Summary of Significant Accounting Policies (Details 4) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revised Condensed Consolidated Balance Sheets [Abstract]
Trade accounts receivable, net	$ 267,439	$ 262,067
Inventories	180,548	183,059
Total current assets	720,681	712,919
Right-of-use assets, net	132,323	88,912
Retirement plan assets	55,743	57,622
Deferred income tax assets	11,419	17,453
Other assets	57,073	55,117
Total assets	2,708,671	2,634,511	$ 2,834,524
Income taxes payable	4,083	6,093
Current portion of operating lease liabilities	30,077	26,001
Total current liabilities	634,024	566,680
Operating lease liabilities	104,654	64,805
Deferred tax liabilities	21,689	32,529
Other liabilities	57,944	56,509
Total liabilities	2,413,084	2,204,845
Accumulated other comprehensive loss	(514,481)	(537,385)
Retained earnings	1,211,234	1,378,835
Total Enviri Corporation stockholders’ equity	255,062	391,515
Total equity	295,587	429,666	553,278	$ 600,050
Total liabilities and equity	2,708,671	2,634,511
Revised Condensed Statements of Operations [Abstract]
Total revenues	2,240,358	2,343,137	2,366,187
Total costs and expenses	2,236,109	2,312,423	2,278,674
Operating income (loss) from continuing operations	4,249	30,714	87,513
Defined benefit pension income (expense)	(21,635)	(17,607)	(22,326)
Income (loss) from continuing operations before income taxes and equity income	(136,819)	(103,580)	(45,847)
Income Tax Expense (Benefit)	(22,986)	(16,834)	(34,530)
Net income (loss)	(163,709)	(124,339)	(84,939)
Net income (loss) attributable to Enviri Corporation common stockholders	(167,601)	(129,651)	(82,962)
Income (loss) from continuing operations, net of tax	$ (163,542)	$ (125,736)	$ (79,161)
Continuing operations (in dollars per share)	$ (2.03)	$ (1.57)	$ (0.99)
Earnings per share, basic (in dollars per share)	(2.08)	(1.62)	(1.04)
Earnings per share, diluted (in dollars per share)	$ (2.08)	$ (1.62)	$ (1.04)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ (163,709)	$ (124,339)	$ (84,939)
Foreign currency translation adjustments, net of deferred income taxes	32,045	(46,106)	28,111
Pension liability adjustment, net of deferred taxes	(3,531)	45,240	(2,461)
Other Comprehensive Income (Loss), Net of Tax, Total	24,763	3,380	25,028
Total comprehensive income (loss)	(138,946)	(120,959)	(59,911)
Comprehensive income (loss) attributable to Enviri Corporation	(144,697)	(125,043)	(57,317)
Revised Consolidated Statement of Cash Flows [Abstract]
Deferred income tax (benefit) expense	(3,892)	(13,153)	6,443
Accounts receivable	10,195	45,372	(38,654)
Inventories	8,129	(7,642)	(6,073)
Accounts payable	7,158	(15,038)	(3,590)
Operating lease liabilities	(31,121)	(30,945)	(31,290)
Retirement plan liabilities, net	18,704	(5,262)	(3,216)
Other assets and liabilities	5,919	12,652	23,490
Net cash used by operating activities	101,407	78,063	114,448
Net cash used by investing activities	(149,877)	(34,073)	(116,585)
Net cash (used) provided by financing activities	80,320	(63,400)	44,772
Effect of exchange rate changes on cash, including restricted cash	3,340	(15,046)	(3,115)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	125,348	90,158	124,614	85,094
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	35,190	(34,456)	39,520
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	429,666	553,278	600,050
Noncontrolling interests	(3,377)	(17,095)	(5)
Proceeds from (Payments to) Noncontrolling Interests		874	1,654
Purchase of subsidiary shares from noncontrolling interest		(1,197)	0
Vesting of restricted stock units and other stock grants	(1,934)	(1,883)	(1,426)
Stock appreciation rights exercised	(46)	(2)
Amortization of unearned stock-based compensation, net of forfeitures	21,009	16,650	12,916
Balances	295,587	429,666	553,278
Common Stock Issued
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity	149,519	146,844	146,105	145,448
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	146,844	146,105	145,448
Vesting of restricted stock units and other stock grants	946	738	657
Stock appreciation rights exercised	19	1
Balances	149,519	146,844	146,105
Treasury
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity	(864,646)	(851,881)	(849,996)	(848,570)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	(851,881)	(849,996)	(848,570)
Vesting of restricted stock units and other stock grants	(1,934)	(1,883)	(1,426)
