Summary of Significant Accounting Policies:	6 Months Ended
Jun. 30, 2018
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”), Old North Utility Services, Inc. (“ONUS”), Emerald Coast Utility Services, Inc. ("ECUS"), and Fort Riley Utility Services, Inc. ("FRUS")). The subsidiaries of ASUS are collectively referred to 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 260,000 customers. GSWC also distributes electricity in several San Bernardino County mountain communities in California serving approximately 24,000 customers through its Bear Valley Electric Service (“BVES”) division. The California Public Utilities Commission (“CPUC”) regulates GSWC’s water and electric businesses in matters including properties, rates, services, facilities and transactions by GSWC with its affiliates. 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 50-year firm fixed-price contracts. These contracts are subject to 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. In September 2017, ASUS was awarded a new 50-year contract by the U.S. government to operate, maintain, and provide construction management services for the water distribution and wastewater collection and treatment facilities at Fort Riley, a United States Army installation located in Kansas. The contract over the 50-year period is subject to annual economic price adjustments. ASUS began operations at Fort Riley in July 2018. 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 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 and ASUS. ASUS owns all of the outstanding Common Shares of the Military Utility Privatization Subsidiaries. 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. Intercompany 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, 2017 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by generally accepted accounting principles ("GAAP") in the United States of America. 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, 2017 filed with the SEC. GSWC's Related Party Transactions: GSWC and ASUS provide and/or 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. GSWC allocated corporate office administrative and general costs to ASUS of approximately $1.0 million during the three months ended June 30, 2018 and 2017, and approximately $2.0 million during the six months ended June 30, 2018 and 2017. AWR has a $150.0 million syndicated credit facility, which was renewed in May 2018. As of June 30, 2018, AWR had $77.0 million outstanding under this facility. All amounts borrowed under the renewed facility are contractually due in May 2023 pursuant to the new terms and are generally priced off a spread to LIBOR. AWR borrows under this facility and provides funds to its subsidiaries, GSWC and ASUS, in support of their operations. The interest rate charged to GSWC and ASUS is sufficient to cover AWR’s interest expense under the credit facility. Amounts owed to AWR by GSWC, including for allocated expenses, are included in GSWC's intercompany payable under "Current Liabilities" as of June 30, 2018 and December 31, 2017. GSWC Long-Term Debt: In March of 2019, $40 million of GSWC's 6.70% senior note will mature. This note has been included in "Current Liabilities" in Registrant's balance sheets as of June 30, 2018. GSWC intends to borrow under its intercompany borrowing arrangement with AWR and/or issue additional long-term debt to fund the repayment of this note. Recently Issued Accounting Pronouncements: In May 2014, the FASB issued Accounting Standard Update 2014-09, Revenue from Contracts with Customers (Topic 606). Under this guidance, an entity recognizes revenue when it transfers goods or services to customers in an amount that reflects what the entity expects in exchange for the goods or services. Registrant adopted this guidance under the modified retrospective approach beginning January 1, 2018. The adoption of this guidance did not have a material impact on its measurement or timing of revenue recognition but requires additional disclosures (see Note 2). In March 2017, the FASB issued Accounting Standards Update 2017-07, Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which changes the financial statement presentation for the costs of defined benefit pension plans and other retirement benefits. Prior to this guidance, the components of net benefit cost for retirement plans (such as service cost, interest cost, expected return on assets, and the amortization of prior service costs and actuarial gains and losses) were aggregated as operating costs for financial statement presentation purposes. Under the new guidance, the service cost component continues to be presented as operating costs, while all other components of net benefit cost are presented outside of operating income. The new guidance also limits any capitalization of net periodic benefits cost to the service cost component. Registrant adopted the new guidance beginning January 1, 2018, which did not have a material impact on its financial statements. Registrant used its prior year's disclosure of its pension and other employee benefit plans as an estimation for applying the retrospective presentation requirements of this guidance. The components of net periodic benefits cost, other than the service cost component, have been included in the line item “Other, net” in Registrant's income statements. In November of 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230) - Restricted Cash. The guidance requires restricted cash to be combined with cash and cash equivalents when reconciling the beginning and end of period cash balances in the statement of cash flows. The adoption of this new guidance in 2018 did not have an impact on Registrant's cash flow statements. In August 2016, the FASB issued Accounting Standards Update 2016-15, Statement of Cash Flows (Topic 230) Classification of Certain Cash Receipts and Cash Payments, which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The adoption of this new guidance in 2018 did not have an impact on Registrant's cash flow statements. In February 2016, the FASB issued a new lease accounting standard, Leases (ASC 842). Under the new standard, lessees will recognize a right-of-use asset and a lease liability for virtually all leases (other than leases that meet the definition of a short-term lease). For income statement purposes, leases will be classified as either operating or finance. Operating leases will result in straight-line expense while finance leases will result in a front-loaded expense pattern. The standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Registrant will use the practical expedients available under this standard and will not reassess: (i) whether any expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases, or (iii) any initial direct costs for existing leases, if any. Management has not yet determined the effect of this standard on Registrant's financial statements, which will depend on Registrant’s lease portfolio as of the adoption date.

