Description of the Company and Basis of Presentation	9 Months Ended
Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Company and Basis of Presentation	Description of the Company and Basis of Presentation Background Evoqua Water Technologies Corp. (referred to herein as "the Company" or "EWT") was incorporated on October 7, 2013. On January 15, 2014, Evoqua Water Technologies Corp., acquired through its wholly owned entities, EWT Holdings II Corp. and EWT Holdings III Corp. (a/k/a Evoqua Water Technologies), all of the outstanding shares of Siemens Water Technologies, a group of legal entity businesses formerly owned by Siemens AG (Siemens). The stock purchase closed on January 15, 2014 and was effective January 16, 2014 (the Acquisition). The stock purchase price, net of cash received, was approximately $730,577. On November 6, 2017, the Company completed its initial public offering (IPO), pursuant to which an aggregate of 27,777 shares of common stock were sold, of which 8,333 were sold by the Company and 19,444 were sold by the selling stockholders, with a par value of $0.01 per share. After underwriting discounts and commissions, the Company received net proceeds from the IPO of approximately $137,605. The Company used a portion of these proceeds to repay $104,936 of indebtedness (including accrued and unpaid interest) under its senior secured First Lien Term Loan facility and the remainder for general corporate purposes. The Company did not receive any proceeds from the sale of shares by the selling stockholders. On November 7, 2017, the selling stockholders sold an additional 4,167 shares of common stock as a result of the exercise in full by the underwriters of an option to purchase additional shares. On March 19, 2018, the Company completed a secondary public offering, pursuant to which 17,500 shares of common stock were sold by certain selling stockholders. On March 21, 2018, the selling stockholders sold an additional 2,625 shares of common stock as a result of the exercise in full by the underwriters of an option to purchase additional shares. The Company did not receive any proceeds from the sale of shares by the selling stockholders. The Business EWT provides a wide range of product brands and advanced water and wastewater treatment systems and technologies, as well as mobile and emergency water supply solutions and service contract options through its segment branch network. Headquartered in Pittsburgh, Pennsylvania, EWT is a multi‑national corporation with operations in the United States, Canada, the United Kingdom, the Netherlands, Germany, Australia, China, and Singapore. The Company is organizationally structured into three reportable segments for the purpose of making operational decisions and assessing financial performance: (i) Industrial, (ii) Municipal and (iii) Products. Basis of Presentation The accompanying Unaudited Condensed Consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP). All intracompany transactions have been eliminated. The unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). 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 fiscal year ended September 30, 2017, as filed with the SEC on December 4, 2017 (2017 Annual Report), in preparing these unaudited condensed consolidated financial statements, with the exception of accounting standard updates described in Note 2. These condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes included in our 2017 Annual Report.

Description of the Company and Basis of Presentation

Background

Evoqua Water Technologies Corp. (referred to herein as "the Company" or "EWT") was incorporated on October 7, 2013. On January 15, 2014, Evoqua Water Technologies Corp., acquired through its wholly owned entities, EWT Holdings II Corp. and EWT Holdings III Corp. (a/k/a Evoqua Water Technologies), all of the outstanding shares of Siemens Water Technologies, a group of legal entity businesses formerly owned by Siemens AG (Siemens). The stock purchase closed on January 15, 2014 and was effective January 16, 2014 (the Acquisition). The stock purchase price, net of cash received, was approximately $730,577. On November 6, 2017, the Company completed its initial public offering (IPO), pursuant to which an aggregate of 27,777 shares of common stock were sold, of which 8,333 were sold by the Company and 19,444 were sold by the selling stockholders, with a par value of $0.01 per share. After underwriting discounts and commissions, the Company received net proceeds from the IPO of approximately $137,605. The Company used a portion of these proceeds to repay $104,936 of indebtedness (including accrued and unpaid interest) under its senior secured First Lien Term Loan facility and the remainder for general corporate purposes. The Company did not receive any proceeds from the sale of shares by the selling stockholders. On November 7, 2017, the selling stockholders sold an additional 4,167 shares of common stock as a result of the exercise in full by the underwriters of an option to purchase additional shares. On March 19, 2018, the Company completed a secondary public offering, pursuant to which 17,500 shares of common stock were sold by certain selling stockholders. On March 21, 2018, the selling stockholders sold an additional 2,625 shares of common stock as a result of the exercise in full by the underwriters of an option to purchase additional shares. The Company did not receive any proceeds from the sale of shares by the selling stockholders.

The Business

EWT provides a wide range of product brands and advanced water and wastewater treatment systems and technologies, as well as mobile and emergency water supply solutions and service contract options through its segment branch network. Headquartered in Pittsburgh, Pennsylvania, EWT is a multi‑national corporation with operations in the United States, Canada, the United Kingdom, the Netherlands, Germany, Australia, China, and Singapore.

The Company is organizationally structured into three reportable segments for the purpose of making operational decisions and assessing financial performance: (i) Industrial, (ii) Municipal and (iii) Products.

Basis of Presentation

The accompanying Unaudited Condensed Consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP). All intracompany transactions have been eliminated.

The unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). 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 fiscal year ended September 30, 2017, as filed with the SEC on December 4, 2017 (2017 Annual Report), in preparing these unaudited condensed consolidated financial statements, with the exception of accounting standard updates described in Note 2. These condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes included in our 2017 Annual Report.