximately $707,000 and $696,000, respectively, of corporate office administrative and general costs. In addition, AWR has a $100.0 million syndicated credit facility. AWR borrows under this facility and provides funds to its subsidiaries, including GSWC, in support of their operations. The interest rate charged to GSWC and ASUS is sufficient to cover AWR’s interest cost under the credit facility. Amounts owed to GSWC by its parent, AWR, or for allocated expenses are included in GSWC's inter-company receivables as of March 31, 2015 and December 31, 2014. Sales and Use Taxes: GSWC bills certain sales and use taxes levied by state or local governments to its customers. Included in these sales and use taxes are franchise fees, which GSWC pays to various municipalities (based on ordinances adopted by these municipalities) in order to use public right of way for utility purposes. GSWC bills these franchise fees to its customers based on a CPUC-authorized rate for each rate-making area as applicable. These franchise fees, which are required to be paid regardless of GSWC’s ability to collect from the customer, are accounted for on a gross basis. GSWC’s franchise fees billed to customers and recorded as operating revenue were approximately $871,000 and $845,000 for the three months ended March 31, 2015 and 2014, respectively. When GSWC acts as an agent, and the tax is not required to be remitted if it is not collected from the customer, the taxes are accounted for on a net basis. Depending on the state in which the operations are conducted, ASUS and its subsidiaries are also subject to certain state non-income tax assessments generally computed on a “gross receipts” or “gross revenues” basis. These non-income tax assessments are required to be paid regardless of whether the subsidiary is reimbursed by the U.S. government for these assessments under its 50-year contracts. The non-income tax assessments are accounted for on a gross basis and totaled $32,000 and $149,000 during the three months ended March 31, 2015 and 2014, respectively. Recently Issued Accounting Pronouncements: In January 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update 2014-05, Service Concession Arrangements, which specifies that an operating entity should not account for a service concession arrangement as a lease in accordance with Topic 840, Leases. The update also specifies that the infrastructure used in a service concession arrangement should not be recognized as property, plant, and equipment of the operating entity. The updated guidance is effective for reporting periods beginning after December 15, 2014. The adoption of the guidance did not, and is not expected to, have a material impact on the Company's consolidated results of operations or consolidated balance sheet. In April 2015, the FASB issued Accounting Standard Update 2015-03, Simplifying the Presentation of Debt Issuance Costs, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt liability, rather than as an asset. The standard does not affect the recognition and measurement of debt issuance costs. This guidance is effective January 1, 2016. As of March 31, 2015, Registrant had $5.1 million in debt issuance costs reflected under "Other Noncurrent Assets."

Summary of Significant Accounting Policies:

Nature of Operations: American States Water Company (“AWR”) is the parent company of Golden State Water Company (“GSWC”) and American States Utility Services, Inc. (“ASUS”) (and its subsidiaries, Fort Bliss Water Services Company (“FBWS”), Terrapin Utility Services, Inc. (“TUS”), Old Dominion Utility Services, Inc. (“ODUS”), Palmetto State Utility Services, Inc. (“PSUS”) and Old North Utility Services, Inc. (“ONUS”)). The subsidiaries of ASUS may be collectively referred to herein as the “Military Utility Privatization Subsidiaries.”

GSWC is a public utility engaged principally in the purchase, production, distribution and sale of water in California serving approximately 258,000 customers. GSWC also distributes electricity in several San Bernardino County mountain communities in California serving approximately 24,000 electric customers through its Bear Valley Electric Service (“BVES”) division. Although Registrant has a diversified base of residential, industrial and other customers, revenues derived from commercial and residential water customers accounted for approximately 90% of total water revenues during the three months ended March 31, 2015 and 2014. The California Public Utilities Commission (“CPUC”) regulates GSWC’s water and electric businesses, in matters including properties, rates, services, facilities and other matters, and transactions by GSWC with its affiliates. AWR’s assets and operating income are primarily those of GSWC.

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 United States military bases pursuant to 50-year firm fixed-price contracts. These contracts are subject to periodic price redeterminations and modifications for changes in circumstances and changes in laws and regulations.