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”), Old North Utility Services, Inc. (“ONUS”), Emerald Coast Utility Services, Inc. ("ECUS"), and Fort Riley Utility Services, Inc. ("FRUS")). The subsidiaries of ASUS are collectively referred to 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 260,000 customers. GSWC also distributes electricity in several San Bernardino County mountain communities in California serving approximately 24,000 customers through its Bear Valley Electric Service (“BVES”) division. The California Public Utilities Commission (“CPUC”) regulates GSWC’s water and electric businesses in matters including properties, rates, services, facilities and transactions by GSWC with its affiliates.

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 50-year firm fixed-price contracts. These contracts are subject to 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. In September 2017, ASUS was awarded a new 50-year contract by the U.S. government to operate, maintain, and provide construction management services for the water distribution and wastewater collection and treatment facilities at Fort Riley, a United States Army installation located in Kansas. The contract over the 50-year period is subject to annual economic price adjustments. ASUS began operations at Fort Riley in July 2018.

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 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 and ASUS. ASUS owns all of the outstanding Common Shares of the Military Utility Privatization Subsidiaries. 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. Intercompany 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, 2017 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by generally accepted accounting principles ("GAAP") in the United States of America. 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, 2017 filed with the SEC.

GSWC's Related Party Transactions: GSWC and ASUS provide and/or 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. GSWC allocated corporate office administrative and general costs to ASUS of approximately $1.0 million during the three months ended June 30, 2018 and 2017, and approximately $2.0 million during the six months ended June 30, 2018 and 2017.

AWR has a $150.0 million syndicated credit facility, which was renewed in May 2018. As of June 30, 2018, AWR had $77.0 million outstanding under this facility. All amounts borrowed under the renewed facility are contractually due in May 2023 pursuant to the new terms and are generally priced off a spread to LIBOR. AWR borrows under this facility and provides funds to its subsidiaries, GSWC and ASUS, in support of their operations. The interest rate charged to GSWC and ASUS is sufficient to cover AWR’s interest expense under the credit facility. Amounts owed to AWR by GSWC, including for allocated expenses, are included in GSWC's intercompany payable under "Current Liabilities" as of June 30, 2018 and December 31, 2017.

GSWC Long-Term Debt: In March of 2019, $40 million of GSWC's 6.70% senior note will mature. This note has been included in "Current Liabilities" in Registrant's balance sheets as of June 30, 2018. GSWC intends to borrow under its intercompany borrowing arrangement with AWR and/or issue additional long-term debt to fund the repayment of this note.

Recently Issued Accounting Pronouncements: In May 2014, the FASB issued Accounting Standard Update 2014-09, Revenue from Contracts with Customers (Topic 606). Under this guidance, an entity recognizes revenue when it transfers goods or services to customers in an amount that reflects what the entity expects in exchange for the goods or services. Registrant adopted this guidance under the modified retrospective approach beginning January 1, 2018. The adoption of this guidance did not have a material impact on its measurement or timing of revenue recognition but requires additional disclosures (see Note 2).

In March 2017, the FASB issued Accounting Standards Update 2017-07, Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which changes the financial statement presentation for the costs of defined benefit pension plans and other retirement benefits. Prior to this guidance, the components of net benefit cost for retirement plans (such as service cost, interest cost, expected return on assets, and the amortization of prior service costs and actuarial gains and losses) were aggregated as operating costs for financial statement presentation purposes. Under the new guidance, the service cost component continues to be presented as operating costs, while all other components of net benefit cost are presented outside of operating income. The new guidance also limits any capitalization of net periodic benefits cost to the service cost component. Registrant adopted the new guidance beginning January 1, 2018, which did not have a material impact on its financial statements. Registrant used its prior year's disclosure of its pension and other employee benefit plans as an estimation for applying the retrospective presentation requirements of this guidance. The components of net periodic benefits cost, other than the service cost component, have been included in the line item “Other, net” in Registrant's income statements.

In November of 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230) - Restricted Cash. The guidance requires restricted cash to be combined with cash and cash equivalents when reconciling the beginning and end of period cash balances in the statement of cash flows. The adoption of this new guidance in 2018 did not have an impact on Registrant's cash flow statements.

In August 2016, the FASB issued Accounting Standards Update 2016-15, Statement of Cash Flows (Topic 230)

Classification of Certain Cash Receipts and Cash Payments, which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The adoption of this new guidance in 2018 did not have an impact on Registrant's cash flow statements.

In February 2016, the FASB issued a new lease accounting standard, Leases (ASC 842). Under the new standard, lessees will recognize a right-of-use asset and a lease liability for virtually all leases (other than leases that meet the definition of a short-term lease). For income statement purposes, leases will be classified as either operating or finance. Operating leases will result in straight-line expense while finance leases will result in a front-loaded expense pattern. The standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Registrant will use the practical expedients available under this standard and will not reassess: (i) whether any expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases, or (iii) any initial direct costs for existing leases, if any. Management has not yet determined the effect of this standard on Registrant's financial statements, which will depend on Registrant’s lease portfolio as of the adoption date.