Background and Basis of Presentation (Policies)	9 Months Ended
Background and Basis of Presentation (Policies)	Sep. 30, 2012
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The interim condensed consolidated and combined financial statements reflect our financial position, results of operations and cash flows in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All intracompany transactions between our businesses have been eliminated. On and prior to the Distribution Date, our financial position, results of operations and cash flows consisted of the water equipment and services businesses of ITT Corporation (“WaterCo”) and have been derived from ITT’s historical accounting records and are presented on a carve-out basis through the Distribution Date, while our financial results for Xylem post Spin-off are prepared on a stand-alone basis. As such, our Condensed Consolidated and Combined Statements of Income, Comprehensive Income and Cash Flows for the periods ended September 30, 2012 consist of the consolidated results of Xylem on a stand-alone basis and for the periods ended September 30, 2011 consist entirely of the combined results of WaterCo on a carve-out basis. For periods prior to the Spin-off, our condensed consolidated and combined financial statements include expense allocations for (i) certain corporate functions historically provided by ITT, including, but not limited to, finance, legal, information technology, human resources, communications, ethics and compliance, and shared services, (ii) employee benefits and incentives, and (iii) share-based compensation. These expenses have been allocated to us on the basis of direct usage when identifiable, with the remainder allocated on the basis of revenue, headcount or other measures. Both Xylem and ITT consider the basis on which the expenses have been allocated to be a reasonable reflection of the utilization of services provided to or the benefit received by us during the periods presented. The allocations may not, however, reflect the expense we would have incurred as an independent, publicly traded company for the periods presented prior to the Distribution Date. Actual costs that may have been incurred if we had been a stand-alone company would depend on a number of factors, including the chosen organizational structure, what functions were outsourced or performed by employees and strategic decisions made in areas such as information technology and infrastructure. Subsequent to the Spin-off, we have performed these functions using our own resources or purchased services, certain of which have been provided by ITT and Exelis under a transition services agreement, at a cost of approximately $1 million per quarter that is expected to extend for a period of 3 to 24 months from the Distribution Date in most circumstances. The unaudited interim condensed combined financial statements have been prepared pursuant to the rules and regulations of the SEC and, in the opinion of management, reflect all adjustments (which include normal recurring adjustments) considered necessary for a fair presentation of the financial position, results of operations, and cash flows for the periods presented. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such SEC rules. We believe that the disclosures made are adequate to make the information presented not misleading. We consistently applied the accounting policies described in our Annual Report on Form 10-K for the year ended December 31, 2011 (“2011 Annual Report”) in preparing these unaudited financial statements, with the exception of accounting standard updates described in Note 2 adopted on January 1, 2012. These financial statements should be read in conjunction with the audited consolidated and combined financial statements and the notes thereto included in our 2011 Annual Report. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Estimates are revised as additional information becomes available. Estimates and assumptions are used for, but not limited to, postretirement obligations and assets, revenue recognition, income tax contingency accruals and valuation allowances, goodwill impairment testing and contingent liabilities. Actual results could differ from these estimates. Additionally, our interim condensed consolidated and combined financial statements may not be indicative of our future performance. Our quarterly financial periods end on the Saturday closest to the last day of the calendar quarter, except for the fourth quarter which ends on December 31. For ease of presentation, the quarterly financial statements included herein are described as ending on the last day of the calendar quarter.
Pronouncements Not Yet Adopted	Pronouncements Not Yet Adopted In July 2012, the Financial Accounting Standards Board ("FASB") provided companies with the option to make an initial qualitative evaluation, based on events and circumstances, to determine the likelihood of an impairment of an indefinite-lived intangible asset. The results of this qualitative assessment determine whether it is necessary to perform the currently required quantitative comparison of the indefinite-lived intangible asset’s fair value to its carrying amount. If it is more likely than not that the fair value of the intangible asset is less than its carrying amount, a company would be required to perform the quantitative assessment. This guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012 with early adoption permitted. The adoption of the guidance is not expected to have a material impact on our financial condition, results of operations or cash flows.
Recently Adopted Pronouncements	Recently Adopted Pronouncements In September 2011, in conjunction with the assessment of the impairment of goodwill, the FASB provided companies with the option to make an initial qualitative evaluation, based on the entity’s events and circumstances, to determine the likelihood of goodwill impairment. The results of this qualitative assessment determine whether it is necessary to perform the required two-step impairment test. If it is more likely than not that the fair value of a reporting unit is less than its carrying amount, a company would be required to perform the two-step impairment test. On January 1, 2012, we adopted this guidance on a prospective basis. The adoption of the guidance is not expected to have a material impact on our financial condition, results of operations or cash flows. In June 2011, the FASB issued authoritative guidance surrounding the presentation of comprehensive income, with an objective of increasing the prominence of items reported in other comprehensive income (“OCI”). The guidance requires most entities to present items of net income and other comprehensive income either in one continuous statement, referred to as the statement of comprehensive income, or in two separate, but consecutive, statements of net income and other comprehensive income. We have adopted this guidance with retrospective application as of January 1, 2012, and have presented total comprehensive income in our Condensed Consolidated and Combined Statements of Comprehensive Income. In May 2011, the FASB issued guidance intended to achieve common fair value measurements and related disclosures between U.S. GAAP and international accounting standards. The amendments primarily clarify existing fair value guidance and are not intended to change the application of existing fair value measurement guidance. However, the amendments include certain instances where a particular principle or requirement for measuring fair value or disclosing information about fair value measurements has changed. On January 1, 2012, we adopted this guidance. The adoption of the guidance did not have a material impact on our financial condition, results of operations or cash flows.