Stock appreciation rights exercised	(46)	(2)
Balances	(864,646)	(851,881)	(849,996)
Additional Paid-in Capital
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity	273,436	255,102	238,416	225,759
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	255,102	238,416	225,759
Purchase of subsidiary shares from noncontrolling interest		775	398
Vesting of restricted stock units and other stock grants	(946)	(738)	(657)
Stock appreciation rights exercised	(19)	(1)
Amortization of unearned stock-based compensation, net of forfeitures	21,009	16,650	12,916
Balances	273,436	255,102	238,416
Retained Earnings
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity	1,211,234	1,378,835	1,508,486	1,591,448
Revised Condensed Statements of Operations [Abstract]
Net income (loss)	(167,601)	(129,651)	(82,962)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)	(167,601)	(129,651)	(82,962)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	1,378,835	1,508,486	1,591,448
Balances	1,211,234	1,378,835	1,508,486
Accumulated Other Comprehensive Income (Loss)
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity	(514,481)	(537,385)	(541,990)	(567,635)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss), Net of Tax, Total	22,904	4,605	25,645
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	(537,385)	(541,990)	(567,635)
Balances	(514,481)	(537,385)	(541,990)
Noncontrolling Interests
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity	40,525	38,151	52,257	53,600
Revised Condensed Statements of Operations [Abstract]
Net income (loss)	3,892	5,312	(1,977)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)	3,892	5,312	(1,977)
Other Comprehensive Income (Loss), Net of Tax, Total	1,859	(1,225)	(617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	38,151	52,257	53,600
Noncontrolling interests	(3,377)	(17,095)	(5)
Proceeds from (Payments to) Noncontrolling Interests		874	1,654
Purchase of subsidiary shares from noncontrolling interest		(1,972)	(398)
Balances	40,525	38,151	52,257
Service revenues
Revised Condensed Statements of Operations [Abstract]
Total revenues	1,988,144	1,977,781	1,930,848
Cost of services and products sold	1,547,681	1,563,391	1,511,097
Total costs and expenses		2,312,423	2,278,674
Product revenues
Revised Condensed Statements of Operations [Abstract]
Total revenues	252,214	365,356	435,339
Cost of services and products sold	265,574	340,719	397,626
Previously Reported
Revised Condensed Consolidated Balance Sheets [Abstract]
Trade accounts receivable, net		260,690
Inventories		182,042
Total current assets		710,525
Right-of-use assets, net		92,153
Retirement plan assets		73,745
Deferred income tax assets		17,578
Other assets		53,744
Total assets		2,650,233
Income taxes payable		5,747
Current portion of operating lease liabilities		26,049
Total current liabilities		566,382
Operating lease liabilities		67,998
Deferred tax liabilities		26,796
Other liabilities		55,136
Total liabilities		2,200,634
Accumulated other comprehensive loss		(538,964)
Retained earnings		1,400,347
Total Enviri Corporation stockholders’ equity		411,448
Total equity		449,599	575,408	623,042
Total liabilities and equity		2,650,233
Revised Condensed Statements of Operations [Abstract]
Total revenues		2,342,645	2,366,020
Operating income (loss) from continuing operations		31,745	79,938
Defined benefit pension income (expense)		(16,728)	(21,574)
Income (loss) from continuing operations before income taxes and equity income		(101,670)	(52,670)
Income Tax Expense (Benefit)		(17,066)	(30,866)
Net income (loss)		(122,661)	(88,098)
Net income (loss) attributable to Enviri Corporation common stockholders		(127,973)	(86,121)
Income (loss) from continuing operations, net of tax		$ (124,058)	$ (82,320)
Continuing operations (in dollars per share)		$ (1.55)	$ (1.03)
Earnings per share, basic (in dollars per share)		(1.60)	(1.08)
Earnings per share, diluted (in dollars per share)		$ (1.60)	$ (1.08)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)		$ (122,661)	$ (88,098)
Foreign currency translation adjustments, net of deferred income taxes		(46,424)	28,988
Pension liability adjustment, net of deferred taxes		41,683	(1,041)
Other Comprehensive Income (Loss), Net of Tax, Total		(495)	27,325
Total comprehensive income (loss)		(123,156)	(60,773)
Comprehensive income (loss) attributable to Enviri Corporation		(127,240)	(58,179)
