Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,035	$ 1,756	$ 11,012	$ (6,550)
Other comprehensive (loss) income
Foreign currency translation adjustments	(2,018)	(3,027)	(2,811)	2,773
Less: Comprehensive income attributable to non‑controlling interest	(242)	(253)	(1,427)	(2,348)
Comprehensive (loss) income attributable to Evoqua Water Technologies Corp.	$ (1,225)	$ (1,524)	$ 6,774	$ (6,125)