Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 12,980	$ 4,895	$ 9,975	$ (8,305)
Other comprehensive income
Foreign currency translation adjustments	(458)	2,581	(793)	5,800
Less: Comprehensive income attributable to non‑controlling interest	(477)	(1,697)	(1,185)	(2,096)
Comprehensive income (loss) attributable to Evoqua Water Technologies Corp.	$ 12,045	$ 5,779	$ 7,997	$ (4,601)