Document And Entity Information Statement - shares	3 Months Ended
	Dec. 31, 2019	Jan. 31, 2020
Document Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2020
Entity Registrant Name	EVOQUA WATER TECHNOLOGIES CORP.
Entity Central Index Key	0001604643
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		115,833,974
Entity Current Reporting Status	Yes