2.2.0.7 false Basis of Presentation 10101 - Disclosure - Basis of Presentation true false false false 1 USD false false Unit1 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Unit13 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Unit12 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 Notes To Financial Statements [Abstract] 0 awk_NotesToFinancialStatementsAbstract awk false na duration Notes to Financial Statements [Abstract] false false false false false true false false false false false false 1 false false false false 0 0 false false false xbrli:stringItemType string Notes to Financial Statements [Abstract] false 3 Basis of Presentation 1 us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock us-gaap true na duration No definition available. false false false false false false false false false false false false 1 false false false false 0 0 <div> Note 1: Basis of Presentation The accompanying Consolidated Balance Sheet of American Water Works Company, Inc. and Subsidiary Companies (the "Company") at September 30, 2010, the Consolidated Statements of Operations and Comprehensive Income for the three and nine months ended September 30, 2010 and 2009, the Consolidated Statements of Cash Flows for the nine months ended September 30, 2010 and 2009, and the Consolidated Statement of Changes in Stockholders' Equity for the nine months ended September 30, 2010 and 2009, are unaudited, but reflect all adjustments, which are, in the opinion of management, necessary to present fairly the consolidated financial position, the consolidated changes in stockholders' equity, the consolidated results of operations and comprehensive income, and the consolidated cash flows for the periods presented. All adjustments are of a normal, recurring nature, except as otherwise disclosed. Because they cover interim periods, the unaudited consolidated financial statements and related notes to the consolidated financial statements do not include all disclosures and notes normally provided in annual financial statements and, therefore, should be read in conjunction with the Company's Consolidated Financial Statements and related Notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2009. The results of operations for interim periods are not necessarily indicative of the results that may be expected for the year, due primarily to the seasonality of the Company's operations. </div> Note 1: Basis of Presentation The accompanying Consolidated Balance Sheet of American Water Works Company, Inc. and Subsidiary Companies (the "Company") at false false false us-types:textBlockItemType textblock Description containing the entire organization, consolidation and basis of presentation of financial statements disclosure. May be provided in more than one note to the financial statements, as long as users are provided with an understanding of (1) the significant judgments and assumptions made by an enterprise in determining whether it must consolidate a VIE and/or disclose information about its involvement with a VIE, (2) the nature of restrictions on a consolidated VIE's assets reported by an enterprise in its statement of financial position, including the carrying amounts of such assets, (3) the nature of, and changes in, the risks associated with an enterprise's involvement with the VIE, and (4) how an enterprise's involvement with the VIE affects the enterprise's financial position, financial performance, and cash flows. Describes procedure if disclosures are provided in more than one note to the financial statements. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS140-4 and FIN46(R)-8 -Paragraph 8, C1, C7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 2-6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 94-6 -Paragraph 10 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 46R -Paragraph 4, 14, 15 false 1 2 false UnKnown UnKnown UnKnown false true