Revised Consolidated Statement of Cash Flows [Abstract]
Deferred income tax (benefit) expense		(12,798)	2,965
Accounts receivable		45,864	(38,487)
Inventories		(7,534)	(3,410)
Accounts payable		(15,038)	(5,090)
Operating lease liabilities		(30,945)	(30,698)
Retirement plan liabilities, net		(6,140)	(3,968)
Other assets and liabilities		10,897	28,957
Net cash used by operating activities		78,063	114,448
Net cash used by investing activities		(34,073)	(116,585)
Net cash (used) provided by financing activities		(63,400)	44,772
Effect of exchange rate changes on cash, including restricted cash		(15,046)	(3,115)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		90,158	124,614	85,094
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		(34,456)	39,520
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	449,599	575,408	623,042
Noncontrolling interests		(17,095)	(5)
Proceeds from (Payments to) Noncontrolling Interests		874	1,654
Purchase of subsidiary shares from noncontrolling interest		(1,197)	0
Vesting of restricted stock units and other stock grants		(1,883)	(1,426)
Stock appreciation rights exercised		(2)
Amortization of unearned stock-based compensation, net of forfeitures		16,650	12,916
Balances		449,599	575,408
Previously Reported | Common Stock Issued
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		146,844	146,105	145,448
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	146,844	146,105	145,448
Vesting of restricted stock units and other stock grants		738	657
Stock appreciation rights exercised		1
Balances		146,844	146,105
Previously Reported | Treasury
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		(851,881)	(849,996)	(848,570)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	(851,881)	(849,996)	(848,570)
Vesting of restricted stock units and other stock grants		(1,883)	(1,426)
Stock appreciation rights exercised		(2)
Balances		(851,881)	(849,996)
Previously Reported | Additional Paid-in Capital
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		255,102	238,416	225,759
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	255,102	238,416	225,759
Purchase of subsidiary shares from noncontrolling interest		775	398
Vesting of restricted stock units and other stock grants		(738)	(657)
Stock appreciation rights exercised		(1)
Amortization of unearned stock-based compensation, net of forfeitures		16,650	12,916
Balances		255,102	238,416
Previously Reported | Retained Earnings
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		1,400,347	1,528,320	1,614,441
Revised Condensed Statements of Operations [Abstract]
Net income (loss)		(127,973)	(86,121)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)		(127,973)	(86,121)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	1,400,347	1,528,320	1,614,441
Balances		1,400,347	1,528,320
Previously Reported | Accumulated Other Comprehensive Income (Loss)
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		(538,964)	(539,694)	(567,636)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss), Net of Tax, Total		730	27,942
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	(538,964)	(539,694)	(567,636)
Balances		(538,964)	(539,694)
Previously Reported | Noncontrolling Interests
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		38,151	52,257	53,600
Revised Condensed Statements of Operations [Abstract]
Net income (loss)		5,312	(1,977)
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)		5,312	(1,977)
Other Comprehensive Income (Loss), Net of Tax, Total		(1,225)	(617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	38,151	52,257	53,600
Noncontrolling interests		(17,095)	(5)
Proceeds from (Payments to) Noncontrolling Interests		874	1,654
Purchase of subsidiary shares from noncontrolling interest		(1,972)	(398)
Balances		38,151	52,257
Previously Reported | Service revenues
Revised Condensed Statements of Operations [Abstract]
Total revenues		1,970,193	1,931,712
Cost of services and products sold		1,557,473	1,511,689
Total costs and expenses		2,310,900	2,286,082
Previously Reported | Product revenues
Revised Condensed Statements of Operations [Abstract]
Total revenues		372,452	434,308
Cost of services and products sold		345,114	404,442
Revision of Prior Period, Error Correction, Adjustment
Revised Condensed Consolidated Balance Sheets [Abstract]
Trade accounts receivable, net		1,377
Inventories		1,017