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 thereto are being presented in a combined report being filed by two separate Registrants: AWR and GSWC. References in this report to “Registrant” are to AWR and GSWC, collectively, unless otherwise specified. Certain prior period amounts in the consolidated and GSWC Statements of Cash Flow have been reclassified to conform to the 2015 presentation of "Regulatory assets" as a separate line item. There were also reclassifications of certain prior period amounts in the consolidated Statements of Cash Flow to conform to the 2015 presentation of certain changes as "Unbilled receivable" rather than as "Receivables from the U.S. government."

The consolidated financial statements of AWR include the accounts of AWR and its subsidiaries, all of which are wholly owned. These financial statements are prepared in conformity with accounting principles generally accepted in the United States of America. Inter-company transactions and balances have been eliminated in the AWR 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, 2014 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by generally accepted accounting principles ("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 those 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, 2014 filed with the SEC.

GSWC's Related Party Transactions: In May 2013, AWR issued an interest bearing promissory note (the "Note") to GSWC for $20.0 million which expires on May 23, 2018. Under the terms of the Note, AWR may borrow from GSWC amounts up to $20.0 million for working capital purposes. AWR agreed to pay any unpaid principal amounts outstanding under the Note, plus accrued interest. As of March 31, 2015, AWR had no amounts outstanding to GSWC under this Note.

GSWC and ASUS provide and receive various support services to and from their parent, AWR, and among themselves. GSWC also allocates certain corporate office administrative and general costs to its affiliate, ASUS, using allocation factors approved by the CPUC. During the three months ended March 31, 2015 and 2014, GSWC allocated to ASUS approximately $707,000 and $696,000, respectively, of corporate office administrative and general costs. In addition, AWR has a $100.0 million syndicated credit facility. AWR borrows under this facility and provides funds to its subsidiaries, including GSWC, in support of their operations. The interest rate charged to GSWC and ASUS is sufficient to cover AWR’s interest cost under the credit facility. Amounts owed to GSWC by its parent, AWR, or for allocated expenses are included in GSWC's inter-company receivables as of March 31, 2015 and December 31, 2014.

Sales and Use Taxes: GSWC bills certain sales and use taxes levied by state or local governments to its customers. Included in these sales and use taxes are franchise fees, which GSWC pays to various municipalities (based on ordinances adopted by these municipalities) in order to use public right of way for utility purposes. GSWC bills these franchise fees to its customers based on a CPUC-authorized rate for each rate-making area as applicable. These franchise fees, which are required to be paid regardless of GSWC’s ability to collect from the customer, are accounted for on a gross basis. GSWC’s franchise fees billed to customers and recorded as operating revenue were approximately $871,000 and $845,000 for the three months ended March 31, 2015 and 2014, respectively. When GSWC acts as an agent, and the tax is not required to be remitted if it is not collected from the customer, the taxes are accounted for on a net basis.

Depending on the state in which the operations are conducted, ASUS and its subsidiaries are also subject to certain state non-income tax assessments generally computed on a “gross receipts” or “gross revenues” basis. These non-income tax assessments are required to be paid regardless of whether the subsidiary is reimbursed by the U.S. government for these assessments under its 50-year contracts. The non-income tax assessments are accounted for on a gross basis and totaled $32,000 and $149,000 during the three months ended March 31, 2015 and 2014, respectively.

Recently Issued Accounting Pronouncements: In January 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update 2014-05, Service Concession Arrangements, which specifies that an operating entity should not account for a service concession arrangement as a lease in accordance with Topic 840, Leases. The update also specifies that the infrastructure used in a service concession arrangement should not be recognized as property, plant, and equipment of the operating entity. The updated guidance is effective for reporting periods beginning after December 15, 2014. The adoption of the guidance did not, and is not expected to, have a material impact on the Company's consolidated results of operations or consolidated balance sheet.

In April 2015, the FASB issued Accounting Standard Update 2015-03, Simplifying the Presentation of Debt Issuance Costs, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt liability, rather than as an asset. The standard does not affect the recognition and measurement of debt issuance costs. This guidance is effective January 1, 2016. As of March 31, 2015, Registrant had $5.1 million in debt issuance costs reflected under "Other Noncurrent Assets."