| Cover | Feb. 08, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 8, 2021 |
| Entity File Number | 001-38272 |
| Entity Registrant Name | EVOQUA WATER TECHNOLOGIES CORP. |
| Entity Central Index Key | 0001604643 |
| Entity Tax Identification Number | 46-4132761 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 210 Sixth Avenue |
| Entity Address, City or Town | Pittsburgh |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15222 |
| City Area Code | 724 |
| Local Phone Number | 772-0044 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | AQUA |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
