Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 72,343	$ 51,662	$ 114,395
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	(9,370)	21,672	(2,830)
Unrealized derivative gain (loss) on cash flow hedges, net of tax	35,188	7,293	(4,717)
Change in pension liability, net of tax	5,698	2,922	79
Total other comprehensive income (loss)	31,516	31,887	(7,468)
Less: Comprehensive income attributable to non‑controlling interest	(145)	(180)	(746)
Comprehensive income attributable to Evoqua Water Technologies Corp.	$ 103,714	$ 83,369	$ 106,181