Reconciliation of Basic and Diluted Shares - Reconciliation of Basic and Diluted Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Earnings Per Share [Abstract]
Income (loss) from continuing operations attributable to Enviri Corporation common stockholders	$ (46,950)	$ (12,704)	$ (59,179)	$ (29,561)
Weighted-average shares outstanding - basic (in shares)	80,629	80,146	80,481	80,045
Dilutive effect of stock-based compensation (in shares)	0	0	0	0
Weighted-average shares outstanding - diluted (in shares)	80,629	80,146	80,481	80,045
Earnings (loss) from continuing operations per common share, attributable to Enviri Corporation common stockholders:
Basic (in dollars per share)	$ (0.58)	$ (0.16)	$ (0.74)	$ (0.37)
Diluted (in dollars per share)	$ (0.58)	$ (0.16)	$ (0.74)	$ (0.37)