Total current assets		2,394
Right-of-use assets, net		(3,241)
Retirement plan assets		(16,123)
Deferred income tax assets		(125)
Other assets		1,373
Total assets		(15,722)
Income taxes payable		346
Current portion of operating lease liabilities		(48)
Total current liabilities		298
Operating lease liabilities		(3,193)
Deferred tax liabilities		5,733
Other liabilities		1,373
Total liabilities		4,211
Accumulated other comprehensive loss		1,579
Retained earnings		(21,512)
Total Enviri Corporation stockholders’ equity		(19,933)
Total equity		(19,933)	(22,130)	(22,992)
Total liabilities and equity		(15,722)
Revised Condensed Statements of Operations [Abstract]
Total revenues		492	167
Operating income (loss) from continuing operations		(1,031)	7,575
Defined benefit pension income (expense)		(879)	(752)
Income (loss) from continuing operations before income taxes and equity income		(1,910)	6,823
Income Tax Expense (Benefit)		232	(3,664)
Net income (loss)		(1,678)	3,159
Net income (loss) attributable to Enviri Corporation common stockholders		(1,678)	3,159
Income (loss) from continuing operations, net of tax		$ (1,678)	$ 3,159
Continuing operations (in dollars per share)		$ (0.02)	$ 0.04
Earnings per share, basic (in dollars per share)		(0.02)	0.04
Earnings per share, diluted (in dollars per share)		$ (0.02)	$ 0.04
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)		$ (1,678)	$ 3,159
Foreign currency translation adjustments, net of deferred income taxes		318	(877)
Pension liability adjustment, net of deferred taxes		3,557	(1,420)
Other Comprehensive Income (Loss), Net of Tax, Total		3,875	(2,297)
Total comprehensive income (loss)		2,197	862
Comprehensive income (loss) attributable to Enviri Corporation		2,197	862
Revised Consolidated Statement of Cash Flows [Abstract]
Deferred income tax (benefit) expense		(355)	3,478
Accounts receivable		(492)	(167)
Inventories		(108)	(2,663)
Accounts payable		0	1,500
Operating lease liabilities		0	(592)
Retirement plan liabilities, net		878	752
Other assets and liabilities		1,755	(5,467)
Net cash used by operating activities		0	0
Net cash used by investing activities		0	0
Net cash (used) provided by financing activities		0	0
Effect of exchange rate changes on cash, including restricted cash		0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		0	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	(19,933)	(22,130)	(22,992)
Balances		(19,933)	(22,130)
Revision of Prior Period, Error Correction, Adjustment | Common Stock Issued
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	0	0	0
Balances		0	0
Revision of Prior Period, Error Correction, Adjustment | Treasury
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	0	0	0
Balances		0	0
Revision of Prior Period, Error Correction, Adjustment | Additional Paid-in Capital
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	0	0	0
Balances		0	0
Revision of Prior Period, Error Correction, Adjustment | Retained Earnings
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		(21,512)	(19,834)	(22,993)
Revised Condensed Statements of Operations [Abstract]
Net income (loss)		(1,678)	3,159
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)		(1,678)	3,159
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	(21,512)	(19,834)	(22,993)
Balances		(21,512)	(19,834)
Revision of Prior Period, Error Correction, Adjustment | Accumulated Other Comprehensive Income (Loss)
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		1,579	(2,296)	1
Revised Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss), Net of Tax, Total		3,875	(2,297)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	1,579	(2,296)	1
Balances		1,579	(2,296)
Revision of Prior Period, Error Correction, Adjustment | Noncontrolling Interests
Revised Condensed Consolidated Balance Sheets [Abstract]
Total equity		0	0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	$ 0	0	0
Balances		0	0
Revision of Prior Period, Error Correction, Adjustment | Service revenues
Revised Condensed Statements of Operations [Abstract]
Total revenues		7,588	(864)
Cost of services and products sold		5,918	(592)
Total costs and expenses		1,523	(7,408)
Revision of Prior Period, Error Correction, Adjustment | Product revenues
Revised Condensed Statements of Operations [Abstract]
Total revenues		(7,096)	1,031
Cost of services and products sold		$ (4,395)	$ (6,816)