Components of Accumulated Other Comprehensive Loss - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Components of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 623,952	$ 623,042	$ 781,095	$ 805,770	$ 623,042	$ 805,770
OCI before reclassifications					12,190	(26,117)
Amounts reclassified from AOCI, net of tax					9,363	8,999
Total other comprehensive income (loss)	14,401	7,152	(29,126)	12,008	21,553	(17,118)
Less: OCI attributable to noncontrolling interests					1,477	3,385
OCI attributable to Enviri Corporation					23,030	(13,733)
Ending balance	627,407	623,952	651,703	781,095	627,407	651,703
Cumulative Foreign Exchange Translation Adjustments
Components of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		(213,104)		(134,889)	(213,104)	(134,889)
OCI before reclassifications					23,035	(61,493)
Amounts reclassified from AOCI, net of tax					0	0
Total other comprehensive income (loss)					23,035	(61,493)
Less: OCI attributable to noncontrolling interests					1,477	3,385
OCI attributable to Enviri Corporation					24,512	(58,108)
Ending balance	(188,592)		(192,997)		(188,592)	(192,997)
Effective Portion of Derivatives Designated as Hedging Instruments
Components of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		157		(3,024)	157	(3,024)
OCI before reclassifications					1,554	1,692
Amounts reclassified from AOCI, net of tax					320	168
Total other comprehensive income (loss)					1,874	1,860
Less: OCI attributable to noncontrolling interests					0	0
OCI attributable to Enviri Corporation					1,874	1,860
Ending balance	2,031		(1,164)		2,031	(1,164)
Cumulative Unrecognized Actuarial Losses on Pension Obligations
Components of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		(354,699)		(422,248)	(354,699)	(422,248)
OCI before reclassifications					(12,405)	33,697
Amounts reclassified from AOCI, net of tax					9,043	8,831
Total other comprehensive income (loss)					(3,362)	42,528
Less: OCI attributable to noncontrolling interests					0	0
OCI attributable to Enviri Corporation					(3,362)	42,528
Ending balance	(358,061)		(379,720)		(358,061)	(379,720)
Unrealized Gain (Loss) on Marketable Securities
Components of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		10		22	10	22
OCI before reclassifications					6	(13)
Amounts reclassified from AOCI, net of tax					0	0
Total other comprehensive income (loss)					6	(13)
Less: OCI attributable to noncontrolling interests					0	0
OCI attributable to Enviri Corporation					6	(13)
Ending balance	16		9		16	9
Accumulated Other Comprehensive Loss
Components of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(560,842)	(567,636)	(547,649)	(560,139)	(567,636)	(560,139)
Total other comprehensive income (loss)	16,236	6,794	(26,223)	12,490
Ending balance	$ (544,606)	$ (560,842)	$ (573,872)	$ (547,649)	$ (544,606)	$ (573,872)